--- /dev/null
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to. The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code. The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * "This product includes cryptographic software written by
+ * Eric Young (eay@cryptsoft.com)"
+ * The word 'cryptographic' can be left out if the rouines from the library
+ * being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ * the apps directory (application code) you must include an acknowledgement:
+ * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed. i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.]
+ *
+ * The DSS routines are based on patches supplied by
+ * Steven Schoch <schoch@sheba.arc.nasa.gov>. */
+
+#include <openssl/dsa.h>
+
+#include <string.h>
+
+#include <openssl/bn.h>
+#include <openssl/dh.h>
+#include <openssl/digest.h>
+#include <openssl/engine.h>
+#include <openssl/err.h>
+#include <openssl/ex_data.h>
+#include <openssl/mem.h>
+#include <openssl/rand.h>
+#include <openssl/sha.h>
+#include <openssl/thread.h>
+
+#include "../fipsmodule/bn/internal.h"
+#include "../internal.h"
+
+
+#define OPENSSL_DSA_MAX_MODULUS_BITS 10000
+
+// Primality test according to FIPS PUB 186[-1], Appendix 2.1: 50 rounds of
+// Rabin-Miller
+#define DSS_prime_checks 50
+
+static int dsa_sign_setup(const DSA *dsa, BN_CTX *ctx_in, BIGNUM **out_kinv,
+ BIGNUM **out_r);
+
+static CRYPTO_EX_DATA_CLASS g_ex_data_class = CRYPTO_EX_DATA_CLASS_INIT;
+
+DSA *DSA_new(void) {
+ DSA *dsa = OPENSSL_malloc(sizeof(DSA));
+ if (dsa == NULL) {
+ OPENSSL_PUT_ERROR(DSA, ERR_R_MALLOC_FAILURE);
+ return NULL;
+ }
+
+ OPENSSL_memset(dsa, 0, sizeof(DSA));
+
+ dsa->references = 1;
+
+ CRYPTO_MUTEX_init(&dsa->method_mont_lock);
+ CRYPTO_new_ex_data(&dsa->ex_data);
+
+ return dsa;
+}
+
+void DSA_free(DSA *dsa) {
+ if (dsa == NULL) {
+ return;
+ }
+
+ if (!CRYPTO_refcount_dec_and_test_zero(&dsa->references)) {
+ return;
+ }
+
+ CRYPTO_free_ex_data(&g_ex_data_class, dsa, &dsa->ex_data);
+
+ BN_clear_free(dsa->p);
+ BN_clear_free(dsa->q);
+ BN_clear_free(dsa->g);
+ BN_clear_free(dsa->pub_key);
+ BN_clear_free(dsa->priv_key);
+ BN_MONT_CTX_free(dsa->method_mont_p);
+ BN_MONT_CTX_free(dsa->method_mont_q);
+ CRYPTO_MUTEX_cleanup(&dsa->method_mont_lock);
+ OPENSSL_free(dsa);
+}
+
+int DSA_up_ref(DSA *dsa) {
+ CRYPTO_refcount_inc(&dsa->references);
+ return 1;
+}
+
+void DSA_get0_key(const DSA *dsa, const BIGNUM **out_pub_key,
+ const BIGNUM **out_priv_key) {
+ if (out_pub_key != NULL) {
+ *out_pub_key = dsa->pub_key;
+ }
+ if (out_priv_key != NULL) {
+ *out_priv_key = dsa->priv_key;
