1 | /* |
2 | * DRBG: Deterministic Random Bits Generator |
3 | * Based on NIST Recommended DRBG from NIST SP800-90A with the following |
4 | * properties: |
5 | * * CTR DRBG with DF with AES-128, AES-192, AES-256 cores |
6 | * * Hash DRBG with DF with SHA-1, SHA-256, SHA-384, SHA-512 cores |
7 | * * HMAC DRBG with DF with SHA-1, SHA-256, SHA-384, SHA-512 cores |
8 | * * with and without prediction resistance |
9 | * |
10 | * Copyright Stephan Mueller <smueller@chronox.de>, 2014 |
11 | * |
12 | * Redistribution and use in source and binary forms, with or without |
13 | * modification, are permitted provided that the following conditions |
14 | * are met: |
15 | * 1. Redistributions of source code must retain the above copyright |
16 | * notice, and the entire permission notice in its entirety, |
17 | * including the disclaimer of warranties. |
18 | * 2. Redistributions in binary form must reproduce the above copyright |
19 | * notice, this list of conditions and the following disclaimer in the |
20 | * documentation and/or other materials provided with the distribution. |
21 | * 3. The name of the author may not be used to endorse or promote |
22 | * products derived from this software without specific prior |
23 | * written permission. |
24 | * |
25 | * ALTERNATIVELY, this product may be distributed under the terms of |
26 | * the GNU General Public License, in which case the provisions of the GPL are |
27 | * required INSTEAD OF the above restrictions. (This clause is |
28 | * necessary due to a potential bad interaction between the GPL and |
29 | * the restrictions contained in a BSD-style copyright.) |
30 | * |
31 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED |
32 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
33 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF |
34 | * WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE |
35 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
36 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
37 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
38 | * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
39 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
40 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE |
41 | * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH |
42 | * DAMAGE. |
43 | * |
44 | * DRBG Usage |
45 | * ========== |
46 | * The SP 800-90A DRBG allows the user to specify a personalization string |
47 | * for initialization as well as an additional information string for each |
48 | * random number request. The following code fragments show how a caller |
49 | * uses the kernel crypto API to use the full functionality of the DRBG. |
50 | * |
51 | * Usage without any additional data |
52 | * --------------------------------- |
53 | * struct crypto_rng *drng; |
54 | * int err; |
55 | * char data[DATALEN]; |
56 | * |
57 | * drng = crypto_alloc_rng(drng_name, 0, 0); |
58 | * err = crypto_rng_get_bytes(drng, &data, DATALEN); |
59 | * crypto_free_rng(drng); |
60 | * |
61 | * |
62 | * Usage with personalization string during initialization |
63 | * ------------------------------------------------------- |
64 | * struct crypto_rng *drng; |
65 | * int err; |
66 | * char data[DATALEN]; |
67 | * struct drbg_string pers; |
68 | * char personalization[11] = "some-string"; |
69 | * |
70 | * drbg_string_fill(&pers, personalization, strlen(personalization)); |
71 | * drng = crypto_alloc_rng(drng_name, 0, 0); |
72 | * // The reset completely re-initializes the DRBG with the provided |
73 | * // personalization string |
74 | * err = crypto_rng_reset(drng, &personalization, strlen(personalization)); |
75 | * err = crypto_rng_get_bytes(drng, &data, DATALEN); |
76 | * crypto_free_rng(drng); |
77 | * |
78 | * |
79 | * Usage with additional information string during random number request |
80 | * --------------------------------------------------------------------- |
81 | * struct crypto_rng *drng; |
82 | * int err; |
83 | * char data[DATALEN]; |
84 | * char addtl_string[11] = "some-string"; |
85 | * string drbg_string addtl; |
86 | * |
87 | * drbg_string_fill(&addtl, addtl_string, strlen(addtl_string)); |
88 | * drng = crypto_alloc_rng(drng_name, 0, 0); |
89 | * // The following call is a wrapper to crypto_rng_get_bytes() and returns |
90 | * // the same error codes. |
91 | * err = crypto_drbg_get_bytes_addtl(drng, &data, DATALEN, &addtl); |
92 | * crypto_free_rng(drng); |
93 | * |
94 | * |
95 | * Usage with personalization and additional information strings |
96 | * ------------------------------------------------------------- |
97 | * Just mix both scenarios above. |
98 | */ |
99 | |
100 | #include <crypto/drbg.h> |
101 | #include <crypto/internal/cipher.h> |
102 | #include <linux/kernel.h> |
103 | #include <linux/jiffies.h> |
104 | |
105 | /*************************************************************** |
106 | * Backend cipher definitions available to DRBG |
107 | ***************************************************************/ |
108 | |
109 | /* |
110 | * The order of the DRBG definitions here matter: every DRBG is registered |
111 | * as stdrng. Each DRBG receives an increasing cra_priority values the later |
112 | * they are defined in this array (see drbg_fill_array). |
113 | * |
114 | * HMAC DRBGs are favored over Hash DRBGs over CTR DRBGs, and |
115 | * the SHA256 / AES 256 over other ciphers. Thus, the favored |
116 | * DRBGs are the latest entries in this array. |
117 | */ |
118 | static const struct drbg_core drbg_cores[] = { |
119 | #ifdef CONFIG_CRYPTO_DRBG_CTR |
120 | { |
121 | .flags = DRBG_CTR | DRBG_STRENGTH128, |
122 | .statelen = 32, /* 256 bits as defined in 10.2.1 */ |
123 | .blocklen_bytes = 16, |
124 | .cra_name = "ctr_aes128" , |
125 | .backend_cra_name = "aes" , |
126 | }, { |
127 | .flags = DRBG_CTR | DRBG_STRENGTH192, |
128 | .statelen = 40, /* 320 bits as defined in 10.2.1 */ |
129 | .blocklen_bytes = 16, |
130 | .cra_name = "ctr_aes192" , |
131 | .backend_cra_name = "aes" , |
132 | }, { |
133 | .flags = DRBG_CTR | DRBG_STRENGTH256, |
134 | .statelen = 48, /* 384 bits as defined in 10.2.1 */ |
135 | .blocklen_bytes = 16, |
136 | .cra_name = "ctr_aes256" , |
137 | .backend_cra_name = "aes" , |
138 | }, |
139 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ |
140 | #ifdef CONFIG_CRYPTO_DRBG_HASH |
141 | { |
142 | .flags = DRBG_HASH | DRBG_STRENGTH128, |
143 | .statelen = 55, /* 440 bits */ |
144 | .blocklen_bytes = 20, |
145 | .cra_name = "sha1" , |
146 | .backend_cra_name = "sha1" , |
147 | }, { |
148 | .flags = DRBG_HASH | DRBG_STRENGTH256, |
149 | .statelen = 111, /* 888 bits */ |
150 | .blocklen_bytes = 48, |
151 | .cra_name = "sha384" , |
152 | .backend_cra_name = "sha384" , |
153 | }, { |
154 | .flags = DRBG_HASH | DRBG_STRENGTH256, |
155 | .statelen = 111, /* 888 bits */ |
156 | .blocklen_bytes = 64, |
157 | .cra_name = "sha512" , |
158 | .backend_cra_name = "sha512" , |
159 | }, { |
160 | .flags = DRBG_HASH | DRBG_STRENGTH256, |
161 | .statelen = 55, /* 440 bits */ |
162 | .blocklen_bytes = 32, |
163 | .cra_name = "sha256" , |
164 | .backend_cra_name = "sha256" , |
165 | }, |
166 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ |
167 | #ifdef CONFIG_CRYPTO_DRBG_HMAC |
168 | { |
169 | .flags = DRBG_HMAC | DRBG_STRENGTH128, |
170 | .statelen = 20, /* block length of cipher */ |
171 | .blocklen_bytes = 20, |
172 | .cra_name = "hmac_sha1" , |
173 | .backend_cra_name = "hmac(sha1)" , |
174 | }, { |
175 | .flags = DRBG_HMAC | DRBG_STRENGTH256, |
176 | .statelen = 48, /* block length of cipher */ |
177 | .blocklen_bytes = 48, |
178 | .cra_name = "hmac_sha384" , |
179 | .backend_cra_name = "hmac(sha384)" , |
180 | }, { |
181 | .flags = DRBG_HMAC | DRBG_STRENGTH256, |
182 | .statelen = 32, /* block length of cipher */ |
183 | .blocklen_bytes = 32, |
184 | .cra_name = "hmac_sha256" , |
185 | .backend_cra_name = "hmac(sha256)" , |
186 | }, { |
187 | .flags = DRBG_HMAC | DRBG_STRENGTH256, |
188 | .statelen = 64, /* block length of cipher */ |
189 | .blocklen_bytes = 64, |
190 | .cra_name = "hmac_sha512" , |
191 | .backend_cra_name = "hmac(sha512)" , |
192 | }, |
193 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ |
194 | }; |
195 | |
196 | static int drbg_uninstantiate(struct drbg_state *drbg); |
197 | |
198 | /****************************************************************** |
199 | * Generic helper functions |
200 | ******************************************************************/ |
201 | |
202 | /* |
203 | * Return strength of DRBG according to SP800-90A section 8.4 |
204 | * |
205 | * @flags DRBG flags reference |
206 | * |
207 | * Return: normalized strength in *bytes* value or 32 as default |
208 | * to counter programming errors |
209 | */ |
210 | static inline unsigned short drbg_sec_strength(drbg_flag_t flags) |
211 | { |
212 | switch (flags & DRBG_STRENGTH_MASK) { |
213 | case DRBG_STRENGTH128: |
214 | return 16; |
215 | case DRBG_STRENGTH192: |
216 | return 24; |
217 | case DRBG_STRENGTH256: |
218 | return 32; |
219 | default: |
220 | return 32; |
221 | } |
222 | } |
223 | |
224 | /* |
225 | * FIPS 140-2 continuous self test for the noise source |
226 | * The test is performed on the noise source input data. Thus, the function |
227 | * implicitly knows the size of the buffer to be equal to the security |
228 | * strength. |
229 | * |
230 | * Note, this function disregards the nonce trailing the entropy data during |
231 | * initial seeding. |
232 | * |
233 | * drbg->drbg_mutex must have been taken. |
234 | * |
235 | * @drbg DRBG handle |
236 | * @entropy buffer of seed data to be checked |
237 | * |
238 | * return: |
239 | * 0 on success |
240 | * -EAGAIN on when the CTRNG is not yet primed |
241 | * < 0 on error |
242 | */ |
243 | static int drbg_fips_continuous_test(struct drbg_state *drbg, |
244 | const unsigned char *entropy) |
245 | { |
