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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> | |
101 | ||
541af946 SM |
102 | /*************************************************************** |
103 | * Backend cipher definitions available to DRBG | |
104 | ***************************************************************/ | |
105 | ||
106 | /* | |
107 | * The order of the DRBG definitions here matter: every DRBG is registered | |
108 | * as stdrng. Each DRBG receives an increasing cra_priority values the later | |
109 | * they are defined in this array (see drbg_fill_array). | |
110 | * | |
111 | * HMAC DRBGs are favored over Hash DRBGs over CTR DRBGs, and | |
112 | * the SHA256 / AES 256 over other ciphers. Thus, the favored | |
113 | * DRBGs are the latest entries in this array. | |
114 | */ | |
115 | static const struct drbg_core drbg_cores[] = { | |
116 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
117 | { | |
118 | .flags = DRBG_CTR | DRBG_STRENGTH128, | |
119 | .statelen = 32, /* 256 bits as defined in 10.2.1 */ | |
541af946 SM |
120 | .blocklen_bytes = 16, |
121 | .cra_name = "ctr_aes128", | |
122 | .backend_cra_name = "ecb(aes)", | |
123 | }, { | |
124 | .flags = DRBG_CTR | DRBG_STRENGTH192, | |
125 | .statelen = 40, /* 320 bits as defined in 10.2.1 */ | |
541af946 SM |
126 | .blocklen_bytes = 16, |
127 | .cra_name = "ctr_aes192", | |
128 | .backend_cra_name = "ecb(aes)", | |
129 | }, { | |
130 | .flags = DRBG_CTR | DRBG_STRENGTH256, | |
131 | .statelen = 48, /* 384 bits as defined in 10.2.1 */ | |
541af946 SM |
132 | .blocklen_bytes = 16, |
133 | .cra_name = "ctr_aes256", | |
134 | .backend_cra_name = "ecb(aes)", | |
135 | }, | |
136 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
137 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
138 | { | |
139 | .flags = DRBG_HASH | DRBG_STRENGTH128, | |
140 | .statelen = 55, /* 440 bits */ | |
541af946 SM |
141 | .blocklen_bytes = 20, |
142 | .cra_name = "sha1", | |
143 | .backend_cra_name = "sha1", | |
144 | }, { | |
145 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
146 | .statelen = 111, /* 888 bits */ | |
541af946 SM |
147 | .blocklen_bytes = 48, |
148 | .cra_name = "sha384", | |
149 | .backend_cra_name = "sha384", | |
150 | }, { | |
151 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
152 | .statelen = 111, /* 888 bits */ | |
541af946 SM |
153 | .blocklen_bytes = 64, |
154 | .cra_name = "sha512", | |
155 | .backend_cra_name = "sha512", | |
156 | }, { | |
157 | .flags = DRBG_HASH | DRBG_STRENGTH256, | |
158 | .statelen = 55, /* 440 bits */ | |
541af946 SM |
159 | .blocklen_bytes = 32, |
160 | .cra_name = "sha256", | |
161 | .backend_cra_name = "sha256", | |
162 | }, | |
163 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
164 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
165 | { | |
5b635e28 | 166 | .flags = DRBG_HMAC | DRBG_STRENGTH128, |
541af946 | 167 | .statelen = 20, /* block length of cipher */ |
541af946 SM |
168 | .blocklen_bytes = 20, |
169 | .cra_name = "hmac_sha1", | |
170 | .backend_cra_name = "hmac(sha1)", | |
171 | }, { | |
172 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
173 | .statelen = 48, /* block length of cipher */ | |
541af946 SM |
174 | .blocklen_bytes = 48, |
175 | .cra_name = "hmac_sha384", | |
176 | .backend_cra_name = "hmac(sha384)", | |
177 | }, { | |
178 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
179 | .statelen = 64, /* block length of cipher */ | |
541af946 SM |
180 | .blocklen_bytes = 64, |
181 | .cra_name = "hmac_sha512", | |
182 | .backend_cra_name = "hmac(sha512)", | |
183 | }, { | |
184 | .flags = DRBG_HMAC | DRBG_STRENGTH256, | |
185 | .statelen = 32, /* block length of cipher */ | |
541af946 SM |
186 | .blocklen_bytes = 32, |
187 | .cra_name = "hmac_sha256", | |
188 | .backend_cra_name = "hmac(sha256)", | |
189 | }, | |
190 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
191 | }; | |
192 | ||
193 | /****************************************************************** | |
194 | * Generic helper functions | |
195 | ******************************************************************/ | |
196 | ||
197 | /* | |
198 | * Return strength of DRBG according to SP800-90A section 8.4 | |
199 | * | |
200 | * @flags DRBG flags reference | |
201 | * | |
202 | * Return: normalized strength in *bytes* value or 32 as default | |
203 | * to counter programming errors | |
204 | */ | |
205 | static inline unsigned short drbg_sec_strength(drbg_flag_t flags) | |
206 | { | |
207 | switch (flags & DRBG_STRENGTH_MASK) { | |
208 | case DRBG_STRENGTH128: | |
209 | return 16; | |
210 | case DRBG_STRENGTH192: | |
211 | return 24; | |
212 | case DRBG_STRENGTH256: | |
213 | return 32; | |
214 | default: | |
215 | return 32; | |
216 | } | |
217 | } | |
218 | ||
219 | /* | |
220 | * FIPS 140-2 continuous self test | |
221 | * The test is performed on the result of one round of the output | |
222 | * function. Thus, the function implicitly knows the size of the | |
223 | * buffer. | |
224 | * | |
541af946 SM |
225 | * @drbg DRBG handle |
226 | * @buf output buffer of random data to be checked | |
227 | * | |
228 | * return: | |
229 | * true on success | |
230 | * false on error | |
231 | */ | |
232 | static bool drbg_fips_continuous_test(struct drbg_state *drbg, | |
233 | const unsigned char *buf) | |
234 | { | |
235 | #ifdef CONFIG_CRYPTO_FIPS | |
236 | int ret = 0; | |
237 | /* skip test if we test the overall system */ | |
238 | if (drbg->test_data) | |
239 | return true; | |
240 | /* only perform test in FIPS mode */ | |
241 | if (0 == fips_enabled) | |
242 | return true; | |
243 | if (!drbg->fips_primed) { | |
244 | /* Priming of FIPS test */ | |
245 | memcpy(drbg->prev, buf, drbg_blocklen(drbg)); | |
246 | drbg->fips_primed = true; | |
247 | /* return false due to priming, i.e. another round is needed */ | |
248 | return false; | |
249 | } | |
250 | ret = memcmp(drbg->prev, buf, drbg_blocklen(drbg)); | |
905b42e5 SM |
251 | if (!ret) |
252 | panic("DRBG continuous self test failed\n"); | |
541af946 SM |
253 | memcpy(drbg->prev, buf, drbg_blocklen(drbg)); |
254 | /* the test shall pass when the two compared values are not equal */ | |
255 | return ret != 0; | |
256 | #else | |
257 | return true; | |
258 | #endif /* CONFIG_CRYPTO_FIPS */ | |
259 | } | |
260 | ||
261 | /* | |
262 | * Convert an integer into a byte representation of this integer. | |
263 | * The byte representation is big-endian | |
264 | * | |
541af946 | 265 | * @val value to be converted |
72f3e00d SM |
266 | * @buf buffer holding the converted integer -- caller must ensure that |
267 | * buffer size is at least 32 bit | |
541af946 SM |
268 | */ |
269 | #if (defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR)) | |
72f3e00d | 270 | static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf) |
541af946 | 271 | { |
72f3e00d | 272 | struct s { |
7c8ae03f | 273 | __be32 conv; |
72f3e00d SM |
274 | }; |
275 | struct s *conversion = (struct s *) buf; | |
541af946 | 276 | |
72f3e00d | 277 | conversion->conv = cpu_to_be32(val); |
541af946 | 278 | } |
541af946 SM |
279 | #endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */ |
280 | ||
281 | /****************************************************************** | |
282 | * CTR DRBG callback functions | |
283 | ******************************************************************/ | |
284 | ||
285 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
e25e47ec | 286 | #define CRYPTO_DRBG_CTR_STRING "CTR " |
0653a7cf SM |
287 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes256"); |
288 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes256"); | |
289 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes192"); | |
290 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192"); | |
291 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128"); | |
292 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128"); | |
62b62b6e | 293 | |
541af946 SM |
294 | static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key, |
295 | unsigned char *outval, const struct drbg_string *in); | |
296 | static int drbg_init_sym_kernel(struct drbg_state *drbg); | |
297 | static int drbg_fini_sym_kernel(struct drbg_state *drbg); | |
298 | ||
299 | /* BCC function for CTR DRBG as defined in 10.4.3 */ | |
300 | static int drbg_ctr_bcc(struct drbg_state *drbg, | |
301 | unsigned char *out, const unsigned char *key, | |
8c987166 | 302 | struct list_head *in) |
541af946 | 303 | { |
8c987166 SM |
304 | int ret = 0; |
305 | struct drbg_string *curr = NULL; | |
541af946 | 306 | struct drbg_string data; |
8c987166 | 307 | short cnt = 0; |
541af946 SM |
308 | |
309 | drbg_string_fill(&data, out, drbg_blocklen(drbg)); | |
310 | ||
311 | /* 10.4.3 step 1 */ | |
312 | memset(out, 0, drbg_blocklen(drbg)); | |
313 | ||
314 | /* 10.4.3 step 2 / 4 */ | |
8c987166 SM |
315 | list_for_each_entry(curr, in, list) { |
316 | const unsigned char *pos = curr->buf; | |
317 | size_t len = curr->len; | |
541af946 | 318 | /* 10.4.3 step 4.1 */ |
8c987166 SM |
319 | while (len) { |
320 | /* 10.4.3 step 4.2 */ | |
321 | if (drbg_blocklen(drbg) == cnt) { | |
322 | cnt = 0; | |
323 | ret = drbg_kcapi_sym(drbg, key, out, &data); | |
324 | if (ret) | |
325 | return ret; | |
541af946 | 326 | } |
8c987166 SM |
327 | out[cnt] ^= *pos; |
328 | pos++; | |
329 | cnt++; | |
330 | len--; | |
541af946 | 331 | } |
