NAME

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

The RSA_sign() function 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. The sigret must point to RSA_size(rsa) bytes of memory. 

The 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. 

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

These functions conform to SSL, PKCS #1 v2.0. 

RESTRICTIONS

Certain signatures with an improper algorithm identifier are accepted for compatibility with SSLeay 0.4.5. 

RETURN VALUES

The RSA_sign() function returns 1 on success, 0 otherwise.  The RSA_verify() function returns 1 on successful verification, 0 otherwise. 

The error codes can be obtained by using the ERR_get_error() function. 

HISTORY

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

SEE ALSO

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