1 | /* |
2 | * QEMU crypto secret support |
3 | * |
4 | * Copyright (c) 2015 Red Hat, Inc. |
5 | * |
6 | * This library is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU Lesser General Public |
8 | * License as published by the Free Software Foundation; either |
9 | * version 2.1 of the License, or (at your option) any later version. |
10 | * |
11 | * This library is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | * Lesser General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU Lesser General Public |
17 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
18 | * |
19 | */ |
20 | |
21 | #include "qemu/osdep.h" |
22 | #include "crypto/secret.h" |
23 | #include "crypto/cipher.h" |
24 | #include "qapi/error.h" |
25 | #include "qom/object_interfaces.h" |
26 | #include "qemu/base64.h" |
27 | #include "qemu/module.h" |
28 | #include "trace.h" |
29 | |
30 | |
31 | static void |
32 | qcrypto_secret_load_data(QCryptoSecret *secret, |
33 | uint8_t **output, |
34 | size_t *outputlen, |
35 | Error **errp) |
36 | { |
37 | char *data = NULL; |
38 | size_t length = 0; |
39 | GError *gerr = NULL; |
40 | |
41 | *output = NULL; |
42 | *outputlen = 0; |
43 | |
44 | if (secret->file) { |
45 | if (secret->data) { |
46 | error_setg(errp, |
47 | "'file' and 'data' are mutually exclusive" ); |
48 | return; |
49 | } |
50 | if (!g_file_get_contents(secret->file, &data, &length, &gerr)) { |
51 | error_setg(errp, |
52 | "Unable to read %s: %s" , |
53 | secret->file, gerr->message); |
54 | g_error_free(gerr); |
55 | return; |
56 | } |
57 | *output = (uint8_t *)data; |
58 | *outputlen = length; |
59 | } else if (secret->data) { |
60 | *outputlen = strlen(secret->data); |
61 | *output = (uint8_t *)g_strdup(secret->data); |
62 | } else { |
63 | error_setg(errp, "Either 'file' or 'data' must be provided" ); |
64 | } |
65 | } |
66 | |
67 | |
68 | static void qcrypto_secret_decrypt(QCryptoSecret *secret, |
69 | const uint8_t *input, |
70 | size_t inputlen, |
71 | uint8_t **output, |
72 | size_t *outputlen, |
73 | Error **errp) |
74 | { |
75 | g_autofree uint8_t *key = NULL; |
76 | g_autofree uint8_t *ciphertext = NULL; |
77 | g_autofree uint8_t *iv = NULL; |
78 | size_t keylen, ciphertextlen, ivlen; |
79 | g_autoptr(QCryptoCipher) aes = NULL; |
80 | g_autofree uint8_t *plaintext = NULL; |
81 | |
82 | *output = NULL; |
83 | *outputlen = 0; |
84 | |
85 | if (qcrypto_secret_lookup(secret->keyid, |
86 | &key, &keylen, |
87 | errp) < 0) { |
88 | return; |
89 | } |
90 | |
91 | if (keylen != 32) { |
92 | error_setg(errp, "Key should be 32 bytes in length" ); |
93 | return; |
94 | } |
95 | |
96 | if (!secret->iv) { |
97 | error_setg(errp, "IV is required to decrypt secret" ); |
98 | return; |
99 | } |
100 | |
101 | iv = qbase64_decode(secret->iv, -1, &ivlen, errp); |
102 | if (!iv) { |
103 | return; |
104 | } |
105 | if (ivlen != 16) { |
106 | error_setg(errp, "IV should be 16 bytes in length not %zu" , |
107 | ivlen); |
108 | return; |
109 | } |
110 | |
111 | aes = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_256, |
112 | QCRYPTO_CIPHER_MODE_CBC, |
113 | key, keylen, |
114 | errp); |
115 | if (!aes) { |
116 | return; |
117 | } |
118 | |
119 | if (qcrypto_cipher_setiv(aes, iv, ivlen, errp) < 0) { |
120 | return; |
121 | } |
122 | |
123 | if (secret->format == QCRYPTO_SECRET_FORMAT_BASE64) { |
