djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2019 Markus Friedl |
| 3 | * |
| 4 | * Permission to use, copy, modify, and distribute this software for any |
| 5 | * purpose with or without fee is hereby granted, provided that the above |
| 6 | * copyright notice and this permission notice appear in all copies. |
| 7 | * |
| 8 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 9 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 10 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| 11 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 12 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 13 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| 14 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 15 | */ |
| 16 | |
| 17 | #include "includes.h" |
| 18 | |
| 19 | #ifdef ENABLE_SK_INTERNAL |
| 20 | |
| 21 | #include <stdint.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <string.h> |
| 24 | #include <stdio.h> |
| 25 | #include <stddef.h> |
| 26 | #include <stdarg.h> |
Damien Miller | c0dfd18 | 2020-05-01 13:29:16 +1000 | [diff] [blame] | 27 | #ifdef HAVE_SHA2_H |
djm@openbsd.org | 59d2de9 | 2020-04-28 04:02:29 +0000 | [diff] [blame] | 28 | #include <sha2.h> |
Damien Miller | c0dfd18 | 2020-05-01 13:29:16 +1000 | [diff] [blame] | 29 | #endif |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 30 | |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 31 | #ifdef WITH_OPENSSL |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 32 | #include <openssl/opensslv.h> |
| 33 | #include <openssl/crypto.h> |
| 34 | #include <openssl/bn.h> |
| 35 | #include <openssl/ec.h> |
| 36 | #include <openssl/ecdsa.h> |
djm@openbsd.org | 59d2de9 | 2020-04-28 04:02:29 +0000 | [diff] [blame] | 37 | #include <openssl/evp.h> |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 38 | #endif /* WITH_OPENSSL */ |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 39 | |
| 40 | #include <fido.h> |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 41 | #include <fido/credman.h> |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 42 | |
| 43 | #ifndef SK_STANDALONE |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 44 | # include "log.h" |
| 45 | # include "xmalloc.h" |
| 46 | /* |
| 47 | * If building as part of OpenSSH, then rename exported functions. |
| 48 | * This must be done before including sk-api.h. |
| 49 | */ |
| 50 | # define sk_api_version ssh_sk_api_version |
| 51 | # define sk_enroll ssh_sk_enroll |
| 52 | # define sk_sign ssh_sk_sign |
| 53 | # define sk_load_resident_keys ssh_sk_load_resident_keys |
| 54 | #endif /* !SK_STANDALONE */ |
| 55 | |
| 56 | #include "sk-api.h" |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 57 | |
| 58 | /* #define SK_DEBUG 1 */ |
| 59 | |
| 60 | #define MAX_FIDO_DEVICES 256 |
| 61 | |
| 62 | /* Compatibility with OpenSSH 1.0.x */ |
| 63 | #if (OPENSSL_VERSION_NUMBER < 0x10100000L) |
| 64 | #define ECDSA_SIG_get0(sig, pr, ps) \ |
| 65 | do { \ |
| 66 | (*pr) = sig->r; \ |
| 67 | (*ps) = sig->s; \ |
| 68 | } while (0) |
| 69 | #endif |
| 70 | |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 71 | /* Return the version of the middleware API */ |
| 72 | uint32_t sk_api_version(void); |
| 73 | |
| 74 | /* Enroll a U2F key (private key generation) */ |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 75 | int sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len, |
djm@openbsd.org | c54cd18 | 2019-12-30 09:23:28 +0000 | [diff] [blame] | 76 | const char *application, uint8_t flags, const char *pin, |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 77 | struct sk_option **options, struct sk_enroll_response **enroll_response); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 78 | |
| 79 | /* Sign a challenge */ |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 80 | int sk_sign(uint32_t alg, const uint8_t *message, size_t message_len, |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 81 | const char *application, const uint8_t *key_handle, size_t key_handle_len, |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 82 | uint8_t flags, const char *pin, struct sk_option **options, |
| 83 | struct sk_sign_response **sign_response); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 84 | |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 85 | /* Load resident keys */ |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 86 | int sk_load_resident_keys(const char *pin, struct sk_option **options, |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 87 | struct sk_resident_key ***rks, size_t *nrks); |
| 88 | |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 89 | static void skdebug(const char *func, const char *fmt, ...) |
| 90 | __attribute__((__format__ (printf, 2, 3))); |
| 91 | |
| 92 | static void |
| 93 | skdebug(const char *func, const char *fmt, ...) |
| 94 | { |
| 95 | #if !defined(SK_STANDALONE) |
| 96 | char *msg; |
| 97 | va_list ap; |
| 98 | |
| 99 | va_start(ap, fmt); |
| 100 | xvasprintf(&msg, fmt, ap); |
| 101 | va_end(ap); |
djm@openbsd.org | 22a8271 | 2019-11-15 02:20:06 +0000 | [diff] [blame] | 102 | debug("%s: %s", func, msg); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 103 | free(msg); |
| 104 | #elif defined(SK_DEBUG) |
| 105 | va_list ap; |
| 106 | |
| 107 | va_start(ap, fmt); |
| 108 | fprintf(stderr, "%s: ", func); |
| 109 | vfprintf(stderr, fmt, ap); |
| 110 | fputc('\n', stderr); |
| 111 | va_end(ap); |
| 112 | #else |
| 113 | (void)func; /* XXX */ |
| 114 | (void)fmt; /* XXX */ |
| 115 | #endif |
| 116 | } |
| 117 | |
| 118 | uint32_t |
| 119 | sk_api_version(void) |
| 120 | { |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 121 | return SSH_SK_VERSION_MAJOR; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 122 | } |
| 123 | |
| 124 | /* Select the first identified FIDO device attached to the system */ |
