security/nss/lib/freebl/drbg.c@b8a032363ba2
security/nss/lib/freebl/drbg.c
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
1 /* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5 #ifdef FREEBL_NO_DEPEND
6 #include "stubs.h"
7 #endif
9 #include "prerror.h"
10 #include "secerr.h"
12 #include "prtypes.h"
13 #include "prinit.h"
14 #include "blapi.h"
15 #include "blapii.h"
16 #include "nssilock.h"
17 #include "secitem.h"
18 #include "sha_fast.h"
19 #include "sha256.h"
20 #include "secrng.h" /* for RNG_SystemRNG() */
21 #include "secmpi.h"
23 /* PRNG_SEEDLEN defined in NIST SP 800-90 section 10.1
24 * for SHA-1, SHA-224, and SHA-256 it's 440 bits.
25 * for SHA-384 and SHA-512 it's 888 bits */
26 #define PRNG_SEEDLEN (440/PR_BITS_PER_BYTE)
27 static const PRInt64 PRNG_MAX_ADDITIONAL_BYTES = LL_INIT(0x1, 0x0);
28 /* 2^35 bits or 2^32 bytes */
29 #define PRNG_MAX_REQUEST_SIZE 0x10000 /* 2^19 bits or 2^16 bytes */
30 #define PRNG_ADDITONAL_DATA_CACHE_SIZE (8*1024) /* must be less than
31 * PRNG_MAX_ADDITIONAL_BYTES
32 */
34 /* RESEED_COUNT is how many calls to the prng before we need to reseed
35 * under normal NIST rules, you must return an error. In the NSS case, we
36 * self-reseed with RNG_SystemRNG(). Count can be a large number. For code
37 * simplicity, we specify count with 2 components: RESEED_BYTE (which is
38 * the same as LOG256(RESEED_COUNT)) and RESEED_VALUE (which is the same as
39 * RESEED_COUNT / (256 ^ RESEED_BYTE)). Another way to look at this is
40 * RESEED_COUNT = RESEED_VALUE * (256 ^ RESEED_BYTE). For Hash based DRBG
41 * we use the maximum count value, 2^48, or RESEED_BYTE=6 and RESEED_VALUE=1
42 */
43 #define RESEED_BYTE 6
44 #define RESEED_VALUE 1
46 #define PRNG_RESET_RESEED_COUNT(rng) \
47 PORT_Memset((rng)->reseed_counter, 0, sizeof (rng)->reseed_counter); \
48 (rng)->reseed_counter[RESEED_BYTE] = 1;
51 /*
52 * The actual values of this enum are specified in SP 800-90, 10.1.1.*
53 * The spec does not name the types, it only uses bare values
54 */
55 typedef enum {
56 prngCGenerateType = 0, /* used when creating a new 'C' */
57 prngReseedType = 1, /* used in reseeding */
58 prngAdditionalDataType = 2, /* used in mixing additional data */
59 prngGenerateByteType = 3 /* used when mixing internal state while
60 * generating bytes */
61 } prngVTypes;
63 /*
64 * Global RNG context
65 */
66 struct RNGContextStr {
67 PZLock *lock; /* Lock to serialize access to global rng */
68 /*
69 * NOTE, a number of steps in the drbg algorithm need to hash
70 * V_type || V. The code, therefore, depends on the V array following
71 * immediately after V_type to avoid extra copies. To accomplish this
72 * in a way that compiliers can't perturb, we declare V_type and V
73 * as a V_Data array and reference them by macros */
74 PRUint8 V_Data[PRNG_SEEDLEN+1]; /* internal state variables */
75 #define V_type V_Data[0]
76 #define V(rng) (((rng)->V_Data)+1)
77 #define VSize(rng) ((sizeof (rng)->V_Data) -1)
78 PRUint8 C[PRNG_SEEDLEN]; /* internal state variables */
79 PRUint8 oldV[PRNG_SEEDLEN]; /* for continuous rng checking */
80 /* If we get calls for the PRNG to return less than the length of our
81 * hash, we extend the request for a full hash (since we'll be doing
82 * the full hash anyway). Future requests for random numbers are fulfilled
83 * from the remainder of the bytes we generated. Requests for bytes longer
84 * than the hash size are fulfilled directly from the HashGen function
85 * of the random number generator. */
86 PRUint8 reseed_counter[RESEED_BYTE+1]; /* number of requests since the
87 * last reseed. Need only be
88 * big enough to hold the whole
89 * reseed count */
90 PRUint8 data[SHA256_LENGTH]; /* when we request less than a block
91 * save the rest of the rng output for
92 * another partial block */
93 PRUint8 dataAvail; /* # bytes of output available in our cache,
94 * [0...SHA256_LENGTH] */
95 /* store additional data that has been shovelled off to us by
96 * RNG_RandomUpdate. */
97 PRUint8 additionalDataCache[PRNG_ADDITONAL_DATA_CACHE_SIZE];
98 PRUint32 additionalAvail;
99 PRBool isValid; /* false if RNG reaches an invalid state */
100 };
102 typedef struct RNGContextStr RNGContext;
103 static RNGContext *globalrng = NULL;
104 static RNGContext theGlobalRng;
107 /*
108 * The next several functions are derived from the NIST SP 800-90
109 * spec. In these functions, an attempt was made to use names consistent
110 * with the names in the spec, even if they differ from normal NSS usage.