541af946 | 332 | } |
8c987166 SM |
333 | /* 10.4.3 step 4.2 for last block */ |
334 | if (cnt) | |
335 | ret = drbg_kcapi_sym(drbg, key, out, &data); | |
336 | ||
337 | return ret; | |
541af946 SM |
338 | } |
339 | ||
340 | /* | |
341 | * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df | |
342 | * (and drbg_ctr_bcc, but this function does not need any temporary buffers), | |
343 | * the scratchpad is used as follows: | |
344 | * drbg_ctr_update: | |
345 | * temp | |
346 | * start: drbg->scratchpad | |
347 | * length: drbg_statelen(drbg) + drbg_blocklen(drbg) | |
348 | * note: the cipher writing into this variable works | |
349 | * blocklen-wise. Now, when the statelen is not a multiple | |
350 | * of blocklen, the generateion loop below "spills over" | |
351 | * by at most blocklen. Thus, we need to give sufficient | |
352 | * memory. | |
353 | * df_data | |
354 | * start: drbg->scratchpad + | |
355 | * drbg_statelen(drbg) + drbg_blocklen(drbg) | |
356 | * length: drbg_statelen(drbg) | |
357 | * | |
358 | * drbg_ctr_df: | |
359 | * pad | |
360 | * start: df_data + drbg_statelen(drbg) | |
361 | * length: drbg_blocklen(drbg) | |
362 | * iv | |
363 | * start: pad + drbg_blocklen(drbg) | |
364 | * length: drbg_blocklen(drbg) | |
365 | * temp | |
366 | * start: iv + drbg_blocklen(drbg) | |
8fecaad7 SM |
367 | * length: drbg_satelen(drbg) + drbg_blocklen(drbg) |
368 | * note: temp is the buffer that the BCC function operates | |
369 | * on. BCC operates blockwise. drbg_statelen(drbg) | |
370 | * is sufficient when the DRBG state length is a multiple | |
371 | * of the block size. For AES192 (and maybe other ciphers) | |
372 | * this is not correct and the length for temp is | |
373 | * insufficient (yes, that also means for such ciphers, | |
374 | * the final output of all BCC rounds are truncated). | |
375 | * Therefore, add drbg_blocklen(drbg) to cover all | |
376 | * possibilities. | |
541af946 SM |
377 | */ |
378 | ||
379 | /* Derivation Function for CTR DRBG as defined in 10.4.2 */ | |
380 | static int drbg_ctr_df(struct drbg_state *drbg, | |
381 | unsigned char *df_data, size_t bytes_to_return, | |
8c987166 | 382 | struct list_head *seedlist) |
541af946 SM |
383 | { |
384 | int ret = -EFAULT; | |
385 | unsigned char L_N[8]; | |
386 | /* S3 is input */ | |
387 | struct drbg_string S1, S2, S4, cipherin; | |
8c987166 | 388 | LIST_HEAD(bcc_list); |
541af946 SM |
389 | unsigned char *pad = df_data + drbg_statelen(drbg); |
390 | unsigned char *iv = pad + drbg_blocklen(drbg); | |
391 | unsigned char *temp = iv + drbg_blocklen(drbg); | |
392 | size_t padlen = 0; | |
393 | unsigned int templen = 0; | |
394 | /* 10.4.2 step 7 */ | |
395 | unsigned int i = 0; | |
396 | /* 10.4.2 step 8 */ | |
397 | const unsigned char *K = (unsigned char *) | |
398 | "\x00\x01\x02\x03\x04\x05\x06\x07" | |
399 | "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" | |
400 | "\x10\x11\x12\x13\x14\x15\x16\x17" | |
401 | "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"; | |
402 | unsigned char *X; | |
403 | size_t generated_len = 0; | |
404 | size_t inputlen = 0; | |
8c987166 | 405 | struct drbg_string *seed = NULL; |
541af946 SM |
406 | |
407 | memset(pad, 0, drbg_blocklen(drbg)); | |
408 | memset(iv, 0, drbg_blocklen(drbg)); | |
409 | memset(temp, 0, drbg_statelen(drbg)); | |
410 | ||
411 | /* 10.4.2 step 1 is implicit as we work byte-wise */ | |
412 | ||
413 | /* 10.4.2 step 2 */ | |
414 | if ((512/8) < bytes_to_return) | |
415 | return -EINVAL; | |
416 | ||
417 | /* 10.4.2 step 2 -- calculate the entire length of all input data */ | |
8c987166 SM |
418 | list_for_each_entry(seed, seedlist, list) |
419 | inputlen += seed->len; | |
72f3e00d | 420 | drbg_cpu_to_be32(inputlen, &L_N[0]); |
541af946 SM |
421 | |
422 | /* 10.4.2 step 3 */ | |
72f3e00d | 423 | drbg_cpu_to_be32(bytes_to_return, &L_N[4]); |
541af946 SM |
424 | |
425 | /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */ | |
426 | padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg)); | |
427 | /* wrap the padlen appropriately */ | |
428 | if (padlen) | |
429 | padlen = drbg_blocklen(drbg) - padlen; | |
430 | /* | |
431 | * pad / padlen contains the 0x80 byte and the following zero bytes. | |
432 | * As the calculated padlen value only covers the number of zero | |
433 | * bytes, this value has to be incremented by one for the 0x80 byte. | |
434 | */ | |
435 | padlen++; | |
436 | pad[0] = 0x80; | |
437 | ||
438 | /* 10.4.2 step 4 -- first fill the linked list and then order it */ | |
439 | drbg_string_fill(&S1, iv, drbg_blocklen(drbg)); | |
8c987166 | 440 | list_add_tail(&S1.list, &bcc_list); |
541af946 | 441 | drbg_string_fill(&S2, L_N, sizeof(L_N)); |
8c987166 SM |
442 | list_add_tail(&S2.list, &bcc_list); |
443 | list_splice_tail(seedlist, &bcc_list); | |
541af946 | 444 | drbg_string_fill(&S4, pad, padlen); |
8c987166 | 445 | list_add_tail(&S4.list, &bcc_list); |
541af946 SM |
446 | |
447 | /* 10.4.2 step 9 */ | |
448 | while (templen < (drbg_keylen(drbg) + (drbg_blocklen(drbg)))) { | |
449 | /* | |
450 | * 10.4.2 step 9.1 - the padding is implicit as the buffer | |
451 | * holds zeros after allocation -- even the increment of i | |
452 | * is irrelevant as the increment remains within length of i | |
453 | */ | |
72f3e00d | 454 | drbg_cpu_to_be32(i, iv); |
541af946 | 455 | /* 10.4.2 step 9.2 -- BCC and concatenation with temp */ |
8c987166 | 456 | ret = drbg_ctr_bcc(drbg, temp + templen, K, &bcc_list); |
541af946 SM |
457 | if (ret) |
458 | goto out; | |
459 | /* 10.4.2 step 9.3 */ | |
460 | i++; | |
461 | templen += drbg_blocklen(drbg); | |
462 | } | |
463 | ||
464 | /* 10.4.2 step 11 */ | |
465 | X = temp + (drbg_keylen(drbg)); | |
466 | drbg_string_fill(&cipherin, X, drbg_blocklen(drbg)); | |
467 | ||
468 | /* 10.4.2 step 12: overwriting of outval is implemented in next step */ | |
469 | ||
470 | /* 10.4.2 step 13 */ | |
471 | while (generated_len < bytes_to_return) { | |
472 | short blocklen = 0; | |
473 | /* | |
474 | * 10.4.2 step 13.1: the truncation of the key length is | |
475 | * implicit as the key is only drbg_blocklen in size based on | |
476 | * the implementation of the cipher function callback | |
477 | */ | |
478 | ret = drbg_kcapi_sym(drbg, temp, X, &cipherin); | |
479 | if (ret) | |
480 | goto out; | |
481 | blocklen = (drbg_blocklen(drbg) < | |
482 | (bytes_to_return - generated_len)) ? | |
483 | drbg_blocklen(drbg) : | |
484 | (bytes_to_return - generated_len); | |
485 | /* 10.4.2 step 13.2 and 14 */ | |
486 | memcpy(df_data + generated_len, X, blocklen); | |
487 | generated_len += blocklen; | |
488 | } | |
489 | ||
490 | ret = 0; | |
491 | ||
492 | out: | |
1471f09f HX |
493 | memset(iv, 0, drbg_blocklen(drbg)); |
494 | memset(temp, 0, drbg_statelen(drbg)); | |
495 | memset(pad, 0, drbg_blocklen(drbg)); | |
541af946 SM |
496 | return ret; |
497 | } | |
498 | ||
72e7c25a SM |
499 | /* |
500 | * update function of CTR DRBG as defined in 10.2.1.2 | |
501 | * | |
502 | * The reseed variable has an enhanced meaning compared to the update | |
503 | * functions of the other DRBGs as follows: | |
504 | * 0 => initial seed from initialization | |
505 | * 1 => reseed via drbg_seed | |
506 | * 2 => first invocation from drbg_ctr_update when addtl is present. In | |
507 | * this case, the df_data scratchpad is not deleted so that it is | |
508 | * available for another calls to prevent calling the DF function | |
509 | * again. | |
510 | * 3 => second invocation from drbg_ctr_update. When the update function | |
511 | * was called with addtl, the df_data memory already contains the | |
512 | * DFed addtl information and we do not need to call DF again. | |
513 | */ | |
8c987166 SM |
514 | static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, |
515 | int reseed) | |
541af946 SM |
516 | { |
517 | int ret = -EFAULT; | |
518 | /* 10.2.1.2 step 1 */ | |
519 | unsigned char *temp = drbg->scratchpad; | |
520 | unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) + | |
521 | drbg_blocklen(drbg); | |
522 | unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */ | |
523 | unsigned int len = 0; | |
524 | struct drbg_string cipherin; | |
541af946 SM |
525 | |
526 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); | |
72e7c25a SM |
527 | if (3 > reseed) |
528 | memset(df_data, 0, drbg_statelen(drbg)); | |
541af946 SM |
529 | |
530 | /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */ | |
8c987166 SM |
531 | if (seed) { |
532 | ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed); | |
541af946 SM |
533 | if (ret) |
534 | goto out; | |
535 | } | |
536 | ||
537 | drbg_string_fill(&cipherin, drbg->V, drbg_blocklen(drbg)); | |
538 | /* | |
539 | * 10.2.1.3.2 steps 2 and 3 are already covered as the allocation | |
540 | * zeroizes all memory during initialization | |
541 | */ | |
542 | while (len < (drbg_statelen(drbg))) { | |
543 | /* 10.2.1.2 step 2.1 */ | |
41a84982 | 544 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
545 | /* |
546 | * 10.2.1.2 step 2.2 */ | |
547 | ret = drbg_kcapi_sym(drbg, drbg->C, temp + len, &cipherin); | |
548 | if (ret) | |
549 | goto out; | |
550 | /* 10.2.1.2 step 2.3 and 3 */ | |
551 | len += drbg_blocklen(drbg); | |
552 | } | |
553 | ||
554 | /* 10.2.1.2 step 4 */ | |
555 | temp_p = temp; | |
556 | df_data_p = df_data; | |
557 | for (len = 0; len < drbg_statelen(drbg); len++) { | |
558 | *temp_p ^= *df_data_p; | |
