/* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ /* * RSA key generation, public key op, private key op. */ #ifdef FREEBL_NO_DEPEND #include "stubs.h" #endif #include "secerr.h" #include "prclist.h" #include "nssilock.h" #include "prinit.h" #include "blapi.h" #include "mpi.h" #include "mpprime.h" #include "mplogic.h" #include "secmpi.h" #include "secitem.h" #include "blapii.h" /* The minimal required randomness is 64 bits */ /* EXP_BLINDING_RANDOMNESS_LEN is the length of the randomness in mp_digits */ /* for 32 bits platforts it is 2 mp_digits (= 2 * 32 bits), for 64 bits it is equal to 128 bits */ #define EXP_BLINDING_RANDOMNESS_LEN ((128 + MP_DIGIT_BIT - 1) / MP_DIGIT_BIT) #define EXP_BLINDING_RANDOMNESS_LEN_BYTES (EXP_BLINDING_RANDOMNESS_LEN * sizeof(mp_digit)) /* ** Number of times to attempt to generate a prime (p or q) from a random ** seed (the seed changes for each iteration). */ #define MAX_PRIME_GEN_ATTEMPTS 10 /* ** Number of times to attempt to generate a key. The primes p and q change ** for each attempt. */ #define MAX_KEY_GEN_ATTEMPTS 10 /* Blinding Parameters max cache size */ #define RSA_BLINDING_PARAMS_MAX_CACHE_SIZE 20 /* exponent should not be greater than modulus */ #define BAD_RSA_KEY_SIZE(modLen, expLen) \ ((expLen) > (modLen) || (modLen) > RSA_MAX_MODULUS_BITS / 8 || \ (expLen) > RSA_MAX_EXPONENT_BITS / 8) struct blindingParamsStr; typedef struct blindingParamsStr blindingParams; struct blindingParamsStr { blindingParams *next; mp_int f, g; /* blinding parameter */ int counter; /* number of remaining uses of (f, g) */ }; /* ** RSABlindingParamsStr ** ** For discussion of Paul Kocher's timing attack against an RSA private key ** operation, see http://www.cryptography.com/timingattack/paper.html. The ** countermeasure to this attack, known as blinding, is also discussed in ** the Handbook of Applied Cryptography, 11.118-11.119. */ struct RSABlindingParamsStr { /* Blinding-specific parameters */ PRCList link; /* link to list of structs */ SECItem modulus; /* list element "key" */ blindingParams *free, *bp; /* Blinding parameters queue */ blindingParams array[RSA_BLINDING_PARAMS_MAX_CACHE_SIZE]; /* precalculate montegomery reduction value */ mp_digit n0i; /* n0i = -( n & MP_DIGIT) ** -1 mod mp_RADIX */ }; typedef struct RSABlindingParamsStr RSABlindingParams; /* ** RSABlindingParamsListStr ** ** List of key-specific blinding params. The arena holds the volatile pool ** of memory for each entry and the list itself. The lock is for list ** operations, in this case insertions and iterations, as well as control ** of the counter for each set of blinding parameters. */ struct RSABlindingParamsListStr { PZLock *lock; /* Lock for the list */ PRCondVar *cVar; /* Condidtion Variable */ int waitCount; /* Number of threads waiting on cVar */ PRCList head; /* Pointer to the list */ }; /* ** The master blinding params list. */ static struct RSABlindingParamsListStr blindingParamsList = { 0 }; /* Number of times to reuse (f, g). Suggested by Paul Kocher */ #define RSA_BLINDING_PARAMS_MAX_REUSE 50 /* Global, allows optional use of blinding. On by default. */ /* Cannot be changed at the moment, due to thread-safety issues. */ static PRBool nssRSAUseBlinding = PR_TRUE; static SECStatus rsa_build_from_primes(const mp_int *p, const mp_int *q, mp_int *e, PRBool needPublicExponent, mp_int *d, PRBool needPrivateExponent, RSAPrivateKey *key, unsigned int keySizeInBits) { mp_int n, phi; mp_int psub1, qsub1, tmp; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; MP_DIGITS(&n) = 0; MP_DIGITS(&phi) = 0; MP_DIGITS(&psub1) = 0; MP_DIGITS(&qsub1) = 0; MP_DIGITS(&tmp) = 0; CHECK_MPI_OK(mp_init(&n)); CHECK_MPI_OK(mp_init(&phi)); CHECK_MPI_OK(mp_init(&psub1)); CHECK_MPI_OK(mp_init(&qsub1)); CHECK_MPI_OK(mp_init(&tmp)); /* p and q must be distinct. */ if (mp_cmp(p, q) == 0) { PORT_SetError(SEC_ERROR_NEED_RANDOM); rv = SECFailure; goto cleanup; } /* 1. Compute n = p*q */ CHECK_MPI_OK(mp_mul(p, q, &n)); /* verify that the modulus has the desired number of bits */ if ((unsigned)mpl_significant_bits(&n) != keySizeInBits) { PORT_SetError(SEC_ERROR_NEED_RANDOM); rv = SECFailure; goto cleanup; } /* at least one exponent must be given */ PORT_Assert(!(needPublicExponent && needPrivateExponent)); /* 2. Compute phi = (p-1)*(q-1) */ CHECK_MPI_OK(mp_sub_d(p, 1, &psub1)); CHECK_MPI_OK(mp_sub_d(q, 1, &qsub1)); if (needPublicExponent || needPrivateExponent) { CHECK_MPI_OK(mp_lcm(&psub1, &qsub1, &phi)); /* 3. Compute d = e**-1 mod(phi) */ /* or e = d**-1 mod(phi) as necessary */ if (needPublicExponent) { err = mp_invmod(d, &phi, e); } else { err = mp_invmod(e, &phi, d); } } else { err = MP_OKAY; } /* Verify that phi(n) and e have no common divisors */ if (err != MP_OKAY) { if (err == MP_UNDEF) { PORT_SetError(SEC_ERROR_NEED_RANDOM); err = MP_OKAY; /* to keep PORT_SetError from being called again */ rv = SECFailure; } goto cleanup; } /* 4. Compute exponent1 = d mod (p-1) */ CHECK_MPI_OK(mp_mod(d, &psub1, &tmp)); MPINT_TO_SECITEM(&tmp, &key->exponent1, key->arena); /* 5. Compute exponent2 = d mod (q-1) */ CHECK_MPI_OK(mp_mod(d, &qsub1, &tmp)); MPINT_TO_SECITEM(&tmp, &key->exponent2, key->arena); /* 6. Compute coefficient = q**-1 mod p */ CHECK_MPI_OK(mp_invmod(q, p, &tmp)); MPINT_TO_SECITEM(&tmp, &key->coefficient, key->arena); /* copy our calculated results, overwrite what is there */ key->modulus.data = NULL; MPINT_TO_SECITEM(&n, &key->modulus, key->arena); key->privateExponent.data = NULL; MPINT_TO_SECITEM(d, &key->privateExponent, key->arena); key->publicExponent.data = NULL; MPINT_TO_SECITEM(e, &key->publicExponent, key->arena); key->prime1.data = NULL; MPINT_TO_SECITEM(p, &key->prime1, key->arena); key->prime2.data = NULL; MPINT_TO_SECITEM(q, &key->prime2, key->arena); cleanup: mp_clear(&n); mp_clear(&phi); mp_clear(&psub1); mp_clear(&qsub1); mp_clear(&tmp); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } SECStatus