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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>
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500101#include <linux/string.h>
Stephan Mueller541af942014-05-31 15:44:17 +0200102
Stephan Mueller541af942014-05-31 15:44:17 +0200103/***************************************************************
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 */
116static 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 */
Stephan Mueller541af942014-05-31 15:44:17 +0200121 .blocklen_bytes = 16,
122 .cra_name = "ctr_aes128",
123 .backend_cra_name = "ecb(aes)",
124 }, {
125 .flags = DRBG_CTR | DRBG_STRENGTH192,
126 .statelen = 40, /* 320 bits as defined in 10.2.1 */
Stephan Mueller541af942014-05-31 15:44:17 +0200127 .blocklen_bytes = 16,
128 .cra_name = "ctr_aes192",
129 .backend_cra_name = "ecb(aes)",
130 }, {
131 .flags = DRBG_CTR | DRBG_STRENGTH256,
132 .statelen = 48, /* 384 bits as defined in 10.2.1 */
Stephan Mueller541af942014-05-31 15:44:17 +0200133 .blocklen_bytes = 16,
134 .cra_name = "ctr_aes256",
135 .backend_cra_name = "ecb(aes)",
136 },
137#endif /* CONFIG_CRYPTO_DRBG_CTR */
138#ifdef CONFIG_CRYPTO_DRBG_HASH
139 {
140 .flags = DRBG_HASH | DRBG_STRENGTH128,
141 .statelen = 55, /* 440 bits */
Stephan Mueller541af942014-05-31 15:44:17 +0200142 .blocklen_bytes = 20,
143 .cra_name = "sha1",
144 .backend_cra_name = "sha1",
145 }, {
146 .flags = DRBG_HASH | DRBG_STRENGTH256,
147 .statelen = 111, /* 888 bits */
Stephan Mueller541af942014-05-31 15:44:17 +0200148 .blocklen_bytes = 48,
149 .cra_name = "sha384",
150 .backend_cra_name = "sha384",
151 }, {
152 .flags = DRBG_HASH | DRBG_STRENGTH256,
153 .statelen = 111, /* 888 bits */
Stephan Mueller541af942014-05-31 15:44:17 +0200154 .blocklen_bytes = 64,
155 .cra_name = "sha512",
156 .backend_cra_name = "sha512",
157 }, {
158 .flags = DRBG_HASH | DRBG_STRENGTH256,
159 .statelen = 55, /* 440 bits */
Stephan Mueller541af942014-05-31 15:44:17 +0200160 .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 {
Stephan Mueller5b635e22014-07-06 02:26:37 +0200167 .flags = DRBG_HMAC | DRBG_STRENGTH128,
Stephan Mueller541af942014-05-31 15:44:17 +0200168 .statelen = 20, /* block length of cipher */
Stephan Mueller541af942014-05-31 15:44:17 +0200169 .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 */
Stephan Mueller541af942014-05-31 15:44:17 +0200175 .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 */
Stephan Mueller541af942014-05-31 15:44:17 +0200181 .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 */
Stephan Mueller541af942014-05-31 15:44:17 +0200187 .blocklen_bytes = 32,
188 .cra_name = "hmac_sha256",
189 .backend_cra_name = "hmac(sha256)",
190 },
191#endif /* CONFIG_CRYPTO_DRBG_HMAC */
192};
193
194/******************************************************************
195 * Generic helper functions
196 ******************************************************************/
197
198/*
199 * Return strength of DRBG according to SP800-90A section 8.4
200 *
201 * @flags DRBG flags reference
202 *
203 * Return: normalized strength in *bytes* value or 32 as default
204 * to counter programming errors
205 */
206static inline unsigned short drbg_sec_strength(drbg_flag_t flags)
207{
208 switch (flags & DRBG_STRENGTH_MASK) {
209 case DRBG_STRENGTH128:
210 return 16;
211 case DRBG_STRENGTH192:
212 return 24;
213 case DRBG_STRENGTH256:
214 return 32;
215 default:
216 return 32;
217 }
218}
219
220/*
221 * FIPS 140-2 continuous self test
222 * The test is performed on the result of one round of the output
223 * function. Thus, the function implicitly knows the size of the
224 * buffer.
225 *
Stephan Mueller541af942014-05-31 15:44:17 +0200226 * @drbg DRBG handle
227 * @buf output buffer of random data to be checked
228 *
229 * return:
230 * true on success
231 * false on error
232 */
233static bool drbg_fips_continuous_test(struct drbg_state *drbg,
234 const unsigned char *buf)
235{
236#ifdef CONFIG_CRYPTO_FIPS
237 int ret = 0;
238 /* skip test if we test the overall system */
239 if (drbg->test_data)
240 return true;
241 /* only perform test in FIPS mode */
242 if (0 == fips_enabled)
243 return true;
244 if (!drbg->fips_primed) {
245 /* Priming of FIPS test */
246 memcpy(drbg->prev, buf, drbg_blocklen(drbg));
247 drbg->fips_primed = true;
248 /* return false due to priming, i.e. another round is needed */
249 return false;
250 }
251 ret = memcmp(drbg->prev, buf, drbg_blocklen(drbg));
Stephan Mueller905b42e2014-12-05 22:40:21 +0100252 if (!ret)
253 panic("DRBG continuous self test failed\n");
Stephan Mueller541af942014-05-31 15:44:17 +0200254 memcpy(drbg->prev, buf, drbg_blocklen(drbg));
255 /* the test shall pass when the two compared values are not equal */
256 return ret != 0;
257#else
258 return true;
259#endif /* CONFIG_CRYPTO_FIPS */
260}
261
262/*
263 * Convert an integer into a byte representation of this integer.
264 * The byte representation is big-endian
265 *
Stephan Mueller541af942014-05-31 15:44:17 +0200266 * @val value to be converted
Stephan Mueller72f3e002014-08-17 17:37:34 +0200267 * @buf buffer holding the converted integer -- caller must ensure that
268 * buffer size is at least 32 bit
Stephan Mueller541af942014-05-31 15:44:17 +0200269 */
270#if (defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR))
Stephan Mueller72f3e002014-08-17 17:37:34 +0200271static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf)
Stephan Mueller541af942014-05-31 15:44:17 +0200272{
Stephan Mueller72f3e002014-08-17 17:37:34 +0200273 struct s {
Stephan Mueller7c8ae032014-08-26 09:32:24 +0200274 __be32 conv;
Stephan Mueller72f3e002014-08-17 17:37:34 +0200275 };
276 struct s *conversion = (struct s *) buf;
Stephan Mueller541af942014-05-31 15:44:17 +0200277
Stephan Mueller72f3e002014-08-17 17:37:34 +0200278 conversion->conv = cpu_to_be32(val);
Stephan Mueller541af942014-05-31 15:44:17 +0200279}
Stephan Mueller541af942014-05-31 15:44:17 +0200280#endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */
281
282/******************************************************************
283 * CTR DRBG callback functions
284 ******************************************************************/
285
286#ifdef CONFIG_CRYPTO_DRBG_CTR
Stephan Muellere25e47e2014-07-06 02:23:03 +0200287#define CRYPTO_DRBG_CTR_STRING "CTR "
Stephan Mueller0653a7c2014-11-25 09:28:43 +0100288MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes256");
289MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes256");
290MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes192");
291MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192");
292MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128");
293MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128");
Stephan Mueller62b62b62014-11-04 03:08:09 +0100294
Stephan Mueller541af942014-05-31 15:44:17 +0200295static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key,
296 unsigned char *outval, const struct drbg_string *in);
297static int drbg_init_sym_kernel(struct drbg_state *drbg);
298static int drbg_fini_sym_kernel(struct drbg_state *drbg);
299
300/* BCC function for CTR DRBG as defined in 10.4.3 */
301static int drbg_ctr_bcc(struct drbg_state *drbg,
302 unsigned char *out, const unsigned char *key,
Stephan Mueller8c987162014-06-28 21:58:24 +0200303 struct list_head *in)
Stephan Mueller541af942014-05-31 15:44:17 +0200304{
Stephan Mueller8c987162014-06-28 21:58:24 +0200305 int ret = 0;
306 struct drbg_string *curr = NULL;
Stephan Mueller541af942014-05-31 15:44:17 +0200307 struct drbg_string data;
Stephan Mueller8c987162014-06-28 21:58:24 +0200308 short cnt = 0;
Stephan Mueller541af942014-05-31 15:44:17 +0200309
310 drbg_string_fill(&data, out, drbg_blocklen(drbg));
311
312 /* 10.4.3 step 1 */
313 memset(out, 0, drbg_blocklen(drbg));
314
315 /* 10.4.3 step 2 / 4 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200316 list_for_each_entry(curr, in, list) {
317 const unsigned char *pos = curr->buf;
318 size_t len = curr->len;
Stephan Mueller541af942014-05-31 15:44:17 +0200319 /* 10.4.3 step 4.1 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200320 while (len) {
321 /* 10.4.3 step 4.2 */
322 if (drbg_blocklen(drbg) == cnt) {
323 cnt = 0;
324 ret = drbg_kcapi_sym(drbg, key, out, &data);
325 if (ret)
326 return ret;
Stephan Mueller541af942014-05-31 15:44:17 +0200327 }
Stephan Mueller8c987162014-06-28 21:58:24 +0200328 out[cnt] ^= *pos;
329 pos++;
330 cnt++;
331 len--;
Stephan Mueller541af942014-05-31 15:44:17 +0200332 }
Stephan Mueller541af942014-05-31 15:44:17 +0200333 }
Stephan Mueller8c987162014-06-28 21:58:24 +0200334 /* 10.4.3 step 4.2 for last block */
335 if (cnt)
336 ret = drbg_kcapi_sym(drbg, key, out, &data);
337
338 return ret;
Stephan Mueller541af942014-05-31 15:44:17 +0200339}
340
341/*
342 * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df
343 * (and drbg_ctr_bcc, but this function does not need any temporary buffers),
344 * the scratchpad is used as follows:
345 * drbg_ctr_update:
346 * temp
347 * start: drbg->scratchpad
348 * length: drbg_statelen(drbg) + drbg_blocklen(drbg)
349 * note: the cipher writing into this variable works
350 * blocklen-wise. Now, when the statelen is not a multiple
351 * of blocklen, the generateion loop below "spills over"
352 * by at most blocklen. Thus, we need to give sufficient
353 * memory.
