2 * Copyright 2011-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
13 #include <openssl/sha.h>
14 #include <openssl/crypto.h>
15 #include <openssl/err.h>
16 #include <openssl/rand.h>
17 #include <openssl/core_dispatch.h>
18 #include <openssl/proverr.h>
19 #include "internal/thread_once.h"
20 #include "prov/providercommon.h"
21 #include "prov/provider_ctx.h"
22 #include "prov/provider_util.h"
23 #include "prov/implementations.h"
24 #include "drbg_local.h"
26 static OSSL_FUNC_rand_newctx_fn drbg_hash_new_wrapper
;
27 static OSSL_FUNC_rand_freectx_fn drbg_hash_free
;
28 static OSSL_FUNC_rand_instantiate_fn drbg_hash_instantiate_wrapper
;
29 static OSSL_FUNC_rand_uninstantiate_fn drbg_hash_uninstantiate_wrapper
;
30 static OSSL_FUNC_rand_generate_fn drbg_hash_generate_wrapper
;
31 static OSSL_FUNC_rand_reseed_fn drbg_hash_reseed_wrapper
;
32 static OSSL_FUNC_rand_settable_ctx_params_fn drbg_hash_settable_ctx_params
;
33 static OSSL_FUNC_rand_set_ctx_params_fn drbg_hash_set_ctx_params
;
34 static OSSL_FUNC_rand_gettable_ctx_params_fn drbg_hash_gettable_ctx_params
;
35 static OSSL_FUNC_rand_get_ctx_params_fn drbg_hash_get_ctx_params
;
36 static OSSL_FUNC_rand_verify_zeroization_fn drbg_hash_verify_zeroization
;
38 /* 888 bits from SP800-90Ar1 10.1 table 2 */
39 #define HASH_PRNG_MAX_SEEDLEN (888/8)
41 /* 440 bits from SP800-90Ar1 10.1 table 2 */
42 #define HASH_PRNG_SMALL_SEEDLEN (440/8)
44 /* Determine what seedlen to use based on the block length */
45 #define MAX_BLOCKLEN_USING_SMALL_SEEDLEN (256/8)
46 #define INBYTE_IGNORE ((unsigned char)0xFF)
48 typedef struct rand_drbg_hash_st
{
52 unsigned char V
[HASH_PRNG_MAX_SEEDLEN
];
53 unsigned char C
[HASH_PRNG_MAX_SEEDLEN
];
54 /* Temporary value storage: should always exceed max digest length */
55 unsigned char vtmp
[HASH_PRNG_MAX_SEEDLEN
];
59 * SP800-90Ar1 10.3.1 Derivation function using a Hash Function (Hash_df).
60 * The input string used is composed of:
61 * inbyte - An optional leading byte (ignore if equal to INBYTE_IGNORE)
62 * in - input string 1 (A Non NULL value).
63 * in2 - optional input string (Can be NULL).
64 * in3 - optional input string (Can be NULL).
65 * These are concatenated as part of the DigestUpdate process.
67 static int hash_df(PROV_DRBG
*drbg
, unsigned char *out
,
68 const unsigned char inbyte
,
69 const unsigned char *in
, size_t inlen
,
70 const unsigned char *in2
, size_t in2len
,
71 const unsigned char *in3
, size_t in3len
)
73 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
74 EVP_MD_CTX
*ctx
= hash
->ctx
;
75 unsigned char *vtmp
= hash
->vtmp
;
76 /* tmp = counter || num_bits_returned || [inbyte] */
77 unsigned char tmp
[1 + 4 + 1];
79 size_t outlen
= drbg
->seedlen
;
80 size_t num_bits_returned
= outlen
* 8;
82 * No need to check outlen size here, as the standard only ever needs
83 * seedlen bytes which is always less than the maximum permitted.
