/src/openssl111/crypto/ec/ecdsa_ossl.c

Source (jump to first uncovered line)
/*
 * Copyright 2002-2019 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the OpenSSL license (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
 */

#include <string.h>
#include <openssl/err.h>
#include <openssl/obj_mac.h>
#include <openssl/rand.h>
#include "crypto/bn.h"
#include "ec_local.h"

int ossl_ecdsa_sign(int type, const unsigned char *dgst, int dlen,
                    unsigned char *sig, unsigned int *siglen,
                    const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey)
{
    ECDSA_SIG *s;

    s = ECDSA_do_sign_ex(dgst, dlen, kinv, r, eckey);
    if (s == NULL) {
        *siglen = 0;
        return 0;
    }
    *siglen = i2d_ECDSA_SIG(s, &sig);
    ECDSA_SIG_free(s);
    return 1;
}

static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in,
                            BIGNUM **kinvp, BIGNUM **rp,
                            const unsigned char *dgst, int dlen)
{
    BN_CTX *ctx = NULL;
    BIGNUM *k = NULL, *r = NULL, *X = NULL;
    const BIGNUM *order;
    EC_POINT *tmp_point = NULL;
    const EC_GROUP *group;
    int ret = 0;
    int order_bits;
    const BIGNUM *priv_key;

    if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    if ((priv_key = EC_KEY_get0_private_key(eckey)) == NULL) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, EC_R_MISSING_PRIVATE_KEY);
        return 0;
    }

    if (!EC_KEY_can_sign(eckey)) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
        return 0;
    }

    if ((ctx = ctx_in) == NULL) {
        if ((ctx = BN_CTX_new()) == NULL) {
            ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
            return 0;
        }
    }

    k = BN_new();               /* this value is later returned in *kinvp */
    r = BN_new();               /* this value is later returned in *rp */
    X = BN_new();
    if (k == NULL || r == NULL || X == NULL) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    if ((tmp_point = EC_POINT_new(group)) == NULL) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
        goto err;
    }
    order = EC_GROUP_get0_order(group);

    /* Preallocate space */
    order_bits = BN_num_bits(order);
    if (!BN_set_bit(k, order_bits)
        || !BN_set_bit(r, order_bits)
        || !BN_set_bit(X, order_bits))
        goto err;

    do {
        /* get random k */
        do {
            if (dgst != NULL) {
                if (!BN_generate_dsa_nonce(k, order, priv_key,
                                           dgst, dlen, ctx)) {
                    ECerr(EC_F_ECDSA_SIGN_SETUP,
                          EC_R_RANDOM_NUMBER_GENERATION_FAILED);
                    goto err;
                }
            } else {
                if (!BN_priv_rand_range(k, order)) {
                    ECerr(EC_F_ECDSA_SIGN_SETUP,
                          EC_R_RANDOM_NUMBER_GENERATION_FAILED);
                    goto err;
                }
            }
        } while (BN_is_zero(k));

        /* compute r the x-coordinate of generator * k */
        if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx)) {
            ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
            goto err;
        }

        if (!EC_POINT_get_affine_coordinates(group, tmp_point, X, NULL, ctx)) {
            ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
            goto err;
        }

        if (!BN_nnmod(r, X, order, ctx)) {
            ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
            goto err;
        }
    } while (BN_is_zero(r));

    /* compute the inverse of k */
    if (!ec_group_do_inverse_ord(group, k, k, ctx)) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
        goto err;
    }

    /* clear old values if necessary */
    BN_clear_free(*rp);
    BN_clear_free(*kinvp);
    /* save the pre-computed values  */
    *rp = r;
    *kinvp = k;
    ret = 1;
 err:
    if (!ret) {
        BN_clear_free(k);
        BN_clear_free(r);
    }
    if (ctx != ctx_in)
        BN_CTX_free(ctx);
    EC_POINT_free(tmp_point);
    BN_clear_free(X);
    return ret;
}

int ossl_ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
                          BIGNUM **rp)
{
    return ecdsa_sign_setup(eckey, ctx_in, kinvp, rp, NULL, 0);
}