111 */
113 /*
114 * Hash Derive function defined in NISP SP 800-90 Section 10.4.1.
115 * This function is used in the Instantiate and Reseed functions.
116 *
117 * NOTE: requested_bytes cannot overlap with input_string_1 or input_string_2.
118 * input_string_1 and input_string_2 are logically concatentated.
119 * input_string_1 must be supplied.
120 * if input_string_2 is not supplied, NULL should be passed for this parameter.
121 */
122 static SECStatus
123 prng_Hash_df(PRUint8 *requested_bytes, unsigned int no_of_bytes_to_return,
124 const PRUint8 *input_string_1, unsigned int input_string_1_len,
125 const PRUint8 *input_string_2, unsigned int input_string_2_len)
126 {
127 SHA256Context ctx;
128 PRUint32 tmp;
129 PRUint8 counter;
131 tmp=SHA_HTONL(no_of_bytes_to_return*8);
133 for (counter = 1 ; no_of_bytes_to_return > 0; counter++) {
134 unsigned int hash_return_len;
135 SHA256_Begin(&ctx);
136 SHA256_Update(&ctx, &counter, 1);
137 SHA256_Update(&ctx, (unsigned char *)&tmp, sizeof tmp);
138 SHA256_Update(&ctx, input_string_1, input_string_1_len);
139 if (input_string_2) {
140 SHA256_Update(&ctx, input_string_2, input_string_2_len);
141 }
142 SHA256_End(&ctx, requested_bytes, &hash_return_len,
143 no_of_bytes_to_return);
144 requested_bytes += hash_return_len;
145 no_of_bytes_to_return -= hash_return_len;
146 }
147 return SECSuccess;
148 }
151 /*
152 * Hash_DRBG Instantiate NIST SP 800-80 10.1.1.2
153 *
154 * NOTE: bytes & len are entropy || nonce || personalization_string. In
155 * normal operation, NSS calculates them all together in a single call.
156 */
157 static SECStatus
158 prng_instantiate(RNGContext *rng, const PRUint8 *bytes, unsigned int len)
159 {
160 if (len < PRNG_SEEDLEN) {
161 /* if the seedlen is to small, it's probably because we failed to get
162 * enough random data */
163 PORT_SetError(SEC_ERROR_NEED_RANDOM);
164 return SECFailure;
165 }
166 prng_Hash_df(V(rng), VSize(rng), bytes, len, NULL, 0);
167 rng->V_type = prngCGenerateType;
168 prng_Hash_df(rng->C,sizeof rng->C,rng->V_Data,sizeof rng->V_Data,NULL,0);
169 PRNG_RESET_RESEED_COUNT(rng)
170 return SECSuccess;
171 }
174 /*
175 * Update the global random number generator with more seeding
176 * material. Use the Hash_DRBG reseed algorithm from NIST SP-800-90
177 * section 10.1.1.3
178 *
179 * If entropy is NULL, it is fetched from the noise generator.
180 */
181 static SECStatus
182 prng_reseed(RNGContext *rng, const PRUint8 *entropy, unsigned int entropy_len,
183 const PRUint8 *additional_input, unsigned int additional_input_len)
184 {
185 PRUint8 noiseData[(sizeof rng->V_Data)+PRNG_SEEDLEN];
186 PRUint8 *noise = &noiseData[0];
188 /* if entropy wasn't supplied, fetch it. (normal operation case) */
189 if (entropy == NULL) {
190 entropy_len = (unsigned int) RNG_SystemRNG(
191 &noiseData[sizeof rng->V_Data], PRNG_SEEDLEN);
192 } else {
193 /* NOTE: this code is only available for testing, not to applications */
194 /* if entropy was too big for the stack variable, get it from malloc */
195 if (entropy_len > PRNG_SEEDLEN) {
196 noise = PORT_Alloc(entropy_len + (sizeof rng->V_Data));
197 if (noise == NULL) {
198 return SECFailure;
199 }
200 }
201 PORT_Memcpy(&noise[sizeof rng->V_Data],entropy, entropy_len);
202 }
204 if (entropy_len < 256/PR_BITS_PER_BYTE) {
205 /* noise == &noiseData[0] at this point, so nothing to free */
206 PORT_SetError(SEC_ERROR_NEED_RANDOM);
207 return SECFailure;
208 }
210 rng->V_type = prngReseedType;
211 PORT_Memcpy(noise, rng->V_Data, sizeof rng->V_Data);
212 prng_Hash_df(V(rng), VSize(rng), noise, (sizeof rng->V_Data) + entropy_len,
213 additional_input, additional_input_len);
214 /* clear potential CSP */
215 PORT_Memset(noise, 0, (sizeof rng->V_Data) + entropy_len);
216 rng->V_type = prngCGenerateType;
217 prng_Hash_df(rng->C,sizeof rng->C,rng->V_Data,sizeof rng->V_Data,NULL,0);
218 PRNG_RESET_RESEED_COUNT(rng)
220 if (noise != &noiseData[0]) {
221 PORT_Free(noise);
222 }
223 return SECSuccess;
224 }
226 /*
227 * SP 800-90 requires we rerun our health tests on reseed
228 */
229 static SECStatus
230 prng_reseed_test(RNGContext *rng, const PRUint8 *entropy,
231 unsigned int entropy_len, const PRUint8 *additional_input,
232 unsigned int additional_input_len)
233 {
234 SECStatus rv;
236 /* do health checks in FIPS mode */
237 rv = PRNGTEST_RunHealthTests();
238 if (rv != SECSuccess) {
239 /* error set by PRNGTEST_RunHealTests() */
240 rng->isValid = PR_FALSE;
241 return SECFailure;
242 }
243 return prng_reseed(rng, entropy, entropy_len,
244 additional_input, additional_input_len);
245 }
247 /*
248 * build some fast inline functions for adding.