124 | ciphertext = qbase64_decode((const gchar*)input, |
125 | inputlen, |
126 | &ciphertextlen, |
127 | errp); |
128 | if (!ciphertext) { |
129 | return; |
130 | } |
131 | plaintext = g_new0(uint8_t, ciphertextlen + 1); |
132 | } else { |
133 | ciphertextlen = inputlen; |
134 | plaintext = g_new0(uint8_t, inputlen + 1); |
135 | } |
136 | if (qcrypto_cipher_decrypt(aes, |
137 | ciphertext ? ciphertext : input, |
138 | plaintext, |
139 | ciphertextlen, |
140 | errp) < 0) { |
141 | return; |
142 | } |
143 | |
144 | if (plaintext[ciphertextlen - 1] > 16 || |
145 | plaintext[ciphertextlen - 1] > ciphertextlen) { |
146 | error_setg(errp, "Incorrect number of padding bytes (%d) " |
147 | "found on decrypted data" , |
148 | (int)plaintext[ciphertextlen - 1]); |
149 | return; |
150 | } |
151 | |
152 | /* Even though plaintext may contain arbitrary NUL |
153 | * ensure it is explicitly NUL terminated. |
154 | */ |
155 | ciphertextlen -= plaintext[ciphertextlen - 1]; |
156 | plaintext[ciphertextlen] = '\0'; |
157 | |
158 | *output = g_steal_pointer(&plaintext); |
159 | *outputlen = ciphertextlen; |
160 | } |
161 | |
162 | |
163 | static void qcrypto_secret_decode(const uint8_t *input, |
164 | size_t inputlen, |
165 | uint8_t **output, |
166 | size_t *outputlen, |
167 | Error **errp) |
168 | { |
169 | *output = qbase64_decode((const gchar*)input, |
170 | inputlen, |
171 | outputlen, |
172 | errp); |
173 | } |
174 | |
175 | |
176 | static void |
177 | qcrypto_secret_prop_set_loaded(Object *obj, |
178 | bool value, |
179 | Error **errp) |
180 | { |
181 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
182 | |
183 | if (value) { |
184 | Error *local_err = NULL; |
185 | uint8_t *input = NULL; |
186 | size_t inputlen = 0; |
187 | uint8_t *output = NULL; |
188 | size_t outputlen = 0; |
189 | |
190 | qcrypto_secret_load_data(secret, &input, &inputlen, &local_err); |
191 | if (local_err) { |
192 | error_propagate(errp, local_err); |
193 | return; |
194 | } |
195 | |
196 | if (secret->keyid) { |
197 | qcrypto_secret_decrypt(secret, input, inputlen, |
198 | &output, &outputlen, &local_err); |
199 | g_free(input); |
200 | if (local_err) { |
201 | error_propagate(errp, local_err); |
202 | return; |
203 | } |
204 | input = output; |
205 | inputlen = outputlen; |
206 | } else { |
207 | if (secret->format != QCRYPTO_SECRET_FORMAT_RAW) { |
208 | qcrypto_secret_decode(input, inputlen, |
209 | &output, &outputlen, &local_err); |
210 | g_free(input); |
211 | if (local_err) { |
212 | error_propagate(errp, local_err); |
213 | return; |
214 | } |
215 | input = output; |
216 | inputlen = outputlen; |
217 | } |
218 | } |
219 | |
220 | secret->rawdata = input; |
221 | secret->rawlen = inputlen; |
222 | } else { |
223 | g_free(secret->rawdata); |
224 | secret->rawlen = 0; |
225 | } |
226 | } |
227 | |
228 | |
229 | static bool |
230 | qcrypto_secret_prop_get_loaded(Object *obj, |
231 | Error **errp G_GNUC_UNUSED) |
232 | { |
233 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
234 | return secret->data != NULL; |
235 | } |
236 | |
237 | |
238 | static void |
239 | qcrypto_secret_prop_set_format(Object *obj, |
240 | int value, |
241 | Error **errp G_GNUC_UNUSED) |
242 | { |
243 | QCryptoSecret *creds = QCRYPTO_SECRET(obj); |
244 | |
245 | creds->format = value; |
246 | } |
247 | |
248 | |