| 125 | static char * |
| 126 | pick_first_device(void) |
| 127 | { |
| 128 | char *ret = NULL; |
| 129 | fido_dev_info_t *devlist = NULL; |
| 130 | size_t olen = 0; |
| 131 | int r; |
| 132 | const fido_dev_info_t *di; |
| 133 | |
| 134 | if ((devlist = fido_dev_info_new(1)) == NULL) { |
| 135 | skdebug(__func__, "fido_dev_info_new failed"); |
| 136 | goto out; |
| 137 | } |
| 138 | if ((r = fido_dev_info_manifest(devlist, 1, &olen)) != FIDO_OK) { |
| 139 | skdebug(__func__, "fido_dev_info_manifest failed: %s", |
| 140 | fido_strerr(r)); |
| 141 | goto out; |
| 142 | } |
| 143 | if (olen != 1) { |
| 144 | skdebug(__func__, "fido_dev_info_manifest bad len %zu", olen); |
| 145 | goto out; |
| 146 | } |
| 147 | di = fido_dev_info_ptr(devlist, 0); |
| 148 | if ((ret = strdup(fido_dev_info_path(di))) == NULL) { |
| 149 | skdebug(__func__, "fido_dev_info_path failed"); |
| 150 | goto out; |
| 151 | } |
| 152 | out: |
| 153 | fido_dev_info_free(&devlist, 1); |
| 154 | return ret; |
| 155 | } |
| 156 | |
| 157 | /* Check if the specified key handle exists on a given device. */ |
| 158 | static int |
| 159 | try_device(fido_dev_t *dev, const uint8_t *message, size_t message_len, |
| 160 | const char *application, const uint8_t *key_handle, size_t key_handle_len) |
| 161 | { |
| 162 | fido_assert_t *assert = NULL; |
| 163 | int r = FIDO_ERR_INTERNAL; |
| 164 | |
| 165 | if ((assert = fido_assert_new()) == NULL) { |
| 166 | skdebug(__func__, "fido_assert_new failed"); |
| 167 | goto out; |
| 168 | } |
| 169 | if ((r = fido_assert_set_clientdata_hash(assert, message, |
| 170 | message_len)) != FIDO_OK) { |
| 171 | skdebug(__func__, "fido_assert_set_clientdata_hash: %s", |
| 172 | fido_strerr(r)); |
| 173 | goto out; |
| 174 | } |
| 175 | if ((r = fido_assert_set_rp(assert, application)) != FIDO_OK) { |
| 176 | skdebug(__func__, "fido_assert_set_rp: %s", fido_strerr(r)); |
| 177 | goto out; |
| 178 | } |
| 179 | if ((r = fido_assert_allow_cred(assert, key_handle, |
| 180 | key_handle_len)) != FIDO_OK) { |
| 181 | skdebug(__func__, "fido_assert_allow_cred: %s", fido_strerr(r)); |
| 182 | goto out; |
| 183 | } |
| 184 | if ((r = fido_assert_set_up(assert, FIDO_OPT_FALSE)) != FIDO_OK) { |
| 185 | skdebug(__func__, "fido_assert_up: %s", fido_strerr(r)); |
| 186 | goto out; |
| 187 | } |
| 188 | r = fido_dev_get_assert(dev, assert, NULL); |
| 189 | skdebug(__func__, "fido_dev_get_assert: %s", fido_strerr(r)); |
djm@openbsd.org | 01362cf | 2019-11-15 03:41:57 +0000 | [diff] [blame] | 190 | if (r == FIDO_ERR_USER_PRESENCE_REQUIRED) { |
| 191 | /* U2F tokens may return this */ |
| 192 | r = FIDO_OK; |
| 193 | } |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 194 | out: |
| 195 | fido_assert_free(&assert); |
| 196 | |
| 197 | return r != FIDO_OK ? -1 : 0; |
| 198 | } |
| 199 | |
| 200 | /* Iterate over configured devices looking for a specific key handle */ |
| 201 | static fido_dev_t * |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 202 | find_device(const char *path, const uint8_t *message, size_t message_len, |
| 203 | const char *application, const uint8_t *key_handle, size_t key_handle_len) |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 204 | { |
| 205 | fido_dev_info_t *devlist = NULL; |
| 206 | fido_dev_t *dev = NULL; |
deraadt@openbsd.org | d165bb5 | 2019-11-15 05:26:56 +0000 | [diff] [blame] | 207 | size_t devlist_len = 0, i; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 208 | int r; |
| 209 | |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 210 | if (path != NULL) { |
| 211 | if ((dev = fido_dev_new()) == NULL) { |
| 212 | skdebug(__func__, "fido_dev_new failed"); |
| 213 | return NULL; |
| 214 | } |
| 215 | if ((r = fido_dev_open(dev, path)) != FIDO_OK) { |
| 216 | skdebug(__func__, "fido_dev_open failed"); |
| 217 | fido_dev_free(&dev); |
| 218 | return NULL; |
| 219 | } |
| 220 | return dev; |
| 221 | } |
| 222 | |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 223 | if ((devlist = fido_dev_info_new(MAX_FIDO_DEVICES)) == NULL) { |
| 224 | skdebug(__func__, "fido_dev_info_new failed"); |
| 225 | goto out; |
| 226 | } |
| 227 | if ((r = fido_dev_info_manifest(devlist, MAX_FIDO_DEVICES, |
| 228 | &devlist_len)) != FIDO_OK) { |
| 229 | skdebug(__func__, "fido_dev_info_manifest: %s", fido_strerr(r)); |
| 230 | goto out; |
| 231 | } |
| 232 | |
| 233 | skdebug(__func__, "found %zu device(s)", devlist_len); |
| 234 | |
deraadt@openbsd.org | d165bb5 | 2019-11-15 05:26:56 +0000 | [diff] [blame] | 235 | for (i = 0; i < devlist_len; i++) { |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 236 | const fido_dev_info_t *di = fido_dev_info_ptr(devlist, i); |
| 237 | |
| 238 | if (di == NULL) { |
| 239 | skdebug(__func__, "fido_dev_info_ptr %zu failed", i); |
| 240 | continue; |
| 241 | } |
| 242 | if ((path = fido_dev_info_path(di)) == NULL) { |
| 243 | skdebug(__func__, "fido_dev_info_path %zu failed", i); |
| 244 | continue; |
| 245 | } |
| 246 | skdebug(__func__, "trying device %zu: %s", i, path); |
| 247 | if ((dev = fido_dev_new()) == NULL) { |
| 248 | skdebug(__func__, "fido_dev_new failed"); |
| 249 | continue; |
| 250 | } |
| 251 | if ((r = fido_dev_open(dev, path)) != FIDO_OK) { |
| 252 | skdebug(__func__, "fido_dev_open failed"); |
| 253 | fido_dev_free(&dev); |
| 254 | continue; |
| 255 | } |
| 256 | if (try_device(dev, message, message_len, application, |
| 257 | key_handle, key_handle_len) == 0) { |
| 258 | skdebug(__func__, "found key"); |
| 259 | break; |
| 260 | } |
| 261 | fido_dev_close(dev); |
| 262 | fido_dev_free(&dev); |
| 263 | } |
| 264 | |
| 265 | out: |
| 266 | if (devlist != NULL) |
| 267 | fido_dev_info_free(&devlist, MAX_FIDO_DEVICES); |
| 268 | |
| 269 | return dev; |
| 270 | } |
| 271 | |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 272 | #ifdef WITH_OPENSSL |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 273 | /* |
