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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); | |
35591285 | 261 | static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, u8 *outbuf, u32 outlen); |
541af946 SM |
262 | |
263 | /* BCC function for CTR DRBG as defined in 10.4.3 */ | |
264 | static int drbg_ctr_bcc(struct drbg_state *drbg, | |
265 | unsigned char *out, const unsigned char *key, | |
8c987166 | 266 | struct list_head *in) |
541af946 | 267 | { |
8c987166 SM |
268 | int ret = 0; |
269 | struct drbg_string *curr = NULL; | |
541af946 | 270 | struct drbg_string data; |
8c987166 | 271 | short cnt = 0; |
541af946 SM |
272 | |
273 | drbg_string_fill(&data, out, drbg_blocklen(drbg)); | |
274 | ||
541af946 | 275 | /* 10.4.3 step 2 / 4 */ |
ed494d4f | 276 | drbg_kcapi_symsetkey(drbg, key); |
8c987166 SM |
277 | list_for_each_entry(curr, in, list) { |
278 | const unsigned char *pos = curr->buf; | |
279 | size_t len = curr->len; | |
541af946 | 280 | /* 10.4.3 step 4.1 */ |
8c987166 SM |
281 | while (len) { |
282 | /* 10.4.3 step 4.2 */ | |
283 | if (drbg_blocklen(drbg) == cnt) { | |
284 | cnt = 0; | |
ed494d4f | 285 | ret = drbg_kcapi_sym(drbg, out, &data); |
8c987166 SM |
286 | if (ret) |
287 | return ret; | |
541af946 | 288 | } |
8c987166 SM |
289 | out[cnt] ^= *pos; |
290 | pos++; | |
291 | cnt++; | |
292 | len--; | |
541af946 | 293 | } |
541af946 | 294 | } |
8c987166 SM |
295 | /* 10.4.3 step 4.2 for last block */ |
296 | if (cnt) | |
ed494d4f | 297 | ret = drbg_kcapi_sym(drbg, out, &data); |
8c987166 SM |
298 | |
299 | return ret; | |
541af946 SM |
300 | } |
301 | ||
302 | /* | |
303 | * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df | |
304 | * (and drbg_ctr_bcc, but this function does not need any temporary buffers), | |
305 | * the scratchpad is used as follows: | |
306 | * drbg_ctr_update: | |
307 | * temp | |
308 | * start: drbg->scratchpad | |
309 | * length: drbg_statelen(drbg) + drbg_blocklen(drbg) | |
310 | * note: the cipher writing into this variable works | |
311 | * blocklen-wise. Now, when the statelen is not a multiple | |
312 | * of blocklen, the generateion loop below "spills over" | |
313 | * by at most blocklen. Thus, we need to give sufficient | |
314 | * memory. | |
315 | * df_data | |
316 | * start: drbg->scratchpad + | |
317 | * drbg_statelen(drbg) + drbg_blocklen(drbg) | |
318 | * length: drbg_statelen(drbg) | |
319 | * | |
320 | * drbg_ctr_df: | |
321 | * pad | |
322 | * start: df_data + drbg_statelen(drbg) | |
323 | * length: drbg_blocklen(drbg) | |
324 | * iv | |
325 | * start: pad + drbg_blocklen(drbg) | |
326 | * length: drbg_blocklen(drbg) | |
327 | * temp | |
328 | * start: iv + drbg_blocklen(drbg) | |
8fecaad7 SM |
329 | * length: drbg_satelen(drbg) + drbg_blocklen(drbg) |
330 | * note: temp is the buffer that the BCC function operates | |
331 | * on. BCC operates blockwise. drbg_statelen(drbg) | |
332 | * is sufficient when the DRBG state length is a multiple | |
333 | * of the block size. For AES192 (and maybe other ciphers) | |
334 | * this is not correct and the length for temp is | |
335 | * insufficient (yes, that also means for such ciphers, | |
336 | * the final output of all BCC rounds are truncated). | |
337 | * Therefore, add drbg_blocklen(drbg) to cover all | |
338 | * possibilities. | |
541af946 SM |
339 | */ |
340 | ||
341 | /* Derivation Function for CTR DRBG as defined in 10.4.2 */ | |
342 | static int drbg_ctr_df(struct drbg_state *drbg, | |
343 | unsigned char *df_data, size_t bytes_to_return, | |
8c987166 | 344 | struct list_head *seedlist) |
541af946 SM |
345 | { |
346 | int ret = -EFAULT; | |
347 | unsigned char L_N[8]; | |
348 | /* S3 is input */ | |
349 | struct drbg_string S1, S2, S4, cipherin; | |
8c987166 | 350 | LIST_HEAD(bcc_list); |
541af946 SM |
351 | unsigned char *pad = df_data + drbg_statelen(drbg); |
352 | unsigned char *iv = pad + drbg_blocklen(drbg); | |
353 | unsigned char *temp = iv + drbg_blocklen(drbg); | |
354 | size_t padlen = 0; | |
355 | unsigned int templen = 0; | |
356 | /* 10.4.2 step 7 */ | |
357 | unsigned int i = 0; | |
358 | /* 10.4.2 step 8 */ | |
359 | const unsigned char *K = (unsigned char *) | |
360 | "\x00\x01\x02\x03\x04\x05\x06\x07" | |
361 | "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" | |
362 | "\x10\x11\x12\x13\x14\x15\x16\x17" | |
363 | "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"; | |
364 | unsigned char *X; | |
365 | size_t generated_len = 0; | |
366 | size_t inputlen = 0; | |
8c987166 | 367 | struct drbg_string *seed = NULL; |
541af946 SM |
368 | |
369 | memset(pad, 0, drbg_blocklen(drbg)); | |
370 | memset(iv, 0, drbg_blocklen(drbg)); | |
541af946 SM |
371 | |
372 | /* 10.4.2 step 1 is implicit as we work byte-wise */ | |
373 | ||
374 | /* 10.4.2 step 2 */ | |
375 | if ((512/8) < bytes_to_return) | |
376 | return -EINVAL; | |
377 | ||
378 | /* 10.4.2 step 2 -- calculate the entire length of all input data */ | |
8c987166 SM |
379 | list_for_each_entry(seed, seedlist, list) |
380 | inputlen += seed->len; | |
72f3e00d | 381 | drbg_cpu_to_be32(inputlen, &L_N[0]); |
541af946 SM |
382 | |
383 | /* 10.4.2 step 3 */ | |
72f3e00d | 384 | drbg_cpu_to_be32(bytes_to_return, &L_N[4]); |
541af946 SM |
385 | |
386 | /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */ | |
387 | padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg)); | |
388 | /* wrap the padlen appropriately */ | |
389 | if (padlen) | |
390 | padlen = drbg_blocklen(drbg) - padlen; | |
391 | /* | |
392 | * pad / padlen contains the 0x80 byte and the following zero bytes. | |
393 | * As the calculated padlen value only covers the number of zero | |
394 | * bytes, this value has to be incremented by one for the 0x80 byte. | |
395 | */ | |
396 | padlen++; | |
397 | pad[0] = 0x80; | |
398 | ||
399 | /* 10.4.2 step 4 -- first fill the linked list and then order it */ | |
400 | drbg_string_fill(&S1, iv, drbg_blocklen(drbg)); | |
8c987166 | 401 | list_add_tail(&S1.list, &bcc_list); |
541af946 | 402 | drbg_string_fill(&S2, L_N, sizeof(L_N)); |
8c987166 SM |
403 | list_add_tail(&S2.list, &bcc_list); |
404 | list_splice_tail(seedlist, &bcc_list); | |
541af946 | 405 | drbg_string_fill(&S4, pad, padlen); |
8c987166 | 406 | list_add_tail(&S4.list, &bcc_list); |
541af946 SM |
407 | |
408 | /* 10.4.2 step 9 */ | |
409 | while (templen < (drbg_keylen(drbg) + (drbg_blocklen(drbg)))) { | |
410 | /* | |
411 | * 10.4.2 step 9.1 - the padding is implicit as the buffer | |
412 | * holds zeros after allocation -- even the increment of i | |
413 | * is irrelevant as the increment remains within length of i | |
414 | */ | |
72f3e00d | 415 | drbg_cpu_to_be32(i, iv); |
541af946 | 416 | /* 10.4.2 step 9.2 -- BCC and concatenation with temp */ |
8c987166 | 417 | ret = drbg_ctr_bcc(drbg, temp + templen, K, &bcc_list); |
541af946 SM |
418 | if (ret) |
419 | goto out; | |
420 | /* 10.4.2 step 9.3 */ | |
421 | i++; | |
422 | templen += drbg_blocklen(drbg); | |
423 | } | |
424 | ||
425 | /* 10.4.2 step 11 */ | |
426 | X = temp + (drbg_keylen(drbg)); | |
427 | drbg_string_fill(&cipherin, X, drbg_blocklen(drbg)); | |
428 | ||
429 | /* 10.4.2 step 12: overwriting of outval is implemented in next step */ | |
430 | ||
431 | /* 10.4.2 step 13 */ | |
ed494d4f | 432 | drbg_kcapi_symsetkey(drbg, temp); |
541af946 SM |
433 | while (generated_len < bytes_to_return) { |
434 | short blocklen = 0; | |
435 | /* | |
436 | * 10.4.2 step 13.1: the truncation of the key length is | |
437 | * implicit as the key is only drbg_blocklen in size based on | |
438 | * the implementation of the cipher function callback | |
439 | */ | |
ed494d4f | 440 | ret = drbg_kcapi_sym(drbg, X, &cipherin); |
541af946 SM |
441 | if (ret) |
442 | goto out; | |
443 | blocklen = (drbg_blocklen(drbg) < | |
444 | (bytes_to_return - generated_len)) ? | |
445 | drbg_blocklen(drbg) : | |
446 | (bytes_to_return - generated_len); | |
447 | /* 10.4.2 step 13.2 and 14 */ | |
448 | memcpy(df_data + generated_len, X, blocklen); | |
449 | generated_len += blocklen; | |
450 | } | |
451 | ||
452 | ret = 0; | |
453 | ||
454 | out: | |
1471f09f | 455 | memset(iv, 0, drbg_blocklen(drbg)); |
8e0498d9 | 456 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
1471f09f | 457 | memset(pad, 0, drbg_blocklen(drbg)); |
541af946 SM |
458 | return ret; |
459 | } | |
460 | ||
72e7c25a SM |
461 | /* |
462 | * update function of CTR DRBG as defined in 10.2.1.2 | |
463 | * | |
464 | * The reseed variable has an enhanced meaning compared to the update | |
465 | * functions of the other DRBGs as follows: | |
466 | * 0 => initial seed from initialization | |
467 | * 1 => reseed via drbg_seed | |
468 | * 2 => first invocation from drbg_ctr_update when addtl is present. In | |
469 | * this case, the df_data scratchpad is not deleted so that it is | |
