2 * DRBG: Deterministic Random Bits Generator
3 * Based on NIST Recommended DRBG from NIST SP800-90A with the following
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
10 * Copyright Stephan Mueller <smueller@chronox.de>, 2014
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
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
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.)
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
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.
51 * Usage without any additional data
52 * ---------------------------------
53 * struct crypto_rng *drng;
57 * drng = crypto_alloc_rng(drng_name, 0, 0);
58 * err = crypto_rng_get_bytes(drng, &data, DATALEN);
59 * crypto_free_rng(drng);
62 * Usage with personalization string during initialization
63 * -------------------------------------------------------
64 * struct crypto_rng *drng;
67 * struct drbg_string pers;
68 * char personalization[11] = "some-string";
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);
79 * Usage with additional information string during random number request
80 * ---------------------------------------------------------------------
81 * struct crypto_rng *drng;
84 * char addtl_string[11] = "some-string";
85 * string drbg_string addtl;
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);
95 * Usage with personalization and additional information strings
96 * -------------------------------------------------------------
97 * Just mix both scenarios above.
100 #include <crypto/drbg.h>
101 #include <crypto/internal/cipher.h>
102 #include <linux/kernel.h>
103 #include <linux/jiffies.h>
105 /***************************************************************
106 * Backend cipher definitions available to DRBG
107 ***************************************************************/
110 * The order of the DRBG definitions here matter: every DRBG is registered
111 * as stdrng. Each DRBG receives an increasing cra_priority values the later
112 * they are defined in this array (see drbg_fill_array).
114 * HMAC DRBGs are favored over Hash DRBGs over CTR DRBGs, and
115 * the SHA256 / AES 256 over other ciphers. Thus, the favored
116 * DRBGs are the latest entries in this array.
118 static const struct drbg_core drbg_cores
[] = {
119 #ifdef CONFIG_CRYPTO_DRBG_CTR
121 .flags
= DRBG_CTR
| DRBG_STRENGTH128
,
122 .statelen
= 32, /* 256 bits as defined in 10.2.1 */
123 .blocklen_bytes
= 16,
124 .cra_name
= "ctr_aes128",
125 .backend_cra_name
= "aes",
127 .flags
= DRBG_CTR
| DRBG_STRENGTH192
,
128 .statelen
= 40, /* 320 bits as defined in 10.2.1 */
129 .blocklen_bytes
= 16,
130 .cra_name
= "ctr_aes192",
131 .backend_cra_name
= "aes",
133 .flags
= DRBG_CTR
| DRBG_STRENGTH256
,
134 .statelen
= 48, /* 384 bits as defined in 10.2.1 */
135 .blocklen_bytes
= 16,
136 .cra_name
= "ctr_aes256",
137 .backend_cra_name
= "aes",
139 #endif /* CONFIG_CRYPTO_DRBG_CTR */
140 #ifdef CONFIG_CRYPTO_DRBG_HASH
142 .flags
= DRBG_HASH
| DRBG_STRENGTH128
,
143 .statelen
= 55, /* 440 bits */
144 .blocklen_bytes
= 20,
146 .backend_cra_name
= "sha1",
148 .flags
= DRBG_HASH
| DRBG_STRENGTH256
,
149 .statelen
= 111, /* 888 bits */
150 .blocklen_bytes
= 48,
151 .cra_name
= "sha384",
152 .backend_cra_name
= "sha384",
154 .flags
= DRBG_HASH
| DRBG_STRENGTH256
,
155 .statelen
= 111, /* 888 bits */
156 .blocklen_bytes
= 64,
157 .cra_name
= "sha512",
158 .backend_cra_name
= "sha512",
160 .flags
= DRBG_HASH
| DRBG_STRENGTH256
,
161 .statelen
= 55, /* 440 bits */
162 .blocklen_bytes
= 32,
163 .cra_name
= "sha256",
164 .backend_cra_name
= "sha256",
166 #endif /* CONFIG_CRYPTO_DRBG_HASH */
167 #ifdef CONFIG_CRYPTO_DRBG_HMAC
169 .flags
= DRBG_HMAC
| DRBG_STRENGTH128
,
170 .statelen
= 20, /* block length of cipher */
171 .blocklen_bytes
= 20,
172 .cra_name
= "hmac_sha1",
173 .backend_cra_name
= "hmac(sha1)",
175 .flags
= DRBG_HMAC
| DRBG_STRENGTH256
,
176 .statelen
= 48, /* block length of cipher */
177 .blocklen_bytes
= 48,
178 .cra_name
= "hmac_sha384",
179 .backend_cra_name
= "hmac(sha384)",
181 .flags
= DRBG_HMAC
| DRBG_STRENGTH256
,
182 .statelen
= 32, /* block length of cipher */
183 .blocklen_bytes
= 32,
184 .cra_name
= "hmac_sha256",
185 .backend_cra_name
= "hmac(sha256)",
187 .flags
= DRBG_HMAC
| DRBG_STRENGTH256
,
188 .statelen
= 64, /* block length of cipher */
189 .blocklen_bytes
= 64,
190 .cra_name
= "hmac_sha512",
191 .backend_cra_name
= "hmac(sha512)",
193 #endif /* CONFIG_CRYPTO_DRBG_HMAC */
196 static int drbg_uninstantiate(struct drbg_state
*drbg
);
198 /******************************************************************
199 * Generic helper functions
200 ******************************************************************/
203 * Return strength of DRBG according to SP800-90A section 8.4
205 * @flags DRBG flags reference
207 * Return: normalized strength in *bytes* value or 32 as default
208 * to counter programming errors
210 static inline unsigned short drbg_sec_strength(drbg_flag_t flags
)
212 switch (flags
& DRBG_STRENGTH_MASK
) {
213 case DRBG_STRENGTH128
:
215 case DRBG_STRENGTH192
:
217 case DRBG_STRENGTH256
:
225 * FIPS 140-2 continuous self test for the noise source
226 * The test is performed on the noise source input data. Thus, the function
227 * implicitly knows the size of the buffer to be equal to the security
230 * Note, this function disregards the nonce trailing the entropy data during
233 * drbg->drbg_mutex must have been taken.
236 * @entropy buffer of seed data to be checked
240 * -EAGAIN on when the CTRNG is not yet primed
243 static int drbg_fips_continuous_test(struct drbg_state
*drbg
,
244 const unsigned char *entropy
)
246 unsigned short entropylen
= drbg_sec_strength(drbg
->core
->flags
);
249 if (!IS_ENABLED(CONFIG_CRYPTO_FIPS
))
252 /* skip test if we test the overall system */
253 if (list_empty(&drbg
->test_data
.list
))
255 /* only perform test in FIPS mode */
259 if (!drbg
->fips_primed
) {
260 /* Priming of FIPS test */
261 memcpy(drbg
->prev
, entropy
, entropylen
);
262 drbg
->fips_primed
= true;
263 /* priming: another round is needed */
266 ret
= memcmp(drbg
->prev
, entropy
, entropylen
);
268 panic("DRBG continuous self test failed\n");
269 memcpy(drbg
->prev
, entropy
, entropylen
);
271 /* the test shall pass when the two values are not equal */
276 * Convert an integer into a byte representation of this integer.
