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541af946 SM |
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> | |
0eb76ba2 | 101 | #include <crypto/internal/cipher.h> |
57225e67 | 102 | #include <linux/kernel.h> |
541af946 | 103 | |
541af946 SM |
104 | /*************************************************************** |
105 | * Backend cipher definitions available to DRBG | |
106 | ***************************************************************/ | |
107 | ||
108 | /* | |
109 | * The order of the DRBG definitions here matter: every DRBG is registered | |
110 | * as stdrng. Each DRBG receives an increasing cra_priority values the later | |
111 | * they are defined in this array (see drbg_fill_array). | |
112 | * | |
113 | * HMAC DRBGs are favored over Hash DRBGs over CTR DRBGs, and | |
114 | * the SHA256 / AES 256 over other ciphers. Thus, the favored | |
115 | * DRBGs are the latest entries in this array. | |
116 | */ | |
117 | static const struct drbg_core drbg_cores[] = { | |
118 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
119 | { | |
120 | .flags = DRBG_CTR | DRBG_STRENGTH128, | |
121 | .statelen = 32, /* 256 bits as defined in 10.2.1 */ | |
541af946 SM |
122 | .blocklen_bytes = 16, |
123 | .cra_name = "ctr_aes128", | |
04bcbfcf | 124 | .backend_cra_name = "aes", |
541af946 SM |
125 | }, { |
126 | .flags = DRBG_CTR | DRBG_STRENGTH192, | |
127 | .statelen = 40, /* 320 bits as defined in 10.2.1 */ | |
541af946 SM |
128 | .blocklen_bytes = 16, |
129 | .cra_name = "ctr_aes192", | |
04bcbfcf | 130 | .backend_cra_name = "aes", |
541af946 SM |
131 | }, { |
132 | .flags = DRBG_CTR | DRBG_STRENGTH256, | |
133 | .statelen = 48, /* 384 bits as defined in 10.2.1 */ | |
541af946 SM |
134 | .blocklen_bytes = 16, |
135 | .cra_name = "ctr_aes256", | |
04bcbfcf | 136 | .backend_cra_name = "aes", |
541af946 SM |
137 | }, |
138 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
139 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
140 | { | |
141 | .flags = DRBG_HASH | DRBG_STRENGTH128, | |
142 | .statelen = 55, /* 440 bits */ | |
541af946 SM |
143 | .blocklen_bytes = 20, |
144 | .cra_name = "sha1", | |
145 | .backend_cra_name = "sha1", | |
146 | }, { | |
147 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
148 | .statelen = 111, /* 888 bits */ | |
541af946 SM |
149 | .blocklen_bytes = 48, |
150 | .cra_name = "sha384", | |
151 | .backend_cra_name = "sha384", | |
152 | }, { | |
153 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
154 | .statelen = 111, /* 888 bits */ | |
541af946 SM |
155 | .blocklen_bytes = 64, |
156 | .cra_name = "sha512", | |
157 | .backend_cra_name = "sha512", | |
158 | }, { | |
159 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
160 | .statelen = 55, /* 440 bits */ | |
541af946 SM |
161 | .blocklen_bytes = 32, |
162 | .cra_name = "sha256", | |
163 | .backend_cra_name = "sha256", | |
164 | }, | |
165 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
166 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
167 | { | |
5b635e28 | 168 | .flags = DRBG_HMAC | DRBG_STRENGTH128, |
541af946 | 169 | .statelen = 20, /* block length of cipher */ |
541af946 SM |
170 | .blocklen_bytes = 20, |
171 | .cra_name = "hmac_sha1", | |
172 | .backend_cra_name = "hmac(sha1)", | |
173 | }, { | |
174 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
175 | .statelen = 48, /* block length of cipher */ | |
541af946 SM |
176 | .blocklen_bytes = 48, |
177 | .cra_name = "hmac_sha384", | |
178 | .backend_cra_name = "hmac(sha384)", | |
541af946 SM |
179 | }, { |
180 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
181 | .statelen = 32, /* block length of cipher */ | |
541af946 SM |
182 | .blocklen_bytes = 32, |
183 | .cra_name = "hmac_sha256", | |
184 | .backend_cra_name = "hmac(sha256)", | |
9b7b9468 SM |
185 | }, { |
186 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
187 | .statelen = 64, /* block length of cipher */ | |
188 | .blocklen_bytes = 64, | |
189 | .cra_name = "hmac_sha512", | |
190 | .backend_cra_name = "hmac(sha512)", | |
541af946 SM |
191 | }, |
192 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
193 | }; | |
194 | ||
57225e67 SM |
195 | static int drbg_uninstantiate(struct drbg_state *drbg); |
196 | ||
541af946 SM |
197 | /****************************************************************** |
198 | * Generic helper functions | |
199 | ******************************************************************/ | |
200 | ||
201 | /* | |
202 | * Return strength of DRBG according to SP800-90A section 8.4 | |
203 | * | |
204 | * @flags DRBG flags reference | |
205 | * | |
206 | * Return: normalized strength in *bytes* value or 32 as default | |
207 | * to counter programming errors | |
208 | */ | |
209 | static inline unsigned short drbg_sec_strength(drbg_flag_t flags) | |
210 | { | |
211 | switch (flags & DRBG_STRENGTH_MASK) { | |
212 | case DRBG_STRENGTH128: | |
213 | return 16; | |
214 | case DRBG_STRENGTH192: | |
215 | return 24; | |
216 | case DRBG_STRENGTH256: | |
217 | return 32; | |
218 | default: | |
219 | return 32; | |
220 | } | |
221 | } | |
222 | ||
db07cd26 SM |
223 | /* |
224 | * FIPS 140-2 continuous self test for the noise source | |
225 | * The test is performed on the noise source input data. Thus, the function | |
226 | * implicitly knows the size of the buffer to be equal to the security | |
227 | * strength. | |
228 | * | |
229 | * Note, this function disregards the nonce trailing the entropy data during | |
230 | * initial seeding. | |
231 | * | |
232 | * drbg->drbg_mutex must have been taken. | |
233 | * | |
234 | * @drbg DRBG handle | |
235 | * @entropy buffer of seed data to be checked | |
236 | * | |
237 | * return: | |
238 | * 0 on success | |
239 | * -EAGAIN on when the CTRNG is not yet primed | |
240 | * < 0 on error | |
241 | */ | |
242 | static int drbg_fips_continuous_test(struct drbg_state *drbg, | |
243 | const unsigned char *entropy) | |
244 | { | |
245 | unsigned short entropylen = drbg_sec_strength(drbg->core->flags); | |
246 | int ret = 0; | |
247 | ||
248 | if (!IS_ENABLED(CONFIG_CRYPTO_FIPS)) | |
249 | return 0; | |
250 | ||
251 | /* skip test if we test the overall system */ | |
252 | if (list_empty(&drbg->test_data.list)) | |
253 | return 0; | |
254 | /* only perform test in FIPS mode */ | |
255 | if (!fips_enabled) | |
256 | return 0; | |
257 | ||
258 | if (!drbg->fips_primed) { | |
259 | /* Priming of FIPS test */ | |
260 | memcpy(drbg->prev, entropy, entropylen); | |
261 | drbg->fips_primed = true; | |
262 | /* priming: another round is needed */ | |
263 | return -EAGAIN; | |
264 | } | |
265 | ret = memcmp(drbg->prev, entropy, entropylen); | |
266 | if (!ret) | |
267 | panic("DRBG continuous self test failed\n"); | |
268 | memcpy(drbg->prev, entropy, entropylen); | |
269 | ||
270 | /* the test shall pass when the two values are not equal */ | |
271 | return 0; | |
272 | } | |
273 | ||
541af946 SM |
274 | /* |
275 | * Convert an integer into a byte representation of this integer. | |
276 | * The byte representation is big-endian | |
277 | * | |
541af946 | 278 | * @val value to be converted |
72f3e00d SM |
279 | * @buf buffer holding the converted integer -- caller must ensure that |
280 | * buffer size is at least 32 bit | |
541af946 SM |
281 | */ |
282 | #if (defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR)) | |
72f3e00d | 283 | static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf) |
541af946 | 284 | { |
72f3e00d | 285 | struct s { |
7c8ae03f | 286 | __be32 conv; |
72f3e00d SM |
287 | }; |
288 | struct s *conversion = (struct s *) buf; | |
541af946 | 289 | |
72f3e00d | 290 | conversion->conv = cpu_to_be32(val); |
541af946 | 291 | } |
541af946 SM |
292 | #endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */ |
293 | ||
294 | /****************************************************************** | |
295 | * CTR DRBG callback functions | |
296 | ******************************************************************/ | |
297 | ||
298 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
e25e47ec | 299 | #define CRYPTO_DRBG_CTR_STRING "CTR " |
0653a7cf SM |
300 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes256"); |
301 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes256"); | |
302 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes192"); | |
303 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192"); | |
304 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128"); | |
305 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128"); | |
62b62b6e | 306 | |
ed494d4f SM |
307 | static void drbg_kcapi_symsetkey(struct drbg_state *drbg, |
308 | const unsigned char *key); | |
309 | static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, | |
310 | const struct drbg_string *in); | |
541af946 SM |
311 | static int drbg_init_sym_kernel(struct drbg_state *drbg); |
312 | static int drbg_fini_sym_kernel(struct drbg_state *drbg); | |
a07203fb SM |
313 | static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, |
314 | u8 *inbuf, u32 inbuflen, | |
315 | u8 *outbuf, u32 outlen); | |
43490e80 | 316 | #define DRBG_OUTSCRATCHLEN 256 |
541af946 SM |
317 | |
318 | /* BCC function for CTR DRBG as defined in 10.4.3 */ | |
319 | static int drbg_ctr_bcc(struct drbg_state *drbg, | |
320 | unsigned char *out, const unsigned char *key, | |
8c987166 | 321 | struct list_head *in) |
541af946 | 322 | { |
8c987166 SM |
323 | int ret = 0; |
324 | struct drbg_string *curr = NULL; | |
541af946 | 325 | struct drbg_string data; |
8c987166 | 326 | short cnt = 0; |
541af946 SM |
327 | |
328 | drbg_string_fill(&data, out, drbg_blocklen(drbg)); | |
329 | ||
541af946 | 330 | /* 10.4.3 step 2 / 4 */ |
ed494d4f | 331 | drbg_kcapi_symsetkey(drbg, key); |
8c987166 SM |
332 | list_for_each_entry(curr, in, list) { |
333 | const unsigned char *pos = curr->buf; | |
334 | size_t len = curr->len; | |
541af946 | 335 | /* 10.4.3 step 4.1 */ |
8c987166 SM |
336 | while (len) { |
337 | /* 10.4.3 step 4.2 */ | |
338 | if (drbg_blocklen(drbg) == cnt) { | |
339 | cnt = 0; | |
ed494d4f | 340 | ret = drbg_kcapi_sym(drbg, out, &data); |
8c987166 SM |
341 | if (ret) |
342 | return ret; | |
541af946 | 343 | } |
8c987166 SM |
344 | out[cnt] ^= *pos; |
345 | pos++; | |
346 | cnt++; | |