354 * df_data
355 * start: drbg->scratchpad +
356 * drbg_statelen(drbg) + drbg_blocklen(drbg)
357 * length: drbg_statelen(drbg)
358 *
359 * drbg_ctr_df:
360 * pad
361 * start: df_data + drbg_statelen(drbg)
362 * length: drbg_blocklen(drbg)
363 * iv
364 * start: pad + drbg_blocklen(drbg)
365 * length: drbg_blocklen(drbg)
366 * temp
367 * start: iv + drbg_blocklen(drbg)
Stephan Mueller8fecaad2014-07-01 17:08:48 +0200368 * length: drbg_satelen(drbg) + drbg_blocklen(drbg)
369 * note: temp is the buffer that the BCC function operates
370 * on. BCC operates blockwise. drbg_statelen(drbg)
371 * is sufficient when the DRBG state length is a multiple
372 * of the block size. For AES192 (and maybe other ciphers)
373 * this is not correct and the length for temp is
374 * insufficient (yes, that also means for such ciphers,
375 * the final output of all BCC rounds are truncated).
376 * Therefore, add drbg_blocklen(drbg) to cover all
377 * possibilities.
Stephan Mueller541af942014-05-31 15:44:17 +0200378 */
379
380/* Derivation Function for CTR DRBG as defined in 10.4.2 */
381static int drbg_ctr_df(struct drbg_state *drbg,
382 unsigned char *df_data, size_t bytes_to_return,
Stephan Mueller8c987162014-06-28 21:58:24 +0200383 struct list_head *seedlist)
Stephan Mueller541af942014-05-31 15:44:17 +0200384{
385 int ret = -EFAULT;
386 unsigned char L_N[8];
387 /* S3 is input */
388 struct drbg_string S1, S2, S4, cipherin;
Stephan Mueller8c987162014-06-28 21:58:24 +0200389 LIST_HEAD(bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200390 unsigned char *pad = df_data + drbg_statelen(drbg);
391 unsigned char *iv = pad + drbg_blocklen(drbg);
392 unsigned char *temp = iv + drbg_blocklen(drbg);
393 size_t padlen = 0;
394 unsigned int templen = 0;
395 /* 10.4.2 step 7 */
396 unsigned int i = 0;
397 /* 10.4.2 step 8 */
398 const unsigned char *K = (unsigned char *)
399 "\x00\x01\x02\x03\x04\x05\x06\x07"
400 "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
401 "\x10\x11\x12\x13\x14\x15\x16\x17"
402 "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f";
403 unsigned char *X;
404 size_t generated_len = 0;
405 size_t inputlen = 0;
Stephan Mueller8c987162014-06-28 21:58:24 +0200406 struct drbg_string *seed = NULL;
Stephan Mueller541af942014-05-31 15:44:17 +0200407
408 memset(pad, 0, drbg_blocklen(drbg));
409 memset(iv, 0, drbg_blocklen(drbg));
410 memset(temp, 0, drbg_statelen(drbg));
411
412 /* 10.4.2 step 1 is implicit as we work byte-wise */
413
414 /* 10.4.2 step 2 */
415 if ((512/8) < bytes_to_return)
416 return -EINVAL;
417
418 /* 10.4.2 step 2 -- calculate the entire length of all input data */
Stephan Mueller8c987162014-06-28 21:58:24 +0200419 list_for_each_entry(seed, seedlist, list)
420 inputlen += seed->len;
Stephan Mueller72f3e002014-08-17 17:37:34 +0200421 drbg_cpu_to_be32(inputlen, &L_N[0]);
Stephan Mueller541af942014-05-31 15:44:17 +0200422
423 /* 10.4.2 step 3 */
Stephan Mueller72f3e002014-08-17 17:37:34 +0200424 drbg_cpu_to_be32(bytes_to_return, &L_N[4]);
Stephan Mueller541af942014-05-31 15:44:17 +0200425
426 /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */
427 padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg));
428 /* wrap the padlen appropriately */
429 if (padlen)
430 padlen = drbg_blocklen(drbg) - padlen;
431 /*
432 * pad / padlen contains the 0x80 byte and the following zero bytes.
433 * As the calculated padlen value only covers the number of zero
434 * bytes, this value has to be incremented by one for the 0x80 byte.
435 */
436 padlen++;
437 pad[0] = 0x80;
438
439 /* 10.4.2 step 4 -- first fill the linked list and then order it */
440 drbg_string_fill(&S1, iv, drbg_blocklen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200441 list_add_tail(&S1.list, &bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200442 drbg_string_fill(&S2, L_N, sizeof(L_N));
Stephan Mueller8c987162014-06-28 21:58:24 +0200443 list_add_tail(&S2.list, &bcc_list);
444 list_splice_tail(seedlist, &bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200445 drbg_string_fill(&S4, pad, padlen);
Stephan Mueller8c987162014-06-28 21:58:24 +0200446 list_add_tail(&S4.list, &bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200447
448 /* 10.4.2 step 9 */
449 while (templen < (drbg_keylen(drbg) + (drbg_blocklen(drbg)))) {
450 /*
451 * 10.4.2 step 9.1 - the padding is implicit as the buffer
452 * holds zeros after allocation -- even the increment of i
453 * is irrelevant as the increment remains within length of i
454 */
Stephan Mueller72f3e002014-08-17 17:37:34 +0200455 drbg_cpu_to_be32(i, iv);
Stephan Mueller541af942014-05-31 15:44:17 +0200456 /* 10.4.2 step 9.2 -- BCC and concatenation with temp */
Stephan Mueller8c987162014-06-28 21:58:24 +0200457 ret = drbg_ctr_bcc(drbg, temp + templen, K, &bcc_list);
Stephan Mueller541af942014-05-31 15:44:17 +0200458 if (ret)
459 goto out;
460 /* 10.4.2 step 9.3 */
461 i++;
462 templen += drbg_blocklen(drbg);
463 }
464
465 /* 10.4.2 step 11 */
466 X = temp + (drbg_keylen(drbg));
467 drbg_string_fill(&cipherin, X, drbg_blocklen(drbg));
468
469 /* 10.4.2 step 12: overwriting of outval is implemented in next step */
470
471 /* 10.4.2 step 13 */
472 while (generated_len < bytes_to_return) {
473 short blocklen = 0;
474 /*
475 * 10.4.2 step 13.1: the truncation of the key length is
476 * implicit as the key is only drbg_blocklen in size based on
477 * the implementation of the cipher function callback
478 */
479 ret = drbg_kcapi_sym(drbg, temp, X, &cipherin);
480 if (ret)
481 goto out;
482 blocklen = (drbg_blocklen(drbg) <
483 (bytes_to_return - generated_len)) ?
484 drbg_blocklen(drbg) :
485 (bytes_to_return - generated_len);
486 /* 10.4.2 step 13.2 and 14 */
487 memcpy(df_data + generated_len, X, blocklen);
488 generated_len += blocklen;
489 }
490
491 ret = 0;
492
493out:
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500494 memzero_explicit(iv, drbg_blocklen(drbg));
495 memzero_explicit(temp, drbg_statelen(drbg));
496 memzero_explicit(pad, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200497 return ret;
498}
499
Stephan Mueller72e7c252014-07-06 02:24:35 +0200500/*
501 * update function of CTR DRBG as defined in 10.2.1.2
502 *
503 * The reseed variable has an enhanced meaning compared to the update
504 * functions of the other DRBGs as follows:
505 * 0 => initial seed from initialization
506 * 1 => reseed via drbg_seed
507 * 2 => first invocation from drbg_ctr_update when addtl is present. In
508 * this case, the df_data scratchpad is not deleted so that it is
509 * available for another calls to prevent calling the DF function
510 * again.
511 * 3 => second invocation from drbg_ctr_update. When the update function
512 * was called with addtl, the df_data memory already contains the
513 * DFed addtl information and we do not need to call DF again.
514 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200515static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed,
516 int reseed)
Stephan Mueller541af942014-05-31 15:44:17 +0200517{
518 int ret = -EFAULT;
519 /* 10.2.1.2 step 1 */
520 unsigned char *temp = drbg->scratchpad;
521 unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) +
522 drbg_blocklen(drbg);
523 unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */
524 unsigned int len = 0;
525 struct drbg_string cipherin;
Stephan Mueller541af942014-05-31 15:44:17 +0200526
527 memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg));
Stephan Mueller72e7c252014-07-06 02:24:35 +0200528 if (3 > reseed)
529 memset(df_data, 0, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200530
531 /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200532 if (seed) {
533 ret = drbg_ctr_df(drbg, df_data, drbg_statelen(drbg), seed);
Stephan Mueller541af942014-05-31 15:44:17 +0200534 if (ret)
535 goto out;
536 }
537
538 drbg_string_fill(&cipherin, drbg->V, drbg_blocklen(drbg));
539 /*
540 * 10.2.1.3.2 steps 2 and 3 are already covered as the allocation
541 * zeroizes all memory during initialization
542 */
543 while (len < (drbg_statelen(drbg))) {
544 /* 10.2.1.2 step 2.1 */
Stephan Mueller41a84982014-10-14 21:50:13 +0200545 crypto_inc(drbg->V, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200546 /*
547 * 10.2.1.2 step 2.2 */
548 ret = drbg_kcapi_sym(drbg, drbg->C, temp + len, &cipherin);
549 if (ret)
550 goto out;
551 /* 10.2.1.2 step 2.3 and 3 */
552 len += drbg_blocklen(drbg);
553 }
554
555 /* 10.2.1.2 step 4 */
556 temp_p = temp;
557 df_data_p = df_data;
558 for (len = 0; len < drbg_statelen(drbg); len++) {
559 *temp_p ^= *df_data_p;
560 df_data_p++; temp_p++;
561 }
562
563 /* 10.2.1.2 step 5 */
564 memcpy(drbg->C, temp, drbg_keylen(drbg));
565 /* 10.2.1.2 step 6 */
566 memcpy(drbg->V, temp + drbg_keylen(drbg), drbg_blocklen(drbg));
567 ret = 0;
568
569out:
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500570 memzero_explicit(temp, drbg_statelen(drbg) + drbg_blocklen(drbg));
Stephan Mueller72e7c252014-07-06 02:24:35 +0200571 if (2 != reseed)
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500572 memzero_explicit(df_data, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200573 return ret;
574}
575
576/*
577 * scratchpad use: drbg_ctr_update is called independently from
578 * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused
579 */
580/* Generate function of CTR DRBG as defined in 10.2.1.5.2 */
581static int drbg_ctr_generate(struct drbg_state *drbg,
582 unsigned char *buf, unsigned int buflen,
Stephan Mueller27e4de22014-07-06 02:25:36 +0200583 struct list_head *addtl)
Stephan Mueller541af942014-05-31 15:44:17 +0200584{
585 int len = 0;
586 int ret = 0;
587 struct drbg_string data;
Stephan Mueller541af942014-05-31 15:44:17 +0200588
589 memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
590
591 /* 10.2.1.5.2 step 2 */
Stephan Mueller27e4de22014-07-06 02:25:36 +0200592 if (addtl && !list_empty(addtl)) {
593 ret = drbg_ctr_update(drbg, addtl, 2);
Stephan Mueller541af942014-05-31 15:44:17 +0200594 if (ret)
595 return 0;
596 }
597
598 /* 10.2.1.5.2 step 4.1 */
Stephan Mueller41a84982014-10-14 21:50:13 +0200599 crypto_inc(drbg->V, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200600 drbg_string_fill(&data, drbg->V, drbg_blocklen(drbg));
601 while (len < buflen) {
602 int outlen = 0;
603 /* 10.2.1.5.2 step 4.2 */
604 ret = drbg_kcapi_sym(drbg, drbg->C, drbg->scratchpad, &data);
605 if (ret) {
606 len = ret;
607 goto out;
608 }
609 outlen = (drbg_blocklen(drbg) < (buflen - len)) ?