249 */
250 #define PRNG_ADD_CARRY_ONLY(dest, start, cy) \
251 carry = cy; \
252 for (k1=start; carry && k1 >=0 ; k1--) { \
253 carry = !(++dest[k1]); \
254 }
256 /*
257 * NOTE: dest must be an array for the following to work.
258 */
259 #define PRNG_ADD_BITS(dest, dest_len, add, len) \
260 carry = 0; \
261 for (k1=dest_len -1, k2=len-1; k2 >= 0; --k1, --k2) { \
262 carry += dest[k1]+ add[k2]; \
263 dest[k1] = (PRUint8) carry; \
264 carry >>= 8; \
265 }
267 #define PRNG_ADD_BITS_AND_CARRY(dest, dest_len, add, len) \
268 PRNG_ADD_BITS(dest, dest_len, add, len) \
269 PRNG_ADD_CARRY_ONLY(dest, k1, carry)
271 /*
272 * This function expands the internal state of the prng to fulfill any number
273 * of bytes we need for this request. We only use this call if we need more
274 * than can be supplied by a single call to SHA256_HashBuf.
275 *
276 * This function is specified in NIST SP 800-90 section 10.1.1.4, Hashgen
277 */
278 static void
279 prng_Hashgen(RNGContext *rng, PRUint8 *returned_bytes,
280 unsigned int no_of_returned_bytes)
281 {
282 PRUint8 data[VSize(rng)];
284 PORT_Memcpy(data, V(rng), VSize(rng));
285 while (no_of_returned_bytes) {
286 SHA256Context ctx;
287 unsigned int len;
288 unsigned int carry;
289 int k1;
291 SHA256_Begin(&ctx);
292 SHA256_Update(&ctx, data, sizeof data);
293 SHA256_End(&ctx, returned_bytes, &len, no_of_returned_bytes);
294 returned_bytes += len;
295 no_of_returned_bytes -= len;
296 /* The carry parameter is a bool (increment or not).
297 * This increments data if no_of_returned_bytes is not zero */
298 PRNG_ADD_CARRY_ONLY(data, (sizeof data)- 1, no_of_returned_bytes);
299 }
300 PORT_Memset(data, 0, sizeof data);
301 }
303 /*
304 * Generates new random bytes and advances the internal prng state.
305 * additional bytes are only used in algorithm testing.
306 *
307 * This function is specified in NIST SP 800-90 section 10.1.1.4
308 */
309 static SECStatus
310 prng_generateNewBytes(RNGContext *rng,
311 PRUint8 *returned_bytes, unsigned int no_of_returned_bytes,
312 const PRUint8 *additional_input,
313 unsigned int additional_input_len)
314 {
315 PRUint8 H[SHA256_LENGTH]; /* both H and w since they
316 * aren't used concurrently */
317 unsigned int carry;
318 int k1, k2;
320 if (!rng->isValid) {
321 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
322 return SECFailure;
323 }
324 /* This code only triggers during tests, normal
325 * prng operation does not use additional_input */
326 if (additional_input){
327 SHA256Context ctx;
328 /* NIST SP 800-90 defines two temporaries in their calculations,
329 * w and H. These temporaries are the same lengths, and used
330 * at different times, so we use the following macro to collapse
331 * them to the same variable, but keeping their unique names for
332 * easy comparison to the spec */
333 #define w H
334 rng->V_type = prngAdditionalDataType;
335 SHA256_Begin(&ctx);
336 SHA256_Update(&ctx, rng->V_Data, sizeof rng->V_Data);
337 SHA256_Update(&ctx, additional_input, additional_input_len);
338 SHA256_End(&ctx, w, NULL, sizeof w);
339 PRNG_ADD_BITS_AND_CARRY(V(rng), VSize(rng), w, sizeof w)
340 PORT_Memset(w, 0, sizeof w);
341 #undef w
342 }
344 if (no_of_returned_bytes == SHA256_LENGTH) {
345 /* short_cut to hashbuf and save a copy and a clear */
346 SHA256_HashBuf(returned_bytes, V(rng), VSize(rng) );
347 } else {
348 prng_Hashgen(rng, returned_bytes, no_of_returned_bytes);
349 }
350 /* advance our internal state... */
351 rng->V_type = prngGenerateByteType;
352 SHA256_HashBuf(H, rng->V_Data, sizeof rng->V_Data);
353 PRNG_ADD_BITS_AND_CARRY(V(rng), VSize(rng), H, sizeof H)
354 PRNG_ADD_BITS(V(rng), VSize(rng), rng->C, sizeof rng->C);
355 PRNG_ADD_BITS_AND_CARRY(V(rng), VSize(rng), rng->reseed_counter,
356 sizeof rng->reseed_counter)
357 PRNG_ADD_CARRY_ONLY(rng->reseed_counter,(sizeof rng->reseed_counter)-1, 1);
359 /* continuous rng check */
360 if (memcmp(V(rng), rng->oldV, sizeof rng->oldV) == 0) {
361 rng->isValid = PR_FALSE;
362 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
363 return SECFailure;
364 }
365 PORT_Memcpy(rng->oldV, V(rng), sizeof rng->oldV);
366 return SECSuccess;
367 }
369 /* Use NSPR to prevent RNG_RNGInit from being called from separate
370 * threads, creating a race condition.
