/* * PSA crypto layer on top of Mbed TLS crypto */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ #include "common.h" #if defined(MBEDTLS_PSA_CRYPTO_C) #if defined(MBEDTLS_PSA_CRYPTO_CONFIG) #include "check_crypto_config.h" #endif #include "psa/crypto.h" #include "psa_crypto_cipher.h" #include "psa_crypto_core.h" #include "psa_crypto_invasive.h" #include "psa_crypto_driver_wrappers.h" #include "psa_crypto_ecp.h" #include "psa_crypto_hash.h" #include "psa_crypto_mac.h" #include "psa_crypto_rsa.h" #include "psa_crypto_ecp.h" #if defined(MBEDTLS_PSA_CRYPTO_SE_C) #include "psa_crypto_se.h" #endif #include "psa_crypto_slot_management.h" /* Include internal declarations that are useful for implementing persistently * stored keys. */ #include "psa_crypto_storage.h" #include "psa_crypto_random_impl.h" #include #include #include "mbedtls/platform.h" #include "mbedtls/aes.h" #include "mbedtls/arc4.h" #include "mbedtls/asn1.h" #include "mbedtls/asn1write.h" #include "mbedtls/bignum.h" #include "mbedtls/blowfish.h" #include "mbedtls/camellia.h" #include "mbedtls/chacha20.h" #include "mbedtls/chachapoly.h" #include "mbedtls/cipher.h" #include "mbedtls/ccm.h" #include "mbedtls/cmac.h" #include "mbedtls/des.h" #include "mbedtls/ecdh.h" #include "mbedtls/ecp.h" #include "mbedtls/entropy.h" #include "mbedtls/error.h" #include "mbedtls/gcm.h" #include "mbedtls/md2.h" #include "mbedtls/md4.h" #include "mbedtls/md5.h" #include "mbedtls/md.h" #include "mbedtls/md_internal.h" #include "mbedtls/pk.h" #include "mbedtls/pk_internal.h" #include "mbedtls/platform_util.h" #include "mbedtls/error.h" #include "mbedtls/ripemd160.h" #include "mbedtls/rsa.h" #include "mbedtls/sha1.h" #include "mbedtls/sha256.h" #include "mbedtls/sha512.h" #include "mbedtls/xtea.h" #define ARRAY_LENGTH(array) (sizeof(array) / sizeof(*(array))) /****************************************************************/ /* Global data, support functions and library management */ /****************************************************************/ static int key_type_is_raw_bytes(psa_key_type_t type) { return PSA_KEY_TYPE_IS_UNSTRUCTURED(type); } /* Values for psa_global_data_t::rng_state */ #define RNG_NOT_INITIALIZED 0 #define RNG_INITIALIZED 1 #define RNG_SEEDED 2 typedef struct { unsigned initialized : 1; unsigned rng_state : 2; mbedtls_psa_random_context_t rng; } psa_global_data_t; static psa_global_data_t global_data; #if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) mbedtls_psa_drbg_context_t *const mbedtls_psa_random_state = &global_data.rng.drbg; #endif #define GUARD_MODULE_INITIALIZED \ if (global_data.initialized == 0) \ return PSA_ERROR_BAD_STATE; psa_status_t mbedtls_to_psa_error(int ret) { /* Mbed TLS error codes can combine a high-level error code and a * low-level error code. The low-level error usually reflects the * root cause better, so dispatch on that preferably. */ int low_level_ret = -(-ret & 0x007f); switch (low_level_ret != 0 ? low_level_ret : ret) { case 0: return PSA_SUCCESS; case MBEDTLS_ERR_AES_INVALID_KEY_LENGTH: case MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH: case MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_AES_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_ARC4_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_ASN1_OUT_OF_DATA: case MBEDTLS_ERR_ASN1_UNEXPECTED_TAG: case MBEDTLS_ERR_ASN1_INVALID_LENGTH: case MBEDTLS_ERR_ASN1_LENGTH_MISMATCH: case MBEDTLS_ERR_ASN1_INVALID_DATA: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_ASN1_ALLOC_FAILED: return PSA_ERROR_INSUFFICIENT_MEMORY; case MBEDTLS_ERR_ASN1_BUF_TOO_SMALL: return PSA_ERROR_BUFFER_TOO_SMALL; #if defined(MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA) case MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA: #elif defined(MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH) case MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH: #endif case MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_BLOWFISH_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; #if defined(MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA) case MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA: #elif defined(MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH) case MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH: #endif case MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_CAMELLIA_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_CCM_BAD_INPUT: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_CCM_AUTH_FAILED: return PSA_ERROR_INVALID_SIGNATURE; case MBEDTLS_ERR_CCM_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_CHACHAPOLY_BAD_STATE: return PSA_ERROR_BAD_STATE; case MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED: return PSA_ERROR_INVALID_SIGNATURE; case MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_CIPHER_ALLOC_FAILED: return PSA_ERROR_INSUFFICIENT_MEMORY; case MBEDTLS_ERR_CIPHER_INVALID_PADDING: return PSA_ERROR_INVALID_PADDING; case MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_CIPHER_AUTH_FAILED: return PSA_ERROR_INVALID_SIGNATURE; case MBEDTLS_ERR_CIPHER_INVALID_CONTEXT: return PSA_ERROR_CORRUPTION_DETECTED; case MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; #if !(defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) || \ defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE)) /* Only check CTR_DRBG error codes if underlying mbedtls_xxx * functions are passed a CTR_DRBG instance. */ case MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED: return PSA_ERROR_INSUFFICIENT_ENTROPY; case MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG: case MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR: return PSA_ERROR_INSUFFICIENT_ENTROPY; #endif case MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_DES_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED: case MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE: case MBEDTLS_ERR_ENTROPY_SOURCE_FAILED: return PSA_ERROR_INSUFFICIENT_ENTROPY; case MBEDTLS_ERR_GCM_AUTH_FAILED: return PSA_ERROR_INVALID_SIGNATURE; case MBEDTLS_ERR_GCM_BAD_INPUT: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_GCM_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; #if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) && \ defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE) /* Only check HMAC_DRBG error codes if underlying mbedtls_xxx * functions are passed a HMAC_DRBG instance. */ case MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED: return PSA_ERROR_INSUFFICIENT_ENTROPY; case MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG: case MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR: return PSA_ERROR_INSUFFICIENT_ENTROPY; #endif case MBEDTLS_ERR_MD2_HW_ACCEL_FAILED: case MBEDTLS_ERR_MD4_HW_ACCEL_FAILED: case MBEDTLS_ERR_MD5_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_MD_BAD_INPUT_DATA: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_MD_ALLOC_FAILED: return PSA_ERROR_INSUFFICIENT_MEMORY; case MBEDTLS_ERR_MD_FILE_IO_ERROR: return PSA_ERROR_STORAGE_FAILURE; case MBEDTLS_ERR_MD_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_MPI_FILE_IO_ERROR: return PSA_ERROR_STORAGE_FAILURE; case MBEDTLS_ERR_MPI_BAD_INPUT_DATA: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_MPI_INVALID_CHARACTER: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL: return PSA_ERROR_BUFFER_TOO_SMALL; case MBEDTLS_ERR_MPI_NEGATIVE_VALUE: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_MPI_DIVISION_BY_ZERO: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_MPI_NOT_ACCEPTABLE: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_MPI_ALLOC_FAILED: return PSA_ERROR_INSUFFICIENT_MEMORY; case MBEDTLS_ERR_PK_ALLOC_FAILED: return PSA_ERROR_INSUFFICIENT_MEMORY; case MBEDTLS_ERR_PK_TYPE_MISMATCH: case MBEDTLS_ERR_PK_BAD_INPUT_DATA: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_PK_FILE_IO_ERROR: return PSA_ERROR_STORAGE_FAILURE; case MBEDTLS_ERR_PK_KEY_INVALID_VERSION: case MBEDTLS_ERR_PK_KEY_INVALID_FORMAT: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_PK_UNKNOWN_PK_ALG: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_PK_PASSWORD_REQUIRED: case MBEDTLS_ERR_PK_PASSWORD_MISMATCH: return PSA_ERROR_NOT_PERMITTED; case MBEDTLS_ERR_PK_INVALID_PUBKEY: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_PK_INVALID_ALG: case MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE: case MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_PK_SIG_LEN_MISMATCH: return PSA_ERROR_INVALID_SIGNATURE; case MBEDTLS_ERR_PK_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_RIPEMD160_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_RSA_BAD_INPUT_DATA: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_RSA_INVALID_PADDING: return PSA_ERROR_INVALID_PADDING; case MBEDTLS_ERR_RSA_KEY_GEN_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_RSA_KEY_CHECK_FAILED: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_RSA_PUBLIC_FAILED: case MBEDTLS_ERR_RSA_PRIVATE_FAILED: return PSA_ERROR_CORRUPTION_DETECTED; case MBEDTLS_ERR_RSA_VERIFY_FAILED: return PSA_ERROR_INVALID_SIGNATURE; case MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE: return PSA_ERROR_BUFFER_TOO_SMALL; case MBEDTLS_ERR_RSA_RNG_FAILED: return PSA_ERROR_INSUFFICIENT_ENTROPY; case MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_RSA_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED: case MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED: case MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_XTEA_INVALID_INPUT_LENGTH: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_XTEA_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_ECP_BAD_INPUT_DATA: case MBEDTLS_ERR_ECP_INVALID_KEY: return PSA_ERROR_INVALID_ARGUMENT; case MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL: return PSA_ERROR_BUFFER_TOO_SMALL; case MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE: return PSA_ERROR_NOT_SUPPORTED; case MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH: case MBEDTLS_ERR_ECP_VERIFY_FAILED: return PSA_ERROR_INVALID_SIGNATURE; case MBEDTLS_ERR_ECP_ALLOC_FAILED: return PSA_ERROR_INSUFFICIENT_MEMORY; case MBEDTLS_ERR_ECP_RANDOM_FAILED: return PSA_ERROR_INSUFFICIENT_ENTROPY; case MBEDTLS_ERR_ECP_HW_ACCEL_FAILED: return PSA_ERROR_HARDWARE_FAILURE; case MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED: return PSA_ERROR_CORRUPTION_DETECTED; default: return PSA_ERROR_GENERIC_ERROR; } } /****************************************************************/ /* Key management */ /****************************************************************/ #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \ defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) mbedtls_ecp_group_id mbedtls_ecc_group_of_psa(psa_ecc_family_t curve, size_t bits, int bits_is_sloppy) { switch (curve) { case PSA_ECC_FAMILY_SECP_R1: switch (bits) { #if defined(PSA_WANT_ECC_SECP_R1_192) case 192: return MBEDTLS_ECP_DP_SECP192R1; #endif #if defined(PSA_WANT_ECC_SECP_R1_224) case 224: return MBEDTLS_ECP_DP_SECP224R1; #endif #if defined(PSA_WANT_ECC_SECP_R1_256) case 256: return MBEDTLS_ECP_DP_SECP256R1; #endif #if defined(PSA_WANT_ECC_SECP_R1_384) case 384: return MBEDTLS_ECP_DP_SECP384R1; #endif #if defined(PSA_WANT_ECC_SECP_R1_521) case 521: return MBEDTLS_ECP_DP_SECP521R1; case 528: if (bits_is_sloppy) { return MBEDTLS_ECP_DP_SECP521R1; } break; #endif } break; case PSA_ECC_FAMILY_BRAINPOOL_P_R1: switch (bits) { #if defined(PSA_WANT_ECC_BRAINPOOL_P_R1_256) case 256: return MBEDTLS_ECP_DP_BP256R1; #endif #if defined(PSA_WANT_ECC_BRAINPOOL_P_R1_384) case 384: return MBEDTLS_ECP_DP_BP384R1; #endif #if defined(PSA_WANT_ECC_BRAINPOOL_P_R1_512) case 512: return MBEDTLS_ECP_DP_BP512R1; #endif } break; case PSA_ECC_FAMILY_MONTGOMERY: switch (bits) { #if defined(PSA_WANT_ECC_MONTGOMERY_255) case 255: return MBEDTLS_ECP_DP_CURVE25519; case 256: if (bits_is_sloppy) { return MBEDTLS_ECP_DP_CURVE25519; } break; #endif #if defined(PSA_WANT_ECC_MONTGOMERY_448) case 448: return MBEDTLS_ECP_DP_CURVE448; #endif } break; case PSA_ECC_FAMILY_SECP_K1: switch (bits) { #if defined(PSA_WANT_ECC_SECP_K1_192) case 192: return MBEDTLS_ECP_DP_SECP192K1; #endif #if defined(PSA_WANT_ECC_SECP_K1_224) case 224: return MBEDTLS_ECP_DP_SECP224K1; #endif #if defined(PSA_WANT_ECC_SECP_K1_256) case 256: return MBEDTLS_ECP_DP_SECP256K1; #endif } break; } (void) bits_is_sloppy; return MBEDTLS_ECP_DP_NONE; } #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) */ static psa_status_t validate_unstructured_key_bit_size(psa_key_type_t type, size_t bits) { /* Check that the bit size is acceptable for the key type */ switch (type) { case PSA_KEY_TYPE_RAW_DATA: case PSA_KEY_TYPE_HMAC: case PSA_KEY_TYPE_DERIVE: break; #if defined(PSA_WANT_KEY_TYPE_AES) case PSA_KEY_TYPE_AES: if (bits != 128 && bits != 192 && bits != 256) { return PSA_ERROR_INVALID_ARGUMENT; } break; #endif #if defined(PSA_WANT_KEY_TYPE_ARIA) case PSA_KEY_TYPE_ARIA: if (bits != 128 && bits != 192 && bits != 256) { return PSA_ERROR_INVALID_ARGUMENT; } break; #endif #if defined(PSA_WANT_KEY_TYPE_CAMELLIA) case PSA_KEY_TYPE_CAMELLIA: if (bits != 128 && bits != 192 && bits != 256) { return PSA_ERROR_INVALID_ARGUMENT; } break; #endif #if defined(PSA_WANT_KEY_TYPE_DES) case PSA_KEY_TYPE_DES: if (bits != 64 && bits != 128 && bits != 192) { return PSA_ERROR_INVALID_ARGUMENT; } break; #endif #if defined(PSA_WANT_KEY_TYPE_ARC4) case PSA_KEY_TYPE_ARC4: if (bits < 8 || bits > 2048) { return PSA_ERROR_INVALID_ARGUMENT; } break; #endif #if defined(PSA_WANT_KEY_TYPE_CHACHA20) case PSA_KEY_TYPE_CHACHA20: if (bits != 256) { return PSA_ERROR_INVALID_ARGUMENT; } break; #endif default: return PSA_ERROR_NOT_SUPPORTED; } if (bits % 8 != 0) { return PSA_ERROR_INVALID_ARGUMENT; } return PSA_SUCCESS; } /** Check whether a given key type is valid for use with a given MAC algorithm * * Upon successful return of this function, the behavior of #PSA_MAC_LENGTH * when called with the validated \p algorithm and \p key_type is well-defined. * * \param[in] algorithm The specific MAC algorithm (can be wildcard). * \param[in] key_type The key type of the key to be used with the * \p algorithm. * * \retval #PSA_SUCCESS * The \p key_type is valid for use with the \p algorithm * \retval #PSA_ERROR_INVALID_ARGUMENT * The \p key_type is not valid for use with the \p algorithm */ MBEDTLS_STATIC_TESTABLE psa_status_t psa_mac_key_can_do( psa_algorithm_t algorithm, psa_key_type_t key_type) { if (PSA_ALG_IS_HMAC(algorithm)) { if (key_type == PSA_KEY_TYPE_HMAC) { return PSA_SUCCESS; } } if (PSA_ALG_IS_BLOCK_CIPHER_MAC(algorithm)) { /* Check that we're calling PSA_BLOCK_CIPHER_BLOCK_LENGTH with a cipher * key. */ if ((key_type & PSA_KEY_TYPE_CATEGORY_MASK) == PSA_KEY_TYPE_CATEGORY_SYMMETRIC) { /* PSA_BLOCK_CIPHER_BLOCK_LENGTH returns 1 for stream ciphers and * the block length (larger than 1) for block ciphers. */ if (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1) { return PSA_SUCCESS; } } } return PSA_ERROR_INVALID_ARGUMENT; } psa_status_t psa_allocate_buffer_to_slot(psa_key_slot_t *slot, size_t buffer_length) { if (slot->key.data != NULL) { return PSA_ERROR_ALREADY_EXISTS; } slot->key.data = mbedtls_calloc(1, buffer_length); if (slot->key.data == NULL) { return PSA_ERROR_INSUFFICIENT_MEMORY; } slot->key.bytes = buffer_length; return PSA_SUCCESS; } psa_status_t psa_copy_key_material_into_slot(psa_key_slot_t *slot, const uint8_t *data, size_t data_length) { psa_status_t status = psa_allocate_buffer_to_slot(slot, data_length); if (status != PSA_SUCCESS) { return status; } memcpy(slot->key.data, data, data_length); return PSA_SUCCESS; } psa_status_t psa_import_key_into_slot( const psa_key_attributes_t *attributes, const uint8_t *data, size_t data_length, uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length, size_t *bits) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_type_t type = attributes->core.type; /* zero-length keys are never supported. */ if (data_length == 0) { return PSA_ERROR_NOT_SUPPORTED; } if (key_type_is_raw_bytes(type)) { *bits = PSA_BYTES_TO_BITS(data_length); /* Ensure that the bytes-to-bits conversion hasn't overflown. */ if (data_length > SIZE_MAX / 8) { return PSA_ERROR_NOT_SUPPORTED; } /* Enforce a size limit, and in particular ensure that the bit * size fits in its representation type. */ if ((*bits) > PSA_MAX_KEY_BITS) { return PSA_ERROR_NOT_SUPPORTED; } status = validate_unstructured_key_bit_size(type, *bits); if (status != PSA_SUCCESS) { return status; } /* Copy the key material. */ memcpy(key_buffer, data, data_length); *key_buffer_length = data_length; (void) key_buffer_size; return PSA_SUCCESS; } else if (PSA_KEY_TYPE_IS_ASYMMETRIC(type)) { #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \ defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) if (PSA_KEY_TYPE_IS_ECC(type)) { return mbedtls_psa_ecp_import_key(attributes, data, data_length, key_buffer, key_buffer_size, key_buffer_length, bits); } #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */ #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) if (PSA_KEY_TYPE_IS_RSA(type)) { return mbedtls_psa_rsa_import_key(attributes, data, data_length, key_buffer, key_buffer_size, key_buffer_length, bits); } #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */ } return PSA_ERROR_NOT_SUPPORTED; } /** Calculate the intersection of two algorithm usage policies. * * Return 0 (which allows no operation) on incompatibility. */ static psa_algorithm_t psa_key_policy_algorithm_intersection( psa_key_type_t key_type, psa_algorithm_t alg1, psa_algorithm_t alg2) { /* Common case: both sides actually specify the same policy. */ if (alg1 == alg2) { return alg1; } /* If the policies are from the same hash-and-sign family, check * if one is a wildcard. If so the other has the specific algorithm. */ if (PSA_ALG_IS_SIGN_HASH(alg1) && PSA_ALG_IS_SIGN_HASH(alg2) && (alg1 & ~PSA_ALG_HASH_MASK) == (alg2 & ~PSA_ALG_HASH_MASK)) { if (PSA_ALG_SIGN_GET_HASH(alg1) == PSA_ALG_ANY_HASH) { return alg2; } if (PSA_ALG_SIGN_GET_HASH(alg2) == PSA_ALG_ANY_HASH) { return alg1; } } /* If the