610 drbg_blocklen(drbg) : (buflen - len);
611 if (!drbg_fips_continuous_test(drbg, drbg->scratchpad)) {
612 /* 10.2.1.5.2 step 6 */
Stephan Mueller41a84982014-10-14 21:50:13 +0200613 crypto_inc(drbg->V, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200614 continue;
615 }
616 /* 10.2.1.5.2 step 4.3 */
617 memcpy(buf + len, drbg->scratchpad, outlen);
618 len += outlen;
619 /* 10.2.1.5.2 step 6 */
620 if (len < buflen)
Stephan Mueller41a84982014-10-14 21:50:13 +0200621 crypto_inc(drbg->V, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200622 }
623
Stephan Mueller72e7c252014-07-06 02:24:35 +0200624 /* 10.2.1.5.2 step 6 */
625 ret = drbg_ctr_update(drbg, NULL, 3);
Stephan Mueller541af942014-05-31 15:44:17 +0200626 if (ret)
627 len = ret;
628
629out:
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500630 memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200631 return len;
632}
633
634static struct drbg_state_ops drbg_ctr_ops = {
635 .update = drbg_ctr_update,
636 .generate = drbg_ctr_generate,
637 .crypto_init = drbg_init_sym_kernel,
638 .crypto_fini = drbg_fini_sym_kernel,
639};
640#endif /* CONFIG_CRYPTO_DRBG_CTR */
641
642/******************************************************************
643 * HMAC DRBG callback functions
644 ******************************************************************/
645
646#if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
647static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key,
Stephan Mueller8c987162014-06-28 21:58:24 +0200648 unsigned char *outval, const struct list_head *in);
Stephan Mueller541af942014-05-31 15:44:17 +0200649static int drbg_init_hash_kernel(struct drbg_state *drbg);
650static int drbg_fini_hash_kernel(struct drbg_state *drbg);
651#endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
652
653#ifdef CONFIG_CRYPTO_DRBG_HMAC
Stephan Muellere25e47e2014-07-06 02:23:03 +0200654#define CRYPTO_DRBG_HMAC_STRING "HMAC "
Stephan Mueller0653a7c2014-11-25 09:28:43 +0100655MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512");
656MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512");
657MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384");
658MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384");
659MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256");
660MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256");
661MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1");
662MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1");
Stephan Mueller62b62b62014-11-04 03:08:09 +0100663
Stephan Mueller541af942014-05-31 15:44:17 +0200664/* update function of HMAC DRBG as defined in 10.1.2.2 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200665static int drbg_hmac_update(struct drbg_state *drbg, struct list_head *seed,
666 int reseed)
Stephan Mueller541af942014-05-31 15:44:17 +0200667{
668 int ret = -EFAULT;
669 int i = 0;
Stephan Mueller8c987162014-06-28 21:58:24 +0200670 struct drbg_string seed1, seed2, vdata;
671 LIST_HEAD(seedlist);
672 LIST_HEAD(vdatalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200673
Stephan Muellerf072f0e2014-08-17 17:38:58 +0200674 if (!reseed)
675 /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */
Stephan Mueller541af942014-05-31 15:44:17 +0200676 memset(drbg->V, 1, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200677
678 drbg_string_fill(&seed1, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200679 list_add_tail(&seed1.list, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +0200680 /* buffer of seed2 will be filled in for loop below with one byte */
681 drbg_string_fill(&seed2, NULL, 1);
Stephan Mueller8c987162014-06-28 21:58:24 +0200682 list_add_tail(&seed2.list, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +0200683 /* input data of seed is allowed to be NULL at this point */
Stephan Mueller8c987162014-06-28 21:58:24 +0200684 if (seed)
685 list_splice_tail(seed, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +0200686
Stephan Mueller8c987162014-06-28 21:58:24 +0200687 drbg_string_fill(&vdata, drbg->V, drbg_statelen(drbg));
688 list_add_tail(&vdata.list, &vdatalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200689 for (i = 2; 0 < i; i--) {
690 /* first round uses 0x0, second 0x1 */
691 unsigned char prefix = DRBG_PREFIX0;
692 if (1 == i)
693 prefix = DRBG_PREFIX1;
694 /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */
695 seed2.buf = &prefix;
Stephan Mueller8c987162014-06-28 21:58:24 +0200696 ret = drbg_kcapi_hash(drbg, drbg->C, drbg->C, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +0200697 if (ret)
698 return ret;
699
700 /* 10.1.2.2 step 2 and 5 -- HMAC for V */
Stephan Mueller8c987162014-06-28 21:58:24 +0200701 ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &vdatalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200702 if (ret)
703 return ret;
704
705 /* 10.1.2.2 step 3 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200706 if (!seed)
Stephan Mueller541af942014-05-31 15:44:17 +0200707 return ret;
708 }
709
710 return 0;
711}
712
713/* generate function of HMAC DRBG as defined in 10.1.2.5 */
714static int drbg_hmac_generate(struct drbg_state *drbg,
715 unsigned char *buf,
716 unsigned int buflen,
Stephan Mueller27e4de22014-07-06 02:25:36 +0200717 struct list_head *addtl)
Stephan Mueller541af942014-05-31 15:44:17 +0200718{
719 int len = 0;
720 int ret = 0;
721 struct drbg_string data;
Stephan Mueller8c987162014-06-28 21:58:24 +0200722 LIST_HEAD(datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200723
724 /* 10.1.2.5 step 2 */
Stephan Mueller27e4de22014-07-06 02:25:36 +0200725 if (addtl && !list_empty(addtl)) {
726 ret = drbg_hmac_update(drbg, addtl, 1);
Stephan Mueller541af942014-05-31 15:44:17 +0200727 if (ret)
728 return ret;
729 }
730
731 drbg_string_fill(&data, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200732 list_add_tail(&data.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200733 while (len < buflen) {
734 unsigned int outlen = 0;
735 /* 10.1.2.5 step 4.1 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200736 ret = drbg_kcapi_hash(drbg, drbg->C, drbg->V, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200737 if (ret)
738 return ret;
739 outlen = (drbg_blocklen(drbg) < (buflen - len)) ?
740 drbg_blocklen(drbg) : (buflen - len);
741 if (!drbg_fips_continuous_test(drbg, drbg->V))
742 continue;
743
744 /* 10.1.2.5 step 4.2 */
745 memcpy(buf + len, drbg->V, outlen);
746 len += outlen;
747 }
748
749 /* 10.1.2.5 step 6 */
Stephan Mueller27e4de22014-07-06 02:25:36 +0200750 if (addtl && !list_empty(addtl))
751 ret = drbg_hmac_update(drbg, addtl, 1);
752 else
Stephan Mueller8c987162014-06-28 21:58:24 +0200753 ret = drbg_hmac_update(drbg, NULL, 1);
Stephan Mueller541af942014-05-31 15:44:17 +0200754 if (ret)
755 return ret;
756
757 return len;
758}
759
760static struct drbg_state_ops drbg_hmac_ops = {
761 .update = drbg_hmac_update,
762 .generate = drbg_hmac_generate,
763 .crypto_init = drbg_init_hash_kernel,
764 .crypto_fini = drbg_fini_hash_kernel,
765
766};
767#endif /* CONFIG_CRYPTO_DRBG_HMAC */
768
769/******************************************************************
770 * Hash DRBG callback functions
771 ******************************************************************/
772
773#ifdef CONFIG_CRYPTO_DRBG_HASH
Stephan Muellere25e47e2014-07-06 02:23:03 +0200774#define CRYPTO_DRBG_HASH_STRING "HASH "
Stephan Mueller0653a7c2014-11-25 09:28:43 +0100775MODULE_ALIAS_CRYPTO("drbg_pr_sha512");
776MODULE_ALIAS_CRYPTO("drbg_nopr_sha512");
777MODULE_ALIAS_CRYPTO("drbg_pr_sha384");
778MODULE_ALIAS_CRYPTO("drbg_nopr_sha384");
779MODULE_ALIAS_CRYPTO("drbg_pr_sha256");
780MODULE_ALIAS_CRYPTO("drbg_nopr_sha256");
781MODULE_ALIAS_CRYPTO("drbg_pr_sha1");
782MODULE_ALIAS_CRYPTO("drbg_nopr_sha1");
Stephan Mueller62b62b62014-11-04 03:08:09 +0100783
Stephan Mueller541af942014-05-31 15:44:17 +0200784/*
Stephan Mueller41a84982014-10-14 21:50:13 +0200785 * Increment buffer
786 *
787 * @dst buffer to increment
788 * @add value to add
789 */
790static inline void drbg_add_buf(unsigned char *dst, size_t dstlen,
791 const unsigned char *add, size_t addlen)
792{
793 /* implied: dstlen > addlen */
794 unsigned char *dstptr;
795 const unsigned char *addptr;
796 unsigned int remainder = 0;
797 size_t len = addlen;
798
799 dstptr = dst + (dstlen-1);
800 addptr = add + (addlen-1);
801 while (len) {
802 remainder += *dstptr + *addptr;
803 *dstptr = remainder & 0xff;
804 remainder >>= 8;
805 len--; dstptr--; addptr--;
806 }
807 len = dstlen - addlen;
808 while (len && remainder > 0) {
809 remainder = *dstptr + 1;
810 *dstptr = remainder & 0xff;
811 remainder >>= 8;
812 len--; dstptr--;
813 }
814}
815
816/*
Stephan Mueller541af942014-05-31 15:44:17 +0200817 * scratchpad usage: as drbg_hash_update and drbg_hash_df are used
818 * interlinked, the scratchpad is used as follows:
819 * drbg_hash_update
820 * start: drbg->scratchpad
821 * length: drbg_statelen(drbg)
822 * drbg_hash_df:
823 * start: drbg->scratchpad + drbg_statelen(drbg)
824 * length: drbg_blocklen(drbg)
825 *
826 * drbg_hash_process_addtl uses the scratchpad, but fully completes
827 * before either of the functions mentioned before are invoked. Therefore,
828 * drbg_hash_process_addtl does not need to be specifically considered.
