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Stephan Mueller541af942014-05-31 15:44:17 +02001/*
2 * DRBG: Deterministic Random Bits Generator
3 * Based on NIST Recommended DRBG from NIST SP800-90A with the following
4 * properties:
5 * * CTR DRBG with DF with AES-128, AES-192, AES-256 cores
6 * * Hash DRBG with DF with SHA-1, SHA-256, SHA-384, SHA-512 cores
7 * * HMAC DRBG with DF with SHA-1, SHA-256, SHA-384, SHA-512 cores
8 * * with and without prediction resistance
9 *
10 * Copyright Stephan Mueller <smueller@chronox.de>, 2014
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, and the entire permission notice in its entirety,
17 * including the disclaimer of warranties.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. The name of the author may not be used to endorse or promote
22 * products derived from this software without specific prior
23 * written permission.
24 *
25 * ALTERNATIVELY, this product may be distributed under the terms of
26 * the GNU General Public License, in which case the provisions of the GPL are
27 * required INSTEAD OF the above restrictions. (This clause is
28 * necessary due to a potential bad interaction between the GPL and
29 * the restrictions contained in a BSD-style copyright.)
30 *
31 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
32 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
34 * WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
35 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
36 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
37 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
38 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
39 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
41 * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
42 * DAMAGE.
43 *
44 * DRBG Usage
45 * ==========
46 * The SP 800-90A DRBG allows the user to specify a personalization string
47 * for initialization as well as an additional information string for each
48 * random number request. The following code fragments show how a caller
49 * uses the kernel crypto API to use the full functionality of the DRBG.
50 *
51 * Usage without any additional data
52 * ---------------------------------
53 * struct crypto_rng *drng;
54 * int err;
55 * char data[DATALEN];
56 *
57 * drng = crypto_alloc_rng(drng_name, 0, 0);
58 * err = crypto_rng_get_bytes(drng, &data, DATALEN);
59 * crypto_free_rng(drng);
60 *
61 *
62 * Usage with personalization string during initialization
63 * -------------------------------------------------------
64 * struct crypto_rng *drng;
65 * int err;
66 * char data[DATALEN];
67 * struct drbg_string pers;
68 * char personalization[11] = "some-string";
69 *
70 * drbg_string_fill(&pers, personalization, strlen(personalization));
71 * drng = crypto_alloc_rng(drng_name, 0, 0);
72 * // The reset completely re-initializes the DRBG with the provided
73 * // personalization string
74 * err = crypto_rng_reset(drng, &personalization, strlen(personalization));
75 * err = crypto_rng_get_bytes(drng, &data, DATALEN);
76 * crypto_free_rng(drng);
77 *
78 *
79 * Usage with additional information string during random number request
80 * ---------------------------------------------------------------------
81 * struct crypto_rng *drng;
82 * int err;
83 * char data[DATALEN];
84 * char addtl_string[11] = "some-string";
85 * string drbg_string addtl;
86 *
87 * drbg_string_fill(&addtl, addtl_string, strlen(addtl_string));
88 * drng = crypto_alloc_rng(drng_name, 0, 0);
89 * // The following call is a wrapper to crypto_rng_get_bytes() and returns
90 * // the same error codes.
91 * err = crypto_drbg_get_bytes_addtl(drng, &data, DATALEN, &addtl);
92 * crypto_free_rng(drng);
93 *
94 *
95 * Usage with personalization and additional information strings
96 * -------------------------------------------------------------
97 * Just mix both scenarios above.
98 */
99
100#include <crypto/drbg.h>
101
Stephan Mueller541af942014-05-31 15:44:17 +0200102/***************************************************************
103 * Backend cipher definitions available to DRBG
104 ***************************************************************/
105
106/*
107 * The order of the DRBG definitions here matter: every DRBG is registered
108 * as stdrng. Each DRBG receives an increasing cra_priority values the later
109 * they are defined in this array (see drbg_fill_array).
110 *
111 * HMAC DRBGs are favored over Hash DRBGs over CTR DRBGs, and
112 * the SHA256 / AES 256 over other ciphers. Thus, the favored
113 * DRBGs are the latest entries in this array.
114 */
115static const struct drbg_core drbg_cores[] = {
116#ifdef CONFIG_CRYPTO_DRBG_CTR
117 {
118 .flags = DRBG_CTR | DRBG_STRENGTH128,
119 .statelen = 32, /* 256 bits as defined in 10.2.1 */
Stephan Mueller541af942014-05-31 15:44:17 +0200120 .blocklen_bytes = 16,
121 .cra_name = "ctr_aes128",
Stephan Mueller04bcbfc2015-03-01 20:39:17 +0100122 .backend_cra_name = "aes",
Stephan Mueller541af942014-05-31 15:44:17 +0200123 }, {
124 .flags = DRBG_CTR | DRBG_STRENGTH192,
125 .statelen = 40, /* 320 bits as defined in 10.2.1 */
Stephan Mueller541af942014-05-31 15:44:17 +0200126 .blocklen_bytes = 16,
127 .cra_name = "ctr_aes192",
Stephan Mueller04bcbfc2015-03-01 20:39:17 +0100128 .backend_cra_name = "aes",
Stephan Mueller541af942014-05-31 15:44:17 +0200129 }, {
130 .flags = DRBG_CTR | DRBG_STRENGTH256,
131 .statelen = 48, /* 384 bits as defined in 10.2.1 */
Stephan Mueller541af942014-05-31 15:44:17 +0200132 .blocklen_bytes = 16,
133 .cra_name = "ctr_aes256",
Stephan Mueller04bcbfc2015-03-01 20:39:17 +0100134 .backend_cra_name = "aes",
Stephan Mueller541af942014-05-31 15:44:17 +0200135 },
136#endif /* CONFIG_CRYPTO_DRBG_CTR */
137#ifdef CONFIG_CRYPTO_DRBG_HASH
138 {
139 .flags = DRBG_HASH | DRBG_STRENGTH128,
140 .statelen = 55, /* 440 bits */
Stephan Mueller541af942014-05-31 15:44:17 +0200141 .blocklen_bytes = 20,
142 .cra_name = "sha1",
143 .backend_cra_name = "sha1",
144 }, {
145 .flags = DRBG_HASH | DRBG_STRENGTH256,
146 .statelen = 111, /* 888 bits */
Stephan Mueller541af942014-05-31 15:44:17 +0200147 .blocklen_bytes = 48,
148 .cra_name = "sha384",
149 .backend_cra_name = "sha384",
150 }, {
151 .flags = DRBG_HASH | DRBG_STRENGTH256,
152 .statelen = 111, /* 888 bits */
Stephan Mueller541af942014-05-31 15:44:17 +0200153 .blocklen_bytes = 64,
154 .cra_name = "sha512",
155 .backend_cra_name = "sha512",
156 }, {
157 .flags = DRBG_HASH | DRBG_STRENGTH256,
158 .statelen = 55, /* 440 bits */
Stephan Mueller541af942014-05-31 15:44:17 +0200159 .blocklen_bytes = 32,
160 .cra_name = "sha256",
161 .backend_cra_name = "sha256",
162 },
163#endif /* CONFIG_CRYPTO_DRBG_HASH */
164#ifdef CONFIG_CRYPTO_DRBG_HMAC
165 {
Stephan Mueller5b635e22014-07-06 02:26:37 +0200166 .flags = DRBG_HMAC | DRBG_STRENGTH128,
Stephan Mueller541af942014-05-31 15:44:17 +0200167 .statelen = 20, /* block length of cipher */
Stephan Mueller541af942014-05-31 15:44:17 +0200168 .blocklen_bytes = 20,
169 .cra_name = "hmac_sha1",
170 .backend_cra_name = "hmac(sha1)",
171 }, {
172 .flags = DRBG_HMAC | DRBG_STRENGTH256,
173 .statelen = 48, /* block length of cipher */
Stephan Mueller541af942014-05-31 15:44:17 +0200174 .blocklen_bytes = 48,
175 .cra_name = "hmac_sha384",
176 .backend_cra_name = "hmac(sha384)",
177 }, {
178 .flags = DRBG_HMAC | DRBG_STRENGTH256,
179 .statelen = 64, /* block length of cipher */
Stephan Mueller541af942014-05-31 15:44:17 +0200180 .blocklen_bytes = 64,
181 .cra_name = "hmac_sha512",
182 .backend_cra_name = "hmac(sha512)",
183 }, {
184 .flags = DRBG_HMAC | DRBG_STRENGTH256,
185 .statelen = 32, /* block length of cipher */
Stephan Mueller541af942014-05-31 15:44:17 +0200186 .blocklen_bytes = 32,
187 .cra_name = "hmac_sha256",
188 .backend_cra_name = "hmac(sha256)",
189 },
190#endif /* CONFIG_CRYPTO_DRBG_HMAC */
191};
192
193/******************************************************************
194 * Generic helper functions
195 ******************************************************************/
196
197/*
198 * Return strength of DRBG according to SP800-90A section 8.4
199 *
200 * @flags DRBG flags reference
201 *
202 * Return: normalized strength in *bytes* value or 32 as default
203 * to counter programming errors
204 */
205static inline unsigned short drbg_sec_strength(drbg_flag_t flags)
206{
207 switch (flags & DRBG_STRENGTH_MASK) {
208 case DRBG_STRENGTH128:
209 return 16;
210 case DRBG_STRENGTH192:
211 return 24;
212 case DRBG_STRENGTH256:
213 return 32;
214 default:
215 return 32;
216 }
217}
218
219/*
220 * FIPS 140-2 continuous self test
221 * The test is performed on the result of one round of the output
222 * function. Thus, the function implicitly knows the size of the
223 * buffer.
224 *
Stephan Mueller541af942014-05-31 15:44:17 +0200225 * @drbg DRBG handle
226 * @buf output buffer of random data to be checked
227 *
228 * return:
229 * true on success
230 * false on error
231 */
232static bool drbg_fips_continuous_test(struct drbg_state *drbg,
233 const unsigned char *buf)
234{
235#ifdef CONFIG_CRYPTO_FIPS
236 int ret = 0;
237 /* skip test if we test the overall system */
238 if (drbg->test_data)
239 return true;
240 /* only perform test in FIPS mode */
241 if (0 == fips_enabled)
242 return true;
243 if (!drbg->fips_primed) {
244 /* Priming of FIPS test */
245 memcpy(drbg->prev, buf, drbg_blocklen(drbg));
246 drbg->fips_primed = true;
247 /* return false due to priming, i.e. another round is needed */
248 return false;
249 }
250 ret = memcmp(drbg->prev, buf, drbg_blocklen(drbg));
Stephan Mueller905b42e2014-12-05 22:40:21 +0100251 if (!ret)
252 panic("DRBG continuous self test failed\n");
Stephan Mueller541af942014-05-31 15:44:17 +0200253 memcpy(drbg->prev, buf, drbg_blocklen(drbg));
254 /* the test shall pass when the two compared values are not equal */
255 return ret != 0;
256#else
257 return true;
258#endif /* CONFIG_CRYPTO_FIPS */
259}
260
261/*
262 * Convert an integer into a byte representation of this integer.
