/* * Copyright 2002-2019 The OpenSSL Project Authors. All Rights Reserved. * Copyright (c) 2002, Oracle and/or its affiliates. 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 */ #include "internal/cryptlib.h" #include #include "ec_lcl.h" #include "internal/refcount.h" #include #include #ifndef FIPS_MODE EC_KEY *EC_KEY_new(void) { return ec_key_new_method_int(NULL, NULL); } #endif EC_KEY *EC_KEY_new_ex(OPENSSL_CTX *ctx) { return ec_key_new_method_int(ctx, NULL); } EC_KEY *EC_KEY_new_by_curve_name_ex(OPENSSL_CTX *ctx, int nid) { EC_KEY *ret = EC_KEY_new_ex(ctx); if (ret == NULL) return NULL; ret->group = EC_GROUP_new_by_curve_name_ex(ctx, nid); if (ret->group == NULL) { EC_KEY_free(ret); return NULL; } if (ret->meth->set_group != NULL && ret->meth->set_group(ret, ret->group) == 0) { EC_KEY_free(ret); return NULL; } return ret; } #ifndef FIPS_MODE EC_KEY *EC_KEY_new_by_curve_name(int nid) { return EC_KEY_new_by_curve_name_ex(NULL, nid); } #endif void EC_KEY_free(EC_KEY *r) { int i; if (r == NULL) return; CRYPTO_DOWN_REF(&r->references, &i, r->lock); REF_PRINT_COUNT("EC_KEY", r); if (i > 0) return; REF_ASSERT_ISNT(i < 0); if (r->meth != NULL && r->meth->finish != NULL) r->meth->finish(r); #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODE) ENGINE_finish(r->engine); #endif if (r->group && r->group->meth->keyfinish) r->group->meth->keyfinish(r); #ifndef FIPS_MODE CRYPTO_free_ex_data(CRYPTO_EX_INDEX_EC_KEY, r, &r->ex_data); #endif CRYPTO_THREAD_lock_free(r->lock); EC_GROUP_free(r->group); EC_POINT_free(r->pub_key); BN_clear_free(r->priv_key); OPENSSL_clear_free((void *)r, sizeof(EC_KEY)); } EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src) { if (dest == NULL || src == NULL) { ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER); return NULL; } if (src->meth != dest->meth) { if (dest->meth->finish != NULL) dest->meth->finish(dest); if (dest->group && dest->group->meth->keyfinish) dest->group->meth->keyfinish(dest); #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODE) if (ENGINE_finish(dest->engine) == 0) return 0; dest->engine = NULL; #endif } dest->libctx = src->libctx; /* copy the parameters */ if (src->group != NULL) { const EC_METHOD *meth = EC_GROUP_method_of(src->group); /* clear the old group */ EC_GROUP_free(dest->group); dest->group = EC_GROUP_new_ex(src->libctx, meth); if (dest->group == NULL) return NULL; if (!EC_GROUP_copy(dest->group, src->group)) return NULL; /* copy the public key */ if (src->pub_key != NULL) { EC_POINT_free(dest->pub_key); dest->pub_key = EC_POINT_new(src->group); if (dest->pub_key == NULL) return NULL; if (!EC_POINT_copy(dest->pub_key, src->pub_key)) return NULL; } /* copy the private key */ if (src->priv_key != NULL) { if (dest->priv_key == NULL) { dest->priv_key = BN_new(); if (dest->priv_key == NULL) return NULL; } if (!BN_copy(dest->priv_key, src->priv_key)) return NULL; if (src->group->meth->keycopy && src->group->meth->keycopy(dest, src) == 0) return NULL; } } /* copy the rest */ dest->enc_flag = src->enc_flag; dest->conv_form = src->conv_form; dest->version = src->version; dest->flags = src->flags; #ifndef FIPS_MODE if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_EC_KEY, &dest->ex_data, &src->ex_data)) return NULL; #endif if (src->meth != dest->meth) { #if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODE) if (src->engine != NULL && ENGINE_init(src->engine) == 0) return NULL; dest->engine = src->engine; #endif dest->meth = src->meth; } if (src->meth->copy != NULL && src->meth->copy(dest, src) == 0) return NULL; return dest; } EC_KEY *EC_KEY_dup(const EC_KEY *ec_key) { EC_KEY *ret = ec_key_new_method_int(ec_key->libctx, ec_key->engine); if (ret == NULL) return NULL; if (EC_KEY_copy(ret, ec_key) == NULL) { EC_KEY_free(ret); return NULL; } return ret; } int EC_KEY_up_ref(EC_KEY *r) { int i; if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0) return 0; REF_PRINT_COUNT("EC_KEY", r); REF_ASSERT_ISNT(i < 2); return ((i > 1) ? 