277 * The byte representation is big-endian
279 * @val value to be converted
280 * @buf buffer holding the converted integer -- caller must ensure that
281 * buffer size is at least 32 bit
283 #if (defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR))
284 static inline void drbg_cpu_to_be32(__u32 val
, unsigned char *buf
)
289 struct s
*conversion
= (struct s
*) buf
;
291 conversion
->conv
= cpu_to_be32(val
);
293 #endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */
295 /******************************************************************
296 * CTR DRBG callback functions
297 ******************************************************************/
299 #ifdef CONFIG_CRYPTO_DRBG_CTR
300 #define CRYPTO_DRBG_CTR_STRING "CTR "
301 MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes256");
302 MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes256");
303 MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes192");
304 MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes192");
305 MODULE_ALIAS_CRYPTO("drbg_pr_ctr_aes128");
306 MODULE_ALIAS_CRYPTO("drbg_nopr_ctr_aes128");
308 static void drbg_kcapi_symsetkey(struct drbg_state
*drbg
,
309 const unsigned char *key
);
310 static int drbg_kcapi_sym(struct drbg_state
*drbg
, unsigned char *outval
,
311 const struct drbg_string
*in
);
312 static int drbg_init_sym_kernel(struct drbg_state
*drbg
);
313 static int drbg_fini_sym_kernel(struct drbg_state
*drbg
);
314 static int drbg_kcapi_sym_ctr(struct drbg_state
*drbg
,
315 u8
*inbuf
, u32 inbuflen
,
316 u8
*outbuf
, u32 outlen
);
317 #define DRBG_OUTSCRATCHLEN 256
319 /* BCC function for CTR DRBG as defined in 10.4.3 */
320 static int drbg_ctr_bcc(struct drbg_state
*drbg
,
321 unsigned char *out
, const unsigned char *key
,
322 struct list_head
*in
)
325 struct drbg_string
*curr
= NULL
;
326 struct drbg_string data
;
329 drbg_string_fill(&data
, out
, drbg_blocklen(drbg
));
331 /* 10.4.3 step 2 / 4 */
332 drbg_kcapi_symsetkey(drbg
, key
);
333 list_for_each_entry(curr
, in
, list
) {
334 const unsigned char *pos
= curr
->buf
;
335 size_t len
= curr
->len
;
336 /* 10.4.3 step 4.1 */
338 /* 10.4.3 step 4.2 */
339 if (drbg_blocklen(drbg
) == cnt
) {
341 ret
= drbg_kcapi_sym(drbg
, out
, &data
);
351 /* 10.4.3 step 4.2 for last block */
353 ret
= drbg_kcapi_sym(drbg
, out
, &data
);
359 * scratchpad usage: drbg_ctr_update is interlinked with drbg_ctr_df
360 * (and drbg_ctr_bcc, but this function does not need any temporary buffers),
361 * the scratchpad is used as follows:
364 * start: drbg->scratchpad
365 * length: drbg_statelen(drbg) + drbg_blocklen(drbg)
366 * note: the cipher writing into this variable works
367 * blocklen-wise. Now, when the statelen is not a multiple
368 * of blocklen, the generateion loop below "spills over"
369 * by at most blocklen. Thus, we need to give sufficient
372 * start: drbg->scratchpad +
373 * drbg_statelen(drbg) + drbg_blocklen(drbg)
374 * length: drbg_statelen(drbg)
378 * start: df_data + drbg_statelen(drbg)
379 * length: drbg_blocklen(drbg)
381 * start: pad + drbg_blocklen(drbg)
382 * length: drbg_blocklen(drbg)
384 * start: iv + drbg_blocklen(drbg)
385 * length: drbg_satelen(drbg) + drbg_blocklen(drbg)
386 * note: temp is the buffer that the BCC function operates
387 * on. BCC operates blockwise. drbg_statelen(drbg)
388 * is sufficient when the DRBG state length is a multiple
389 * of the block size. For AES192 (and maybe other ciphers)
390 * this is not correct and the length for temp is
391 * insufficient (yes, that also means for such ciphers,
392 * the final output of all BCC rounds are truncated).
393 * Therefore, add drbg_blocklen(drbg) to cover all
397 /* Derivation Function for CTR DRBG as defined in 10.4.2 */
398 static int drbg_ctr_df(struct drbg_state
*drbg
,
399 unsigned char *df_data
, size_t bytes_to_return
,
400 struct list_head
*seedlist
)
403 unsigned char L_N
[8];
405 struct drbg_string S1
, S2
, S4
, cipherin
;
407 unsigned char *pad
= df_data
+ drbg_statelen(drbg
);
408 unsigned char *iv
= pad
+ drbg_blocklen(drbg
);
409 unsigned char *temp
= iv
+ drbg_blocklen(drbg
);
411 unsigned int templen
= 0;
415 const unsigned char *K
= (unsigned char *)
416 "\x00\x01\x02\x03\x04\x05\x06\x07"
417 "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
418 "\x10\x11\x12\x13\x14\x15\x16\x17"
419 "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f";
421 size_t generated_len
= 0;
423 struct drbg_string
*seed
= NULL
;
425 memset(pad
, 0, drbg_blocklen(drbg
));
426 memset(iv
, 0, drbg_blocklen(drbg
));
428 /* 10.4.2 step 1 is implicit as we work byte-wise */
431 if ((512/8) < bytes_to_return
)
434 /* 10.4.2 step 2 -- calculate the entire length of all input data */
435 list_for_each_entry(seed
, seedlist
, list
)
436 inputlen
+= seed
->len
;
437 drbg_cpu_to_be32(inputlen
, &L_N
[0]);
440 drbg_cpu_to_be32(bytes_to_return
, &L_N
[4]);
442 /* 10.4.2 step 5: length is L_N, input_string, one byte, padding */
443 padlen
= (inputlen
+ sizeof(L_N
) + 1) % (drbg_blocklen(drbg
));
444 /* wrap the padlen appropriately */
446 padlen
= drbg_blocklen(drbg
) - padlen
;
448 * pad / padlen contains the 0x80 byte and the following zero bytes.
449 * As the calculated padlen value only covers the number of zero
450 * bytes, this value has to be incremented by one for the 0x80 byte.
455 /* 10.4.2 step 4 -- first fill the linked list and then order it */
456 drbg_string_fill(&S1
, iv
, drbg_blocklen(drbg
));
457 list_add_tail(&S1
.list
, &bcc_list
);
458 drbg_string_fill(&S2
, L_N
, sizeof(L_N
));
459 list_add_tail(&S2
.list
, &bcc_list
);
460 list_splice_tail(seedlist
, &bcc_list
);
461 drbg_string_fill(&S4
, pad
, padlen
);
462 list_add_tail(&S4
.list
, &bcc_list
);
465 while (templen
< (drbg_keylen(drbg
) + (drbg_blocklen(drbg
)))) {
467 * 10.4.2 step 9.1 - the padding is implicit as the buffer
468 * holds zeros after allocation -- even the increment of i
469 * is irrelevant as the increment remains within length of i
471 drbg_cpu_to_be32(i
, iv
);
472 /* 10.4.2 step 9.2 -- BCC and concatenation with temp */
473 ret
= drbg_ctr_bcc(drbg
, temp
+ templen
, K
, &bcc_list
);
476 /* 10.4.2 step 9.3 */
478 templen
+= drbg_blocklen(drbg
);
482 X
= temp
+ (drbg_keylen(drbg
));
483 drbg_string_fill(&cipherin
, X
, drbg_blocklen(drbg
));
485 /* 10.4.2 step 12: overwriting of outval is implemented in next step */
488 drbg_kcapi_symsetkey(drbg
, temp
);
489 while (generated_len
< bytes_to_return
) {
492 * 10.4.2 step 13.1: the truncation of the key length is
493 * implicit as the key is only drbg_blocklen in size based on
494 * the implementation of the cipher function callback
496 ret
= drbg_kcapi_sym(drbg
, X
, &cipherin
);
499 blocklen
= (drbg_blocklen(drbg
) <
500 (bytes_to_return
- generated_len
)) ?
501 drbg_blocklen(drbg
) :
502 (bytes_to_return
- generated_len
);
503 /* 10.4.2 step 13.2 and 14 */
504 memcpy(df_data
+ generated_len
, X
, blocklen
);
505 generated_len
+= blocklen
;
511 memset(iv
, 0, drbg_blocklen(drbg
));
512 memset(temp
, 0, drbg_statelen(drbg
) + drbg_blocklen(drbg
));
513 memset(pad
, 0, drbg_blocklen(drbg
));
518 * update function of CTR DRBG as defined in 10.2.1.2
520 * The reseed variable has an enhanced meaning compared to the update
521 * functions of the other DRBGs as follows:
522 * 0 => initial seed from initialization
523 * 1 => reseed via drbg_seed
524 * 2 => first invocation from drbg_ctr_update when addtl is present. In
525 * this case, the df_data scratchpad is not deleted so that it is
526 * available for another calls to prevent calling the DF function
528 * 3 => second invocation from drbg_ctr_update. When the update function
529 * was called with addtl, the df_data memory already contains the
530 * DFed addtl information and we do not need to call DF again.
