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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> | |
57225e67 | 101 | #include <linux/kernel.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", | |
04bcbfcf | 123 | .backend_cra_name = "aes", |
541af946 SM |
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", | |
04bcbfcf | 129 | .backend_cra_name = "aes", |
541af946 SM |
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", | |
04bcbfcf | 135 | .backend_cra_name = "aes", |
541af946 SM |
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 | ||
57225e67 SM |
194 | static int drbg_uninstantiate(struct drbg_state *drbg); |
195 | ||
541af946 SM |
196 | /****************************************************************** |
197 | * Generic helper functions | |
198 | ******************************************************************/ | |
199 | ||
200 | /* | |
201 | * Return strength of DRBG according to SP800-90A section 8.4 | |
202 | * | |
203 | * @flags DRBG flags reference | |
204 | * | |
205 | * Return: normalized strength in *bytes* value or 32 as default | |
206 | * to counter programming errors | |
207 | */ | |
208 | static inline unsigned short drbg_sec_strength(drbg_flag_t flags) | |
209 | { | |
210 | switch (flags & DRBG_STRENGTH_MASK) { | |
211 | case DRBG_STRENGTH128: | |
212 | return 16; | |
213 | case DRBG_STRENGTH192: | |
214 | return 24; | |
215 | case DRBG_STRENGTH256: | |
216 | return 32; | |
217 | default: | |
218 | return 32; | |
219 | } | |
220 | } | |
221 | ||
541af946 SM |
222 | /* |
223 | * Convert an integer into a byte representation of this integer. | |
224 | * The byte representation is big-endian | |
225 | * | |
541af946 | 226 | * @val value to be converted |
72f3e00d SM |
227 | * @buf buffer holding the converted integer -- caller must ensure that |
228 | * buffer size is at least 32 bit | |
541af946 SM |
229 | */ |
230 | #if (defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR)) | |
72f3e00d | 231 | static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf) |
541af946 | 232 | { |
72f3e00d | 233 | struct s { |
7c8ae03f | 234 | __be32 conv; |
72f3e00d SM |
235 | }; |
236 | struct s *conversion = (struct s *) buf; | |
541af946 | 237 | |
72f3e00d | 238 | conversion->conv = cpu_to_be32(val); |
541af946 | 239 | } |
541af946 SM |
240 | #endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */ |
241 | ||
242 | /****************************************************************** | |
243 | * CTR DRBG callback functions | |
244 | ******************************************************************/ | |
245 | ||
246 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
e25e47ec | 247 | #define CRYPTO_DRBG_CTR_STRING "CTR " |
0653a7cf SM |
248 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes256"); |
249 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes256"); | |
250 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes192"); | |
251 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192"); | |
252 | MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128"); | |
253 | MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128"); | |
62b62b6e | 254 | |
ed494d4f SM |
255 | static void drbg_kcapi_symsetkey(struct drbg_state *drbg, |
256 | const unsigned char *key); | |
257 | static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, | |
258 | const struct drbg_string *in); | |
541af946 SM |
259 | static int drbg_init_sym_kernel(struct drbg_state *drbg); |
260 | static int drbg_fini_sym_kernel(struct drbg_state *drbg); | |
261 | ||
262 | /* BCC function for CTR DRBG as defined in 10.4.3 */ | |
263 | static int drbg_ctr_bcc(struct drbg_state *drbg, | |
264 | unsigned char *out, const unsigned char *key, | |
8c987166 | 265 | struct list_head *in) |
541af946 | 266 | { |
8c987166 SM |
267 | int ret = 0; |
268 | struct drbg_string *curr = NULL; | |
541af946 | 269 | struct drbg_string data; |
8c987166 | 270 | short cnt = 0; |
541af946 SM |
271 | |
272 | drbg_string_fill(&data, out, drbg_blocklen(drbg)); | |
273 | ||
541af946 | 274 | /* 10.4.3 step 2 / 4 */ |
ed494d4f | 275 | drbg_kcapi_symsetkey(drbg, key); |
8c987166 SM |
276 | list_for_each_entry(curr, in, list) { |
277 | const unsigned char *pos = curr->buf; | |
278 | size_t len = curr->len; | |
541af946 | 279 | /* 10.4.3 step 4.1 */ |
8c987166 SM |
280 | while (len) { |
281 | /* 10.4.3 step 4.2 */ | |
282 | if (drbg_blocklen(drbg) == cnt) { | |
283 | cnt = 0; | |
ed494d4f | 284 | ret = drbg_kcapi_sym(drbg, out, &data); |
8c987166 SM |
285 | if (ret) |
286 | return ret; | |
541af946 | 287 | } |
8c987166 SM |
288 | out[cnt] ^= *pos; |
289 | pos++; | |
290 | cnt++; | |
291 | len--; | |
541af946 | 292 | } |
541af946 | 293 | } |
8c987166 SM |
294 | /* 10.4.3 step 4.2 for last block */ |
295 | if (cnt) | |
ed494d4f | 296 | ret = drbg_kcapi_sym(drbg, out, &data); |
8c987166 SM |
297 | |
298 | return ret; | |
541af946 SM |
299 | } |
300 | ||
301 | /* | |
302 | * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df | |
303 | * (and drbg_ctr_bcc, but this function does not need any temporary buffers), | |
304 | * the scratchpad is used as follows: | |
305 | * drbg_ctr_update: | |
306 | * temp | |
307 | * start: drbg->scratchpad | |
308 | * length: drbg_statelen(drbg) + drbg_blocklen(drbg) | |
309 | * note: the cipher writing into this variable works | |
310 | * blocklen-wise. Now, when the statelen is not a multiple | |
311 | * of blocklen, the generateion loop below "spills over" | |
312 | * by at most blocklen. Thus, we need to give sufficient | |
313 | * memory. | |
314 | * df_data | |
315 | * start: drbg->scratchpad + | |
316 | * drbg_statelen(drbg) + drbg_blocklen(drbg) | |
317 | * length: drbg_statelen(drbg) | |
318 | * | |
319 | * drbg_ctr_df: | |
320 | * pad | |
321 | * start: df_data + drbg_statelen(drbg) | |
322 | * length: drbg_blocklen(drbg) | |
323 | * iv | |
324 | * start: pad + drbg_blocklen(drbg) | |
325 | * length: drbg_blocklen(drbg) | |
326 | * temp | |
327 | * start: iv + drbg_blocklen(drbg) | |
8fecaad7 SM |
328 | * length: drbg_satelen(drbg) + drbg_blocklen(drbg) |
329 | * note: temp is the buffer that the BCC function operates | |
330 | * on. BCC operates blockwise. drbg_statelen(drbg) | |
331 | * is sufficient when the DRBG state length is a multiple | |
332 | * of the block size. For AES192 (and maybe other ciphers) | |
333 | * this is not correct and the length for temp is | |
334 | * insufficient (yes, that also means for such ciphers, | |
335 | * the final output of all BCC rounds are truncated). | |
336 | * Therefore, add drbg_blocklen(drbg) to cover all | |
337 | * possibilities. | |
541af946 SM |
338 | */ |
339 | ||
340 | /* Derivation Function for CTR DRBG as defined in 10.4.2 */ | |
341 | static int drbg_ctr_df(struct drbg_state *drbg, | |
342 | unsigned char *df_data, size_t bytes_to_return, | |
8c987166 | 343 | struct list_head *seedlist) |
541af946 SM |
344 | { |
345 | int ret = -EFAULT; | |
346 | unsigned char L_N[8]; | |
347 | /* S3 is input */ | |
348 | struct drbg_string S1, S2, S4, cipherin; | |
8c987166 | 349 | LIST_HEAD(bcc_list); |
541af946 SM |
350 | unsigned char *pad = df_data + drbg_statelen(drbg); |
351 | unsigned char *iv = pad + drbg_blocklen(drbg); | |
352 | unsigned char *temp = iv + drbg_blocklen(drbg); | |
353 | size_t padlen = 0; | |
354 | unsigned int templen = 0; | |
355 | /* 10.4.2 step 7 */ | |
356 | unsigned int i = 0; | |
357 | /* 10.4.2 step 8 */ | |
358 | const unsigned char *K = (unsigned char *) | |
359 | "\x00\x01\x02\x03\x04\x05\x06\x07" | |
360 | "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" | |
361 | "\x10\x11\x12\x13\x14\x15\x16\x17" | |
362 | "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"; | |
363 | unsigned char *X; | |
364 | size_t generated_len = 0; | |
365 | size_t inputlen = 0; | |
8c987166 | 366 | struct drbg_string *seed = NULL; |
541af946 SM |
367 | |
368 | memset(pad, 0, drbg_blocklen(drbg)); | |
369 | memset(iv, 0, drbg_blocklen(drbg)); | |
541af946 SM |
370 | |
371 | /* 10.4.2 step 1 is implicit as we work byte-wise */ | |
372 | ||
373 | /* 10.4.2 step 2 */ | |
374 | if ((512/8) < bytes_to_return) | |
375 | return -EINVAL; | |
376 | ||
377 | /* 10.4.2 step 2 -- calculate the entire length of all input data */ | |
8c987166 SM |
378 | list_for_each_entry(seed, seedlist, list) |
379 | inputlen += seed->len; | |
72f3e00d | 380 | drbg_cpu_to_be32(inputlen, &L_N[0]); |
541af946 SM |
381 | |
382 | /* 10.4.2 step 3 */ | |
72f3e00d | 383 | drbg_cpu_to_be32(bytes_to_return, &L_N[4]); |
541af946 SM |
384 | |
385 | /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */ | |
386 | padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg)); | |
387 | /* wrap the padlen appropriately */ | |
388 | if (padlen) | |
389 | padlen = drbg_blocklen(drbg) - padlen; | |
390 | /* | |
391 | * pad / padlen contains the 0x80 byte and the following zero bytes. | |