470 | * available for another calls to prevent calling the DF function | |
471 | * again. | |
472 | * 3 => second invocation from drbg_ctr_update. When the update function | |
473 | * was called with addtl, the df_data memory already contains the | |
474 | * DFed addtl information and we do not need to call DF again. | |
475 | */ | |
8c987166 SM |
476 | static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, |
477 | int reseed) | |
541af946 SM |
478 | { |
479 | int ret = -EFAULT; | |
480 | /* 10.2.1.2 step 1 */ | |
481 | unsigned char *temp = drbg->scratchpad; | |
482 | unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) + | |
483 | drbg_blocklen(drbg); | |
484 | unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */ | |
485 | unsigned int len = 0; | |
541af946 | 486 | |
72e7c25a SM |
487 | if (3 > reseed) |
488 | memset(df_data, 0, drbg_statelen(drbg)); | |
541af946 | 489 | |
35591285 SM |
490 | if (!reseed) { |
491 | /* | |
492 | * The DRBG uses the CTR mode of the underlying AES cipher. The | |
493 | * CTR mode increments the counter value after the AES operation | |
494 | * but SP800-90A requires that the counter is incremented before | |
495 | * the AES operation. Hence, we increment it at the time we set | |
496 | * it by one. | |
497 | */ | |
498 | crypto_inc(drbg->V, drbg_blocklen(drbg)); | |
499 | ||
500 | ret = crypto_skcipher_setkey(drbg->ctr_handle, drbg->C, | |
501 | drbg_keylen(drbg)); | |
541af946 SM |
502 | if (ret) |
503 | goto out; | |
504 | } | |
505 | ||
35591285 SM |
506 | /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */ |
507 | if (seed) { | |
508 | ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed); | |
541af946 SM |
509 | if (ret) |
510 | goto out; | |
541af946 SM |
511 | } |
512 | ||
35591285 SM |
513 | ret = drbg_kcapi_sym_ctr(drbg, temp, drbg_statelen(drbg)); |
514 | if (ret) | |
515 | return ret; | |
516 | ||
541af946 SM |
517 | /* 10.2.1.2 step 4 */ |
518 | temp_p = temp; | |
519 | df_data_p = df_data; | |
520 | for (len = 0; len < drbg_statelen(drbg); len++) { | |
521 | *temp_p ^= *df_data_p; | |
522 | df_data_p++; temp_p++; | |
523 | } | |
524 | ||
525 | /* 10.2.1.2 step 5 */ | |
526 | memcpy(drbg->C, temp, drbg_keylen(drbg)); | |
35591285 SM |
527 | ret = crypto_skcipher_setkey(drbg->ctr_handle, drbg->C, |
528 | drbg_keylen(drbg)); | |
529 | if (ret) | |
530 | goto out; | |
541af946 SM |
531 | /* 10.2.1.2 step 6 */ |
532 | memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg)); | |
35591285 SM |
533 | /* See above: increment counter by one to compensate timing of CTR op */ |
534 | crypto_inc(drbg->V, drbg_blocklen(drbg)); | |
541af946 SM |
535 | ret = 0; |
536 | ||
537 | out: | |
1471f09f | 538 | memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); |
72e7c25a | 539 | if (2 != reseed) |
1471f09f | 540 | memset(df_data, 0, drbg_statelen(drbg)); |
541af946 SM |
541 | return ret; |
542 | } | |
543 | ||
544 | /* | |
545 | * scratchpad use: drbg_ctr_update is called independently from | |
546 | * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused | |
547 | */ | |
548 | /* Generate function of CTR DRBG as defined in 10.2.1.5.2 */ | |
549 | static int drbg_ctr_generate(struct drbg_state *drbg, | |
550 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 551 | struct list_head *addtl) |
541af946 | 552 | { |
35591285 SM |
553 | int ret; |
554 | int len = min_t(int, buflen, INT_MAX); | |
541af946 | 555 | |
541af946 | 556 | /* 10.2.1.5.2 step 2 */ |
27e4de2b SM |
557 | if (addtl && !list_empty(addtl)) { |
558 | ret = drbg_ctr_update(drbg, addtl, 2); | |
541af946 SM |
559 | if (ret) |
560 | return 0; | |
561 | } | |
562 | ||
563 | /* 10.2.1.5.2 step 4.1 */ | |
35591285 SM |
564 | ret = drbg_kcapi_sym_ctr(drbg, buf, len); |
565 | if (ret) | |
566 | return ret; | |
541af946 | 567 | |
72e7c25a SM |
568 | /* 10.2.1.5.2 step 6 */ |
569 | ret = drbg_ctr_update(drbg, NULL, 3); | |
541af946 SM |
570 | if (ret) |
571 | len = ret; | |
572 | ||
541af946 SM |
573 | return len; |
574 | } | |
575 | ||
e4bc02ac | 576 | static const struct drbg_state_ops drbg_ctr_ops = { |
541af946 SM |
577 | .update = drbg_ctr_update, |
578 | .generate = drbg_ctr_generate, | |
579 | .crypto_init = drbg_init_sym_kernel, | |
580 | .crypto_fini = drbg_fini_sym_kernel, | |
581 | }; | |
582 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
583 | ||
584 | /****************************************************************** | |
585 | * HMAC DRBG callback functions | |
586 | ******************************************************************/ | |
587 | ||
588 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
4218ebe8 SM |
589 | static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, |
590 | const struct list_head *in); | |
591 | static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg, | |
592 | const unsigned char *key); | |
541af946 SM |
593 | static int drbg_init_hash_kernel(struct drbg_state *drbg); |
594 | static int drbg_fini_hash_kernel(struct drbg_state *drbg); | |
595 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
596 | ||
597 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
e25e47ec | 598 | #define CRYPTO_DRBG_HMAC_STRING "HMAC " |
0653a7cf SM |
599 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512"); |
600 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512"); | |
601 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384"); | |
602 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384"); | |
603 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256"); | |
604 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256"); | |
605 | MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1"); | |
606 | MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1"); | |
62b62b6e | 607 | |
541af946 | 608 | /* update function of HMAC DRBG as defined in 10.1.2.2 */ |
8c987166 SM |
609 | static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed, |
610 | int reseed) | |
541af946 SM |
611 | { |
612 | int ret = -EFAULT; | |
613 | int i = 0; | |
8c987166 SM |
614 | struct drbg_string seed1, seed2, vdata; |
615 | LIST_HEAD(seedlist); | |
616 | LIST_HEAD(vdatalist); | |
541af946 | 617 | |
4218ebe8 | 618 | if (!reseed) { |
f072f0e0 | 619 | /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */ |
541af946 | 620 | memset(drbg->V, 1, drbg_statelen(drbg)); |
4218ebe8 SM |
621 | drbg_kcapi_hmacsetkey(drbg, drbg->C); |
622 | } | |
541af946 SM |
623 | |
624 | drbg_string_fill(&seed1, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 625 | list_add_tail(&seed1.list, &seedlist); |
541af946 SM |
626 | /* buffer of seed2 will be filled in for loop below with one byte */ |
627 | drbg_string_fill(&seed2, NULL, 1); | |
8c987166 | 628 | list_add_tail(&seed2.list, &seedlist); |
541af946 | 629 | /* input data of seed is allowed to be NULL at this point */ |
8c987166 SM |
630 | if (seed) |
631 | list_splice_tail(seed, &seedlist); | |
541af946 | 632 | |
8c987166 SM |
633 | drbg_string_fill(&vdata, drbg->V, drbg_statelen(drbg)); |
634 | list_add_tail(&vdata.list, &vdatalist); | |
541af946 SM |
635 | for (i = 2; 0 < i; i--) { |
636 | /* first round uses 0x0, second 0x1 */ | |
637 | unsigned char prefix = DRBG_PREFIX0; | |
638 | if (1 == i) | |
639 | prefix = DRBG_PREFIX1; | |
640 | /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */ | |
641 | seed2.buf = &prefix; | |
4218ebe8 | 642 | ret = drbg_kcapi_hash(drbg, drbg->C, &seedlist); |
541af946 SM |
643 | if (ret) |
644 | return ret; | |
4218ebe8 | 645 | drbg_kcapi_hmacsetkey(drbg, drbg->C); |
541af946 SM |
646 | |
647 | /* 10.1.2.2 step 2 and 5 -- HMAC for V */ | |
4218ebe8 | 648 | ret = drbg_kcapi_hash(drbg, drbg->V, &vdatalist); |
541af946 SM |
649 | if (ret) |
650 | return ret; | |
651 | ||
652 | /* 10.1.2.2 step 3 */ | |
8c987166 | 653 | if (!seed) |
541af946 SM |
654 | return ret; |
655 | } | |
656 | ||
657 | return 0; | |
658 | } | |
659 | ||
660 | /* generate function of HMAC DRBG as defined in 10.1.2.5 */ | |
661 | static int drbg_hmac_generate(struct drbg_state *drbg, | |
662 | unsigned char *buf, | |
663 | unsigned int buflen, | |
27e4de2b | 664 | struct list_head *addtl) |
541af946 SM |
665 | { |
666 | int len = 0; | |
667 | int ret = 0; | |
668 | struct drbg_string data; | |
8c987166 | 669 | LIST_HEAD(datalist); |
541af946 SM |
670 | |
671 | /* 10.1.2.5 step 2 */ | |
27e4de2b SM |
672 | if (addtl && !list_empty(addtl)) { |
673 | ret = drbg_hmac_update(drbg, addtl, 1); | |
541af946 SM |
674 | if (ret) |
675 | return ret; | |
676 | } | |
677 | ||
678 | drbg_string_fill(&data, drbg->V, drbg_statelen(drbg)); | |
8c987166 | 679 | list_add_tail(&data.list, &datalist); |
541af946 SM |
680 | while (len < buflen) { |
681 | unsigned int outlen = 0; | |
682 | /* 10.1.2.5 step 4.1 */ | |
4218ebe8 | 683 | ret = drbg_kcapi_hash(drbg, drbg->V, &datalist); |
541af946 SM |
684 | if (ret) |
685 | return ret; | |
