DSA_sign - DSA signatures
#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);
DSA_sign(3openssl) OpenSSL DSA_sign(3openssl)
NAME
DSA_sign, DSA_sign_setup, DSA_verify - DSA signatures
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);
DESCRIPTION
DSA_sign() computes a digital signature on the len byte message digest
dgst using the private key dsa and places its ASN.1 DER encoding at
sigret. The length of the signature is places in *siglen. sigret must
point to DSA_size(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 dsa
to contain DSA parameters. It places the precomputed values in newly
allocated BIGNUMs at *kinvp and *rp, after freeing the old ones unless
*kinvp and *rp are NULL. These values may be passed to DSA_sign() in
dsa->kinv and dsa->r. ctx is a pre-allocated BN_CTX or NULL. The
precomputed values from DSA_sign_setup() MUST NOT be used for more than
one signature: using the same dsa->kinv and dsa->r pair twice under the
same private key on different plaintexts will result in permanently
exposing the DSA private key.
DSA_verify() verifies that the signature sigbuf of size siglen matches
a given message digest dgst of size len. dsa is the signer's public
key.
The type parameter is ignored.
The PRNG must be seeded before DSA_sign() (or DSA_sign_setup()) is
called.
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
ERR_get_error(3).
CONFORMING TO
US Federal Information Processing Standard FIPS 186 (Digital Signature
Standard, DSS), ANSI X9.30
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------------+
|Availability | library/security/openssl |
+---------------+--------------------------+
|Stability | Pass-through uncommitted |
+---------------+--------------------------+
SEE ALSO
dsa(3), ERR_get_error(3), rand(3), DSA_do_sign(3)
HISTORY
DSA_sign() and DSA_verify() are available in all versions of SSLeay.
DSA_sign_setup() was added in SSLeay 0.8.
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://www.openssl.org/source/openssl-1.0.2ze.tar.gz.
Further information about this software can be found on the open source
community website at https://www.openssl.org/.
1.0.2ze 2022-05-03 DSA_sign(3openssl)