249 | static int |
250 | qcrypto_secret_prop_get_format(Object *obj, |
251 | Error **errp G_GNUC_UNUSED) |
252 | { |
253 | QCryptoSecret *creds = QCRYPTO_SECRET(obj); |
254 | |
255 | return creds->format; |
256 | } |
257 | |
258 | |
259 | static void |
260 | qcrypto_secret_prop_set_data(Object *obj, |
261 | const char *value, |
262 | Error **errp) |
263 | { |
264 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
265 | |
266 | g_free(secret->data); |
267 | secret->data = g_strdup(value); |
268 | } |
269 | |
270 | |
271 | static char * |
272 | qcrypto_secret_prop_get_data(Object *obj, |
273 | Error **errp) |
274 | { |
275 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
276 | return g_strdup(secret->data); |
277 | } |
278 | |
279 | |
280 | static void |
281 | qcrypto_secret_prop_set_file(Object *obj, |
282 | const char *value, |
283 | Error **errp) |
284 | { |
285 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
286 | |
287 | g_free(secret->file); |
288 | secret->file = g_strdup(value); |
289 | } |
290 | |
291 | |
292 | static char * |
293 | qcrypto_secret_prop_get_file(Object *obj, |
294 | Error **errp) |
295 | { |
296 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
297 | return g_strdup(secret->file); |
298 | } |
299 | |
300 | |
301 | static void |
302 | qcrypto_secret_prop_set_iv(Object *obj, |
303 | const char *value, |
304 | Error **errp) |
305 | { |
306 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
307 | |
308 | g_free(secret->iv); |
309 | secret->iv = g_strdup(value); |
310 | } |
311 | |
312 | |
313 | static char * |
314 | qcrypto_secret_prop_get_iv(Object *obj, |
315 | Error **errp) |
316 | { |
317 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
318 | return g_strdup(secret->iv); |
319 | } |
320 | |
321 | |
322 | static void |
323 | qcrypto_secret_prop_set_keyid(Object *obj, |
324 | const char *value, |
325 | Error **errp) |
326 | { |
327 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
328 | |
329 | g_free(secret->keyid); |
330 | secret->keyid = g_strdup(value); |
331 | } |
332 | |
333 | |
334 | static char * |
335 | qcrypto_secret_prop_get_keyid(Object *obj, |
336 | Error **errp) |
337 | { |
338 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
339 | return g_strdup(secret->keyid); |
340 | } |
341 | |
342 | |
343 | static void |
344 | qcrypto_secret_complete(UserCreatable *uc, Error **errp) |
345 | { |
346 | object_property_set_bool(OBJECT(uc), true, "loaded" , errp); |
347 | } |
348 | |
349 | |
350 | static void |
351 | qcrypto_secret_finalize(Object *obj) |
352 | { |
353 | QCryptoSecret *secret = QCRYPTO_SECRET(obj); |
354 | |
355 | g_free(secret->iv); |
356 | g_free(secret->file); |
357 | g_free(secret->keyid); |
358 | g_free(secret->rawdata); |
359 | g_free(secret->data); |
360 | } |
361 | |
362 | static void |
363 | qcrypto_secret_class_init(ObjectClass *oc, void *data) |
364 | { |
365 | UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); |
366 | |
367 | ucc->complete = qcrypto_secret_complete; |
368 | |
369 | object_class_property_add_bool(oc, "loaded" , |
370 | qcrypto_secret_prop_get_loaded, |
371 | qcrypto_secret_prop_set_loaded, |
372 | NULL); |
373 | object_class_property_add_enum(oc, "format" , |
374 | "QCryptoSecretFormat" , |
375 | &QCryptoSecretFormat_lookup, |
376 | qcrypto_secret_prop_get_format, |