392 | * As the calculated padlen value only covers the number of zero | |
393 | * bytes, this value has to be incremented by one for the 0x80 byte. | |
394 | */ | |
395 | padlen++; | |
396 | pad[0] = 0x80; | |
397 | ||
398 | /* 10.4.2 step 4 -- first fill the linked list and then order it */ | |
399 | drbg_string_fill(&S1, iv, drbg_blocklen(drbg)); | |
8c987166 | 400 | list_add_tail(&S1.list, &bcc_list); |
541af946 | 401 | drbg_string_fill(&S2, L_N, sizeof(L_N)); |
8c987166 SM |
402 | list_add_tail(&S2.list, &bcc_list); |
403 | list_splice_tail(seedlist, &bcc_list); | |
541af946 | 404 | drbg_string_fill(&S4, pad, padlen); |
8c987166 | 405 | list_add_tail(&S4.list, &bcc_list); |
541af946 SM |
406 | |
407 | /* 10.4.2 step 9 */ | |
408 | while (templen < (drbg_keylen(drbg) + (drbg_blocklen(drbg)))) { | |
409 | /* | |
410 | * 10.4.2 step 9.1 - the padding is implicit as the buffer | |
411 | * holds zeros after allocation -- even the increment of i | |
412 | * is irrelevant as the increment remains within length of i | |
413 | */ | |
72f3e00d | 414 | drbg_cpu_to_be32(i, iv); |
541af946 | 415 | /* 10.4.2 step 9.2 -- BCC and concatenation with temp */ |
8c987166 | 416 | ret = drbg_ctr_bcc(drbg, temp + templen, K, &bcc_list); |
541af946 SM |
417 | if (ret) |
418 | goto out; | |
419 | /* 10.4.2 step 9.3 */ | |
420 | i++; | |
421 | templen += drbg_blocklen(drbg); | |
422 | } | |
423 | ||
424 | /* 10.4.2 step 11 */ | |
425 | X = temp + (drbg_keylen(drbg)); | |
426 | drbg_string_fill(&cipherin, X, drbg_blocklen(drbg)); | |
427 | ||
428 | /* 10.4.2 step 12: overwriting of outval is implemented in next step */ | |
429 | ||
430 | /* 10.4.2 step 13 */ | |
ed494d4f | 431 | drbg_kcapi_symsetkey(drbg, temp); |
541af946 SM |
432 | while (generated_len < bytes_to_return) { |
433 | short blocklen = 0; | |
434 | /* | |
435 | * 10.4.2 step 13.1: the truncation of the key length is | |
436 | * implicit as the key is only drbg_blocklen in size based on | |
437 | * the implementation of the cipher function callback | |
438 | */ | |
ed494d4f | 439 | ret = drbg_kcapi_sym(drbg, X, &cipherin); |
541af946 SM |
440 | if (ret) |
441 | goto out; | |
442 | blocklen = (drbg_blocklen(drbg) < | |
443 | (bytes_to_return - generated_len)) ? | |
444 | drbg_blocklen(drbg) : | |
445 | (bytes_to_return - generated_len); | |
446 | /* 10.4.2 step 13.2 and 14 */ | |
447 | memcpy(df_data + generated_len, X, blocklen); | |
448 | generated_len += blocklen; | |
449 | } | |
450 | ||
451 | ret = 0; | |
452 | ||
453 | out: | |
1471f09f | 454 | memset(iv, 0, drbg_blocklen(drbg)); |
8e0498d9 | 455 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
1471f09f | 456 | memset(pad, 0, drbg_blocklen(drbg)); |
541af946 SM |
457 | return ret; |
458 | } | |
459 | ||
72e7c25a SM |
460 | /* |
461 | * update function of CTR DRBG as defined in 10.2.1.2 | |
462 | * | |
463 | * The reseed variable has an enhanced meaning compared to the update | |
464 | * functions of the other DRBGs as follows: | |
465 | * 0 => initial seed from initialization | |
466 | * 1 => reseed via drbg_seed | |
467 | * 2 => first invocation from drbg_ctr_update when addtl is present. In | |
468 | * this case, the df_data scratchpad is not deleted so that it is | |
469 | * available for another calls to prevent calling the DF function | |
470 | * again. | |
471 | * 3 => second invocation from drbg_ctr_update. When the update function | |
472 | * was called with addtl, the df_data memory already contains the | |
473 | * DFed addtl information and we do not need to call DF again. | |
474 | */ | |
8c987166 SM |
475 | static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, |
476 | int reseed) | |
541af946 SM |
477 | { |
478 | int ret = -EFAULT; | |
479 | /* 10.2.1.2 step 1 */ | |
480 | unsigned char *temp = drbg->scratchpad; | |
481 | unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) + | |
482 | drbg_blocklen(drbg); | |
483 | unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */ | |
484 | unsigned int len = 0; | |
485 | struct drbg_string cipherin; | |
541af946 | 486 | |
72e7c25a SM |
487 | if (3 > reseed) |
488 | memset(df_data, 0, drbg_statelen(drbg)); | |
541af946 SM |
489 | |
490 | /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */ | |
8c987166 SM |
491 | if (seed) { |
492 | ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed); | |
541af946 SM |
493 | if (ret) |
494 | goto out; | |
ed494d4f | 495 | drbg_kcapi_symsetkey(drbg, drbg->C); |
541af946 SM |
496 | } |
497 | ||
498 | drbg_string_fill(&cipherin, drbg->V, drbg_blocklen(drbg)); | |
499 | /* | |
500 | * 10.2.1.3.2 steps 2 and 3 are already covered as the allocation | |
501 | * zeroizes all memory during initialization | |
502 | */ | |
503 | while (len < (drbg_statelen(drbg))) { | |
504 | /* 10.2.1.2 step 2.1 */ | |
41a84982 | 505 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
506 | /* |
507 | * 10.2.1.2 step 2.2 */ | |
ed494d4f | 508 | ret = drbg_kcapi_sym(drbg, temp + len, &cipherin); |
541af946 SM |
509 | if (ret) |
510 | goto out; | |
511 | /* 10.2.1.2 step 2.3 and 3 */ | |
512 | len += drbg_blocklen(drbg); | |
513 | } | |
514 | ||
515 | /* 10.2.1.2 step 4 */ | |
516 | temp_p = temp; | |
517 | df_data_p = df_data; | |
518 | for (len = 0; len < drbg_statelen(drbg); len++) { | |
519 | *temp_p ^= *df_data_p; | |
520 | df_data_p++; temp_p++; | |
521 | } | |
522 | ||
523 | /* 10.2.1.2 step 5 */ | |
524 | memcpy(drbg->C, temp, drbg_keylen(drbg)); | |
ed494d4f | 525 | drbg_kcapi_symsetkey(drbg, drbg->C); |
541af946 SM |
526 | /* 10.2.1.2 step 6 */ |
527 | memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg)); | |
528 | ret = 0; | |
529 | ||
530 | out: | |
1471f09f | 531 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
72e7c25a | 532 | if (2 != reseed) |
1471f09f | 533 | memset(df_data, 0, drbg_statelen(drbg)); |
541af946 SM |
534 | return ret; |
535 | } | |
536 | ||
537 | /* | |
538 | * scratchpad use: drbg_ctr_update is called independently from | |
539 | * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused | |
540 | */ | |
541 | /* Generate function of CTR DRBG as defined in 10.2.1.5.2 */ | |
542 | static int drbg_ctr_generate(struct drbg_state *drbg, | |
543 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 544 | struct list_head *addtl) |
541af946 SM |
545 | { |
546 | int len = 0; | |
547 | int ret = 0; | |
548 | struct drbg_string data; | |
541af946 | 549 | |
541af946 | 550 | /* 10.2.1.5.2 step 2 */ |
27e4de2b SM |
551 | if (addtl && !list_empty(addtl)) { |
552 | ret = drbg_ctr_update(drbg, addtl, 2); | |
541af946 SM |
553 | if (ret) |
554 | return 0; | |
ed494d4f | 555 | drbg_kcapi_symsetkey(drbg, drbg->C); |
541af946 SM |
556 | } |
557 | ||
558 | /* 10.2.1.5.2 step 4.1 */ | |
41a84982 | 559 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
560 | drbg_string_fill(&data, drbg->V, drbg_blocklen(drbg)); |
561 | while (len < buflen) { | |
562 | int outlen = 0; | |
563 | /* 10.2.1.5.2 step 4.2 */ | |
ed494d4f | 564 | ret = drbg_kcapi_sym(drbg, drbg->scratchpad, &data); |
541af946 SM |
565 | if (ret) { |
566 | len = ret; | |
567 | goto out; | |
568 | } | |
569 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
570 | drbg_blocklen(drbg) : (buflen - len); | |
541af946 SM |
571 | /* 10.2.1.5.2 step 4.3 */ |
572 | memcpy(buf + len, drbg->scratchpad, outlen); | |
573 | len += outlen; | |
574 | /* 10.2.1.5.2 step 6 */ | |
575 | if (len < buflen) | |
41a84982 | 576 | crypto_inc(drbg->V, drbg_blocklen(drbg)); |
541af946 SM |
577 | } |
578 | ||
72e7c25a SM |
579 | /* 10.2.1.5.2 step 6 */ |
580 | ret = drbg_ctr_update(drbg, NULL, 3); | |
541af946 SM |
581 | if (ret) |
582 | len = ret; | |
583 | ||
584 | out: | |
1471f09f | 585 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
586 | return len; |
587 | } | |
588 | ||
e4bc02ac | 589 | static const struct drbg_state_ops drbg_ctr_ops = { |
541af946 SM |
590 | .update = drbg_ctr_update, |
591 | .generate = drbg_ctr_generate, | |
592 | .crypto_init = drbg_init_sym_kernel, | |
593 | .crypto_fini = drbg_fini_sym_kernel, | |
594 | }; | |
595 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
596 | ||
597 | /****************************************************************** | |
598 | * HMAC DRBG callback functions | |
599 | ******************************************************************/ | |
600 | ||
601 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
4218ebe8 SM |
602 | static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, |
603 | const struct list_head *in); | |
604 | static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg, | |
605 | const unsigned char *key); | |
541af946 SM |
606 | static int drbg_init_hash_kernel(struct drbg_state *drbg); |
607 | static int drbg_fini_hash_kernel(struct drbg_state *drbg); | |
608 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
609 | ||