ECDSA_SIG *ossl_ecdsa_sign_sig(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;
    const BIGNUM *order, *ckinv;
    BN_CTX *ctx = NULL;
    const EC_GROUP *group;
    ECDSA_SIG *ret;
    const BIGNUM *priv_key;

    group = EC_KEY_get0_group(eckey);
    priv_key = EC_KEY_get0_private_key(eckey);

    if (group == NULL) {
        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_PASSED_NULL_PARAMETER);
        return NULL;
    }
    if (priv_key == NULL) {
        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_MISSING_PRIVATE_KEY);
        return NULL;
    }

    if (!EC_KEY_can_sign(eckey)) {
        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
        return NULL;
    }

    ret = ECDSA_SIG_new();
    if (ret == NULL) {
        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
        return NULL;
    }
    ret->r = BN_new();
    ret->s = BN_new();
    if (ret->r == NULL || ret->s == NULL) {
        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    s = ret->s;

    if ((ctx = BN_CTX_new()) == NULL
        || (m = BN_new()) == NULL) {
        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    order = EC_GROUP_get0_order(group);
    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)) {
        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, 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))) {
        ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
        goto err;
    }
    do {
        if (in_kinv == NULL || in_r == NULL) {
            if (!ecdsa_sign_setup(eckey, ctx, &kinv, &ret->r, dgst, dgst_len)) {
                ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_ECDSA_LIB);
                goto err;
            }
            ckinv = kinv;
        } else {
            ckinv = in_kinv;
            if (BN_copy(ret->r, in_r) == NULL) {
                ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
                goto err;
            }
        }

        /*
         * With only one multiplicant being in Montgomery domain
         * multiplication yields real result without post-conversion.
         * Also note that all operations but last are performed with
         * zero-padded vectors. Last operation, BN_mod_mul_montgomery
         * below, returns user-visible value with removed zero padding.
         */
        if (!bn_to_mont_fixed_top(s, ret->r, group->mont_data, ctx)
            || !bn_mul_mont_fixed_top(s, s, priv_key, group->mont_data, ctx)) {
            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
            goto err;
        }
        if (!bn_mod_add_fixed_top(s, s, m, order)) {
            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
            goto err;
        }
        /*
         * |s| can still be larger than modulus, because |m| can be. In
         * such case we count on Montgomery reduction to tie it up.
         */
        if (!bn_to_mont_fixed_top(s, s, group->mont_data, ctx)
            || !BN_mod_mul_montgomery(s, s, ckinv, group->mont_data, ctx)) {
            ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
            goto err;
        }

        if (BN_is_zero(s)) {
            /*
             * if kinv and r have been supplied by the caller, don't
             * generate new kinv and r values
             */
            if (in_kinv != NULL && in_r != NULL) {
                ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_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;
    }
    BN_CTX_free(ctx);
    BN_clear_free(m);
    BN_clear_free(kinv);
    return ret;
}

/*-
 * returns
 *      1: correct signature
 *      0: incorrect signature
 *     -1: error
 */
int ossl_ecdsa_verify(int type, const unsigned char *dgst, int dgst_len,
                      const unsigned char *sigbuf, int sig_len, EC_KEY *eckey)
{
    ECDSA_SIG *s;
    const unsigned char *p = sigbuf;
    unsigned char *der = NULL;
    int derlen = -1;
    int ret = -1;

    s = ECDSA_SIG_new();
    if (s == NULL)
        return ret;
    if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL)
        goto err;
    /* Ensure signature uses DER and doesn't have trailing garbage */
    derlen = i2d_ECDSA_SIG(s, &der);
    if (derlen != sig_len || memcmp(sigbuf, der, derlen) != 0)
        goto err;
    ret = ECDSA_do_verify(dgst, dgst_len, s, eckey);
 err:
    OPENSSL_free(der);
    ECDSA_SIG_free(s);
    return ret;
}

int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
                          const ECDSA_SIG *sig, EC_KEY *eckey)
{
    int ret = -1, i;
    BN_CTX *ctx;
    const BIGNUM *order;
    BIGNUM *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) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_MISSING_PARAMETERS);
        return -1;
    }

    if (!EC_KEY_can_sign(eckey)) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
        return -1;
    }