377 | qcrypto_secret_prop_set_format, |
378 | NULL); |
379 | object_class_property_add_str(oc, "data" , |
380 | qcrypto_secret_prop_get_data, |
381 | qcrypto_secret_prop_set_data, |
382 | NULL); |
383 | object_class_property_add_str(oc, "file" , |
384 | qcrypto_secret_prop_get_file, |
385 | qcrypto_secret_prop_set_file, |
386 | NULL); |
387 | object_class_property_add_str(oc, "keyid" , |
388 | qcrypto_secret_prop_get_keyid, |
389 | qcrypto_secret_prop_set_keyid, |
390 | NULL); |
391 | object_class_property_add_str(oc, "iv" , |
392 | qcrypto_secret_prop_get_iv, |
393 | qcrypto_secret_prop_set_iv, |
394 | NULL); |
395 | } |
396 | |
397 | |
398 | int qcrypto_secret_lookup(const char *secretid, |
399 | uint8_t **data, |
400 | size_t *datalen, |
401 | Error **errp) |
402 | { |
403 | Object *obj; |
404 | QCryptoSecret *secret; |
405 | |
406 | obj = object_resolve_path_component( |
407 | object_get_objects_root(), secretid); |
408 | if (!obj) { |
409 | error_setg(errp, "No secret with id '%s'" , secretid); |
410 | return -1; |
411 | } |
412 | |
413 | secret = (QCryptoSecret *) |
414 | object_dynamic_cast(obj, |
415 | TYPE_QCRYPTO_SECRET); |
416 | if (!secret) { |
417 | error_setg(errp, "Object with id '%s' is not a secret" , |
418 | secretid); |
419 | return -1; |
420 | } |
421 | |
422 | if (!secret->rawdata) { |
423 | error_setg(errp, "Secret with id '%s' has no data" , |
424 | secretid); |
425 | return -1; |
426 | } |
427 | |
428 | *data = g_new0(uint8_t, secret->rawlen + 1); |
429 | memcpy(*data, secret->rawdata, secret->rawlen); |
430 | (*data)[secret->rawlen] = '\0'; |
431 | *datalen = secret->rawlen; |
432 | |
433 | return 0; |
434 | } |
435 | |
436 | |
437 | char *qcrypto_secret_lookup_as_utf8(const char *secretid, |
438 | Error **errp) |
439 | { |
440 | uint8_t *data; |
441 | size_t datalen; |
442 | |
443 | if (qcrypto_secret_lookup(secretid, |
444 | &data, |
445 | &datalen, |
446 | errp) < 0) { |
447 | return NULL; |
448 | } |
449 | |
450 | if (!g_utf8_validate((const gchar*)data, datalen, NULL)) { |
451 | error_setg(errp, |
452 | "Data from secret %s is not valid UTF-8" , |
453 | secretid); |
454 | g_free(data); |
455 | return NULL; |
456 | } |
457 | |
458 | return (char *)data; |
459 | } |
460 | |
461 | |
462 | char *qcrypto_secret_lookup_as_base64(const char *secretid, |
463 | Error **errp) |
464 | { |
465 | uint8_t *data; |
466 | size_t datalen; |
467 | char *ret; |
468 | |
469 | if (qcrypto_secret_lookup(secretid, |
470 | &data, |
471 | &datalen, |
472 | errp) < 0) { |
473 | return NULL; |
474 | } |
475 | |
476 | ret = g_base64_encode(data, datalen); |
477 | g_free(data); |
478 | return ret; |
479 | } |
480 | |
481 | |
482 | static const TypeInfo qcrypto_secret_info = { |
483 | .parent = TYPE_OBJECT, |
484 | .name = TYPE_QCRYPTO_SECRET, |
485 | .instance_size = sizeof(QCryptoSecret), |
486 | .instance_finalize = qcrypto_secret_finalize, |
487 | .class_size = sizeof(QCryptoSecretClass), |
488 | .class_init = qcrypto_secret_class_init, |
489 | .interfaces = (InterfaceInfo[]) { |
490 | { TYPE_USER_CREATABLE }, |
491 | { } |
492 | } |
493 | }; |
494 | |
495 | |
496 | static void |
497 | qcrypto_secret_register_types(void) |
498 | { |
499 | type_register_static(&qcrypto_secret_info); |
500 | } |
501 | |
502 | |
503 | type_init(qcrypto_secret_register_types); |
504 | |