86 /* (Step 3) counter = 1 (tmp[0] is the 8 bit counter) */
88 /* tmp[1..4] is the fixed 32 bit no_of_bits_to_return */
89 tmp
[tmp_sz
++] = (unsigned char)((num_bits_returned
>> 24) & 0xff);
90 tmp
[tmp_sz
++] = (unsigned char)((num_bits_returned
>> 16) & 0xff);
91 tmp
[tmp_sz
++] = (unsigned char)((num_bits_returned
>> 8) & 0xff);
92 tmp
[tmp_sz
++] = (unsigned char)(num_bits_returned
& 0xff);
93 /* Tack the additional input byte onto the end of tmp if it exists */
94 if (inbyte
!= INBYTE_IGNORE
)
95 tmp
[tmp_sz
++] = inbyte
;
100 * (Step 4.1) out = out || Hash(tmp || in || [in2] || [in3])
101 * (where tmp = counter || num_bits_returned || [inbyte])
103 if (!(EVP_DigestInit_ex(ctx
, ossl_prov_digest_md(&hash
->digest
), NULL
)
104 && EVP_DigestUpdate(ctx
, tmp
, tmp_sz
)
105 && EVP_DigestUpdate(ctx
, in
, inlen
)
106 && (in2
== NULL
|| EVP_DigestUpdate(ctx
, in2
, in2len
))
107 && (in3
== NULL
|| EVP_DigestUpdate(ctx
, in3
, in3len
))))
110 if (outlen
< hash
->blocklen
) {
111 if (!EVP_DigestFinal(ctx
, vtmp
, NULL
))
113 memcpy(out
, vtmp
, outlen
);
114 OPENSSL_cleanse(vtmp
, hash
->blocklen
);
116 } else if(!EVP_DigestFinal(ctx
, out
, NULL
)) {
120 outlen
-= hash
->blocklen
;
123 /* (Step 4.2) counter++ */
125 out
+= hash
->blocklen
;
130 /* Helper function that just passes 2 input parameters to hash_df() */
131 static int hash_df1(PROV_DRBG
*drbg
, unsigned char *out
,
132 const unsigned char in_byte
,
133 const unsigned char *in1
, size_t in1len
)
135 return hash_df(drbg
, out
, in_byte
, in1
, in1len
, NULL
, 0, NULL
, 0);
139 * Add 2 byte buffers together. The first elements in each buffer are the top
140 * most bytes. The result is stored in the dst buffer.
141 * The final carry is ignored i.e: dst = (dst + in) mod (2^seedlen_bits).
142 * where dst size is drbg->seedlen, and inlen <= drbg->seedlen.
144 static int add_bytes(PROV_DRBG
*drbg
, unsigned char *dst
,
145 unsigned char *in
, size_t inlen
)
149 const unsigned char *add
;
150 unsigned char carry
= 0, *d
;
152 assert(drbg
->seedlen
>= 1 && inlen
>= 1 && inlen
<= drbg
->seedlen
);
154 d
= &dst
[drbg
->seedlen
- 1];
155 add
= &in
[inlen
- 1];
157 for (i
= inlen
; i
> 0; i
--, d
--, add
--) {
158 result
= *d
+ *add
+ carry
;
159 carry
= (unsigned char)(result
>> 8);
160 *d
= (unsigned char)(result
& 0xff);
164 /* Add the carry to the top of the dst if inlen is not the same size */
165 for (i
= drbg
->seedlen
- inlen
; i
> 0; --i
, d
--) {
166 *d
+= 1; /* Carry can only be 1 */
167 if (*d
!= 0) /* exit if carry doesnt propagate to the next byte */
174 /* V = (V + Hash(inbyte || V || [additional_input]) mod (2^seedlen) */
175 static int add_hash_to_v(PROV_DRBG
*drbg
, unsigned char inbyte
,
176 const unsigned char *adin
, size_t adinlen
)
178 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
179 EVP_MD_CTX
*ctx
= hash
->ctx
;
181 return EVP_DigestInit_ex(ctx
, ossl_prov_digest_md(&hash
->digest
), NULL
)
182 && EVP_DigestUpdate(ctx
, &inbyte
, 1)
183 && EVP_DigestUpdate(ctx
, hash
->V
, drbg
->seedlen
)
184 && (adin
== NULL
|| EVP_DigestUpdate(ctx
, adin
, adinlen
))
185 && EVP_DigestFinal(ctx
, hash
->vtmp
, NULL
)
186 && add_bytes(drbg
, hash
->V
, hash
->vtmp
, hash
->blocklen
);
190 * The Hashgen() as listed in SP800-90Ar1 10.1.1.4 Hash_DRBG_Generate_Process.