532 static int drbg_ctr_update(struct drbg_state
*drbg
, struct list_head
*seed
,
536 /* 10.2.1.2 step 1 */
537 unsigned char *temp
= drbg
->scratchpad
;
538 unsigned char *df_data
= drbg
->scratchpad
+ drbg_statelen(drbg
) +
542 memset(df_data
, 0, drbg_statelen(drbg
));
546 * The DRBG uses the CTR mode of the underlying AES cipher. The
547 * CTR mode increments the counter value after the AES operation
548 * but SP800-90A requires that the counter is incremented before
549 * the AES operation. Hence, we increment it at the time we set
552 crypto_inc(drbg
->V
, drbg_blocklen(drbg
));
554 ret
= crypto_skcipher_setkey(drbg
->ctr_handle
, drbg
->C
,
560 /* 10.2.1.3.2 step 2 and 10.2.1.4.2 step 2 */
562 ret
= drbg_ctr_df(drbg
, df_data
, drbg_statelen(drbg
), seed
);
567 ret
= drbg_kcapi_sym_ctr(drbg
, df_data
, drbg_statelen(drbg
),
568 temp
, drbg_statelen(drbg
));
572 /* 10.2.1.2 step 5 */
573 ret
= crypto_skcipher_setkey(drbg
->ctr_handle
, temp
,
577 /* 10.2.1.2 step 6 */
578 memcpy(drbg
->V
, temp
+ drbg_keylen(drbg
), drbg_blocklen(drbg
));
579 /* See above: increment counter by one to compensate timing of CTR op */
580 crypto_inc(drbg
->V
, drbg_blocklen(drbg
));
584 memset(temp
, 0, drbg_statelen(drbg
) + drbg_blocklen(drbg
));
586 memset(df_data
, 0, drbg_statelen(drbg
));
591 * scratchpad use: drbg_ctr_update is called independently from
592 * drbg_ctr_extract_bytes. Therefore, the scratchpad is reused
594 /* Generate function of CTR DRBG as defined in 10.2.1.5.2 */
595 static int drbg_ctr_generate(struct drbg_state
*drbg
,
596 unsigned char *buf
, unsigned int buflen
,
597 struct list_head
*addtl
)
600 int len
= min_t(int, buflen
, INT_MAX
);
602 /* 10.2.1.5.2 step 2 */
603 if (addtl
&& !list_empty(addtl
)) {
604 ret
= drbg_ctr_update(drbg
, addtl
, 2);
609 /* 10.2.1.5.2 step 4.1 */
610 ret
= drbg_kcapi_sym_ctr(drbg
, NULL
, 0, buf
, len
);
614 /* 10.2.1.5.2 step 6 */
615 ret
= drbg_ctr_update(drbg
, NULL
, 3);
622 static const struct drbg_state_ops drbg_ctr_ops
= {
623 .update
= drbg_ctr_update
,
624 .generate
= drbg_ctr_generate
,
625 .crypto_init
= drbg_init_sym_kernel
,
626 .crypto_fini
= drbg_fini_sym_kernel
,
628 #endif /* CONFIG_CRYPTO_DRBG_CTR */
630 /******************************************************************
631 * HMAC DRBG callback functions
632 ******************************************************************/
634 #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
635 static int drbg_kcapi_hash(struct drbg_state
*drbg
, unsigned char *outval
,
636 const struct list_head
*in
);
637 static void drbg_kcapi_hmacsetkey(struct drbg_state
*drbg
,
638 const unsigned char *key
);
639 static int drbg_init_hash_kernel(struct drbg_state
*drbg
);
640 static int drbg_fini_hash_kernel(struct drbg_state
*drbg
);
641 #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
643 #ifdef CONFIG_CRYPTO_DRBG_HMAC
644 #define CRYPTO_DRBG_HMAC_STRING "HMAC "
645 MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512");
646 MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512");
647 MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha384");
648 MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha384");
649 MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha256");
650 MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha256");
651 MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha1");
652 MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha1");
654 /* update function of HMAC DRBG as defined in 10.1.2.2 */
655 static int drbg_hmac_update(struct drbg_state
*drbg
, struct list_head
*seed
,
660 struct drbg_string seed1
, seed2
, vdata
;
662 LIST_HEAD(vdatalist
);
665 /* 10.1.2.3 step 2 -- memset(0) of C is implicit with kzalloc */
666 memset(drbg
->V
, 1, drbg_statelen(drbg
));
667 drbg_kcapi_hmacsetkey(drbg
, drbg
->C
);
670 drbg_string_fill(&seed1
, drbg
->V
, drbg_statelen(drbg
));
671 list_add_tail(&seed1
.list
, &seedlist
);
672 /* buffer of seed2 will be filled in for loop below with one byte */
673 drbg_string_fill(&seed2
, NULL
, 1);
674 list_add_tail(&seed2
.list
, &seedlist
);
675 /* input data of seed is allowed to be NULL at this point */
677 list_splice_tail(seed
, &seedlist
);
679 drbg_string_fill(&vdata
, drbg
->V
, drbg_statelen(drbg
));
680 list_add_tail(&vdata
.list
, &vdatalist
);
681 for (i
= 2; 0 < i
; i
--) {
682 /* first round uses 0x0, second 0x1 */
683 unsigned char prefix
= DRBG_PREFIX0
;
685 prefix
= DRBG_PREFIX1
;
686 /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */
688 ret
= drbg_kcapi_hash(drbg
, drbg
->C
, &seedlist
);
691 drbg_kcapi_hmacsetkey(drbg
, drbg
->C
);
693 /* 10.1.2.2 step 2 and 5 -- HMAC for V */
694 ret
= drbg_kcapi_hash(drbg
, drbg
->V
, &vdatalist
);
698 /* 10.1.2.2 step 3 */
706 /* generate function of HMAC DRBG as defined in 10.1.2.5 */
707 static int drbg_hmac_generate(struct drbg_state
*drbg
,
710 struct list_head
*addtl
)
714 struct drbg_string data
;
717 /* 10.1.2.5 step 2 */
718 if (addtl
&& !list_empty(addtl
)) {
719 ret
= drbg_hmac_update(drbg
, addtl
, 1);
724 drbg_string_fill(&data
, drbg
->V
, drbg_statelen(drbg
));
725 list_add_tail(&data
.list
, &datalist
);
726 while (len
< buflen
) {
727 unsigned int outlen
= 0;
728 /* 10.1.2.5 step 4.1 */
729 ret
= drbg_kcapi_hash(drbg
, drbg
->V
, &datalist
);
732 outlen
= (drbg_blocklen(drbg
) < (buflen
- len
)) ?
733 drbg_blocklen(drbg
) : (buflen
- len
);
735 /* 10.1.2.5 step 4.2 */
736 memcpy(buf
+ len
, drbg
->V
, outlen
);
740 /* 10.1.2.5 step 6 */
741 if (addtl
&& !list_empty(addtl
))
742 ret
= drbg_hmac_update(drbg
, addtl
, 1);
744 ret
= drbg_hmac_update(drbg
, NULL
, 1);
751 static const struct drbg_state_ops drbg_hmac_ops
= {
752 .update
= drbg_hmac_update
,
753 .generate
= drbg_hmac_generate
,
754 .crypto_init
= drbg_init_hash_kernel
,
755 .crypto_fini
= drbg_fini_hash_kernel
,
757 #endif /* CONFIG_CRYPTO_DRBG_HMAC */
759 /******************************************************************
760 * Hash DRBG callback functions
761 ******************************************************************/
763 #ifdef CONFIG_CRYPTO_DRBG_HASH
764 #define CRYPTO_DRBG_HASH_STRING "HASH "
765 MODULE_ALIAS_CRYPTO("drbg_pr_sha512");
766 MODULE_ALIAS_CRYPTO("drbg_nopr_sha512");
767 MODULE_ALIAS_CRYPTO("drbg_pr_sha384");
768 MODULE_ALIAS_CRYPTO("drbg_nopr_sha384");
769 MODULE_ALIAS_CRYPTO("drbg_pr_sha256");
770 MODULE_ALIAS_CRYPTO("drbg_nopr_sha256");
771 MODULE_ALIAS_CRYPTO("drbg_pr_sha1");
772 MODULE_ALIAS_CRYPTO("drbg_nopr_sha1");
777 * @dst buffer to increment
780 static inline void drbg_add_buf(unsigned char *dst
, size_t dstlen
,
781 const unsigned char *add
, size_t addlen
)
783 /* implied: dstlen > addlen */
784 unsigned char *dstptr
;
785 const unsigned char *addptr
;
786 unsigned int remainder
= 0;
789 dstptr
= dst
+ (dstlen
-1);
790 addptr
= add
+ (addlen
-1);
792 remainder
+= *dstptr
+ *addptr
;
793 *dstptr
= remainder
& 0xff;
795 len
--; dstptr
--; addptr
--;
797 len
= dstlen
- addlen
;
798 while (len
&& remainder
> 0) {
799 remainder
= *dstptr
+ 1;
800 *dstptr
= remainder
& 0xff;
807 * scratchpad usage: as drbg_hash_update and drbg_hash_df are used
808 * interlinked, the scratchpad is used as follows:
810 * start: drbg->scratchpad
811 * length: drbg_statelen(drbg)
813 * start: drbg->scratchpad + drbg_statelen(drbg)
814 * length: drbg_blocklen(drbg)
816 * drbg_hash_process_addtl uses the scratchpad, but fully completes
817 * before either of the functions mentioned before are invoked. Therefore,
818 * drbg_hash_process_addtl does not need to be specifically considered.
821 /* Derivation Function for Hash DRBG as defined in 10.4.1 */
822 static int drbg_hash_df(struct drbg_state
*drbg
,
823 unsigned char *outval
, size_t outlen
,
824 struct list_head
*entropylist
)
828 unsigned char input
[5];
829 unsigned char *tmp
= drbg
->scratchpad
+ drbg_statelen(drbg
);
830 struct drbg_string data
;
834 drbg_cpu_to_be32((outlen
* 8), &input
[1]);
836 /* 10.4.1 step 4.1 -- concatenation of data for input into hash */
837 drbg_string_fill(&data
, input
, 5);
838 list_add(&data
.list
, entropylist
);
841 while (len
< outlen
) {
843 /* 10.4.1 step 4.1 */
844 ret
= drbg_kcapi_hash(drbg
, tmp
, entropylist
);
847 /* 10.4.1 step 4.2 */
849 blocklen
= (drbg_blocklen(drbg
) < (outlen
- len
)) ?