371 */
372 static const PRCallOnceType pristineCallOnce;
373 static PRCallOnceType coRNGInit;
374 static PRStatus rng_init(void)
375 {
376 PRUint8 bytes[PRNG_SEEDLEN*2]; /* entropy + nonce */
377 unsigned int numBytes;
378 SECStatus rv = SECSuccess;
380 if (globalrng == NULL) {
381 /* bytes needs to have enough space to hold
382 * a SHA256 hash value. Blow up at compile time if this isn't true */
383 PR_STATIC_ASSERT(sizeof(bytes) >= SHA256_LENGTH);
384 /* create a new global RNG context */
385 globalrng = &theGlobalRng;
386 PORT_Assert(NULL == globalrng->lock);
387 /* create a lock for it */
388 globalrng->lock = PZ_NewLock(nssILockOther);
389 if (globalrng->lock == NULL) {
390 globalrng = NULL;
391 PORT_SetError(PR_OUT_OF_MEMORY_ERROR);
392 return PR_FAILURE;
393 }
395 /* Try to get some seed data for the RNG */
396 numBytes = (unsigned int) RNG_SystemRNG(bytes, sizeof bytes);
397 PORT_Assert(numBytes == 0 || numBytes == sizeof bytes);
398 if (numBytes != 0) {
399 /* if this is our first call, instantiate, otherwise reseed
400 * prng_instantiate gets a new clean state, we want to mix
401 * any previous entropy we may have collected */
402 if (V(globalrng)[0] == 0) {
403 rv = prng_instantiate(globalrng, bytes, numBytes);
404 } else {
405 rv = prng_reseed_test(globalrng, bytes, numBytes, NULL, 0);
406 }
407 memset(bytes, 0, numBytes);
408 } else {
409 PZ_DestroyLock(globalrng->lock);
410 globalrng->lock = NULL;
411 globalrng = NULL;
412 return PR_FAILURE;
413 }
415 if (rv != SECSuccess) {
416 return PR_FAILURE;
417 }
418 /* the RNG is in a valid state */
419 globalrng->isValid = PR_TRUE;
421 /* fetch one random value so that we can populate rng->oldV for our
422 * continous random number test. */
423 prng_generateNewBytes(globalrng, bytes, SHA256_LENGTH, NULL, 0);
425 /* Fetch more entropy into the PRNG */
426 RNG_SystemInfoForRNG();
427 }
428 return PR_SUCCESS;
429 }
431 /*
432 * Clean up the global RNG context
433 */
434 static void
435 prng_freeRNGContext(RNGContext *rng)
436 {
437 PRUint8 inputhash[VSize(rng) + (sizeof rng->C)];
439 /* destroy context lock */
440 SKIP_AFTER_FORK(PZ_DestroyLock(globalrng->lock));
442 /* zero global RNG context except for C & V to preserve entropy */
443 prng_Hash_df(inputhash, sizeof rng->C, rng->C, sizeof rng->C, NULL, 0);
444 prng_Hash_df(&inputhash[sizeof rng->C], VSize(rng), V(rng), VSize(rng),
445 NULL, 0);
446 memset(rng, 0, sizeof *rng);
447 memcpy(rng->C, inputhash, sizeof rng->C);
448 memcpy(V(rng), &inputhash[sizeof rng->C], VSize(rng));
450 memset(inputhash, 0, sizeof inputhash);
451 }
453 /*
454 * Public functions
455 */
457 /*
458 * Initialize the global RNG context and give it some seed input taken
459 * from the system. This function is thread-safe and will only allow
460 * the global context to be initialized once. The seed input is likely
461 * small, so it is imperative that RNG_RandomUpdate() be called with
462 * additional seed data before the generator is used. A good way to
463 * provide the generator with additional entropy is to call
464 * RNG_SystemInfoForRNG(). Note that C_Initialize() does exactly that.