+ }
+}
+
+void DSA_get0_pqg(const DSA *dsa, const BIGNUM **out_p, const BIGNUM **out_q,
+ const BIGNUM **out_g) {
+ if (out_p != NULL) {
+ *out_p = dsa->p;
+ }
+ if (out_q != NULL) {
+ *out_q = dsa->q;
+ }
+ if (out_g != NULL) {
+ *out_g = dsa->g;
+ }
+}
+
+int DSA_set0_key(DSA *dsa, BIGNUM *pub_key, BIGNUM *priv_key) {
+ if (dsa->pub_key == NULL && pub_key == NULL) {
+ return 0;
+ }
+
+ if (pub_key != NULL) {
+ BN_free(dsa->pub_key);
+ dsa->pub_key = pub_key;
+ }
+ if (priv_key != NULL) {
+ BN_free(dsa->priv_key);
+ dsa->priv_key = priv_key;
+ }
+
+ return 1;
+}
+
+int DSA_set0_pqg(DSA *dsa, BIGNUM *p, BIGNUM *q, BIGNUM *g) {
+ if ((dsa->p == NULL && p == NULL) ||
+ (dsa->q == NULL && q == NULL) ||
+ (dsa->g == NULL && g == NULL)) {
+ return 0;
+ }
+
+ if (p != NULL) {
+ BN_free(dsa->p);
+ dsa->p = p;
+ }
+ if (q != NULL) {
+ BN_free(dsa->q);
+ dsa->q = q;
+ }
+ if (g != NULL) {
+ BN_free(dsa->g);
+ dsa->g = g;
+ }
+
+ return 1;
+}
+
+int DSA_generate_parameters_ex(DSA *dsa, unsigned bits, const uint8_t *seed_in,
+ size_t seed_len, int *out_counter,
+ unsigned long *out_h, BN_GENCB *cb) {
+ int ok = 0;
+ unsigned char seed[SHA256_DIGEST_LENGTH];
+ unsigned char md[SHA256_DIGEST_LENGTH];
+ unsigned char buf[SHA256_DIGEST_LENGTH], buf2[SHA256_DIGEST_LENGTH];
+ BIGNUM *r0, *W, *X, *c, *test;
+ BIGNUM *g = NULL, *q = NULL, *p = NULL;
+ BN_MONT_CTX *mont = NULL;
+ int k, n = 0, m = 0;
+ unsigned i;
+ int counter = 0;
+ int r = 0;
+ BN_CTX *ctx = NULL;
+ unsigned int h = 2;
+ unsigned qsize;
+ const EVP_MD *evpmd;
+
+ evpmd = (bits >= 2048) ? EVP_sha256() : EVP_sha1();
+ qsize = EVP_MD_size(evpmd);
+
+ if (bits < 512) {
+ bits = 512;
+ }
+
+ bits = (bits + 63) / 64 * 64;
+
+ if (seed_in != NULL) {
+ if (seed_len < (size_t)qsize) {
+ return 0;
+ }
+ if (seed_len > (size_t)qsize) {
+ // Only consume as much seed as is expected.
+ seed_len = qsize;
+ }
+ OPENSSL_memcpy(seed, seed_in, seed_len);
+ }
+
+ ctx = BN_CTX_new();
+ if (ctx == NULL) {
+ goto err;
+ }
+ BN_CTX_start(ctx);
+
+ r0 = BN_CTX_get(ctx);
+ g = BN_CTX_get(ctx);
+ W = BN_CTX_get(ctx);
+ q = BN_CTX_get(ctx);
+ X = BN_CTX_get(ctx);
+ c = BN_CTX_get(ctx);
+ p = BN_CTX_get(ctx);
+ test = BN_CTX_get(ctx);
+
+ if (test == NULL || !BN_lshift(test, BN_value_one(), bits - 1)) {
+ goto err;
+ }
+
+ for (;;) {
+ // Find q.
+ for (;;) {
+ // step 1
+ if (!BN_GENCB_call(cb, 0, m++)) {
+ goto err;
+ }
+
+ int use_random_seed = (seed_in == NULL);
+ if (use_random_seed) {
+ if (!RAND_bytes(seed, qsize)) {
+ goto err;
+ }
+ } else {
+ // If we come back through, use random seed next time.