| 274 | * The key returned via fido_cred_pubkey_ptr() is in affine coordinates, |
| 275 | * but the API expects a SEC1 octet string. |
| 276 | */ |
| 277 | static int |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 278 | pack_public_key_ecdsa(const fido_cred_t *cred, |
| 279 | struct sk_enroll_response *response) |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 280 | { |
| 281 | const uint8_t *ptr; |
| 282 | BIGNUM *x = NULL, *y = NULL; |
| 283 | EC_POINT *q = NULL; |
| 284 | EC_GROUP *g = NULL; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 285 | int ret = -1; |
| 286 | |
| 287 | response->public_key = NULL; |
| 288 | response->public_key_len = 0; |
| 289 | |
djm@openbsd.org | fd1a964 | 2019-11-15 06:00:20 +0000 | [diff] [blame] | 290 | if ((x = BN_new()) == NULL || |
| 291 | (y = BN_new()) == NULL || |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 292 | (g = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1)) == NULL || |
| 293 | (q = EC_POINT_new(g)) == NULL) { |
| 294 | skdebug(__func__, "libcrypto setup failed"); |
| 295 | goto out; |
| 296 | } |
| 297 | if ((ptr = fido_cred_pubkey_ptr(cred)) == NULL) { |
| 298 | skdebug(__func__, "fido_cred_pubkey_ptr failed"); |
| 299 | goto out; |
| 300 | } |
| 301 | if (fido_cred_pubkey_len(cred) != 64) { |
| 302 | skdebug(__func__, "bad fido_cred_pubkey_len %zu", |
| 303 | fido_cred_pubkey_len(cred)); |
| 304 | goto out; |
| 305 | } |
| 306 | |
| 307 | if (BN_bin2bn(ptr, 32, x) == NULL || |
| 308 | BN_bin2bn(ptr + 32, 32, y) == NULL) { |
| 309 | skdebug(__func__, "BN_bin2bn failed"); |
| 310 | goto out; |
| 311 | } |
djm@openbsd.org | fd1a964 | 2019-11-15 06:00:20 +0000 | [diff] [blame] | 312 | if (EC_POINT_set_affine_coordinates_GFp(g, q, x, y, NULL) != 1) { |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 313 | skdebug(__func__, "EC_POINT_set_affine_coordinates_GFp failed"); |
| 314 | goto out; |
| 315 | } |
| 316 | response->public_key_len = EC_POINT_point2oct(g, q, |
djm@openbsd.org | fd1a964 | 2019-11-15 06:00:20 +0000 | [diff] [blame] | 317 | POINT_CONVERSION_UNCOMPRESSED, NULL, 0, NULL); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 318 | if (response->public_key_len == 0 || response->public_key_len > 2048) { |
| 319 | skdebug(__func__, "bad pubkey length %zu", |
| 320 | response->public_key_len); |
| 321 | goto out; |
| 322 | } |
| 323 | if ((response->public_key = malloc(response->public_key_len)) == NULL) { |
| 324 | skdebug(__func__, "malloc pubkey failed"); |
| 325 | goto out; |
| 326 | } |
| 327 | if (EC_POINT_point2oct(g, q, POINT_CONVERSION_UNCOMPRESSED, |
djm@openbsd.org | fd1a964 | 2019-11-15 06:00:20 +0000 | [diff] [blame] | 328 | response->public_key, response->public_key_len, NULL) == 0) { |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 329 | skdebug(__func__, "EC_POINT_point2oct failed"); |
| 330 | goto out; |
| 331 | } |
| 332 | /* success */ |
| 333 | ret = 0; |
| 334 | out: |
| 335 | if (ret != 0 && response->public_key != NULL) { |
| 336 | memset(response->public_key, 0, response->public_key_len); |
| 337 | free(response->public_key); |
| 338 | response->public_key = NULL; |
| 339 | } |
| 340 | EC_POINT_free(q); |
| 341 | EC_GROUP_free(g); |
djm@openbsd.org | fd1a964 | 2019-11-15 06:00:20 +0000 | [diff] [blame] | 342 | BN_clear_free(x); |
| 343 | BN_clear_free(y); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 344 | return ret; |
| 345 | } |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 346 | #endif /* WITH_OPENSSL */ |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 347 | |
| 348 | static int |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 349 | pack_public_key_ed25519(const fido_cred_t *cred, |
| 350 | struct sk_enroll_response *response) |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 351 | { |
| 352 | const uint8_t *ptr; |
| 353 | size_t len; |
| 354 | int ret = -1; |
| 355 | |
| 356 | response->public_key = NULL; |
| 357 | response->public_key_len = 0; |
| 358 | |
| 359 | if ((len = fido_cred_pubkey_len(cred)) != 32) { |
| 360 | skdebug(__func__, "bad fido_cred_pubkey_len len %zu", len); |
| 361 | goto out; |
| 362 | } |
| 363 | if ((ptr = fido_cred_pubkey_ptr(cred)) == NULL) { |
| 364 | skdebug(__func__, "fido_cred_pubkey_ptr failed"); |
| 365 | goto out; |
| 366 | } |
| 367 | response->public_key_len = len; |
| 368 | if ((response->public_key = malloc(response->public_key_len)) == NULL) { |
| 369 | skdebug(__func__, "malloc pubkey failed"); |
| 370 | goto out; |
| 371 | } |
| 372 | memcpy(response->public_key, ptr, len); |
| 373 | ret = 0; |
| 374 | out: |
| 375 | if (ret != 0) |
| 376 | free(response->public_key); |
| 377 | return ret; |
| 378 | } |
| 379 | |
| 380 | static int |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 381 | pack_public_key(uint32_t alg, const fido_cred_t *cred, |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 382 | struct sk_enroll_response *response) |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 383 | { |
| 384 | switch(alg) { |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 385 | #ifdef WITH_OPENSSL |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 386 | case SSH_SK_ECDSA: |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 387 | return pack_public_key_ecdsa(cred, response); |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 388 | #endif /* WITH_OPENSSL */ |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 389 | case SSH_SK_ED25519: |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 390 | return pack_public_key_ed25519(cred, response); |
| 391 | default: |
| 392 | return -1; |
| 393 | } |
| 394 | } |
| 395 | |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 396 | static int |
| 397 | fidoerr_to_skerr(int fidoerr) |
| 398 | { |
| 399 | switch (fidoerr) { |