263 * The byte representation is big-endian
264 *
Stephan Mueller541af942014-05-31 15:44:17 +0200265 * @val value to be converted
Stephan Mueller72f3e002014-08-17 17:37:34 +0200266 * @buf buffer holding the converted integer -- caller must ensure that
267 * buffer size is at least 32 bit
Stephan Mueller541af942014-05-31 15:44:17 +0200268 */
269#if (defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR))
Stephan Mueller72f3e002014-08-17 17:37:34 +0200270static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf)
Stephan Mueller541af942014-05-31 15:44:17 +0200271{
Stephan Mueller72f3e002014-08-17 17:37:34 +0200272 struct s {
Stephan Mueller7c8ae032014-08-26 09:32:24 +0200273 __be32 conv;
Stephan Mueller72f3e002014-08-17 17:37:34 +0200274 };
275 struct s *conversion = (struct s *) buf;
Stephan Mueller541af942014-05-31 15:44:17 +0200276
Stephan Mueller72f3e002014-08-17 17:37:34 +0200277 conversion->conv = cpu_to_be32(val);
Stephan Mueller541af942014-05-31 15:44:17 +0200278}
Stephan Mueller541af942014-05-31 15:44:17 +0200279#endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */
280
281/******************************************************************
282 * CTR DRBG callback functions
283 ******************************************************************/
284
285#ifdef CONFIG_CRYPTO_DRBG_CTR
Stephan Muellere25e47e2014-07-06 02:23:03 +0200286#define CRYPTO_DRBG_CTR_STRING "CTR "
Stephan Mueller0653a7c2014-11-25 09:28:43 +0100287MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes256");
288MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes256");
289MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes192");
290MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192");
291MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128");
292MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128");
Stephan Mueller62b62b62014-11-04 03:08:09 +0100293
Stephan Mueller541af942014-05-31 15:44:17 +0200294static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key,
295 unsigned char *outval, const struct drbg_string *in);
296static int drbg_init_sym_kernel(struct drbg_state *drbg);
297static int drbg_fini_sym_kernel(struct drbg_state *drbg);
298
299/* BCC function for CTR DRBG as defined in 10.4.3 */
300static int drbg_ctr_bcc(struct drbg_state *drbg,
301 unsigned char *out, const unsigned char *key,
Stephan Mueller8c987162014-06-28 21:58:24 +0200302 struct list_head *in)
Stephan Mueller541af942014-05-31 15:44:17 +0200303{
Stephan Mueller8c987162014-06-28 21:58:24 +0200304 int ret = 0;
305 struct drbg_string *curr = NULL;
Stephan Mueller541af942014-05-31 15:44:17 +0200306 struct drbg_string data;
Stephan Mueller8c987162014-06-28 21:58:24 +0200307 short cnt = 0;
Stephan Mueller541af942014-05-31 15:44:17 +0200308
309 drbg_string_fill(&data, out, drbg_blocklen(drbg));
310
Stephan Mueller541af942014-05-31 15:44:17 +0200311 /* 10.4.3 step 2 / 4 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200312 list_for_each_entry(curr, in, list) {
313 const unsigned char *pos = curr->buf;
314 size_t len = curr->len;
Stephan Mueller541af942014-05-31 15:44:17 +0200315 /* 10.4.3 step 4.1 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200316 while (len) {
317 /* 10.4.3 step 4.2 */
318 if (drbg_blocklen(drbg) == cnt) {
319 cnt = 0;
320 ret = drbg_kcapi_sym(drbg, key, out, &data);
321 if (ret)
322 return ret;
Stephan Mueller541af942014-05-31 15:44:17 +0200323 }
Stephan Mueller8c987162014-06-28 21:58:24 +0200324 out[cnt] ^= *pos;
325 pos++;
326 cnt++;
327 len--;
Stephan Mueller541af942014-05-31 15:44:17 +0200328 }
Stephan Mueller541af942014-05-31 15:44:17 +0200329 }
Stephan Mueller8c987162014-06-28 21:58:24 +0200330 /* 10.4.3 step 4.2 for last block */
331 if (cnt)
332 ret = drbg_kcapi_sym(drbg, key, out, &data);
333
334 return ret;
Stephan Mueller541af942014-05-31 15:44:17 +0200335}
336
337/*
338 * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df
339 * (and drbg_ctr_bcc, but this function does not need any temporary buffers),
340 * the scratchpad is used as follows:
341 * drbg_ctr_update:
342 * temp
343 * start: drbg->scratchpad
344 * length: drbg_statelen(drbg) + drbg_blocklen(drbg)
345 * note: the cipher writing into this variable works
346 * blocklen-wise. Now, when the statelen is not a multiple
347 * of blocklen, the generateion loop below "spills over"
348 * by at most blocklen. Thus, we need to give sufficient
349 * memory.
350 * df_data
351 * start: drbg->scratchpad +
352 * drbg_statelen(drbg) + drbg_blocklen(drbg)
353 * length: drbg_statelen(drbg)
354 *
355 * drbg_ctr_df:
356 * pad
357 * start: df_data + drbg_statelen(drbg)
358 * length: drbg_blocklen(drbg)
359 * iv
360 * start: pad + drbg_blocklen(drbg)
361 * length: drbg_blocklen(drbg)
362 * temp
363 * start: iv + drbg_blocklen(drbg)
Stephan Mueller8fecaad2014-07-01 17:08:48 +0200364 * length: drbg_satelen(drbg) + drbg_blocklen(drbg)
365 * note: temp is the buffer that the BCC function operates
366 * on. BCC operates blockwise. drbg_statelen(drbg)
367 * is sufficient when the DRBG state length is a multiple
368 * of the block size. For AES192 (and maybe other ciphers)
369 * this is not correct and the length for temp is
370 * insufficient (yes, that also means for such ciphers,
371 * the final output of all BCC rounds are truncated).
372 * Therefore, add drbg_blocklen(drbg) to cover all
373 * possibilities.
Stephan Mueller541af942014-05-31 15:44:17 +0200374 */
375
376/* Derivation Function for CTR DRBG as defined in 10.4.2 */
377static int drbg_ctr_df(struct drbg_state *drbg,
378 unsigned char *df_data, size_t bytes_to_return,
Stephan Mueller8c987162014-06-28 21:58:24 +0200379 struct list_head *seedlist)
Stephan Mueller541af942014-05-31 15:44:17 +0200380{
381 int ret = -EFAULT;
382 unsigned char L_N[8];
383 /* S3 is input */
384 struct drbg_string S1, S2, S4, cipherin;
Stephan Mueller8c987162014-06-28 21:58:24 +0200385 LIST_HEAD(bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200386 unsigned char *pad = df_data + drbg_statelen(drbg);
387 unsigned char *iv = pad + drbg_blocklen(drbg);
388 unsigned char *temp = iv + drbg_blocklen(drbg);
389 size_t padlen = 0;
390 unsigned int templen = 0;
391 /* 10.4.2 step 7 */
392 unsigned int i = 0;
393 /* 10.4.2 step 8 */
394 const unsigned char *K = (unsigned char *)
395 "\x00\x01\x02\x03\x04\x05\x06\x07"
396 "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
397 "\x10\x11\x12\x13\x14\x15\x16\x17"
398 "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f";
399 unsigned char *X;
400 size_t generated_len = 0;
401 size_t inputlen = 0;
Stephan Mueller8c987162014-06-28 21:58:24 +0200402 struct drbg_string *seed = NULL;
Stephan Mueller541af942014-05-31 15:44:17 +0200403
404 memset(pad, 0, drbg_blocklen(drbg));
405 memset(iv, 0, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200406
407 /* 10.4.2 step 1 is implicit as we work byte-wise */
408
409 /* 10.4.2 step 2 */
410 if ((512/8) < bytes_to_return)
411 return -EINVAL;
412
413 /* 10.4.2 step 2 -- calculate the entire length of all input data */
Stephan Mueller8c987162014-06-28 21:58:24 +0200414 list_for_each_entry(seed, seedlist, list)
415 inputlen += seed->len;
Stephan Mueller72f3e002014-08-17 17:37:34 +0200416 drbg_cpu_to_be32(inputlen, &L_N[0]);
Stephan Mueller541af942014-05-31 15:44:17 +0200417
418 /* 10.4.2 step 3 */
Stephan Mueller72f3e002014-08-17 17:37:34 +0200419 drbg_cpu_to_be32(bytes_to_return, &L_N[4]);
Stephan Mueller541af942014-05-31 15:44:17 +0200420
421 /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */
422 padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg));
423 /* wrap the padlen appropriately */
424 if (padlen)
425 padlen = drbg_blocklen(drbg) - padlen;
426 /*
427 * pad / padlen contains the 0x80 byte and the following zero bytes.
428 * As the calculated padlen value only covers the number of zero
429 * bytes, this value has to be incremented by one for the 0x80 byte.
430 */
431 padlen++;
432 pad[0] = 0x80;
433
434 /* 10.4.2 step 4 -- first fill the linked list and then order it */
435 drbg_string_fill(&S1, iv, drbg_blocklen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200436 list_add_tail(&S1.list, &bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200437 drbg_string_fill(&S2, L_N, sizeof(L_N));
Stephan Mueller8c987162014-06-28 21:58:24 +0200438 list_add_tail(&S2.list, &bcc_list);
439 list_splice_tail(seedlist, &bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200440 drbg_string_fill(&S4, pad, padlen);
Stephan Mueller8c987162014-06-28 21:58:24 +0200441 list_add_tail(&S4.list, &bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200442
443 /* 10.4.2 step 9 */
444 while (templen < (drbg_keylen(drbg) + (drbg_blocklen(drbg)))) {
445 /*
446 * 10.4.2 step 9.1 - the padding is implicit as the buffer
447 * holds zeros after allocation -- even the increment of i
448 * is irrelevant as the increment remains within length of i
449 */
Stephan Mueller72f3e002014-08-17 17:37:34 +0200450 drbg_cpu_to_be32(i, iv);
Stephan Mueller541af942014-05-31 15:44:17 +0200451 /* 10.4.2 step 9.2 -- BCC and concatenation with temp */
Stephan Mueller8c987162014-06-28 21:58:24 +0200452 ret = drbg_ctr_bcc(drbg, temp + templen, K, &bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200453 if (ret)
454 goto out;
455 /* 10.4.2 step 9.3 */
456 i++;
457 templen += drbg_blocklen(drbg);
458 }
459
460 /* 10.4.2 step 11 */
461 X = temp + (drbg_keylen(drbg));
462 drbg_string_fill(&cipherin, X, drbg_blocklen(drbg));
463
464 /* 10.4.2 step 12: overwriting of outval is implemented in next step */
465
466 /* 10.4.2 step 13 */
467 while (generated_len < bytes_to_return) {
468 short blocklen = 0;
469 /*
470 * 10.4.2 step 13.1: the truncation of the key length is
471 * implicit as the key is only drbg_blocklen in size based on
472 * the implementation of the cipher function callback
473 */
474 ret = drbg_kcapi_sym(drbg, temp, X, &cipherin);
475 if (ret)
476 goto out;
477 blocklen = (drbg_blocklen(drbg) <
478 (bytes_to_return - generated_len)) ?