+ seed_in = NULL;
+ }
+ OPENSSL_memcpy(buf, seed, qsize);
+ OPENSSL_memcpy(buf2, seed, qsize);
+ // precompute "SEED + 1" for step 7:
+ for (i = qsize - 1; i < qsize; i--) {
+ buf[i]++;
+ if (buf[i] != 0) {
+ break;
+ }
+ }
+
+ // step 2
+ if (!EVP_Digest(seed, qsize, md, NULL, evpmd, NULL) ||
+ !EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL)) {
+ goto err;
+ }
+ for (i = 0; i < qsize; i++) {
+ md[i] ^= buf2[i];
+ }
+
+ // step 3
+ md[0] |= 0x80;
+ md[qsize - 1] |= 0x01;
+ if (!BN_bin2bn(md, qsize, q)) {
+ goto err;
+ }
+
+ // step 4
+ r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx, use_random_seed, cb);
+ if (r > 0) {
+ break;
+ }
+ if (r != 0) {
+ goto err;
+ }
+
+ // do a callback call
+ // step 5
+ }
+
+ if (!BN_GENCB_call(cb, 2, 0) || !BN_GENCB_call(cb, 3, 0)) {
+ goto err;
+ }
+
+ // step 6
+ counter = 0;
+ // "offset = 2"
+
+ n = (bits - 1) / 160;
+
+ for (;;) {
+ if ((counter != 0) && !BN_GENCB_call(cb, 0, counter)) {
+ goto err;
+ }
+
+ // step 7
+ BN_zero(W);
+ // now 'buf' contains "SEED + offset - 1"
+ for (k = 0; k <= n; k++) {
+ // obtain "SEED + offset + k" by incrementing:
+ for (i = qsize - 1; i < qsize; i--) {
+ buf[i]++;
+ if (buf[i] != 0) {
+ break;
+ }
+ }
+
+ if (!EVP_Digest(buf, qsize, md, NULL, evpmd, NULL)) {
+ goto err;
+ }
+
+ // step 8
+ if (!BN_bin2bn(md, qsize, r0) ||
+ !BN_lshift(r0, r0, (qsize << 3) * k) ||
+ !BN_add(W, W, r0)) {
+ goto err;
+ }
+ }
+
+ // more of step 8
+ if (!BN_mask_bits(W, bits - 1) ||
+ !BN_copy(X, W) ||
+ !BN_add(X, X, test)) {
+ goto err;
+ }
+
+ // step 9
+ if (!BN_lshift1(r0, q) ||
+ !BN_mod(c, X, r0, ctx) ||
+ !BN_sub(r0, c, BN_value_one()) ||
+ !BN_sub(p, X, r0)) {
+ goto err;
+ }
+
+ // step 10
+ if (BN_cmp(p, test) >= 0) {
+ // step 11
+ r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb);
+ if (r > 0) {
+ goto end; // found it
+ }
+ if (r != 0) {
+ goto err;
+ }
+ }
+
+ // step 13
+ counter++;
+ // "offset = offset + n + 1"
+
+ // step 14
+ if (counter >= 4096) {
+ break;
+ }
+ }
+ }
+end:
+ if (!BN_GENCB_call(cb, 2, 1)) {
+ goto err;
+ }
+
+ // We now need to generate g
+ // Set r0=(p-1)/q
+ if (!BN_sub(test, p, BN_value_one()) ||
+ !BN_div(r0, NULL, test, q, ctx)) {
+ goto err;
+ }
+
+ mont = BN_MONT_CTX_new_for_modulus(p, ctx);
+ if (mont == NULL ||
+ !BN_set_word(test, h)) {
+ goto err;
+ }
+
+ for (;;) {
+ // g=test^r0%p
+ if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont)) {
+ goto err;
+ }
+ if (!BN_is_one(g)) {
+ break;
+ }
+ if (!BN_add(test, test, BN_value_one())) {
+ goto err;
+ }
+ h++;
+ }
+
+ if (!BN_GENCB_call(cb, 3, 1)) {
+ goto err;
+ }
+
+ ok = 1;
+
+err:
+ if (ok) {
+ BN_free(dsa->p);
+ BN_free(dsa->q);
+ BN_free(dsa->g);
+ dsa->p = BN_dup(p);
+ dsa->q = BN_dup(q);
+ dsa->g = BN_dup(g);
+ if (dsa->p == NULL || dsa->q == NULL || dsa->g == NULL) {
+ ok = 0;
+ goto err;
+ }
+ if (out_counter != NULL) {
+ *out_counter = counter;
+ }
+ if (out_h != NULL) {