559 | df_data_p++; temp_p++; | |
560 | } | |
561 | ||
562 | /* 10.2.1.2 step 5 */ | |
563 | memcpy(drbg->C, temp, drbg_keylen(drbg)); | |
564 | /* 10.2.1.2 step 6 */ | |
565 | memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg)); | |
566 | ret = 0; | |
567 | ||
568 | out: | |
1471f09f | 569 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
72e7c25a | 570 | if (2 != reseed) |
1471f09f | 571 | memset(df_data, 0, drbg_statelen(drbg)); |
541af946 SM |
572 | return ret; |
573 | } | |
574 | ||
575 | /* | |
576 | * scratchpad use: drbg_ctr_update is called independently from | |
577 | * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused | |
578 | */ | |
579 | /* Generate function of CTR DRBG as defined in 10.2.1.5.2 */ | |
580 | static int drbg_ctr_generate(struct drbg_state *drbg, | |
581 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 582 | struct list_head *addtl) |
541af946 SM |
583 | { |
584 | int len = 0; | |
585 | int ret = 0; | |
586 | struct drbg_string data; | |
541af946 SM |
587 | |
588 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); | |
589 | ||
590 | /* 10.2.1.5.2 step 2 */ | |
27e4de2b SM |
591 | if (addtl && !list_empty(addtl)) { |
592 | ret = drbg_ctr_update(drbg, addtl, 2); | |
541af946 SM |
593 | if (ret) |
594 | return 0; | |
595 | } | |
596 | ||
597 | /* 10.2.1.5.2 step 4.1 */ | |
41a84982 | 598 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
599 | drbg_string_fill(&data, drbg->V, drbg_blocklen(drbg)); |
600 | while (len < buflen) { | |
601 | int outlen = 0; | |
602 | /* 10.2.1.5.2 step 4.2 */ | |
603 | ret = drbg_kcapi_sym(drbg, drbg->C, drbg->scratchpad, &data); | |
604 | if (ret) { | |
605 | len = ret; | |
606 | goto out; | |
607 | } | |
608 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
609 | drbg_blocklen(drbg) : (buflen - len); | |
610 | if (!drbg_fips_continuous_test(drbg, drbg->scratchpad)) { | |
611 | /* 10.2.1.5.2 step 6 */ | |
41a84982 | 612 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
613 | continue; |
614 | } | |
615 | /* 10.2.1.5.2 step 4.3 */ | |
616 | memcpy(buf + len, drbg->scratchpad, outlen); | |
617 | len += outlen; | |
618 | /* 10.2.1.5.2 step 6 */ | |
619 | if (len < buflen) | |
41a84982 | 620 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
621 | } |
622 | ||
72e7c25a SM |
623 | /* 10.2.1.5.2 step 6 */ |
624 | ret = drbg_ctr_update(drbg, NULL, 3); | |
541af946 SM |
625 | if (ret) |
626 | len = ret; | |
627 | ||
628 | out: | |
1471f09f | 629 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
630 | return len; |
631 | } | |
632 | ||
633 | static struct drbg_state_ops drbg_ctr_ops = { | |
634 | .update = drbg_ctr_update, | |
635 | .generate = drbg_ctr_generate, | |
636 | .crypto_init = drbg_init_sym_kernel, | |
637 | .crypto_fini = drbg_fini_sym_kernel, | |
638 | }; | |
639 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
640 | ||
641 | /****************************************************************** | |
642 | * HMAC DRBG callback functions | |
643 | ******************************************************************/ | |
644 | ||
645 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
646 | static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key, | |
8c987166 | 647 | unsigned char *outval, const struct list_head *in); |
541af946 SM |
648 | static int drbg_init_hash_kernel(struct drbg_state *drbg); |
649 | static int drbg_fini_hash_kernel(struct drbg_state *drbg); | |
650 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
651 | ||
652 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
e25e47ec | 653 | #define CRYPTO_DRBG_HMAC_STRING "HMAC " |
0653a7cf SM |
654 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512"); |
655 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512"); | |
656 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384"); | |
657 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384"); | |
658 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256"); | |
659 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256"); | |
660 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1"); | |
661 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1"); | |
62b62b6e | 662 | |
541af946 | 663 | /* update function of HMAC DRBG as defined in 10.1.2.2 */ |
8c987166 SM |
664 | static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed, |
665 | int reseed) | |
541af946 SM |
666 | { |
667 | int ret = -EFAULT; | |
668 | int i = 0; | |
8c987166 SM |
669 | struct drbg_string seed1, seed2, vdata; |
670 | LIST_HEAD(seedlist); | |
671 | LIST_HEAD(vdatalist); | |
541af946 | 672 | |
f072f0e0 SM |
673 | if (!reseed) |
674 | /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */ | |
541af946 | 675 | memset(drbg->V, 1, drbg_statelen(drbg)); |
541af946 SM |
676 | |
677 | drbg_string_fill(&seed1, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 678 | list_add_tail(&seed1.list, &seedlist); |
541af946 SM |
679 | /* buffer of seed2 will be filled in for loop below with one byte */ |
680 | drbg_string_fill(&seed2, NULL, 1); | |
8c987166 | 681 | list_add_tail(&seed2.list, &seedlist); |
541af946 | 682 | /* input data of seed is allowed to be NULL at this point */ |
8c987166 SM |
683 | if (seed) |
684 | list_splice_tail(seed, &seedlist); | |
541af946 | 685 | |
8c987166 SM |
686 | drbg_string_fill(&vdata, drbg->V, drbg_statelen(drbg)); |
687 | list_add_tail(&vdata.list, &vdatalist); | |
541af946 SM |
688 | for (i = 2; 0 < i; i--) { |
689 | /* first round uses 0x0, second 0x1 */ | |
690 | unsigned char prefix = DRBG_PREFIX0; | |
691 | if (1 == i) | |
692 | prefix = DRBG_PREFIX1; | |
693 | /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */ | |
694 | seed2.buf = &prefix; | |
8c987166 | 695 | ret = drbg_kcapi_hash(drbg, drbg->C, drbg->C, &seedlist); |
541af946 SM |
696 | if (ret) |
697 | return ret; | |
698 | ||
699 | /* 10.1.2.2 step 2 and 5 -- HMAC for V */ | |
8c987166 | 700 | ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &vdatalist); |
541af946 SM |
701 | if (ret) |
702 | return ret; | |
703 | ||
704 | /* 10.1.2.2 step 3 */ | |
8c987166 | 705 | if (!seed) |
541af946 SM |
706 | return ret; |
707 | } | |
708 | ||
709 | return 0; | |
710 | } | |
711 | ||
712 | /* generate function of HMAC DRBG as defined in 10.1.2.5 */ | |
713 | static int drbg_hmac_generate(struct drbg_state *drbg, | |
714 | unsigned char *buf, | |
715 | unsigned int buflen, | |
27e4de2b | 716 | struct list_head *addtl) |
541af946 SM |
717 | { |
718 | int len = 0; | |
719 | int ret = 0; | |
720 | struct drbg_string data; | |
8c987166 | 721 | LIST_HEAD(datalist); |
541af946 SM |
722 | |
723 | /* 10.1.2.5 step 2 */ | |
27e4de2b SM |
724 | if (addtl && !list_empty(addtl)) { |
725 | ret = drbg_hmac_update(drbg, addtl, 1); | |
541af946 SM |
726 | if (ret) |
727 | return ret; | |
728 | } | |
729 | ||
730 | drbg_string_fill(&data, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 731 | list_add_tail(&data.list, &datalist); |
541af946 SM |
732 | while (len < buflen) { |
733 | unsigned int outlen = 0; | |
734 | /* 10.1.2.5 step 4.1 */ | |
8c987166 | 735 | ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &datalist); |
541af946 SM |
736 | if (ret) |
737 | return ret; | |
738 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
739 | drbg_blocklen(drbg) : (buflen - len); | |
740 | if (!drbg_fips_continuous_test(drbg, drbg->V)) | |
741 | continue; | |
742 | ||
743 | /* 10.1.2.5 step 4.2 */ | |
744 | memcpy(buf + len, drbg->V, outlen); | |
745 | len += outlen; | |
746 | } | |
747 | ||
748 | /* 10.1.2.5 step 6 */ | |
27e4de2b SM |
749 | if (addtl && !list_empty(addtl)) |
750 | ret = drbg_hmac_update(drbg, addtl, 1); | |
751 | else | |
8c987166 | 752 | ret = drbg_hmac_update(drbg, NULL, 1); |
541af946 SM |
753 | if (ret) |
754 | return ret; | |
755 | ||
756 | return len; | |
757 | } | |
758 | ||
759 | static struct drbg_state_ops drbg_hmac_ops = { | |
760 | .update = drbg_hmac_update, | |
761 | .generate = drbg_hmac_generate, | |
762 | .crypto_init = drbg_init_hash_kernel, | |
763 | .crypto_fini = drbg_fini_hash_kernel, | |
764 | ||
765 | }; | |
766 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
767 | ||
768 | /****************************************************************** | |
769 | * Hash DRBG callback functions | |
770 | ******************************************************************/ | |
771 | ||
772 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
e25e47ec | 773 | #define CRYPTO_DRBG_HASH_STRING "HASH " |
0653a7cf SM |
774 | MODULE_ALIAS_CRYPTO("drbg_pr_sha512"); |
775 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha512"); | |
776 | MODULE_ALIAS_CRYPTO("drbg_pr_sha384"); | |
777 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha384"); | |
778 | MODULE_ALIAS_CRYPTO("drbg_pr_sha256"); | |
779 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha256"); | |
780 | MODULE_ALIAS_CRYPTO("drbg_pr_sha1"); | |
781 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha1"); | |
62b62b6e | 782 | |
41a84982 SM |
783 | /* |
784 | * Increment buffer | |
785 | * | |
786 | * @dst buffer to increment | |
787 | * @add value to add | |
788 | */ | |
789 | static inline void drbg_add_buf(unsigned char *dst, size_t dstlen, | |
790 | const unsigned char *add, size_t addlen) | |
791 | { | |
792 | /* implied: dstlen > addlen */ | |
793 | unsigned char *dstptr; | |
794 | const unsigned char *addptr; | |
