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comparison: security/nss/lib/freebl/rsa.c

security/nss/lib/freebl/rsa.c

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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/. */
4
5 /*
6 * RSA key generation, public key op, private key op.
7 */
8 #ifdef FREEBL_NO_DEPEND
9 #include "stubs.h"
10 #endif
11
12 #include "secerr.h"
13
14 #include "prclist.h"
15 #include "nssilock.h"
16 #include "prinit.h"
17 #include "blapi.h"
18 #include "mpi.h"
19 #include "mpprime.h"
20 #include "mplogic.h"
21 #include "secmpi.h"
22 #include "secitem.h"
23 #include "blapii.h"
24
25 /*
26 ** Number of times to attempt to generate a prime (p or q) from a random
27 ** seed (the seed changes for each iteration).
28 */
29 #define MAX_PRIME_GEN_ATTEMPTS 10
30 /*
31 ** Number of times to attempt to generate a key. The primes p and q change
32 ** for each attempt.
33 */
34 #define MAX_KEY_GEN_ATTEMPTS 10
35
36 /* Blinding Parameters max cache size */
37 #define RSA_BLINDING_PARAMS_MAX_CACHE_SIZE 20
38
39 /* exponent should not be greater than modulus */
40 #define BAD_RSA_KEY_SIZE(modLen, expLen) \
41 ((expLen) > (modLen) || (modLen) > RSA_MAX_MODULUS_BITS/8 || \
42 (expLen) > RSA_MAX_EXPONENT_BITS/8)
43
44 struct blindingParamsStr;
45 typedef struct blindingParamsStr blindingParams;
46
47 struct blindingParamsStr {
48 blindingParams *next;
49 mp_int f, g; /* blinding parameter */
50 int counter; /* number of remaining uses of (f, g) */
51 };
52
53 /*
54 ** RSABlindingParamsStr
55 **
56 ** For discussion of Paul Kocher's timing attack against an RSA private key
57 ** operation, see http://www.cryptography.com/timingattack/paper.html. The
58 ** countermeasure to this attack, known as blinding, is also discussed in
59 ** the Handbook of Applied Cryptography, 11.118-11.119.
60 */
61 struct RSABlindingParamsStr
62 {
63 /* Blinding-specific parameters */
64 PRCList link; /* link to list of structs */
65 SECItem modulus; /* list element "key" */
66 blindingParams *free, *bp; /* Blinding parameters queue */
67 blindingParams array[RSA_BLINDING_PARAMS_MAX_CACHE_SIZE];
68 };
69 typedef struct RSABlindingParamsStr RSABlindingParams;
70
71 /*
72 ** RSABlindingParamsListStr
73 **
74 ** List of key-specific blinding params. The arena holds the volatile pool
75 ** of memory for each entry and the list itself. The lock is for list
76 ** operations, in this case insertions and iterations, as well as control
77 ** of the counter for each set of blinding parameters.
78 */
79 struct RSABlindingParamsListStr
80 {
81 PZLock *lock; /* Lock for the list */
82 PRCondVar *cVar; /* Condidtion Variable */
83 int waitCount; /* Number of threads waiting on cVar */
84 PRCList head; /* Pointer to the list */
85 };
86
87 /*
88 ** The master blinding params list.
89 */
90 static struct RSABlindingParamsListStr blindingParamsList = { 0 };
91
92 /* Number of times to reuse (f, g). Suggested by Paul Kocher */
93 #define RSA_BLINDING_PARAMS_MAX_REUSE 50
94
95 /* Global, allows optional use of blinding. On by default. */
96 /* Cannot be changed at the moment, due to thread-safety issues. */
97 static PRBool nssRSAUseBlinding = PR_TRUE;
98
99 static SECStatus
100 rsa_build_from_primes(const mp_int *p, const mp_int *q,
101 mp_int *e, PRBool needPublicExponent,
102 mp_int *d, PRBool needPrivateExponent,
103 RSAPrivateKey *key, unsigned int keySizeInBits)
104 {
105 mp_int n, phi;
106 mp_int psub1, qsub1, tmp;
107 mp_err err = MP_OKAY;
108 SECStatus rv = SECSuccess;
109 MP_DIGITS(&n) = 0;
110 MP_DIGITS(&phi) = 0;
111 MP_DIGITS(&psub1) = 0;
112 MP_DIGITS(&qsub1) = 0;
113 MP_DIGITS(&tmp) = 0;
114 CHECK_MPI_OK( mp_init(&n) );
115 CHECK_MPI_OK( mp_init(&phi) );
116 CHECK_MPI_OK( mp_init(&psub1) );
117 CHECK_MPI_OK( mp_init(&qsub1) );
118 CHECK_MPI_OK( mp_init(&tmp) );
119 /* p and q must be distinct. */
120 if (mp_cmp(p, q) == 0) {
121 PORT_SetError(SEC_ERROR_NEED_RANDOM);
122 rv = SECFailure;
123 goto cleanup;
124 }
125 /* 1. Compute n = p*q */
126 CHECK_MPI_OK( mp_mul(p, q, &n) );
127 /* verify that the modulus has the desired number of bits */
128 if ((unsigned)mpl_significant_bits(&n) != keySizeInBits) {
129 PORT_SetError(SEC_ERROR_NEED_RANDOM);
130 rv = SECFailure;
131 goto cleanup;
132 }
133
134 /* at least one exponent must be given */
135 PORT_Assert(!(needPublicExponent && needPrivateExponent));
136
137 /* 2. Compute phi = (p-1)*(q-1) */
138 CHECK_MPI_OK( mp_sub_d(p, 1, &psub1) );
139 CHECK_MPI_OK( mp_sub_d(q, 1, &qsub1) );
140 if (needPublicExponent || needPrivateExponent) {
141 CHECK_MPI_OK( mp_mul(&psub1, &qsub1, &phi) );
142 /* 3. Compute d = e**-1 mod(phi) */
143 /* or e = d**-1 mod(phi) as necessary */
144 if (needPublicExponent) {
145 err = mp_invmod(d, &phi, e);
146 } else {
147 err = mp_invmod(e, &phi, d);
148 }
149 } else {
150 err = MP_OKAY;
151 }
152 /* Verify that phi(n) and e have no common divisors */
153 if (err != MP_OKAY) {
154 if (err == MP_UNDEF) {
155 PORT_SetError(SEC_ERROR_NEED_RANDOM);
156 err = MP_OKAY; /* to keep PORT_SetError from being called again */
157 rv = SECFailure;
158 }
159 goto cleanup;
160 }
161
162 /* 4. Compute exponent1 = d mod (p-1) */
163 CHECK_MPI_OK( mp_mod(d, &psub1, &tmp) );
164 MPINT_TO_SECITEM(&tmp, &key->exponent1, key->arena);
165 /* 5. Compute exponent2 = d mod (q-1) */
166 CHECK_MPI_OK( mp_mod(d, &qsub1, &tmp) );
167 MPINT_TO_SECITEM(&tmp, &key->exponent2, key->arena);
168 /* 6. Compute coefficient = q**-1 mod p */
169 CHECK_MPI_OK( mp_invmod(q, p, &tmp) );
170 MPINT_TO_SECITEM(&tmp, &key->coefficient, key->arena);
171
172 /* copy our calculated results, overwrite what is there */
173 key->modulus.data = NULL;
174 MPINT_TO_SECITEM(&n, &key->modulus, key->arena);
175 key->privateExponent.data = NULL;
176 MPINT_TO_SECITEM(d, &key->privateExponent, key->arena);
177 key->publicExponent.data = NULL;
178 MPINT_TO_SECITEM(e, &key->publicExponent, key->arena);
179 key->prime1.data = NULL;
180 MPINT_TO_SECITEM(p, &key->prime1, key->arena);
181 key->prime2.data = NULL;
182 MPINT_TO_SECITEM(q, &key->prime2, key->arena);
183 cleanup:
184 mp_clear(&n);
185 mp_clear(&phi);
186 mp_clear(&psub1);
187 mp_clear(&qsub1);
188 mp_clear(&tmp);
189 if (err) {
190 MP_TO_SEC_ERROR(err);
191 rv = SECFailure;
192 }
193 return rv;
194 }
195 static SECStatus
196 generate_prime(mp_int *prime, int primeLen)
197 {
198 mp_err err = MP_OKAY;
199 SECStatus rv = SECSuccess;
200 unsigned long counter = 0;
201 int piter;
202 unsigned char *pb = NULL;
203 pb = PORT_Alloc(primeLen);
204 if (!pb) {
205 PORT_SetError(SEC_ERROR_NO_MEMORY);
206 goto cleanup;
207 }
208 for (piter = 0; piter < MAX_PRIME_GEN_ATTEMPTS; piter++) {
209 CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(pb, primeLen) );
210 pb[0] |= 0xC0; /* set two high-order bits */
211 pb[primeLen-1] |= 0x01; /* set low-order bit */
212 CHECK_MPI_OK( mp_read_unsigned_octets(prime, pb, primeLen) );
213 err = mpp_make_prime(prime, primeLen * 8, PR_FALSE, &counter);
214 if (err != MP_NO)
215 goto cleanup;
216 /* keep going while err == MP_NO */
217 }
218 cleanup:
219 if (pb)
220 PORT_ZFree(pb, primeLen);
221 if (err) {
222 MP_TO_SEC_ERROR(err);
223 rv = SECFailure;
224 }
225 return rv;
226 }
227
228 /*
229 ** Generate and return a new RSA public and private key.
