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4c5e512e LH |
1 | /* |
2 | * QEMU Crypto akcipher algorithms | |
3 | * | |
4 | * Copyright (c) 2022 Bytedance | |
5 | * Author: lei he <helei.sig11@bytedance.com> | |
6 | * | |
7 | * This library is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; either | |
10 | * version 2.1 of the License, or (at your option) any later version. | |
11 | * | |
12 | * This library is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. | |
19 | * | |
20 | */ | |
21 | ||
22 | #include <nettle/rsa.h> | |
23 | ||
24 | #include "qemu/osdep.h" | |
25 | #include "qemu/host-utils.h" | |
26 | #include "crypto/akcipher.h" | |
27 | #include "crypto/random.h" | |
28 | #include "qapi/error.h" | |
29 | #include "sysemu/cryptodev.h" | |
30 | #include "rsakey.h" | |
31 | ||
32 | typedef struct QCryptoNettleRSA { | |
33 | QCryptoAkCipher akcipher; | |
34 | struct rsa_public_key pub; | |
35 | struct rsa_private_key priv; | |
36 | QCryptoRSAPaddingAlgorithm padding_alg; | |
37 | QCryptoHashAlgorithm hash_alg; | |
38 | } QCryptoNettleRSA; | |
39 | ||
40 | static void qcrypto_nettle_rsa_free(QCryptoAkCipher *akcipher) | |
41 | { | |
42 | QCryptoNettleRSA *rsa = (QCryptoNettleRSA *)akcipher; | |
43 | if (!rsa) { | |
44 | return; | |
45 | } | |
46 | ||
47 | rsa_public_key_clear(&rsa->pub); | |
48 | rsa_private_key_clear(&rsa->priv); | |
49 | g_free(rsa); | |
50 | } | |
51 | ||
52 | static QCryptoAkCipher *qcrypto_nettle_rsa_new( | |
53 | const QCryptoAkCipherOptionsRSA *opt, | |
54 | QCryptoAkCipherKeyType type, | |
55 | const uint8_t *key, size_t keylen, | |
56 | Error **errp); | |
57 | ||
58 | QCryptoAkCipher *qcrypto_akcipher_new(const QCryptoAkCipherOptions *opts, | |
59 | QCryptoAkCipherKeyType type, | |
60 | const uint8_t *key, size_t keylen, | |
61 | Error **errp) | |
62 | { | |
63 | switch (opts->alg) { | |
64 | case QCRYPTO_AKCIPHER_ALG_RSA: | |
65 | return qcrypto_nettle_rsa_new(&opts->u.rsa, type, key, keylen, errp); | |
66 | ||
67 | default: | |
68 | error_setg(errp, "Unsupported algorithm: %u", opts->alg); | |
69 | return NULL; | |
70 | } | |
71 | ||
72 | return NULL; | |
73 | } | |
74 | ||
75 | static void qcrypto_nettle_rsa_set_akcipher_size(QCryptoAkCipher *akcipher, | |
76 | int key_size) | |
77 | { | |
78 | akcipher->max_plaintext_len = key_size; | |
79 | akcipher->max_ciphertext_len = key_size; | |
80 | akcipher->max_signature_len = key_size; | |
81 | akcipher->max_dgst_len = key_size; | |
82 | } | |
83 | ||
84 | static int qcrypt_nettle_parse_rsa_private_key(QCryptoNettleRSA *rsa, | |
85 | const uint8_t *key, | |
86 | size_t keylen, | |
87 | Error **errp) | |
88 | { | |
89 | g_autoptr(QCryptoAkCipherRSAKey) rsa_key = qcrypto_akcipher_rsakey_parse( | |
90 | QCRYPTO_AKCIPHER_KEY_TYPE_PRIVATE, key, keylen, errp); | |
91 | ||
92 | if (!rsa_key) { | |
93 | return -1; | |
94 | } | |
95 | ||
96 | nettle_mpz_init_set_str_256_u(rsa->pub.n, rsa_key->n.len, rsa_key->n.data); | |