generate_prime(mp_int *prime, int primeLen) { mp_err err = MP_OKAY; SECStatus rv = SECSuccess; int piter; unsigned char *pb = NULL; pb = PORT_Alloc(primeLen); if (!pb) { PORT_SetError(SEC_ERROR_NO_MEMORY); goto cleanup; } for (piter = 0; piter < MAX_PRIME_GEN_ATTEMPTS; piter++) { CHECK_SEC_OK(RNG_GenerateGlobalRandomBytes(pb, primeLen)); pb[0] |= 0xC0; /* set two high-order bits */ pb[primeLen - 1] |= 0x01; /* set low-order bit */ CHECK_MPI_OK(mp_read_unsigned_octets(prime, pb, primeLen)); err = mpp_make_prime_secure(prime, primeLen * 8, PR_FALSE); if (err != MP_NO) goto cleanup; /* keep going while err == MP_NO */ } cleanup: if (pb) PORT_ZFree(pb, primeLen); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } /* * make sure the key components meet fips186 requirements. */ static PRBool rsa_fips186_verify(mp_int *p, mp_int *q, mp_int *d, int keySizeInBits) { mp_int pq_diff; mp_err err = MP_OKAY; PRBool ret = PR_FALSE; if (keySizeInBits < 250) { /* not a valid FIPS length, no point in our other tests */ /* if you are here, and in FIPS mode, you are outside the security * policy */ return PR_TRUE; } /* p & q are already known to be greater then sqrt(2)*2^(keySize/2-1) */ /* we also know that gcd(p-1,e) = 1 and gcd(q-1,e) = 1 because the * mp_invmod() function will fail. */ /* now check p-q > 2^(keysize/2-100) */ MP_DIGITS(&pq_diff) = 0; CHECK_MPI_OK(mp_init(&pq_diff)); /* NSS always has p > q, so we know pq_diff is positive */ CHECK_MPI_OK(mp_sub(p, q, &pq_diff)); if ((unsigned)mpl_significant_bits(&pq_diff) < (keySizeInBits / 2 - 100)) { goto cleanup; } /* now verify d is large enough*/ if ((unsigned)mpl_significant_bits(d) < (keySizeInBits / 2)) { goto cleanup; } ret = PR_TRUE; cleanup: mp_clear(&pq_diff); return ret; } /* ** Generate and return a new RSA public and private key. ** Both keys are encoded in a single RSAPrivateKey structure. ** "cx" is the random number generator context ** "keySizeInBits" is the size of the key to be generated, in bits. ** 512, 1024, etc. ** "publicExponent" when not NULL is a pointer to some data that ** represents the public exponent to use. The data is a byte ** encoded integer, in "big endian" order. */ RSAPrivateKey * RSA_NewKey(int keySizeInBits, SECItem *publicExponent) { unsigned int primeLen; mp_int p = { 0, 0, 0, NULL }; mp_int q = { 0, 0, 0, NULL }; mp_int e = { 0, 0, 0, NULL }; mp_int d = { 0, 0, 0, NULL }; int kiter; int max_attempts; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; int prerr = 0; RSAPrivateKey *key = NULL; PLArenaPool *arena = NULL; /* Require key size to be a multiple of 16 bits. */ if (!publicExponent || keySizeInBits % 16 != 0 || BAD_RSA_KEY_SIZE((unsigned int)keySizeInBits / 8, publicExponent->len)) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return NULL; } /* 1. Set the public exponent and check if it's uneven and greater than 2.*/ MP_DIGITS(&e) = 0; CHECK_MPI_OK(mp_init(&e)); SECITEM_TO_MPINT(*publicExponent, &e); if (mp_iseven(&e) || !(mp_cmp_d(&e, 2) > 0)) { PORT_SetError(SEC_ERROR_INVALID_ARGS); goto cleanup; } #ifndef NSS_FIPS_DISABLED /* Check that the exponent is not smaller than 65537 */ if (mp_cmp_d(&e, 0x10001) < 0) { PORT_SetError(SEC_ERROR_INVALID_ARGS); goto cleanup; } #endif /* 2. Allocate arena & key */ arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE); if (!arena) { PORT_SetError(SEC_ERROR_NO_MEMORY); goto cleanup; } key = PORT_ArenaZNew(arena, RSAPrivateKey); if (!key) { PORT_SetError(SEC_ERROR_NO_MEMORY); goto cleanup; } key->arena = arena; /* length of primes p and q (in bytes) */ primeLen = keySizeInBits / (2 * PR_BITS_PER_BYTE); MP_DIGITS(&p) = 0; MP_DIGITS(&q) = 0; MP_DIGITS(&d) = 0; CHECK_MPI_OK(mp_init(&p)); CHECK_MPI_OK(mp_init(&q)); CHECK_MPI_OK(mp_init(&d)); /* 3. Set the version number (PKCS1 v1.5 says it should be zero) */ SECITEM_AllocItem(arena, &key->version, 1); key->version.data[0] = 0; kiter = 0; max_attempts = 5 * (keySizeInBits / 2); /* FIPS 186-4 B.3.3 steps 4.7 and 5.8 */ do { PORT_SetError(0); CHECK_SEC_OK(generate_prime(&p, primeLen)); CHECK_SEC_OK(generate_prime(&q, primeLen)); /* Assure p > q */ /* NOTE: PKCS #1 does not require p > q, and NSS doesn't use any * implementation optimization that requires p > q. We can remove * this code in the future. */ if (mp_cmp(&p, &q) < 0) mp_exch(&p, &q); /* Attempt to use these primes to generate a key */ rv = rsa_build_from_primes(&p, &q, &e, PR_FALSE, /* needPublicExponent=false */ &d, PR_TRUE, /* needPrivateExponent=true */ key, keySizeInBits); if (rv == SECSuccess) { if (rsa_fips186_verify(&p, &q, &d, keySizeInBits)) { break; } prerr = SEC_ERROR_NEED_RANDOM; /* retry with different values */ } else { prerr = PORT_GetError(); } kiter++; /* loop until have primes */ } while (prerr == SEC_ERROR_NEED_RANDOM && kiter < max_attempts); cleanup: mp_clear(&p); mp_clear(&q); mp_clear(&e); mp_clear(&d); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } if (rv && arena) { PORT_FreeArena(arena, PR_TRUE); key = NULL; } return key; } mp_err rsa_is_prime(mp_int *p) { int res; /* run a Fermat test */ res = mpp_fermat(p, 2); if (res != MP_OKAY) { return res; } /* If that passed, run some Miller-Rabin tests */ res = mpp_pprime_secure(p, 2); return res; } /* * Factorize a RSA modulus n into p and q by using the exponents e and d. * * In: e, d, n * Out: p, q * * See Handbook of Applied Cryptography, 8.2.2(i). * * The algorithm is probabilistic, it is run 64 times and each run has a 50% * chance of succeeding with a runtime of O(log(e*d)). * * The returned p might be smaller than q. */ static mp_err rsa_factorize_n_from_exponents(mp_int *e, mp_int *d, mp_int *p, mp_int *q, mp_int *n) { /* lambda is the private modulus: e*d = 1 mod lambda */ /* so: e*d - 1 = k*lambda = t*2^s where t is odd */ mp_int klambda; mp_int t, onetwentyeight; unsigned long s = 