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/*
* Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* 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
*/
/*
* DSA low level APIs are deprecated for public use, but still ok for
* internal use.
*/
#include "internal/deprecated.h"
#include <openssl/bn.h>
#include "internal/cryptlib.h"
#include "dsa_local.h"
#include "crypto/asn1_dsa.h"
#include "crypto/dsa.h"
DSA_SIG *DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
{
return dsa->meth->dsa_do_sign(dgst, dlen, dsa);
}
#ifndef OPENSSL_NO_DEPRECATED_3_0
int DSA_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
{
return dsa->meth->dsa_sign_setup(dsa, ctx_in, kinvp, rp);
}
#endif
DSA_SIG *DSA_SIG_new(void)
{
DSA_SIG *sig = OPENSSL_zalloc(sizeof(*sig));
return sig;
}
void DSA_SIG_free(DSA_SIG *sig)
{
if (sig == NULL)
return;
BN_clear_free(sig->r);
BN_clear_free(sig->s);
OPENSSL_free(sig);
}
DSA_SIG *d2i_DSA_SIG(DSA_SIG **psig, const unsigned char **ppin, long len)
{
DSA_SIG *sig;
if (len < 0)
return NULL;
if (psig != NULL && *psig != NULL) {
sig = *psig;
} else {
sig = DSA_SIG_new();
if (sig == NULL)
return NULL;
}
if (sig->r == NULL)
sig->r = BN_new();
if (sig->s == NULL)
sig->s = BN_new();
if (sig->r == NULL || sig->s == NULL
|| ossl_decode_der_dsa_sig(sig->r, sig->s, ppin, (size_t)len) == 0) {
if (psig == NULL || *psig == NULL)
DSA_SIG_free(sig);
return NULL;
}
if (psig != NULL && *psig == NULL)
*psig = sig;
return sig;
}
int i2d_DSA_SIG(const DSA_SIG *sig, unsigned char **ppout)
{
BUF_MEM *buf = NULL;
size_t encoded_len;
WPACKET pkt;
if (ppout == NULL) {
if (!WPACKET_init_null(&pkt, 0))
return -1;
} else if (*ppout == NULL) {
if ((buf = BUF_MEM_new()) == NULL
|| !WPACKET_init_len(&pkt, buf, 0)) {
BUF_MEM_free(buf);
return -1;
}
} else {
if (!WPACKET_init_static_len(&pkt, *ppout, SIZE_MAX, 0))
return -1;
}
if (!ossl_encode_der_dsa_sig(&pkt, sig->r, sig->s)
|| !WPACKET_get_total_written(&pkt, &encoded_len)
|| !WPACKET_finish(&pkt)) {
BUF_MEM_free(buf);
WPACKET_cleanup(&pkt);
return -1;
}
if (ppout != NULL) {
if (*ppout == NULL) {
*ppout = (unsigned char *)buf->data;
buf->data = NULL;
BUF_MEM_free(buf);
} else {
*ppout += encoded_len;
}
}
return (int)encoded_len;
}
int DSA_size(const DSA *dsa)
{
int ret = -1;
DSA_SIG sig;
if (dsa->params.q != NULL) {
sig.r = sig.s = dsa->params.q;
ret = i2d_DSA_SIG(&sig, NULL);
if (ret < 0)
ret = 0;
}
return ret;
}
void DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **pr, const BIGNUM **ps)
{
if (pr != NULL)
*pr = sig->r;
if (ps != NULL)
*ps = sig->s;
}
int DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s)
{
if (r == NULL || s == NULL)
return 0;
BN_clear_free(sig->r);
BN_clear_free(sig->s);
sig->r = r;
sig->s = s;
return 1;
}
int ossl_dsa_sign_int(int type, const unsigned char *dgst, int dlen,
unsigned char *sig, unsigned int *siglen, DSA *dsa,
unsigned int nonce_type, const char *digestname,
OSSL_LIB_CTX *libctx, const char *propq)
{
DSA_SIG *s;
if (sig == NULL) {
*siglen = DSA_size(dsa);
return 1;
}
/* legacy case uses the method table */
if (dsa->libctx == NULL || dsa->meth != DSA_get_default_method())
s = DSA_do_sign(dgst, dlen, dsa);
else
s = ossl_dsa_do_sign_int(dgst, dlen, dsa,
nonce_type, digestname, libctx, propq);
if (s == NULL) {
*siglen = 0;
return 0;
}
*siglen = i2d_DSA_SIG(s, &sig);
DSA_SIG_free(s);
return 1;
}
int DSA_sign(int type, const unsigned char *dgst, int dlen,
unsigned char *sig, unsigned int *siglen, DSA *dsa)
{
return ossl_dsa_sign_int(type, dgst, dlen, sig, siglen, dsa,
0, NULL, NULL, NULL);
}
/* data has already been hashed (probably with SHA or SHA-1). */
/*-
* returns
* 1: correct signature
* 0: incorrect signature
* -1: error
*/
int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
const unsigned char *sigbuf, int siglen, DSA *dsa)
{
DSA_SIG *s;
const unsigned char *p = sigbuf;
unsigned char *der = NULL;
int derlen = -1;
int ret = -1;
s = DSA_SIG_new();
if (s == NULL)
return ret;
if (d2i_DSA_SIG(&s, &p, siglen) == NULL)
goto err;
/* Ensure signature uses DER and doesn't have trailing garbage */
derlen = i2d_DSA_SIG(s, &der);
if (derlen != siglen || memcmp(sigbuf, der, derlen))
goto err;
ret = DSA_do_verify(dgst, dgst_len, s, dsa);
err:
OPENSSL_clear_free(der, derlen);
DSA_SIG_free(s);
return ret;
}
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