465 */
466 SECStatus
467 RNG_RNGInit(void)
468 {
469 /* Allow only one call to initialize the context */
470 PR_CallOnce(&coRNGInit, rng_init);
471 /* Make sure there is a context */
472 return (globalrng != NULL) ? SECSuccess : SECFailure;
473 }
475 /*
476 ** Update the global random number generator with more seeding
477 ** material.
478 */
479 SECStatus
480 RNG_RandomUpdate(const void *data, size_t bytes)
481 {
482 SECStatus rv;
484 /* Make sure our assumption that size_t is unsigned is true */
485 PR_STATIC_ASSERT(((size_t)-1) > (size_t)1);
487 #if defined(NS_PTR_GT_32) || (defined(NSS_USE_64) && !defined(NS_PTR_LE_32))
488 /*
489 * NIST 800-90 requires us to verify our inputs. This value can
490 * come from the application, so we need to make sure it's within the
491 * spec. The spec says it must be less than 2^32 bytes (2^35 bits).
492 * This can only happen if size_t is greater than 32 bits (i.e. on
493 * most 64 bit platforms). The 90% case (perhaps 100% case), size_t
494 * is less than or equal to 32 bits if the platform is not 64 bits, and
495 * greater than 32 bits if it is a 64 bit platform. The corner
496 * cases are handled with explicit defines NS_PTR_GT_32 and NS_PTR_LE_32.
497 *
498 * In general, neither NS_PTR_GT_32 nor NS_PTR_LE_32 will need to be
499 * defined. If you trip over the next two size ASSERTS at compile time,
500 * you will need to define them for your platform.
501 *
502 * if 'sizeof(size_t) > 4' is triggered it means that we were expecting
503 * sizeof(size_t) to be greater than 4, but it wasn't. Setting
504 * NS_PTR_LE_32 will correct that mistake.
505 *
506 * if 'sizeof(size_t) <= 4' is triggered, it means that we were expecting
507 * sizeof(size_t) to be less than or equal to 4, but it wasn't. Setting
508 * NS_PTR_GT_32 will correct that mistake.
509 */
511 PR_STATIC_ASSERT(sizeof(size_t) > 4);
513 if (bytes > PRNG_MAX_ADDITIONAL_BYTES) {
514 bytes = PRNG_MAX_ADDITIONAL_BYTES;
515 }
516 #else
517 PR_STATIC_ASSERT(sizeof(size_t) <= 4);
518 #endif
520 PZ_Lock(globalrng->lock);
521 /* if we're passed more than our additionalDataCache, simply
522 * call reseed with that data */
523 if (bytes > sizeof (globalrng->additionalDataCache)) {
524 rv = prng_reseed_test(globalrng, NULL, 0, data, (unsigned int) bytes);
525 /* if we aren't going to fill or overflow the buffer, just cache it */
526 } else if (bytes < ((sizeof globalrng->additionalDataCache)
527 - globalrng->additionalAvail)) {
528 PORT_Memcpy(globalrng->additionalDataCache+globalrng->additionalAvail,
529 data, bytes);
530 globalrng->additionalAvail += (PRUint32) bytes;
531 rv = SECSuccess;
532 } else {
533 /* we are going to fill or overflow the buffer. In this case we will
534 * fill the entropy buffer, reseed with it, start a new buffer with the
535 * remainder. We know the remainder will fit in the buffer because
536 * we already handled the case where bytes > the size of the buffer.
537 */
538 size_t bufRemain = (sizeof globalrng->additionalDataCache)
539 - globalrng->additionalAvail;
540 /* fill the rest of the buffer */
541 if (bufRemain) {
542 PORT_Memcpy(globalrng->additionalDataCache
543 +globalrng->additionalAvail,
544 data, bufRemain);
545 data = ((unsigned char *)data) + bufRemain;
546 bytes -= bufRemain;
547 }
548 /* reseed from buffer */
549 rv = prng_reseed_test(globalrng, NULL, 0,
550 globalrng->additionalDataCache,
551 sizeof globalrng->additionalDataCache);
553 /* copy the rest into the cache */
554 PORT_Memcpy(globalrng->additionalDataCache, data, bytes);
555 globalrng->additionalAvail = (PRUint32) bytes;
556 }
558 PZ_Unlock(globalrng->lock);
559 return rv;
560 }
562 /*
563 ** Generate some random bytes, using the global random number generator
564 ** object.
565 */
566 static SECStatus
567 prng_GenerateGlobalRandomBytes(RNGContext *rng,
568 void *dest, size_t len)
569 {
570 SECStatus rv = SECSuccess;
571 PRUint8 *output = dest;
572 /* check for a valid global RNG context */
573 PORT_Assert(rng != NULL);
574 if (rng == NULL) {
575 PORT_SetError(SEC_ERROR_INVALID_ARGS);
576 return SECFailure;
577 }
578 /* FIPS limits the amount of entropy available in a single request */
579 if (len > PRNG_MAX_REQUEST_SIZE) {
580 PORT_SetError(SEC_ERROR_INVALID_ARGS);
581 return SECFailure;
582 }
583 /* --- LOCKED --- */
584 PZ_Lock(rng->lock);
585 /* Check the amount of seed data in the generator. If not enough,
586 * don't produce any data.