479 drbg_blocklen(drbg) :
480 (bytes_to_return - generated_len);
481 /* 10.4.2 step 13.2 and 14 */
482 memcpy(df_data + generated_len, X, blocklen);
483 generated_len += blocklen;
484 }
485
486 ret = 0;
487
488out:
Herbert Xu1471f092015-01-05 10:44:09 +1100489 memset(iv, 0, drbg_blocklen(drbg));
490 memset(temp, 0, drbg_statelen(drbg));
491 memset(pad, 0, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200492 return ret;
493}
494
Stephan Mueller72e7c252014-07-06 02:24:35 +0200495/*
496 * update function of CTR DRBG as defined in 10.2.1.2
497 *
498 * The reseed variable has an enhanced meaning compared to the update
499 * functions of the other DRBGs as follows:
500 * 0 => initial seed from initialization
501 * 1 => reseed via drbg_seed
502 * 2 => first invocation from drbg_ctr_update when addtl is present. In
503 * this case, the df_data scratchpad is not deleted so that it is
504 * available for another calls to prevent calling the DF function
505 * again.
506 * 3 => second invocation from drbg_ctr_update. When the update function
507 * was called with addtl, the df_data memory already contains the
508 * DFed addtl information and we do not need to call DF again.
509 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200510static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed,
511 int reseed)
Stephan Mueller541af942014-05-31 15:44:17 +0200512{
513 int ret = -EFAULT;
514 /* 10.2.1.2 step 1 */
515 unsigned char *temp = drbg->scratchpad;
516 unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) +
517 drbg_blocklen(drbg);
518 unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */
519 unsigned int len = 0;
520 struct drbg_string cipherin;
Stephan Mueller541af942014-05-31 15:44:17 +0200521
Stephan Mueller72e7c252014-07-06 02:24:35 +0200522 if (3 > reseed)
523 memset(df_data, 0, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200524
525 /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200526 if (seed) {
527 ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed);
Stephan Mueller541af942014-05-31 15:44:17 +0200528 if (ret)
529 goto out;
530 }
531
532 drbg_string_fill(&cipherin, drbg->V, drbg_blocklen(drbg));
533 /*
534 * 10.2.1.3.2 steps 2 and 3 are already covered as the allocation
535 * zeroizes all memory during initialization
536 */
537 while (len < (drbg_statelen(drbg))) {
538 /* 10.2.1.2 step 2.1 */
Stephan Mueller41a84982014-10-14 21:50:13 +0200539 crypto_inc(drbg->V, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200540 /*
541 * 10.2.1.2 step 2.2 */
542 ret = drbg_kcapi_sym(drbg, drbg->C, temp + len, &cipherin);
543 if (ret)
544 goto out;
545 /* 10.2.1.2 step 2.3 and 3 */
546 len += drbg_blocklen(drbg);
547 }
548
549 /* 10.2.1.2 step 4 */
550 temp_p = temp;
551 df_data_p = df_data;
552 for (len = 0; len < drbg_statelen(drbg); len++) {
553 *temp_p ^= *df_data_p;
554 df_data_p++; temp_p++;
555 }
556
557 /* 10.2.1.2 step 5 */
558 memcpy(drbg->C, temp, drbg_keylen(drbg));
559 /* 10.2.1.2 step 6 */
560 memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg));
561 ret = 0;
562
563out:
Herbert Xu1471f092015-01-05 10:44:09 +1100564 memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg));
Stephan Mueller72e7c252014-07-06 02:24:35 +0200565 if (2 != reseed)
Herbert Xu1471f092015-01-05 10:44:09 +1100566 memset(df_data, 0, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200567 return ret;
568}
569
570/*
571 * scratchpad use: drbg_ctr_update is called independently from
572 * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused
573 */
574/* Generate function of CTR DRBG as defined in 10.2.1.5.2 */
575static int drbg_ctr_generate(struct drbg_state *drbg,
576 unsigned char *buf, unsigned int buflen,
Stephan Mueller27e4de22014-07-06 02:25:36 +0200577 struct list_head *addtl)
Stephan Mueller541af942014-05-31 15:44:17 +0200578{
579 int len = 0;
580 int ret = 0;
581 struct drbg_string data;
Stephan Mueller541af942014-05-31 15:44:17 +0200582
Stephan Mueller541af942014-05-31 15:44:17 +0200583 /* 10.2.1.5.2 step 2 */
Stephan Mueller27e4de22014-07-06 02:25:36 +0200584 if (addtl && !list_empty(addtl)) {
585 ret = drbg_ctr_update(drbg, addtl, 2);
Stephan Mueller541af942014-05-31 15:44:17 +0200586 if (ret)
587 return 0;
588 }
589
590 /* 10.2.1.5.2 step 4.1 */
Stephan Mueller41a84982014-10-14 21:50:13 +0200591 crypto_inc(drbg->V, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200592 drbg_string_fill(&data, drbg->V, drbg_blocklen(drbg));
593 while (len < buflen) {
594 int outlen = 0;
595 /* 10.2.1.5.2 step 4.2 */
596 ret = drbg_kcapi_sym(drbg, drbg->C, drbg->scratchpad, &data);
597 if (ret) {
598 len = ret;
599 goto out;
600 }
601 outlen = (drbg_blocklen(drbg) < (buflen - len)) ?
602 drbg_blocklen(drbg) : (buflen - len);
603 if (!drbg_fips_continuous_test(drbg, drbg->scratchpad)) {
604 /* 10.2.1.5.2 step 6 */
Stephan Mueller41a84982014-10-14 21:50:13 +0200605 crypto_inc(drbg->V, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200606 continue;
607 }
608 /* 10.2.1.5.2 step 4.3 */
609 memcpy(buf + len, drbg->scratchpad, outlen);
610 len += outlen;
611 /* 10.2.1.5.2 step 6 */
612 if (len < buflen)
Stephan Mueller41a84982014-10-14 21:50:13 +0200613 crypto_inc(drbg->V, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200614 }
615
Stephan Mueller72e7c252014-07-06 02:24:35 +0200616 /* 10.2.1.5.2 step 6 */
617 ret = drbg_ctr_update(drbg, NULL, 3);
Stephan Mueller541af942014-05-31 15:44:17 +0200618 if (ret)
619 len = ret;
620
621out:
Herbert Xu1471f092015-01-05 10:44:09 +1100622 memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200623 return len;
624}
625
626static struct drbg_state_ops drbg_ctr_ops = {
627 .update = drbg_ctr_update,
628 .generate = drbg_ctr_generate,
629 .crypto_init = drbg_init_sym_kernel,
630 .crypto_fini = drbg_fini_sym_kernel,
631};
632#endif /* CONFIG_CRYPTO_DRBG_CTR */
633
634/******************************************************************
635 * HMAC DRBG callback functions
636 ******************************************************************/
637
638#if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
639static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key,
Stephan Mueller8c987162014-06-28 21:58:24 +0200640 unsigned char *outval, const struct list_head *in);
Stephan Mueller541af942014-05-31 15:44:17 +0200641static int drbg_init_hash_kernel(struct drbg_state *drbg);
642static int drbg_fini_hash_kernel(struct drbg_state *drbg);
643#endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
644
645#ifdef CONFIG_CRYPTO_DRBG_HMAC
Stephan Muellere25e47e2014-07-06 02:23:03 +0200646#define CRYPTO_DRBG_HMAC_STRING "HMAC "
Stephan Mueller0653a7c2014-11-25 09:28:43 +0100647MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512");
648MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512");
649MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384");
650MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384");
651MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256");
652MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256");
653MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1");
654MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1");
Stephan Mueller62b62b62014-11-04 03:08:09 +0100655
Stephan Mueller541af942014-05-31 15:44:17 +0200656/* update function of HMAC DRBG as defined in 10.1.2.2 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200657static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed,
658 int reseed)
Stephan Mueller541af942014-05-31 15:44:17 +0200659{
660 int ret = -EFAULT;
661 int i = 0;
Stephan Mueller8c987162014-06-28 21:58:24 +0200662 struct drbg_string seed1, seed2, vdata;
663 LIST_HEAD(seedlist);
664 LIST_HEAD(vdatalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200665
Stephan Muellerf072f0e2014-08-17 17:38:58 +0200666 if (!reseed)
667 /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */
Stephan Mueller541af942014-05-31 15:44:17 +0200668 memset(drbg->V, 1, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200669
670 drbg_string_fill(&seed1, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200671 list_add_tail(&seed1.list, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +0200672 /* buffer of seed2 will be filled in for loop below with one byte */
673 drbg_string_fill(&seed2, NULL, 1);
Stephan Mueller8c987162014-06-28 21:58:24 +0200674 list_add_tail(&seed2.list, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +0200675 /* input data of seed is allowed to be NULL at this point */
Stephan Mueller8c987162014-06-28 21:58:24 +0200676 if (seed)
677 list_splice_tail(seed, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +0200678
Stephan Mueller8c987162014-06-28 21:58:24 +0200679 drbg_string_fill(&vdata, drbg->V, drbg_statelen(drbg));
680 list_add_tail(&vdata.list, &vdatalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200681 for (i = 2; 0 < i; i--) {
682 /* first round uses 0x0, second 0x1 */
683 unsigned char prefix = DRBG_PREFIX0;
684 if (1 == i)
685 prefix = DRBG_PREFIX1;
686 /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */
687 seed2.buf = &prefix;
Stephan Mueller8c987162014-06-28 21:58:24 +0200688 ret = drbg_kcapi_hash(drbg, drbg->C, drbg->C, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +0200689 if (ret)
690 return ret;
691
692 /* 10.1.2.2 step 2 and 5 -- HMAC for V */
Stephan Mueller8c987162014-06-28 21:58:24 +0200693 ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &vdatalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200694 if (ret)
695 return ret;
696
697 /* 10.1.2.2 step 3 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200698 if (!seed)
Stephan Mueller541af942014-05-31 15:44:17 +0200699 return ret;
700 }
701
702 return 0;
703}
704
705/* generate function of HMAC DRBG as defined in 10.1.2.5 */
706static int drbg_hmac_generate(struct drbg_state *drbg,
707 unsigned char *buf,
708 unsigned int buflen,
Stephan Mueller27e4de22014-07-06 02:25:36 +0200709 struct list_head *addtl)
Stephan Mueller541af942014-05-31 15:44:17 +0200710{
711 int len = 0;
712 int ret = 0;
713 struct drbg_string data;
Stephan Mueller8c987162014-06-28 21:58:24 +0200714 LIST_HEAD(datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200715
716 /* 10.1.2.5 step 2 */
Stephan Mueller27e4de22014-07-06 02:25:36 +0200717 if (addtl && !list_empty(addtl)) {
718 ret = drbg_hmac_update(drbg, addtl, 1);
Stephan Mueller541af942014-05-31 15:44:17 +0200719 if (ret)
720 return ret;
721 }
722
723 drbg_string_fill(&data, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200724 list_add_tail(&data.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200725 while (len < buflen) {
726 unsigned int outlen = 0;
727 /* 10.1.2.5 step 4.1 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200728 ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200729 if (ret)
730 return ret;
731 outlen = (drbg_blocklen(drbg) < (buflen - len)) ?