686 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
687 | drbg_blocklen(drbg) : (buflen - len); | |
541af946 SM |
688 | |
689 | /* 10.1.2.5 step 4.2 */ | |
690 | memcpy(buf + len, drbg->V, outlen); | |
691 | len += outlen; | |
692 | } | |
693 | ||
694 | /* 10.1.2.5 step 6 */ | |
27e4de2b SM |
695 | if (addtl && !list_empty(addtl)) |
696 | ret = drbg_hmac_update(drbg, addtl, 1); | |
697 | else | |
8c987166 | 698 | ret = drbg_hmac_update(drbg, NULL, 1); |
541af946 SM |
699 | if (ret) |
700 | return ret; | |
701 | ||
702 | return len; | |
703 | } | |
704 | ||
e4bc02ac | 705 | static const struct drbg_state_ops drbg_hmac_ops = { |
541af946 SM |
706 | .update = drbg_hmac_update, |
707 | .generate = drbg_hmac_generate, | |
708 | .crypto_init = drbg_init_hash_kernel, | |
709 | .crypto_fini = drbg_fini_hash_kernel, | |
541af946 SM |
710 | }; |
711 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
712 | ||
713 | /****************************************************************** | |
714 | * Hash DRBG callback functions | |
715 | ******************************************************************/ | |
716 | ||
717 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
e25e47ec | 718 | #define CRYPTO_DRBG_HASH_STRING "HASH " |
0653a7cf SM |
719 | MODULE_ALIAS_CRYPTO("drbg_pr_sha512"); |
720 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha512"); | |
721 | MODULE_ALIAS_CRYPTO("drbg_pr_sha384"); | |
722 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha384"); | |
723 | MODULE_ALIAS_CRYPTO("drbg_pr_sha256"); | |
724 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha256"); | |
725 | MODULE_ALIAS_CRYPTO("drbg_pr_sha1"); | |
726 | MODULE_ALIAS_CRYPTO("drbg_nopr_sha1"); | |
62b62b6e | 727 | |
41a84982 SM |
728 | /* |
729 | * Increment buffer | |
730 | * | |
731 | * @dst buffer to increment | |
732 | * @add value to add | |
733 | */ | |
734 | static inline void drbg_add_buf(unsigned char *dst, size_t dstlen, | |
735 | const unsigned char *add, size_t addlen) | |
736 | { | |
737 | /* implied: dstlen > addlen */ | |
738 | unsigned char *dstptr; | |
739 | const unsigned char *addptr; | |
740 | unsigned int remainder = 0; | |
741 | size_t len = addlen; | |
742 | ||
743 | dstptr = dst + (dstlen-1); | |
744 | addptr = add + (addlen-1); | |
745 | while (len) { | |
746 | remainder += *dstptr + *addptr; | |
747 | *dstptr = remainder & 0xff; | |
748 | remainder >>= 8; | |
749 | len--; dstptr--; addptr--; | |
750 | } | |
751 | len = dstlen - addlen; | |
752 | while (len && remainder > 0) { | |
753 | remainder = *dstptr + 1; | |
754 | *dstptr = remainder & 0xff; | |
755 | remainder >>= 8; | |
756 | len--; dstptr--; | |
757 | } | |
758 | } | |
759 | ||
541af946 SM |
760 | /* |
761 | * scratchpad usage: as drbg_hash_update and drbg_hash_df are used | |
762 | * interlinked, the scratchpad is used as follows: | |
763 | * drbg_hash_update | |
764 | * start: drbg->scratchpad | |
765 | * length: drbg_statelen(drbg) | |
766 | * drbg_hash_df: | |
767 | * start: drbg->scratchpad + drbg_statelen(drbg) | |
768 | * length: drbg_blocklen(drbg) | |
769 | * | |
770 | * drbg_hash_process_addtl uses the scratchpad, but fully completes | |
771 | * before either of the functions mentioned before are invoked. Therefore, | |
772 | * drbg_hash_process_addtl does not need to be specifically considered. | |
773 | */ | |
774 | ||
775 | /* Derivation Function for Hash DRBG as defined in 10.4.1 */ | |
776 | static int drbg_hash_df(struct drbg_state *drbg, | |
777 | unsigned char *outval, size_t outlen, | |
8c987166 | 778 | struct list_head *entropylist) |
541af946 SM |
779 | { |
780 | int ret = 0; | |
781 | size_t len = 0; | |
782 | unsigned char input[5]; | |
783 | unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg); | |
8c987166 | 784 | struct drbg_string data; |
541af946 | 785 | |
541af946 SM |
786 | /* 10.4.1 step 3 */ |
787 | input[0] = 1; | |
72f3e00d | 788 | drbg_cpu_to_be32((outlen * 8), &input[1]); |
541af946 SM |
789 | |
790 | /* 10.4.1 step 4.1 -- concatenation of data for input into hash */ | |
8c987166 SM |
791 | drbg_string_fill(&data, input, 5); |
792 | list_add(&data.list, entropylist); | |
541af946 SM |
793 | |
794 | /* 10.4.1 step 4 */ | |
795 | while (len < outlen) { | |
796 | short blocklen = 0; | |
797 | /* 10.4.1 step 4.1 */ | |
4218ebe8 | 798 | ret = drbg_kcapi_hash(drbg, tmp, entropylist); |
541af946 SM |
799 | if (ret) |
800 | goto out; | |
801 | /* 10.4.1 step 4.2 */ | |
802 | input[0]++; | |
803 | blocklen = (drbg_blocklen(drbg) < (outlen - len)) ? | |
804 | drbg_blocklen(drbg) : (outlen - len); | |
805 | memcpy(outval + len, tmp, blocklen); | |
806 | len += blocklen; | |
807 | } | |
808 | ||
809 | out: | |
1471f09f | 810 | memset(tmp, 0, drbg_blocklen(drbg)); |
541af946 SM |
811 | return ret; |
812 | } | |
813 | ||
814 | /* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */ | |
8c987166 | 815 | static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed, |
541af946 SM |
816 | int reseed) |
817 | { | |
818 | int ret = 0; | |
819 | struct drbg_string data1, data2; | |
8c987166 SM |
820 | LIST_HEAD(datalist); |
821 | LIST_HEAD(datalist2); | |
541af946 SM |
822 | unsigned char *V = drbg->scratchpad; |
823 | unsigned char prefix = DRBG_PREFIX1; | |
824 | ||
541af946 SM |
825 | if (!seed) |
826 | return -EINVAL; | |
827 | ||
828 | if (reseed) { | |
829 | /* 10.1.1.3 step 1 */ | |
830 | memcpy(V, drbg->V, drbg_statelen(drbg)); | |
831 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 832 | list_add_tail(&data1.list, &datalist); |
541af946 | 833 | drbg_string_fill(&data2, V, drbg_statelen(drbg)); |
8c987166 | 834 | list_add_tail(&data2.list, &datalist); |
541af946 | 835 | } |
8c987166 | 836 | list_splice_tail(seed, &datalist); |
541af946 SM |
837 | |
838 | /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */ | |
8c987166 | 839 | ret = drbg_hash_df(drbg, drbg->V, drbg_statelen(drbg), &datalist); |
541af946 SM |
840 | if (ret) |
841 | goto out; | |
842 | ||
843 | /* 10.1.1.2 / 10.1.1.3 step 4 */ | |
844 | prefix = DRBG_PREFIX0; | |
845 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 846 | list_add_tail(&data1.list, &datalist2); |
541af946 | 847 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 | 848 | list_add_tail(&data2.list, &datalist2); |
541af946 | 849 | /* 10.1.1.2 / 10.1.1.3 step 4 */ |
8c987166 | 850 | ret = drbg_hash_df(drbg, drbg->C, drbg_statelen(drbg), &datalist2); |
541af946 SM |
851 | |
852 | out: | |
1471f09f | 853 | memset(drbg->scratchpad, 0, drbg_statelen(drbg)); |
541af946 SM |
854 | return ret; |
855 | } | |
856 | ||
857 | /* processing of additional information string for Hash DRBG */ | |
858 | static int drbg_hash_process_addtl(struct drbg_state *drbg, | |
27e4de2b | 859 | struct list_head *addtl) |
541af946 SM |
860 | { |
861 | int ret = 0; | |
862 | struct drbg_string data1, data2; | |
8c987166 | 863 | LIST_HEAD(datalist); |
541af946 SM |
864 | unsigned char prefix = DRBG_PREFIX2; |
865 | ||
541af946 | 866 | /* 10.1.1.4 step 2 */ |
27e4de2b | 867 | if (!addtl || list_empty(addtl)) |
541af946 SM |
868 | return 0; |
869 | ||
870 | /* 10.1.1.4 step 2a */ | |
871 | drbg_string_fill(&data1, &prefix, 1); | |
872 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); | |
8c987166 SM |
873 | list_add_tail(&data1.list, &datalist); |
874 | list_add_tail(&data2.list, &datalist); | |
27e4de2b | 875 | list_splice_tail(addtl, &datalist); |
4218ebe8 | 876 | ret = drbg_kcapi_hash(drbg, drbg->scratchpad, &datalist); |
541af946 SM |
877 | if (ret) |
878 | goto out; | |
879 | ||
880 | /* 10.1.1.4 step 2b */ | |
881 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
882 | drbg->scratchpad, drbg_blocklen(drbg)); | |
883 | ||
884 | out: | |
1471f09f | 885 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
886 | return ret; |
887 | } | |
888 | ||
889 | /* Hashgen defined in 10.1.1.4 */ | |
890 | static int drbg_hash_hashgen(struct drbg_state *drbg, | |
891 | unsigned char *buf, | |
892 | unsigned int buflen) | |
893 | { | |
894 | int len = 0; | |
895 | int ret = 0; | |
896 | unsigned char *src = drbg->scratchpad; | |
897 | unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg); | |
898 | struct drbg_string data; | |
8c987166 | 899 | LIST_HEAD(datalist); |
541af946 | 900 | |
541af946 SM |
901 | /* 10.1.1.4 step hashgen 2 */ |
902 | memcpy(src, drbg->V, drbg_statelen(drbg)); | |
903 | ||
904 | drbg_string_fill(&data, src, drbg_statelen(drbg)); | |
8c987166 | 905 | list_add_tail(&data.list, &datalist); |
541af946 SM |
906 | while (len < buflen) { |
907 | unsigned int outlen = 0; | |
908 | /* 10.1.1.4 step hashgen 4.1 */ | |
4218ebe8 | 909 | ret = drbg_kcapi_hash(drbg, dst, &datalist); |
541af946 SM |
910 | if (ret) { |
911 | len = ret; | |
912 | goto out; | |
913 | } | |
914 | outlen = (drbg_blocklen(drbg) < (buflen - len)) ? | |
915 | drbg_blocklen(drbg) : (buflen - len); | |