246 | unsigned short entropylen = drbg_sec_strength(flags: drbg->core->flags); |
247 | int ret = 0; |
248 | |
249 | if (!IS_ENABLED(CONFIG_CRYPTO_FIPS)) |
250 | return 0; |
251 | |
252 | /* skip test if we test the overall system */ |
253 | if (list_empty(head: &drbg->test_data.list)) |
254 | return 0; |
255 | /* only perform test in FIPS mode */ |
256 | if (!fips_enabled) |
257 | return 0; |
258 | |
259 | if (!drbg->fips_primed) { |
260 | /* Priming of FIPS test */ |
261 | memcpy(drbg->prev, entropy, entropylen); |
262 | drbg->fips_primed = true; |
263 | /* priming: another round is needed */ |
264 | return -EAGAIN; |
265 | } |
266 | ret = memcmp(p: drbg->prev, q: entropy, size: entropylen); |
267 | if (!ret) |
268 | panic(fmt: "DRBG continuous self test failed\n" ); |
269 | memcpy(drbg->prev, entropy, entropylen); |
270 | |
271 | /* the test shall pass when the two values are not equal */ |
272 | return 0; |
273 | } |
274 | |
275 | /* |
276 | * Convert an integer into a byte representation of this integer. |
277 | * The byte representation is big-endian |
278 | * |
279 | * @val value to be converted |
280 | * @buf buffer holding the converted integer -- caller must ensure that |
281 | * buffer size is at least 32 bit |
282 | */ |
283 | #if (defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR)) |
284 | static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf) |
285 | { |
286 | struct s { |
287 | __be32 conv; |
288 | }; |
289 | struct s *conversion = (struct s *) buf; |
290 | |
291 | conversion->conv = cpu_to_be32(val); |
292 | } |
293 | #endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */ |
294 | |
295 | /****************************************************************** |
296 | * CTR DRBG callback functions |
297 | ******************************************************************/ |
298 | |
299 | #ifdef CONFIG_CRYPTO_DRBG_CTR |
300 | #define CRYPTO_DRBG_CTR_STRING "CTR " |
301 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes256" ); |
302 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes256" ); |
303 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes192" ); |
304 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192" ); |
305 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128" ); |
306 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128" ); |
307 | |
308 | static void drbg_kcapi_symsetkey(struct drbg_state *drbg, |
309 | const unsigned char *key); |
310 | static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, |
311 | const struct drbg_string *in); |
312 | static int drbg_init_sym_kernel(struct drbg_state *drbg); |
313 | static int drbg_fini_sym_kernel(struct drbg_state *drbg); |
314 | static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, |
315 | u8 *inbuf, u32 inbuflen, |
316 | u8 *outbuf, u32 outlen); |
317 | #define DRBG_OUTSCRATCHLEN 256 |
318 | |
319 | /* BCC function for CTR DRBG as defined in 10.4.3 */ |
320 | static int drbg_ctr_bcc(struct drbg_state *drbg, |
321 | unsigned char *out, const unsigned char *key, |
322 | struct list_head *in) |
323 | { |
324 | int ret = 0; |
325 | struct drbg_string *curr = NULL; |
326 | struct drbg_string data; |
327 | short cnt = 0; |
328 | |
329 | drbg_string_fill(string: &data, buf: out, len: drbg_blocklen(drbg)); |
330 | |
331 | /* 10.4.3 step 2 / 4 */ |
332 | drbg_kcapi_symsetkey(drbg, key); |
333 | list_for_each_entry(curr, in, list) { |
334 | const unsigned char *pos = curr->buf; |
335 | size_t len = curr->len; |
336 | /* 10.4.3 step 4.1 */ |
337 | while (len) { |
338 | /* 10.4.3 step 4.2 */ |
339 | if (drbg_blocklen(drbg) == cnt) { |
340 | cnt = 0; |
341 | ret = drbg_kcapi_sym(drbg, outval: out, in: &data); |
342 | if (ret) |
343 | return ret; |
344 | } |
345 | out[cnt] ^= *pos; |
346 | pos++; |
347 | cnt++; |
348 | len--; |
349 | } |
350 | } |
351 | /* 10.4.3 step 4.2 for last block */ |
352 | if (cnt) |
353 | ret = drbg_kcapi_sym(drbg, outval: out, in: &data); |
354 | |
355 | return ret; |
356 | } |
357 | |
358 | /* |
359 | * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df |
360 | * (and drbg_ctr_bcc, but this function does not need any temporary buffers), |
361 | * the scratchpad is used as follows: |
362 | * drbg_ctr_update: |
363 | * temp |
364 | * start: drbg->scratchpad |
365 | * length: drbg_statelen(drbg) + drbg_blocklen(drbg) |
366 | * note: the cipher writing into this variable works |
367 | * blocklen-wise. Now, when the statelen is not a multiple |
368 | * of blocklen, the generateion loop below "spills over" |
369 | * by at most blocklen. Thus, we need to give sufficient |
370 | * memory. |
371 | * df_data |
372 | * start: drbg->scratchpad + |
373 | * drbg_statelen(drbg) + drbg_blocklen(drbg) |
374 | * length: drbg_statelen(drbg) |
375 | * |
376 | * drbg_ctr_df: |
377 | * pad |
378 | * start: df_data + drbg_statelen(drbg) |
379 | * length: drbg_blocklen(drbg) |
380 | * iv |
381 | * start: pad + drbg_blocklen(drbg) |
382 | * length: drbg_blocklen(drbg) |
383 | * temp |
384 | * start: iv + drbg_blocklen(drbg) |
385 | * length: drbg_satelen(drbg) + drbg_blocklen(drbg) |
386 | * note: temp is the buffer that the BCC function operates |
387 | * on. BCC operates blockwise. drbg_statelen(drbg) |
388 | * is sufficient when the DRBG state length is a multiple |
389 | * of the block size. For AES192 (and maybe other ciphers) |
390 | * this is not correct and the length for temp is |
391 | * insufficient (yes, that also means for such ciphers, |
392 | * the final output of all BCC rounds are truncated). |
393 | * Therefore, add drbg_blocklen(drbg) to cover all |
394 | * possibilities. |
395 | */ |
396 | |
397 | /* Derivation Function for CTR DRBG as defined in 10.4.2 */ |
398 | static int drbg_ctr_df(struct drbg_state *drbg, |
399 | unsigned char *df_data, size_t bytes_to_return, |
400 | struct list_head *seedlist) |
401 | { |
402 | int ret = -EFAULT; |
403 | unsigned char L_N[8]; |
404 | /* S3 is input */ |
405 | struct drbg_string S1, S2, S4, cipherin; |
406 | LIST_HEAD(bcc_list); |
407 | unsigned char *pad = df_data + drbg_statelen(drbg); |
408 | unsigned char *iv = pad + drbg_blocklen(drbg); |
409 | unsigned char *temp = iv + drbg_blocklen(drbg); |
410 | size_t padlen = 0; |
411 | unsigned int templen = 0; |
412 | /* 10.4.2 step 7 */ |
413 | unsigned int i = 0; |
414 | /* 10.4.2 step 8 */ |
415 | const unsigned char *K = (unsigned char *) |
416 | "\x00\x01\x02\x03\x04\x05\x06\x07" |
417 | "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" |
418 | "\x10\x11\x12\x13\x14\x15\x16\x17" |
419 | "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" ; |
420 | unsigned char *X; |
421 | size_t generated_len = 0; |
422 | size_t inputlen = 0; |
423 | struct drbg_string *seed = NULL; |
424 | |
425 | memset(pad, 0, drbg_blocklen(drbg)); |
426 | memset(iv, 0, drbg_blocklen(drbg)); |
427 | |
428 | /* 10.4.2 step 1 is implicit as we work byte-wise */ |
429 | |
430 | /* 10.4.2 step 2 */ |
431 | if ((512/8) < bytes_to_return) |
432 | return -EINVAL; |
433 | |
434 | /* 10.4.2 step 2 -- calculate the entire length of all input data */ |
435 | list_for_each_entry(seed, seedlist, list) |
436 | inputlen += seed->len; |
437 | drbg_cpu_to_be32(val: inputlen, buf: &L_N[0]); |
438 | |
439 | /* 10.4.2 step 3 */ |
440 | drbg_cpu_to_be32(val: bytes_to_return, buf: &L_N[4]); |
441 | |
442 | /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */ |
443 | padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg)); |
444 | /* wrap the padlen appropriately */ |
445 | if (padlen) |
446 | padlen = drbg_blocklen(drbg) - padlen; |
447 | /* |
448 | * pad / padlen contains the 0x80 byte and the following zero bytes. |
449 | * As the calculated padlen value only covers the number of zero |
450 | * bytes, this value has to be incremented by one for the 0x80 byte. |
451 | */ |
452 | padlen++; |
453 | pad[0] = 0x80; |
454 | |
455 | /* 10.4.2 step 4 -- first fill the linked list and then order it */ |
456 | drbg_string_fill(string: &S1, buf: iv, len: drbg_blocklen(drbg)); |
457 | list_add_tail(new: &S1.list, head: &bcc_list); |
458 | drbg_string_fill(string: &S2, buf: L_N, len: sizeof(L_N)); |
459 | list_add_tail(new: &S2.list, head: &bcc_list); |
460 | list_splice_tail(list: seedlist, head: &bcc_list); |
461 | drbg_string_fill(string: &S4, buf: pad, len: padlen); |
462 | list_add_tail(new: &S4.list, head: &bcc_list); |
463 | |
464 | /* 10.4.2 step 9 */ |
465 | while (templen < (drbg_keylen(drbg) + (drbg_blocklen(drbg)))) { |
466 | /* |
467 | * 10.4.2 step 9.1 - the padding is implicit as the buffer |
468 | * holds zeros after allocation -- even the increment of i |
469 | * is irrelevant as the increment remains within length of i |
470 | */ |
471 | drbg_cpu_to_be32(val: i, buf: iv); |
472 | /* 10.4.2 step 9.2 -- BCC and concatenation with temp */ |
473 | ret = drbg_ctr_bcc(drbg, out: temp + templen, key: K, in: &bcc_list); |
474 | if (ret) |
475 | goto out; |
476 | /* 10.4.2 step 9.3 */ |
477 | i++; |
478 | templen += drbg_blocklen(drbg); |
479 | } |
480 | |
481 | /* 10.4.2 step 11 */ |
482 | X = temp + (drbg_keylen(drbg)); |
483 | drbg_string_fill(string: &cipherin, buf: X, len: drbg_blocklen(drbg)); |
484 | |
485 | /* 10.4.2 step 12: overwriting of outval is implemented in next step */ |
486 | |
487 | /* 10.4.2 step 13 */ |
488 | drbg_kcapi_symsetkey(drbg, key: temp); |
489 | while (generated_len < bytes_to_return) { |
490 | short blocklen = 0; |
491 | /* |
492 | * 10.4.2 step 13.1: the truncation of the key length is |
493 | * implicit as the key is only drbg_blocklen in size based on |
494 | * the implementation of the cipher function callback |
495 | */ |
496 | ret = drbg_kcapi_sym(drbg, outval: X, in: &cipherin); |
497 | if (ret) |
498 | goto out; |
499 | blocklen = (drbg_blocklen(drbg) < |
500 | (bytes_to_return - generated_len)) ? |
501 | drbg_blocklen(drbg) : |
502 | (bytes_to_return - generated_len); |
503 | /* 10.4.2 step 13.2 and 14 */ |