732 drbg_blocklen(drbg) : (buflen - len);
733 if (!drbg_fips_continuous_test(drbg, drbg->V))
734 continue;
735
736 /* 10.1.2.5 step 4.2 */
737 memcpy(buf + len, drbg->V, outlen);
738 len += outlen;
739 }
740
741 /* 10.1.2.5 step 6 */
Stephan Mueller27e4de22014-07-06 02:25:36 +0200742 if (addtl && !list_empty(addtl))
743 ret = drbg_hmac_update(drbg, addtl, 1);
744 else
Stephan Mueller8c987162014-06-28 21:58:24 +0200745 ret = drbg_hmac_update(drbg, NULL, 1);
Stephan Mueller541af942014-05-31 15:44:17 +0200746 if (ret)
747 return ret;
748
749 return len;
750}
751
752static struct drbg_state_ops drbg_hmac_ops = {
753 .update = drbg_hmac_update,
754 .generate = drbg_hmac_generate,
755 .crypto_init = drbg_init_hash_kernel,
756 .crypto_fini = drbg_fini_hash_kernel,
Stephan Mueller541af942014-05-31 15:44:17 +0200757};
758#endif /* CONFIG_CRYPTO_DRBG_HMAC */
759
760/******************************************************************
761 * Hash DRBG callback functions
762 ******************************************************************/
763
764#ifdef CONFIG_CRYPTO_DRBG_HASH
Stephan Muellere25e47e2014-07-06 02:23:03 +0200765#define CRYPTO_DRBG_HASH_STRING "HASH "
Stephan Mueller0653a7c2014-11-25 09:28:43 +0100766MODULE_ALIAS_CRYPTO("drbg_pr_sha512");
767MODULE_ALIAS_CRYPTO("drbg_nopr_sha512");
768MODULE_ALIAS_CRYPTO("drbg_pr_sha384");
769MODULE_ALIAS_CRYPTO("drbg_nopr_sha384");
770MODULE_ALIAS_CRYPTO("drbg_pr_sha256");
771MODULE_ALIAS_CRYPTO("drbg_nopr_sha256");
772MODULE_ALIAS_CRYPTO("drbg_pr_sha1");
773MODULE_ALIAS_CRYPTO("drbg_nopr_sha1");
Stephan Mueller62b62b62014-11-04 03:08:09 +0100774
Stephan Mueller541af942014-05-31 15:44:17 +0200775/*
Stephan Mueller41a84982014-10-14 21:50:13 +0200776 * Increment buffer
777 *
778 * @dst buffer to increment
779 * @add value to add
780 */
781static inline void drbg_add_buf(unsigned char *dst, size_t dstlen,
782 const unsigned char *add, size_t addlen)
783{
784 /* implied: dstlen > addlen */
785 unsigned char *dstptr;
786 const unsigned char *addptr;
787 unsigned int remainder = 0;
788 size_t len = addlen;
789
790 dstptr = dst + (dstlen-1);
791 addptr = add + (addlen-1);
792 while (len) {
793 remainder += *dstptr + *addptr;
794 *dstptr = remainder & 0xff;
795 remainder >>= 8;
796 len--; dstptr--; addptr--;
797 }
798 len = dstlen - addlen;
799 while (len && remainder > 0) {
800 remainder = *dstptr + 1;
801 *dstptr = remainder & 0xff;
802 remainder >>= 8;
803 len--; dstptr--;
804 }
805}
806
807/*
Stephan Mueller541af942014-05-31 15:44:17 +0200808 * scratchpad usage: as drbg_hash_update and drbg_hash_df are used
809 * interlinked, the scratchpad is used as follows:
810 * drbg_hash_update
811 * start: drbg->scratchpad
812 * length: drbg_statelen(drbg)
813 * drbg_hash_df:
814 * start: drbg->scratchpad + drbg_statelen(drbg)
815 * length: drbg_blocklen(drbg)
816 *
817 * drbg_hash_process_addtl uses the scratchpad, but fully completes
818 * before either of the functions mentioned before are invoked. Therefore,
819 * drbg_hash_process_addtl does not need to be specifically considered.
820 */
821
822/* Derivation Function for Hash DRBG as defined in 10.4.1 */
823static int drbg_hash_df(struct drbg_state *drbg,
824 unsigned char *outval, size_t outlen,
Stephan Mueller8c987162014-06-28 21:58:24 +0200825 struct list_head *entropylist)
Stephan Mueller541af942014-05-31 15:44:17 +0200826{
827 int ret = 0;
828 size_t len = 0;
829 unsigned char input[5];
830 unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg);
Stephan Mueller8c987162014-06-28 21:58:24 +0200831 struct drbg_string data;
Stephan Mueller541af942014-05-31 15:44:17 +0200832
Stephan Mueller541af942014-05-31 15:44:17 +0200833 /* 10.4.1 step 3 */
834 input[0] = 1;
Stephan Mueller72f3e002014-08-17 17:37:34 +0200835 drbg_cpu_to_be32((outlen * 8), &input[1]);
Stephan Mueller541af942014-05-31 15:44:17 +0200836
837 /* 10.4.1 step 4.1 -- concatenation of data for input into hash */
Stephan Mueller8c987162014-06-28 21:58:24 +0200838 drbg_string_fill(&data, input, 5);
839 list_add(&data.list, entropylist);
Stephan Mueller541af942014-05-31 15:44:17 +0200840
841 /* 10.4.1 step 4 */
842 while (len < outlen) {
843 short blocklen = 0;
844 /* 10.4.1 step 4.1 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200845 ret = drbg_kcapi_hash(drbg, NULL, tmp, entropylist);
Stephan Mueller541af942014-05-31 15:44:17 +0200846 if (ret)
847 goto out;
848 /* 10.4.1 step 4.2 */
849 input[0]++;
850 blocklen = (drbg_blocklen(drbg) < (outlen - len)) ?
851 drbg_blocklen(drbg) : (outlen - len);
852 memcpy(outval + len, tmp, blocklen);
853 len += blocklen;
854 }
855
856out:
Herbert Xu1471f092015-01-05 10:44:09 +1100857 memset(tmp, 0, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200858 return ret;
859}
860
861/* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200862static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed,
Stephan Mueller541af942014-05-31 15:44:17 +0200863 int reseed)
864{
865 int ret = 0;
866 struct drbg_string data1, data2;
Stephan Mueller8c987162014-06-28 21:58:24 +0200867 LIST_HEAD(datalist);
868 LIST_HEAD(datalist2);
Stephan Mueller541af942014-05-31 15:44:17 +0200869 unsigned char *V = drbg->scratchpad;
870 unsigned char prefix = DRBG_PREFIX1;
871
Stephan Mueller541af942014-05-31 15:44:17 +0200872 if (!seed)
873 return -EINVAL;
874
875 if (reseed) {
876 /* 10.1.1.3 step 1 */
877 memcpy(V, drbg->V, drbg_statelen(drbg));
878 drbg_string_fill(&data1, &prefix, 1);
Stephan Mueller8c987162014-06-28 21:58:24 +0200879 list_add_tail(&data1.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200880 drbg_string_fill(&data2, V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200881 list_add_tail(&data2.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200882 }
Stephan Mueller8c987162014-06-28 21:58:24 +0200883 list_splice_tail(seed, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200884
885 /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200886 ret = drbg_hash_df(drbg, drbg->V, drbg_statelen(drbg), &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200887 if (ret)
888 goto out;
889
890 /* 10.1.1.2 / 10.1.1.3 step 4 */
891 prefix = DRBG_PREFIX0;
892 drbg_string_fill(&data1, &prefix, 1);
Stephan Mueller8c987162014-06-28 21:58:24 +0200893 list_add_tail(&data1.list, &datalist2);
Stephan Mueller541af942014-05-31 15:44:17 +0200894 drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200895 list_add_tail(&data2.list, &datalist2);
Stephan Mueller541af942014-05-31 15:44:17 +0200896 /* 10.1.1.2 / 10.1.1.3 step 4 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200897 ret = drbg_hash_df(drbg, drbg->C, drbg_statelen(drbg), &datalist2);
Stephan Mueller541af942014-05-31 15:44:17 +0200898
899out:
Herbert Xu1471f092015-01-05 10:44:09 +1100900 memset(drbg->scratchpad, 0, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200901 return ret;
902}
903
904/* processing of additional information string for Hash DRBG */
905static int drbg_hash_process_addtl(struct drbg_state *drbg,
Stephan Mueller27e4de22014-07-06 02:25:36 +0200906 struct list_head *addtl)
Stephan Mueller541af942014-05-31 15:44:17 +0200907{
908 int ret = 0;
909 struct drbg_string data1, data2;
Stephan Mueller8c987162014-06-28 21:58:24 +0200910 LIST_HEAD(datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200911 unsigned char prefix = DRBG_PREFIX2;
912
Stephan Mueller541af942014-05-31 15:44:17 +0200913 /* 10.1.1.4 step 2 */
Stephan Mueller27e4de22014-07-06 02:25:36 +0200914 if (!addtl || list_empty(addtl))
Stephan Mueller541af942014-05-31 15:44:17 +0200915 return 0;
916
917 /* 10.1.1.4 step 2a */
918 drbg_string_fill(&data1, &prefix, 1);
919 drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200920 list_add_tail(&data1.list, &datalist);
921 list_add_tail(&data2.list, &datalist);
Stephan Mueller27e4de22014-07-06 02:25:36 +0200922 list_splice_tail(addtl, &datalist);
Stephan Mueller8c987162014-06-28 21:58:24 +0200923 ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200924 if (ret)
925 goto out;
926
927 /* 10.1.1.4 step 2b */
928 drbg_add_buf(drbg->V, drbg_statelen(drbg),
929 drbg->scratchpad, drbg_blocklen(drbg));
930
931out:
Herbert Xu1471f092015-01-05 10:44:09 +1100932 memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200933 return ret;
934}
935
936/* Hashgen defined in 10.1.1.4 */
937static int drbg_hash_hashgen(struct drbg_state *drbg,
938 unsigned char *buf,
939 unsigned int buflen)
940{
941 int len = 0;
942 int ret = 0;
943 unsigned char *src = drbg->scratchpad;
944 unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg);
945 struct drbg_string data;
Stephan Mueller8c987162014-06-28 21:58:24 +0200946 LIST_HEAD(datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200947
Stephan Mueller541af942014-05-31 15:44:17 +0200948 /* 10.1.1.4 step hashgen 2 */
949 memcpy(src, drbg->V, drbg_statelen(drbg));
950
951 drbg_string_fill(&data, src, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200952 list_add_tail(&data.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200953 while (len < buflen) {
954 unsigned int outlen = 0;
955 /* 10.1.1.4 step hashgen 4.1 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200956 ret = drbg_kcapi_hash(drbg, NULL, dst, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200957 if (ret) {
958 len = ret;
959 goto out;
960 }
961 outlen = (drbg_blocklen(drbg) < (buflen - len)) ?