610 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
e25e47ec | 611 | #define CRYPTO_DRBG_HMAC_STRING "HMAC " |
0653a7cf SM |
612 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512"); |
613 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512"); | |
614 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384"); | |
615 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384"); | |
616 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256"); | |
617 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256"); | |
618 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1"); | |
619 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1"); | |
62b62b6e | 620 | |
541af946 | 621 | /* update function of HMAC DRBG as defined in 10.1.2.2 */ |
8c987166 SM |
622 | static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed, |
623 | int reseed) | |
541af946 SM |
624 | { |
625 | int ret = -EFAULT; | |
626 | int i = 0; | |
8c987166 SM |
627 | struct drbg_string seed1, seed2, vdata; |
628 | LIST_HEAD(seedlist); | |
629 | LIST_HEAD(vdatalist); | |
541af946 | 630 | |
4218ebe8 | 631 | if (!reseed) { |
f072f0e0 | 632 | /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */ |
541af946 | 633 | memset(drbg->V, 1, drbg_statelen(drbg)); |
4218ebe8 SM |
634 | drbg_kcapi_hmacsetkey(drbg, drbg->C); |
635 | } | |
541af946 SM |
636 | |
637 | drbg_string_fill(&seed1, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 638 | list_add_tail(&seed1.list, &seedlist); |
541af946 SM |
639 | /* buffer of seed2 will be filled in for loop below with one byte */ |
640 | drbg_string_fill(&seed2, NULL, 1); | |
8c987166 | 641 | list_add_tail(&seed2.list, &seedlist); |
541af946 | 642 | /* input data of seed is allowed to be NULL at this point */ |
8c987166 SM |
643 | if (seed) |
644 | list_splice_tail(seed, &seedlist); | |
541af946 | 645 | |
8c987166 SM |
646 | drbg_string_fill(&vdata, drbg->V, drbg_statelen(drbg)); |
647 | list_add_tail(&vdata.list, &vdatalist); | |
541af946 SM |
648 | for (i = 2; 0 < i; i--) { |
649 | /* first round uses 0x0, second 0x1 */ | |
650 | unsigned char prefix = DRBG_PREFIX0; | |
651 | if (1 == i) | |
652 | prefix = DRBG_PREFIX1; | |
653 | /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */ | |
654 | seed2.buf = &prefix; | |
4218ebe8 | 655 | ret = drbg_kcapi_hash(drbg, drbg->C, &seedlist); |
541af946 SM |
656 | if (ret) |
657 | return ret; | |
4218ebe8 | 658 | drbg_kcapi_hmacsetkey(drbg, drbg->C); |
541af946 SM |
659 | |
660 | /* 10.1.2.2 step 2 and 5 -- HMAC for V */ | |
4218ebe8 | 661 | ret = drbg_kcapi_hash(drbg, drbg->V, &vdatalist); |
541af946 SM |
662 | if (ret) |
663 | return ret; | |
664 | ||
665 | /* 10.1.2.2 step 3 */ | |
8c987166 | 666 | if (!seed) |
541af946 SM |
667 | return ret; |
668 | } | |
669 | ||
670 | return 0; | |
671 | } | |
672 | ||
673 | /* generate function of HMAC DRBG as defined in 10.1.2.5 */ | |
674 | static int drbg_hmac_generate(struct drbg_state *drbg, | |
675 | unsigned char *buf, | |
676 | unsigned int buflen, | |
27e4de2b | 677 | struct list_head *addtl) |
541af946 SM |
678 | { |
679 | int len = 0; | |
680 | int ret = 0; | |
681 | struct drbg_string data; | |
8c987166 | 682 | LIST_HEAD(datalist); |
541af946 SM |
683 | |
684 | /* 10.1.2.5 step 2 */ | |
27e4de2b SM |
685 | if (addtl && !list_empty(addtl)) { |
686 | ret = drbg_hmac_update(drbg, addtl, 1); | |
541af946 SM |
687 | if (ret) |
688 | return ret; | |
689 | } | |
690 | ||
691 | drbg_string_fill(&data, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 692 | list_add_tail(&data.list, &datalist); |
541af946 SM |
693 | while (len < buflen) { |
694 | unsigned int outlen = 0; | |
695 | /* 10.1.2.5 step 4.1 */ | |
4218ebe8 | 696 | ret = drbg_kcapi_hash(drbg, drbg->V, &datalist); |
541af946 SM |
697 | if (ret) |
698 | return ret; | |
699 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
700 | drbg_blocklen(drbg) : (buflen - len); | |
541af946 SM |
701 | |
702 | /* 10.1.2.5 step 4.2 */ | |
703 | memcpy(buf + len, drbg->V, outlen); | |
704 | len += outlen; | |
705 | } | |
706 | ||
707 | /* 10.1.2.5 step 6 */ | |
27e4de2b SM |
708 | if (addtl && !list_empty(addtl)) |
709 | ret = drbg_hmac_update(drbg, addtl, 1); | |
710 | else | |
8c987166 | 711 | ret = drbg_hmac_update(drbg, NULL, 1); |
541af946 SM |
712 | if (ret) |
713 | return ret; | |
714 | ||
715 | return len; | |
716 | } | |
717 | ||
e4bc02ac | 718 | static const struct drbg_state_ops drbg_hmac_ops = { |
541af946 SM |
719 | .update = drbg_hmac_update, |
720 | .generate = drbg_hmac_generate, | |
721 | .crypto_init = drbg_init_hash_kernel, | |
722 | .crypto_fini = drbg_fini_hash_kernel, | |
541af946 SM |
723 | }; |
724 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
725 | ||
726 | /****************************************************************** | |
727 | * Hash DRBG callback functions | |
728 | ******************************************************************/ | |
729 | ||
730 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
e25e47ec | 731 | #define CRYPTO_DRBG_HASH_STRING "HASH " |
0653a7cf SM |
732 | MODULE_ALIAS_CRYPTO("drbg_pr_sha512"); |
733 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha512"); | |
734 | MODULE_ALIAS_CRYPTO("drbg_pr_sha384"); | |
735 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha384"); | |
736 | MODULE_ALIAS_CRYPTO("drbg_pr_sha256"); | |
737 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha256"); | |
738 | MODULE_ALIAS_CRYPTO("drbg_pr_sha1"); | |
739 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha1"); | |
62b62b6e | 740 | |
41a84982 SM |
741 | /* |
742 | * Increment buffer | |
743 | * | |
744 | * @dst buffer to increment | |
745 | * @add value to add | |
746 | */ | |
747 | static inline void drbg_add_buf(unsigned char *dst, size_t dstlen, | |
748 | const unsigned char *add, size_t addlen) | |
749 | { | |
750 | /* implied: dstlen > addlen */ | |
751 | unsigned char *dstptr; | |
752 | const unsigned char *addptr; | |
753 | unsigned int remainder = 0; | |
754 | size_t len = addlen; | |
755 | ||
756 | dstptr = dst + (dstlen-1); | |
757 | addptr = add + (addlen-1); | |
758 | while (len) { | |
759 | remainder += *dstptr + *addptr; | |
760 | *dstptr = remainder & 0xff; | |
761 | remainder >>= 8; | |
762 | len--; dstptr--; addptr--; | |
763 | } | |
764 | len = dstlen - addlen; | |
765 | while (len && remainder > 0) { | |
766 | remainder = *dstptr + 1; | |
767 | *dstptr = remainder & 0xff; | |
768 | remainder >>= 8; | |
769 | len--; dstptr--; | |
770 | } | |
771 | } | |
772 | ||
541af946 SM |
773 | /* |
774 | * scratchpad usage: as drbg_hash_update and drbg_hash_df are used | |
775 | * interlinked, the scratchpad is used as follows: | |
776 | * drbg_hash_update | |
777 | * start: drbg->scratchpad | |
778 | * length: drbg_statelen(drbg) | |
779 | * drbg_hash_df: | |
780 | * start: drbg->scratchpad + drbg_statelen(drbg) | |
781 | * length: drbg_blocklen(drbg) | |
782 | * | |
783 | * drbg_hash_process_addtl uses the scratchpad, but fully completes | |
784 | * before either of the functions mentioned before are invoked. Therefore, | |
785 | * drbg_hash_process_addtl does not need to be specifically considered. | |
786 | */ | |
787 | ||
788 | /* Derivation Function for Hash DRBG as defined in 10.4.1 */ | |
789 | static int drbg_hash_df(struct drbg_state *drbg, | |
790 | unsigned char *outval, size_t outlen, | |
8c987166 | 791 | struct list_head *entropylist) |
541af946 SM |
792 | { |
793 | int ret = 0; | |
794 | size_t len = 0; | |
795 | unsigned char input[5]; | |
796 | unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg); | |
8c987166 | 797 | struct drbg_string data; |
541af946 | 798 | |
541af946 SM |
799 | /* 10.4.1 step 3 */ |
800 | input[0] = 1; | |
72f3e00d | 801 | drbg_cpu_to_be32((outlen * 8), &input[1]); |
541af946 SM |
802 | |
803 | /* 10.4.1 step 4.1 -- concatenation of data for input into hash */ | |
8c987166 SM |
804 | drbg_string_fill(&data, input, 5); |
805 | list_add(&data.list, entropylist); | |
541af946 SM |
806 | |
807 | /* 10.4.1 step 4 */ | |
808 | while (len < outlen) { | |
809 | short blocklen = 0; | |
810 | /* 10.4.1 step 4.1 */ | |
4218ebe8 | 811 | ret = drbg_kcapi_hash(drbg, tmp, entropylist); |
541af946 SM |
812 | if (ret) |
813 | goto out; | |
814 | /* 10.4.1 step 4.2 */ | |
815 | input[0]++; | |
816 | blocklen = (drbg_blocklen(drbg) < (outlen - len)) ? | |
817 | drbg_blocklen(drbg) : (outlen - len); | |
818 | memcpy(outval + len, tmp, blocklen); | |
819 | len += blocklen; | |
820 | } | |
821 | ||
822 | out: | |
1471f09f | 823 | memset(tmp, 0, drbg_blocklen(drbg)); |
541af946 SM |
824 | return ret; |
825 | } | |
826 | ||
827 | /* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */ | |
8c987166 | 828 | static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed, |
541af946 SM |
829 | int reseed) |
830 | { | |
831 | int ret = 0; | |
832 | struct drbg_string data1, data2; | |