504 | memcpy(df_data + generated_len, X, blocklen); |
505 | generated_len += blocklen; |
506 | } |
507 | |
508 | ret = 0; |
509 | |
510 | out: |
511 | memset(iv, 0, drbg_blocklen(drbg)); |
512 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
513 | memset(pad, 0, drbg_blocklen(drbg)); |
514 | return ret; |
515 | } |
516 | |
517 | /* |
518 | * update function of CTR DRBG as defined in 10.2.1.2 |
519 | * |
520 | * The reseed variable has an enhanced meaning compared to the update |
521 | * functions of the other DRBGs as follows: |
522 | * 0 => initial seed from initialization |
523 | * 1 => reseed via drbg_seed |
524 | * 2 => first invocation from drbg_ctr_update when addtl is present. In |
525 | * this case, the df_data scratchpad is not deleted so that it is |
526 | * available for another calls to prevent calling the DF function |
527 | * again. |
528 | * 3 => second invocation from drbg_ctr_update. When the update function |
529 | * was called with addtl, the df_data memory already contains the |
530 | * DFed addtl information and we do not need to call DF again. |
531 | */ |
532 | static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, |
533 | int reseed) |
534 | { |
535 | int ret = -EFAULT; |
536 | /* 10.2.1.2 step 1 */ |
537 | unsigned char *temp = drbg->scratchpad; |
538 | unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) + |
539 | drbg_blocklen(drbg); |
540 | |
541 | if (3 > reseed) |
542 | memset(df_data, 0, drbg_statelen(drbg)); |
543 | |
544 | if (!reseed) { |
545 | /* |
546 | * The DRBG uses the CTR mode of the underlying AES cipher. The |
547 | * CTR mode increments the counter value after the AES operation |
548 | * but SP800-90A requires that the counter is incremented before |
549 | * the AES operation. Hence, we increment it at the time we set |
550 | * it by one. |
551 | */ |
552 | crypto_inc(a: drbg->V, size: drbg_blocklen(drbg)); |
553 | |
554 | ret = crypto_skcipher_setkey(tfm: drbg->ctr_handle, key: drbg->C, |
555 | keylen: drbg_keylen(drbg)); |
556 | if (ret) |
557 | goto out; |
558 | } |
559 | |
560 | /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */ |
561 | if (seed) { |
562 | ret = drbg_ctr_df(drbg, df_data, bytes_to_return: drbg_statelen(drbg), seedlist: seed); |
563 | if (ret) |
564 | goto out; |
565 | } |
566 | |
567 | ret = drbg_kcapi_sym_ctr(drbg, inbuf: df_data, inbuflen: drbg_statelen(drbg), |
568 | outbuf: temp, outlen: drbg_statelen(drbg)); |
569 | if (ret) |
570 | return ret; |
571 | |
572 | /* 10.2.1.2 step 5 */ |
573 | ret = crypto_skcipher_setkey(tfm: drbg->ctr_handle, key: temp, |
574 | keylen: drbg_keylen(drbg)); |
575 | if (ret) |
576 | goto out; |
577 | /* 10.2.1.2 step 6 */ |
578 | memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg)); |
579 | /* See above: increment counter by one to compensate timing of CTR op */ |
580 | crypto_inc(a: drbg->V, size: drbg_blocklen(drbg)); |
581 | ret = 0; |
582 | |
583 | out: |
584 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
585 | if (2 != reseed) |
586 | memset(df_data, 0, drbg_statelen(drbg)); |
587 | return ret; |
588 | } |
589 | |
590 | /* |
591 | * scratchpad use: drbg_ctr_update is called independently from |
592 | * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused |
593 | */ |
594 | /* Generate function of CTR DRBG as defined in 10.2.1.5.2 */ |
595 | static int drbg_ctr_generate(struct drbg_state *drbg, |
596 | unsigned char *buf, unsigned int buflen, |
597 | struct list_head *addtl) |
598 | { |
599 | int ret; |
600 | int len = min_t(int, buflen, INT_MAX); |
601 | |
602 | /* 10.2.1.5.2 step 2 */ |
603 | if (addtl && !list_empty(head: addtl)) { |
604 | ret = drbg_ctr_update(drbg, seed: addtl, reseed: 2); |
605 | if (ret) |
606 | return 0; |
607 | } |
608 | |
609 | /* 10.2.1.5.2 step 4.1 */ |
610 | ret = drbg_kcapi_sym_ctr(drbg, NULL, inbuflen: 0, outbuf: buf, outlen: len); |
611 | if (ret) |
612 | return ret; |
613 | |
614 | /* 10.2.1.5.2 step 6 */ |
615 | ret = drbg_ctr_update(drbg, NULL, reseed: 3); |
616 | if (ret) |
617 | len = ret; |
618 | |
619 | return len; |
620 | } |
621 | |
622 | static const struct drbg_state_ops drbg_ctr_ops = { |
623 | .update = drbg_ctr_update, |
624 | .generate = drbg_ctr_generate, |
625 | .crypto_init = drbg_init_sym_kernel, |
626 | .crypto_fini = drbg_fini_sym_kernel, |
627 | }; |
628 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ |
629 | |
630 | /****************************************************************** |
631 | * HMAC DRBG callback functions |
632 | ******************************************************************/ |
633 | |
634 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) |
635 | static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, |
636 | const struct list_head *in); |
637 | static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg, |
638 | const unsigned char *key); |
639 | static int drbg_init_hash_kernel(struct drbg_state *drbg); |
640 | static int drbg_fini_hash_kernel(struct drbg_state *drbg); |
641 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ |
642 | |
643 | #ifdef CONFIG_CRYPTO_DRBG_HMAC |
644 | #define CRYPTO_DRBG_HMAC_STRING "HMAC " |
645 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512" ); |
646 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512" ); |
647 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384" ); |
648 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384" ); |
649 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256" ); |
650 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256" ); |
651 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1" ); |
652 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1" ); |
653 | |
654 | /* update function of HMAC DRBG as defined in 10.1.2.2 */ |
655 | static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed, |
656 | int reseed) |
657 | { |
658 | int ret = -EFAULT; |
659 | int i = 0; |
660 | struct drbg_string seed1, seed2, vdata; |
661 | LIST_HEAD(seedlist); |
662 | LIST_HEAD(vdatalist); |
663 | |
664 | if (!reseed) { |
665 | /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */ |
666 | memset(drbg->V, 1, drbg_statelen(drbg)); |
667 | drbg_kcapi_hmacsetkey(drbg, key: drbg->C); |
668 | } |
669 | |
670 | drbg_string_fill(string: &seed1, buf: drbg->V, len: drbg_statelen(drbg)); |
671 | list_add_tail(new: &seed1.list, head: &seedlist); |
672 | /* buffer of seed2 will be filled in for loop below with one byte */ |
673 | drbg_string_fill(string: &seed2, NULL, len: 1); |
674 | list_add_tail(new: &seed2.list, head: &seedlist); |
675 | /* input data of seed is allowed to be NULL at this point */ |
676 | if (seed) |
677 | list_splice_tail(list: seed, head: &seedlist); |
678 | |
679 | drbg_string_fill(string: &vdata, buf: drbg->V, len: drbg_statelen(drbg)); |
680 | list_add_tail(new: &vdata.list, head: &vdatalist); |
681 | for (i = 2; 0 < i; i--) { |
682 | /* first round uses 0x0, second 0x1 */ |
683 | unsigned char prefix = DRBG_PREFIX0; |
684 | if (1 == i) |
685 | prefix = DRBG_PREFIX1; |
686 | /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */ |
687 | seed2.buf = &prefix; |
688 | ret = drbg_kcapi_hash(drbg, outval: drbg->C, in: &seedlist); |
689 | if (ret) |
690 | return ret; |
691 | drbg_kcapi_hmacsetkey(drbg, key: drbg->C); |
692 | |
693 | /* 10.1.2.2 step 2 and 5 -- HMAC for V */ |
694 | ret = drbg_kcapi_hash(drbg, outval: drbg->V, in: &vdatalist); |
695 | if (ret) |
696 | return ret; |
697 | |
698 | /* 10.1.2.2 step 3 */ |
699 | if (!seed) |
700 | return ret; |
701 | } |
702 | |
703 | return 0; |
704 | } |
705 | |
706 | /* generate function of HMAC DRBG as defined in 10.1.2.5 */ |
707 | static int drbg_hmac_generate(struct drbg_state *drbg, |
708 | unsigned char *buf, |
709 | unsigned int buflen, |
710 | struct list_head *addtl) |
711 | { |
712 | int len = 0; |
713 | int ret = 0; |
714 | struct drbg_string data; |
715 | LIST_HEAD(datalist); |
716 | |
717 | /* 10.1.2.5 step 2 */ |
718 | if (addtl && !list_empty(head: addtl)) { |
719 | ret = drbg_hmac_update(drbg, seed: addtl, reseed: 1); |
720 | if (ret) |
721 | return ret; |
722 | } |
723 | |
724 | drbg_string_fill(string: &data, buf: drbg->V, len: drbg_statelen(drbg)); |
725 | list_add_tail(new: &data.list, head: &datalist); |
726 | while (len < buflen) { |
727 | unsigned int outlen = 0; |
728 | /* 10.1.2.5 step 4.1 */ |
729 | ret = drbg_kcapi_hash(drbg, outval: drbg->V, in: &datalist); |
730 | if (ret) |
731 | return ret; |
732 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? |
733 | drbg_blocklen(drbg) : (buflen - len); |
734 | |
735 | /* 10.1.2.5 step 4.2 */ |
736 | memcpy(buf + len, drbg->V, outlen); |
737 | len += outlen; |
738 | } |
739 | |
740 | /* 10.1.2.5 step 6 */ |
741 | if (addtl && !list_empty(head: addtl)) |
742 | ret = drbg_hmac_update(drbg, seed: addtl, reseed: 1); |
743 | else |
744 | ret = drbg_hmac_update(drbg, NULL, reseed: 1); |
745 | if (ret) |
746 | return ret; |
747 | |
748 | return len; |
749 | } |
750 | |
751 | static const struct drbg_state_ops drbg_hmac_ops = { |
752 | .update = drbg_hmac_update, |
753 | .generate = drbg_hmac_generate, |
754 | .crypto_init = drbg_init_hash_kernel, |
755 | .crypto_fini = drbg_fini_hash_kernel, |
756 | }; |
757 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ |
758 | |
759 | /****************************************************************** |
760 | * Hash DRBG callback functions |
761 | ******************************************************************/ |
762 | |
763 | #ifdef CONFIG_CRYPTO_DRBG_HASH |
764 | #define CRYPTO_DRBG_HASH_STRING "HASH " |
765 | MODULE_ALIAS_CRYPTO("drbg_pr_sha512" ); |
766 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha512" ); |
767 | MODULE_ALIAS_CRYPTO("drbg_pr_sha384" ); |
768 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha384" ); |
769 | MODULE_ALIAS_CRYPTO("drbg_pr_sha256" ); |