829 */
830
831/* Derivation Function for Hash DRBG as defined in 10.4.1 */
832static int drbg_hash_df(struct drbg_state *drbg,
833 unsigned char *outval, size_t outlen,
Stephan Mueller8c987162014-06-28 21:58:24 +0200834 struct list_head *entropylist)
Stephan Mueller541af942014-05-31 15:44:17 +0200835{
836 int ret = 0;
837 size_t len = 0;
838 unsigned char input[5];
839 unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg);
Stephan Mueller8c987162014-06-28 21:58:24 +0200840 struct drbg_string data;
Stephan Mueller541af942014-05-31 15:44:17 +0200841
842 memset(tmp, 0, drbg_blocklen(drbg));
843
844 /* 10.4.1 step 3 */
845 input[0] = 1;
Stephan Mueller72f3e002014-08-17 17:37:34 +0200846 drbg_cpu_to_be32((outlen * 8), &input[1]);
Stephan Mueller541af942014-05-31 15:44:17 +0200847
848 /* 10.4.1 step 4.1 -- concatenation of data for input into hash */
Stephan Mueller8c987162014-06-28 21:58:24 +0200849 drbg_string_fill(&data, input, 5);
850 list_add(&data.list, entropylist);
Stephan Mueller541af942014-05-31 15:44:17 +0200851
852 /* 10.4.1 step 4 */
853 while (len < outlen) {
854 short blocklen = 0;
855 /* 10.4.1 step 4.1 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200856 ret = drbg_kcapi_hash(drbg, NULL, tmp, entropylist);
Stephan Mueller541af942014-05-31 15:44:17 +0200857 if (ret)
858 goto out;
859 /* 10.4.1 step 4.2 */
860 input[0]++;
861 blocklen = (drbg_blocklen(drbg) < (outlen - len)) ?
862 drbg_blocklen(drbg) : (outlen - len);
863 memcpy(outval + len, tmp, blocklen);
864 len += blocklen;
865 }
866
867out:
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500868 memzero_explicit(tmp, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200869 return ret;
870}
871
872/* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200873static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed,
Stephan Mueller541af942014-05-31 15:44:17 +0200874 int reseed)
875{
876 int ret = 0;
877 struct drbg_string data1, data2;
Stephan Mueller8c987162014-06-28 21:58:24 +0200878 LIST_HEAD(datalist);
879 LIST_HEAD(datalist2);
Stephan Mueller541af942014-05-31 15:44:17 +0200880 unsigned char *V = drbg->scratchpad;
881 unsigned char prefix = DRBG_PREFIX1;
882
883 memset(drbg->scratchpad, 0, drbg_statelen(drbg));
884 if (!seed)
885 return -EINVAL;
886
887 if (reseed) {
888 /* 10.1.1.3 step 1 */
889 memcpy(V, drbg->V, drbg_statelen(drbg));
890 drbg_string_fill(&data1, &prefix, 1);
Stephan Mueller8c987162014-06-28 21:58:24 +0200891 list_add_tail(&data1.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200892 drbg_string_fill(&data2, V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200893 list_add_tail(&data2.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200894 }
Stephan Mueller8c987162014-06-28 21:58:24 +0200895 list_splice_tail(seed, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200896
897 /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200898 ret = drbg_hash_df(drbg, drbg->V, drbg_statelen(drbg), &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200899 if (ret)
900 goto out;
901
902 /* 10.1.1.2 / 10.1.1.3 step 4 */
903 prefix = DRBG_PREFIX0;
904 drbg_string_fill(&data1, &prefix, 1);
Stephan Mueller8c987162014-06-28 21:58:24 +0200905 list_add_tail(&data1.list, &datalist2);
Stephan Mueller541af942014-05-31 15:44:17 +0200906 drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200907 list_add_tail(&data2.list, &datalist2);
Stephan Mueller541af942014-05-31 15:44:17 +0200908 /* 10.1.1.2 / 10.1.1.3 step 4 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200909 ret = drbg_hash_df(drbg, drbg->C, drbg_statelen(drbg), &datalist2);
Stephan Mueller541af942014-05-31 15:44:17 +0200910
911out:
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500912 memzero_explicit(drbg->scratchpad, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200913 return ret;
914}
915
916/* processing of additional information string for Hash DRBG */
917static int drbg_hash_process_addtl(struct drbg_state *drbg,
Stephan Mueller27e4de22014-07-06 02:25:36 +0200918 struct list_head *addtl)
Stephan Mueller541af942014-05-31 15:44:17 +0200919{
920 int ret = 0;
921 struct drbg_string data1, data2;
Stephan Mueller8c987162014-06-28 21:58:24 +0200922 LIST_HEAD(datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200923 unsigned char prefix = DRBG_PREFIX2;
924
925 /* this is value w as per documentation */
926 memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
927
928 /* 10.1.1.4 step 2 */
Stephan Mueller27e4de22014-07-06 02:25:36 +0200929 if (!addtl || list_empty(addtl))
Stephan Mueller541af942014-05-31 15:44:17 +0200930 return 0;
931
932 /* 10.1.1.4 step 2a */
933 drbg_string_fill(&data1, &prefix, 1);
934 drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200935 list_add_tail(&data1.list, &datalist);
936 list_add_tail(&data2.list, &datalist);
Stephan Mueller27e4de22014-07-06 02:25:36 +0200937 list_splice_tail(addtl, &datalist);
Stephan Mueller8c987162014-06-28 21:58:24 +0200938 ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200939 if (ret)
940 goto out;
941
942 /* 10.1.1.4 step 2b */
943 drbg_add_buf(drbg->V, drbg_statelen(drbg),
944 drbg->scratchpad, drbg_blocklen(drbg));
945
946out:
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500947 memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200948 return ret;
949}
950
951/* Hashgen defined in 10.1.1.4 */
952static int drbg_hash_hashgen(struct drbg_state *drbg,
953 unsigned char *buf,
954 unsigned int buflen)
955{
956 int len = 0;
957 int ret = 0;
958 unsigned char *src = drbg->scratchpad;
959 unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg);
960 struct drbg_string data;
Stephan Mueller8c987162014-06-28 21:58:24 +0200961 LIST_HEAD(datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200962
963 memset(src, 0, drbg_statelen(drbg));
964 memset(dst, 0, drbg_blocklen(drbg));
965
966 /* 10.1.1.4 step hashgen 2 */
967 memcpy(src, drbg->V, drbg_statelen(drbg));
968
969 drbg_string_fill(&data, src, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +0200970 list_add_tail(&data.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200971 while (len < buflen) {
972 unsigned int outlen = 0;
973 /* 10.1.1.4 step hashgen 4.1 */
Stephan Mueller8c987162014-06-28 21:58:24 +0200974 ret = drbg_kcapi_hash(drbg, NULL, dst, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +0200975 if (ret) {
976 len = ret;
977 goto out;
978 }
979 outlen = (drbg_blocklen(drbg) < (buflen - len)) ?
