DSA_DO_SIGN(3) Library Functions Manual DSA_DO_SIGN(3)

DSA_do_sign, DSA_do_verifyraw DSA signature operations

#include <openssl/dsa.h>

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

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

() computes a digital signature on the dlen 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.

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

DSA_do_sign() returns the signature or 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).

DSA_get0_key(3), DSA_meth_set_sign(3), DSA_new(3), DSA_SIG_new(3), DSA_sign(3)

DSA_do_sign() and DSA_do_verify() first appeared in OpenSSL 0.9.3 and have been available since OpenBSD 2.6.

June 10, 2019 OpenBSD 7.5