diff options
Diffstat (limited to 'src/crypto/ecdsa/ecdsa.c')
| -rw-r--r-- | src/crypto/ecdsa/ecdsa.c | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/src/crypto/ecdsa/ecdsa.c b/src/crypto/ecdsa/ecdsa.c new file mode 100644 index 0000000..d389799 --- /dev/null +++ b/src/crypto/ecdsa/ecdsa.c @@ -0,0 +1,496 @@ +/* ==================================================================== + * Copyright (c) 1998-2005 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 <openssl/ecdsa.h> + +#include <string.h> + +#include <openssl/bn.h> +#include <openssl/err.h> +#include <openssl/mem.h> +#include <openssl/thread.h> + +#include "../ec/internal.h" + + +int ECDSA_sign(int type, const uint8_t *digest, size_t digest_len, uint8_t *sig, + unsigned int *sig_len, EC_KEY *eckey) { + if (eckey->ecdsa_meth && eckey->ecdsa_meth->sign) { + return eckey->ecdsa_meth->sign(digest, digest_len, sig, sig_len, eckey); + } + + return ECDSA_sign_ex(type, digest, digest_len, sig, sig_len, NULL, NULL, + eckey); +} + +int ECDSA_verify(int type, const uint8_t *digest, size_t digest_len, + const uint8_t *sig, size_t sig_len, EC_KEY *eckey) { + ECDSA_SIG *s; + int ret = 0; + uint8_t *der = NULL; + + if (eckey->ecdsa_meth && eckey->ecdsa_meth->verify) { + return eckey->ecdsa_meth->verify(digest, digest_len, sig, sig_len, eckey); + } + + s = ECDSA_SIG_new(); + const uint8_t *sigp = sig; + if (s == NULL || d2i_ECDSA_SIG(&s, &sigp, sig_len) == NULL || + sigp != sig + sig_len) { + goto err; + } + + /* Ensure that the signature uses DER and doesn't have trailing garbage. */ + const int der_len = i2d_ECDSA_SIG(s, &der); + if (der_len < 0 || (size_t) der_len != sig_len || memcmp(sig, der, sig_len)) { + goto err; + } + + ret = ECDSA_do_verify(digest, digest_len, s, eckey); + +err: + if (der != NULL) { + OPENSSL_free(der); + } + if (s != NULL) { + ECDSA_SIG_free(s); + } + return ret; +} + +/* digest_to_bn interprets |digest_len| bytes from |digest| as a big-endian + * number and sets |out| to that value. It then truncates |out| so that it's, + * at most, as long as |order|. It returns one on success and zero otherwise. */ +static int digest_to_bn(BIGNUM *out, const uint8_t *digest, size_t digest_len, + const BIGNUM *order) { + size_t num_bits; + + num_bits = BN_num_bits(order); + /* Need to truncate digest if it is too long: first truncate whole + * bytes. */ + if (8 * digest_len > num_bits) { + digest_len = (num_bits + 7) / 8; + } + if (!BN_bin2bn(digest, digest_len, out)) { + OPENSSL_PUT_ERROR(ECDSA, digest_to_bn, ERR_R_BN_LIB); + return 0; + } + + /* If still too long truncate remaining bits with a shift */ + if ((8 * digest_len > num_bits) && + !BN_rshift(out, out, 8 - (num_bits & 0x7))) { + OPENSSL_PUT_ERROR(ECDSA, digest_to_bn, ERR_R_BN_LIB); + return 0; + } + + return 1; +} + +ECDSA_SIG *ECDSA_do_sign(const uint8_t *digest, size_t digest_len, + EC_KEY *key) { + return ECDSA_do_sign_ex(digest, digest_len, NULL, NULL, key); +} + +int ECDSA_do_verify(const uint8_t *digest, size_t digest_len, + const ECDSA_SIG *sig, EC_KEY *eckey) { + int ret = 0; + BN_CTX *ctx; + BIGNUM *order, *u1, *u2, *m, *X; + EC_POINT *point = NULL; + const EC_GROUP *group; + const EC_POINT *pub_key; + + if (eckey->ecdsa_meth && eckey->ecdsa_meth->verify) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ECDSA_R_NOT_IMPLEMENTED); + return 0; + } + + /* check input values */ + if ((group = EC_KEY_get0_group(eckey)) == NULL || + (pub_key = EC_KEY_get0_public_key(eckey)) == NULL || + sig == NULL) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ECDSA_R_MISSING_PARAMETERS); + return 0; + } + + ctx = BN_CTX_new(); + if (!ctx) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_MALLOC_FAILURE); + return 0; + } + 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) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); + goto err; + } + + if (!EC_GROUP_get_order(group, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, 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) { + OPENSSL_PUT_ERROR(ECDSA, 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)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); + goto err; + } + if (!digest_to_bn(m, digest, digest_len, order)) { + goto err; + } + /* u1 = m * tmp mod order */ + if (!BN_mod_mul(u1, m, u2, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); + goto err; + } + /* u2 = r * w mod q */ + if (!BN_mod_mul(u2, sig->r, u2, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_BN_LIB); + goto err; + } + + point = EC_POINT_new(group); + if (point == NULL) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_MALLOC_FAILURE); + goto err; + } + if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_EC_LIB); + goto err; + } + if (!EC_POINT_get_affine_coordinates_GFp(group, point, X, NULL, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_verify, ERR_R_EC_LIB); + goto err; + } + if (!BN_nnmod(u1, X, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, 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; +} + +static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp, + BIGNUM **rp, const uint8_t *digest, + size_t digest_len) { + 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) { + OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_PASSED_NULL_PARAMETER); + return 0; + } + + if (ctx_in == NULL) { + if ((ctx = BN_CTX_new()) == NULL) { + OPENSSL_PUT_ERROR(ECDSA, 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) { + OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_MALLOC_FAILURE); + goto err; + } + tmp_point = EC_POINT_new(group); + if (tmp_point == NULL) { + OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_EC_LIB); + goto err; + } + if (!EC_GROUP_get_order(group, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_EC_LIB); + goto err; + } + + do { + /* If possible, we'll include the private key and message digest in the k + * generation. The |digest| argument is only empty if |ECDSA_sign_setup| is + * being used. */ + do { + int ok; + + if (digest_len > 0) { + ok = BN_generate_dsa_nonce(k, order, EC_KEY_get0_private_key(eckey), + digest, digest_len, ctx); + } else { + ok = BN_rand_range(k, order); + } + if (!ok) { + OPENSSL_PUT_ERROR(ECDSA, 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)) { + OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_EC_LIB); + goto err; + } + if (!EC_POINT_get_affine_coordinates_GFp(group, tmp_point, X, NULL, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ecdsa_sign_setup, ERR_R_EC_LIB); + goto err; + } + + if (!BN_nnmod(r, X, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, 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)) { + OPENSSL_PUT_ERROR(ECDSA, 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; +} + +int ECDSA_sign_setup(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinv, BIGNUM **rp) { + return ecdsa_sign_setup(eckey, ctx, kinv, rp, NULL, 0); +} + +ECDSA_SIG *ECDSA_do_sign_ex(const uint8_t *digest, size_t digest_len, + const BIGNUM *in_kinv, const BIGNUM *in_r, + EC_KEY *eckey) { + int ok = 0; + BIGNUM *kinv = NULL, *s, *m = NULL, *tmp = NULL, *order = NULL; + const BIGNUM *ckinv; + BN_CTX *ctx = NULL; + const EC_GROUP *group; + ECDSA_SIG *ret; + const BIGNUM *priv_key; + + if (eckey->ecdsa_meth && eckey->ecdsa_meth->sign) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ECDSA_R_NOT_IMPLEMENTED); + return NULL; + } + + group = EC_KEY_get0_group(eckey); + priv_key = EC_KEY_get0_private_key(eckey); + + if (group == NULL || priv_key == NULL) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_PASSED_NULL_PARAMETER); + return NULL; + } + + ret = ECDSA_SIG_new(); + if (!ret) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, 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) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_MALLOC_FAILURE); + goto err; + } + + if (!EC_GROUP_get_order(group, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_EC_LIB); + goto err; + } + if (!digest_to_bn(m, digest, digest_len, order)) { + goto err; + } + for (;;) { + if (in_kinv == NULL || in_r == NULL) { + if (!ecdsa_sign_setup(eckey, ctx, &kinv, &ret->r, digest, digest_len)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_ECDSA_LIB); + goto err; + } + ckinv = kinv; + } else { + ckinv = in_kinv; + if (BN_copy(ret->r, in_r) == NULL) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_MALLOC_FAILURE); + goto err; + } + } + + if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_BN_LIB); + goto err; + } + if (!BN_mod_add_quick(s, tmp, m, order)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ERR_R_BN_LIB); + goto err; + } + if (!BN_mod_mul(s, s, ckinv, order, ctx)) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, 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) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_do_sign_ex, ECDSA_R_NEED_NEW_SETUP_VALUES); + goto err; + } + } else { + /* s != 0 => we have a valid signature */ + break; + } + } + + 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; +} + +int ECDSA_sign_ex(int type, const uint8_t *digest, size_t digest_len, + uint8_t *sig, unsigned int *sig_len, const BIGNUM *kinv, + const BIGNUM *r, EC_KEY *eckey) { + ECDSA_SIG *s = NULL; + + if (eckey->ecdsa_meth && eckey->ecdsa_meth->sign) { + OPENSSL_PUT_ERROR(ECDSA, ECDSA_sign_ex, ECDSA_R_NOT_IMPLEMENTED); + *sig_len = 0; + return 0; + } + + s = ECDSA_do_sign_ex(digest, digest_len, kinv, r, eckey); + if (s == NULL) { + *sig_len = 0; + return 0; + } + *sig_len = i2d_ECDSA_SIG(s, &sig); + ECDSA_SIG_free(s); + return 1; +} |