347 | len--; | |
541af946 | 348 | } |
541af946 | 349 | } |
8c987166 SM |
350 | /* 10.4.3 step 4.2 for last block */ |
351 | if (cnt) | |
ed494d4f | 352 | ret = drbg_kcapi_sym(drbg, out, &data); |
8c987166 SM |
353 | |
354 | return ret; | |
541af946 SM |
355 | } |
356 | ||
357 | /* | |
358 | * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df | |
359 | * (and drbg_ctr_bcc, but this function does not need any temporary buffers), | |
360 | * the scratchpad is used as follows: | |
361 | * drbg_ctr_update: | |
362 | * temp | |
363 | * start: drbg->scratchpad | |
364 | * length: drbg_statelen(drbg) + drbg_blocklen(drbg) | |
365 | * note: the cipher writing into this variable works | |
366 | * blocklen-wise. Now, when the statelen is not a multiple | |
367 | * of blocklen, the generateion loop below "spills over" | |
368 | * by at most blocklen. Thus, we need to give sufficient | |
369 | * memory. | |
370 | * df_data | |
371 | * start: drbg->scratchpad + | |
372 | * drbg_statelen(drbg) + drbg_blocklen(drbg) | |
373 | * length: drbg_statelen(drbg) | |
374 | * | |
375 | * drbg_ctr_df: | |
376 | * pad | |
377 | * start: df_data + drbg_statelen(drbg) | |
378 | * length: drbg_blocklen(drbg) | |
379 | * iv | |
380 | * start: pad + drbg_blocklen(drbg) | |
381 | * length: drbg_blocklen(drbg) | |
382 | * temp | |
383 | * start: iv + drbg_blocklen(drbg) | |
8fecaad7 SM |
384 | * length: drbg_satelen(drbg) + drbg_blocklen(drbg) |
385 | * note: temp is the buffer that the BCC function operates | |
386 | * on. BCC operates blockwise. drbg_statelen(drbg) | |
387 | * is sufficient when the DRBG state length is a multiple | |
388 | * of the block size. For AES192 (and maybe other ciphers) | |
389 | * this is not correct and the length for temp is | |
390 | * insufficient (yes, that also means for such ciphers, | |
391 | * the final output of all BCC rounds are truncated). | |
392 | * Therefore, add drbg_blocklen(drbg) to cover all | |
393 | * possibilities. | |
541af946 SM |
394 | */ |
395 | ||
396 | /* Derivation Function for CTR DRBG as defined in 10.4.2 */ | |
397 | static int drbg_ctr_df(struct drbg_state *drbg, | |
398 | unsigned char *df_data, size_t bytes_to_return, | |
8c987166 | 399 | struct list_head *seedlist) |
541af946 SM |
400 | { |
401 | int ret = -EFAULT; | |
402 | unsigned char L_N[8]; | |
403 | /* S3 is input */ | |
404 | struct drbg_string S1, S2, S4, cipherin; | |
8c987166 | 405 | LIST_HEAD(bcc_list); |
541af946 SM |
406 | unsigned char *pad = df_data + drbg_statelen(drbg); |
407 | unsigned char *iv = pad + drbg_blocklen(drbg); | |
408 | unsigned char *temp = iv + drbg_blocklen(drbg); | |
409 | size_t padlen = 0; | |
410 | unsigned int templen = 0; | |
411 | /* 10.4.2 step 7 */ | |
412 | unsigned int i = 0; | |
413 | /* 10.4.2 step 8 */ | |
414 | const unsigned char *K = (unsigned char *) | |
415 | "\x00\x01\x02\x03\x04\x05\x06\x07" | |
416 | "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" | |
417 | "\x10\x11\x12\x13\x14\x15\x16\x17" | |
418 | "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"; | |
419 | unsigned char *X; | |
420 | size_t generated_len = 0; | |
421 | size_t inputlen = 0; | |
8c987166 | 422 | struct drbg_string *seed = NULL; |
541af946 SM |
423 | |
424 | memset(pad, 0, drbg_blocklen(drbg)); | |
425 | memset(iv, 0, drbg_blocklen(drbg)); | |
541af946 SM |
426 | |
427 | /* 10.4.2 step 1 is implicit as we work byte-wise */ | |
428 | ||
429 | /* 10.4.2 step 2 */ | |
430 | if ((512/8) < bytes_to_return) | |
431 | return -EINVAL; | |
432 | ||
433 | /* 10.4.2 step 2 -- calculate the entire length of all input data */ | |
8c987166 SM |
434 | list_for_each_entry(seed, seedlist, list) |
435 | inputlen += seed->len; | |
72f3e00d | 436 | drbg_cpu_to_be32(inputlen, &L_N[0]); |
541af946 SM |
437 | |
438 | /* 10.4.2 step 3 */ | |
72f3e00d | 439 | drbg_cpu_to_be32(bytes_to_return, &L_N[4]); |
541af946 SM |
440 | |
441 | /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */ | |
442 | padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg)); | |
443 | /* wrap the padlen appropriately */ | |
444 | if (padlen) | |
445 | padlen = drbg_blocklen(drbg) - padlen; | |
446 | /* | |
447 | * pad / padlen contains the 0x80 byte and the following zero bytes. | |
448 | * As the calculated padlen value only covers the number of zero | |
449 | * bytes, this value has to be incremented by one for the 0x80 byte. | |
450 | */ | |
451 | padlen++; | |
452 | pad[0] = 0x80; | |
453 | ||
454 | /* 10.4.2 step 4 -- first fill the linked list and then order it */ | |
455 | drbg_string_fill(&S1, iv, drbg_blocklen(drbg)); | |
8c987166 | 456 | list_add_tail(&S1.list, &bcc_list); |
541af946 | 457 | drbg_string_fill(&S2, L_N, sizeof(L_N)); |
8c987166 SM |
458 | list_add_tail(&S2.list, &bcc_list); |
459 | list_splice_tail(seedlist, &bcc_list); | |
541af946 | 460 | drbg_string_fill(&S4, pad, padlen); |
8c987166 | 461 | list_add_tail(&S4.list, &bcc_list); |
541af946 SM |
462 | |
463 | /* 10.4.2 step 9 */ | |
464 | while (templen < (drbg_keylen(drbg) + (drbg_blocklen(drbg)))) { | |
465 | /* | |
466 | * 10.4.2 step 9.1 - the padding is implicit as the buffer | |
467 | * holds zeros after allocation -- even the increment of i | |
468 | * is irrelevant as the increment remains within length of i | |
469 | */ | |
72f3e00d | 470 | drbg_cpu_to_be32(i, iv); |
541af946 | 471 | /* 10.4.2 step 9.2 -- BCC and concatenation with temp */ |
8c987166 | 472 | ret = drbg_ctr_bcc(drbg, temp + templen, K, &bcc_list); |
541af946 SM |
473 | if (ret) |
474 | goto out; | |
475 | /* 10.4.2 step 9.3 */ | |
476 | i++; | |
477 | templen += drbg_blocklen(drbg); | |
478 | } | |
479 | ||
480 | /* 10.4.2 step 11 */ | |
481 | X = temp + (drbg_keylen(drbg)); | |
482 | drbg_string_fill(&cipherin, X, drbg_blocklen(drbg)); | |
483 | ||
484 | /* 10.4.2 step 12: overwriting of outval is implemented in next step */ | |
485 | ||
486 | /* 10.4.2 step 13 */ | |
ed494d4f | 487 | drbg_kcapi_symsetkey(drbg, temp); |
541af946 SM |
488 | while (generated_len < bytes_to_return) { |
489 | short blocklen = 0; | |
490 | /* | |
491 | * 10.4.2 step 13.1: the truncation of the key length is | |
492 | * implicit as the key is only drbg_blocklen in size based on | |
493 | * the implementation of the cipher function callback | |
494 | */ | |
ed494d4f | 495 | ret = drbg_kcapi_sym(drbg, X, &cipherin); |
541af946 SM |
496 | if (ret) |
497 | goto out; | |
498 | blocklen = (drbg_blocklen(drbg) < | |
499 | (bytes_to_return - generated_len)) ? | |
500 | drbg_blocklen(drbg) : | |
501 | (bytes_to_return - generated_len); | |
502 | /* 10.4.2 step 13.2 and 14 */ | |
503 | memcpy(df_data + generated_len, X, blocklen); | |
504 | generated_len += blocklen; | |
505 | } | |
506 | ||
507 | ret = 0; | |
508 | ||
509 | out: | |
1471f09f | 510 | memset(iv, 0, drbg_blocklen(drbg)); |
8e0498d9 | 511 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
1471f09f | 512 | memset(pad, 0, drbg_blocklen(drbg)); |
541af946 SM |
513 | return ret; |
514 | } | |
515 | ||
72e7c25a SM |
516 | /* |
517 | * update function of CTR DRBG as defined in 10.2.1.2 | |
518 | * | |
519 | * The reseed variable has an enhanced meaning compared to the update | |
520 | * functions of the other DRBGs as follows: | |
521 | * 0 => initial seed from initialization | |
522 | * 1 => reseed via drbg_seed | |
523 | * 2 => first invocation from drbg_ctr_update when addtl is present. In | |
524 | * this case, the df_data scratchpad is not deleted so that it is | |
525 | * available for another calls to prevent calling the DF function | |
526 | * again. | |
527 | * 3 => second invocation from drbg_ctr_update. When the update function | |
528 | * was called with addtl, the df_data memory already contains the | |
529 | * DFed addtl information and we do not need to call DF again. | |
530 | */ | |
8c987166 SM |
531 | static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, |
532 | int reseed) | |
541af946 SM |
533 | { |
534 | int ret = -EFAULT; | |
535 | /* 10.2.1.2 step 1 */ | |
536 | unsigned char *temp = drbg->scratchpad; | |
537 | unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) + | |
538 | drbg_blocklen(drbg); | |
541af946 | 539 | |
72e7c25a SM |
540 | if (3 > reseed) |
541 | memset(df_data, 0, drbg_statelen(drbg)); | |
541af946 | 542 | |
35591285 SM |
543 | if (!reseed) { |
544 | /* | |
545 | * The DRBG uses the CTR mode of the underlying AES cipher. The | |
546 | * CTR mode increments the counter value after the AES operation | |
547 | * but SP800-90A requires that the counter is incremented before | |
548 | * the AES operation. Hence, we increment it at the time we set | |
549 | * it by one. | |
550 | */ | |
551 | crypto_inc(drbg->V, drbg_blocklen(drbg)); | |
552 | ||
553 | ret = crypto_skcipher_setkey(drbg->ctr_handle, drbg->C, | |
554 | drbg_keylen(drbg)); | |
541af946 SM |
555 | if (ret) |
556 | goto out; | |
557 | } | |
558 | ||
35591285 SM |
559 | /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */ |
560 | if (seed) { | |
561 | ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed); | |
541af946 SM |
562 | if (ret) |
563 | goto out; | |
541af946 SM |
564 | } |
565 | ||
a07203fb SM |
566 | ret = drbg_kcapi_sym_ctr(drbg, df_data, drbg_statelen(drbg), |
567 | temp, drbg_statelen(drbg)); | |
35591285 SM |
568 | if (ret) |
569 | return ret; | |
570 | ||
541af946 | 571 | /* 10.2.1.2 step 5 */ |
103eb3f7 | 572 | ret = crypto_skcipher_setkey(drbg->ctr_handle, temp, |
35591285 SM |
573 | drbg_keylen(drbg)); |
574 | if (ret) | |
575 | goto out; | |
541af946 SM |
576 | /* 10.2.1.2 step 6 */ |
577 | memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg)); | |
35591285 SM |
578 | /* See above: increment counter by one to compensate timing of CTR op */ |
579 | crypto_inc(drbg->V, drbg_blocklen(drbg)); | |
541af946 SM |
580 | ret = 0; |
581 | ||
582 | out: | |
1471f09f | 583 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
72e7c25a | 584 | if (2 != reseed) |
1471f09f | 585 | memset(df_data, 0, drbg_statelen(drbg)); |
541af946 SM |
586 | return ret; |
587 | } | |
588 | ||
589 | /* | |
590 | * scratchpad use: drbg_ctr_update is called independently from | |
591 | * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused | |
592 | */ | |
593 | /* Generate function of CTR DRBG as defined in 10.2.1.5.2 */ | |