770 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha256" ); |
771 | MODULE_ALIAS_CRYPTO("drbg_pr_sha1" ); |
772 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha1" ); |
773 | |
774 | /* |
775 | * Increment buffer |
776 | * |
777 | * @dst buffer to increment |
778 | * @add value to add |
779 | */ |
780 | static inline void drbg_add_buf(unsigned char *dst, size_t dstlen, |
781 | const unsigned char *add, size_t addlen) |
782 | { |
783 | /* implied: dstlen > addlen */ |
784 | unsigned char *dstptr; |
785 | const unsigned char *addptr; |
786 | unsigned int remainder = 0; |
787 | size_t len = addlen; |
788 | |
789 | dstptr = dst + (dstlen-1); |
790 | addptr = add + (addlen-1); |
791 | while (len) { |
792 | remainder += *dstptr + *addptr; |
793 | *dstptr = remainder & 0xff; |
794 | remainder >>= 8; |
795 | len--; dstptr--; addptr--; |
796 | } |
797 | len = dstlen - addlen; |
798 | while (len && remainder > 0) { |
799 | remainder = *dstptr + 1; |
800 | *dstptr = remainder & 0xff; |
801 | remainder >>= 8; |
802 | len--; dstptr--; |
803 | } |
804 | } |
805 | |
806 | /* |
807 | * scratchpad usage: as drbg_hash_update and drbg_hash_df are used |
808 | * interlinked, the scratchpad is used as follows: |
809 | * drbg_hash_update |
810 | * start: drbg->scratchpad |
811 | * length: drbg_statelen(drbg) |
812 | * drbg_hash_df: |
813 | * start: drbg->scratchpad + drbg_statelen(drbg) |
814 | * length: drbg_blocklen(drbg) |
815 | * |
816 | * drbg_hash_process_addtl uses the scratchpad, but fully completes |
817 | * before either of the functions mentioned before are invoked. Therefore, |
818 | * drbg_hash_process_addtl does not need to be specifically considered. |
819 | */ |
820 | |
821 | /* Derivation Function for Hash DRBG as defined in 10.4.1 */ |
822 | static int drbg_hash_df(struct drbg_state *drbg, |
823 | unsigned char *outval, size_t outlen, |
824 | struct list_head *entropylist) |
825 | { |
826 | int ret = 0; |
827 | size_t len = 0; |
828 | unsigned char input[5]; |
829 | unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg); |
830 | struct drbg_string data; |
831 | |
832 | /* 10.4.1 step 3 */ |
833 | input[0] = 1; |
834 | drbg_cpu_to_be32(val: (outlen * 8), buf: &input[1]); |
835 | |
836 | /* 10.4.1 step 4.1 -- concatenation of data for input into hash */ |
837 | drbg_string_fill(string: &data, buf: input, len: 5); |
838 | list_add(new: &data.list, head: entropylist); |
839 | |
840 | /* 10.4.1 step 4 */ |
841 | while (len < outlen) { |
842 | short blocklen = 0; |
843 | /* 10.4.1 step 4.1 */ |
844 | ret = drbg_kcapi_hash(drbg, outval: tmp, in: entropylist); |
845 | if (ret) |
846 | goto out; |
847 | /* 10.4.1 step 4.2 */ |
848 | input[0]++; |
849 | blocklen = (drbg_blocklen(drbg) < (outlen - len)) ? |
850 | drbg_blocklen(drbg) : (outlen - len); |
851 | memcpy(outval + len, tmp, blocklen); |
852 | len += blocklen; |
853 | } |
854 | |
855 | out: |
856 | memset(tmp, 0, drbg_blocklen(drbg)); |
857 | return ret; |
858 | } |
859 | |
860 | /* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */ |
861 | static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed, |
862 | int reseed) |
863 | { |
864 | int ret = 0; |
865 | struct drbg_string data1, data2; |
866 | LIST_HEAD(datalist); |
867 | LIST_HEAD(datalist2); |
868 | unsigned char *V = drbg->scratchpad; |
869 | unsigned char prefix = DRBG_PREFIX1; |
870 | |
871 | if (!seed) |
872 | return -EINVAL; |
873 | |
874 | if (reseed) { |
875 | /* 10.1.1.3 step 1 */ |
876 | memcpy(V, drbg->V, drbg_statelen(drbg)); |
877 | drbg_string_fill(string: &data1, buf: &prefix, len: 1); |
878 | list_add_tail(new: &data1.list, head: &datalist); |
879 | drbg_string_fill(string: &data2, buf: V, len: drbg_statelen(drbg)); |
880 | list_add_tail(new: &data2.list, head: &datalist); |
881 | } |
882 | list_splice_tail(list: seed, head: &datalist); |
883 | |
884 | /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */ |
885 | ret = drbg_hash_df(drbg, outval: drbg->V, outlen: drbg_statelen(drbg), entropylist: &datalist); |
886 | if (ret) |
887 | goto out; |
888 | |
889 | /* 10.1.1.2 / 10.1.1.3 step 4 */ |
890 | prefix = DRBG_PREFIX0; |
891 | drbg_string_fill(string: &data1, buf: &prefix, len: 1); |
892 | list_add_tail(new: &data1.list, head: &datalist2); |
893 | drbg_string_fill(string: &data2, buf: drbg->V, len: drbg_statelen(drbg)); |
894 | list_add_tail(new: &data2.list, head: &datalist2); |
895 | /* 10.1.1.2 / 10.1.1.3 step 4 */ |
896 | ret = drbg_hash_df(drbg, outval: drbg->C, outlen: drbg_statelen(drbg), entropylist: &datalist2); |
897 | |
898 | out: |
899 | memset(drbg->scratchpad, 0, drbg_statelen(drbg)); |
900 | return ret; |
901 | } |
902 | |
903 | /* processing of additional information string for Hash DRBG */ |
904 | static int drbg_hash_process_addtl(struct drbg_state *drbg, |
905 | struct list_head *addtl) |
906 | { |
907 | int ret = 0; |
908 | struct drbg_string data1, data2; |
909 | LIST_HEAD(datalist); |
910 | unsigned char prefix = DRBG_PREFIX2; |
911 | |
912 | /* 10.1.1.4 step 2 */ |
913 | if (!addtl || list_empty(head: addtl)) |
914 | return 0; |
915 | |
916 | /* 10.1.1.4 step 2a */ |
917 | drbg_string_fill(string: &data1, buf: &prefix, len: 1); |
918 | drbg_string_fill(string: &data2, buf: drbg->V, len: drbg_statelen(drbg)); |
919 | list_add_tail(new: &data1.list, head: &datalist); |
920 | list_add_tail(new: &data2.list, head: &datalist); |
921 | list_splice_tail(list: addtl, head: &datalist); |
922 | ret = drbg_kcapi_hash(drbg, outval: drbg->scratchpad, in: &datalist); |
923 | if (ret) |
924 | goto out; |
925 | |
926 | /* 10.1.1.4 step 2b */ |
927 | drbg_add_buf(dst: drbg->V, dstlen: drbg_statelen(drbg), |
928 | add: drbg->scratchpad, addlen: drbg_blocklen(drbg)); |
929 | |
930 | out: |
931 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
932 | return ret; |
933 | } |
934 | |
935 | /* Hashgen defined in 10.1.1.4 */ |
936 | static int drbg_hash_hashgen(struct drbg_state *drbg, |
937 | unsigned char *buf, |
938 | unsigned int buflen) |
939 | { |
940 | int len = 0; |
941 | int ret = 0; |
942 | unsigned char *src = drbg->scratchpad; |
943 | unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg); |
944 | struct drbg_string data; |
945 | LIST_HEAD(datalist); |
946 | |
947 | /* 10.1.1.4 step hashgen 2 */ |
948 | memcpy(src, drbg->V, drbg_statelen(drbg)); |
949 | |
950 | drbg_string_fill(string: &data, buf: src, len: drbg_statelen(drbg)); |
951 | list_add_tail(new: &data.list, head: &datalist); |
952 | while (len < buflen) { |
953 | unsigned int outlen = 0; |
954 | /* 10.1.1.4 step hashgen 4.1 */ |
955 | ret = drbg_kcapi_hash(drbg, outval: dst, in: &datalist); |
956 | if (ret) { |
957 | len = ret; |
958 | goto out; |
959 | } |
960 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? |
961 | drbg_blocklen(drbg) : (buflen - len); |
962 | /* 10.1.1.4 step hashgen 4.2 */ |
963 | memcpy(buf + len, dst, outlen); |
964 | len += outlen; |
965 | /* 10.1.1.4 hashgen step 4.3 */ |
966 | if (len < buflen) |
967 | crypto_inc(a: src, size: drbg_statelen(drbg)); |
968 | } |
969 | |
970 | out: |
971 | memset(drbg->scratchpad, 0, |
972 | (drbg_statelen(drbg) + drbg_blocklen(drbg))); |
973 | return len; |
974 | } |
975 | |
976 | /* generate function for Hash DRBG as defined in 10.1.1.4 */ |
977 | static int drbg_hash_generate(struct drbg_state *drbg, |
978 | unsigned char *buf, unsigned int buflen, |
979 | struct list_head *addtl) |
980 | { |
981 | int len = 0; |
982 | int ret = 0; |
983 | union { |
984 | unsigned char req[8]; |
985 | __be64 req_int; |
986 | } u; |
987 | unsigned char prefix = DRBG_PREFIX3; |
988 | struct drbg_string data1, data2; |
989 | LIST_HEAD(datalist); |
990 | |
991 | /* 10.1.1.4 step 2 */ |
992 | ret = drbg_hash_process_addtl(drbg, addtl); |
993 | if (ret) |
994 | return ret; |
995 | /* 10.1.1.4 step 3 */ |
996 | len = drbg_hash_hashgen(drbg, buf, buflen); |
997 | |
998 | /* this is the value H as documented in 10.1.1.4 */ |
999 | /* 10.1.1.4 step 4 */ |
1000 | drbg_string_fill(string: &data1, buf: &prefix, len: 1); |
1001 | list_add_tail(new: &data1.list, head: &datalist); |
1002 | drbg_string_fill(string: &data2, buf: drbg->V, len: drbg_statelen(drbg)); |
1003 | list_add_tail(new: &data2.list, head: &datalist); |
1004 | ret = drbg_kcapi_hash(drbg, outval: drbg->scratchpad, in: &datalist); |
1005 | if (ret) { |
1006 | len = ret; |
1007 | goto out; |
1008 | } |
1009 | |
1010 | /* 10.1.1.4 step 5 */ |
1011 | drbg_add_buf(dst: drbg->V, dstlen: drbg_statelen(drbg), |
1012 | add: drbg->scratchpad, addlen: drbg_blocklen(drbg)); |
1013 | drbg_add_buf(dst: drbg->V, dstlen: drbg_statelen(drbg), |
1014 | add: drbg->C, addlen: drbg_statelen(drbg)); |
1015 | u.req_int = cpu_to_be64(drbg->reseed_ctr); |
1016 | drbg_add_buf(dst: drbg->V, dstlen: drbg_statelen(drbg), add: u.req, addlen: 8); |
1017 | |
1018 | out: |
1019 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
1020 | return len; |
1021 | } |
1022 | |
1023 | /* |
1024 | * scratchpad usage: as update and generate are used isolated, both |
1025 | * can use the scratchpad |
1026 | */ |
1027 | static const struct drbg_state_ops drbg_hash_ops = { |
1028 | .update = drbg_hash_update, |
1029 | .generate = drbg_hash_generate, |
1030 | .crypto_init = drbg_init_hash_kernel, |
1031 | .crypto_fini = drbg_fini_hash_kernel, |
1032 | }; |
1033 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ |
1034 | |
1035 | /****************************************************************** |
1036 | * Functions common for DRBG implementations |
1037 | ******************************************************************/ |
1038 | |
1039 | static inline int __drbg_seed(struct drbg_state *drbg, struct list_head *seed, |
1040 | int reseed, enum drbg_seed_state new_seed_state) |
1041 | { |
1042 | int ret = drbg->d_ops->update(drbg, seed, reseed); |
1043 | |
1044 | if (ret) |
1045 | return ret; |
1046 | |
1047 | drbg->seeded = new_seed_state; |