230 ** Both keys are encoded in a single RSAPrivateKey structure.
231 ** "cx" is the random number generator context
232 ** "keySizeInBits" is the size of the key to be generated, in bits.
233 ** 512, 1024, etc.
234 ** "publicExponent" when not NULL is a pointer to some data that
235 ** represents the public exponent to use. The data is a byte
236 ** encoded integer, in "big endian" order.
237 */
238 RSAPrivateKey *
239 RSA_NewKey(int keySizeInBits, SECItem *publicExponent)
240 {
241 unsigned int primeLen;
242 mp_int p, q, e, d;
243 int kiter;
244 mp_err err = MP_OKAY;
245 SECStatus rv = SECSuccess;
246 int prerr = 0;
247 RSAPrivateKey *key = NULL;
248 PLArenaPool *arena = NULL;
249 /* Require key size to be a multiple of 16 bits. */
250 if (!publicExponent || keySizeInBits % 16 != 0 ||
251 BAD_RSA_KEY_SIZE(keySizeInBits/8, publicExponent->len)) {
252 PORT_SetError(SEC_ERROR_INVALID_ARGS);
253 return NULL;
254 }
255 /* 1. Allocate arena & key */
256 arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE);
257 if (!arena) {
258 PORT_SetError(SEC_ERROR_NO_MEMORY);
259 return NULL;
260 }
261 key = PORT_ArenaZNew(arena, RSAPrivateKey);
262 if (!key) {
263 PORT_SetError(SEC_ERROR_NO_MEMORY);
264 PORT_FreeArena(arena, PR_TRUE);
265 return NULL;
266 }
267 key->arena = arena;
268 /* length of primes p and q (in bytes) */
269 primeLen = keySizeInBits / (2 * PR_BITS_PER_BYTE);
270 MP_DIGITS(&p) = 0;
271 MP_DIGITS(&q) = 0;
272 MP_DIGITS(&e) = 0;
273 MP_DIGITS(&d) = 0;
274 CHECK_MPI_OK( mp_init(&p) );
275 CHECK_MPI_OK( mp_init(&q) );
276 CHECK_MPI_OK( mp_init(&e) );
277 CHECK_MPI_OK( mp_init(&d) );
278 /* 2. Set the version number (PKCS1 v1.5 says it should be zero) */
279 SECITEM_AllocItem(arena, &key->version, 1);
280 key->version.data[0] = 0;
281 /* 3. Set the public exponent */
282 SECITEM_TO_MPINT(*publicExponent, &e);
283 kiter = 0;
284 do {
285 prerr = 0;
286 PORT_SetError(0);
287 CHECK_SEC_OK( generate_prime(&p, primeLen) );
288 CHECK_SEC_OK( generate_prime(&q, primeLen) );
289 /* Assure p > q */
290 /* NOTE: PKCS #1 does not require p > q, and NSS doesn't use any
291 * implementation optimization that requires p > q. We can remove
292 * this code in the future.
293 */
294 if (mp_cmp(&p, &q) < 0)
295 mp_exch(&p, &q);
296 /* Attempt to use these primes to generate a key */
297 rv = rsa_build_from_primes(&p, &q,
298 &e, PR_FALSE, /* needPublicExponent=false */
299 &d, PR_TRUE, /* needPrivateExponent=true */
300 key, keySizeInBits);
301 if (rv == SECSuccess)
302 break; /* generated two good primes */
303 prerr = PORT_GetError();
304 kiter++;
305 /* loop until have primes */
306 } while (prerr == SEC_ERROR_NEED_RANDOM && kiter < MAX_KEY_GEN_ATTEMPTS);
307 if (prerr)
308 goto cleanup;
309 cleanup:
310 mp_clear(&p);
311 mp_clear(&q);
312 mp_clear(&e);
313 mp_clear(&d);
314 if (err) {
315 MP_TO_SEC_ERROR(err);
316 rv = SECFailure;
317 }
318 if (rv && arena) {
319 PORT_FreeArena(arena, PR_TRUE);
320 key = NULL;
321 }
322 return key;
323 }
324
325 mp_err
326 rsa_is_prime(mp_int *p) {
327 int res;
328
329 /* run a Fermat test */
330 res = mpp_fermat(p, 2);
331 if (res != MP_OKAY) {
332 return res;
333 }
334
335 /* If that passed, run some Miller-Rabin tests */
336 res = mpp_pprime(p, 2);
337 return res;
338 }
339
340 /*
341 * Try to find the two primes based on 2 exponents plus either a prime
342 * or a modulus.
343 *
344 * In: e, d and either p or n (depending on the setting of hasModulus).
345 * Out: p,q.
346 *
347 * Step 1, Since d = e**-1 mod phi, we know that d*e == 1 mod phi, or
348 * d*e = 1+k*phi, or d*e-1 = k*phi. since d is less than phi and e is
349 * usually less than d, then k must be an integer between e-1 and 1
350 * (probably on the order of e).
351 * Step 1a, If we were passed just a prime, we can divide k*phi by that
352 * prime-1 and get k*(q-1). This will reduce the size of our division
353 * through the rest of the loop.
354 * Step 2, Loop through the values k=e-1 to 1 looking for k. k should be on
355 * the order or e, and e is typically small. This may take a while for
356 * a large random e. We are looking for a k that divides kphi
357 * evenly. Once we find a k that divides kphi evenly, we assume it
358 * is the true k. It's possible this k is not the 'true' k but has
359 * swapped factors of p-1 and/or q-1. Because of this, we
360 * tentatively continue Steps 3-6 inside this loop, and may return looking
361 * for another k on failure.
362 * Step 3, Calculate are tentative phi=kphi/k. Note: real phi is (p-1)*(q-1).
363 * Step 4a, if we have a prime, kphi is already k*(q-1), so phi is or tenative
364 * q-1. q = phi+1. If k is correct, q should be the right length and
365 * prime.
366 * Step 4b, It's possible q-1 and k could have swapped factors. We now have a
367 * possible solution that meets our criteria. It may not be the only
368 * solution, however, so we keep looking. If we find more than one,
369 * we will fail since we cannot determine which is the correct
370 * solution, and returning the wrong modulus will compromise both
371 * moduli. If no other solution is found, we return the unique solution.
372 * Step 5a, If we have the modulus (n=pq), then use the following formula to
373 * calculate s=(p+q): , phi = (p-1)(q-1) = pq -p-q +1 = n-s+1. so
374 * s=n-phi+1.
375 * Step 5b, Use n=pq and s=p+q to solve for p and q as follows:
376 * since q=s-p, then n=p*(s-p)= sp - p^2, rearranging p^2-s*p+n = 0.
377 * from the quadratic equation we have p=1/2*(s+sqrt(s*s-4*n)) and
378 * q=1/2*(s-sqrt(s*s-4*n)) if s*s-4*n is a perfect square, we are DONE.
379 * If it is not, continue in our look looking for another k. NOTE: the
380 * code actually distributes the 1/2 and results in the equations:
381 * sqrt = sqrt(s/2*s/2-n), p=s/2+sqrt, q=s/2-sqrt. The algebra saves us
382 * and extra divide by 2 and a multiply by 4.
383 *
384 * This will return p & q. q may be larger than p in the case that p was given
385 * and it was the smaller prime.
