--- /dev/null
+/* crypto/ecdsa/ecs_ossl.c */
+/*
+ * Written by Nils Larsch for the OpenSSL project
+ */
+/* ====================================================================
+ * Copyright (c) 1998-2004 The OpenSSL Project. All rights reserved.
+ *
+ * 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 above 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 acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED 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 OpenSSL PROJECT OR
+ * ITS 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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#include "ecs_locl.h"
+#include <openssl/err.h>
+#include <openssl/obj_mac.h>
+#include <openssl/bn.h>
+
+static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen,
+ const BIGNUM *, const BIGNUM *, EC_KEY *eckey);
+static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
+ BIGNUM **rp);
+static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
+ const ECDSA_SIG *sig, EC_KEY *eckey);
+
+static ECDSA_METHOD openssl_ecdsa_meth = {
+ "OpenSSL ECDSA method",
+ ecdsa_do_sign,
+ ecdsa_sign_setup,
+ ecdsa_do_verify,
+#if 0
+ NULL, /* init */
+ NULL, /* finish */
+#endif
+ 0, /* flags */
+ NULL /* app_data */
+};
+
+const ECDSA_METHOD *ECDSA_OpenSSL(void)
+{
+ return &openssl_ecdsa_meth;
+}
+
+static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
+ BIGNUM **rp)
+{
+ BN_CTX *ctx = NULL;
+ BIGNUM *k = NULL, *r = NULL, *order = NULL, *X = NULL;
+ EC_POINT *tmp_point=NULL;
+ const EC_GROUP *group;
+ int ret = 0;
+
+ if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
+ return 0;
+ }
+
+ if (ctx_in == NULL)
+ {
+ if ((ctx = BN_CTX_new()) == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+ }
+ else
+ ctx = ctx_in;
+
+ k = BN_new(); /* this value is later returned in *kinvp */
+ r = BN_new(); /* this value is later returned in *rp */
+ order = BN_new();
+ X = BN_new();
+ if (!k || !r || !order || !X)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ if ((tmp_point = EC_POINT_new(group)) == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
+ goto err;
+ }
+ if (!EC_GROUP_get_order(group, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
+ goto err;
+ }
+
+ do
+ {
+ /* get random k */
+ do
+ if (!BN_rand_range(k, order))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,
+ ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED);
+ goto err;
+ }
+ while (BN_is_zero(k));
+
+ /* We do not want timing information to leak the length of k,
+ * so we compute G*k using an equivalent scalar of fixed
+ * bit-length. */
+
+ if (!BN_add(k, k, order)) goto err;
+ if (BN_num_bits(k) <= BN_num_bits(order))
+ if (!BN_add(k, k, order)) goto err;
+
+ /* compute r the x-coordinate of generator * k */
+ if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
+ goto err;
+ }
+ if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
+ {
+ if (!EC_POINT_get_affine_coordinates_GFp(group,
+ tmp_point, X, NULL, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_EC_LIB);
+ goto err;
+ }
+ }
+#ifndef OPENSSL_NO_EC2M
+ else /* NID_X9_62_characteristic_two_field */
+ {
+ if (!EC_POINT_get_affine_coordinates_GF2m(group,
+ tmp_point, X, NULL, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_EC_LIB);
+ goto err;
+ }
+ }
+#endif
+ if (!BN_nnmod(r, X, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
+ goto err;
+ }
+ }
+ while (BN_is_zero(r));
+
+ /* compute the inverse of k */
+ if (!BN_mod_inverse(k, k, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
+ goto err;
+ }
+ /* clear old values if necessary */
+ if (*rp != NULL)
+ BN_clear_free(*rp);
+ if (*kinvp != NULL)
+ BN_clear_free(*kinvp);
+ /* save the pre-computed values */
+ *rp = r;
+ *kinvp = k;
+ ret = 1;
+err:
+ if (!ret)
+ {
+ if (k != NULL) BN_clear_free(k);
+ if (r != NULL) BN_clear_free(r);
+ }
+ if (ctx_in == NULL)
+ BN_CTX_free(ctx);
+ if (order != NULL)
+ BN_free(order);
+ if (tmp_point != NULL)
+ EC_POINT_free(tmp_point);
+ if (X)
+ BN_clear_free(X);
+ return(ret);
+}
+
+
+static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len,
+ const BIGNUM *in_kinv, const BIGNUM *in_r, EC_KEY *eckey)
+{
+ int ok = 0, i;
+ BIGNUM *kinv=NULL, *s, *m=NULL,*tmp=NULL,*order=NULL;
+ const BIGNUM *ckinv;
+ BN_CTX *ctx = NULL;
+ const EC_GROUP *group;
+ ECDSA_SIG *ret;
+ ECDSA_DATA *ecdsa;
+ const BIGNUM *priv_key;
+
+ ecdsa = ecdsa_check(eckey);
+ group = EC_KEY_get0_group(eckey);
+ priv_key = EC_KEY_get0_private_key(eckey);
+
+ if (group == NULL || priv_key == NULL || ecdsa == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_PASSED_NULL_PARAMETER);
+ return NULL;
+ }
+
+ ret = ECDSA_SIG_new();
+ if (!ret)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
+ return NULL;
+ }
+ s = ret->s;
+
+ if ((ctx = BN_CTX_new()) == NULL || (order = BN_new()) == NULL ||
+ (tmp = BN_new()) == NULL || (m = BN_new()) == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ if (!EC_GROUP_get_order(group, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_EC_LIB);
+ goto err;
+ }
+ i = BN_num_bits(order);
+ /* Need to truncate digest if it is too long: first truncate whole
+ * bytes.