8c987166 SM |
833 | LIST_HEAD(datalist); |
834 | LIST_HEAD(datalist2); | |
541af946 SM |
835 | unsigned char *V = drbg->scratchpad; |
836 | unsigned char prefix = DRBG_PREFIX1; | |
837 | ||
541af946 SM |
838 | if (!seed) |
839 | return -EINVAL; | |
840 | ||
841 | if (reseed) { | |
842 | /* 10.1.1.3 step 1 */ | |
843 | memcpy(V, drbg->V, drbg_statelen(drbg)); | |
844 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 845 | list_add_tail(&data1.list, &datalist); |
541af946 | 846 | drbg_string_fill(&data2, V, drbg_statelen(drbg)); |
8c987166 | 847 | list_add_tail(&data2.list, &datalist); |
541af946 | 848 | } |
8c987166 | 849 | list_splice_tail(seed, &datalist); |
541af946 SM |
850 | |
851 | /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */ | |
8c987166 | 852 | ret = drbg_hash_df(drbg, drbg->V, drbg_statelen(drbg), &datalist); |
541af946 SM |
853 | if (ret) |
854 | goto out; | |
855 | ||
856 | /* 10.1.1.2 / 10.1.1.3 step 4 */ | |
857 | prefix = DRBG_PREFIX0; | |
858 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 859 | list_add_tail(&data1.list, &datalist2); |
541af946 | 860 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 | 861 | list_add_tail(&data2.list, &datalist2); |
541af946 | 862 | /* 10.1.1.2 / 10.1.1.3 step 4 */ |
8c987166 | 863 | ret = drbg_hash_df(drbg, drbg->C, drbg_statelen(drbg), &datalist2); |
541af946 SM |
864 | |
865 | out: | |
1471f09f | 866 | memset(drbg->scratchpad, 0, drbg_statelen(drbg)); |
541af946 SM |
867 | return ret; |
868 | } | |
869 | ||
870 | /* processing of additional information string for Hash DRBG */ | |
871 | static int drbg_hash_process_addtl(struct drbg_state *drbg, | |
27e4de2b | 872 | struct list_head *addtl) |
541af946 SM |
873 | { |
874 | int ret = 0; | |
875 | struct drbg_string data1, data2; | |
8c987166 | 876 | LIST_HEAD(datalist); |
541af946 SM |
877 | unsigned char prefix = DRBG_PREFIX2; |
878 | ||
541af946 | 879 | /* 10.1.1.4 step 2 */ |
27e4de2b | 880 | if (!addtl || list_empty(addtl)) |
541af946 SM |
881 | return 0; |
882 | ||
883 | /* 10.1.1.4 step 2a */ | |
884 | drbg_string_fill(&data1, &prefix, 1); | |
885 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); | |
8c987166 SM |
886 | list_add_tail(&data1.list, &datalist); |
887 | list_add_tail(&data2.list, &datalist); | |
27e4de2b | 888 | list_splice_tail(addtl, &datalist); |
4218ebe8 | 889 | ret = drbg_kcapi_hash(drbg, drbg->scratchpad, &datalist); |
541af946 SM |
890 | if (ret) |
891 | goto out; | |
892 | ||
893 | /* 10.1.1.4 step 2b */ | |
894 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
895 | drbg->scratchpad, drbg_blocklen(drbg)); | |
896 | ||
897 | out: | |
1471f09f | 898 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
899 | return ret; |
900 | } | |
901 | ||
902 | /* Hashgen defined in 10.1.1.4 */ | |
903 | static int drbg_hash_hashgen(struct drbg_state *drbg, | |
904 | unsigned char *buf, | |
905 | unsigned int buflen) | |
906 | { | |
907 | int len = 0; | |
908 | int ret = 0; | |
909 | unsigned char *src = drbg->scratchpad; | |
910 | unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg); | |
911 | struct drbg_string data; | |
8c987166 | 912 | LIST_HEAD(datalist); |
541af946 | 913 | |
541af946 SM |
914 | /* 10.1.1.4 step hashgen 2 */ |
915 | memcpy(src, drbg->V, drbg_statelen(drbg)); | |
916 | ||
917 | drbg_string_fill(&data, src, drbg_statelen(drbg)); | |
8c987166 | 918 | list_add_tail(&data.list, &datalist); |
541af946 SM |
919 | while (len < buflen) { |
920 | unsigned int outlen = 0; | |
921 | /* 10.1.1.4 step hashgen 4.1 */ | |
4218ebe8 | 922 | ret = drbg_kcapi_hash(drbg, dst, &datalist); |
541af946 SM |
923 | if (ret) { |
924 | len = ret; | |
925 | goto out; | |
926 | } | |
927 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
928 | drbg_blocklen(drbg) : (buflen - len); | |
541af946 SM |
929 | /* 10.1.1.4 step hashgen 4.2 */ |
930 | memcpy(buf + len, dst, outlen); | |
931 | len += outlen; | |
932 | /* 10.1.1.4 hashgen step 4.3 */ | |
933 | if (len < buflen) | |
41a84982 | 934 | crypto_inc(src, drbg_statelen(drbg)); |
541af946 SM |
935 | } |
936 | ||
937 | out: | |
1471f09f | 938 | memset(drbg->scratchpad, 0, |
541af946 SM |
939 | (drbg_statelen(drbg) + drbg_blocklen(drbg))); |
940 | return len; | |
941 | } | |
942 | ||
943 | /* generate function for Hash DRBG as defined in 10.1.1.4 */ | |
944 | static int drbg_hash_generate(struct drbg_state *drbg, | |
945 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 946 | struct list_head *addtl) |
541af946 SM |
947 | { |
948 | int len = 0; | |
949 | int ret = 0; | |
72f3e00d SM |
950 | union { |
951 | unsigned char req[8]; | |
7c8ae03f | 952 | __be64 req_int; |
72f3e00d | 953 | } u; |
541af946 SM |
954 | unsigned char prefix = DRBG_PREFIX3; |
955 | struct drbg_string data1, data2; | |
8c987166 | 956 | LIST_HEAD(datalist); |
541af946 SM |
957 | |
958 | /* 10.1.1.4 step 2 */ | |
959 | ret = drbg_hash_process_addtl(drbg, addtl); | |
960 | if (ret) | |
961 | return ret; | |
962 | /* 10.1.1.4 step 3 */ | |
963 | len = drbg_hash_hashgen(drbg, buf, buflen); | |
964 | ||
965 | /* this is the value H as documented in 10.1.1.4 */ | |
541af946 SM |
966 | /* 10.1.1.4 step 4 */ |
967 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 968 | list_add_tail(&data1.list, &datalist); |
541af946 | 969 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 | 970 | list_add_tail(&data2.list, &datalist); |
4218ebe8 | 971 | ret = drbg_kcapi_hash(drbg, drbg->scratchpad, &datalist); |
541af946 SM |
972 | if (ret) { |
973 | len = ret; | |
974 | goto out; | |
975 | } | |
976 | ||
977 | /* 10.1.1.4 step 5 */ | |
978 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
979 | drbg->scratchpad, drbg_blocklen(drbg)); | |
980 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
981 | drbg->C, drbg_statelen(drbg)); | |
72f3e00d SM |
982 | u.req_int = cpu_to_be64(drbg->reseed_ctr); |
983 | drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8); | |
541af946 SM |
984 | |
985 | out: | |
1471f09f | 986 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
987 | return len; |
988 | } | |
989 | ||
990 | /* | |
991 | * scratchpad usage: as update and generate are used isolated, both | |
992 | * can use the scratchpad | |
993 | */ | |
e4bc02ac | 994 | static const struct drbg_state_ops drbg_hash_ops = { |
541af946 SM |
995 | .update = drbg_hash_update, |
996 | .generate = drbg_hash_generate, | |
997 | .crypto_init = drbg_init_hash_kernel, | |
998 | .crypto_fini = drbg_fini_hash_kernel, | |
999 | }; | |
1000 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1001 | ||
1002 | /****************************************************************** | |
1003 | * Functions common for DRBG implementations | |
1004 | ******************************************************************/ | |
1005 | ||
3d6a5f75 SM |
1006 | static inline int __drbg_seed(struct drbg_state *drbg, struct list_head *seed, |
1007 | int reseed) | |
1008 | { | |
1009 | int ret = drbg->d_ops->update(drbg, seed, reseed); | |
1010 | ||
1011 | if (ret) | |
1012 | return ret; | |
1013 | ||
1014 | drbg->seeded = true; | |
1015 | /* 10.1.1.2 / 10.1.1.3 step 5 */ | |
1016 | drbg->reseed_ctr = 1; | |
1017 | ||
1018 | return ret; | |
1019 | } | |
1020 | ||
4c787990 SM |
1021 | static void drbg_async_seed(struct work_struct *work) |
1022 | { | |
1023 | struct drbg_string data; | |
1024 | LIST_HEAD(seedlist); | |
1025 | struct drbg_state *drbg = container_of(work, struct drbg_state, | |
1026 | seed_work); | |
57225e67 SM |
1027 | unsigned int entropylen = drbg_sec_strength(drbg->core->flags); |
1028 | unsigned char entropy[32]; | |
4c787990 | 1029 | |
57225e67 SM |
1030 | BUG_ON(!entropylen); |
1031 | BUG_ON(entropylen > sizeof(entropy)); | |
1032 | get_random_bytes(entropy, entropylen); | |
4c787990 | 1033 | |
57225e67 | 1034 | drbg_string_fill(&data, entropy, entropylen); |
4c787990 | 1035 | list_add_tail(&data.list, &seedlist); |
57225e67 | 1036 | |
4c787990 | 1037 | mutex_lock(&drbg->drbg_mutex); |
57225e67 SM |
1038 | |
1039 | /* If nonblocking pool is initialized, deactivate Jitter RNG */ | |
1040 | crypto_free_rng(drbg->jent); | |
1041 | drbg->jent = NULL; | |
1042 | ||
1043 | /* Set seeded to false so that if __drbg_seed fails the | |
1044 | * next generate call will trigger a reseed. | |
1045 | */ | |
1046 | drbg->seeded = false; | |
1047 | ||
1048 | __drbg_seed(drbg, &seedlist, true); | |
1049 | ||
42ea507f SM |
1050 | if (drbg->seeded) |
1051 | drbg->reseed_threshold = drbg_max_requests(drbg); | |
1052 | ||
4c787990 | 1053 | mutex_unlock(&drbg->drbg_mutex); |
57225e67 SM |
1054 | |
1055 | memzero_explicit(entropy, entropylen); | |
4c787990 SM |
1056 | } |
1057 | ||
541af946 SM |
1058 | /* |
1059 | * Seeding or reseeding of the DRBG | |
1060 | * | |
1061 | * @drbg: DRBG state struct | |
1062 | * @pers: personalization / additional information buffer | |