1048 | drbg->last_seed_time = jiffies; |
1049 | /* 10.1.1.2 / 10.1.1.3 step 5 */ |
1050 | drbg->reseed_ctr = 1; |
1051 | |
1052 | switch (drbg->seeded) { |
1053 | case DRBG_SEED_STATE_UNSEEDED: |
1054 | /* Impossible, but handle it to silence compiler warnings. */ |
1055 | fallthrough; |
1056 | case DRBG_SEED_STATE_PARTIAL: |
1057 | /* |
1058 | * Require frequent reseeds until the seed source is |
1059 | * fully initialized. |
1060 | */ |
1061 | drbg->reseed_threshold = 50; |
1062 | break; |
1063 | |
1064 | case DRBG_SEED_STATE_FULL: |
1065 | /* |
1066 | * Seed source has become fully initialized, frequent |
1067 | * reseeds no longer required. |
1068 | */ |
1069 | drbg->reseed_threshold = drbg_max_requests(drbg); |
1070 | break; |
1071 | } |
1072 | |
1073 | return ret; |
1074 | } |
1075 | |
1076 | static inline int drbg_get_random_bytes(struct drbg_state *drbg, |
1077 | unsigned char *entropy, |
1078 | unsigned int entropylen) |
1079 | { |
1080 | int ret; |
1081 | |
1082 | do { |
1083 | get_random_bytes(buf: entropy, len: entropylen); |
1084 | ret = drbg_fips_continuous_test(drbg, entropy); |
1085 | if (ret && ret != -EAGAIN) |
1086 | return ret; |
1087 | } while (ret); |
1088 | |
1089 | return 0; |
1090 | } |
1091 | |
1092 | static int drbg_seed_from_random(struct drbg_state *drbg) |
1093 | { |
1094 | struct drbg_string data; |
1095 | LIST_HEAD(seedlist); |
1096 | unsigned int entropylen = drbg_sec_strength(flags: drbg->core->flags); |
1097 | unsigned char entropy[32]; |
1098 | int ret; |
1099 | |
1100 | BUG_ON(!entropylen); |
1101 | BUG_ON(entropylen > sizeof(entropy)); |
1102 | |
1103 | drbg_string_fill(string: &data, buf: entropy, len: entropylen); |
1104 | list_add_tail(new: &data.list, head: &seedlist); |
1105 | |
1106 | ret = drbg_get_random_bytes(drbg, entropy, entropylen); |
1107 | if (ret) |
1108 | goto out; |
1109 | |
1110 | ret = __drbg_seed(drbg, seed: &seedlist, reseed: true, new_seed_state: DRBG_SEED_STATE_FULL); |
1111 | |
1112 | out: |
1113 | memzero_explicit(s: entropy, count: entropylen); |
1114 | return ret; |
1115 | } |
1116 | |
1117 | static bool drbg_nopr_reseed_interval_elapsed(struct drbg_state *drbg) |
1118 | { |
1119 | unsigned long next_reseed; |
1120 | |
1121 | /* Don't ever reseed from get_random_bytes() in test mode. */ |
1122 | if (list_empty(head: &drbg->test_data.list)) |
1123 | return false; |
1124 | |
1125 | /* |
1126 | * Obtain fresh entropy for the nopr DRBGs after 300s have |
1127 | * elapsed in order to still achieve sort of partial |
1128 | * prediction resistance over the time domain at least. Note |
1129 | * that the period of 300s has been chosen to match the |
1130 | * CRNG_RESEED_INTERVAL of the get_random_bytes()' chacha |
1131 | * rngs. |
1132 | */ |
1133 | next_reseed = drbg->last_seed_time + 300 * HZ; |
1134 | return time_after(jiffies, next_reseed); |
1135 | } |
1136 | |
1137 | /* |
1138 | * Seeding or reseeding of the DRBG |
1139 | * |
1140 | * @drbg: DRBG state struct |
1141 | * @pers: personalization / additional information buffer |
1142 | * @reseed: 0 for initial seed process, 1 for reseeding |
1143 | * |
1144 | * return: |
1145 | * 0 on success |
1146 | * error value otherwise |
1147 | */ |
1148 | static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers, |
1149 | bool reseed) |
1150 | { |
1151 | int ret; |
1152 | unsigned char entropy[((32 + 16) * 2)]; |
1153 | unsigned int entropylen = drbg_sec_strength(flags: drbg->core->flags); |
1154 | struct drbg_string data1; |
1155 | LIST_HEAD(seedlist); |
1156 | enum drbg_seed_state new_seed_state = DRBG_SEED_STATE_FULL; |
1157 | |
1158 | /* 9.1 / 9.2 / 9.3.1 step 3 */ |
1159 | if (pers && pers->len > (drbg_max_addtl(drbg))) { |
1160 | pr_devel("DRBG: personalization string too long %zu\n" , |
1161 | pers->len); |
1162 | return -EINVAL; |
1163 | } |
1164 | |
1165 | if (list_empty(head: &drbg->test_data.list)) { |
1166 | drbg_string_fill(string: &data1, buf: drbg->test_data.buf, |
1167 | len: drbg->test_data.len); |
1168 | pr_devel("DRBG: using test entropy\n" ); |
1169 | } else { |
1170 | /* |
1171 | * Gather entropy equal to the security strength of the DRBG. |
1172 | * With a derivation function, a nonce is required in addition |
1173 | * to the entropy. A nonce must be at least 1/2 of the security |
1174 | * strength of the DRBG in size. Thus, entropy + nonce is 3/2 |
1175 | * of the strength. The consideration of a nonce is only |
1176 | * applicable during initial seeding. |
1177 | */ |
1178 | BUG_ON(!entropylen); |
1179 | if (!reseed) |
1180 | entropylen = ((entropylen + 1) / 2) * 3; |
1181 | BUG_ON((entropylen * 2) > sizeof(entropy)); |
1182 | |
1183 | /* Get seed from in-kernel /dev/urandom */ |
1184 | if (!rng_is_initialized()) |
1185 | new_seed_state = DRBG_SEED_STATE_PARTIAL; |
1186 | |
1187 | ret = drbg_get_random_bytes(drbg, entropy, entropylen); |
1188 | if (ret) |
1189 | goto out; |
1190 | |
1191 | if (!drbg->jent) { |
1192 | drbg_string_fill(string: &data1, buf: entropy, len: entropylen); |
1193 | pr_devel("DRBG: (re)seeding with %u bytes of entropy\n" , |
1194 | entropylen); |
1195 | } else { |
1196 | /* |
1197 | * Get seed from Jitter RNG, failures are |
1198 | * fatal only in FIPS mode. |
1199 | */ |
1200 | ret = crypto_rng_get_bytes(tfm: drbg->jent, |
1201 | rdata: entropy + entropylen, |
1202 | dlen: entropylen); |
1203 | if (fips_enabled && ret) { |
1204 | pr_devel("DRBG: jent failed with %d\n" , ret); |
1205 | |
1206 | /* |
1207 | * Do not treat the transient failure of the |
1208 | * Jitter RNG as an error that needs to be |
1209 | * reported. The combined number of the |
1210 | * maximum reseed threshold times the maximum |
1211 | * number of Jitter RNG transient errors is |
1212 | * less than the reseed threshold required by |
1213 | * SP800-90A allowing us to treat the |
1214 | * transient errors as such. |
1215 | * |
1216 | * However, we mandate that at least the first |
1217 | * seeding operation must succeed with the |
1218 | * Jitter RNG. |
1219 | */ |
1220 | if (!reseed || ret != -EAGAIN) |
1221 | goto out; |
1222 | } |
1223 | |
1224 | drbg_string_fill(string: &data1, buf: entropy, len: entropylen * 2); |
1225 | pr_devel("DRBG: (re)seeding with %u bytes of entropy\n" , |
1226 | entropylen * 2); |
1227 | } |
1228 | } |
1229 | list_add_tail(new: &data1.list, head: &seedlist); |
1230 | |
1231 | /* |
1232 | * concatenation of entropy with personalization str / addtl input) |
1233 | * the variable pers is directly handed in by the caller, so check its |
1234 | * contents whether it is appropriate |
1235 | */ |
1236 | if (pers && pers->buf && 0 < pers->len) { |
1237 | list_add_tail(new: &pers->list, head: &seedlist); |
1238 | pr_devel("DRBG: using personalization string\n" ); |
1239 | } |
1240 | |
1241 | if (!reseed) { |
1242 | memset(drbg->V, 0, drbg_statelen(drbg)); |
1243 | memset(drbg->C, 0, drbg_statelen(drbg)); |
1244 | } |
1245 | |
1246 | ret = __drbg_seed(drbg, seed: &seedlist, reseed, new_seed_state); |
1247 | |
1248 | out: |
1249 | memzero_explicit(s: entropy, count: entropylen * 2); |
1250 | |
1251 | return ret; |
1252 | } |
1253 | |
1254 | /* Free all substructures in a DRBG state without the DRBG state structure */ |
1255 | static inline void drbg_dealloc_state(struct drbg_state *drbg) |
1256 | { |
1257 | if (!drbg) |
1258 | return; |
1259 | kfree_sensitive(objp: drbg->Vbuf); |
1260 | drbg->Vbuf = NULL; |
1261 | drbg->V = NULL; |
1262 | kfree_sensitive(objp: drbg->Cbuf); |
1263 | drbg->Cbuf = NULL; |
1264 | drbg->C = NULL; |
1265 | kfree_sensitive(objp: drbg->scratchpadbuf); |
1266 | drbg->scratchpadbuf = NULL; |
1267 | drbg->reseed_ctr = 0; |
1268 | drbg->d_ops = NULL; |
1269 | drbg->core = NULL; |
1270 | if (IS_ENABLED(CONFIG_CRYPTO_FIPS)) { |
1271 | kfree_sensitive(objp: drbg->prev); |
1272 | drbg->prev = NULL; |
1273 | drbg->fips_primed = false; |
1274 | } |
1275 | } |
1276 | |
1277 | /* |
1278 | * Allocate all sub-structures for a DRBG state. |
1279 | * The DRBG state structure must already be allocated. |
1280 | */ |
1281 | static inline int drbg_alloc_state(struct drbg_state *drbg) |
1282 | { |
1283 | int ret = -ENOMEM; |
1284 | unsigned int sb_size = 0; |
1285 | |
1286 | switch (drbg->core->flags & DRBG_TYPE_MASK) { |
1287 | #ifdef CONFIG_CRYPTO_DRBG_HMAC |
1288 | case DRBG_HMAC: |
1289 | drbg->d_ops = &drbg_hmac_ops; |
1290 | break; |
1291 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ |
1292 | #ifdef CONFIG_CRYPTO_DRBG_HASH |
1293 | case DRBG_HASH: |
1294 | drbg->d_ops = &drbg_hash_ops; |
1295 | break; |
1296 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ |
1297 | #ifdef CONFIG_CRYPTO_DRBG_CTR |
1298 | case DRBG_CTR: |
1299 | drbg->d_ops = &drbg_ctr_ops; |
1300 | break; |
1301 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ |
1302 | default: |
1303 | ret = -EOPNOTSUPP; |
1304 | goto err; |
1305 | } |
1306 | |
1307 | ret = drbg->d_ops->crypto_init(drbg); |
1308 | if (ret < 0) |
1309 | goto err; |
1310 | |
1311 | drbg->Vbuf = kmalloc(size: drbg_statelen(drbg) + ret, GFP_KERNEL); |
1312 | if (!drbg->Vbuf) { |
1313 | ret = -ENOMEM; |
1314 | goto fini; |
1315 | } |
1316 | drbg->V = PTR_ALIGN(drbg->Vbuf, ret + 1); |
1317 | drbg->Cbuf = kmalloc(size: drbg_statelen(drbg) + ret, GFP_KERNEL); |
1318 | if (!drbg->Cbuf) { |
1319 | ret = -ENOMEM; |
1320 | goto fini; |
1321 | } |
1322 | drbg->C = PTR_ALIGN(drbg->Cbuf, ret + 1); |
1323 | /* scratchpad is only generated for CTR and Hash */ |
1324 | if (drbg->core->flags & DRBG_HMAC) |
1325 | sb_size = 0; |
1326 | else if (drbg->core->flags & DRBG_CTR) |
1327 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg) + /* temp */ |
1328 | drbg_statelen(drbg) + /* df_data */ |
1329 | drbg_blocklen(drbg) + /* pad */ |
1330 | drbg_blocklen(drbg) + /* iv */ |
1331 | drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */ |
1332 | else |
1333 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg); |
1334 | |