policies are from the same AEAD family, check whether * one of them is a minimum-tag-length wildcard. Calculate the most * restrictive tag length. */ if (PSA_ALG_IS_AEAD(alg1) && PSA_ALG_IS_AEAD(alg2) && (PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg1, 0) == PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg2, 0))) { size_t alg1_len = PSA_ALG_AEAD_GET_TAG_LENGTH(alg1); size_t alg2_len = PSA_ALG_AEAD_GET_TAG_LENGTH(alg2); size_t restricted_len = alg1_len > alg2_len ? alg1_len : alg2_len; /* If both are wildcards, return most restrictive wildcard */ if (((alg1 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) && ((alg2 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0)) { return PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG( alg1, restricted_len); } /* If only one is a wildcard, return specific algorithm if compatible. */ if (((alg1 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) && (alg1_len <= alg2_len)) { return alg2; } if (((alg2 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) && (alg2_len <= alg1_len)) { return alg1; } } /* If the policies are from the same MAC family, check whether one * of them is a minimum-MAC-length policy. Calculate the most * restrictive tag length. */ if (PSA_ALG_IS_MAC(alg1) && PSA_ALG_IS_MAC(alg2) && (PSA_ALG_FULL_LENGTH_MAC(alg1) == PSA_ALG_FULL_LENGTH_MAC(alg2))) { /* Validate the combination of key type and algorithm. Since the base * algorithm of alg1 and alg2 are the same, we only need this once. */ if (PSA_SUCCESS != psa_mac_key_can_do(alg1, key_type)) { return 0; } /* Get the (exact or at-least) output lengths for both sides of the * requested intersection. None of the currently supported algorithms * have an output length dependent on the actual key size, so setting it * to a bogus value of 0 is currently OK. * * Note that for at-least-this-length wildcard algorithms, the output * length is set to the shortest allowed length, which allows us to * calculate the most restrictive tag length for the intersection. */ size_t alg1_len = PSA_MAC_LENGTH(key_type, 0, alg1); size_t alg2_len = PSA_MAC_LENGTH(key_type, 0, alg2); size_t restricted_len = alg1_len > alg2_len ? alg1_len : alg2_len; /* If both are wildcards, return most restrictive wildcard */ if (((alg1 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) && ((alg2 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0)) { return PSA_ALG_AT_LEAST_THIS_LENGTH_MAC(alg1, restricted_len); } /* If only one is an at-least-this-length policy, the intersection would * be the other (fixed-length) policy as long as said fixed length is * equal to or larger than the shortest allowed length. */ if ((alg1 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) { return (alg1_len <= alg2_len) ? alg2 : 0; } if ((alg2 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) { return (alg2_len <= alg1_len) ? alg1 : 0; } /* If none of them are wildcards, check whether they define the same tag * length. This is still possible here when one is default-length and * the other specific-length. Ensure to always return the * specific-length version for the intersection. */ if (alg1_len == alg2_len) { return PSA_ALG_TRUNCATED_MAC(alg1, alg1_len); } } /* If the policies are incompatible, allow nothing. */ return 0; } static int psa_key_algorithm_permits(psa_key_type_t key_type, psa_algorithm_t policy_alg, psa_algorithm_t requested_alg) { /* Common case: the policy only allows requested_alg. */ if (requested_alg == policy_alg) { return 1; } /* If policy_alg is a hash-and-sign with a wildcard for the hash, * and requested_alg is the same hash-and-sign family with any hash, * then requested_alg is compliant with policy_alg. */ if (PSA_ALG_IS_SIGN_HASH(requested_alg) && PSA_ALG_SIGN_GET_HASH(policy_alg) == PSA_ALG_ANY_HASH) { return (policy_alg & ~PSA_ALG_HASH_MASK) == (requested_alg & ~PSA_ALG_HASH_MASK); } /* If policy_alg is a wildcard AEAD algorithm of the same base as * the requested algorithm, check the requested tag length to be * equal-length or longer than the wildcard-specified length. */ if (PSA_ALG_IS_AEAD(policy_alg) && PSA_ALG_IS_AEAD(requested_alg) && (PSA_ALG_AEAD_WITH_SHORTENED_TAG(policy_alg, 0) == PSA_ALG_AEAD_WITH_SHORTENED_TAG(requested_alg, 0)) && ((policy_alg & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0)) { return PSA_ALG_AEAD_GET_TAG_LENGTH(policy_alg) <= PSA_ALG_AEAD_GET_TAG_LENGTH(requested_alg); } /* If policy_alg is a MAC algorithm of the same base as the requested * algorithm, check whether their MAC lengths are compatible. */ if (PSA_ALG_IS_MAC(policy_alg) && PSA_ALG_IS_MAC(requested_alg) && (PSA_ALG_FULL_LENGTH_MAC(policy_alg) == PSA_ALG_FULL_LENGTH_MAC(requested_alg))) { /* Validate the combination of key type and algorithm. Since the policy * and requested algorithms are the same, we only need this once. */ if (PSA_SUCCESS != psa_mac_key_can_do(policy_alg, key_type)) { return 0; } /* Get both the requested output length for the algorithm which is to be * verified, and the default output length for the base algorithm. * Note that none of the currently supported algorithms have an output * length dependent on actual key size, so setting it to a bogus value * of 0 is currently OK. */ size_t requested_output_length = PSA_MAC_LENGTH( key_type, 0, requested_alg); size_t default_output_length = PSA_MAC_LENGTH( key_type, 0, PSA_ALG_FULL_LENGTH_MAC(requested_alg)); /* If the policy is default-length, only allow an algorithm with * a declared exact-length matching the default. */ if (PSA_MAC_TRUNCATED_LENGTH(policy_alg) == 0) { return requested_output_length == default_output_length; } /* If the requested algorithm is default-length, allow it if the policy * length exactly matches the default length. */ if (PSA_MAC_TRUNCATED_LENGTH(requested_alg) == 0 && PSA_MAC_TRUNCATED_LENGTH(policy_alg) == default_output_length) { return 1; } /* If policy_alg is an at-least-this-length wildcard MAC algorithm, * check for the requested MAC length to be equal to or longer than the * minimum allowed length. */ if ((policy_alg & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) { return PSA_MAC_TRUNCATED_LENGTH(policy_alg) <= requested_output_length; } } /* If policy_alg is a generic key agreement operation, then using it for * a key derivation with that key agreement should also be allowed. This * behaviour is expected to be defined in a future specification version. */ if (PSA_ALG_IS_RAW_KEY_AGREEMENT(policy_alg) && PSA_ALG_IS_KEY_AGREEMENT(requested_alg)) { return PSA_ALG_KEY_AGREEMENT_GET_BASE(requested_alg) == policy_alg; } /* If it isn't explicitly permitted, it's forbidden. */ return 0; } /** Test whether a policy permits an algorithm. * * The caller must test usage flags separately. * * \note This function requires providing the key type for which the policy is * being validated, since some algorithm policy definitions (e.g. MAC) * have different properties depending on what kind of cipher it is * combined with. * * \retval PSA_SUCCESS When \p alg is a specific algorithm * allowed by the \p policy. * \retval PSA_ERROR_INVALID_ARGUMENT When \p alg is not a specific algorithm * \retval PSA_ERROR_NOT_PERMITTED When \p alg is a specific algorithm, but * the \p policy does not allow it. */ static psa_status_t psa_key_policy_permits(const psa_key_policy_t *policy, psa_key_type_t key_type, psa_algorithm_t alg) { /* '0' is not a valid algorithm */ if (alg == 0) { return PSA_ERROR_INVALID_ARGUMENT; } /* A requested algorithm cannot be a wildcard. */ if (PSA_ALG_IS_WILDCARD(alg)) { return PSA_ERROR_INVALID_ARGUMENT; } if (psa_key_algorithm_permits(key_type, policy->alg, alg) || psa_key_algorithm_permits(key_type, policy->alg2, alg)) { return PSA_SUCCESS; } else { return PSA_ERROR_NOT_PERMITTED; } } /** Restrict a key policy based on a constraint. * * \note This function requires providing the key type for which the policy is * being restricted, since some algorithm policy definitions (e.g. MAC) * have different properties depending on what kind of cipher it is * combined with. * * \param[in] key_type The key type for which to restrict the policy * \param[in,out] policy The policy to restrict. * \param[in] constraint The policy constraint to apply. * * \retval #PSA_SUCCESS * \c *policy contains the intersection of the original value of * \c *policy and \c *constraint. * \retval #PSA_ERROR_INVALID_ARGUMENT * \c key_type, \c *policy and \c *constraint are incompatible. * \c *policy is unchanged. */ static psa_status_t psa_restrict_key_policy( psa_key_type_t key_type, psa_key_policy_t *policy, const psa_key_policy_t *constraint) { psa_algorithm_t intersection_alg = psa_key_policy_algorithm_intersection(key_type, policy->alg, constraint->alg); psa_algorithm_t intersection_alg2 = psa_key_policy_algorithm_intersection(key_type, policy->alg2, constraint->alg2); if (intersection_alg == 0 && policy->alg != 0 && constraint->alg != 0) { return PSA_ERROR_INVALID_ARGUMENT; } if (intersection_alg2 == 0 && policy->alg2 != 0 && constraint->alg2 != 0) { return PSA_ERROR_INVALID_ARGUMENT; } policy->usage &= constraint->usage; policy->alg = intersection_alg; policy->alg2 = intersection_alg2; return PSA_SUCCESS; } /** Get the description of a key given its identifier and policy constraints * and lock it. * * The key must have allow all the usage flags set in \p usage. If \p alg is * nonzero, the key must allow operations with this algorithm. If \p alg is * zero, the algorithm is not checked. * * In case of a persistent key, the function loads the description of the key * into a key slot if not already done. * * On success, the returned key slot is locked. It is the responsibility of * the caller to unlock the key slot when it does not access it anymore. */ static psa_status_t psa_get_and_lock_key_slot_with_policy( mbedtls_svc_key_id_t key, psa_key_slot_t **p_slot, psa_key_usage_t usage, psa_algorithm_t alg) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; status = psa_get_and_lock_key_slot(key, p_slot); if (status != PSA_SUCCESS) { return status; } slot = *p_slot; /* Enforce that usage policy for the key slot contains all the flags * required by the usage parameter. There is one exception: public * keys can always be exported, so we treat public key objects as * if they had the export flag. */ if (PSA_KEY_TYPE_IS_PUBLIC_KEY(slot->attr.type)) { usage &= ~PSA_KEY_USAGE_EXPORT; } if ((slot->attr.policy.usage & usage) != usage) { status = PSA_ERROR_NOT_PERMITTED; goto error; } /* Enforce that the usage policy permits the requested algorithm. */ if (alg != 0) { status = psa_key_policy_permits(&slot->attr.policy, slot->attr.type, alg); if (status != PSA_SUCCESS) { goto error; } } return PSA_SUCCESS; error: *p_slot = NULL; psa_unlock_key_slot(slot); return status; } /** Get a key slot containing a transparent key and lock it. * * A transparent key is a key for which the key material is directly * available, as opposed to a key in a secure element and/or to be used * by a secure element. * * This is a temporary function that may be used instead of * psa_get_and_lock_key_slot_with_policy() when there is no opaque key support * for a cryptographic operation. * * On success, the returned key slot is locked. It is the responsibility of the * caller to unlock the key slot when it does not access it anymore. */ static psa_status_t psa_get_and_lock_transparent_key_slot_with_policy( mbedtls_svc_key_id_t key, psa_key_slot_t **p_slot, psa_key_usage_t usage, psa_algorithm_t alg) { psa_status_t status = psa_get_and_lock_key_slot_with_policy(key, p_slot, usage, alg); if (status != PSA_SUCCESS) { return status; } if (psa_key_lifetime_is_external((*p_slot)->attr.lifetime)) { psa_unlock_key_slot(*p_slot); *p_slot = NULL; return PSA_ERROR_NOT_SUPPORTED; } return PSA_SUCCESS; } psa_status_t psa_remove_key_data_from_memory(psa_key_slot_t *slot) { /* Data pointer will always be either a valid pointer or NULL in an * initialized slot, so we can just free it. */ if (slot->key.data != NULL) { mbedtls_platform_zeroize(slot->key.data, slot->key.bytes); } mbedtls_free(slot->key.data); slot->key.data = NULL; slot->key.bytes = 0; return PSA_SUCCESS; } /** Completely wipe a slot in memory, including its policy. * Persistent storage is not affected. */ psa_status_t psa_wipe_key_slot(psa_key_slot_t *slot) { psa_status_t status = psa_remove_key_data_from_memory(slot); /* * As the return error code may not be handled in case of multiple errors, * do our best to report an unexpected lock counter: if available * call MBEDTLS_PARAM_FAILED that may terminate execution (if called as * part of the execution of a test suite this will stop the test suite * execution). */ if (slot->lock_count != 1) { #ifdef MBEDTLS_CHECK_PARAMS MBEDTLS_PARAM_FAILED(slot->lock_count == 1); #endif status = PSA_ERROR_CORRUPTION_DETECTED; } /* Multipart operations may still be using the key. This is safe * because all multipart operation objects are independent from * the key slot: if they need to access the key after the setup * phase, they have a copy of the key. Note that this means that * key material can linger until all operations are completed. */ /* At this point, key material and other type-specific content has * been wiped. Clear remaining metadata. We can call memset and not * zeroize because the metadata is not particularly sensitive. */ memset(slot, 0, sizeof(*slot)); return status; } psa_status_t psa_destroy_key(mbedtls_svc_key_id_t key) { psa_key_slot_t *slot; psa_status_t status; /* status of the last operation */ psa_status_t overall_status = PSA_SUCCESS; #if defined(MBEDTLS_PSA_CRYPTO_SE_C) psa_se_drv_table_entry_t *driver; #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ if (mbedtls_svc_key_id_is_null(key)) { return PSA_SUCCESS; } /* * Get the description of the key in a key slot. In case of a persistent * key, this will load the key description from persistent memory if not * done yet. We cannot avoid this loading as without it we don't know if * the key is operated by an SE or not and this information is needed by * the current implementation. */ status = psa_get_and_lock_key_slot(key, &slot); if (status != PSA_SUCCESS) { return status; } /* * If the key slot containing the key description is under access by the * library (apart from the present access), the key cannot be destroyed * yet. For the time being, just return in error. Eventually (to be * implemented), the key should be destroyed when all accesses have * stopped. */ if (slot->lock_count > 1) { psa_unlock_key_slot(slot); return PSA_ERROR_GENERIC_ERROR; } if (PSA_KEY_LIFETIME_IS_READ_ONLY(slot->attr.lifetime)) { /* Refuse the destruction of a read-only key (which may or may not work * if we attempt it, depending on whether the key is merely read-only * by policy or actually physically read-only). * Just do the best we can, which is to wipe the copy in memory * (done in this function's cleanup code). */ overall_status = PSA_ERROR_NOT_PERMITTED; goto exit; } #if defined(MBEDTLS_PSA_CRYPTO_SE_C) driver = psa_get_se_driver_entry(slot->attr.lifetime); if (driver != NULL) { /* For a key in a secure element, we need to do three things: * remove the key file in internal storage, destroy the * key inside the secure element, and update the driver's * persistent data. Start a transaction that will encompass these * three actions. */ psa_crypto_prepare_transaction(PSA_CRYPTO_TRANSACTION_DESTROY_KEY); psa_crypto_transaction.key.lifetime = slot->attr.lifetime; psa_crypto_transaction.key.slot = psa_key_slot_get_slot_number(slot); psa_crypto_transaction.key.id = slot->attr.id; status = psa_crypto_save_transaction(); if (status != PSA_SUCCESS) { (void) psa_crypto_stop_transaction(); /* We should still try to destroy the key in the secure * element and the key metadata in storage. This is especially * important if the error is that the storage is full. * But how to do it exactly without risking an inconsistent * state after a reset? * https://github.com/ARMmbed/mbed-crypto/issues/215 */ overall_status = status; goto exit; } status = psa_destroy_se_key(driver, psa_key_slot_get_slot_number(slot)); if (overall_status == PSA_SUCCESS) { overall_status = status; } } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ #if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) if (!PSA_KEY_LIFETIME_IS_VOLATILE(slot->attr.lifetime)) { status = psa_destroy_persistent_key(slot->attr.id); if (overall_status == PSA_SUCCESS) { overall_status = status; } /* TODO: other slots may have a copy of the same key. We should * invalidate them. * https://github.com/ARMmbed/mbed-crypto/issues/214 */ } #endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */ #if defined(MBEDTLS_PSA_CRYPTO_SE_C) if (driver != NULL) { status = psa_save_se_persistent_data(driver); if (overall_status == PSA_SUCCESS) { overall_status = status; } status = psa_crypto_stop_transaction(); if (overall_status == PSA_SUCCESS) { overall_status = status; } } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ exit: status = psa_wipe_key_slot(slot); /* Prioritize CORRUPTION_DETECTED from wiping over a storage error */ if (status != PSA_SUCCESS) { overall_status = status; } return overall_status; } #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) static psa_status_t psa_get_rsa_public_exponent( const mbedtls_rsa_context *rsa, psa_key_attributes_t *attributes) { mbedtls_mpi mpi; int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; uint8_t *buffer = NULL; size_t buflen; mbedtls_mpi_init(&mpi); ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &mpi); if (ret != 0) { goto exit; } if (mbedtls_mpi_cmp_int(&mpi, 65537) == 0) { /* It's the default value, which is reported as an empty string, * so there's nothing to do. */ goto exit; } buflen = mbedtls_mpi_size(&mpi); buffer = mbedtls_calloc(1, buflen); if (buffer == NULL) { ret = MBEDTLS_ERR_MPI_ALLOC_FAILED; goto exit; } ret = mbedtls_mpi_write_binary(&mpi, buffer, buflen); if (ret != 0) { goto exit; } attributes->domain_parameters = buffer; attributes->domain_parameters_size = buflen; exit: mbedtls_mpi_free(&mpi); if (ret != 0) { mbedtls_free(buffer); } return