386 */
387 static mp_err
388 rsa_get_primes_from_exponents(mp_int *e, mp_int *d, mp_int *p, mp_int *q,
389 mp_int *n, PRBool hasModulus,
390 unsigned int keySizeInBits)
391 {
392 mp_int kphi; /* k*phi */
393 mp_int k; /* current guess at 'k' */
394 mp_int phi; /* (p-1)(q-1) */
395 mp_int s; /* p+q/2 (s/2 in the algebra) */
396 mp_int r; /* remainder */
397 mp_int tmp; /* p-1 if p is given, n+1 is modulus is given */
398 mp_int sqrt; /* sqrt(s/2*s/2-n) */
399 mp_err err = MP_OKAY;
400 unsigned int order_k;
401
402 MP_DIGITS(&kphi) = 0;
403 MP_DIGITS(&phi) = 0;
404 MP_DIGITS(&s) = 0;
405 MP_DIGITS(&k) = 0;
406 MP_DIGITS(&r) = 0;
407 MP_DIGITS(&tmp) = 0;
408 MP_DIGITS(&sqrt) = 0;
409 CHECK_MPI_OK( mp_init(&kphi) );
410 CHECK_MPI_OK( mp_init(&phi) );
411 CHECK_MPI_OK( mp_init(&s) );
412 CHECK_MPI_OK( mp_init(&k) );
413 CHECK_MPI_OK( mp_init(&r) );
414 CHECK_MPI_OK( mp_init(&tmp) );
415 CHECK_MPI_OK( mp_init(&sqrt) );
416
417 /* our algorithm looks for a factor k whose maximum size is dependent
418 * on the size of our smallest exponent, which had better be the public
419 * exponent (if it's the private, the key is vulnerable to a brute force
420 * attack).
421 *
422 * since our factor search is linear, we need to limit the maximum
423 * size of the public key. this should not be a problem normally, since
424 * public keys are usually small.
425 *
426 * if we want to handle larger public key sizes, we should have
427 * a version which tries to 'completely' factor k*phi (where completely
428 * means 'factor into primes, or composites with which are products of
429 * large primes). Once we have all the factors, we can sort them out and
430 * try different combinations to form our phi. The risk is if (p-1)/2,
431 * (q-1)/2, and k are all large primes. In any case if the public key
432 * is small (order of 20 some bits), then a linear search for k is
433 * manageable.
434 */
435 if (mpl_significant_bits(e) > 23) {
436 err=MP_RANGE;
437 goto cleanup;
438 }
439
440 /* calculate k*phi = e*d - 1 */
441 CHECK_MPI_OK( mp_mul(e, d, &kphi) );
442 CHECK_MPI_OK( mp_sub_d(&kphi, 1, &kphi) );
443
444
445 /* kphi is (e*d)-1, which is the same as k*(p-1)(q-1)
446 * d < (p-1)(q-1), therefor k must be less than e-1
447 * We can narrow down k even more, though. Since p and q are odd and both
448 * have their high bit set, then we know that phi must be on order of
449 * keySizeBits.
450 */
451 order_k = (unsigned)mpl_significant_bits(&kphi) - keySizeInBits;
452
453 /* for (k=kinit; order(k) >= order_k; k--) { */
454 /* k=kinit: k can't be bigger than kphi/2^(keySizeInBits -1) */
455 CHECK_MPI_OK( mp_2expt(&k,keySizeInBits-1) );
456 CHECK_MPI_OK( mp_div(&kphi, &k, &k, NULL));
457 if (mp_cmp(&k,e) >= 0) {
458 /* also can't be bigger then e-1 */
459 CHECK_MPI_OK( mp_sub_d(e, 1, &k) );
460 }
461
462 /* calculate our temp value */
463 /* This saves recalculating this value when the k guess is wrong, which
464 * is reasonably frequent. */
465 /* for the modulus case, tmp = n+1 (used to calculate p+q = tmp - phi) */
466 /* for the prime case, tmp = p-1 (used to calculate q-1= phi/tmp) */
467 if (hasModulus) {
468 CHECK_MPI_OK( mp_add_d(n, 1, &tmp) );
469 } else {
470 CHECK_MPI_OK( mp_sub_d(p, 1, &tmp) );
471 CHECK_MPI_OK(mp_div(&kphi,&tmp,&kphi,&r));
472 if (mp_cmp_z(&r) != 0) {
473 /* p-1 doesn't divide kphi, some parameter wasn't correct */
474 err=MP_RANGE;
475 goto cleanup;
476 }
477 mp_zero(q);
478 /* kphi is now k*(q-1) */
479 }
480
481 /* rest of the for loop */
482 for (; (err == MP_OKAY) && (mpl_significant_bits(&k) >= order_k);
483 err = mp_sub_d(&k, 1, &k)) {
484 /* looking for k as a factor of kphi */
485 CHECK_MPI_OK(mp_div(&kphi,&k,&phi,&r));
486 if (mp_cmp_z(&r) != 0) {
487 /* not a factor, try the next one */
488 continue;
489 }
490 /* we have a possible phi, see if it works */
491 if (!hasModulus) {
492 if ((unsigned)mpl_significant_bits(&phi) != keySizeInBits/2) {
493 /* phi is not the right size */
494 continue;
495 }
496 /* phi should be divisible by 2, since
497 * q is odd and phi=(q-1). */
498 if (mpp_divis_d(&phi,2) == MP_NO) {
499 /* phi is not divisible by 4 */
500 continue;
501 }
502 /* we now have a candidate for the second prime */
503 CHECK_MPI_OK(mp_add_d(&phi, 1, &tmp));
504
505 /* check to make sure it is prime */
506 err = rsa_is_prime(&tmp);
507 if (err != MP_OKAY) {
508 if (err == MP_NO) {
509 /* No, then we still have the wrong phi */
510 err = MP_OKAY;
511 continue;
512 }
513 goto cleanup;
514 }
515 /*
516 * It is possible that we have the wrong phi if
517 * k_guess*(q_guess-1) = k*(q-1) (k and q-1 have swapped factors).
518 * since our q_quess is prime, however. We have found a valid
519 * rsa key because:
520 * q is the correct order of magnitude.
521 * phi = (p-1)(q-1) where p and q are both primes.
522 * e*d mod phi = 1.
523 * There is no way to know from the info given if this is the
524 * original key. We never want to return the wrong key because if
525 * two moduli with the same factor is known, then euclid's gcd
526 * algorithm can be used to find that factor. Even though the
527 * caller didn't pass the original modulus, it doesn't mean the
528 * modulus wasn't known or isn't available somewhere. So to be safe
529 * if we can't be sure we have the right q, we don't return any.
530 *
531 * So to make sure we continue looking for other valid q's. If none
532 * are found, then we can safely return this one, otherwise we just
533 * fail */
534 if (mp_cmp_z(q) != 0) {
535 /* this is the second valid q, don't return either,
536 * just fail */
537 err = MP_RANGE;
538 break;
539 }
540 /* we only have one q so far, save it and if no others are found,
541 * it's safe to return it */
542 CHECK_MPI_OK(mp_copy(&tmp, q));
543 continue;
544 }
545 /* test our tentative phi */
546 /* phi should be the correct order */
547 if ((unsigned)mpl_significant_bits(&phi) != keySizeInBits) {
548 /* phi is not the right size */
549 continue;
550 }
551 /* phi should be divisible by 4, since
552 * p and q are odd and phi=(p-1)(q-1). */
553 if (mpp_divis_d(&phi,4) == MP_NO) {
554 /* phi is not divisible by 4 */
555 continue;
556 }
557 /* n was given, calculate s/2=(p+q)/2 */
558 CHECK_MPI_OK( mp_sub(&tmp, &phi, &s) );
559 CHECK_MPI_OK( mp_div_2(&s, &s) );
560
561 /* calculate sqrt(s/2*s/2-n) */
562 CHECK_MPI_OK(mp_sqr(&s,&sqrt));
563 CHECK_MPI_OK(mp_sub(&sqrt,n,&r)); /* r as a tmp */
564 CHECK_MPI_OK(mp_sqrt(&r,&sqrt));
565 /* make sure it's a perfect square */
566 /* r is our original value we took the square root of */
567 /* q is the square of our tentative square root. They should be equal*/
568 CHECK_MPI_OK(mp_sqr(&sqrt,q)); /* q as a tmp */
569 if (mp_cmp(&r,q) != 0) {
570 /* sigh according to the doc, mp_sqrt could return sqrt-1 */
571 CHECK_MPI_OK(mp_add_d(&sqrt,1,&sqrt));
572 CHECK_MPI_OK(mp_sqr(&sqrt,q));
573 if (mp_cmp(&r,q) != 0) {
574 /* s*s-n not a perfect square, this phi isn't valid, find * another.*/
575 continue;
576 }
577 }
578
579 /* NOTE: In this case we know we have the one and only answer.
