1 /*
2 * Copyright (c) 2022-2023 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include "hvb_hash_sha256.h"
18 #include "hvb_crypto.h"
19 #include "hvb_rsa.h"
20 #include "hvb_util.h"
21 #include "hvb_sysdeps.h"
22 #include "hvb_rsa_verify.h"
23
24
25 #define SHA256_DIGEST_LEN 32
26 #define PSS_EM_PADDING_LEN 2
27 #define PSS_MTMP_PADDING_LEN 8
28 #define PSS_DB_PADDING_LEN 1
29 #define PSS_END_PADDING_UNIT 0xBC
30 #define PSS_LEFTMOST_BIT_MASK 0xFFU
31
32 #define PADDING_UNIT_ZERO 0x00
33 #define PADDING_UNIT_ONE 0x01
34 #define RSA_WIDTH_MAX 8192
35
36 #define WORD_BYTE_SIZE sizeof(unsigned long)
37 #define WORD_BIT_SIZE (WORD_BYTE_SIZE * 8)
38 #define WORD_BIT_MASK (((1UL << WORD_BIT_SIZE) - 1))
39 #define bit2byte(bits) ((bits) >> 3)
40 #define byte2bit(byte) ((byte) << 3)
41 #define bit_val(x) (1U << (x))
42 #define bit_mask(x) (bit_val(x) - 1U)
43 #define bit_align(n, bit) (((n) + bit_mask(bit)) & (~(bit_mask(bit))))
44 #define bit2byte_align(bits) bit2byte(bit_align(bits, 3))
45 #define byte2dword(bytes) (((bytes) + (WORD_BYTE_SIZE) - 1) / WORD_BYTE_SIZE)
46 #define dword2byte(words) ((words) * WORD_BYTE_SIZE)
47
48 /* calc M' = (0x)00 00 00 00 00 00 00 00 || mHash || salt */
emsa_pss_calc_m(const uint8_t * pdigest,uint32_t digestlen,uint8_t * salt,uint32_t saltlen,uint8_t ** m)49 static int emsa_pss_calc_m(const uint8_t *pdigest, uint32_t digestlen,
50 uint8_t *salt, uint32_t saltlen,
51 uint8_t **m)
52 {
53 uint8_t *m_tmp = NULL;
54 uint32_t m_tmp_len;
55
56 m_tmp_len = digestlen + saltlen + PSS_MTMP_PADDING_LEN;
57 m_tmp = (uint8_t *)hvb_malloc(m_tmp_len);
58 if (!m_tmp) {
59 return PARAM_EMPTY_ERROR;
60 }
61
62 hvb_memset(m_tmp, 0, PSS_MTMP_PADDING_LEN);
63 hvb_memcpy(&m_tmp[PSS_MTMP_PADDING_LEN], pdigest, digestlen);
64
65 if (saltlen != 0 && salt) {
66 hvb_memcpy(&m_tmp[PSS_MTMP_PADDING_LEN + digestlen], salt, saltlen);
67 }
68
69 *m = m_tmp;
70 return VERIFY_OK;
71 }
72
73 /* rsa verify last step compare hash value */
emsa_pss_hash_cmp(uint8_t * m_tmp,uint32_t m_tmp_len,uint8_t * hash,uint32_t digestlen)74 static int emsa_pss_hash_cmp(uint8_t *m_tmp, uint32_t m_tmp_len,
75 uint8_t *hash, uint32_t digestlen)
76 {
77 int ret;
78 uint8_t *hash_tmp = NULL;
79
80 hash_tmp = (uint8_t *)hvb_malloc(digestlen);
81 if (!hash_tmp) {
82 return HASH_CMP_FAIL;
83 }
84 if (hash_sha256_single(m_tmp, m_tmp_len, hash_tmp, digestlen) != HASH_OK) {
85 ret = HASH_CMP_FAIL;
86 goto rsa_error;
87 }
88 /* compare twice */
89 ret = VERIFY_OK;
90 ret += hvb_memcmp(hash, hash_tmp, digestlen);
91 ret += hvb_memcmp(hash, hash_tmp, digestlen);
92 if (ret != VERIFY_OK)
93 ret = HASH_CMP_FAIL;
94 rsa_error:
95 hvb_free(hash_tmp);
96 return ret;
97 }
98
rsa_pss_get_emlen(uint32_t klen,struct long_int_num * pn,uint32_t * emlen,uint32_t * embits)99 static int rsa_pss_get_emlen(uint32_t klen, struct long_int_num *pn,
100 uint32_t *emlen, uint32_t *embits)
101 {
102 *embits = lin_get_bitlen(pn);
103 if (*embits == 0) {
104 return CALC_EMLEN_ERROR;
105 }
106 (*embits)--;
107
108 *emlen = bit2byte_align(*embits);
109 if (*emlen == 0) {
110 return CALC_EMLEN_ERROR;
111 }
112