    ctx = BN_CTX_new();
    if (ctx == NULL) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
        return -1;
    }
    BN_CTX_start(ctx);
    u1 = BN_CTX_get(ctx);
    u2 = BN_CTX_get(ctx);
    m = BN_CTX_get(ctx);
    X = BN_CTX_get(ctx);
    if (X == NULL) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
        goto err;
    }

    order = EC_GROUP_get0_order(group);
    if (order == NULL) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, 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) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_BAD_SIGNATURE);
        ret = 0;                /* signature is invalid */
        goto err;
    }
    /* calculate tmp1 = inv(S) mod order */
    if (!ec_group_do_inverse_ord(group, u2, sig->s, ctx)) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, 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)) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, 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))) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
        goto err;
    }
    /* u1 = m * tmp mod order */
    if (!BN_mod_mul(u1, m, u2, order, ctx)) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
        goto err;
    }
    /* u2 = r * w mod q */
    if (!BN_mod_mul(u2, sig->r, u2, order, ctx)) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
        goto err;
    }

    if ((point = EC_POINT_new(group)) == NULL) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx)) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
        goto err;
    }

    if (!EC_POINT_get_affine_coordinates(group, point, X, NULL, ctx)) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
        goto err;
    }

    if (!BN_nnmod(u1, X, order, ctx)) {
        ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, 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);
    EC_POINT_free(point);
    return ret;
}