192 * drbg contains the current value of V.
193 * outlen is the requested number of bytes.
194 * out is a buffer to return the generated bits.
196 * The algorithm to generate the bits is:
200 * W = W || Hash(data)
201 * data = (data + 1) mod (2^seedlen)
203 * out = Leftmost(W, outlen)
205 * Returns zero if an error occurs otherwise it returns 1.
207 static int hash_gen(PROV_DRBG
*drbg
, unsigned char *out
, size_t outlen
)
209 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
210 unsigned char one
= 1;
214 memcpy(hash
->vtmp
, hash
->V
, drbg
->seedlen
);
216 if (!EVP_DigestInit_ex(hash
->ctx
, ossl_prov_digest_md(&hash
->digest
),
218 || !EVP_DigestUpdate(hash
->ctx
, hash
->vtmp
, drbg
->seedlen
))
221 if (outlen
< hash
->blocklen
) {
222 if (!EVP_DigestFinal(hash
->ctx
, hash
->vtmp
, NULL
))
224 memcpy(out
, hash
->vtmp
, outlen
);
227 if (!EVP_DigestFinal(hash
->ctx
, out
, NULL
))
229 outlen
-= hash
->blocklen
;
232 out
+= hash
->blocklen
;
234 add_bytes(drbg
, hash
->vtmp
, &one
, 1);
240 * SP800-90Ar1 10.1.1.2 Hash_DRBG_Instantiate_Process:
242 * ent is entropy input obtained from a randomness source of length ent_len.
243 * nonce is a string of bytes of length nonce_len.
244 * pstr is a personalization string received from an application. May be NULL.
246 * Returns zero if an error occurs otherwise it returns 1.
248 static int drbg_hash_instantiate(PROV_DRBG
*drbg
,
249 const unsigned char *ent
, size_t ent_len
,
250 const unsigned char *nonce
, size_t nonce_len
,
251 const unsigned char *pstr
, size_t pstr_len
)
253 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
255 EVP_MD_CTX_free(hash
->ctx
);
256 hash
->ctx
= EVP_MD_CTX_new();
258 /* (Step 1-3) V = Hash_df(entropy||nonce||pers, seedlen) */
259 return hash
->ctx
!= NULL
260 && hash_df(drbg
, hash
->V
, INBYTE_IGNORE
,
261 ent
, ent_len
, nonce
, nonce_len
, pstr
, pstr_len
)
262 /* (Step 4) C = Hash_df(0x00||V, seedlen) */
263 && hash_df1(drbg
, hash
->C
, 0x00, hash
->V
, drbg
->seedlen
);
266 static int drbg_hash_instantiate_wrapper(void *vdrbg
, unsigned int strength
,
267 int prediction_resistance
,
268 const unsigned char *pstr
,
270 const OSSL_PARAM params
[])
272 PROV_DRBG
*drbg
= (PROV_DRBG
*)vdrbg
;
274 if (!ossl_prov_is_running() || !drbg_hash_set_ctx_params(drbg
, params
))
276 return ossl_prov_drbg_instantiate(drbg
, strength
, prediction_resistance
,
281 * SP800-90Ar1 10.1.1.3 Hash_DRBG_Reseed_Process:
283 * ent is entropy input bytes obtained from a randomness source.
284 * addin is additional input received from an application. May be NULL.
286 * Returns zero if an error occurs otherwise it returns 1.