1063 | * @reseed: 0 for initial seed process, 1 for reseeding | |
1064 | * | |
1065 | * return: | |
1066 | * 0 on success | |
1067 | * error value otherwise | |
1068 | */ | |
1069 | static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers, | |
1070 | bool reseed) | |
1071 | { | |
57225e67 SM |
1072 | int ret; |
1073 | unsigned char entropy[((32 + 16) * 2)]; | |
1074 | unsigned int entropylen = drbg_sec_strength(drbg->core->flags); | |
541af946 | 1075 | struct drbg_string data1; |
8c987166 | 1076 | LIST_HEAD(seedlist); |
541af946 SM |
1077 | |
1078 | /* 9.1 / 9.2 / 9.3.1 step 3 */ | |
1079 | if (pers && pers->len > (drbg_max_addtl(drbg))) { | |
a9089571 | 1080 | pr_devel("DRBG: personalization string too long %zu\n", |
541af946 SM |
1081 | pers->len); |
1082 | return -EINVAL; | |
1083 | } | |
1084 | ||
8fded592 HX |
1085 | if (list_empty(&drbg->test_data.list)) { |
1086 | drbg_string_fill(&data1, drbg->test_data.buf, | |
1087 | drbg->test_data.len); | |
541af946 SM |
1088 | pr_devel("DRBG: using test entropy\n"); |
1089 | } else { | |
57225e67 SM |
1090 | /* |
1091 | * Gather entropy equal to the security strength of the DRBG. | |
1092 | * With a derivation function, a nonce is required in addition | |
1093 | * to the entropy. A nonce must be at least 1/2 of the security | |
1094 | * strength of the DRBG in size. Thus, entropy + nonce is 3/2 | |
1095 | * of the strength. The consideration of a nonce is only | |
1096 | * applicable during initial seeding. | |
1097 | */ | |
1098 | BUG_ON(!entropylen); | |
1099 | if (!reseed) | |
1100 | entropylen = ((entropylen + 1) / 2) * 3; | |
1101 | BUG_ON((entropylen * 2) > sizeof(entropy)); | |
1102 | ||
b8ec5ba4 | 1103 | /* Get seed from in-kernel /dev/urandom */ |
57225e67 SM |
1104 | get_random_bytes(entropy, entropylen); |
1105 | ||
1106 | if (!drbg->jent) { | |
1107 | drbg_string_fill(&data1, entropy, entropylen); | |
1108 | pr_devel("DRBG: (re)seeding with %u bytes of entropy\n", | |
1109 | entropylen); | |
b8ec5ba4 | 1110 | } else { |
57225e67 SM |
1111 | /* Get seed from Jitter RNG */ |
1112 | ret = crypto_rng_get_bytes(drbg->jent, | |
1113 | entropy + entropylen, | |
1114 | entropylen); | |
1115 | if (ret) { | |
1116 | pr_devel("DRBG: jent failed with %d\n", ret); | |
1117 | return ret; | |
1118 | } | |
1119 | ||
1120 | drbg_string_fill(&data1, entropy, entropylen * 2); | |
1121 | pr_devel("DRBG: (re)seeding with %u bytes of entropy\n", | |
1122 | entropylen * 2); | |
b8ec5ba4 | 1123 | } |
541af946 | 1124 | } |
8c987166 | 1125 | list_add_tail(&data1.list, &seedlist); |
541af946 SM |
1126 | |
1127 | /* | |
1128 | * concatenation of entropy with personalization str / addtl input) | |
1129 | * the variable pers is directly handed in by the caller, so check its | |
1130 | * contents whether it is appropriate | |
1131 | */ | |
8c987166 SM |
1132 | if (pers && pers->buf && 0 < pers->len) { |
1133 | list_add_tail(&pers->list, &seedlist); | |
541af946 SM |
1134 | pr_devel("DRBG: using personalization string\n"); |
1135 | } | |
1136 | ||
e6c0244a SM |
1137 | if (!reseed) { |
1138 | memset(drbg->V, 0, drbg_statelen(drbg)); | |
1139 | memset(drbg->C, 0, drbg_statelen(drbg)); | |
1140 | } | |
1141 | ||
3d6a5f75 SM |
1142 | ret = __drbg_seed(drbg, &seedlist, reseed); |
1143 | ||
57225e67 | 1144 | memzero_explicit(entropy, entropylen * 2); |
4c787990 | 1145 | |
541af946 SM |
1146 | return ret; |
1147 | } | |
1148 | ||
1149 | /* Free all substructures in a DRBG state without the DRBG state structure */ | |
1150 | static inline void drbg_dealloc_state(struct drbg_state *drbg) | |
1151 | { | |
1152 | if (!drbg) | |
1153 | return; | |
46f64f6e | 1154 | kzfree(drbg->V); |
541af946 | 1155 | drbg->V = NULL; |
46f64f6e | 1156 | kzfree(drbg->C); |
541af946 | 1157 | drbg->C = NULL; |
46f64f6e | 1158 | kzfree(drbg->scratchpad); |
541af946 SM |
1159 | drbg->scratchpad = NULL; |
1160 | drbg->reseed_ctr = 0; | |
2a57e424 HX |
1161 | drbg->d_ops = NULL; |
1162 | drbg->core = NULL; | |
541af946 SM |
1163 | } |
1164 | ||
1165 | /* | |
1166 | * Allocate all sub-structures for a DRBG state. | |
1167 | * The DRBG state structure must already be allocated. | |
1168 | */ | |
1169 | static inline int drbg_alloc_state(struct drbg_state *drbg) | |
1170 | { | |
1171 | int ret = -ENOMEM; | |
1172 | unsigned int sb_size = 0; | |
1173 | ||
2a57e424 HX |
1174 | switch (drbg->core->flags & DRBG_TYPE_MASK) { |
1175 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
1176 | case DRBG_HMAC: | |
1177 | drbg->d_ops = &drbg_hmac_ops; | |
1178 | break; | |
1179 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
1180 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
1181 | case DRBG_HASH: | |
1182 | drbg->d_ops = &drbg_hash_ops; | |
1183 | break; | |
1184 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1185 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1186 | case DRBG_CTR: | |
1187 | drbg->d_ops = &drbg_ctr_ops; | |
1188 | break; | |
1189 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
1190 | default: | |
1191 | ret = -EOPNOTSUPP; | |
1192 | goto err; | |
1193 | } | |
1194 | ||
e6c0244a | 1195 | drbg->V = kmalloc(drbg_statelen(drbg), GFP_KERNEL); |
541af946 SM |
1196 | if (!drbg->V) |
1197 | goto err; | |
e6c0244a | 1198 | drbg->C = kmalloc(drbg_statelen(drbg), GFP_KERNEL); |
541af946 SM |
1199 | if (!drbg->C) |
1200 | goto err; | |
541af946 SM |
1201 | /* scratchpad is only generated for CTR and Hash */ |
1202 | if (drbg->core->flags & DRBG_HMAC) | |
1203 | sb_size = 0; | |
1204 | else if (drbg->core->flags & DRBG_CTR) | |
1205 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg) + /* temp */ | |
1206 | drbg_statelen(drbg) + /* df_data */ | |
1207 | drbg_blocklen(drbg) + /* pad */ | |
1208 | drbg_blocklen(drbg) + /* iv */ | |
8fecaad7 | 1209 | drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */ |
541af946 SM |
1210 | else |
1211 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg); | |
1212 | ||
1213 | if (0 < sb_size) { | |
1214 | drbg->scratchpad = kzalloc(sb_size, GFP_KERNEL); | |
1215 | if (!drbg->scratchpad) | |
1216 | goto err; | |
1217 | } | |
3d6a5f75 | 1218 | |
541af946 SM |
1219 | return 0; |
1220 | ||
1221 | err: | |
1222 | drbg_dealloc_state(drbg); | |
1223 | return ret; | |
1224 | } | |
1225 | ||
541af946 SM |
1226 | /************************************************************************* |
1227 | * DRBG interface functions | |
1228 | *************************************************************************/ | |
1229 | ||
1230 | /* | |
1231 | * DRBG generate function as required by SP800-90A - this function | |
1232 | * generates random numbers | |
1233 | * | |
1234 | * @drbg DRBG state handle | |
1235 | * @buf Buffer where to store the random numbers -- the buffer must already | |
1236 | * be pre-allocated by caller | |
1237 | * @buflen Length of output buffer - this value defines the number of random | |
1238 | * bytes pulled from DRBG | |
1239 | * @addtl Additional input that is mixed into state, may be NULL -- note | |
1240 | * the entropy is pulled by the DRBG internally unconditionally | |
1241 | * as defined in SP800-90A. The additional input is mixed into | |
1242 | * the state in addition to the pulled entropy. | |
1243 | * | |
cde001e4 | 1244 | * return: 0 when all bytes are generated; < 0 in case of an error |
541af946 SM |
1245 | */ |
1246 | static int drbg_generate(struct drbg_state *drbg, | |
1247 | unsigned char *buf, unsigned int buflen, | |
1248 | struct drbg_string *addtl) | |
1249 | { | |
1250 | int len = 0; | |
27e4de2b | 1251 | LIST_HEAD(addtllist); |
541af946 | 1252 | |
2a57e424 HX |
1253 | if (!drbg->core) { |
1254 | pr_devel("DRBG: not yet seeded\n"); | |
1255 | return -EINVAL; | |
1256 | } | |
541af946 SM |
1257 | if (0 == buflen || !buf) { |
1258 | pr_devel("DRBG: no output buffer provided\n"); | |
1259 | return -EINVAL; | |
1260 | } | |
1261 | if (addtl && NULL == addtl->buf && 0 < addtl->len) { | |
1262 | pr_devel("DRBG: wrong format of additional information\n"); | |
1263 | return -EINVAL; | |
1264 | } | |
1265 | ||
541af946 SM |
1266 | /* 9.3.1 step 2 */ |
1267 | len = -EINVAL; | |
76899a41 | 1268 | if (buflen > (drbg_max_request_bytes(drbg))) { |
541af946 SM |
1269 | pr_devel("DRBG: requested random numbers too large %u\n", |
1270 | buflen); | |
1271 | goto err; | |
1272 | } | |
1273 | ||
1274 | /* 9.3.1 step 3 is implicit with the chosen DRBG */ | |
1275 | ||
1276 | /* 9.3.1 step 4 */ | |
76899a41 | 1277 | if (addtl && addtl->len > (drbg_max_addtl(drbg))) { |
541af946 SM |
1278 | pr_devel("DRBG: additional information string too long %zu\n", |
1279 | addtl->len); | |
1280 | goto err; | |
1281 | } | |
1282 | /* 9.3.1 step 5 is implicit with the chosen DRBG */ | |
1283 | ||
1284 | /* | |
1285 | * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented | |
1286 | * here. The spec is a bit convoluted here, we make it simpler. | |
1287 | */ | |
