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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> | |
421d82f5 | 101 | #include <linux/string.h> |
541af946 | 102 | |
541af946 SM |
103 | /*************************************************************** |
104 | * Backend cipher definitions available to DRBG | |
105 | ***************************************************************/ | |
106 | ||
107 | /* | |
108 | * The order of the DRBG definitions here matter: every DRBG is registered | |
109 | * as stdrng. Each DRBG receives an increasing cra_priority values the later | |
110 | * they are defined in this array (see drbg_fill_array). | |
111 | * | |
112 | * HMAC DRBGs are favored over Hash DRBGs over CTR DRBGs, and | |
113 | * the SHA256 / AES 256 over other ciphers. Thus, the favored | |
114 | * DRBGs are the latest entries in this array. | |
115 | */ | |
116 | static const struct drbg_core drbg_cores[] = { | |
117 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
118 | { | |
119 | .flags = DRBG_CTR | DRBG_STRENGTH128, | |
120 | .statelen = 32, /* 256 bits as defined in 10.2.1 */ | |
541af946 SM |
121 | .blocklen_bytes = 16, |
122 | .cra_name = "ctr_aes128", | |
123 | .backend_cra_name = "ecb(aes)", | |
124 | }, { | |
125 | .flags = DRBG_CTR | DRBG_STRENGTH192, | |
126 | .statelen = 40, /* 320 bits as defined in 10.2.1 */ | |
541af946 SM |
127 | .blocklen_bytes = 16, |
128 | .cra_name = "ctr_aes192", | |
129 | .backend_cra_name = "ecb(aes)", | |
130 | }, { | |
131 | .flags = DRBG_CTR | DRBG_STRENGTH256, | |
132 | .statelen = 48, /* 384 bits as defined in 10.2.1 */ | |
541af946 SM |
133 | .blocklen_bytes = 16, |
134 | .cra_name = "ctr_aes256", | |
135 | .backend_cra_name = "ecb(aes)", | |
136 | }, | |
137 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
138 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
139 | { | |
140 | .flags = DRBG_HASH | DRBG_STRENGTH128, | |
141 | .statelen = 55, /* 440 bits */ | |
541af946 SM |
142 | .blocklen_bytes = 20, |
143 | .cra_name = "sha1", | |
144 | .backend_cra_name = "sha1", | |
145 | }, { | |
146 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
147 | .statelen = 111, /* 888 bits */ | |
541af946 SM |
148 | .blocklen_bytes = 48, |
149 | .cra_name = "sha384", | |
150 | .backend_cra_name = "sha384", | |
151 | }, { | |
152 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
153 | .statelen = 111, /* 888 bits */ | |
541af946 SM |
154 | .blocklen_bytes = 64, |
155 | .cra_name = "sha512", | |
156 | .backend_cra_name = "sha512", | |
157 | }, { | |
158 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
159 | .statelen = 55, /* 440 bits */ | |
541af946 SM |
160 | .blocklen_bytes = 32, |
161 | .cra_name = "sha256", | |
162 | .backend_cra_name = "sha256", | |
163 | }, | |
164 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
165 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
166 | { | |
5b635e28 | 167 | .flags = DRBG_HMAC | DRBG_STRENGTH128, |
541af946 | 168 | .statelen = 20, /* block length of cipher */ |
541af946 SM |
169 | .blocklen_bytes = 20, |
170 | .cra_name = "hmac_sha1", | |
171 | .backend_cra_name = "hmac(sha1)", | |
172 | }, { | |
173 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
174 | .statelen = 48, /* block length of cipher */ | |
541af946 SM |
175 | .blocklen_bytes = 48, |
176 | .cra_name = "hmac_sha384", | |
177 | .backend_cra_name = "hmac(sha384)", | |
178 | }, { | |
179 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
180 | .statelen = 64, /* block length of cipher */ | |
541af946 SM |
181 | .blocklen_bytes = 64, |
182 | .cra_name = "hmac_sha512", | |
183 | .backend_cra_name = "hmac(sha512)", | |
184 | }, { | |
185 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
186 | .statelen = 32, /* block length of cipher */ | |
541af946 SM |
187 | .blocklen_bytes = 32, |
188 | .cra_name = "hmac_sha256", | |
189 | .backend_cra_name = "hmac(sha256)", | |
190 | }, | |
191 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
192 | }; | |
193 | ||
194 | /****************************************************************** | |
195 | * Generic helper functions | |
196 | ******************************************************************/ | |
197 | ||
198 | /* | |
199 | * Return strength of DRBG according to SP800-90A section 8.4 | |
200 | * | |
201 | * @flags DRBG flags reference | |
202 | * | |
203 | * Return: normalized strength in *bytes* value or 32 as default | |
204 | * to counter programming errors | |
205 | */ | |
206 | static inline unsigned short drbg_sec_strength(drbg_flag_t flags) | |
207 | { | |
208 | switch (flags & DRBG_STRENGTH_MASK) { | |
209 | case DRBG_STRENGTH128: | |
210 | return 16; | |
211 | case DRBG_STRENGTH192: | |
212 | return 24; | |
213 | case DRBG_STRENGTH256: | |
214 | return 32; | |
215 | default: | |
216 | return 32; | |
217 | } | |
218 | } | |
219 | ||
220 | /* | |
221 | * FIPS 140-2 continuous self test | |
222 | * The test is performed on the result of one round of the output | |
223 | * function. Thus, the function implicitly knows the size of the | |
224 | * buffer. | |
225 | * | |
226 | * The FIPS test can be called in an endless loop until it returns | |
227 | * true. Although the code looks like a potential for a deadlock, it | |
228 | * is not the case, because returning a false cannot mathematically | |
229 | * occur (except once when a reseed took place and the updated state | |
230 | * would is now set up such that the generation of new value returns | |
231 | * an identical one -- this is most unlikely and would happen only once). | |
232 | * Thus, if this function repeatedly returns false and thus would cause | |
233 | * a deadlock, the integrity of the entire kernel is lost. | |
234 | * | |
235 | * @drbg DRBG handle | |
236 | * @buf output buffer of random data to be checked | |
237 | * | |
238 | * return: | |
239 | * true on success | |
240 | * false on error | |
241 | */ | |
242 | static bool drbg_fips_continuous_test(struct drbg_state *drbg, | |
243 | const unsigned char *buf) | |
244 | { | |
245 | #ifdef CONFIG_CRYPTO_FIPS | |
246 | int ret = 0; | |
247 | /* skip test if we test the overall system */ | |
248 | if (drbg->test_data) | |
249 | return true; | |
250 | /* only perform test in FIPS mode */ | |
251 | if (0 == fips_enabled) | |
252 | return true; | |
253 | if (!drbg->fips_primed) { | |
254 | /* Priming of FIPS test */ | |
255 | memcpy(drbg->prev, buf, drbg_blocklen(drbg)); | |
256 | drbg->fips_primed = true; | |
257 | /* return false due to priming, i.e. another round is needed */ | |
258 | return false; | |
259 | } | |
260 | ret = memcmp(drbg->prev, buf, drbg_blocklen(drbg)); | |
261 | memcpy(drbg->prev, buf, drbg_blocklen(drbg)); | |
262 | /* the test shall pass when the two compared values are not equal */ | |
263 | return ret != 0; | |
264 | #else | |
265 | return true; | |
266 | #endif /* CONFIG_CRYPTO_FIPS */ | |
267 | } | |
268 | ||
269 | /* | |
270 | * Convert an integer into a byte representation of this integer. | |
271 | * The byte representation is big-endian | |
272 | * | |
541af946 | 273 | * @val value to be converted |
72f3e00d SM |
274 | * @buf buffer holding the converted integer -- caller must ensure that |
275 | * buffer size is at least 32 bit | |
541af946 SM |
276 | */ |
277 | #if (defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR)) | |
72f3e00d | 278 | static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf) |
541af946 | 279 | { |
72f3e00d | 280 | struct s { |
7c8ae03f | 281 | __be32 conv; |
72f3e00d SM |
282 | }; |
283 | struct s *conversion = (struct s *) buf; | |
541af946 | 284 | |
72f3e00d | 285 | conversion->conv = cpu_to_be32(val); |
541af946 | 286 | } |
541af946 SM |
287 | #endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */ |
288 | ||
289 | /****************************************************************** | |
290 | * CTR DRBG callback functions | |
291 | ******************************************************************/ | |
292 | ||
293 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
e25e47ec | 294 | #define CRYPTO_DRBG_CTR_STRING "CTR " |
0653a7cf SM |
295 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes256"); |
296 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes256"); | |
297 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes192"); | |
298 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192"); | |
299 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128"); | |
300 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128"); | |
62b62b6e | 301 | |
541af946 SM |
302 | static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key, |
303 | unsigned char *outval, const struct drbg_string *in); | |
304 | static int drbg_init_sym_kernel(struct drbg_state *drbg); | |
305 | static int drbg_fini_sym_kernel(struct drbg_state *drbg); | |
306 | ||
307 | /* BCC function for CTR DRBG as defined in 10.4.3 */ | |
308 | static int drbg_ctr_bcc(struct drbg_state *drbg, | |
309 | unsigned char *out, const unsigned char *key, | |
8c987166 | 310 | struct list_head *in) |
541af946 | 311 | { |
8c987166 SM |
312 | int ret = 0; |
313 | struct drbg_string *curr = NULL; | |
541af946 | 314 | struct drbg_string data; |
8c987166 | 315 | short cnt = 0; |
541af946 SM |
316 | |
317 | drbg_string_fill(&data, out, drbg_blocklen(drbg)); | |
318 | ||
319 | /* 10.4.3 step 1 */ | |
320 | memset(out, 0, drbg_blocklen(drbg)); | |
321 | ||
322 | /* 10.4.3 step 2 / 4 */ | |
8c987166 SM |
323 | list_for_each_entry(curr, in, list) { |