594 | static int drbg_ctr_generate(struct drbg_state *drbg, | |
595 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 596 | struct list_head *addtl) |
541af946 | 597 | { |
35591285 SM |
598 | int ret; |
599 | int len = min_t(int, buflen, INT_MAX); | |
541af946 | 600 | |
541af946 | 601 | /* 10.2.1.5.2 step 2 */ |
27e4de2b SM |
602 | if (addtl && !list_empty(addtl)) { |
603 | ret = drbg_ctr_update(drbg, addtl, 2); | |
541af946 SM |
604 | if (ret) |
605 | return 0; | |
606 | } | |
607 | ||
608 | /* 10.2.1.5.2 step 4.1 */ | |
43490e80 | 609 | ret = drbg_kcapi_sym_ctr(drbg, NULL, 0, buf, len); |
35591285 SM |
610 | if (ret) |
611 | return ret; | |
541af946 | 612 | |
72e7c25a SM |
613 | /* 10.2.1.5.2 step 6 */ |
614 | ret = drbg_ctr_update(drbg, NULL, 3); | |
541af946 SM |
615 | if (ret) |
616 | len = ret; | |
617 | ||
541af946 SM |
618 | return len; |
619 | } | |
620 | ||
e4bc02ac | 621 | static const struct drbg_state_ops drbg_ctr_ops = { |
541af946 SM |
622 | .update = drbg_ctr_update, |
623 | .generate = drbg_ctr_generate, | |
624 | .crypto_init = drbg_init_sym_kernel, | |
625 | .crypto_fini = drbg_fini_sym_kernel, | |
626 | }; | |
627 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
628 | ||
629 | /****************************************************************** | |
630 | * HMAC DRBG callback functions | |
631 | ******************************************************************/ | |
632 | ||
633 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
4218ebe8 SM |
634 | static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, |
635 | const struct list_head *in); | |
636 | static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg, | |
637 | const unsigned char *key); | |
541af946 SM |
638 | static int drbg_init_hash_kernel(struct drbg_state *drbg); |
639 | static int drbg_fini_hash_kernel(struct drbg_state *drbg); | |
640 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
641 | ||
642 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
e25e47ec | 643 | #define CRYPTO_DRBG_HMAC_STRING "HMAC " |
0653a7cf SM |
644 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512"); |
645 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512"); | |
646 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384"); | |
647 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384"); | |
648 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256"); | |
649 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256"); | |
650 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1"); | |
651 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1"); | |
62b62b6e | 652 | |
541af946 | 653 | /* update function of HMAC DRBG as defined in 10.1.2.2 */ |
8c987166 SM |
654 | static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed, |
655 | int reseed) | |
541af946 SM |
656 | { |
657 | int ret = -EFAULT; | |
658 | int i = 0; | |
8c987166 SM |
659 | struct drbg_string seed1, seed2, vdata; |
660 | LIST_HEAD(seedlist); | |
661 | LIST_HEAD(vdatalist); | |
541af946 | 662 | |
4218ebe8 | 663 | if (!reseed) { |
f072f0e0 | 664 | /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */ |
541af946 | 665 | memset(drbg->V, 1, drbg_statelen(drbg)); |
4218ebe8 SM |
666 | drbg_kcapi_hmacsetkey(drbg, drbg->C); |
667 | } | |
541af946 SM |
668 | |
669 | drbg_string_fill(&seed1, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 670 | list_add_tail(&seed1.list, &seedlist); |
541af946 SM |
671 | /* buffer of seed2 will be filled in for loop below with one byte */ |
672 | drbg_string_fill(&seed2, NULL, 1); | |
8c987166 | 673 | list_add_tail(&seed2.list, &seedlist); |
541af946 | 674 | /* input data of seed is allowed to be NULL at this point */ |
8c987166 SM |
675 | if (seed) |
676 | list_splice_tail(seed, &seedlist); | |
541af946 | 677 | |
8c987166 SM |
678 | drbg_string_fill(&vdata, drbg->V, drbg_statelen(drbg)); |
679 | list_add_tail(&vdata.list, &vdatalist); | |
541af946 SM |
680 | for (i = 2; 0 < i; i--) { |
681 | /* first round uses 0x0, second 0x1 */ | |
682 | unsigned char prefix = DRBG_PREFIX0; | |
683 | if (1 == i) | |
684 | prefix = DRBG_PREFIX1; | |
685 | /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */ | |
686 | seed2.buf = &prefix; | |
4218ebe8 | 687 | ret = drbg_kcapi_hash(drbg, drbg->C, &seedlist); |
541af946 SM |
688 | if (ret) |
689 | return ret; | |
4218ebe8 | 690 | drbg_kcapi_hmacsetkey(drbg, drbg->C); |
541af946 SM |
691 | |
692 | /* 10.1.2.2 step 2 and 5 -- HMAC for V */ | |
4218ebe8 | 693 | ret = drbg_kcapi_hash(drbg, drbg->V, &vdatalist); |
541af946 SM |
694 | if (ret) |
695 | return ret; | |
696 | ||
697 | /* 10.1.2.2 step 3 */ | |
8c987166 | 698 | if (!seed) |
541af946 SM |
699 | return ret; |
700 | } | |
701 | ||
702 | return 0; | |
703 | } | |
704 | ||
705 | /* generate function of HMAC DRBG as defined in 10.1.2.5 */ | |
706 | static int drbg_hmac_generate(struct drbg_state *drbg, | |
707 | unsigned char *buf, | |
708 | unsigned int buflen, | |
27e4de2b | 709 | struct list_head *addtl) |
541af946 SM |
710 | { |
711 | int len = 0; | |
712 | int ret = 0; | |
713 | struct drbg_string data; | |
8c987166 | 714 | LIST_HEAD(datalist); |
541af946 SM |
715 | |
716 | /* 10.1.2.5 step 2 */ | |
27e4de2b SM |
717 | if (addtl && !list_empty(addtl)) { |
718 | ret = drbg_hmac_update(drbg, addtl, 1); | |
541af946 SM |
719 | if (ret) |
720 | return ret; | |
721 | } | |
722 | ||
723 | drbg_string_fill(&data, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 724 | list_add_tail(&data.list, &datalist); |
541af946 SM |
725 | while (len < buflen) { |
726 | unsigned int outlen = 0; | |
727 | /* 10.1.2.5 step 4.1 */ | |
4218ebe8 | 728 | ret = drbg_kcapi_hash(drbg, drbg->V, &datalist); |
541af946 SM |
729 | if (ret) |
730 | return ret; | |
731 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
732 | drbg_blocklen(drbg) : (buflen - len); | |
541af946 SM |
733 | |
734 | /* 10.1.2.5 step 4.2 */ | |
735 | memcpy(buf + len, drbg->V, outlen); | |
736 | len += outlen; | |
737 | } | |
738 | ||
739 | /* 10.1.2.5 step 6 */ | |
27e4de2b SM |
740 | if (addtl && !list_empty(addtl)) |
741 | ret = drbg_hmac_update(drbg, addtl, 1); | |
742 | else | |
8c987166 | 743 | ret = drbg_hmac_update(drbg, NULL, 1); |
541af946 SM |
744 | if (ret) |
745 | return ret; | |
746 | ||
747 | return len; | |
748 | } | |
749 | ||
e4bc02ac | 750 | static const struct drbg_state_ops drbg_hmac_ops = { |
541af946 SM |
751 | .update = drbg_hmac_update, |
752 | .generate = drbg_hmac_generate, | |
753 | .crypto_init = drbg_init_hash_kernel, | |
754 | .crypto_fini = drbg_fini_hash_kernel, | |
541af946 SM |
755 | }; |
756 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
757 | ||
758 | /****************************************************************** | |
759 | * Hash DRBG callback functions | |
760 | ******************************************************************/ | |
761 | ||
762 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
e25e47ec | 763 | #define CRYPTO_DRBG_HASH_STRING "HASH " |
0653a7cf SM |
764 | MODULE_ALIAS_CRYPTO("drbg_pr_sha512"); |
765 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha512"); | |
766 | MODULE_ALIAS_CRYPTO("drbg_pr_sha384"); | |
767 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha384"); | |
768 | MODULE_ALIAS_CRYPTO("drbg_pr_sha256"); | |
769 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha256"); | |
770 | MODULE_ALIAS_CRYPTO("drbg_pr_sha1"); | |
771 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha1"); | |
62b62b6e | 772 | |
41a84982 SM |
773 | /* |
774 | * Increment buffer | |
775 | * | |
776 | * @dst buffer to increment | |
777 | * @add value to add | |
778 | */ | |
779 | static inline void drbg_add_buf(unsigned char *dst, size_t dstlen, | |
780 | const unsigned char *add, size_t addlen) | |
781 | { | |
782 | /* implied: dstlen > addlen */ | |
783 | unsigned char *dstptr; | |
784 | const unsigned char *addptr; | |
785 | unsigned int remainder = 0; | |
786 | size_t len = addlen; | |
787 | ||
788 | dstptr = dst + (dstlen-1); | |
789 | addptr = add + (addlen-1); | |
790 | while (len) { | |
791 | remainder += *dstptr + *addptr; | |
792 | *dstptr = remainder & 0xff; | |
793 | remainder >>= 8; | |
794 | len--; dstptr--; addptr--; | |
795 | } | |
796 | len = dstlen - addlen; | |
797 | while (len && remainder > 0) { | |
798 | remainder = *dstptr + 1; | |
799 | *dstptr = remainder & 0xff; | |
800 | remainder >>= 8; | |
801 | len--; dstptr--; | |
802 | } | |
803 | } | |
804 | ||
541af946 SM |
805 | /* |
806 | * scratchpad usage: as drbg_hash_update and drbg_hash_df are used | |
807 | * interlinked, the scratchpad is used as follows: | |
808 | * drbg_hash_update | |
809 | * start: drbg->scratchpad | |
810 | * length: drbg_statelen(drbg) | |
811 | * drbg_hash_df: | |
812 | * start: drbg->scratchpad + drbg_statelen(drbg) | |
813 | * length: drbg_blocklen(drbg) | |
814 | * | |
815 | * drbg_hash_process_addtl uses the scratchpad, but fully completes | |
816 | * before either of the functions mentioned before are invoked. Therefore, | |
817 | * drbg_hash_process_addtl does not need to be specifically considered. | |
818 | */ | |
819 | ||
820 | /* Derivation Function for Hash DRBG as defined in 10.4.1 */ | |
821 | static int drbg_hash_df(struct drbg_state *drbg, | |
822 | unsigned char *outval, size_t outlen, | |
8c987166 | 823 | struct list_head *entropylist) |
541af946 SM |
824 | { |
825 | int ret = 0; | |
826 | size_t len = 0; | |
827 | unsigned char input[5]; | |
828 | unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg); | |
8c987166 | 829 | struct drbg_string data; |
541af946 | 830 | |
541af946 SM |
831 | /* 10.4.1 step 3 */ |
832 | input[0] = 1; | |
72f3e00d | 833 | drbg_cpu_to_be32((outlen * 8), &input[1]); |
541af946 SM |
834 | |
835 | /* 10.4.1 step 4.1 -- concatenation of data for input into hash */ | |
8c987166 SM |
836 | drbg_string_fill(&data, input, 5); |
837 | list_add(&data.list, entropylist); | |
541af946 SM |
838 | |
839 | /* 10.4.1 step 4 */ | |
840 | while (len < outlen) { | |
841 | short blocklen = 0; | |
842 | /* 10.4.1 step 4.1 */ | |
4218ebe8 | 843 | ret = drbg_kcapi_hash(drbg, tmp, entropylist); |
541af946 SM |
844 | if (ret) |
845 | goto out; | |
846 | /* 10.4.1 step 4.2 */ | |
847 | input[0]++; | |
