.\" $OpenBSD: X509_sign.3,v 1.9 2021/10/30 16:20:35 schwarze Exp $ .\" full merge up to: OpenSSL df75c2bf Dec 9 01:02:36 2018 +0100 .\" .\" This file was written by Dr. Stephen Henson . .\" Copyright (c) 2015, 2016 The OpenSSL Project. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. 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IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: October 30 2021 $ .Dt X509_SIGN 3 .Os .Sh NAME .Nm X509_sign , .Nm X509_sign_ctx , .Nm X509_verify , .Nm X509_REQ_sign , .Nm X509_REQ_sign_ctx , .Nm X509_REQ_verify , .Nm X509_CRL_sign , .Nm X509_CRL_sign_ctx , .Nm X509_CRL_verify .Nd sign or verify certificate, certificate request, or CRL signature .Sh SYNOPSIS .In openssl/x509.h .Ft int .Fo X509_sign .Fa "X509 *x" .Fa "EVP_PKEY *pkey" .Fa "const EVP_MD *md" .Fc .Ft int .Fo X509_sign_ctx .Fa "X509 *x" .Fa "EVP_MD_CTX *ctx" .Fc .Ft int .Fo X509_verify .Fa "X509 *a" .Fa "EVP_PKEY *r" .Fc .Ft int .Fo X509_REQ_sign .Fa "X509_REQ *x" .Fa "EVP_PKEY *pkey" .Fa "const EVP_MD *md" .Fc .Ft int .Fo X509_REQ_sign_ctx .Fa "X509_REQ *x" .Fa "EVP_MD_CTX *ctx" .Fc .Ft int .Fo X509_REQ_verify .Fa "X509_REQ *a" .Fa "EVP_PKEY *r" .Fc .Ft int .Fo X509_CRL_sign .Fa "X509_CRL *x" .Fa "EVP_PKEY *pkey" .Fa "const EVP_MD *md" .Fc .Ft int .Fo X509_CRL_sign_ctx .Fa "X509_CRL *x" .Fa "EVP_MD_CTX *ctx" .Fc .Ft int .Fo X509_CRL_verify .Fa "X509_CRL *a" .Fa "EVP_PKEY *r" .Fc .Sh DESCRIPTION .Fn X509_sign signs the certificate .Fa x using the private key .Fa pkey and the message digest .Fa md and sets the signature in .Fa x . .Fn X509_sign_ctx also signs the certificate .Fa x but uses the parameters contained in digest context .Fa ctx . .Pp .Fn X509_verify verifies the signature of certificate .Fa x using the public key .Fa pkey . Only the signature is checked: no other checks (such as certificate chain validity) are performed. .Pp .Fn X509_REQ_sign , .Fn X509_REQ_sign_ctx , .Fn X509_REQ_verify , .Fn X509_CRL_sign , .Fn X509_CRL_sign_ctx , and .Fn X509_CRL_verify sign and verify certificate requests and CRLs, respectively. .Pp If .Xr X509_CRL_set_default_method 3 was in effect at the time the .Vt X509_CRL object was created, .Fn X509_CRL_verify calls the .Fn crl_verify callback function instead of performing the default action. .Pp .Fn X509_sign_ctx is used where the default parameters for the corresponding public key and digest are not suitable. It can be used to sign keys using RSA-PSS for example. .Pp For efficiency reasons and to work around ASN.1 encoding issues, the encoding of the signed portion of a certificate, certificate request, and CRL is cached internally. If the signed portion of the structure is modified, the encoding is not always updated, meaning a stale version is sometimes used. This is not normally a problem because modifying the signed portion will invalidate the signature and signing will always update the encoding. .Sh RETURN VALUES .Fn X509_sign , .Fn X509_sign_ctx , .Fn X509_REQ_sign , .Fn X509_REQ_sign_ctx , .Fn X509_CRL_sign , and .Fn X509_CRL_sign_ctx return the size of the signature in bytes for success or 0 for failure. .Pp .Fn X509_verify , .Fn X509_REQ_verify , and .Fn X509_CRL_verify return 1 if the signature is valid or 0 if the signature check fails. If the signature could not be checked at all because it was invalid or some other error occurred, then -1 is returned. .Pp In some cases of failure, the reason can be determined with .Xr ERR_get_error 3 . .Sh SEE ALSO .Xr d2i_X509 3 , .Xr EVP_DigestInit 3 , .Xr X509_CRL_get0_by_serial 3 , .Xr X509_CRL_METHOD_new 3 , .Xr X509_CRL_new 3 , .Xr X509_get_pubkey 3 , .Xr X509_get_subject_name 3 , .Xr X509_get_version 3 , .Xr X509_NAME_add_entry_by_txt 3 , .Xr X509_NAME_ENTRY_get_object 3 , .Xr X509_NAME_get_index_by_NID 3 , .Xr X509_NAME_print_ex 3 , .Xr X509_new 3 , .Xr X509_REQ_new 3 , .Xr X509_verify_cert 3 , .Xr X509V3_get_d2i 3 .Sh HISTORY .Fn X509_verify appeared in SSLeay 0.4 or earlier. .Fn X509_sign and .Fn X509_REQ_sign first appeared in SSLeay 0.4.4. .Fn X509_REQ_verify and .Fn X509_CRL_verify first appeared in SSLeay 0.4.5b. .Fn X509_CRL_sign first appeared in SSLeay 0.5.1. These functions have been available since .Ox 2.4 . .Pp .Fn X509_sign_ctx , .Fn X509_REQ_sign_ctx , and .Fn X509_CRL_sign_ctx first appeared in OpenSSL 1.0.1 and have been available since .Ox 5.3 .