795 | unsigned int remainder = 0; | |
796 | size_t len = addlen; | |
797 | ||
798 | dstptr = dst + (dstlen-1); | |
799 | addptr = add + (addlen-1); | |
800 | while (len) { | |
801 | remainder += *dstptr + *addptr; | |
802 | *dstptr = remainder & 0xff; | |
803 | remainder >>= 8; | |
804 | len--; dstptr--; addptr--; | |
805 | } | |
806 | len = dstlen - addlen; | |
807 | while (len && remainder > 0) { | |
808 | remainder = *dstptr + 1; | |
809 | *dstptr = remainder & 0xff; | |
810 | remainder >>= 8; | |
811 | len--; dstptr--; | |
812 | } | |
813 | } | |
814 | ||
541af946 SM |
815 | /* |
816 | * scratchpad usage: as drbg_hash_update and drbg_hash_df are used | |
817 | * interlinked, the scratchpad is used as follows: | |
818 | * drbg_hash_update | |
819 | * start: drbg->scratchpad | |
820 | * length: drbg_statelen(drbg) | |
821 | * drbg_hash_df: | |
822 | * start: drbg->scratchpad + drbg_statelen(drbg) | |
823 | * length: drbg_blocklen(drbg) | |
824 | * | |
825 | * drbg_hash_process_addtl uses the scratchpad, but fully completes | |
826 | * before either of the functions mentioned before are invoked. Therefore, | |
827 | * drbg_hash_process_addtl does not need to be specifically considered. | |
828 | */ | |
829 | ||
830 | /* Derivation Function for Hash DRBG as defined in 10.4.1 */ | |
831 | static int drbg_hash_df(struct drbg_state *drbg, | |
832 | unsigned char *outval, size_t outlen, | |
8c987166 | 833 | struct list_head *entropylist) |
541af946 SM |
834 | { |
835 | int ret = 0; | |
836 | size_t len = 0; | |
837 | unsigned char input[5]; | |
838 | unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg); | |
8c987166 | 839 | struct drbg_string data; |
541af946 SM |
840 | |
841 | memset(tmp, 0, drbg_blocklen(drbg)); | |
842 | ||
843 | /* 10.4.1 step 3 */ | |
844 | input[0] = 1; | |
72f3e00d | 845 | drbg_cpu_to_be32((outlen * 8), &input[1]); |
541af946 SM |
846 | |
847 | /* 10.4.1 step 4.1 -- concatenation of data for input into hash */ | |
8c987166 SM |
848 | drbg_string_fill(&data, input, 5); |
849 | list_add(&data.list, entropylist); | |
541af946 SM |
850 | |
851 | /* 10.4.1 step 4 */ | |
852 | while (len < outlen) { | |
853 | short blocklen = 0; | |
854 | /* 10.4.1 step 4.1 */ | |
8c987166 | 855 | ret = drbg_kcapi_hash(drbg, NULL, tmp, entropylist); |
541af946 SM |
856 | if (ret) |
857 | goto out; | |
858 | /* 10.4.1 step 4.2 */ | |
859 | input[0]++; | |
860 | blocklen = (drbg_blocklen(drbg) < (outlen - len)) ? | |
861 | drbg_blocklen(drbg) : (outlen - len); | |
862 | memcpy(outval + len, tmp, blocklen); | |
863 | len += blocklen; | |
864 | } | |
865 | ||
866 | out: | |
1471f09f | 867 | memset(tmp, 0, drbg_blocklen(drbg)); |
541af946 SM |
868 | return ret; |
869 | } | |
870 | ||
871 | /* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */ | |
8c987166 | 872 | static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed, |
541af946 SM |
873 | int reseed) |
874 | { | |
875 | int ret = 0; | |
876 | struct drbg_string data1, data2; | |
8c987166 SM |
877 | LIST_HEAD(datalist); |
878 | LIST_HEAD(datalist2); | |
541af946 SM |
879 | unsigned char *V = drbg->scratchpad; |
880 | unsigned char prefix = DRBG_PREFIX1; | |
881 | ||
882 | memset(drbg->scratchpad, 0, drbg_statelen(drbg)); | |
883 | if (!seed) | |
884 | return -EINVAL; | |
885 | ||
886 | if (reseed) { | |
887 | /* 10.1.1.3 step 1 */ | |
888 | memcpy(V, drbg->V, drbg_statelen(drbg)); | |
889 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 890 | list_add_tail(&data1.list, &datalist); |
541af946 | 891 | drbg_string_fill(&data2, V, drbg_statelen(drbg)); |
8c987166 | 892 | list_add_tail(&data2.list, &datalist); |
541af946 | 893 | } |
8c987166 | 894 | list_splice_tail(seed, &datalist); |
541af946 SM |
895 | |
896 | /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */ | |
8c987166 | 897 | ret = drbg_hash_df(drbg, drbg->V, drbg_statelen(drbg), &datalist); |
541af946 SM |
898 | if (ret) |
899 | goto out; | |
900 | ||
901 | /* 10.1.1.2 / 10.1.1.3 step 4 */ | |
902 | prefix = DRBG_PREFIX0; | |
903 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 904 | list_add_tail(&data1.list, &datalist2); |
541af946 | 905 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 | 906 | list_add_tail(&data2.list, &datalist2); |
541af946 | 907 | /* 10.1.1.2 / 10.1.1.3 step 4 */ |
8c987166 | 908 | ret = drbg_hash_df(drbg, drbg->C, drbg_statelen(drbg), &datalist2); |
541af946 SM |
909 | |
910 | out: | |
1471f09f | 911 | memset(drbg->scratchpad, 0, drbg_statelen(drbg)); |
541af946 SM |
912 | return ret; |
913 | } | |
914 | ||
915 | /* processing of additional information string for Hash DRBG */ | |
916 | static int drbg_hash_process_addtl(struct drbg_state *drbg, | |
27e4de2b | 917 | struct list_head *addtl) |
541af946 SM |
918 | { |
919 | int ret = 0; | |
920 | struct drbg_string data1, data2; | |
8c987166 | 921 | LIST_HEAD(datalist); |
541af946 SM |
922 | unsigned char prefix = DRBG_PREFIX2; |
923 | ||
924 | /* this is value w as per documentation */ | |
925 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); | |
926 | ||
927 | /* 10.1.1.4 step 2 */ | |
27e4de2b | 928 | if (!addtl || list_empty(addtl)) |
541af946 SM |
929 | return 0; |
930 | ||
931 | /* 10.1.1.4 step 2a */ | |
932 | drbg_string_fill(&data1, &prefix, 1); | |
933 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); | |
8c987166 SM |
934 | list_add_tail(&data1.list, &datalist); |
935 | list_add_tail(&data2.list, &datalist); | |
27e4de2b | 936 | list_splice_tail(addtl, &datalist); |
8c987166 | 937 | ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist); |
541af946 SM |
938 | if (ret) |
939 | goto out; | |
940 | ||
941 | /* 10.1.1.4 step 2b */ | |
942 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
943 | drbg->scratchpad, drbg_blocklen(drbg)); | |
944 | ||
945 | out: | |
1471f09f | 946 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
947 | return ret; |
948 | } | |
949 | ||
950 | /* Hashgen defined in 10.1.1.4 */ | |
951 | static int drbg_hash_hashgen(struct drbg_state *drbg, | |
952 | unsigned char *buf, | |
953 | unsigned int buflen) | |
954 | { | |
955 | int len = 0; | |
956 | int ret = 0; | |
957 | unsigned char *src = drbg->scratchpad; | |
958 | unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg); | |
959 | struct drbg_string data; | |
8c987166 | 960 | LIST_HEAD(datalist); |
541af946 SM |
961 | |
962 | memset(src, 0, drbg_statelen(drbg)); | |
963 | memset(dst, 0, drbg_blocklen(drbg)); | |
964 | ||
965 | /* 10.1.1.4 step hashgen 2 */ | |
966 | memcpy(src, drbg->V, drbg_statelen(drbg)); | |
967 | ||
968 | drbg_string_fill(&data, src, drbg_statelen(drbg)); | |
8c987166 | 969 | list_add_tail(&data.list, &datalist); |
541af946 SM |
970 | while (len < buflen) { |
971 | unsigned int outlen = 0; | |
972 | /* 10.1.1.4 step hashgen 4.1 */ | |
8c987166 | 973 | ret = drbg_kcapi_hash(drbg, NULL, dst, &datalist); |
541af946 SM |
974 | if (ret) { |
975 | len = ret; | |
976 | goto out; | |
977 | } | |
978 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
979 | drbg_blocklen(drbg) : (buflen - len); | |
980 | if (!drbg_fips_continuous_test(drbg, dst)) { | |
41a84982 | 981 | crypto_inc(src, drbg_statelen(drbg)); |
541af946 SM |
982 | continue; |
983 | } | |
984 | /* 10.1.1.4 step hashgen 4.2 */ | |
985 | memcpy(buf + len, dst, outlen); | |
986 | len += outlen; | |
987 | /* 10.1.1.4 hashgen step 4.3 */ | |
988 | if (len < buflen) | |
41a84982 | 989 | crypto_inc(src, drbg_statelen(drbg)); |
541af946 SM |
990 | } |
991 | ||
992 | out: | |
1471f09f | 993 | memset(drbg->scratchpad, 0, |
541af946 SM |
994 | (drbg_statelen(drbg) + drbg_blocklen(drbg))); |
995 | return len; | |
996 | } | |
997 | ||
998 | /* generate function for Hash DRBG as defined in 10.1.1.4 */ | |
999 | static int drbg_hash_generate(struct drbg_state *drbg, | |
1000 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 1001 | struct list_head *addtl) |
541af946 SM |
1002 | { |
1003 | int len = 0; | |
1004 | int ret = 0; | |
72f3e00d SM |
1005 | union { |
1006 | unsigned char req[8]; | |
7c8ae03f | 1007 | __be64 req_int; |
72f3e00d | 1008 | } u; |
541af946 SM |
1009 | unsigned char prefix = DRBG_PREFIX3; |
1010 | struct drbg_string data1, data2; | |
8c987166 | 1011 | LIST_HEAD(datalist); |
541af946 SM |
1012 | |
1013 | /* 10.1.1.4 step 2 */ | |
1014 | ret = drbg_hash_process_addtl(drbg, addtl); | |
1015 | if (ret) | |
1016 | return ret; | |
1017 | /* 10.1.1.4 step 3 */ | |
1018 | len = drbg_hash_hashgen(drbg, buf, buflen); | |
1019 | ||
1020 | /* this is the value H as documented in 10.1.1.4 */ | |
1021 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); | |
1022 | /* 10.1.1.4 step 4 */ | |
1023 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 1024 | list_add_tail(&data1.list, &datalist); |
541af946 | 1025 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 SM |
1026 | list_add_tail(&data2.list, &datalist); |
1027 | ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist); | |
541af946 SM |
1028 | if (ret) { |
1029 | len = ret; | |
1030 | goto out; | |
1031 | } | |
1032 | ||
1033 | /* 10.1.1.4 step 5 */ | |
1034 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
1035 | drbg->scratchpad, drbg_blocklen(drbg)); | |
1036 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
1037 | drbg->C, drbg_statelen(drbg)); | |
72f3e00d SM |
1038 | u.req_int = cpu_to_be64(drbg->reseed_ctr); |
1039 | drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8); | |