848 | blocklen = (drbg_blocklen(drbg) < (outlen - len)) ? | |
849 | drbg_blocklen(drbg) : (outlen - len); | |
850 | memcpy(outval + len, tmp, blocklen); | |
851 | len += blocklen; | |
852 | } | |
853 | ||
854 | out: | |
1471f09f | 855 | memset(tmp, 0, drbg_blocklen(drbg)); |
541af946 SM |
856 | return ret; |
857 | } | |
858 | ||
859 | /* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */ | |
8c987166 | 860 | static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed, |
541af946 SM |
861 | int reseed) |
862 | { | |
863 | int ret = 0; | |
864 | struct drbg_string data1, data2; | |
8c987166 SM |
865 | LIST_HEAD(datalist); |
866 | LIST_HEAD(datalist2); | |
541af946 SM |
867 | unsigned char *V = drbg->scratchpad; |
868 | unsigned char prefix = DRBG_PREFIX1; | |
869 | ||
541af946 SM |
870 | if (!seed) |
871 | return -EINVAL; | |
872 | ||
873 | if (reseed) { | |
874 | /* 10.1.1.3 step 1 */ | |
875 | memcpy(V, drbg->V, drbg_statelen(drbg)); | |
876 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 877 | list_add_tail(&data1.list, &datalist); |
541af946 | 878 | drbg_string_fill(&data2, V, drbg_statelen(drbg)); |
8c987166 | 879 | list_add_tail(&data2.list, &datalist); |
541af946 | 880 | } |
8c987166 | 881 | list_splice_tail(seed, &datalist); |
541af946 SM |
882 | |
883 | /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */ | |
8c987166 | 884 | ret = drbg_hash_df(drbg, drbg->V, drbg_statelen(drbg), &datalist); |
541af946 SM |
885 | if (ret) |
886 | goto out; | |
887 | ||
888 | /* 10.1.1.2 / 10.1.1.3 step 4 */ | |
889 | prefix = DRBG_PREFIX0; | |
890 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 891 | list_add_tail(&data1.list, &datalist2); |
541af946 | 892 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 | 893 | list_add_tail(&data2.list, &datalist2); |
541af946 | 894 | /* 10.1.1.2 / 10.1.1.3 step 4 */ |
8c987166 | 895 | ret = drbg_hash_df(drbg, drbg->C, drbg_statelen(drbg), &datalist2); |
541af946 SM |
896 | |
897 | out: | |
1471f09f | 898 | memset(drbg->scratchpad, 0, drbg_statelen(drbg)); |
541af946 SM |
899 | return ret; |
900 | } | |
901 | ||
902 | /* processing of additional information string for Hash DRBG */ | |
903 | static int drbg_hash_process_addtl(struct drbg_state *drbg, | |
27e4de2b | 904 | struct list_head *addtl) |
541af946 SM |
905 | { |
906 | int ret = 0; | |
907 | struct drbg_string data1, data2; | |
8c987166 | 908 | LIST_HEAD(datalist); |
541af946 SM |
909 | unsigned char prefix = DRBG_PREFIX2; |
910 | ||
541af946 | 911 | /* 10.1.1.4 step 2 */ |
27e4de2b | 912 | if (!addtl || list_empty(addtl)) |
541af946 SM |
913 | return 0; |
914 | ||
915 | /* 10.1.1.4 step 2a */ | |
916 | drbg_string_fill(&data1, &prefix, 1); | |
917 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); | |
8c987166 SM |
918 | list_add_tail(&data1.list, &datalist); |
919 | list_add_tail(&data2.list, &datalist); | |
27e4de2b | 920 | list_splice_tail(addtl, &datalist); |
4218ebe8 | 921 | ret = drbg_kcapi_hash(drbg, drbg->scratchpad, &datalist); |
541af946 SM |
922 | if (ret) |
923 | goto out; | |
924 | ||
925 | /* 10.1.1.4 step 2b */ | |
926 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
927 | drbg->scratchpad, drbg_blocklen(drbg)); | |
928 | ||
929 | out: | |
1471f09f | 930 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
931 | return ret; |
932 | } | |
933 | ||
934 | /* Hashgen defined in 10.1.1.4 */ | |
935 | static int drbg_hash_hashgen(struct drbg_state *drbg, | |
936 | unsigned char *buf, | |
937 | unsigned int buflen) | |
938 | { | |
939 | int len = 0; | |
940 | int ret = 0; | |
941 | unsigned char *src = drbg->scratchpad; | |
942 | unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg); | |
943 | struct drbg_string data; | |
8c987166 | 944 | LIST_HEAD(datalist); |
541af946 | 945 | |
541af946 SM |
946 | /* 10.1.1.4 step hashgen 2 */ |
947 | memcpy(src, drbg->V, drbg_statelen(drbg)); | |
948 | ||
949 | drbg_string_fill(&data, src, drbg_statelen(drbg)); | |
8c987166 | 950 | list_add_tail(&data.list, &datalist); |
541af946 SM |
951 | while (len < buflen) { |
952 | unsigned int outlen = 0; | |
953 | /* 10.1.1.4 step hashgen 4.1 */ | |
4218ebe8 | 954 | ret = drbg_kcapi_hash(drbg, dst, &datalist); |
541af946 SM |
955 | if (ret) { |
956 | len = ret; | |
957 | goto out; | |
958 | } | |
959 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
960 | drbg_blocklen(drbg) : (buflen - len); | |
541af946 SM |
961 | /* 10.1.1.4 step hashgen 4.2 */ |
962 | memcpy(buf + len, dst, outlen); | |
963 | len += outlen; | |
964 | /* 10.1.1.4 hashgen step 4.3 */ | |
965 | if (len < buflen) | |
41a84982 | 966 | crypto_inc(src, drbg_statelen(drbg)); |
541af946 SM |
967 | } |
968 | ||
969 | out: | |
1471f09f | 970 | memset(drbg->scratchpad, 0, |
541af946 SM |
971 | (drbg_statelen(drbg) + drbg_blocklen(drbg))); |
972 | return len; | |
973 | } | |
974 | ||
975 | /* generate function for Hash DRBG as defined in 10.1.1.4 */ | |
976 | static int drbg_hash_generate(struct drbg_state *drbg, | |
977 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 978 | struct list_head *addtl) |
541af946 SM |
979 | { |
980 | int len = 0; | |
981 | int ret = 0; | |
72f3e00d SM |
982 | union { |
983 | unsigned char req[8]; | |
7c8ae03f | 984 | __be64 req_int; |
72f3e00d | 985 | } u; |
541af946 SM |
986 | unsigned char prefix = DRBG_PREFIX3; |
987 | struct drbg_string data1, data2; | |
8c987166 | 988 | LIST_HEAD(datalist); |
541af946 SM |
989 | |
990 | /* 10.1.1.4 step 2 */ | |
991 | ret = drbg_hash_process_addtl(drbg, addtl); | |
992 | if (ret) | |
993 | return ret; | |
994 | /* 10.1.1.4 step 3 */ | |
995 | len = drbg_hash_hashgen(drbg, buf, buflen); | |
996 | ||
997 | /* this is the value H as documented in 10.1.1.4 */ | |
541af946 SM |
998 | /* 10.1.1.4 step 4 */ |
999 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 1000 | list_add_tail(&data1.list, &datalist); |
541af946 | 1001 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 | 1002 | list_add_tail(&data2.list, &datalist); |
4218ebe8 | 1003 | ret = drbg_kcapi_hash(drbg, drbg->scratchpad, &datalist); |
541af946 SM |
1004 | if (ret) { |
1005 | len = ret; | |
1006 | goto out; | |
1007 | } | |
1008 | ||
1009 | /* 10.1.1.4 step 5 */ | |
1010 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
1011 | drbg->scratchpad, drbg_blocklen(drbg)); | |
1012 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
1013 | drbg->C, drbg_statelen(drbg)); | |
72f3e00d SM |
1014 | u.req_int = cpu_to_be64(drbg->reseed_ctr); |
1015 | drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8); | |
541af946 SM |
1016 | |
1017 | out: | |
1471f09f | 1018 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
1019 | return len; |
1020 | } | |
1021 | ||
1022 | /* | |
1023 | * scratchpad usage: as update and generate are used isolated, both | |
1024 | * can use the scratchpad | |
1025 | */ | |
e4bc02ac | 1026 | static const struct drbg_state_ops drbg_hash_ops = { |
541af946 SM |
1027 | .update = drbg_hash_update, |
1028 | .generate = drbg_hash_generate, | |
1029 | .crypto_init = drbg_init_hash_kernel, | |
1030 | .crypto_fini = drbg_fini_hash_kernel, | |
1031 | }; | |
1032 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1033 | ||
1034 | /****************************************************************** | |
1035 | * Functions common for DRBG implementations | |
1036 | ******************************************************************/ | |
1037 | ||
3d6a5f75 | 1038 | static inline int __drbg_seed(struct drbg_state *drbg, struct list_head *seed, |
2bcd2544 | 1039 | int reseed, enum drbg_seed_state new_seed_state) |
3d6a5f75 SM |
1040 | { |
1041 | int ret = drbg->d_ops->update(drbg, seed, reseed); | |
1042 | ||
1043 | if (ret) | |
1044 | return ret; | |
1045 | ||
2bcd2544 | 1046 | drbg->seeded = new_seed_state; |
3d6a5f75 SM |
1047 | /* 10.1.1.2 / 10.1.1.3 step 5 */ |
1048 | drbg->reseed_ctr = 1; | |
1049 | ||
262d83a4 NS |
1050 | switch (drbg->seeded) { |
1051 | case DRBG_SEED_STATE_UNSEEDED: | |
1052 | /* Impossible, but handle it to silence compiler warnings. */ | |
1053 | fallthrough; | |
1054 | case DRBG_SEED_STATE_PARTIAL: | |
1055 | /* | |
1056 | * Require frequent reseeds until the seed source is | |
1057 | * fully initialized. | |
1058 | */ | |
1059 | drbg->reseed_threshold = 50; | |
1060 | break; | |
1061 | ||
1062 | case DRBG_SEED_STATE_FULL: | |
1063 | /* | |
1064 | * Seed source has become fully initialized, frequent | |
1065 | * reseeds no longer required. | |
1066 | */ | |
1067 | drbg->reseed_threshold = drbg_max_requests(drbg); | |
1068 | break; | |
1069 | } | |
1070 | ||
3d6a5f75 SM |
1071 | return ret; |
1072 | } | |
1073 | ||
db07cd26 SM |
1074 | static inline int drbg_get_random_bytes(struct drbg_state *drbg, |
1075 | unsigned char *entropy, | |
1076 | unsigned int entropylen) | |
1077 | { | |
1078 | int ret; | |
1079 | ||
1080 | do { | |
1081 | get_random_bytes(entropy, entropylen); | |
1082 | ret = drbg_fips_continuous_test(drbg, entropy); | |
1083 | if (ret && ret != -EAGAIN) | |
1084 | return ret; | |
1085 | } while (ret); | |
1086 | ||
1087 | return 0; | |
1088 | } | |
1089 | ||
074bcd40 | 1090 | static int drbg_seed_from_random(struct drbg_state *drbg) |
4c787990 SM |
1091 | { |
1092 | struct drbg_string data; | |
1093 | LIST_HEAD(seedlist); | |
57225e67 SM |
1094 | unsigned int entropylen = drbg_sec_strength(drbg->core->flags); |
1095 | unsigned char entropy[32]; | |
db07cd26 | 1096 | int ret; |
4c787990 | 1097 | |
57225e67 SM |
1098 | BUG_ON(!entropylen); |
1099 | BUG_ON(entropylen > sizeof(entropy)); | |
4c787990 | 1100 | |
57225e67 | 1101 | drbg_string_fill(&data, entropy, entropylen); |
4c787990 | 1102 | list_add_tail(&data.list, &seedlist); |
57225e67 | 1103 | |
db07cd26 SM |
1104 | ret = drbg_get_random_bytes(drbg, entropy, entropylen); |
1105 | if (ret) | |
074bcd40 | 1106 | goto out; |
57225e67 | 1107 | |
074bcd40 | 1108 | ret = __drbg_seed(drbg, &seedlist, true, DRBG_SEED_STATE_FULL); |
57225e67 | 1109 | |
074bcd40 | 1110 | out: |
57225e67 | 1111 | memzero_explicit(entropy, entropylen); |
074bcd40 | 1112 | return ret; |
4c787990 SM |
1113 | } |
1114 | ||
541af946 SM |
1115 | /* |
1116 | * Seeding or reseeding of the DRBG | |
1117 | * | |
1118 | * @drbg: DRBG state struct | |