580 * "Why?", you ask. Because:
581 * 1) n is a composite of two large primes (or it wasn't a
582 * valid RSA modulus).
583 * 2) If we know any number such that x^2-n is a perfect square
584 * and x is not (n+1)/2, then we can calculate 2 non-trivial
585 * factors of n.
586 * 3) Since we know that n has only 2 non-trivial prime factors,
587 * we know the two factors we have are the only possible factors.
588 */
589
590 /* Now we are home free to calculate p and q */
591 /* p = s/2 + sqrt, q= s/2 - sqrt */
592 CHECK_MPI_OK(mp_add(&s,&sqrt,p));
593 CHECK_MPI_OK(mp_sub(&s,&sqrt,q));
594 break;
595 }
596 if ((unsigned)mpl_significant_bits(&k) < order_k) {
597 if (hasModulus || (mp_cmp_z(q) == 0)) {
598 /* If we get here, something was wrong with the parameters we
599 * were given */
600 err = MP_RANGE;
601 }
602 }
603 cleanup:
604 mp_clear(&kphi);
605 mp_clear(&phi);
606 mp_clear(&s);
607 mp_clear(&k);
608 mp_clear(&r);
609 mp_clear(&tmp);
610 mp_clear(&sqrt);
611 return err;
612 }
613
614 /*
615 * take a private key with only a few elements and fill out the missing pieces.
616 *
617 * All the entries will be overwritten with data allocated out of the arena
618 * If no arena is supplied, one will be created.
619 *
620 * The following fields must be supplied in order for this function
621 * to succeed:
622 * one of either publicExponent or privateExponent
623 * two more of the following 5 parameters.
624 * modulus (n)
625 * prime1 (p)
626 * prime2 (q)
627 * publicExponent (e)
628 * privateExponent (d)
629 *
630 * NOTE: if only the publicExponent, privateExponent, and one prime is given,
631 * then there may be more than one RSA key that matches that combination.
632 *
633 * All parameters will be replaced in the key structure with new parameters
634 * Allocated out of the arena. There is no attempt to free the old structures.
635 * Prime1 will always be greater than prime2 (even if the caller supplies the
636 * smaller prime as prime1 or the larger prime as prime2). The parameters are
637 * not overwritten on failure.
638 *
639 * How it works:
640 * We can generate all the parameters from:
641 * one of the exponents, plus the two primes. (rsa_build_key_from_primes) *
642 * If we are given one of the exponents and both primes, we are done.
643 * If we are given one of the exponents, the modulus and one prime, we
644 * caclulate the second prime by dividing the modulus by the given
645 * prime, giving us and exponent and 2 primes.
646 * If we are given 2 exponents and either the modulus or one of the primes
647 * we calculate k*phi = d*e-1, where k is an integer less than d which
648 * divides d*e-1. We find factor k so we can isolate phi.
649 * phi = (p-1)(q-1)
650 * If one of the primes are given, we can use phi to find the other prime
651 * as follows: q = (phi/(p-1)) + 1. We now have 2 primes and an
652 * exponent. (NOTE: if more then one prime meets this condition, the
653 * operation will fail. See comments elsewhere in this file about this).
654 * If the modulus is given, then we can calculate the sum of the primes
655 * as follows: s := (p+q), phi = (p-1)(q-1) = pq -p - q +1, pq = n ->
656 * phi = n - s + 1, s = n - phi +1. Now that we have s = p+q and n=pq,
657 * we can solve our 2 equations and 2 unknowns as follows: q=s-p ->
658 * n=p*(s-p)= sp -p^2 -> p^2-sp+n = 0. Using the quadratic to solve for
659 * p, p=1/2*(s+ sqrt(s*s-4*n)) [q=1/2*(s-sqrt(s*s-4*n)]. We again have
660 * 2 primes and an exponent.
661 *
662 */
663 SECStatus
664 RSA_PopulatePrivateKey(RSAPrivateKey *key)
665 {
666 PLArenaPool *arena = NULL;
667 PRBool needPublicExponent = PR_TRUE;
668 PRBool needPrivateExponent = PR_TRUE;
669 PRBool hasModulus = PR_FALSE;
670 unsigned int keySizeInBits = 0;
671 int prime_count = 0;
672 /* standard RSA nominclature */
673 mp_int p, q, e, d, n;
674 /* remainder */
675 mp_int r;
676 mp_err err = 0;
677 SECStatus rv = SECFailure;
678
679 MP_DIGITS(&p) = 0;
680 MP_DIGITS(&q) = 0;
681 MP_DIGITS(&e) = 0;
682 MP_DIGITS(&d) = 0;
683 MP_DIGITS(&n) = 0;
684 MP_DIGITS(&r) = 0;
685 CHECK_MPI_OK( mp_init(&p) );
686 CHECK_MPI_OK( mp_init(&q) );
687 CHECK_MPI_OK( mp_init(&e) );
688 CHECK_MPI_OK( mp_init(&d) );
689 CHECK_MPI_OK( mp_init(&n) );
690 CHECK_MPI_OK( mp_init(&r) );
691
692 /* if the key didn't already have an arena, create one. */
693 if (key->arena == NULL) {
694 arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE);
695 if (!arena) {
696 goto cleanup;
697 }
698 key->arena = arena;
699 }
700
701 /* load up the known exponents */
702 if (key->publicExponent.data) {
703 SECITEM_TO_MPINT(key->publicExponent, &e);
704 needPublicExponent = PR_FALSE;
705 }
706 if (key->privateExponent.data) {
707 SECITEM_TO_MPINT(key->privateExponent, &d);
708 needPrivateExponent = PR_FALSE;
709 }
710 if (needPrivateExponent && needPublicExponent) {
711 /* Not enough information, we need at least one exponent */
712 err = MP_BADARG;
713 goto cleanup;
714 }
715
716 /* load up the known primes. If only one prime is given, it will be
717 * assigned 'p'. Once we have both primes, well make sure p is the larger.
718 * The value prime_count tells us howe many we have acquired.
719 */
720 if (key->prime1.data) {
721 int primeLen = key->prime1.len;
722 if (key->prime1.data[0] == 0) {
723 primeLen--;
724 }
725 keySizeInBits = primeLen * 2 * PR_BITS_PER_BYTE;
726 SECITEM_TO_MPINT(key->prime1, &p);
727 prime_count++;
728 }
729 if (key->prime2.data) {
730 int primeLen = key->prime2.len;
731 if (key->prime2.data[0] == 0) {
732 primeLen--;
733 }
734 keySizeInBits = primeLen * 2 * PR_BITS_PER_BYTE;
735 SECITEM_TO_MPINT(key->prime2, prime_count ? &q : &p);
736 prime_count++;
737 }
738 /* load up the modulus */
739 if (key->modulus.data) {
740 int modLen = key->modulus.len;
741 if (key->modulus.data[0] == 0) {
742 modLen--;
743 }
744 keySizeInBits = modLen * PR_BITS_PER_BYTE;
745 SECITEM_TO_MPINT(key->modulus, &n);
746 hasModulus = PR_TRUE;
747 }
748 /* if we have the modulus and one prime, calculate the second. */
749 if ((prime_count == 1) && (hasModulus)) {
750 mp_div(&n,&p,&q,&r);
751 if (mp_cmp_z(&r) != 0) {
752 /* p is not a factor or n, fail */
753 err = MP_BADARG;
754 goto cleanup;
755 }
756 prime_count++;
757 }
758
759 /* If we didn't have enough primes try to calculate the primes from
760 * the exponents */
761 if (prime_count < 2) {
762 /* if we don't have at least 2 primes at this point, then we need both
763 * exponents and one prime or a modulus*/
764 if (!needPublicExponent && !needPrivateExponent &&
765 ((prime_count > 0) || hasModulus)) {
766 CHECK_MPI_OK(rsa_get_primes_from_exponents(&e,&d,&p,&q,
767 &n,hasModulus,keySizeInBits));
768 } else {
769 /* not enough given parameters to get both primes */
770 err = MP_BADARG;
771 goto cleanup;
772 }
773 }
774
775 /* Assure p > q */
776 /* NOTE: PKCS #1 does not require p > q, and NSS doesn't use any
777 * implementation optimization that requires p > q. We can remove
778 * this code in the future.