| 400 | case FIDO_ERR_UNSUPPORTED_OPTION: |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 401 | case FIDO_ERR_UNSUPPORTED_ALGORITHM: |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 402 | return SSH_SK_ERR_UNSUPPORTED; |
| 403 | case FIDO_ERR_PIN_REQUIRED: |
| 404 | case FIDO_ERR_PIN_INVALID: |
| 405 | return SSH_SK_ERR_PIN_REQUIRED; |
| 406 | default: |
| 407 | return -1; |
| 408 | } |
| 409 | } |
| 410 | |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 411 | static int |
| 412 | check_enroll_options(struct sk_option **options, char **devicep, |
| 413 | uint8_t *user_id, size_t user_id_len) |
| 414 | { |
| 415 | size_t i; |
| 416 | |
| 417 | if (options == NULL) |
| 418 | return 0; |
| 419 | for (i = 0; options[i] != NULL; i++) { |
| 420 | if (strcmp(options[i]->name, "device") == 0) { |
| 421 | if ((*devicep = strdup(options[i]->value)) == NULL) { |
| 422 | skdebug(__func__, "strdup device failed"); |
| 423 | return -1; |
| 424 | } |
| 425 | skdebug(__func__, "requested device %s", *devicep); |
djm@openbsd.org | 3cc60c8 | 2020-01-06 02:39:30 +0000 | [diff] [blame] | 426 | } else if (strcmp(options[i]->name, "user") == 0) { |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 427 | if (strlcpy(user_id, options[i]->value, user_id_len) >= |
| 428 | user_id_len) { |
| 429 | skdebug(__func__, "user too long"); |
| 430 | return -1; |
| 431 | } |
| 432 | skdebug(__func__, "requested user %s", |
| 433 | (char *)user_id); |
| 434 | } else { |
| 435 | skdebug(__func__, "requested unsupported option %s", |
| 436 | options[i]->name); |
| 437 | if (options[i]->required) { |
| 438 | skdebug(__func__, "unknown required option"); |
| 439 | return -1; |
| 440 | } |
| 441 | } |
| 442 | } |
| 443 | return 0; |
| 444 | } |
| 445 | |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 446 | int |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 447 | sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len, |
djm@openbsd.org | c54cd18 | 2019-12-30 09:23:28 +0000 | [diff] [blame] | 448 | const char *application, uint8_t flags, const char *pin, |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 449 | struct sk_option **options, struct sk_enroll_response **enroll_response) |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 450 | { |
| 451 | fido_cred_t *cred = NULL; |
| 452 | fido_dev_t *dev = NULL; |
| 453 | const uint8_t *ptr; |
| 454 | uint8_t user_id[32]; |
| 455 | struct sk_enroll_response *response = NULL; |
| 456 | size_t len; |
| 457 | int cose_alg; |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 458 | int ret = SSH_SK_ERR_GENERAL; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 459 | int r; |
| 460 | char *device = NULL; |
| 461 | |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 462 | #ifdef SK_DEBUG |
| 463 | fido_init(FIDO_DEBUG); |
| 464 | #endif |
markus@openbsd.org | d431778 | 2019-11-15 15:41:01 +0000 | [diff] [blame] | 465 | if (enroll_response == NULL) { |
| 466 | skdebug(__func__, "enroll_response == NULL"); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 467 | goto out; |
| 468 | } |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 469 | memset(user_id, 0, sizeof(user_id)); |
| 470 | if (check_enroll_options(options, &device, |
| 471 | user_id, sizeof(user_id)) != 0) |
| 472 | goto out; /* error already logged */ |
| 473 | |
markus@openbsd.org | d431778 | 2019-11-15 15:41:01 +0000 | [diff] [blame] | 474 | *enroll_response = NULL; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 475 | switch(alg) { |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 476 | #ifdef WITH_OPENSSL |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 477 | case SSH_SK_ECDSA: |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 478 | cose_alg = COSE_ES256; |
| 479 | break; |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 480 | #endif /* WITH_OPENSSL */ |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 481 | case SSH_SK_ED25519: |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 482 | cose_alg = COSE_EDDSA; |
| 483 | break; |
| 484 | default: |
| 485 | skdebug(__func__, "unsupported key type %d", alg); |
| 486 | goto out; |
| 487 | } |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 488 | if (device == NULL && (device = pick_first_device()) == NULL) { |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 489 | ret = SSH_SK_ERR_DEVICE_NOT_FOUND; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 490 | skdebug(__func__, "pick_first_device failed"); |
| 491 | goto out; |
| 492 | } |
| 493 | skdebug(__func__, "using device %s", device); |
| 494 | if ((cred = fido_cred_new()) == NULL) { |
| 495 | skdebug(__func__, "fido_cred_new failed"); |
| 496 | goto out; |
| 497 | } |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 498 | if ((r = fido_cred_set_type(cred, cose_alg)) != FIDO_OK) { |
| 499 | skdebug(__func__, "fido_cred_set_type: %s", fido_strerr(r)); |
| 500 | goto out; |
| 501 | } |
| 502 | if ((r = fido_cred_set_clientdata_hash(cred, challenge, |
| 503 | challenge_len)) != FIDO_OK) { |
| 504 | skdebug(__func__, "fido_cred_set_clientdata_hash: %s", |
| 505 | fido_strerr(r)); |
| 506 | goto out; |
| 507 | } |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 508 | if ((r = fido_cred_set_rk(cred, (flags & SSH_SK_RESIDENT_KEY) != 0 ? |
djm@openbsd.org | 4532bd0 | 2019-12-30 09:19:52 +0000 | [diff] [blame] | 509 | FIDO_OPT_TRUE : FIDO_OPT_OMIT)) != FIDO_OK) { |
| 510 | skdebug(__func__, "fido_cred_set_rk: %s", fido_strerr(r)); |
| 511 | goto out; |
| 512 | } |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 513 | if ((r = fido_cred_set_user(cred, user_id, sizeof(user_id), |
| 514 | "openssh", "openssh", NULL)) != FIDO_OK) { |
| 515 | skdebug(__func__, "fido_cred_set_user: %s", fido_strerr(r)); |
| 516 | goto out; |
| 517 | } |
| 518 | if ((r = fido_cred_set_rp(cred, application, NULL)) != FIDO_OK) { |
