2000-01-27 19:31:26 +00:00
|
|
|
=pod
|
|
|
|
|
|
|
|
|
|
=head1 NAME
|
|
|
|
|
|
|
|
|
|
DSA_sign, DSA_sign_setup, DSA_verify - DSA signatures
|
|
|
|
|
|
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
|
|
|
|
|
|
#include <openssl/dsa.h>
|
|
|
|
|
|
|
|
|
|
int DSA_sign(int type, const unsigned char *dgst, int len,
|
|
|
|
|
unsigned char *sigret, unsigned int *siglen, DSA *dsa);
|
|
|
|
|
|
|
|
|
|
int DSA_sign_setup(DSA *dsa, BN_CTX *ctx, BIGNUM **kinvp,
|
|
|
|
|
BIGNUM **rp);
|
|
|
|
|
|
|
|
|
|
int DSA_verify(int type, const unsigned char *dgst, int len,
|
|
|
|
|
unsigned char *sigbuf, int siglen, DSA *dsa);
|
|
|
|
|
|
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
|
|
|
|
|
|
DSA_sign() computes a digital signature on the B<len> byte message
|
|
|
|
|
digest B<dgst> using the private key B<dsa> and places its ASN.1 DER
|
|
|
|
|
encoding at B<sigret>. The length of the signature is places in
|
|
|
|
|
*B<siglen>. B<sigret> must point to DSA_size(B<dsa>) bytes of memory.
|
|
|
|
|
|
|
|
|
|
DSA_sign_setup() may be used to precompute part of the signing
|
|
|
|
|
operation in case signature generation is time-critical. It expects
|
|
|
|
|
B<dsa> to contain DSA parameters. It places the precomputed values
|
|
|
|
|
in newly allocated B<BIGNUM>s at *B<kinvp> and *B<rp>, after freeing
|
|
|
|
|
the old ones unless *B<kinvp> and *B<rp> are NULL. These values may
|
|
|
|
|
be passed to DSA_sign() in B<dsa-E<gt>kinv> and B<dsa-E<gt>r>.
|
|
|
|
|
B<ctx> is a pre-allocated B<BN_CTX> or NULL.
|
|
|
|
|
|
|
|
|
|
DSA_verify() verifies that the signature B<sigbuf> of size B<siglen>
|
|
|
|
|
matches a given message digest B<dgst> of size B<len>.
|
|
|
|
|
B<dsa> is the signer's public key.
|
|
|
|
|
|
|
|
|
|
The B<type> parameter is ignored.
|
|
|
|
|
|
2000-01-30 22:16:47 +00:00
|
|
|
The PRNG must be seeded before DSA_sign() (or DSA_sign_setup())
|
|
|
|
|
is called.
|
|
|
|
|
|
2000-01-27 19:31:26 +00:00
|
|
|
=head1 RETURN VALUES
|
|
|
|
|
|
|
|
|
|
DSA_sign() and DSA_sign_setup() return 1 on success, 0 on error.
|
|
|
|
|
DSA_verify() returns 1 for a valid signature, 0 for an incorrect
|
|
|
|
|
signature and -1 on error. The error codes can be obtained by
|
|
|
|
|
L<ERR_get_error(3)|ERR_get_error(3)>.
|
|
|
|
|
|
|
|
|
|
=head1 CONFORMING TO
|
|
|
|
|
|
|
|
|
|
US Federal Information Processing Standard FIPS 186 (Digital Signature
|
|
|
|
|
Standard, DSS), ANSI X9.30
|
|
|
|
|
|
|
|
|
|
=head1 SEE ALSO
|
|
|
|
|
|
2002-09-25 13:34:37 +00:00
|
|
|
L<dsa(3)|dsa(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<rand(3)|rand(3)>,
|
2000-01-30 22:16:47 +00:00
|
|
|
L<DSA_do_sign(3)|DSA_do_sign(3)>
|
2000-01-27 19:31:26 +00:00
|
|
|
|
|
|
|
|
=head1 HISTORY
|
|
|
|
|
|
|
|
|
|
DSA_sign() and DSA_verify() are available in all versions of SSLeay.
|
|
|
|
|
DSA_sign_setup() was added in SSLeay 0.8.
|
|
|
|
|
|
|
|
|
|
=cut
|
