1=pod 2 3=head1 NAME 4 5DSA_sign, DSA_sign_setup, DSA_verify - DSA signatures 6 7=head1 SYNOPSIS 8 9 #include <openssl/dsa.h> 10 11The following functions have been deprecated since OpenSSL 3.0, and can be 12hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 13see L<openssl_user_macros(7)>: 14 15 int DSA_sign(int type, const unsigned char *dgst, int len, 16 unsigned char *sigret, unsigned int *siglen, DSA *dsa); 17 18 int DSA_sign_setup(DSA *dsa, BN_CTX *ctx, BIGNUM **kinvp, BIGNUM **rp); 19 20 int DSA_verify(int type, const unsigned char *dgst, int len, 21 unsigned char *sigbuf, int siglen, DSA *dsa); 22 23=head1 DESCRIPTION 24 25All of the functions described on this page are deprecated. 26Applications should instead use L<EVP_PKEY_sign_init(3)>, L<EVP_PKEY_sign(3)>, 27L<EVP_PKEY_verify_init(3)> and L<EVP_PKEY_verify(3)>. 28 29DSA_sign() computes a digital signature on the B<len> byte message 30digest B<dgst> using the private key B<dsa> and places its ASN.1 DER 31encoding at B<sigret>. The length of the signature is places in 32*B<siglen>. B<sigret> must point to DSA_size(B<dsa>) bytes of memory. 33 34DSA_sign_setup() is defined only for backward binary compatibility and 35should not be used. 36Since OpenSSL 1.1.0 the DSA type is opaque and the output of 37DSA_sign_setup() cannot be used anyway: calling this function will only 38cause overhead, and does not affect the actual signature 39(pre-)computation. 40 41DSA_verify() verifies that the signature B<sigbuf> of size B<siglen> 42matches a given message digest B<dgst> of size B<len>. 43B<dsa> is the signer's public key. 44 45The B<type> parameter is ignored. 46 47The random generator must be seeded when DSA_sign() (or DSA_sign_setup()) 48is called. 49If the automatic seeding or reseeding of the OpenSSL CSPRNG fails due to 50external circumstances (see L<RAND(7)>), the operation will fail. 51 52=head1 RETURN VALUES 53 54DSA_sign() and DSA_sign_setup() return 1 on success, 0 on error. 55DSA_verify() returns 1 for a valid signature, 0 for an incorrect 56signature and -1 on error. The error codes can be obtained by 57L<ERR_get_error(3)>. 58 59=head1 CONFORMING TO 60 61US Federal Information Processing Standard FIPS186-4 (Digital Signature 62Standard, DSS), ANSI X9.30 63 64=head1 SEE ALSO 65 66L<DSA_new(3)>, L<ERR_get_error(3)>, L<RAND_bytes(3)>, 67L<DSA_do_sign(3)>, 68L<RAND(7)> 69 70=head1 HISTORY 71 72All of these functions were deprecated in OpenSSL 3.0. 73 74=head1 COPYRIGHT 75 76Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved. 77 78Licensed under the Apache License 2.0 (the "License"). You may not use 79this file except in compliance with the License. You can obtain a copy 80in the file LICENSE in the source distribution or at 81L<https://www.openssl.org/source/license.html>. 82 83=cut 84