42ea507f | 1288 | if (drbg->reseed_threshold < drbg->reseed_ctr) |
76899a41 | 1289 | drbg->seeded = false; |
541af946 | 1290 | |
76899a41 | 1291 | if (drbg->pr || !drbg->seeded) { |
541af946 SM |
1292 | pr_devel("DRBG: reseeding before generation (prediction " |
1293 | "resistance: %s, state %s)\n", | |
1294 | drbg->pr ? "true" : "false", | |
1295 | drbg->seeded ? "seeded" : "unseeded"); | |
1296 | /* 9.3.1 steps 7.1 through 7.3 */ | |
76899a41 | 1297 | len = drbg_seed(drbg, addtl, true); |
541af946 SM |
1298 | if (len) |
1299 | goto err; | |
1300 | /* 9.3.1 step 7.4 */ | |
1301 | addtl = NULL; | |
1302 | } | |
27e4de2b | 1303 | |
27e4de2b SM |
1304 | if (addtl && 0 < addtl->len) |
1305 | list_add_tail(&addtl->list, &addtllist); | |
541af946 | 1306 | /* 9.3.1 step 8 and 10 */ |
76899a41 | 1307 | len = drbg->d_ops->generate(drbg, buf, buflen, &addtllist); |
541af946 SM |
1308 | |
1309 | /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */ | |
76899a41 | 1310 | drbg->reseed_ctr++; |
541af946 SM |
1311 | if (0 >= len) |
1312 | goto err; | |
1313 | ||
1314 | /* | |
1315 | * Section 11.3.3 requires to re-perform self tests after some | |
1316 | * generated random numbers. The chosen value after which self | |
1317 | * test is performed is arbitrary, but it should be reasonable. | |
1318 | * However, we do not perform the self tests because of the following | |
1319 | * reasons: it is mathematically impossible that the initial self tests | |
1320 | * were successfully and the following are not. If the initial would | |
1321 | * pass and the following would not, the kernel integrity is violated. | |
1322 | * In this case, the entire kernel operation is questionable and it | |
1323 | * is unlikely that the integrity violation only affects the | |
1324 | * correct operation of the DRBG. | |
1325 | * | |
1326 | * Albeit the following code is commented out, it is provided in | |
1327 | * case somebody has a need to implement the test of 11.3.3. | |
1328 | */ | |
1329 | #if 0 | |
76899a41 | 1330 | if (drbg->reseed_ctr && !(drbg->reseed_ctr % 4096)) { |
541af946 SM |
1331 | int err = 0; |
1332 | pr_devel("DRBG: start to perform self test\n"); | |
1333 | if (drbg->core->flags & DRBG_HMAC) | |
1334 | err = alg_test("drbg_pr_hmac_sha256", | |
1335 | "drbg_pr_hmac_sha256", 0, 0); | |
1336 | else if (drbg->core->flags & DRBG_CTR) | |
1337 | err = alg_test("drbg_pr_ctr_aes128", | |
1338 | "drbg_pr_ctr_aes128", 0, 0); | |
1339 | else | |
1340 | err = alg_test("drbg_pr_sha256", | |
1341 | "drbg_pr_sha256", 0, 0); | |
1342 | if (err) { | |
1343 | pr_err("DRBG: periodical self test failed\n"); | |
1344 | /* | |
1345 | * uninstantiate implies that from now on, only errors | |
1346 | * are returned when reusing this DRBG cipher handle | |
1347 | */ | |
1348 | drbg_uninstantiate(drbg); | |
541af946 SM |
1349 | return 0; |
1350 | } else { | |
1351 | pr_devel("DRBG: self test successful\n"); | |
1352 | } | |
1353 | } | |
1354 | #endif | |
1355 | ||
cde001e4 SM |
1356 | /* |
1357 | * All operations were successful, return 0 as mandated by | |
1358 | * the kernel crypto API interface. | |
1359 | */ | |
1360 | len = 0; | |
541af946 | 1361 | err: |
541af946 SM |
1362 | return len; |
1363 | } | |
1364 | ||
1365 | /* | |
1366 | * Wrapper around drbg_generate which can pull arbitrary long strings | |
1367 | * from the DRBG without hitting the maximum request limitation. | |
1368 | * | |
1369 | * Parameters: see drbg_generate | |
1370 | * Return codes: see drbg_generate -- if one drbg_generate request fails, | |
1371 | * the entire drbg_generate_long request fails | |
1372 | */ | |
1373 | static int drbg_generate_long(struct drbg_state *drbg, | |
1374 | unsigned char *buf, unsigned int buflen, | |
1375 | struct drbg_string *addtl) | |
1376 | { | |
082eb10b | 1377 | unsigned int len = 0; |
541af946 SM |
1378 | unsigned int slice = 0; |
1379 | do { | |
082eb10b | 1380 | int err = 0; |
541af946 SM |
1381 | unsigned int chunk = 0; |
1382 | slice = ((buflen - len) / drbg_max_request_bytes(drbg)); | |
1383 | chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len); | |
76899a41 | 1384 | mutex_lock(&drbg->drbg_mutex); |
082eb10b | 1385 | err = drbg_generate(drbg, buf + len, chunk, addtl); |
76899a41 | 1386 | mutex_unlock(&drbg->drbg_mutex); |
082eb10b SM |
1387 | if (0 > err) |
1388 | return err; | |
1389 | len += chunk; | |
ce5481d0 | 1390 | } while (slice > 0 && (len < buflen)); |
082eb10b | 1391 | return 0; |
541af946 SM |
1392 | } |
1393 | ||
57225e67 SM |
1394 | static void drbg_schedule_async_seed(struct random_ready_callback *rdy) |
1395 | { | |
1396 | struct drbg_state *drbg = container_of(rdy, struct drbg_state, | |
1397 | random_ready); | |
1398 | ||
1399 | schedule_work(&drbg->seed_work); | |
1400 | } | |
1401 | ||
1402 | static int drbg_prepare_hrng(struct drbg_state *drbg) | |
1403 | { | |
1404 | int err; | |
1405 | ||
1406 | /* We do not need an HRNG in test mode. */ | |
1407 | if (list_empty(&drbg->test_data.list)) | |
1408 | return 0; | |
1409 | ||
1410 | INIT_WORK(&drbg->seed_work, drbg_async_seed); | |
1411 | ||
1412 | drbg->random_ready.owner = THIS_MODULE; | |
1413 | drbg->random_ready.func = drbg_schedule_async_seed; | |
1414 | ||
1415 | err = add_random_ready_callback(&drbg->random_ready); | |
1416 | ||
1417 | switch (err) { | |
1418 | case 0: | |
1419 | break; | |
1420 | ||
1421 | case -EALREADY: | |
1422 | err = 0; | |
1423 | /* fall through */ | |
1424 | ||
1425 | default: | |
1426 | drbg->random_ready.func = NULL; | |
1427 | return err; | |
1428 | } | |
1429 | ||
1430 | drbg->jent = crypto_alloc_rng("jitterentropy_rng", 0, 0); | |
1431 | ||
42ea507f SM |
1432 | /* |
1433 | * Require frequent reseeds until the seed source is fully | |
1434 | * initialized. | |
1435 | */ | |
1436 | drbg->reseed_threshold = 50; | |
1437 | ||
57225e67 SM |
1438 | return err; |
1439 | } | |
1440 | ||
541af946 SM |
1441 | /* |
1442 | * DRBG instantiation function as required by SP800-90A - this function | |
1443 | * sets up the DRBG handle, performs the initial seeding and all sanity | |
1444 | * checks required by SP800-90A | |
1445 | * | |
1446 | * @drbg memory of state -- if NULL, new memory is allocated | |
1447 | * @pers Personalization string that is mixed into state, may be NULL -- note | |
1448 | * the entropy is pulled by the DRBG internally unconditionally | |
1449 | * as defined in SP800-90A. The additional input is mixed into | |
1450 | * the state in addition to the pulled entropy. | |
1451 | * @coreref reference to core | |
1452 | * @pr prediction resistance enabled | |
1453 | * | |
1454 | * return | |
1455 | * 0 on success | |
1456 | * error value otherwise | |
1457 | */ | |
1458 | static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, | |
1459 | int coreref, bool pr) | |
1460 | { | |
2a57e424 HX |
1461 | int ret; |
1462 | bool reseed = true; | |
541af946 SM |
1463 | |
1464 | pr_devel("DRBG: Initializing DRBG core %d with prediction resistance " | |
1465 | "%s\n", coreref, pr ? "enabled" : "disabled"); | |
76899a41 | 1466 | mutex_lock(&drbg->drbg_mutex); |
541af946 SM |
1467 | |
1468 | /* 9.1 step 1 is implicit with the selected DRBG type */ | |
1469 | ||
1470 | /* | |
1471 | * 9.1 step 2 is implicit as caller can select prediction resistance | |
1472 | * and the flag is copied into drbg->flags -- | |
1473 | * all DRBG types support prediction resistance | |
1474 | */ | |
1475 | ||
1476 | /* 9.1 step 4 is implicit in drbg_sec_strength */ | |
1477 | ||
2a57e424 HX |
1478 | if (!drbg->core) { |
1479 | drbg->core = &drbg_cores[coreref]; | |
1480 | drbg->pr = pr; | |
1481 | drbg->seeded = false; | |
42ea507f | 1482 | drbg->reseed_threshold = drbg_max_requests(drbg); |
541af946 | 1483 | |
2a57e424 HX |
1484 | ret = drbg_alloc_state(drbg); |
1485 | if (ret) | |
1486 | goto unlock; | |
1487 | ||
1488 | ret = -EFAULT; | |
1489 | if (drbg->d_ops->crypto_init(drbg)) | |
1490 | goto err; | |
1491 | ||
57225e67 SM |
1492 | ret = drbg_prepare_hrng(drbg); |
1493 | if (ret) | |
1494 | goto free_everything; | |
1495 | ||
1496 | if (IS_ERR(drbg->jent)) { | |
1497 | ret = PTR_ERR(drbg->jent); | |
1498 | drbg->jent = NULL; | |
1499 | if (fips_enabled || ret != -ENOENT) | |
1500 | goto free_everything; | |
1501 | pr_info("DRBG: Continuing without Jitter RNG\n"); | |
1502 | } | |
1503 | ||
2a57e424 HX |
1504 | reseed = false; |
1505 | } | |
1506 | ||
1507 | ret = drbg_seed(drbg, pers, reseed); | |
1508 | ||
57225e67 SM |
1509 | if (ret && !reseed) |
1510 | goto free_everything; | |
541af946 | 1511 | |
76899a41 | 1512 | mutex_unlock(&drbg->drbg_mutex); |
2a57e424 | 1513 | return ret; |
541af946 SM |
1514 | |
1515 | err: | |
1516 | drbg_dealloc_state(drbg); | |
76899a41 SM |
1517 | unlock: |
1518 | mutex_unlock(&drbg->drbg_mutex); | |
541af946 | 1519 | return ret; |
57225e67 SM |
1520 | |
1521 | free_everything: | |