1119 | * @pers: personalization / additional information buffer | |
1120 | * @reseed: 0 for initial seed process, 1 for reseeding | |
1121 | * | |
1122 | * return: | |
1123 | * 0 on success | |
1124 | * error value otherwise | |
1125 | */ | |
1126 | static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers, | |
1127 | bool reseed) | |
1128 | { | |
57225e67 SM |
1129 | int ret; |
1130 | unsigned char entropy[((32 + 16) * 2)]; | |
1131 | unsigned int entropylen = drbg_sec_strength(drbg->core->flags); | |
541af946 | 1132 | struct drbg_string data1; |
8c987166 | 1133 | LIST_HEAD(seedlist); |
2bcd2544 | 1134 | enum drbg_seed_state new_seed_state = DRBG_SEED_STATE_FULL; |
541af946 SM |
1135 | |
1136 | /* 9.1 / 9.2 / 9.3.1 step 3 */ | |
1137 | if (pers && pers->len > (drbg_max_addtl(drbg))) { | |
a9089571 | 1138 | pr_devel("DRBG: personalization string too long %zu\n", |
541af946 SM |
1139 | pers->len); |
1140 | return -EINVAL; | |
1141 | } | |
1142 | ||
8fded592 HX |
1143 | if (list_empty(&drbg->test_data.list)) { |
1144 | drbg_string_fill(&data1, drbg->test_data.buf, | |
1145 | drbg->test_data.len); | |
541af946 SM |
1146 | pr_devel("DRBG: using test entropy\n"); |
1147 | } else { | |
57225e67 SM |
1148 | /* |
1149 | * Gather entropy equal to the security strength of the DRBG. | |
1150 | * With a derivation function, a nonce is required in addition | |
1151 | * to the entropy. A nonce must be at least 1/2 of the security | |
1152 | * strength of the DRBG in size. Thus, entropy + nonce is 3/2 | |
1153 | * of the strength. The consideration of a nonce is only | |
1154 | * applicable during initial seeding. | |
1155 | */ | |
1156 | BUG_ON(!entropylen); | |
1157 | if (!reseed) | |
1158 | entropylen = ((entropylen + 1) / 2) * 3; | |
1159 | BUG_ON((entropylen * 2) > sizeof(entropy)); | |
1160 | ||
b8ec5ba4 | 1161 | /* Get seed from in-kernel /dev/urandom */ |
2bcd2544 NS |
1162 | if (!rng_is_initialized()) |
1163 | new_seed_state = DRBG_SEED_STATE_PARTIAL; | |
1164 | ||
db07cd26 SM |
1165 | ret = drbg_get_random_bytes(drbg, entropy, entropylen); |
1166 | if (ret) | |
1167 | goto out; | |
57225e67 SM |
1168 | |
1169 | if (!drbg->jent) { | |
1170 | drbg_string_fill(&data1, entropy, entropylen); | |
1171 | pr_devel("DRBG: (re)seeding with %u bytes of entropy\n", | |
1172 | entropylen); | |
b8ec5ba4 | 1173 | } else { |
57225e67 SM |
1174 | /* Get seed from Jitter RNG */ |
1175 | ret = crypto_rng_get_bytes(drbg->jent, | |
1176 | entropy + entropylen, | |
1177 | entropylen); | |
1178 | if (ret) { | |
1179 | pr_devel("DRBG: jent failed with %d\n", ret); | |
97f2650e SM |
1180 | |
1181 | /* | |
1182 | * Do not treat the transient failure of the | |
1183 | * Jitter RNG as an error that needs to be | |
1184 | * reported. The combined number of the | |
1185 | * maximum reseed threshold times the maximum | |
1186 | * number of Jitter RNG transient errors is | |
1187 | * less than the reseed threshold required by | |
1188 | * SP800-90A allowing us to treat the | |
1189 | * transient errors as such. | |
1190 | * | |
1191 | * However, we mandate that at least the first | |
1192 | * seeding operation must succeed with the | |
1193 | * Jitter RNG. | |
1194 | */ | |
1195 | if (!reseed || ret != -EAGAIN) | |
1196 | goto out; | |
57225e67 SM |
1197 | } |
1198 | ||
1199 | drbg_string_fill(&data1, entropy, entropylen * 2); | |
1200 | pr_devel("DRBG: (re)seeding with %u bytes of entropy\n", | |
1201 | entropylen * 2); | |
b8ec5ba4 | 1202 | } |
541af946 | 1203 | } |
8c987166 | 1204 | list_add_tail(&data1.list, &seedlist); |
541af946 SM |
1205 | |
1206 | /* | |
1207 | * concatenation of entropy with personalization str / addtl input) | |
1208 | * the variable pers is directly handed in by the caller, so check its | |
1209 | * contents whether it is appropriate | |
1210 | */ | |
8c987166 SM |
1211 | if (pers && pers->buf && 0 < pers->len) { |
1212 | list_add_tail(&pers->list, &seedlist); | |
541af946 SM |
1213 | pr_devel("DRBG: using personalization string\n"); |
1214 | } | |
1215 | ||
e6c0244a SM |
1216 | if (!reseed) { |
1217 | memset(drbg->V, 0, drbg_statelen(drbg)); | |
1218 | memset(drbg->C, 0, drbg_statelen(drbg)); | |
1219 | } | |
1220 | ||
2bcd2544 | 1221 | ret = __drbg_seed(drbg, &seedlist, reseed, new_seed_state); |
3d6a5f75 | 1222 | |
db07cd26 | 1223 | out: |
57225e67 | 1224 | memzero_explicit(entropy, entropylen * 2); |
4c787990 | 1225 | |
541af946 SM |
1226 | return ret; |
1227 | } | |
1228 | ||
1229 | /* Free all substructures in a DRBG state without the DRBG state structure */ | |
1230 | static inline void drbg_dealloc_state(struct drbg_state *drbg) | |
1231 | { | |
1232 | if (!drbg) | |
1233 | return; | |
453431a5 | 1234 | kfree_sensitive(drbg->Vbuf); |
eea0d3ea | 1235 | drbg->Vbuf = NULL; |
bd6227a1 | 1236 | drbg->V = NULL; |
453431a5 | 1237 | kfree_sensitive(drbg->Cbuf); |
eea0d3ea | 1238 | drbg->Cbuf = NULL; |
bd6227a1 | 1239 | drbg->C = NULL; |
453431a5 | 1240 | kfree_sensitive(drbg->scratchpadbuf); |
3cfc3b97 | 1241 | drbg->scratchpadbuf = NULL; |
541af946 | 1242 | drbg->reseed_ctr = 0; |
2a57e424 HX |
1243 | drbg->d_ops = NULL; |
1244 | drbg->core = NULL; | |
db07cd26 | 1245 | if (IS_ENABLED(CONFIG_CRYPTO_FIPS)) { |
453431a5 | 1246 | kfree_sensitive(drbg->prev); |
db07cd26 SM |
1247 | drbg->prev = NULL; |
1248 | drbg->fips_primed = false; | |
1249 | } | |
541af946 SM |
1250 | } |
1251 | ||
1252 | /* | |
1253 | * Allocate all sub-structures for a DRBG state. | |
1254 | * The DRBG state structure must already be allocated. | |
1255 | */ | |
1256 | static inline int drbg_alloc_state(struct drbg_state *drbg) | |
1257 | { | |
1258 | int ret = -ENOMEM; | |
1259 | unsigned int sb_size = 0; | |
1260 | ||
2a57e424 HX |
1261 | switch (drbg->core->flags & DRBG_TYPE_MASK) { |
1262 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
1263 | case DRBG_HMAC: | |
1264 | drbg->d_ops = &drbg_hmac_ops; | |
1265 | break; | |
1266 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
1267 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
1268 | case DRBG_HASH: | |
1269 | drbg->d_ops = &drbg_hash_ops; | |
1270 | break; | |
1271 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1272 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1273 | case DRBG_CTR: | |
1274 | drbg->d_ops = &drbg_ctr_ops; | |
1275 | break; | |
1276 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
1277 | default: | |
1278 | ret = -EOPNOTSUPP; | |
1279 | goto err; | |
1280 | } | |
1281 | ||
3cfc3b97 SM |
1282 | ret = drbg->d_ops->crypto_init(drbg); |
1283 | if (ret < 0) | |
541af946 | 1284 | goto err; |
3cfc3b97 SM |
1285 | |
1286 | drbg->Vbuf = kmalloc(drbg_statelen(drbg) + ret, GFP_KERNEL); | |
1a45d7e3 WY |
1287 | if (!drbg->Vbuf) { |
1288 | ret = -ENOMEM; | |
3cfc3b97 | 1289 | goto fini; |
1a45d7e3 | 1290 | } |
3cfc3b97 SM |
1291 | drbg->V = PTR_ALIGN(drbg->Vbuf, ret + 1); |
1292 | drbg->Cbuf = kmalloc(drbg_statelen(drbg) + ret, GFP_KERNEL); | |
1a45d7e3 WY |
1293 | if (!drbg->Cbuf) { |
1294 | ret = -ENOMEM; | |
3cfc3b97 | 1295 | goto fini; |
1a45d7e3 | 1296 | } |
3cfc3b97 | 1297 | drbg->C = PTR_ALIGN(drbg->Cbuf, ret + 1); |
541af946 SM |
1298 | /* scratchpad is only generated for CTR and Hash */ |
1299 | if (drbg->core->flags & DRBG_HMAC) | |
1300 | sb_size = 0; | |
1301 | else if (drbg->core->flags & DRBG_CTR) | |
1302 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg) + /* temp */ | |
1303 | drbg_statelen(drbg) + /* df_data */ | |
1304 | drbg_blocklen(drbg) + /* pad */ | |
1305 | drbg_blocklen(drbg) + /* iv */ | |
8fecaad7 | 1306 | drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */ |
541af946 SM |
1307 | else |
1308 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg); | |
1309 | ||
1310 | if (0 < sb_size) { | |
3cfc3b97 | 1311 | drbg->scratchpadbuf = kzalloc(sb_size + ret, GFP_KERNEL); |
1a45d7e3 WY |
1312 | if (!drbg->scratchpadbuf) { |
1313 | ret = -ENOMEM; | |
3cfc3b97 | 1314 | goto fini; |
1a45d7e3 | 1315 | } |
3cfc3b97 | 1316 | drbg->scratchpad = PTR_ALIGN(drbg->scratchpadbuf, ret + 1); |
541af946 | 1317 | } |
3d6a5f75 | 1318 | |
db07cd26 SM |
1319 | if (IS_ENABLED(CONFIG_CRYPTO_FIPS)) { |
1320 | drbg->prev = kzalloc(drbg_sec_strength(drbg->core->flags), | |
1321 | GFP_KERNEL); | |
e0664ebc WY |
1322 | if (!drbg->prev) { |
1323 | ret = -ENOMEM; | |
db07cd26 | 1324 | goto fini; |
e0664ebc | 1325 | } |
db07cd26 SM |
1326 | drbg->fips_primed = false; |
1327 | } | |
1328 | ||
541af946 SM |
1329 | return 0; |
1330 | ||
3cfc3b97 SM |
1331 | fini: |
1332 | drbg->d_ops->crypto_fini(drbg); | |
541af946 SM |
1333 | err: |
1334 | drbg_dealloc_state(drbg); | |
1335 | return ret; | |
1336 | } | |
1337 | ||
541af946 SM |
1338 | /************************************************************************* |
1339 | * DRBG interface functions | |
1340 | *************************************************************************/ | |
1341 | ||
1342 | /* | |
1343 | * DRBG generate function as required by SP800-90A - this function | |
1344 | * generates random numbers | |
1345 | * | |
1346 | * @drbg DRBG state handle | |
1347 | * @buf Buffer where to store the random numbers -- the buffer must already | |
1348 | * be pre-allocated by caller | |
1349 | * @buflen Length of output buffer - this value defines the number of random | |
1350 | * bytes pulled from DRBG | |
1351 | * @addtl Additional input that is mixed into state, may be NULL -- note | |
1352 | * the entropy is pulled by the DRBG internally unconditionally | |
1353 | * as defined in SP800-90A. The additional input is mixed into | |
1354 | * the state in addition to the pulled entropy. | |
1355 | * | |
cde001e4 | 1356 | * return: 0 when all bytes are generated; < 0 in case of an error |
541af946 SM |
1357 | */ |
1358 | static int drbg_generate(struct drbg_state *drbg, | |
1359 | unsigned char *buf, unsigned int buflen, | |
1360 | struct drbg_string *addtl) | |
1361 | { | |
1362 | int len = 0; | |
27e4de2b | 1363 | LIST_HEAD(addtllist); |
541af946 | 1364 | |
2a57e424 HX |
1365 | if (!drbg->core) { |
1366 | pr_devel("DRBG: not yet seeded\n"); | |
1367 | return -EINVAL; | |
1368 | } | |
541af946 SM |
1369 | if (0 == buflen || !buf) { |
1370 | pr_devel("DRBG: no output buffer provided\n"); | |
1371 | return -EINVAL; | |
1372 | } | |
1373 | if (addtl && NULL == addtl->buf && 0 < addtl->len) { | |