324 | const unsigned char *pos = curr->buf; | |
325 | size_t len = curr->len; | |
541af946 | 326 | /* 10.4.3 step 4.1 */ |
8c987166 SM |
327 | while (len) { |
328 | /* 10.4.3 step 4.2 */ | |
329 | if (drbg_blocklen(drbg) == cnt) { | |
330 | cnt = 0; | |
331 | ret = drbg_kcapi_sym(drbg, key, out, &data); | |
332 | if (ret) | |
333 | return ret; | |
541af946 | 334 | } |
8c987166 SM |
335 | out[cnt] ^= *pos; |
336 | pos++; | |
337 | cnt++; | |
338 | len--; | |
541af946 | 339 | } |
541af946 | 340 | } |
8c987166 SM |
341 | /* 10.4.3 step 4.2 for last block */ |
342 | if (cnt) | |
343 | ret = drbg_kcapi_sym(drbg, key, out, &data); | |
344 | ||
345 | return ret; | |
541af946 SM |
346 | } |
347 | ||
348 | /* | |
349 | * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df | |
350 | * (and drbg_ctr_bcc, but this function does not need any temporary buffers), | |
351 | * the scratchpad is used as follows: | |
352 | * drbg_ctr_update: | |
353 | * temp | |
354 | * start: drbg->scratchpad | |
355 | * length: drbg_statelen(drbg) + drbg_blocklen(drbg) | |
356 | * note: the cipher writing into this variable works | |
357 | * blocklen-wise. Now, when the statelen is not a multiple | |
358 | * of blocklen, the generateion loop below "spills over" | |
359 | * by at most blocklen. Thus, we need to give sufficient | |
360 | * memory. | |
361 | * df_data | |
362 | * start: drbg->scratchpad + | |
363 | * drbg_statelen(drbg) + drbg_blocklen(drbg) | |
364 | * length: drbg_statelen(drbg) | |
365 | * | |
366 | * drbg_ctr_df: | |
367 | * pad | |
368 | * start: df_data + drbg_statelen(drbg) | |
369 | * length: drbg_blocklen(drbg) | |
370 | * iv | |
371 | * start: pad + drbg_blocklen(drbg) | |
372 | * length: drbg_blocklen(drbg) | |
373 | * temp | |
374 | * start: iv + drbg_blocklen(drbg) | |
8fecaad7 SM |
375 | * length: drbg_satelen(drbg) + drbg_blocklen(drbg) |
376 | * note: temp is the buffer that the BCC function operates | |
377 | * on. BCC operates blockwise. drbg_statelen(drbg) | |
378 | * is sufficient when the DRBG state length is a multiple | |
379 | * of the block size. For AES192 (and maybe other ciphers) | |
380 | * this is not correct and the length for temp is | |
381 | * insufficient (yes, that also means for such ciphers, | |
382 | * the final output of all BCC rounds are truncated). | |
383 | * Therefore, add drbg_blocklen(drbg) to cover all | |
384 | * possibilities. | |
541af946 SM |
385 | */ |
386 | ||
387 | /* Derivation Function for CTR DRBG as defined in 10.4.2 */ | |
388 | static int drbg_ctr_df(struct drbg_state *drbg, | |
389 | unsigned char *df_data, size_t bytes_to_return, | |
8c987166 | 390 | struct list_head *seedlist) |
541af946 SM |
391 | { |
392 | int ret = -EFAULT; | |
393 | unsigned char L_N[8]; | |
394 | /* S3 is input */ | |
395 | struct drbg_string S1, S2, S4, cipherin; | |
8c987166 | 396 | LIST_HEAD(bcc_list); |
541af946 SM |
397 | unsigned char *pad = df_data + drbg_statelen(drbg); |
398 | unsigned char *iv = pad + drbg_blocklen(drbg); | |
399 | unsigned char *temp = iv + drbg_blocklen(drbg); | |
400 | size_t padlen = 0; | |
401 | unsigned int templen = 0; | |
402 | /* 10.4.2 step 7 */ | |
403 | unsigned int i = 0; | |
404 | /* 10.4.2 step 8 */ | |
405 | const unsigned char *K = (unsigned char *) | |
406 | "\x00\x01\x02\x03\x04\x05\x06\x07" | |
407 | "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" | |
408 | "\x10\x11\x12\x13\x14\x15\x16\x17" | |
409 | "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"; | |
410 | unsigned char *X; | |
411 | size_t generated_len = 0; | |
412 | size_t inputlen = 0; | |
8c987166 | 413 | struct drbg_string *seed = NULL; |
541af946 SM |
414 | |
415 | memset(pad, 0, drbg_blocklen(drbg)); | |
416 | memset(iv, 0, drbg_blocklen(drbg)); | |
417 | memset(temp, 0, drbg_statelen(drbg)); | |
418 | ||
419 | /* 10.4.2 step 1 is implicit as we work byte-wise */ | |
420 | ||
421 | /* 10.4.2 step 2 */ | |
422 | if ((512/8) < bytes_to_return) | |
423 | return -EINVAL; | |
424 | ||
425 | /* 10.4.2 step 2 -- calculate the entire length of all input data */ | |
8c987166 SM |
426 | list_for_each_entry(seed, seedlist, list) |
427 | inputlen += seed->len; | |
72f3e00d | 428 | drbg_cpu_to_be32(inputlen, &L_N[0]); |
541af946 SM |
429 | |
430 | /* 10.4.2 step 3 */ | |
72f3e00d | 431 | drbg_cpu_to_be32(bytes_to_return, &L_N[4]); |
541af946 SM |
432 | |
433 | /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */ | |
434 | padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg)); | |
435 | /* wrap the padlen appropriately */ | |
436 | if (padlen) | |
437 | padlen = drbg_blocklen(drbg) - padlen; | |
438 | /* | |
439 | * pad / padlen contains the 0x80 byte and the following zero bytes. | |
440 | * As the calculated padlen value only covers the number of zero | |
441 | * bytes, this value has to be incremented by one for the 0x80 byte. | |
442 | */ | |
443 | padlen++; | |
444 | pad[0] = 0x80; | |
445 | ||
446 | /* 10.4.2 step 4 -- first fill the linked list and then order it */ | |
447 | drbg_string_fill(&S1, iv, drbg_blocklen(drbg)); | |
8c987166 | 448 | list_add_tail(&S1.list, &bcc_list); |
541af946 | 449 | drbg_string_fill(&S2, L_N, sizeof(L_N)); |
8c987166 SM |
450 | list_add_tail(&S2.list, &bcc_list); |
451 | list_splice_tail(seedlist, &bcc_list); | |
541af946 | 452 | drbg_string_fill(&S4, pad, padlen); |
8c987166 | 453 | list_add_tail(&S4.list, &bcc_list); |
541af946 SM |
454 | |
455 | /* 10.4.2 step 9 */ | |
456 | while (templen < (drbg_keylen(drbg) + (drbg_blocklen(drbg)))) { | |
457 | /* | |
458 | * 10.4.2 step 9.1 - the padding is implicit as the buffer | |
459 | * holds zeros after allocation -- even the increment of i | |
460 | * is irrelevant as the increment remains within length of i | |
461 | */ | |
72f3e00d | 462 | drbg_cpu_to_be32(i, iv); |
541af946 | 463 | /* 10.4.2 step 9.2 -- BCC and concatenation with temp */ |
8c987166 | 464 | ret = drbg_ctr_bcc(drbg, temp + templen, K, &bcc_list); |
541af946 SM |
465 | if (ret) |
466 | goto out; | |
467 | /* 10.4.2 step 9.3 */ | |
468 | i++; | |
469 | templen += drbg_blocklen(drbg); | |
470 | } | |
471 | ||
472 | /* 10.4.2 step 11 */ | |
473 | X = temp + (drbg_keylen(drbg)); | |
474 | drbg_string_fill(&cipherin, X, drbg_blocklen(drbg)); | |
475 | ||
476 | /* 10.4.2 step 12: overwriting of outval is implemented in next step */ | |
477 | ||
478 | /* 10.4.2 step 13 */ | |
479 | while (generated_len < bytes_to_return) { | |
480 | short blocklen = 0; | |
481 | /* | |
482 | * 10.4.2 step 13.1: the truncation of the key length is | |
483 | * implicit as the key is only drbg_blocklen in size based on | |
484 | * the implementation of the cipher function callback | |
485 | */ | |
486 | ret = drbg_kcapi_sym(drbg, temp, X, &cipherin); | |
487 | if (ret) | |
488 | goto out; | |
489 | blocklen = (drbg_blocklen(drbg) < | |
490 | (bytes_to_return - generated_len)) ? | |
491 | drbg_blocklen(drbg) : | |
492 | (bytes_to_return - generated_len); | |
493 | /* 10.4.2 step 13.2 and 14 */ | |
494 | memcpy(df_data + generated_len, X, blocklen); | |
495 | generated_len += blocklen; | |
496 | } | |
497 | ||
498 | ret = 0; | |
499 | ||
500 | out: | |
421d82f5 NW |
501 | memzero_explicit(iv, drbg_blocklen(drbg)); |
502 | memzero_explicit(temp, drbg_statelen(drbg)); | |
503 | memzero_explicit(pad, drbg_blocklen(drbg)); | |
541af946 SM |
504 | return ret; |
505 | } | |
506 | ||
72e7c25a SM |
507 | /* |
508 | * update function of CTR DRBG as defined in 10.2.1.2 | |
509 | * | |
510 | * The reseed variable has an enhanced meaning compared to the update | |
511 | * functions of the other DRBGs as follows: | |
512 | * 0 => initial seed from initialization | |
513 | * 1 => reseed via drbg_seed | |
514 | * 2 => first invocation from drbg_ctr_update when addtl is present. In | |
515 | * this case, the df_data scratchpad is not deleted so that it is | |
516 | * available for another calls to prevent calling the DF function | |
517 | * again. | |
518 | * 3 => second invocation from drbg_ctr_update. When the update function | |
519 | * was called with addtl, the df_data memory already contains the | |
520 | * DFed addtl information and we do not need to call DF again. | |
521 | */ | |
8c987166 SM |
522 | static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, |
523 | int reseed) | |
541af946 SM |
524 | { |
525 | int ret = -EFAULT; | |
526 | /* 10.2.1.2 step 1 */ | |
527 | unsigned char *temp = drbg->scratchpad; | |
528 | unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) + | |
529 | drbg_blocklen(drbg); | |
530 | unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */ | |
531 | unsigned int len = 0; | |
532 | struct drbg_string cipherin; | |
541af946 SM |
533 | |
534 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); | |
72e7c25a SM |
535 | if (3 > reseed) |
536 | memset(df_data, 0, drbg_statelen(drbg)); | |
541af946 SM |
537 | |
538 | /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */ | |
8c987166 SM |
539 | if (seed) { |
540 | ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed); | |
541af946 SM |
541 | if (ret) |
542 | goto out; | |
543 | } | |
544 | ||
545 | drbg_string_fill(&cipherin, drbg->V, drbg_blocklen(drbg)); | |
546 | /* | |
547 | * 10.2.1.3.2 steps 2 and 3 are already covered as the allocation | |
548 | * zeroizes all memory during initialization | |
549 | */ | |
550 | while (len < (drbg_statelen(drbg))) { | |
551 | /* 10.2.1.2 step 2.1 */ | |
41a84982 | 552 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
