/** * \file nist_kw.h * * \brief This file provides an API for key wrapping (KW) and key wrapping with * padding (KWP) as defined in NIST SP 800-38F. * https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38F.pdf * * Key wrapping specifies a deterministic authenticated-encryption mode * of operation, according to NIST SP 800-38F: Recommendation for * Block Cipher Modes of Operation: Methods for Key Wrapping. Its * purpose is to protect cryptographic keys. * * Its equivalent is RFC 3394 for KW, and RFC 5649 for KWP. * https://tools.ietf.org/html/rfc3394 * https://tools.ietf.org/html/rfc5649 * */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later * * This file is provided under the Apache License 2.0, or the * GNU General Public License v2.0 or later. * * ********** * Apache License 2.0: * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * ********** * * ********** * GNU General Public License v2.0 or later: * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * ********** */ #ifndef MBEDTLS_NIST_KW_H #define MBEDTLS_NIST_KW_H #if !defined(MBEDTLS_CONFIG_FILE) #include "config.h" #else #include MBEDTLS_CONFIG_FILE #endif #include "cipher.h" #ifdef __cplusplus extern "C" { #endif typedef enum { MBEDTLS_KW_MODE_KW = 0, MBEDTLS_KW_MODE_KWP = 1 } mbedtls_nist_kw_mode_t; #if !defined(MBEDTLS_NIST_KW_ALT) // Regular implementation // /** * \brief The key wrapping context-type definition. The key wrapping context is passed * to the APIs called. * * \note The definition of this type may change in future library versions. * Don't make any assumptions on this context! */ typedef struct { mbedtls_cipher_context_t cipher_ctx; /*!< The cipher context used. */ } mbedtls_nist_kw_context; #else /* MBEDTLS_NIST_key wrapping_ALT */ #include "nist_kw_alt.h" #endif /* MBEDTLS_NIST_KW_ALT */ /** * \brief This function initializes the specified key wrapping context * to make references valid and prepare the context * for mbedtls_nist_kw_setkey() or mbedtls_nist_kw_free(). * * \param ctx The key wrapping context to initialize. * */ void mbedtls_nist_kw_init( mbedtls_nist_kw_context *ctx ); /** * \brief This function initializes the key wrapping context set in the * \p ctx parameter and sets the encryption key. * * \param ctx The key wrapping context. * \param cipher The 128-bit block cipher to use. Only AES is supported. * \param key The Key Encryption Key (KEK). * \param keybits The KEK size in bits. This must be acceptable by the cipher. * \param is_wrap Specify whether the operation within the context is wrapping or unwrapping * * \return \c 0 on success. * \return \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for any invalid input. * \return \c MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE for 128-bit block ciphers * which are not supported. * \return cipher-specific error code on failure of the underlying cipher. */ int mbedtls_nist_kw_setkey( mbedtls_nist_kw_context *ctx, mbedtls_cipher_id_t cipher, const unsigned char *key, unsigned int keybits, const int is_wrap ); /** * \brief This function releases and clears the specified key wrapping context * and underlying cipher sub-context. * * \param ctx The key wrapping context to clear. */ void mbedtls_nist_kw_free( mbedtls_nist_kw_context *ctx ); /** * \brief This function encrypts a buffer using key wrapping. * * \param ctx The key wrapping context to use for encryption. * \param mode The key wrapping mode to use (MBEDTLS_KW_MODE_KW or MBEDTLS_KW_MODE_KWP) * \param input The buffer holding the input data. * \param in_len The length of the input data in Bytes. * The input uses units of 8 Bytes called semiblocks. * * \param[out] output The buffer holding the output data. * * \param[out] out_len The number of bytes written to the output buffer. \c 0 on failure. * \param[in] out_size The capacity of the output buffer. * * \return \c 0 on success. * \return \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for invalid input length. * \return cipher-specific error code on failure of the underlying cipher. */ int mbedtls_nist_kw_wrap( mbedtls_nist_kw_context *ctx, mbedtls_nist_kw_mode_t mode, const unsigned char *input, size_t in_len, unsigned char *output, size_t* out_len, size_t out_size ); /** * \brief This function decrypts a buffer using key wrapping. * * \param ctx The key wrapping context to use for decryption. * \param mode The key wrapping mode to use (MBEDTLS_KW_MODE_KW or MBEDTLS_KW_MODE_KWP) * \param input The buffer holding the input data. * \param in_len The length of the input data in Bytes. * The input uses units of 8 Bytes called semiblocks. * The input must be a multiple of semiblocks. * * \param[out] output The buffer holding the output data. * The output buffer's minimal length is 8 bytes shorter than \p in_len. * \param[out] out_len The number of bytes written to the output buffer. \c 0 on failure. * For KWP mode, the length could be up to 15 bytes shorter than \p in_len, * depending on how much padding was added to the data. * \param[in] out_size The capacity of the output buffer. * * \return \c 0 on success. * \return \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for invalid input length. * \return \c MBEDTLS_ERR_CIPHER_AUTH_FAILED for verification failure of the ciphertext. * \return cipher-specific error code on failure of the underlying cipher. */ int mbedtls_nist_kw_unwrap( mbedtls_nist_kw_context *ctx, mbedtls_nist_kw_mode_t mode, const unsigned char *input, size_t in_len, unsigned char *output, size_t* out_len, size_t out_size); #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C) /** * \brief The key wrapping checkup routine. * * \return \c 0 on success. * \return \c 1 on failure. */ int mbedtls_nist_kw_self_test( int verbose ); #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */ #ifdef __cplusplus } #endif #endif /* MBEDTLS_NIST_KW_H */