97 | nettle_mpz_init_set_str_256_u(rsa->pub.e, rsa_key->e.len, rsa_key->e.data); | |
98 | nettle_mpz_init_set_str_256_u(rsa->priv.d, rsa_key->d.len, rsa_key->d.data); | |
99 | nettle_mpz_init_set_str_256_u(rsa->priv.p, rsa_key->p.len, rsa_key->p.data); | |
100 | nettle_mpz_init_set_str_256_u(rsa->priv.q, rsa_key->q.len, rsa_key->q.data); | |
101 | nettle_mpz_init_set_str_256_u(rsa->priv.a, rsa_key->dp.len, | |
102 | rsa_key->dp.data); | |
103 | nettle_mpz_init_set_str_256_u(rsa->priv.b, rsa_key->dq.len, | |
104 | rsa_key->dq.data); | |
105 | nettle_mpz_init_set_str_256_u(rsa->priv.c, rsa_key->u.len, rsa_key->u.data); | |
106 | ||
107 | if (!rsa_public_key_prepare(&rsa->pub)) { | |
108 | error_setg(errp, "Failed to check RSA key"); | |
109 | return -1; | |
110 | } | |
111 | ||
112 | /** | |
113 | * Since in the kernel's unit test, the p, q, a, b, c of some | |
114 | * private keys is 0, only the simplest length check is done here | |
115 | */ | |
116 | if (rsa_key->p.len > 1 && | |
117 | rsa_key->q.len > 1 && | |
118 | rsa_key->dp.len > 1 && | |
119 | rsa_key->dq.len > 1 && | |
120 | rsa_key->u.len > 1) { | |
121 | if (!rsa_private_key_prepare(&rsa->priv)) { | |
122 | error_setg(errp, "Failed to check RSA key"); | |
123 | return -1; | |
124 | } | |
125 | } else { | |
126 | rsa->priv.size = rsa->pub.size; | |
127 | } | |
128 | qcrypto_nettle_rsa_set_akcipher_size( | |
129 | (QCryptoAkCipher *)rsa, rsa->priv.size); | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static int qcrypt_nettle_parse_rsa_public_key(QCryptoNettleRSA *rsa, | |
135 | const uint8_t *key, | |
136 | size_t keylen, | |
137 | Error **errp) | |
138 | { | |
139 | g_autoptr(QCryptoAkCipherRSAKey) rsa_key = qcrypto_akcipher_rsakey_parse( | |
140 | QCRYPTO_AKCIPHER_KEY_TYPE_PUBLIC, key, keylen, errp); | |
141 | ||
142 | if (!rsa_key) { | |
143 | return -1; | |
144 | } | |
145 | nettle_mpz_init_set_str_256_u(rsa->pub.n, rsa_key->n.len, rsa_key->n.data); | |
146 | nettle_mpz_init_set_str_256_u(rsa->pub.e, rsa_key->e.len, rsa_key->e.data); | |
147 | ||
148 | if (!rsa_public_key_prepare(&rsa->pub)) { | |
149 | error_setg(errp, "Failed to check RSA key"); | |
150 | return -1; | |
151 | } | |
152 | qcrypto_nettle_rsa_set_akcipher_size( | |
153 | (QCryptoAkCipher *)rsa, rsa->pub.size); | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | static void wrap_nettle_random_func(void *ctx, size_t len, uint8_t *out) | |
159 | { | |
160 | qcrypto_random_bytes(out, len, &error_abort); | |
161 | } | |
162 | ||
163 | static int qcrypto_nettle_rsa_encrypt(QCryptoAkCipher *akcipher, | |
164 | const void *data, size_t data_len, | |
165 | void *enc, size_t enc_len, | |
166 | Error **errp) | |
167 | { | |
168 | ||
169 | QCryptoNettleRSA *rsa = (QCryptoNettleRSA *)akcipher; | |
170 | mpz_t c; | |
171 | int ret = -1; | |
172 | ||
173 | if (data_len > rsa->pub.size) { | |
