/usr/man/cat.3/DSA_do_sign.3

DSA_do_sign(3)               OpenSSL               DSA_do_sign(3)

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 allocated DSA_SIG structure.

     DSA_sign_setup(3) may be used to precompute part of the
     signing operation 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               Last change: 2019-09-10                    1

See also DSA_do_verify(3)