850 drbg_blocklen(drbg
) : (outlen
- len
);
851 memcpy(outval
+ len
, tmp
, blocklen
);
856 memset(tmp
, 0, drbg_blocklen(drbg
));
860 /* update function for Hash DRBG as defined in 10.1.1.2 / 10.1.1.3 */
861 static int drbg_hash_update(struct drbg_state
*drbg
, struct list_head
*seed
,
865 struct drbg_string data1
, data2
;
867 LIST_HEAD(datalist2
);
868 unsigned char *V
= drbg
->scratchpad
;
869 unsigned char prefix
= DRBG_PREFIX1
;
875 /* 10.1.1.3 step 1 */
876 memcpy(V
, drbg
->V
, drbg_statelen(drbg
));
877 drbg_string_fill(&data1
, &prefix
, 1);
878 list_add_tail(&data1
.list
, &datalist
);
879 drbg_string_fill(&data2
, V
, drbg_statelen(drbg
));
880 list_add_tail(&data2
.list
, &datalist
);
882 list_splice_tail(seed
, &datalist
);
884 /* 10.1.1.2 / 10.1.1.3 step 2 and 3 */
885 ret
= drbg_hash_df(drbg
, drbg
->V
, drbg_statelen(drbg
), &datalist
);
889 /* 10.1.1.2 / 10.1.1.3 step 4 */
890 prefix
= DRBG_PREFIX0
;
891 drbg_string_fill(&data1
, &prefix
, 1);
892 list_add_tail(&data1
.list
, &datalist2
);
893 drbg_string_fill(&data2
, drbg
->V
, drbg_statelen(drbg
));
894 list_add_tail(&data2
.list
, &datalist2
);
895 /* 10.1.1.2 / 10.1.1.3 step 4 */
896 ret
= drbg_hash_df(drbg
, drbg
->C
, drbg_statelen(drbg
), &datalist2
);
899 memset(drbg
->scratchpad
, 0, drbg_statelen(drbg
));
903 /* processing of additional information string for Hash DRBG */
904 static int drbg_hash_process_addtl(struct drbg_state
*drbg
,
905 struct list_head
*addtl
)
908 struct drbg_string data1
, data2
;
910 unsigned char prefix
= DRBG_PREFIX2
;
912 /* 10.1.1.4 step 2 */
913 if (!addtl
|| list_empty(addtl
))
916 /* 10.1.1.4 step 2a */
917 drbg_string_fill(&data1
, &prefix
, 1);
918 drbg_string_fill(&data2
, drbg
->V
, drbg_statelen(drbg
));
919 list_add_tail(&data1
.list
, &datalist
);
920 list_add_tail(&data2
.list
, &datalist
);
921 list_splice_tail(addtl
, &datalist
);
922 ret
= drbg_kcapi_hash(drbg
, drbg
->scratchpad
, &datalist
);
926 /* 10.1.1.4 step 2b */
927 drbg_add_buf(drbg
->V
, drbg_statelen(drbg
),
928 drbg
->scratchpad
, drbg_blocklen(drbg
));
931 memset(drbg
->scratchpad
, 0, drbg_blocklen(drbg
));
935 /* Hashgen defined in 10.1.1.4 */
936 static int drbg_hash_hashgen(struct drbg_state
*drbg
,
942 unsigned char *src
= drbg
->scratchpad
;
943 unsigned char *dst
= drbg
->scratchpad
+ drbg_statelen(drbg
);
944 struct drbg_string data
;
947 /* 10.1.1.4 step hashgen 2 */
948 memcpy(src
, drbg
->V
, drbg_statelen(drbg
));
950 drbg_string_fill(&data
, src
, drbg_statelen(drbg
));
951 list_add_tail(&data
.list
, &datalist
);
952 while (len
< buflen
) {
953 unsigned int outlen
= 0;
954 /* 10.1.1.4 step hashgen 4.1 */
955 ret
= drbg_kcapi_hash(drbg
, dst
, &datalist
);
960 outlen
= (drbg_blocklen(drbg
) < (buflen
- len
)) ?
961 drbg_blocklen(drbg
) : (buflen
- len
);
962 /* 10.1.1.4 step hashgen 4.2 */
963 memcpy(buf
+ len
, dst
, outlen
);
965 /* 10.1.1.4 hashgen step 4.3 */
967 crypto_inc(src
, drbg_statelen(drbg
));
971 memset(drbg
->scratchpad
, 0,
972 (drbg_statelen(drbg
) + drbg_blocklen(drbg
)));
976 /* generate function for Hash DRBG as defined in 10.1.1.4 */
977 static int drbg_hash_generate(struct drbg_state
*drbg
,
978 unsigned char *buf
, unsigned int buflen
,
979 struct list_head
*addtl
)
984 unsigned char req
[8];
987 unsigned char prefix
= DRBG_PREFIX3
;
988 struct drbg_string data1
, data2
;
991 /* 10.1.1.4 step 2 */
992 ret
= drbg_hash_process_addtl(drbg
, addtl
);
995 /* 10.1.1.4 step 3 */
996 len
= drbg_hash_hashgen(drbg
, buf
, buflen
);
998 /* this is the value H as documented in 10.1.1.4 */
999 /* 10.1.1.4 step 4 */
1000 drbg_string_fill(&data1
, &prefix
, 1);
1001 list_add_tail(&data1
.list
, &datalist
);
1002 drbg_string_fill(&data2
, drbg
->V
, drbg_statelen(drbg
));
1003 list_add_tail(&data2
.list
, &datalist
);
1004 ret
= drbg_kcapi_hash(drbg
, drbg
->scratchpad
, &datalist
);
1010 /* 10.1.1.4 step 5 */
1011 drbg_add_buf(drbg
->V
, drbg_statelen(drbg
),
1012 drbg
->scratchpad
, drbg_blocklen(drbg
));
1013 drbg_add_buf(drbg
->V
, drbg_statelen(drbg
),
1014 drbg
->C
, drbg_statelen(drbg
));
1015 u
.req_int
= cpu_to_be64(drbg
->reseed_ctr
);
1016 drbg_add_buf(drbg
->V
, drbg_statelen(drbg
), u
.req
, 8);
1019 memset(drbg
->scratchpad
, 0, drbg_blocklen(drbg
));
1024 * scratchpad usage: as update and generate are used isolated, both
1025 * can use the scratchpad
1027 static const struct drbg_state_ops drbg_hash_ops
= {
1028 .update
= drbg_hash_update
,
1029 .generate
= drbg_hash_generate
,
1030 .crypto_init
= drbg_init_hash_kernel
,
1031 .crypto_fini
= drbg_fini_hash_kernel
,
1033 #endif /* CONFIG_CRYPTO_DRBG_HASH */
1035 /******************************************************************
1036 * Functions common for DRBG implementations
1037 ******************************************************************/
1039 static inline int __drbg_seed(struct drbg_state
*drbg
, struct list_head
*seed
,
1040 int reseed
, enum drbg_seed_state new_seed_state
)
1042 int ret
= drbg
->d_ops
->update(drbg
, seed
, reseed
);
1047 drbg
->seeded
= new_seed_state
;
1048 drbg
->last_seed_time
= jiffies
;
1049 /* 10.1.1.2 / 10.1.1.3 step 5 */
1050 drbg
->reseed_ctr
= 1;
1052 switch (drbg
->seeded
) {
1053 case DRBG_SEED_STATE_UNSEEDED
:
1054 /* Impossible, but handle it to silence compiler warnings. */
1056 case DRBG_SEED_STATE_PARTIAL
:
1058 * Require frequent reseeds until the seed source is
1059 * fully initialized.
1061 drbg
->reseed_threshold
= 50;
1064 case DRBG_SEED_STATE_FULL
:
1066 * Seed source has become fully initialized, frequent
1067 * reseeds no longer required.