Coverage Report

Created: 2023-09-25 06:42

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 2002-2019 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the OpenSSL license (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9
10		#include <string.h>
11		#include <openssl/err.h>
12		#include <openssl/obj_mac.h>
13		#include <openssl/rand.h>
14		#include "crypto/bn.h"
15		#include "ec_local.h"
16
17		int ossl_ecdsa_sign(int type, const unsigned char *dgst, int dlen,
18		unsigned char sig, unsigned int siglen,
19		const BIGNUM kinv, const BIGNUM r, EC_KEY *eckey)
20	0	{
21	0	ECDSA_SIG *s;
22
23	0	s = ECDSA_do_sign_ex(dgst, dlen, kinv, r, eckey);
24	0	if (s == NULL) {
25	0	*siglen = 0;
26	0	return 0;
27	0	}
28	0	*siglen = i2d_ECDSA_SIG(s, &sig);
29	0	ECDSA_SIG_free(s);
30	0	return 1;
31	0	}
32
33		static int ecdsa_sign_setup(EC_KEY eckey, BN_CTX ctx_in,
34		BIGNUM kinvp, BIGNUM rp,
35		const unsigned char *dgst, int dlen)
36	0	{
37	0	BN_CTX *ctx = NULL;
38	0	BIGNUM k = NULL, r = NULL, *X = NULL;
39	0	const BIGNUM *order;
40	0	EC_POINT *tmp_point = NULL;
41	0	const EC_GROUP *group;
42	0	int ret = 0;
43	0	int order_bits;
44	0	const BIGNUM *priv_key;
45
46	0	if (eckey == NULL \|\| (group = EC_KEY_get0_group(eckey)) == NULL) {
47	0	ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
48	0	return 0;
49	0	}
50	0	if ((priv_key = EC_KEY_get0_private_key(eckey)) == NULL) {
51	0	ECerr(EC_F_ECDSA_SIGN_SETUP, EC_R_MISSING_PRIVATE_KEY);
52	0	return 0;
53	0	}
54
55	0	if (!EC_KEY_can_sign(eckey)) {
56	0	ECerr(EC_F_ECDSA_SIGN_SETUP, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
57	0	return 0;
58	0	}
59
60	0	if ((ctx = ctx_in) == NULL) {
61	0	if ((ctx = BN_CTX_new()) == NULL) {
62	0	ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
63	0	return 0;
64	0	}
65	0	}
66
67	0	k = BN_new(); /* this value is later returned in kinvp /
68	0	r = BN_new(); /* this value is later returned in rp /
69	0	X = BN_new();
70	0	if (k == NULL \|\| r == NULL \|\| X == NULL) {
71	0	ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
72	0	goto err;
73	0	}
74	0	if ((tmp_point = EC_POINT_new(group)) == NULL) {
75	0	ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
76	0	goto err;
77	0	}
78	0	order = EC_GROUP_get0_order(group);
79
80		/* Preallocate space */
81	0	order_bits = BN_num_bits(order);
82	0	if (!BN_set_bit(k, order_bits)
83	0	\|\| !BN_set_bit(r, order_bits)
84	0	\|\| !BN_set_bit(X, order_bits))
85	0	goto err;
86
87	0	do {
88		/* get random k */
89	0	do {
90	0	if (dgst != NULL) {
91	0	if (!BN_generate_dsa_nonce(k, order, priv_key,
92	0	dgst, dlen, ctx)) {
93	0	ECerr(EC_F_ECDSA_SIGN_SETUP,
94	0	EC_R_RANDOM_NUMBER_GENERATION_FAILED);
95	0	goto err;
96	0	}
97	0	} else {
98	0	if (!BN_priv_rand_range(k, order)) {
99	0	ECerr(EC_F_ECDSA_SIGN_SETUP,
100	0	EC_R_RANDOM_NUMBER_GENERATION_FAILED);
101	0	goto err;
102	0	}
103	0	}
104	0	} while (BN_is_zero(k));
105
106		/* compute r the x-coordinate of generator * k */
107	0	if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx)) {
108	0	ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
109	0	goto err;
110	0	}
111
112	0	if (!EC_POINT_get_affine_coordinates(group, tmp_point, X, NULL, ctx)) {
113	0	ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
114	0	goto err;
115	0	}
116
117	0	if (!BN_nnmod(r, X, order, ctx)) {
118	0	ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
119	0	goto err;
120	0	}
121	0	} while (BN_is_zero(r));
122
123		/* compute the inverse of k */
124	0	if (!ec_group_do_inverse_ord(group, k, k, ctx)) {
125	0	ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
126	0	goto err;
127	0	}
128
129		/* clear old values if necessary */
130	0	BN_clear_free(*rp);
131	0	BN_clear_free(*kinvp);
132		/* save the pre-computed values */
133	0	*rp = r;
134	0	*kinvp = k;
135	0	ret = 1;
136	0	err:
137	0	if (!ret) {
138	0	BN_clear_free(k);
139	0	BN_clear_free(r);
140	0	}
141	0	if (ctx != ctx_in)
142	0	BN_CTX_free(ctx);
143	0	EC_POINT_free(tmp_point);
144	0	BN_clear_free(X);
145	0	return ret;
146	0	}
147
148		int ossl_ecdsa_sign_setup(EC_KEY eckey, BN_CTX ctx_in, BIGNUM **kinvp,
149		BIGNUM **rp)
150	0	{
151	0	return ecdsa_sign_setup(eckey, ctx_in, kinvp, rp, NULL, 0);