+ */
+ if (8 * dgst_len > i)
+ dgst_len = (i + 7)/8;
+ if (!BN_bin2bn(dgst, dgst_len, m))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
+ goto err;
+ }
+ /* If still too long truncate remaining bits with a shift */
+ if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
+ goto err;
+ }
+ do
+ {
+ if (in_kinv == NULL || in_r == NULL)
+ {
+ if (!ECDSA_sign_setup(eckey, ctx, &kinv, &ret->r))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,ERR_R_ECDSA_LIB);
+ goto err;
+ }
+ ckinv = kinv;
+ }
+ else
+ {
+ ckinv = in_kinv;
+ if (BN_copy(ret->r, in_r) == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ }
+
+ if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
+ goto err;
+ }
+ if (!BN_mod_add_quick(s, tmp, m, order))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
+ goto err;
+ }
+ if (!BN_mod_mul(s, s, ckinv, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
+ goto err;
+ }
+ if (BN_is_zero(s))
+ {
+ /* if kinv and r have been supplied by the caller
+ * don't to generate new kinv and r values */
+ if (in_kinv != NULL && in_r != NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ECDSA_R_NEED_NEW_SETUP_VALUES);
+ goto err;
+ }
+ }
+ else
+ /* s != 0 => we have a valid signature */
+ break;
+ }
+ while (1);
+
+ ok = 1;
+err:
+ if (!ok)
+ {
+ ECDSA_SIG_free(ret);
+ ret = NULL;
+ }
+ if (ctx)
+ BN_CTX_free(ctx);
+ if (m)
+ BN_clear_free(m);
+ if (tmp)
+ BN_clear_free(tmp);
+ if (order)
+ BN_free(order);
+ if (kinv)
+ BN_clear_free(kinv);
+ return ret;
+}
+
+static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
+ const ECDSA_SIG *sig, EC_KEY *eckey)
+{
+ int ret = -1, i;
+ BN_CTX *ctx;
+ BIGNUM *order, *u1, *u2, *m, *X;
+ EC_POINT *point = NULL;
+ const EC_GROUP *group;
+ const EC_POINT *pub_key;
+
+ /* check input values */
+ if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL ||
+ (pub_key = EC_KEY_get0_public_key(eckey)) == NULL || sig == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_MISSING_PARAMETERS);
+ return -1;
+ }
+
+ ctx = BN_CTX_new();
+ if (!ctx)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
+ return -1;
+ }
+ BN_CTX_start(ctx);
+ order = BN_CTX_get(ctx);
+ u1 = BN_CTX_get(ctx);
+ u2 = BN_CTX_get(ctx);
+ m = BN_CTX_get(ctx);
+ X = BN_CTX_get(ctx);
+ if (!X)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
+ goto err;
+ }
+
+ if (!EC_GROUP_get_order(group, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
+ goto err;
+ }
+
+ if (BN_is_zero(sig->r) || BN_is_negative(sig->r) ||
+ BN_ucmp(sig->r, order) >= 0 || BN_is_zero(sig->s) ||
+ BN_is_negative(sig->s) || BN_ucmp(sig->s, order) >= 0)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_BAD_SIGNATURE);
+ ret = 0; /* signature is invalid */
+ goto err;
+ }
+ /* calculate tmp1 = inv(S) mod order */
+ if (!BN_mod_inverse(u2, sig->s, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
+ goto err;
+ }
+ /* digest -> m */
+ i = BN_num_bits(order);
+ /* Need to truncate digest if it is too long: first truncate whole
+ * bytes.
+ */
+ if (8 * dgst_len > i)
+ dgst_len = (i + 7)/8;
+ if (!BN_bin2bn(dgst, dgst_len, m))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
+ goto err;
+ }
+ /* If still too long truncate remaining bits with a shift */
+ if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
+ goto err;
+ }
+ /* u1 = m * tmp mod order */
+ if (!BN_mod_mul(u1, m, u2, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
+ goto err;
+ }
+ /* u2 = r * w mod q */
+ if (!BN_mod_mul(u2, sig->r, u2, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
+ goto err;
+ }
+
+ if ((point = EC_POINT_new(group)) == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
+ goto err;
+ }
+ if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
+ {
+ if (!EC_POINT_get_affine_coordinates_GFp(group,
+ point, X, NULL, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
+ goto err;
+ }
+ }
+#ifndef OPENSSL_NO_EC2M
+ else /* NID_X9_62_characteristic_two_field */
+ {
+ if (!EC_POINT_get_affine_coordinates_GF2m(group,
+ point, X, NULL, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
+ goto err;
+ }
+ }
+#endif
+ if (!BN_nnmod(u1, X, order, ctx))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
+ goto err;
+ }
+ /* if the signature is correct u1 is equal to sig->r */
+ ret = (BN_ucmp(u1, sig->r) == 0);
+err:
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ if (point)
+ EC_POINT_free(point);
+ return ret;
+}
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