0; unsigned long i; /* cand = a^(t * 2^i) mod n, next_cand = a^(t * 2^(i+1)) mod n */ mp_int a; mp_int cand; mp_int next_cand; mp_int n_minus_one; mp_err err = MP_OKAY; MP_DIGITS(&klambda) = 0; MP_DIGITS(&t) = 0; MP_DIGITS(&a) = 0; MP_DIGITS(&cand) = 0; MP_DIGITS(&n_minus_one) = 0; MP_DIGITS(&next_cand) = 0; MP_DIGITS(&onetwentyeight) = 0; CHECK_MPI_OK(mp_init(&klambda)); CHECK_MPI_OK(mp_init(&t)); CHECK_MPI_OK(mp_init(&a)); CHECK_MPI_OK(mp_init(&cand)); CHECK_MPI_OK(mp_init(&n_minus_one)); CHECK_MPI_OK(mp_init(&next_cand)); CHECK_MPI_OK(mp_init(&onetwentyeight)); mp_set_int(&onetwentyeight, 128); /* calculate k*lambda = e*d - 1 */ CHECK_MPI_OK(mp_mul(e, d, &klambda)); CHECK_MPI_OK(mp_sub_d(&klambda, 1, &klambda)); /* factorize klambda into t*2^s */ CHECK_MPI_OK(mp_copy(&klambda, &t)); while (mpp_divis_d(&t, 2) == MP_YES) { CHECK_MPI_OK(mp_div_2(&t, &t)); s += 1; } /* precompute n_minus_one = n - 1 */ CHECK_MPI_OK(mp_copy(n, &n_minus_one)); CHECK_MPI_OK(mp_sub_d(&n_minus_one, 1, &n_minus_one)); /* pick random bases a, each one has a 50% leading to a factorization */ CHECK_MPI_OK(mp_set_int(&a, 2)); /* The following is equivalent to for (a=2, a <= 128, a+=2) */ while (mp_cmp(&a, &onetwentyeight) <= 0) { /* compute the base cand = a^(t * 2^0) [i = 0] */ CHECK_MPI_OK(mp_exptmod(&a, &t, n, &cand)); for (i = 0; i < s; i++) { /* condition 1: skip the base if we hit a trivial factor of n */ if (mp_cmp(&cand, &n_minus_one) == 0 || mp_cmp_d(&cand, 1) == 0) { break; } /* increase i in a^(t * 2^i) by squaring the number */ CHECK_MPI_OK(mp_exptmod_d(&cand, 2, n, &next_cand)); /* condition 2: a^(t * 2^(i+1)) = 1 mod n */ if (mp_cmp_d(&next_cand, 1) == 0) { /* conditions verified, gcd(a^(t * 2^i) - 1, n) is a factor */ CHECK_MPI_OK(mp_sub_d(&cand, 1, &cand)); CHECK_MPI_OK(mp_gcd(&cand, n, p)); if (mp_cmp_d(p, 1) == 0) { CHECK_MPI_OK(mp_add_d(&cand, 1, &cand)); break; } CHECK_MPI_OK(mp_div(n, p, q, NULL)); goto cleanup; } CHECK_MPI_OK(mp_copy(&next_cand, &cand)); } CHECK_MPI_OK(mp_add_d(&a, 2, &a)); } /* if we reach here it's likely (2^64 - 1 / 2^64) that d is wrong */ err = MP_RANGE; cleanup: mp_clear(&klambda); mp_clear(&t); mp_clear(&a); mp_clear(&cand); mp_clear(&n_minus_one); mp_clear(&next_cand); mp_clear(&onetwentyeight); return err; } /* * Try to find the two primes based on 2 exponents plus a prime. * * In: e, d and p. * Out: p,q. * * Step 1, Since d = e**-1 mod phi, we know that d*e == 1 mod phi, or * d*e = 1+k*phi, or d*e-1 = k*phi. since d is less than phi and e is * usually less than d, then k must be an integer between e-1 and 1 * (probably on the order of e). * Step 1a, We can divide k*phi by prime-1 and get k*(q-1). This will reduce * the size of our division through the rest of the loop. * Step 2, Loop through the values k=e-1 to 1 looking for k. k should be on * the order or e, and e is typically small. This may take a while for * a large random e. We are looking for a k that divides kphi * evenly. Once we find a k that divides kphi evenly, we assume it * is the true k. It's possible this k is not the 'true' k but has * swapped factors of p-1 and/or q-1. Because of this, we * tentatively continue Steps 3-6 inside this loop, and may return looking * for another k on failure. * Step 3, Calculate our tentative phi=kphi/k. Note: real phi is (p-1)*(q-1). * Step 4a, kphi is k*(q-1), so phi is our tenative q-1. q = phi+1. * If k is correct, q should be the right length and prime. * Step 4b, It's possible q-1 and k could have swapped factors. We now have a * possible solution that meets our criteria. It may not be the only * solution, however, so we keep looking. If we find more than one, * we will fail since we cannot determine which is the correct * solution, and returning the wrong modulus will compromise both * moduli. If no other solution is found, we return the unique solution. * * This will return p & q. q may be larger than p in the case that p was given * and it was the smaller prime. */ static mp_err rsa_get_prime_from_exponents(mp_int *e, mp_int *d, mp_int *p, mp_int *q, mp_int *n, unsigned int keySizeInBits) { mp_int kphi; /* k*phi */ mp_int k; /* current guess at 'k' */ mp_int phi; /* (p-1)(q-1) */ mp_int r; /* remainder */ mp_int tmp; /* p-1 if p is given */ mp_err err = MP_OKAY; unsigned int order_k; MP_DIGITS(&kphi) = 0; MP_DIGITS(&phi) = 0; MP_DIGITS(&k) = 0; MP_DIGITS(&r) = 0; MP_DIGITS(&tmp) = 0; CHECK_MPI_OK(mp_init(&kphi)); CHECK_MPI_OK(mp_init(&phi)); CHECK_MPI_OK(mp_init(&k)); CHECK_MPI_OK(mp_init(&r)); CHECK_MPI_OK(mp_init(&tmp)); /* our algorithm looks for a factor k whose maximum size is dependent * on the size of our smallest exponent, which had better be the public * exponent (if it's the private, the key is vulnerable to a brute force * attack). * * since our factor search is linear, we need to limit the maximum * size of the public key. this should not be a problem normally, since * public keys are usually small. * * if we want to handle larger public key sizes, we should have * a version which tries to 'completely' factor k*phi (where completely * means 'factor into primes, or composites with which are products of * large primes). Once we have all the factors, we can sort them out and * try different combinations to form our phi. The risk is if (p-1)/2, * (q-1)/2, and k are all large primes. In any case if the public key * is small (order of 20 some bits), then a linear search for k is * manageable. */ if (mpl_significant_bits(e) > 23) { err = MP_RANGE; goto cleanup; } /* calculate k*phi = e*d - 1 */ CHECK_MPI_OK(mp_mul(e, d, &kphi)); CHECK_MPI_OK(mp_sub_d(&kphi, 1, &kphi)); /* kphi is (e*d)-1, which is the same as k*(p-1)(q-1) * d < (p-1)(q-1), therefor k must be less than e-1 * We can narrow down k even more, though. Since p and q are odd and both * have their high bit set, then we know that phi must be on order of * keySizeBits. */ order_k = (unsigned)mpl_significant_bits(&kphi) - keySizeInBits; if (order_k <= 1) { err = MP_RANGE; goto cleanup; } /* for (k=kinit; order(k) >= order_k; k--) { */ /* k=kinit: k can't be bigger than kphi/2^(keySizeInBits -1) */ CHECK_MPI_OK(mp_2expt(&k, keySizeInBits - 1)); CHECK_MPI_OK(mp_div(&kphi, &k, &k, NULL)); if (mp_cmp(&k, e) >= 0) { /* also can't be bigger then e-1 */ CHECK_MPI_OK(mp_sub_d(e, 1, &k)); } /* calculate our temp value */ /* This saves recalculating this value when the k guess is wrong, which * is reasonably frequent. */ /* tmp = p-1 (used to calculate q-1= phi/tmp) */ CHECK_MPI_OK(mp_sub_d(p, 1, &tmp)); CHECK_MPI_OK(mp_div(&kphi, &tmp, &kphi, &r)); if (mp_cmp_z(&r) != 0) { /* p-1 doesn't divide kphi, some parameter wasn't correct */ err = MP_RANGE; goto cleanup; } mp_zero(q); /* kphi is now k*(q-1) */ /* rest of the for loop */ for (; (err == MP_OKAY) && (mpl_significant_bits(&k) >= order_k); err = mp_sub_d(&k, 1, &k)) { CHECK_MPI_OK(err); /* looking for k as a factor of kphi */ CHECK_MPI_OK(mp_div(&kphi, &k, &phi, &r)); if (mp_cmp_z(&r) != 0) { /* not a factor, try the next one */ continue; } /* we have a possible phi, see if it works */ if ((unsigned)mpl_significant_bits(&phi) != keySizeInBits / 2) { /* phi is not the right size */ continue; } /* phi should be divisible by 2, since * q is odd and phi=(q-1). */ if (mpp_divis_d(&phi, 2) == MP_NO) { /* phi is not divisible by 4 */ continue; } /* we now have a candidate for the second prime */ CHECK_MPI_OK(mp_add_d(&phi, 1, &tmp)); /* check to make sure it is prime */ err = rsa_is_prime(&tmp); if (err != MP_OKAY) { if (err == MP_NO) { /* No, then we still have the wrong phi */ continue; } goto cleanup; } /* * It is possible that we have the wrong phi if * k_guess*(q_guess-1) = k*(q-1) (k and q-1 have swapped factors). * since our q_quess is prime, however. We have found a valid * rsa key because: * q is the correct order of magnitude. * phi = (p-1)(q-1) where p and q are both primes. * e*d mod phi = 1. * There is no way to know from the info given if this is the * original key. We never want to return the wrong key because if * two moduli with the same factor is known, then euclid's gcd * algorithm can be used to find that factor. Even though the * caller didn't pass the original modulus, it doesn't mean the * modulus wasn't known or isn't available somewhere. So to be safe * if we can't be sure we have the right q, we don't return any. * * So to make sure we continue looking for other valid q's. If none * are found, then we can safely return this one, otherwise we just * fail */ if (mp_cmp_z(q) != 0) { /* this is the second valid q, don't return either, * just fail */ err = MP_RANGE; break; } /* we only have one q so far, save it and if no others are found, * it's safe to return it */ CHECK_MPI_OK(mp_copy(&tmp, q)); continue; } if ((unsigned)mpl_significant_bits(&k) < order_k) { if (mp_cmp_z(q) == 0) { /* If we get here, something was wrong with the parameters we * were given */ err = MP_RANGE; } } cleanup: mp_clear(&kphi); mp_clear(&phi); mp_clear(&k); mp_clear(&r); mp_clear(&tmp); return err; } /* * take a private key with only a few elements and fill out the missing pieces. * * All the entries will be overwritten with data allocated out of the arena * If no arena is supplied, one will be created. * * The following fields must be supplied in order for this function * to succeed: * one of either publicExponent or privateExponent * two more of the following 5 parameters. * modulus (n) * prime1 (p) * prime2 (q) * publicExponent (e) * privateExponent (d) * * NOTE: if only the publicExponent, privateExponent, and one prime is given, * then there may be more than one RSA key that matches that combination. * * All parameters will be replaced in the key structure with new parameters * Allocated out of the arena. There is no attempt to free the old structures. * Prime1 will always be greater than prime2 (even if the caller supplies the * smaller prime as prime1 or the larger prime as prime2). The parameters are * not overwritten on failure. * * How it works: * We can generate all the parameters from one of the exponents, plus the * two primes. (rsa_build_key_from_primes) * If we are given one of the exponents and both primes, we are done. * If we are given one of the exponents, the modulus and one prime, we * caclulate the second prime by dividing the modulus by the given * prime, giving us an exponent and 2 primes. * If we are given 2 exponents and one of the primes we calculate * k*phi = d*e-1, where k is an integer less than d which * divides d*e-1. We find factor k so we can isolate phi. * phi = (p-1)(q-1) * We can use phi to find the other prime as follows: * q = (phi/(p-1)) + 1. We now have 2 primes and an exponent. * (NOTE: if more then one prime meets this condition, the operation * will fail. See comments elsewhere in this file about this). * (rsa_get_prime_from_exponents) * If we are given 2 exponents and the modulus we factor the modulus to * get the 2 missing primes (rsa_factorize_n_from_exponents) * */ SECStatus RSA_PopulatePrivateKey(RSAPrivateKey *key) { PLArenaPool *arena = NULL; PRBool needPublicExponent = PR_TRUE; PRBool needPrivateExponent = PR_TRUE; PRBool hasModulus = PR_FALSE; unsigned int keySizeInBits = 0; int prime_count = 0; /* standard RSA nominclature */ mp_int p, q, e, d, n; /* remainder */ mp_int r; mp_err err = 0; SECStatus rv = SECFailure; MP_DIGITS(&p) = 0; MP_DIGITS(&q) = 0; MP_DIGITS(&e) = 0; MP_DIGITS(&d) = 0; MP_DIGITS(&n) = 0; MP_DIGITS(&r) = 0; CHECK_MPI_OK(mp_init(&p)); CHECK_MPI_OK(mp_init(&q)); CHECK_MPI_OK(mp_init(&e)); CHECK_MPI_OK(mp_init(&d)); CHECK_MPI_OK(mp_init(&n)); CHECK_MPI_OK(mp_init(&r)); /* if the key didn't already have an arena, create one. */ if (key->arena == NULL) { arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE); if (!arena) { goto