152	0	}
153
154		ECDSA_SIG ossl_ecdsa_sign_sig(const unsigned char dgst, int dgst_len,
155		const BIGNUM in_kinv, const BIGNUM in_r,
156		EC_KEY *eckey)
157	0	{
158	0	int ok = 0, i;
159	0	BIGNUM kinv = NULL, s, *m = NULL;
160	0	const BIGNUM order, ckinv;
161	0	BN_CTX *ctx = NULL;
162	0	const EC_GROUP *group;
163	0	ECDSA_SIG *ret;
164	0	const BIGNUM *priv_key;
165
166	0	group = EC_KEY_get0_group(eckey);
167	0	priv_key = EC_KEY_get0_private_key(eckey);
168
169	0	if (group == NULL) {
170	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_PASSED_NULL_PARAMETER);
171	0	return NULL;
172	0	}
173	0	if (priv_key == NULL) {
174	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_MISSING_PRIVATE_KEY);
175	0	return NULL;
176	0	}
177
178	0	if (!EC_KEY_can_sign(eckey)) {
179	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
180	0	return NULL;
181	0	}
182
183	0	ret = ECDSA_SIG_new();
184	0	if (ret == NULL) {
185	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
186	0	return NULL;
187	0	}
188	0	ret->r = BN_new();
189	0	ret->s = BN_new();
190	0	if (ret->r == NULL \|\| ret->s == NULL) {
191	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
192	0	goto err;
193	0	}
194	0	s = ret->s;
195
196	0	if ((ctx = BN_CTX_new()) == NULL
197	0	\|\| (m = BN_new()) == NULL) {
198	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
199	0	goto err;
200	0	}
201
202	0	order = EC_GROUP_get0_order(group);
203	0	i = BN_num_bits(order);
204		/*
205		* Need to truncate digest if it is too long: first truncate whole bytes.
206		*/
207	0	if (8 * dgst_len > i)
208	0	dgst_len = (i + 7) / 8;
209	0	if (!BN_bin2bn(dgst, dgst_len, m)) {
210	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
211	0	goto err;
212	0	}
213		/* If still too long, truncate remaining bits with a shift */
214	0	if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7))) {
215	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
216	0	goto err;
217	0	}
218	0	do {
219	0	if (in_kinv == NULL \|\| in_r == NULL) {
220	0	if (!ecdsa_sign_setup(eckey, ctx, &kinv, &ret->r, dgst, dgst_len)) {
221	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_ECDSA_LIB);
222	0	goto err;
223	0	}
224	0	ckinv = kinv;
225	0	} else {
226	0	ckinv = in_kinv;
227	0	if (BN_copy(ret->r, in_r) == NULL) {
228	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
229	0	goto err;
230	0	}
231	0	}
232
233		/*
234		* With only one multiplicant being in Montgomery domain
235		* multiplication yields real result without post-conversion.
236		* Also note that all operations but last are performed with
237		* zero-padded vectors. Last operation, BN_mod_mul_montgomery
238		* below, returns user-visible value with removed zero padding.
239		*/
240	0	if (!bn_to_mont_fixed_top(s, ret->r, group->mont_data, ctx)
241	0	\|\| !bn_mul_mont_fixed_top(s, s, priv_key, group->mont_data, ctx)) {
242	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
243	0	goto err;
244	0	}
245	0	if (!bn_mod_add_fixed_top(s, s, m, order)) {
246	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
247	0	goto err;
248	0	}
249		/*
250		* \|s\| can still be larger than modulus, because \|m\| can be. In
251		* such case we count on Montgomery reduction to tie it up.
252		*/
253	0	if (!bn_to_mont_fixed_top(s, s, group->mont_data, ctx)
254	0	\|\| !BN_mod_mul_montgomery(s, s, ckinv, group->mont_data, ctx)) {
255	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
256	0	goto err;
257	0	}
258
259	0	if (BN_is_zero(s)) {
260		/*
261		* if kinv and r have been supplied by the caller, don't
262		* generate new kinv and r values
263		*/
264	0	if (in_kinv != NULL && in_r != NULL) {
265	0	ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_NEED_NEW_SETUP_VALUES);
266	0	goto err;
267	0	}
268	0	} else {
269		/* s != 0 => we have a valid signature */
270	0	break;
271	0	}
272	0	} while (1);
273
274	0	ok = 1;
275	0	err:
276	0	if (!ok) {
277	0	ECDSA_SIG_free(ret);
278	0	ret = NULL;
279	0	}
280	0	BN_CTX_free(ctx);
281	0	BN_clear_free(m);
282	0	BN_clear_free(kinv);
283	0	return ret;
284	0	}
285
286		/*-
287		* returns
288		* 1: correct signature
289		* 0: incorrect signature
290		* -1: error
291		*/
