1 /*
2 * Copyright 2002-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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 /*
11 * ECDSA low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include "ec_local.h"
17 #include <openssl/err.h>
18
EC_GROUP_check_named_curve(const EC_GROUP * group,int nist_only,BN_CTX * ctx)19 int EC_GROUP_check_named_curve(const EC_GROUP *group, int nist_only,
20 BN_CTX *ctx)
21 {
22 int nid;
23 BN_CTX *new_ctx = NULL;
24
25 if (group == NULL) {
26 ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER);
27 return NID_undef;
28 }
29
30 if (ctx == NULL) {
31 ctx = new_ctx = BN_CTX_new_ex(NULL);
32 if (ctx == NULL) {
33 ERR_raise(ERR_LIB_EC, ERR_R_BN_LIB);
34 return NID_undef;
35 }
36 }
37
38 nid = ossl_ec_curve_nid_from_params(group, ctx);
39 if (nid > 0 && nist_only && EC_curve_nid2nist(nid) == NULL)
40 nid = NID_undef;
41
42 BN_CTX_free(new_ctx);
43 return nid;
44 }
45
EC_GROUP_check(const EC_GROUP * group,BN_CTX * ctx)46 int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx)
47 {
48 #ifdef FIPS_MODULE
49 /*
50 * ECC domain parameter validation.
51 * See SP800-56A R3 5.5.2 "Assurances of Domain-Parameter Validity" Part 1b.
52 */
53 return EC_GROUP_check_named_curve(group, 1, ctx) >= 0 ? 1 : 0;
54 #else
55 int ret = 0;
56 const BIGNUM *order;
57 BN_CTX *new_ctx = NULL;
58 EC_POINT *point = NULL;
59
60 if (group == NULL || group->meth == NULL) {
61 ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER);
62 return 0;
63 }
64
65 /* Custom curves assumed to be correct */
66 if ((group->meth->flags & EC_FLAGS_CUSTOM_CURVE) != 0)
67 return 1;
68
69 if (ctx == NULL) {
70 ctx = new_ctx = BN_CTX_new();
71 if (ctx == NULL) {
72 ERR_raise(ERR_LIB_EC, ERR_R_BN_LIB);
73 goto err;
74 }
75 }
76
77 /* check the discriminant */
78 if (!EC_GROUP_check_discriminant(group, ctx)) {
79 ERR_raise(ERR_LIB_EC, EC_R_DISCRIMINANT_IS_ZERO);
80 goto err;
81 }
82
83 /* check the generator */
84 if (group->generator == NULL) {
85 ERR_raise(ERR_LIB_EC, EC_R_UNDEFINED_GENERATOR);
86 goto err;
87 }
88 if (EC_POINT_is_on_curve(group, group->generator, ctx) <= 0) {
89 ERR_raise(ERR_LIB_EC, EC_R_POINT_IS_NOT_ON_CURVE);
90 goto err;
91 }
92
93 /* check the order of the generator */
94 if ((point = EC_POINT_new(group)) == NULL)
95 goto err;
96 order = EC_GROUP_get0_order(group);
97 if (order == NULL)
98 goto err;
99 if (BN_is_zero(order)) {
100 ERR_raise(ERR_LIB_EC, EC_R_UNDEFINED_ORDER);
101 goto err;
102 }
103
104 if (!EC_POINT_mul(group, point, order, NULL, NULL, ctx))
105 goto err;
106 if (!EC_POINT_is_at_infinity(group, point)) {
107 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GROUP_ORDER);
108 goto err;
109 }
110
111 ret = 1;
112
113 err:
114 BN_CTX_free(new_ctx);
115 EC_POINT_free(point);
116 return ret;
117 #endif /* FIPS_MODULE */
118 }
119