779 */
780 if (mp_cmp(&p, &q) < 0)
781 mp_exch(&p, &q);
782
783 /* we now have our 2 primes and at least one exponent, we can fill
784 * in the key */
785 rv = rsa_build_from_primes(&p, &q,
786 &e, needPublicExponent,
787 &d, needPrivateExponent,
788 key, keySizeInBits);
789 cleanup:
790 mp_clear(&p);
791 mp_clear(&q);
792 mp_clear(&e);
793 mp_clear(&d);
794 mp_clear(&n);
795 mp_clear(&r);
796 if (err) {
797 MP_TO_SEC_ERROR(err);
798 rv = SECFailure;
799 }
800 if (rv && arena) {
801 PORT_FreeArena(arena, PR_TRUE);
802 key->arena = NULL;
803 }
804 return rv;
805 }
806
807 static unsigned int
808 rsa_modulusLen(SECItem *modulus)
809 {
810 unsigned char byteZero = modulus->data[0];
811 unsigned int modLen = modulus->len - !byteZero;
812 return modLen;
813 }
814
815 /*
816 ** Perform a raw public-key operation
817 ** Length of input and output buffers are equal to key's modulus len.
818 */
819 SECStatus
820 RSA_PublicKeyOp(RSAPublicKey *key,
821 unsigned char *output,
822 const unsigned char *input)
823 {
824 unsigned int modLen, expLen, offset;
825 mp_int n, e, m, c;
826 mp_err err = MP_OKAY;
827 SECStatus rv = SECSuccess;
828 if (!key || !output || !input) {
829 PORT_SetError(SEC_ERROR_INVALID_ARGS);
830 return SECFailure;
831 }
832 MP_DIGITS(&n) = 0;
833 MP_DIGITS(&e) = 0;
834 MP_DIGITS(&m) = 0;
835 MP_DIGITS(&c) = 0;
836 CHECK_MPI_OK( mp_init(&n) );
837 CHECK_MPI_OK( mp_init(&e) );
838 CHECK_MPI_OK( mp_init(&m) );
839 CHECK_MPI_OK( mp_init(&c) );
840 modLen = rsa_modulusLen(&key->modulus);
841 expLen = rsa_modulusLen(&key->publicExponent);
842 /* 1. Obtain public key (n, e) */
843 if (BAD_RSA_KEY_SIZE(modLen, expLen)) {
844 PORT_SetError(SEC_ERROR_INVALID_KEY);
845 rv = SECFailure;
846 goto cleanup;
847 }
848 SECITEM_TO_MPINT(key->modulus, &n);
849 SECITEM_TO_MPINT(key->publicExponent, &e);
850 if (e.used > n.used) {
851 /* exponent should not be greater than modulus */
852 PORT_SetError(SEC_ERROR_INVALID_KEY);
853 rv = SECFailure;
854 goto cleanup;
855 }
856 /* 2. check input out of range (needs to be in range [0..n-1]) */
857 offset = (key->modulus.data[0] == 0) ? 1 : 0; /* may be leading 0 */
858 if (memcmp(input, key->modulus.data + offset, modLen) >= 0) {
859 PORT_SetError(SEC_ERROR_INPUT_LEN);
860 rv = SECFailure;
861 goto cleanup;
862 }
863 /* 2 bis. Represent message as integer in range [0..n-1] */
864 CHECK_MPI_OK( mp_read_unsigned_octets(&m, input, modLen) );
865 /* 3. Compute c = m**e mod n */
866 #ifdef USE_MPI_EXPT_D
867 /* XXX see which is faster */
868 if (MP_USED(&e) == 1) {
869 CHECK_MPI_OK( mp_exptmod_d(&m, MP_DIGIT(&e, 0), &n, &c) );
870 } else
871 #endif
872 CHECK_MPI_OK( mp_exptmod(&m, &e, &n, &c) );
873 /* 4. result c is ciphertext */
874 err = mp_to_fixlen_octets(&c, output, modLen);
875 if (err >= 0) err = MP_OKAY;
876 cleanup:
877 mp_clear(&n);
878 mp_clear(&e);
879 mp_clear(&m);
880 mp_clear(&c);
881 if (err) {
882 MP_TO_SEC_ERROR(err);
883 rv = SECFailure;
884 }
885 return rv;
886 }
887
888 /*
889 ** RSA Private key operation (no CRT).
890 */
891 static SECStatus
892 rsa_PrivateKeyOpNoCRT(RSAPrivateKey *key, mp_int *m, mp_int *c, mp_int *n,
893 unsigned int modLen)
894 {
895 mp_int d;
896 mp_err err = MP_OKAY;
897 SECStatus rv = SECSuccess;
898 MP_DIGITS(&d) = 0;
899 CHECK_MPI_OK( mp_init(&d) );
900 SECITEM_TO_MPINT(key->privateExponent, &d);
901 /* 1. m = c**d mod n */
902 CHECK_MPI_OK( mp_exptmod(c, &d, n, m) );
903 cleanup:
904 mp_clear(&d);
905 if (err) {
906 MP_TO_SEC_ERROR(err);
907 rv = SECFailure;
908 }
909 return rv;
910 }
911
912 /*
913 ** RSA Private key operation using CRT.
914 */
915 static SECStatus
916 rsa_PrivateKeyOpCRTNoCheck(RSAPrivateKey *key, mp_int *m, mp_int *c)
917 {
918 mp_int p, q, d_p, d_q, qInv;
919 mp_int m1, m2, h, ctmp;
920 mp_err err = MP_OKAY;
921 SECStatus rv = SECSuccess;
922 MP_DIGITS(&p) = 0;
923 MP_DIGITS(&q) = 0;
924 MP_DIGITS(&d_p) = 0;
925 MP_DIGITS(&d_q) = 0;
926 MP_DIGITS(&qInv) = 0;
927 MP_DIGITS(&m1) = 0;
928 MP_DIGITS(&m2) = 0;
929 MP_DIGITS(&h) = 0;
930 MP_DIGITS(&ctmp) = 0;
931 CHECK_MPI_OK( mp_init(&p) );
932 CHECK_MPI_OK( mp_init(&q) );
933 CHECK_MPI_OK( mp_init(&d_p) );
934 CHECK_MPI_OK( mp_init(&d_q) );
935 CHECK_MPI_OK( mp_init(&qInv) );
936 CHECK_MPI_OK( mp_init(&m1) );
937 CHECK_MPI_OK( mp_init(&m2) );
938 CHECK_MPI_OK( mp_init(&h) );
939 CHECK_MPI_OK( mp_init(&ctmp) );
940 /* copy private key parameters into mp integers */
941 SECITEM_TO_MPINT(key->prime1, &p); /* p */
942 SECITEM_TO_MPINT(key->prime2, &q); /* q */
943 SECITEM_TO_MPINT(key->exponent1, &d_p); /* d_p = d mod (p-1) */
944 SECITEM_TO_MPINT(key->exponent2, &d_q); /* d_q = d mod (q-1) */
945 SECITEM_TO_MPINT(key->coefficient, &qInv); /* qInv = q**-1 mod p */
946 /* 1. m1 = c**d_p mod p */
947 CHECK_MPI_OK( mp_mod(c, &p, &ctmp) );
948 CHECK_MPI_OK( mp_exptmod(&ctmp, &d_p, &p, &m1) );
949 /* 2. m2 = c**d_q mod q */
950 CHECK_MPI_OK( mp_mod(c, &q, &ctmp) );
951 CHECK_MPI_OK( mp_exptmod(&ctmp, &d_q, &q, &m2) );
952 /* 3. h = (m1 - m2) * qInv mod p */
953 CHECK_MPI_OK( mp_submod(&m1, &m2, &p, &h) );
954 CHECK_MPI_OK( mp_mulmod(&h, &qInv, &p, &h) );
955 /* 4. m = m2 + h * q */
956 CHECK_MPI_OK( mp_mul(&h, &q, m) );
957 CHECK_MPI_OK( mp_add(m, &m2, m) );
958 cleanup:
959 mp_clear(&p);
960 mp_clear(&q);
961 mp_clear(&d_p);
962 mp_clear(&d_q);
963 mp_clear(&qInv);
964 mp_clear(&m1);
965 mp_clear(&m2);
966 mp_clear(&h);
967 mp_clear(&ctmp);
968 if (err) {
969 MP_TO_SEC_ERROR(err);
970 rv = SECFailure;
971 }
972 return rv;
973 }
974
975 /*
976 ** An attack against RSA CRT was described by Boneh, DeMillo, and Lipton in:
977 ** "On the Importance of Eliminating Errors in Cryptographic Computations",
978 ** http://theory.stanford.edu/~dabo/papers/faults.ps.gz
979 **
980 ** As a defense against the attack, carry out the private key operation,
981 ** followed up with a public key operation to invert the result.