689309c4 | 174 | error_setg(errp, "Plaintext length %zu is greater than key size: %zu", |
4c5e512e LH |
175 | data_len, rsa->pub.size); |
176 | return ret; | |
177 | } | |
178 | ||
179 | if (enc_len < rsa->pub.size) { | |
180 | error_setg(errp, "Ciphertext buffer length %zu is less than " | |
689309c4 | 181 | "key size: %zu", enc_len, rsa->pub.size); |
4c5e512e LH |
182 | return ret; |
183 | } | |
184 | ||
185 | /* Nettle do not support RSA encryption without any padding */ | |
186 | switch (rsa->padding_alg) { | |
187 | case QCRYPTO_RSA_PADDING_ALG_RAW: | |
188 | error_setg(errp, "RSA with raw padding is not supported"); | |
189 | break; | |
190 | ||
191 | case QCRYPTO_RSA_PADDING_ALG_PKCS1: | |
192 | mpz_init(c); | |
193 | if (rsa_encrypt(&rsa->pub, NULL, wrap_nettle_random_func, | |
194 | data_len, (uint8_t *)data, c) != 1) { | |
195 | error_setg(errp, "Failed to encrypt"); | |
196 | } else { | |
197 | nettle_mpz_get_str_256(enc_len, (uint8_t *)enc, c); | |
198 | ret = nettle_mpz_sizeinbase_256_u(c); | |
199 | } | |
200 | mpz_clear(c); | |
201 | break; | |
202 | ||
203 | default: | |
204 | error_setg(errp, "Unknown padding"); | |
205 | } | |
206 | ||
207 | return ret; | |
208 | } | |
209 | ||
210 | static int qcrypto_nettle_rsa_decrypt(QCryptoAkCipher *akcipher, | |
211 | const void *enc, size_t enc_len, | |
212 | void *data, size_t data_len, | |
213 | Error **errp) | |
214 | { | |
215 | QCryptoNettleRSA *rsa = (QCryptoNettleRSA *)akcipher; | |
216 | mpz_t c; | |
217 | int ret = -1; | |
218 | ||
219 | if (enc_len > rsa->priv.size) { | |
220 | error_setg(errp, "Ciphertext length %zu is greater than key size: %zu", | |
689309c4 | 221 | enc_len, rsa->priv.size); |
4c5e512e LH |
222 | return ret; |
223 | } | |
224 | ||
225 | switch (rsa->padding_alg) { | |
226 | case QCRYPTO_RSA_PADDING_ALG_RAW: | |
227 | error_setg(errp, "RSA with raw padding is not supported"); | |
228 | break; | |
229 | ||
230 | case QCRYPTO_RSA_PADDING_ALG_PKCS1: | |
231 | nettle_mpz_init_set_str_256_u(c, enc_len, enc); | |
232 | if (!rsa_decrypt(&rsa->priv, &data_len, (uint8_t *)data, c)) { | |
233 | error_setg(errp, "Failed to decrypt"); | |
234 | } else { | |
235 | ret = data_len; | |
236 | } | |
237 | ||
238 | mpz_clear(c); | |
239 | break; | |
240 | ||
241 | default: | |
242 | error_setg(errp, "Unknown padding algorithm: %d", rsa->padding_alg); | |
243 | } | |
244 | ||
245 | return ret; | |
246 | } | |
247 | ||
248 | static int qcrypto_nettle_rsa_sign(QCryptoAkCipher *akcipher, | |
249 | const void *data, size_t data_len, | |
250 | void *sig, size_t sig_len, Error **errp) | |
251 | { | |
252 | QCryptoNettleRSA *rsa = (QCryptoNettleRSA *)akcipher; | |
253 | int ret = -1, rv; | |
254 | mpz_t s; | |
255 | ||
256 | /** | |
257 | * The RSA algorithm cannot be used for signature/verification | |
258 | * without padding. | |
259 | */ | |
260 | if (rsa->padding_alg == QCRYPTO_RSA_PADDING_ALG_RAW) { | |