587 */
588 if (rng->reseed_counter[0] >= RESEED_VALUE) {
589 rv = prng_reseed_test(rng, NULL, 0, NULL, 0);
590 PZ_Unlock(rng->lock);
591 if (rv != SECSuccess) {
592 return rv;
593 }
594 RNG_SystemInfoForRNG();
595 PZ_Lock(rng->lock);
596 }
597 /*
598 * see if we have enough bytes to fulfill the request.
599 */
600 if (len <= rng->dataAvail) {
601 memcpy(output, rng->data + ((sizeof rng->data) - rng->dataAvail), len);
602 memset(rng->data + ((sizeof rng->data) - rng->dataAvail), 0, len);
603 rng->dataAvail -= len;
604 rv = SECSuccess;
605 /* if we are asking for a small number of bytes, cache the rest of
606 * the bytes */
607 } else if (len < sizeof rng->data) {
608 rv = prng_generateNewBytes(rng, rng->data, sizeof rng->data,
609 rng->additionalAvail ? rng->additionalDataCache : NULL,
610 rng->additionalAvail);
611 rng->additionalAvail = 0;
612 if (rv == SECSuccess) {
613 memcpy(output, rng->data, len);
614 memset(rng->data, 0, len);
615 rng->dataAvail = (sizeof rng->data) - len;
616 }
617 /* we are asking for lots of bytes, just ask the generator to pass them */
618 } else {
619 rv = prng_generateNewBytes(rng, output, len,
620 rng->additionalAvail ? rng->additionalDataCache : NULL,
621 rng->additionalAvail);
622 rng->additionalAvail = 0;
623 }
624 PZ_Unlock(rng->lock);
625 /* --- UNLOCKED --- */
626 return rv;
627 }
629 /*
630 ** Generate some random bytes, using the global random number generator
631 ** object.
632 */
633 SECStatus
634 RNG_GenerateGlobalRandomBytes(void *dest, size_t len)
635 {
636 return prng_GenerateGlobalRandomBytes(globalrng, dest, len);
637 }
639 void
640 RNG_RNGShutdown(void)
641 {
642 /* check for a valid global RNG context */
643 PORT_Assert(globalrng != NULL);
644 if (globalrng == NULL) {
645 /* Should set a "not initialized" error code. */
646 PORT_SetError(SEC_ERROR_NO_MEMORY);
647 return;
648 }
649 /* clear */
650 prng_freeRNGContext(globalrng);
651 globalrng = NULL;
652 /* reset the callonce struct to allow a new call to RNG_RNGInit() */
653 coRNGInit = pristineCallOnce;
654 }
656 /*
657 * Test case interface. used by fips testing and power on self test
658 */
659 /* make sure the test context is separate from the global context, This
660 * allows us to test the internal random number generator without losing
661 * entropy we may have previously collected. */
662 RNGContext testContext;
664 /*
665 * Test vector API. Use NIST SP 800-90 general interface so one of the
666 * other NIST SP 800-90 algorithms may be used in the future.
667 */
668 SECStatus
669 PRNGTEST_Instantiate(const PRUint8 *entropy, unsigned int entropy_len,
670 const PRUint8 *nonce, unsigned int nonce_len,
671 const PRUint8 *personal_string, unsigned int ps_len)
672 {
673 int bytes_len = entropy_len + nonce_len + ps_len;
674 PRUint8 *bytes = NULL;
675 SECStatus rv;
677 if (entropy_len < 256/PR_BITS_PER_BYTE) {
678 PORT_SetError(SEC_ERROR_NEED_RANDOM);
679 return SECFailure;
680 }
682 bytes = PORT_Alloc(bytes_len);
683 if (bytes == NULL) {
684 PORT_SetError(SEC_ERROR_NO_MEMORY);
685 return SECFailure;
686 }
687 /* concatenate the various inputs, internally NSS only instantiates with
688 * a single long string */
689 PORT_Memcpy(bytes, entropy, entropy_len);
690 if (nonce) {
691 PORT_Memcpy(&bytes[entropy_len], nonce, nonce_len);
692 } else {
693 PORT_Assert(nonce_len == 0);
694 }
695 if (personal_string) {
696 PORT_Memcpy(&bytes[entropy_len+nonce_len], personal_string, ps_len);
697 } else {
698 PORT_Assert(ps_len == 0);
699 }
700 rv = prng_instantiate(&testContext, bytes, bytes_len);
701 PORT_ZFree(bytes, bytes_len);
702 if (rv == SECFailure) {
703 return SECFailure;
704 }
705 testContext.isValid = PR_TRUE;
706 return SECSuccess;
707 }
709 SECStatus
710 PRNGTEST_Reseed(const PRUint8 *entropy, unsigned int entropy_len,