cleanup; } key->arena = arena; } /* load up the known exponents */ if (key->publicExponent.data) { SECITEM_TO_MPINT(key->publicExponent, &e); needPublicExponent = PR_FALSE; } if (key->privateExponent.data) { SECITEM_TO_MPINT(key->privateExponent, &d); needPrivateExponent = PR_FALSE; } if (needPrivateExponent && needPublicExponent) { /* Not enough information, we need at least one exponent */ err = MP_BADARG; goto cleanup; } /* load up the known primes. If only one prime is given, it will be * assigned 'p'. Once we have both primes, well make sure p is the larger. * The value prime_count tells us howe many we have acquired. */ if (key->prime1.data) { int primeLen = key->prime1.len; if (key->prime1.data[0] == 0) { primeLen--; } keySizeInBits = primeLen * 2 * PR_BITS_PER_BYTE; SECITEM_TO_MPINT(key->prime1, &p); prime_count++; } if (key->prime2.data) { int primeLen = key->prime2.len; if (key->prime2.data[0] == 0) { primeLen--; } keySizeInBits = primeLen * 2 * PR_BITS_PER_BYTE; SECITEM_TO_MPINT(key->prime2, prime_count ? &q : &p); prime_count++; } /* load up the modulus */ if (key->modulus.data) { int modLen = key->modulus.len; if (key->modulus.data[0] == 0) { modLen--; } keySizeInBits = modLen * PR_BITS_PER_BYTE; SECITEM_TO_MPINT(key->modulus, &n); hasModulus = PR_TRUE; } /* if we have the modulus and one prime, calculate the second. */ if ((prime_count == 1) && (hasModulus)) { if (mp_div(&n, &p, &q, &r) != MP_OKAY || mp_cmp_z(&r) != 0) { /* p is not a factor or n, fail */ err = MP_BADARG; goto cleanup; } prime_count++; } /* If we didn't have enough primes try to calculate the primes from * the exponents */ if (prime_count < 2) { /* if we don't have at least 2 primes at this point, then we need both * exponents and one prime or a modulus*/ if (!needPublicExponent && !needPrivateExponent && (prime_count > 0)) { CHECK_MPI_OK(rsa_get_prime_from_exponents(&e, &d, &p, &q, &n, keySizeInBits)); } else if (!needPublicExponent && !needPrivateExponent && hasModulus) { CHECK_MPI_OK(rsa_factorize_n_from_exponents(&e, &d, &p, &q, &n)); } else { /* not enough given parameters to get both primes */ err = MP_BADARG; goto cleanup; } } /* Assure p > q */ /* NOTE: PKCS #1 does not require p > q, and NSS doesn't use any * implementation optimization that requires p > q. We can remove * this code in the future. */ if (mp_cmp(&p, &q) < 0) mp_exch(&p, &q); /* we now have our 2 primes and at least one exponent, we can fill * in the key */ rv = rsa_build_from_primes(&p, &q, &e, needPublicExponent, &d, needPrivateExponent, key, keySizeInBits); cleanup: mp_clear(&p); mp_clear(&q); mp_clear(&e); mp_clear(&d); mp_clear(&n); mp_clear(&r); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } if (rv && arena) { PORT_FreeArena(arena, PR_TRUE); key->arena = NULL; } return rv; } static unsigned int rsa_modulusLen(SECItem *modulus) { if (modulus->len == 0) { return 0; }; unsigned char byteZero = modulus->data[0]; unsigned int modLen = modulus->len - !byteZero; return modLen; } /* ** Perform a raw public-key operation ** Length of input and output buffers are equal to key's modulus len. */ SECStatus RSA_PublicKeyOp(RSAPublicKey *key, unsigned char *output, const unsigned char *input) { unsigned int modLen, expLen, offset; mp_int n, e, m, c; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; if (!key || !output || !input) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } MP_DIGITS(&n) = 0; MP_DIGITS(&e) = 0; MP_DIGITS(&m) = 0; MP_DIGITS(&c) = 0; CHECK_MPI_OK(mp_init(&n)); CHECK_MPI_OK(mp_init(&e)); CHECK_MPI_OK(mp_init(&m)); CHECK_MPI_OK(mp_init(&c)); modLen = rsa_modulusLen(&key->modulus); expLen = rsa_modulusLen(&key->publicExponent); if (modLen == 0) { PORT_SetError(SEC_ERROR_INVALID_ARGS); rv = SECFailure; goto cleanup; } /* 1. Obtain public key (n, e) */ if (BAD_RSA_KEY_SIZE(modLen, expLen)) { PORT_SetError(SEC_ERROR_INVALID_KEY); rv = SECFailure; goto cleanup; } SECITEM_TO_MPINT(key->modulus, &n); SECITEM_TO_MPINT(key->publicExponent, &e); if (e.used > n.used) { /* exponent should not be greater than modulus */ PORT_SetError(SEC_ERROR_INVALID_KEY); rv = SECFailure; goto cleanup; } /* 2. check input out of range (needs to be in range [0..n-1]) */ offset = (key->modulus.data[0] == 0) ? 1 : 0; /* may be leading 0 */ if (memcmp(input, key->modulus.data + offset, modLen) >= 0) { PORT_SetError(SEC_ERROR_INPUT_LEN); rv = SECFailure; goto cleanup; } /* 2 bis. Represent message as integer in range [0..n-1] */ CHECK_MPI_OK(mp_read_unsigned_octets(&m, input, modLen)); /* 3. Compute c = m**e mod n */ #ifdef USE_MPI_EXPT_D /* XXX see which is faster */ if (MP_USED(&e) == 1) { CHECK_MPI_OK(mp_exptmod_d(&m, MP_DIGIT(&e, 0), &n, &c)); } else #endif CHECK_MPI_OK(mp_exptmod(&m, &e, &n, &c)); /* 4. result c is ciphertext */ err = mp_to_fixlen_octets(&c, output, modLen); if (err >= 0) err = MP_OKAY; cleanup: mp_clear(&n); mp_clear(&e); mp_clear(&m); mp_clear(&c); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } /* ** RSA Private key operation (no CRT). */ static SECStatus rsa_PrivateKeyOpNoCRT(RSAPrivateKey *key, mp_int *m, mp_int *c, mp_int *n, unsigned int modLen) { mp_int d; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; MP_DIGITS(&d) = 0; CHECK_MPI_OK(mp_init(&d)); SECITEM_TO_MPINT(key->privateExponent, &d); /* 1. m = c**d mod n */ CHECK_MPI_OK(mp_exptmod(c, &d, n, m)); cleanup: mp_clear(&d); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } /* ** RSA Private key operation using CRT. */ static SECStatus rsa_PrivateKeyOpCRTNoCheck(RSAPrivateKey *key, mp_int *m, mp_int *c) { mp_int p, q, d_p, d_q, qInv; /* The length of the randomness comes from the papers: https://link.springer.com/chapter/10.1007/978-3-642-29912-4_7 https://link.springer.com/chapter/10.1007/978-3-642-21554-4_5. */ mp_int blinding_dp, blinding_dq, r1, r2; unsigned char random_block[EXP_BLINDING_RANDOMNESS_LEN_BYTES]; mp_int