mbedtls_to_psa_error(ret); } #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */ /** Retrieve all the publicly-accessible attributes of a key. */ psa_status_t psa_get_key_attributes(mbedtls_svc_key_id_t key, psa_key_attributes_t *attributes) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; psa_reset_key_attributes(attributes); status = psa_get_and_lock_key_slot_with_policy(key, &slot, 0, 0); if (status != PSA_SUCCESS) { return status; } attributes->core = slot->attr; attributes->core.flags &= (MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY | MBEDTLS_PSA_KA_MASK_DUAL_USE); #if defined(MBEDTLS_PSA_CRYPTO_SE_C) if (psa_get_se_driver_entry(slot->attr.lifetime) != NULL) { psa_set_key_slot_number(attributes, psa_key_slot_get_slot_number(slot)); } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ switch (slot->attr.type) { #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) case PSA_KEY_TYPE_RSA_KEY_PAIR: case PSA_KEY_TYPE_RSA_PUBLIC_KEY: /* TODO: reporting the public exponent for opaque keys * is not yet implemented. * https://github.com/ARMmbed/mbed-crypto/issues/216 */ if (!psa_key_lifetime_is_external(slot->attr.lifetime)) { mbedtls_rsa_context *rsa = NULL; status = mbedtls_psa_rsa_load_representation( slot->attr.type, slot->key.data, slot->key.bytes, &rsa); if (status != PSA_SUCCESS) { break; } status = psa_get_rsa_public_exponent(rsa, attributes); mbedtls_rsa_free(rsa); mbedtls_free(rsa); } break; #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */ default: /* Nothing else to do. */ break; } if (status != PSA_SUCCESS) { psa_reset_key_attributes(attributes); } unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } #if defined(MBEDTLS_PSA_CRYPTO_SE_C) psa_status_t psa_get_key_slot_number( const psa_key_attributes_t *attributes, psa_key_slot_number_t *slot_number) { if (attributes->core.flags & MBEDTLS_PSA_KA_FLAG_HAS_SLOT_NUMBER) { *slot_number = attributes->slot_number; return PSA_SUCCESS; } else { return PSA_ERROR_INVALID_ARGUMENT; } } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ static psa_status_t psa_export_key_buffer_internal(const uint8_t *key_buffer, size_t key_buffer_size, uint8_t *data, size_t data_size, size_t *data_length) { if (key_buffer_size > data_size) { return PSA_ERROR_BUFFER_TOO_SMALL; } memcpy(data, key_buffer, key_buffer_size); memset(data + key_buffer_size, 0, data_size - key_buffer_size); *data_length = key_buffer_size; return PSA_SUCCESS; } psa_status_t psa_export_key_internal( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, uint8_t *data, size_t data_size, size_t *data_length) { psa_key_type_t type = attributes->core.type; if (key_type_is_raw_bytes(type) || PSA_KEY_TYPE_IS_RSA(type) || PSA_KEY_TYPE_IS_ECC(type)) { return psa_export_key_buffer_internal( key_buffer, key_buffer_size, data, data_size, data_length); } else { /* This shouldn't happen in the reference implementation, but it is valid for a special-purpose implementation to omit support for exporting certain key types. */ return PSA_ERROR_NOT_SUPPORTED; } } psa_status_t psa_export_key(mbedtls_svc_key_id_t key, uint8_t *data, size_t data_size, size_t *data_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; /* Reject a zero-length output buffer now, since this can never be a * valid key representation. This way we know that data must be a valid * pointer and we can do things like memset(data, ..., data_size). */ if (data_size == 0) { return PSA_ERROR_BUFFER_TOO_SMALL; } /* Set the key to empty now, so that even when there are errors, we always * set data_length to a value between 0 and data_size. On error, setting * the key to empty is a good choice because an empty key representation is * unlikely to be accepted anywhere. */ *data_length = 0; /* Export requires the EXPORT flag. There is an exception for public keys, * which don't require any flag, but * psa_get_and_lock_key_slot_with_policy() takes care of this. */ status = psa_get_and_lock_key_slot_with_policy(key, &slot, PSA_KEY_USAGE_EXPORT, 0); if (status != PSA_SUCCESS) { return status; } psa_key_attributes_t attributes = { .core = slot->attr }; status = psa_driver_wrapper_export_key(&attributes, slot->key.data, slot->key.bytes, data, data_size, data_length); unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } psa_status_t psa_export_public_key_internal( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, uint8_t *data, size_t data_size, size_t *data_length) { psa_key_type_t type = attributes->core.type; if (PSA_KEY_TYPE_IS_RSA(type) || PSA_KEY_TYPE_IS_ECC(type)) { if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type)) { /* Exporting public -> public */ return psa_export_key_buffer_internal( key_buffer, key_buffer_size, data, data_size, data_length); } if (PSA_KEY_TYPE_IS_RSA(type)) { #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) return mbedtls_psa_rsa_export_public_key(attributes, key_buffer, key_buffer_size, data, data_size, data_length); #else /* We don't know how to convert a private RSA key to public. */ return PSA_ERROR_NOT_SUPPORTED; #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */ } else { #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \ defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) return mbedtls_psa_ecp_export_public_key(attributes, key_buffer, key_buffer_size, data, data_size, data_length); #else /* We don't know how to convert a private ECC key to public */ return PSA_ERROR_NOT_SUPPORTED; #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */ } } else { /* This shouldn't happen in the reference implementation, but it is valid for a special-purpose implementation to omit support for exporting certain key types. */ return PSA_ERROR_NOT_SUPPORTED; } } psa_status_t psa_export_public_key(mbedtls_svc_key_id_t key, uint8_t *data, size_t data_size, size_t *data_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t attributes; psa_key_slot_t *slot; /* Reject a zero-length output buffer now, since this can never be a * valid key representation. This way we know that data must be a valid * pointer and we can do things like memset(data, ..., data_size). */ if (data_size == 0) { return PSA_ERROR_BUFFER_TOO_SMALL; } /* Set the key to empty now, so that even when there are errors, we always * set data_length to a value between 0 and data_size. On error, setting * the key to empty is a good choice because an empty key representation is * unlikely to be accepted anywhere. */ *data_length = 0; /* Exporting a public key doesn't require a usage flag. */ status = psa_get_and_lock_key_slot_with_policy(key, &slot, 0, 0); if (status != PSA_SUCCESS) { return status; } if (!PSA_KEY_TYPE_IS_ASYMMETRIC(slot->attr.type)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } attributes = (psa_key_attributes_t) { .core = slot->attr }; status = psa_driver_wrapper_export_public_key( &attributes, slot->key.data, slot->key.bytes, data, data_size, data_length); exit: unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } MBEDTLS_STATIC_ASSERT((MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE) == 0, "One or more key attribute flag is listed as both external-only and dual-use") MBEDTLS_STATIC_ASSERT((PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE) == 0, "One or more key attribute flag is listed as both internal-only and dual-use") MBEDTLS_STATIC_ASSERT((PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY) == 0, "One or more key attribute flag is listed as both internal-only and external-only") /** Validate that a key policy is internally well-formed. * * This function only rejects invalid policies. It does not validate the * consistency of the policy with respect to other attributes of the key * such as the key type. */ static psa_status_t psa_validate_key_policy(const psa_key_policy_t *policy) { if ((policy->usage & ~(PSA_KEY_USAGE_EXPORT | PSA_KEY_USAGE_COPY | PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT | PSA_KEY_USAGE_SIGN_MESSAGE | PSA_KEY_USAGE_VERIFY_MESSAGE | PSA_KEY_USAGE_SIGN_HASH | PSA_KEY_USAGE_VERIFY_HASH | PSA_KEY_USAGE_DERIVE)) != 0) { return PSA_ERROR_INVALID_ARGUMENT; } return PSA_SUCCESS; } /** Validate the internal consistency of key attributes. * * This function only rejects invalid attribute values. If does not * validate the consistency of the attributes with any key data that may * be involved in the creation of the key. * * Call this function early in the key creation process. * * \param[in] attributes Key attributes for the new key. * \param[out] p_drv On any return, the driver for the key, if any. * NULL for a transparent key. * */ static psa_status_t psa_validate_key_attributes( const psa_key_attributes_t *attributes, psa_se_drv_table_entry_t **p_drv) { psa_status_t status = PSA_ERROR_INVALID_ARGUMENT; psa_key_lifetime_t lifetime = psa_get_key_lifetime(attributes); mbedtls_svc_key_id_t key = psa_get_key_id(attributes); status = psa_validate_key_location(lifetime, p_drv); if (status != PSA_SUCCESS) { return status; } status = psa_validate_key_persistence(lifetime); if (status != PSA_SUCCESS) { return status; } if (PSA_KEY_LIFETIME_IS_VOLATILE(lifetime)) { if (MBEDTLS_SVC_KEY_ID_GET_KEY_ID(key) != 0) { return PSA_ERROR_INVALID_ARGUMENT; } } else { if (!psa_is_valid_key_id(psa_get_key_id(attributes), 0)) { return PSA_ERROR_INVALID_ARGUMENT; } } status = psa_validate_key_policy(&attributes->core.policy); if (status != PSA_SUCCESS) { return status; } /* Refuse to create overly large keys. * Note that this doesn't trigger on import if the attributes don't * explicitly specify a size (so psa_get_key_bits returns 0), so * psa_import_key() needs its own checks. */ if (psa_get_key_bits(attributes) > PSA_MAX_KEY_BITS) { return PSA_ERROR_NOT_SUPPORTED; } /* Reject invalid flags. These should not be reachable through the API. */ if (attributes->core.flags & ~(MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY | MBEDTLS_PSA_KA_MASK_DUAL_USE)) { return PSA_ERROR_INVALID_ARGUMENT; } return PSA_SUCCESS; } /** Prepare a key slot to receive key material. * * This function allocates a key slot and sets its metadata. * * If this function fails, call psa_fail_key_creation(). * * This function is intended to be used as follows: * -# Call psa_start_key_creation() to allocate a key slot, prepare * it with the specified attributes, and in case of a volatile key assign it * a volatile key identifier. * -# Populate the slot with the key material. * -# Call psa_finish_key_creation() to finalize the creation of the slot. * In case of failure at any step, stop the sequence and call * psa_fail_key_creation(). * * On success, the key slot is locked. It is the responsibility of the caller * to unlock the key slot when it does not access it anymore. * * \param method An identification of the calling function. * \param[in] attributes Key attributes for the new key. * \param[out] p_slot On success, a pointer to the prepared slot. * \param[out] p_drv On any return, the driver for the key, if any. * NULL for a transparent key. * * \retval #PSA_SUCCESS * The key slot is ready to receive key material. * \return If this function fails, the key slot is an invalid state. * You must call psa_fail_key_creation() to wipe and free the slot. */ static psa_status_t psa_start_key_creation( psa_key_creation_method_t method, const psa_key_attributes_t *attributes, psa_key_slot_t **p_slot, psa_se_drv_table_entry_t **p_drv) { psa_status_t status; psa_key_id_t volatile_key_id; psa_key_slot_t *slot; (void) method; *p_drv = NULL; status = psa_validate_key_attributes(attributes, p_drv); if (status != PSA_SUCCESS) { return status; } status = psa_get_empty_key_slot(&volatile_key_id, p_slot); if (status != PSA_SUCCESS) { return status; } slot = *p_slot; /* We're storing the declared bit-size of the key. It's up to each * creation mechanism to verify that this information is correct. * It's automatically correct for mechanisms that use the bit-size as * an input (generate, device) but not for those where the bit-size * is optional (import, copy). In case of a volatile key, assign it the * volatile key identifier associated to the slot returned to contain its * definition. */ slot->attr = attributes->core; if (PSA_KEY_LIFETIME_IS_VOLATILE(slot->attr.lifetime)) { #if !defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER) slot->attr.id = volatile_key_id; #else slot->attr.id.key_id = volatile_key_id; #endif } /* Erase external-only flags from the internal copy. To access * external-only flags, query `attributes`. Thanks to the check * in psa_validate_key_attributes(), this leaves the dual-use * flags and any internal flag that psa_get_empty_key_slot() * may have set. */ slot->attr.flags &= ~MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY; #if defined(MBEDTLS_PSA_CRYPTO_SE_C) /* For a key in a secure element, we need to do three things * when creating or registering a persistent key: * create the key file in internal storage, create the * key inside the secure element, and update the driver's * persistent data. This is done by starting a transaction that will * encompass these three actions. * For registering a volatile key, we just need to find an appropriate * slot number inside the SE. Since the key is designated volatile, creating * a transaction is not required. */ /* The first thing to do is to find a slot number for the new key. * We save the slot number in persistent storage as part of the * transaction data. It will be needed to recover if the power * fails during the key creation process, to clean up on the secure * element side after restarting. Obtaining a slot number from the * secure element driver updates its persistent state, but we do not yet * save the driver's persistent state, so that if the power fails, * we can roll back to a state where the key doesn't exist. */ if (*p_drv != NULL) { psa_key_slot_number_t slot_number; status = psa_find_se_slot_for_key(attributes, method, *p_drv, &slot_number); if (status != PSA_SUCCESS) { return status; } if (!PSA_KEY_LIFETIME_IS_VOLATILE(attributes->core.lifetime)) { psa_crypto_prepare_transaction(PSA_CRYPTO_TRANSACTION_CREATE_KEY); psa_crypto_transaction.key.lifetime = slot->attr.lifetime; psa_crypto_transaction.key.slot = slot_number; psa_crypto_transaction.key.id = slot->attr.id; status = psa_crypto_save_transaction(); if (status != PSA_SUCCESS) { (void) psa_crypto_stop_transaction(); return status; } } status = psa_copy_key_material_into_slot( slot, (uint8_t *) (&slot_number), sizeof(slot_number)); } if (*p_drv == NULL && method == PSA_KEY_CREATION_REGISTER) { /* Key registration only makes sense with a secure element. */ return PSA_ERROR_INVALID_ARGUMENT; } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ return PSA_SUCCESS; } /** Finalize the creation of a key once its key material has been set. * * This entails writing the key to persistent storage. * * If this function fails, call psa_fail_key_creation(). * See the documentation of psa_start_key_creation() for the intended use * of this function. * * If the finalization succeeds, the function unlocks the key slot (it was * locked by psa_start_key_creation()) and the key slot cannot be accessed * anymore as part of the key creation process. * * \param[in,out] slot Pointer to the slot with key material. * \param[in] driver The secure element driver for the key, * or NULL for a transparent key. * \param[out] key On success, identifier of the key. Note that the * key identifier is also stored in the key slot. * * \retval #PSA_SUCCESS * The key was successfully created. * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription * \retval #PSA_ERROR_INSUFFICIENT_STORAGE \emptydescription * \retval #PSA_ERROR_ALREADY_EXISTS \emptydescription * \retval #PSA_ERROR_DATA_INVALID \emptydescription * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription * * \return If this function fails, the key slot is an invalid state. * You must call psa_fail_key_creation() to wipe and free the slot. */ static psa_status_t psa_finish_key_creation( psa_key_slot_t *slot, psa_se_drv_table_entry_t *driver, mbedtls_svc_key_id_t *key) { psa_status_t status = PSA_SUCCESS; (void) slot; (void) driver; #if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) if (!PSA_KEY_LIFETIME_IS_VOLATILE(slot->attr.lifetime)) { #if defined(MBEDTLS_PSA_CRYPTO_SE_C) if (driver != NULL) { psa_se_key_data_storage_t data; psa_key_slot_number_t slot_number = psa_key_slot_get_slot_number(slot); MBEDTLS_STATIC_ASSERT(sizeof(slot_number) == sizeof(data.slot_number), "Slot number size does not match psa_se_key_data_storage_t"); memcpy(&data.slot_number, &slot_number, sizeof(slot_number)); status = psa_save_persistent_key(&slot->attr, (uint8_t *) &data, sizeof(data)); } else #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ { /* Key material is saved in export representation in the slot, so * just pass the slot buffer for storage. */ status = psa_save_persistent_key(&slot->attr, slot->key.data, slot->key.bytes); } } #endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */ #if defined(MBEDTLS_PSA_CRYPTO_SE_C) /* Finish the transaction for a key creation. This does not * happen when registering an existing key. Detect this case * by checking whether a transaction is in progress (actual * creation of a persistent key in a secure element requires a transaction, * but registration or volatile key creation doesn't use one). */ if (driver != NULL && psa_crypto_transaction.unknown.type == PSA_CRYPTO_TRANSACTION_CREATE_KEY) { status = psa_save_se_persistent_data(driver); if (status != PSA_SUCCESS) { psa_destroy_persistent_key(slot->attr.id); return status; } status = psa_crypto_stop_transaction(); } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ if (status == PSA_SUCCESS) { *key = slot->attr.id; status = psa_unlock_key_slot(slot); if (status != PSA_SUCCESS) { *key = MBEDTLS_SVC_KEY_ID_INIT; } } return status; } /** Abort the creation of a key. * * You may call this function after calling psa_start_key_creation(), * or after psa_finish_key_creation() fails. In other circumstances, this * function may not clean up persistent storage. * See the