+ *out_h = h;
+ }
+ }
+
+ if (ctx) {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
+
+ BN_MONT_CTX_free(mont);
+
+ return ok;
+}
+
+DSA *DSAparams_dup(const DSA *dsa) {
+ DSA *ret = DSA_new();
+ if (ret == NULL) {
+ return NULL;
+ }
+ ret->p = BN_dup(dsa->p);
+ ret->q = BN_dup(dsa->q);
+ ret->g = BN_dup(dsa->g);
+ if (ret->p == NULL || ret->q == NULL || ret->g == NULL) {
+ DSA_free(ret);
+ return NULL;
+ }
+ return ret;
+}
+
+int DSA_generate_key(DSA *dsa) {
+ int ok = 0;
+ BN_CTX *ctx = NULL;
+ BIGNUM *pub_key = NULL, *priv_key = NULL;
+
+ ctx = BN_CTX_new();
+ if (ctx == NULL) {
+ goto err;
+ }
+
+ priv_key = dsa->priv_key;
+ if (priv_key == NULL) {
+ priv_key = BN_new();
+ if (priv_key == NULL) {
+ goto err;
+ }
+ }
+
+ if (!BN_rand_range_ex(priv_key, 1, dsa->q)) {
+ goto err;
+ }
+
+ pub_key = dsa->pub_key;
+ if (pub_key == NULL) {
+ pub_key = BN_new();
+ if (pub_key == NULL) {
+ goto err;
+ }
+ }
+
+ if (!BN_MONT_CTX_set_locked(&dsa->method_mont_p, &dsa->method_mont_lock,
+ dsa->p, ctx) ||
+ !BN_mod_exp_mont_consttime(pub_key, dsa->g, priv_key, dsa->p, ctx,
+ dsa->method_mont_p)) {
+ goto err;
+ }
+
+ dsa->priv_key = priv_key;
+ dsa->pub_key = pub_key;
+ ok = 1;
+
+err:
+ if (dsa->pub_key == NULL) {
+ BN_free(pub_key);
+ }
+ if (dsa->priv_key == NULL) {
+ BN_free(priv_key);
+ }
+ BN_CTX_free(ctx);
+
+ return ok;
+}
+
+DSA_SIG *DSA_SIG_new(void) {
+ DSA_SIG *sig;
+ sig = OPENSSL_malloc(sizeof(DSA_SIG));
+ if (!sig) {
+ return NULL;
+ }
+ sig->r = NULL;
+ sig->s = NULL;
+ return sig;
+}
+
+void DSA_SIG_free(DSA_SIG *sig) {
+ if (!sig) {
+ return;
+ }
+
+ BN_free(sig->r);
+ BN_free(sig->s);
+ OPENSSL_free(sig);
+}
+
+DSA_SIG *DSA_do_sign(const uint8_t *digest, size_t digest_len, const DSA *dsa) {
+ BIGNUM *kinv = NULL, *r = NULL, *s = NULL;
+ BIGNUM m;
+ BIGNUM xr;
+ BN_CTX *ctx = NULL;
+ int reason = ERR_R_BN_LIB;
+ DSA_SIG *ret = NULL;
+
+ BN_init(&m);
+ BN_init(&xr);
+
+ if (!dsa->p || !dsa->q || !dsa->g) {
+ reason = DSA_R_MISSING_PARAMETERS;
+ goto err;
+ }
+
+ s = BN_new();
+ if (s == NULL) {
+ goto err;
+ }
+ ctx = BN_CTX_new();
+ if (ctx == NULL) {
+ goto err;
+ }
+
+redo:
+ if (!dsa_sign_setup(dsa, ctx, &kinv, &r)) {
+ goto err;
+ }
+
+ if (digest_len > BN_num_bytes(dsa->q)) {
+ // if the digest length is greater than the size of q use the
+ // BN_num_bits(dsa->q) leftmost bits of the digest, see
+ // fips 186-3, 4.2
+ digest_len = BN_num_bytes(dsa->q);
+ }
+
+ if (BN_bin2bn(digest, digest_len, &m) == NULL) {
+ goto err;
+ }
+
+ // Compute s = inv(k) (m + xr) mod q
+ if (!BN_mod_mul(&xr, dsa->priv_key, r, dsa->q, ctx)) {
+ goto err; // s = xr
+ }
+ if (!BN_add(s, &xr, &m)) {
+ goto err; // s = m + xr
+ }
+ if (BN_cmp(s, dsa->q) > 0) {
+ if (!BN_sub(s, s, dsa->q)) {
+ goto err;
+ }
+ }
+ if (!BN_mod_mul(s, s, kinv, dsa->q, ctx)) {
+ goto err;
+ }
+
+ // Redo if r or s is zero as required by FIPS 186-3: this is
+ // very unlikely.