1522 | mutex_unlock(&drbg->drbg_mutex); | |
1523 | drbg_uninstantiate(drbg); | |
1524 | return ret; | |
541af946 SM |
1525 | } |
1526 | ||
1527 | /* | |
1528 | * DRBG uninstantiate function as required by SP800-90A - this function | |
1529 | * frees all buffers and the DRBG handle | |
1530 | * | |
1531 | * @drbg DRBG state handle | |
1532 | * | |
1533 | * return | |
1534 | * 0 on success | |
1535 | */ | |
1536 | static int drbg_uninstantiate(struct drbg_state *drbg) | |
1537 | { | |
57225e67 SM |
1538 | if (drbg->random_ready.func) { |
1539 | del_random_ready_callback(&drbg->random_ready); | |
1540 | cancel_work_sync(&drbg->seed_work); | |
1541 | crypto_free_rng(drbg->jent); | |
1542 | drbg->jent = NULL; | |
1543 | } | |
1544 | ||
2a57e424 HX |
1545 | if (drbg->d_ops) |
1546 | drbg->d_ops->crypto_fini(drbg); | |
541af946 SM |
1547 | drbg_dealloc_state(drbg); |
1548 | /* no scrubbing of test_data -- this shall survive an uninstantiate */ | |
541af946 SM |
1549 | return 0; |
1550 | } | |
1551 | ||
1552 | /* | |
1553 | * Helper function for setting the test data in the DRBG | |
1554 | * | |
1555 | * @drbg DRBG state handle | |
8fded592 HX |
1556 | * @data test data |
1557 | * @len test data length | |
541af946 | 1558 | */ |
8fded592 HX |
1559 | static void drbg_kcapi_set_entropy(struct crypto_rng *tfm, |
1560 | const u8 *data, unsigned int len) | |
541af946 | 1561 | { |
8fded592 HX |
1562 | struct drbg_state *drbg = crypto_rng_ctx(tfm); |
1563 | ||
1564 | mutex_lock(&drbg->drbg_mutex); | |
1565 | drbg_string_fill(&drbg->test_data, data, len); | |
76899a41 | 1566 | mutex_unlock(&drbg->drbg_mutex); |
541af946 SM |
1567 | } |
1568 | ||
1569 | /*************************************************************** | |
1570 | * Kernel crypto API cipher invocations requested by DRBG | |
1571 | ***************************************************************/ | |
1572 | ||
1573 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
1574 | struct sdesc { | |
1575 | struct shash_desc shash; | |
1576 | char ctx[]; | |
1577 | }; | |
1578 | ||
1579 | static int drbg_init_hash_kernel(struct drbg_state *drbg) | |
1580 | { | |
1581 | struct sdesc *sdesc; | |
1582 | struct crypto_shash *tfm; | |
1583 | ||
1584 | tfm = crypto_alloc_shash(drbg->core->backend_cra_name, 0, 0); | |
1585 | if (IS_ERR(tfm)) { | |
593dfbd9 SS |
1586 | pr_info("DRBG: could not allocate digest TFM handle: %s\n", |
1587 | drbg->core->backend_cra_name); | |
541af946 SM |
1588 | return PTR_ERR(tfm); |
1589 | } | |
1590 | BUG_ON(drbg_blocklen(drbg) != crypto_shash_digestsize(tfm)); | |
1591 | sdesc = kzalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm), | |
1592 | GFP_KERNEL); | |
1593 | if (!sdesc) { | |
1594 | crypto_free_shash(tfm); | |
1595 | return -ENOMEM; | |
1596 | } | |
1597 | ||
1598 | sdesc->shash.tfm = tfm; | |
1599 | sdesc->shash.flags = 0; | |
1600 | drbg->priv_data = sdesc; | |
1601 | return 0; | |
1602 | } | |
1603 | ||
1604 | static int drbg_fini_hash_kernel(struct drbg_state *drbg) | |
1605 | { | |
1606 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
1607 | if (sdesc) { | |
1608 | crypto_free_shash(sdesc->shash.tfm); | |
1609 | kzfree(sdesc); | |
1610 | } | |
1611 | drbg->priv_data = NULL; | |
1612 | return 0; | |
1613 | } | |
1614 | ||
4218ebe8 SM |
1615 | static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg, |
1616 | const unsigned char *key) | |
1617 | { | |
1618 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
1619 | ||
1620 | crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg)); | |
1621 | } | |
1622 | ||
1623 | static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, | |
1624 | const struct list_head *in) | |
541af946 SM |
1625 | { |
1626 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
8c987166 | 1627 | struct drbg_string *input = NULL; |
541af946 | 1628 | |
541af946 | 1629 | crypto_shash_init(&sdesc->shash); |
8c987166 SM |
1630 | list_for_each_entry(input, in, list) |
1631 | crypto_shash_update(&sdesc->shash, input->buf, input->len); | |
541af946 SM |
1632 | return crypto_shash_final(&sdesc->shash, outval); |
1633 | } | |
1634 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
1635 | ||
1636 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1637 | static int drbg_init_sym_kernel(struct drbg_state *drbg) | |
1638 | { | |
1639 | int ret = 0; | |
04bcbfcf | 1640 | struct crypto_cipher *tfm; |
541af946 | 1641 | |
04bcbfcf | 1642 | tfm = crypto_alloc_cipher(drbg->core->backend_cra_name, 0, 0); |
541af946 | 1643 | if (IS_ERR(tfm)) { |
593dfbd9 SS |
1644 | pr_info("DRBG: could not allocate cipher TFM handle: %s\n", |
1645 | drbg->core->backend_cra_name); | |
541af946 SM |
1646 | return PTR_ERR(tfm); |
1647 | } | |
04bcbfcf | 1648 | BUG_ON(drbg_blocklen(drbg) != crypto_cipher_blocksize(tfm)); |
541af946 SM |
1649 | drbg->priv_data = tfm; |
1650 | return ret; | |
1651 | } | |
1652 | ||
1653 | static int drbg_fini_sym_kernel(struct drbg_state *drbg) | |
1654 | { | |
04bcbfcf SM |
1655 | struct crypto_cipher *tfm = |
1656 | (struct crypto_cipher *)drbg->priv_data; | |
541af946 | 1657 | if (tfm) |
04bcbfcf | 1658 | crypto_free_cipher(tfm); |
541af946 SM |
1659 | drbg->priv_data = NULL; |
1660 | return 0; | |
1661 | } | |
1662 | ||
ed494d4f SM |
1663 | static void drbg_kcapi_symsetkey(struct drbg_state *drbg, |
1664 | const unsigned char *key) | |
541af946 | 1665 | { |
04bcbfcf SM |
1666 | struct crypto_cipher *tfm = |
1667 | (struct crypto_cipher *)drbg->priv_data; | |
541af946 | 1668 | |
04bcbfcf | 1669 | crypto_cipher_setkey(tfm, key, (drbg_keylen(drbg))); |
ed494d4f SM |
1670 | } |
1671 | ||
1672 | static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, | |
1673 | const struct drbg_string *in) | |
1674 | { | |
1675 | struct crypto_cipher *tfm = | |
1676 | (struct crypto_cipher *)drbg->priv_data; | |
1677 | ||
04bcbfcf SM |
1678 | /* there is only component in *in */ |
1679 | BUG_ON(in->len < drbg_blocklen(drbg)); | |
1680 | crypto_cipher_encrypt_one(tfm, outval, in->buf); | |
1681 | return 0; | |
541af946 SM |
1682 | } |
1683 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
1684 | ||
1685 | /*************************************************************** | |
1686 | * Kernel crypto API interface to register DRBG | |
1687 | ***************************************************************/ | |
1688 | ||
1689 | /* | |
1690 | * Look up the DRBG flags by given kernel crypto API cra_name | |
1691 | * The code uses the drbg_cores definition to do this | |
1692 | * | |
1693 | * @cra_name kernel crypto API cra_name | |
1694 | * @coreref reference to integer which is filled with the pointer to | |
1695 | * the applicable core | |
1696 | * @pr reference for setting prediction resistance | |
1697 | * | |
1698 | * return: flags | |
1699 | */ | |
1700 | static inline void drbg_convert_tfm_core(const char *cra_driver_name, | |
1701 | int *coreref, bool *pr) | |
1702 | { | |
1703 | int i = 0; | |
1704 | size_t start = 0; | |
1705 | int len = 0; | |
1706 | ||
1707 | *pr = true; | |
1708 | /* disassemble the names */ | |
1709 | if (!memcmp(cra_driver_name, "drbg_nopr_", 10)) { | |
1710 | start = 10; | |
1711 | *pr = false; | |
1712 | } else if (!memcmp(cra_driver_name, "drbg_pr_", 8)) { | |
1713 | start = 8; | |
1714 | } else { | |
1715 | return; | |
1716 | } | |
1717 | ||
1718 | /* remove the first part */ | |
1719 | len = strlen(cra_driver_name) - start; | |
1720 | for (i = 0; ARRAY_SIZE(drbg_cores) > i; i++) { | |
1721 | if (!memcmp(cra_driver_name + start, drbg_cores[i].cra_name, | |
1722 | len)) { | |
1723 | *coreref = i; | |
1724 | return; | |
1725 | } | |
1726 | } | |
1727 | } | |
1728 | ||
1729 | static int drbg_kcapi_init(struct crypto_tfm *tfm) | |
1730 | { | |
1731 | struct drbg_state *drbg = crypto_tfm_ctx(tfm); | |
541af946 | 1732 | |
76899a41 | 1733 | mutex_init(&drbg->drbg_mutex); |
2a57e424 HX |
1734 | |
1735 | return 0; | |
541af946 SM |
1736 | } |
1737 | ||
1738 | static void drbg_kcapi_cleanup(struct crypto_tfm *tfm) | |
1739 | { | |
1740 | drbg_uninstantiate(crypto_tfm_ctx(tfm)); | |
1741 | } | |
1742 | ||
1743 | /* | |
1744 | * Generate random numbers invoked by the kernel crypto API: | |
1745 | * The API of the kernel crypto API is extended as follows: | |
1746 | * | |
8fded592 HX |
1747 | * src is additional input supplied to the RNG. |
1748 | * slen is the length of src. | |
1749 | * dst is the output buffer where random data is to be stored. | |
1750 | * dlen is the length of dst. | |
541af946 | 1751 | */ |
8fded592 HX |
1752 | static int drbg_kcapi_random(struct crypto_rng *tfm, |
1753 | const u8 *src, unsigned int slen, | |
1754 | u8 *dst, unsigned int dlen) | |
541af946 SM |
1755 | { |
1756 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
8fded592 HX |
1757 | struct drbg_string *addtl = NULL; |
1758 | struct drbg_string string; | |
1759 | ||
1760 | if (slen) { | |
