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RSA_sign(3)                         OpenSSL                        RSA_sign(3)



NAME
       RSA_sign, RSA_verify - RSA signatures

LIBRARY
       libcrypto, -lcrypto

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>.



1.1.1i                            2018-09-23                       RSA_sign(3)