1335 | if (0 < sb_size) { |
1336 | drbg->scratchpadbuf = kzalloc(size: sb_size + ret, GFP_KERNEL); |
1337 | if (!drbg->scratchpadbuf) { |
1338 | ret = -ENOMEM; |
1339 | goto fini; |
1340 | } |
1341 | drbg->scratchpad = PTR_ALIGN(drbg->scratchpadbuf, ret + 1); |
1342 | } |
1343 | |
1344 | if (IS_ENABLED(CONFIG_CRYPTO_FIPS)) { |
1345 | drbg->prev = kzalloc(size: drbg_sec_strength(flags: drbg->core->flags), |
1346 | GFP_KERNEL); |
1347 | if (!drbg->prev) { |
1348 | ret = -ENOMEM; |
1349 | goto fini; |
1350 | } |
1351 | drbg->fips_primed = false; |
1352 | } |
1353 | |
1354 | return 0; |
1355 | |
1356 | fini: |
1357 | drbg->d_ops->crypto_fini(drbg); |
1358 | err: |
1359 | drbg_dealloc_state(drbg); |
1360 | return ret; |
1361 | } |
1362 | |
1363 | /************************************************************************* |
1364 | * DRBG interface functions |
1365 | *************************************************************************/ |
1366 | |
1367 | /* |
1368 | * DRBG generate function as required by SP800-90A - this function |
1369 | * generates random numbers |
1370 | * |
1371 | * @drbg DRBG state handle |
1372 | * @buf Buffer where to store the random numbers -- the buffer must already |
1373 | * be pre-allocated by caller |
1374 | * @buflen Length of output buffer - this value defines the number of random |
1375 | * bytes pulled from DRBG |
1376 | * @addtl Additional input that is mixed into state, may be NULL -- note |
1377 | * the entropy is pulled by the DRBG internally unconditionally |
1378 | * as defined in SP800-90A. The additional input is mixed into |
1379 | * the state in addition to the pulled entropy. |
1380 | * |
1381 | * return: 0 when all bytes are generated; < 0 in case of an error |
1382 | */ |
1383 | static int drbg_generate(struct drbg_state *drbg, |
1384 | unsigned char *buf, unsigned int buflen, |
1385 | struct drbg_string *addtl) |
1386 | { |
1387 | int len = 0; |
1388 | LIST_HEAD(addtllist); |
1389 | |
1390 | if (!drbg->core) { |
1391 | pr_devel("DRBG: not yet seeded\n" ); |
1392 | return -EINVAL; |
1393 | } |
1394 | if (0 == buflen || !buf) { |
1395 | pr_devel("DRBG: no output buffer provided\n" ); |
1396 | return -EINVAL; |
1397 | } |
1398 | if (addtl && NULL == addtl->buf && 0 < addtl->len) { |
1399 | pr_devel("DRBG: wrong format of additional information\n" ); |
1400 | return -EINVAL; |
1401 | } |
1402 | |
1403 | /* 9.3.1 step 2 */ |
1404 | len = -EINVAL; |
1405 | if (buflen > (drbg_max_request_bytes(drbg))) { |
1406 | pr_devel("DRBG: requested random numbers too large %u\n" , |
1407 | buflen); |
1408 | goto err; |
1409 | } |
1410 | |
1411 | /* 9.3.1 step 3 is implicit with the chosen DRBG */ |
1412 | |
1413 | /* 9.3.1 step 4 */ |
1414 | if (addtl && addtl->len > (drbg_max_addtl(drbg))) { |
1415 | pr_devel("DRBG: additional information string too long %zu\n" , |
1416 | addtl->len); |
1417 | goto err; |
1418 | } |
1419 | /* 9.3.1 step 5 is implicit with the chosen DRBG */ |
1420 | |
1421 | /* |
1422 | * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented |
1423 | * here. The spec is a bit convoluted here, we make it simpler. |
1424 | */ |
1425 | if (drbg->reseed_threshold < drbg->reseed_ctr) |
1426 | drbg->seeded = DRBG_SEED_STATE_UNSEEDED; |
1427 | |
1428 | if (drbg->pr || drbg->seeded == DRBG_SEED_STATE_UNSEEDED) { |
1429 | pr_devel("DRBG: reseeding before generation (prediction " |
1430 | "resistance: %s, state %s)\n" , |
1431 | drbg->pr ? "true" : "false" , |
1432 | (drbg->seeded == DRBG_SEED_STATE_FULL ? |
1433 | "seeded" : "unseeded" )); |
1434 | /* 9.3.1 steps 7.1 through 7.3 */ |
1435 | len = drbg_seed(drbg, pers: addtl, reseed: true); |
1436 | if (len) |
1437 | goto err; |
1438 | /* 9.3.1 step 7.4 */ |
1439 | addtl = NULL; |
1440 | } else if (rng_is_initialized() && |
1441 | (drbg->seeded == DRBG_SEED_STATE_PARTIAL || |
1442 | drbg_nopr_reseed_interval_elapsed(drbg))) { |
1443 | len = drbg_seed_from_random(drbg); |
1444 | if (len) |
1445 | goto err; |
1446 | } |
1447 | |
1448 | if (addtl && 0 < addtl->len) |
1449 | list_add_tail(new: &addtl->list, head: &addtllist); |
1450 | /* 9.3.1 step 8 and 10 */ |
1451 | len = drbg->d_ops->generate(drbg, buf, buflen, &addtllist); |
1452 | |
1453 | /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */ |
1454 | drbg->reseed_ctr++; |
1455 | if (0 >= len) |
1456 | goto err; |
1457 | |
1458 | /* |
1459 | * Section 11.3.3 requires to re-perform self tests after some |
1460 | * generated random numbers. The chosen value after which self |
1461 | * test is performed is arbitrary, but it should be reasonable. |
1462 | * However, we do not perform the self tests because of the following |
1463 | * reasons: it is mathematically impossible that the initial self tests |
1464 | * were successfully and the following are not. If the initial would |
1465 | * pass and the following would not, the kernel integrity is violated. |
1466 | * In this case, the entire kernel operation is questionable and it |
1467 | * is unlikely that the integrity violation only affects the |
1468 | * correct operation of the DRBG. |
1469 | * |
1470 | * Albeit the following code is commented out, it is provided in |
1471 | * case somebody has a need to implement the test of 11.3.3. |
1472 | */ |
1473 | #if 0 |
1474 | if (drbg->reseed_ctr && !(drbg->reseed_ctr % 4096)) { |
1475 | int err = 0; |
1476 | pr_devel("DRBG: start to perform self test\n" ); |
1477 | if (drbg->core->flags & DRBG_HMAC) |
1478 | err = alg_test("drbg_pr_hmac_sha256" , |
1479 | "drbg_pr_hmac_sha256" , 0, 0); |
1480 | else if (drbg->core->flags & DRBG_CTR) |
1481 | err = alg_test("drbg_pr_ctr_aes128" , |
1482 | "drbg_pr_ctr_aes128" , 0, 0); |
1483 | else |
1484 | err = alg_test("drbg_pr_sha256" , |
1485 | "drbg_pr_sha256" , 0, 0); |
1486 | if (err) { |
1487 | pr_err("DRBG: periodical self test failed\n" ); |
1488 | /* |
1489 | * uninstantiate implies that from now on, only errors |
1490 | * are returned when reusing this DRBG cipher handle |
1491 | */ |
1492 | drbg_uninstantiate(drbg); |
1493 | return 0; |
1494 | } else { |
1495 | pr_devel("DRBG: self test successful\n" ); |
1496 | } |
1497 | } |
1498 | #endif |
1499 | |
1500 | /* |
1501 | * All operations were successful, return 0 as mandated by |
1502 | * the kernel crypto API interface. |
1503 | */ |
1504 | len = 0; |
1505 | err: |
1506 | return len; |
1507 | } |
1508 | |
1509 | /* |
1510 | * Wrapper around drbg_generate which can pull arbitrary long strings |
1511 | * from the DRBG without hitting the maximum request limitation. |
1512 | * |
1513 | * Parameters: see drbg_generate |
1514 | * Return codes: see drbg_generate -- if one drbg_generate request fails, |
1515 | * the entire drbg_generate_long request fails |
1516 | */ |
1517 | static int drbg_generate_long(struct drbg_state *drbg, |
1518 | unsigned char *buf, unsigned int buflen, |
1519 | struct drbg_string *addtl) |
1520 | { |
1521 | unsigned int len = 0; |
1522 | unsigned int slice = 0; |
1523 | do { |
1524 | int err = 0; |
1525 | unsigned int chunk = 0; |
1526 | slice = ((buflen - len) / drbg_max_request_bytes(drbg)); |
1527 | chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len); |
1528 | mutex_lock(&drbg->drbg_mutex); |
1529 | err = drbg_generate(drbg, buf: buf + len, buflen: chunk, addtl); |
1530 | mutex_unlock(lock: &drbg->drbg_mutex); |
1531 | if (0 > err) |
1532 | return err; |
1533 | len += chunk; |
1534 | } while (slice > 0 && (len < buflen)); |
1535 | return 0; |
1536 | } |
1537 | |
1538 | static int drbg_prepare_hrng(struct drbg_state *drbg) |
1539 | { |
1540 | /* We do not need an HRNG in test mode. */ |
1541 | if (list_empty(head: &drbg->test_data.list)) |
1542 | return 0; |
1543 | |
1544 | drbg->jent = crypto_alloc_rng(alg_name: "jitterentropy_rng" , type: 0, mask: 0); |
1545 | if (IS_ERR(ptr: drbg->jent)) { |
1546 | const int err = PTR_ERR(ptr: drbg->jent); |
1547 | |
1548 | drbg->jent = NULL; |
1549 | if (fips_enabled) |
1550 | return err; |
1551 | pr_info("DRBG: Continuing without Jitter RNG\n" ); |
1552 | } |
1553 | |
1554 | return 0; |
1555 | } |
1556 | |
1557 | /* |
1558 | * DRBG instantiation function as required by SP800-90A - this function |
1559 | * sets up the DRBG handle, performs the initial seeding and all sanity |
1560 | * checks required by SP800-90A |
1561 | * |
1562 | * @drbg memory of state -- if NULL, new memory is allocated |
1563 | * @pers Personalization string that is mixed into state, may be NULL -- note |
1564 | * the entropy is pulled by the DRBG internally unconditionally |
1565 | * as defined in SP800-90A. The additional input is mixed into |
1566 | * the state in addition to the pulled entropy. |
1567 | * @coreref reference to core |
1568 | * @pr prediction resistance enabled |
1569 | * |
1570 | * return |
1571 | * 0 on success |
1572 | * error value otherwise |
1573 | */ |
1574 | static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, |
1575 | int coreref, bool pr) |
1576 | { |
1577 | int ret; |
1578 | bool reseed = true; |
1579 | |
1580 | pr_devel("DRBG: Initializing DRBG core %d with prediction resistance " |
1581 | "%s\n" , coreref, pr ? "enabled" : "disabled" ); |
1582 | mutex_lock(&drbg->drbg_mutex); |
1583 | |
1584 | /* 9.1 step 1 is implicit with the selected DRBG type */ |
1585 | |
1586 | /* |
1587 | * 9.1 step 2 is implicit as caller can select prediction resistance |
1588 | * and the flag is copied into drbg->flags -- |
1589 | * all DRBG types support prediction resistance |
1590 | */ |
1591 | |
1592 | /* 9.1 step 4 is implicit in drbg_sec_strength */ |
1593 | |
1594 | if (!drbg->core) { |
1595 | drbg->core = &drbg_cores[coreref]; |
1596 | drbg->pr = pr; |
1597 | drbg->seeded = DRBG_SEED_STATE_UNSEEDED; |
1598 | drbg->last_seed_time = 0; |
1599 | drbg->reseed_threshold = drbg_max_requests(drbg); |
1600 | |
1601 | ret = drbg_alloc_state(drbg); |
1602 | if (ret) |
1603 | goto unlock; |
1604 | |