711 const PRUint8 *additional, unsigned int additional_len)
712 {
713 if (!testContext.isValid) {
714 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
715 return SECFailure;
716 }
717 /* This magic input tells us to set the reseed count to it's max count,
718 * so we can simulate PRNGTEST_Generate reaching max reseed count */
719 if ((entropy == NULL) && (entropy_len == 0) &&
720 (additional == NULL) && (additional_len == 0)) {
721 testContext.reseed_counter[0] = RESEED_VALUE;
722 return SECSuccess;
723 }
724 return prng_reseed(&testContext, entropy, entropy_len, additional,
725 additional_len);
727 }
729 SECStatus
730 PRNGTEST_Generate(PRUint8 *bytes, unsigned int bytes_len,
731 const PRUint8 *additional, unsigned int additional_len)
732 {
733 SECStatus rv;
734 if (!testContext.isValid) {
735 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
736 return SECFailure;
737 }
738 /* replicate reseed test from prng_GenerateGlobalRandomBytes */
739 if (testContext.reseed_counter[0] >= RESEED_VALUE) {
740 rv = prng_reseed(&testContext, NULL, 0, NULL, 0);
741 if (rv != SECSuccess) {
742 return rv;
743 }
744 }
745 return prng_generateNewBytes(&testContext, bytes, bytes_len,
746 additional, additional_len);
748 }
750 SECStatus
751 PRNGTEST_Uninstantiate()
752 {
753 if (!testContext.isValid) {
754 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
755 return SECFailure;
756 }
757 PORT_Memset(&testContext, 0, sizeof testContext);
758 return SECSuccess;
759 }
761 SECStatus
762 PRNGTEST_RunHealthTests()
763 {
764 static const PRUint8 entropy[] = {
765 0x8e,0x9c,0x0d,0x25,0x75,0x22,0x04,0xf9,
766 0xc5,0x79,0x10,0x8b,0x23,0x79,0x37,0x14,
767 0x9f,0x2c,0xc7,0x0b,0x39,0xf8,0xee,0xef,
768 0x95,0x0c,0x97,0x59,0xfc,0x0a,0x85,0x41,
769 0x76,0x9d,0x6d,0x67,0x00,0x4e,0x19,0x12,
770 0x02,0x16,0x53,0xea,0xf2,0x73,0xd7,0xd6,
771 0x7f,0x7e,0xc8,0xae,0x9c,0x09,0x99,0x7d,
772 0xbb,0x9e,0x48,0x7f,0xbb,0x96,0x46,0xb3,
773 0x03,0x75,0xf8,0xc8,0x69,0x45,0x3f,0x97,
774 0x5e,0x2e,0x48,0xe1,0x5d,0x58,0x97,0x4c };
775 static const PRUint8 rng_known_result[] = {
776 0x16,0xe1,0x8c,0x57,0x21,0xd8,0xf1,0x7e,
777 0x5a,0xa0,0x16,0x0b,0x7e,0xa6,0x25,0xb4,
778 0x24,0x19,0xdb,0x54,0xfa,0x35,0x13,0x66,
779 0xbb,0xaa,0x2a,0x1b,0x22,0x33,0x2e,0x4a,
780 0x14,0x07,0x9d,0x52,0xfc,0x73,0x61,0x48,
781 0xac,0xc1,0x22,0xfc,0xa4,0xfc,0xac,0xa4,
782 0xdb,0xda,0x5b,0x27,0x33,0xc4,0xb3 };
783 static const PRUint8 reseed_entropy[] = {
784 0xc6,0x0b,0x0a,0x30,0x67,0x07,0xf4,0xe2,
785 0x24,0xa7,0x51,0x6f,0x5f,0x85,0x3e,0x5d,
786 0x67,0x97,0xb8,0x3b,0x30,0x9c,0x7a,0xb1,
787 0x52,0xc6,0x1b,0xc9,0x46,0xa8,0x62,0x79 };
788 static const PRUint8 additional_input[] = {
789 0x86,0x82,0x28,0x98,0xe7,0xcb,0x01,0x14,
790 0xae,0x87,0x4b,0x1d,0x99,0x1b,0xc7,0x41,
791 0x33,0xff,0x33,0x66,0x40,0x95,0x54,0xc6,
792 0x67,0x4d,0x40,0x2a,0x1f,0xf9,0xeb,0x65 };
793 static const PRUint8 rng_reseed_result[] = {
794 0x02,0x0c,0xc6,0x17,0x86,0x49,0xba,0xc4,
795 0x7b,0x71,0x35,0x05,0xf0,0xdb,0x4a,0xc2,
796 0x2c,0x38,0xc1,0xa4,0x42,0xe5,0x46,0x4a,
797 0x7d,0xf0,0xbe,0x47,0x88,0xb8,0x0e,0xc6,
798 0x25,0x2b,0x1d,0x13,0xef,0xa6,0x87,0x96,
799 0xa3,0x7d,0x5b,0x80,0xc2,0x38,0x76,0x61,
800 0xc7,0x80,0x5d,0x0f,0x05,0x76,0x85 };
801 static const PRUint8 rng_no_reseed_result[] = {
802 0xc4,0x40,0x41,0x8c,0xbf,0x2f,0x70,0x23,
803 0x88,0xf2,0x7b,0x30,0xc3,0xca,0x1e,0xf3,
804 0xef,0x53,0x81,0x5d,0x30,0xed,0x4c,0xf1,
805 0xff,0x89,0xa5,0xee,0x92,0xf8,0xc0,0x0f,
806 0x88,0x53,0xdf,0xb6,0x76,0xf0,0xaa,0xd3,
807 0x2e,0x1d,0x64,0x37,0x3e,0xe8,0x4a,0x02,
808 0xff,0x0a,0x7f,0xe5,0xe9,0x2b,0x6d };
810 SECStatus rng_status = SECSuccess;
811 PR_STATIC_ASSERT(sizeof(rng_known_result) >= sizeof(rng_reseed_result));
812 PRUint8 result[sizeof(rng_known_result)];
814 /********************************************/
815 /* First test instantiate error path. */