261 | error_setg(errp, "Try to make signature without padding"); | |
262 | return ret; | |
263 | } | |
264 | ||
265 | if (data_len > rsa->priv.size) { | |
266 | error_setg(errp, "Data length %zu is greater than key size: %zu", | |
689309c4 | 267 | data_len, rsa->priv.size); |
4c5e512e LH |
268 | return ret; |
269 | } | |
270 | ||
271 | if (sig_len < rsa->priv.size) { | |
272 | error_setg(errp, "Signature buffer length %zu is less than " | |
689309c4 | 273 | "key size: %zu", sig_len, rsa->priv.size); |
4c5e512e LH |
274 | return ret; |
275 | } | |
276 | ||
277 | mpz_init(s); | |
278 | switch (rsa->hash_alg) { | |
279 | case QCRYPTO_HASH_ALG_MD5: | |
280 | rv = rsa_md5_sign_digest(&rsa->priv, data, s); | |
281 | break; | |
282 | ||
283 | case QCRYPTO_HASH_ALG_SHA1: | |
284 | rv = rsa_sha1_sign_digest(&rsa->priv, data, s); | |
285 | break; | |
286 | ||
287 | case QCRYPTO_HASH_ALG_SHA256: | |
288 | rv = rsa_sha256_sign_digest(&rsa->priv, data, s); | |
289 | break; | |
290 | ||
291 | case QCRYPTO_HASH_ALG_SHA512: | |
292 | rv = rsa_sha512_sign_digest(&rsa->priv, data, s); | |
293 | break; | |
294 | ||
295 | default: | |
296 | error_setg(errp, "Unknown hash algorithm: %d", rsa->hash_alg); | |
297 | goto cleanup; | |
298 | } | |
299 | ||
300 | if (rv != 1) { | |
301 | error_setg(errp, "Failed to make signature"); | |
302 | goto cleanup; | |
303 | } | |
304 | nettle_mpz_get_str_256(sig_len, (uint8_t *)sig, s); | |
305 | ret = nettle_mpz_sizeinbase_256_u(s); | |
306 | ||
307 | cleanup: | |
308 | mpz_clear(s); | |
309 | ||
310 | return ret; | |
311 | } | |
312 | ||
313 | static int qcrypto_nettle_rsa_verify(QCryptoAkCipher *akcipher, | |
314 | const void *sig, size_t sig_len, | |
315 | const void *data, size_t data_len, | |
316 | Error **errp) | |
317 | { | |
318 | QCryptoNettleRSA *rsa = (QCryptoNettleRSA *)akcipher; | |
319 | ||
320 | int ret = -1, rv; | |
321 | mpz_t s; | |
322 | ||
323 | /** | |
324 | * The RSA algorithm cannot be used for signature/verification | |
325 | * without padding. | |
326 | */ | |
327 | if (rsa->padding_alg == QCRYPTO_RSA_PADDING_ALG_RAW) { | |
328 | error_setg(errp, "Try to verify signature without padding"); | |
329 | return ret; | |
330 | } | |
331 | if (data_len > rsa->pub.size) { | |
332 | error_setg(errp, "Data length %zu is greater than key size: %zu", | |
689309c4 | 333 | data_len, rsa->pub.size); |
4c5e512e LH |
334 | return ret; |
335 | } | |
336 | if (sig_len < rsa->pub.size) { | |
337 | error_setg(errp, "Signature length %zu is greater than key size: %zu", | |
689309c4 | 338 | sig_len, rsa->pub.size); |
4c5e512e LH |
339 | return ret; |
340 | } | |
341 | ||
342 | nettle_mpz_init_set_str_256_u(s, sig_len, sig); | |
343 | switch (rsa->hash_alg) { | |
344 | case QCRYPTO_HASH_ALG_MD5: | |
345 | rv = rsa_md5_verify_digest(&rsa->pub, data, s); | |
346 | break; | |
347 | ||
348 | case QCRYPTO_HASH_ALG_SHA1: | |
349 | rv = rsa_sha1_verify_digest(&rsa->pub, data, s); | |