1374 | pr_devel("DRBG: wrong format of additional information\n"); | |
1375 | return -EINVAL; | |
1376 | } | |
1377 | ||
541af946 SM |
1378 | /* 9.3.1 step 2 */ |
1379 | len = -EINVAL; | |
76899a41 | 1380 | if (buflen > (drbg_max_request_bytes(drbg))) { |
541af946 SM |
1381 | pr_devel("DRBG: requested random numbers too large %u\n", |
1382 | buflen); | |
1383 | goto err; | |
1384 | } | |
1385 | ||
1386 | /* 9.3.1 step 3 is implicit with the chosen DRBG */ | |
1387 | ||
1388 | /* 9.3.1 step 4 */ | |
76899a41 | 1389 | if (addtl && addtl->len > (drbg_max_addtl(drbg))) { |
541af946 SM |
1390 | pr_devel("DRBG: additional information string too long %zu\n", |
1391 | addtl->len); | |
1392 | goto err; | |
1393 | } | |
1394 | /* 9.3.1 step 5 is implicit with the chosen DRBG */ | |
1395 | ||
1396 | /* | |
1397 | * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented | |
1398 | * here. The spec is a bit convoluted here, we make it simpler. | |
1399 | */ | |
42ea507f | 1400 | if (drbg->reseed_threshold < drbg->reseed_ctr) |
ce8ce31b | 1401 | drbg->seeded = DRBG_SEED_STATE_UNSEEDED; |
541af946 | 1402 | |
ce8ce31b | 1403 | if (drbg->pr || drbg->seeded == DRBG_SEED_STATE_UNSEEDED) { |
541af946 SM |
1404 | pr_devel("DRBG: reseeding before generation (prediction " |
1405 | "resistance: %s, state %s)\n", | |
1406 | drbg->pr ? "true" : "false", | |
ce8ce31b NS |
1407 | (drbg->seeded == DRBG_SEED_STATE_FULL ? |
1408 | "seeded" : "unseeded")); | |
541af946 | 1409 | /* 9.3.1 steps 7.1 through 7.3 */ |
76899a41 | 1410 | len = drbg_seed(drbg, addtl, true); |
541af946 SM |
1411 | if (len) |
1412 | goto err; | |
1413 | /* 9.3.1 step 7.4 */ | |
1414 | addtl = NULL; | |
074bcd40 NS |
1415 | } else if (rng_is_initialized() && |
1416 | drbg->seeded == DRBG_SEED_STATE_PARTIAL) { | |
1417 | len = drbg_seed_from_random(drbg); | |
1418 | if (len) | |
1419 | goto err; | |
541af946 | 1420 | } |
27e4de2b | 1421 | |
27e4de2b SM |
1422 | if (addtl && 0 < addtl->len) |
1423 | list_add_tail(&addtl->list, &addtllist); | |
541af946 | 1424 | /* 9.3.1 step 8 and 10 */ |
76899a41 | 1425 | len = drbg->d_ops->generate(drbg, buf, buflen, &addtllist); |
541af946 SM |
1426 | |
1427 | /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */ | |
76899a41 | 1428 | drbg->reseed_ctr++; |
541af946 SM |
1429 | if (0 >= len) |
1430 | goto err; | |
1431 | ||
1432 | /* | |
1433 | * Section 11.3.3 requires to re-perform self tests after some | |
1434 | * generated random numbers. The chosen value after which self | |
1435 | * test is performed is arbitrary, but it should be reasonable. | |
1436 | * However, we do not perform the self tests because of the following | |
1437 | * reasons: it is mathematically impossible that the initial self tests | |
1438 | * were successfully and the following are not. If the initial would | |
1439 | * pass and the following would not, the kernel integrity is violated. | |
1440 | * In this case, the entire kernel operation is questionable and it | |
1441 | * is unlikely that the integrity violation only affects the | |
1442 | * correct operation of the DRBG. | |
1443 | * | |
1444 | * Albeit the following code is commented out, it is provided in | |
1445 | * case somebody has a need to implement the test of 11.3.3. | |
1446 | */ | |
1447 | #if 0 | |
76899a41 | 1448 | if (drbg->reseed_ctr && !(drbg->reseed_ctr % 4096)) { |
541af946 SM |
1449 | int err = 0; |
1450 | pr_devel("DRBG: start to perform self test\n"); | |
1451 | if (drbg->core->flags & DRBG_HMAC) | |
1452 | err = alg_test("drbg_pr_hmac_sha256", | |
1453 | "drbg_pr_hmac_sha256", 0, 0); | |
1454 | else if (drbg->core->flags & DRBG_CTR) | |
1455 | err = alg_test("drbg_pr_ctr_aes128", | |
1456 | "drbg_pr_ctr_aes128", 0, 0); | |
1457 | else | |
1458 | err = alg_test("drbg_pr_sha256", | |
1459 | "drbg_pr_sha256", 0, 0); | |
1460 | if (err) { | |
1461 | pr_err("DRBG: periodical self test failed\n"); | |
1462 | /* | |
1463 | * uninstantiate implies that from now on, only errors | |
1464 | * are returned when reusing this DRBG cipher handle | |
1465 | */ | |
1466 | drbg_uninstantiate(drbg); | |
541af946 SM |
1467 | return 0; |
1468 | } else { | |
1469 | pr_devel("DRBG: self test successful\n"); | |
1470 | } | |
1471 | } | |
1472 | #endif | |
1473 | ||
cde001e4 SM |
1474 | /* |
1475 | * All operations were successful, return 0 as mandated by | |
1476 | * the kernel crypto API interface. | |
1477 | */ | |
1478 | len = 0; | |
541af946 | 1479 | err: |
541af946 SM |
1480 | return len; |
1481 | } | |
1482 | ||
1483 | /* | |
1484 | * Wrapper around drbg_generate which can pull arbitrary long strings | |
1485 | * from the DRBG without hitting the maximum request limitation. | |
1486 | * | |
1487 | * Parameters: see drbg_generate | |
1488 | * Return codes: see drbg_generate -- if one drbg_generate request fails, | |
1489 | * the entire drbg_generate_long request fails | |
1490 | */ | |
1491 | static int drbg_generate_long(struct drbg_state *drbg, | |
1492 | unsigned char *buf, unsigned int buflen, | |
1493 | struct drbg_string *addtl) | |
1494 | { | |
082eb10b | 1495 | unsigned int len = 0; |
541af946 SM |
1496 | unsigned int slice = 0; |
1497 | do { | |
082eb10b | 1498 | int err = 0; |
541af946 SM |
1499 | unsigned int chunk = 0; |
1500 | slice = ((buflen - len) / drbg_max_request_bytes(drbg)); | |
1501 | chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len); | |
76899a41 | 1502 | mutex_lock(&drbg->drbg_mutex); |
082eb10b | 1503 | err = drbg_generate(drbg, buf + len, chunk, addtl); |
76899a41 | 1504 | mutex_unlock(&drbg->drbg_mutex); |
082eb10b SM |
1505 | if (0 > err) |
1506 | return err; | |
1507 | len += chunk; | |
ce5481d0 | 1508 | } while (slice > 0 && (len < buflen)); |
082eb10b | 1509 | return 0; |
541af946 SM |
1510 | } |
1511 | ||
57225e67 SM |
1512 | static int drbg_prepare_hrng(struct drbg_state *drbg) |
1513 | { | |
57225e67 SM |
1514 | /* We do not need an HRNG in test mode. */ |
1515 | if (list_empty(&drbg->test_data.list)) | |
1516 | return 0; | |
1517 | ||
97f2650e | 1518 | drbg->jent = crypto_alloc_rng("jitterentropy_rng", 0, 0); |
559edd47 NS |
1519 | if (IS_ERR(drbg->jent)) { |
1520 | const int err = PTR_ERR(drbg->jent); | |
1521 | ||
1522 | drbg->jent = NULL; | |
1523 | if (fips_enabled || err != -ENOENT) | |
1524 | return err; | |
1525 | pr_info("DRBG: Continuing without Jitter RNG\n"); | |
1526 | } | |
97f2650e | 1527 | |
074bcd40 | 1528 | return 0; |
57225e67 SM |
1529 | } |
1530 | ||
541af946 SM |
1531 | /* |
1532 | * DRBG instantiation function as required by SP800-90A - this function | |
1533 | * sets up the DRBG handle, performs the initial seeding and all sanity | |
1534 | * checks required by SP800-90A | |
1535 | * | |
1536 | * @drbg memory of state -- if NULL, new memory is allocated | |
1537 | * @pers Personalization string that is mixed into state, may be NULL -- note | |
1538 | * the entropy is pulled by the DRBG internally unconditionally | |
1539 | * as defined in SP800-90A. The additional input is mixed into | |
1540 | * the state in addition to the pulled entropy. | |
1541 | * @coreref reference to core | |
1542 | * @pr prediction resistance enabled | |
1543 | * | |
1544 | * return | |
1545 | * 0 on success | |
1546 | * error value otherwise | |
1547 | */ | |
1548 | static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, | |
1549 | int coreref, bool pr) | |
1550 | { | |
2a57e424 HX |
1551 | int ret; |
1552 | bool reseed = true; | |
541af946 SM |
1553 | |
1554 | pr_devel("DRBG: Initializing DRBG core %d with prediction resistance " | |
1555 | "%s\n", coreref, pr ? "enabled" : "disabled"); | |
76899a41 | 1556 | mutex_lock(&drbg->drbg_mutex); |
541af946 SM |
1557 | |
1558 | /* 9.1 step 1 is implicit with the selected DRBG type */ | |
1559 | ||
1560 | /* | |
1561 | * 9.1 step 2 is implicit as caller can select prediction resistance | |
1562 | * and the flag is copied into drbg->flags -- | |
1563 | * all DRBG types support prediction resistance | |
1564 | */ | |
1565 | ||
1566 | /* 9.1 step 4 is implicit in drbg_sec_strength */ | |
1567 | ||
2a57e424 HX |
1568 | if (!drbg->core) { |
1569 | drbg->core = &drbg_cores[coreref]; | |
1570 | drbg->pr = pr; | |
ce8ce31b | 1571 | drbg->seeded = DRBG_SEED_STATE_UNSEEDED; |
42ea507f | 1572 | drbg->reseed_threshold = drbg_max_requests(drbg); |
541af946 | 1573 | |
2a57e424 HX |
1574 | ret = drbg_alloc_state(drbg); |
1575 | if (ret) | |
1576 | goto unlock; | |
1577 | ||
57225e67 SM |
1578 | ret = drbg_prepare_hrng(drbg); |
1579 | if (ret) | |
1580 | goto free_everything; | |
1581 | ||
2a57e424 HX |
1582 | reseed = false; |
1583 | } | |
1584 | ||
1585 | ret = drbg_seed(drbg, pers, reseed); | |
1586 | ||
57225e67 SM |
1587 | if (ret && !reseed) |
1588 | goto free_everything; | |
541af946 | 1589 | |
76899a41 | 1590 | mutex_unlock(&drbg->drbg_mutex); |
2a57e424 | 1591 | return ret; |
541af946 | 1592 | |
76899a41 SM |
1593 | unlock: |
1594 | mutex_unlock(&drbg->drbg_mutex); | |
541af946 | 1595 | return ret; |
57225e67 SM |
1596 | |
1597 | free_everything: | |
1598 | mutex_unlock(&drbg->drbg_mutex); | |
1599 | drbg_uninstantiate(drbg); | |
1600 | return ret; | |
541af946 SM |
1601 | } |
1602 | ||
1603 | /* | |
1604 | * DRBG uninstantiate function as required by SP800-90A - this function | |
1605 | * frees all buffers and the DRBG handle | |
1606 | * | |
1607 | * @drbg DRBG state handle | |
1608 | * | |
1609 | * return | |
1610 | * 0 on success | |
1611 | */ | |
1612 | static int drbg_uninstantiate(struct drbg_state *drbg) | |
1613 | { | |
819966c0 SM |
1614 | if (!IS_ERR_OR_NULL(drbg->jent)) |
1615 | crypto_free_rng(drbg->jent); | |
1616 | drbg->jent = NULL; | |
1617 | ||
2a57e424 HX |
1618 | if (drbg->d_ops) |
1619 | drbg->d_ops->crypto_fini(drbg); | |
541af946 SM |
1620 | drbg_dealloc_state(drbg); |
1621 | /* no scrubbing of test_data -- this shall survive an uninstantiate */ | |
541af946 SM |
1622 | return 0; |
1623 | } | |
1624 | ||
1625 | /* | |
1626 | * Helper function for setting the test data in the DRBG | |
1627 | * | |
1628 | * @drbg DRBG state handle | |
8fded592 HX |
1629 | * @data test data |
1630 | * @len test data length | |
541af946 | 1631 | */ |
8fded592 HX |
1632 | static void drbg_kcapi_set_entropy(struct crypto_rng *tfm, |