553 | /* |
554 | * 10.2.1.2 step 2.2 */ | |
555 | ret = drbg_kcapi_sym(drbg, drbg->C, temp + len, &cipherin); | |
556 | if (ret) | |
557 | goto out; | |
558 | /* 10.2.1.2 step 2.3 and 3 */ | |
559 | len += drbg_blocklen(drbg); | |
560 | } | |
561 | ||
562 | /* 10.2.1.2 step 4 */ | |
563 | temp_p = temp; | |
564 | df_data_p = df_data; | |
565 | for (len = 0; len < drbg_statelen(drbg); len++) { | |
566 | *temp_p ^= *df_data_p; | |
567 | df_data_p++; temp_p++; | |
568 | } | |
569 | ||
570 | /* 10.2.1.2 step 5 */ | |
571 | memcpy(drbg->C, temp, drbg_keylen(drbg)); | |
572 | /* 10.2.1.2 step 6 */ | |
573 | memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg)); | |
574 | ret = 0; | |
575 | ||
576 | out: | |
421d82f5 | 577 | memzero_explicit(temp, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
72e7c25a | 578 | if (2 != reseed) |
421d82f5 | 579 | memzero_explicit(df_data, drbg_statelen(drbg)); |
541af946 SM |
580 | return ret; |
581 | } | |
582 | ||
583 | /* | |
584 | * scratchpad use: drbg_ctr_update is called independently from | |
585 | * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused | |
586 | */ | |
587 | /* Generate function of CTR DRBG as defined in 10.2.1.5.2 */ | |
588 | static int drbg_ctr_generate(struct drbg_state *drbg, | |
589 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 590 | struct list_head *addtl) |
541af946 SM |
591 | { |
592 | int len = 0; | |
593 | int ret = 0; | |
594 | struct drbg_string data; | |
541af946 SM |
595 | |
596 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); | |
597 | ||
598 | /* 10.2.1.5.2 step 2 */ | |
27e4de2b SM |
599 | if (addtl && !list_empty(addtl)) { |
600 | ret = drbg_ctr_update(drbg, addtl, 2); | |
541af946 SM |
601 | if (ret) |
602 | return 0; | |
603 | } | |
604 | ||
605 | /* 10.2.1.5.2 step 4.1 */ | |
41a84982 | 606 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
607 | drbg_string_fill(&data, drbg->V, drbg_blocklen(drbg)); |
608 | while (len < buflen) { | |
609 | int outlen = 0; | |
610 | /* 10.2.1.5.2 step 4.2 */ | |
611 | ret = drbg_kcapi_sym(drbg, drbg->C, drbg->scratchpad, &data); | |
612 | if (ret) { | |
613 | len = ret; | |
614 | goto out; | |
615 | } | |
616 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
617 | drbg_blocklen(drbg) : (buflen - len); | |
618 | if (!drbg_fips_continuous_test(drbg, drbg->scratchpad)) { | |
619 | /* 10.2.1.5.2 step 6 */ | |
41a84982 | 620 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
621 | continue; |
622 | } | |
623 | /* 10.2.1.5.2 step 4.3 */ | |
624 | memcpy(buf + len, drbg->scratchpad, outlen); | |
625 | len += outlen; | |
626 | /* 10.2.1.5.2 step 6 */ | |
627 | if (len < buflen) | |
41a84982 | 628 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
629 | } |
630 | ||
72e7c25a SM |
631 | /* 10.2.1.5.2 step 6 */ |
632 | ret = drbg_ctr_update(drbg, NULL, 3); | |
541af946 SM |
633 | if (ret) |
634 | len = ret; | |
635 | ||
636 | out: | |
421d82f5 | 637 | memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg)); |
541af946 SM |
638 | return len; |
639 | } | |
640 | ||
641 | static struct drbg_state_ops drbg_ctr_ops = { | |
642 | .update = drbg_ctr_update, | |
643 | .generate = drbg_ctr_generate, | |
644 | .crypto_init = drbg_init_sym_kernel, | |
645 | .crypto_fini = drbg_fini_sym_kernel, | |
646 | }; | |
647 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
648 | ||
649 | /****************************************************************** | |
650 | * HMAC DRBG callback functions | |
651 | ******************************************************************/ | |
652 | ||
653 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
654 | static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key, | |
8c987166 | 655 | unsigned char *outval, const struct list_head *in); |
541af946 SM |
656 | static int drbg_init_hash_kernel(struct drbg_state *drbg); |
657 | static int drbg_fini_hash_kernel(struct drbg_state *drbg); | |
658 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
659 | ||
660 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
e25e47ec | 661 | #define CRYPTO_DRBG_HMAC_STRING "HMAC " |
0653a7cf SM |
662 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512"); |
663 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512"); | |
664 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384"); | |
665 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384"); | |
666 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256"); | |
667 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256"); | |
668 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1"); | |
669 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1"); | |
62b62b6e | 670 | |
541af946 | 671 | /* update function of HMAC DRBG as defined in 10.1.2.2 */ |
8c987166 SM |
672 | static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed, |
673 | int reseed) | |
541af946 SM |
674 | { |
675 | int ret = -EFAULT; | |
676 | int i = 0; | |
8c987166 SM |
677 | struct drbg_string seed1, seed2, vdata; |
678 | LIST_HEAD(seedlist); | |
679 | LIST_HEAD(vdatalist); | |
541af946 | 680 | |
f072f0e0 SM |
681 | if (!reseed) |
682 | /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */ | |
541af946 | 683 | memset(drbg->V, 1, drbg_statelen(drbg)); |
541af946 SM |
684 | |
685 | drbg_string_fill(&seed1, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 686 | list_add_tail(&seed1.list, &seedlist); |
541af946 SM |
687 | /* buffer of seed2 will be filled in for loop below with one byte */ |
688 | drbg_string_fill(&seed2, NULL, 1); | |
8c987166 | 689 | list_add_tail(&seed2.list, &seedlist); |
541af946 | 690 | /* input data of seed is allowed to be NULL at this point */ |
8c987166 SM |
691 | if (seed) |
692 | list_splice_tail(seed, &seedlist); | |
541af946 | 693 | |
8c987166 SM |
694 | drbg_string_fill(&vdata, drbg->V, drbg_statelen(drbg)); |
695 | list_add_tail(&vdata.list, &vdatalist); | |
541af946 SM |
696 | for (i = 2; 0 < i; i--) { |
697 | /* first round uses 0x0, second 0x1 */ | |
698 | unsigned char prefix = DRBG_PREFIX0; | |
699 | if (1 == i) | |
700 | prefix = DRBG_PREFIX1; | |
701 | /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */ | |
702 | seed2.buf = &prefix; | |
8c987166 | 703 | ret = drbg_kcapi_hash(drbg, drbg->C, drbg->C, &seedlist); |
541af946 SM |
704 | if (ret) |
705 | return ret; | |
706 | ||
707 | /* 10.1.2.2 step 2 and 5 -- HMAC for V */ | |
8c987166 | 708 | ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &vdatalist); |
541af946 SM |
709 | if (ret) |
710 | return ret; | |
711 | ||
712 | /* 10.1.2.2 step 3 */ | |
8c987166 | 713 | if (!seed) |
541af946 SM |
714 | return ret; |
715 | } | |
716 | ||
717 | return 0; | |
718 | } | |
719 | ||
720 | /* generate function of HMAC DRBG as defined in 10.1.2.5 */ | |
721 | static int drbg_hmac_generate(struct drbg_state *drbg, | |
722 | unsigned char *buf, | |
723 | unsigned int buflen, | |
27e4de2b | 724 | struct list_head *addtl) |
541af946 SM |
725 | { |
726 | int len = 0; | |
727 | int ret = 0; | |
728 | struct drbg_string data; | |
8c987166 | 729 | LIST_HEAD(datalist); |
541af946 SM |
730 | |
731 | /* 10.1.2.5 step 2 */ | |
27e4de2b SM |
732 | if (addtl && !list_empty(addtl)) { |
733 | ret = drbg_hmac_update(drbg, addtl, 1); | |
541af946 SM |
734 | if (ret) |
735 | return ret; | |
736 | } | |
737 | ||
738 | drbg_string_fill(&data, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 739 | list_add_tail(&data.list, &datalist); |
541af946 SM |
740 | while (len < buflen) { |
741 | unsigned int outlen = 0; | |
742 | /* 10.1.2.5 step 4.1 */ | |
8c987166 | 743 | ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &datalist); |
541af946 SM |
744 | if (ret) |
745 | return ret; | |
746 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
747 | drbg_blocklen(drbg) : (buflen - len); | |
748 | if (!drbg_fips_continuous_test(drbg, drbg->V)) | |
749 | continue; | |
750 | ||
751 | /* 10.1.2.5 step 4.2 */ | |
752 | memcpy(buf + len, drbg->V, outlen); | |
753 | len += outlen; | |
754 | } | |
755 | ||
756 | /* 10.1.2.5 step 6 */ | |
27e4de2b SM |
757 | if (addtl && !list_empty(addtl)) |
758 | ret = drbg_hmac_update(drbg, addtl, 1); | |
759 | else | |
8c987166 | 760 | ret = drbg_hmac_update(drbg, NULL, 1); |
541af946 SM |
761 | if (ret) |
762 | return ret; | |
763 | ||
764 | return len; | |
765 | } | |
766 | ||
767 | static struct drbg_state_ops drbg_hmac_ops = { | |
768 | .update = drbg_hmac_update, | |
769 | .generate = drbg_hmac_generate, | |
770 | .crypto_init = drbg_init_hash_kernel, | |
771 | .crypto_fini = drbg_fini_hash_kernel, | |
772 | ||
773 | }; | |
774 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
775 | ||
776 | /****************************************************************** | |
777 | * Hash DRBG callback functions | |
778 | ******************************************************************/ | |
779 | ||
780 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
e25e47ec | 781 | #define CRYPTO_DRBG_HASH_STRING "HASH " |
0653a7cf SM |
782 | MODULE_ALIAS_CRYPTO("drbg_pr_sha512"); |
783 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha512"); | |
784 | MODULE_ALIAS_CRYPTO("drbg_pr_sha384"); | |
785 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha384"); | |
786 | MODULE_ALIAS_CRYPTO("drbg_pr_sha256"); | |
787 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha256"); | |
788 | MODULE_ALIAS_CRYPTO("drbg_pr_sha1"); | |
789 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha1"); | |
62b62b6e | 790 | |
41a84982 SM |