962 drbg_blocklen(drbg) : (buflen - len);
963 if (!drbg_fips_continuous_test(drbg, dst)) {
Stephan Mueller41a84982014-10-14 21:50:13 +0200964 crypto_inc(src, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200965 continue;
966 }
967 /* 10.1.1.4 step hashgen 4.2 */
968 memcpy(buf + len, dst, outlen);
969 len += outlen;
970 /* 10.1.1.4 hashgen step 4.3 */
971 if (len < buflen)
Stephan Mueller41a84982014-10-14 21:50:13 +0200972 crypto_inc(src, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200973 }
974
975out:
Herbert Xu1471f092015-01-05 10:44:09 +1100976 memset(drbg->scratchpad, 0,
Stephan Mueller541af942014-05-31 15:44:17 +0200977 (drbg_statelen(drbg) + drbg_blocklen(drbg)));
978 return len;
979}
980
981/* generate function for Hash DRBG as defined in 10.1.1.4 */
982static int drbg_hash_generate(struct drbg_state *drbg,
983 unsigned char *buf, unsigned int buflen,
Stephan Mueller27e4de22014-07-06 02:25:36 +0200984 struct list_head *addtl)
Stephan Mueller541af942014-05-31 15:44:17 +0200985{
986 int len = 0;
987 int ret = 0;
Stephan Mueller72f3e002014-08-17 17:37:34 +0200988 union {
989 unsigned char req[8];
Stephan Mueller7c8ae032014-08-26 09:32:24 +0200990 __be64 req_int;
Stephan Mueller72f3e002014-08-17 17:37:34 +0200991 } u;
Stephan Mueller541af942014-05-31 15:44:17 +0200992 unsigned char prefix = DRBG_PREFIX3;
993 struct drbg_string data1, data2;
Stephan Mueller8c987162014-06-28 21:58:24 +0200994 LIST_HEAD(datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200995
996 /* 10.1.1.4 step 2 */
997 ret = drbg_hash_process_addtl(drbg, addtl);
998 if (ret)
999 return ret;
1000 /* 10.1.1.4 step 3 */
1001 len = drbg_hash_hashgen(drbg, buf, buflen);
1002
1003 /* this is the value H as documented in 10.1.1.4 */
Stephan Mueller541af942014-05-31 15:44:17 +02001004 /* 10.1.1.4 step 4 */
1005 drbg_string_fill(&data1, &prefix, 1);
Stephan Mueller8c987162014-06-28 21:58:24 +02001006 list_add_tail(&data1.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +02001007 drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +02001008 list_add_tail(&data2.list, &datalist);
1009 ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +02001010 if (ret) {
1011 len = ret;
1012 goto out;
1013 }
1014
1015 /* 10.1.1.4 step 5 */
1016 drbg_add_buf(drbg->V, drbg_statelen(drbg),
1017 drbg->scratchpad, drbg_blocklen(drbg));
1018 drbg_add_buf(drbg->V, drbg_statelen(drbg),
1019 drbg->C, drbg_statelen(drbg));
Stephan Mueller72f3e002014-08-17 17:37:34 +02001020 u.req_int = cpu_to_be64(drbg->reseed_ctr);
1021 drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8);
Stephan Mueller541af942014-05-31 15:44:17 +02001022
1023out:
Herbert Xu1471f092015-01-05 10:44:09 +11001024 memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +02001025 return len;
1026}
1027
1028/*
1029 * scratchpad usage: as update and generate are used isolated, both
1030 * can use the scratchpad
1031 */
1032static struct drbg_state_ops drbg_hash_ops = {
1033 .update = drbg_hash_update,
1034 .generate = drbg_hash_generate,
1035 .crypto_init = drbg_init_hash_kernel,
1036 .crypto_fini = drbg_fini_hash_kernel,
1037};
1038#endif /* CONFIG_CRYPTO_DRBG_HASH */
1039
1040/******************************************************************
1041 * Functions common for DRBG implementations
1042 ******************************************************************/
1043
1044/*
1045 * Seeding or reseeding of the DRBG
1046 *
1047 * @drbg: DRBG state struct
1048 * @pers: personalization / additional information buffer
1049 * @reseed: 0 for initial seed process, 1 for reseeding
1050 *
1051 * return:
1052 * 0 on success
1053 * error value otherwise
1054 */
1055static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers,
1056 bool reseed)
1057{
1058 int ret = 0;
1059 unsigned char *entropy = NULL;
1060 size_t entropylen = 0;
1061 struct drbg_string data1;
Stephan Mueller8c987162014-06-28 21:58:24 +02001062 LIST_HEAD(seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +02001063
1064 /* 9.1 / 9.2 / 9.3.1 step 3 */
1065 if (pers && pers->len > (drbg_max_addtl(drbg))) {
Stephan Muellera9089572014-07-06 02:24:03 +02001066 pr_devel("DRBG: personalization string too long %zu\n",
Stephan Mueller541af942014-05-31 15:44:17 +02001067 pers->len);
1068 return -EINVAL;
1069 }
1070
1071 if (drbg->test_data && drbg->test_data->testentropy) {
1072 drbg_string_fill(&data1, drbg->test_data->testentropy->buf,
1073 drbg->test_data->testentropy->len);
1074 pr_devel("DRBG: using test entropy\n");
1075 } else {
1076 /*
1077 * Gather entropy equal to the security strength of the DRBG.
1078 * With a derivation function, a nonce is required in addition
1079 * to the entropy. A nonce must be at least 1/2 of the security
1080 * strength of the DRBG in size. Thus, entropy * nonce is 3/2
1081 * of the strength. The consideration of a nonce is only
1082 * applicable during initial seeding.
1083 */
1084 entropylen = drbg_sec_strength(drbg->core->flags);
1085 if (!entropylen)
1086 return -EFAULT;
1087 if (!reseed)
1088 entropylen = ((entropylen + 1) / 2) * 3;
1089 pr_devel("DRBG: (re)seeding with %zu bytes of entropy\n",
1090 entropylen);
1091 entropy = kzalloc(entropylen, GFP_KERNEL);
1092 if (!entropy)
1093 return -ENOMEM;
1094 get_random_bytes(entropy, entropylen);
1095 drbg_string_fill(&data1, entropy, entropylen);
1096 }
Stephan Mueller8c987162014-06-28 21:58:24 +02001097 list_add_tail(&data1.list, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +02001098
1099 /*
1100 * concatenation of entropy with personalization str / addtl input)
1101 * the variable pers is directly handed in by the caller, so check its
1102 * contents whether it is appropriate
1103 */
Stephan Mueller8c987162014-06-28 21:58:24 +02001104 if (pers && pers->buf && 0 < pers->len) {
1105 list_add_tail(&pers->list, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +02001106 pr_devel("DRBG: using personalization string\n");
1107 }
1108
Stephan Muellere6c02442014-08-17 17:39:31 +02001109 if (!reseed) {
1110 memset(drbg->V, 0, drbg_statelen(drbg));
1111 memset(drbg->C, 0, drbg_statelen(drbg));
1112 }
1113
Stephan Mueller8c987162014-06-28 21:58:24 +02001114 ret = drbg->d_ops->update(drbg, &seedlist, reseed);
Stephan Mueller541af942014-05-31 15:44:17 +02001115 if (ret)
1116 goto out;
1117
1118 drbg->seeded = true;
1119 /* 10.1.1.2 / 10.1.1.3 step 5 */
1120 drbg->reseed_ctr = 1;
1121
1122out:
Stephan Mueller46f64f62014-08-17 17:37:59 +02001123 kzfree(entropy);
Stephan Mueller541af942014-05-31 15:44:17 +02001124 return ret;
1125}
1126
1127/* Free all substructures in a DRBG state without the DRBG state structure */
1128static inline void drbg_dealloc_state(struct drbg_state *drbg)
1129{
1130 if (!drbg)
1131 return;
Stephan Mueller46f64f62014-08-17 17:37:59 +02001132 kzfree(drbg->V);
Stephan Mueller541af942014-05-31 15:44:17 +02001133 drbg->V = NULL;
Stephan Mueller46f64f62014-08-17 17:37:59 +02001134 kzfree(drbg->C);
Stephan Mueller541af942014-05-31 15:44:17 +02001135 drbg->C = NULL;
Stephan Mueller46f64f62014-08-17 17:37:59 +02001136 kzfree(drbg->scratchpad);
Stephan Mueller541af942014-05-31 15:44:17 +02001137 drbg->scratchpad = NULL;
1138 drbg->reseed_ctr = 0;
1139#ifdef CONFIG_CRYPTO_FIPS
Stephan Mueller46f64f62014-08-17 17:37:59 +02001140 kzfree(drbg->prev);
Stephan Mueller541af942014-05-31 15:44:17 +02001141 drbg->prev = NULL;
1142 drbg->fips_primed = false;
1143#endif
1144}
1145
1146/*
1147 * Allocate all sub-structures for a DRBG state.
1148 * The DRBG state structure must already be allocated.
1149 */
1150static inline int drbg_alloc_state(struct drbg_state *drbg)
1151{
1152 int ret = -ENOMEM;
1153 unsigned int sb_size = 0;
1154
Stephan Muellere6c02442014-08-17 17:39:31 +02001155 drbg->V = kmalloc(drbg_statelen(drbg), GFP_KERNEL);
Stephan Mueller541af942014-05-31 15:44:17 +02001156 if (!drbg->V)
1157 goto err;
Stephan Muellere6c02442014-08-17 17:39:31 +02001158 drbg->C = kmalloc(drbg_statelen(drbg), GFP_KERNEL);
Stephan Mueller541af942014-05-31 15:44:17 +02001159 if (!drbg->C)
1160 goto err;
1161#ifdef CONFIG_CRYPTO_FIPS
Stephan Muellere6c02442014-08-17 17:39:31 +02001162 drbg->prev = kmalloc(drbg_blocklen(drbg), GFP_KERNEL);
Stephan Mueller541af942014-05-31 15:44:17 +02001163 if (!drbg->prev)
1164 goto err;
1165 drbg->fips_primed = false;
1166#endif
1167 /* scratchpad is only generated for CTR and Hash */
1168 if (drbg->core->flags & DRBG_HMAC)
1169 sb_size = 0;
1170 else if (drbg->core->flags & DRBG_CTR)
1171 sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg) + /* temp */
1172 drbg_statelen(drbg) + /* df_data */
1173 drbg_blocklen(drbg) + /* pad */
1174 drbg_blocklen(drbg) + /* iv */
Stephan Mueller8fecaad2014-07-01 17:08:48 +02001175 drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */
Stephan Mueller541af942014-05-31 15:44:17 +02001176 else
1177 sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg);
1178
1179 if (0 < sb_size) {
1180 drbg->scratchpad = kzalloc(sb_size, GFP_KERNEL);
1181 if (!drbg->scratchpad)
1182 goto err;
1183 }
1184 spin_lock_init(&drbg->drbg_lock);
1185 return 0;
1186
1187err:
1188 drbg_dealloc_state(drbg);
1189 return ret;
1190}
1191
1192/*
1193 * Strategy to avoid holding long term locks: generate a shadow copy of DRBG
1194 * and perform all operations on this shadow copy. After finishing, restore
1195 * the updated state of the shadow copy into original drbg state. This way,
1196 * only the read and write operations of the original drbg state must be
1197 * locked
1198 */
1199static inline void drbg_copy_drbg(struct drbg_state *src,
1200 struct drbg_state *dst)
1201{
1202 if (!src || !dst)
1203 return;
1204 memcpy(dst->V, src->V, drbg_statelen(src));
1205 memcpy(dst->C, src->C, drbg_statelen(src));
1206 dst->reseed_ctr = src->reseed_ctr;
1207 dst->seeded = src->seeded;
1208 dst->pr = src->pr;
1209#ifdef CONFIG_CRYPTO_FIPS
1210 dst->fips_primed = src->fips_primed;
1211 memcpy(dst->prev, src->prev, drbg_blocklen(src));
1212#endif
1213 /*
1214 * Not copied:
1215 * scratchpad is initialized drbg_alloc_state;
1216 * priv_data is initialized with call to crypto_init;
1217 * d_ops and core are set outside, as these parameters are const;
1218 * test_data is set outside to prevent it being copied back.
