Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20210921' into staging
[qemu.git] / crypto / secret_common.c
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_common.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 qcrypto_secret_decrypt(QCryptoSecretCommon *secret,
32 const uint8_t *input,
33 size_t inputlen,
34 uint8_t **output,
35 size_t *outputlen,
36 Error **errp)
37 {
38 g_autofree uint8_t *iv = NULL;
39 g_autofree uint8_t *key = NULL;
40 g_autofree uint8_t *ciphertext = NULL;
41 size_t keylen, ciphertextlen, ivlen;
42 g_autoptr(QCryptoCipher) aes = NULL;
43 g_autofree uint8_t *plaintext = NULL;
44
45 *output = NULL;
46 *outputlen = 0;
47
48 if (qcrypto_secret_lookup(secret->keyid,
49 &key, &keylen,
50 errp) < 0) {
51 return;
52 }
53
54 if (keylen != 32) {
55 error_setg(errp, "Key should be 32 bytes in length");
56 return;
57 }
58
59 if (!secret->iv) {
60 error_setg(errp, "IV is required to decrypt secret");
61 return;
62 }
63
64 iv = qbase64_decode(secret->iv, -1, &ivlen, errp);
65 if (!iv) {
66 return;
67 }
68 if (ivlen != 16) {
69 error_setg(errp, "IV should be 16 bytes in length not %zu",
70 ivlen);
71 return;
72 }
73
74 aes = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_256,
75 QCRYPTO_CIPHER_MODE_CBC,
76 key, keylen,
77 errp);
78 if (!aes) {
79 return;
80 }
81
82 if (qcrypto_cipher_setiv(aes, iv, ivlen, errp) < 0) {
83 return;
84 }
85
86 if (secret->format == QCRYPTO_SECRET_FORMAT_BASE64) {
87 ciphertext = qbase64_decode((const gchar *)input,
88 inputlen,
89 &ciphertextlen,
90 errp);
91 if (!ciphertext) {
92 return;
93 }
94 plaintext = g_new0(uint8_t, ciphertextlen + 1);
95 } else {
96 ciphertextlen = inputlen;
97 plaintext = g_new0(uint8_t, inputlen + 1);
98 }
99 if (qcrypto_cipher_decrypt(aes,
100 ciphertext ? ciphertext : input,
101 plaintext,
102 ciphertextlen,
103 errp) < 0) {
104 return;
105 }
106
107 if (plaintext[ciphertextlen - 1] > 16 ||
108 plaintext[ciphertextlen - 1] > ciphertextlen) {
109 error_setg(errp, "Incorrect number of padding bytes (%d) "
110 "found on decrypted data",
111 (int)plaintext[ciphertextlen - 1]);
112 return;
113 }
114
115 /*
116 * Even though plaintext may contain arbitrary NUL
117 * ensure it is explicitly NUL terminated.