1633 | const u8 *data, unsigned int len) | |
541af946 | 1634 | { |
8fded592 HX |
1635 | struct drbg_state *drbg = crypto_rng_ctx(tfm); |
1636 | ||
1637 | mutex_lock(&drbg->drbg_mutex); | |
1638 | drbg_string_fill(&drbg->test_data, data, len); | |
76899a41 | 1639 | mutex_unlock(&drbg->drbg_mutex); |
541af946 SM |
1640 | } |
1641 | ||
1642 | /*************************************************************** | |
1643 | * Kernel crypto API cipher invocations requested by DRBG | |
1644 | ***************************************************************/ | |
1645 | ||
1646 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
1647 | struct sdesc { | |
1648 | struct shash_desc shash; | |
1649 | char ctx[]; | |
1650 | }; | |
1651 | ||
1652 | static int drbg_init_hash_kernel(struct drbg_state *drbg) | |
1653 | { | |
1654 | struct sdesc *sdesc; | |
1655 | struct crypto_shash *tfm; | |
1656 | ||
1657 | tfm = crypto_alloc_shash(drbg->core->backend_cra_name, 0, 0); | |
1658 | if (IS_ERR(tfm)) { | |
593dfbd9 SS |
1659 | pr_info("DRBG: could not allocate digest TFM handle: %s\n", |
1660 | drbg->core->backend_cra_name); | |
541af946 SM |
1661 | return PTR_ERR(tfm); |
1662 | } | |
1663 | BUG_ON(drbg_blocklen(drbg) != crypto_shash_digestsize(tfm)); | |
1664 | sdesc = kzalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm), | |
1665 | GFP_KERNEL); | |
1666 | if (!sdesc) { | |
1667 | crypto_free_shash(tfm); | |
1668 | return -ENOMEM; | |
1669 | } | |
1670 | ||
1671 | sdesc->shash.tfm = tfm; | |
541af946 | 1672 | drbg->priv_data = sdesc; |
3cfc3b97 SM |
1673 | |
1674 | return crypto_shash_alignmask(tfm); | |
541af946 SM |
1675 | } |
1676 | ||
1677 | static int drbg_fini_hash_kernel(struct drbg_state *drbg) | |
1678 | { | |
1679 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
1680 | if (sdesc) { | |
1681 | crypto_free_shash(sdesc->shash.tfm); | |
453431a5 | 1682 | kfree_sensitive(sdesc); |
541af946 SM |
1683 | } |
1684 | drbg->priv_data = NULL; | |
1685 | return 0; | |
1686 | } | |
1687 | ||
4218ebe8 SM |
1688 | static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg, |
1689 | const unsigned char *key) | |
1690 | { | |
1691 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
1692 | ||
1693 | crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg)); | |
1694 | } | |
1695 | ||
1696 | static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, | |
1697 | const struct list_head *in) | |
541af946 SM |
1698 | { |
1699 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
8c987166 | 1700 | struct drbg_string *input = NULL; |
541af946 | 1701 | |
541af946 | 1702 | crypto_shash_init(&sdesc->shash); |
8c987166 SM |
1703 | list_for_each_entry(input, in, list) |
1704 | crypto_shash_update(&sdesc->shash, input->buf, input->len); | |
541af946 SM |
1705 | return crypto_shash_final(&sdesc->shash, outval); |
1706 | } | |
1707 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
1708 | ||
1709 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
35591285 SM |
1710 | static int drbg_fini_sym_kernel(struct drbg_state *drbg) |
1711 | { | |
1712 | struct crypto_cipher *tfm = | |
1713 | (struct crypto_cipher *)drbg->priv_data; | |
1714 | if (tfm) | |
1715 | crypto_free_cipher(tfm); | |
1716 | drbg->priv_data = NULL; | |
1717 | ||
1718 | if (drbg->ctr_handle) | |
1719 | crypto_free_skcipher(drbg->ctr_handle); | |
1720 | drbg->ctr_handle = NULL; | |
1721 | ||
1722 | if (drbg->ctr_req) | |
88f1d316 | 1723 | skcipher_request_free(drbg->ctr_req); |
35591285 SM |
1724 | drbg->ctr_req = NULL; |
1725 | ||
51029812 SM |
1726 | kfree(drbg->outscratchpadbuf); |
1727 | drbg->outscratchpadbuf = NULL; | |
1728 | ||
35591285 SM |
1729 | return 0; |
1730 | } | |
1731 | ||
541af946 SM |
1732 | static int drbg_init_sym_kernel(struct drbg_state *drbg) |
1733 | { | |
04bcbfcf | 1734 | struct crypto_cipher *tfm; |
35591285 SM |
1735 | struct crypto_skcipher *sk_tfm; |
1736 | struct skcipher_request *req; | |
1737 | unsigned int alignmask; | |
1738 | char ctr_name[CRYPTO_MAX_ALG_NAME]; | |
541af946 | 1739 | |
04bcbfcf | 1740 | tfm = crypto_alloc_cipher(drbg->core->backend_cra_name, 0, 0); |
541af946 | 1741 | if (IS_ERR(tfm)) { |
593dfbd9 SS |
1742 | pr_info("DRBG: could not allocate cipher TFM handle: %s\n", |
1743 | drbg->core->backend_cra_name); | |
541af946 SM |
1744 | return PTR_ERR(tfm); |
1745 | } | |
04bcbfcf | 1746 | BUG_ON(drbg_blocklen(drbg) != crypto_cipher_blocksize(tfm)); |
541af946 | 1747 | drbg->priv_data = tfm; |
541af946 | 1748 | |
35591285 SM |
1749 | if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", |
1750 | drbg->core->backend_cra_name) >= CRYPTO_MAX_ALG_NAME) { | |
1751 | drbg_fini_sym_kernel(drbg); | |
1752 | return -EINVAL; | |
1753 | } | |
1754 | sk_tfm = crypto_alloc_skcipher(ctr_name, 0, 0); | |
1755 | if (IS_ERR(sk_tfm)) { | |
1756 | pr_info("DRBG: could not allocate CTR cipher TFM handle: %s\n", | |
1757 | ctr_name); | |
1758 | drbg_fini_sym_kernel(drbg); | |
1759 | return PTR_ERR(sk_tfm); | |
1760 | } | |
1761 | drbg->ctr_handle = sk_tfm; | |
85a2dea4 | 1762 | crypto_init_wait(&drbg->ctr_wait); |
35591285 SM |
1763 | |
1764 | req = skcipher_request_alloc(sk_tfm, GFP_KERNEL); | |
1765 | if (!req) { | |
1766 | pr_info("DRBG: could not allocate request queue\n"); | |
1767 | drbg_fini_sym_kernel(drbg); | |
01ac9458 | 1768 | return -ENOMEM; |
35591285 SM |
1769 | } |
1770 | drbg->ctr_req = req; | |
85a2dea4 GBY |
1771 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | |
1772 | CRYPTO_TFM_REQ_MAY_SLEEP, | |
1773 | crypto_req_done, &drbg->ctr_wait); | |
35591285 SM |
1774 | |
1775 | alignmask = crypto_skcipher_alignmask(sk_tfm); | |
51029812 SM |
1776 | drbg->outscratchpadbuf = kmalloc(DRBG_OUTSCRATCHLEN + alignmask, |
1777 | GFP_KERNEL); | |
1778 | if (!drbg->outscratchpadbuf) { | |
1779 | drbg_fini_sym_kernel(drbg); | |
1780 | return -ENOMEM; | |
1781 | } | |
1782 | drbg->outscratchpad = (u8 *)PTR_ALIGN(drbg->outscratchpadbuf, | |
1783 | alignmask + 1); | |
1784 | ||
cf862cbc | 1785 | sg_init_table(&drbg->sg_in, 1); |
43490e80 | 1786 | sg_init_one(&drbg->sg_out, drbg->outscratchpad, DRBG_OUTSCRATCHLEN); |
cf862cbc | 1787 | |
3cfc3b97 | 1788 | return alignmask; |
541af946 SM |
1789 | } |
1790 | ||
ed494d4f SM |
1791 | static void drbg_kcapi_symsetkey(struct drbg_state *drbg, |
1792 | const unsigned char *key) | |
541af946 | 1793 | { |
04bcbfcf SM |
1794 | struct crypto_cipher *tfm = |
1795 | (struct crypto_cipher *)drbg->priv_data; | |
541af946 | 1796 | |
04bcbfcf | 1797 | crypto_cipher_setkey(tfm, key, (drbg_keylen(drbg))); |
ed494d4f SM |
1798 | } |
1799 | ||
1800 | static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, | |
1801 | const struct drbg_string *in) | |
1802 | { | |
1803 | struct crypto_cipher *tfm = | |
1804 | (struct crypto_cipher *)drbg->priv_data; | |
1805 | ||
04bcbfcf SM |
1806 | /* there is only component in *in */ |
1807 | BUG_ON(in->len < drbg_blocklen(drbg)); | |
1808 | crypto_cipher_encrypt_one(tfm, outval, in->buf); | |
1809 | return 0; | |
541af946 | 1810 | } |
35591285 | 1811 | |
a07203fb SM |
1812 | static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, |
1813 | u8 *inbuf, u32 inlen, | |
1814 | u8 *outbuf, u32 outlen) | |
35591285 | 1815 | { |
cf862cbc | 1816 | struct scatterlist *sg_in = &drbg->sg_in, *sg_out = &drbg->sg_out; |
43490e80 | 1817 | u32 scratchpad_use = min_t(u32, outlen, DRBG_OUTSCRATCHLEN); |
51029812 | 1818 | int ret; |
35591285 | 1819 | |
43490e80 SM |
1820 | if (inbuf) { |
1821 | /* Use caller-provided input buffer */ | |
1822 | sg_set_buf(sg_in, inbuf, inlen); | |
1823 | } else { | |
1824 | /* Use scratchpad for in-place operation */ | |
1825 | inlen = scratchpad_use; | |
1826 | memset(drbg->outscratchpad, 0, scratchpad_use); | |
1827 | sg_set_buf(sg_in, drbg->outscratchpad, scratchpad_use); | |
1828 | } | |
35591285 SM |
1829 | |
1830 | while (outlen) { | |
51029812 | 1831 | u32 cryptlen = min3(inlen, outlen, (u32)DRBG_OUTSCRATCHLEN); |
35591285 | 1832 | |
51029812 | 1833 | /* Output buffer may not be valid for SGL, use scratchpad */ |
cf862cbc | 1834 | skcipher_request_set_crypt(drbg->ctr_req, sg_in, sg_out, |
35591285 | 1835 | cryptlen, drbg->V); |
85a2dea4 GBY |
1836 | ret = crypto_wait_req(crypto_skcipher_encrypt(drbg->ctr_req), |
1837 | &drbg->ctr_wait); | |
1838 | if (ret) | |
51029812 | 1839 | goto out; |
85a2dea4 GBY |
1840 | |
1841 | crypto_init_wait(&drbg->ctr_wait); | |
35591285 | 1842 | |
51029812 | 1843 | memcpy(outbuf, drbg->outscratchpad, cryptlen); |
43490e80 | 1844 | memzero_explicit(drbg->outscratchpad, cryptlen); |
51029812 | 1845 | |
35591285 | 1846 | outlen -= cryptlen; |
8ff4c191 | 1847 | outbuf += cryptlen; |
35591285 | 1848 | } |
51029812 | 1849 | ret = 0; |
35591285 | 1850 | |
51029812 | 1851 | out: |
51029812 | 1852 | return ret; |
35591285 | 1853 | } |
541af946 SM |
1854 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ |
1855 | ||
1856 | /*************************************************************** | |
1857 | * Kernel crypto API interface to register DRBG | |
1858 | ***************************************************************/ | |
1859 | ||
1860 | /* | |
1861 | * Look up the DRBG flags by given kernel crypto API cra_name | |
1862 | * The code uses the drbg_cores definition to do this | |
1863 | * | |
1864 | * @cra_name kernel crypto API cra_name | |
1865 | * @coreref reference to integer which is filled with the pointer to | |
1866 | * the applicable core | |
1867 | * @pr reference for setting prediction resistance | |
1868 | * | |
1869 | * return: flags | |
1870 | */ | |
1871 | static inline void drbg_convert_tfm_core(const char *cra_driver_name, | |
1872 | int *coreref, bool *pr) | |
1873 | { | |
1874 | int i = 0; | |
1875 | size_t start = 0; | |
1876 | int len = 0; | |
1877 | ||
1878 | *pr = true; | |
1879 | /* disassemble the names */ | |
1880 | if (!memcmp(cra_driver_name, "drbg_nopr_", 10)) { | |
1881 | start = 10; | |
1882 | *pr = false; | |
1883 | } else if (!memcmp(cra_driver_name, "drbg_pr_", 8)) { | |
1884 | start = 8; | |
1885 | } else { | |
1886 | return; | |
1887 | } | |
1888 | ||
1889 | /* remove the first part */ | |
1890 | len = strlen(cra_driver_name) - start; | |
1891 | for (i = 0; ARRAY_SIZE(drbg_cores) > i; i++) { | |
1892 | if (!memcmp(cra_driver_name + start, drbg_cores[i].cra_name, | |