1605 | ret = drbg_prepare_hrng(drbg); |
1606 | if (ret) |
1607 | goto free_everything; |
1608 | |
1609 | reseed = false; |
1610 | } |
1611 | |
1612 | ret = drbg_seed(drbg, pers, reseed); |
1613 | |
1614 | if (ret && !reseed) |
1615 | goto free_everything; |
1616 | |
1617 | mutex_unlock(lock: &drbg->drbg_mutex); |
1618 | return ret; |
1619 | |
1620 | unlock: |
1621 | mutex_unlock(lock: &drbg->drbg_mutex); |
1622 | return ret; |
1623 | |
1624 | free_everything: |
1625 | mutex_unlock(lock: &drbg->drbg_mutex); |
1626 | drbg_uninstantiate(drbg); |
1627 | return ret; |
1628 | } |
1629 | |
1630 | /* |
1631 | * DRBG uninstantiate function as required by SP800-90A - this function |
1632 | * frees all buffers and the DRBG handle |
1633 | * |
1634 | * @drbg DRBG state handle |
1635 | * |
1636 | * return |
1637 | * 0 on success |
1638 | */ |
1639 | static int drbg_uninstantiate(struct drbg_state *drbg) |
1640 | { |
1641 | if (!IS_ERR_OR_NULL(ptr: drbg->jent)) |
1642 | crypto_free_rng(tfm: drbg->jent); |
1643 | drbg->jent = NULL; |
1644 | |
1645 | if (drbg->d_ops) |
1646 | drbg->d_ops->crypto_fini(drbg); |
1647 | drbg_dealloc_state(drbg); |
1648 | /* no scrubbing of test_data -- this shall survive an uninstantiate */ |
1649 | return 0; |
1650 | } |
1651 | |
1652 | /* |
1653 | * Helper function for setting the test data in the DRBG |
1654 | * |
1655 | * @drbg DRBG state handle |
1656 | * @data test data |
1657 | * @len test data length |
1658 | */ |
1659 | static void drbg_kcapi_set_entropy(struct crypto_rng *tfm, |
1660 | const u8 *data, unsigned int len) |
1661 | { |
1662 | struct drbg_state *drbg = crypto_rng_ctx(tfm); |
1663 | |
1664 | mutex_lock(&drbg->drbg_mutex); |
1665 | drbg_string_fill(string: &drbg->test_data, buf: data, len); |
1666 | mutex_unlock(lock: &drbg->drbg_mutex); |
1667 | } |
1668 | |
1669 | /*************************************************************** |
1670 | * Kernel crypto API cipher invocations requested by DRBG |
1671 | ***************************************************************/ |
1672 | |
1673 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) |
1674 | struct sdesc { |
1675 | struct shash_desc shash; |
1676 | char ctx[]; |
1677 | }; |
1678 | |
1679 | static int drbg_init_hash_kernel(struct drbg_state *drbg) |
1680 | { |
1681 | struct sdesc *sdesc; |
1682 | struct crypto_shash *tfm; |
1683 | |
1684 | tfm = crypto_alloc_shash(alg_name: drbg->core->backend_cra_name, type: 0, mask: 0); |
1685 | if (IS_ERR(ptr: tfm)) { |
1686 | pr_info("DRBG: could not allocate digest TFM handle: %s\n" , |
1687 | drbg->core->backend_cra_name); |
1688 | return PTR_ERR(ptr: tfm); |
1689 | } |
1690 | BUG_ON(drbg_blocklen(drbg) != crypto_shash_digestsize(tfm)); |
1691 | sdesc = kzalloc(size: sizeof(struct shash_desc) + crypto_shash_descsize(tfm), |
1692 | GFP_KERNEL); |
1693 | if (!sdesc) { |
1694 | crypto_free_shash(tfm); |
1695 | return -ENOMEM; |
1696 | } |
1697 | |
1698 | sdesc->shash.tfm = tfm; |
1699 | drbg->priv_data = sdesc; |
1700 | |
1701 | return 0; |
1702 | } |
1703 | |
1704 | static int drbg_fini_hash_kernel(struct drbg_state *drbg) |
1705 | { |
1706 | struct sdesc *sdesc = drbg->priv_data; |
1707 | if (sdesc) { |
1708 | crypto_free_shash(tfm: sdesc->shash.tfm); |
1709 | kfree_sensitive(objp: sdesc); |
1710 | } |
1711 | drbg->priv_data = NULL; |
1712 | return 0; |
1713 | } |
1714 | |
1715 | static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg, |
1716 | const unsigned char *key) |
1717 | { |
1718 | struct sdesc *sdesc = drbg->priv_data; |
1719 | |
1720 | crypto_shash_setkey(tfm: sdesc->shash.tfm, key, keylen: drbg_statelen(drbg)); |
1721 | } |
1722 | |
1723 | static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, |
1724 | const struct list_head *in) |
1725 | { |
1726 | struct sdesc *sdesc = drbg->priv_data; |
1727 | struct drbg_string *input = NULL; |
1728 | |
1729 | crypto_shash_init(desc: &sdesc->shash); |
1730 | list_for_each_entry(input, in, list) |
1731 | crypto_shash_update(desc: &sdesc->shash, data: input->buf, len: input->len); |
1732 | return crypto_shash_final(desc: &sdesc->shash, out: outval); |
1733 | } |
1734 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ |
1735 | |
1736 | #ifdef CONFIG_CRYPTO_DRBG_CTR |
1737 | static int drbg_fini_sym_kernel(struct drbg_state *drbg) |
1738 | { |
1739 | struct crypto_cipher *tfm = |
1740 | (struct crypto_cipher *)drbg->priv_data; |
1741 | if (tfm) |
1742 | crypto_free_cipher(tfm); |
1743 | drbg->priv_data = NULL; |
1744 | |
1745 | if (drbg->ctr_handle) |
1746 | crypto_free_skcipher(tfm: drbg->ctr_handle); |
1747 | drbg->ctr_handle = NULL; |
1748 | |
1749 | if (drbg->ctr_req) |
1750 | skcipher_request_free(req: drbg->ctr_req); |
1751 | drbg->ctr_req = NULL; |
1752 | |
1753 | kfree(objp: drbg->outscratchpadbuf); |
1754 | drbg->outscratchpadbuf = NULL; |
1755 | |
1756 | return 0; |
1757 | } |
1758 | |
1759 | static int drbg_init_sym_kernel(struct drbg_state *drbg) |
1760 | { |
1761 | struct crypto_cipher *tfm; |
1762 | struct crypto_skcipher *sk_tfm; |
1763 | struct skcipher_request *req; |
1764 | unsigned int alignmask; |
1765 | char ctr_name[CRYPTO_MAX_ALG_NAME]; |
1766 | |
1767 | tfm = crypto_alloc_cipher(alg_name: drbg->core->backend_cra_name, type: 0, mask: 0); |
1768 | if (IS_ERR(ptr: tfm)) { |
1769 | pr_info("DRBG: could not allocate cipher TFM handle: %s\n" , |
1770 | drbg->core->backend_cra_name); |
1771 | return PTR_ERR(ptr: tfm); |
1772 | } |
1773 | BUG_ON(drbg_blocklen(drbg) != crypto_cipher_blocksize(tfm)); |
1774 | drbg->priv_data = tfm; |
1775 | |
1776 | if (snprintf(buf: ctr_name, CRYPTO_MAX_ALG_NAME, fmt: "ctr(%s)" , |
1777 | drbg->core->backend_cra_name) >= CRYPTO_MAX_ALG_NAME) { |
1778 | drbg_fini_sym_kernel(drbg); |
1779 | return -EINVAL; |
1780 | } |
1781 | sk_tfm = crypto_alloc_skcipher(alg_name: ctr_name, type: 0, mask: 0); |
1782 | if (IS_ERR(ptr: sk_tfm)) { |
1783 | pr_info("DRBG: could not allocate CTR cipher TFM handle: %s\n" , |
1784 | ctr_name); |
1785 | drbg_fini_sym_kernel(drbg); |
1786 | return PTR_ERR(ptr: sk_tfm); |
1787 | } |
1788 | drbg->ctr_handle = sk_tfm; |
1789 | crypto_init_wait(wait: &drbg->ctr_wait); |
1790 | |
1791 | req = skcipher_request_alloc(tfm: sk_tfm, GFP_KERNEL); |
1792 | if (!req) { |
1793 | pr_info("DRBG: could not allocate request queue\n" ); |
1794 | drbg_fini_sym_kernel(drbg); |
1795 | return -ENOMEM; |
1796 | } |
1797 | drbg->ctr_req = req; |
1798 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | |
1799 | CRYPTO_TFM_REQ_MAY_SLEEP, |
1800 | compl: crypto_req_done, data: &drbg->ctr_wait); |
1801 | |
1802 | alignmask = crypto_skcipher_alignmask(tfm: sk_tfm); |
1803 | drbg->outscratchpadbuf = kmalloc(DRBG_OUTSCRATCHLEN + alignmask, |
1804 | GFP_KERNEL); |
1805 | if (!drbg->outscratchpadbuf) { |
1806 | drbg_fini_sym_kernel(drbg); |
1807 | return -ENOMEM; |
1808 | } |
1809 | drbg->outscratchpad = (u8 *)PTR_ALIGN(drbg->outscratchpadbuf, |
1810 | alignmask + 1); |
1811 | |
1812 | sg_init_table(&drbg->sg_in, 1); |
1813 | sg_init_one(&drbg->sg_out, drbg->outscratchpad, DRBG_OUTSCRATCHLEN); |
1814 | |
1815 | return alignmask; |
1816 | } |
1817 | |
1818 | static void drbg_kcapi_symsetkey(struct drbg_state *drbg, |
1819 | const unsigned char *key) |
1820 | { |
1821 | struct crypto_cipher *tfm = drbg->priv_data; |
1822 | |
1823 | crypto_cipher_setkey(tfm, key, keylen: (drbg_keylen(drbg))); |
1824 | } |
1825 | |
1826 | static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, |
1827 | const struct drbg_string *in) |
1828 | { |
1829 | struct crypto_cipher *tfm = drbg->priv_data; |
1830 | |
1831 | /* there is only component in *in */ |
1832 | BUG_ON(in->len < drbg_blocklen(drbg)); |
1833 | crypto_cipher_encrypt_one(tfm, dst: outval, src: in->buf); |
1834 | return 0; |
1835 | } |
1836 | |
1837 | static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, |
1838 | u8 *inbuf, u32 inlen, |
1839 | u8 *outbuf, u32 outlen) |
1840 | { |
1841 | struct scatterlist *sg_in = &drbg->sg_in, *sg_out = &drbg->sg_out; |
1842 | u32 scratchpad_use = min_t(u32, outlen, DRBG_OUTSCRATCHLEN); |
1843 | int ret; |
1844 | |
1845 | if (inbuf) { |
1846 | /* Use caller-provided input buffer */ |
1847 | sg_set_buf(sg: sg_in, buf: inbuf, buflen: inlen); |
1848 | } else { |
1849 | /* Use scratchpad for in-place operation */ |
1850 | inlen = scratchpad_use; |
1851 | memset(drbg->outscratchpad, 0, scratchpad_use); |
1852 | sg_set_buf(sg: sg_in, buf: drbg->outscratchpad, buflen: scratchpad_use); |
1853 | } |
1854 | |
1855 | while (outlen) { |
1856 | u32 cryptlen = min3(inlen, outlen, (u32)DRBG_OUTSCRATCHLEN); |
1857 | |
1858 | /* Output buffer may not be valid for SGL, use scratchpad */ |
1859 | skcipher_request_set_crypt(req: drbg->ctr_req, src: sg_in, dst: sg_out, |
1860 | cryptlen, iv: drbg->V); |
1861 | ret = crypto_wait_req(err: crypto_skcipher_encrypt(req: drbg->ctr_req), |
1862 | wait: &drbg->ctr_wait); |
1863 | if (ret) |
1864 | goto out; |
1865 | |
1866 | crypto_init_wait(wait: &drbg->ctr_wait); |
1867 | |
1868 | memcpy(outbuf, drbg->outscratchpad, cryptlen); |
1869 | memzero_explicit(s: drbg->outscratchpad, count: cryptlen); |
1870 | |
1871 | outlen -= cryptlen; |
1872 | outbuf += cryptlen; |
1873 | } |
1874 | ret = 0; |
1875 | |
1876 | out: |
1877 | return ret; |
1878 | } |
1879 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ |
1880 | |
1881 | /*************************************************************** |
1882 | * Kernel crypto API interface to register DRBG |
1883 | ***************************************************************/ |
1884 | |
1885 | /* |
1886 | * Look up the DRBG flags by given kernel crypto API cra_name |
1887 | * The code uses the drbg_cores definition to do this |
1888 | * |
1889 | * @cra_name kernel crypto API cra_name |
1890 | * @coreref reference to integer which is filled with the pointer to |
1891 | * the applicable core |
1892 | * @pr reference for setting prediction resistance |