+ if (BN_is_zero(r) || BN_is_zero(s)) {
+ goto redo;
+ }
+ ret = DSA_SIG_new();
+ if (ret == NULL) {
+ goto err;
+ }
+ ret->r = r;
+ ret->s = s;
+
+err:
+ if (ret == NULL) {
+ OPENSSL_PUT_ERROR(DSA, reason);
+ BN_free(r);
+ BN_free(s);
+ }
+ BN_CTX_free(ctx);
+ BN_clear_free(&m);
+ BN_clear_free(&xr);
+ BN_clear_free(kinv);
+
+ return ret;
+}
+
+int DSA_do_verify(const uint8_t *digest, size_t digest_len, DSA_SIG *sig,
+ const DSA *dsa) {
+ int valid;
+ if (!DSA_do_check_signature(&valid, digest, digest_len, sig, dsa)) {
+ return -1;
+ }
+ return valid;
+}
+
+int DSA_do_check_signature(int *out_valid, const uint8_t *digest,
+ size_t digest_len, DSA_SIG *sig, const DSA *dsa) {
+ BN_CTX *ctx;
+ BIGNUM u1, u2, t1;
+ int ret = 0;
+ unsigned i;
+
+ *out_valid = 0;
+
+ if (!dsa->p || !dsa->q || !dsa->g) {
+ OPENSSL_PUT_ERROR(DSA, DSA_R_MISSING_PARAMETERS);
+ return 0;
+ }
+
+ i = BN_num_bits(dsa->q);
+ // fips 186-3 allows only different sizes for q
+ if (i != 160 && i != 224 && i != 256) {
+ OPENSSL_PUT_ERROR(DSA, DSA_R_BAD_Q_VALUE);
+ return 0;
+ }
+
+ if (BN_num_bits(dsa->p) > OPENSSL_DSA_MAX_MODULUS_BITS) {
+ OPENSSL_PUT_ERROR(DSA, DSA_R_MODULUS_TOO_LARGE);
+ return 0;
+ }
+
+ BN_init(&u1);
+ BN_init(&u2);
+ BN_init(&t1);
+
+ ctx = BN_CTX_new();
+ if (ctx == NULL) {
+ goto err;
+ }
+
+ if (BN_is_zero(sig->r) || BN_is_negative(sig->r) ||
+ BN_ucmp(sig->r, dsa->q) >= 0) {
+ ret = 1;
+ goto err;
+ }
+ if (BN_is_zero(sig->s) || BN_is_negative(sig->s) ||
+ BN_ucmp(sig->s, dsa->q) >= 0) {
+ ret = 1;
+ goto err;
+ }
+
+ // Calculate W = inv(S) mod Q
+ // save W in u2
+ if (BN_mod_inverse(&u2, sig->s, dsa->q, ctx) == NULL) {
+ goto err;
+ }
+
+ // save M in u1
+ if (digest_len > (i >> 3)) {
+ // if the digest length is greater than the size of q use the
+ // BN_num_bits(dsa->q) leftmost bits of the digest, see
+ // fips 186-3, 4.2
+ digest_len = (i >> 3);
+ }
+
+ if (BN_bin2bn(digest, digest_len, &u1) == NULL) {
+ goto err;
+ }
+
+ // u1 = M * w mod q
+ if (!BN_mod_mul(&u1, &u1, &u2, dsa->q, ctx)) {
+ goto err;
+ }
+
+ // u2 = r * w mod q
+ if (!BN_mod_mul(&u2, sig->r, &u2, dsa->q, ctx)) {
+ goto err;
+ }
+
+ if (!BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
+ (CRYPTO_MUTEX *)&dsa->method_mont_lock, dsa->p,
+ ctx)) {
+ goto err;
+ }
+
+ if (!BN_mod_exp2_mont(&t1, dsa->g, &u1, dsa->pub_key, &u2, dsa->p, ctx,
+ dsa->method_mont_p)) {
+ goto err;
+ }
+
+ // BN_copy(&u1,&t1);
+ // let u1 = u1 mod q
+ if (!BN_mod(&u1, &t1, dsa->q, ctx)) {
+ goto err;
+ }
+
+ // V is now in u1. If the signature is correct, it will be
+ // equal to R.