980 drbg_blocklen(drbg) : (buflen - len);
981 if (!drbg_fips_continuous_test(drbg, dst)) {
Stephan Mueller41a84982014-10-14 21:50:13 +0200982 crypto_inc(src, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200983 continue;
984 }
985 /* 10.1.1.4 step hashgen 4.2 */
986 memcpy(buf + len, dst, outlen);
987 len += outlen;
988 /* 10.1.1.4 hashgen step 4.3 */
989 if (len < buflen)
Stephan Mueller41a84982014-10-14 21:50:13 +0200990 crypto_inc(src, drbg_statelen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +0200991 }
992
993out:
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -0500994 memzero_explicit(drbg->scratchpad,
Stephan Mueller541af942014-05-31 15:44:17 +0200995 (drbg_statelen(drbg) + drbg_blocklen(drbg)));
996 return len;
997}
998
999/* generate function for Hash DRBG as defined in 10.1.1.4 */
1000static int drbg_hash_generate(struct drbg_state *drbg,
1001 unsigned char *buf, unsigned int buflen,
Stephan Mueller27e4de22014-07-06 02:25:36 +02001002 struct list_head *addtl)
Stephan Mueller541af942014-05-31 15:44:17 +02001003{
1004 int len = 0;
1005 int ret = 0;
Stephan Mueller72f3e002014-08-17 17:37:34 +02001006 union {
1007 unsigned char req[8];
Stephan Mueller7c8ae032014-08-26 09:32:24 +02001008 __be64 req_int;
Stephan Mueller72f3e002014-08-17 17:37:34 +02001009 } u;
Stephan Mueller541af942014-05-31 15:44:17 +02001010 unsigned char prefix = DRBG_PREFIX3;
1011 struct drbg_string data1, data2;
Stephan Mueller8c987162014-06-28 21:58:24 +02001012 LIST_HEAD(datalist);
Stephan Mueller541af942014-05-31 15:44:17 +02001013
1014 /* 10.1.1.4 step 2 */
1015 ret = drbg_hash_process_addtl(drbg, addtl);
1016 if (ret)
1017 return ret;
1018 /* 10.1.1.4 step 3 */
1019 len = drbg_hash_hashgen(drbg, buf, buflen);
1020
1021 /* this is the value H as documented in 10.1.1.4 */
1022 memset(drbg->scratchpad, 0, drbg_blocklen(drbg));
1023 /* 10.1.1.4 step 4 */
1024 drbg_string_fill(&data1, &prefix, 1);
Stephan Mueller8c987162014-06-28 21:58:24 +02001025 list_add_tail(&data1.list, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +02001026 drbg_string_fill(&data2, drbg->V, drbg_statelen(drbg));
Stephan Mueller8c987162014-06-28 21:58:24 +02001027 list_add_tail(&data2.list, &datalist);
1028 ret = drbg_kcapi_hash(drbg, NULL, drbg->scratchpad, &datalist);
Stephan Mueller541af942014-05-31 15:44:17 +02001029 if (ret) {
1030 len = ret;
1031 goto out;
1032 }
1033
1034 /* 10.1.1.4 step 5 */
1035 drbg_add_buf(drbg->V, drbg_statelen(drbg),
1036 drbg->scratchpad, drbg_blocklen(drbg));
1037 drbg_add_buf(drbg->V, drbg_statelen(drbg),
1038 drbg->C, drbg_statelen(drbg));
Stephan Mueller72f3e002014-08-17 17:37:34 +02001039 u.req_int = cpu_to_be64(drbg->reseed_ctr);
1040 drbg_add_buf(drbg->V, drbg_statelen(drbg), u.req, 8);
Stephan Mueller541af942014-05-31 15:44:17 +02001041
1042out:
Nickolaus Woodruff421d82f2014-11-26 13:40:57 -05001043 memzero_explicit(drbg->scratchpad, drbg_blocklen(drbg));
Stephan Mueller541af942014-05-31 15:44:17 +02001044 return len;
1045}
1046
1047/*
1048 * scratchpad usage: as update and generate are used isolated, both
1049 * can use the scratchpad
1050 */
1051static struct drbg_state_ops drbg_hash_ops = {
1052 .update = drbg_hash_update,
1053 .generate = drbg_hash_generate,
1054 .crypto_init = drbg_init_hash_kernel,
1055 .crypto_fini = drbg_fini_hash_kernel,
1056};
1057#endif /* CONFIG_CRYPTO_DRBG_HASH */
1058
1059/******************************************************************
1060 * Functions common for DRBG implementations
1061 ******************************************************************/
1062
1063/*
1064 * Seeding or reseeding of the DRBG
1065 *
1066 * @drbg: DRBG state struct
1067 * @pers: personalization / additional information buffer
1068 * @reseed: 0 for initial seed process, 1 for reseeding
1069 *
1070 * return:
1071 * 0 on success
1072 * error value otherwise
1073 */
1074static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers,
1075 bool reseed)
1076{
1077 int ret = 0;
1078 unsigned char *entropy = NULL;
1079 size_t entropylen = 0;
1080 struct drbg_string data1;
Stephan Mueller8c987162014-06-28 21:58:24 +02001081 LIST_HEAD(seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +02001082
1083 /* 9.1 / 9.2 / 9.3.1 step 3 */
1084 if (pers && pers->len > (drbg_max_addtl(drbg))) {
Stephan Muellera9089572014-07-06 02:24:03 +02001085 pr_devel("DRBG: personalization string too long %zu\n",
Stephan Mueller541af942014-05-31 15:44:17 +02001086 pers->len);
1087 return -EINVAL;
1088 }
1089
1090 if (drbg->test_data && drbg->test_data->testentropy) {
1091 drbg_string_fill(&data1, drbg->test_data->testentropy->buf,
1092 drbg->test_data->testentropy->len);
1093 pr_devel("DRBG: using test entropy\n");
1094 } else {
1095 /*
1096 * Gather entropy equal to the security strength of the DRBG.
1097 * With a derivation function, a nonce is required in addition
1098 * to the entropy. A nonce must be at least 1/2 of the security
1099 * strength of the DRBG in size. Thus, entropy * nonce is 3/2
1100 * of the strength. The consideration of a nonce is only
1101 * applicable during initial seeding.
1102 */
1103 entropylen = drbg_sec_strength(drbg->core->flags);
1104 if (!entropylen)
1105 return -EFAULT;
1106 if (!reseed)
1107 entropylen = ((entropylen + 1) / 2) * 3;
1108 pr_devel("DRBG: (re)seeding with %zu bytes of entropy\n",
1109 entropylen);
1110 entropy = kzalloc(entropylen, GFP_KERNEL);
1111 if (!entropy)
1112 return -ENOMEM;
1113 get_random_bytes(entropy, entropylen);
1114 drbg_string_fill(&data1, entropy, entropylen);
1115 }
Stephan Mueller8c987162014-06-28 21:58:24 +02001116 list_add_tail(&data1.list, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +02001117
1118 /*
1119 * concatenation of entropy with personalization str / addtl input)
1120 * the variable pers is directly handed in by the caller, so check its
1121 * contents whether it is appropriate
1122 */
Stephan Mueller8c987162014-06-28 21:58:24 +02001123 if (pers && pers->buf && 0 < pers->len) {
1124 list_add_tail(&pers->list, &seedlist);
Stephan Mueller541af942014-05-31 15:44:17 +02001125 pr_devel("DRBG: using personalization string\n");
1126 }
1127
Stephan Muellere6c02442014-08-17 17:39:31 +02001128 if (!reseed) {
1129 memset(drbg->V, 0, drbg_statelen(drbg));
1130 memset(drbg->C, 0, drbg_statelen(drbg));
1131 }
1132
Stephan Mueller8c987162014-06-28 21:58:24 +02001133 ret = drbg->d_ops->update(drbg, &seedlist, reseed);
Stephan Mueller541af942014-05-31 15:44:17 +02001134 if (ret)
1135 goto out;
1136
1137 drbg->seeded = true;
1138 /* 10.1.1.2 / 10.1.1.3 step 5 */
1139 drbg->reseed_ctr = 1;
1140
1141out:
Stephan Mueller46f64f62014-08-17 17:37:59 +02001142 kzfree(entropy);
Stephan Mueller541af942014-05-31 15:44:17 +02001143 return ret;
1144}
1145
1146/* Free all substructures in a DRBG state without the DRBG state structure */
1147static inline void drbg_dealloc_state(struct drbg_state *drbg)
1148{
1149 if (!drbg)
1150 return;
Stephan Mueller46f64f62014-08-17 17:37:59 +02001151 kzfree(drbg->V);
Stephan Mueller541af942014-05-31 15:44:17 +02001152 drbg->V = NULL;
Stephan Mueller46f64f62014-08-17 17:37:59 +02001153 kzfree(drbg->C);
Stephan Mueller541af942014-05-31 15:44:17 +02001154 drbg->C = NULL;
Stephan Mueller46f64f62014-08-17 17:37:59 +02001155 kzfree(drbg->scratchpad);
Stephan Mueller541af942014-05-31 15:44:17 +02001156 drbg->scratchpad = NULL;
1157 drbg->reseed_ctr = 0;
1158#ifdef CONFIG_CRYPTO_FIPS
Stephan Mueller46f64f62014-08-17 17:37:59 +02001159 kzfree(drbg->prev);
Stephan Mueller541af942014-05-31 15:44:17 +02001160 drbg->prev = NULL;
1161 drbg->fips_primed = false;
1162#endif
1163}
1164
1165/*
1166 * Allocate all sub-structures for a DRBG state.
1167 * The DRBG state structure must already be allocated.
1168 */
1169static inline int drbg_alloc_state(struct drbg_state *drbg)
1170{
1171 int ret = -ENOMEM;
1172 unsigned int sb_size = 0;
1173
Stephan Muellere6c02442014-08-17 17:39:31 +02001174 drbg->V = kmalloc(drbg_statelen(drbg), GFP_KERNEL);
Stephan Mueller541af942014-05-31 15:44:17 +02001175 if (!drbg->V)
1176 goto err;
Stephan Muellere6c02442014-08-17 17:39:31 +02001177 drbg->C = kmalloc(drbg_statelen(drbg), GFP_KERNEL);
Stephan Mueller541af942014-05-31 15:44:17 +02001178 if (!drbg->C)
1179 goto err;
1180#ifdef CONFIG_CRYPTO_FIPS
Stephan Muellere6c02442014-08-17 17:39:31 +02001181 drbg->prev = kmalloc(drbg_blocklen(drbg), GFP_KERNEL);
Stephan Mueller541af942014-05-31 15:44:17 +02001182 if (!drbg->prev)
1183 goto err;
1184 drbg->fips_primed = false;
1185#endif
1186 /* scratchpad is only generated for CTR and Hash */
1187 if (drbg->core->flags & DRBG_HMAC)
1188 sb_size = 0;
1189 else if (drbg->core->flags & DRBG_CTR)
1190 sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg) + /* temp */
1191 drbg_statelen(drbg) + /* df_data */
1192 drbg_blocklen(drbg) + /* pad */
1193 drbg_blocklen(drbg) + /* iv */
Stephan Mueller8fecaad2014-07-01 17:08:48 +02001194 drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */
Stephan Mueller541af942014-05-31 15:44:17 +02001195 else
1196 sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg);
1197
1198 if (0 < sb_size) {
1199 drbg->scratchpad = kzalloc(sb_size, GFP_KERNEL);
1200 if (!drbg->scratchpad)
1201 goto err;
1202 }
1203 spin_lock_init(&drbg->drbg_lock);
1204 return 0;
1205
1206err:
1207 drbg_dealloc_state(drbg);
1208 return ret;
1209}
1210
1211/*
1212 * Strategy to avoid holding long term locks: generate a shadow copy of DRBG
1213 * and perform all operations on this shadow copy. After finishing, restore
1214 * the updated state of the shadow copy into original drbg state. This way,
1215 * only the read and write operations of the original drbg state must be
1216 * locked
1217 */
1218static inline void drbg_copy_drbg(struct drbg_state *src,
1219 struct drbg_state *dst)
1220{
1221 if (!src || !dst)
1222 return;
1223 memcpy(dst->V, src->V, drbg_statelen(src));
1224 memcpy(dst->C, src->C, drbg_statelen(src));
1225 dst->reseed_ctr = src->reseed_ctr;
1226 dst->seeded = src->seeded;
1227 dst->pr = src->pr;
1228#ifdef CONFIG_CRYPTO_FIPS
1229 dst->fips_primed = src->fips_primed;
1230 memcpy(dst->prev, src->prev, drbg_blocklen(src));
1231#endif
1232 /*
1233 * Not copied:
1234 * scratchpad is initialized drbg_alloc_state;
1235 * priv_data is initialized with call to crypto_init;
1236 * d_ops and core are set outside, as these parameters are const;
1237 * test_data is set outside to prevent it being copied back.