1893 | * |
1894 | * return: flags |
1895 | */ |
1896 | static inline void drbg_convert_tfm_core(const char *cra_driver_name, |
1897 | int *coreref, bool *pr) |
1898 | { |
1899 | int i = 0; |
1900 | size_t start = 0; |
1901 | int len = 0; |
1902 | |
1903 | *pr = true; |
1904 | /* disassemble the names */ |
1905 | if (!memcmp(p: cra_driver_name, q: "drbg_nopr_" , size: 10)) { |
1906 | start = 10; |
1907 | *pr = false; |
1908 | } else if (!memcmp(p: cra_driver_name, q: "drbg_pr_" , size: 8)) { |
1909 | start = 8; |
1910 | } else { |
1911 | return; |
1912 | } |
1913 | |
1914 | /* remove the first part */ |
1915 | len = strlen(cra_driver_name) - start; |
1916 | for (i = 0; ARRAY_SIZE(drbg_cores) > i; i++) { |
1917 | if (!memcmp(p: cra_driver_name + start, q: drbg_cores[i].cra_name, |
1918 | size: len)) { |
1919 | *coreref = i; |
1920 | return; |
1921 | } |
1922 | } |
1923 | } |
1924 | |
1925 | static int drbg_kcapi_init(struct crypto_tfm *tfm) |
1926 | { |
1927 | struct drbg_state *drbg = crypto_tfm_ctx(tfm); |
1928 | |
1929 | mutex_init(&drbg->drbg_mutex); |
1930 | |
1931 | return 0; |
1932 | } |
1933 | |
1934 | static void drbg_kcapi_cleanup(struct crypto_tfm *tfm) |
1935 | { |
1936 | drbg_uninstantiate(drbg: crypto_tfm_ctx(tfm)); |
1937 | } |
1938 | |
1939 | /* |
1940 | * Generate random numbers invoked by the kernel crypto API: |
1941 | * The API of the kernel crypto API is extended as follows: |
1942 | * |
1943 | * src is additional input supplied to the RNG. |
1944 | * slen is the length of src. |
1945 | * dst is the output buffer where random data is to be stored. |
1946 | * dlen is the length of dst. |
1947 | */ |
1948 | static int drbg_kcapi_random(struct crypto_rng *tfm, |
1949 | const u8 *src, unsigned int slen, |
1950 | u8 *dst, unsigned int dlen) |
1951 | { |
1952 | struct drbg_state *drbg = crypto_rng_ctx(tfm); |
1953 | struct drbg_string *addtl = NULL; |
1954 | struct drbg_string string; |
1955 | |
1956 | if (slen) { |
1957 | /* linked list variable is now local to allow modification */ |
1958 | drbg_string_fill(string: &string, buf: src, len: slen); |
1959 | addtl = &string; |
1960 | } |
1961 | |
1962 | return drbg_generate_long(drbg, buf: dst, buflen: dlen, addtl); |
1963 | } |
1964 | |
1965 | /* |
1966 | * Seed the DRBG invoked by the kernel crypto API |
1967 | */ |
1968 | static int drbg_kcapi_seed(struct crypto_rng *tfm, |
1969 | const u8 *seed, unsigned int slen) |
1970 | { |
1971 | struct drbg_state *drbg = crypto_rng_ctx(tfm); |
1972 | struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm); |
1973 | bool pr = false; |
1974 | struct drbg_string string; |
1975 | struct drbg_string *seed_string = NULL; |
1976 | int coreref = 0; |
1977 | |
1978 | drbg_convert_tfm_core(cra_driver_name: crypto_tfm_alg_driver_name(tfm: tfm_base), coreref: &coreref, |
1979 | pr: &pr); |
1980 | if (0 < slen) { |
1981 | drbg_string_fill(string: &string, buf: seed, len: slen); |
1982 | seed_string = &string; |
1983 | } |
1984 | |
1985 | return drbg_instantiate(drbg, pers: seed_string, coreref, pr); |
1986 | } |
1987 | |
1988 | /*************************************************************** |
1989 | * Kernel module: code to load the module |
1990 | ***************************************************************/ |
1991 | |
1992 | /* |
1993 | * Tests as defined in 11.3.2 in addition to the cipher tests: testing |
1994 | * of the error handling. |
1995 | * |
1996 | * Note: testing of failing seed source as defined in 11.3.2 is not applicable |
1997 | * as seed source of get_random_bytes does not fail. |
1998 | * |
1999 | * Note 2: There is no sensible way of testing the reseed counter |
2000 | * enforcement, so skip it. |
2001 | */ |
2002 | static inline int __init drbg_healthcheck_sanity(void) |
2003 | { |
2004 | int len = 0; |
2005 | #define OUTBUFLEN 16 |
2006 | unsigned char buf[OUTBUFLEN]; |
2007 | struct drbg_state *drbg = NULL; |
2008 | int ret; |
2009 | int rc = -EFAULT; |
2010 | bool pr = false; |
2011 | int coreref = 0; |
2012 | struct drbg_string addtl; |
2013 | size_t max_addtllen, max_request_bytes; |
2014 | |
2015 | /* only perform test in FIPS mode */ |
2016 | if (!fips_enabled) |
2017 | return 0; |
2018 | |
2019 | #ifdef CONFIG_CRYPTO_DRBG_CTR |
2020 | drbg_convert_tfm_core(cra_driver_name: "drbg_nopr_ctr_aes128" , coreref: &coreref, pr: &pr); |
2021 | #elif defined CONFIG_CRYPTO_DRBG_HASH |
2022 | drbg_convert_tfm_core("drbg_nopr_sha256" , &coreref, &pr); |
2023 | #else |
2024 | drbg_convert_tfm_core("drbg_nopr_hmac_sha256" , &coreref, &pr); |
2025 | #endif |
2026 | |
2027 | drbg = kzalloc(size: sizeof(struct drbg_state), GFP_KERNEL); |
2028 | if (!drbg) |
2029 | return -ENOMEM; |
2030 | |
2031 | mutex_init(&drbg->drbg_mutex); |
2032 | drbg->core = &drbg_cores[coreref]; |
2033 | drbg->reseed_threshold = drbg_max_requests(drbg); |
2034 | |
2035 | /* |
2036 | * if the following tests fail, it is likely that there is a buffer |
2037 | * overflow as buf is much smaller than the requested or provided |
2038 | * string lengths -- in case the error handling does not succeed |
2039 | * we may get an OOPS. And we want to get an OOPS as this is a |
2040 | * grave bug. |
2041 | */ |
2042 | |
2043 | max_addtllen = drbg_max_addtl(drbg); |
2044 | max_request_bytes = drbg_max_request_bytes(drbg); |
2045 | drbg_string_fill(string: &addtl, buf, len: max_addtllen + 1); |
2046 | /* overflow addtllen with additonal info string */ |
2047 | len = drbg_generate(drbg, buf, OUTBUFLEN, addtl: &addtl); |
2048 | BUG_ON(0 < len); |
2049 | /* overflow max_bits */ |
2050 | len = drbg_generate(drbg, buf, buflen: (max_request_bytes + 1), NULL); |
2051 | BUG_ON(0 < len); |
2052 | |
2053 | /* overflow max addtllen with personalization string */ |
2054 | ret = drbg_seed(drbg, pers: &addtl, reseed: false); |
2055 | BUG_ON(0 == ret); |
2056 | /* all tests passed */ |
2057 | rc = 0; |
2058 | |
2059 | pr_devel("DRBG: Sanity tests for failure code paths successfully " |
2060 | "completed\n" ); |
2061 | |
2062 | kfree(objp: drbg); |
2063 | return rc; |
2064 | } |
2065 | |
2066 | static struct rng_alg drbg_algs[22]; |
2067 | |
2068 | /* |
2069 | * Fill the array drbg_algs used to register the different DRBGs |
2070 | * with the kernel crypto API. To fill the array, the information |
2071 | * from drbg_cores[] is used. |
2072 | */ |
2073 | static inline void __init drbg_fill_array(struct rng_alg *alg, |
2074 | const struct drbg_core *core, int pr) |
2075 | { |
2076 | int pos = 0; |
2077 | static int priority = 200; |
2078 | |
2079 | memcpy(alg->base.cra_name, "stdrng" , 6); |
2080 | if (pr) { |
2081 | memcpy(alg->base.cra_driver_name, "drbg_pr_" , 8); |
2082 | pos = 8; |
2083 | } else { |
2084 | memcpy(alg->base.cra_driver_name, "drbg_nopr_" , 10); |
2085 | pos = 10; |
2086 | } |
2087 | memcpy(alg->base.cra_driver_name + pos, core->cra_name, |
2088 | strlen(core->cra_name)); |
2089 | |
2090 | alg->base.cra_priority = priority; |
2091 | priority++; |
2092 | /* |
2093 | * If FIPS mode enabled, the selected DRBG shall have the |
2094 | * highest cra_priority over other stdrng instances to ensure |
2095 | * it is selected. |
2096 | */ |
2097 | if (fips_enabled) |
2098 | alg->base.cra_priority += 200; |
2099 | |
2100 | alg->base.cra_ctxsize = sizeof(struct drbg_state); |
2101 | alg->base.cra_module = THIS_MODULE; |
2102 | alg->base.cra_init = drbg_kcapi_init; |
2103 | alg->base.cra_exit = drbg_kcapi_cleanup; |
2104 | alg->generate = drbg_kcapi_random; |
2105 | alg->seed = drbg_kcapi_seed; |
2106 | alg->set_ent = drbg_kcapi_set_entropy; |
2107 | alg->seedsize = 0; |
2108 | } |
2109 | |
2110 | static int __init drbg_init(void) |
2111 | { |
2112 | unsigned int i = 0; /* pointer to drbg_algs */ |
2113 | unsigned int j = 0; /* pointer to drbg_cores */ |
2114 | int ret; |
2115 | |
2116 | ret = drbg_healthcheck_sanity(); |
2117 | if (ret) |
2118 | return ret; |
2119 | |
2120 | if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) { |
2121 | pr_info("DRBG: Cannot register all DRBG types" |
2122 | "(slots needed: %zu, slots available: %zu)\n" , |
2123 | ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs)); |
2124 | return -EFAULT; |
2125 | } |
2126 | |
2127 | /* |
2128 | * each DRBG definition can be used with PR and without PR, thus |
2129 | * we instantiate each DRBG in drbg_cores[] twice. |
2130 | * |
2131 | * As the order of placing them into the drbg_algs array matters |
2132 | * (the later DRBGs receive a higher cra_priority) we register the |
2133 | * prediction resistance DRBGs first as the should not be too |
2134 | * interesting. |
2135 | */ |
2136 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) |
2137 | drbg_fill_array(alg: &drbg_algs[i], core: &drbg_cores[j], pr: 1); |
2138 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) |
2139 | drbg_fill_array(alg: &drbg_algs[i], core: &drbg_cores[j], pr: 0); |
2140 | return crypto_register_rngs(algs: drbg_algs, count: (ARRAY_SIZE(drbg_cores) * 2)); |
2141 | } |
2142 | |
2143 | static void __exit drbg_exit(void) |
2144 | { |
2145 | crypto_unregister_rngs(algs: drbg_algs, count: (ARRAY_SIZE(drbg_cores) * 2)); |
2146 | } |
2147 | |
2148 | subsys_initcall(drbg_init); |
2149 | module_exit(drbg_exit); |
2150 | #ifndef CRYPTO_DRBG_HASH_STRING |
2151 | #define CRYPTO_DRBG_HASH_STRING "" |
2152 | #endif |
2153 | #ifndef CRYPTO_DRBG_HMAC_STRING |
2154 | #define CRYPTO_DRBG_HMAC_STRING "" |
2155 | #endif |
2156 | #ifndef CRYPTO_DRBG_CTR_STRING |
2157 | #define CRYPTO_DRBG_CTR_STRING "" |
2158 | #endif |
2159 | MODULE_LICENSE("GPL" ); |
2160 | MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>" ); |
2161 | MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) " |
2162 | "using following cores: " |
2163 | CRYPTO_DRBG_HASH_STRING |
2164 | CRYPTO_DRBG_HMAC_STRING |
2165 | CRYPTO_DRBG_CTR_STRING); |
2166 | MODULE_ALIAS_CRYPTO("stdrng" ); |
2167 | MODULE_IMPORT_NS(CRYPTO_INTERNAL); |
2168 | |