791 | /* |
792 | * Increment buffer | |
793 | * | |
794 | * @dst buffer to increment | |
795 | * @add value to add | |
796 | */ | |
797 | static inline void drbg_add_buf(unsigned char *dst, size_t dstlen, | |
798 | const unsigned char *add, size_t addlen) | |
799 | { | |
800 | /* implied: dstlen > addlen */ | |
801 | unsigned char *dstptr; | |
802 | const unsigned char *addptr; | |
803 | unsigned int remainder = 0; | |
804 | size_t len = addlen; | |
805 | ||
806 | dstptr = dst + (dstlen-1); | |
807 | addptr = add + (addlen-1); | |
808 | while (len) { | |
809 | remainder += *dstptr + *addptr; | |
810 | *dstptr = remainder & 0xff; | |
811 | remainder >>= 8; | |
812 | len--; dstptr--; addptr--; | |
813 | } | |
814 | len = dstlen - addlen; | |
815 | while (len && remainder > 0) { | |
816 | remainder = *dstptr + 1; | |
817 | *dstptr = remainder & 0xff; | |
818 | remainder >>= 8; | |
819 | len--; dstptr--; | |
820 | } | |
821 | } | |
822 | ||
541af946 SM |
823 | /* |
824 | * scratchpad usage: as drbg_hash_update and drbg_hash_df are used | |
825 | * interlinked, the scratchpad is used as follows: | |
826 | * drbg_hash_update | |
827 | * start: drbg->scratchpad | |
828 | * length: drbg_statelen(drbg) | |
829 | * drbg_hash_df: | |
830 | * start: drbg->scratchpad + drbg_statelen(drbg) | |
831 | * length: drbg_blocklen(drbg) | |
832 | * | |
833 | * drbg_hash_process_addtl uses the scratchpad, but fully completes | |
834 | * before either of the functions mentioned before are invoked. Therefore, | |
835 | * drbg_hash_process_addtl does not need to be specifically considered. | |
836 | */ | |
837 | ||
838 | /* Derivation Function for Hash DRBG as defined in 10.4.1 */ | |
839 | static int drbg_hash_df(struct drbg_state *drbg, | |
840 | unsigned char *outval, size_t outlen, | |
8c987166 | 841 | struct list_head *entropylist) |
541af946 SM |
842 | { |
843 | int ret = 0; | |
844 | size_t len = 0; | |
845 | unsigned char input[5]; | |
846 | unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg); | |
8c987166 | 847 | struct drbg_string data; |
541af946 SM |
848 | |
849 | memset(tmp, 0, drbg_blocklen(drbg)); | |
850 | ||
851 | /* 10.4.1 step 3 */ | |
852 | input[0] = 1; | |
72f3e00d | 853 | drbg_cpu_to_be32((outlen * 8), &input[1]); |
541af946 SM |
854 | |
855 | /* 10.4.1 step 4.1 -- concatenation of data for input into hash */ | |
8c987166 SM |
856 | drbg_string_fill(&data, input, 5); |
857 | list_add(&data.list, entropylist); | |
541af946 SM |
858 | |
859 | /* 10.4.1 step 4 */ | |
860 | while (len < outlen) { | |
861 | short blocklen = 0; | |
862 | /* 10.4.1 step 4.1 */ | |
8c987166 | 863 | ret = drbg_kcapi_hash(drbg, NULL, tmp, entropylist); |
541af946 SM |
864 | if (ret) |
865 | goto out; | |
866 | /* 10.4.1 step 4.2 */ | |
867 | input[0]++; | |
868 | blocklen = (drbg_blocklen(drbg) < (outlen - len)) ? | |
869 | drbg_blocklen(drbg) : (outlen - len); | |
870 | memcpy(outval + len, tmp, blocklen); | |
871 | len += blocklen; | |
872 | } | |
873 | ||
874 | out: | |
421d82f5 | 875 | memzero_explicit(tmp, drbg_blocklen(drbg)); |
541af946 SM |
876 | return ret; |
877 | } | |
878 | ||
879 | /* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */ | |
8c987166 | 880 | static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed, |
541af946 SM |
881 | int reseed) |
882 | { | |
883 | int ret = 0; | |
884 | struct drbg_string data1, data2; | |
8c987166 SM |
885 | LIST_HEAD(datalist); |
886 | LIST_HEAD(datalist2); | |
541af946 SM |
887 | unsigned char *V = drbg->scratchpad; |
888 | unsigned char prefix = DRBG_PREFIX1; | |
889 | ||
890 | memset(drbg->scratchpad, 0, drbg_statelen(drbg)); | |
891 | if (!seed) | |
892 | return -EINVAL; | |
893 | ||
894 | if (reseed) { | |
895 | /* 10.1.1.3 step 1 */ | |
896 | memcpy(V, drbg->V, drbg_statelen(drbg)); | |
897 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 898 | list_add_tail(&data1.list, &datalist); |
541af946 | 899 | drbg_string_fill(&data2, V, drbg_statelen(drbg)); |
8c987166 | 900 | list_add_tail(&data2.list, &datalist); |
541af946 | 901 | } |
8c987166 | 902 | list_splice_tail(seed, &datalist); |
541af946 SM |
903 | |
904 | /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */ | |
8c987166 | 905 | ret = drbg_hash_df(drbg, drbg->V, drbg_statelen(drbg), &datalist); |
541af946 SM |
906 | if (ret) |
907 | goto out; | |
908 | ||
909 | /* 10.1.1.2 / 10.1.1.3 step 4 */ | |
910 | prefix = DRBG_PREFIX0; | |
911 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 912 | list_add_tail(&data1.list, &datalist2); |
541af946 | 913 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 | 914 | list_add_tail(&data2.list, &datalist2); |
541af946 | 915 | /* 10.1.1.2 / 10.1.1.3 step 4 */ |
8c987166 | 916 | ret = drbg_hash_df(drbg, drbg->C, drbg_statelen(drbg), &datalist2); |
541af946 SM |
917 | |
918 | out: | |
421d82f5 | 919 | memzero_explicit(drbg->scratchpad, drbg_statelen(drbg)); |
541af946 SM |
920 | return ret; |
921 | } | |
922 | ||
923 | /* processing of additional information string for Hash DRBG */ | |
924 | static int drbg_hash_process_addtl(struct drbg_state *drbg, | |
27e4de2b | 925 | struct list_head *addtl) |
541af946 SM |
926 | { |
927 | int ret = 0; | |
928 | struct drbg_string data1, data2; | |
8c987166 | 929 | LIST_HEAD(datalist); |
541af946 SM |
930 | unsigned char prefix = DRBG_PREFIX2; |
931 | ||
932 | /* this is value w as per documentation */ | |
933 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); | |
934 | ||
935 | /* 10.1.1.4 step 2 */ | |
27e4de2b | 936 | if (!addtl || list_empty(addtl)) |
541af946 SM |
937 | return 0; |
938 | ||
939 | /* 10.1.1.4 step 2a */ | |
940 | drbg_string_fill(&data1, &prefix, 1); | |
941 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); | |
8c987166 SM |
942 | list_add_tail(&data1.list, &datalist); |
943 | list_add_tail(&data2.list, &datalist); | |
27e4de2b | 944 | list_splice_tail(addtl, &datalist); |
8c987166 | 945 | ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist); |
541af946 SM |
946 | if (ret) |
947 | goto out; | |
948 | ||
949 | /* 10.1.1.4 step 2b */ | |
950 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
951 | drbg->scratchpad, drbg_blocklen(drbg)); | |
952 | ||
953 | out: | |
421d82f5 | 954 | memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg)); |
541af946 SM |
955 | return ret; |
956 | } | |
957 | ||
958 | /* Hashgen defined in 10.1.1.4 */ | |
959 | static int drbg_hash_hashgen(struct drbg_state *drbg, | |
960 | unsigned char *buf, | |
961 | unsigned int buflen) | |
962 | { | |
963 | int len = 0; | |
964 | int ret = 0; | |
965 | unsigned char *src = drbg->scratchpad; | |
966 | unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg); | |
967 | struct drbg_string data; | |
8c987166 | 968 | LIST_HEAD(datalist); |
541af946 SM |
969 | |
970 | memset(src, 0, drbg_statelen(drbg)); | |
971 | memset(dst, 0, drbg_blocklen(drbg)); | |
972 | ||
973 | /* 10.1.1.4 step hashgen 2 */ | |
974 | memcpy(src, drbg->V, drbg_statelen(drbg)); | |
975 | ||
976 | drbg_string_fill(&data, src, drbg_statelen(drbg)); | |
8c987166 | 977 | list_add_tail(&data.list, &datalist); |
541af946 SM |
978 | while (len < buflen) { |
979 | unsigned int outlen = 0; | |
980 | /* 10.1.1.4 step hashgen 4.1 */ | |
8c987166 | 981 | ret = drbg_kcapi_hash(drbg, NULL, dst, &datalist); |
541af946 SM |
982 | if (ret) { |
983 | len = ret; | |
984 | goto out; | |
985 | } | |
986 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
987 | drbg_blocklen(drbg) : (buflen - len); | |
988 | if (!drbg_fips_continuous_test(drbg, dst)) { | |
41a84982 | 989 | crypto_inc(src, drbg_statelen(drbg)); |
541af946 SM |
990 | continue; |
991 | } | |
992 | /* 10.1.1.4 step hashgen 4.2 */ | |
993 | memcpy(buf + len, dst, outlen); | |
994 | len += outlen; | |
995 | /* 10.1.1.4 hashgen step 4.3 */ | |
996 | if (len < buflen) | |
41a84982 | 997 | crypto_inc(src, drbg_statelen(drbg)); |
541af946 SM |
998 | } |
999 | ||
1000 | out: | |
421d82f5 | 1001 | memzero_explicit(drbg->scratchpad, |
541af946 SM |
1002 | (drbg_statelen(drbg) + drbg_blocklen(drbg))); |
1003 | return len; | |
1004 | } | |
1005 | ||
1006 | /* generate function for Hash DRBG as defined in 10.1.1.4 */ | |
1007 | static int drbg_hash_generate(struct drbg_state *drbg, | |
1008 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 1009 | struct list_head *addtl) |
541af946 SM |
1010 | { |
1011 | int len = 0; | |
1012 | int ret = 0; | |
72f3e00d SM |
1013 | union { |
1014 | unsigned char req[8]; | |
7c8ae03f | 1015 | __be64 req_int; |
72f3e00d | 1016 | } u; |
541af946 SM |
1017 | unsigned char prefix = DRBG_PREFIX3; |
1018 | struct drbg_string data1, data2; | |
8c987166 | 1019 | LIST_HEAD(datalist); |
541af946 SM |
1020 | |
1021 | /* 10.1.1.4 step 2 */ | |
1022 | ret = drbg_hash_process_addtl(drbg, addtl); | |
1023 | if (ret) | |
1024 | return ret; | |
1025 | /* 10.1.1.4 step 3 */ | |
1026 | len = drbg_hash_hashgen(drbg, buf, buflen); | |
1027 | ||
1028 | /* this is the value H as documented in 10.1.1.4 */ | |
1029 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); | |
1030 | /* 10.1.1.4 step 4 */ | |
1031 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 1032 | list_add_tail(&data1.list, &datalist); |
541af946 | 1033 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 SM |
1034 | list_add_tail(&data2.list, &datalist); |
1035 | ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist); | |
541af946 SM |
1036 | if (ret) { |
1037 | len = ret; | |
1038 | goto out; | |
1039 | } | |
1040 | ||