288 static int drbg_hash_reseed(PROV_DRBG
*drbg
,
289 const unsigned char *ent
, size_t ent_len
,
290 const unsigned char *adin
, size_t adin_len
)
292 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
294 /* (Step 1-2) V = Hash_df(0x01 || V || entropy_input || additional_input) */
295 /* V about to be updated so use C as output instead */
296 if (!hash_df(drbg
, hash
->C
, 0x01, hash
->V
, drbg
->seedlen
, ent
, ent_len
,
299 memcpy(hash
->V
, hash
->C
, drbg
->seedlen
);
300 /* (Step 4) C = Hash_df(0x00||V, seedlen) */
301 return hash_df1(drbg
, hash
->C
, 0x00, hash
->V
, drbg
->seedlen
);
304 static int drbg_hash_reseed_wrapper(void *vdrbg
, int prediction_resistance
,
305 const unsigned char *ent
, size_t ent_len
,
306 const unsigned char *adin
, size_t adin_len
)
308 PROV_DRBG
*drbg
= (PROV_DRBG
*)vdrbg
;
310 return ossl_prov_drbg_reseed(drbg
, prediction_resistance
, ent
, ent_len
,
315 * SP800-90Ar1 10.1.1.4 Hash_DRBG_Generate_Process:
317 * Generates pseudo random bytes using the drbg.
318 * out is a buffer to fill with outlen bytes of pseudo random data.
319 * addin is additional input received from an application. May be NULL.
321 * Returns zero if an error occurs otherwise it returns 1.
323 static int drbg_hash_generate(PROV_DRBG
*drbg
,
324 unsigned char *out
, size_t outlen
,
325 const unsigned char *adin
, size_t adin_len
)
327 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
328 unsigned char counter
[4];
329 int reseed_counter
= drbg
->generate_counter
;
331 counter
[0] = (unsigned char)((reseed_counter
>> 24) & 0xff);
332 counter
[1] = (unsigned char)((reseed_counter
>> 16) & 0xff);
333 counter
[2] = (unsigned char)((reseed_counter
>> 8) & 0xff);
334 counter
[3] = (unsigned char)(reseed_counter
& 0xff);
336 return hash
->ctx
!= NULL
338 /* (Step 2) if adin != NULL then V = V + Hash(0x02||V||adin) */
340 || add_hash_to_v(drbg
, 0x02, adin
, adin_len
))
341 /* (Step 3) Hashgen(outlen, V) */
342 && hash_gen(drbg
, out
, outlen
)
343 /* (Step 4/5) H = V = (V + Hash(0x03||V) mod (2^seedlen_bits) */
344 && add_hash_to_v(drbg
, 0x03, NULL
, 0)
345 /* (Step 5) V = (V + H + C + reseed_counter) mod (2^seedlen_bits) */
346 /* V = (V + C) mod (2^seedlen_bits) */
347 && add_bytes(drbg
, hash
->V
, hash
->C
, drbg
->seedlen
)
348 /* V = (V + reseed_counter) mod (2^seedlen_bits) */
349 && add_bytes(drbg
, hash
->V
, counter
, 4);
352 static int drbg_hash_generate_wrapper
353 (void *vdrbg
, unsigned char *out
, size_t outlen
, unsigned int strength
,
354 int prediction_resistance
, const unsigned char *adin
, size_t adin_len
)
356 PROV_DRBG
*drbg
= (PROV_DRBG
*)vdrbg
;
358 return ossl_prov_drbg_generate(drbg
, out
, outlen
, strength
,
359 prediction_resistance