541af946 SM |
916 | /* 10.1.1.4 step hashgen 4.2 */ |
917 | memcpy(buf + len, dst, outlen); | |
918 | len += outlen; | |
919 | /* 10.1.1.4 hashgen step 4.3 */ | |
920 | if (len < buflen) | |
41a84982 | 921 | crypto_inc(src, drbg_statelen(drbg)); |
541af946 SM |
922 | } |
923 | ||
924 | out: | |
1471f09f | 925 | memset(drbg->scratchpad, 0, |
541af946 SM |
926 | (drbg_statelen(drbg) + drbg_blocklen(drbg))); |
927 | return len; | |
928 | } | |
929 | ||
930 | /* generate function for Hash DRBG as defined in 10.1.1.4 */ | |
931 | static int drbg_hash_generate(struct drbg_state *drbg, | |
932 | unsigned char *buf, unsigned int buflen, | |
27e4de2b | 933 | struct list_head *addtl) |
541af946 SM |
934 | { |
935 | int len = 0; | |
936 | int ret = 0; | |
72f3e00d SM |
937 | union { |
938 | unsigned char req[8]; | |
7c8ae03f | 939 | __be64 req_int; |
72f3e00d | 940 | } u; |
541af946 SM |
941 | unsigned char prefix = DRBG_PREFIX3; |
942 | struct drbg_string data1, data2; | |
8c987166 | 943 | LIST_HEAD(datalist); |
541af946 SM |
944 | |
945 | /* 10.1.1.4 step 2 */ | |
946 | ret = drbg_hash_process_addtl(drbg, addtl); | |
947 | if (ret) | |
948 | return ret; | |
949 | /* 10.1.1.4 step 3 */ | |
950 | len = drbg_hash_hashgen(drbg, buf, buflen); | |
951 | ||
952 | /* this is the value H as documented in 10.1.1.4 */ | |
541af946 SM |
953 | /* 10.1.1.4 step 4 */ |
954 | drbg_string_fill(&data1, &prefix, 1); | |
8c987166 | 955 | list_add_tail(&data1.list, &datalist); |
541af946 | 956 | drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg)); |
8c987166 | 957 | list_add_tail(&data2.list, &datalist); |
4218ebe8 | 958 | ret = drbg_kcapi_hash(drbg, drbg->scratchpad, &datalist); |
541af946 SM |
959 | if (ret) { |
960 | len = ret; | |
961 | goto out; | |
962 | } | |
963 | ||
964 | /* 10.1.1.4 step 5 */ | |
965 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
966 | drbg->scratchpad, drbg_blocklen(drbg)); | |
967 | drbg_add_buf(drbg->V, drbg_statelen(drbg), | |
968 | drbg->C, drbg_statelen(drbg)); | |
72f3e00d SM |
969 | u.req_int = cpu_to_be64(drbg->reseed_ctr); |
970 | drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8); | |
541af946 SM |
971 | |
972 | out: | |
1471f09f | 973 | memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); |
541af946 SM |
974 | return len; |
975 | } | |
976 | ||
977 | /* | |
978 | * scratchpad usage: as update and generate are used isolated, both | |
979 | * can use the scratchpad | |
980 | */ | |
e4bc02ac | 981 | static const struct drbg_state_ops drbg_hash_ops = { |
541af946 SM |
982 | .update = drbg_hash_update, |
983 | .generate = drbg_hash_generate, | |
984 | .crypto_init = drbg_init_hash_kernel, | |
985 | .crypto_fini = drbg_fini_hash_kernel, | |
986 | }; | |
987 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
988 | ||
989 | /****************************************************************** | |
990 | * Functions common for DRBG implementations | |
991 | ******************************************************************/ | |
992 | ||
3d6a5f75 SM |
993 | static inline int __drbg_seed(struct drbg_state *drbg, struct list_head *seed, |
994 | int reseed) | |
995 | { | |
996 | int ret = drbg->d_ops->update(drbg, seed, reseed); | |
997 | ||
998 | if (ret) | |
999 | return ret; | |
1000 | ||
1001 | drbg->seeded = true; | |
1002 | /* 10.1.1.2 / 10.1.1.3 step 5 */ | |
1003 | drbg->reseed_ctr = 1; | |
1004 | ||
1005 | return ret; | |
1006 | } | |
1007 | ||
4c787990 SM |
1008 | static void drbg_async_seed(struct work_struct *work) |
1009 | { | |
1010 | struct drbg_string data; | |
1011 | LIST_HEAD(seedlist); | |
1012 | struct drbg_state *drbg = container_of(work, struct drbg_state, | |
1013 | seed_work); | |
57225e67 SM |
1014 | unsigned int entropylen = drbg_sec_strength(drbg->core->flags); |
1015 | unsigned char entropy[32]; | |
4c787990 | 1016 | |
57225e67 SM |
1017 | BUG_ON(!entropylen); |
1018 | BUG_ON(entropylen > sizeof(entropy)); | |
1019 | get_random_bytes(entropy, entropylen); | |
4c787990 | 1020 | |
57225e67 | 1021 | drbg_string_fill(&data, entropy, entropylen); |
4c787990 | 1022 | list_add_tail(&data.list, &seedlist); |
57225e67 | 1023 | |
4c787990 | 1024 | mutex_lock(&drbg->drbg_mutex); |
57225e67 SM |
1025 | |
1026 | /* If nonblocking pool is initialized, deactivate Jitter RNG */ | |
1027 | crypto_free_rng(drbg->jent); | |
1028 | drbg->jent = NULL; | |
1029 | ||
1030 | /* Set seeded to false so that if __drbg_seed fails the | |
1031 | * next generate call will trigger a reseed. | |
1032 | */ | |
1033 | drbg->seeded = false; | |
1034 | ||
1035 | __drbg_seed(drbg, &seedlist, true); | |
1036 | ||
42ea507f SM |
1037 | if (drbg->seeded) |
1038 | drbg->reseed_threshold = drbg_max_requests(drbg); | |
1039 | ||
4c787990 | 1040 | mutex_unlock(&drbg->drbg_mutex); |
57225e67 SM |
1041 | |
1042 | memzero_explicit(entropy, entropylen); | |
4c787990 SM |
1043 | } |
1044 | ||
541af946 SM |
1045 | /* |
1046 | * Seeding or reseeding of the DRBG | |
1047 | * | |
1048 | * @drbg: DRBG state struct | |
1049 | * @pers: personalization / additional information buffer | |
1050 | * @reseed: 0 for initial seed process, 1 for reseeding | |
1051 | * | |
1052 | * return: | |
1053 | * 0 on success | |
1054 | * error value otherwise | |
1055 | */ | |
1056 | static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers, | |
1057 | bool reseed) | |
1058 | { | |
57225e67 SM |
1059 | int ret; |
1060 | unsigned char entropy[((32 + 16) * 2)]; | |
1061 | unsigned int entropylen = drbg_sec_strength(drbg->core->flags); | |
541af946 | 1062 | struct drbg_string data1; |
8c987166 | 1063 | LIST_HEAD(seedlist); |
541af946 SM |
1064 | |
1065 | /* 9.1 / 9.2 / 9.3.1 step 3 */ | |
1066 | if (pers && pers->len > (drbg_max_addtl(drbg))) { | |
a9089571 | 1067 | pr_devel("DRBG: personalization string too long %zu\n", |
541af946 SM |
1068 | pers->len); |
1069 | return -EINVAL; | |
1070 | } | |
1071 | ||
8fded592 HX |
1072 | if (list_empty(&drbg->test_data.list)) { |
1073 | drbg_string_fill(&data1, drbg->test_data.buf, | |
1074 | drbg->test_data.len); | |
541af946 SM |
1075 | pr_devel("DRBG: using test entropy\n"); |
1076 | } else { | |
57225e67 SM |
1077 | /* |
1078 | * Gather entropy equal to the security strength of the DRBG. | |
1079 | * With a derivation function, a nonce is required in addition | |
1080 | * to the entropy. A nonce must be at least 1/2 of the security | |
1081 | * strength of the DRBG in size. Thus, entropy + nonce is 3/2 | |
1082 | * of the strength. The consideration of a nonce is only | |
1083 | * applicable during initial seeding. | |
1084 | */ | |
1085 | BUG_ON(!entropylen); | |
1086 | if (!reseed) | |
1087 | entropylen = ((entropylen + 1) / 2) * 3; | |
1088 | BUG_ON((entropylen * 2) > sizeof(entropy)); | |
1089 | ||
b8ec5ba4 | 1090 | /* Get seed from in-kernel /dev/urandom */ |
57225e67 SM |
1091 | get_random_bytes(entropy, entropylen); |
1092 | ||
1093 | if (!drbg->jent) { | |
1094 | drbg_string_fill(&data1, entropy, entropylen); | |
1095 | pr_devel("DRBG: (re)seeding with %u bytes of entropy\n", | |
1096 | entropylen); | |
b8ec5ba4 | 1097 | } else { |
57225e67 SM |
1098 | /* Get seed from Jitter RNG */ |
1099 | ret = crypto_rng_get_bytes(drbg->jent, | |
1100 | entropy + entropylen, | |
1101 | entropylen); | |
1102 | if (ret) { | |
1103 | pr_devel("DRBG: jent failed with %d\n", ret); | |
1104 | return ret; | |
1105 | } | |
1106 | ||
1107 | drbg_string_fill(&data1, entropy, entropylen * 2); | |
1108 | pr_devel("DRBG: (re)seeding with %u bytes of entropy\n", | |
1109 | entropylen * 2); | |
b8ec5ba4 | 1110 | } |
541af946 | 1111 | } |
8c987166 | 1112 | list_add_tail(&data1.list, &seedlist); |
541af946 SM |
1113 | |
1114 | /* | |
1115 | * concatenation of entropy with personalization str / addtl input) | |
1116 | * the variable pers is directly handed in by the caller, so check its | |
1117 | * contents whether it is appropriate | |
1118 | */ | |
8c987166 SM |
1119 | if (pers && pers->buf && 0 < pers->len) { |
1120 | list_add_tail(&pers->list, &seedlist); | |
541af946 SM |
1121 | pr_devel("DRBG: using personalization string\n"); |
1122 | } | |
1123 | ||
e6c0244a SM |
1124 | if (!reseed) { |
1125 | memset(drbg->V, 0, drbg_statelen(drbg)); | |
1126 | memset(drbg->C, 0, drbg_statelen(drbg)); | |
1127 | } | |
1128 | ||
3d6a5f75 SM |
1129 | ret = __drbg_seed(drbg, &seedlist, reseed); |
1130 | ||
57225e67 | 1131 | memzero_explicit(entropy, entropylen * 2); |
4c787990 | 1132 | |
541af946 SM |
1133 | return ret; |
1134 | } | |
1135 | ||
1136 | /* Free all substructures in a DRBG state without the DRBG state structure */ | |
1137 | static inline void drbg_dealloc_state(struct drbg_state *drbg) | |
1138 | { | |
1139 | if (!drbg) | |
1140 | return; | |
46f64f6e | 1141 | kzfree(drbg->V); |
3cfc3b97 | 1142 | drbg->Vbuf = NULL; |
46f64f6e | 1143 | kzfree(drbg->C); |
3cfc3b97 SM |
