RSA_sign, RSA_verify - RSA signatures


SYNOPSIS

        #include <openssl/rsa.h>

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

        int RSA_verify(int type, 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 as specified in PKCS #1 v2.0. It
       stores the signature in sigret and the signature size in
       siglen. sigret must point to RSA_size(rsa) bytes of
       memory.

       type denotes the message digest algorithm that was used to
       generate m. It usually is one of NID_sha1, NID_ripemd160
       and NID_md5; see objects(3) for details. 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, 0 otherwise.
       RSA_verify() returns 1 on successful verification, 0
       otherwise.

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


BUGS

       Certain signatures with an improper algorithm identifier
       are accepted for compatibility with SSLeay 0.4.5 :-)


CONFORMING TO

       SSL, PKCS #1 v2.0


SEE ALSO

       err(3), objects(3), rsa(3), RSA_private_encrypt(3),
       RSA_public_decrypt(3)


HISTORY

       RSA_sign() and RSA_verify() are available in all versions
       of SSLeay and OpenSSL.



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