541af946 SM |
1040 | |
1041 | out: | |
1471f09f | 1042 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
1043 | return len; |
1044 | } | |
1045 | ||
1046 | /* | |
1047 | * scratchpad usage: as update and generate are used isolated, both | |
1048 | * can use the scratchpad | |
1049 | */ | |
1050 | static struct drbg_state_ops drbg_hash_ops = { | |
1051 | .update = drbg_hash_update, | |
1052 | .generate = drbg_hash_generate, | |
1053 | .crypto_init = drbg_init_hash_kernel, | |
1054 | .crypto_fini = drbg_fini_hash_kernel, | |
1055 | }; | |
1056 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1057 | ||
1058 | /****************************************************************** | |
1059 | * Functions common for DRBG implementations | |
1060 | ******************************************************************/ | |
1061 | ||
1062 | /* | |
1063 | * Seeding or reseeding of the DRBG | |
1064 | * | |
1065 | * @drbg: DRBG state struct | |
1066 | * @pers: personalization / additional information buffer | |
1067 | * @reseed: 0 for initial seed process, 1 for reseeding | |
1068 | * | |
1069 | * return: | |
1070 | * 0 on success | |
1071 | * error value otherwise | |
1072 | */ | |
1073 | static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers, | |
1074 | bool reseed) | |
1075 | { | |
1076 | int ret = 0; | |
1077 | unsigned char *entropy = NULL; | |
1078 | size_t entropylen = 0; | |
1079 | struct drbg_string data1; | |
8c987166 | 1080 | LIST_HEAD(seedlist); |
541af946 SM |
1081 | |
1082 | /* 9.1 / 9.2 / 9.3.1 step 3 */ | |
1083 | if (pers && pers->len > (drbg_max_addtl(drbg))) { | |
a9089571 | 1084 | pr_devel("DRBG: personalization string too long %zu\n", |
541af946 SM |
1085 | pers->len); |
1086 | return -EINVAL; | |
1087 | } | |
1088 | ||
1089 | if (drbg->test_data && drbg->test_data->testentropy) { | |
1090 | drbg_string_fill(&data1, drbg->test_data->testentropy->buf, | |
1091 | drbg->test_data->testentropy->len); | |
1092 | pr_devel("DRBG: using test entropy\n"); | |
1093 | } else { | |
1094 | /* | |
1095 | * Gather entropy equal to the security strength of the DRBG. | |
1096 | * With a derivation function, a nonce is required in addition | |
1097 | * to the entropy. A nonce must be at least 1/2 of the security | |
1098 | * strength of the DRBG in size. Thus, entropy * nonce is 3/2 | |
1099 | * of the strength. The consideration of a nonce is only | |
1100 | * applicable during initial seeding. | |
1101 | */ | |
1102 | entropylen = drbg_sec_strength(drbg->core->flags); | |
1103 | if (!entropylen) | |
1104 | return -EFAULT; | |
1105 | if (!reseed) | |
1106 | entropylen = ((entropylen + 1) / 2) * 3; | |
1107 | pr_devel("DRBG: (re)seeding with %zu bytes of entropy\n", | |
1108 | entropylen); | |
1109 | entropy = kzalloc(entropylen, GFP_KERNEL); | |
1110 | if (!entropy) | |
1111 | return -ENOMEM; | |
1112 | get_random_bytes(entropy, entropylen); | |
1113 | drbg_string_fill(&data1, entropy, entropylen); | |
1114 | } | |
8c987166 | 1115 | list_add_tail(&data1.list, &seedlist); |
541af946 SM |
1116 | |
1117 | /* | |
1118 | * concatenation of entropy with personalization str / addtl input) | |
1119 | * the variable pers is directly handed in by the caller, so check its | |
1120 | * contents whether it is appropriate | |
1121 | */ | |
8c987166 SM |
1122 | if (pers && pers->buf && 0 < pers->len) { |
1123 | list_add_tail(&pers->list, &seedlist); | |
541af946 SM |
1124 | pr_devel("DRBG: using personalization string\n"); |
1125 | } | |
1126 | ||
e6c0244a SM |
1127 | if (!reseed) { |
1128 | memset(drbg->V, 0, drbg_statelen(drbg)); | |
1129 | memset(drbg->C, 0, drbg_statelen(drbg)); | |
1130 | } | |
1131 | ||
8c987166 | 1132 | ret = drbg->d_ops->update(drbg, &seedlist, reseed); |
541af946 SM |
1133 | if (ret) |
1134 | goto out; | |
1135 | ||
1136 | drbg->seeded = true; | |
1137 | /* 10.1.1.2 / 10.1.1.3 step 5 */ | |
1138 | drbg->reseed_ctr = 1; | |
1139 | ||
1140 | out: | |
46f64f6e | 1141 | kzfree(entropy); |
541af946 SM |
1142 | return ret; |
1143 | } | |
1144 | ||
1145 | /* Free all substructures in a DRBG state without the DRBG state structure */ | |
1146 | static inline void drbg_dealloc_state(struct drbg_state *drbg) | |
1147 | { | |
1148 | if (!drbg) | |
1149 | return; | |
46f64f6e | 1150 | kzfree(drbg->V); |
541af946 | 1151 | drbg->V = NULL; |
46f64f6e | 1152 | kzfree(drbg->C); |
541af946 | 1153 | drbg->C = NULL; |
46f64f6e | 1154 | kzfree(drbg->scratchpad); |
541af946 SM |
1155 | drbg->scratchpad = NULL; |
1156 | drbg->reseed_ctr = 0; | |
1157 | #ifdef CONFIG_CRYPTO_FIPS | |
46f64f6e | 1158 | kzfree(drbg->prev); |
541af946 SM |
1159 | drbg->prev = NULL; |
1160 | drbg->fips_primed = false; | |
1161 | #endif | |
1162 | } | |
1163 | ||
1164 | /* | |
1165 | * Allocate all sub-structures for a DRBG state. | |
1166 | * The DRBG state structure must already be allocated. | |
1167 | */ | |
1168 | static inline int drbg_alloc_state(struct drbg_state *drbg) | |
1169 | { | |
1170 | int ret = -ENOMEM; | |
1171 | unsigned int sb_size = 0; | |
1172 | ||
e6c0244a | 1173 | drbg->V = kmalloc(drbg_statelen(drbg), GFP_KERNEL); |
541af946 SM |
1174 | if (!drbg->V) |
1175 | goto err; | |
e6c0244a | 1176 | drbg->C = kmalloc(drbg_statelen(drbg), GFP_KERNEL); |
541af946 SM |
1177 | if (!drbg->C) |
1178 | goto err; | |
1179 | #ifdef CONFIG_CRYPTO_FIPS | |
e6c0244a | 1180 | drbg->prev = kmalloc(drbg_blocklen(drbg), GFP_KERNEL); |
541af946 SM |
1181 | if (!drbg->prev) |
1182 | goto err; | |
1183 | drbg->fips_primed = false; | |
1184 | #endif | |
1185 | /* scratchpad is only generated for CTR and Hash */ | |
1186 | if (drbg->core->flags & DRBG_HMAC) | |
1187 | sb_size = 0; | |
1188 | else if (drbg->core->flags & DRBG_CTR) | |
1189 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg) + /* temp */ | |
1190 | drbg_statelen(drbg) + /* df_data */ | |
1191 | drbg_blocklen(drbg) + /* pad */ | |
1192 | drbg_blocklen(drbg) + /* iv */ | |
8fecaad7 | 1193 | drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */ |
541af946 SM |
1194 | else |
1195 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg); | |
1196 | ||
1197 | if (0 < sb_size) { | |
1198 | drbg->scratchpad = kzalloc(sb_size, GFP_KERNEL); | |
1199 | if (!drbg->scratchpad) | |
1200 | goto err; | |
1201 | } | |
1202 | spin_lock_init(&drbg->drbg_lock); | |
1203 | return 0; | |
1204 | ||
1205 | err: | |
1206 | drbg_dealloc_state(drbg); | |
1207 | return ret; | |
1208 | } | |
1209 | ||
1210 | /* | |
1211 | * Strategy to avoid holding long term locks: generate a shadow copy of DRBG | |
1212 | * and perform all operations on this shadow copy. After finishing, restore | |
1213 | * the updated state of the shadow copy into original drbg state. This way, | |
1214 | * only the read and write operations of the original drbg state must be | |
1215 | * locked | |
1216 | */ | |
1217 | static inline void drbg_copy_drbg(struct drbg_state *src, | |
1218 | struct drbg_state *dst) | |
1219 | { | |
1220 | if (!src || !dst) | |
1221 | return; | |
1222 | memcpy(dst->V, src->V, drbg_statelen(src)); | |
1223 | memcpy(dst->C, src->C, drbg_statelen(src)); | |
1224 | dst->reseed_ctr = src->reseed_ctr; | |
1225 | dst->seeded = src->seeded; | |
1226 | dst->pr = src->pr; | |
1227 | #ifdef CONFIG_CRYPTO_FIPS | |
1228 | dst->fips_primed = src->fips_primed; | |
1229 | memcpy(dst->prev, src->prev, drbg_blocklen(src)); | |
1230 | #endif | |
1231 | /* | |
1232 | * Not copied: | |
1233 | * scratchpad is initialized drbg_alloc_state; | |
1234 | * priv_data is initialized with call to crypto_init; | |
1235 | * d_ops and core are set outside, as these parameters are const; | |
1236 | * test_data is set outside to prevent it being copied back. | |
1237 | */ | |
1238 | } | |
1239 | ||
1240 | static int drbg_make_shadow(struct drbg_state *drbg, struct drbg_state **shadow) | |
1241 | { | |
1242 | int ret = -ENOMEM; | |
1243 | struct drbg_state *tmp = NULL; | |
1244 | ||
541af946 SM |
1245 | tmp = kzalloc(sizeof(struct drbg_state), GFP_KERNEL); |
1246 | if (!tmp) | |
1247 | return -ENOMEM; | |
1248 | ||
1249 | /* read-only data as they are defined as const, no lock needed */ | |
1250 | tmp->core = drbg->core; | |
1251 | tmp->d_ops = drbg->d_ops; | |
1252 | ||
1253 | ret = drbg_alloc_state(tmp); | |
1254 | if (ret) | |
1255 | goto err; | |
1256 | ||
1257 | spin_lock_bh(&drbg->drbg_lock); | |
1258 | drbg_copy_drbg(drbg, tmp); | |
1259 | /* only make a link to the test buffer, as we only read that data */ | |
1260 | tmp->test_data = drbg->test_data; | |
1261 | spin_unlock_bh(&drbg->drbg_lock); | |
1262 | *shadow = tmp; | |
1263 | return 0; | |
1264 | ||
1265 | err: | |
46f64f6e | 1266 | kzfree(tmp); |
541af946 SM |
1267 | return ret; |
1268 | } | |
1269 | ||
1270 | static void drbg_restore_shadow(struct drbg_state *drbg, | |
1271 | struct drbg_state **shadow) | |
1272 | { | |
1273 | struct drbg_state *tmp = *shadow; | |
1274 | ||
1275 | spin_lock_bh(&drbg->drbg_lock); | |
1276 | drbg_copy_drbg(tmp, drbg); | |
1277 | spin_unlock_bh(&drbg->drbg_lock); | |
1278 | drbg_dealloc_state(tmp); | |
1279 | kzfree(tmp); | |
1280 | *shadow = NULL; | |
1281 | } | |
1282 | ||
1283 | /************************************************************************* | |
1284 | * DRBG interface functions | |
1285 | *************************************************************************/ | |
1286 | ||
1287 | /* | |
