DSA_do_sign.3ssl man page

DSA_do_sign, DSA_do_verify — raw DSA signature operations


 #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);


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).

See Also

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


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


2016-09-26 1.0.2j OpenSSL