, adin
, adin_len
);
362 static int drbg_hash_uninstantiate(PROV_DRBG
*drbg
)
364 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
366 OPENSSL_cleanse(hash
->V
, sizeof(hash
->V
));
367 OPENSSL_cleanse(hash
->C
, sizeof(hash
->C
));
368 OPENSSL_cleanse(hash
->vtmp
, sizeof(hash
->vtmp
));
369 return ossl_prov_drbg_uninstantiate(drbg
);
372 static int drbg_hash_uninstantiate_wrapper(void *vdrbg
)
374 return drbg_hash_uninstantiate((PROV_DRBG
*)vdrbg
);
377 static int drbg_hash_verify_zeroization(void *vdrbg
)
379 PROV_DRBG
*drbg
= (PROV_DRBG
*)vdrbg
;
380 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
382 PROV_DRBG_VERYIFY_ZEROIZATION(hash
->V
);
383 PROV_DRBG_VERYIFY_ZEROIZATION(hash
->C
);
384 PROV_DRBG_VERYIFY_ZEROIZATION(hash
->vtmp
);
388 static int drbg_hash_new(PROV_DRBG
*ctx
)
390 PROV_DRBG_HASH
*hash
;
392 hash
= OPENSSL_secure_zalloc(sizeof(*hash
));
394 ERR_raise(ERR_LIB_PROV
, ERR_R_MALLOC_FAILURE
);
399 ctx
->seedlen
= HASH_PRNG_MAX_SEEDLEN
;
400 ctx
->max_entropylen
= DRBG_MAX_LENGTH
;
401 ctx
->max_noncelen
= DRBG_MAX_LENGTH
;
402 ctx
->max_perslen
= DRBG_MAX_LENGTH
;
403 ctx
->max_adinlen
= DRBG_MAX_LENGTH
;
405 /* Maximum number of bits per request = 2^19 = 2^16 bytes */
406 ctx
->max_request
= 1 << 16;
410 static void *drbg_hash_new_wrapper(void *provctx
, void *parent
,
411 const OSSL_DISPATCH
*parent_dispatch
)
413 return ossl_rand_drbg_new(provctx
, parent
, parent_dispatch
, &drbg_hash_new
,
414 &drbg_hash_instantiate
, &drbg_hash_uninstantiate
,
415 &drbg_hash_reseed
, &drbg_hash_generate
);
418 static void drbg_hash_free(void *vdrbg
)
420 PROV_DRBG
*drbg
= (PROV_DRBG
*)vdrbg
;
421 PROV_DRBG_HASH
*hash
;
423 if (drbg
!= NULL
&& (hash
= (PROV_DRBG_HASH
*)drbg
->data
) != NULL
) {
424 EVP_MD_CTX_free(hash
->ctx
);
425 ossl_prov_digest_reset(&hash
->digest
);
426 OPENSSL_secure_clear_free(hash
, sizeof(*hash
));
428 ossl_rand_drbg_free(drbg
);
431 static int drbg_hash_get_ctx_params(void *vdrbg
, OSSL_PARAM params
[])
433 PROV_DRBG
*drbg
= (PROV_DRBG
*)vdrbg
;
434 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)drbg
->data
;
438 p
= OSSL_PARAM_locate(params
, OSSL_DRBG_PARAM_DIGEST
);
440 md
= ossl_prov_digest_md(&hash
->digest
);
441 if (md
== NULL
|| !OSSL_PARAM_set_utf8_string(p
, EVP_MD_name(md
)))
445 return ossl_drbg_get_ctx_params(drbg
, params
);
448 static const OSSL_PARAM
*drbg_hash_gettable_ctx_params(ossl_unused
void *vctx
,
449 ossl_unused
void *p_ctx
)
451 static const OSSL_PARAM known_gettable_ctx_params
[] = {
452 OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST
, NULL
, 0),
453 OSSL_PARAM_DRBG_GETTABLE_CTX_COMMON
,
456 return known_gettable_ctx_params
;
459 static int drbg_hash_set_ctx_params(void *vctx
