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>.