documentation of psa_start_key_creation() for the intended use * of this function. * * \param[in,out] slot Pointer to the slot with key material. * \param[in] driver The secure element driver for the key, * or NULL for a transparent key. */ static void psa_fail_key_creation(psa_key_slot_t *slot, psa_se_drv_table_entry_t *driver) { (void) driver; if (slot == NULL) { return; } #if defined(MBEDTLS_PSA_CRYPTO_SE_C) /* TODO: If the key has already been created in the secure * element, and the failure happened later (when saving metadata * to internal storage), we need to destroy the key in the secure * element. * https://github.com/ARMmbed/mbed-crypto/issues/217 */ /* Abort the ongoing transaction if any (there may not be one if * the creation process failed before starting one, or if the * key creation is a registration of a key in a secure element). * Earlier functions must already have done what it takes to undo any * partial creation. All that's left is to update the transaction data * itself. */ (void) psa_crypto_stop_transaction(); #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ psa_wipe_key_slot(slot); } /** Validate optional attributes during key creation. * * Some key attributes are optional during key creation. If they are * specified in the attributes structure, check that they are consistent * with the data in the slot. * * This function should be called near the end of key creation, after * the slot in memory is fully populated but before saving persistent data. */ static psa_status_t psa_validate_optional_attributes( const psa_key_slot_t *slot, const psa_key_attributes_t *attributes) { if (attributes->core.type != 0) { if (attributes->core.type != slot->attr.type) { return PSA_ERROR_INVALID_ARGUMENT; } } if (attributes->domain_parameters_size != 0) { #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \ defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) if (PSA_KEY_TYPE_IS_RSA(slot->attr.type)) { mbedtls_rsa_context *rsa = NULL; mbedtls_mpi actual, required; int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; psa_status_t status = mbedtls_psa_rsa_load_representation( slot->attr.type, slot->key.data, slot->key.bytes, &rsa); if (status != PSA_SUCCESS) { return status; } mbedtls_mpi_init(&actual); mbedtls_mpi_init(&required); ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &actual); mbedtls_rsa_free(rsa); mbedtls_free(rsa); if (ret != 0) { goto rsa_exit; } ret = mbedtls_mpi_read_binary(&required, attributes->domain_parameters, attributes->domain_parameters_size); if (ret != 0) { goto rsa_exit; } if (mbedtls_mpi_cmp_mpi(&actual, &required) != 0) { ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA; } rsa_exit: mbedtls_mpi_free(&actual); mbedtls_mpi_free(&required); if (ret != 0) { return mbedtls_to_psa_error(ret); } } else #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */ { return PSA_ERROR_INVALID_ARGUMENT; } } if (attributes->core.bits != 0) { if (attributes->core.bits != slot->attr.bits) { return PSA_ERROR_INVALID_ARGUMENT; } } return PSA_SUCCESS; } psa_status_t psa_import_key(const psa_key_attributes_t *attributes, const uint8_t *data, size_t data_length, mbedtls_svc_key_id_t *key) { psa_status_t status; psa_key_slot_t *slot = NULL; psa_se_drv_table_entry_t *driver = NULL; size_t bits; *key = MBEDTLS_SVC_KEY_ID_INIT; /* Reject zero-length symmetric keys (including raw data key objects). * This also rejects any key which might be encoded as an empty string, * which is never valid. */ if (data_length == 0) { return PSA_ERROR_INVALID_ARGUMENT; } status = psa_start_key_creation(PSA_KEY_CREATION_IMPORT, attributes, &slot, &driver); if (status != PSA_SUCCESS) { goto exit; } /* In the case of a transparent key or an opaque key stored in local * storage (thus not in the case of generating a key in a secure element * or cryptoprocessor with storage), we have to allocate a buffer to * hold the generated key material. */ if (slot->key.data == NULL) { status = psa_allocate_buffer_to_slot(slot, data_length); if (status != PSA_SUCCESS) { goto exit; } } bits = slot->attr.bits; status = psa_driver_wrapper_import_key(attributes, data, data_length, slot->key.data, slot->key.bytes, &slot->key.bytes, &bits); if (status != PSA_SUCCESS) { goto exit; } if (slot->attr.bits == 0) { slot->attr.bits = (psa_key_bits_t) bits; } else if (bits != slot->attr.bits) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } status = psa_validate_optional_attributes(slot, attributes); if (status != PSA_SUCCESS) { goto exit; } status = psa_finish_key_creation(slot, driver, key); exit: if (status != PSA_SUCCESS) { psa_fail_key_creation(slot, driver); } return status; } #if defined(MBEDTLS_PSA_CRYPTO_SE_C) psa_status_t mbedtls_psa_register_se_key( const psa_key_attributes_t *attributes) { psa_status_t status; psa_key_slot_t *slot = NULL; psa_se_drv_table_entry_t *driver = NULL; mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT; /* Leaving attributes unspecified is not currently supported. * It could make sense to query the key type and size from the * secure element, but not all secure elements support this * and the driver HAL doesn't currently support it. */ if (psa_get_key_type(attributes) == PSA_KEY_TYPE_NONE) { return PSA_ERROR_NOT_SUPPORTED; } if (psa_get_key_bits(attributes) == 0) { return PSA_ERROR_NOT_SUPPORTED; } status = psa_start_key_creation(PSA_KEY_CREATION_REGISTER, attributes, &slot, &driver); if (status != PSA_SUCCESS) { goto exit; } status = psa_finish_key_creation(slot, driver, &key); exit: if (status != PSA_SUCCESS) { psa_fail_key_creation(slot, driver); } /* Registration doesn't keep the key in RAM. */ psa_close_key(key); return status; } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ static psa_status_t psa_copy_key_material(const psa_key_slot_t *source, psa_key_slot_t *target) { psa_status_t status = psa_copy_key_material_into_slot(target, source->key.data, source->key.bytes); if (status != PSA_SUCCESS) { return status; } target->attr.type = source->attr.type; target->attr.bits = source->attr.bits; return PSA_SUCCESS; } psa_status_t psa_copy_key(mbedtls_svc_key_id_t source_key, const psa_key_attributes_t *specified_attributes, mbedtls_svc_key_id_t *target_key) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *source_slot = NULL; psa_key_slot_t *target_slot = NULL; psa_key_attributes_t actual_attributes = *specified_attributes; psa_se_drv_table_entry_t *driver = NULL; *target_key = MBEDTLS_SVC_KEY_ID_INIT; status = psa_get_and_lock_transparent_key_slot_with_policy( source_key, &source_slot, PSA_KEY_USAGE_COPY, 0); if (status != PSA_SUCCESS) { goto exit; } status = psa_validate_optional_attributes(source_slot, specified_attributes); if (status != PSA_SUCCESS) { goto exit; } status = psa_restrict_key_policy(source_slot->attr.type, &actual_attributes.core.policy, &source_slot->attr.policy); if (status != PSA_SUCCESS) { goto exit; } status = psa_start_key_creation(PSA_KEY_CREATION_COPY, &actual_attributes, &target_slot, &driver); if (status != PSA_SUCCESS) { goto exit; } #if defined(MBEDTLS_PSA_CRYPTO_SE_C) if (driver != NULL) { /* Copying to a secure element is not implemented yet. */ status = PSA_ERROR_NOT_SUPPORTED; goto exit; } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ if (psa_key_lifetime_is_external(actual_attributes.core.lifetime)) { /* * Copying through an opaque driver is not implemented yet, consider * a lifetime with an external location as an invalid parameter for * now. */ status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } status = psa_copy_key_material(source_slot, target_slot); if (status != PSA_SUCCESS) { goto exit; } status = psa_finish_key_creation(target_slot, driver, target_key); exit: if (status != PSA_SUCCESS) { psa_fail_key_creation(target_slot, driver); } unlock_status = psa_unlock_key_slot(source_slot); return (status == PSA_SUCCESS) ? unlock_status : status; } /****************************************************************/ /* Message digests */ /****************************************************************/ psa_status_t psa_hash_abort(psa_hash_operation_t *operation) { /* Aborting a non-active operation is allowed */ if (operation->id == 0) { return PSA_SUCCESS; } psa_status_t status = psa_driver_wrapper_hash_abort(operation); operation->id = 0; return status; } psa_status_t psa_hash_setup(psa_hash_operation_t *operation, psa_algorithm_t alg) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; /* A context must be freshly initialized before it can be set up. */ if (operation->id != 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (!PSA_ALG_IS_HASH(alg)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } /* Ensure all of the context is zeroized, since PSA_HASH_OPERATION_INIT only * directly zeroes the int-sized dummy member of the context union. */ memset(&operation->ctx, 0, sizeof(operation->ctx)); status = psa_driver_wrapper_hash_setup(operation, alg); exit: if (status != PSA_SUCCESS) { psa_hash_abort(operation); } return status; } psa_status_t psa_hash_update(psa_hash_operation_t *operation, const uint8_t *input, size_t input_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; if (operation->id == 0) { status = PSA_ERROR_BAD_STATE; goto exit; } /* Don't require hash implementations to behave correctly on a * zero-length input, which may have an invalid pointer. */ if (input_length == 0) { return PSA_SUCCESS; } status = psa_driver_wrapper_hash_update(operation, input, input_length); exit: if (status != PSA_SUCCESS) { psa_hash_abort(operation); } return status; } psa_status_t psa_hash_finish(psa_hash_operation_t *operation, uint8_t *hash, size_t hash_size, size_t *hash_length) { *hash_length = 0; if (operation->id == 0) { return PSA_ERROR_BAD_STATE; } psa_status_t status = psa_driver_wrapper_hash_finish( operation, hash, hash_size, hash_length); psa_hash_abort(operation); return status; } psa_status_t psa_hash_verify(psa_hash_operation_t *operation, const uint8_t *hash, size_t hash_length) { uint8_t actual_hash[PSA_HASH_MAX_SIZE]; size_t actual_hash_length; psa_status_t status = psa_hash_finish( operation, actual_hash, sizeof(actual_hash), &actual_hash_length); if (status != PSA_SUCCESS) { goto exit; } if (actual_hash_length != hash_length) { status = PSA_ERROR_INVALID_SIGNATURE; goto exit; } if (mbedtls_psa_safer_memcmp(hash, actual_hash, actual_hash_length) != 0) { status = PSA_ERROR_INVALID_SIGNATURE; } exit: mbedtls_platform_zeroize(actual_hash, sizeof(actual_hash)); if (status != PSA_SUCCESS) { psa_hash_abort(operation); } return status; } psa_status_t psa_hash_compute(psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *hash, size_t hash_size, size_t *hash_length) { *hash_length = 0; if (!PSA_ALG_IS_HASH(alg)) { return PSA_ERROR_INVALID_ARGUMENT; } return psa_driver_wrapper_hash_compute(alg, input, input_length, hash, hash_size, hash_length); } psa_status_t psa_hash_compare(psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *hash, size_t hash_length) { uint8_t actual_hash[PSA_HASH_MAX_SIZE]; size_t actual_hash_length; if (!PSA_ALG_IS_HASH(alg)) { return PSA_ERROR_INVALID_ARGUMENT; } psa_status_t status = psa_driver_wrapper_hash_compute( alg, input, input_length, actual_hash, sizeof(actual_hash), &actual_hash_length); if (status != PSA_SUCCESS) { goto exit; } if (actual_hash_length != hash_length) { status = PSA_ERROR_INVALID_SIGNATURE; goto exit; } if (mbedtls_psa_safer_memcmp(hash, actual_hash, actual_hash_length) != 0) { status = PSA_ERROR_INVALID_SIGNATURE; } exit: mbedtls_platform_zeroize(actual_hash, sizeof(actual_hash)); return status; } psa_status_t psa_hash_clone(const psa_hash_operation_t *source_operation, psa_hash_operation_t *target_operation) { if (source_operation->id == 0 || target_operation->id != 0) { return PSA_ERROR_BAD_STATE; } psa_status_t status = psa_driver_wrapper_hash_clone(source_operation, target_operation); if (status != PSA_SUCCESS) { psa_hash_abort(target_operation); } return status; } /****************************************************************/ /* MAC */ /****************************************************************/ psa_status_t psa_mac_abort(psa_mac_operation_t *operation) { /* Aborting a non-active operation is allowed */ if (operation->id == 0) { return PSA_SUCCESS; } psa_status_t status = psa_driver_wrapper_mac_abort(operation); operation->mac_size = 0; operation->is_sign = 0; operation->id = 0; return status; } static psa_status_t psa_mac_finalize_alg_and_key_validation( psa_algorithm_t alg, const psa_key_attributes_t *attributes, uint8_t *mac_size) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_type_t key_type = psa_get_key_type(attributes); size_t key_bits = psa_get_key_bits(attributes); if (!PSA_ALG_IS_MAC(alg)) { return PSA_ERROR_INVALID_ARGUMENT; } /* Validate the combination of key type and algorithm */ status = psa_mac_key_can_do(alg, key_type); if (status != PSA_SUCCESS) { return status; } /* Get the output length for the algorithm and key combination */ *mac_size = PSA_MAC_LENGTH(key_type, key_bits, alg); if (*mac_size < 4) { /* A very short MAC is too short for security since it can be * brute-forced. Ancient protocols with 32-bit MACs do exist, * so we make this our minimum, even though 32 bits is still * too small for security. */ return PSA_ERROR_NOT_SUPPORTED; } if (*mac_size > PSA_MAC_LENGTH(key_type, key_bits, PSA_ALG_FULL_LENGTH_MAC(alg))) { /* It's impossible to "truncate" to a larger length than the full length * of the algorithm. */ return PSA_ERROR_INVALID_ARGUMENT; } if (*mac_size > PSA_MAC_MAX_SIZE) { /* PSA_MAC_LENGTH returns the correct length even for a MAC algorithm * that is disabled in the compile-time configuration. The result can * therefore be larger than PSA_MAC_MAX_SIZE, which does take the * configuration into account. In this case, force a return of * PSA_ERROR_NOT_SUPPORTED here. Otherwise psa_mac_verify(), or * psa_mac_compute(mac_size=PSA_MAC_MAX_SIZE), would return * PSA_ERROR_BUFFER_TOO_SMALL for an unsupported algorithm whose MAC size * is larger than PSA_MAC_MAX_SIZE, which is misleading and which breaks * systematically generated tests. */ return PSA_ERROR_NOT_SUPPORTED; } return PSA_SUCCESS; } static psa_status_t psa_mac_setup(psa_mac_operation_t *operation, mbedtls_svc_key_id_t key, psa_algorithm_t alg, int is_sign) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t attributes; psa_key_slot_t *slot = NULL; /* A context must be freshly initialized before it can be set up. */ if (operation->id != 0) { status = PSA_ERROR_BAD_STATE; goto exit; } status = psa_get_and_lock_key_slot_with_policy( key, &slot, is_sign ? PSA_KEY_USAGE_SIGN_MESSAGE : PSA_KEY_USAGE_VERIFY_MESSAGE, alg); if (status != PSA_SUCCESS) { goto exit; } attributes = (psa_key_attributes_t) { .core = slot->attr }; status = psa_mac_finalize_alg_and_key_validation(alg, &attributes, &operation->mac_size); if (status != PSA_SUCCESS) { goto exit; } operation->is_sign = is_sign; /* Dispatch the MAC setup call with validated input */ if (is_sign) { status = psa_driver_wrapper_mac_sign_setup(operation, &attributes, slot->key.data, slot->key.bytes, alg); } else { status = psa_driver_wrapper_mac_verify_setup(operation, &attributes, slot->key.data, slot->key.bytes, alg); } exit: if (status != PSA_SUCCESS) { psa_mac_abort(operation); } unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } psa_status_t psa_mac_sign_setup(psa_mac_operation_t *operation, mbedtls_svc_key_id_t key, psa_algorithm_t alg) { return psa_mac_setup(operation, key, alg, 1); } psa_status_t psa_mac_verify_setup(psa_mac_operation_t *operation, mbedtls_svc_key_id_t key, psa_algorithm_t alg) { return psa_mac_setup(operation, key, alg, 0); } psa_status_t psa_mac_update(psa_mac_operation_t *operation, const uint8_t *input, size_t input_length) { if (operation->id == 0) { return PSA_ERROR_BAD_STATE; } /* Don't require hash implementations to behave correctly on a * zero-length input, which may have an invalid pointer. */ if (input_length == 0) { return PSA_SUCCESS; } psa_status_t status = psa_driver_wrapper_mac_update(operation, input, input_length); if (status != PSA_SUCCESS) { psa_mac_abort(operation); } return status; } psa_status_t psa_mac_sign_finish(psa_mac_operation_t *operation, uint8_t *mac, size_t mac_size, size_t *mac_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED; if (operation->id == 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (!operation->is_sign) { status = PSA_ERROR_BAD_STATE; goto exit; } /* Sanity check. This will guarantee that mac_size != 0 (and so mac != NULL) * once all the error checks are done. */ if (operation->mac_size == 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (mac_size < operation->mac_size) { status = PSA_ERROR_BUFFER_TOO_SMALL; goto exit; } status = psa_driver_wrapper_mac_sign_finish(operation, mac, operation->mac_size, mac_length); exit: /* In case of success, set the potential excess room in the output buffer * to an invalid value, to avoid potentially leaking a longer MAC. * In case of error, set the output length and content to a safe default, * such that in case the caller misses an error check, the output would be * an unachievable MAC. */ if (status != PSA_SUCCESS) { *mac_length = mac_size; operation->mac_size = 0; } if (mac_size > operation->mac_size) { memset(&mac[operation->mac_size], '!', mac_size - operation->mac_size); } abort_status = psa_mac_abort(operation); return status == PSA_SUCCESS ? abort_status : status; } psa_status_t psa_mac_verify_finish(psa_mac_operation_t *operation, const uint8_t *mac, size_t mac_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED; if (operation->id == 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (operation->is_sign) { status = PSA_ERROR_BAD_STATE; goto exit; } if (operation->mac_size != mac_length) { status = PSA_ERROR_INVALID_SIGNATURE; goto exit; } status = psa_driver_wrapper_mac_verify_finish(operation, mac, mac_length); exit: abort_status = psa_mac_abort(operation); return status == PSA_SUCCESS ? abort_status : status; } static psa_status_t psa_mac_compute_internal(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *mac, size_t