1 | /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL |
2 | * project 2006. |
3 | */ |
4 | /* ==================================================================== |
5 | * Copyright (c) 2006 The OpenSSL Project. All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * |
11 | * 1. Redistributions of source code must retain the above copyright |
12 | * notice, this list of conditions and the following disclaimer. |
13 | * |
14 | * 2. Redistributions in binary form must reproduce the above copyright |
15 | * notice, this list of conditions and the following disclaimer in |
16 | * the documentation and/or other materials provided with the |
17 | * distribution. |
18 | * |
19 | * 3. All advertising materials mentioning features or use of this |
20 | * software must display the following acknowledgment: |
21 | * "This product includes software developed by the OpenSSL Project |
22 | * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" |
23 | * |
24 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
25 | * endorse or promote products derived from this software without |
26 | * prior written permission. For written permission, please contact |
27 | * licensing@OpenSSL.org. |
28 | * |
29 | * 5. Products derived from this software may not be called "OpenSSL" |
30 | * nor may "OpenSSL" appear in their names without prior written |
31 | * permission of the OpenSSL Project. |
32 | * |
33 | * 6. Redistributions of any form whatsoever must retain the following |
34 | * acknowledgment: |
35 | * "This product includes software developed by the OpenSSL Project |
36 | * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" |
37 | * |
38 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
39 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
40 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
41 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
42 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
43 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
44 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
45 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
46 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
47 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
48 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
49 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
50 | * ==================================================================== |
51 | * |
52 | * This product includes cryptographic software written by Eric Young |
53 | * (eay@cryptsoft.com). This product includes software written by Tim |
54 | * Hudson (tjh@cryptsoft.com). */ |
55 | |
56 | #include <openssl/evp.h> |
57 | |
58 | #include <openssl/bn.h> |
59 | #include <openssl/bytestring.h> |
60 | #include <openssl/ec.h> |
61 | #include <openssl/ec_key.h> |
62 | #include <openssl/ecdsa.h> |
63 | #include <openssl/err.h> |
64 | |
65 | #include "internal.h" |
66 | |
67 | |
68 | static int eckey_pub_encode(CBB *out, const EVP_PKEY *key) { |
69 | const EC_KEY *ec_key = key->pkey.ec; |
70 | const EC_GROUP *group = EC_KEY_get0_group(ec_key); |
71 | const EC_POINT *public_key = EC_KEY_get0_public_key(ec_key); |
72 | |
73 | // See RFC 5480, section 2. |
74 | CBB spki, algorithm, oid, key_bitstring; |
75 | if (!CBB_add_asn1(out, &spki, CBS_ASN1_SEQUENCE) || |
76 | !CBB_add_asn1(&spki, &algorithm, CBS_ASN1_SEQUENCE) || |
77 | !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) || |
78 | !CBB_add_bytes(&oid, ec_asn1_meth.oid, ec_asn1_meth.oid_len) || |
79 | !EC_KEY_marshal_curve_name(&algorithm, group) || |
80 | !CBB_add_asn1(&spki, &key_bitstring, CBS_ASN1_BITSTRING) || |
81 | !CBB_add_u8(&key_bitstring, 0 /* padding */) || |
82 | !EC_POINT_point2cbb(&key_bitstring, group, public_key, |
83 | POINT_CONVERSION_UNCOMPRESSED, NULL) || |
84 | !CBB_flush(out)) { |
85 | OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR); |
86 | return 0; |
87 | } |
88 | |
89 | return 1; |
90 | } |
91 | |
92 | static int eckey_pub_decode(EVP_PKEY *out, CBS *params, CBS *key) { |
93 | // See RFC 5480, section 2. |
94 | |
95 | // The parameters are a named curve. |
96 | EC_POINT *point = NULL; |
97 | EC_KEY *eckey = NULL; |
98 | EC_GROUP *group = EC_KEY_parse_curve_name(params); |
99 | if (group == NULL || CBS_len(params) != 0) { |
100 | OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR); |
101 | goto err; |
102 | } |
103 | |
104 | eckey = EC_KEY_new(); |
105 | if (eckey == NULL || !EC_KEY_set_group(eckey, group)) { |
106 | goto err; |
107 | } |
108 | |
109 | point = EC_POINT_new(group); |
110 | if (point == NULL || |
111 | !EC_POINT_oct2point(group, point, CBS_data(key), CBS_len(key), NULL) || |