m1, m2, h, ctmp; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; MP_DIGITS(&p) = 0; MP_DIGITS(&q) = 0; MP_DIGITS(&d_p) = 0; MP_DIGITS(&d_q) = 0; MP_DIGITS(&qInv) = 0; MP_DIGITS(&m1) = 0; MP_DIGITS(&m2) = 0; MP_DIGITS(&h) = 0; MP_DIGITS(&ctmp) = 0; MP_DIGITS(&blinding_dp) = 0; MP_DIGITS(&blinding_dq) = 0; MP_DIGITS(&r1) = 0; MP_DIGITS(&r2) = 0; CHECK_MPI_OK(mp_init(&p)); CHECK_MPI_OK(mp_init(&q)); CHECK_MPI_OK(mp_init(&d_p)); CHECK_MPI_OK(mp_init(&d_q)); CHECK_MPI_OK(mp_init(&qInv)); CHECK_MPI_OK(mp_init(&m1)); CHECK_MPI_OK(mp_init(&m2)); CHECK_MPI_OK(mp_init(&h)); CHECK_MPI_OK(mp_init(&ctmp)); CHECK_MPI_OK(mp_init(&blinding_dp)); CHECK_MPI_OK(mp_init(&blinding_dq)); CHECK_MPI_OK(mp_init_size(&r1, EXP_BLINDING_RANDOMNESS_LEN)); CHECK_MPI_OK(mp_init_size(&r2, EXP_BLINDING_RANDOMNESS_LEN)); /* copy private key parameters into mp integers */ SECITEM_TO_MPINT(key->prime1, &p); /* p */ SECITEM_TO_MPINT(key->prime2, &q); /* q */ SECITEM_TO_MPINT(key->exponent1, &d_p); /* d_p = d mod (p-1) */ SECITEM_TO_MPINT(key->exponent2, &d_q); /* d_q = d mod (q-1) */ SECITEM_TO_MPINT(key->coefficient, &qInv); /* qInv = q**-1 mod p */ // blinding_dp = 1 CHECK_MPI_OK(mp_set_int(&blinding_dp, 1)); // blinding_dp = p - 1 CHECK_MPI_OK(mp_sub(&p, &blinding_dp, &blinding_dp)); // generating a random value RNG_GenerateGlobalRandomBytes(random_block, EXP_BLINDING_RANDOMNESS_LEN_BYTES); MP_USED(&r1) = EXP_BLINDING_RANDOMNESS_LEN; memcpy(MP_DIGITS(&r1), random_block, sizeof(random_block)); // blinding_dp = random * (p - 1) CHECK_MPI_OK(mp_mul(&blinding_dp, &r1, &blinding_dp)); //d_p = d_p + random * (p - 1) CHECK_MPI_OK(mp_add(&d_p, &blinding_dp, &d_p)); // blinding_dq = 1 CHECK_MPI_OK(mp_set_int(&blinding_dq, 1)); // blinding_dq = q - 1 CHECK_MPI_OK(mp_sub(&q, &blinding_dq, &blinding_dq)); // generating a random value RNG_GenerateGlobalRandomBytes(random_block, EXP_BLINDING_RANDOMNESS_LEN_BYTES); memcpy(MP_DIGITS(&r2), random_block, sizeof(random_block)); MP_USED(&r2) = EXP_BLINDING_RANDOMNESS_LEN; // blinding_dq = random * (q - 1) CHECK_MPI_OK(mp_mul(&blinding_dq, &r2, &blinding_dq)); //d_q = d_q + random * (q-1) CHECK_MPI_OK(mp_add(&d_q, &blinding_dq, &d_q)); /* 1. m1 = c**d_p mod p */ CHECK_MPI_OK(mp_mod(c, &p, &ctmp)); CHECK_MPI_OK(mp_exptmod(&ctmp, &d_p, &p, &m1)); /* 2. m2 = c**d_q mod q */ CHECK_MPI_OK(mp_mod(c, &q, &ctmp)); CHECK_MPI_OK(mp_exptmod(&ctmp, &d_q, &q, &m2)); /* 3. h = (m1 - m2) * qInv mod p */ CHECK_MPI_OK(mp_submod(&m1, &m2, &p, &h)); CHECK_MPI_OK(mp_mulmod(&h, &qInv, &p, &h)); /* 4. m = m2 + h * q */ CHECK_MPI_OK(mp_mul(&h, &q, m)); CHECK_MPI_OK(mp_add(m, &m2, m)); cleanup: mp_clear(&p); mp_clear(&q); mp_clear(&d_p); mp_clear(&d_q); mp_clear(&qInv); mp_clear(&m1); mp_clear(&m2); mp_clear(&h); mp_clear(&ctmp); mp_clear(&blinding_dp); mp_clear(&blinding_dq); mp_clear(&r1); mp_clear(&r2); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } /* ** An attack against RSA CRT was described by Boneh, DeMillo, and Lipton in: ** "On the Importance of Eliminating Errors in Cryptographic Computations", ** http://theory.stanford.edu/~dabo/papers/faults.ps.gz ** ** As a defense against the attack, carry out the private key operation, ** followed up with a public key operation to invert the result. ** Verify that result against the input. */ static SECStatus rsa_PrivateKeyOpCRTCheckedPubKey(RSAPrivateKey *key, mp_int *m, mp_int *c) { mp_int n, e, v; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; MP_DIGITS(&n) = 0; MP_DIGITS(&e) = 0; MP_DIGITS(&v) = 0; CHECK_MPI_OK(mp_init(&n)); CHECK_MPI_OK(mp_init(&e)); CHECK_MPI_OK(mp_init(&v)); CHECK_SEC_OK(rsa_PrivateKeyOpCRTNoCheck(key, m, c)); SECITEM_TO_MPINT(key->modulus, &n); SECITEM_TO_MPINT(key->publicExponent, &e); /* Perform a public key operation v = m ** e mod n */ CHECK_MPI_OK(mp_exptmod(m, &e, &n, &v)); if (mp_cmp(&v, c) != 0) { rv = SECFailure; } cleanup: mp_clear(&n); mp_clear(&e); mp_clear(&v); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } static PRCallOnceType coBPInit = { 0, 0, 0 }; static PRStatus init_blinding_params_list(void) { blindingParamsList.lock = PZ_NewLock(nssILockOther); if (!blindingParamsList.lock) { PORT_SetError(SEC_ERROR_NO_MEMORY); return PR_FAILURE; } blindingParamsList.cVar = PR_NewCondVar(blindingParamsList.lock); if (!blindingParamsList.cVar) { PORT_SetError(SEC_ERROR_NO_MEMORY); return PR_FAILURE; } blindingParamsList.waitCount = 0; PR_INIT_CLIST(&blindingParamsList.head); return PR_SUCCESS; } static SECStatus generate_blinding_params(RSAPrivateKey *key, mp_int *f, mp_int *g, mp_int *n, unsigned int modLen) { SECStatus rv = SECSuccess; mp_int e, k; mp_err err = MP_OKAY; unsigned char *kb = NULL; MP_DIGITS(&e) = 0; MP_DIGITS(&k) = 0; CHECK_MPI_OK(mp_init(&e)); CHECK_MPI_OK(mp_init(&k)); SECITEM_TO_MPINT(key->publicExponent, &e); /* generate random k < n */ kb = PORT_Alloc(modLen); if (!kb) { PORT_SetError(SEC_ERROR_NO_MEMORY); goto cleanup; } CHECK_SEC_OK(RNG_GenerateGlobalRandomBytes(kb, modLen)); CHECK_MPI_OK(mp_read_unsigned_octets(&k, kb, modLen)); /* k < n */ CHECK_MPI_OK(mp_mod(&k, n, &k)); /* f = k**e mod n */ CHECK_MPI_OK(mp_exptmod(&k, &e, n, f)); /* g = k**-1 mod n */ CHECK_MPI_OK(mp_invmod(&k, n, g)); /* g in montgomery form.. */ CHECK_MPI_OK(mp_to_mont(g, n, g)); cleanup: if (kb) PORT_ZFree(kb, modLen); mp_clear(&k); mp_clear(&e); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } static SECStatus init_blinding_params(RSABlindingParams *rsabp, RSAPrivateKey *key, mp_int *n, unsigned int modLen) { blindingParams *bp = rsabp->array; int i = 0; /* Initialize the list pointer for the element */ PR_INIT_CLIST(&rsabp->link); for (i = 0; i < RSA_BLINDING_PARAMS_MAX_CACHE_SIZE; ++i, ++bp) { bp->next = bp + 1; MP_DIGITS(&bp->f) = 0; MP_DIGITS(&bp->g) = 0; bp->counter = 0; } /* The last bp->next value was initialized with out * of rsabp->array pointer and must be set