/usr/man2/cat.3/DSA_do_sign.3.Z

NAME

       DSA_do_sign, DSA_do_verify - raw DSA signature operations

SYNOPSIS

        #include <openssl/dsa.h>

        DSA_SIG *DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);

        int DSA_do_verify(const unsigned char *dgst, int dgst_len,
                    DSA_SIG *sig, DSA *dsa);

DESCRIPTION

       DSA_do_sign() computes a digital signature on the len byte message
       digest dgst using the private key dsa and returns it in a newly allo-
       cated DSA_SIG structure.

       DSA_sign_setup(3) may be used to precompute part of the signing opera-
       tion for each signature in case signature generation is time-critical.

       DSA_do_verify() verifies that the signature sig matches a given message
       digest dgst of size len.  dsa is the signer's public key.

RETURN VALUES

       DSA_do_sign() returns the signature, NULL on error.  DSA_do_verify()
       returns 1 for a valid signature, 0 for an incorrect signature and -1 on
       error. The error codes can be obtained by ERR_get_error(3).

SEE ALSO

       dsa(3), ERR_get_error(3), rand(3), DSA_SIG_new(3), DSA_sign(3)

HISTORY

       DSA_do_sign() and DSA_do_verify() were added in OpenSSL 0.9.3.

1.0.2t                            2019-09-10                    DSA_do_sign(3)
See also DSA_do_verify(3)