+ *out_valid = BN_ucmp(&u1, sig->r) == 0;
+ ret = 1;
+
+err:
+ if (ret != 1) {
+ OPENSSL_PUT_ERROR(DSA, ERR_R_BN_LIB);
+ }
+ BN_CTX_free(ctx);
+ BN_free(&u1);
+ BN_free(&u2);
+ BN_free(&t1);
+
+ return ret;
+}
+
+int DSA_sign(int type, const uint8_t *digest, size_t digest_len,
+ uint8_t *out_sig, unsigned int *out_siglen, const DSA *dsa) {
+ DSA_SIG *s;
+
+ s = DSA_do_sign(digest, digest_len, dsa);
+ if (s == NULL) {
+ *out_siglen = 0;
+ return 0;
+ }
+
+ *out_siglen = i2d_DSA_SIG(s, &out_sig);
+ DSA_SIG_free(s);
+ return 1;
+}
+
+int DSA_verify(int type, const uint8_t *digest, size_t digest_len,
+ const uint8_t *sig, size_t sig_len, const DSA *dsa) {
+ int valid;
+ if (!DSA_check_signature(&valid, digest, digest_len, sig, sig_len, dsa)) {
+ return -1;
+ }
+ return valid;
+}
+
+int DSA_check_signature(int *out_valid, const uint8_t *digest,
+ size_t digest_len, const uint8_t *sig, size_t sig_len,
+ const DSA *dsa) {
+ DSA_SIG *s = NULL;
+ int ret = 0;
+ uint8_t *der = NULL;
+
+ s = DSA_SIG_new();
+ if (s == NULL) {
+ goto err;
+ }
+
+ const uint8_t *sigp = sig;
+ if (d2i_DSA_SIG(&s, &sigp, sig_len) == NULL || sigp != sig + sig_len) {
+ goto err;
+ }
+
+ // Ensure that the signature uses DER and doesn't have trailing garbage.
+ int der_len = i2d_DSA_SIG(s, &der);
+ if (der_len < 0 || (size_t)der_len != sig_len ||
+ OPENSSL_memcmp(sig, der, sig_len)) {
+ goto err;
+ }
+
+ ret = DSA_do_check_signature(out_valid, digest, digest_len, s, dsa);
+
+err:
+ OPENSSL_free(der);
+ DSA_SIG_free(s);
+ return ret;
+}
+
+// der_len_len returns the number of bytes needed to represent a length of |len|
+// in DER.
+static size_t der_len_len(size_t len) {
+ if (len < 0x80) {
+ return 1;
+ }
+ size_t ret = 1;
+ while (len > 0) {
+ ret++;
+ len >>= 8;
+ }
+ return ret;
+}
+
+int DSA_size(const DSA *dsa) {
+ size_t order_len = BN_num_bytes(dsa->q);
+ // Compute the maximum length of an |order_len| byte integer. Defensively
+ // assume that the leading 0x00 is included.
+ size_t integer_len = 1 /* tag */ + der_len_len(order_len + 1) + 1 + order_len;
+ if (integer_len < order_len) {
+ return 0;
+ }
+ // A DSA signature is two INTEGERs.
+ size_t value_len = 2 * integer_len;
+ if (value_len < integer_len) {
+ return 0;
+ }
+ // Add the header.