to NULL */ rsabp->array[RSA_BLINDING_PARAMS_MAX_CACHE_SIZE - 1].next = NULL; bp = rsabp->array; rsabp->bp = NULL; rsabp->free = bp; /* precalculate montgomery reduction parameter */ rsabp->n0i = mp_calculate_mont_n0i(n); /* List elements are keyed using the modulus */ return SECITEM_CopyItem(NULL, &rsabp->modulus, &key->modulus); } static SECStatus get_blinding_params(RSAPrivateKey *key, mp_int *n, unsigned int modLen, mp_int *f, mp_int *g, mp_digit *n0i) { RSABlindingParams *rsabp = NULL; blindingParams *bpUnlinked = NULL; blindingParams *bp; PRCList *el; SECStatus rv = SECSuccess; mp_err err = MP_OKAY; int cmp = -1; PRBool holdingLock = PR_FALSE; do { if (blindingParamsList.lock == NULL) { PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); return SECFailure; } /* Acquire the list lock */ PZ_Lock(blindingParamsList.lock); holdingLock = PR_TRUE; /* Walk the list looking for the private key */ for (el = PR_NEXT_LINK(&blindingParamsList.head); el != &blindingParamsList.head; el = PR_NEXT_LINK(el)) { rsabp = (RSABlindingParams *)el; cmp = SECITEM_CompareItem(&rsabp->modulus, &key->modulus); if (cmp >= 0) { /* The key is found or not in the list. */ break; } } if (cmp) { /* At this point, the key is not in the list. el should point to ** the list element before which this key should be inserted. */ rsabp = PORT_ZNew(RSABlindingParams); if (!rsabp) { PORT_SetError(SEC_ERROR_NO_MEMORY); goto cleanup; } rv = init_blinding_params(rsabp, key, n, modLen); if (rv != SECSuccess) { PORT_ZFree(rsabp, sizeof(RSABlindingParams)); goto cleanup; } /* Insert the new element into the list ** If inserting in the middle of the list, el points to the link ** to insert before. Otherwise, the link needs to be appended to ** the end of the list, which is the same as inserting before the ** head (since el would have looped back to the head). */ PR_INSERT_BEFORE(&rsabp->link, el); } /* We've found (or created) the RSAblindingParams struct for this key. * Now, search its list of ready blinding params for a usable one. */ *n0i = rsabp->n0i; while (0 != (bp = rsabp->bp)) { #ifdef UNSAFE_FUZZER_MODE /* Found a match and there are still remaining uses left */ /* Return the parameters */ CHECK_MPI_OK(mp_copy(&bp->f, f)); CHECK_MPI_OK(mp_copy(&bp->g, g)); PZ_Unlock(blindingParamsList.lock); return SECSuccess; #else if (--(bp->counter) > 0) { /* Found a match and there are still remaining uses left */ /* Return the parameters */ CHECK_MPI_OK(mp_copy(&bp->f, f)); CHECK_MPI_OK(mp_copy(&bp->g, g)); PZ_Unlock(blindingParamsList.lock); return SECSuccess; } /* exhausted this one, give its values to caller, and * then retire it. */ mp_exch(&bp->f, f); mp_exch(&bp->g, g); mp_clear(&bp->f); mp_clear(&bp->g); bp->counter = 0; /* Move to free list */ rsabp->bp = bp->next; bp->next = rsabp->free; rsabp->free = bp; /* In case there're threads waiting for new blinding * value - notify 1 thread the value is ready */ if (blindingParamsList.waitCount > 0) { PR_NotifyCondVar(blindingParamsList.cVar); blindingParamsList.waitCount--; } PZ_Unlock(blindingParamsList.lock); return SECSuccess; #endif } /* We did not find a usable set of blinding params. Can we make one? */ /* Find a free bp struct. */ if ((bp = rsabp->free) != NULL) { /* unlink this bp */ rsabp->free = bp->next; bp->next = NULL; bpUnlinked = bp; /* In case we fail */ PZ_Unlock(blindingParamsList.lock); holdingLock = PR_FALSE; /* generate blinding parameter values for the current thread */ CHECK_SEC_OK(generate_blinding_params(key, f, g, n, modLen)); /* put the blinding parameter values into cache */ CHECK_MPI_OK(mp_init(&bp->f)); CHECK_MPI_OK(mp_init(&bp->g)); CHECK_MPI_OK(mp_copy(f, &bp->f)); CHECK_MPI_OK(mp_copy(g, &bp->g)); /* Put this at head of queue of usable params. */ PZ_Lock(blindingParamsList.lock); holdingLock = PR_TRUE; (void)holdingLock; /* initialize RSABlindingParamsStr */ bp->counter = RSA_BLINDING_PARAMS_MAX_REUSE; bp->next = rsabp->bp; rsabp->bp = bp; bpUnlinked = NULL; /* In case there're threads waiting for new blinding value * just notify them the value is ready */ if (blindingParamsList.waitCount > 0) { PR_NotifyAllCondVar(blindingParamsList.cVar); blindingParamsList.waitCount = 0; } PZ_Unlock(blindingParamsList.lock); return SECSuccess; } /* Here, there are no usable blinding parameters available, * and no free bp blocks, presumably because they're all * actively having parameters generated for them. * So, we need to wait here and not eat up CPU until some * change happens. */ blindingParamsList.waitCount++; PR_WaitCondVar(blindingParamsList.cVar, PR_INTERVAL_NO_TIMEOUT); PZ_Unlock(blindingParamsList.lock); holdingLock = PR_FALSE; (void)holdingLock; } while (1); cleanup: /* It is possible to reach this after the lock is already released. */ if (bpUnlinked) { if (!holdingLock) { PZ_Lock(blindingParamsList.lock); holdingLock = PR_TRUE; } bp = bpUnlinked; mp_clear(&bp->f); mp_clear(&bp->g); bp->counter = 0; /* Must put the unlinked bp back on the free list */ bp->next = rsabp->free; rsabp->free = bp; } if (holdingLock) { PZ_Unlock(blindingParamsList.lock); } if (err) { MP_TO_SEC_ERROR(err); } *n0i = 0; return SECFailure; } /* ** Perform a raw private-key operation ** Length of input and output buffers are equal to key's modulus len. */ static SECStatus rsa_PrivateKeyOp(RSAPrivateKey *key, unsigned char *output, const unsigned char *input, PRBool check) { unsigned int modLen; unsigned int offset; SECStatus rv = SECSuccess; mp_err err; mp_int n, c, m; mp_int f, g; mp_digit n0i; if (!key || !output || !input) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } /* check input out of range (needs to be in range [0..n-1]) */ modLen = rsa_modulusLen(&key->modulus); if (modLen == 0) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } offset = (key->modulus.data[0] == 0) ? 