1219 */
1220}
1221
1222static int drbg_make_shadow(struct drbg_state *drbg, struct drbg_state **shadow)
1223{
1224 int ret = -ENOMEM;
1225 struct drbg_state *tmp = NULL;
1226
Stephan Mueller541af942014-05-31 15:44:17 +02001227 tmp = kzalloc(sizeof(struct drbg_state), GFP_KERNEL);
1228 if (!tmp)
1229 return -ENOMEM;
1230
1231 /* read-only data as they are defined as const, no lock needed */
1232 tmp->core = drbg->core;
1233 tmp->d_ops = drbg->d_ops;
1234
1235 ret = drbg_alloc_state(tmp);
1236 if (ret)
1237 goto err;
1238
1239 spin_lock_bh(&drbg->drbg_lock);
1240 drbg_copy_drbg(drbg, tmp);
1241 /* only make a link to the test buffer, as we only read that data */
1242 tmp->test_data = drbg->test_data;
1243 spin_unlock_bh(&drbg->drbg_lock);
1244 *shadow = tmp;
1245 return 0;
1246
1247err:
Stephan Mueller46f64f62014-08-17 17:37:59 +02001248 kzfree(tmp);
Stephan Mueller541af942014-05-31 15:44:17 +02001249 return ret;
1250}
1251
1252static void drbg_restore_shadow(struct drbg_state *drbg,
1253 struct drbg_state **shadow)
1254{
1255 struct drbg_state *tmp = *shadow;
1256
1257 spin_lock_bh(&drbg->drbg_lock);
1258 drbg_copy_drbg(tmp, drbg);
1259 spin_unlock_bh(&drbg->drbg_lock);
1260 drbg_dealloc_state(tmp);
1261 kzfree(tmp);
1262 *shadow = NULL;
1263}
1264
1265/*************************************************************************
1266 * DRBG interface functions
1267 *************************************************************************/
1268
1269/*
1270 * DRBG generate function as required by SP800-90A - this function
1271 * generates random numbers
1272 *
1273 * @drbg DRBG state handle
1274 * @buf Buffer where to store the random numbers -- the buffer must already
1275 * be pre-allocated by caller
1276 * @buflen Length of output buffer - this value defines the number of random
1277 * bytes pulled from DRBG
1278 * @addtl Additional input that is mixed into state, may be NULL -- note
1279 * the entropy is pulled by the DRBG internally unconditionally
1280 * as defined in SP800-90A. The additional input is mixed into
1281 * the state in addition to the pulled entropy.
1282 *
Stephan Muellercde001e2015-03-06 08:26:31 +01001283 * return: 0 when all bytes are generated; < 0 in case of an error
Stephan Mueller541af942014-05-31 15:44:17 +02001284 */
1285static int drbg_generate(struct drbg_state *drbg,
1286 unsigned char *buf, unsigned int buflen,
1287 struct drbg_string *addtl)
1288{
1289 int len = 0;
1290 struct drbg_state *shadow = NULL;
Stephan Mueller27e4de22014-07-06 02:25:36 +02001291 LIST_HEAD(addtllist);
1292 struct drbg_string timestamp;
1293 union {
1294 cycles_t cycles;
1295 unsigned char char_cycles[sizeof(cycles_t)];
1296 } now;
Stephan Mueller541af942014-05-31 15:44:17 +02001297
1298 if (0 == buflen || !buf) {
1299 pr_devel("DRBG: no output buffer provided\n");
1300 return -EINVAL;
1301 }
1302 if (addtl && NULL == addtl->buf && 0 < addtl->len) {
1303 pr_devel("DRBG: wrong format of additional information\n");
1304 return -EINVAL;
1305 }
1306
1307 len = drbg_make_shadow(drbg, &shadow);
1308 if (len) {
1309 pr_devel("DRBG: shadow copy cannot be generated\n");
1310 return len;
1311 }
1312
1313 /* 9.3.1 step 2 */
1314 len = -EINVAL;
1315 if (buflen > (drbg_max_request_bytes(shadow))) {
1316 pr_devel("DRBG: requested random numbers too large %u\n",
1317 buflen);
1318 goto err;
1319 }
1320
1321 /* 9.3.1 step 3 is implicit with the chosen DRBG */
1322
1323 /* 9.3.1 step 4 */
1324 if (addtl && addtl->len > (drbg_max_addtl(shadow))) {
1325 pr_devel("DRBG: additional information string too long %zu\n",
1326 addtl->len);
1327 goto err;
1328 }
1329 /* 9.3.1 step 5 is implicit with the chosen DRBG */
1330
1331 /*
1332 * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented
1333 * here. The spec is a bit convoluted here, we make it simpler.
1334 */
1335 if ((drbg_max_requests(shadow)) < shadow->reseed_ctr)
1336 shadow->seeded = false;
1337
1338 /* allocate cipher handle */
Stephan Mueller45943a52014-08-17 17:38:29 +02001339 len = shadow->d_ops->crypto_init(shadow);
1340 if (len)
1341 goto err;
Stephan Mueller541af942014-05-31 15:44:17 +02001342
1343 if (shadow->pr || !shadow->seeded) {
1344 pr_devel("DRBG: reseeding before generation (prediction "
1345 "resistance: %s, state %s)\n",
1346 drbg->pr ? "true" : "false",
1347 drbg->seeded ? "seeded" : "unseeded");
1348 /* 9.3.1 steps 7.1 through 7.3 */
1349 len = drbg_seed(shadow, addtl, true);
1350 if (len)
1351 goto err;
1352 /* 9.3.1 step 7.4 */
1353 addtl = NULL;
1354 }
Stephan Mueller27e4de22014-07-06 02:25:36 +02001355
1356 /*
1357 * Mix the time stamp into the DRBG state if the DRBG is not in
1358 * test mode. If there are two callers invoking the DRBG at the same
1359 * time, i.e. before the first caller merges its shadow state back,
1360 * both callers would obtain the same random number stream without
1361 * changing the state here.
1362 */
1363 if (!drbg->test_data) {
1364 now.cycles = random_get_entropy();
1365 drbg_string_fill(&timestamp, now.char_cycles, sizeof(cycles_t));
1366 list_add_tail(&timestamp.list, &addtllist);
1367 }
1368 if (addtl && 0 < addtl->len)
1369 list_add_tail(&addtl->list, &addtllist);
Stephan Mueller541af942014-05-31 15:44:17 +02001370 /* 9.3.1 step 8 and 10 */
Stephan Mueller27e4de22014-07-06 02:25:36 +02001371 len = shadow->d_ops->generate(shadow, buf, buflen, &addtllist);
Stephan Mueller541af942014-05-31 15:44:17 +02001372
1373 /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */
1374 shadow->reseed_ctr++;
1375 if (0 >= len)
1376 goto err;
1377
1378 /*
1379 * Section 11.3.3 requires to re-perform self tests after some
1380 * generated random numbers. The chosen value after which self
1381 * test is performed is arbitrary, but it should be reasonable.
1382 * However, we do not perform the self tests because of the following
1383 * reasons: it is mathematically impossible that the initial self tests
1384 * were successfully and the following are not. If the initial would
1385 * pass and the following would not, the kernel integrity is violated.
1386 * In this case, the entire kernel operation is questionable and it
1387 * is unlikely that the integrity violation only affects the
1388 * correct operation of the DRBG.
1389 *
1390 * Albeit the following code is commented out, it is provided in
1391 * case somebody has a need to implement the test of 11.3.3.
1392 */
1393#if 0
1394 if (shadow->reseed_ctr && !(shadow->reseed_ctr % 4096)) {
1395 int err = 0;
1396 pr_devel("DRBG: start to perform self test\n");
1397 if (drbg->core->flags & DRBG_HMAC)
1398 err = alg_test("drbg_pr_hmac_sha256",
1399 "drbg_pr_hmac_sha256", 0, 0);
1400 else if (drbg->core->flags & DRBG_CTR)
1401 err = alg_test("drbg_pr_ctr_aes128",
1402 "drbg_pr_ctr_aes128", 0, 0);
1403 else
1404 err = alg_test("drbg_pr_sha256",
1405 "drbg_pr_sha256", 0, 0);
1406 if (err) {
1407 pr_err("DRBG: periodical self test failed\n");
1408 /*
1409 * uninstantiate implies that from now on, only errors
1410 * are returned when reusing this DRBG cipher handle
1411 */
1412 drbg_uninstantiate(drbg);
1413 drbg_dealloc_state(shadow);
1414 kzfree(shadow);
1415 return 0;
1416 } else {
1417 pr_devel("DRBG: self test successful\n");
1418 }
1419 }
1420#endif
1421
Stephan Muellercde001e2015-03-06 08:26:31 +01001422 /*
1423 * All operations were successful, return 0 as mandated by
1424 * the kernel crypto API interface.
1425 */
1426 len = 0;
Stephan Mueller541af942014-05-31 15:44:17 +02001427err:
Stephan Mueller45943a52014-08-17 17:38:29 +02001428 shadow->d_ops->crypto_fini(shadow);
Stephan Mueller541af942014-05-31 15:44:17 +02001429 drbg_restore_shadow(drbg, &shadow);
1430 return len;
1431}
1432
1433/*
1434 * Wrapper around drbg_generate which can pull arbitrary long strings
1435 * from the DRBG without hitting the maximum request limitation.