1288 | * DRBG generate function as required by SP800-90A - this function | |
1289 | * generates random numbers | |
1290 | * | |
1291 | * @drbg DRBG state handle | |
1292 | * @buf Buffer where to store the random numbers -- the buffer must already | |
1293 | * be pre-allocated by caller | |
1294 | * @buflen Length of output buffer - this value defines the number of random | |
1295 | * bytes pulled from DRBG | |
1296 | * @addtl Additional input that is mixed into state, may be NULL -- note | |
1297 | * the entropy is pulled by the DRBG internally unconditionally | |
1298 | * as defined in SP800-90A. The additional input is mixed into | |
1299 | * the state in addition to the pulled entropy. | |
1300 | * | |
1301 | * return: generated number of bytes | |
1302 | */ | |
1303 | static int drbg_generate(struct drbg_state *drbg, | |
1304 | unsigned char *buf, unsigned int buflen, | |
1305 | struct drbg_string *addtl) | |
1306 | { | |
1307 | int len = 0; | |
1308 | struct drbg_state *shadow = NULL; | |
27e4de2b SM |
1309 | LIST_HEAD(addtllist); |
1310 | struct drbg_string timestamp; | |
1311 | union { | |
1312 | cycles_t cycles; | |
1313 | unsigned char char_cycles[sizeof(cycles_t)]; | |
1314 | } now; | |
541af946 SM |
1315 | |
1316 | if (0 == buflen || !buf) { | |
1317 | pr_devel("DRBG: no output buffer provided\n"); | |
1318 | return -EINVAL; | |
1319 | } | |
1320 | if (addtl && NULL == addtl->buf && 0 < addtl->len) { | |
1321 | pr_devel("DRBG: wrong format of additional information\n"); | |
1322 | return -EINVAL; | |
1323 | } | |
1324 | ||
1325 | len = drbg_make_shadow(drbg, &shadow); | |
1326 | if (len) { | |
1327 | pr_devel("DRBG: shadow copy cannot be generated\n"); | |
1328 | return len; | |
1329 | } | |
1330 | ||
1331 | /* 9.3.1 step 2 */ | |
1332 | len = -EINVAL; | |
1333 | if (buflen > (drbg_max_request_bytes(shadow))) { | |
1334 | pr_devel("DRBG: requested random numbers too large %u\n", | |
1335 | buflen); | |
1336 | goto err; | |
1337 | } | |
1338 | ||
1339 | /* 9.3.1 step 3 is implicit with the chosen DRBG */ | |
1340 | ||
1341 | /* 9.3.1 step 4 */ | |
1342 | if (addtl && addtl->len > (drbg_max_addtl(shadow))) { | |
1343 | pr_devel("DRBG: additional information string too long %zu\n", | |
1344 | addtl->len); | |
1345 | goto err; | |
1346 | } | |
1347 | /* 9.3.1 step 5 is implicit with the chosen DRBG */ | |
1348 | ||
1349 | /* | |
1350 | * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented | |
1351 | * here. The spec is a bit convoluted here, we make it simpler. | |
1352 | */ | |
1353 | if ((drbg_max_requests(shadow)) < shadow->reseed_ctr) | |
1354 | shadow->seeded = false; | |
1355 | ||
1356 | /* allocate cipher handle */ | |
45943a58 SM |
1357 | len = shadow->d_ops->crypto_init(shadow); |
1358 | if (len) | |
1359 | goto err; | |
541af946 SM |
1360 | |
1361 | if (shadow->pr || !shadow->seeded) { | |
1362 | pr_devel("DRBG: reseeding before generation (prediction " | |
1363 | "resistance: %s, state %s)\n", | |
1364 | drbg->pr ? "true" : "false", | |
1365 | drbg->seeded ? "seeded" : "unseeded"); | |
1366 | /* 9.3.1 steps 7.1 through 7.3 */ | |
1367 | len = drbg_seed(shadow, addtl, true); | |
1368 | if (len) | |
1369 | goto err; | |
1370 | /* 9.3.1 step 7.4 */ | |
1371 | addtl = NULL; | |
1372 | } | |
27e4de2b SM |
1373 | |
1374 | /* | |
1375 | * Mix the time stamp into the DRBG state if the DRBG is not in | |
1376 | * test mode. If there are two callers invoking the DRBG at the same | |
1377 | * time, i.e. before the first caller merges its shadow state back, | |
1378 | * both callers would obtain the same random number stream without | |
1379 | * changing the state here. | |
1380 | */ | |
1381 | if (!drbg->test_data) { | |
1382 | now.cycles = random_get_entropy(); | |
1383 | drbg_string_fill(×tamp, now.char_cycles, sizeof(cycles_t)); | |
1384 | list_add_tail(×tamp.list, &addtllist); | |
1385 | } | |
1386 | if (addtl && 0 < addtl->len) | |
1387 | list_add_tail(&addtl->list, &addtllist); | |
541af946 | 1388 | /* 9.3.1 step 8 and 10 */ |
27e4de2b | 1389 | len = shadow->d_ops->generate(shadow, buf, buflen, &addtllist); |
541af946 SM |
1390 | |
1391 | /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */ | |
1392 | shadow->reseed_ctr++; | |
1393 | if (0 >= len) | |
1394 | goto err; | |
1395 | ||
1396 | /* | |
1397 | * Section 11.3.3 requires to re-perform self tests after some | |
1398 | * generated random numbers. The chosen value after which self | |
1399 | * test is performed is arbitrary, but it should be reasonable. | |
1400 | * However, we do not perform the self tests because of the following | |
1401 | * reasons: it is mathematically impossible that the initial self tests | |
1402 | * were successfully and the following are not. If the initial would | |
1403 | * pass and the following would not, the kernel integrity is violated. | |
1404 | * In this case, the entire kernel operation is questionable and it | |
1405 | * is unlikely that the integrity violation only affects the | |
1406 | * correct operation of the DRBG. | |
1407 | * | |
1408 | * Albeit the following code is commented out, it is provided in | |
1409 | * case somebody has a need to implement the test of 11.3.3. | |
1410 | */ | |
1411 | #if 0 | |
1412 | if (shadow->reseed_ctr && !(shadow->reseed_ctr % 4096)) { | |
1413 | int err = 0; | |
1414 | pr_devel("DRBG: start to perform self test\n"); | |
1415 | if (drbg->core->flags & DRBG_HMAC) | |
1416 | err = alg_test("drbg_pr_hmac_sha256", | |
1417 | "drbg_pr_hmac_sha256", 0, 0); | |
1418 | else if (drbg->core->flags & DRBG_CTR) | |
1419 | err = alg_test("drbg_pr_ctr_aes128", | |
1420 | "drbg_pr_ctr_aes128", 0, 0); | |
1421 | else | |
1422 | err = alg_test("drbg_pr_sha256", | |
1423 | "drbg_pr_sha256", 0, 0); | |
1424 | if (err) { | |
1425 | pr_err("DRBG: periodical self test failed\n"); | |
1426 | /* | |
1427 | * uninstantiate implies that from now on, only errors | |
1428 | * are returned when reusing this DRBG cipher handle | |
1429 | */ | |
1430 | drbg_uninstantiate(drbg); | |
1431 | drbg_dealloc_state(shadow); | |
1432 | kzfree(shadow); | |
1433 | return 0; | |
1434 | } else { | |
1435 | pr_devel("DRBG: self test successful\n"); | |
1436 | } | |
1437 | } | |
1438 | #endif | |
1439 | ||
1440 | err: | |
45943a58 | 1441 | shadow->d_ops->crypto_fini(shadow); |
541af946 SM |
1442 | drbg_restore_shadow(drbg, &shadow); |
1443 | return len; | |
1444 | } | |
1445 | ||
1446 | /* | |
1447 | * Wrapper around drbg_generate which can pull arbitrary long strings | |
1448 | * from the DRBG without hitting the maximum request limitation. | |
1449 | * | |
1450 | * Parameters: see drbg_generate | |
1451 | * Return codes: see drbg_generate -- if one drbg_generate request fails, | |
1452 | * the entire drbg_generate_long request fails | |
1453 | */ | |
1454 | static int drbg_generate_long(struct drbg_state *drbg, | |
1455 | unsigned char *buf, unsigned int buflen, | |
1456 | struct drbg_string *addtl) | |
1457 | { | |
1458 | int len = 0; | |
1459 | unsigned int slice = 0; | |
1460 | do { | |
1461 | int tmplen = 0; | |
1462 | unsigned int chunk = 0; | |
1463 | slice = ((buflen - len) / drbg_max_request_bytes(drbg)); | |
1464 | chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len); | |
1465 | tmplen = drbg_generate(drbg, buf + len, chunk, addtl); | |
1466 | if (0 >= tmplen) | |
1467 | return tmplen; | |
1468 | len += tmplen; | |
ce5481d0 | 1469 | } while (slice > 0 && (len < buflen)); |
541af946 SM |
1470 | return len; |
1471 | } | |
1472 | ||
1473 | /* | |
1474 | * DRBG instantiation function as required by SP800-90A - this function | |
1475 | * sets up the DRBG handle, performs the initial seeding and all sanity | |
1476 | * checks required by SP800-90A | |
1477 | * | |
1478 | * @drbg memory of state -- if NULL, new memory is allocated | |
1479 | * @pers Personalization string that is mixed into state, may be NULL -- note | |
1480 | * the entropy is pulled by the DRBG internally unconditionally | |
1481 | * as defined in SP800-90A. The additional input is mixed into | |
1482 | * the state in addition to the pulled entropy. | |
1483 | * @coreref reference to core | |
1484 | * @pr prediction resistance enabled | |
1485 | * | |
1486 | * return | |
1487 | * 0 on success | |
1488 | * error value otherwise | |
1489 | */ | |
1490 | static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, | |
1491 | int coreref, bool pr) | |
1492 | { | |
1493 | int ret = -ENOMEM; | |
1494 | ||
1495 | pr_devel("DRBG: Initializing DRBG core %d with prediction resistance " | |
1496 | "%s\n", coreref, pr ? "enabled" : "disabled"); | |
1497 | drbg->core = &drbg_cores[coreref]; | |
1498 | drbg->pr = pr; | |
1499 | drbg->seeded = false; | |
1500 | switch (drbg->core->flags & DRBG_TYPE_MASK) { | |
1501 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
1502 | case DRBG_HMAC: | |
1503 | drbg->d_ops = &drbg_hmac_ops; | |
1504 | break; | |
1505 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
1506 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
1507 | case DRBG_HASH: | |
1508 | drbg->d_ops = &drbg_hash_ops; | |
1509 | break; | |
1510 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1511 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1512 | case DRBG_CTR: | |
1513 | drbg->d_ops = &drbg_ctr_ops; | |
1514 | break; | |
1515 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
1516 | default: | |
1517 | return -EOPNOTSUPP; | |
1518 | } | |