1144 | drbg->Cbuf = NULL; |
1145 | kzfree(drbg->scratchpadbuf); | |
1146 | drbg->scratchpadbuf = NULL; | |
541af946 | 1147 | drbg->reseed_ctr = 0; |
2a57e424 HX |
1148 | drbg->d_ops = NULL; |
1149 | drbg->core = NULL; | |
541af946 SM |
1150 | } |
1151 | ||
1152 | /* | |
1153 | * Allocate all sub-structures for a DRBG state. | |
1154 | * The DRBG state structure must already be allocated. | |
1155 | */ | |
1156 | static inline int drbg_alloc_state(struct drbg_state *drbg) | |
1157 | { | |
1158 | int ret = -ENOMEM; | |
1159 | unsigned int sb_size = 0; | |
1160 | ||
2a57e424 HX |
1161 | switch (drbg->core->flags & DRBG_TYPE_MASK) { |
1162 | #ifdef CONFIG_CRYPTO_DRBG_HMAC | |
1163 | case DRBG_HMAC: | |
1164 | drbg->d_ops = &drbg_hmac_ops; | |
1165 | break; | |
1166 | #endif /* CONFIG_CRYPTO_DRBG_HMAC */ | |
1167 | #ifdef CONFIG_CRYPTO_DRBG_HASH | |
1168 | case DRBG_HASH: | |
1169 | drbg->d_ops = &drbg_hash_ops; | |
1170 | break; | |
1171 | #endif /* CONFIG_CRYPTO_DRBG_HASH */ | |
1172 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1173 | case DRBG_CTR: | |
1174 | drbg->d_ops = &drbg_ctr_ops; | |
1175 | break; | |
1176 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ | |
1177 | default: | |
1178 | ret = -EOPNOTSUPP; | |
1179 | goto err; | |
1180 | } | |
1181 | ||
3cfc3b97 SM |
1182 | ret = drbg->d_ops->crypto_init(drbg); |
1183 | if (ret < 0) | |
541af946 | 1184 | goto err; |
3cfc3b97 SM |
1185 | |
1186 | drbg->Vbuf = kmalloc(drbg_statelen(drbg) + ret, GFP_KERNEL); | |
1187 | if (!drbg->Vbuf) | |
1188 | goto fini; | |
1189 | drbg->V = PTR_ALIGN(drbg->Vbuf, ret + 1); | |
1190 | drbg->Cbuf = kmalloc(drbg_statelen(drbg) + ret, GFP_KERNEL); | |
1191 | if (!drbg->Cbuf) | |
1192 | goto fini; | |
1193 | drbg->C = PTR_ALIGN(drbg->Cbuf, ret + 1); | |
541af946 SM |
1194 | /* scratchpad is only generated for CTR and Hash */ |
1195 | if (drbg->core->flags & DRBG_HMAC) | |
1196 | sb_size = 0; | |
1197 | else if (drbg->core->flags & DRBG_CTR) | |
1198 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg) + /* temp */ | |
1199 | drbg_statelen(drbg) + /* df_data */ | |
1200 | drbg_blocklen(drbg) + /* pad */ | |
1201 | drbg_blocklen(drbg) + /* iv */ | |
8fecaad7 | 1202 | drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */ |
541af946 SM |
1203 | else |
1204 | sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg); | |
1205 | ||
1206 | if (0 < sb_size) { | |
3cfc3b97 SM |
1207 | drbg->scratchpadbuf = kzalloc(sb_size + ret, GFP_KERNEL); |
1208 | if (!drbg->scratchpadbuf) | |
1209 | goto fini; | |
1210 | drbg->scratchpad = PTR_ALIGN(drbg->scratchpadbuf, ret + 1); | |
541af946 | 1211 | } |
3d6a5f75 | 1212 | |
541af946 SM |
1213 | return 0; |
1214 | ||
3cfc3b97 SM |
1215 | fini: |
1216 | drbg->d_ops->crypto_fini(drbg); | |
541af946 SM |
1217 | err: |
1218 | drbg_dealloc_state(drbg); | |
1219 | return ret; | |
1220 | } | |
1221 | ||
541af946 SM |
1222 | /************************************************************************* |
1223 | * DRBG interface functions | |
1224 | *************************************************************************/ | |
1225 | ||
1226 | /* | |
1227 | * DRBG generate function as required by SP800-90A - this function | |
1228 | * generates random numbers | |
1229 | * | |
1230 | * @drbg DRBG state handle | |
1231 | * @buf Buffer where to store the random numbers -- the buffer must already | |
1232 | * be pre-allocated by caller | |
1233 | * @buflen Length of output buffer - this value defines the number of random | |
1234 | * bytes pulled from DRBG | |
1235 | * @addtl Additional input that is mixed into state, may be NULL -- note | |
1236 | * the entropy is pulled by the DRBG internally unconditionally | |
1237 | * as defined in SP800-90A. The additional input is mixed into | |
1238 | * the state in addition to the pulled entropy. | |
1239 | * | |
cde001e4 | 1240 | * return: 0 when all bytes are generated; < 0 in case of an error |
541af946 SM |
1241 | */ |
1242 | static int drbg_generate(struct drbg_state *drbg, | |
1243 | unsigned char *buf, unsigned int buflen, | |
1244 | struct drbg_string *addtl) | |
1245 | { | |
1246 | int len = 0; | |
27e4de2b | 1247 | LIST_HEAD(addtllist); |
541af946 | 1248 | |
2a57e424 HX |
1249 | if (!drbg->core) { |
1250 | pr_devel("DRBG: not yet seeded\n"); | |
1251 | return -EINVAL; | |
1252 | } | |
541af946 SM |
1253 | if (0 == buflen || !buf) { |
1254 | pr_devel("DRBG: no output buffer provided\n"); | |
1255 | return -EINVAL; | |
1256 | } | |
1257 | if (addtl && NULL == addtl->buf && 0 < addtl->len) { | |
1258 | pr_devel("DRBG: wrong format of additional information\n"); | |
1259 | return -EINVAL; | |
1260 | } | |
1261 | ||
541af946 SM |
1262 | /* 9.3.1 step 2 */ |
1263 | len = -EINVAL; | |
76899a41 | 1264 | if (buflen > (drbg_max_request_bytes(drbg))) { |
541af946 SM |
1265 | pr_devel("DRBG: requested random numbers too large %u\n", |
1266 | buflen); | |
1267 | goto err; | |
1268 | } | |
1269 | ||
1270 | /* 9.3.1 step 3 is implicit with the chosen DRBG */ | |
1271 | ||
1272 | /* 9.3.1 step 4 */ | |
76899a41 | 1273 | if (addtl && addtl->len > (drbg_max_addtl(drbg))) { |
541af946 SM |
1274 | pr_devel("DRBG: additional information string too long %zu\n", |
1275 | addtl->len); | |
1276 | goto err; | |
1277 | } | |
1278 | /* 9.3.1 step 5 is implicit with the chosen DRBG */ | |
1279 | ||
1280 | /* | |
1281 | * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented | |
1282 | * here. The spec is a bit convoluted here, we make it simpler. | |
1283 | */ | |
42ea507f | 1284 | if (drbg->reseed_threshold < drbg->reseed_ctr) |
76899a41 | 1285 | drbg->seeded = false; |
541af946 | 1286 | |
76899a41 | 1287 | if (drbg->pr || !drbg->seeded) { |
541af946 SM |
1288 | pr_devel("DRBG: reseeding before generation (prediction " |
1289 | "resistance: %s, state %s)\n", | |
1290 | drbg->pr ? "true" : "false", | |
1291 | drbg->seeded ? "seeded" : "unseeded"); | |
1292 | /* 9.3.1 steps 7.1 through 7.3 */ | |
76899a41 | 1293 | len = drbg_seed(drbg, addtl, true); |
541af946 SM |
1294 | if (len) |
1295 | goto err; | |
1296 | /* 9.3.1 step 7.4 */ | |
1297 | addtl = NULL; | |
1298 | } | |
27e4de2b | 1299 | |
27e4de2b SM |
1300 | if (addtl && 0 < addtl->len) |
1301 | list_add_tail(&addtl->list, &addtllist); | |
541af946 | 1302 | /* 9.3.1 step 8 and 10 */ |
76899a41 | 1303 | len = drbg->d_ops->generate(drbg, buf, buflen, &addtllist); |
541af946 SM |
1304 | |
1305 | /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */ | |
76899a41 | 1306 | drbg->reseed_ctr++; |
541af946 SM |
1307 | if (0 >= len) |
1308 | goto err; | |
1309 | ||
1310 | /* | |
1311 | * Section 11.3.3 requires to re-perform self tests after some | |
1312 | * generated random numbers. The chosen value after which self | |
1313 | * test is performed is arbitrary, but it should be reasonable. | |
1314 | * However, we do not perform the self tests because of the following | |
1315 | * reasons: it is mathematically impossible that the initial self tests | |
1316 | * were successfully and the following are not. If the initial would | |
1317 | * pass and the following would not, the kernel integrity is violated. | |
1318 | * In this case, the entire kernel operation is questionable and it | |
1319 | * is unlikely that the integrity violation only affects the | |
1320 | * correct operation of the DRBG. | |
1321 | * | |
1322 | * Albeit the following code is commented out, it is provided in | |
1323 | * case somebody has a need to implement the test of 11.3.3. | |
1324 | */ | |
1325 | #if 0 | |
76899a41 | 1326 | if (drbg->reseed_ctr && !(drbg->reseed_ctr % 4096)) { |
541af946 SM |
1327 | int err = 0; |
1328 | pr_devel("DRBG: start to perform self test\n"); | |
1329 | if (drbg->core->flags & DRBG_HMAC) | |
1330 | err = alg_test("drbg_pr_hmac_sha256", | |
1331 | "drbg_pr_hmac_sha256", 0, 0); | |
1332 | else if (drbg->core->flags & DRBG_CTR) | |
1333 | err = alg_test("drbg_pr_ctr_aes128", | |
1334 | "drbg_pr_ctr_aes128", 0, 0); | |
1335 | else | |
1336 | err = alg_test("drbg_pr_sha256", | |
1337 | "drbg_pr_sha256", 0, 0); | |
1338 | if (err) { | |
1339 | pr_err("DRBG: periodical self test failed\n"); | |
1340 | /* | |
1341 | * uninstantiate implies that from now on, only errors | |
1342 | * are returned when reusing this DRBG cipher handle | |
1343 | */ | |
1344 | drbg_uninstantiate(drbg); | |
541af946 SM |
1345 | return 0; |
1346 | } else { | |
1347 | pr_devel("DRBG: self test successful\n"); | |
1348 | } | |
1349 | } | |
1350 | #endif | |
1351 | ||
cde001e4 SM |
1352 | /* |
1353 | * All operations were successful, return 0 as mandated by | |
1354 | * the kernel crypto API interface. | |
1355 | */ | |
1356 | len = 0; | |
541af946 | 1357 | err: |
541af946 SM |
1358 | return len; |
1359 | } | |
1360 | ||
1361 | /* | |
1362 | * Wrapper around drbg_generate which can pull arbitrary long strings | |