1238 */
1239}
1240
1241static int drbg_make_shadow(struct drbg_state *drbg, struct drbg_state **shadow)
1242{
1243 int ret = -ENOMEM;
1244 struct drbg_state *tmp = NULL;
1245
Stephan Mueller541af942014-05-31 15:44:17 +02001246 tmp = kzalloc(sizeof(struct drbg_state), GFP_KERNEL);
1247 if (!tmp)
1248 return -ENOMEM;
1249
1250 /* read-only data as they are defined as const, no lock needed */
1251 tmp->core = drbg->core;
1252 tmp->d_ops = drbg->d_ops;
1253
1254 ret = drbg_alloc_state(tmp);
1255 if (ret)
1256 goto err;
1257
1258 spin_lock_bh(&drbg->drbg_lock);
1259 drbg_copy_drbg(drbg, tmp);
1260 /* only make a link to the test buffer, as we only read that data */
1261 tmp->test_data = drbg->test_data;
1262 spin_unlock_bh(&drbg->drbg_lock);
1263 *shadow = tmp;
1264 return 0;
1265
1266err:
Stephan Mueller46f64f62014-08-17 17:37:59 +02001267 kzfree(tmp);
Stephan Mueller541af942014-05-31 15:44:17 +02001268 return ret;
1269}
1270
1271static void drbg_restore_shadow(struct drbg_state *drbg,
1272 struct drbg_state **shadow)
1273{
1274 struct drbg_state *tmp = *shadow;
1275
1276 spin_lock_bh(&drbg->drbg_lock);
1277 drbg_copy_drbg(tmp, drbg);
1278 spin_unlock_bh(&drbg->drbg_lock);
1279 drbg_dealloc_state(tmp);
1280 kzfree(tmp);
1281 *shadow = NULL;
1282}
1283
1284/*************************************************************************
1285 * DRBG interface functions
1286 *************************************************************************/
1287
1288/*
1289 * DRBG generate function as required by SP800-90A - this function
1290 * generates random numbers
1291 *
1292 * @drbg DRBG state handle
1293 * @buf Buffer where to store the random numbers -- the buffer must already
1294 * be pre-allocated by caller
1295 * @buflen Length of output buffer - this value defines the number of random
1296 * bytes pulled from DRBG
1297 * @addtl Additional input that is mixed into state, may be NULL -- note
1298 * the entropy is pulled by the DRBG internally unconditionally
1299 * as defined in SP800-90A. The additional input is mixed into
1300 * the state in addition to the pulled entropy.
1301 *
1302 * return: generated number of bytes
1303 */
1304static int drbg_generate(struct drbg_state *drbg,
1305 unsigned char *buf, unsigned int buflen,
1306 struct drbg_string *addtl)
1307{
1308 int len = 0;
1309 struct drbg_state *shadow = NULL;
Stephan Mueller27e4de22014-07-06 02:25:36 +02001310 LIST_HEAD(addtllist);
1311 struct drbg_string timestamp;
1312 union {
1313 cycles_t cycles;
1314 unsigned char char_cycles[sizeof(cycles_t)];
1315 } now;
Stephan Mueller541af942014-05-31 15:44:17 +02001316
1317 if (0 == buflen || !buf) {
1318 pr_devel("DRBG: no output buffer provided\n");
1319 return -EINVAL;
1320 }
1321 if (addtl && NULL == addtl->buf && 0 < addtl->len) {
1322 pr_devel("DRBG: wrong format of additional information\n");
1323 return -EINVAL;
1324 }
1325
1326 len = drbg_make_shadow(drbg, &shadow);
1327 if (len) {
1328 pr_devel("DRBG: shadow copy cannot be generated\n");
1329 return len;
1330 }
1331
1332 /* 9.3.1 step 2 */
1333 len = -EINVAL;
1334 if (buflen > (drbg_max_request_bytes(shadow))) {
1335 pr_devel("DRBG: requested random numbers too large %u\n",
1336 buflen);
1337 goto err;
1338 }
1339
1340 /* 9.3.1 step 3 is implicit with the chosen DRBG */
1341
1342 /* 9.3.1 step 4 */
1343 if (addtl && addtl->len > (drbg_max_addtl(shadow))) {
1344 pr_devel("DRBG: additional information string too long %zu\n",
1345 addtl->len);
1346 goto err;
1347 }
1348 /* 9.3.1 step 5 is implicit with the chosen DRBG */
1349
1350 /*
1351 * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented
1352 * here. The spec is a bit convoluted here, we make it simpler.
1353 */
1354 if ((drbg_max_requests(shadow)) < shadow->reseed_ctr)
1355 shadow->seeded = false;
1356
1357 /* allocate cipher handle */
Stephan Mueller45943a52014-08-17 17:38:29 +02001358 len = shadow->d_ops->crypto_init(shadow);
1359 if (len)
1360 goto err;
Stephan Mueller541af942014-05-31 15:44:17 +02001361
1362 if (shadow->pr || !shadow->seeded) {
1363 pr_devel("DRBG: reseeding before generation (prediction "
1364 "resistance: %s, state %s)\n",
1365 drbg->pr ? "true" : "false",
1366 drbg->seeded ? "seeded" : "unseeded");
1367 /* 9.3.1 steps 7.1 through 7.3 */
1368 len = drbg_seed(shadow, addtl, true);
1369 if (len)
1370 goto err;
1371 /* 9.3.1 step 7.4 */
1372 addtl = NULL;
1373 }
Stephan Mueller27e4de22014-07-06 02:25:36 +02001374
1375 /*
1376 * Mix the time stamp into the DRBG state if the DRBG is not in
1377 * test mode. If there are two callers invoking the DRBG at the same
1378 * time, i.e. before the first caller merges its shadow state back,
1379 * both callers would obtain the same random number stream without
1380 * changing the state here.
1381 */
1382 if (!drbg->test_data) {
1383 now.cycles = random_get_entropy();
1384 drbg_string_fill(&timestamp, now.char_cycles, sizeof(cycles_t));
1385 list_add_tail(&timestamp.list, &addtllist);
1386 }
1387 if (addtl && 0 < addtl->len)
1388 list_add_tail(&addtl->list, &addtllist);
Stephan Mueller541af942014-05-31 15:44:17 +02001389 /* 9.3.1 step 8 and 10 */
Stephan Mueller27e4de22014-07-06 02:25:36 +02001390 len = shadow->d_ops->generate(shadow, buf, buflen, &addtllist);
Stephan Mueller541af942014-05-31 15:44:17 +02001391
1392 /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */
1393 shadow->reseed_ctr++;
1394 if (0 >= len)
1395 goto err;
1396
1397 /*
1398 * Section 11.3.3 requires to re-perform self tests after some
1399 * generated random numbers. The chosen value after which self
1400 * test is performed is arbitrary, but it should be reasonable.
1401 * However, we do not perform the self tests because of the following
1402 * reasons: it is mathematically impossible that the initial self tests
1403 * were successfully and the following are not. If the initial would
1404 * pass and the following would not, the kernel integrity is violated.
1405 * In this case, the entire kernel operation is questionable and it
1406 * is unlikely that the integrity violation only affects the
1407 * correct operation of the DRBG.
1408 *
1409 * Albeit the following code is commented out, it is provided in
1410 * case somebody has a need to implement the test of 11.3.3.
1411 */
1412#if 0
1413 if (shadow->reseed_ctr && !(shadow->reseed_ctr % 4096)) {
1414 int err = 0;
1415 pr_devel("DRBG: start to perform self test\n");
1416 if (drbg->core->flags & DRBG_HMAC)
1417 err = alg_test("drbg_pr_hmac_sha256",
1418 "drbg_pr_hmac_sha256", 0, 0);
1419 else if (drbg->core->flags & DRBG_CTR)
1420 err = alg_test("drbg_pr_ctr_aes128",
1421 "drbg_pr_ctr_aes128", 0, 0);
1422 else
1423 err = alg_test("drbg_pr_sha256",
1424 "drbg_pr_sha256", 0, 0);
1425 if (err) {
1426 pr_err("DRBG: periodical self test failed\n");
1427 /*
1428 * uninstantiate implies that from now on, only errors
1429 * are returned when reusing this DRBG cipher handle
1430 */
1431 drbg_uninstantiate(drbg);
1432 drbg_dealloc_state(shadow);
1433 kzfree(shadow);
1434 return 0;
1435 } else {
1436 pr_devel("DRBG: self test successful\n");
1437 }
1438 }
1439#endif
1440
1441err:
Stephan Mueller45943a52014-08-17 17:38:29 +02001442 shadow->d_ops->crypto_fini(shadow);
Stephan Mueller541af942014-05-31 15:44:17 +02001443 drbg_restore_shadow(drbg, &shadow);
1444 return len;
1445}
1446
1447/*
1448 * Wrapper around drbg_generate which can pull arbitrary long strings
1449 * from the DRBG without hitting the maximum request limitation.
1450 *
1451 * Parameters: see drbg_generate
1452 * Return codes: see drbg_generate -- if one drbg_generate request fails,
1453 * the entire drbg_generate_long request fails
1454 */
1455static int drbg_generate_long(struct drbg_state *drbg,
1456 unsigned char *buf, unsigned int buflen,
1457 struct drbg_string *addtl)
1458{
1459 int len = 0;
1460 unsigned int slice = 0;
1461 do {
1462 int tmplen = 0;
1463 unsigned int chunk = 0;
1464 slice = ((buflen - len) / drbg_max_request_bytes(drbg));
1465 chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len);
1466 tmplen = drbg_generate(drbg, buf + len, chunk, addtl);
1467 if (0 >= tmplen)
1468 return tmplen;
1469 len += tmplen;
Stephan Muellerce5481d2014-07-31 21:47:33 +02001470 } while (slice > 0 && (len < buflen));
Stephan Mueller541af942014-05-31 15:44:17 +02001471 return len;
1472}
1473
1474/*
1475 * DRBG instantiation function as required by SP800-90A - this function
1476 * sets up the DRBG handle, performs the initial seeding and all sanity
1477 * checks required by SP800-90A
1478 *
1479 * @drbg memory of state -- if NULL, new memory is allocated
1480 * @pers Personalization string that is mixed into state, may be NULL -- note
1481 * the entropy is pulled by the DRBG internally unconditionally
1482 * as defined in SP800-90A. The additional input is mixed into
1483 * the state in addition to the pulled entropy.