| 519 | skdebug(__func__, "fido_cred_set_rp: %s", fido_strerr(r)); |
| 520 | goto out; |
| 521 | } |
| 522 | if ((dev = fido_dev_new()) == NULL) { |
| 523 | skdebug(__func__, "fido_dev_new failed"); |
| 524 | goto out; |
| 525 | } |
| 526 | if ((r = fido_dev_open(dev, device)) != FIDO_OK) { |
| 527 | skdebug(__func__, "fido_dev_open: %s", fido_strerr(r)); |
| 528 | goto out; |
| 529 | } |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 530 | if ((r = fido_dev_make_cred(dev, cred, pin)) != FIDO_OK) { |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 531 | skdebug(__func__, "fido_dev_make_cred: %s", fido_strerr(r)); |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 532 | ret = fidoerr_to_skerr(r); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 533 | goto out; |
| 534 | } |
| 535 | if (fido_cred_x5c_ptr(cred) != NULL) { |
| 536 | if ((r = fido_cred_verify(cred)) != FIDO_OK) { |
| 537 | skdebug(__func__, "fido_cred_verify: %s", |
| 538 | fido_strerr(r)); |
| 539 | goto out; |
| 540 | } |
| 541 | } else { |
| 542 | skdebug(__func__, "self-attested credential"); |
| 543 | if ((r = fido_cred_verify_self(cred)) != FIDO_OK) { |
| 544 | skdebug(__func__, "fido_cred_verify_self: %s", |
| 545 | fido_strerr(r)); |
| 546 | goto out; |
| 547 | } |
| 548 | } |
| 549 | if ((response = calloc(1, sizeof(*response))) == NULL) { |
| 550 | skdebug(__func__, "calloc response failed"); |
| 551 | goto out; |
| 552 | } |
| 553 | if (pack_public_key(alg, cred, response) != 0) { |
| 554 | skdebug(__func__, "pack_public_key failed"); |
| 555 | goto out; |
| 556 | } |
| 557 | if ((ptr = fido_cred_id_ptr(cred)) != NULL) { |
| 558 | len = fido_cred_id_len(cred); |
| 559 | if ((response->key_handle = calloc(1, len)) == NULL) { |
| 560 | skdebug(__func__, "calloc key handle failed"); |
| 561 | goto out; |
| 562 | } |
| 563 | memcpy(response->key_handle, ptr, len); |
| 564 | response->key_handle_len = len; |
| 565 | } |
| 566 | if ((ptr = fido_cred_sig_ptr(cred)) != NULL) { |
| 567 | len = fido_cred_sig_len(cred); |
| 568 | if ((response->signature = calloc(1, len)) == NULL) { |
| 569 | skdebug(__func__, "calloc signature failed"); |
| 570 | goto out; |
| 571 | } |
| 572 | memcpy(response->signature, ptr, len); |
| 573 | response->signature_len = len; |
| 574 | } |
| 575 | if ((ptr = fido_cred_x5c_ptr(cred)) != NULL) { |
| 576 | len = fido_cred_x5c_len(cred); |
djm@openbsd.org | 24c0f75 | 2020-01-28 08:01:34 +0000 | [diff] [blame] | 577 | debug3("%s: attestation cert len=%zu", __func__, len); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 578 | if ((response->attestation_cert = calloc(1, len)) == NULL) { |
| 579 | skdebug(__func__, "calloc attestation cert failed"); |
| 580 | goto out; |
| 581 | } |
| 582 | memcpy(response->attestation_cert, ptr, len); |
| 583 | response->attestation_cert_len = len; |
| 584 | } |
markus@openbsd.org | d431778 | 2019-11-15 15:41:01 +0000 | [diff] [blame] | 585 | *enroll_response = response; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 586 | response = NULL; |
| 587 | ret = 0; |
| 588 | out: |
| 589 | free(device); |
| 590 | if (response != NULL) { |
| 591 | free(response->public_key); |
| 592 | free(response->key_handle); |
| 593 | free(response->signature); |
| 594 | free(response->attestation_cert); |
| 595 | free(response); |
| 596 | } |
| 597 | if (dev != NULL) { |
| 598 | fido_dev_close(dev); |
| 599 | fido_dev_free(&dev); |
| 600 | } |
| 601 | if (cred != NULL) { |
| 602 | fido_cred_free(&cred); |
| 603 | } |
| 604 | return ret; |
| 605 | } |
| 606 | |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 607 | #ifdef WITH_OPENSSL |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 608 | static int |
| 609 | pack_sig_ecdsa(fido_assert_t *assert, struct sk_sign_response *response) |
| 610 | { |
| 611 | ECDSA_SIG *sig = NULL; |
| 612 | const BIGNUM *sig_r, *sig_s; |
| 613 | const unsigned char *cp; |
| 614 | size_t sig_len; |
| 615 | int ret = -1; |
| 616 | |
| 617 | cp = fido_assert_sig_ptr(assert, 0); |
| 618 | sig_len = fido_assert_sig_len(assert, 0); |
| 619 | if ((sig = d2i_ECDSA_SIG(NULL, &cp, sig_len)) == NULL) { |
| 620 | skdebug(__func__, "d2i_ECDSA_SIG failed"); |
| 621 | goto out; |
| 622 | } |
| 623 | ECDSA_SIG_get0(sig, &sig_r, &sig_s); |
| 624 | response->sig_r_len = BN_num_bytes(sig_r); |
| 625 | response->sig_s_len = BN_num_bytes(sig_s); |
| 626 | if ((response->sig_r = calloc(1, response->sig_r_len)) == NULL || |
| 627 | (response->sig_s = calloc(1, response->sig_s_len)) == NULL) { |
| 628 | skdebug(__func__, "calloc signature failed"); |
| 629 | goto out; |
| 630 | } |
| 631 | BN_bn2bin(sig_r, response->sig_r); |
| 632 | BN_bn2bin(sig_s, response->sig_s); |
| 633 | ret = 0; |
| 634 | out: |
| 635 | ECDSA_SIG_free(sig); |
| 636 | if (ret != 0) { |
| 637 | free(response->sig_r); |
| 638 | free(response->sig_s); |
| 639 | response->sig_r = NULL; |
| 640 | response->sig_s = NULL; |
| 641 | } |
| 642 | return ret; |
| 643 | } |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 644 | #endif /* WITH_OPENSSL */ |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 645 | |
| 646 | static int |
| 647 | pack_sig_ed25519(fido_assert_t *assert, struct sk_sign_response *response) |
| 648 | { |
| 649 | const unsigned char *ptr; |
| 650 | size_t len; |
| 651 | int ret = -1; |
| 652 | |
| 653 | ptr = fido_assert_sig_ptr(assert, 0); |
| 654 | len = fido_assert_sig_len(assert, 0); |
| 655 | if (len != 64) { |
| 656 | skdebug(__func__, "bad length %zu", len); |
| 657 | goto out; |
| 658 | } |
| 659 | response->sig_r_len = len; |
| 660 | if ((response->sig_r = calloc(1, response->sig_r_len)) == NULL) { |
| 661 | skdebug(__func__, "calloc signature failed"); |
| 662 | goto out; |
| 663 | } |
| 664 | memcpy(response->sig_r, ptr, len); |
| 665 | ret = 0; |
| 666 | out: |
| 667 | if (ret != 0) { |