1519 | ||
1520 | /* 9.1 step 1 is implicit with the selected DRBG type */ | |
1521 | ||
1522 | /* | |
1523 | * 9.1 step 2 is implicit as caller can select prediction resistance | |
1524 | * and the flag is copied into drbg->flags -- | |
1525 | * all DRBG types support prediction resistance | |
1526 | */ | |
1527 | ||
1528 | /* 9.1 step 4 is implicit in drbg_sec_strength */ | |
1529 | ||
1530 | ret = drbg_alloc_state(drbg); | |
1531 | if (ret) | |
1532 | return ret; | |
1533 | ||
1534 | ret = -EFAULT; | |
45943a58 | 1535 | if (drbg->d_ops->crypto_init(drbg)) |
541af946 SM |
1536 | goto err; |
1537 | ret = drbg_seed(drbg, pers, false); | |
45943a58 | 1538 | drbg->d_ops->crypto_fini(drbg); |
541af946 SM |
1539 | if (ret) |
1540 | goto err; | |
1541 | ||
1542 | return 0; | |
1543 | ||
1544 | err: | |
1545 | drbg_dealloc_state(drbg); | |
1546 | return ret; | |
1547 | } | |
1548 | ||
1549 | /* | |
1550 | * DRBG uninstantiate function as required by SP800-90A - this function | |
1551 | * frees all buffers and the DRBG handle | |
1552 | * | |
1553 | * @drbg DRBG state handle | |
1554 | * | |
1555 | * return | |
1556 | * 0 on success | |
1557 | */ | |
1558 | static int drbg_uninstantiate(struct drbg_state *drbg) | |
1559 | { | |
1560 | spin_lock_bh(&drbg->drbg_lock); | |
1561 | drbg_dealloc_state(drbg); | |
1562 | /* no scrubbing of test_data -- this shall survive an uninstantiate */ | |
1563 | spin_unlock_bh(&drbg->drbg_lock); | |
1564 | return 0; | |
1565 | } | |
1566 | ||
1567 | /* | |
1568 | * Helper function for setting the test data in the DRBG | |
1569 | * | |
1570 | * @drbg DRBG state handle | |
1571 | * @test_data test data to sets | |
1572 | */ | |
1573 | static inline void drbg_set_testdata(struct drbg_state *drbg, | |
1574 | struct drbg_test_data *test_data) | |
1575 | { | |
1576 | if (!test_data || !test_data->testentropy) | |
1577 | return; | |
1578 | spin_lock_bh(&drbg->drbg_lock); | |
1579 | drbg->test_data = test_data; | |
1580 | spin_unlock_bh(&drbg->drbg_lock); | |
1581 | } | |
1582 | ||
1583 | /*************************************************************** | |
1584 | * Kernel crypto API cipher invocations requested by DRBG | |
1585 | ***************************************************************/ | |
1586 | ||
1587 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
1588 | struct sdesc { | |
1589 | struct shash_desc shash; | |
1590 | char ctx[]; | |
1591 | }; | |
1592 | ||
1593 | static int drbg_init_hash_kernel(struct drbg_state *drbg) | |
1594 | { | |
1595 | struct sdesc *sdesc; | |
1596 | struct crypto_shash *tfm; | |
1597 | ||
1598 | tfm = crypto_alloc_shash(drbg->core->backend_cra_name, 0, 0); | |
1599 | if (IS_ERR(tfm)) { | |
1600 | pr_info("DRBG: could not allocate digest TFM handle\n"); | |
1601 | return PTR_ERR(tfm); | |
1602 | } | |
1603 | BUG_ON(drbg_blocklen(drbg) != crypto_shash_digestsize(tfm)); | |
1604 | sdesc = kzalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm), | |
1605 | GFP_KERNEL); | |
1606 | if (!sdesc) { | |
1607 | crypto_free_shash(tfm); | |
1608 | return -ENOMEM; | |
1609 | } | |
1610 | ||
1611 | sdesc->shash.tfm = tfm; | |
1612 | sdesc->shash.flags = 0; | |
1613 | drbg->priv_data = sdesc; | |
1614 | return 0; | |
1615 | } | |
1616 | ||
1617 | static int drbg_fini_hash_kernel(struct drbg_state *drbg) | |
1618 | { | |
1619 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
1620 | if (sdesc) { | |
1621 | crypto_free_shash(sdesc->shash.tfm); | |
1622 | kzfree(sdesc); | |
1623 | } | |
1624 | drbg->priv_data = NULL; | |
1625 | return 0; | |
1626 | } | |
1627 | ||
1628 | static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key, | |
8c987166 | 1629 | unsigned char *outval, const struct list_head *in) |
541af946 SM |
1630 | { |
1631 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
8c987166 | 1632 | struct drbg_string *input = NULL; |
541af946 SM |
1633 | |
1634 | if (key) | |
1635 | crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg)); | |
1636 | crypto_shash_init(&sdesc->shash); | |
8c987166 SM |
1637 | list_for_each_entry(input, in, list) |
1638 | crypto_shash_update(&sdesc->shash, input->buf, input->len); | |
541af946 SM |
1639 | return crypto_shash_final(&sdesc->shash, outval); |
1640 | } | |
1641 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
1642 | ||
1643 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1644 | static int drbg_init_sym_kernel(struct drbg_state *drbg) | |
1645 | { | |
1646 | int ret = 0; | |
1647 | struct crypto_blkcipher *tfm; | |
1648 | ||
1649 | tfm = crypto_alloc_blkcipher(drbg->core->backend_cra_name, 0, 0); | |
1650 | if (IS_ERR(tfm)) { | |
1651 | pr_info("DRBG: could not allocate cipher TFM handle\n"); | |
1652 | return PTR_ERR(tfm); | |
1653 | } | |
1654 | BUG_ON(drbg_blocklen(drbg) != crypto_blkcipher_blocksize(tfm)); | |
1655 | drbg->priv_data = tfm; | |
1656 | return ret; | |
1657 | } | |
1658 | ||
1659 | static int drbg_fini_sym_kernel(struct drbg_state *drbg) | |
1660 | { | |
1661 | struct crypto_blkcipher *tfm = | |
1662 | (struct crypto_blkcipher *)drbg->priv_data; | |
1663 | if (tfm) | |
1664 | crypto_free_blkcipher(tfm); | |
1665 | drbg->priv_data = NULL; | |
1666 | return 0; | |
1667 | } | |
1668 | ||
1669 | static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key, | |
1670 | unsigned char *outval, const struct drbg_string *in) | |
1671 | { | |
1672 | int ret = 0; | |
1673 | struct scatterlist sg_in, sg_out; | |
1674 | struct blkcipher_desc desc; | |
1675 | struct crypto_blkcipher *tfm = | |
1676 | (struct crypto_blkcipher *)drbg->priv_data; | |
1677 | ||
1678 | desc.tfm = tfm; | |
1679 | desc.flags = 0; | |
1680 | crypto_blkcipher_setkey(tfm, key, (drbg_keylen(drbg))); | |
1681 | /* there is only component in *in */ | |
1682 | sg_init_one(&sg_in, in->buf, in->len); | |
1683 | sg_init_one(&sg_out, outval, drbg_blocklen(drbg)); | |
1684 | ret = crypto_blkcipher_encrypt(&desc, &sg_out, &sg_in, in->len); | |
1685 | ||
1686 | return ret; | |
1687 | } | |
1688 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
1689 | ||
1690 | /*************************************************************** | |
1691 | * Kernel crypto API interface to register DRBG | |
1692 | ***************************************************************/ | |
1693 | ||
1694 | /* | |
1695 | * Look up the DRBG flags by given kernel crypto API cra_name | |
1696 | * The code uses the drbg_cores definition to do this | |
1697 | * | |
1698 | * @cra_name kernel crypto API cra_name | |
1699 | * @coreref reference to integer which is filled with the pointer to | |
1700 | * the applicable core | |
1701 | * @pr reference for setting prediction resistance | |
1702 | * | |
1703 | * return: flags | |
1704 | */ | |
1705 | static inline void drbg_convert_tfm_core(const char *cra_driver_name, | |
1706 | int *coreref, bool *pr) | |
1707 | { | |
1708 | int i = 0; | |
1709 | size_t start = 0; | |
1710 | int len = 0; | |
1711 | ||
1712 | *pr = true; | |
1713 | /* disassemble the names */ | |
1714 | if (!memcmp(cra_driver_name, "drbg_nopr_", 10)) { | |
1715 | start = 10; | |
1716 | *pr = false; | |
1717 | } else if (!memcmp(cra_driver_name, "drbg_pr_", 8)) { | |
1718 | start = 8; | |
1719 | } else { | |
1720 | return; | |
1721 | } | |
1722 | ||
1723 | /* remove the first part */ | |
1724 | len = strlen(cra_driver_name) - start; | |
1725 | for (i = 0; ARRAY_SIZE(drbg_cores) > i; i++) { | |
1726 | if (!memcmp(cra_driver_name + start, drbg_cores[i].cra_name, | |
1727 | len)) { | |
1728 | *coreref = i; | |
1729 | return; | |
1730 | } | |
1731 | } | |
1732 | } | |
1733 | ||
1734 | static int drbg_kcapi_init(struct crypto_tfm *tfm) | |
1735 | { | |
1736 | struct drbg_state *drbg = crypto_tfm_ctx(tfm); | |
1737 | bool pr = false; | |
1738 | int coreref = 0; | |
1739 | ||
4f150718 | 1740 | drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm), &coreref, &pr); |
541af946 SM |
1741 | /* |
1742 | * when personalization string is needed, the caller must call reset | |
1743 | * and provide the personalization string as seed information | |
1744 | */ | |
1745 | return drbg_instantiate(drbg, NULL, coreref, pr); | |
1746 | } | |
1747 | ||
1748 | static void drbg_kcapi_cleanup(struct crypto_tfm *tfm) | |
1749 | { | |
1750 | drbg_uninstantiate(crypto_tfm_ctx(tfm)); | |
1751 | } | |
1752 | ||
1753 | /* | |
1754 | * Generate random numbers invoked by the kernel crypto API: | |
1755 | * The API of the kernel crypto API is extended as follows: | |
1756 | * | |
1757 | * If dlen is larger than zero, rdata is interpreted as the output buffer | |
1758 | * where random data is to be stored. | |
1759 | * | |
1760 | * If dlen is zero, rdata is interpreted as a pointer to a struct drbg_gen | |
1761 | * which holds the additional information string that is used for the | |
1762 | * DRBG generation process. The output buffer that is to be used to store | |
1763 | * data is also pointed to by struct drbg_gen. | |
1764 | */ | |
1765 | static int drbg_kcapi_random(struct crypto_rng *tfm, u8 *rdata, | |
1766 | unsigned int dlen) | |
1767 | { | |
1768 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
1769 | if (0 < dlen) { | |
1770 | return drbg_generate_long(drbg, rdata, dlen, NULL); | |
1771 | } else { | |
1772 | struct drbg_gen *data = (struct drbg_gen *)rdata; | |
8c987166 | 1773 | struct drbg_string addtl; |
541af946 SM |
1774 | /* catch NULL pointer */ |
1775 | if (!data) | |