1484 * @coreref reference to core
1485 * @pr prediction resistance enabled
1486 *
1487 * return
1488 * 0 on success
1489 * error value otherwise
1490 */
1491static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers,
1492 int coreref, bool pr)
1493{
1494 int ret = -ENOMEM;
1495
1496 pr_devel("DRBG: Initializing DRBG core %d with prediction resistance "
1497 "%s\n", coreref, pr ? "enabled" : "disabled");
1498 drbg->core = &drbg_cores[coreref];
1499 drbg->pr = pr;
1500 drbg->seeded = false;
1501 switch (drbg->core->flags & DRBG_TYPE_MASK) {
1502#ifdef CONFIG_CRYPTO_DRBG_HMAC
1503 case DRBG_HMAC:
1504 drbg->d_ops = &drbg_hmac_ops;
1505 break;
1506#endif /* CONFIG_CRYPTO_DRBG_HMAC */
1507#ifdef CONFIG_CRYPTO_DRBG_HASH
1508 case DRBG_HASH:
1509 drbg->d_ops = &drbg_hash_ops;
1510 break;
1511#endif /* CONFIG_CRYPTO_DRBG_HASH */
1512#ifdef CONFIG_CRYPTO_DRBG_CTR
1513 case DRBG_CTR:
1514 drbg->d_ops = &drbg_ctr_ops;
1515 break;
1516#endif /* CONFIG_CRYPTO_DRBG_CTR */
1517 default:
1518 return -EOPNOTSUPP;
1519 }
1520
1521 /* 9.1 step 1 is implicit with the selected DRBG type */
1522
1523 /*
1524 * 9.1 step 2 is implicit as caller can select prediction resistance
1525 * and the flag is copied into drbg->flags --
1526 * all DRBG types support prediction resistance
1527 */
1528
1529 /* 9.1 step 4 is implicit in drbg_sec_strength */
1530
1531 ret = drbg_alloc_state(drbg);
1532 if (ret)
1533 return ret;
1534
1535 ret = -EFAULT;
Stephan Mueller45943a52014-08-17 17:38:29 +02001536 if (drbg->d_ops->crypto_init(drbg))
Stephan Mueller541af942014-05-31 15:44:17 +02001537 goto err;
1538 ret = drbg_seed(drbg, pers, false);
Stephan Mueller45943a52014-08-17 17:38:29 +02001539 drbg->d_ops->crypto_fini(drbg);
Stephan Mueller541af942014-05-31 15:44:17 +02001540 if (ret)
1541 goto err;
1542
1543 return 0;
1544
1545err:
1546 drbg_dealloc_state(drbg);
1547 return ret;
1548}
1549
1550/*
1551 * DRBG uninstantiate function as required by SP800-90A - this function
1552 * frees all buffers and the DRBG handle
1553 *
1554 * @drbg DRBG state handle
1555 *
1556 * return
1557 * 0 on success
1558 */
1559static int drbg_uninstantiate(struct drbg_state *drbg)
1560{
1561 spin_lock_bh(&drbg->drbg_lock);
1562 drbg_dealloc_state(drbg);
1563 /* no scrubbing of test_data -- this shall survive an uninstantiate */
1564 spin_unlock_bh(&drbg->drbg_lock);
1565 return 0;
1566}
1567
1568/*
1569 * Helper function for setting the test data in the DRBG
1570 *
1571 * @drbg DRBG state handle
1572 * @test_data test data to sets
1573 */
1574static inline void drbg_set_testdata(struct drbg_state *drbg,
1575 struct drbg_test_data *test_data)
1576{
1577 if (!test_data || !test_data->testentropy)
1578 return;
1579 spin_lock_bh(&drbg->drbg_lock);
1580 drbg->test_data = test_data;
1581 spin_unlock_bh(&drbg->drbg_lock);
1582}
1583
1584/***************************************************************
1585 * Kernel crypto API cipher invocations requested by DRBG
1586 ***************************************************************/
1587
1588#if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
1589struct sdesc {
1590 struct shash_desc shash;
1591 char ctx[];
1592};
1593
1594static int drbg_init_hash_kernel(struct drbg_state *drbg)
1595{
1596 struct sdesc *sdesc;
1597 struct crypto_shash *tfm;
1598
1599 tfm = crypto_alloc_shash(drbg->core->backend_cra_name, 0, 0);
1600 if (IS_ERR(tfm)) {
1601 pr_info("DRBG: could not allocate digest TFM handle\n");
1602 return PTR_ERR(tfm);
1603 }
1604 BUG_ON(drbg_blocklen(drbg) != crypto_shash_digestsize(tfm));
1605 sdesc = kzalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm),
1606 GFP_KERNEL);
1607 if (!sdesc) {
1608 crypto_free_shash(tfm);
1609 return -ENOMEM;
1610 }
1611
1612 sdesc->shash.tfm = tfm;
1613 sdesc->shash.flags = 0;
1614 drbg->priv_data = sdesc;
1615 return 0;
1616}
1617
1618static int drbg_fini_hash_kernel(struct drbg_state *drbg)
1619{
1620 struct sdesc *sdesc = (struct sdesc *)drbg->priv_data;
1621 if (sdesc) {
1622 crypto_free_shash(sdesc->shash.tfm);
1623 kzfree(sdesc);
1624 }
1625 drbg->priv_data = NULL;
1626 return 0;
1627}
1628
1629static int drbg_kcapi_hash(struct drbg_state *drbg, const unsigned char *key,
Stephan Mueller8c987162014-06-28 21:58:24 +02001630 unsigned char *outval, const struct list_head *in)
Stephan Mueller541af942014-05-31 15:44:17 +02001631{
1632 struct sdesc *sdesc = (struct sdesc *)drbg->priv_data;
Stephan Mueller8c987162014-06-28 21:58:24 +02001633 struct drbg_string *input = NULL;
Stephan Mueller541af942014-05-31 15:44:17 +02001634
1635 if (key)
1636 crypto_shash_setkey(sdesc->shash.tfm, key, drbg_statelen(drbg));
1637 crypto_shash_init(&sdesc->shash);
Stephan Mueller8c987162014-06-28 21:58:24 +02001638 list_for_each_entry(input, in, list)
1639 crypto_shash_update(&sdesc->shash, input->buf, input->len);
Stephan Mueller541af942014-05-31 15:44:17 +02001640 return crypto_shash_final(&sdesc->shash, outval);
1641}
1642#endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
1643
1644#ifdef CONFIG_CRYPTO_DRBG_CTR
1645static int drbg_init_sym_kernel(struct drbg_state *drbg)
1646{
1647 int ret = 0;
1648 struct crypto_blkcipher *tfm;
1649
1650 tfm = crypto_alloc_blkcipher(drbg->core->backend_cra_name, 0, 0);
1651 if (IS_ERR(tfm)) {
1652 pr_info("DRBG: could not allocate cipher TFM handle\n");
1653 return PTR_ERR(tfm);
1654 }
1655 BUG_ON(drbg_blocklen(drbg) != crypto_blkcipher_blocksize(tfm));
1656 drbg->priv_data = tfm;
1657 return ret;
1658}
1659
1660static int drbg_fini_sym_kernel(struct drbg_state *drbg)
1661{
1662 struct crypto_blkcipher *tfm =
1663 (struct crypto_blkcipher *)drbg->priv_data;
1664 if (tfm)
1665 crypto_free_blkcipher(tfm);
1666 drbg->priv_data = NULL;
1667 return 0;
1668}
1669
1670static int drbg_kcapi_sym(struct drbg_state *drbg, const unsigned char *key,
1671 unsigned char *outval, const struct drbg_string *in)
1672{
1673 int ret = 0;
1674 struct scatterlist sg_in, sg_out;
1675 struct blkcipher_desc desc;
1676 struct crypto_blkcipher *tfm =
1677 (struct crypto_blkcipher *)drbg->priv_data;
1678
1679 desc.tfm = tfm;
1680 desc.flags = 0;
1681 crypto_blkcipher_setkey(tfm, key, (drbg_keylen(drbg)));
1682 /* there is only component in *in */
1683 sg_init_one(&sg_in, in->buf, in->len);
1684 sg_init_one(&sg_out, outval, drbg_blocklen(drbg));
1685 ret = crypto_blkcipher_encrypt(&desc, &sg_out, &sg_in, in->len);
1686
1687 return ret;
1688}
1689#endif /* CONFIG_CRYPTO_DRBG_CTR */
1690
1691/***************************************************************
1692 * Kernel crypto API interface to register DRBG
1693 ***************************************************************/
1694
1695/*
1696 * Look up the DRBG flags by given kernel crypto API cra_name
1697 * The code uses the drbg_cores definition to do this
1698 *
1699 * @cra_name kernel crypto API cra_name
1700 * @coreref reference to integer which is filled with the pointer to
1701 * the applicable core
1702 * @pr reference for setting prediction resistance
1703 *
1704 * return: flags
1705 */
1706static inline void drbg_convert_tfm_core(const char *cra_driver_name,
1707 int *coreref, bool *pr)
1708{
1709 int i = 0;
1710 size_t start = 0;
1711 int len = 0;
1712
1713 *pr = true;
1714 /* disassemble the names */
1715 if (!memcmp(cra_driver_name, "drbg_nopr_", 10)) {
1716 start = 10;
1717 *pr = false;
1718 } else if (!memcmp(cra_driver_name, "drbg_pr_", 8)) {
1719 start = 8;
1720 } else {
1721 return;
1722 }
1723
1724 /* remove the first part */
1725 len = strlen(cra_driver_name) - start;
1726 for (i = 0; ARRAY_SIZE(drbg_cores) > i; i++) {
1727 if (!memcmp(cra_driver_name + start, drbg_cores[i].cra_name,
1728 len)) {
1729 *coreref = i;
1730 return;
1731 }
1732 }
1733}
1734
1735static int drbg_kcapi_init(struct crypto_tfm *tfm)
1736{
1737 struct drbg_state *drbg = crypto_tfm_ctx(tfm);
1738 bool pr = false;
1739 int coreref = 0;
1740
Stephan Mueller4f150712014-07-06 02:25:04 +02001741 drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm), &coreref, &pr);
Stephan Mueller541af942014-05-31 15:44:17 +02001742 /*
1743 * when personalization string is needed, the caller must call reset
1744 * and provide the personalization string as seed information
1745 */
1746 return drbg_instantiate(drbg, NULL, coreref, pr);
1747}
1748
1749static void drbg_kcapi_cleanup(struct crypto_tfm *tfm)
1750{
1751 drbg_uninstantiate(crypto_tfm_ctx(tfm));
1752}
1753
1754/*
1755 * Generate random numbers invoked by the kernel crypto API:
1756 * The API of the kernel crypto API is extended as follows:
1757 *
1758 * If dlen is larger than zero, rdata is interpreted as the output buffer
1759 * where random data is to be stored.
1760 *
1761 * If dlen is zero, rdata is interpreted as a pointer to a struct drbg_gen
1762 * which holds the additional information string that is used for the
1763 * DRBG generation process. The output buffer that is to be used to store
1764 * data is also pointed to by struct drbg_gen.