982 ** Verify that result against the input.
983 */
984 static SECStatus
985 rsa_PrivateKeyOpCRTCheckedPubKey(RSAPrivateKey *key, mp_int *m, mp_int *c)
986 {
987 mp_int n, e, v;
988 mp_err err = MP_OKAY;
989 SECStatus rv = SECSuccess;
990 MP_DIGITS(&n) = 0;
991 MP_DIGITS(&e) = 0;
992 MP_DIGITS(&v) = 0;
993 CHECK_MPI_OK( mp_init(&n) );
994 CHECK_MPI_OK( mp_init(&e) );
995 CHECK_MPI_OK( mp_init(&v) );
996 CHECK_SEC_OK( rsa_PrivateKeyOpCRTNoCheck(key, m, c) );
997 SECITEM_TO_MPINT(key->modulus, &n);
998 SECITEM_TO_MPINT(key->publicExponent, &e);
999 /* Perform a public key operation v = m ** e mod n */
1000 CHECK_MPI_OK( mp_exptmod(m, &e, &n, &v) );
1001 if (mp_cmp(&v, c) != 0) {
1002 rv = SECFailure;
1003 }
1004 cleanup:
1005 mp_clear(&n);
1006 mp_clear(&e);
1007 mp_clear(&v);
1008 if (err) {
1009 MP_TO_SEC_ERROR(err);
1010 rv = SECFailure;
1011 }
1012 return rv;
1013 }
1014
1015 static PRCallOnceType coBPInit = { 0, 0, 0 };
1016 static PRStatus
1017 init_blinding_params_list(void)
1018 {
1019 blindingParamsList.lock = PZ_NewLock(nssILockOther);
1020 if (!blindingParamsList.lock) {
1021 PORT_SetError(SEC_ERROR_NO_MEMORY);
1022 return PR_FAILURE;
1023 }
1024 blindingParamsList.cVar = PR_NewCondVar( blindingParamsList.lock );
1025 if (!blindingParamsList.cVar) {
1026 PORT_SetError(SEC_ERROR_NO_MEMORY);
1027 return PR_FAILURE;
1028 }
1029 blindingParamsList.waitCount = 0;
1030 PR_INIT_CLIST(&blindingParamsList.head);
1031 return PR_SUCCESS;
1032 }
1033
1034 static SECStatus
1035 generate_blinding_params(RSAPrivateKey *key, mp_int* f, mp_int* g, mp_int *n,
1036 unsigned int modLen)
1037 {
1038 SECStatus rv = SECSuccess;
1039 mp_int e, k;
1040 mp_err err = MP_OKAY;
1041 unsigned char *kb = NULL;
1042
1043 MP_DIGITS(&e) = 0;
1044 MP_DIGITS(&k) = 0;
1045 CHECK_MPI_OK( mp_init(&e) );
1046 CHECK_MPI_OK( mp_init(&k) );
1047 SECITEM_TO_MPINT(key->publicExponent, &e);
1048 /* generate random k < n */
1049 kb = PORT_Alloc(modLen);
1050 if (!kb) {
1051 PORT_SetError(SEC_ERROR_NO_MEMORY);
1052 goto cleanup;
1053 }
1054 CHECK_SEC_OK( RNG_GenerateGlobalRandomBytes(kb, modLen) );
1055 CHECK_MPI_OK( mp_read_unsigned_octets(&k, kb, modLen) );
1056 /* k < n */
1057 CHECK_MPI_OK( mp_mod(&k, n, &k) );
1058 /* f = k**e mod n */
1059 CHECK_MPI_OK( mp_exptmod(&k, &e, n, f) );
1060 /* g = k**-1 mod n */
1061 CHECK_MPI_OK( mp_invmod(&k, n, g) );
1062 cleanup:
1063 if (kb)
1064 PORT_ZFree(kb, modLen);
1065 mp_clear(&k);
1066 mp_clear(&e);
1067 if (err) {
1068 MP_TO_SEC_ERROR(err);
1069 rv = SECFailure;
1070 }
1071 return rv;
1072 }
1073
1074 static SECStatus
1075 init_blinding_params(RSABlindingParams *rsabp, RSAPrivateKey *key,
1076 mp_int *n, unsigned int modLen)
1077 {
1078 blindingParams * bp = rsabp->array;
1079 int i = 0;
1080
1081 /* Initialize the list pointer for the element */
1082 PR_INIT_CLIST(&rsabp->link);
1083 for (i = 0; i < RSA_BLINDING_PARAMS_MAX_CACHE_SIZE; ++i, ++bp) {
1084 bp->next = bp + 1;
1085 MP_DIGITS(&bp->f) = 0;
1086 MP_DIGITS(&bp->g) = 0;
1087 bp->counter = 0;
1088 }
1089 /* The last bp->next value was initialized with out
1090 * of rsabp->array pointer and must be set to NULL
1091 */
1092 rsabp->array[RSA_BLINDING_PARAMS_MAX_CACHE_SIZE - 1].next = NULL;
1093
1094 bp = rsabp->array;
1095 rsabp->bp = NULL;
1096 rsabp->free = bp;
1097
1098 /* List elements are keyed using the modulus */
1099 SECITEM_CopyItem(NULL, &rsabp->modulus, &key->modulus);
1100
1101 return SECSuccess;
1102 }
1103
1104 static SECStatus
1105 get_blinding_params(RSAPrivateKey *key, mp_int *n, unsigned int modLen,
1106 mp_int *f, mp_int *g)
1107 {
1108 RSABlindingParams *rsabp = NULL;
1109 blindingParams *bpUnlinked = NULL;
1110 blindingParams *bp;
1111 PRCList *el;
1112 SECStatus rv = SECSuccess;
1113 mp_err err = MP_OKAY;
1114 int cmp = -1;
1115 PRBool holdingLock = PR_FALSE;
1116
1117 do {
1118 if (blindingParamsList.lock == NULL) {
1119 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
1120 return SECFailure;
1121 }
1122 /* Acquire the list lock */
1123 PZ_Lock(blindingParamsList.lock);
1124 holdingLock = PR_TRUE;
1125
1126 /* Walk the list looking for the private key */
1127 for (el = PR_NEXT_LINK(&blindingParamsList.head);
1128 el != &blindingParamsList.head;
1129 el = PR_NEXT_LINK(el)) {
1130 rsabp = (RSABlindingParams *)el;
1131 cmp = SECITEM_CompareItem(&rsabp->modulus, &key->modulus);
1132 if (cmp >= 0) {
1133 /* The key is found or not in the list. */
1134 break;
1135 }
1136 }
1137
1138 if (cmp) {
1139 /* At this point, the key is not in the list. el should point to
1140 ** the list element before which this key should be inserted.
1141 */
1142 rsabp = PORT_ZNew(RSABlindingParams);
1143 if (!rsabp) {
1144 PORT_SetError(SEC_ERROR_NO_MEMORY);
1145 goto cleanup;
1146 }
1147
1148 rv = init_blinding_params(rsabp, key, n, modLen);
1149 if (rv != SECSuccess) {
1150 PORT_ZFree(rsabp, sizeof(RSABlindingParams));
1151 goto cleanup;
1152 }
1153
1154 /* Insert the new element into the list
1155 ** If inserting in the middle of the list, el points to the link
1156 ** to insert before. Otherwise, the link needs to be appended to
1157 ** the end of the list, which is the same as inserting before the
1158 ** head (since el would have looped back to the head).
1159 */
1160 PR_INSERT_BEFORE(&rsabp->link, el);
1161 }
1162
1163 /* We've found (or created) the RSAblindingParams struct for this key.