1041 | /* 10.1.1.4 step 5 */ | |
1042 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
1043 | drbg->scratchpad, drbg_blocklen(drbg)); | |
1044 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
1045 | drbg->C, drbg_statelen(drbg)); | |
72f3e00d SM |
1046 | u.req_int = cpu_to_be64(drbg->reseed_ctr); |
1047 | drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8); | |
541af946 SM |
1048 | |
1049 | out: | |
421d82f5 | 1050 | memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg)); |
541af946 SM |
1051 | return len; |
1052 | } | |
1053 | ||
1054 | /* | |
1055 | * scratchpad usage: as update and generate are used isolated, both | |
1056 | * can use the scratchpad | |
1057 | */ | |
1058 | static struct drbg_state_ops drbg_hash_ops = { | |
1059 | .update = drbg_hash_update, | |
1060 | .generate = drbg_hash_generate, | |
1061 | .crypto_init = drbg_init_hash_kernel, | |
1062 | .crypto_fini = drbg_fini_hash_kernel, | |
1063 | }; | |
1064 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1065 | ||
1066 | /****************************************************************** | |
1067 | * Functions common for DRBG implementations | |
1068 | ******************************************************************/ | |
1069 | ||
1070 | /* | |
1071 | * Seeding or reseeding of the DRBG | |
1072 | * | |
1073 | * @drbg: DRBG state struct | |
1074 | * @pers: personalization / additional information buffer | |
1075 | * @reseed: 0 for initial seed process, 1 for reseeding | |
1076 | * | |
1077 | * return: | |
1078 | * 0 on success | |
1079 | * error value otherwise | |
1080 | */ | |
1081 | static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers, | |
1082 | bool reseed) | |
1083 | { | |
1084 | int ret = 0; | |
1085 | unsigned char *entropy = NULL; | |
1086 | size_t entropylen = 0; | |
1087 | struct drbg_string data1; | |
8c987166 | 1088 | LIST_HEAD(seedlist); |
541af946 SM |
1089 | |
1090 | /* 9.1 / 9.2 / 9.3.1 step 3 */ | |
1091 | if (pers && pers->len > (drbg_max_addtl(drbg))) { | |
a9089571 | 1092 | pr_devel("DRBG: personalization string too long %zu\n", |
541af946 SM |
1093 | pers->len); |
1094 | return -EINVAL; | |
1095 | } | |
1096 | ||
1097 | if (drbg->test_data && drbg->test_data->testentropy) { | |
1098 | drbg_string_fill(&data1, drbg->test_data->testentropy->buf, | |
1099 | drbg->test_data->testentropy->len); | |
1100 | pr_devel("DRBG: using test entropy\n"); | |
1101 | } else { | |
1102 | /* | |
1103 | * Gather entropy equal to the security strength of the DRBG. | |
1104 | * With a derivation function, a nonce is required in addition | |
1105 | * to the entropy. A nonce must be at least 1/2 of the security | |
1106 | * strength of the DRBG in size. Thus, entropy * nonce is 3/2 | |
1107 | * of the strength. The consideration of a nonce is only | |
1108 | * applicable during initial seeding. | |
1109 | */ | |
1110 | entropylen = drbg_sec_strength(drbg->core->flags); | |
1111 | if (!entropylen) | |
1112 | return -EFAULT; | |
1113 | if (!reseed) | |
1114 | entropylen = ((entropylen + 1) / 2) * 3; | |
1115 | pr_devel("DRBG: (re)seeding with %zu bytes of entropy\n", | |
1116 | entropylen); | |
1117 | entropy = kzalloc(entropylen, GFP_KERNEL); | |
1118 | if (!entropy) | |
1119 | return -ENOMEM; | |
1120 | get_random_bytes(entropy, entropylen); | |
1121 | drbg_string_fill(&data1, entropy, entropylen); | |
1122 | } | |
8c987166 | 1123 | list_add_tail(&data1.list, &seedlist); |
541af946 SM |
1124 | |
1125 | /* | |
1126 | * concatenation of entropy with personalization str / addtl input) | |
1127 | * the variable pers is directly handed in by the caller, so check its | |
1128 | * contents whether it is appropriate | |
1129 | */ | |
8c987166 SM |
1130 | if (pers && pers->buf && 0 < pers->len) { |
1131 | list_add_tail(&pers->list, &seedlist); | |
541af946 SM |
1132 | pr_devel("DRBG: using personalization string\n"); |
1133 | } | |
1134 | ||
e6c0244a SM |
1135 | if (!reseed) { |
1136 | memset(drbg->V, 0, drbg_statelen(drbg)); | |
1137 | memset(drbg->C, 0, drbg_statelen(drbg)); | |
1138 | } | |
1139 | ||
8c987166 | 1140 | ret = drbg->d_ops->update(drbg, &seedlist, reseed); |
541af946 SM |
1141 | if (ret) |
1142 | goto out; | |
1143 | ||
1144 | drbg->seeded = true; | |
1145 | /* 10.1.1.2 / 10.1.1.3 step 5 */ | |
1146 | drbg->reseed_ctr = 1; | |
1147 | ||
1148 | out: | |
46f64f6e | 1149 | kzfree(entropy); |
541af946 SM |
1150 | return ret; |
1151 | } | |
1152 | ||
1153 | /* Free all substructures in a DRBG state without the DRBG state structure */ | |
1154 | static inline void drbg_dealloc_state(struct drbg_state *drbg) | |
1155 | { | |
1156 | if (!drbg) | |
1157 | return; | |
46f64f6e | 1158 | kzfree(drbg->V); |
541af946 | 1159 | drbg->V = NULL; |
46f64f6e | 1160 | kzfree(drbg->C); |
541af946 | 1161 | drbg->C = NULL; |
46f64f6e | 1162 | kzfree(drbg->scratchpad); |
541af946 SM |
1163 | drbg->scratchpad = NULL; |
1164 | drbg->reseed_ctr = 0; | |
1165 | #ifdef CONFIG_CRYPTO_FIPS | |
46f64f6e | 1166 | kzfree(drbg->prev); |
541af946 SM |
1167 | drbg->prev = NULL; |
1168 | drbg->fips_primed = false; | |
1169 | #endif | |
1170 | } | |
1171 | ||
1172 | /* | |
1173 | * Allocate all sub-structures for a DRBG state. | |
1174 | * The DRBG state structure must already be allocated. | |
1175 | */ | |
1176 | static inline int drbg_alloc_state(struct drbg_state *drbg) | |
1177 | { | |
1178 | int ret = -ENOMEM; | |
1179 | unsigned int sb_size = 0; | |
1180 | ||
e6c0244a | 1181 | drbg->V = kmalloc(drbg_statelen(drbg), GFP_KERNEL); |
541af946 SM |
1182 | if (!drbg->V) |
1183 | goto err; | |
e6c0244a | 1184 | drbg->C = kmalloc(drbg_statelen(drbg), GFP_KERNEL); |
541af946 SM |
1185 | if (!drbg->C) |
1186 | goto err; | |
1187 | #ifdef CONFIG_CRYPTO_FIPS | |
e6c0244a | 1188 | drbg->prev = kmalloc(drbg_blocklen(drbg), GFP_KERNEL); |
541af946 SM |
1189 | if (!drbg->prev) |
1190 | goto err; | |
1191 | drbg->fips_primed = false; | |
1192 | #endif | |
1193 | /* scratchpad is only generated for CTR and Hash */ | |
1194 | if (drbg->core->flags & DRBG_HMAC) | |
1195 | sb_size = 0; | |
1196 | else if (drbg->core->flags & DRBG_CTR) | |
1197 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg) + /* temp */ | |
1198 | drbg_statelen(drbg) + /* df_data */ | |
1199 | drbg_blocklen(drbg) + /* pad */ | |
1200 | drbg_blocklen(drbg) + /* iv */ | |
8fecaad7 | 1201 | drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */ |
541af946 SM |
1202 | else |
1203 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg); | |
1204 | ||
1205 | if (0 < sb_size) { | |
1206 | drbg->scratchpad = kzalloc(sb_size, GFP_KERNEL); | |
1207 | if (!drbg->scratchpad) | |
1208 | goto err; | |
1209 | } | |
1210 | spin_lock_init(&drbg->drbg_lock); | |
1211 | return 0; | |
1212 | ||
1213 | err: | |
1214 | drbg_dealloc_state(drbg); | |
1215 | return ret; | |
1216 | } | |
1217 | ||
1218 | /* | |
1219 | * Strategy to avoid holding long term locks: generate a shadow copy of DRBG | |
1220 | * and perform all operations on this shadow copy. After finishing, restore | |
1221 | * the updated state of the shadow copy into original drbg state. This way, | |
1222 | * only the read and write operations of the original drbg state must be | |
1223 | * locked | |
1224 | */ | |
1225 | static inline void drbg_copy_drbg(struct drbg_state *src, | |
1226 | struct drbg_state *dst) | |
1227 | { | |
1228 | if (!src || !dst) | |
1229 | return; | |
1230 | memcpy(dst->V, src->V, drbg_statelen(src)); | |
1231 | memcpy(dst->C, src->C, drbg_statelen(src)); | |
1232 | dst->reseed_ctr = src->reseed_ctr; | |
1233 | dst->seeded = src->seeded; | |
1234 | dst->pr = src->pr; | |
1235 | #ifdef CONFIG_CRYPTO_FIPS | |
1236 | dst->fips_primed = src->fips_primed; | |
1237 | memcpy(dst->prev, src->prev, drbg_blocklen(src)); | |
1238 | #endif | |
1239 | /* | |
1240 | * Not copied: | |
1241 | * scratchpad is initialized drbg_alloc_state; | |
1242 | * priv_data is initialized with call to crypto_init; | |
1243 | * d_ops and core are set outside, as these parameters are const; | |
1244 | * test_data is set outside to prevent it being copied back. | |
1245 | */ | |
1246 | } | |
1247 | ||
1248 | static int drbg_make_shadow(struct drbg_state *drbg, struct drbg_state **shadow) | |
1249 | { | |
1250 | int ret = -ENOMEM; | |
1251 | struct drbg_state *tmp = NULL; | |
1252 | ||
541af946 SM |
1253 | tmp = kzalloc(sizeof(struct drbg_state), GFP_KERNEL); |
1254 | if (!tmp) | |
1255 | return -ENOMEM; | |
1256 | ||
1257 | /* read-only data as they are defined as const, no lock needed */ | |
1258 | tmp->core = drbg->core; | |
1259 | tmp->d_ops = drbg->d_ops; | |
1260 | ||
1261 | ret = drbg_alloc_state(tmp); | |
1262 | if (ret) | |
1263 | goto err; | |
1264 | ||
1265 | spin_lock_bh(&drbg->drbg_lock); | |
1266 | drbg_copy_drbg(drbg, tmp); | |
1267 | /* only make a link to the test buffer, as we only read that data */ | |
1268 | tmp->test_data = drbg->test_data; | |
1269 | spin_unlock_bh(&drbg->drbg_lock); | |
1270 | *shadow = tmp; | |
1271 | return 0; | |
1272 | ||
1273 | err: | |
46f64f6e | 1274 | kzfree(tmp); |
541af946 SM |
1275 | return ret; |
1276 | } | |
1277 | ||
1278 | static void drbg_restore_shadow(struct drbg_state *drbg, | |
1279 | struct drbg_state **shadow) | |
1280 | { | |
1281 | struct drbg_state *tmp = *shadow; | |
1282 | ||
1283 | spin_lock_bh(&drbg->drbg_lock); | |
1284 | drbg_copy_drbg(tmp, drbg); | |
1285 | spin_unlock_bh(&drbg->drbg_lock); | |
1286 | drbg_dealloc_state(tmp); | |
1287 | kzfree(tmp); | |
1288 | *shadow = NULL; | |