816 /* In this case we supply enough entropy, */
817 /* but not enough seed. This will trigger */
818 /* the code that checks for a entropy */
819 /* source failure. */
820 /********************************************/
821 rng_status = PRNGTEST_Instantiate(entropy, 256/PR_BITS_PER_BYTE,
822 NULL, 0, NULL, 0);
823 if (rng_status == SECSuccess) {
824 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
825 return SECFailure;
826 }
827 if (PORT_GetError() != SEC_ERROR_NEED_RANDOM) {
828 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
829 return SECFailure;
830 }
831 /* we failed with the proper error code, we can continue */
833 /********************************************/
834 /* Generate random bytes with a known seed. */
835 /********************************************/
836 rng_status = PRNGTEST_Instantiate(entropy, sizeof entropy,
837 NULL, 0, NULL, 0);
838 if (rng_status != SECSuccess) {
839 /* Error set by PRNGTEST_Instantiate */
840 return SECFailure;
841 }
842 rng_status = PRNGTEST_Generate(result, sizeof rng_known_result, NULL, 0);
843 if ( ( rng_status != SECSuccess) ||
844 ( PORT_Memcmp( result, rng_known_result,
845 sizeof rng_known_result ) != 0 ) ) {
846 PRNGTEST_Uninstantiate();
847 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
848 return SECFailure;
849 }
850 rng_status = PRNGTEST_Reseed(reseed_entropy, sizeof reseed_entropy,
851 additional_input, sizeof additional_input);
852 if (rng_status != SECSuccess) {
853 /* Error set by PRNG_Reseed */
854 PRNGTEST_Uninstantiate();
855 return SECFailure;
856 }
857 rng_status = PRNGTEST_Generate(result, sizeof rng_reseed_result, NULL, 0);
858 if ( ( rng_status != SECSuccess) ||
859 ( PORT_Memcmp( result, rng_reseed_result,
860 sizeof rng_reseed_result ) != 0 ) ) {
861 PRNGTEST_Uninstantiate();
862 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
863 return SECFailure;
864 }
865 /* This magic forces the reseed count to it's max count, so we can see if
866 * PRNGTEST_Generate will actually when it reaches it's count */
867 rng_status = PRNGTEST_Reseed(NULL, 0, NULL, 0);
868 if (rng_status != SECSuccess) {
869 PRNGTEST_Uninstantiate();
870 /* Error set by PRNG_Reseed */
871 return SECFailure;
872 }
873 /* This generate should now reseed */
874 rng_status = PRNGTEST_Generate(result, sizeof rng_reseed_result, NULL, 0);
875 if ( ( rng_status != SECSuccess) ||
876 /* NOTE we fail if the result is equal to the no_reseed_result.
877 * no_reseed_result is the value we would have gotten if we didn't
878 * do an automatic reseed in PRNGTEST_Generate */
879 ( PORT_Memcmp( result, rng_no_reseed_result,
880 sizeof rng_no_reseed_result ) == 0 ) ) {
881 PRNGTEST_Uninstantiate();
882 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
883 return SECFailure;
884 }
885 /* make sure reseed fails when we don't supply enough entropy */
886 rng_status = PRNGTEST_Reseed(reseed_entropy, 4, NULL, 0);
887 if (rng_status == SECSuccess) {
888 PRNGTEST_Uninstantiate();
889 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
890 return SECFailure;
891 }
892 if (PORT_GetError() != SEC_ERROR_NEED_RANDOM) {
893 PRNGTEST_Uninstantiate();
894 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
895 return SECFailure;
896 }
897 rng_status = PRNGTEST_Uninstantiate();
898 if (rng_status != SECSuccess) {
899 /* Error set by PRNG_Uninstantiate */
900 return rng_status;
901 }
902 /* make sure uninstantiate fails if the contest is not initiated (also tests
903 * if the context was cleared in the previous Uninstantiate) */
904 rng_status = PRNGTEST_Uninstantiate();
905 if (rng_status == SECSuccess) {
906 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
907 return SECFailure;
908 }
909 if (PORT_GetError() != SEC_ERROR_LIBRARY_FAILURE) {
910 return rng_status;
911 }
913 return SECSuccess;
914 }