1363 | * from the DRBG without hitting the maximum request limitation. | |
1364 | * | |
1365 | * Parameters: see drbg_generate | |
1366 | * Return codes: see drbg_generate -- if one drbg_generate request fails, | |
1367 | * the entire drbg_generate_long request fails | |
1368 | */ | |
1369 | static int drbg_generate_long(struct drbg_state *drbg, | |
1370 | unsigned char *buf, unsigned int buflen, | |
1371 | struct drbg_string *addtl) | |
1372 | { | |
082eb10b | 1373 | unsigned int len = 0; |
541af946 SM |
1374 | unsigned int slice = 0; |
1375 | do { | |
082eb10b | 1376 | int err = 0; |
541af946 SM |
1377 | unsigned int chunk = 0; |
1378 | slice = ((buflen - len) / drbg_max_request_bytes(drbg)); | |
1379 | chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len); | |
76899a41 | 1380 | mutex_lock(&drbg->drbg_mutex); |
082eb10b | 1381 | err = drbg_generate(drbg, buf + len, chunk, addtl); |
76899a41 | 1382 | mutex_unlock(&drbg->drbg_mutex); |
082eb10b SM |
1383 | if (0 > err) |
1384 | return err; | |
1385 | len += chunk; | |
ce5481d0 | 1386 | } while (slice > 0 && (len < buflen)); |
082eb10b | 1387 | return 0; |
541af946 SM |
1388 | } |
1389 | ||
57225e67 SM |
1390 | static void drbg_schedule_async_seed(struct random_ready_callback *rdy) |
1391 | { | |
1392 | struct drbg_state *drbg = container_of(rdy, struct drbg_state, | |
1393 | random_ready); | |
1394 | ||
1395 | schedule_work(&drbg->seed_work); | |
1396 | } | |
1397 | ||
1398 | static int drbg_prepare_hrng(struct drbg_state *drbg) | |
1399 | { | |
1400 | int err; | |
1401 | ||
1402 | /* We do not need an HRNG in test mode. */ | |
1403 | if (list_empty(&drbg->test_data.list)) | |
1404 | return 0; | |
1405 | ||
1406 | INIT_WORK(&drbg->seed_work, drbg_async_seed); | |
1407 | ||
1408 | drbg->random_ready.owner = THIS_MODULE; | |
1409 | drbg->random_ready.func = drbg_schedule_async_seed; | |
1410 | ||
1411 | err = add_random_ready_callback(&drbg->random_ready); | |
1412 | ||
1413 | switch (err) { | |
1414 | case 0: | |
1415 | break; | |
1416 | ||
1417 | case -EALREADY: | |
1418 | err = 0; | |
1419 | /* fall through */ | |
1420 | ||
1421 | default: | |
1422 | drbg->random_ready.func = NULL; | |
1423 | return err; | |
1424 | } | |
1425 | ||
1426 | drbg->jent = crypto_alloc_rng("jitterentropy_rng", 0, 0); | |
1427 | ||
42ea507f SM |
1428 | /* |
1429 | * Require frequent reseeds until the seed source is fully | |
1430 | * initialized. | |
1431 | */ | |
1432 | drbg->reseed_threshold = 50; | |
1433 | ||
57225e67 SM |
1434 | return err; |
1435 | } | |
1436 | ||
541af946 SM |
1437 | /* |
1438 | * DRBG instantiation function as required by SP800-90A - this function | |
1439 | * sets up the DRBG handle, performs the initial seeding and all sanity | |
1440 | * checks required by SP800-90A | |
1441 | * | |
1442 | * @drbg memory of state -- if NULL, new memory is allocated | |
1443 | * @pers Personalization string that is mixed into state, may be NULL -- note | |
1444 | * the entropy is pulled by the DRBG internally unconditionally | |
1445 | * as defined in SP800-90A. The additional input is mixed into | |
1446 | * the state in addition to the pulled entropy. | |
1447 | * @coreref reference to core | |
1448 | * @pr prediction resistance enabled | |
1449 | * | |
1450 | * return | |
1451 | * 0 on success | |
1452 | * error value otherwise | |
1453 | */ | |
1454 | static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, | |
1455 | int coreref, bool pr) | |
1456 | { | |
2a57e424 HX |
1457 | int ret; |
1458 | bool reseed = true; | |
541af946 SM |
1459 | |
1460 | pr_devel("DRBG: Initializing DRBG core %d with prediction resistance " | |
1461 | "%s\n", coreref, pr ? "enabled" : "disabled"); | |
76899a41 | 1462 | mutex_lock(&drbg->drbg_mutex); |
541af946 SM |
1463 | |
1464 | /* 9.1 step 1 is implicit with the selected DRBG type */ | |
1465 | ||
1466 | /* | |
1467 | * 9.1 step 2 is implicit as caller can select prediction resistance | |
1468 | * and the flag is copied into drbg->flags -- | |
1469 | * all DRBG types support prediction resistance | |
1470 | */ | |
1471 | ||
1472 | /* 9.1 step 4 is implicit in drbg_sec_strength */ | |
1473 | ||
2a57e424 HX |
1474 | if (!drbg->core) { |
1475 | drbg->core = &drbg_cores[coreref]; | |
1476 | drbg->pr = pr; | |
1477 | drbg->seeded = false; | |
42ea507f | 1478 | drbg->reseed_threshold = drbg_max_requests(drbg); |
541af946 | 1479 | |
2a57e424 HX |
1480 | ret = drbg_alloc_state(drbg); |
1481 | if (ret) | |
1482 | goto unlock; | |
1483 | ||
57225e67 SM |
1484 | ret = drbg_prepare_hrng(drbg); |
1485 | if (ret) | |
1486 | goto free_everything; | |
1487 | ||
1488 | if (IS_ERR(drbg->jent)) { | |
1489 | ret = PTR_ERR(drbg->jent); | |
1490 | drbg->jent = NULL; | |
1491 | if (fips_enabled || ret != -ENOENT) | |
1492 | goto free_everything; | |
1493 | pr_info("DRBG: Continuing without Jitter RNG\n"); | |
1494 | } | |
1495 | ||
2a57e424 HX |
1496 | reseed = false; |
1497 | } | |
1498 | ||
1499 | ret = drbg_seed(drbg, pers, reseed); | |
1500 | ||
57225e67 SM |
1501 | if (ret && !reseed) |
1502 | goto free_everything; | |
541af946 | 1503 | |
76899a41 | 1504 | mutex_unlock(&drbg->drbg_mutex); |
2a57e424 | 1505 | return ret; |
541af946 | 1506 | |
76899a41 SM |
1507 | unlock: |
1508 | mutex_unlock(&drbg->drbg_mutex); | |
541af946 | 1509 | return ret; |
57225e67 SM |
1510 | |
1511 | free_everything: | |
1512 | mutex_unlock(&drbg->drbg_mutex); | |
1513 | drbg_uninstantiate(drbg); | |
1514 | return ret; | |
541af946 SM |
1515 | } |
1516 | ||
1517 | /* | |
1518 | * DRBG uninstantiate function as required by SP800-90A - this function | |
1519 | * frees all buffers and the DRBG handle | |
1520 | * | |
1521 | * @drbg DRBG state handle | |
1522 | * | |
1523 | * return | |
1524 | * 0 on success | |
1525 | */ | |
1526 | static int drbg_uninstantiate(struct drbg_state *drbg) | |
1527 | { | |
57225e67 SM |
1528 | if (drbg->random_ready.func) { |
1529 | del_random_ready_callback(&drbg->random_ready); | |
1530 | cancel_work_sync(&drbg->seed_work); | |
1531 | crypto_free_rng(drbg->jent); | |
1532 | drbg->jent = NULL; | |
1533 | } | |
1534 | ||
2a57e424 HX |
1535 | if (drbg->d_ops) |
1536 | drbg->d_ops->crypto_fini(drbg); | |
541af946 SM |
1537 | drbg_dealloc_state(drbg); |
1538 | /* no scrubbing of test_data -- this shall survive an uninstantiate */ | |
541af946 SM |
1539 | return 0; |
1540 | } | |
1541 | ||
1542 | /* | |
1543 | * Helper function for setting the test data in the DRBG | |
1544 | * | |
1545 | * @drbg DRBG state handle | |
8fded592 HX |
1546 | * @data test data |
1547 | * @len test data length | |
541af946 | 1548 | */ |
8fded592 HX |
1549 | static void drbg_kcapi_set_entropy(struct crypto_rng *tfm, |
1550 | const u8 *data, unsigned int len) | |
541af946 | 1551 | { |
8fded592 HX |
1552 | struct drbg_state *drbg = crypto_rng_ctx(tfm); |
1553 | ||
1554 | mutex_lock(&drbg->drbg_mutex); | |
1555 | drbg_string_fill(&drbg->test_data, data, len); | |
76899a41 | 1556 | mutex_unlock(&drbg->drbg_mutex); |
541af946 SM |
1557 | } |
1558 | ||
1559 | /*************************************************************** | |
1560 | * Kernel crypto API cipher invocations requested by DRBG | |
1561 | ***************************************************************/ | |
1562 | ||
1563 | #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) | |
1564 | struct sdesc { | |
1565 | struct shash_desc shash; | |
1566 | char ctx[]; | |
1567 | }; | |
1568 | ||
1569 | static int drbg_init_hash_kernel(struct drbg_state *drbg) | |
1570 | { | |
1571 | struct sdesc *sdesc; | |
1572 | struct crypto_shash *tfm; | |
1573 | ||
1574 | tfm = crypto_alloc_shash(drbg->core->backend_cra_name, 0, 0); | |
1575 | if (IS_ERR(tfm)) { | |
593dfbd9 SS |
1576 | pr_info("DRBG: could not allocate digest TFM handle: %s\n", |
1577 | drbg->core->backend_cra_name); | |
541af946 SM |
1578 | return PTR_ERR(tfm); |
1579 | } | |
1580 | BUG_ON(drbg_blocklen(drbg) != crypto_shash_digestsize(tfm)); | |
1581 | sdesc = kzalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm), | |
1582 | GFP_KERNEL); | |
1583 | if (!sdesc) { | |
1584 | crypto_free_shash(tfm); | |
1585 | return -ENOMEM; | |
1586 | } | |
1587 | ||
1588 | sdesc->shash.tfm = tfm; | |
1589 | sdesc->shash.flags = 0; | |
1590 | drbg->priv_data = sdesc; | |
3cfc3b97 SM |
1591 | |
1592 | return crypto_shash_alignmask(tfm); | |
541af946 SM |
1593 | } |
1594 | ||
1595 | static int drbg_fini_hash_kernel(struct drbg_state *drbg) | |
1596 | { | |
1597 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
1598 | if (sdesc) { | |
1599 | crypto_free_shash(sdesc->shash.tfm); | |
1600 | kzfree(sdesc); | |
1601 | } | |
1602 | drbg->priv_data = NULL; | |
1603 | return 0; | |
1604 | } | |
1605 | ||
4218ebe8 SM |
1606 | static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg, |
1607 | const unsigned char *key) | |
1608 | { | |
1609 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