113 if (*emlen > klen) {
114 return CALC_EMLEN_ERROR;
115 }
116
117 return VERIFY_OK;
118 }
119
120 /* make generate function V1 */
rsa_gen_mask_mgf_v1(uint8_t * seed,uint32_t seed_len,uint8_t * mask,uint32_t mask_len)121 static int rsa_gen_mask_mgf_v1(uint8_t *seed, uint32_t seed_len,
122 uint8_t *mask, uint32_t mask_len)
123 {
124 int ret = VERIFY_OK;
125 uint32_t cnt = 0;
126 uint32_t cnt_maxsize = 0;
127 uint8_t *p_tmp = NULL;
128 uint8_t *pt = NULL;
129 uint8_t *pc = NULL;
130 const uint32_t hash_len = SHA256_DIGEST_LEN;
131
132 /* Step 1: mask length is smaller than the maximum key length */
133 if (mask_len > bit2byte(RSA_WIDTH_MAX)) {
134 return CALC_MASK_ERROR;
135 }
136
137 /* Step 2: Let pt and pt_tmp be the empty octet string. */
138 pt = (uint8_t *)hvb_malloc(mask_len + hash_len);
139 if (!pt) {
140 return CALC_MASK_ERROR;
141 }
142
143 pc = (uint8_t *)hvb_malloc(seed_len + sizeof(uint32_t));
144 if (!pc) {
145 ret = CALC_MASK_ERROR;
146 goto rsa_error;
147 }
148
149 /*
150 * Step 3: For counter from 0 to (mask_len + hash_len - 1) / hash_len ,
151 * do the following:
152 * string T: T = T || Hash (pseed || counter)
153 */
154 p_tmp = pt;
155 hvb_memcpy(pc, seed, seed_len);
156
157 hvb_memset(pc + seed_len, 0, sizeof(uint32_t));
158 /* step 3.1: count of Hash blocks needed for mask calculation */
159 cnt_maxsize = (uint32_t)((mask_len + hash_len - 1) / hash_len);
160
161 for (cnt = 0; cnt < cnt_maxsize; cnt++) {
162 /* step 3.2: pt_tmp = pseed ||Counter */
163 pc[seed_len + sizeof(uint32_t) - sizeof(uint8_t)] = cnt;
164
165 /* step 3.3: calc T, T = T || Hash (pt_tmp) */
166 if (hash_sha256_single(pc, seed_len + sizeof(uint32_t), p_tmp, hash_len) != HASH_OK) {
167 ret = CALC_MASK_ERROR;
168 goto rsa_error;
169 }
170 p_tmp += hash_len;
171 }
172 /* Step 4: Output the leading L octets of T as the octet string mask. */
173 hvb_memcpy(mask, pt, mask_len);
174
175 rsa_error:
176 hvb_free(pt);
177 hvb_free(pc);
178 return ret;
179 }
180
emsa_pss_verify_check_db(uint8_t * db,uint32_t db_len,uint32_t emlen,uint32_t digestlen,uint32_t saltlen)181 static int emsa_pss_verify_check_db(uint8_t *db, uint32_t db_len,
182 uint32_t emlen, uint32_t digestlen,
183 uint32_t saltlen)
184 {
185 int i;
186
187 for (i = 0; i < emlen - digestlen - saltlen - PSS_EM_PADDING_LEN; i++) {
188 if (db[i] != PADDING_UNIT_ZERO) {
189 return CHECK_DB_ERROR;
190 }
191 }
192
193 if (db[db_len - saltlen - PSS_DB_PADDING_LEN] != PADDING_UNIT_ONE) {
194 return CMP_DB_FAIL;
195 }
196
197 return VERIFY_OK;
198 }
199
emsa_pss_verify(uint32_t saltlen,const uint8_t * pdigest,uint32_t digestlen,uint32_t emlen,uint32_t embits,uint8_t * pem)200 static int emsa_pss_verify(uint32_t saltlen, const uint8_t *pdigest,
201 uint32_t digestlen, uint32_t emlen,
202 uint32_t embits, uint8_t *pem)
203 {
204 int ret;
205 uint32_t i;
206 uint32_t masklen;
207 uint32_t m_tmp_len;
208 uint32_t db_len = 0;
209 uint8_t *hash = NULL;
210 uint8_t *m_tmp = NULL;
211 uint8_t *maskedb = NULL;
212 uint8_t *salt = NULL;
213 uint8_t *db = NULL;
214
215 masklen = byte2bit(emlen) - embits;
216
217 /*
218 * Step 1: Skip digest calculate