350 | break; | |
351 | ||
352 | case QCRYPTO_HASH_ALG_SHA256: | |
353 | rv = rsa_sha256_verify_digest(&rsa->pub, data, s); | |
354 | break; | |
355 | ||
356 | case QCRYPTO_HASH_ALG_SHA512: | |
357 | rv = rsa_sha512_verify_digest(&rsa->pub, data, s); | |
358 | break; | |
359 | ||
360 | default: | |
361 | error_setg(errp, "Unsupported hash algorithm: %d", rsa->hash_alg); | |
362 | goto cleanup; | |
363 | } | |
364 | ||
365 | if (rv != 1) { | |
366 | error_setg(errp, "Failed to verify signature"); | |
367 | goto cleanup; | |
368 | } | |
369 | ret = 0; | |
370 | ||
371 | cleanup: | |
372 | mpz_clear(s); | |
373 | ||
374 | return ret; | |
375 | } | |
376 | ||
377 | QCryptoAkCipherDriver nettle_rsa = { | |
378 | .encrypt = qcrypto_nettle_rsa_encrypt, | |
379 | .decrypt = qcrypto_nettle_rsa_decrypt, | |
380 | .sign = qcrypto_nettle_rsa_sign, | |
381 | .verify = qcrypto_nettle_rsa_verify, | |
382 | .free = qcrypto_nettle_rsa_free, | |
383 | }; | |
384 | ||
385 | static QCryptoAkCipher *qcrypto_nettle_rsa_new( | |
386 | const QCryptoAkCipherOptionsRSA *opt, | |
387 | QCryptoAkCipherKeyType type, | |
388 | const uint8_t *key, size_t keylen, | |
389 | Error **errp) | |
390 | { | |
391 | QCryptoNettleRSA *rsa = g_new0(QCryptoNettleRSA, 1); | |
392 | ||
393 | rsa->padding_alg = opt->padding_alg; | |
394 | rsa->hash_alg = opt->hash_alg; | |
395 | rsa->akcipher.driver = &nettle_rsa; | |
396 | rsa_public_key_init(&rsa->pub); | |
397 | rsa_private_key_init(&rsa->priv); | |
398 | ||
399 | switch (type) { | |
400 | case QCRYPTO_AKCIPHER_KEY_TYPE_PRIVATE: | |
401 | if (qcrypt_nettle_parse_rsa_private_key(rsa, key, keylen, errp) != 0) { | |
402 | goto error; | |
403 | } | |
404 | break; | |
405 | ||
406 | case QCRYPTO_AKCIPHER_KEY_TYPE_PUBLIC: | |
407 | if (qcrypt_nettle_parse_rsa_public_key(rsa, key, keylen, errp) != 0) { | |
408 | goto error; | |
409 | } | |
410 | break; | |
411 | ||
412 | default: | |
413 | error_setg(errp, "Unknown akcipher key type %d", type); | |
414 | goto error; | |
415 | } | |
416 | ||
417 | return (QCryptoAkCipher *)rsa; | |
418 | ||
419 | error: | |
420 | qcrypto_nettle_rsa_free((QCryptoAkCipher *)rsa); | |
421 | return NULL; | |
422 | } | |
423 | ||
424 | ||
425 | bool qcrypto_akcipher_supports(QCryptoAkCipherOptions *opts) | |
426 | { | |
427 | switch (opts->alg) { | |
428 | case QCRYPTO_AKCIPHER_ALG_RSA: | |
429 | switch (opts->u.rsa.padding_alg) { | |
430 | case QCRYPTO_RSA_PADDING_ALG_PKCS1: | |
431 | switch (opts->u.rsa.hash_alg) { | |
432 | case QCRYPTO_HASH_ALG_MD5: | |
433 | case QCRYPTO_HASH_ALG_SHA1: | |
434 | case QCRYPTO_HASH_ALG_SHA256: | |
435 | case QCRYPTO_HASH_ALG_SHA512: | |
436 | return true; | |
437 | ||
438 | default: | |
439 | return false; | |
440 | } | |
441 | ||
442 | case QCRYPTO_RSA_PADDING_ALG_RAW: | |
443 | default: | |
444 | return false; | |
445 | } | |
446 | break; | |
447 | ||
448 | default: | |
449 | return false; | |
450 | } | |
451 | } |