1 : 0); } ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey) { return eckey->engine; } int EC_KEY_generate_key(EC_KEY *eckey) { if (eckey == NULL || eckey->group == NULL) { ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER); return 0; } if (eckey->meth->keygen != NULL) return eckey->meth->keygen(eckey); ECerr(EC_F_EC_KEY_GENERATE_KEY, EC_R_OPERATION_NOT_SUPPORTED); return 0; } int ossl_ec_key_gen(EC_KEY *eckey) { return eckey->group->meth->keygen(eckey); } /* * ECC Key generation. * See SP800-56AR3 5.6.1.2.2 "Key Pair Generation by Testing Candidates" * * Params: * eckey An EC key object that contains domain params. The generated keypair * is stored in this object. * Returns 1 if the keypair was generated or 0 otherwise. */ int ec_key_simple_generate_key(EC_KEY *eckey) { int ok = 0; BIGNUM *priv_key = NULL; const BIGNUM *order = NULL; EC_POINT *pub_key = NULL; const EC_GROUP *group = eckey->group; BN_CTX *ctx = BN_CTX_secure_new_ex(eckey->libctx); if (ctx == NULL) goto err; if (eckey->priv_key == NULL) { priv_key = BN_secure_new(); if (priv_key == NULL) goto err; } else priv_key = eckey->priv_key; /* * Steps (1-2): Check domain parameters and security strength. * These steps must be done by the user. This would need to be * stated in the security policy. */ order = EC_GROUP_get0_order(group); if (order == NULL) goto err; /* * Steps (3-7): priv_key = DRBG_RAND(order_n_bits) (range [1, n-1]). * Although this is slightly different from the standard, it is effectively * equivalent as it gives an unbiased result ranging from 1..n-1. It is also * faster as the standard needs to retry more often. Also doing * 1 + rand[0..n-2] would effect the way that tests feed dummy entropy into * rand so the simpler backward compatible method has been used here. */ do if (!BN_priv_rand_range_ex(priv_key, order, ctx)) goto err; while (BN_is_zero(priv_key)) ; if (eckey->pub_key == NULL) { pub_key = EC_POINT_new(group); if (pub_key == NULL) goto err; } else pub_key = eckey->pub_key; /* Step (8) : pub_key = priv_key * G (where G is a point on the curve) */ if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx)) goto err; eckey->priv_key = priv_key; eckey->pub_key = pub_key; priv_key = NULL; pub_key = NULL; ok = 1; err: /* Step (9): If there is an error return an invalid keypair. */ if (!ok) { BN_clear(eckey->priv_key); if (eckey->pub_key != NULL) EC_POINT_set_to_infinity(group, eckey->pub_key); } EC_POINT_free(pub_key); BN_clear_free(priv_key); BN_CTX_free(ctx); return ok; } int ec_key_simple_generate_public_key(EC_KEY *eckey) { /* * See SP800-56AR3 5.6.1.2.2: Step (8) * pub_key = priv_key * G (where G is a point on the curve) */ return EC_POINT_mul(eckey->group, eckey->pub_key, eckey->priv_key, NULL, NULL, NULL); } int EC_KEY_check_key(const EC_KEY *eckey) { if (eckey == NULL || eckey->group == NULL || eckey->pub_key == NULL) { ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER); return 0; } if (eckey->group->meth->keycheck == NULL) { ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); return 0; } return eckey->group->meth->keycheck(eckey); } /* * Check the range of the EC public key. * See SP800-56A R3 Section 5.6.2.3.3 (Part 2) * i.e. * - If q = odd prime p: Verify that xQ and yQ are integers in the * interval[0, p - 1], OR * - If q = 2m: Verify that xQ and yQ are bit strings of length m bits. * Returns 1 if the public key has a valid range, otherwise it returns 0. */ static int ec_key_public_range_check(BN_CTX *ctx, const EC_KEY *key) { int ret = 0; BIGNUM *x, *y; BN_CTX_start(ctx); x = BN_CTX_get(ctx); y = BN_CTX_get(ctx); if (y == NULL) goto err; if (!EC_POINT_get_affine_coordinates(key->group, key->pub_key, x, y, ctx)) goto err; if (EC_METHOD_get_field_type(key->group->meth) == NID_X9_62_prime_field) { if (BN_is_negative(x) || BN_cmp(x, key->group->field) >= 0 || BN_is_negative(y) || BN_cmp(y, key->group->field) >= 0) { goto err; } } else { int m = EC_GROUP_get_degree(key->group); if (BN_num_bits(x) > m || BN_num_bits(y) > m) { goto err; } } ret = 1; err: BN_CTX_end(ctx); return ret; } /* * ECC Key validation as specified in SP800-56A R3. * Section 5.6.2.3.3 ECC Full Public-Key Validation * Section 5.6.2.1.2 Owner Assurance of Private-Key Validity * Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency * NOTES: * Before calling this method in fips mode, there should be an assurance that * an approved