1765 */
1766static int drbg_kcapi_random(struct crypto_rng *tfm, u8 *rdata,
1767 unsigned int dlen)
1768{
1769 struct drbg_state *drbg = crypto_rng_ctx(tfm);
1770 if (0 < dlen) {
1771 return drbg_generate_long(drbg, rdata, dlen, NULL);
1772 } else {
1773 struct drbg_gen *data = (struct drbg_gen *)rdata;
Stephan Mueller8c987162014-06-28 21:58:24 +02001774 struct drbg_string addtl;
Stephan Mueller541af942014-05-31 15:44:17 +02001775 /* catch NULL pointer */
1776 if (!data)
1777 return 0;
1778 drbg_set_testdata(drbg, data->test_data);
Stephan Mueller8c987162014-06-28 21:58:24 +02001779 /* linked list variable is now local to allow modification */
1780 drbg_string_fill(&addtl, data->addtl->buf, data->addtl->len);
Stephan Mueller541af942014-05-31 15:44:17 +02001781 return drbg_generate_long(drbg, data->outbuf, data->outlen,
Stephan Mueller8c987162014-06-28 21:58:24 +02001782 &addtl);
Stephan Mueller541af942014-05-31 15:44:17 +02001783 }
1784}
1785
1786/*
1787 * Reset the DRBG invoked by the kernel crypto API
1788 * The reset implies a full re-initialization of the DRBG. Similar to the
1789 * generate function of drbg_kcapi_random, this function extends the
1790 * kernel crypto API interface with struct drbg_gen
1791 */
1792static int drbg_kcapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
1793{
1794 struct drbg_state *drbg = crypto_rng_ctx(tfm);
1795 struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm);
1796 bool pr = false;
1797 struct drbg_string seed_string;
1798 int coreref = 0;
1799
1800 drbg_uninstantiate(drbg);
1801 drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref,
1802 &pr);
1803 if (0 < slen) {
1804 drbg_string_fill(&seed_string, seed, slen);
1805 return drbg_instantiate(drbg, &seed_string, coreref, pr);
1806 } else {
1807 struct drbg_gen *data = (struct drbg_gen *)seed;
1808 /* allow invocation of API call with NULL, 0 */
1809 if (!data)
1810 return drbg_instantiate(drbg, NULL, coreref, pr);
1811 drbg_set_testdata(drbg, data->test_data);
Stephan Mueller8c987162014-06-28 21:58:24 +02001812 /* linked list variable is now local to allow modification */
1813 drbg_string_fill(&seed_string, data->addtl->buf,
1814 data->addtl->len);
1815 return drbg_instantiate(drbg, &seed_string, coreref, pr);
Stephan Mueller541af942014-05-31 15:44:17 +02001816 }
1817}
1818
1819/***************************************************************
1820 * Kernel module: code to load the module
1821 ***************************************************************/
1822
1823/*
1824 * Tests as defined in 11.3.2 in addition to the cipher tests: testing
1825 * of the error handling.
1826 *
1827 * Note: testing of failing seed source as defined in 11.3.2 is not applicable
1828 * as seed source of get_random_bytes does not fail.
1829 *
1830 * Note 2: There is no sensible way of testing the reseed counter
1831 * enforcement, so skip it.
1832 */
1833static inline int __init drbg_healthcheck_sanity(void)
1834{
1835#ifdef CONFIG_CRYPTO_FIPS
1836 int len = 0;
1837#define OUTBUFLEN 16
1838 unsigned char buf[OUTBUFLEN];
1839 struct drbg_state *drbg = NULL;
1840 int ret = -EFAULT;
1841 int rc = -EFAULT;
1842 bool pr = false;
1843 int coreref = 0;
1844 struct drbg_string addtl;
1845 size_t max_addtllen, max_request_bytes;
1846
1847 /* only perform test in FIPS mode */
1848 if (!fips_enabled)
1849 return 0;
1850
1851#ifdef CONFIG_CRYPTO_DRBG_CTR
1852 drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref, &pr);
Stephan Muellere25e47e2014-07-06 02:23:03 +02001853#elif defined CONFIG_CRYPTO_DRBG_HASH
Stephan Mueller541af942014-05-31 15:44:17 +02001854 drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr);
1855#else
1856 drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref, &pr);
1857#endif
1858
1859 drbg = kzalloc(sizeof(struct drbg_state), GFP_KERNEL);
1860 if (!drbg)
1861 return -ENOMEM;
1862
1863 /*
1864 * if the following tests fail, it is likely that there is a buffer
1865 * overflow as buf is much smaller than the requested or provided
1866 * string lengths -- in case the error handling does not succeed
1867 * we may get an OOPS. And we want to get an OOPS as this is a
1868 * grave bug.
1869 */
1870
1871 /* get a valid instance of DRBG for following tests */
1872 ret = drbg_instantiate(drbg, NULL, coreref, pr);
1873 if (ret) {
1874 rc = ret;
1875 goto outbuf;
1876 }
1877 max_addtllen = drbg_max_addtl(drbg);
1878 max_request_bytes = drbg_max_request_bytes(drbg);
1879 drbg_string_fill(&addtl, buf, max_addtllen + 1);
1880 /* overflow addtllen with additonal info string */
1881 len = drbg_generate(drbg, buf, OUTBUFLEN, &addtl);
1882 BUG_ON(0 < len);
1883 /* overflow max_bits */
1884 len = drbg_generate(drbg, buf, (max_request_bytes + 1), NULL);
1885 BUG_ON(0 < len);
1886 drbg_uninstantiate(drbg);
1887
1888 /* overflow max addtllen with personalization string */
1889 ret = drbg_instantiate(drbg, &addtl, coreref, pr);
1890 BUG_ON(0 == ret);
Stephan Mueller541af942014-05-31 15:44:17 +02001891 /* all tests passed */
1892 rc = 0;
1893
1894 pr_devel("DRBG: Sanity tests for failure code paths successfully "
1895 "completed\n");
1896
1897 drbg_uninstantiate(drbg);
1898outbuf:
1899 kzfree(drbg);
1900 return rc;
1901#else /* CONFIG_CRYPTO_FIPS */
1902 return 0;
1903#endif /* CONFIG_CRYPTO_FIPS */
1904}
1905
1906static struct crypto_alg drbg_algs[22];
1907
1908/*
1909 * Fill the array drbg_algs used to register the different DRBGs
1910 * with the kernel crypto API. To fill the array, the information
1911 * from drbg_cores[] is used.
1912 */
1913static inline void __init drbg_fill_array(struct crypto_alg *alg,
1914 const struct drbg_core *core, int pr)
1915{
1916 int pos = 0;
1917 static int priority = 100;
1918
1919 memset(alg, 0, sizeof(struct crypto_alg));
1920 memcpy(alg->cra_name, "stdrng", 6);
1921 if (pr) {
1922 memcpy(alg->cra_driver_name, "drbg_pr_", 8);
1923 pos = 8;
1924 } else {
1925 memcpy(alg->cra_driver_name, "drbg_nopr_", 10);
1926 pos = 10;
1927 }
1928 memcpy(alg->cra_driver_name + pos, core->cra_name,
1929 strlen(core->cra_name));
1930
1931 alg->cra_priority = priority;
1932 priority++;
1933 /*
1934 * If FIPS mode enabled, the selected DRBG shall have the
1935 * highest cra_priority over other stdrng instances to ensure
1936 * it is selected.
1937 */
1938 if (fips_enabled)
1939 alg->cra_priority += 200;
1940
1941 alg->cra_flags = CRYPTO_ALG_TYPE_RNG;
1942 alg->cra_ctxsize = sizeof(struct drbg_state);
1943 alg->cra_type = &crypto_rng_type;
1944 alg->cra_module = THIS_MODULE;
1945 alg->cra_init = drbg_kcapi_init;
1946 alg->cra_exit = drbg_kcapi_cleanup;
1947 alg->cra_u.rng.rng_make_random = drbg_kcapi_random;
1948 alg->cra_u.rng.rng_reset = drbg_kcapi_reset;
1949 alg->cra_u.rng.seedsize = 0;
1950}
1951
1952static int __init drbg_init(void)
1953{
1954 unsigned int i = 0; /* pointer to drbg_algs */
1955 unsigned int j = 0; /* pointer to drbg_cores */
1956 int ret = -EFAULT;
1957
1958 ret = drbg_healthcheck_sanity();
1959 if (ret)
1960 return ret;
1961
1962 if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) {
1963 pr_info("DRBG: Cannot register all DRBG types"
Stephan Muellera9089572014-07-06 02:24:03 +02001964 "(slots needed: %zu, slots available: %zu)\n",
Stephan Mueller541af942014-05-31 15:44:17 +02001965 ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs));
1966 return ret;
1967 }
1968
1969 /*
1970 * each DRBG definition can be used with PR and without PR, thus
1971 * we instantiate each DRBG in drbg_cores[] twice.
1972 *
1973 * As the order of placing them into the drbg_algs array matters
1974 * (the later DRBGs receive a higher cra_priority) we register the
1975 * prediction resistance DRBGs first as the should not be too
1976 * interesting.
1977 */
1978 for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++)
1979 drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1);
1980 for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++)
1981 drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0);
1982 return crypto_register_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2));
1983}
1984
Fengguang Wu96956ae2014-07-10 16:52:04 +08001985static void __exit drbg_exit(void)
Stephan Mueller541af942014-05-31 15:44:17 +02001986{
1987 crypto_unregister_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2));
1988}
1989
1990module_init(drbg_init);
1991module_exit(drbg_exit);
Stephan Muellere25e47e2014-07-06 02:23:03 +02001992#ifndef CRYPTO_DRBG_HASH_STRING
1993#define CRYPTO_DRBG_HASH_STRING ""
1994#endif
1995#ifndef CRYPTO_DRBG_HMAC_STRING
1996#define CRYPTO_DRBG_HMAC_STRING ""
1997#endif
1998#ifndef CRYPTO_DRBG_CTR_STRING
1999#define CRYPTO_DRBG_CTR_STRING ""
2000#endif
Stephan Mueller541af942014-05-31 15:44:17 +02002001MODULE_LICENSE("GPL");
2002MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
Stephan Muellere25e47e2014-07-06 02:23:03 +02002003MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) "
2004 "using following cores: "
2005 CRYPTO_DRBG_HASH_STRING
2006 CRYPTO_DRBG_HMAC_STRING
2007 CRYPTO_DRBG_CTR_STRING);