219 * Step 2: Check sizes, emLen < hLen + sLen + 2
220 */
221 if (emlen < digestlen + PSS_EM_PADDING_LEN || saltlen > (emlen - digestlen - PSS_EM_PADDING_LEN)) {
222 return CALC_EMLEN_ERROR;
223 }
224 /* Step 3: if rightmost of EM is oxbc */
225 if (pem[emlen - PSS_DB_PADDING_LEN] != PSS_END_PADDING_UNIT) {
226 return CALC_0XBC_ERROR;
227 }
228
229 /* Step 4: set maskedDB and H */
230 maskedb = pem;
231 db_len = emlen - digestlen - PSS_DB_PADDING_LEN;
232 hash = &pem[db_len];
233
234 /* Step 5: Check that the leftmost bits in the leftmost octet of EM have the value 0 */
235 if ((maskedb[0] & (~(PSS_LEFTMOST_BIT_MASK >> masklen))) != 0) {
236 return CALC_EM_ERROR;
237 }
238
239 /* Step 6: calc dbMask, MGF(H) */
240 db = (uint8_t *)hvb_malloc(db_len); /* db is dbmask */
241 if (!db) {
242 return CALC_DB_ERROR;
243 }
244 ret = rsa_gen_mask_mgf_v1(hash, digestlen, db, db_len);
245 if (ret != VERIFY_OK) {
246 goto rsa_error;
247 }
248 /* Step 7: calc db, maskedDB ^ db_mask */
249 for (i = 0; i < db_len; i++) {
250 db[i] = maskedb[i] ^ db[i];
251 }
252
253 /* Step 8: Set the leftmost 8*emLen-emBits bits in DB to zero */
254 db[0] &= PSS_LEFTMOST_BIT_MASK >> masklen;
255
256 /* Step 9: check db padding data */
257 ret = emsa_pss_verify_check_db(db, db_len, emlen, digestlen, saltlen);
258 if (ret != VERIFY_OK) {
259 goto rsa_error;
260 }
261 /* Step 10: set salt be the last slen of DB */
262 if (saltlen != 0) {
263 salt = &db[db_len - saltlen];
264 }
265
266 /* Step 11: calc M' = (0x)00 00 00 00 00 00 00 00 || mHash || salt */
267 ret = emsa_pss_calc_m(pdigest, digestlen, salt, saltlen, &m_tmp);
268 if (ret != VERIFY_OK) {
269 goto rsa_error;
270 }
271 /* Step 12: hash_tmp = H' = Hash(M') */
272 m_tmp_len = PSS_MTMP_PADDING_LEN + digestlen + saltlen;
273 ret = emsa_pss_hash_cmp(m_tmp, m_tmp_len, hash, digestlen);
274
275 rsa_error:
276 hvb_free(db);
277 hvb_free(m_tmp);
278 return ret;
279 }
280
invert_copy(uint8_t * dst,uint8_t * src,uint32_t len)281 static inline void invert_copy(uint8_t *dst, uint8_t *src, uint32_t len)
282 {
283 for (uint32_t i = 0; i < len; i++) {
284 dst[i] = src[len - i - 1];
285 }
286 }
287
hvb_rsa_verify_pss_param_check(const struct hvb_rsa_pubkey * pkey,const uint8_t * pdigest,uint32_t digestlen,uint8_t * psign,uint32_t signlen)288 static int hvb_rsa_verify_pss_param_check(const struct hvb_rsa_pubkey *pkey, const uint8_t *pdigest,
289 uint32_t digestlen, uint8_t *psign, uint32_t signlen)
290 {
291 uint32_t klen;
292
293 if (!pkey || !pdigest || !psign) {
294 return PARAM_EMPTY_ERROR;
295 }
296 if (!pkey->pn || !pkey->p_rr || pkey->n_n0_i == 0) {
297 return PUBKEY_EMPTY_ERROR;
298 }
299 klen = bit2byte(pkey->width);
300 if (digestlen != SHA256_DIGEST_LEN) {
301 return DIGEST_LEN_ERROR;
302 }
303 if (pkey->nlen != klen || pkey->rlen > pkey->nlen) {
304 return PUBKEY_LEN_ERROR;
305 }
306 if (signlen > klen) {
307 return SIGN_LEN_ERROR;
308 }
309
310 return VERIFY_OK;
311 }
312
hvb_rsa_verify_pss_param_convert(const struct hvb_rsa_pubkey * pkey,uint8_t * psign,uint32_t signlen,struct long_int_num * p_n,struct long_int_num * p_rr,struct long_int_num * p_m)313 static int hvb_rsa_verify_pss_param_convert(const struct hvb_rsa_pubkey *pkey, uint8_t *psign,