1 : 0; /* may be leading 0 */ if (memcmp(input, key->modulus.data + offset, modLen) >= 0) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } MP_DIGITS(&n) = 0; MP_DIGITS(&c) = 0; MP_DIGITS(&m) = 0; MP_DIGITS(&f) = 0; MP_DIGITS(&g) = 0; CHECK_MPI_OK(mp_init(&n)); CHECK_MPI_OK(mp_init(&c)); CHECK_MPI_OK(mp_init(&m)); CHECK_MPI_OK(mp_init(&f)); CHECK_MPI_OK(mp_init(&g)); SECITEM_TO_MPINT(key->modulus, &n); OCTETS_TO_MPINT(input, &c, modLen); /* If blinding, compute pre-image of ciphertext by multiplying by ** blinding factor */ if (nssRSAUseBlinding) { CHECK_SEC_OK(get_blinding_params(key, &n, modLen, &f, &g, &n0i)); /* c' = c*f mod n */ CHECK_MPI_OK(mp_mulmod(&c, &f, &n, &c)); } /* Do the private key operation m = c**d mod n */ if (key->prime1.len == 0 || key->prime2.len == 0 || key->exponent1.len == 0 || key->exponent2.len == 0 || key->coefficient.len == 0) { CHECK_SEC_OK(rsa_PrivateKeyOpNoCRT(key, &m, &c, &n, modLen)); } else if (check) { CHECK_SEC_OK(rsa_PrivateKeyOpCRTCheckedPubKey(key, &m, &c)); } else { CHECK_SEC_OK(rsa_PrivateKeyOpCRTNoCheck(key, &m, &c)); } /* If blinding, compute post-image of plaintext by multiplying by ** blinding factor */ if (nssRSAUseBlinding) { /* m = m'*g mod n */ CHECK_MPI_OK(mp_mulmontmodCT(&m, &g, &n, n0i, &m)); } err = mp_to_fixlen_octets(&m, output, modLen); if (err >= 0) err = MP_OKAY; cleanup: mp_clear(&n); mp_clear(&c); mp_clear(&m); mp_clear(&f); mp_clear(&g); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } SECStatus RSA_PrivateKeyOp(RSAPrivateKey *key, unsigned char *output, const unsigned char *input) { return rsa_PrivateKeyOp(key, output, input, PR_FALSE); } SECStatus RSA_PrivateKeyOpDoubleChecked(RSAPrivateKey *key, unsigned char *output, const unsigned char *input) { return rsa_PrivateKeyOp(key, output, input, PR_TRUE); } SECStatus RSA_PrivateKeyCheck(const RSAPrivateKey *key) { mp_int p, q, n, psub1, qsub1, e, d, d_p, d_q, qInv, res; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; MP_DIGITS(&p) = 0; MP_DIGITS(&q) = 0; MP_DIGITS(&n) = 0; MP_DIGITS(&psub1) = 0; MP_DIGITS(&qsub1) = 0; MP_DIGITS(&e) = 0; MP_DIGITS(&d) = 0; MP_DIGITS(&d_p) = 0; MP_DIGITS(&d_q) = 0; MP_DIGITS(&qInv) = 0; MP_DIGITS(&res) = 0; CHECK_MPI_OK(mp_init(&p)); CHECK_MPI_OK(mp_init(&q)); CHECK_MPI_OK(mp_init(&n)); CHECK_MPI_OK(mp_init(&psub1)); CHECK_MPI_OK(mp_init(&qsub1)); CHECK_MPI_OK(mp_init(&e)); CHECK_MPI_OK(mp_init(&d)); CHECK_MPI_OK(mp_init(&d_p)); CHECK_MPI_OK(mp_init(&d_q)); CHECK_MPI_OK(mp_init(&qInv)); CHECK_MPI_OK(mp_init(&res)); if (!key->modulus.data || !key->prime1.data || !key->prime2.data || !key->publicExponent.data || !key->privateExponent.data || !key->exponent1.data || !key->exponent2.data || !key->coefficient.data) { /* call RSA_PopulatePrivateKey first, if the application wishes to * recover these parameters */ err = MP_BADARG; goto cleanup; } SECITEM_TO_MPINT(key->modulus, &n); SECITEM_TO_MPINT(key->prime1, &p); SECITEM_TO_MPINT(key->prime2, &q); SECITEM_TO_MPINT(key->publicExponent, &e); SECITEM_TO_MPINT(key->privateExponent, &d); SECITEM_TO_MPINT(key->exponent1, &d_p); SECITEM_TO_MPINT(key->exponent2, &d_q); SECITEM_TO_MPINT(key->coefficient, &qInv); /* p and q must be distinct. */ if (mp_cmp(&p, &q) == 0) { rv = SECFailure; goto cleanup; } #define VERIFY_MPI_EQUAL(m1, m2) \ if (mp_cmp(m1, m2) != 0) { \ rv = SECFailure; \ goto cleanup; \ } #define VERIFY_MPI_EQUAL_1(m) \ if (mp_cmp_d(m, 1) != 0) { \ rv = SECFailure; \ goto cleanup; \ } /* n == p * q */ CHECK_MPI_OK(mp_mul(&p, &q, &res)); VERIFY_MPI_EQUAL(&res, &n); /* gcd(e, p-1) == 1 */ CHECK_MPI_OK(mp_sub_d(&p, 1, &psub1)); CHECK_MPI_OK(mp_gcd(&e, &psub1, &res)); VERIFY_MPI_EQUAL_1(&res); /* gcd(e, q-1) == 1 */ CHECK_MPI_OK(mp_sub_d(&q, 1, &qsub1)); CHECK_MPI_OK(mp_gcd(&e, &qsub1, &res)); VERIFY_MPI_EQUAL_1(&res); /* d*e == 1 mod p-1 */ CHECK_MPI_OK(mp_mulmod(&d, &e, &psub1, &res)); VERIFY_MPI_EQUAL_1(&res); /* d*e == 1 mod q-1 */ CHECK_MPI_OK(mp_mulmod(&d, &e, &qsub1, &res)); VERIFY_MPI_EQUAL_1(&res); /* d_p == d mod p-1 */ CHECK_MPI_OK(mp_mod(&d, &psub1, &res)); VERIFY_MPI_EQUAL(&res, &d_p); /* d_q == d mod q-1 */ CHECK_MPI_OK(mp_mod(&d, &qsub1, &res)); VERIFY_MPI_EQUAL(&res, &d_q); /* q * q**-1 == 1 mod p */ CHECK_MPI_OK(mp_mulmod(&q, &qInv, &p, &res)); VERIFY_MPI_EQUAL_1(&res); cleanup: mp_clear(&n); mp_clear(&p); mp_clear(&q); mp_clear(&psub1); mp_clear(&qsub1); mp_clear(&e); mp_clear(&d); mp_clear(&d_p); mp_clear(&d_q); mp_clear(&qInv); mp_clear(&res); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } SECStatus RSA_Init(void) { if (PR_CallOnce(&coBPInit, init_blinding_params_list) != PR_SUCCESS) { PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); return SECFailure; } return SECSuccess; } /* cleanup at shutdown */ void RSA_Cleanup(void) { blindingParams *bp = NULL; if (!coBPInit.initialized) return; while (!PR_CLIST_IS_EMPTY(&blindingParamsList.head)) { RSABlindingParams *rsabp = (RSABlindingParams *)PR_LIST_HEAD(&blindingParamsList.head); PR_REMOVE_LINK(&rsabp->link); /* clear parameters cache */ while (rsabp->bp != NULL) { bp = rsabp->bp; rsabp->bp = rsabp->bp->next; mp_clear(&bp->f); mp_clear(&bp->g); } SECITEM_ZfreeItem(&rsabp->modulus, PR_FALSE); PORT_Free(rsabp); } if (blindingParamsList.cVar) { PR_DestroyCondVar(blindingParamsList.cVar); blindingParamsList.cVar = NULL; } if (blindingParamsList.lock) { SKIP_AFTER_FORK(PZ_DestroyLock(blindingParamsList.lock)); blindingParamsList.lock = NULL; } coBPInit.initialized = 0; coBPInit.inProgress = 0; coBPInit.status = 0; } /* * need a central place for this function to free up all the memory that * free_bl may have allocated along the way. Currently only RSA does this, * so I've put it here for now. */ void BL_Cleanup(void) { RSA_Cleanup(); } PRBool bl_parentForkedAfterC_Initialize; /* * Set fork flag so it can be tested in SKIP_AFTER_FORK on relevant platforms. */ void BL_SetForkState(PRBool forked) { bl_parentForkedAfterC_Initialize = forked; }