1776 | return 0; | |
1777 | drbg_set_testdata(drbg, data->test_data); | |
8c987166 SM |
1778 | /* linked list variable is now local to allow modification */ |
1779 | drbg_string_fill(&addtl, data->addtl->buf, data->addtl->len); | |
541af946 | 1780 | return drbg_generate_long(drbg, data->outbuf, data->outlen, |
8c987166 | 1781 | &addtl); |
541af946 SM |
1782 | } |
1783 | } | |
1784 | ||
1785 | /* | |
1786 | * Reset the DRBG invoked by the kernel crypto API | |
1787 | * The reset implies a full re-initialization of the DRBG. Similar to the | |
1788 | * generate function of drbg_kcapi_random, this function extends the | |
1789 | * kernel crypto API interface with struct drbg_gen | |
1790 | */ | |
1791 | static int drbg_kcapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen) | |
1792 | { | |
1793 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
1794 | struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm); | |
1795 | bool pr = false; | |
1796 | struct drbg_string seed_string; | |
1797 | int coreref = 0; | |
1798 | ||
1799 | drbg_uninstantiate(drbg); | |
1800 | drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref, | |
1801 | &pr); | |
1802 | if (0 < slen) { | |
1803 | drbg_string_fill(&seed_string, seed, slen); | |
1804 | return drbg_instantiate(drbg, &seed_string, coreref, pr); | |
1805 | } else { | |
1806 | struct drbg_gen *data = (struct drbg_gen *)seed; | |
1807 | /* allow invocation of API call with NULL, 0 */ | |
1808 | if (!data) | |
1809 | return drbg_instantiate(drbg, NULL, coreref, pr); | |
1810 | drbg_set_testdata(drbg, data->test_data); | |
8c987166 SM |
1811 | /* linked list variable is now local to allow modification */ |
1812 | drbg_string_fill(&seed_string, data->addtl->buf, | |
1813 | data->addtl->len); | |
1814 | return drbg_instantiate(drbg, &seed_string, coreref, pr); | |
541af946 SM |
1815 | } |
1816 | } | |
1817 | ||
1818 | /*************************************************************** | |
1819 | * Kernel module: code to load the module | |
1820 | ***************************************************************/ | |
1821 | ||
1822 | /* | |
1823 | * Tests as defined in 11.3.2 in addition to the cipher tests: testing | |
1824 | * of the error handling. | |
1825 | * | |
1826 | * Note: testing of failing seed source as defined in 11.3.2 is not applicable | |
1827 | * as seed source of get_random_bytes does not fail. | |
1828 | * | |
1829 | * Note 2: There is no sensible way of testing the reseed counter | |
1830 | * enforcement, so skip it. | |
1831 | */ | |
1832 | static inline int __init drbg_healthcheck_sanity(void) | |
1833 | { | |
1834 | #ifdef CONFIG_CRYPTO_FIPS | |
1835 | int len = 0; | |
1836 | #define OUTBUFLEN 16 | |
1837 | unsigned char buf[OUTBUFLEN]; | |
1838 | struct drbg_state *drbg = NULL; | |
1839 | int ret = -EFAULT; | |
1840 | int rc = -EFAULT; | |
1841 | bool pr = false; | |
1842 | int coreref = 0; | |
1843 | struct drbg_string addtl; | |
1844 | size_t max_addtllen, max_request_bytes; | |
1845 | ||
1846 | /* only perform test in FIPS mode */ | |
1847 | if (!fips_enabled) | |
1848 | return 0; | |
1849 | ||
1850 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1851 | drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref, &pr); | |
e25e47ec | 1852 | #elif defined CONFIG_CRYPTO_DRBG_HASH |
541af946 SM |
1853 | drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr); |
1854 | #else | |
1855 | drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref, &pr); | |
1856 | #endif | |
1857 | ||
1858 | drbg = kzalloc(sizeof(struct drbg_state), GFP_KERNEL); | |
1859 | if (!drbg) | |
1860 | return -ENOMEM; | |
1861 | ||
1862 | /* | |
1863 | * if the following tests fail, it is likely that there is a buffer | |
1864 | * overflow as buf is much smaller than the requested or provided | |
1865 | * string lengths -- in case the error handling does not succeed | |
1866 | * we may get an OOPS. And we want to get an OOPS as this is a | |
1867 | * grave bug. | |
1868 | */ | |
1869 | ||
1870 | /* get a valid instance of DRBG for following tests */ | |
1871 | ret = drbg_instantiate(drbg, NULL, coreref, pr); | |
1872 | if (ret) { | |
1873 | rc = ret; | |
1874 | goto outbuf; | |
1875 | } | |
1876 | max_addtllen = drbg_max_addtl(drbg); | |
1877 | max_request_bytes = drbg_max_request_bytes(drbg); | |
1878 | drbg_string_fill(&addtl, buf, max_addtllen + 1); | |
1879 | /* overflow addtllen with additonal info string */ | |
1880 | len = drbg_generate(drbg, buf, OUTBUFLEN, &addtl); | |
1881 | BUG_ON(0 < len); | |
1882 | /* overflow max_bits */ | |
1883 | len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL); | |
1884 | BUG_ON(0 < len); | |
1885 | drbg_uninstantiate(drbg); | |
1886 | ||
1887 | /* overflow max addtllen with personalization string */ | |
1888 | ret = drbg_instantiate(drbg, &addtl, coreref, pr); | |
1889 | BUG_ON(0 == ret); | |
541af946 SM |
1890 | /* all tests passed */ |
1891 | rc = 0; | |
1892 | ||
1893 | pr_devel("DRBG: Sanity tests for failure code paths successfully " | |
1894 | "completed\n"); | |
1895 | ||
1896 | drbg_uninstantiate(drbg); | |
1897 | outbuf: | |
1898 | kzfree(drbg); | |
1899 | return rc; | |
1900 | #else /* CONFIG_CRYPTO_FIPS */ | |
1901 | return 0; | |
1902 | #endif /* CONFIG_CRYPTO_FIPS */ | |
1903 | } | |
1904 | ||
1905 | static struct crypto_alg drbg_algs[22]; | |
1906 | ||
1907 | /* | |
1908 | * Fill the array drbg_algs used to register the different DRBGs | |
1909 | * with the kernel crypto API. To fill the array, the information | |
1910 | * from drbg_cores[] is used. | |
1911 | */ | |
1912 | static inline void __init drbg_fill_array(struct crypto_alg *alg, | |
1913 | const struct drbg_core *core, int pr) | |
1914 | { | |
1915 | int pos = 0; | |
1916 | static int priority = 100; | |
1917 | ||
1918 | memset(alg, 0, sizeof(struct crypto_alg)); | |
1919 | memcpy(alg->cra_name, "stdrng", 6); | |
1920 | if (pr) { | |
1921 | memcpy(alg->cra_driver_name, "drbg_pr_", 8); | |
1922 | pos = 8; | |
1923 | } else { | |
1924 | memcpy(alg->cra_driver_name, "drbg_nopr_", 10); | |
1925 | pos = 10; | |
1926 | } | |
1927 | memcpy(alg->cra_driver_name + pos, core->cra_name, | |
1928 | strlen(core->cra_name)); | |
1929 | ||
1930 | alg->cra_priority = priority; | |
1931 | priority++; | |
1932 | /* | |
1933 | * If FIPS mode enabled, the selected DRBG shall have the | |
1934 | * highest cra_priority over other stdrng instances to ensure | |
1935 | * it is selected. | |
1936 | */ | |
1937 | if (fips_enabled) | |
1938 | alg->cra_priority += 200; | |
1939 | ||
1940 | alg->cra_flags = CRYPTO_ALG_TYPE_RNG; | |
1941 | alg->cra_ctxsize = sizeof(struct drbg_state); | |
1942 | alg->cra_type = &crypto_rng_type; | |
1943 | alg->cra_module = THIS_MODULE; | |
1944 | alg->cra_init = drbg_kcapi_init; | |
1945 | alg->cra_exit = drbg_kcapi_cleanup; | |
1946 | alg->cra_u.rng.rng_make_random = drbg_kcapi_random; | |
1947 | alg->cra_u.rng.rng_reset = drbg_kcapi_reset; | |
1948 | alg->cra_u.rng.seedsize = 0; | |
1949 | } | |
1950 | ||
1951 | static int __init drbg_init(void) | |
1952 | { | |
1953 | unsigned int i = 0; /* pointer to drbg_algs */ | |
1954 | unsigned int j = 0; /* pointer to drbg_cores */ | |
1955 | int ret = -EFAULT; | |
1956 | ||
1957 | ret = drbg_healthcheck_sanity(); | |
1958 | if (ret) | |
1959 | return ret; | |
1960 | ||
1961 | if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) { | |
1962 | pr_info("DRBG: Cannot register all DRBG types" | |
a9089571 | 1963 | "(slots needed: %zu, slots available: %zu)\n", |
541af946 SM |
1964 | ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs)); |
1965 | return ret; | |
1966 | } | |
1967 | ||
1968 | /* | |
1969 | * each DRBG definition can be used with PR and without PR, thus | |
1970 | * we instantiate each DRBG in drbg_cores[] twice. | |
1971 | * | |
1972 | * As the order of placing them into the drbg_algs array matters | |
1973 | * (the later DRBGs receive a higher cra_priority) we register the | |
1974 | * prediction resistance DRBGs first as the should not be too | |
1975 | * interesting. | |
1976 | */ | |
1977 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
1978 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1); | |
1979 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
1980 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0); | |
1981 | return crypto_register_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); | |
1982 | } | |
1983 | ||
96956aef | 1984 | static void __exit drbg_exit(void) |
541af946 SM |
1985 | { |
1986 | crypto_unregister_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); | |
1987 | } | |
1988 | ||
1989 | module_init(drbg_init); | |
1990 | module_exit(drbg_exit); | |
e25e47ec SM |
1991 | #ifndef CRYPTO_DRBG_HASH_STRING |
1992 | #define CRYPTO_DRBG_HASH_STRING "" | |
541af946 | 1993 | #endif |
e25e47ec SM |
1994 | #ifndef CRYPTO_DRBG_HMAC_STRING |
1995 | #define CRYPTO_DRBG_HMAC_STRING "" | |
541af946 | 1996 | #endif |
e25e47ec SM |
1997 | #ifndef CRYPTO_DRBG_CTR_STRING |
1998 | #define CRYPTO_DRBG_CTR_STRING "" | |
541af946 | 1999 | #endif |
e25e47ec SM |
2000 | MODULE_LICENSE("GPL"); |
2001 | MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); | |
2002 | MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) " | |
2003 | "using following cores: " | |
2004 | CRYPTO_DRBG_HASH_STRING | |
2005 | CRYPTO_DRBG_HMAC_STRING | |
2006 | CRYPTO_DRBG_CTR_STRING); |