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DSA_SIGN(3ossl) OpenSSL DSA_SIGN(3ossl)
NAME
DSA_sign, DSA_sign_setup, DSA_verify - DSA signatures
SYNOPSIS
#include <openssl/dsa.h>
The following functions have been deprecated since OpenSSL 3.0, and can
be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
version value, see openssl_user_macros(7):
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
All of the functions described on this page are deprecated.
Applications should instead use EVP_PKEY_sign_init(3),
EVP_PKEY_sign(3), EVP_PKEY_verify_init(3) and EVP_PKEY_verify(3).
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() is defined only for backward binary compatibility and
should not be used. Since OpenSSL 1.1.0 the DSA type is opaque and the
output of DSA_sign_setup() cannot be used anyway: calling this function
will only cause overhead, and does not affect the actual signature
(pre-)computation.
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 random generator must be seeded when DSA_sign() (or
DSA_sign_setup()) is called. If the automatic seeding or reseeding of
the OpenSSL CSPRNG fails due to external circumstances (see RAND(7)),
the operation will fail.
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 FIPS186-4 (Digital Signature
Standard, DSS), ANSI X9.30
SEE ALSO
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
3.0.11 2023-09-19 DSA_SIGN(3ossl)