292		int ossl_ecdsa_verify(int type, const unsigned char *dgst, int dgst_len,
293		const unsigned char sigbuf, int sig_len, EC_KEY eckey)
294	0	{
295	0	ECDSA_SIG *s;
296	0	const unsigned char *p = sigbuf;
297	0	unsigned char *der = NULL;
298	0	int derlen = -1;
299	0	int ret = -1;
300
301	0	s = ECDSA_SIG_new();
302	0	if (s == NULL)
303	0	return ret;
304	0	if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL)
305	0	goto err;
306		/* Ensure signature uses DER and doesn't have trailing garbage */
307	0	derlen = i2d_ECDSA_SIG(s, &der);
308	0	if (derlen != sig_len \|\| memcmp(sigbuf, der, derlen) != 0)
309	0	goto err;
310	0	ret = ECDSA_do_verify(dgst, dgst_len, s, eckey);
311	0	err:
312	0	OPENSSL_free(der);
313	0	ECDSA_SIG_free(s);
314	0	return ret;
315	0	}
316
317		int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
318		const ECDSA_SIG sig, EC_KEY eckey)
319	0	{
320	0	int ret = -1, i;
321	0	BN_CTX *ctx;
322	0	const BIGNUM *order;
323	0	BIGNUM u1, u2, m, X;
324	0	EC_POINT *point = NULL;
325	0	const EC_GROUP *group;
326	0	const EC_POINT *pub_key;
327
328		/* check input values */
329	0	if (eckey == NULL \|\| (group = EC_KEY_get0_group(eckey)) == NULL \|\|
330	0	(pub_key = EC_KEY_get0_public_key(eckey)) == NULL \|\| sig == NULL) {
331	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_MISSING_PARAMETERS);
332	0	return -1;
333	0	}
334
335	0	if (!EC_KEY_can_sign(eckey)) {
336	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
337	0	return -1;
338	0	}
339
340	0	ctx = BN_CTX_new();
341	0	if (ctx == NULL) {
342	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
343	0	return -1;
344	0	}
345	0	BN_CTX_start(ctx);
346	0	u1 = BN_CTX_get(ctx);
347	0	u2 = BN_CTX_get(ctx);
348	0	m = BN_CTX_get(ctx);
349	0	X = BN_CTX_get(ctx);
350	0	if (X == NULL) {
351	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
352	0	goto err;
353	0	}
354
355	0	order = EC_GROUP_get0_order(group);
356	0	if (order == NULL) {
357	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
358	0	goto err;
359	0	}
360
361	0	if (BN_is_zero(sig->r) \|\| BN_is_negative(sig->r) \|\|
362	0	BN_ucmp(sig->r, order) >= 0 \|\| BN_is_zero(sig->s) \|\|
363	0	BN_is_negative(sig->s) \|\| BN_ucmp(sig->s, order) >= 0) {
364	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_BAD_SIGNATURE);
365	0	ret = 0; /* signature is invalid */
366	0	goto err;
367	0	}
368		/* calculate tmp1 = inv(S) mod order */
369	0	if (!ec_group_do_inverse_ord(group, u2, sig->s, ctx)) {
370	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
371	0	goto err;
372	0	}
373		/* digest -> m */
374	0	i = BN_num_bits(order);
375		/*
376		* Need to truncate digest if it is too long: first truncate whole bytes.
377		*/
378	0	if (8 * dgst_len > i)
379	0	dgst_len = (i + 7) / 8;
380	0	if (!BN_bin2bn(dgst, dgst_len, m)) {
381	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
382	0	goto err;
383	0	}
384		/* If still too long truncate remaining bits with a shift */
385	0	if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7))) {
386	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
387	0	goto err;
388	0	}
389		/* u1 = m * tmp mod order */
390	0	if (!BN_mod_mul(u1, m, u2, order, ctx)) {
391	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
392	0	goto err;
393	0	}
394		/* u2 = r * w mod q */
395	0	if (!BN_mod_mul(u2, sig->r, u2, order, ctx)) {
396	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
397	0	goto err;
398	0	}
399
400	0	if ((point = EC_POINT_new(group)) == NULL) {
401	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
402	0	goto err;
403	0	}
404	0	if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx)) {
405	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
406	0	goto err;
407	0	}
408
409	0	if (!EC_POINT_get_affine_coordinates(group, point, X, NULL, ctx)) {
410	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
411	0	goto err;
412	0	}
413
414	0	if (!BN_nnmod(u1, X, order, ctx)) {
415	0	ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
416	0	goto err;
417	0	}
418		/* if the signature is correct u1 is equal to sig->r */
419	0	ret = (BN_ucmp(u1, sig->r) == 0);
420	0	err:
421	0	BN_CTX_end(ctx);
422	0	BN_CTX_free(ctx);
423	0	EC_POINT_free(point);
424	0	return ret;
425	0	}