1069 drbg
->reseed_threshold
= drbg_max_requests(drbg
);
1076 static inline int drbg_get_random_bytes(struct drbg_state
*drbg
,
1077 unsigned char *entropy
,
1078 unsigned int entropylen
)
1083 get_random_bytes(entropy
, entropylen
);
1084 ret
= drbg_fips_continuous_test(drbg
, entropy
);
1085 if (ret
&& ret
!= -EAGAIN
)
1092 static int drbg_seed_from_random(struct drbg_state
*drbg
)
1094 struct drbg_string data
;
1095 LIST_HEAD(seedlist
);
1096 unsigned int entropylen
= drbg_sec_strength(drbg
->core
->flags
);
1097 unsigned char entropy
[32];
1100 BUG_ON(!entropylen
);
1101 BUG_ON(entropylen
> sizeof(entropy
));
1103 drbg_string_fill(&data
, entropy
, entropylen
);
1104 list_add_tail(&data
.list
, &seedlist
);
1106 ret
= drbg_get_random_bytes(drbg
, entropy
, entropylen
);
1110 ret
= __drbg_seed(drbg
, &seedlist
, true, DRBG_SEED_STATE_FULL
);
1113 memzero_explicit(entropy
, entropylen
);
1117 static bool drbg_nopr_reseed_interval_elapsed(struct drbg_state
*drbg
)
1119 unsigned long next_reseed
;
1121 /* Don't ever reseed from get_random_bytes() in test mode. */
1122 if (list_empty(&drbg
->test_data
.list
))
1126 * Obtain fresh entropy for the nopr DRBGs after 300s have
1127 * elapsed in order to still achieve sort of partial
1128 * prediction resistance over the time domain at least. Note
1129 * that the period of 300s has been chosen to match the
1130 * CRNG_RESEED_INTERVAL of the get_random_bytes()' chacha
1133 next_reseed
= drbg
->last_seed_time
+ 300 * HZ
;
1134 return time_after(jiffies
, next_reseed
);
1138 * Seeding or reseeding of the DRBG
1140 * @drbg: DRBG state struct
1141 * @pers: personalization / additional information buffer
1142 * @reseed: 0 for initial seed process, 1 for reseeding
1146 * error value otherwise
1148 static int drbg_seed(struct drbg_state
*drbg
, struct drbg_string
*pers
,
1152 unsigned char entropy
[((32 + 16) * 2)];
1153 unsigned int entropylen
= drbg_sec_strength(drbg
->core
->flags
);
1154 struct drbg_string data1
;
1155 LIST_HEAD(seedlist
);
1156 enum drbg_seed_state new_seed_state
= DRBG_SEED_STATE_FULL
;
1158 /* 9.1 / 9.2 / 9.3.1 step 3 */
1159 if (pers
&& pers
->len
> (drbg_max_addtl(drbg
))) {
1160 pr_devel("DRBG: personalization string too long %zu\n",
1165 if (list_empty(&drbg
->test_data
.list
)) {
1166 drbg_string_fill(&data1
, drbg
->test_data
.buf
,
1167 drbg
->test_data
.len
);
1168 pr_devel("DRBG: using test entropy\n");
1171 * Gather entropy equal to the security strength of the DRBG.
1172 * With a derivation function, a nonce is required in addition
1173 * to the entropy. A nonce must be at least 1/2 of the security
1174 * strength of the DRBG in size. Thus, entropy + nonce is 3/2
1175 * of the strength. The consideration of a nonce is only
1176 * applicable during initial seeding.
1178 BUG_ON(!entropylen
);
1180 entropylen
= ((entropylen
+ 1) / 2) * 3;
1181 BUG_ON((entropylen
* 2) > sizeof(entropy
));
1183 /* Get seed from in-kernel /dev/urandom */
1184 if (!rng_is_initialized())
1185 new_seed_state
= DRBG_SEED_STATE_PARTIAL
;
1187 ret
= drbg_get_random_bytes(drbg
, entropy
, entropylen
);
1192 drbg_string_fill(&data1
, entropy
, entropylen
);
1193 pr_devel("DRBG: (re)seeding with %u bytes of entropy\n",
1197 * Get seed from Jitter RNG, failures are
1198 * fatal only in FIPS mode.
1200 ret
= crypto_rng_get_bytes(drbg
->jent
,
1201 entropy
+ entropylen
,
1203 if (fips_enabled
&& ret
) {
1204 pr_devel("DRBG: jent failed with %d\n", ret
);
1207 * Do not treat the transient failure of the
1208 * Jitter RNG as an error that needs to be
1209 * reported. The combined number of the
1210 * maximum reseed threshold times the maximum
1211 * number of Jitter RNG transient errors is
1212 * less than the reseed threshold required by
1213 * SP800-90A allowing us to treat the
1214 * transient errors as such.
1216 * However, we mandate that at least the first
1217 * seeding operation must succeed with the
1220 if (!reseed
|| ret
!= -EAGAIN
)
1224 drbg_string_fill(&data1
, entropy
, entropylen
* 2);
1225 pr_devel("DRBG: (re)seeding with %u bytes of entropy\n",
1229 list_add_tail(&data1
.list
, &seedlist
);
1232 * concatenation of entropy with personalization str / addtl input)
1233 * the variable pers is directly handed in by the caller, so check its
1234 * contents whether it is appropriate
1236 if (pers
&& pers
->buf
&& 0 < pers
->len
) {
1237 list_add_tail(&pers
->list
, &seedlist
);
1238 pr_devel("DRBG: using personalization string\n");
1242 memset(drbg
->V
, 0, drbg_statelen(drbg
));
1243 memset(drbg
->C
, 0, drbg_statelen(drbg
));
1246 ret
= __drbg_seed(drbg
, &seedlist
, reseed
, new_seed_state
);
1249 memzero_explicit(entropy
, entropylen
* 2);
1254 /* Free all substructures in a DRBG state without the DRBG state structure */
1255 static inline void drbg_dealloc_state(struct drbg_state
*drbg
)
1259 kfree_sensitive(drbg
->Vbuf
);
1262 kfree_sensitive(drbg
->Cbuf
);
1265 kfree_sensitive(drbg
->scratchpadbuf
);
1266 drbg
->scratchpadbuf
= NULL
;
1267 drbg
->reseed_ctr
= 0;
1270 if (IS_ENABLED(CONFIG_CRYPTO_FIPS
)) {
1271 kfree_sensitive(drbg
->prev
);
1273 drbg
->fips_primed
= false;
1278 * Allocate all sub-structures for a DRBG state.
1279 * The DRBG state structure must already be allocated.
1281 static inline int drbg_alloc_state(struct drbg_state
*drbg
)
1284 unsigned int sb_size
= 0;
1286 switch (drbg
->core
->flags
& DRBG_TYPE_MASK
) {
1287 #ifdef CONFIG_CRYPTO_DRBG_HMAC
1289 drbg
->d_ops
= &drbg_hmac_ops
;
1291 #endif /* CONFIG_CRYPTO_DRBG_HMAC */
1292 #ifdef CONFIG_CRYPTO_DRBG_HASH
1294 drbg
->d_ops
= &drbg_hash_ops
;
1296 #endif /* CONFIG_CRYPTO_DRBG_HASH */
1297 #ifdef CONFIG_CRYPTO_DRBG_CTR
1299 drbg
->d_ops
= &drbg_ctr_ops
;
1301 #endif /* CONFIG_CRYPTO_DRBG_CTR */
1307 ret
= drbg
->d_ops
->crypto_init(drbg
);
1311 drbg
->Vbuf
= kmalloc(drbg_statelen(drbg
) + ret
, GFP_KERNEL
);
1316 drbg
->V
= PTR_ALIGN(drbg
->Vbuf
, ret
+ 1);
1317 drbg
->Cbuf
= kmalloc(drbg_statelen(drbg
) + ret
, GFP_KERNEL
);
1322 drbg
->C
= PTR_ALIGN(drbg
->Cbuf
, ret
+ 1);
1323 /* scratchpad is only generated for CTR and Hash */
1324 if (drbg
->core
->flags
& DRBG_HMAC
)
1326 else if (drbg
->core
->flags
& DRBG_CTR
)
1327 sb_size
= drbg_statelen(drbg
) + drbg_blocklen(drbg
) + /* temp */
1328 drbg_statelen(drbg
) + /* df_data */
1329 drbg_blocklen(drbg
) + /* pad */
1330 drbg_blocklen(drbg
) + /* iv */
1331 drbg_statelen(drbg
) + drbg_blocklen(drbg
); /* temp */
1333 sb_size
= drbg_statelen(drbg
) + drbg_blocklen(drbg
);
1336 drbg
->scratchpadbuf
= kzalloc(sb_size
+ ret
, GFP_KERNEL
);
1337 if (!drbg
->scratchpadbuf
) {
1341 drbg
->scratchpad
= PTR_ALIGN(drbg
->scratchpadbuf
, ret
+ 1);
1344 if (IS_ENABLED(CONFIG_CRYPTO_FIPS
)) {
1345 drbg
->prev
= kzalloc(drbg_sec_strength(drbg
->core
->flags
),
1351 drbg
->fips_primed
= false;
1357 drbg
->d_ops
->crypto_fini(drbg
);
1359 drbg_dealloc_state(drbg
);
1363 /*************************************************************************
1364 * DRBG interface functions
1365 *************************************************************************/
1368 * DRBG generate function as required by SP800-90A - this function
1369 * generates random numbers
1371 * @drbg DRBG state handle
1372 * @buf Buffer where to store the random numbers -- the buffer must already
1373 * be pre-allocated by caller
1374 * @buflen Length of output buffer - this value defines the number of random
1375 * bytes pulled from DRBG
1376 * @addtl Additional input that is mixed into state, may be NULL -- note
1377 * the entropy is pulled by the DRBG internally unconditionally
1378 * as defined in SP800-90A. The additional input is mixed into
1379 * the state in addition to the pulled entropy.