mac_size, size_t *mac_length, int is_sign) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t attributes; psa_key_slot_t *slot; uint8_t operation_mac_size = 0; status = psa_get_and_lock_key_slot_with_policy( key, &slot, is_sign ? PSA_KEY_USAGE_SIGN_MESSAGE : PSA_KEY_USAGE_VERIFY_MESSAGE, alg); if (status != PSA_SUCCESS) { goto exit; } attributes = (psa_key_attributes_t) { .core = slot->attr }; status = psa_mac_finalize_alg_and_key_validation(alg, &attributes, &operation_mac_size); if (status != PSA_SUCCESS) { goto exit; } if (mac_size < operation_mac_size) { status = PSA_ERROR_BUFFER_TOO_SMALL; goto exit; } status = psa_driver_wrapper_mac_compute( &attributes, slot->key.data, slot->key.bytes, alg, input, input_length, mac, operation_mac_size, mac_length); exit: /* In case of success, set the potential excess room in the output buffer * to an invalid value, to avoid potentially leaking a longer MAC. * In case of error, set the output length and content to a safe default, * such that in case the caller misses an error check, the output would be * an unachievable MAC. */ if (status != PSA_SUCCESS) { *mac_length = mac_size; operation_mac_size = 0; } if (mac_size > operation_mac_size) { memset(&mac[operation_mac_size], '!', mac_size - operation_mac_size); } unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } psa_status_t psa_mac_compute(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *mac, size_t mac_size, size_t *mac_length) { return psa_mac_compute_internal(key, alg, input, input_length, mac, mac_size, mac_length, 1); } psa_status_t psa_mac_verify(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *mac, size_t mac_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; uint8_t actual_mac[PSA_MAC_MAX_SIZE]; size_t actual_mac_length; status = psa_mac_compute_internal(key, alg, input, input_length, actual_mac, sizeof(actual_mac), &actual_mac_length, 0); if (status != PSA_SUCCESS) { goto exit; } if (mac_length != actual_mac_length) { status = PSA_ERROR_INVALID_SIGNATURE; goto exit; } if (mbedtls_psa_safer_memcmp(mac, actual_mac, actual_mac_length) != 0) { status = PSA_ERROR_INVALID_SIGNATURE; goto exit; } exit: mbedtls_platform_zeroize(actual_mac, sizeof(actual_mac)); return status; } /****************************************************************/ /* Asymmetric cryptography */ /****************************************************************/ static psa_status_t psa_sign_verify_check_alg(int input_is_message, psa_algorithm_t alg) { if (input_is_message) { if (!PSA_ALG_IS_SIGN_MESSAGE(alg)) { return PSA_ERROR_INVALID_ARGUMENT; } if (PSA_ALG_IS_SIGN_HASH(alg)) { if (!PSA_ALG_IS_HASH(PSA_ALG_SIGN_GET_HASH(alg))) { return PSA_ERROR_INVALID_ARGUMENT; } } } else { if (!PSA_ALG_IS_SIGN_HASH(alg)) { return PSA_ERROR_INVALID_ARGUMENT; } } return PSA_SUCCESS; } static psa_status_t psa_sign_internal(mbedtls_svc_key_id_t key, int input_is_message, psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *signature, size_t signature_size, size_t *signature_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t attributes; psa_key_slot_t *slot; *signature_length = 0; status = psa_sign_verify_check_alg(input_is_message, alg); if (status != PSA_SUCCESS) { return status; } /* Immediately reject a zero-length signature buffer. This guarantees * that signature must be a valid pointer. (On the other hand, the input * buffer can in principle be empty since it doesn't actually have * to be a hash.) */ if (signature_size == 0) { return PSA_ERROR_BUFFER_TOO_SMALL; } status = psa_get_and_lock_key_slot_with_policy( key, &slot, input_is_message ? PSA_KEY_USAGE_SIGN_MESSAGE : PSA_KEY_USAGE_SIGN_HASH, alg); if (status != PSA_SUCCESS) { goto exit; } if (!PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } attributes = (psa_key_attributes_t) { .core = slot->attr }; if (input_is_message) { status = psa_driver_wrapper_sign_message( &attributes, slot->key.data, slot->key.bytes, alg, input, input_length, signature, signature_size, signature_length); } else { status = psa_driver_wrapper_sign_hash( &attributes, slot->key.data, slot->key.bytes, alg, input, input_length, signature, signature_size, signature_length); } exit: /* Fill the unused part of the output buffer (the whole buffer on error, * the trailing part on success) with something that isn't a valid signature * (barring an attack on the signature and deliberately-crafted input), * in case the caller doesn't check the return status properly. */ if (status == PSA_SUCCESS) { memset(signature + *signature_length, '!', signature_size - *signature_length); } else { memset(signature, '!', signature_size); } /* If signature_size is 0 then we have nothing to do. We must not call * memset because signature may be NULL in this case. */ unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } static psa_status_t psa_verify_internal(mbedtls_svc_key_id_t key, int input_is_message, psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *signature, size_t signature_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; status = psa_sign_verify_check_alg(input_is_message, alg); if (status != PSA_SUCCESS) { return status; } status = psa_get_and_lock_key_slot_with_policy( key, &slot, input_is_message ? PSA_KEY_USAGE_VERIFY_MESSAGE : PSA_KEY_USAGE_VERIFY_HASH, alg); if (status != PSA_SUCCESS) { return status; } psa_key_attributes_t attributes = { .core = slot->attr }; if (input_is_message) { status = psa_driver_wrapper_verify_message( &attributes, slot->key.data, slot->key.bytes, alg, input, input_length, signature, signature_length); } else { status = psa_driver_wrapper_verify_hash( &attributes, slot->key.data, slot->key.bytes, alg, input, input_length, signature, signature_length); } unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } psa_status_t psa_sign_message_builtin( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *signature, size_t signature_size, size_t *signature_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; if (PSA_ALG_IS_SIGN_HASH(alg)) { size_t hash_length; uint8_t hash[PSA_HASH_MAX_SIZE]; status = psa_driver_wrapper_hash_compute( PSA_ALG_SIGN_GET_HASH(alg), input, input_length, hash, sizeof(hash), &hash_length); if (status != PSA_SUCCESS) { return status; } return psa_driver_wrapper_sign_hash( attributes, key_buffer, key_buffer_size, alg, hash, hash_length, signature, signature_size, signature_length); } return PSA_ERROR_NOT_SUPPORTED; } psa_status_t psa_sign_message(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *signature, size_t signature_size, size_t *signature_length) { return psa_sign_internal( key, 1, alg, input, input_length, signature, signature_size, signature_length); } psa_status_t psa_verify_message_builtin( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *signature, size_t signature_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; if (PSA_ALG_IS_SIGN_HASH(alg)) { size_t hash_length; uint8_t hash[PSA_HASH_MAX_SIZE]; status = psa_driver_wrapper_hash_compute( PSA_ALG_SIGN_GET_HASH(alg), input, input_length, hash, sizeof(hash), &hash_length); if (status != PSA_SUCCESS) { return status; } return psa_driver_wrapper_verify_hash( attributes, key_buffer, key_buffer_size, alg, hash, hash_length, signature, signature_length); } return PSA_ERROR_NOT_SUPPORTED; } psa_status_t psa_verify_message(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *signature, size_t signature_length) { return psa_verify_internal( key, 1, alg, input, input_length, signature, signature_length); } psa_status_t psa_sign_hash_builtin( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *hash, size_t hash_length, uint8_t *signature, size_t signature_size, size_t *signature_length) { if (attributes->core.type == PSA_KEY_TYPE_RSA_KEY_PAIR) { if (PSA_ALG_IS_RSA_PKCS1V15_SIGN(alg) || PSA_ALG_IS_RSA_PSS(alg)) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) return mbedtls_psa_rsa_sign_hash( attributes, key_buffer, key_buffer_size, alg, hash, hash_length, signature, signature_size, signature_length); #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */ } else { return PSA_ERROR_INVALID_ARGUMENT; } } else if (PSA_KEY_TYPE_IS_ECC(attributes->core.type)) { if (PSA_ALG_IS_ECDSA(alg)) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) return mbedtls_psa_ecdsa_sign_hash( attributes, key_buffer, key_buffer_size, alg, hash, hash_length, signature, signature_size, signature_length); #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */ } else { return PSA_ERROR_INVALID_ARGUMENT; } } (void) key_buffer; (void) key_buffer_size; (void) hash; (void) hash_length; (void) signature; (void) signature_size; (void) signature_length; return PSA_ERROR_NOT_SUPPORTED; } psa_status_t psa_sign_hash(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *hash, size_t hash_length, uint8_t *signature, size_t signature_size, size_t *signature_length) { return psa_sign_internal( key, 0, alg, hash, hash_length, signature, signature_size, signature_length); } psa_status_t psa_verify_hash_builtin( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *hash, size_t hash_length, const uint8_t *signature, size_t signature_length) { if (PSA_KEY_TYPE_IS_RSA(attributes->core.type)) { if (PSA_ALG_IS_RSA_PKCS1V15_SIGN(alg) || PSA_ALG_IS_RSA_PSS(alg)) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) return mbedtls_psa_rsa_verify_hash( attributes, key_buffer, key_buffer_size, alg, hash, hash_length, signature, signature_length); #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */ } else { return PSA_ERROR_INVALID_ARGUMENT; } } else if (PSA_KEY_TYPE_IS_ECC(attributes->core.type)) { if (PSA_ALG_IS_ECDSA(alg)) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) return mbedtls_psa_ecdsa_verify_hash( attributes, key_buffer, key_buffer_size, alg, hash, hash_length, signature, signature_length); #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */ } else { return PSA_ERROR_INVALID_ARGUMENT; } } (void) key_buffer; (void) key_buffer_size; (void) hash; (void) hash_length; (void) signature; (void) signature_length; return PSA_ERROR_NOT_SUPPORTED; } psa_status_t psa_verify_hash(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *hash, size_t hash_length, const uint8_t *signature, size_t signature_length) { return psa_verify_internal( key, 0, alg, hash, hash_length, signature, signature_length); } #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) static void psa_rsa_oaep_set_padding_mode(psa_algorithm_t alg, mbedtls_rsa_context *rsa) { psa_algorithm_t hash_alg = PSA_ALG_RSA_OAEP_GET_HASH(alg); const mbedtls_md_info_t *md_info = mbedtls_md_info_from_psa(hash_alg); mbedtls_md_type_t md_alg = mbedtls_md_get_type(md_info); mbedtls_rsa_set_padding(rsa, MBEDTLS_RSA_PKCS_V21, md_alg); } #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) */ psa_status_t psa_asymmetric_encrypt(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *salt, size_t salt_length, uint8_t *output, size_t output_size, size_t *output_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; (void) input; (void) input_length; (void) salt; (void) output; (void) output_size; *output_length = 0; if (!PSA_ALG_IS_RSA_OAEP(alg) && salt_length != 0) { return PSA_ERROR_INVALID_ARGUMENT; } status = psa_get_and_lock_transparent_key_slot_with_policy( key, &slot, PSA_KEY_USAGE_ENCRYPT, alg); if (status != PSA_SUCCESS) { return status; } if (!(PSA_KEY_TYPE_IS_PUBLIC_KEY(slot->attr.type) || PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type))) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } if (PSA_KEY_TYPE_IS_RSA(slot->attr.type)) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) mbedtls_rsa_context *rsa = NULL; status = mbedtls_psa_rsa_load_representation(slot->attr.type, slot->key.data, slot->key.bytes, &rsa); if (status != PSA_SUCCESS) { goto rsa_exit; } if (output_size < mbedtls_rsa_get_len(rsa)) { status = PSA_ERROR_BUFFER_TOO_SMALL; goto rsa_exit; } #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) */ if (alg == PSA_ALG_RSA_PKCS1V15_CRYPT) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) status = mbedtls_to_psa_error( mbedtls_rsa_pkcs1_encrypt(rsa, mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE, MBEDTLS_RSA_PUBLIC, input_length, input, output)); #else status = PSA_ERROR_NOT_SUPPORTED; #endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT */ } else if (PSA_ALG_IS_RSA_OAEP(alg)) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) psa_rsa_oaep_set_padding_mode(alg, rsa); status = mbedtls_to_psa_error( mbedtls_rsa_rsaes_oaep_encrypt(rsa, mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE, MBEDTLS_RSA_PUBLIC, salt, salt_length, input_length, input, output)); #else status = PSA_ERROR_NOT_SUPPORTED; #endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP */ } else { status = PSA_ERROR_INVALID_ARGUMENT; } #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) rsa_exit: if (status == PSA_SUCCESS) { *output_length = mbedtls_rsa_get_len(rsa); } mbedtls_rsa_free(rsa); mbedtls_free(rsa); #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) */ } else { status = PSA_ERROR_NOT_SUPPORTED; } exit: unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } psa_status_t psa_asymmetric_decrypt(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *salt, size_t salt_length, uint8_t *output, size_t output_size, size_t *output_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; (void) input; (void) input_length; (void) salt; (void) output; (void) output_size; *output_length = 0; if (!PSA_ALG_IS_RSA_OAEP(alg) && salt_length != 0) { return PSA_ERROR_INVALID_ARGUMENT; } status = psa_get_and_lock_transparent_key_slot_with_policy( key, &slot, PSA_KEY_USAGE_DECRYPT, alg); if (status != PSA_SUCCESS) { return status; } if (!PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } if (slot->attr.type == PSA_KEY_TYPE_RSA_KEY_PAIR) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) mbedtls_rsa_context *rsa = NULL; status = mbedtls_psa_rsa_load_representation(slot->attr.type, slot->key.data, slot->key.bytes, &rsa); if (status != PSA_SUCCESS) { goto exit; } if (input_length != mbedtls_rsa_get_len(rsa)) { status = PSA_ERROR_INVALID_ARGUMENT; goto rsa_exit; } #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) */ if (alg == PSA_ALG_RSA_PKCS1V15_CRYPT) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) status = mbedtls_to_psa_error( mbedtls_rsa_pkcs1_decrypt(rsa, mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE, MBEDTLS_RSA_PRIVATE, output_length, input, output, output_size)); #else status = PSA_ERROR_NOT_SUPPORTED; #endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT */ } else if (PSA_ALG_IS_RSA_OAEP(alg)) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) psa_rsa_oaep_set_padding_mode(alg, rsa); status = mbedtls_to_psa_error( mbedtls_rsa_rsaes_oaep_decrypt(rsa, mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE, MBEDTLS_RSA_PRIVATE, salt, salt_length, output_length, input, output, output_size)); #else status = PSA_ERROR_NOT_SUPPORTED; #endif /* MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP */ } else { status = PSA_ERROR_INVALID_ARGUMENT; } #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) rsa_exit: mbedtls_rsa_free(rsa); mbedtls_free(rsa); #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_CRYPT) || * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP) */ } else { status = PSA_ERROR_NOT_SUPPORTED; } exit: unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } /****************************************************************/ /* Symmetric cryptography */ /****************************************************************/ static psa_status_t psa_cipher_setup(psa_cipher_operation_t *operation, mbedtls_svc_key_id_t key, psa_algorithm_t alg, mbedtls_operation_t cipher_operation) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t attributes; psa_key_slot_t *slot = NULL; psa_key_usage_t usage = (cipher_operation == MBEDTLS_ENCRYPT ? PSA_KEY_USAGE_ENCRYPT : PSA_KEY_USAGE_DECRYPT); /* A context must be freshly initialized before it can be set up. */ if (operation->id != 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (!PSA_ALG_IS_CIPHER(alg)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } status = psa_get_and_lock_key_slot_with_policy(key, &slot, usage, alg); if (status != PSA_SUCCESS) { goto exit; } /* Initialize the operation struct members, except for id. The id member * is used to indicate to psa_cipher_abort that there are resources to free, * so we only set it (in the driver wrapper) after resources have been * allocated/initialized. */ operation->iv_set = 0; if (alg == PSA_ALG_ECB_NO_PADDING) { operation->iv_required = 0; } else if (slot->attr.type == PSA_KEY_TYPE_ARC4) { operation->iv_required = 0; } else { operation->iv_required = 1; } operation->default_iv_length = PSA_CIPHER_IV_LENGTH(slot->attr.type, alg); attributes = (psa_key_attributes_t) { .core = slot->attr }; /* Try doing the operation through a driver before using software fallback. */ if (cipher_operation == MBEDTLS_ENCRYPT) { status = psa_driver_wrapper_cipher_encrypt_setup(operation, &attributes, slot->key.data, slot->key.bytes, alg); } else { status = psa_driver_wrapper_cipher_decrypt_setup(operation, &attributes, slot->key.data, slot->key.bytes, alg); } exit: if (status != PSA_SUCCESS) { psa_cipher_abort(operation); } unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } psa_status_t psa_cipher_encrypt_setup(psa_cipher_operation_t *operation, mbedtls_svc_key_id_t key, psa_algorithm_t alg) { return psa_cipher_setup(operation, key, alg, MBEDTLS_ENCRYPT); } psa_status_t psa_cipher_decrypt_setup(psa_cipher_operation_t *operation, mbedtls_svc_key_id_t key, psa_algorithm_t alg) { return psa_cipher_setup(operation, key, alg, MBEDTLS_DECRYPT); } psa_status_t psa_cipher_generate_iv(psa_cipher_operation_t *operation, uint8_t *iv, size_t iv_size, size_t *iv_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; uint8_t local_iv[PSA_CIPHER_IV_MAX_SIZE]; size_t default_iv_length = 0; if (operation->id == 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (operation->iv_set || !operation->iv_required) { status = PSA_ERROR_BAD_STATE; goto exit; } default_iv_length = operation->default_iv_length; if (iv_size < default_iv_length) { status = PSA_ERROR_BUFFER_TOO_SMALL; goto exit; } if (default_iv_length > PSA_CIPHER_IV_MAX_SIZE) { status = PSA_ERROR_GENERIC_ERROR; goto exit; } status = psa_generate_random(local_iv, default_iv_length); if (status != PSA_SUCCESS) { goto exit; } status = psa_driver_wrapper_cipher_set_iv(operation, local_iv, default_iv_length); exit: if (status == PSA_SUCCESS) { memcpy(iv, local_iv, default_iv_length); *iv_length = default_iv_length; operation->iv_set = 1; } else { *iv_length = 0; psa_cipher_abort(operation); } return status; } psa_status_t psa_cipher_set_iv(psa_cipher_operation_t *operation, const uint8_t *iv, size_t iv_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; if (operation->id == 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (operation->iv_set || !operation->iv_required) { status = PSA_ERROR_BAD_STATE; goto exit; } if (iv_length > PSA_CIPHER_IV_MAX_SIZE) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } status = psa_driver_wrapper_cipher_set_iv(operation, iv, iv_length); exit: if (status == PSA_SUCCESS) { operation->iv_set = 1; } else { psa_cipher_abort(operation); } return status; } psa_status_t psa_cipher_update(psa_cipher_operation_t *operation, const uint8_t *input, size_t input_length, uint8_t *output, size_t output_size, size_t *output_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; if (operation->id == 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (operation->iv_required && !operation->iv_set) { status = PSA_ERROR_BAD_STATE; goto exit; } status = psa_driver_wrapper_cipher_update(operation, input, input_length, output, output_size, output_length); exit: if (status != PSA_SUCCESS) { psa_cipher_abort(operation); } return status; } psa_status_t psa_cipher_finish(psa_cipher_operation_t *operation, uint8_t *output, size_t output_size, size_t *output_length) { psa_status_t status = PSA_ERROR_GENERIC_ERROR; if (operation->id == 0) { status = PSA_ERROR_BAD_STATE; goto exit; } if (operation->iv_required && !operation->iv_set) { status = PSA_ERROR_BAD_STATE; goto exit; } status = psa_driver_wrapper_cipher_finish(operation, output, output_size, output_length); exit: if (status == PSA_SUCCESS) { return psa_cipher_abort(operation); } else { *output_length = 0; (void) psa_cipher_abort(operation); return status; } } psa_status_t psa_cipher_abort(psa_cipher_operation_t *operation) { if (operation->id == 0) { /* The object has (apparently) been initialized but it is not (yet) * in use. It's ok to call abort on such an object, and there's * nothing to do. */ return PSA_SUCCESS; } psa_driver_wrapper_cipher_abort(operation); operation->id = 0; operation->iv_set = 0; operation->iv_required = 0; return PSA_SUCCESS; } psa_status_t psa_cipher_encrypt(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *output, size_t output_size, size_t *output_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t attributes; psa_key_slot_t *slot = NULL; uint8_t local_iv[PSA_CIPHER_IV_MAX_SIZE]; size_t default_iv_length = 0; if (!PSA_ALG_IS_CIPHER(alg)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } status = psa_get_and_lock_key_slot_with_policy(key, &slot, PSA_KEY_USAGE_ENCRYPT, alg); if (status != PSA_SUCCESS) { goto exit; } attributes = (psa_key_attributes_t) { .core = slot->attr }; default_iv_length = PSA_CIPHER_IV_LENGTH(slot->attr.type, alg); if (default_iv_length > PSA_CIPHER_IV_MAX_SIZE) { status = PSA_ERROR_GENERIC_ERROR; goto exit; } if (default_iv_length > 0) { if (output_size < default_iv_length) { status = PSA_ERROR_BUFFER_TOO_SMALL; goto exit; } status = psa_generate_random(local_iv, default_iv_length); if (status != PSA_SUCCESS) { goto exit; } } status = psa_driver_wrapper_cipher_encrypt( &attributes, slot->key.data, slot->key.bytes, alg, local_iv, default_iv_length, input, input_length, mbedtls_buffer_offset(output, default_iv_length), output_size - default_iv_length, output_length); exit: unlock_status = psa_unlock_key_slot(slot); if (status == PSA_SUCCESS) { status = unlock_status; } if (status == PSA_SUCCESS) { if (default_iv_length > 0) { memcpy(output, local_iv, default_iv_length); } *output_length += default_iv_length; } else { *output_length = 0; } return status; } psa_status_t psa_cipher_decrypt(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *output, size_t output_size, size_t *output_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t attributes; psa_key_slot_t *slot = NULL; if (!PSA_ALG_IS_CIPHER(alg)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } status = psa_get_and_lock_key_slot_with_policy(key, &slot, PSA_KEY_USAGE_DECRYPT, alg); if (status != PSA_SUCCESS) { goto exit; } attributes = (psa_key_attributes_t) { .core = slot->attr }; if (input_length < PSA_CIPHER_IV_LENGTH(slot->attr.type, alg)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } status = psa_driver_wrapper_cipher_decrypt( &attributes, slot->key.data, slot->key.bytes, alg, input, input_length, output, output_size, output_length); exit: unlock_status = psa_unlock_key_slot(slot); if (status == PSA_SUCCESS) { status = unlock_status; } if (status != PSA_SUCCESS) { *output_length = 0; } return status; } /****************************************************************/ /* AEAD */ /****************************************************************/ psa_status_t psa_aead_encrypt(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *nonce, size_t nonce_length, const uint8_t *additional_data, size_t additional_data_length, const uint8_t *plaintext, size_t plaintext_length, uint8_t *ciphertext, size_t ciphertext_size, size_t *ciphertext_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; *ciphertext_length = 0; if (!PSA_ALG_IS_AEAD(alg) || PSA_ALG_IS_WILDCARD(alg)) { return PSA_ERROR_NOT_SUPPORTED; } status = psa_get_and_lock_key_slot_with_policy( key, &slot, PSA_KEY_USAGE_ENCRYPT, alg); if (status != PSA_SUCCESS) { return status; } psa_key_attributes_t attributes = { .core = slot->attr }; status = psa_driver_wrapper_aead_encrypt( &attributes, slot->key.data, slot->key.bytes, alg, nonce, nonce_length, additional_data, additional_data_length, plaintext, plaintext_length, ciphertext, ciphertext_size, ciphertext_length); if (status != PSA_SUCCESS && ciphertext_size != 0) { memset(ciphertext, 0, ciphertext_size); } psa_unlock_key_slot(slot); return status; } psa_status_t psa_aead_decrypt(mbedtls_svc_key_id_t key, psa_algorithm_t alg, const uint8_t *nonce, size_t nonce_length, const uint8_t *additional_data, size_t additional_data_length, const uint8_t *ciphertext, size_t ciphertext_length, uint8_t *plaintext, size_t plaintext_size, size_t *plaintext_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; *plaintext_length = 0; if (!PSA_ALG_IS_AEAD(alg) || PSA_ALG_IS_WILDCARD(alg)) { return PSA_ERROR_NOT_SUPPORTED; } status = psa_get_and_lock_key_slot_with_policy( key, &slot, PSA_KEY_USAGE_DECRYPT, alg); if (status != PSA_SUCCESS) { return status; } psa_key_attributes_t attributes = { .core = slot->attr }; status = psa_driver_wrapper_aead_decrypt( &attributes, slot->key.data, slot->key.bytes, alg, nonce, nonce_length, additional_data, additional_data_length, ciphertext, ciphertext_length, plaintext, plaintext_size, plaintext_length); if (status != PSA_SUCCESS && plaintext_size != 0) { memset(plaintext, 0, plaintext_size); } psa_unlock_key_slot(slot); return status; } /****************************************************************/ /* Generators */ /****************************************************************/ #if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) #define AT_LEAST_ONE_BUILTIN_KDF #endif /* At least one builtin KDF */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) static psa_status_t psa_key_derivation_start_hmac( psa_mac_operation_t *operation, psa_algorithm_t hash_alg, const uint8_t *hmac_key, size_t hmac_key_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; psa_set_key_type(&attributes, PSA_KEY_TYPE_HMAC); psa_set_key_bits(&attributes, PSA_BYTES_TO_BITS(hmac_key_length)); psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_SIGN_HASH); operation->is_sign = 1; operation->mac_size = PSA_HASH_LENGTH(hash_alg); status = psa_driver_wrapper_mac_sign_setup(operation, &attributes, hmac_key, hmac_key_length, PSA_ALG_HMAC(hash_alg)); psa_reset_key_attributes(&attributes); return status; } #endif /* KDF algorithms reliant on HMAC */ #define HKDF_STATE_INIT 0 /* no input yet */ #define HKDF_STATE_STARTED 1 /* got salt */ #define HKDF_STATE_KEYED 2 /* got key */ #define HKDF_STATE_OUTPUT 3 /* output started */ static psa_algorithm_t psa_key_derivation_get_kdf_alg( const psa_key_derivation_operation_t *operation) { if (PSA_ALG_IS_KEY_AGREEMENT(operation->alg)) { return PSA_ALG_KEY_AGREEMENT_GET_KDF(operation->alg); } else { return operation->alg; } } psa_status_t psa_key_derivation_abort(psa_key_derivation_operation_t *operation) { psa_status_t status = PSA_SUCCESS; psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation); if (kdf_alg == 0) { /* The object has (apparently) been initialized but it is not * in use. It's ok to call abort on such an object, and there's * nothing to do. */ } else #if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) if (PSA_ALG_IS_HKDF(kdf_alg)) { mbedtls_free(operation->ctx.hkdf.info); status = psa_mac_abort(&operation->ctx.hkdf.hmac); } else #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) if (PSA_ALG_IS_TLS12_PRF(kdf_alg) || /* TLS-1.2 PSK-to-MS KDF uses the same core as TLS-1.2 PRF */ PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) { if (operation->ctx.tls12_prf.secret != NULL) { mbedtls_platform_zeroize(operation->ctx.tls12_prf.secret, operation->ctx.tls12_prf.secret_length); mbedtls_free(operation->ctx.tls12_prf.secret); } if (operation->ctx.tls12_prf.seed != NULL) { mbedtls_platform_zeroize(operation->ctx.tls12_prf.seed, operation->ctx.tls12_prf.seed_length); mbedtls_free(operation->ctx.tls12_prf.seed); } if (operation->ctx.tls12_prf.label != NULL) { mbedtls_platform_zeroize(operation->ctx.tls12_prf.label, operation->ctx.tls12_prf.label_length); mbedtls_free(operation->ctx.tls12_prf.label); } status = PSA_SUCCESS; /* We leave the fields Ai and output_block to be erased safely by the * mbedtls_platform_zeroize() in the end of this function. */ } else #endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || * defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) */ { status = PSA_ERROR_BAD_STATE; } mbedtls_platform_zeroize(operation, sizeof(*operation)); return status; } psa_status_t psa_key_derivation_get_capacity(const psa_key_derivation_operation_t *operation, size_t *capacity) { if (operation->alg == 0) { /* This is a blank key derivation operation. */ return PSA_ERROR_BAD_STATE; } *capacity = operation->capacity; return PSA_SUCCESS; } psa_status_t psa_key_derivation_set_capacity(psa_key_derivation_operation_t *operation, size_t capacity) { if (operation->alg == 0) { return PSA_ERROR_BAD_STATE; } if (capacity > operation->capacity) { return PSA_ERROR_INVALID_ARGUMENT; } operation->capacity = capacity; return PSA_SUCCESS; } #if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) /* Read some bytes from an HKDF-based operation. This performs a chunk * of the expand phase of the HKDF algorithm. */ static psa_status_t psa_key_derivation_hkdf_read(psa_hkdf_key_derivation_t *hkdf, psa_algorithm_t hash_alg, uint8_t *output, size_t output_length) { uint8_t hash_length = PSA_HASH_LENGTH(hash_alg); size_t hmac_output_length; psa_status_t status; if (hkdf->state < HKDF_STATE_KEYED || !hkdf->info_set) { return PSA_ERROR_BAD_STATE; } hkdf->state = HKDF_STATE_OUTPUT; while (output_length != 0) { /* Copy what remains of the current block */ uint8_t n = hash_length - hkdf->offset_in_block; if (n > output_length) { n = (uint8_t) output_length; } memcpy(output, hkdf->output_block + hkdf->offset_in_block, n); output += n; output_length -= n; hkdf->offset_in_block += n; if (output_length == 0) { break; } /* We can't be wanting more output after block 0xff, otherwise * the capacity check in psa_key_derivation_output_bytes() would have * prevented this call. It could happen only if the operation * object was corrupted or if this function is called directly * inside the library. */ if (hkdf->block_number == 0xff) { return PSA_ERROR_BAD_STATE; } /* We need a new block */ ++hkdf->block_number; hkdf->offset_in_block = 0; status = psa_key_derivation_start_hmac(&hkdf->hmac, hash_alg, hkdf->prk, hash_length); if (status != PSA_SUCCESS) { return status; } if (hkdf->block_number != 1) { status = psa_mac_update(&hkdf->hmac, hkdf->output_block, hash_length); if (status != PSA_SUCCESS) { return status; } } status = psa_mac_update(&hkdf->hmac, hkdf->info, hkdf->info_length); if (status != PSA_SUCCESS) { return status; } status = psa_mac_update(&hkdf->hmac, &hkdf->block_number, 1); if (status != PSA_SUCCESS) { return status; } status = psa_mac_sign_finish(&hkdf->hmac, hkdf->output_block, sizeof(hkdf->output_block), &hmac_output_length); if (status != PSA_SUCCESS) { return status; } } return PSA_SUCCESS; } #endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) static psa_status_t psa_key_derivation_tls12_prf_generate_next_block( psa_tls12_prf_key_derivation_t *tls12_prf, psa_algorithm_t alg) { psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(alg); uint8_t hash_length = PSA_HASH_LENGTH(hash_alg); psa_mac_operation_t hmac = PSA_MAC_OPERATION_INIT; size_t hmac_output_length; psa_status_t status, cleanup_status; /* We can't be wanting more output after block 0xff, otherwise * the capacity check in psa_key_derivation_output_bytes() would have * prevented this call. It could happen only if the operation * object was corrupted or if this function is called directly * inside the library. */ if (tls12_prf->block_number == 0xff) { return PSA_ERROR_CORRUPTION_DETECTED; } /* We need a new block */ ++tls12_prf->block_number; tls12_prf->left_in_block = hash_length; /* Recall the definition of the TLS-1.2-PRF from RFC 5246: * * PRF(secret, label, seed) = P_(secret, label + seed) * * P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) + * HMAC_hash(secret, A(2) + seed) + * HMAC_hash(secret, A(3) + seed) + ... * * A(0) = seed * A(i) = HMAC_hash(secret, A(i-1)) * * The `psa_tls12_prf_key_derivation` structure saves the block * `HMAC_hash(secret, A(i) + seed)` from which the output * is currently extracted as `output_block` and where i is * `block_number`. */ status = psa_key_derivation_start_hmac(&hmac, hash_alg, tls12_prf->secret, tls12_prf->secret_length); if (status != PSA_SUCCESS) { goto cleanup; } /* Calculate A(i) where i = tls12_prf->block_number. */ if (tls12_prf->block_number == 1) { /* A(1) = HMAC_hash(secret, A(0)), where A(0) = seed. (The RFC overloads * the variable seed and in this instance means it in the context of the * P_hash function, where seed = label + seed.) */ status = psa_mac_update(&hmac, tls12_prf->label, tls12_prf->label_length); if (status != PSA_SUCCESS) { goto cleanup; } status = psa_mac_update(&hmac, tls12_prf->seed, tls12_prf->seed_length); if (status != PSA_SUCCESS) { goto cleanup; } } else { /* A(i) = HMAC_hash(secret, A(i-1)) */ status = psa_mac_update(&hmac, tls12_prf->Ai, hash_length); if (status != PSA_SUCCESS) { goto cleanup; } } status = psa_mac_sign_finish(&hmac, tls12_prf->Ai, hash_length, &hmac_output_length); if (hmac_output_length != hash_length) { status = PSA_ERROR_CORRUPTION_DETECTED; } if (status != PSA_SUCCESS) { goto cleanup; } /* Calculate HMAC_hash(secret, A(i) + label + seed). */ status = psa_key_derivation_start_hmac(&hmac, hash_alg, tls12_prf->secret, tls12_prf->secret_length); if (status != PSA_SUCCESS) { goto cleanup; } status = psa_mac_update(&hmac, tls12_prf->Ai, hash_length); if (status != PSA_SUCCESS) { goto cleanup; } status = psa_mac_update(&hmac, tls12_prf->label, tls12_prf->label_length); if (status != PSA_SUCCESS) { goto cleanup; } status = psa_mac_update(&hmac, tls12_prf->seed, tls12_prf->seed_length); if (status != PSA_SUCCESS) { goto cleanup; } status = psa_mac_sign_finish(&hmac, tls12_prf->output_block, hash_length, &hmac_output_length); if (status != PSA_SUCCESS) { goto cleanup; } cleanup: cleanup_status = psa_mac_abort(&hmac); if (status == PSA_SUCCESS && cleanup_status != PSA_SUCCESS) { status = cleanup_status; } return status; } static psa_status_t psa_key_derivation_tls12_prf_read( psa_tls12_prf_key_derivation_t *tls12_prf, psa_algorithm_t alg, uint8_t *output, size_t output_length) { psa_algorithm_t hash_alg = PSA_ALG_TLS12_PRF_GET_HASH(alg); uint8_t hash_length = PSA_HASH_LENGTH(hash_alg); psa_status_t status; uint8_t offset, length; switch (tls12_prf->state) { case PSA_TLS12_PRF_STATE_LABEL_SET: tls12_prf->state = PSA_TLS12_PRF_STATE_OUTPUT; break; case PSA_TLS12_PRF_STATE_OUTPUT: break; default: return PSA_ERROR_BAD_STATE; } while (output_length != 0) { /* Check if we have fully processed the current block. */ if (tls12_prf->left_in_block == 0) { status = psa_key_derivation_tls12_prf_generate_next_block(tls12_prf, alg); if (status != PSA_SUCCESS) { return status; } continue; } if (tls12_prf->left_in_block > output_length) { length = (uint8_t) output_length; } else { length = tls12_prf->left_in_block; } offset = hash_length - tls12_prf->left_in_block; memcpy(output, tls12_prf->output_block + offset, length); output += length; output_length -= length; tls12_prf->left_in_block -= length; } return PSA_SUCCESS; } #endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF || * MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */ psa_status_t psa_key_derivation_output_bytes( psa_key_derivation_operation_t *operation, uint8_t *output, size_t output_length) { psa_status_t status; psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation); if (operation->alg == 0) { /* This is a blank operation. */ return PSA_ERROR_BAD_STATE; } if (output_length > operation->capacity) { operation->capacity = 0; /* Go through the error path to wipe all confidential data now * that the operation object is useless. */ status = PSA_ERROR_INSUFFICIENT_DATA; goto exit; } if (output_length == 0 && operation->capacity == 0) { /* Edge case: this is a finished operation, and 0 bytes * were requested. The right error in this case could * be either INSUFFICIENT_CAPACITY or BAD_STATE. Return * INSUFFICIENT_CAPACITY, which is right for a finished * operation, for consistency with the case when * output_length > 0. */ return PSA_ERROR_INSUFFICIENT_DATA; } operation->capacity -= output_length; #if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) if (PSA_ALG_IS_HKDF(kdf_alg)) { psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(kdf_alg); status = psa_key_derivation_hkdf_read(&operation->ctx.hkdf, hash_alg, output, output_length); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) if (PSA_ALG_IS_TLS12_PRF(kdf_alg) || PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) { status = psa_key_derivation_tls12_prf_read(&operation->ctx.tls12_prf, kdf_alg, output, output_length); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF || * MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */ { (void) kdf_alg; return PSA_ERROR_BAD_STATE; } exit: if (status != PSA_SUCCESS) { /* Preserve the algorithm upon errors, but clear all sensitive state. * This allows us to differentiate between exhausted operations and * blank operations, so we can return PSA_ERROR_BAD_STATE on blank * operations. */ psa_algorithm_t alg = operation->alg; psa_key_derivation_abort(operation); operation->alg = alg; memset(output, '!', output_length); } return status; } #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES) static void psa_des_set_key_parity(uint8_t *data, size_t data_size) { if (data_size >= 8) { mbedtls_des_key_set_parity(data); } if (data_size >= 16) { mbedtls_des_key_set_parity(data + 8); } if (data_size >= 24) { mbedtls_des_key_set_parity(data + 16); } } #endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */ static psa_status_t psa_generate_derived_key_internal( psa_key_slot_t *slot, size_t bits, psa_key_derivation_operation_t *operation) { uint8_t *data = NULL; size_t bytes = PSA_BITS_TO_BYTES(bits); psa_status_t status; psa_key_attributes_t attributes; if (!key_type_is_raw_bytes(slot->attr.type)) { return PSA_ERROR_INVALID_ARGUMENT; } if (bits % 8 != 0) { return PSA_ERROR_INVALID_ARGUMENT; } data = mbedtls_calloc(1, bytes); if (data == NULL) { return PSA_ERROR_INSUFFICIENT_MEMORY; } status = psa_key_derivation_output_bytes(operation, data, bytes); if (status != PSA_SUCCESS) { goto exit; } #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES) if (slot->attr.type == PSA_KEY_TYPE_DES) { psa_des_set_key_parity(data, bytes); } #endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */ status = psa_allocate_buffer_to_slot(slot, bytes); if (status != PSA_SUCCESS) { goto exit; } slot->attr.bits = (psa_key_bits_t) bits; attributes = (psa_key_attributes_t) { .core = slot->attr }; status = psa_driver_wrapper_import_key(&attributes, data, bytes, slot->key.data, slot->key.bytes, &slot->key.bytes, &bits); if (bits != slot->attr.bits) { status = PSA_ERROR_INVALID_ARGUMENT; } exit: mbedtls_free(data); return status; } psa_status_t psa_key_derivation_output_key(const psa_key_attributes_t *attributes, psa_key_derivation_operation_t *operation, mbedtls_svc_key_id_t *key) { psa_status_t status; psa_key_slot_t *slot = NULL; psa_se_drv_table_entry_t *driver = NULL; *key = MBEDTLS_SVC_KEY_ID_INIT; /* Reject any attempt to create a zero-length key so that we don't * risk tripping up later, e.g. on a malloc(0) that returns NULL. */ if (psa_get_key_bits(attributes) == 0) { return PSA_ERROR_INVALID_ARGUMENT; } if (operation->alg == PSA_ALG_NONE) { return PSA_ERROR_BAD_STATE; } if (!operation->can_output_key) { return PSA_ERROR_NOT_PERMITTED; } status = psa_start_key_creation(PSA_KEY_CREATION_DERIVE, attributes, &slot, &driver); #if defined(MBEDTLS_PSA_CRYPTO_SE_C) if (driver != NULL) { /* Deriving a key in a secure element is not implemented yet. */ status = PSA_ERROR_NOT_SUPPORTED; } #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ if (status == PSA_SUCCESS) { status = psa_generate_derived_key_internal(slot, attributes->core.bits, operation); } if (status == PSA_SUCCESS) { status = psa_finish_key_creation(slot, driver, key); } if (status != PSA_SUCCESS) { psa_fail_key_creation(slot, driver); } return status; } /****************************************************************/ /* Key derivation */ /****************************************************************/ #if defined(AT_LEAST_ONE_BUILTIN_KDF) static int is_kdf_alg_supported(psa_algorithm_t kdf_alg) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) if (PSA_ALG_IS_HKDF(kdf_alg)) { return 1; } #endif #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) if (PSA_ALG_IS_TLS12_PRF(kdf_alg)) { return 1; } #endif #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) if (PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) { return 1; } #endif return 0; } static psa_status_t psa_hash_try_support(psa_algorithm_t alg) { psa_hash_operation_t operation = PSA_HASH_OPERATION_INIT; psa_status_t status = psa_hash_setup(&operation, alg); psa_hash_abort(&operation); return status; } static psa_status_t psa_key_derivation_setup_kdf( psa_key_derivation_operation_t *operation, psa_algorithm_t kdf_alg) { /* Make sure that operation->ctx is properly zero-initialised. (Macro * initialisers for this union leave some bytes unspecified.) */ memset(&operation->ctx, 0, sizeof(operation->ctx)); /* Make sure that kdf_alg is a supported key derivation algorithm. */ if (!is_kdf_alg_supported(kdf_alg)) { return PSA_ERROR_NOT_SUPPORTED; } /* All currently supported key derivation algorithms are based on a * hash algorithm. */ psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(kdf_alg); size_t hash_size = PSA_HASH_LENGTH(hash_alg); if (hash_size == 0) { return PSA_ERROR_NOT_SUPPORTED; } /* Make sure that hash_alg is a supported hash algorithm. Otherwise * we might fail later, which is somewhat unfriendly and potentially * risk-prone. */ psa_status_t status = psa_hash_try_support(hash_alg); if (status != PSA_SUCCESS) { return status; } if ((PSA_ALG_IS_TLS12_PRF(kdf_alg) || PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) && !(hash_alg == PSA_ALG_SHA_256 || hash_alg == PSA_ALG_SHA_384)) { return PSA_ERROR_NOT_SUPPORTED; } operation->capacity = 255 * hash_size; return PSA_SUCCESS; } static psa_status_t psa_key_agreement_try_support(psa_algorithm_t alg) { #if defined(PSA_WANT_ALG_ECDH) if (alg == PSA_ALG_ECDH) { return PSA_SUCCESS; } #endif (void) alg; return PSA_ERROR_NOT_SUPPORTED; } #endif /* AT_LEAST_ONE_BUILTIN_KDF */ psa_status_t psa_key_derivation_setup(psa_key_derivation_operation_t *operation, psa_algorithm_t alg) { psa_status_t status; if (operation->alg != 0) { return PSA_ERROR_BAD_STATE; } if (PSA_ALG_IS_RAW_KEY_AGREEMENT(alg)) { return PSA_ERROR_INVALID_ARGUMENT; } else if (PSA_ALG_IS_KEY_AGREEMENT(alg)) { #if defined(AT_LEAST_ONE_BUILTIN_KDF) psa_algorithm_t kdf_alg = PSA_ALG_KEY_AGREEMENT_GET_KDF(alg); psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE(alg); status = psa_key_agreement_try_support(ka_alg); if (status != PSA_SUCCESS) { return status; } status = psa_key_derivation_setup_kdf(operation, kdf_alg); #else return PSA_ERROR_NOT_SUPPORTED; #endif /* AT_LEAST_ONE_BUILTIN_KDF */ } else if (PSA_ALG_IS_KEY_DERIVATION(alg)) { #if defined(AT_LEAST_ONE_BUILTIN_KDF) status = psa_key_derivation_setup_kdf(operation, alg); #else return PSA_ERROR_NOT_SUPPORTED; #endif /* AT_LEAST_ONE_BUILTIN_KDF */ } else { return PSA_ERROR_INVALID_ARGUMENT; } if (status == PSA_SUCCESS) { operation->alg = alg; } return status; } #if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) static psa_status_t psa_hkdf_input(psa_hkdf_key_derivation_t *hkdf, psa_algorithm_t hash_alg, psa_key_derivation_step_t step, const uint8_t *data, size_t data_length) { psa_status_t status; switch (step) { case PSA_KEY_DERIVATION_INPUT_SALT: if (hkdf->state != HKDF_STATE_INIT) { return PSA_ERROR_BAD_STATE; } else { status = psa_key_derivation_start_hmac(&hkdf->hmac, hash_alg, data, data_length); if (status != PSA_SUCCESS) { return status; } hkdf->state = HKDF_STATE_STARTED; return PSA_SUCCESS; } case PSA_KEY_DERIVATION_INPUT_SECRET: /* If no salt was provided, use an empty salt. */ if (hkdf->state == HKDF_STATE_INIT) { status = psa_key_derivation_start_hmac(&hkdf->hmac, hash_alg, NULL, 0); if (status != PSA_SUCCESS) { return status; } hkdf->state = HKDF_STATE_STARTED; } if (hkdf->state != HKDF_STATE_STARTED) { return PSA_ERROR_BAD_STATE; } status = psa_mac_update(&hkdf->hmac, data, data_length); if (status != PSA_SUCCESS) { return status; } status = psa_mac_sign_finish(&hkdf->hmac, hkdf->prk, sizeof(hkdf->prk), &data_length); if (status != PSA_SUCCESS) { return status; } hkdf->offset_in_block = PSA_HASH_LENGTH(hash_alg); hkdf->block_number = 0; hkdf->state = HKDF_STATE_KEYED; return PSA_SUCCESS; case PSA_KEY_DERIVATION_INPUT_INFO: if (hkdf->state == HKDF_STATE_OUTPUT) { return PSA_ERROR_BAD_STATE; } if (hkdf->info_set) { return PSA_ERROR_BAD_STATE; } hkdf->info_length = data_length; if (data_length != 0) { hkdf->info = mbedtls_calloc(1, data_length); if (hkdf->info == NULL) { return PSA_ERROR_INSUFFICIENT_MEMORY; } memcpy(hkdf->info, data, data_length); } hkdf->info_set = 1; return PSA_SUCCESS; default: return PSA_ERROR_INVALID_ARGUMENT; } } #endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \ defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) static psa_status_t psa_tls12_prf_set_seed(psa_tls12_prf_key_derivation_t *prf, const uint8_t *data, size_t data_length) { if (prf->state != PSA_TLS12_PRF_STATE_INIT) { return PSA_ERROR_BAD_STATE; } if (data_length != 0) { prf->seed = mbedtls_calloc(1, data_length); if (prf->seed == NULL) { return PSA_ERROR_INSUFFICIENT_MEMORY; } memcpy(prf->seed, data, data_length); prf->seed_length = data_length; } prf->state = PSA_TLS12_PRF_STATE_SEED_SET; return PSA_SUCCESS; } static psa_status_t psa_tls12_prf_set_key(psa_tls12_prf_key_derivation_t *prf, const uint8_t *data, size_t data_length) { if (prf->state != PSA_TLS12_PRF_STATE_SEED_SET) { return PSA_ERROR_BAD_STATE; } if (data_length != 0) { prf->secret = mbedtls_calloc(1, data_length); if (prf->secret == NULL) { return PSA_ERROR_INSUFFICIENT_MEMORY; } memcpy(prf->secret, data, data_length); prf->secret_length = data_length; } prf->state = PSA_TLS12_PRF_STATE_KEY_SET; return PSA_SUCCESS; } static psa_status_t psa_tls12_prf_set_label(psa_tls12_prf_key_derivation_t *prf, const uint8_t *data, size_t data_length) { if (prf->state != PSA_TLS12_PRF_STATE_KEY_SET) { return PSA_ERROR_BAD_STATE; } if (data_length != 0) { prf->label = mbedtls_calloc(1, data_length); if (prf->label == NULL) { return PSA_ERROR_INSUFFICIENT_MEMORY; } memcpy(prf->label, data, data_length); prf->label_length = data_length; } prf->state = PSA_TLS12_PRF_STATE_LABEL_SET; return PSA_SUCCESS; } static psa_status_t psa_tls12_prf_input(psa_tls12_prf_key_derivation_t *prf, psa_key_derivation_step_t step, const uint8_t *data, size_t data_length) { switch (step) { case PSA_KEY_DERIVATION_INPUT_SEED: return psa_tls12_prf_set_seed(prf, data, data_length); case PSA_KEY_DERIVATION_INPUT_SECRET: return psa_tls12_prf_set_key(prf, data, data_length); case PSA_KEY_DERIVATION_INPUT_LABEL: return psa_tls12_prf_set_label(prf, data, data_length); default: return PSA_ERROR_INVALID_ARGUMENT; } } #endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || * MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) static psa_status_t psa_tls12_prf_psk_to_ms_set_key( psa_tls12_prf_key_derivation_t *prf, const uint8_t *data, size_t data_length) { psa_status_t status; uint8_t pms[4 + 2 * PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE]; uint8_t *cur = pms; if (data_length > PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE) { return PSA_ERROR_INVALID_ARGUMENT; } /* Quoting RFC 4279, Section 2: * * The premaster secret is formed as follows: if the PSK is N octets * long, concatenate a uint16 with the value N, N zero octets, a second * uint16 with the value N, and the PSK itself. */ *cur++ = MBEDTLS_BYTE_1(data_length); *cur++ = MBEDTLS_BYTE_0(data_length); memset(cur, 0, data_length); cur += data_length; *cur++ = pms[0]; *cur++ = pms[1]; memcpy(cur, data, data_length); cur += data_length; status = psa_tls12_prf_set_key(prf, pms, cur - pms); mbedtls_platform_zeroize(pms, sizeof(pms)); return status; } static psa_status_t psa_tls12_prf_psk_to_ms_input( psa_tls12_prf_key_derivation_t *prf, psa_key_derivation_step_t step, const uint8_t *data, size_t data_length) { if (step == PSA_KEY_DERIVATION_INPUT_SECRET) { return psa_tls12_prf_psk_to_ms_set_key(prf, data, data_length); } return psa_tls12_prf_input(prf, step, data, data_length); } #endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */ /** Check whether the given key type is acceptable for the given * input step of a key derivation. * * Secret inputs must have the type #PSA_KEY_TYPE_DERIVE. * Non-secret inputs must have the type #PSA_KEY_TYPE_RAW_DATA. * Both secret and non-secret inputs can alternatively have the type * #PSA_KEY_TYPE_NONE, which is never the type of a key object, meaning * that the input was passed as a buffer rather than via a key object. */ static int psa_key_derivation_check_input_type( psa_key_derivation_step_t step, psa_key_type_t key_type) { switch (step) { case PSA_KEY_DERIVATION_INPUT_SECRET: if (key_type == PSA_KEY_TYPE_DERIVE) { return PSA_SUCCESS; } if (key_type == PSA_KEY_TYPE_NONE) { return PSA_SUCCESS; } break; case PSA_KEY_DERIVATION_INPUT_LABEL: case PSA_KEY_DERIVATION_INPUT_SALT: case PSA_KEY_DERIVATION_INPUT_INFO: case PSA_KEY_DERIVATION_INPUT_SEED: if (key_type == PSA_KEY_TYPE_RAW_DATA) { return PSA_SUCCESS; } if (key_type == PSA_KEY_TYPE_NONE) { return PSA_SUCCESS; } break; } return PSA_ERROR_INVALID_ARGUMENT; } static psa_status_t psa_key_derivation_input_internal( psa_key_derivation_operation_t *operation, psa_key_derivation_step_t step, psa_key_type_t key_type, const uint8_t *data, size_t data_length) { psa_status_t status; psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation); status = psa_key_derivation_check_input_type(step, key_type); if (status != PSA_SUCCESS) { goto exit; } #if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) if (PSA_ALG_IS_HKDF(kdf_alg)) { status = psa_hkdf_input(&operation->ctx.hkdf, PSA_ALG_HKDF_GET_HASH(kdf_alg), step, data, data_length); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) if (PSA_ALG_IS_TLS12_PRF(kdf_alg)) { status = psa_tls12_prf_input(&operation->ctx.tls12_prf, step, data, data_length); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) if (PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) { status = psa_tls12_prf_psk_to_ms_input(&operation->ctx.tls12_prf, step, data, data_length); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */ { /* This can't happen unless the operation object was not initialized */ (void) data; (void) data_length; (void) kdf_alg; return PSA_ERROR_BAD_STATE; } exit: if (status != PSA_SUCCESS) { psa_key_derivation_abort(operation); } return status; } psa_status_t psa_key_derivation_input_bytes( psa_key_derivation_operation_t *operation, psa_key_derivation_step_t step, const uint8_t *data, size_t data_length) { return psa_key_derivation_input_internal(operation, step, PSA_KEY_TYPE_NONE, data, data_length); } psa_status_t psa_key_derivation_input_key( psa_key_derivation_operation_t *operation, psa_key_derivation_step_t step, mbedtls_svc_key_id_t key) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; status = psa_get_and_lock_transparent_key_slot_with_policy( key, &slot, PSA_KEY_USAGE_DERIVE, operation->alg); if (status != PSA_SUCCESS) { psa_key_derivation_abort(operation); return status; } /* Passing a key object as a SECRET input unlocks the permission * to output to a key object. */ if (step == PSA_KEY_DERIVATION_INPUT_SECRET) { operation->can_output_key = 1; } status = psa_key_derivation_input_internal(operation, step, slot->attr.type, slot->key.data, slot->key.bytes); unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } /****************************************************************/ /* Key agreement */ /****************************************************************/ #if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) static psa_status_t psa_key_agreement_ecdh(const uint8_t *peer_key, size_t peer_key_length, const mbedtls_ecp_keypair *our_key, uint8_t *shared_secret, size_t shared_secret_size, size_t *shared_secret_length) { mbedtls_ecp_keypair *their_key = NULL; mbedtls_ecdh_context ecdh; psa_status_t status; size_t bits = 0; psa_ecc_family_t curve = mbedtls_ecc_group_to_psa(our_key->grp.id, &bits); mbedtls_ecdh_init(&ecdh); status = mbedtls_psa_ecp_load_representation( PSA_KEY_TYPE_ECC_PUBLIC_KEY(curve), bits, peer_key, peer_key_length, &their_key); if (status != PSA_SUCCESS) { goto exit; } status = mbedtls_to_psa_error( mbedtls_ecdh_get_params(&ecdh, their_key, MBEDTLS_ECDH_THEIRS)); if (status != PSA_SUCCESS) { goto exit; } status = mbedtls_to_psa_error( mbedtls_ecdh_get_params(&ecdh, our_key, MBEDTLS_ECDH_OURS)); if (status != PSA_SUCCESS) { goto exit; } status = mbedtls_to_psa_error( mbedtls_ecdh_calc_secret(&ecdh, shared_secret_length, shared_secret, shared_secret_size, mbedtls_psa_get_random, MBEDTLS_PSA_RANDOM_STATE)); if (status != PSA_SUCCESS) { goto exit; } if (PSA_BITS_TO_BYTES(bits) != *shared_secret_length) { status = PSA_ERROR_CORRUPTION_DETECTED; } exit: if (status != PSA_SUCCESS) { mbedtls_platform_zeroize(shared_secret, shared_secret_size); } mbedtls_ecdh_free(&ecdh); mbedtls_ecp_keypair_free(their_key); mbedtls_free(their_key); return status; } #endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */ #define PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE MBEDTLS_ECP_MAX_BYTES static psa_status_t psa_key_agreement_raw_internal(psa_algorithm_t alg, psa_key_slot_t *private_key, const uint8_t *peer_key, size_t peer_key_length, uint8_t *shared_secret, size_t shared_secret_size, size_t *shared_secret_length) { mbedtls_ecp_keypair *ecp = NULL; psa_status_t status; switch (alg) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) case PSA_ALG_ECDH: if (!PSA_KEY_TYPE_IS_ECC_KEY_PAIR(private_key->attr.type)) { return PSA_ERROR_INVALID_ARGUMENT; } status = mbedtls_psa_ecp_load_representation( private_key->attr.type, private_key->attr.bits, private_key->key.data, private_key->key.bytes, &ecp); if (status != PSA_SUCCESS) { return status; } status = psa_key_agreement_ecdh(peer_key, peer_key_length, ecp, shared_secret, shared_secret_size, shared_secret_length); mbedtls_ecp_keypair_free(ecp); mbedtls_free(ecp); return status; #endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */ default: (void) ecp; (void) status; (void) private_key; (void) peer_key; (void) peer_key_length; (void) shared_secret; (void) shared_secret_size; (void) shared_secret_length; return PSA_ERROR_NOT_SUPPORTED; } } /* Note that if this function fails, you must call psa_key_derivation_abort() * to potentially free embedded data structures and wipe confidential data. */ static psa_status_t psa_key_agreement_internal(psa_key_derivation_operation_t *operation, psa_key_derivation_step_t step, psa_key_slot_t *private_key, const uint8_t *peer_key, size_t peer_key_length) { psa_status_t status; uint8_t shared_secret[PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE]; size_t shared_secret_length = 0; psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE(operation->alg); /* Step 1: run the secret agreement algorithm to generate the shared * secret. */ status = psa_key_agreement_raw_internal(ka_alg, private_key, peer_key, peer_key_length, shared_secret, sizeof(shared_secret), &shared_secret_length); if (status != PSA_SUCCESS) { goto exit; } /* Step 2: set up the key derivation to generate key material from * the shared secret. A shared secret is permitted wherever a key * of type DERIVE is permitted. */ status = psa_key_derivation_input_internal(operation, step, PSA_KEY_TYPE_DERIVE, shared_secret, shared_secret_length); exit: mbedtls_platform_zeroize(shared_secret, shared_secret_length); return status; } psa_status_t psa_key_derivation_key_agreement(psa_key_derivation_operation_t *operation, psa_key_derivation_step_t step, mbedtls_svc_key_id_t private_key, const uint8_t *peer_key, size_t peer_key_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot; if (!PSA_ALG_IS_KEY_AGREEMENT(operation->alg)) { return PSA_ERROR_INVALID_ARGUMENT; } status = psa_get_and_lock_transparent_key_slot_with_policy( private_key, &slot, PSA_KEY_USAGE_DERIVE, operation->alg); if (status != PSA_SUCCESS) { return status; } status = psa_key_agreement_internal(operation, step, slot, peer_key, peer_key_length); if (status != PSA_SUCCESS) { psa_key_derivation_abort(operation); } else { /* If a private key has been added as SECRET, we allow the derived * key material to be used as a key in PSA Crypto. */ if (step == PSA_KEY_DERIVATION_INPUT_SECRET) { operation->can_output_key = 1; } } unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } psa_status_t psa_raw_key_agreement(psa_algorithm_t alg, mbedtls_svc_key_id_t private_key, const uint8_t *peer_key, size_t peer_key_length, uint8_t *output, size_t output_size, size_t *output_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_slot_t *slot = NULL; size_t expected_length; if (!PSA_ALG_IS_KEY_AGREEMENT(alg)) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } status = psa_get_and_lock_transparent_key_slot_with_policy( private_key, &slot, PSA_KEY_USAGE_DERIVE, alg); if (status != PSA_SUCCESS) { goto exit; } /* PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() is in general an upper bound * for the output size. The PSA specification only guarantees that this * function works if output_size >= PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(...), * but it might be nice to allow smaller buffers if the output fits. * At the time of writing this comment, with only ECDH implemented, * PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() is exact so the point is moot. * If FFDH is implemented, PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() can easily * be exact for it as well. */ expected_length = PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(slot->attr.type, slot->attr.bits); if (output_size < expected_length) { status = PSA_ERROR_BUFFER_TOO_SMALL; goto exit; } status = psa_key_agreement_raw_internal(alg, slot, peer_key, peer_key_length, output, output_size, output_length); exit: if (status != PSA_SUCCESS) { /* If an error happens and is not handled properly, the output * may be used as a key to protect sensitive data. Arrange for such * a key to be random, which is likely to result in decryption or * verification errors. This is better than filling the buffer with * some constant data such as zeros, which would result in the data * being protected with a reproducible, easily knowable key. */ psa_generate_random(output, output_size); *output_length = output_size; } unlock_status = psa_unlock_key_slot(slot); return (status == PSA_SUCCESS) ? unlock_status : status; } /****************************************************************/ /* Random generation */ /****************************************************************/ #if defined(MBEDTLS_PSA_INJECT_ENTROPY) #include "mbedtls/entropy_poll.h" #endif /** Initialize the PSA random generator. */ static void mbedtls_psa_random_init(mbedtls_psa_random_context_t *rng) { #if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) memset(rng, 0, sizeof(*rng)); #else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ /* Set default configuration if * mbedtls_psa_crypto_configure_entropy_sources() hasn't been called. */ if (rng->entropy_init == NULL) { rng->entropy_init = mbedtls_entropy_init; } if (rng->entropy_free == NULL) { rng->entropy_free = mbedtls_entropy_free; } rng->entropy_init(&rng->entropy); #if defined(MBEDTLS_PSA_INJECT_ENTROPY) && \ defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES) /* The PSA entropy injection feature depends on using NV seed as an entropy * source. Add NV seed as an entropy source for PSA entropy injection. */ mbedtls_entropy_add_source(&rng->entropy, mbedtls_nv_seed_poll, NULL, MBEDTLS_ENTROPY_BLOCK_SIZE, MBEDTLS_ENTROPY_SOURCE_STRONG); #endif mbedtls_psa_drbg_init(MBEDTLS_PSA_RANDOM_STATE); #endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ } /** Deinitialize the PSA random generator. */ static void mbedtls_psa_random_free(mbedtls_psa_random_context_t *rng) { #if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) memset(rng, 0, sizeof(*rng)); #else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ mbedtls_psa_drbg_free(MBEDTLS_PSA_RANDOM_STATE); rng->entropy_free(&rng->entropy); #endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ } /** Seed the PSA random generator. */ static psa_status_t mbedtls_psa_random_seed(mbedtls_psa_random_context_t *rng) { #if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) /* Do nothing: the external RNG seeds itself. */ (void) rng; return PSA_SUCCESS; #else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ const unsigned char drbg_seed[] = "PSA"; int ret = mbedtls_psa_drbg_seed(&rng->entropy, drbg_seed, sizeof(drbg_seed) - 1); return mbedtls_to_psa_error(ret); #endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ } psa_status_t psa_generate_random(uint8_t *output, size_t output_size) { GUARD_MODULE_INITIALIZED; #if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) size_t output_length = 0; psa_status_t status = mbedtls_psa_external_get_random(&global_data.rng, output, output_size, &output_length); if (status != PSA_SUCCESS) { return status; } /* Breaking up a request into smaller chunks is currently not supported * for the external RNG interface. */ if (output_length != output_size) { return PSA_ERROR_INSUFFICIENT_ENTROPY; } return PSA_SUCCESS; #else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ while (output_size > 0) { size_t request_size = (output_size > MBEDTLS_PSA_RANDOM_MAX_REQUEST ? MBEDTLS_PSA_RANDOM_MAX_REQUEST : output_size); int ret = mbedtls_psa_get_random(MBEDTLS_PSA_RANDOM_STATE, output, request_size); if (ret != 0) { return mbedtls_to_psa_error(ret); } output_size -= request_size; output += request_size; } return PSA_SUCCESS; #endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ } /* Wrapper function allowing the classic API to use the PSA RNG. * * `mbedtls_psa_get_random(MBEDTLS_PSA_RANDOM_STATE, ...)` calls * `psa_generate_random(...)`. The state parameter is ignored since the * PSA API doesn't support passing an explicit state. * * In the non-external case, psa_generate_random() calls an * `mbedtls_xxx_drbg_random` function which has exactly the same signature * and semantics as mbedtls_psa_get_random(). As an optimization, * instead of doing this back-and-forth between the PSA API and the * classic API, psa_crypto_random_impl.h defines `mbedtls_psa_get_random` * as a constant function pointer to `mbedtls_xxx_drbg_random`. */ #if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) int mbedtls_psa_get_random(void *p_rng, unsigned char *output, size_t output_size) { /* This function takes a pointer to the RNG state because that's what * classic mbedtls functions using an RNG expect. The PSA RNG manages * its own state internally and doesn't let the caller access that state. * So we just ignore the state parameter, and in practice we'll pass * NULL. */ (void) p_rng; psa_status_t status = psa_generate_random(output, output_size); if (status == PSA_SUCCESS) { return 0; } else { return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED; } } #endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */ #if defined(MBEDTLS_PSA_INJECT_ENTROPY) psa_status_t mbedtls_psa_inject_entropy(const uint8_t *seed, size_t seed_size) { if (global_data.initialized) { return PSA_ERROR_NOT_PERMITTED; } if (((seed_size < MBEDTLS_ENTROPY_MIN_PLATFORM) || (seed_size < MBEDTLS_ENTROPY_BLOCK_SIZE)) || (seed_size > MBEDTLS_ENTROPY_MAX_SEED_SIZE)) { return PSA_ERROR_INVALID_ARGUMENT; } return mbedtls_psa_storage_inject_entropy(seed, seed_size); } #endif /* MBEDTLS_PSA_INJECT_ENTROPY */ /** Validate the key type and size for key generation * * \param type The key type * \param bits The number of bits of the key * * \retval #PSA_SUCCESS * The key type and size are valid. * \retval #PSA_ERROR_INVALID_ARGUMENT * The size in bits of the key is not valid. * \retval #PSA_ERROR_NOT_SUPPORTED * The type and/or the size in bits of the key or the combination of * the two is not supported. */ static psa_status_t psa_validate_key_type_and_size_for_key_generation( psa_key_type_t type, size_t bits) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; if (key_type_is_raw_bytes(type)) { status = validate_unstructured_key_bit_size(type, bits); if (status != PSA_SUCCESS) { return status; } } else #if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR) if (PSA_KEY_TYPE_IS_RSA(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) { if (bits > PSA_VENDOR_RSA_MAX_KEY_BITS) { return PSA_ERROR_NOT_SUPPORTED; } /* Accept only byte-aligned keys, for the same reasons as * in psa_import_rsa_key(). */ if (bits % 8 != 0) { return PSA_ERROR_NOT_SUPPORTED; } } else #endif /* defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR) */ #if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR) if (PSA_KEY_TYPE_IS_ECC(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) { /* To avoid empty block, return successfully here. */ return PSA_SUCCESS; } else #endif /* defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR) */ { return PSA_ERROR_NOT_SUPPORTED; } return PSA_SUCCESS; } psa_status_t psa_generate_key_internal( const psa_key_attributes_t *attributes, uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_type_t type = attributes->core.type; if ((attributes->domain_parameters == NULL) && (attributes->domain_parameters_size != 0)) { return PSA_ERROR_INVALID_ARGUMENT; } if (key_type_is_raw_bytes(type)) { status = psa_generate_random(key_buffer, key_buffer_size); if (status != PSA_SUCCESS) { return status; } #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES) if (type == PSA_KEY_TYPE_DES) { psa_des_set_key_parity(key_buffer, key_buffer_size); } #endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */ } else #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) && \ defined(MBEDTLS_GENPRIME) if (type == PSA_KEY_TYPE_RSA_KEY_PAIR) { return mbedtls_psa_rsa_generate_key(attributes, key_buffer, key_buffer_size, key_buffer_length); } else #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) * defined(MBEDTLS_GENPRIME) */ #if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) if (PSA_KEY_TYPE_IS_ECC(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) { return mbedtls_psa_ecp_generate_key(attributes, key_buffer, key_buffer_size, key_buffer_length); } else #endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) */ { (void) key_buffer_length; return PSA_ERROR_NOT_SUPPORTED; } return PSA_SUCCESS; } psa_status_t psa_generate_key(const psa_key_attributes_t *attributes, mbedtls_svc_key_id_t *key) { psa_status_t status; psa_key_slot_t *slot = NULL; psa_se_drv_table_entry_t *driver = NULL; size_t key_buffer_size; *key = MBEDTLS_SVC_KEY_ID_INIT; /* Reject any attempt to create a zero-length key so that we don't * risk tripping up later, e.g. on a malloc(0) that returns NULL. */ if (psa_get_key_bits(attributes) == 0) { return PSA_ERROR_INVALID_ARGUMENT; } /* Reject any attempt to create a public key. */ if (PSA_KEY_TYPE_IS_PUBLIC_KEY(attributes->core.type)) { return PSA_ERROR_INVALID_ARGUMENT; } status = psa_start_key_creation(PSA_KEY_CREATION_GENERATE, attributes, &slot, &driver); if (status != PSA_SUCCESS) { goto exit; } /* In the case of a transparent key or an opaque key stored in local * storage (thus not in the case of generating a key in a secure element * or cryptoprocessor with storage), we have to allocate a buffer to * hold the generated key material. */ if (slot->key.data == NULL) { if (PSA_KEY_LIFETIME_GET_LOCATION(attributes->core.lifetime) == PSA_KEY_LOCATION_LOCAL_STORAGE) { status = psa_validate_key_type_and_size_for_key_generation( attributes->core.type, attributes->core.bits); if (status != PSA_SUCCESS) { goto exit; } key_buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE( attributes->core.type, attributes->core.bits); } else { status = psa_driver_wrapper_get_key_buffer_size( attributes, &key_buffer_size); if (status != PSA_SUCCESS) { goto exit; } } status = psa_allocate_buffer_to_slot(slot, key_buffer_size); if (status != PSA_SUCCESS) { goto exit; } } status = psa_driver_wrapper_generate_key(attributes, slot->key.data, slot->key.bytes, &slot->key.bytes); if (status != PSA_SUCCESS) { psa_remove_key_data_from_memory(slot); } exit: if (status == PSA_SUCCESS) { status = psa_finish_key_creation(slot, driver, key); } if (status != PSA_SUCCESS) { psa_fail_key_creation(slot, driver); } return status; } /****************************************************************/ /* Module setup */ /****************************************************************/ #if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) psa_status_t mbedtls_psa_crypto_configure_entropy_sources( void (* entropy_init)(mbedtls_entropy_context *ctx), void (* entropy_free)(mbedtls_entropy_context *ctx)) { if (global_data.rng_state != RNG_NOT_INITIALIZED) { return PSA_ERROR_BAD_STATE; } global_data.rng.entropy_init = entropy_init; global_data.rng.entropy_free = entropy_free; return PSA_SUCCESS; } #endif /* !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) */ void mbedtls_psa_crypto_free(void) { psa_wipe_all_key_slots(); if (global_data.rng_state != RNG_NOT_INITIALIZED) { mbedtls_psa_random_free(&global_data.rng); } /* Wipe all remaining data, including configuration. * In particular, this sets all state indicator to the value * indicating "uninitialized". */ mbedtls_platform_zeroize(&global_data, sizeof(global_data)); /* Terminate drivers */ psa_driver_wrapper_free(); } #if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS) /** Recover a transaction that was interrupted by a power failure. * * This function is called during initialization, before psa_crypto_init() * returns. If this function returns a failure status, the initialization * fails. */ static psa_status_t psa_crypto_recover_transaction( const psa_crypto_transaction_t *transaction) { switch (transaction->unknown.type) { case PSA_CRYPTO_TRANSACTION_CREATE_KEY: case PSA_CRYPTO_TRANSACTION_DESTROY_KEY: /* TODO - fall through to the failure case until this * is implemented. * https://github.com/ARMmbed/mbed-crypto/issues/218 */ default: /* We found an unsupported transaction in the storage. * We don't know what state the storage is in. Give up. */ return PSA_ERROR_DATA_INVALID; } } #endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */ psa_status_t psa_crypto_init(void) { psa_status_t status; /* Double initialization is explicitly allowed. */ if (global_data.initialized != 0) { return PSA_SUCCESS; } /* Initialize and seed the random generator. */ mbedtls_psa_random_init(&global_data.rng); global_data.rng_state = RNG_INITIALIZED; status = mbedtls_psa_random_seed(&global_data.rng); if (status != PSA_SUCCESS) { goto exit; } global_data.rng_state = RNG_SEEDED; status = psa_initialize_key_slots(); if (status != PSA_SUCCESS) { goto exit; } /* Init drivers */ status = psa_driver_wrapper_init(); if (status != PSA_SUCCESS) { goto exit; } #if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS) status = psa_crypto_load_transaction(); if (status == PSA_SUCCESS) { status = psa_crypto_recover_transaction(&psa_crypto_transaction); if (status != PSA_SUCCESS) { goto exit; } status = psa_crypto_stop_transaction(); } else if (status == PSA_ERROR_DOES_NOT_EXIST) { /* There's no transaction to complete. It's all good. */ status = PSA_SUCCESS; } #endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */ /* All done. */ global_data.initialized = 1; exit: if (status != PSA_SUCCESS) { mbedtls_psa_crypto_free(); } return status; } #endif /* MBEDTLS_PSA_CRYPTO_C */