xref: /freebsd/crypto/openssl/doc/man3/DSA_do_sign.pod (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1=pod
2
3=head1 NAME
4
5DSA_do_sign, DSA_do_verify - raw DSA signature operations
6
7=head1 SYNOPSIS
8
9 #include <openssl/dsa.h>
10
11 DSA_SIG *DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
12
13 int DSA_do_verify(const unsigned char *dgst, int dgst_len,
14                   DSA_SIG *sig, DSA *dsa);
15
16=head1 DESCRIPTION
17
18DSA_do_sign() computes a digital signature on the B<len> byte message
19digest B<dgst> using the private key B<dsa> and returns it in a
20newly allocated B<DSA_SIG> structure.
21
22L<DSA_sign_setup(3)> may be used to precompute part
23of the signing operation in case signature generation is
24time-critical.
25
26DSA_do_verify() verifies that the signature B<sig> matches a given
27message digest B<dgst> of size B<len>.  B<dsa> is the signer's public
28key.
29
30=head1 RETURN VALUES
31
32DSA_do_sign() returns the signature, NULL on error.  DSA_do_verify()
33returns 1 for a valid signature, 0 for an incorrect signature and -1
34on error. The error codes can be obtained by
35L<ERR_get_error(3)>.
36
37=head1 SEE ALSO
38
39L<DSA_new(3)>, L<ERR_get_error(3)>, L<RAND_bytes(3)>,
40L<DSA_SIG_new(3)>,
41L<DSA_sign(3)>
42
43=head1 COPYRIGHT
44
45Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
46
47Licensed under the OpenSSL license (the "License").  You may not use
48this file except in compliance with the License.  You can obtain a copy
49in the file LICENSE in the source distribution or at
50L<https://www.openssl.org/source/license.html>.
51
52=cut
53