+ size_t ret = 1 /* tag */ + der_len_len(value_len) + value_len;
+ if (ret < value_len) {
+ return 0;
+ }
+ return ret;
+}
+
+static int dsa_sign_setup(const DSA *dsa, BN_CTX *ctx_in, BIGNUM **out_kinv,
+ BIGNUM **out_r) {
+ BN_CTX *ctx;
+ BIGNUM k, *kinv = NULL, *r = NULL;
+ int ret = 0;
+
+ if (!dsa->p || !dsa->q || !dsa->g) {
+ OPENSSL_PUT_ERROR(DSA, DSA_R_MISSING_PARAMETERS);
+ return 0;
+ }
+
+ BN_init(&k);
+
+ ctx = ctx_in;
+ if (ctx == NULL) {
+ ctx = BN_CTX_new();
+ if (ctx == NULL) {
+ goto err;
+ }
+ }
+
+ r = BN_new();
+ kinv = BN_new();
+ if (r == NULL || kinv == NULL ||
+ // Get random k
+ !BN_rand_range_ex(&k, 1, dsa->q) ||
+ !BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
+ (CRYPTO_MUTEX *)&dsa->method_mont_lock, dsa->p,
+ ctx) ||
+ !BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_q,
+ (CRYPTO_MUTEX *)&dsa->method_mont_lock, dsa->q,
+ ctx) ||
+ // Compute r = (g^k mod p) mod q
+ !BN_mod_exp_mont_consttime(r, dsa->g, &k, dsa->p, ctx,
+ dsa->method_mont_p) ||
+ !BN_mod(r, r, dsa->q, ctx) ||
+ // Compute part of 's = inv(k) (m + xr) mod q' using Fermat's Little
+ // Theorem.
+ !bn_mod_inverse_prime(kinv, &k, dsa->q, ctx, dsa->method_mont_q)) {
+ goto err;
+ }
+
+ BN_clear_free(*out_kinv);
+ *out_kinv = kinv;
+ kinv = NULL;
+ BN_clear_free(*out_r);
+ *out_r = r;
+ ret = 1;
+
+err:
+ if (!ret) {
+ OPENSSL_PUT_ERROR(DSA, ERR_R_BN_LIB);
+ if (r != NULL) {
+ BN_clear_free(r);
+ }
+ }
+
+ if (ctx_in == NULL) {
+ BN_CTX_free(ctx);
+ }
+ BN_clear_free(&k);
+ BN_clear_free(kinv);
+ return ret;
+}
+
+int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
+ CRYPTO_EX_dup *dup_unused, CRYPTO_EX_free *free_func) {
+ int index;
+ if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp,
+ free_func)) {
+ return -1;
+ }
+ return index;
+}
+
+int DSA_set_ex_data(DSA *dsa, int idx, void *arg) {
+ return CRYPTO_set_ex_data(&dsa->ex_data, idx, arg);
+}
+
+void *DSA_get_ex_data(const DSA *dsa, int idx) {
+ return CRYPTO_get_ex_data(&dsa->ex_data, idx);
+}
+
+DH *DSA_dup_DH(const DSA *dsa) {
+ if (dsa == NULL) {
+ return NULL;
+ }
+
+ DH *ret = DH_new();
+ if (ret == NULL) {
+ goto err;
+ }
+ if (dsa->q != NULL) {
+ ret->priv_length = BN_num_bits(dsa->q);
+ if ((ret->q = BN_dup(dsa->q)) == NULL) {
+ goto err;
+ }
+ }
+ if ((dsa->p != NULL && (ret->p = BN_dup(dsa->p)) == NULL) ||
+ (dsa->g != NULL && (ret->g = BN_dup(dsa->g)) == NULL) ||
+ (dsa->pub_key != NULL && (ret->pub_key = BN_dup(dsa->pub_key)) == NULL) ||
+ (dsa->priv_key != NULL &&
+ (ret->priv_key = BN_dup(dsa->priv_key)) == NULL)) {
+ goto err;
+ }
+
+ return ret;
+
+err:
+ DH_free(ret);
+ return NULL;
+}
git://repos.xcallymotion.com / motion2.git / blobdiff