| 668 | free(response->sig_r); |
| 669 | response->sig_r = NULL; |
| 670 | } |
| 671 | return ret; |
| 672 | } |
| 673 | |
| 674 | static int |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 675 | pack_sig(uint32_t alg, fido_assert_t *assert, |
| 676 | struct sk_sign_response *response) |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 677 | { |
| 678 | switch(alg) { |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 679 | #ifdef WITH_OPENSSL |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 680 | case SSH_SK_ECDSA: |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 681 | return pack_sig_ecdsa(assert, response); |
naddy@openbsd.org | 723a536 | 2019-11-18 16:08:57 +0000 | [diff] [blame] | 682 | #endif /* WITH_OPENSSL */ |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 683 | case SSH_SK_ED25519: |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 684 | return pack_sig_ed25519(assert, response); |
| 685 | default: |
| 686 | return -1; |
| 687 | } |
| 688 | } |
| 689 | |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 690 | /* Checks sk_options for sk_sign() and sk_load_resident_keys() */ |
| 691 | static int |
| 692 | check_sign_load_resident_options(struct sk_option **options, char **devicep) |
| 693 | { |
| 694 | size_t i; |
| 695 | |
| 696 | if (options == NULL) |
| 697 | return 0; |
| 698 | for (i = 0; options[i] != NULL; i++) { |
| 699 | if (strcmp(options[i]->name, "device") == 0) { |
| 700 | if ((*devicep = strdup(options[i]->value)) == NULL) { |
| 701 | skdebug(__func__, "strdup device failed"); |
| 702 | return -1; |
| 703 | } |
| 704 | skdebug(__func__, "requested device %s", *devicep); |
| 705 | } else { |
| 706 | skdebug(__func__, "requested unsupported option %s", |
| 707 | options[i]->name); |
| 708 | if (options[i]->required) { |
| 709 | skdebug(__func__, "unknown required option"); |
| 710 | return -1; |
| 711 | } |
| 712 | } |
| 713 | } |
| 714 | return 0; |
| 715 | } |
| 716 | |
djm@openbsd.org | 59d2de9 | 2020-04-28 04:02:29 +0000 | [diff] [blame] | 717 | /* Calculate SHA256(m) */ |
| 718 | static int |
| 719 | sha256_mem(const void *m, size_t mlen, u_char *d, size_t dlen) |
| 720 | { |
| 721 | #ifdef WITH_OPENSSL |
| 722 | u_int mdlen; |
| 723 | #endif |
| 724 | |
| 725 | if (dlen != 32) |
| 726 | return -1; |
| 727 | #ifdef WITH_OPENSSL |
| 728 | mdlen = dlen; |
| 729 | if (!EVP_Digest(m, mlen, d, &mdlen, EVP_sha256(), NULL)) |
| 730 | return -1; |
| 731 | #else |
| 732 | SHA256Data(m, mlen, d); |
| 733 | #endif |
| 734 | return 0; |
| 735 | } |
| 736 | |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 737 | int |
djm@openbsd.org | 59d2de9 | 2020-04-28 04:02:29 +0000 | [diff] [blame] | 738 | sk_sign(uint32_t alg, const uint8_t *data, size_t datalen, |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 739 | const char *application, |
| 740 | const uint8_t *key_handle, size_t key_handle_len, |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 741 | uint8_t flags, const char *pin, struct sk_option **options, |
| 742 | struct sk_sign_response **sign_response) |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 743 | { |
| 744 | fido_assert_t *assert = NULL; |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 745 | char *device = NULL; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 746 | fido_dev_t *dev = NULL; |
| 747 | struct sk_sign_response *response = NULL; |
djm@openbsd.org | 59d2de9 | 2020-04-28 04:02:29 +0000 | [diff] [blame] | 748 | uint8_t message[32]; |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 749 | int ret = SSH_SK_ERR_GENERAL; |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 750 | int r; |
| 751 | |
| 752 | #ifdef SK_DEBUG |
| 753 | fido_init(FIDO_DEBUG); |
| 754 | #endif |
| 755 | |
| 756 | if (sign_response == NULL) { |
| 757 | skdebug(__func__, "sign_response == NULL"); |
| 758 | goto out; |
| 759 | } |
| 760 | *sign_response = NULL; |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 761 | if (check_sign_load_resident_options(options, &device) != 0) |
| 762 | goto out; /* error already logged */ |
djm@openbsd.org | 59d2de9 | 2020-04-28 04:02:29 +0000 | [diff] [blame] | 763 | /* hash data to be signed before it goes to the security key */ |
| 764 | if ((r = sha256_mem(data, datalen, message, sizeof(message))) != 0) { |
| 765 | skdebug(__func__, "hash message failed"); |
| 766 | goto out; |
| 767 | } |
| 768 | if ((dev = find_device(device, message, sizeof(message), |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 769 | application, key_handle, key_handle_len)) == NULL) { |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 770 | skdebug(__func__, "couldn't find device for key handle"); |
| 771 | goto out; |
| 772 | } |
| 773 | if ((assert = fido_assert_new()) == NULL) { |
| 774 | skdebug(__func__, "fido_assert_new failed"); |
| 775 | goto out; |
| 776 | } |
| 777 | if ((r = fido_assert_set_clientdata_hash(assert, message, |
djm@openbsd.org | 59d2de9 | 2020-04-28 04:02:29 +0000 | [diff] [blame] | 778 | sizeof(message))) != FIDO_OK) { |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 779 | skdebug(__func__, "fido_assert_set_clientdata_hash: %s", |
| 780 | fido_strerr(r)); |
| 781 | goto out; |
| 782 | } |
| 783 | if ((r = fido_assert_set_rp(assert, application)) != FIDO_OK) { |
| 784 | skdebug(__func__, "fido_assert_set_rp: %s", fido_strerr(r)); |
| 785 | goto out; |
| 786 | } |
| 787 | if ((r = fido_assert_allow_cred(assert, key_handle, |
| 788 | key_handle_len)) != FIDO_OK) { |
| 789 | skdebug(__func__, "fido_assert_allow_cred: %s", fido_strerr(r)); |
| 790 | goto out; |
| 791 | } |
| 792 | if ((r = fido_assert_set_up(assert, |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 793 | (flags & SSH_SK_USER_PRESENCE_REQD) ? |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 794 | FIDO_OPT_TRUE : FIDO_OPT_FALSE)) != FIDO_OK) { |
