Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Copyright (c) 2022 Yubico AB. All rights reserved. |
3 | | * Use of this source code is governed by a BSD-style |
4 | | * license that can be found in the LICENSE file. |
5 | | */ |
6 | | |
7 | | #include <openssl/bn.h> |
8 | | #include <openssl/ecdsa.h> |
9 | | #include <openssl/obj_mac.h> |
10 | | |
11 | | #include "fido.h" |
12 | | #include "fido/es384.h" |
13 | | |
14 | | #if OPENSSL_VERSION_NUMBER >= 0x30000000 |
15 | | #define get0_EC_KEY(x) EVP_PKEY_get0_EC_KEY((x)) |
16 | | #else |
17 | 12 | #define get0_EC_KEY(x) EVP_PKEY_get0((x)) |
18 | | #endif |
19 | | |
20 | | static int |
21 | | decode_coord(const cbor_item_t *item, void *xy, size_t xy_len) |
22 | 14 | { |
23 | 14 | if (cbor_isa_bytestring(item) == false || |
24 | 14 | cbor_bytestring_is_definite(item) == false || |
25 | 14 | cbor_bytestring_length(item) != xy_len) { |
26 | 0 | fido_log_debug("%s: cbor type", __func__); |
27 | 0 | return (-1); |
28 | 0 | } |
29 | | |
30 | 14 | memcpy(xy, cbor_bytestring_handle(item), xy_len); |
31 | | |
32 | 14 | return (0); |
33 | 14 | } |
34 | | |
35 | | static int |
36 | | decode_pubkey_point(const cbor_item_t *key, const cbor_item_t *val, void *arg) |
37 | 35 | { |
38 | 35 | es384_pk_t *k = arg; |
39 | | |
40 | 35 | if (cbor_isa_negint(key) == false || |
41 | 35 | cbor_int_get_width(key) != CBOR_INT_8) |
42 | 14 | return (0); /* ignore */ |
43 | | |
44 | 21 | switch (cbor_get_uint8(key)) { |
45 | 7 | case 1: /* x coordinate */ |
46 | 7 | return (decode_coord(val, &k->x, sizeof(k->x))); |
47 | 7 | case 2: /* y coordinate */ |
48 | 7 | return (decode_coord(val, &k->y, sizeof(k->y))); |
49 | 21 | } |
50 | | |
51 | 7 | return (0); /* ignore */ |
52 | 21 | } |
53 | | |
54 | | int |
55 | | es384_pk_decode(const cbor_item_t *item, es384_pk_t *k) |
56 | 9 | { |
57 | 9 | if (cbor_isa_map(item) == false || |
58 | 9 | cbor_map_is_definite(item) == false || |
59 | 9 | cbor_map_iter(item, k, decode_pubkey_point) < 0) { |
60 | 2 | fido_log_debug("%s: cbor type", __func__); |
61 | 2 | return (-1); |
62 | 2 | } |
63 | | |
64 | 7 | return (0); |
65 | 9 | } |
66 | | |
67 | | es384_pk_t * |
68 | | es384_pk_new(void) |
69 | 275 | { |
70 | 275 | return (calloc(1, sizeof(es384_pk_t))); |
71 | 275 | } |
72 | | |
73 | | void |
74 | | es384_pk_free(es384_pk_t **pkp) |
75 | 2.01k | { |
76 | 2.01k | es384_pk_t *pk; |
77 | | |
78 | 2.01k | if (pkp == NULL || (pk = *pkp) == NULL) |
79 | 1.74k | return; |
80 | | |
81 | 273 | freezero(pk, sizeof(*pk)); |
82 | 273 | *pkp = NULL; |
83 | 273 | } |
84 | | |
85 | | int |
86 | | es384_pk_from_ptr(es384_pk_t *pk, const void *ptr, size_t len) |
87 | 261 | { |
88 | 261 | const uint8_t *p = ptr; |
89 | 261 | EVP_PKEY *pkey; |
90 | | |
91 | 261 | if (len < sizeof(*pk)) |
92 | 211 | return (FIDO_ERR_INVALID_ARGUMENT); |
93 | | |
94 | 50 | if (len == sizeof(*pk) + 1 && *p == 0x04) |
95 | 1 | memcpy(pk, ++p, sizeof(*pk)); /* uncompressed format */ |
96 | 49 | else |
97 | 49 | memcpy(pk, ptr, sizeof(*pk)); /* libfido2 x||y format */ |
98 | | |
99 | 50 | if ((pkey = es384_pk_to_EVP_PKEY(pk)) == NULL) { |