1610 | ||
1611 | crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg)); | |
1612 | } | |
1613 | ||
1614 | static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval, | |
1615 | const struct list_head *in) | |
541af946 SM |
1616 | { |
1617 | struct sdesc *sdesc = (struct sdesc *)drbg->priv_data; | |
8c987166 | 1618 | struct drbg_string *input = NULL; |
541af946 | 1619 | |
541af946 | 1620 | crypto_shash_init(&sdesc->shash); |
8c987166 SM |
1621 | list_for_each_entry(input, in, list) |
1622 | crypto_shash_update(&sdesc->shash, input->buf, input->len); | |
541af946 SM |
1623 | return crypto_shash_final(&sdesc->shash, outval); |
1624 | } | |
1625 | #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */ | |
1626 | ||
1627 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
35591285 SM |
1628 | static int drbg_fini_sym_kernel(struct drbg_state *drbg) |
1629 | { | |
1630 | struct crypto_cipher *tfm = | |
1631 | (struct crypto_cipher *)drbg->priv_data; | |
1632 | if (tfm) | |
1633 | crypto_free_cipher(tfm); | |
1634 | drbg->priv_data = NULL; | |
1635 | ||
1636 | if (drbg->ctr_handle) | |
1637 | crypto_free_skcipher(drbg->ctr_handle); | |
1638 | drbg->ctr_handle = NULL; | |
1639 | ||
1640 | if (drbg->ctr_req) | |
1641 | skcipher_request_free(drbg->ctr_req);; | |
1642 | drbg->ctr_req = NULL; | |
1643 | ||
1644 | kfree(drbg->ctr_null_value_buf); | |
1645 | drbg->ctr_null_value = NULL; | |
1646 | ||
1647 | return 0; | |
1648 | } | |
1649 | ||
1650 | static void drbg_skcipher_cb(struct crypto_async_request *req, int error) | |
1651 | { | |
1652 | struct drbg_state *drbg = req->data; | |
1653 | ||
1654 | if (error == -EINPROGRESS) | |
1655 | return; | |
1656 | drbg->ctr_async_err = error; | |
1657 | complete(&drbg->ctr_completion); | |
1658 | } | |
1659 | ||
1660 | #define DRBG_CTR_NULL_LEN 128 | |
541af946 SM |
1661 | static int drbg_init_sym_kernel(struct drbg_state *drbg) |
1662 | { | |
04bcbfcf | 1663 | struct crypto_cipher *tfm; |
35591285 SM |
1664 | struct crypto_skcipher *sk_tfm; |
1665 | struct skcipher_request *req; | |
1666 | unsigned int alignmask; | |
1667 | char ctr_name[CRYPTO_MAX_ALG_NAME]; | |
541af946 | 1668 | |
04bcbfcf | 1669 | tfm = crypto_alloc_cipher(drbg->core->backend_cra_name, 0, 0); |
541af946 | 1670 | if (IS_ERR(tfm)) { |
593dfbd9 SS |
1671 | pr_info("DRBG: could not allocate cipher TFM handle: %s\n", |
1672 | drbg->core->backend_cra_name); | |
541af946 SM |
1673 | return PTR_ERR(tfm); |
1674 | } | |
04bcbfcf | 1675 | BUG_ON(drbg_blocklen(drbg) != crypto_cipher_blocksize(tfm)); |
541af946 | 1676 | drbg->priv_data = tfm; |
541af946 | 1677 | |
35591285 SM |
1678 | if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", |
1679 | drbg->core->backend_cra_name) >= CRYPTO_MAX_ALG_NAME) { | |
1680 | drbg_fini_sym_kernel(drbg); | |
1681 | return -EINVAL; | |
1682 | } | |
1683 | sk_tfm = crypto_alloc_skcipher(ctr_name, 0, 0); | |
1684 | if (IS_ERR(sk_tfm)) { | |
1685 | pr_info("DRBG: could not allocate CTR cipher TFM handle: %s\n", | |
1686 | ctr_name); | |
1687 | drbg_fini_sym_kernel(drbg); | |
1688 | return PTR_ERR(sk_tfm); | |
1689 | } | |
1690 | drbg->ctr_handle = sk_tfm; | |
1691 | ||
1692 | req = skcipher_request_alloc(sk_tfm, GFP_KERNEL); | |
1693 | if (!req) { | |
1694 | pr_info("DRBG: could not allocate request queue\n"); | |
1695 | drbg_fini_sym_kernel(drbg); | |
1696 | return PTR_ERR(req); | |
1697 | } | |
1698 | drbg->ctr_req = req; | |
1699 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
1700 | drbg_skcipher_cb, drbg); | |
1701 | ||
1702 | alignmask = crypto_skcipher_alignmask(sk_tfm); | |
1703 | drbg->ctr_null_value_buf = kzalloc(DRBG_CTR_NULL_LEN + alignmask, | |
1704 | GFP_KERNEL); | |
1705 | if (!drbg->ctr_null_value_buf) { | |
1706 | drbg_fini_sym_kernel(drbg); | |
1707 | return -ENOMEM; | |
1708 | } | |
1709 | drbg->ctr_null_value = (u8 *)PTR_ALIGN(drbg->ctr_null_value_buf, | |
1710 | alignmask + 1); | |
1711 | ||
3cfc3b97 | 1712 | return alignmask; |
541af946 SM |
1713 | } |
1714 | ||
ed494d4f SM |
1715 | static void drbg_kcapi_symsetkey(struct drbg_state *drbg, |
1716 | const unsigned char *key) | |
541af946 | 1717 | { |
04bcbfcf SM |
1718 | struct crypto_cipher *tfm = |
1719 | (struct crypto_cipher *)drbg->priv_data; | |
541af946 | 1720 | |
04bcbfcf | 1721 | crypto_cipher_setkey(tfm, key, (drbg_keylen(drbg))); |
ed494d4f SM |
1722 | } |
1723 | ||
1724 | static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval, | |
1725 | const struct drbg_string *in) | |
1726 | { | |
1727 | struct crypto_cipher *tfm = | |
1728 | (struct crypto_cipher *)drbg->priv_data; | |
1729 | ||
04bcbfcf SM |
1730 | /* there is only component in *in */ |
1731 | BUG_ON(in->len < drbg_blocklen(drbg)); | |
1732 | crypto_cipher_encrypt_one(tfm, outval, in->buf); | |
1733 | return 0; | |
541af946 | 1734 | } |
35591285 SM |
1735 | |
1736 | static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, u8 *outbuf, u32 outlen) | |
1737 | { | |
1738 | struct scatterlist sg_in; | |
1739 | ||
1740 | sg_init_one(&sg_in, drbg->ctr_null_value, DRBG_CTR_NULL_LEN); | |
1741 | ||
1742 | while (outlen) { | |
1743 | u32 cryptlen = min_t(u32, outlen, DRBG_CTR_NULL_LEN); | |
1744 | struct scatterlist sg_out; | |
1745 | int ret; | |
1746 | ||
1747 | sg_init_one(&sg_out, outbuf, cryptlen); | |
1748 | skcipher_request_set_crypt(drbg->ctr_req, &sg_in, &sg_out, | |
1749 | cryptlen, drbg->V); | |
1750 | ret = crypto_skcipher_encrypt(drbg->ctr_req); | |
1751 | switch (ret) { | |
1752 | case 0: | |
1753 | break; | |
1754 | case -EINPROGRESS: | |
1755 | case -EBUSY: | |
1756 | ret = wait_for_completion_interruptible( | |
1757 | &drbg->ctr_completion); | |
1758 | if (!ret && !drbg->ctr_async_err) { | |
1759 | reinit_completion(&drbg->ctr_completion); | |
1760 | break; | |
1761 | } | |
1762 | default: | |
1763 | return ret; | |
1764 | } | |
1765 | init_completion(&drbg->ctr_completion); | |
1766 | ||
1767 | outlen -= cryptlen; | |
1768 | } | |
1769 | ||
1770 | return 0; | |
1771 | } | |
541af946 SM |
1772 | #endif /* CONFIG_CRYPTO_DRBG_CTR */ |
1773 | ||
1774 | /*************************************************************** | |
1775 | * Kernel crypto API interface to register DRBG | |
1776 | ***************************************************************/ | |
1777 | ||
1778 | /* | |
1779 | * Look up the DRBG flags by given kernel crypto API cra_name | |
1780 | * The code uses the drbg_cores definition to do this | |
1781 | * | |
1782 | * @cra_name kernel crypto API cra_name | |
1783 | * @coreref reference to integer which is filled with the pointer to | |
1784 | * the applicable core | |
1785 | * @pr reference for setting prediction resistance | |
1786 | * | |
1787 | * return: flags | |
1788 | */ | |
1789 | static inline void drbg_convert_tfm_core(const char *cra_driver_name, | |
1790 | int *coreref, bool *pr) | |
1791 | { | |
1792 | int i = 0; | |
1793 | size_t start = 0; | |
1794 | int len = 0; | |
1795 | ||
1796 | *pr = true; | |
1797 | /* disassemble the names */ | |
1798 | if (!memcmp(cra_driver_name, "drbg_nopr_", 10)) { | |
1799 | start = 10; | |
1800 | *pr = false; | |
1801 | } else if (!memcmp(cra_driver_name, "drbg_pr_", 8)) { | |
1802 | start = 8; | |
1803 | } else { | |
1804 | return; | |
1805 | } | |
1806 | ||
1807 | /* remove the first part */ | |
1808 | len = strlen(cra_driver_name) - start; | |
1809 | for (i = 0; ARRAY_SIZE(drbg_cores) > i; i++) { | |
1810 | if (!memcmp(cra_driver_name + start, drbg_cores[i].cra_name, | |
1811 | len)) { | |
1812 | *coreref = i; | |
1813 | return; | |
1814 | } | |
1815 | } | |
1816 | } | |
1817 | ||
1818 | static int drbg_kcapi_init(struct crypto_tfm *tfm) | |
1819 | { | |
1820 | struct drbg_state *drbg = crypto_tfm_ctx(tfm); | |
541af946 | 1821 | |
76899a41 | 1822 | mutex_init(&drbg->drbg_mutex); |
2a57e424 HX |
1823 | |
1824 | return 0; | |
541af946 SM |
1825 | } |
1826 | ||
1827 | static void drbg_kcapi_cleanup(struct crypto_tfm *tfm) | |
1828 | { | |
1829 | drbg_uninstantiate(crypto_tfm_ctx(tfm)); | |
1830 | } | |
1831 | ||
1832 | /* | |
1833 | * Generate random numbers invoked by the kernel crypto API: | |
1834 | * The API of the kernel crypto API is extended as follows: | |
1835 | * | |
8fded592 HX |
1836 | * src is additional input supplied to the RNG. |
1837 | * slen is the length of src. | |
1838 | * dst is the output buffer where random data is to be stored. | |
1839 | * dlen is the length of dst. | |
541af946 | 1840 | */ |
8fded592 HX |
1841 | static int drbg_kcapi_random(struct crypto_rng *tfm, |
1842 | const u8 *src, unsigned int slen, | |
1843 | u8 *dst, unsigned int dlen) | |
541af946 SM |
1844 | { |
1845 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
8fded592 HX |
1846 | struct drbg_string *addtl = NULL; |
1847 | struct drbg_string string; | |
1848 | ||
1849 | if (slen) { | |