| 795 | skdebug(__func__, "fido_assert_set_up: %s", fido_strerr(r)); |
| 796 | goto out; |
| 797 | } |
| 798 | if ((r = fido_dev_get_assert(dev, assert, NULL)) != FIDO_OK) { |
| 799 | skdebug(__func__, "fido_dev_get_assert: %s", fido_strerr(r)); |
| 800 | goto out; |
| 801 | } |
| 802 | if ((response = calloc(1, sizeof(*response))) == NULL) { |
| 803 | skdebug(__func__, "calloc response failed"); |
| 804 | goto out; |
| 805 | } |
| 806 | response->flags = fido_assert_flags(assert, 0); |
| 807 | response->counter = fido_assert_sigcount(assert, 0); |
| 808 | if (pack_sig(alg, assert, response) != 0) { |
| 809 | skdebug(__func__, "pack_sig failed"); |
| 810 | goto out; |
| 811 | } |
| 812 | *sign_response = response; |
| 813 | response = NULL; |
| 814 | ret = 0; |
| 815 | out: |
djm@openbsd.org | 59d2de9 | 2020-04-28 04:02:29 +0000 | [diff] [blame] | 816 | explicit_bzero(message, sizeof(message)); |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 817 | free(device); |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 818 | if (response != NULL) { |
| 819 | free(response->sig_r); |
| 820 | free(response->sig_s); |
| 821 | free(response); |
| 822 | } |
| 823 | if (dev != NULL) { |
| 824 | fido_dev_close(dev); |
| 825 | fido_dev_free(&dev); |
| 826 | } |
| 827 | if (assert != NULL) { |
| 828 | fido_assert_free(&assert); |
| 829 | } |
| 830 | return ret; |
| 831 | } |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 832 | |
| 833 | static int |
| 834 | read_rks(const char *devpath, const char *pin, |
| 835 | struct sk_resident_key ***rksp, size_t *nrksp) |
| 836 | { |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 837 | int ret = SSH_SK_ERR_GENERAL, r = -1; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 838 | fido_dev_t *dev = NULL; |
| 839 | fido_credman_metadata_t *metadata = NULL; |
| 840 | fido_credman_rp_t *rp = NULL; |
| 841 | fido_credman_rk_t *rk = NULL; |
| 842 | size_t i, j, nrp, nrk; |
| 843 | const fido_cred_t *cred; |
| 844 | struct sk_resident_key *srk = NULL, **tmp; |
| 845 | |
| 846 | if ((dev = fido_dev_new()) == NULL) { |
| 847 | skdebug(__func__, "fido_dev_new failed"); |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 848 | return ret; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 849 | } |
| 850 | if ((r = fido_dev_open(dev, devpath)) != FIDO_OK) { |
| 851 | skdebug(__func__, "fido_dev_open %s failed: %s", |
| 852 | devpath, fido_strerr(r)); |
| 853 | fido_dev_free(&dev); |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 854 | return ret; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 855 | } |
| 856 | if ((metadata = fido_credman_metadata_new()) == NULL) { |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 857 | skdebug(__func__, "alloc failed"); |
| 858 | goto out; |
| 859 | } |
| 860 | |
| 861 | if ((r = fido_credman_get_dev_metadata(dev, metadata, pin)) != 0) { |
| 862 | if (r == FIDO_ERR_INVALID_COMMAND) { |
| 863 | skdebug(__func__, "device %s does not support " |
| 864 | "resident keys", devpath); |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 865 | ret = 0; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 866 | goto out; |
| 867 | } |
| 868 | skdebug(__func__, "get metadata for %s failed: %s", |
| 869 | devpath, fido_strerr(r)); |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 870 | ret = fidoerr_to_skerr(r); |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 871 | goto out; |
| 872 | } |
| 873 | skdebug(__func__, "existing %llu, remaining %llu", |
| 874 | (unsigned long long)fido_credman_rk_existing(metadata), |
| 875 | (unsigned long long)fido_credman_rk_remaining(metadata)); |
| 876 | if ((rp = fido_credman_rp_new()) == NULL) { |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 877 | skdebug(__func__, "alloc rp failed"); |
| 878 | goto out; |
| 879 | } |
| 880 | if ((r = fido_credman_get_dev_rp(dev, rp, pin)) != 0) { |
| 881 | skdebug(__func__, "get RPs for %s failed: %s", |
| 882 | devpath, fido_strerr(r)); |
| 883 | goto out; |
| 884 | } |
| 885 | nrp = fido_credman_rp_count(rp); |
| 886 | skdebug(__func__, "Device %s has resident keys for %zu RPs", |
| 887 | devpath, nrp); |
| 888 | |
| 889 | /* Iterate over RP IDs that have resident keys */ |
| 890 | for (i = 0; i < nrp; i++) { |
| 891 | skdebug(__func__, "rp %zu: name=\"%s\" id=\"%s\" hashlen=%zu", |
| 892 | i, fido_credman_rp_name(rp, i), fido_credman_rp_id(rp, i), |
| 893 | fido_credman_rp_id_hash_len(rp, i)); |
| 894 | |
| 895 | /* Skip non-SSH RP IDs */ |
| 896 | if (strncasecmp(fido_credman_rp_id(rp, i), "ssh:", 4) != 0) |
| 897 | continue; |
| 898 | |
| 899 | fido_credman_rk_free(&rk); |
| 900 | if ((rk = fido_credman_rk_new()) == NULL) { |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 901 | skdebug(__func__, "alloc rk failed"); |
| 902 | goto out; |
| 903 | } |
| 904 | if ((r = fido_credman_get_dev_rk(dev, fido_credman_rp_id(rp, i), |
| 905 | rk, pin)) != 0) { |
| 906 | skdebug(__func__, "get RKs for %s slot %zu failed: %s", |
| 907 | devpath, i, fido_strerr(r)); |
| 908 | goto out; |
| 909 | } |
| 910 | nrk = fido_credman_rk_count(rk); |
| 911 | skdebug(__func__, "RP \"%s\" has %zu resident keys", |
| 912 | fido_credman_rp_id(rp, i), nrk); |
| 913 | |
| 914 | /* Iterate over resident keys for this RP ID */ |
| 915 | for (j = 0; j < nrk; j++) { |
| 916 | if ((cred = fido_credman_rk(rk, j)) == NULL) { |
| 917 | skdebug(__func__, "no RK in slot %zu", j); |
| 918 | continue; |
| 919 | } |
| 920 | skdebug(__func__, "Device %s RP \"%s\" slot %zu: " |
| 921 | "type %d", devpath, fido_credman_rp_id(rp, i), j, |
| 922 | fido_cred_type(cred)); |
| 923 | |
| 924 | /* build response entry */ |
| 925 | if ((srk = calloc(1, sizeof(*srk))) == NULL || |
| 926 | (srk->key.key_handle = calloc(1, |
| 927 | fido_cred_id_len(cred))) == NULL || |
| 928 | (srk->application = strdup(fido_credman_rp_id(rp, |