1289 | } | |
1290 | ||
1291 | /************************************************************************* | |
1292 | * DRBG interface functions | |
1293 | *************************************************************************/ | |
1294 | ||
1295 | /* | |
1296 | * DRBG generate function as required by SP800-90A - this function | |
1297 | * generates random numbers | |
1298 | * | |
1299 | * @drbg DRBG state handle | |
1300 | * @buf Buffer where to store the random numbers -- the buffer must already | |
1301 | * be pre-allocated by caller | |
1302 | * @buflen Length of output buffer - this value defines the number of random | |
1303 | * bytes pulled from DRBG | |
1304 | * @addtl Additional input that is mixed into state, may be NULL -- note | |
1305 | * the entropy is pulled by the DRBG internally unconditionally | |
1306 | * as defined in SP800-90A. The additional input is mixed into | |
1307 | * the state in addition to the pulled entropy. | |
1308 | * | |
1309 | * return: generated number of bytes | |
1310 | */ | |
1311 | static int drbg_generate(struct drbg_state *drbg, | |
1312 | unsigned char *buf, unsigned int buflen, | |
1313 | struct drbg_string *addtl) | |
1314 | { | |
1315 | int len = 0; | |
1316 | struct drbg_state *shadow = NULL; | |
27e4de2b SM |
1317 | LIST_HEAD(addtllist); |
1318 | struct drbg_string timestamp; | |
1319 | union { | |
1320 | cycles_t cycles; | |
1321 | unsigned char char_cycles[sizeof(cycles_t)]; | |
1322 | } now; | |
541af946 SM |
1323 | |
1324 | if (0 == buflen || !buf) { | |
1325 | pr_devel("DRBG: no output buffer provided\n"); | |
1326 | return -EINVAL; | |
1327 | } | |
1328 | if (addtl && NULL == addtl->buf && 0 < addtl->len) { | |
1329 | pr_devel("DRBG: wrong format of additional information\n"); | |
1330 | return -EINVAL; | |
1331 | } | |
1332 | ||
1333 | len = drbg_make_shadow(drbg, &shadow); | |
1334 | if (len) { | |
1335 | pr_devel("DRBG: shadow copy cannot be generated\n"); | |
1336 | return len; | |
1337 | } | |
1338 | ||
1339 | /* 9.3.1 step 2 */ | |
1340 | len = -EINVAL; | |
1341 | if (buflen > (drbg_max_request_bytes(shadow))) { | |
1342 | pr_devel("DRBG: requested random numbers too large %u\n", | |
1343 | buflen); | |
1344 | goto err; | |
1345 | } | |
1346 | ||
1347 | /* 9.3.1 step 3 is implicit with the chosen DRBG */ | |
1348 | ||
1349 | /* 9.3.1 step 4 */ | |
1350 | if (addtl && addtl->len > (drbg_max_addtl(shadow))) { | |
1351 | pr_devel("DRBG: additional information string too long %zu\n", | |
1352 | addtl->len); | |
1353 | goto err; | |
1354 | } | |
1355 | /* 9.3.1 step 5 is implicit with the chosen DRBG */ | |
1356 | ||
1357 | /* | |
1358 | * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented | |
1359 | * here. The spec is a bit convoluted here, we make it simpler. | |
1360 | */ | |
1361 | if ((drbg_max_requests(shadow)) < shadow->reseed_ctr) | |
1362 | shadow->seeded = false; | |
1363 | ||
1364 | /* allocate cipher handle */ | |
45943a58 SM |
1365 | len = shadow->d_ops->crypto_init(shadow); |
1366 | if (len) | |
1367 | goto err; | |
541af946 SM |
1368 | |
1369 | if (shadow->pr || !shadow->seeded) { | |
1370 | pr_devel("DRBG: reseeding before generation (prediction " | |
1371 | "resistance: %s, state %s)\n", | |
1372 | drbg->pr ? "true" : "false", | |
1373 | drbg->seeded ? "seeded" : "unseeded"); | |
1374 | /* 9.3.1 steps 7.1 through 7.3 */ | |
1375 | len = drbg_seed(shadow, addtl, true); | |
1376 | if (len) | |
1377 | goto err; | |
1378 | /* 9.3.1 step 7.4 */ | |
1379 | addtl = NULL; | |
1380 | } | |
27e4de2b SM |
1381 | |
1382 | /* | |
1383 | * Mix the time stamp into the DRBG state if the DRBG is not in | |
1384 | * test mode. If there are two callers invoking the DRBG at the same | |
1385 | * time, i.e. before the first caller merges its shadow state back, | |
1386 | * both callers would obtain the same random number stream without | |
1387 | * changing the state here. | |
1388 | */ | |
1389 | if (!drbg->test_data) { | |
1390 | now.cycles = random_get_entropy(); | |
1391 | drbg_string_fill(×tamp, now.char_cycles, sizeof(cycles_t)); | |
1392 | list_add_tail(×tamp.list, &addtllist); | |
1393 | } | |
1394 | if (addtl && 0 < addtl->len) | |
1395 | list_add_tail(&addtl->list, &addtllist); | |
541af946 | 1396 | /* 9.3.1 step 8 and 10 */ |
27e4de2b | 1397 | len = shadow->d_ops->generate(shadow, buf, buflen, &addtllist); |
541af946 SM |
1398 | |
1399 | /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */ | |
1400 | shadow->reseed_ctr++; | |
1401 | if (0 >= len) | |
1402 | goto err; | |
1403 | ||
1404 | /* | |
1405 | * Section 11.3.3 requires to re-perform self tests after some | |
1406 | * generated random numbers. The chosen value after which self | |
1407 | * test is performed is arbitrary, but it should be reasonable. | |
1408 | * However, we do not perform the self tests because of the following | |
1409 | * reasons: it is mathematically impossible that the initial self tests | |
1410 | * were successfully and the following are not. If the initial would | |
1411 | * pass and the following would not, the kernel integrity is violated. | |
1412 | * In this case, the entire kernel operation is questionable and it | |
1413 | * is unlikely that the integrity violation only affects the | |
1414 | * correct operation of the DRBG. | |
1415 | * | |
1416 | * Albeit the following code is commented out, it is provided in | |
1417 | * case somebody has a need to implement the test of 11.3.3. | |
1418 | */ | |
1419 | #if 0 | |
1420 | if (shadow->reseed_ctr && !(shadow->reseed_ctr % 4096)) { | |
1421 | int err = 0; | |
1422 | pr_devel("DRBG: start to perform self test\n"); | |
1423 | if (drbg->core->flags & DRBG_HMAC) | |
1424 | err = alg_test("drbg_pr_hmac_sha256", | |
1425 | "drbg_pr_hmac_sha256", 0, 0); | |
1426 | else if (drbg->core->flags & DRBG_CTR) | |
1427 | err = alg_test("drbg_pr_ctr_aes128", | |
1428 | "drbg_pr_ctr_aes128", 0, 0); | |
1429 | else | |
1430 | err = alg_test("drbg_pr_sha256", | |
1431 | "drbg_pr_sha256", 0, 0); | |
1432 | if (err) { | |
1433 | pr_err("DRBG: periodical self test failed\n"); | |
1434 | /* | |
1435 | * uninstantiate implies that from now on, only errors | |
1436 | * are returned when reusing this DRBG cipher handle | |
1437 | */ | |
1438 | drbg_uninstantiate(drbg); | |
1439 | drbg_dealloc_state(shadow); | |
1440 | kzfree(shadow); | |
1441 | return 0; | |
1442 | } else { | |
1443 | pr_devel("DRBG: self test successful\n"); | |
1444 | } | |
1445 | } | |
1446 | #endif | |
1447 | ||
1448 | err: | |
45943a58 | 1449 | shadow->d_ops->crypto_fini(shadow); |
541af946 SM |
1450 | drbg_restore_shadow(drbg, &shadow); |
1451 | return len; | |
1452 | } | |
1453 | ||
1454 | /* | |
1455 | * Wrapper around drbg_generate which can pull arbitrary long strings | |
1456 | * from the DRBG without hitting the maximum request limitation. | |
1457 | * | |
1458 | * Parameters: see drbg_generate | |
1459 | * Return codes: see drbg_generate -- if one drbg_generate request fails, | |
1460 | * the entire drbg_generate_long request fails | |
1461 | */ | |
1462 | static int drbg_generate_long(struct drbg_state *drbg, | |
1463 | unsigned char *buf, unsigned int buflen, | |
1464 | struct drbg_string *addtl) | |
1465 | { | |
1466 | int len = 0; | |
1467 | unsigned int slice = 0; | |
1468 | do { | |
1469 | int tmplen = 0; | |
1470 | unsigned int chunk = 0; | |
1471 | slice = ((buflen - len) / drbg_max_request_bytes(drbg)); | |
1472 | chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len); | |
1473 | tmplen = drbg_generate(drbg, buf + len, chunk, addtl); | |
1474 | if (0 >= tmplen) | |
1475 | return tmplen; | |
1476 | len += tmplen; | |
ce5481d0 | 1477 | } while (slice > 0 && (len < buflen)); |
541af946 SM |
1478 | return len; |
1479 | } | |
1480 | ||
1481 | /* | |
1482 | * DRBG instantiation function as required by SP800-90A - this function | |
1483 | * sets up the DRBG handle, performs the initial seeding and all sanity | |
1484 | * checks required by SP800-90A | |
1485 | * | |
1486 | * @drbg memory of state -- if NULL, new memory is allocated | |
1487 | * @pers Personalization string that is mixed into state, may be NULL -- note | |
1488 | * the entropy is pulled by the DRBG internally unconditionally | |
1489 | * as defined in SP800-90A. The additional input is mixed into | |
1490 | * the state in addition to the pulled entropy. | |
1491 | * @coreref reference to core | |
1492 | * @pr prediction resistance enabled | |
1493 | * | |
1494 | * return | |
1495 | * 0 on success | |
1496 | * error value otherwise | |
1497 | */ | |
1498 | static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, | |
1499 | int coreref, bool pr) | |
1500 | { | |
1501 | int ret = -ENOMEM; | |
1502 | ||
1503 | pr_devel("DRBG: Initializing DRBG core %d with prediction resistance " | |
1504 | "%s\n", coreref, pr ? "enabled" : "disabled"); | |
1505 | drbg->core = &drbg_cores[coreref]; | |
1506 | drbg->pr = pr; | |
1507 | drbg->seeded = false; | |
1508 | switch (drbg->core->flags & DRBG_TYPE_MASK) { | |
1509 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
1510 | case DRBG_HMAC: | |
1511 | drbg->d_ops = &drbg_hmac_ops; | |
1512 | break; | |
1513 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
1514 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
1515 | case DRBG_HASH: | |
1516 | drbg->d_ops = &drbg_hash_ops; | |
1517 | break; | |
1518 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1519 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1520 | case DRBG_CTR: | |