112 | !EC_KEY_set_public_key(eckey, point)) { |
113 | goto err; |
114 | } |
115 | |
116 | EC_GROUP_free(group); |
117 | EC_POINT_free(point); |
118 | EVP_PKEY_assign_EC_KEY(out, eckey); |
119 | return 1; |
120 | |
121 | err: |
122 | EC_GROUP_free(group); |
123 | EC_POINT_free(point); |
124 | EC_KEY_free(eckey); |
125 | return 0; |
126 | } |
127 | |
128 | static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b) { |
129 | int r; |
130 | const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec); |
131 | const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec), |
132 | *pb = EC_KEY_get0_public_key(b->pkey.ec); |
133 | r = EC_POINT_cmp(group, pa, pb, NULL); |
134 | if (r == 0) { |
135 | return 1; |
136 | } else if (r == 1) { |
137 | return 0; |
138 | } else { |
139 | return -2; |
140 | } |
141 | } |
142 | |
143 | static int eckey_priv_decode(EVP_PKEY *out, CBS *params, CBS *key) { |
144 | // See RFC 5915. |
145 | EC_GROUP *group = EC_KEY_parse_parameters(params); |
146 | if (group == NULL || CBS_len(params) != 0) { |
147 | OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR); |
148 | EC_GROUP_free(group); |
149 | return 0; |
150 | } |
151 | |
152 | EC_KEY *ec_key = EC_KEY_parse_private_key(key, group); |
153 | EC_GROUP_free(group); |
154 | if (ec_key == NULL || CBS_len(key) != 0) { |
155 | OPENSSL_PUT_ERROR(EVP, EVP_R_DECODE_ERROR); |
156 | EC_KEY_free(ec_key); |
157 | return 0; |
158 | } |
159 | |
160 | EVP_PKEY_assign_EC_KEY(out, ec_key); |
161 | return 1; |
162 | } |
163 | |
164 | static int eckey_priv_encode(CBB *out, const EVP_PKEY *key) { |
165 | const EC_KEY *ec_key = key->pkey.ec; |
166 | |
167 | // Omit the redundant copy of the curve name. This contradicts RFC 5915 but |
168 | // aligns with PKCS #11. SEC 1 only says they may be omitted if known by other |
169 | // means. Both OpenSSL and NSS omit the redundant parameters, so we omit them |
170 | // as well. |
171 | unsigned enc_flags = EC_KEY_get_enc_flags(ec_key) | EC_PKEY_NO_PARAMETERS; |
172 | |
173 | // See RFC 5915. |
174 | CBB pkcs8, algorithm, oid, private_key; |
175 | if (!CBB_add_asn1(out, &pkcs8, CBS_ASN1_SEQUENCE) || |
176 | !CBB_add_asn1_uint64(&pkcs8, 0 /* version */) || |
177 | !CBB_add_asn1(&pkcs8, &algorithm, CBS_ASN1_SEQUENCE) || |
178 | !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT) || |
179 | !CBB_add_bytes(&oid, ec_asn1_meth.oid, ec_asn1_meth.oid_len) || |
180 | !EC_KEY_marshal_curve_name(&algorithm, EC_KEY_get0_group(ec_key)) || |
181 | !CBB_add_asn1(&pkcs8, &private_key, CBS_ASN1_OCTETSTRING) || |
182 | !EC_KEY_marshal_private_key(&private_key, ec_key, enc_flags) || |
183 | !CBB_flush(out)) { |
184 | OPENSSL_PUT_ERROR(EVP, EVP_R_ENCODE_ERROR); |
185 | return 0; |
186 | } |
187 | |
188 | return 1; |
189 | } |
190 | |
191 | static int int_ec_size(const EVP_PKEY *pkey) { |
192 | return ECDSA_size(pkey->pkey.ec); |
193 | } |
194 | |
195 | static int ec_bits(const EVP_PKEY *pkey) { |
196 | const EC_GROUP *group = EC_KEY_get0_group(pkey->pkey.ec); |
197 | if (group == NULL) { |
198 | ERR_clear_error(); |
199 | return 0; |
200 | } |
201 | return BN_num_bits(EC_GROUP_get0_order(group)); |
202 | } |
203 | |
204 | static int ec_missing_parameters(const EVP_PKEY *pkey) { |
205 | return EC_KEY_get0_group(pkey->pkey.ec) == NULL; |
206 | } |
207 | |
208 | static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from) { |
209 | return EC_KEY_set_group(to->pkey.ec, EC_KEY_get0_group(from->pkey.ec)); |
210 | } |
211 | |
212 | static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b) { |
213 | const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec), |
214 | *group_b = EC_KEY_get0_group(b->pkey.ec); |
215 | if (EC_GROUP_cmp(group_a, group_b, NULL) != 0) { |
216 | // mismatch |
217 | return 0; |
218 | } |
219 | return 1; |
220 | } |
221 | |
222 | static void int_ec_free(EVP_PKEY *pkey) { EC_KEY_free(pkey->pkey.ec); } |
223 | |
224 | static int eckey_opaque(const EVP_PKEY *pkey) { |
225 | return EC_KEY_is_opaque(pkey->pkey.ec); |
226 | } |
227 | |
228 | const EVP_PKEY_ASN1_METHOD ec_asn1_meth = { |
229 | EVP_PKEY_EC, |
230 | // 1.2.840.10045.2.1 |
231 | {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01}, 7, |
232 | |
233 | eckey_pub_decode, |
234 | eckey_pub_encode, |
235 | eckey_pub_cmp, |
236 | |
237 | eckey_priv_decode, |
238 | eckey_priv_encode, |
239 | |
240 | NULL /* set_priv_raw */, |
241 | NULL /* set_pub_raw */, |
242 | NULL /* get_priv_raw */, |
243 | NULL /* get_pub_raw */, |
244 | |
245 | eckey_opaque, |
246 | |
247 | int_ec_size, |
248 | ec_bits, |
249 | |
250 | ec_missing_parameters, |
251 | ec_copy_parameters, |
252 | ec_cmp_parameters, |
253 | |
254 | int_ec_free, |
255 | }; |
256 | |