elliptic-curve group is used. * Returns 1 if the key is valid, otherwise it returns 0. */ int ec_key_simple_check_key(const EC_KEY *eckey) { int ok = 0; BN_CTX *ctx = NULL; const BIGNUM *order = NULL; EC_POINT *point = NULL; if (eckey == NULL || eckey->group == NULL || eckey->pub_key == NULL) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER); return 0; } /* 5.6.2.3.3 (Step 1): Q != infinity */ if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_POINT_AT_INFINITY); goto err; } if ((ctx = BN_CTX_new_ex(eckey->libctx)) == NULL) goto err; if ((point = EC_POINT_new(eckey->group)) == NULL) goto err; /* 5.6.2.3.3 (Step 2) Test if the public key is in range */ if (!ec_key_public_range_check(ctx, eckey)) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_COORDINATES_OUT_OF_RANGE); goto err; } /* 5.6.2.3.3 (Step 3) is the pub_key on the elliptic curve */ if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE); goto err; } order = eckey->group->order; if (BN_is_zero(order)) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_INVALID_GROUP_ORDER); goto err; } /* 5.6.2.3.3 (Step 4) : pub_key * order is the point at infinity. */ if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_EC_LIB); goto err; } if (!EC_POINT_is_at_infinity(eckey->group, point)) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_WRONG_ORDER); goto err; } if (eckey->priv_key != NULL) { /* * 5.6.2.1.2 Owner Assurance of Private-Key Validity * The private key is in the range [1, order-1] */ if (BN_cmp(eckey->priv_key, BN_value_one()) < 0 || BN_cmp(eckey->priv_key, order) >= 0) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_WRONG_ORDER); goto err; } /* * Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency (b) * Check if generator * priv_key = pub_key */ if (!EC_POINT_mul(eckey->group, point, eckey->priv_key, NULL, NULL, ctx)) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_EC_LIB); goto err; } if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) { ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY); goto err; } } ok = 1; err: BN_CTX_free(ctx); EC_POINT_free(point); return ok; } int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, BIGNUM *y) { BN_CTX *ctx = NULL; BIGNUM *tx, *ty; EC_POINT *point = NULL; int ok = 0; if (key == NULL || key->group == NULL || x == NULL || y == NULL) { ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES, ERR_R_PASSED_NULL_PARAMETER); return 0; } ctx = BN_CTX_new_ex(key->libctx); if (ctx == NULL) return 0; BN_CTX_start(ctx); point = EC_POINT_new(key->group); if (point == NULL) goto err; tx = BN_CTX_get(ctx); ty = BN_CTX_get(ctx); if (ty == NULL) goto err; if (!EC_POINT_set_affine_coordinates(key->group, point, x, y, ctx)) goto err; if (!EC_POINT_get_affine_coordinates(key->group, point, tx, ty, ctx)) goto err; /* * Check if retrieved coordinates match originals. The range check is done * inside EC_KEY_check_key(). */ if (BN_cmp(x, tx) || BN_cmp(y, ty)) { ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES, EC_R_COORDINATES_OUT_OF_RANGE); goto err; } if (!EC_KEY_set_public_key(key, point)) goto err; if (EC_KEY_check_key(key) == 0) goto err; ok = 1; err: BN_CTX_end(ctx); BN_CTX_free(ctx); EC_POINT_free(point); return ok; } const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key) { return key->group; } int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group) { if (key->meth->set_group != NULL && key->meth->set_group(key, group) == 0) return 0; EC_GROUP_free(key->group); key->group = EC_GROUP_dup(group); return (key->group == NULL) ? 0 : 1; } const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key) { return key->priv_key; } int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key) { if (key->group == NULL || key->group->meth == NULL) return 0; if (key->group->meth->set_private != NULL && key->group->meth->set_private(key, priv_key) == 0) return 0; if (key->meth->set_private != NULL && key->meth->set_private(key, priv_key) == 0) return 0; BN_clear_free(key->priv_key); key->priv_key = BN_dup(priv_key); return (key->priv_key == NULL) ? 