1521 | drbg->d_ops = &drbg_ctr_ops; | |
1522 | break; | |
1523 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
1524 | default: | |
1525 | return -EOPNOTSUPP; | |
1526 | } | |
1527 | ||
1528 | /* 9.1 step 1 is implicit with the selected DRBG type */ | |
1529 | ||
1530 | /* | |
1531 | * 9.1 step 2 is implicit as caller can select prediction resistance | |
1532 | * and the flag is copied into drbg->flags -- | |
1533 | * all DRBG types support prediction resistance | |
1534 | */ | |
1535 | ||
1536 | /* 9.1 step 4 is implicit in drbg_sec_strength */ | |
1537 | ||
1538 | ret = drbg_alloc_state(drbg); | |
1539 | if (ret) | |
1540 | return ret; | |
1541 | ||
1542 | ret = -EFAULT; | |
45943a58 | 1543 | if (drbg->d_ops->crypto_init(drbg)) |
541af946 SM |
1544 | goto err; |
1545 | ret = drbg_seed(drbg, pers, false); | |
45943a58 | 1546 | drbg->d_ops->crypto_fini(drbg); |
541af946 SM |
1547 | if (ret) |
1548 | goto err; | |
1549 | ||
1550 | return 0; | |
1551 | ||
1552 | err: | |
1553 | drbg_dealloc_state(drbg); | |
1554 | return ret; | |
1555 | } | |
1556 | ||
1557 | /* | |
1558 | * DRBG uninstantiate function as required by SP800-90A - this function | |
1559 | * frees all buffers and the DRBG handle | |
1560 | * | |
1561 | * @drbg DRBG state handle | |
1562 | * | |
1563 | * return | |
1564 | * 0 on success | |
1565 | */ | |
1566 | static int drbg_uninstantiate(struct drbg_state *drbg) | |
1567 | { | |
1568 | spin_lock_bh(&drbg->drbg_lock); | |
1569 | drbg_dealloc_state(drbg); | |
1570 | /* no scrubbing of test_data -- this shall survive an uninstantiate */ | |
1571 | spin_unlock_bh(&drbg->drbg_lock); | |
1572 | return 0; | |
1573 | } | |
1574 | ||
1575 | /* | |
1576 | * Helper function for setting the test data in the DRBG | |
1577 | * | |
1578 | * @drbg DRBG state handle | |
1579 | * @test_data test data to sets | |
1580 | */ | |
1581 | static inline void drbg_set_testdata(struct drbg_state *drbg, | |
1582 | struct drbg_test_data *test_data) | |
1583 | { | |
1584 | if (!test_data || !test_data->testentropy) | |
1585 | return; | |
1586 | spin_lock_bh(&drbg->drbg_lock); | |
1587 | drbg->test_data = test_data; | |
1588 | spin_unlock_bh(&drbg->drbg_lock); | |
1589 | } | |
1590 | ||
1591 | /*************************************************************** | |
1592 | * Kernel crypto API cipher invocations requested by DRBG | |
1593 | ***************************************************************/ | |
1594 | ||
1595 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
1596 | struct sdesc { | |
1597 | struct shash_desc shash; | |
1598 | char ctx[]; | |
1599 | }; | |
1600 | ||
1601 | static int drbg_init_hash_kernel(struct drbg_state *drbg) | |
1602 | { | |
1603 | struct sdesc *sdesc; | |
1604 | struct crypto_shash *tfm; | |
1605 | ||
1606 | tfm = crypto_alloc_shash(drbg->core->backend_cra_name, 0, 0); | |
1607 | if (IS_ERR(tfm)) { | |
1608 | pr_info("DRBG: could not allocate digest TFM handle\n"); | |
1609 | return PTR_ERR(tfm); | |
1610 | } | |
1611 | BUG_ON(drbg_blocklen(drbg) != crypto_shash_digestsize(tfm)); | |
1612 | sdesc = kzalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm), | |
1613 | GFP_KERNEL); | |
1614 | if (!sdesc) { | |
1615 | crypto_free_shash(tfm); | |
1616 | return -ENOMEM; | |
1617 | } | |
1618 | ||
1619 | sdesc->shash.tfm = tfm; | |
1620 | sdesc->shash.flags = 0; | |
1621 | drbg->priv_data = sdesc; | |
1622 | return 0; | |
1623 | } | |
1624 | ||
1625 | static int drbg_fini_hash_kernel(struct drbg_state *drbg) | |
1626 | { | |
1627 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
1628 | if (sdesc) { | |
1629 | crypto_free_shash(sdesc->shash.tfm); | |
1630 | kzfree(sdesc); | |
1631 | } | |
1632 | drbg->priv_data = NULL; | |
1633 | return 0; | |
1634 | } | |
1635 | ||
1636 | static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key, | |
8c987166 | 1637 | unsigned char *outval, const struct list_head *in) |
541af946 SM |
1638 | { |
1639 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
8c987166 | 1640 | struct drbg_string *input = NULL; |
541af946 SM |
1641 | |
1642 | if (key) | |
1643 | crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg)); | |
1644 | crypto_shash_init(&sdesc->shash); | |
8c987166 SM |
1645 | list_for_each_entry(input, in, list) |
1646 | crypto_shash_update(&sdesc->shash, input->buf, input->len); | |
541af946 SM |
1647 | return crypto_shash_final(&sdesc->shash, outval); |
1648 | } | |
1649 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
1650 | ||
1651 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1652 | static int drbg_init_sym_kernel(struct drbg_state *drbg) | |
1653 | { | |
1654 | int ret = 0; | |
1655 | struct crypto_blkcipher *tfm; | |
1656 | ||
1657 | tfm = crypto_alloc_blkcipher(drbg->core->backend_cra_name, 0, 0); | |
1658 | if (IS_ERR(tfm)) { | |
1659 | pr_info("DRBG: could not allocate cipher TFM handle\n"); | |
1660 | return PTR_ERR(tfm); | |
1661 | } | |
1662 | BUG_ON(drbg_blocklen(drbg) != crypto_blkcipher_blocksize(tfm)); | |
1663 | drbg->priv_data = tfm; | |
1664 | return ret; | |
1665 | } | |
1666 | ||
1667 | static int drbg_fini_sym_kernel(struct drbg_state *drbg) | |
1668 | { | |
1669 | struct crypto_blkcipher *tfm = | |
1670 | (struct crypto_blkcipher *)drbg->priv_data; | |
1671 | if (tfm) | |
1672 | crypto_free_blkcipher(tfm); | |
1673 | drbg->priv_data = NULL; | |
1674 | return 0; | |
1675 | } | |
1676 | ||
1677 | static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key, | |
1678 | unsigned char *outval, const struct drbg_string *in) | |
1679 | { | |
1680 | int ret = 0; | |
1681 | struct scatterlist sg_in, sg_out; | |
1682 | struct blkcipher_desc desc; | |
1683 | struct crypto_blkcipher *tfm = | |
1684 | (struct crypto_blkcipher *)drbg->priv_data; | |
1685 | ||
1686 | desc.tfm = tfm; | |
1687 | desc.flags = 0; | |
1688 | crypto_blkcipher_setkey(tfm, key, (drbg_keylen(drbg))); | |
1689 | /* there is only component in *in */ | |
1690 | sg_init_one(&sg_in, in->buf, in->len); | |
1691 | sg_init_one(&sg_out, outval, drbg_blocklen(drbg)); | |
1692 | ret = crypto_blkcipher_encrypt(&desc, &sg_out, &sg_in, in->len); | |
1693 | ||
1694 | return ret; | |
1695 | } | |
1696 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
1697 | ||
1698 | /*************************************************************** | |
1699 | * Kernel crypto API interface to register DRBG | |
1700 | ***************************************************************/ | |
1701 | ||
1702 | /* | |
1703 | * Look up the DRBG flags by given kernel crypto API cra_name | |
1704 | * The code uses the drbg_cores definition to do this | |
1705 | * | |
1706 | * @cra_name kernel crypto API cra_name | |
1707 | * @coreref reference to integer which is filled with the pointer to | |
1708 | * the applicable core | |
1709 | * @pr reference for setting prediction resistance | |
1710 | * | |
1711 | * return: flags | |
1712 | */ | |
1713 | static inline void drbg_convert_tfm_core(const char *cra_driver_name, | |
1714 | int *coreref, bool *pr) | |
1715 | { | |
1716 | int i = 0; | |
1717 | size_t start = 0; | |
1718 | int len = 0; | |
1719 | ||
1720 | *pr = true; | |
1721 | /* disassemble the names */ | |
1722 | if (!memcmp(cra_driver_name, "drbg_nopr_", 10)) { | |
1723 | start = 10; | |
1724 | *pr = false; | |
1725 | } else if (!memcmp(cra_driver_name, "drbg_pr_", 8)) { | |
1726 | start = 8; | |
1727 | } else { | |
1728 | return; | |
1729 | } | |
1730 | ||
1731 | /* remove the first part */ | |
1732 | len = strlen(cra_driver_name) - start; | |
1733 | for (i = 0; ARRAY_SIZE(drbg_cores) > i; i++) { | |
1734 | if (!memcmp(cra_driver_name + start, drbg_cores[i].cra_name, | |
1735 | len)) { | |
1736 | *coreref = i; | |
1737 | return; | |
1738 | } | |
1739 | } | |
1740 | } | |
1741 | ||
1742 | static int drbg_kcapi_init(struct crypto_tfm *tfm) | |
1743 | { | |
1744 | struct drbg_state *drbg = crypto_tfm_ctx(tfm); | |
1745 | bool pr = false; | |
1746 | int coreref = 0; | |
1747 | ||
4f150718 | 1748 | drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm), &coreref, &pr); |
541af946 SM |
1749 | /* |
1750 | * when personalization string is needed, the caller must call reset | |
1751 | * and provide the personalization string as seed information | |
1752 | */ | |
1753 | return drbg_instantiate(drbg, NULL, coreref, pr); | |
1754 | } | |
1755 | ||
1756 | static void drbg_kcapi_cleanup(struct crypto_tfm *tfm) | |
1757 | { | |
1758 | drbg_uninstantiate(crypto_tfm_ctx(tfm)); | |
1759 | } | |
1760 | ||
1761 | /* | |
1762 | * Generate random numbers invoked by the kernel crypto API: | |
1763 | * The API of the kernel crypto API is extended as follows: | |
1764 | * | |
1765 | * If dlen is larger than zero, rdata is interpreted as the output buffer | |
1766 | * where random data is to be stored. | |
1767 | * | |
1768 | * If dlen is zero, rdata is interpreted as a pointer to a struct drbg_gen | |
1769 | * which holds the additional information string that is used for the | |
1770 | * DRBG generation process. The output buffer that is to be used to store | |
1771 | * data is also pointed to by struct drbg_gen. | |
1772 | */ | |
1773 | static int drbg_kcapi_random(struct crypto_rng *tfm, u8 *rdata, | |
1774 | unsigned int dlen) | |
1775 | { | |
1776 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
1777 | if (0 < dlen) { | |
1778 | return drbg_generate_long(drbg, rdata, dlen, NULL); | |
1779 | } else { | |
1780 | struct drbg_gen *data = (struct drbg_gen *)rdata; | |
