NAME    [Toc]    [Back]

       DSA_do_sign, DSA_do_verify - raw DSA signature operations

LIBRARY    [Toc]    [Back]

       libcrypto, -lcrypto

SYNOPSIS    [Toc]    [Back]

        #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    [Toc]    [Back]

       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 timecritical.


       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    [Toc]    [Back]

       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    [Toc]    [Back]

       openssl_dsa(3), openssl_err(3), openssl_rand(3),
       DSA_SIG_new(3), DSA_sign(3)

HISTORY    [Toc]    [Back]

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



2000-07-22                    0.9.6g               DSA_do_sign(3)