1436 *
1437 * Parameters: see drbg_generate
1438 * Return codes: see drbg_generate -- if one drbg_generate request fails,
1439 * the entire drbg_generate_long request fails
1440 */
1441static int drbg_generate_long(struct drbg_state *drbg,
1442 unsigned char *buf, unsigned int buflen,
1443 struct drbg_string *addtl)
1444{
1445 int len = 0;
1446 unsigned int slice = 0;
1447 do {
1448 int tmplen = 0;
1449 unsigned int chunk = 0;
1450 slice = ((buflen - len) / drbg_max_request_bytes(drbg));
1451 chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len);
1452 tmplen = drbg_generate(drbg, buf + len, chunk, addtl);
1453 if (0 >= tmplen)
1454 return tmplen;
1455 len += tmplen;
Stephan Muellerce5481d2014-07-31 21:47:33 +02001456 } while (slice > 0 && (len < buflen));
Stephan Mueller541af942014-05-31 15:44:17 +02001457 return len;
1458}
1459
1460/*
1461 * DRBG instantiation function as required by SP800-90A - this function
1462 * sets up the DRBG handle, performs the initial seeding and all sanity
1463 * checks required by SP800-90A
1464 *
1465 * @drbg memory of state -- if NULL, new memory is allocated
1466 * @pers Personalization string that is mixed into state, may be NULL -- note
1467 * the entropy is pulled by the DRBG internally unconditionally
1468 * as defined in SP800-90A. The additional input is mixed into
1469 * the state in addition to the pulled entropy.
1470 * @coreref reference to core
1471 * @pr prediction resistance enabled
1472 *
1473 * return
1474 * 0 on success
1475 * error value otherwise
1476 */
1477static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers,
1478 int coreref, bool pr)
1479{
1480 int ret = -ENOMEM;
1481
1482 pr_devel("DRBG: Initializing DRBG core %d with prediction resistance "
1483 "%s\n", coreref, pr ? "enabled" : "disabled");
1484 drbg->core = &drbg_cores[coreref];
1485 drbg->pr = pr;
1486 drbg->seeded = false;
1487 switch (drbg->core->flags & DRBG_TYPE_MASK) {
1488#ifdef CONFIG_CRYPTO_DRBG_HMAC
1489 case DRBG_HMAC:
1490 drbg->d_ops = &drbg_hmac_ops;
1491 break;
1492#endif /* CONFIG_CRYPTO_DRBG_HMAC */
1493#ifdef CONFIG_CRYPTO_DRBG_HASH
1494 case DRBG_HASH:
1495 drbg->d_ops = &drbg_hash_ops;
1496 break;
1497#endif /* CONFIG_CRYPTO_DRBG_HASH */
1498#ifdef CONFIG_CRYPTO_DRBG_CTR
1499 case DRBG_CTR:
1500 drbg->d_ops = &drbg_ctr_ops;
1501 break;
1502#endif /* CONFIG_CRYPTO_DRBG_CTR */
1503 default:
1504 return -EOPNOTSUPP;
1505 }
1506
1507 /* 9.1 step 1 is implicit with the selected DRBG type */
1508
1509 /*
1510 * 9.1 step 2 is implicit as caller can select prediction resistance
1511 * and the flag is copied into drbg->flags --
1512 * all DRBG types support prediction resistance
1513 */
1514
1515 /* 9.1 step 4 is implicit in drbg_sec_strength */
1516
1517 ret = drbg_alloc_state(drbg);
1518 if (ret)
1519 return ret;
1520
1521 ret = -EFAULT;
Stephan Mueller45943a52014-08-17 17:38:29 +02001522 if (drbg->d_ops->crypto_init(drbg))
Stephan Mueller541af942014-05-31 15:44:17 +02001523 goto err;
1524 ret = drbg_seed(drbg, pers, false);
Stephan Mueller45943a52014-08-17 17:38:29 +02001525 drbg->d_ops->crypto_fini(drbg);
Stephan Mueller541af942014-05-31 15:44:17 +02001526 if (ret)
1527 goto err;
1528
1529 return 0;
1530
1531err:
1532 drbg_dealloc_state(drbg);
1533 return ret;
1534}
1535
1536/*
1537 * DRBG uninstantiate function as required by SP800-90A - this function
1538 * frees all buffers and the DRBG handle
1539 *
1540 * @drbg DRBG state handle
1541 *
1542 * return
1543 * 0 on success
1544 */
1545static int drbg_uninstantiate(struct drbg_state *drbg)
1546{
1547 spin_lock_bh(&drbg->drbg_lock);
1548 drbg_dealloc_state(drbg);
1549 /* no scrubbing of test_data -- this shall survive an uninstantiate */
1550 spin_unlock_bh(&drbg->drbg_lock);
1551 return 0;
1552}
1553
1554/*
1555 * Helper function for setting the test data in the DRBG
1556 *
1557 * @drbg DRBG state handle
1558 * @test_data test data to sets
1559 */
1560static inline void drbg_set_testdata(struct drbg_state *drbg,
1561 struct drbg_test_data *test_data)
1562{
1563 if (!test_data || !test_data->testentropy)
1564 return;
1565 spin_lock_bh(&drbg->drbg_lock);
1566 drbg->test_data = test_data;
1567 spin_unlock_bh(&drbg->drbg_lock);
1568}
1569
1570/***************************************************************
1571 * Kernel crypto API cipher invocations requested by DRBG
1572 ***************************************************************/
1573
1574#if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
1575struct sdesc {
1576 struct shash_desc shash;
1577 char ctx[];
1578};
1579
1580static int drbg_init_hash_kernel(struct drbg_state *drbg)
1581{
1582 struct sdesc *sdesc;
1583 struct crypto_shash *tfm;
1584
1585 tfm = crypto_alloc_shash(drbg->core->backend_cra_name, 0, 0);
1586 if (IS_ERR(tfm)) {
1587 pr_info("DRBG: could not allocate digest TFM handle\n");
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
1604static 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
1615static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key,
Stephan Mueller8c987162014-06-28 21:58:24 +02001616 unsigned char *outval, const struct list_head *in)
Stephan Mueller541af942014-05-31 15:44:17 +02001617{
1618 struct sdesc *sdesc = (struct sdesc *)drbg->priv_data;
Stephan Mueller8c987162014-06-28 21:58:24 +02001619 struct drbg_string *input = NULL;
Stephan Mueller541af942014-05-31 15:44:17 +02001620
1621 if (key)
1622 crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg));
1623 crypto_shash_init(&sdesc->shash);
Stephan Mueller8c987162014-06-28 21:58:24 +02001624 list_for_each_entry(input, in, list)
1625 crypto_shash_update(&sdesc->shash, input->buf, input->len);
Stephan Mueller541af942014-05-31 15:44:17 +02001626 return crypto_shash_final(&sdesc->shash, outval);
1627}
1628#endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
1629
1630#ifdef CONFIG_CRYPTO_DRBG_CTR
1631static int drbg_init_sym_kernel(struct drbg_state *drbg)
1632{
1633 int ret = 0;
Stephan Mueller04bcbfc2015-03-01 20:39:17 +01001634 struct crypto_cipher *tfm;
Stephan Mueller541af942014-05-31 15:44:17 +02001635
Stephan Mueller04bcbfc2015-03-01 20:39:17 +01001636 tfm = crypto_alloc_cipher(drbg->core->backend_cra_name, 0, 0);
Stephan Mueller541af942014-05-31 15:44:17 +02001637 if (IS_ERR(tfm)) {
1638 pr_info("DRBG: could not allocate cipher TFM handle\n");
1639 return PTR_ERR(tfm);
1640 }
Stephan Mueller04bcbfc2015-03-01 20:39:17 +01001641 BUG_ON(drbg_blocklen(drbg) != crypto_cipher_blocksize(tfm));
Stephan Mueller541af942014-05-31 15:44:17 +02001642 drbg->priv_data = tfm;
1643 return ret;
1644}
1645
1646static int drbg_fini_sym_kernel(struct drbg_state *drbg)
1647{
Stephan Mueller04bcbfc2015-03-01 20:39:17 +01001648 struct crypto_cipher *tfm =
1649 (struct crypto_cipher *)drbg->priv_data;
Stephan Mueller541af942014-05-31 15:44:17 +02001650 if (tfm)
Stephan Mueller04bcbfc2015-03-01 20:39:17 +01001651 crypto_free_cipher(tfm);
Stephan Mueller541af942014-05-31 15:44:17 +02001652 drbg->priv_data = NULL;
1653 return 0;
1654}
1655
1656static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key,
1657 unsigned char *outval, const struct drbg_string *in)
1658{
Stephan Mueller04bcbfc2015-03-01 20:39:17 +01001659 struct crypto_cipher *tfm =
1660 (struct crypto_cipher *)drbg->priv_data;
Stephan Mueller541af942014-05-31 15:44:17 +02001661
Stephan Mueller04bcbfc2015-03-01 20:39:17 +01001662 crypto_cipher_setkey(tfm, key, (drbg_keylen(drbg)));
Stephan Mueller541af942014-05-31 15:44:17 +02001663 /* there is only component in *in */
Stephan Mueller04bcbfc2015-03-01 20:39:17 +01001664 BUG_ON(in->len < drbg_blocklen(drbg));
1665 crypto_cipher_encrypt_one(tfm, outval, in->buf);
1666 return 0;
Stephan Mueller541af942014-05-31 15:44:17 +02001667}
1668#endif /* CONFIG_CRYPTO_DRBG_CTR */
1669
1670/***************************************************************
1671 * Kernel crypto API interface to register DRBG
1672 ***************************************************************/
1673
1674/*
1675 * Look up the DRBG flags by given kernel crypto API cra_name
1676 * The code uses the drbg_cores definition to do this
1677 *
1678 * @cra_name kernel crypto API cra_name
1679 * @coreref reference to integer which is filled with the pointer to
1680 * the applicable core
1681 * @pr reference for setting prediction resistance
1682 *
1683 * return: flags
1684 */
1685static inline void drbg_convert_tfm_core(const char *cra_driver_name,
1686 int *coreref, bool *pr)
1687{
1688 int i = 0;
1689 size_t start = 0;
1690 int len = 0;
1691
1692 *pr = true;
1693 /* disassemble the names */
1694 if (!memcmp(cra_driver_name, "drbg_nopr_", 10)) {
1695 start = 10;
1696 *pr = false;
1697 } else if (!memcmp(cra_driver_name, "drbg_pr_", 8)) {
1698 start = 8;
1699 } else {
1700 return;
1701 }
1702
1703 /* remove the first part */
1704 len = strlen(cra_driver_name) - start;
1705 for (i = 0; ARRAY_SIZE(drbg_cores) > i; i++) {
1706 if (!memcmp(cra_driver_name + start, drbg_cores[i].cra_name,
1707 len)) {
1708 *coreref = i;
1709 return;
1710 }
1711 }
1712}
1713
1714static int drbg_kcapi_init(struct crypto_tfm *tfm)
1715{
1716 struct drbg_state *drbg = crypto_tfm_ctx(tfm);
1717 bool pr = false;
1718 int coreref = 0;
1719
Stephan Mueller4f150712014-07-06 02:25:04 +02001720 drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm), &coreref, &pr);
Stephan Mueller541af942014-05-31 15:44:17 +02001721 /*
1722 * when personalization string is needed, the caller must call reset
1723 * and provide the personalization string as seed information
1724 */
1725 return drbg_instantiate(drbg, NULL, coreref, pr);
1726}
1727
1728static void drbg_kcapi_cleanup(struct crypto_tfm *tfm)
1729{
1730 drbg_uninstantiate(crypto_tfm_ctx(tfm));
1731}
1732
1733/*
1734 * Generate random numbers invoked by the kernel crypto API:
1735 * The API of the kernel crypto API is extended as follows:
1736 *
1737 * If dlen is larger than zero, rdata is interpreted as the output buffer
1738 * where random data is to be stored.