8c987166 | 1781 | struct drbg_string addtl; |
541af946 SM |
1782 | /* catch NULL pointer */ |
1783 | if (!data) | |
1784 | return 0; | |
1785 | drbg_set_testdata(drbg, data->test_data); | |
8c987166 SM |
1786 | /* linked list variable is now local to allow modification */ |
1787 | drbg_string_fill(&addtl, data->addtl->buf, data->addtl->len); | |
541af946 | 1788 | return drbg_generate_long(drbg, data->outbuf, data->outlen, |
8c987166 | 1789 | &addtl); |
541af946 SM |
1790 | } |
1791 | } | |
1792 | ||
1793 | /* | |
1794 | * Reset the DRBG invoked by the kernel crypto API | |
1795 | * The reset implies a full re-initialization of the DRBG. Similar to the | |
1796 | * generate function of drbg_kcapi_random, this function extends the | |
1797 | * kernel crypto API interface with struct drbg_gen | |
1798 | */ | |
1799 | static int drbg_kcapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen) | |
1800 | { | |
1801 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
1802 | struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm); | |
1803 | bool pr = false; | |
1804 | struct drbg_string seed_string; | |
1805 | int coreref = 0; | |
1806 | ||
1807 | drbg_uninstantiate(drbg); | |
1808 | drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref, | |
1809 | &pr); | |
1810 | if (0 < slen) { | |
1811 | drbg_string_fill(&seed_string, seed, slen); | |
1812 | return drbg_instantiate(drbg, &seed_string, coreref, pr); | |
1813 | } else { | |
1814 | struct drbg_gen *data = (struct drbg_gen *)seed; | |
1815 | /* allow invocation of API call with NULL, 0 */ | |
1816 | if (!data) | |
1817 | return drbg_instantiate(drbg, NULL, coreref, pr); | |
1818 | drbg_set_testdata(drbg, data->test_data); | |
8c987166 SM |
1819 | /* linked list variable is now local to allow modification */ |
1820 | drbg_string_fill(&seed_string, data->addtl->buf, | |
1821 | data->addtl->len); | |
1822 | return drbg_instantiate(drbg, &seed_string, coreref, pr); | |
541af946 SM |
1823 | } |
1824 | } | |
1825 | ||
1826 | /*************************************************************** | |
1827 | * Kernel module: code to load the module | |
1828 | ***************************************************************/ | |
1829 | ||
1830 | /* | |
1831 | * Tests as defined in 11.3.2 in addition to the cipher tests: testing | |
1832 | * of the error handling. | |
1833 | * | |
1834 | * Note: testing of failing seed source as defined in 11.3.2 is not applicable | |
1835 | * as seed source of get_random_bytes does not fail. | |
1836 | * | |
1837 | * Note 2: There is no sensible way of testing the reseed counter | |
1838 | * enforcement, so skip it. | |
1839 | */ | |
1840 | static inline int __init drbg_healthcheck_sanity(void) | |
1841 | { | |
1842 | #ifdef CONFIG_CRYPTO_FIPS | |
1843 | int len = 0; | |
1844 | #define OUTBUFLEN 16 | |
1845 | unsigned char buf[OUTBUFLEN]; | |
1846 | struct drbg_state *drbg = NULL; | |
1847 | int ret = -EFAULT; | |
1848 | int rc = -EFAULT; | |
1849 | bool pr = false; | |
1850 | int coreref = 0; | |
1851 | struct drbg_string addtl; | |
1852 | size_t max_addtllen, max_request_bytes; | |
1853 | ||
1854 | /* only perform test in FIPS mode */ | |
1855 | if (!fips_enabled) | |
1856 | return 0; | |
1857 | ||
1858 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1859 | drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref, &pr); | |
e25e47ec | 1860 | #elif defined CONFIG_CRYPTO_DRBG_HASH |
541af946 SM |
1861 | drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr); |
1862 | #else | |
1863 | drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref, &pr); | |
1864 | #endif | |
1865 | ||
1866 | drbg = kzalloc(sizeof(struct drbg_state), GFP_KERNEL); | |
1867 | if (!drbg) | |
1868 | return -ENOMEM; | |
1869 | ||
1870 | /* | |
1871 | * if the following tests fail, it is likely that there is a buffer | |
1872 | * overflow as buf is much smaller than the requested or provided | |
1873 | * string lengths -- in case the error handling does not succeed | |
1874 | * we may get an OOPS. And we want to get an OOPS as this is a | |
1875 | * grave bug. | |
1876 | */ | |
1877 | ||
1878 | /* get a valid instance of DRBG for following tests */ | |
1879 | ret = drbg_instantiate(drbg, NULL, coreref, pr); | |
1880 | if (ret) { | |
1881 | rc = ret; | |
1882 | goto outbuf; | |
1883 | } | |
1884 | max_addtllen = drbg_max_addtl(drbg); | |
1885 | max_request_bytes = drbg_max_request_bytes(drbg); | |
1886 | drbg_string_fill(&addtl, buf, max_addtllen + 1); | |
1887 | /* overflow addtllen with additonal info string */ | |
1888 | len = drbg_generate(drbg, buf, OUTBUFLEN, &addtl); | |
1889 | BUG_ON(0 < len); | |
1890 | /* overflow max_bits */ | |
1891 | len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL); | |
1892 | BUG_ON(0 < len); | |
1893 | drbg_uninstantiate(drbg); | |
1894 | ||
1895 | /* overflow max addtllen with personalization string */ | |
1896 | ret = drbg_instantiate(drbg, &addtl, coreref, pr); | |
1897 | BUG_ON(0 == ret); | |
541af946 SM |
1898 | /* all tests passed */ |
1899 | rc = 0; | |
1900 | ||
1901 | pr_devel("DRBG: Sanity tests for failure code paths successfully " | |
1902 | "completed\n"); | |
1903 | ||
1904 | drbg_uninstantiate(drbg); | |
1905 | outbuf: | |
1906 | kzfree(drbg); | |
1907 | return rc; | |
1908 | #else /* CONFIG_CRYPTO_FIPS */ | |
1909 | return 0; | |
1910 | #endif /* CONFIG_CRYPTO_FIPS */ | |
1911 | } | |
1912 | ||
1913 | static struct crypto_alg drbg_algs[22]; | |
1914 | ||
1915 | /* | |
1916 | * Fill the array drbg_algs used to register the different DRBGs | |
1917 | * with the kernel crypto API. To fill the array, the information | |
1918 | * from drbg_cores[] is used. | |
1919 | */ | |
1920 | static inline void __init drbg_fill_array(struct crypto_alg *alg, | |
1921 | const struct drbg_core *core, int pr) | |
1922 | { | |
1923 | int pos = 0; | |
1924 | static int priority = 100; | |
1925 | ||
1926 | memset(alg, 0, sizeof(struct crypto_alg)); | |
1927 | memcpy(alg->cra_name, "stdrng", 6); | |
1928 | if (pr) { | |
1929 | memcpy(alg->cra_driver_name, "drbg_pr_", 8); | |
1930 | pos = 8; | |
1931 | } else { | |
1932 | memcpy(alg->cra_driver_name, "drbg_nopr_", 10); | |
1933 | pos = 10; | |
1934 | } | |
1935 | memcpy(alg->cra_driver_name + pos, core->cra_name, | |
1936 | strlen(core->cra_name)); | |
1937 | ||
1938 | alg->cra_priority = priority; | |
1939 | priority++; | |
1940 | /* | |
1941 | * If FIPS mode enabled, the selected DRBG shall have the | |
1942 | * highest cra_priority over other stdrng instances to ensure | |
1943 | * it is selected. | |
1944 | */ | |
1945 | if (fips_enabled) | |
1946 | alg->cra_priority += 200; | |
1947 | ||
1948 | alg->cra_flags = CRYPTO_ALG_TYPE_RNG; | |
1949 | alg->cra_ctxsize = sizeof(struct drbg_state); | |
1950 | alg->cra_type = &crypto_rng_type; | |
1951 | alg->cra_module = THIS_MODULE; | |
1952 | alg->cra_init = drbg_kcapi_init; | |
1953 | alg->cra_exit = drbg_kcapi_cleanup; | |
1954 | alg->cra_u.rng.rng_make_random = drbg_kcapi_random; | |
1955 | alg->cra_u.rng.rng_reset = drbg_kcapi_reset; | |
1956 | alg->cra_u.rng.seedsize = 0; | |
1957 | } | |
1958 | ||
1959 | static int __init drbg_init(void) | |
1960 | { | |
1961 | unsigned int i = 0; /* pointer to drbg_algs */ | |
1962 | unsigned int j = 0; /* pointer to drbg_cores */ | |
1963 | int ret = -EFAULT; | |
1964 | ||
1965 | ret = drbg_healthcheck_sanity(); | |
1966 | if (ret) | |
1967 | return ret; | |
1968 | ||
1969 | if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) { | |
1970 | pr_info("DRBG: Cannot register all DRBG types" | |
a9089571 | 1971 | "(slots needed: %zu, slots available: %zu)\n", |
541af946 SM |
1972 | ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs)); |
1973 | return ret; | |
1974 | } | |
1975 | ||
1976 | /* | |
1977 | * each DRBG definition can be used with PR and without PR, thus | |
1978 | * we instantiate each DRBG in drbg_cores[] twice. | |
1979 | * | |
1980 | * As the order of placing them into the drbg_algs array matters | |
1981 | * (the later DRBGs receive a higher cra_priority) we register the | |
1982 | * prediction resistance DRBGs first as the should not be too | |
1983 | * interesting. | |
1984 | */ | |
1985 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
1986 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1); | |
1987 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
1988 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0); | |
1989 | return crypto_register_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); | |
1990 | } | |
1991 | ||
96956aef | 1992 | static void __exit drbg_exit(void) |
541af946 SM |
1993 | { |
1994 | crypto_unregister_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); | |
1995 | } | |
1996 | ||
1997 | module_init(drbg_init); | |
1998 | module_exit(drbg_exit); | |
e25e47ec SM |
1999 | #ifndef CRYPTO_DRBG_HASH_STRING |
2000 | #define CRYPTO_DRBG_HASH_STRING "" | |
541af946 | 2001 | #endif |
e25e47ec SM |
2002 | #ifndef CRYPTO_DRBG_HMAC_STRING |
2003 | #define CRYPTO_DRBG_HMAC_STRING "" | |
541af946 | 2004 | #endif |
e25e47ec SM |
2005 | #ifndef CRYPTO_DRBG_CTR_STRING |
2006 | #define CRYPTO_DRBG_CTR_STRING "" | |
541af946 | 2007 | #endif |
e25e47ec SM |
2008 | MODULE_LICENSE("GPL"); |
2009 | MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); | |
2010 | MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) " | |
2011 | "using following cores: " | |
2012 | CRYPTO_DRBG_HASH_STRING | |
2013 | CRYPTO_DRBG_HMAC_STRING | |
2014 | CRYPTO_DRBG_CTR_STRING); |