314 uint32_t signlen, struct long_int_num *p_n,
315 struct long_int_num *p_rr, struct long_int_num *p_m)
316 {
317 invert_copy((uint8_t *)p_n->p_uint, pkey->pn, pkey->nlen);
318 p_n->valid_word_len = byte2dword(pkey->nlen);
319 lin_update_valid_len(p_n);
320 if (!p_n) {
321 return PUBKEY_EMPTY_ERROR;
322 }
323
324 invert_copy((uint8_t *)p_m->p_uint, psign, signlen);
325 p_m->valid_word_len = byte2dword(pkey->nlen);
326 lin_update_valid_len(p_m);
327 if (!p_m) {
328 return SIGN_EMPTY_ERROR;
329 }
330
331 invert_copy((uint8_t *)p_rr->p_uint, pkey->p_rr, pkey->rlen);
332 p_rr->valid_word_len = byte2dword(pkey->nlen);
333 lin_update_valid_len(p_rr);
334 if (!p_rr) {
335 return PUBKEY_EMPTY_ERROR;
336 }
337
338 return VERIFY_OK;
339 }
340
hvb_rsa_verify_pss(const struct hvb_rsa_pubkey * pkey,const uint8_t * pdigest,uint32_t digestlen,uint8_t * psign,uint32_t signlen,uint32_t saltlen)341 int hvb_rsa_verify_pss(const struct hvb_rsa_pubkey
342 *pkey, const uint8_t *pdigest,
343 uint32_t digestlen, uint8_t *psign,
344 uint32_t signlen, uint32_t saltlen)
345 {
346 int ret;
347 uint32_t klen;
348 uint32_t emlen;
349 uint32_t embits;
350 unsigned long n_n0_i;
351 struct long_int_num *p_n = NULL;
352 struct long_int_num *p_m = NULL;
353 struct long_int_num *p_rr = NULL;
354 struct long_int_num *em = NULL;
355 uint8_t *em_data = NULL;
356
357 ret = hvb_rsa_verify_pss_param_check(pkey, pdigest, digestlen, psign, signlen);
358 if (ret != VERIFY_OK) {
359 return ret;
360 }
361
362 n_n0_i = (unsigned long)pkey->n_n0_i;
363 klen = bit2byte(pkey->width);
364 p_n = lin_create(byte2dword(pkey->nlen));
365 if (!p_n) {
366 return MEMORY_ERROR;
367 }
368 p_m = lin_create(byte2dword(pkey->nlen));
369 if (!p_m) {
370 ret = MEMORY_ERROR;
371 goto rsa_error;
372 }
373 p_rr = lin_create(byte2dword(pkey->nlen));
374 if (!p_rr) {
375 ret = MEMORY_ERROR;
376 goto rsa_error;
377 }
378 ret = hvb_rsa_verify_pss_param_convert(pkey, psign, signlen, p_n, p_rr, p_m);
379 if (ret != VERIFY_OK) {
380 goto rsa_error;
381 }
382 /* Step 1: RSA prim decrypt */
383 em = montgomery_mod_exp(p_m, p_n, n_n0_i, p_rr, pkey->e);
384 if (!em) {
385 ret = MOD_EXP_CALC_FAIL;
386 goto rsa_error;
387 }
388 em->valid_word_len = byte2dword(pkey->nlen);
389 lin_update_valid_len(em);
390 em_data = hvb_malloc(dword2byte(em->valid_word_len));
391 if (!em_data) {
392 ret = MOD_EXP_CALC_FAIL;
393 goto rsa_error;
394 }
395 invert_copy(em_data, (uint8_t *)em->p_uint, dword2byte(em->valid_word_len));
396 /* Step 2: emsa pss verify */
397 ret = rsa_pss_get_emlen(klen, p_n, &emlen, &embits);
398 if (ret != VERIFY_OK) {
399 goto rsa_error;
400 }
401 if (klen - emlen == 1 && em_data[0] != 0) {
402 ret = MOD_EXP_CALC_FAIL;
403 goto rsa_error;
404 }
405 ret = emsa_pss_verify(saltlen, pdigest, digestlen, emlen, embits, em_data + klen - emlen);
406
407 rsa_error:
408 lin_free(em);
409 lin_free(p_n);
410 lin_free(p_m);
411 lin_free(p_rr);
412 if (em_data) {
413 hvb_free(em_data);
414 }
415
416 return ret;
417 }
418