1381 * return: 0 when all bytes are generated; < 0 in case of an error
1383 static int drbg_generate(struct drbg_state
*drbg
,
1384 unsigned char *buf
, unsigned int buflen
,
1385 struct drbg_string
*addtl
)
1388 LIST_HEAD(addtllist
);
1391 pr_devel("DRBG: not yet seeded\n");
1394 if (0 == buflen
|| !buf
) {
1395 pr_devel("DRBG: no output buffer provided\n");
1398 if (addtl
&& NULL
== addtl
->buf
&& 0 < addtl
->len
) {
1399 pr_devel("DRBG: wrong format of additional information\n");
1405 if (buflen
> (drbg_max_request_bytes(drbg
))) {
1406 pr_devel("DRBG: requested random numbers too large %u\n",
1411 /* 9.3.1 step 3 is implicit with the chosen DRBG */
1414 if (addtl
&& addtl
->len
> (drbg_max_addtl(drbg
))) {
1415 pr_devel("DRBG: additional information string too long %zu\n",
1419 /* 9.3.1 step 5 is implicit with the chosen DRBG */
1422 * 9.3.1 step 6 and 9 supplemented by 9.3.2 step c is implemented
1423 * here. The spec is a bit convoluted here, we make it simpler.
1425 if (drbg
->reseed_threshold
< drbg
->reseed_ctr
)
1426 drbg
->seeded
= DRBG_SEED_STATE_UNSEEDED
;
1428 if (drbg
->pr
|| drbg
->seeded
== DRBG_SEED_STATE_UNSEEDED
) {
1429 pr_devel("DRBG: reseeding before generation (prediction "
1430 "resistance: %s, state %s)\n",
1431 drbg
->pr
? "true" : "false",
1432 (drbg
->seeded
== DRBG_SEED_STATE_FULL
?
1433 "seeded" : "unseeded"));
1434 /* 9.3.1 steps 7.1 through 7.3 */
1435 len
= drbg_seed(drbg
, addtl
, true);
1438 /* 9.3.1 step 7.4 */
1440 } else if (rng_is_initialized() &&
1441 (drbg
->seeded
== DRBG_SEED_STATE_PARTIAL
||
1442 drbg_nopr_reseed_interval_elapsed(drbg
))) {
1443 len
= drbg_seed_from_random(drbg
);
1448 if (addtl
&& 0 < addtl
->len
)
1449 list_add_tail(&addtl
->list
, &addtllist
);
1450 /* 9.3.1 step 8 and 10 */
1451 len
= drbg
->d_ops
->generate(drbg
, buf
, buflen
, &addtllist
);
1453 /* 10.1.1.4 step 6, 10.1.2.5 step 7, 10.2.1.5.2 step 7 */
1459 * Section 11.3.3 requires to re-perform self tests after some
1460 * generated random numbers. The chosen value after which self
1461 * test is performed is arbitrary, but it should be reasonable.
1462 * However, we do not perform the self tests because of the following
1463 * reasons: it is mathematically impossible that the initial self tests
1464 * were successfully and the following are not. If the initial would
1465 * pass and the following would not, the kernel integrity is violated.
1466 * In this case, the entire kernel operation is questionable and it
1467 * is unlikely that the integrity violation only affects the
1468 * correct operation of the DRBG.
1470 * Albeit the following code is commented out, it is provided in
1471 * case somebody has a need to implement the test of 11.3.3.
1474 if (drbg
->reseed_ctr
&& !(drbg
->reseed_ctr
% 4096)) {
1476 pr_devel("DRBG: start to perform self test\n");
1477 if (drbg
->core
->flags
& DRBG_HMAC
)
1478 err
= alg_test("drbg_pr_hmac_sha256",
1479 "drbg_pr_hmac_sha256", 0, 0);
1480 else if (drbg
->core
->flags
& DRBG_CTR
)
1481 err
= alg_test("drbg_pr_ctr_aes128",
1482 "drbg_pr_ctr_aes128", 0, 0);
1484 err
= alg_test("drbg_pr_sha256",
1485 "drbg_pr_sha256", 0, 0);
1487 pr_err("DRBG: periodical self test failed\n");
1489 * uninstantiate implies that from now on, only errors
1490 * are returned when reusing this DRBG cipher handle
1492 drbg_uninstantiate(drbg
);
1495 pr_devel("DRBG: self test successful\n");
1501 * All operations were successful, return 0 as mandated by
1502 * the kernel crypto API interface.
1510 * Wrapper around drbg_generate which can pull arbitrary long strings
1511 * from the DRBG without hitting the maximum request limitation.
1513 * Parameters: see drbg_generate
1514 * Return codes: see drbg_generate -- if one drbg_generate request fails,
1515 * the entire drbg_generate_long request fails
1517 static int drbg_generate_long(struct drbg_state
*drbg
,
1518 unsigned char *buf
, unsigned int buflen
,
1519 struct drbg_string
*addtl
)
1521 unsigned int len
= 0;
1522 unsigned int slice
= 0;
1525 unsigned int chunk
= 0;
1526 slice
= ((buflen
- len
) / drbg_max_request_bytes(drbg
));
1527 chunk
= slice
? drbg_max_request_bytes(drbg
) : (buflen
- len
);
1528 mutex_lock(&drbg
->drbg_mutex
);
1529 err
= drbg_generate(drbg
, buf
+ len
, chunk
, addtl
);
1530 mutex_unlock(&drbg
->drbg_mutex
);
1534 } while (slice
> 0 && (len
< buflen
));
1538 static int drbg_prepare_hrng(struct drbg_state
*drbg
)
1540 /* We do not need an HRNG in test mode. */
1541 if (list_empty(&drbg
->test_data
.list
))
1544 drbg
->jent
= crypto_alloc_rng("jitterentropy_rng", 0, 0);
1545 if (IS_ERR(drbg
->jent
)) {
1546 const int err
= PTR_ERR(drbg
->jent
);
1549 if (fips_enabled
|| err
!= -ENOENT
)
1551 pr_info("DRBG: Continuing without Jitter RNG\n");
1558 * DRBG instantiation function as required by SP800-90A - this function
1559 * sets up the DRBG handle, performs the initial seeding and all sanity
1560 * checks required by SP800-90A
1562 * @drbg memory of state -- if NULL, new memory is allocated
1563 * @pers Personalization string that is mixed into state, may be NULL -- note
1564 * the entropy is pulled by the DRBG internally unconditionally
1565 * as defined in SP800-90A. The additional input is mixed into
1566 * the state in addition to the pulled entropy.