118 */
119 ciphertextlen -= plaintext[ciphertextlen - 1];
120 plaintext[ciphertextlen] = '\0';
121
122 *output = g_steal_pointer(&plaintext);
123 *outputlen = ciphertextlen;
124 }
125
126
127 static void qcrypto_secret_decode(const uint8_t *input,
128 size_t inputlen,
129 uint8_t **output,
130 size_t *outputlen,
131 Error **errp)
132 {
133 *output = qbase64_decode((const gchar *)input,
134 inputlen,
135 outputlen,
136 errp);
137 }
138
139
140 static void
141 qcrypto_secret_prop_set_loaded(Object *obj,
142 bool value,
143 Error **errp)
144 {
145 QCryptoSecretCommon *secret = QCRYPTO_SECRET_COMMON(obj);
146 QCryptoSecretCommonClass *sec_class
147 = QCRYPTO_SECRET_COMMON_GET_CLASS(obj);
148
149 if (value) {
150 Error *local_err = NULL;
151 uint8_t *input = NULL;
152 size_t inputlen = 0;
153 uint8_t *output = NULL;
154 size_t outputlen = 0;
155
156 if (sec_class->load_data) {
157 sec_class->load_data(secret, &input, &inputlen, &local_err);
158 if (local_err) {
159 error_propagate(errp, local_err);
160 return;
161 }
162 } else {
163 error_setg(errp, "%s provides no 'load_data' method'",
164 object_get_typename(obj));
165 return;
166 }
167
168 if (secret->keyid) {
169 qcrypto_secret_decrypt(secret, input, inputlen,
170 &output, &outputlen, &local_err);
171 g_free(input);
172 if (local_err) {
173 error_propagate(errp, local_err);
174 return;
175 }
176 input = output;
177 inputlen = outputlen;
178 } else {
179 if (secret->format == QCRYPTO_SECRET_FORMAT_BASE64) {
180 qcrypto_secret_decode(input, inputlen,
181 &output, &outputlen, &local_err);
182 g_free(input);
183 if (local_err) {
184 error_propagate(errp, local_err);
185 return;
186 }
187 input = output;
188 inputlen = outputlen;
189 }
190 }
191
192 secret->rawdata = input;
193 secret->rawlen = inputlen;
194 } else if (secret->rawdata) {
195 error_setg(errp, "Cannot unload secret");
196 return;
197 }
198 }
199
200
201 static bool
202 qcrypto_secret_prop_get_loaded(Object *obj,
203 Error **errp G_GNUC_UNUSED)
204 {
205 QCryptoSecretCommon *secret = QCRYPTO_SECRET_COMMON(obj);
206 return secret->rawdata != NULL;
207 }
208
209
210 static void
211 qcrypto_secret_prop_set_format(Object *obj,
212 int value,
213 Error **errp G_GNUC_UNUSED)
214 {
215 QCryptoSecretCommon *creds = QCRYPTO_SECRET_COMMON(obj);
216 creds->format = value;
217 }
218
219
220 static int
221 qcrypto_secret_prop_get_format(Object *obj,
222 Error **errp G_GNUC_UNUSED)
223 {
224 QCryptoSecretCommon *creds = QCRYPTO_SECRET_COMMON(obj);
225 return creds->format;
226 }
227
228
229 static void
230 qcrypto_secret_prop_set_iv(Object *obj,
231 const char *value,
232 Error **errp)
233 {
234 QCryptoSecretCommon *secret = QCRYPTO_SECRET_COMMON(obj);
235
236 g_free(secret->iv);
237 secret->iv = g_strdup(value);
238 }
239
240
241 static char *
242 qcrypto_secret_prop_get_iv(Object *obj,
243 Error **errp)
244 {
245 QCryptoSecretCommon *secret = QCRYPTO_SECRET_COMMON(obj);
246 return g_strdup(secret->iv);
247 }
248
249
250 static void
251 qcrypto_secret_prop_set_keyid(Object *obj,
252 const char *value,
253 Error **errp)
254 {
255 QCryptoSecretCommon *secret = QCRYPTO_SECRET_COMMON(obj);
256
257 g_free(secret->keyid);
258 secret->keyid = g_strdup(value);
259 }
260
261
262 static char *
263 qcrypto_secret_prop_get_keyid(Object *obj,
264 Error **errp)
265 {
266 QCryptoSecretCommon *secret = QCRYPTO_SECRET_COMMON(obj);
267 return g_strdup(secret->keyid);
268 }
269
270