, const OSSL_PARAM params
[])
461 PROV_DRBG
*ctx
= (PROV_DRBG
*)vctx
;
462 PROV_DRBG_HASH
*hash
= (PROV_DRBG_HASH
*)ctx
->data
;
463 OSSL_LIB_CTX
*libctx
= PROV_LIBCTX_OF(ctx
->provctx
);
466 if (!ossl_prov_digest_load_from_params(&hash
->digest
, params
, libctx
))
469 md
= ossl_prov_digest_md(&hash
->digest
);
471 if ((EVP_MD_flags(md
) & EVP_MD_FLAG_XOF
) != 0) {
472 ERR_raise(ERR_LIB_PROV
, PROV_R_XOF_DIGESTS_NOT_ALLOWED
);
476 /* These are taken from SP 800-90 10.1 Table 2 */
477 hash
->blocklen
= EVP_MD_size(md
);
478 /* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
479 ctx
->strength
= 64 * (hash
->blocklen
>> 3);
480 if (ctx
->strength
> 256)
482 if (hash
->blocklen
> MAX_BLOCKLEN_USING_SMALL_SEEDLEN
)
483 ctx
->seedlen
= HASH_PRNG_MAX_SEEDLEN
;
485 ctx
->seedlen
= HASH_PRNG_SMALL_SEEDLEN
;
487 ctx
->min_entropylen
= ctx
->strength
/ 8;
488 ctx
->min_noncelen
= ctx
->min_entropylen
/ 2;
491 return ossl_drbg_set_ctx_params(ctx
, params
);
494 static const OSSL_PARAM
*drbg_hash_settable_ctx_params(ossl_unused
void *vctx
,
495 ossl_unused
void *p_ctx
)
497 static const OSSL_PARAM known_settable_ctx_params
[] = {
498 OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_PROPERTIES
, NULL
, 0),
499 OSSL_PARAM_utf8_string(OSSL_DRBG_PARAM_DIGEST
, NULL
, 0),
500 OSSL_PARAM_DRBG_SETTABLE_CTX_COMMON
,
503 return known_settable_ctx_params
;
506 const OSSL_DISPATCH ossl_drbg_hash_functions
[] = {
507 { OSSL_FUNC_RAND_NEWCTX
, (void(*)(void))drbg_hash_new_wrapper
},
508 { OSSL_FUNC_RAND_FREECTX
, (void(*)(void))drbg_hash_free
},
509 { OSSL_FUNC_RAND_INSTANTIATE
,
510 (void(*)(void))drbg_hash_instantiate_wrapper
},
511 { OSSL_FUNC_RAND_UNINSTANTIATE
,
512 (void(*)(void))drbg_hash_uninstantiate_wrapper
},
513 { OSSL_FUNC_RAND_GENERATE
, (void(*)(void))drbg_hash_generate_wrapper
},
514 { OSSL_FUNC_RAND_RESEED
, (void(*)(void))drbg_hash_reseed_wrapper
},
515 { OSSL_FUNC_RAND_ENABLE_LOCKING
, (void(*)(void))ossl_drbg_enable_locking
},
516 { OSSL_FUNC_RAND_LOCK
, (void(*)(void))ossl_drbg_lock
},
517 { OSSL_FUNC_RAND_UNLOCK
, (void(*)(void))ossl_drbg_unlock
},
518 { OSSL_FUNC_RAND_SETTABLE_CTX_PARAMS
,
519 (void(*)(void))drbg_hash_settable_ctx_params
},
520 { OSSL_FUNC_RAND_SET_CTX_PARAMS
, (void(*)(void))drbg_hash_set_ctx_params
},
521 { OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS
,
522 (void(*)(void))drbg_hash_gettable_ctx_params
},
523 { OSSL_FUNC_RAND_GET_CTX_PARAMS
, (void(*)(void))drbg_hash_get_ctx_params
},
524 { OSSL_FUNC_RAND_VERIFY_ZEROIZATION
,
525 (void(*)(void))drbg_hash_verify_zeroization
},
526 { OSSL_FUNC_RAND_GET_SEED
, (void(*)(void))ossl_drbg_get_seed
},
527 { OSSL_FUNC_RAND_CLEAR_SEED
, (void(*)(void))ossl_drbg_clear_seed
},