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 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).