271 static void
272 qcrypto_secret_complete(UserCreatable *uc, Error **errp)
273 {
274 object_property_set_bool(OBJECT(uc), "loaded", true, errp);
275 }
276
277
278 static void
279 qcrypto_secret_finalize(Object *obj)
280 {
281 QCryptoSecretCommon *secret = QCRYPTO_SECRET_COMMON(obj);
282
283 g_free(secret->iv);
284 g_free(secret->keyid);
285 g_free(secret->rawdata);
286 }
287
288 static void
289 qcrypto_secret_class_init(ObjectClass *oc, void *data)
290 {
291 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
292
293 ucc->complete = qcrypto_secret_complete;
294
295 object_class_property_add_bool(oc, "loaded",
296 qcrypto_secret_prop_get_loaded,
297 qcrypto_secret_prop_set_loaded);
298 object_class_property_add_enum(oc, "format",
299 "QCryptoSecretFormat",
300 &QCryptoSecretFormat_lookup,
301 qcrypto_secret_prop_get_format,
302 qcrypto_secret_prop_set_format);
303 object_class_property_add_str(oc, "keyid",
304 qcrypto_secret_prop_get_keyid,
305 qcrypto_secret_prop_set_keyid);
306 object_class_property_add_str(oc, "iv",
307 qcrypto_secret_prop_get_iv,
308 qcrypto_secret_prop_set_iv);
309 }
310
311
312 int qcrypto_secret_lookup(const char *secretid,
313 uint8_t **data,
314 size_t *datalen,
315 Error **errp)
316 {
317 Object *obj;
318 QCryptoSecretCommon *secret;
319
320 obj = object_resolve_path_component(
321 object_get_objects_root(), secretid);
322 if (!obj) {
323 error_setg(errp, "No secret with id '%s'", secretid);
324 return -1;
325 }
326
327 secret = (QCryptoSecretCommon *)
328 object_dynamic_cast(obj,
329 TYPE_QCRYPTO_SECRET_COMMON);
330 if (!secret) {
331 error_setg(errp, "Object with id '%s' is not a secret",
332 secretid);
333 return -1;
334 }
335
336 if (!secret->rawdata) {
337 error_setg(errp, "Secret with id '%s' has no data",
338 secretid);
339 return -1;
340 }
341
342 *data = g_new0(uint8_t, secret->rawlen + 1);
343 memcpy(*data, secret->rawdata, secret->rawlen);
344 (*data)[secret->rawlen] = '\0';
345 *datalen = secret->rawlen;
346
347 return 0;
348 }
349
350
351 char *qcrypto_secret_lookup_as_utf8(const char *secretid,
352 Error **errp)
353 {
354 uint8_t *data;
355 size_t datalen;
356
357 if (qcrypto_secret_lookup(secretid,
358 &data,
359 &datalen,
360 errp) < 0) {
361 return NULL;
362 }
363
364 if (!g_utf8_validate((const gchar *)data, datalen, NULL)) {
365 error_setg(errp,
366 "Data from secret %s is not valid UTF-8",
367 secretid);
368 g_free(data);
369 return NULL;
370 }
371
372 return (char *)data;
373 }
374
375
376 char *qcrypto_secret_lookup_as_base64(const char *secretid,
377 Error **errp)
378 {
379 uint8_t *data;
380 size_t datalen;
381 char *ret;
382
383 if (qcrypto_secret_lookup(secretid,
384 &data,
385 &datalen,
386 errp) < 0) {
387 return NULL;
388 }
389
390 ret = g_base64_encode(data, datalen);
391 g_free(data);
392 return ret;
393 }
394
395
396 static const TypeInfo qcrypto_secret_info = {
397 .parent = TYPE_OBJECT,
398 .name = TYPE_QCRYPTO_SECRET_COMMON,
399 .instance_size = sizeof(QCryptoSecretCommon),
400 .instance_finalize = qcrypto_secret_finalize,
401 .class_size = sizeof(QCryptoSecretCommonClass),
402 .class_init = qcrypto_secret_class_init,
403 .abstract = true,
404 .interfaces = (InterfaceInfo[]) {
405 { TYPE_USER_CREATABLE },
406 { }
407 }
408 };
409
410
411 static void
412 qcrypto_secret_register_types(void)
413 {
414 type_register_static(&qcrypto_secret_info);
415 }
416
417
418 type_init(qcrypto_secret_register_types);