100 | 35 | fido_log_debug("%s: es384_pk_to_EVP_PKEY", __func__); |
101 | 35 | explicit_bzero(pk, sizeof(*pk)); |
102 | 35 | return (FIDO_ERR_INVALID_ARGUMENT); |
103 | 35 | } |
104 | | |
105 | 15 | EVP_PKEY_free(pkey); |
106 | | |
107 | 15 | return (FIDO_OK); |
108 | 50 | } |
109 | | |
110 | | EVP_PKEY * |
111 | | es384_pk_to_EVP_PKEY(const es384_pk_t *k) |
112 | 356 | { |
113 | 356 | BN_CTX *bnctx = NULL; |
114 | 356 | EC_KEY *ec = NULL; |
115 | 356 | EC_POINT *q = NULL; |
116 | 356 | EVP_PKEY *pkey = NULL; |
117 | 356 | BIGNUM *x = NULL; |
118 | 356 | BIGNUM *y = NULL; |
119 | 356 | const EC_GROUP *g = NULL; |
120 | 356 | int ok = -1; |
121 | | |
122 | 356 | if ((bnctx = BN_CTX_new()) == NULL) |
123 | 7 | goto fail; |
124 | | |
125 | 349 | BN_CTX_start(bnctx); |
126 | | |
127 | 349 | if ((x = BN_CTX_get(bnctx)) == NULL || |
128 | 349 | (y = BN_CTX_get(bnctx)) == NULL) |
129 | 8 | goto fail; |
130 | | |
131 | 341 | if (BN_bin2bn(k->x, sizeof(k->x), x) == NULL || |
132 | 341 | BN_bin2bn(k->y, sizeof(k->y), y) == NULL) { |
133 | 31 | fido_log_debug("%s: BN_bin2bn", __func__); |
134 | 31 | goto fail; |
135 | 31 | } |
136 | | |
137 | 310 | if ((ec = EC_KEY_new_by_curve_name(NID_secp384r1)) == NULL || |
138 | 310 | (g = EC_KEY_get0_group(ec)) == NULL) { |
139 | 10 | fido_log_debug("%s: EC_KEY init", __func__); |
140 | 10 | goto fail; |
141 | 10 | } |
142 | | |
143 | 300 | if ((q = EC_POINT_new(g)) == NULL || |
144 | 300 | EC_POINT_set_affine_coordinates_GFp(g, q, x, y, bnctx) == 0 || |
145 | 300 | EC_KEY_set_public_key(ec, q) == 0) { |
146 | 267 | fido_log_debug("%s: EC_KEY_set_public_key", __func__); |
147 | 267 | goto fail; |
148 | 267 | } |
149 | | |
150 | 33 | if ((pkey = EVP_PKEY_new()) == NULL || |
151 | 33 | EVP_PKEY_assign_EC_KEY(pkey, ec) == 0) { |
152 | 2 | fido_log_debug("%s: EVP_PKEY_assign_EC_KEY", __func__); |
153 | 2 | goto fail; |
154 | 2 | } |
155 | | |
156 | 31 | ec = NULL; /* at this point, ec belongs to evp */ |
157 | | |
158 | 31 | ok = 0; |
159 | 356 | fail: |
160 | 356 | if (bnctx != NULL) { |
161 | 349 | BN_CTX_end(bnctx); |
162 | 349 | BN_CTX_free(bnctx); |
163 | 349 | } |
164 | | |
165 | 356 | if (ec != NULL) |
166 | 275 | EC_KEY_free(ec); |
167 | 356 | if (q != NULL) |
168 | 295 | EC_POINT_free(q); |
169 | | |
170 | 356 | if (ok < 0 && pkey != NULL) { |
171 | 1 | EVP_PKEY_free(pkey); |
172 | 1 | pkey = NULL; |
173 | 1 | } |
174 | | |
175 | 356 | return (pkey); |
176 | 31 | } |
177 | | |
178 | | int |
179 | | es384_pk_from_EC_KEY(es384_pk_t *pk, const EC_KEY *ec) |
180 | 12 | { |
181 | 12 | BN_CTX *bnctx = NULL; |
182 | 12 | BIGNUM *x = NULL; |
183 | 12 | BIGNUM *y = NULL; |
184 | 12 | const EC_POINT *q = NULL; |
185 | 12 | EC_GROUP *g = NULL; |
186 | 12 | size_t dx; |
187 | 12 | size_t dy; |
188 | 12 | int ok = FIDO_ERR_INTERNAL; |
189 | 12 | int nx; |
190 | 12 | int ny; |
191 | | |
192 | 12 | if ((q = EC_KEY_get0_public_key(ec)) == NULL || |
193 | 12 | (g = EC_GROUP_new_by_curve_name(NID_secp384r1)) == NULL || |
194 | 12 | (bnctx = BN_CTX_new()) == NULL) |
195 | 1 | goto fail; |
196 | | |
197 | 11 | BN_CTX_start(bnctx); |