8c987166 | 1850 | /* linked list variable is now local to allow modification */ |
8fded592 HX |
1851 | drbg_string_fill(&string, src, slen); |
1852 | addtl = &string; | |
541af946 | 1853 | } |
8fded592 HX |
1854 | |
1855 | return drbg_generate_long(drbg, dst, dlen, addtl); | |
541af946 SM |
1856 | } |
1857 | ||
1858 | /* | |
2a57e424 | 1859 | * Seed the DRBG invoked by the kernel crypto API |
541af946 | 1860 | */ |
8fded592 HX |
1861 | static int drbg_kcapi_seed(struct crypto_rng *tfm, |
1862 | const u8 *seed, unsigned int slen) | |
541af946 SM |
1863 | { |
1864 | struct drbg_state *drbg = crypto_rng_ctx(tfm); | |
1865 | struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm); | |
1866 | bool pr = false; | |
8fded592 HX |
1867 | struct drbg_string string; |
1868 | struct drbg_string *seed_string = NULL; | |
541af946 SM |
1869 | int coreref = 0; |
1870 | ||
541af946 SM |
1871 | drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref, |
1872 | &pr); | |
1873 | if (0 < slen) { | |
8fded592 HX |
1874 | drbg_string_fill(&string, seed, slen); |
1875 | seed_string = &string; | |
541af946 | 1876 | } |
8fded592 HX |
1877 | |
1878 | return drbg_instantiate(drbg, seed_string, coreref, pr); | |
541af946 SM |
1879 | } |
1880 | ||
1881 | /*************************************************************** | |
1882 | * Kernel module: code to load the module | |
1883 | ***************************************************************/ | |
1884 | ||
1885 | /* | |
1886 | * Tests as defined in 11.3.2 in addition to the cipher tests: testing | |
1887 | * of the error handling. | |
1888 | * | |
1889 | * Note: testing of failing seed source as defined in 11.3.2 is not applicable | |
1890 | * as seed source of get_random_bytes does not fail. | |
1891 | * | |
1892 | * Note 2: There is no sensible way of testing the reseed counter | |
1893 | * enforcement, so skip it. | |
1894 | */ | |
1895 | static inline int __init drbg_healthcheck_sanity(void) | |
1896 | { | |
541af946 SM |
1897 | int len = 0; |
1898 | #define OUTBUFLEN 16 | |
1899 | unsigned char buf[OUTBUFLEN]; | |
1900 | struct drbg_state *drbg = NULL; | |
1901 | int ret = -EFAULT; | |
1902 | int rc = -EFAULT; | |
1903 | bool pr = false; | |
1904 | int coreref = 0; | |
1905 | struct drbg_string addtl; | |
1906 | size_t max_addtllen, max_request_bytes; | |
1907 | ||
1908 | /* only perform test in FIPS mode */ | |
1909 | if (!fips_enabled) | |
1910 | return 0; | |
1911 | ||
1912 | #ifdef CONFIG_CRYPTO_DRBG_CTR | |
1913 | drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref, &pr); | |
e25e47ec | 1914 | #elif defined CONFIG_CRYPTO_DRBG_HASH |
541af946 SM |
1915 | drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr); |
1916 | #else | |
1917 | drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref, &pr); | |
1918 | #endif | |
1919 | ||
1920 | drbg = kzalloc(sizeof(struct drbg_state), GFP_KERNEL); | |
1921 | if (!drbg) | |
1922 | return -ENOMEM; | |
1923 | ||
e11a7548 HX |
1924 | mutex_init(&drbg->drbg_mutex); |
1925 | ||
541af946 SM |
1926 | /* |
1927 | * if the following tests fail, it is likely that there is a buffer | |
1928 | * overflow as buf is much smaller than the requested or provided | |
1929 | * string lengths -- in case the error handling does not succeed | |
1930 | * we may get an OOPS. And we want to get an OOPS as this is a | |
1931 | * grave bug. | |
1932 | */ | |
1933 | ||
1934 | /* get a valid instance of DRBG for following tests */ | |
1935 | ret = drbg_instantiate(drbg, NULL, coreref, pr); | |
1936 | if (ret) { | |
1937 | rc = ret; | |
1938 | goto outbuf; | |
1939 | } | |
1940 | max_addtllen = drbg_max_addtl(drbg); | |
1941 | max_request_bytes = drbg_max_request_bytes(drbg); | |
1942 | drbg_string_fill(&addtl, buf, max_addtllen + 1); | |
1943 | /* overflow addtllen with additonal info string */ | |
1944 | len = drbg_generate(drbg, buf, OUTBUFLEN, &addtl); | |
1945 | BUG_ON(0 < len); | |
1946 | /* overflow max_bits */ | |
1947 | len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL); | |
1948 | BUG_ON(0 < len); | |
1949 | drbg_uninstantiate(drbg); | |
1950 | ||
1951 | /* overflow max addtllen with personalization string */ | |
1952 | ret = drbg_instantiate(drbg, &addtl, coreref, pr); | |
1953 | BUG_ON(0 == ret); | |
541af946 SM |
1954 | /* all tests passed */ |
1955 | rc = 0; | |
1956 | ||
1957 | pr_devel("DRBG: Sanity tests for failure code paths successfully " | |
1958 | "completed\n"); | |
1959 | ||
1960 | drbg_uninstantiate(drbg); | |
1961 | outbuf: | |
1962 | kzfree(drbg); | |
1963 | return rc; | |
541af946 SM |
1964 | } |
1965 | ||
8fded592 | 1966 | static struct rng_alg drbg_algs[22]; |
541af946 SM |
1967 | |
1968 | /* | |
1969 | * Fill the array drbg_algs used to register the different DRBGs | |
1970 | * with the kernel crypto API. To fill the array, the information | |
1971 | * from drbg_cores[] is used. | |
1972 | */ | |
8fded592 | 1973 | static inline void __init drbg_fill_array(struct rng_alg *alg, |
541af946 SM |
1974 | const struct drbg_core *core, int pr) |
1975 | { | |
1976 | int pos = 0; | |
51ee1422 | 1977 | static int priority = 200; |
541af946 | 1978 | |
8fded592 | 1979 | memcpy(alg->base.cra_name, "stdrng", 6); |
541af946 | 1980 | if (pr) { |
8fded592 | 1981 | memcpy(alg->base.cra_driver_name, "drbg_pr_", 8); |
541af946 SM |
1982 | pos = 8; |
1983 | } else { | |
8fded592 | 1984 | memcpy(alg->base.cra_driver_name, "drbg_nopr_", 10); |
541af946 SM |
1985 | pos = 10; |
1986 | } | |
8fded592 | 1987 | memcpy(alg->base.cra_driver_name + pos, core->cra_name, |
541af946 SM |
1988 | strlen(core->cra_name)); |
1989 | ||
8fded592 | 1990 | alg->base.cra_priority = priority; |
541af946 SM |
1991 | priority++; |
1992 | /* | |
1993 | * If FIPS mode enabled, the selected DRBG shall have the | |
1994 | * highest cra_priority over other stdrng instances to ensure | |
1995 | * it is selected. | |
1996 | */ | |
1997 | if (fips_enabled) | |
8fded592 HX |
1998 | alg->base.cra_priority += 200; |
1999 | ||
2000 | alg->base.cra_ctxsize = sizeof(struct drbg_state); | |
2001 | alg->base.cra_module = THIS_MODULE; | |
2002 | alg->base.cra_init = drbg_kcapi_init; | |
2003 | alg->base.cra_exit = drbg_kcapi_cleanup; | |
2004 | alg->generate = drbg_kcapi_random; | |
2005 | alg->seed = drbg_kcapi_seed; | |
2006 | alg->set_ent = drbg_kcapi_set_entropy; | |
2007 | alg->seedsize = 0; | |
541af946 SM |
2008 | } |
2009 | ||
2010 | static int __init drbg_init(void) | |
2011 | { | |
2012 | unsigned int i = 0; /* pointer to drbg_algs */ | |
2013 | unsigned int j = 0; /* pointer to drbg_cores */ | |
2014 | int ret = -EFAULT; | |
2015 | ||
2016 | ret = drbg_healthcheck_sanity(); | |
2017 | if (ret) | |
2018 | return ret; | |
2019 | ||
2020 | if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) { | |
2021 | pr_info("DRBG: Cannot register all DRBG types" | |
a9089571 | 2022 | "(slots needed: %zu, slots available: %zu)\n", |
541af946 SM |
2023 | ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs)); |
2024 | return ret; | |
2025 | } | |
2026 | ||
2027 | /* | |
2028 | * each DRBG definition can be used with PR and without PR, thus | |
2029 | * we instantiate each DRBG in drbg_cores[] twice. | |
2030 | * | |
2031 | * As the order of placing them into the drbg_algs array matters | |
2032 | * (the later DRBGs receive a higher cra_priority) we register the | |
2033 | * prediction resistance DRBGs first as the should not be too | |
2034 | * interesting. | |
2035 | */ | |
2036 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
2037 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1); | |
2038 | for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) | |
2039 | drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0); | |
8fded592 | 2040 | return crypto_register_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); |
541af946 SM |
2041 | } |
2042 | ||
96956aef | 2043 | static void __exit drbg_exit(void) |
541af946 | 2044 | { |
8fded592 | 2045 | crypto_unregister_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); |
541af946 SM |
2046 | } |
2047 | ||
2048 | module_init(drbg_init); | |
2049 | module_exit(drbg_exit); | |
e25e47ec SM |
2050 | #ifndef CRYPTO_DRBG_HASH_STRING |
2051 | #define CRYPTO_DRBG_HASH_STRING "" | |
541af946 | 2052 | #endif |
e25e47ec SM |
2053 | #ifndef CRYPTO_DRBG_HMAC_STRING |
2054 | #define CRYPTO_DRBG_HMAC_STRING "" | |
541af946 | 2055 | #endif |
e25e47ec SM |
2056 | #ifndef CRYPTO_DRBG_CTR_STRING |
2057 | #define CRYPTO_DRBG_CTR_STRING "" | |
541af946 | 2058 | #endif |
e25e47ec SM |
2059 | MODULE_LICENSE("GPL"); |
2060 | MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); | |
2061 | MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) " | |
2062 | "using following cores: " | |
2063 | CRYPTO_DRBG_HASH_STRING | |
2064 | CRYPTO_DRBG_HMAC_STRING | |
2065 | CRYPTO_DRBG_CTR_STRING); | |
51ee1422 | 2066 | MODULE_ALIAS_CRYPTO("stdrng"); |