NAME

       RSA_sign, RSA_verify - RSA signatures

SYNOPSIS

        #include <openssl/rsa.h>

        int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
                     unsigned char *sigret, unsigned int *siglen, RSA *rsa);

        int RSA_verify(int type, const unsigned char *m, unsigned int m_len,
                       unsigned char *sigbuf, unsigned int siglen, RSA *rsa);

DESCRIPTION

       RSA_sign() signs the message digest m of size m_len using the private key rsa using
       RSASSA-PKCS1-v1_5 as specified in RFC 3447. It stores the signature in sigret and the
       signature size in siglen.  sigret must point to RSA_size(rsa) bytes of memory.  Note that
       PKCS #1 adds meta-data, placing limits on the size of the key that can be used.  See
       RSA_private_encrypt(3) for lower-level operations.

       type denotes the message digest algorithm that was used to generate m.  If type is
       NID_md5_sha1, an SSL signature (MD5 and SHA1 message digests with PKCS #1 padding and no
       algorithm identifier) is created.

       RSA_verify() verifies that the signature sigbuf of size siglen matches a given message
       digest m of size m_len. type denotes the message digest algorithm that was used to
       generate the signature.  rsa is the signer's public key.

RETURN VALUES

       RSA_sign() returns 1 on success.  RSA_verify() returns 1 on successful verification.

       The error codes can be obtained by ERR_get_error(3).

CONFORMING TO

       SSL, PKCS #1 v2.0

SEE ALSO

       ERR_get_error(3), RSA_private_encrypt(3), RSA_public_decrypt(3)

COPYRIGHT

       Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use this file except in
       compliance with the License.  You can obtain a copy in the file LICENSE in the source
       distribution or at <https://www.openssl.org/source/license.html>.