0 : 1; } const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key) { return key->pub_key; } int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key) { if (key->meth->set_public != NULL && key->meth->set_public(key, pub_key) == 0) return 0; EC_POINT_free(key->pub_key); key->pub_key = EC_POINT_dup(pub_key, key->group); return (key->pub_key == NULL) ? 0 : 1; } unsigned int EC_KEY_get_enc_flags(const EC_KEY *key) { return key->enc_flag; } void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags) { key->enc_flag = flags; } point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key) { return key->conv_form; } void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform) { key->conv_form = cform; if (key->group != NULL) EC_GROUP_set_point_conversion_form(key->group, cform); } void EC_KEY_set_asn1_flag(EC_KEY *key, int flag) { if (key->group != NULL) EC_GROUP_set_asn1_flag(key->group, flag); } int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx) { if (key->group == NULL) return 0; return EC_GROUP_precompute_mult(key->group, ctx); } int EC_KEY_get_flags(const EC_KEY *key) { return key->flags; } void EC_KEY_set_flags(EC_KEY *key, int flags) { key->flags |= flags; } void EC_KEY_clear_flags(EC_KEY *key, int flags) { key->flags &= ~flags; } size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form, unsigned char **pbuf, BN_CTX *ctx) { if (key == NULL || key->pub_key == NULL || key->group == NULL) return 0; return EC_POINT_point2buf(key->group, key->pub_key, form, pbuf, ctx); } int EC_KEY_oct2key(EC_KEY *key, const unsigned char *buf, size_t len, BN_CTX *ctx) { if (key == NULL || key->group == NULL) return 0; if (key->pub_key == NULL) key->pub_key = EC_POINT_new(key->group); if (key->pub_key == NULL) return 0; if (EC_POINT_oct2point(key->group, key->pub_key, buf, len, ctx) == 0) return 0; /* * Save the point conversion form. * For non-custom curves the first octet of the buffer (excluding * the last significant bit) contains the point conversion form. * EC_POINT_oct2point() has already performed sanity checking of * the buffer so we know it is valid. */ if ((key->group->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) key->conv_form = (point_conversion_form_t)(buf[0] & ~0x01); return 1; } size_t EC_KEY_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len) { if (eckey->group == NULL || eckey->group->meth == NULL) return 0; if (eckey->group->meth->priv2oct == NULL) { ECerr(EC_F_EC_KEY_PRIV2OCT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); return 0; } return eckey->group->meth->priv2oct(eckey, buf, len); } size_t ec_key_simple_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len) { size_t buf_len; buf_len = (EC_GROUP_order_bits(eckey->group) + 7) / 8; if (eckey->priv_key == NULL) return 0; if (buf == NULL) return buf_len; else if (len < buf_len) return 0; /* Octetstring may need leading zeros if BN is to short */ if (BN_bn2binpad(eckey->priv_key, buf, buf_len) == -1) { ECerr(EC_F_EC_KEY_SIMPLE_PRIV2OCT, EC_R_BUFFER_TOO_SMALL); return 0; } return buf_len; } int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len) { if (eckey->group == NULL || eckey->group->meth == NULL) return 0; if (eckey->group->meth->oct2priv == NULL) { ECerr(EC_F_EC_KEY_OCT2PRIV, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); return 0; } return eckey->group->meth->oct2priv(eckey, buf, len); } int ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len) { if (eckey->priv_key == NULL) eckey->priv_key = BN_secure_new(); if (eckey->priv_key == NULL) { ECerr(EC_F_EC_KEY_SIMPLE_OCT2PRIV, ERR_R_MALLOC_FAILURE); return 0; } eckey->priv_key = BN_bin2bn(buf, len, eckey->priv_key); if (eckey->priv_key == NULL) { ECerr(EC_F_EC_KEY_SIMPLE_OCT2PRIV, ERR_R_BN_LIB); return 0; } return 1; } size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf) { size_t len; unsigned char *buf; len = EC_KEY_priv2oct(eckey, NULL, 0); if (len == 0) return 0; if ((buf = OPENSSL_malloc(len)) == NULL) { ECerr(EC_F_EC_KEY_PRIV2BUF, ERR_R_MALLOC_FAILURE); return 0; } len = EC_KEY_priv2oct(eckey, buf, len); if (len == 0) { OPENSSL_free(buf); return 0; } *pbuf = buf; return len; } int EC_KEY_can_sign(const EC_KEY *eckey) { if (eckey->group == NULL || eckey->group->meth == NULL || (eckey->group->meth->flags & EC_FLAGS_NO_SIGN)) return 0; return 1; }