| 929 | i))) == NULL) { |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 930 | skdebug(__func__, "alloc sk_resident_key"); |
| 931 | goto out; |
| 932 | } |
| 933 | |
| 934 | srk->key.key_handle_len = fido_cred_id_len(cred); |
| 935 | memcpy(srk->key.key_handle, |
| 936 | fido_cred_id_ptr(cred), |
| 937 | srk->key.key_handle_len); |
| 938 | |
| 939 | switch (fido_cred_type(cred)) { |
| 940 | case COSE_ES256: |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 941 | srk->alg = SSH_SK_ECDSA; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 942 | break; |
| 943 | case COSE_EDDSA: |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 944 | srk->alg = SSH_SK_ED25519; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 945 | break; |
| 946 | default: |
| 947 | skdebug(__func__, "unsupported key type %d", |
| 948 | fido_cred_type(cred)); |
djm@openbsd.org | 59d01f1 | 2020-01-25 23:13:09 +0000 | [diff] [blame] | 949 | goto out; /* XXX free rk and continue */ |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 950 | } |
| 951 | |
| 952 | if ((r = pack_public_key(srk->alg, cred, |
| 953 | &srk->key)) != 0) { |
| 954 | skdebug(__func__, "pack public key failed"); |
| 955 | goto out; |
| 956 | } |
| 957 | /* append */ |
| 958 | if ((tmp = recallocarray(*rksp, *nrksp, (*nrksp) + 1, |
| 959 | sizeof(**rksp))) == NULL) { |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 960 | skdebug(__func__, "alloc rksp"); |
| 961 | goto out; |
| 962 | } |
| 963 | *rksp = tmp; |
| 964 | (*rksp)[(*nrksp)++] = srk; |
| 965 | srk = NULL; |
| 966 | } |
| 967 | } |
| 968 | /* Success */ |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 969 | ret = 0; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 970 | out: |
| 971 | if (srk != NULL) { |
| 972 | free(srk->application); |
| 973 | freezero(srk->key.public_key, srk->key.public_key_len); |
| 974 | freezero(srk->key.key_handle, srk->key.key_handle_len); |
| 975 | freezero(srk, sizeof(*srk)); |
| 976 | } |
| 977 | fido_credman_rp_free(&rp); |
| 978 | fido_credman_rk_free(&rk); |
| 979 | fido_dev_close(dev); |
| 980 | fido_dev_free(&dev); |
| 981 | fido_credman_metadata_free(&metadata); |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 982 | return ret; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 983 | } |
| 984 | |
| 985 | int |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 986 | sk_load_resident_keys(const char *pin, struct sk_option **options, |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 987 | struct sk_resident_key ***rksp, size_t *nrksp) |
| 988 | { |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 989 | int ret = SSH_SK_ERR_GENERAL, r = -1; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 990 | fido_dev_info_t *devlist = NULL; |
| 991 | size_t i, ndev = 0, nrks = 0; |
| 992 | const fido_dev_info_t *di; |
| 993 | struct sk_resident_key **rks = NULL; |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 994 | char *device = NULL; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 995 | *rksp = NULL; |
| 996 | *nrksp = 0; |
| 997 | |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 998 | if (check_sign_load_resident_options(options, &device) != 0) |
| 999 | goto out; /* error already logged */ |
| 1000 | if (device != NULL) { |
| 1001 | skdebug(__func__, "trying %s", device); |
| 1002 | if ((r = read_rks(device, pin, &rks, &nrks)) != 0) { |
djm@openbsd.org | ff5784e | 2020-01-06 02:24:28 +0000 | [diff] [blame] | 1003 | skdebug(__func__, "read_rks failed for %s", device); |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 1004 | ret = r; |
| 1005 | goto out; |
| 1006 | } |
| 1007 | } else { |
| 1008 | /* Try all devices */ |
| 1009 | if ((devlist = fido_dev_info_new(MAX_FIDO_DEVICES)) == NULL) { |
| 1010 | skdebug(__func__, "fido_dev_info_new failed"); |
| 1011 | goto out; |
| 1012 | } |
| 1013 | if ((r = fido_dev_info_manifest(devlist, |
| 1014 | MAX_FIDO_DEVICES, &ndev)) != FIDO_OK) { |
| 1015 | skdebug(__func__, "fido_dev_info_manifest failed: %s", |
| 1016 | fido_strerr(r)); |
| 1017 | goto out; |
| 1018 | } |
| 1019 | for (i = 0; i < ndev; i++) { |
| 1020 | if ((di = fido_dev_info_ptr(devlist, i)) == NULL) { |
| 1021 | skdebug(__func__, "no dev info at %zu", i); |
| 1022 | continue; |
| 1023 | } |
| 1024 | skdebug(__func__, "trying %s", fido_dev_info_path(di)); |
| 1025 | if ((r = read_rks(fido_dev_info_path(di), pin, |
| 1026 | &rks, &nrks)) != 0) { |
| 1027 | skdebug(__func__, "read_rks failed for %s", |
| 1028 | fido_dev_info_path(di)); |
| 1029 | /* remember last error */ |
| 1030 | ret = r; |
| 1031 | continue; |
| 1032 | } |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 1033 | } |
| 1034 | } |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 1035 | /* success, unless we have no keys but a specific error */ |
| 1036 | if (nrks > 0 || ret == SSH_SK_ERR_GENERAL) |
| 1037 | ret = 0; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 1038 | *rksp = rks; |
| 1039 | *nrksp = nrks; |
| 1040 | rks = NULL; |
| 1041 | nrks = 0; |
| 1042 | out: |
djm@openbsd.org | c312ca0 | 2020-01-06 02:00:46 +0000 | [diff] [blame] | 1043 | free(device); |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 1044 | for (i = 0; i < nrks; i++) { |
| 1045 | free(rks[i]->application); |
| 1046 | freezero(rks[i]->key.public_key, rks[i]->key.public_key_len); |
| 1047 | freezero(rks[i]->key.key_handle, rks[i]->key.key_handle_len); |
| 1048 | freezero(rks[i], sizeof(*rks[i])); |
| 1049 | } |
| 1050 | free(rks); |
| 1051 | fido_dev_info_free(&devlist, MAX_FIDO_DEVICES); |
djm@openbsd.org | 43ce964 | 2019-12-30 09:24:45 +0000 | [diff] [blame] | 1052 | return ret; |
djm@openbsd.org | 14cea36 | 2019-12-30 09:21:16 +0000 | [diff] [blame] | 1053 | } |
| 1054 | |
djm@openbsd.org | 6bff952 | 2019-11-14 21:27:29 +0000 | [diff] [blame] | 1055 | #endif /* ENABLE_SK_INTERNAL */ |