1164 * Now, search its list of ready blinding params for a usable one.
1165 */
1166 while (0 != (bp = rsabp->bp)) {
1167 if (--(bp->counter) > 0) {
1168 /* Found a match and there are still remaining uses left */
1169 /* Return the parameters */
1170 CHECK_MPI_OK( mp_copy(&bp->f, f) );
1171 CHECK_MPI_OK( mp_copy(&bp->g, g) );
1172
1173 PZ_Unlock(blindingParamsList.lock);
1174 return SECSuccess;
1175 }
1176 /* exhausted this one, give its values to caller, and
1177 * then retire it.
1178 */
1179 mp_exch(&bp->f, f);
1180 mp_exch(&bp->g, g);
1181 mp_clear( &bp->f );
1182 mp_clear( &bp->g );
1183 bp->counter = 0;
1184 /* Move to free list */
1185 rsabp->bp = bp->next;
1186 bp->next = rsabp->free;
1187 rsabp->free = bp;
1188 /* In case there're threads waiting for new blinding
1189 * value - notify 1 thread the value is ready
1190 */
1191 if (blindingParamsList.waitCount > 0) {
1192 PR_NotifyCondVar( blindingParamsList.cVar );
1193 blindingParamsList.waitCount--;
1194 }
1195 PZ_Unlock(blindingParamsList.lock);
1196 return SECSuccess;
1197 }
1198 /* We did not find a usable set of blinding params. Can we make one? */
1199 /* Find a free bp struct. */
1200 if ((bp = rsabp->free) != NULL) {
1201 /* unlink this bp */
1202 rsabp->free = bp->next;
1203 bp->next = NULL;
1204 bpUnlinked = bp; /* In case we fail */
1205
1206 PZ_Unlock(blindingParamsList.lock);
1207 holdingLock = PR_FALSE;
1208 /* generate blinding parameter values for the current thread */
1209 CHECK_SEC_OK( generate_blinding_params(key, f, g, n, modLen ) );
1210
1211 /* put the blinding parameter values into cache */
1212 CHECK_MPI_OK( mp_init( &bp->f) );
1213 CHECK_MPI_OK( mp_init( &bp->g) );
1214 CHECK_MPI_OK( mp_copy( f, &bp->f) );
1215 CHECK_MPI_OK( mp_copy( g, &bp->g) );
1216
1217 /* Put this at head of queue of usable params. */
1218 PZ_Lock(blindingParamsList.lock);
1219 holdingLock = PR_TRUE;
1220 /* initialize RSABlindingParamsStr */
1221 bp->counter = RSA_BLINDING_PARAMS_MAX_REUSE;
1222 bp->next = rsabp->bp;
1223 rsabp->bp = bp;
1224 bpUnlinked = NULL;
1225 /* In case there're threads waiting for new blinding value
1226 * just notify them the value is ready
1227 */
1228 if (blindingParamsList.waitCount > 0) {
1229 PR_NotifyAllCondVar( blindingParamsList.cVar );
1230 blindingParamsList.waitCount = 0;
1231 }
1232 PZ_Unlock(blindingParamsList.lock);
1233 return SECSuccess;
1234 }
1235 /* Here, there are no usable blinding parameters available,
1236 * and no free bp blocks, presumably because they're all
1237 * actively having parameters generated for them.
1238 * So, we need to wait here and not eat up CPU until some
1239 * change happens.
1240 */
1241 blindingParamsList.waitCount++;
1242 PR_WaitCondVar( blindingParamsList.cVar, PR_INTERVAL_NO_TIMEOUT );
1243 PZ_Unlock(blindingParamsList.lock);
1244 holdingLock = PR_FALSE;
1245 } while (1);
1246
1247 cleanup:
1248 /* It is possible to reach this after the lock is already released. */
1249 if (bpUnlinked) {
1250 if (!holdingLock) {
1251 PZ_Lock(blindingParamsList.lock);
1252 holdingLock = PR_TRUE;
1253 }
1254 bp = bpUnlinked;
1255 mp_clear( &bp->f );
1256 mp_clear( &bp->g );
1257 bp->counter = 0;
1258 /* Must put the unlinked bp back on the free list */
1259 bp->next = rsabp->free;
1260 rsabp->free = bp;
1261 }
1262 if (holdingLock) {
1263 PZ_Unlock(blindingParamsList.lock);
1264 holdingLock = PR_FALSE;
1265 }
1266 if (err) {
1267 MP_TO_SEC_ERROR(err);
1268 }
1269 return SECFailure;
1270 }
1271
1272 /*
1273 ** Perform a raw private-key operation
1274 ** Length of input and output buffers are equal to key's modulus len.
1275 */
1276 static SECStatus
1277 rsa_PrivateKeyOp(RSAPrivateKey *key,
1278 unsigned char *output,
1279 const unsigned char *input,
1280 PRBool check)
1281 {
1282 unsigned int modLen;
1283 unsigned int offset;
1284 SECStatus rv = SECSuccess;
1285 mp_err err;
1286 mp_int n, c, m;
1287 mp_int f, g;
1288 if (!key || !output || !input) {
1289 PORT_SetError(SEC_ERROR_INVALID_ARGS);
1290 return SECFailure;
1291 }
1292 /* check input out of range (needs to be in range [0..n-1]) */
1293 modLen = rsa_modulusLen(&key->modulus);
1294 offset = (key->modulus.data[0] == 0) ? 1 : 0; /* may be leading 0 */
1295 if (memcmp(input, key->modulus.data + offset, modLen) >= 0) {
1296 PORT_SetError(SEC_ERROR_INVALID_ARGS);
1297 return SECFailure;
1298 }
1299 MP_DIGITS(&n) = 0;
1300 MP_DIGITS(&c) = 0;
1301 MP_DIGITS(&m) = 0;
1302 MP_DIGITS(&f) = 0;
1303 MP_DIGITS(&g) = 0;
1304 CHECK_MPI_OK( mp_init(&n) );
1305 CHECK_MPI_OK( mp_init(&c) );
1306 CHECK_MPI_OK( mp_init(&m) );
1307 CHECK_MPI_OK( mp_init(&f) );
1308 CHECK_MPI_OK( mp_init(&g) );
1309 SECITEM_TO_MPINT(key->modulus, &n);
1310 OCTETS_TO_MPINT(input, &c, modLen);
1311 /* If blinding, compute pre-image of ciphertext by multiplying by
1312 ** blinding factor
1313 */
1314 if (nssRSAUseBlinding) {
1315 CHECK_SEC_OK( get_blinding_params(key, &n, modLen, &f, &g) );
1316 /* c' = c*f mod n */
1317 CHECK_MPI_OK( mp_mulmod(&c, &f, &n, &c) );
1318 }
1319 /* Do the private key operation m = c**d mod n */
1320 if ( key->prime1.len == 0 ||
1321 key->prime2.len == 0 ||
1322 key->exponent1.len == 0 ||
1323 key->exponent2.len == 0 ||
1324 key->coefficient.len == 0) {
1325 CHECK_SEC_OK( rsa_PrivateKeyOpNoCRT(key, &m, &c, &n, modLen) );
1326 } else if (check) {
1327 CHECK_SEC_OK( rsa_PrivateKeyOpCRTCheckedPubKey(key, &m, &c) );
1328 } else {
1329 CHECK_SEC_OK( rsa_PrivateKeyOpCRTNoCheck(key, &m, &c) );
1330 }
1331 /* If blinding, compute post-image of plaintext by multiplying by
1332 ** blinding factor
1333 */
1334 if (nssRSAUseBlinding) {
1335 /* m = m'*g mod n */
1336 CHECK_MPI_OK( mp_mulmod(&m, &g, &n, &m) );
1337 }
1338 err = mp_to_fixlen_octets(&m, output, modLen);
1339 if (err >= 0) err = MP_OKAY;
1340 cleanup:
1341 mp_clear(&n);
1342 mp_clear(&c);
1343 mp_clear(&m);
1344 mp_clear(&f);
1345 mp_clear(&g);
1346 if (err) {
1347 MP_TO_SEC_ERROR(err);
1348 rv = SECFailure;
1349 }
1350 return rv;
1351 }
1352
1353 SECStatus
1354 RSA_PrivateKeyOp(RSAPrivateKey *key,
1355 unsigned char *output,
1356 const unsigned char *input)
1357 {
1358 return rsa_PrivateKeyOp(key, output, input, PR_FALSE);
1359 }
1360
1361 SECStatus
1362 RSA_PrivateKeyOpDoubleChecked(RSAPrivateKey *key,
1363 unsigned char *output,
1364 const unsigned char *input)
1365 {
1366 return rsa_PrivateKeyOp(key, output, input, PR_TRUE);
1367 }
1368
1369 SECStatus
1370 RSA_PrivateKeyCheck(const RSAPrivateKey *key)
1371 {
1372 mp_int p, q, n, psub1, qsub1, e, d, d_p, d_q, qInv, res;
1373 mp_err err = MP_OKAY;
1374 SECStatus rv = SECSuccess;
1375 MP_DIGITS(&p) = 0;
1376 MP_DIGITS(&q) = 0;
1377 MP_DIGITS(&n) = 0;
1378 MP_DIGITS(&psub1)= 0;
1379 MP_DIGITS(&qsub1)= 0;
1380 MP_DIGITS(&e) = 0;
1381 MP_DIGITS(&d) = 0;
1382 MP_DIGITS(&d_p) = 0;
1383 MP_DIGITS(&d_q) = 0;
1384 MP_DIGITS(&qInv) = 0;
1385 MP_DIGITS(&res) = 0;
1386 CHECK_MPI_OK( mp_init(&p) );
1387 CHECK_MPI_OK( mp_init(&q) );
1388 CHECK_MPI_OK( mp_init(&n) );
1389 CHECK_MPI_OK( mp_init(&psub1));
1390 CHECK_MPI_OK( mp_init(&qsub1));
1391 CHECK_MPI_OK( mp_init(&e) );
1392 CHECK_MPI_OK( mp_init(&d) );
1393 CHECK_MPI_OK( mp_init(&d_p) );
1394 CHECK_MPI_OK( mp_init(&d_q) );
1395 CHECK_MPI_OK( mp_init(&qInv) );
1396 CHECK_MPI_OK( mp_init(&res) );
1397
1398 if (!key->modulus.data || !key->prime1.data || !key->prime2.data ||
1399 !key->publicExponent.data || !key->privateExponent.data ||
1400 !key->exponent1.data || !key->exponent2.data ||
1401 !key->coefficient.data) {
1402 /* call RSA_PopulatePrivateKey first, if the application wishes to
1403 * recover these parameters */
1404 err = MP_BADARG;
1405 goto cleanup;
1406 }
1407
1408 SECITEM_TO_MPINT(key->modulus, &n);
1409 SECITEM_TO_MPINT(key->prime1, &p);
1410 SECITEM_TO_MPINT(key->prime2, &q);
1411 SECITEM_TO_MPINT(key->publicExponent, &e);
1412 SECITEM_TO_MPINT(key->privateExponent, &d);
1413 SECITEM_TO_MPINT(key->exponent1, &d_p);
1414 SECITEM_TO_MPINT(key->exponent2, &d_q);
1415 SECITEM_TO_MPINT(key->coefficient, &qInv);
1416 /* p and q must be distinct. */
1417 if (mp_cmp(&p, &q) == 0) {
1418 rv = SECFailure;
1419 goto cleanup;
1420 }
1421 #define VERIFY_MPI_EQUAL(m1, m2) \
1422 if (mp_cmp(m1, m2) != 0) { \
1423 rv = SECFailure; \
1424 goto cleanup; \
1425 }
1426 #define VERIFY_MPI_EQUAL_1(m) \
1427 if (mp_cmp_d(m, 1) != 0) { \
1428 rv = SECFailure; \
1429 goto cleanup; \
1430 }
1431 /* n == p * q */
1432 CHECK_MPI_OK( mp_mul(&p, &q, &res) );
1433 VERIFY_MPI_EQUAL(&res, &n);
1434 /* gcd(e, p-1) == 1 */
1435 CHECK_MPI_OK( mp_sub_d(&p, 1, &psub1) );
1436 CHECK_MPI_OK( mp_gcd(&e, &psub1, &res) );
1437 VERIFY_MPI_EQUAL_1(&res);
1438 /* gcd(e, q-1) == 1 */
1439 CHECK_MPI_OK( mp_sub_d(&q, 1, &qsub1) );
1440 CHECK_MPI_OK( mp_gcd(&e, &qsub1, &res) );
1441 VERIFY_MPI_EQUAL_1(&res);
1442 /* d*e == 1 mod p-1 */
1443 CHECK_MPI_OK( mp_mulmod(&d, &e, &psub1, &res) );
1444 VERIFY_MPI_EQUAL_1(&res);
1445 /* d*e == 1 mod q-1 */
1446 CHECK_MPI_OK( mp_mulmod(&d, &e, &qsub1, &res) );
1447 VERIFY_MPI_EQUAL_1(&res);
1448 /* d_p == d mod p-1 */
1449 CHECK_MPI_OK( mp_mod(&d, &psub1, &res) );
1450 VERIFY_MPI_EQUAL(&res, &d_p);
1451 /* d_q == d mod q-1 */
1452 CHECK_MPI_OK( mp_mod(&d, &qsub1, &res) );
1453 VERIFY_MPI_EQUAL(&res, &d_q);
1454 /* q * q**-1 == 1 mod p */
1455 CHECK_MPI_OK( mp_mulmod(&q, &qInv, &p, &res) );
1456 VERIFY_MPI_EQUAL_1(&res);
1457
1458 cleanup:
1459 mp_clear(&n);
1460 mp_clear(&p);
1461 mp_clear(&q);
1462 mp_clear(&psub1);
1463 mp_clear(&qsub1);
1464 mp_clear(&e);
1465 mp_clear(&d);
1466 mp_clear(&d_p);
1467 mp_clear(&d_q);
1468 mp_clear(&qInv);
1469 mp_clear(&res);
1470 if (err) {
1471 MP_TO_SEC_ERROR(err);
1472 rv = SECFailure;
1473 }
1474 return rv;
1475 }
1476
1477 static SECStatus RSA_Init(void)
1478 {
1479 if (PR_CallOnce(&coBPInit, init_blinding_params_list) != PR_SUCCESS) {
1480 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
1481 return SECFailure;
1482 }
1483 return SECSuccess;
1484 }
1485
1486 SECStatus BL_Init(void)
1487 {
1488 return RSA_Init();
1489 }
1490
1491 /* cleanup at shutdown */
1492 void RSA_Cleanup(void)
1493 {
1494 blindingParams * bp = NULL;
1495 if (!coBPInit.initialized)
1496 return;
1497
1498 while (!PR_CLIST_IS_EMPTY(&blindingParamsList.head)) {
1499 RSABlindingParams *rsabp =
1500 (RSABlindingParams *)PR_LIST_HEAD(&blindingParamsList.head);
1501 PR_REMOVE_LINK(&rsabp->link);
1502 /* clear parameters cache */
1503 while (rsabp->bp != NULL) {
1504 bp = rsabp->bp;
1505 rsabp->bp = rsabp->bp->next;
1506 mp_clear( &bp->f );
1507 mp_clear( &bp->g );
1508 }
1509 SECITEM_FreeItem(&rsabp->modulus,PR_FALSE);
1510 PORT_Free(rsabp);
1511 }
1512
1513 if (blindingParamsList.cVar) {
1514 PR_DestroyCondVar(blindingParamsList.cVar);
1515 blindingParamsList.cVar = NULL;
1516 }
1517
1518 if (blindingParamsList.lock) {
1519 SKIP_AFTER_FORK(PZ_DestroyLock(blindingParamsList.lock));
1520 blindingParamsList.lock = NULL;
1521 }
1522
1523 coBPInit.initialized = 0;
1524 coBPInit.inProgress = 0;
1525 coBPInit.status = 0;
1526 }
1527
1528 /*
1529 * need a central place for this function to free up all the memory that
1530 * free_bl may have allocated along the way. Currently only RSA does this,
1531 * so I've put it here for now.
1532 */
1533 void BL_Cleanup(void)
1534 {
1535 RSA_Cleanup();
1536 }
1537
1538 PRBool bl_parentForkedAfterC_Initialize;
1539
1540 /*
1541 * Set fork flag so it can be tested in SKIP_AFTER_FORK on relevant platforms.
1542 */
1543 void BL_SetForkState(PRBool forked)
1544 {
1545 bl_parentForkedAfterC_Initialize = forked;
1546 }
1547

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