1567 * @coreref reference to core
1568 * @pr prediction resistance enabled
1572 * error value otherwise
1574 static int drbg_instantiate(struct drbg_state
*drbg
, struct drbg_string
*pers
,
1575 int coreref
, bool pr
)
1580 pr_devel("DRBG: Initializing DRBG core %d with prediction resistance "
1581 "%s\n", coreref
, pr
? "enabled" : "disabled");
1582 mutex_lock(&drbg
->drbg_mutex
);
1584 /* 9.1 step 1 is implicit with the selected DRBG type */
1587 * 9.1 step 2 is implicit as caller can select prediction resistance
1588 * and the flag is copied into drbg->flags --
1589 * all DRBG types support prediction resistance
1592 /* 9.1 step 4 is implicit in drbg_sec_strength */
1595 drbg
->core
= &drbg_cores
[coreref
];
1597 drbg
->seeded
= DRBG_SEED_STATE_UNSEEDED
;
1598 drbg
->last_seed_time
= 0;
1599 drbg
->reseed_threshold
= drbg_max_requests(drbg
);
1601 ret
= drbg_alloc_state(drbg
);
1605 ret
= drbg_prepare_hrng(drbg
);
1607 goto free_everything
;
1612 ret
= drbg_seed(drbg
, pers
, reseed
);
1615 goto free_everything
;
1617 mutex_unlock(&drbg
->drbg_mutex
);
1621 mutex_unlock(&drbg
->drbg_mutex
);
1625 mutex_unlock(&drbg
->drbg_mutex
);
1626 drbg_uninstantiate(drbg
);
1631 * DRBG uninstantiate function as required by SP800-90A - this function
1632 * frees all buffers and the DRBG handle
1634 * @drbg DRBG state handle
1639 static int drbg_uninstantiate(struct drbg_state
*drbg
)
1641 if (!IS_ERR_OR_NULL(drbg
->jent
))
1642 crypto_free_rng(drbg
->jent
);
1646 drbg
->d_ops
->crypto_fini(drbg
);
1647 drbg_dealloc_state(drbg
);
1648 /* no scrubbing of test_data -- this shall survive an uninstantiate */
1653 * Helper function for setting the test data in the DRBG
1655 * @drbg DRBG state handle
1657 * @len test data length
1659 static void drbg_kcapi_set_entropy(struct crypto_rng
*tfm
,
1660 const u8
*data
, unsigned int len
)
1662 struct drbg_state
*drbg
= crypto_rng_ctx(tfm
);
1664 mutex_lock(&drbg
->drbg_mutex
);
1665 drbg_string_fill(&drbg
->test_data
, data
, len
);
1666 mutex_unlock(&drbg
->drbg_mutex
);
1669 /***************************************************************
1670 * Kernel crypto API cipher invocations requested by DRBG
1671 ***************************************************************/
1673 #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
1675 struct shash_desc shash
;
1679 static int drbg_init_hash_kernel(struct drbg_state
*drbg
)
1681 struct sdesc
*sdesc
;
1682 struct crypto_shash
*tfm
;
1684 tfm
= crypto_alloc_shash(drbg
->core
->backend_cra_name
, 0, 0);
1686 pr_info("DRBG: could not allocate digest TFM handle: %s\n",
1687 drbg
->core
->backend_cra_name
);
1688 return PTR_ERR(tfm
);
1690 BUG_ON(drbg_blocklen(drbg
) != crypto_shash_digestsize(tfm
));
1691 sdesc
= kzalloc(sizeof(struct shash_desc
) + crypto_shash_descsize(tfm
),
1694 crypto_free_shash(tfm
);
1698 sdesc
->shash
.tfm
= tfm
;
1699 drbg
->priv_data
= sdesc
;
1701 return crypto_shash_alignmask(tfm
);
1704 static int drbg_fini_hash_kernel(struct drbg_state
*drbg
)
1706 struct sdesc
*sdesc
= (struct sdesc
*)drbg
->priv_data
;
1708 crypto_free_shash(sdesc
->shash
.tfm
);
1709 kfree_sensitive(sdesc
);
1711 drbg
->priv_data
= NULL
;
1715 static void drbg_kcapi_hmacsetkey(struct drbg_state
*drbg
,
1716 const unsigned char *key
)
1718 struct sdesc
*sdesc
= (struct sdesc
*)drbg
->priv_data
;
1720 crypto_shash_setkey(sdesc
->shash
.tfm
, key
, drbg_statelen(drbg
));
1723 static int drbg_kcapi_hash(struct drbg_state
*drbg
, unsigned char *outval
,
1724 const struct list_head
*in
)
1726 struct sdesc
*sdesc
= (struct sdesc
*)drbg
->priv_data
;
1727 struct drbg_string
*input
= NULL
;
1729 crypto_shash_init(&sdesc
->shash
);
1730 list_for_each_entry(input
, in
, list
)
1731 crypto_shash_update(&sdesc
->shash
, input
->buf
, input
->len
);
1732 return crypto_shash_final(&sdesc
->shash
, outval
);
1734 #endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
1736 #ifdef CONFIG_CRYPTO_DRBG_CTR
1737 static int drbg_fini_sym_kernel(struct drbg_state
*drbg
)
1739 struct crypto_cipher
*tfm
=
1740 (struct crypto_cipher
*)drbg
->priv_data
;
1742 crypto_free_cipher(tfm
);
1743 drbg
->priv_data
= NULL
;
1745 if (drbg
->ctr_handle
)
1746 crypto_free_skcipher(drbg
->ctr_handle
);
1747 drbg
->ctr_handle
= NULL
;
1750 skcipher_request_free(drbg
->ctr_req
);
1751 drbg
->ctr_req
= NULL
;
1753 kfree(drbg
->outscratchpadbuf
);
1754 drbg
->outscratchpadbuf
= NULL
;
1759 static int drbg_init_sym_kernel(struct drbg_state
*drbg
)
1761 struct crypto_cipher
*tfm
;
1762 struct crypto_skcipher
*sk_tfm
;
1763 struct skcipher_request
*req
;
1764 unsigned int alignmask
;
1765 char ctr_name
[CRYPTO_MAX_ALG_NAME
];
1767 tfm
= crypto_alloc_cipher(drbg
->core
->backend_cra_name
, 0, 0);
1769 pr_info("DRBG: could not allocate cipher TFM handle: %s\n",
1770 drbg
->core
->backend_cra_name
);
1771 return PTR_ERR(tfm
);
1773 BUG_ON(drbg_blocklen(drbg
) != crypto_cipher_blocksize(tfm
));
1774 drbg
->priv_data
= tfm
;
1776 if (snprintf(ctr_name
, CRYPTO_MAX_ALG_NAME
, "ctr(%s)",
1777 drbg
->core
->backend_cra_name
) >= CRYPTO_MAX_ALG_NAME
) {
1778 drbg_fini_sym_kernel(drbg
);
1781 sk_tfm
= crypto_alloc_skcipher(ctr_name
, 0, 0);
1782 if (IS_ERR(sk_tfm
)) {
1783 pr_info("DRBG: could not allocate CTR cipher TFM handle: %s\n",
1785 drbg_fini_sym_kernel(drbg
);
1786 return PTR_ERR(sk_tfm
);
1788 drbg
->ctr_handle
= sk_tfm
;
1789 crypto_init_wait(&drbg
->ctr_wait
);
1791 req
= skcipher_request_alloc(sk_tfm
, GFP_KERNEL
);
1793 pr_info("DRBG: could not allocate request queue\n");
1794 drbg_fini_sym_kernel(drbg
);
1797 drbg
->ctr_req
= req
;
1798 skcipher_request_set_callback(req
, CRYPTO_TFM_REQ_MAY_BACKLOG
|
1799 CRYPTO_TFM_REQ_MAY_SLEEP
,
1800 crypto_req_done
, &drbg
->ctr_wait
);
1802 alignmask
= crypto_skcipher_alignmask(sk_tfm
);
1803 drbg
->outscratchpadbuf
= kmalloc(DRBG_OUTSCRATCHLEN
+ alignmask
,
1805 if (!drbg
->outscratchpadbuf
) {
1806 drbg_fini_sym_kernel(drbg
);
1809 drbg
->outscratchpad
= (u8
*)PTR_ALIGN(drbg
->outscratchpadbuf
,
1812 sg_init_table(&drbg
->sg_in
, 1);
1813 sg_init_one(&drbg
->sg_out
, drbg
->outscratchpad
, DRBG_OUTSCRATCHLEN
);
1818 static void drbg_kcapi_symsetkey(struct drbg_state
*drbg
,
1819 const unsigned char *key
)
1821 struct crypto_cipher
*tfm
=
1822 (struct crypto_cipher
*)drbg
->priv_data
;
1824 crypto_cipher_setkey(tfm
, key
, (drbg_keylen(drbg
)));
1827 static int drbg_kcapi_sym(struct drbg_state
*drbg
, unsigned char *outval
,
1828 const struct drbg_string
*in
)
1830 struct crypto_cipher
*tfm
=
1831 (struct crypto_cipher
*)drbg
->priv_data
;
1833 /* there is only component in *in */
1834 BUG_ON(in
->len
< drbg_blocklen(drbg
));
1835 crypto_cipher_encrypt_one(tfm
, outval
, in
->buf
);
1839 static int drbg_kcapi_sym_ctr(struct drbg_state
*drbg
,
1840 u8
*inbuf
, u32 inlen
,
1841 u8
*outbuf
, u32 outlen
)
1843 struct scatterlist
*sg_in
= &drbg
->sg_in
, *sg_out
= &drbg
->sg_out
;
1844 u32 scratchpad_use
= min_t(u32
, outlen
, DRBG_OUTSCRATCHLEN
);
1848 /* Use caller-provided input buffer */
1849 sg_set_buf(sg_in
, inbuf
, inlen
);
1851 /* Use scratchpad for in-place operation */
1852 inlen
= scratchpad_use
;
1853 memset(drbg
->outscratchpad
, 0, scratchpad_use
);
1854 sg_set_buf(sg_in
, drbg
->outscratchpad
, scratchpad_use
);
1858 u32 cryptlen
= min3(inlen
, outlen
, (u32
)DRBG_OUTSCRATCHLEN
);
1860 /* Output buffer may not be valid for SGL, use scratchpad */
1861 skcipher_request_set_crypt(drbg
->ctr_req
, sg_in
, sg_out
,
1863 ret
= crypto_wait_req(crypto_skcipher_encrypt(drbg
->ctr_req
),
1868 crypto_init_wait(&drbg
->ctr_wait
);
1870 memcpy(outbuf
, drbg
->outscratchpad
, cryptlen
);
1871 memzero_explicit(drbg
->outscratchpad
, cryptlen
);
1881 #endif /* CONFIG_CRYPTO_DRBG_CTR */
1883 /***************************************************************
1884 * Kernel crypto API interface to register DRBG
1885 ***************************************************************/
1888 * Look up the DRBG flags by given kernel crypto API cra_name
1889 * The code uses the drbg_cores definition to do this
1891 * @cra_name kernel crypto API cra_name
1892 * @coreref reference to integer which is filled with the pointer to
1893 * the applicable core
1894 * @pr reference for setting prediction resistance
1898 static inline void drbg_convert_tfm_core(const char *cra_driver_name
,
1899 int *coreref
, bool *pr
)
1906 /* disassemble the names */
1907 if (!memcmp(cra_driver_name
, "drbg_nopr_", 10)) {
1910 } else if (!memcmp(cra_driver_name
, "drbg_pr_", 8)) {
1916 /* remove the first part */
1917 len
= strlen(cra_driver_name
) - start
;
1918 for (i
= 0; ARRAY_SIZE(drbg_cores
) > i
; i
++) {
1919 if (!memcmp(cra_driver_name
+ start
, drbg_cores
[i
].cra_name
,
1927 static int drbg_kcapi_init(struct crypto_tfm
*tfm
)
1929 struct drbg_state
*drbg
= crypto_tfm_ctx(tfm
);
1931 mutex_init(&drbg
->drbg_mutex
);
1936 static void drbg_kcapi_cleanup(struct crypto_tfm
*tfm
)
1938 drbg_uninstantiate(crypto_tfm_ctx(tfm
));
1942 * Generate random numbers invoked by the kernel crypto API:
1943 * The API of the kernel crypto API is extended as follows:
1945 * src is additional input supplied to the RNG.