1739 *
1740 * If dlen is zero, rdata is interpreted as a pointer to a struct drbg_gen
1741 * which holds the additional information string that is used for the
1742 * DRBG generation process. The output buffer that is to be used to store
1743 * data is also pointed to by struct drbg_gen.
1744 */
1745static int drbg_kcapi_random(struct crypto_rng *tfm, u8 *rdata,
1746 unsigned int dlen)
1747{
1748 struct drbg_state *drbg = crypto_rng_ctx(tfm);
1749 if (0 < dlen) {
1750 return drbg_generate_long(drbg, rdata, dlen, NULL);
1751 } else {
1752 struct drbg_gen *data = (struct drbg_gen *)rdata;
Stephan Mueller8c987162014-06-28 21:58:24 +02001753 struct drbg_string addtl;
Stephan Mueller541af942014-05-31 15:44:17 +02001754 /* catch NULL pointer */
1755 if (!data)
1756 return 0;
1757 drbg_set_testdata(drbg, data->test_data);
Stephan Mueller8c987162014-06-28 21:58:24 +02001758 /* linked list variable is now local to allow modification */
1759 drbg_string_fill(&addtl, data->addtl->buf, data->addtl->len);
Stephan Mueller541af942014-05-31 15:44:17 +02001760 return drbg_generate_long(drbg, data->outbuf, data->outlen,
Stephan Mueller8c987162014-06-28 21:58:24 +02001761 &addtl);
Stephan Mueller541af942014-05-31 15:44:17 +02001762 }
1763}
1764
1765/*
1766 * Reset the DRBG invoked by the kernel crypto API
1767 * The reset implies a full re-initialization of the DRBG. Similar to the
1768 * generate function of drbg_kcapi_random, this function extends the
1769 * kernel crypto API interface with struct drbg_gen
1770 */
1771static int drbg_kcapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
1772{
1773 struct drbg_state *drbg = crypto_rng_ctx(tfm);
1774 struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm);
1775 bool pr = false;
1776 struct drbg_string seed_string;
1777 int coreref = 0;
1778
1779 drbg_uninstantiate(drbg);
1780 drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref,
1781 &pr);
1782 if (0 < slen) {
1783 drbg_string_fill(&seed_string, seed, slen);
1784 return drbg_instantiate(drbg, &seed_string, coreref, pr);
1785 } else {
1786 struct drbg_gen *data = (struct drbg_gen *)seed;
1787 /* allow invocation of API call with NULL, 0 */
1788 if (!data)
1789 return drbg_instantiate(drbg, NULL, coreref, pr);
1790 drbg_set_testdata(drbg, data->test_data);
Stephan Mueller8c987162014-06-28 21:58:24 +02001791 /* linked list variable is now local to allow modification */
1792 drbg_string_fill(&seed_string, data->addtl->buf,
1793 data->addtl->len);
1794 return drbg_instantiate(drbg, &seed_string, coreref, pr);
Stephan Mueller541af942014-05-31 15:44:17 +02001795 }
1796}
1797
1798/***************************************************************
1799 * Kernel module: code to load the module
1800 ***************************************************************/
1801
1802/*
1803 * Tests as defined in 11.3.2 in addition to the cipher tests: testing
1804 * of the error handling.
1805 *
1806 * Note: testing of failing seed source as defined in 11.3.2 is not applicable
1807 * as seed source of get_random_bytes does not fail.
1808 *
1809 * Note 2: There is no sensible way of testing the reseed counter
1810 * enforcement, so skip it.
1811 */
1812static inline int __init drbg_healthcheck_sanity(void)
1813{
1814#ifdef CONFIG_CRYPTO_FIPS
1815 int len = 0;
1816#define OUTBUFLEN 16
1817 unsigned char buf[OUTBUFLEN];
1818 struct drbg_state *drbg = NULL;
1819 int ret = -EFAULT;
1820 int rc = -EFAULT;
1821 bool pr = false;
1822 int coreref = 0;
1823 struct drbg_string addtl;
1824 size_t max_addtllen, max_request_bytes;
1825
1826 /* only perform test in FIPS mode */
1827 if (!fips_enabled)
1828 return 0;
1829
1830#ifdef CONFIG_CRYPTO_DRBG_CTR
1831 drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref, &pr);
Stephan Muellere25e47e2014-07-06 02:23:03 +02001832#elif defined CONFIG_CRYPTO_DRBG_HASH
Stephan Mueller541af942014-05-31 15:44:17 +02001833 drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr);
1834#else
1835 drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref, &pr);
1836#endif
1837
1838 drbg = kzalloc(sizeof(struct drbg_state), GFP_KERNEL);
1839 if (!drbg)
1840 return -ENOMEM;
1841
1842 /*
1843 * if the following tests fail, it is likely that there is a buffer
1844 * overflow as buf is much smaller than the requested or provided
1845 * string lengths -- in case the error handling does not succeed
1846 * we may get an OOPS. And we want to get an OOPS as this is a
1847 * grave bug.
1848 */
1849
1850 /* get a valid instance of DRBG for following tests */
1851 ret = drbg_instantiate(drbg, NULL, coreref, pr);
1852 if (ret) {
1853 rc = ret;
1854 goto outbuf;
1855 }
1856 max_addtllen = drbg_max_addtl(drbg);
1857 max_request_bytes = drbg_max_request_bytes(drbg);
1858 drbg_string_fill(&addtl, buf, max_addtllen + 1);
1859 /* overflow addtllen with additonal info string */
1860 len = drbg_generate(drbg, buf, OUTBUFLEN, &addtl);
1861 BUG_ON(0 < len);
1862 /* overflow max_bits */
1863 len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL);
1864 BUG_ON(0 < len);
1865 drbg_uninstantiate(drbg);
1866
1867 /* overflow max addtllen with personalization string */
1868 ret = drbg_instantiate(drbg, &addtl, coreref, pr);
1869 BUG_ON(0 == ret);
Stephan Mueller541af942014-05-31 15:44:17 +02001870 /* all tests passed */
1871 rc = 0;
1872
1873 pr_devel("DRBG: Sanity tests for failure code paths successfully "
1874 "completed\n");
1875
1876 drbg_uninstantiate(drbg);
1877outbuf:
1878 kzfree(drbg);
1879 return rc;
1880#else /* CONFIG_CRYPTO_FIPS */
1881 return 0;
1882#endif /* CONFIG_CRYPTO_FIPS */
1883}
1884
1885static struct crypto_alg drbg_algs[22];
1886
1887/*
1888 * Fill the array drbg_algs used to register the different DRBGs
1889 * with the kernel crypto API. To fill the array, the information
1890 * from drbg_cores[] is used.
1891 */
1892static inline void __init drbg_fill_array(struct crypto_alg *alg,
1893 const struct drbg_core *core, int pr)
1894{
1895 int pos = 0;
1896 static int priority = 100;
1897
1898 memset(alg, 0, sizeof(struct crypto_alg));
1899 memcpy(alg->cra_name, "stdrng", 6);
1900 if (pr) {
1901 memcpy(alg->cra_driver_name, "drbg_pr_", 8);
1902 pos = 8;
1903 } else {
1904 memcpy(alg->cra_driver_name, "drbg_nopr_", 10);
1905 pos = 10;
1906 }
1907 memcpy(alg->cra_driver_name + pos, core->cra_name,
1908 strlen(core->cra_name));
1909
1910 alg->cra_priority = priority;
1911 priority++;
1912 /*
1913 * If FIPS mode enabled, the selected DRBG shall have the
1914 * highest cra_priority over other stdrng instances to ensure
1915 * it is selected.
1916 */
1917 if (fips_enabled)
1918 alg->cra_priority += 200;
1919
1920 alg->cra_flags = CRYPTO_ALG_TYPE_RNG;
1921 alg->cra_ctxsize = sizeof(struct drbg_state);
1922 alg->cra_type = &crypto_rng_type;
1923 alg->cra_module = THIS_MODULE;
1924 alg->cra_init = drbg_kcapi_init;
1925 alg->cra_exit = drbg_kcapi_cleanup;
1926 alg->cra_u.rng.rng_make_random = drbg_kcapi_random;
1927 alg->cra_u.rng.rng_reset = drbg_kcapi_reset;
1928 alg->cra_u.rng.seedsize = 0;
1929}
1930
1931static int __init drbg_init(void)
1932{
1933 unsigned int i = 0; /* pointer to drbg_algs */
1934 unsigned int j = 0; /* pointer to drbg_cores */
1935 int ret = -EFAULT;
1936
1937 ret = drbg_healthcheck_sanity();
1938 if (ret)
1939 return ret;
1940
1941 if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) {
1942 pr_info("DRBG: Cannot register all DRBG types"
Stephan Muellera9089572014-07-06 02:24:03 +02001943 "(slots needed: %zu, slots available: %zu)\n",
Stephan Mueller541af942014-05-31 15:44:17 +02001944 ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs));
1945 return ret;
1946 }
1947
1948 /*
1949 * each DRBG definition can be used with PR and without PR, thus
1950 * we instantiate each DRBG in drbg_cores[] twice.
1951 *
1952 * As the order of placing them into the drbg_algs array matters
1953 * (the later DRBGs receive a higher cra_priority) we register the
1954 * prediction resistance DRBGs first as the should not be too
1955 * interesting.
1956 */
1957 for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++)
1958 drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1);
1959 for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++)
1960 drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0);
1961 return crypto_register_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2));
1962}
1963
Fengguang Wu96956ae2014-07-10 16:52:04 +08001964static void __exit drbg_exit(void)
Stephan Mueller541af942014-05-31 15:44:17 +02001965{
1966 crypto_unregister_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2));
1967}
1968
1969module_init(drbg_init);
1970module_exit(drbg_exit);
Stephan Muellere25e47e2014-07-06 02:23:03 +02001971#ifndef CRYPTO_DRBG_HASH_STRING
1972#define CRYPTO_DRBG_HASH_STRING ""
1973#endif
1974#ifndef CRYPTO_DRBG_HMAC_STRING
1975#define CRYPTO_DRBG_HMAC_STRING ""
1976#endif
1977#ifndef CRYPTO_DRBG_CTR_STRING
1978#define CRYPTO_DRBG_CTR_STRING ""
1979#endif
Stephan Mueller541af942014-05-31 15:44:17 +02001980MODULE_LICENSE("GPL");
1981MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
Stephan Muellere25e47e2014-07-06 02:23:03 +02001982MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) "
1983 "using following cores: "
1984 CRYPTO_DRBG_HASH_STRING
1985 CRYPTO_DRBG_HMAC_STRING
1986 CRYPTO_DRBG_CTR_STRING);