198 | | |
199 | 11 | if ((x = BN_CTX_get(bnctx)) == NULL || |
200 | 11 | (y = BN_CTX_get(bnctx)) == NULL) |
201 | 2 | goto fail; |
202 | | |
203 | 9 | if (EC_POINT_is_on_curve(g, q, bnctx) != 1) { |
204 | 0 | fido_log_debug("%s: EC_POINT_is_on_curve", __func__); |
205 | 0 | ok = FIDO_ERR_INVALID_ARGUMENT; |
206 | 0 | goto fail; |
207 | 0 | } |
208 | | |
209 | 9 | if (EC_POINT_get_affine_coordinates_GFp(g, q, x, y, bnctx) == 0 || |
210 | 9 | (nx = BN_num_bytes(x)) < 0 || (size_t)nx > sizeof(pk->x) || |
211 | 9 | (ny = BN_num_bytes(y)) < 0 || (size_t)ny > sizeof(pk->y)) { |
212 | 1 | fido_log_debug("%s: EC_POINT_get_affine_coordinates_GFp", |
213 | 1 | __func__); |
214 | 1 | goto fail; |
215 | 1 | } |
216 | | |
217 | 8 | dx = sizeof(pk->x) - (size_t)nx; |
218 | 8 | dy = sizeof(pk->y) - (size_t)ny; |
219 | | |
220 | 8 | if ((nx = BN_bn2bin(x, pk->x + dx)) < 0 || (size_t)nx > sizeof(pk->x) || |
221 | 8 | (ny = BN_bn2bin(y, pk->y + dy)) < 0 || (size_t)ny > sizeof(pk->y)) { |
222 | 2 | fido_log_debug("%s: BN_bn2bin", __func__); |
223 | 2 | goto fail; |
224 | 2 | } |
225 | | |
226 | 6 | ok = FIDO_OK; |
227 | 12 | fail: |
228 | 12 | EC_GROUP_free(g); |
229 | | |
230 | 12 | if (bnctx != NULL) { |
231 | 11 | BN_CTX_end(bnctx); |
232 | 11 | BN_CTX_free(bnctx); |
233 | 11 | } |
234 | | |
235 | 12 | return (ok); |
236 | 6 | } |
237 | | |
238 | | int |
239 | | es384_pk_from_EVP_PKEY(es384_pk_t *pk, const EVP_PKEY *pkey) |
240 | 12 | { |
241 | 12 | const EC_KEY *ec; |
242 | | |
243 | 12 | if (EVP_PKEY_base_id(pkey) != EVP_PKEY_EC || |
244 | 12 | (ec = get0_EC_KEY(pkey)) == NULL) |
245 | 0 | return (FIDO_ERR_INVALID_ARGUMENT); |
246 | | |
247 | 12 | return (es384_pk_from_EC_KEY(pk, ec)); |
248 | 12 | } |
249 | | |
250 | | int |
251 | | es384_verify_sig(const fido_blob_t *dgst, EVP_PKEY *pkey, |
252 | | const fido_blob_t *sig) |
253 | 7 | { |
254 | 7 | EVP_PKEY_CTX *pctx = NULL; |
255 | 7 | int ok = -1; |
256 | | |
257 | 7 | if (EVP_PKEY_base_id(pkey) != EVP_PKEY_EC) { |
258 | 0 | fido_log_debug("%s: EVP_PKEY_base_id", __func__); |
259 | 0 | goto fail; |
260 | 0 | } |
261 | | |
262 | 7 | if ((pctx = EVP_PKEY_CTX_new(pkey, NULL)) == NULL || |
263 | 7 | EVP_PKEY_verify_init(pctx) != 1 || |
264 | 7 | EVP_PKEY_verify(pctx, sig->ptr, sig->len, dgst->ptr, |
265 | 7 | dgst->len) != 1) { |
266 | 7 | fido_log_debug("%s: EVP_PKEY_verify", __func__); |
267 | 7 | goto fail; |
268 | 7 | } |
269 | | |
270 | 0 | ok = 0; |
271 | 7 | fail: |
272 | 7 | EVP_PKEY_CTX_free(pctx); |
273 | | |
274 | 7 | return (ok); |
275 | 0 | } |
276 | | |
277 | | int |
278 | | es384_pk_verify_sig(const fido_blob_t *dgst, const es384_pk_t *pk, |
279 | | const fido_blob_t *sig) |
280 | 45 | { |
281 | 45 | EVP_PKEY *pkey; |
282 | 45 | int ok = -1; |
283 | | |
284 | 45 | if ((pkey = es384_pk_to_EVP_PKEY(pk)) == NULL || |
285 | 45 | es384_verify_sig(dgst, pkey, sig) < 0) { |
286 | 45 | fido_log_debug("%s: es384_verify_sig", __func__); |
287 | 45 | goto fail; |
288 | 45 | } |
289 | | |
290 | 0 | ok = 0; |
291 | 45 | fail: |
292 | 45 | EVP_PKEY_free(pkey); |
293 | | |
294 | 45 | return (ok); |
295 | 0 | } |