1946 * slen is the length of src.
1947 * dst is the output buffer where random data is to be stored.
1948 * dlen is the length of dst.
1950 static int drbg_kcapi_random(struct crypto_rng
*tfm
,
1951 const u8
*src
, unsigned int slen
,
1952 u8
*dst
, unsigned int dlen
)
1954 struct drbg_state
*drbg
= crypto_rng_ctx(tfm
);
1955 struct drbg_string
*addtl
= NULL
;
1956 struct drbg_string string
;
1959 /* linked list variable is now local to allow modification */
1960 drbg_string_fill(&string
, src
, slen
);
1964 return drbg_generate_long(drbg
, dst
, dlen
, addtl
);
1968 * Seed the DRBG invoked by the kernel crypto API
1970 static int drbg_kcapi_seed(struct crypto_rng
*tfm
,
1971 const u8
*seed
, unsigned int slen
)
1973 struct drbg_state
*drbg
= crypto_rng_ctx(tfm
);
1974 struct crypto_tfm
*tfm_base
= crypto_rng_tfm(tfm
);
1976 struct drbg_string string
;
1977 struct drbg_string
*seed_string
= NULL
;
1980 drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base
), &coreref
,
1983 drbg_string_fill(&string
, seed
, slen
);
1984 seed_string
= &string
;
1987 return drbg_instantiate(drbg
, seed_string
, coreref
, pr
);
1990 /***************************************************************
1991 * Kernel module: code to load the module
1992 ***************************************************************/
1995 * Tests as defined in 11.3.2 in addition to the cipher tests: testing
1996 * of the error handling.
1998 * Note: testing of failing seed source as defined in 11.3.2 is not applicable
1999 * as seed source of get_random_bytes does not fail.
2001 * Note 2: There is no sensible way of testing the reseed counter
2002 * enforcement, so skip it.
2004 static inline int __init
drbg_healthcheck_sanity(void)
2007 #define OUTBUFLEN 16
2008 unsigned char buf
[OUTBUFLEN
];
2009 struct drbg_state
*drbg
= NULL
;
2014 struct drbg_string addtl
;
2015 size_t max_addtllen
, max_request_bytes
;
2017 /* only perform test in FIPS mode */
2021 #ifdef CONFIG_CRYPTO_DRBG_CTR
2022 drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref
, &pr
);
2023 #elif defined CONFIG_CRYPTO_DRBG_HASH
2024 drbg_convert_tfm_core("drbg_nopr_sha256", &coreref
, &pr
);
2026 drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref
, &pr
);
2029 drbg
= kzalloc(sizeof(struct drbg_state
), GFP_KERNEL
);
2033 mutex_init(&drbg
->drbg_mutex
);
2034 drbg
->core
= &drbg_cores
[coreref
];
2035 drbg
->reseed_threshold
= drbg_max_requests(drbg
);
2038 * if the following tests fail, it is likely that there is a buffer
2039 * overflow as buf is much smaller than the requested or provided
2040 * string lengths -- in case the error handling does not succeed
2041 * we may get an OOPS. And we want to get an OOPS as this is a
2045 max_addtllen
= drbg_max_addtl(drbg
);
2046 max_request_bytes
= drbg_max_request_bytes(drbg
);
2047 drbg_string_fill(&addtl
, buf
, max_addtllen
+ 1);
2048 /* overflow addtllen with additonal info string */
2049 len
= drbg_generate(drbg
, buf
, OUTBUFLEN
, &addtl
);
2051 /* overflow max_bits */
2052 len
= drbg_generate(drbg
, buf
, (max_request_bytes
+ 1), NULL
);
2055 /* overflow max addtllen with personalization string */
2056 ret
= drbg_seed(drbg
, &addtl
, false);
2058 /* all tests passed */
2061 pr_devel("DRBG: Sanity tests for failure code paths successfully "
2068 static struct rng_alg drbg_algs
[22];
2071 * Fill the array drbg_algs used to register the different DRBGs
2072 * with the kernel crypto API. To fill the array, the information
2073 * from drbg_cores[] is used.
2075 static inline void __init
drbg_fill_array(struct rng_alg
*alg
,
2076 const struct drbg_core
*core
, int pr
)
2079 static int priority
= 200;
2081 memcpy(alg
->base
.cra_name
, "stdrng", 6);
2083 memcpy(alg
->base
.cra_driver_name
, "drbg_pr_", 8);
2086 memcpy(alg
->base
.cra_driver_name
, "drbg_nopr_", 10);
2089 memcpy(alg
->base
.cra_driver_name
+ pos
, core
->cra_name
,
2090 strlen(core
->cra_name
));
2092 alg
->base
.cra_priority
= priority
;
2095 * If FIPS mode enabled, the selected DRBG shall have the
2096 * highest cra_priority over other stdrng instances to ensure
2100 alg
->base
.cra_priority
+= 200;
2102 alg
->base
.cra_ctxsize
= sizeof(struct drbg_state
);
2103 alg
->base
.cra_module
= THIS_MODULE
;
2104 alg
->base
.cra_init
= drbg_kcapi_init
;
2105 alg
->base
.cra_exit
= drbg_kcapi_cleanup
;
2106 alg
->generate
= drbg_kcapi_random
;
2107 alg
->seed
= drbg_kcapi_seed
;
2108 alg
->set_ent
= drbg_kcapi_set_entropy
;
2112 static int __init
drbg_init(void)
2114 unsigned int i
= 0; /* pointer to drbg_algs */
2115 unsigned int j
= 0; /* pointer to drbg_cores */
2118 ret
= drbg_healthcheck_sanity();
2122 if (ARRAY_SIZE(drbg_cores
) * 2 > ARRAY_SIZE(drbg_algs
)) {
2123 pr_info("DRBG: Cannot register all DRBG types"
2124 "(slots needed: %zu, slots available: %zu)\n",
2125 ARRAY_SIZE(drbg_cores
) * 2, ARRAY_SIZE(drbg_algs
));
2130 * each DRBG definition can be used with PR and without PR, thus
2131 * we instantiate each DRBG in drbg_cores[] twice.
2133 * As the order of placing them into the drbg_algs array matters
2134 * (the later DRBGs receive a higher cra_priority) we register the
2135 * prediction resistance DRBGs first as the should not be too
2138 for (j
= 0; ARRAY_SIZE(drbg_cores
) > j
; j
++, i
++)
2139 drbg_fill_array(&drbg_algs
[i
], &drbg_cores
[j
], 1);
2140 for (j
= 0; ARRAY_SIZE(drbg_cores
) > j
; j
++, i
++)
2141 drbg_fill_array(&drbg_algs
[i
], &drbg_cores
[j
], 0);
2142 return crypto_register_rngs(drbg_algs
, (ARRAY_SIZE(drbg_cores
) * 2));
2145 static void __exit
drbg_exit(void)
2147 crypto_unregister_rngs(drbg_algs
, (ARRAY_SIZE(drbg_cores
) * 2));
2150 subsys_initcall(drbg_init
);
2151 module_exit(drbg_exit
);
2152 #ifndef CRYPTO_DRBG_HASH_STRING
2153 #define CRYPTO_DRBG_HASH_STRING ""
2155 #ifndef CRYPTO_DRBG_HMAC_STRING
2156 #define CRYPTO_DRBG_HMAC_STRING ""
2158 #ifndef CRYPTO_DRBG_CTR_STRING
2159 #define CRYPTO_DRBG_CTR_STRING ""
2161 MODULE_LICENSE("GPL");
2162 MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
2163 MODULE_DESCRIPTION("NIST SP800-90A Deterministic Random Bit Generator (DRBG) "
2164 "using following cores: "
2165 CRYPTO_DRBG_HASH_STRING
2166 CRYPTO_DRBG_HMAC_STRING
2167 CRYPTO_DRBG_CTR_STRING
);
2168 MODULE_ALIAS_CRYPTO("stdrng");
2169 MODULE_IMPORT_NS(CRYPTO_INTERNAL
);