8c987166 | 1761 | /* linked list variable is now local to allow modification */ |
8fded592 HX |
1762 | drbg_string_fill(&string, src, slen); |
1763 | addtl = &string; | |
541af946 | 1764 | } |
8fded592 HX |
1765 | |
1766 | return drbg_generate_long(drbg, dst, dlen, addtl); | |
541af946 SM |
1767 | } |
1768 | ||
1769 | /* | |
2a57e424 | 1770 | * Seed the DRBG invoked by the kernel crypto API |
541af946 | 1771 | */ |
8fded592 HX |
1772 | static int drbg_kcapi_seed(struct crypto_rng *tfm, |
1773 | const u8 *seed, unsigned int slen) | |
541af946 SM |
1774 | { |
1775 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
1776 | struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm); | |
1777 | bool pr = false; | |
8fded592 HX |
1778 | struct drbg_string string; |
1779 | struct drbg_string *seed_string = NULL; | |
541af946 SM |
1780 | int coreref = 0; |
1781 | ||
541af946 SM |
1782 | drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref, |
1783 | &pr); | |
1784 | if (0 < slen) { | |
8fded592 HX |
1785 | drbg_string_fill(&string, seed, slen); |
1786 | seed_string = &string; | |
541af946 | 1787 | } |
8fded592 HX |
1788 | |
1789 | return drbg_instantiate(drbg, seed_string, coreref, pr); | |
541af946 SM |
1790 | } |
1791 | ||
1792 | /*************************************************************** | |
1793 | * Kernel module: code to load the module | |
1794 | ***************************************************************/ | |
1795 | ||
1796 | /* | |
1797 | * Tests as defined in 11.3.2 in addition to the cipher tests: testing | |
1798 | * of the error handling. | |
1799 | * | |
1800 | * Note: testing of failing seed source as defined in 11.3.2 is not applicable | |
1801 | * as seed source of get_random_bytes does not fail. | |
1802 | * | |
1803 | * Note 2: There is no sensible way of testing the reseed counter | |
1804 | * enforcement, so skip it. | |
1805 | */ | |
1806 | static inline int __init drbg_healthcheck_sanity(void) | |
1807 | { | |
541af946 SM |
1808 | int len = 0; |
1809 | #define OUTBUFLEN 16 | |
1810 | unsigned char buf[OUTBUFLEN]; | |
1811 | struct drbg_state *drbg = NULL; | |
1812 | int ret = -EFAULT; | |
1813 | int rc = -EFAULT; | |
1814 | bool pr = false; | |
1815 | int coreref = 0; | |
1816 | struct drbg_string addtl; | |
1817 | size_t max_addtllen, max_request_bytes; | |
1818 | ||
1819 | /* only perform test in FIPS mode */ | |
1820 | if (!fips_enabled) | |
1821 | return 0; | |
1822 | ||
1823 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1824 | drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref, &pr); | |
e25e47ec | 1825 | #elif defined CONFIG_CRYPTO_DRBG_HASH |
541af946 SM |
1826 | drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr); |
1827 | #else | |
1828 | drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref, &pr); | |
1829 | #endif | |
1830 | ||
1831 | drbg = kzalloc(sizeof(struct drbg_state), GFP_KERNEL); | |
1832 | if (!drbg) | |
1833 | return -ENOMEM; | |
1834 | ||
e11a7548 HX |
1835 | mutex_init(&drbg->drbg_mutex); |
1836 | ||
541af946 SM |
1837 | /* |
1838 | * if the following tests fail, it is likely that there is a buffer | |
1839 | * overflow as buf is much smaller than the requested or provided | |
1840 | * string lengths -- in case the error handling does not succeed | |
1841 | * we may get an OOPS. And we want to get an OOPS as this is a | |
1842 | * grave bug. | |
1843 | */ | |
1844 | ||
1845 | /* get a valid instance of DRBG for following tests */ | |
1846 | ret = drbg_instantiate(drbg, NULL, coreref, pr); | |
1847 | if (ret) { | |
1848 | rc = ret; | |
1849 | goto outbuf; | |
1850 | } | |
1851 | max_addtllen = drbg_max_addtl(drbg); | |
1852 | max_request_bytes = drbg_max_request_bytes(drbg); | |
1853 | drbg_string_fill(&addtl, buf, max_addtllen + 1); | |
1854 | /* overflow addtllen with additonal info string */ | |
1855 | len = drbg_generate(drbg, buf, OUTBUFLEN, &addtl); | |
1856 | BUG_ON(0 < len); | |
1857 | /* overflow max_bits */ | |
1858 | len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL); | |
1859 | BUG_ON(0 < len); | |
1860 | drbg_uninstantiate(drbg); | |
1861 | ||
1862 | /* overflow max addtllen with personalization string */ | |
1863 | ret = drbg_instantiate(drbg, &addtl, coreref, pr); | |
1864 | BUG_ON(0 == ret); | |
541af946 SM |
1865 | /* all tests passed */ |
1866 | rc = 0; | |
1867 | ||
1868 | pr_devel("DRBG: Sanity tests for failure code paths successfully " | |
1869 | "completed\n"); | |
1870 | ||
1871 | drbg_uninstantiate(drbg); | |
1872 | outbuf: | |
1873 | kzfree(drbg); | |
1874 | return rc; | |
541af946 SM |
1875 | } |
1876 | ||
8fded592 | 1877 | static struct rng_alg drbg_algs[22]; |
541af946 SM |
1878 | |
1879 | /* | |
1880 | * Fill the array drbg_algs used to register the different DRBGs | |
1881 | * with the kernel crypto API. To fill the array, the information | |
1882 | * from drbg_cores[] is used. | |
1883 | */ | |
8fded592 | 1884 | static inline void __init drbg_fill_array(struct rng_alg *alg, |
541af946 SM |
1885 | const struct drbg_core *core, int pr) |
1886 | { | |
1887 | int pos = 0; | |
51ee1422 | 1888 | static int priority = 200; |
541af946 | 1889 | |
8fded592 | 1890 | memcpy(alg->base.cra_name, "stdrng", 6); |
541af946 | 1891 | if (pr) { |
8fded592 | 1892 | memcpy(alg->base.cra_driver_name, "drbg_pr_", 8); |
541af946 SM |
1893 | pos = 8; |
1894 | } else { | |
8fded592 | 1895 | memcpy(alg->base.cra_driver_name, "drbg_nopr_", 10); |
541af946 SM |
1896 | pos = 10; |
1897 | } | |
8fded592 | 1898 | memcpy(alg->base.cra_driver_name + pos, core->cra_name, |
541af946 SM |
1899 | strlen(core->cra_name)); |
1900 | ||
8fded592 | 1901 | alg->base.cra_priority = priority; |
541af946 SM |
1902 | priority++; |
1903 | /* | |
1904 | * If FIPS mode enabled, the selected DRBG shall have the | |
1905 | * highest cra_priority over other stdrng instances to ensure | |
1906 | * it is selected. | |
1907 | */ | |
1908 | if (fips_enabled) | |
8fded592 HX |
1909 | alg->base.cra_priority += 200; |
1910 | ||
1911 | alg->base.cra_ctxsize = sizeof(struct drbg_state); | |
1912 | alg->base.cra_module = THIS_MODULE; | |
1913 | alg->base.cra_init = drbg_kcapi_init; | |
1914 | alg->base.cra_exit = drbg_kcapi_cleanup; | |
1915 | alg->generate = drbg_kcapi_random; | |
1916 | alg->seed = drbg_kcapi_seed; | |
1917 | alg->set_ent = drbg_kcapi_set_entropy; | |
1918 | alg->seedsize = 0; | |
541af946 SM |
1919 | } |
1920 | ||
1921 | static int __init drbg_init(void) | |
1922 | { | |
1923 | unsigned int i = 0; /* pointer to drbg_algs */ | |
1924 | unsigned int j = 0; /* pointer to drbg_cores */ | |
1925 | int ret = -EFAULT; | |
1926 | ||
1927 | ret = drbg_healthcheck_sanity(); | |
1928 | if (ret) | |
1929 | return ret; | |
1930 | ||
1931 | if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) { | |
1932 | pr_info("DRBG: Cannot register all DRBG types" | |
a9089571 | 1933 | "(slots needed: %zu, slots available: %zu)\n", |
541af946 SM |
1934 | ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs)); |
1935 | return ret; | |
1936 | } | |
1937 | ||
1938 | /* | |
1939 | * each DRBG definition can be used with PR and without PR, thus | |
1940 | * we instantiate each DRBG in drbg_cores[] twice. | |
1941 | * | |
1942 | * As the order of placing them into the drbg_algs array matters | |
1943 | * (the later DRBGs receive a higher cra_priority) we register the | |
1944 | * prediction resistance DRBGs first as the should not be too | |
1945 | * interesting. | |
1946 | */ | |
1947 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
1948 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1); | |
1949 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
1950 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0); | |
8fded592 | 1951 | return crypto_register_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); |
541af946 SM |
1952 | } |
1953 | ||
96956aef | 1954 | static void __exit drbg_exit(void) |
541af946 | 1955 | { |
8fded592 | 1956 | crypto_unregister_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); |
541af946 SM |
1957 | } |
1958 | ||
1959 | module_init(drbg_init); | |
1960 | module_exit(drbg_exit); | |
e25e47ec SM |
1961 | #ifndef CRYPTO_DRBG_HASH_STRING |
1962 | #define CRYPTO_DRBG_HASH_STRING "" | |
541af946 | 1963 | #endif |
e25e47ec SM |
1964 | #ifndef CRYPTO_DRBG_HMAC_STRING |
1965 | #define CRYPTO_DRBG_HMAC_STRING "" | |
541af946 | 1966 | #endif |
e25e47ec SM |
1967 | #ifndef CRYPTO_DRBG_CTR_STRING |
1968 | #define CRYPTO_DRBG_CTR_STRING "" | |
541af946 | 1969 | #endif |
e25e47ec SM |
1970 | MODULE_LICENSE("GPL"); |
1971 | MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); | |
1972 | MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) " | |
1973 | "using following cores: " | |
1974 | CRYPTO_DRBG_HASH_STRING | |
1975 | CRYPTO_DRBG_HMAC_STRING | |
1976 | CRYPTO_DRBG_CTR_STRING); | |
51ee1422 | 1977 | MODULE_ALIAS_CRYPTO("stdrng"); |