1893 | len)) { | |
1894 | *coreref = i; | |
1895 | return; | |
1896 | } | |
1897 | } | |
1898 | } | |
1899 | ||
1900 | static int drbg_kcapi_init(struct crypto_tfm *tfm) | |
1901 | { | |
1902 | struct drbg_state *drbg = crypto_tfm_ctx(tfm); | |
541af946 | 1903 | |
76899a41 | 1904 | mutex_init(&drbg->drbg_mutex); |
2a57e424 HX |
1905 | |
1906 | return 0; | |
541af946 SM |
1907 | } |
1908 | ||
1909 | static void drbg_kcapi_cleanup(struct crypto_tfm *tfm) | |
1910 | { | |
1911 | drbg_uninstantiate(crypto_tfm_ctx(tfm)); | |
1912 | } | |
1913 | ||
1914 | /* | |
1915 | * Generate random numbers invoked by the kernel crypto API: | |
1916 | * The API of the kernel crypto API is extended as follows: | |
1917 | * | |
8fded592 HX |
1918 | * src is additional input supplied to the RNG. |
1919 | * slen is the length of src. | |
1920 | * dst is the output buffer where random data is to be stored. | |
1921 | * dlen is the length of dst. | |
541af946 | 1922 | */ |
8fded592 HX |
1923 | static int drbg_kcapi_random(struct crypto_rng *tfm, |
1924 | const u8 *src, unsigned int slen, | |
1925 | u8 *dst, unsigned int dlen) | |
541af946 SM |
1926 | { |
1927 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
8fded592 HX |
1928 | struct drbg_string *addtl = NULL; |
1929 | struct drbg_string string; | |
1930 | ||
1931 | if (slen) { | |
8c987166 | 1932 | /* linked list variable is now local to allow modification */ |
8fded592 HX |
1933 | drbg_string_fill(&string, src, slen); |
1934 | addtl = &string; | |
541af946 | 1935 | } |
8fded592 HX |
1936 | |
1937 | return drbg_generate_long(drbg, dst, dlen, addtl); | |
541af946 SM |
1938 | } |
1939 | ||
1940 | /* | |
2a57e424 | 1941 | * Seed the DRBG invoked by the kernel crypto API |
541af946 | 1942 | */ |
8fded592 HX |
1943 | static int drbg_kcapi_seed(struct crypto_rng *tfm, |
1944 | const u8 *seed, unsigned int slen) | |
541af946 SM |
1945 | { |
1946 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
1947 | struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm); | |
1948 | bool pr = false; | |
8fded592 HX |
1949 | struct drbg_string string; |
1950 | struct drbg_string *seed_string = NULL; | |
541af946 SM |
1951 | int coreref = 0; |
1952 | ||
541af946 SM |
1953 | drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref, |
1954 | &pr); | |
1955 | if (0 < slen) { | |
8fded592 HX |
1956 | drbg_string_fill(&string, seed, slen); |
1957 | seed_string = &string; | |
541af946 | 1958 | } |
8fded592 HX |
1959 | |
1960 | return drbg_instantiate(drbg, seed_string, coreref, pr); | |
541af946 SM |
1961 | } |
1962 | ||
1963 | /*************************************************************** | |
1964 | * Kernel module: code to load the module | |
1965 | ***************************************************************/ | |
1966 | ||
1967 | /* | |
1968 | * Tests as defined in 11.3.2 in addition to the cipher tests: testing | |
1969 | * of the error handling. | |
1970 | * | |
1971 | * Note: testing of failing seed source as defined in 11.3.2 is not applicable | |
1972 | * as seed source of get_random_bytes does not fail. | |
1973 | * | |
1974 | * Note 2: There is no sensible way of testing the reseed counter | |
1975 | * enforcement, so skip it. | |
1976 | */ | |
1977 | static inline int __init drbg_healthcheck_sanity(void) | |
1978 | { | |
541af946 SM |
1979 | int len = 0; |
1980 | #define OUTBUFLEN 16 | |
1981 | unsigned char buf[OUTBUFLEN]; | |
1982 | struct drbg_state *drbg = NULL; | |
81f53028 | 1983 | int ret; |
541af946 SM |
1984 | int rc = -EFAULT; |
1985 | bool pr = false; | |
1986 | int coreref = 0; | |
1987 | struct drbg_string addtl; | |
1988 | size_t max_addtllen, max_request_bytes; | |
1989 | ||
1990 | /* only perform test in FIPS mode */ | |
1991 | if (!fips_enabled) | |
1992 | return 0; | |
1993 | ||
1994 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1995 | drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref, &pr); | |
e25e47ec | 1996 | #elif defined CONFIG_CRYPTO_DRBG_HASH |
541af946 SM |
1997 | drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr); |
1998 | #else | |
1999 | drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref, &pr); | |
2000 | #endif | |
2001 | ||
2002 | drbg = kzalloc(sizeof(struct drbg_state), GFP_KERNEL); | |
2003 | if (!drbg) | |
2004 | return -ENOMEM; | |
2005 | ||
e11a7548 | 2006 | mutex_init(&drbg->drbg_mutex); |
d89a6713 SM |
2007 | drbg->core = &drbg_cores[coreref]; |
2008 | drbg->reseed_threshold = drbg_max_requests(drbg); | |
e11a7548 | 2009 | |
541af946 SM |
2010 | /* |
2011 | * if the following tests fail, it is likely that there is a buffer | |
2012 | * overflow as buf is much smaller than the requested or provided | |
2013 | * string lengths -- in case the error handling does not succeed | |
2014 | * we may get an OOPS. And we want to get an OOPS as this is a | |
2015 | * grave bug. | |
2016 | */ | |
2017 | ||
541af946 SM |
2018 | max_addtllen = drbg_max_addtl(drbg); |
2019 | max_request_bytes = drbg_max_request_bytes(drbg); | |
2020 | drbg_string_fill(&addtl, buf, max_addtllen + 1); | |
2021 | /* overflow addtllen with additonal info string */ | |
2022 | len = drbg_generate(drbg, buf, OUTBUFLEN, &addtl); | |
2023 | BUG_ON(0 < len); | |
2024 | /* overflow max_bits */ | |
2025 | len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL); | |
2026 | BUG_ON(0 < len); | |
541af946 SM |
2027 | |
2028 | /* overflow max addtllen with personalization string */ | |
d89a6713 | 2029 | ret = drbg_seed(drbg, &addtl, false); |
541af946 | 2030 | BUG_ON(0 == ret); |
541af946 SM |
2031 | /* all tests passed */ |
2032 | rc = 0; | |
2033 | ||
2034 | pr_devel("DRBG: Sanity tests for failure code paths successfully " | |
2035 | "completed\n"); | |
2036 | ||
d89a6713 | 2037 | kfree(drbg); |
541af946 | 2038 | return rc; |
541af946 SM |
2039 | } |
2040 | ||
8fded592 | 2041 | static struct rng_alg drbg_algs[22]; |
541af946 SM |
2042 | |
2043 | /* | |
2044 | * Fill the array drbg_algs used to register the different DRBGs | |
2045 | * with the kernel crypto API. To fill the array, the information | |
2046 | * from drbg_cores[] is used. | |
2047 | */ | |
8fded592 | 2048 | static inline void __init drbg_fill_array(struct rng_alg *alg, |
541af946 SM |
2049 | const struct drbg_core *core, int pr) |
2050 | { | |
2051 | int pos = 0; | |
51ee1422 | 2052 | static int priority = 200; |
541af946 | 2053 | |
8fded592 | 2054 | memcpy(alg->base.cra_name, "stdrng", 6); |
541af946 | 2055 | if (pr) { |
8fded592 | 2056 | memcpy(alg->base.cra_driver_name, "drbg_pr_", 8); |
541af946 SM |
2057 | pos = 8; |
2058 | } else { | |
8fded592 | 2059 | memcpy(alg->base.cra_driver_name, "drbg_nopr_", 10); |
541af946 SM |
2060 | pos = 10; |
2061 | } | |
8fded592 | 2062 | memcpy(alg->base.cra_driver_name + pos, core->cra_name, |
541af946 SM |
2063 | strlen(core->cra_name)); |
2064 | ||
8fded592 | 2065 | alg->base.cra_priority = priority; |
541af946 SM |
2066 | priority++; |
2067 | /* | |
2068 | * If FIPS mode enabled, the selected DRBG shall have the | |
2069 | * highest cra_priority over other stdrng instances to ensure | |
2070 | * it is selected. | |
2071 | */ | |
2072 | if (fips_enabled) | |
8fded592 HX |
2073 | alg->base.cra_priority += 200; |
2074 | ||
2075 | alg->base.cra_ctxsize = sizeof(struct drbg_state); | |
2076 | alg->base.cra_module = THIS_MODULE; | |
2077 | alg->base.cra_init = drbg_kcapi_init; | |
2078 | alg->base.cra_exit = drbg_kcapi_cleanup; | |
2079 | alg->generate = drbg_kcapi_random; | |
2080 | alg->seed = drbg_kcapi_seed; | |
2081 | alg->set_ent = drbg_kcapi_set_entropy; | |
2082 | alg->seedsize = 0; | |
541af946 SM |
2083 | } |
2084 | ||
2085 | static int __init drbg_init(void) | |
2086 | { | |
2087 | unsigned int i = 0; /* pointer to drbg_algs */ | |
2088 | unsigned int j = 0; /* pointer to drbg_cores */ | |
1a45d7e3 | 2089 | int ret; |
541af946 SM |
2090 | |
2091 | ret = drbg_healthcheck_sanity(); | |
2092 | if (ret) | |
2093 | return ret; | |
2094 | ||
2095 | if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) { | |
2096 | pr_info("DRBG: Cannot register all DRBG types" | |
a9089571 | 2097 | "(slots needed: %zu, slots available: %zu)\n", |
541af946 | 2098 | ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs)); |
1a45d7e3 | 2099 | return -EFAULT; |
541af946 SM |
2100 | } |
2101 | ||
2102 | /* | |
2103 | * each DRBG definition can be used with PR and without PR, thus | |
2104 | * we instantiate each DRBG in drbg_cores[] twice. | |
2105 | * | |
2106 | * As the order of placing them into the drbg_algs array matters | |
2107 | * (the later DRBGs receive a higher cra_priority) we register the | |
2108 | * prediction resistance DRBGs first as the should not be too | |
2109 | * interesting. | |
2110 | */ | |
2111 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
2112 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1); | |
2113 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
2114 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0); | |
8fded592 | 2115 | return crypto_register_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); |
541af946 SM |
2116 | } |
2117 | ||
96956aef | 2118 | static void __exit drbg_exit(void) |
541af946 | 2119 | { |
8fded592 | 2120 | crypto_unregister_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); |
541af946 SM |
2121 | } |
2122 | ||
c4741b23 | 2123 | subsys_initcall(drbg_init); |
541af946 | 2124 | module_exit(drbg_exit); |
e25e47ec SM |
2125 | #ifndef CRYPTO_DRBG_HASH_STRING |
2126 | #define CRYPTO_DRBG_HASH_STRING "" | |
541af946 | 2127 | #endif |
e25e47ec SM |
2128 | #ifndef CRYPTO_DRBG_HMAC_STRING |
2129 | #define CRYPTO_DRBG_HMAC_STRING "" | |
541af946 | 2130 | #endif |
e25e47ec SM |
2131 | #ifndef CRYPTO_DRBG_CTR_STRING |
2132 | #define CRYPTO_DRBG_CTR_STRING "" | |
541af946 | 2133 | #endif |
e25e47ec SM |
2134 | MODULE_LICENSE("GPL"); |
2135 | MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); | |
2136 | MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) " | |
2137 | "using following cores: " | |
2138 | CRYPTO_DRBG_HASH_STRING | |
2139 | CRYPTO_DRBG_HMAC_STRING | |
2140 | CRYPTO_DRBG_CTR_STRING); | |
51ee1422 | 2141 | MODULE_ALIAS_CRYPTO("stdrng"); |
0eb76ba2 | 2142 | MODULE_IMPORT_NS(CRYPTO_INTERNAL); |