/* 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/. */ /* * PQG parameter generation/verification. Based on FIPS 186-3. */ #ifdef FREEBL_NO_DEPEND #include "stubs.h" #endif #include "prerr.h" #include "secerr.h" #include "prtypes.h" #include "blapi.h" #include "secitem.h" #include "mpi.h" #include "mpprime.h" #include "mplogic.h" #include "secmpi.h" #define MAX_ITERATIONS 1000 /* Maximum number of iterations of primegen */ typedef enum { FIPS186_1_TYPE, /* Probablistic */ FIPS186_3_TYPE, /* Probablistic */ FIPS186_3_ST_TYPE /* Shawe-Taylor provable */ } pqgGenType; /* * These test iterations are quite a bit larger than we previously had. * This is because FIPS 186-3 is worried about the primes in PQG generation. * It may be possible to purposefully construct composites which more * iterations of Miller-Rabin than the for your normal randomly selected * numbers.There are 3 ways to counter this: 1) use one of the cool provably * prime algorithms (which would require a lot more work than DSA-2 deservers. * 2) add a Lucas primality test (which requires coding a Lucas primality test, * or 3) use a larger M-R test count. I chose the latter. It increases the time * that it takes to prove the selected prime, but it shouldn't increase the * overall time to run the algorithm (non-primes should still faile M-R * realively quickly). If you want to get that last bit of performance, * implement Lucas and adjust these two functions. See FIPS 186-3 Appendix C * and F for more information. */ int prime_testcount_p(int L, int N) { switch (L) { case 1024: return 40; case 2048: return 56; case 3072: return 64; default: break; } return 50; /* L = 512-960 */ } /* The q numbers are different if you run M-R followd by Lucas. I created * a separate function so if someone wanted to add the Lucas check, they * could do so fairly easily */ int prime_testcount_q(int L, int N) { return prime_testcount_p(L,N); } /* * generic function to make sure our input matches DSA2 requirements * this gives us one place to go if we need to bump the requirements in the * future. */ static SECStatus pqg_validate_dsa2(unsigned int L, unsigned int N) { switch (L) { case 1024: if (N != DSA1_Q_BITS) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } break; case 2048: if ((N != 224) && (N != 256)) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } break; case 3072: if (N != 256) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } break; default: PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } return SECSuccess; } static unsigned int pqg_get_default_N(unsigned int L) { unsigned int N = 0; switch (L) { case 1024: N = DSA1_Q_BITS; break; case 2048: N = 224; break; case 3072: N = 256; break; default: PORT_SetError(SEC_ERROR_INVALID_ARGS); break; /* N already set to zero */ } return N; } /* * Select the lowest hash algorithm usable */ static HASH_HashType getFirstHash(unsigned int L, unsigned int N) { if (N < 224) { return HASH_AlgSHA1; } if (N < 256) { return HASH_AlgSHA224; } if (N < 384) { return HASH_AlgSHA256; } if (N < 512) { return HASH_AlgSHA384; } return HASH_AlgSHA512; } /* * find the next usable hash algorthim */ static HASH_HashType getNextHash(HASH_HashType hashtype) { switch (hashtype) { case HASH_AlgSHA1: hashtype = HASH_AlgSHA224; break; case HASH_AlgSHA224: hashtype = HASH_AlgSHA256; break; case HASH_AlgSHA256: hashtype = HASH_AlgSHA384; break; case HASH_AlgSHA384: hashtype = HASH_AlgSHA512; break; case HASH_AlgSHA512: default: hashtype = HASH_AlgTOTAL; break; } return hashtype; } static unsigned int HASH_ResultLen(HASH_HashType type) { const SECHashObject *hash_obj = HASH_GetRawHashObject(type); if (hash_obj == NULL) { return 0; } return hash_obj->length; } static SECStatus HASH_HashBuf(HASH_HashType type, unsigned char *dest, const unsigned char *src, PRUint32 src_len) { const SECHashObject *hash_obj = HASH_GetRawHashObject(type); void *hashcx = NULL; unsigned int dummy; if (hash_obj == NULL) { return SECFailure; } hashcx = hash_obj->create(); if (hashcx == NULL) { return SECFailure; } hash_obj->begin(hashcx); hash_obj->update(hashcx,src,src_len); hash_obj->end(hashcx,dest, &dummy, hash_obj->length); hash_obj->destroy(hashcx, PR_TRUE); return SECSuccess; } unsigned int PQG_GetLength(const SECItem *obj) { unsigned int len = obj->len; if (obj->data == NULL) { return 0; } if (len > 1 && obj->data[0] == 0) { len--; } return len; } SECStatus PQG_Check(const PQGParams *params) { unsigned int L,N; SECStatus rv = SECSuccess; if (params == NULL) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } L = PQG_GetLength(¶ms->prime)*PR_BITS_PER_BYTE; N = PQG_GetLength(¶ms->subPrime)*PR_BITS_PER_BYTE; if (L < 1024) { int j; /* handle DSA1 pqg parameters with less thatn 1024 bits*/ if ( N != DSA1_Q_BITS ) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } j = PQG_PBITS_TO_INDEX(L); if ( j < 0 ) { PORT_SetError(SEC_ERROR_INVALID_ARGS); rv = SECFailure; } } else { /* handle DSA2 parameters (includes DSA1, 1024 bits) */ rv = pqg_validate_dsa2(L, N); } return rv; } HASH_HashType PQG_GetHashType(const PQGParams *params) { unsigned int L,N; if (params == NULL) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return HASH_AlgNULL; } L = PQG_GetLength(¶ms->prime)*PR_BITS_PER_BYTE; N = PQG_GetLength(¶ms->subPrime)*PR_BITS_PER_BYTE; return getFirstHash(L, N); } /* Get a seed for generating P and Q. If in testing mode, copy in the ** seed from FIPS 186-1 appendix 5. Otherwise, obtain bytes from the ** global random number generator. */ static SECStatus getPQseed(SECItem *seed, PLArenaPool* arena) { SECStatus rv; if (!seed->data) { seed->data = (unsigned char*)PORT_ArenaZAlloc(arena, seed->len); } if (!seed->data) { PORT_SetError(SEC_ERROR_NO_MEMORY); return SECFailure; } rv = RNG_GenerateGlobalRandomBytes(seed->data, seed->len); /* * NIST CMVP disallows a sequence of 20 bytes with the most * significant byte equal to 0. Perhaps they interpret * "a sequence of at least 160 bits" as "a number >= 2^159". * So we always set the most significant bit to 1. (bug 334533) */ seed->data[0] |= 0x80; return rv; } /* Generate a candidate h value. If in testing mode, use the h value ** specified in FIPS 186-1 appendix 5, h = 2. Otherwise, obtain bytes ** from the global random number generator. */ static SECStatus generate_h_candidate(SECItem *hit, mp_int *H) { SECStatus rv = SECSuccess; mp_err err = MP_OKAY; #ifdef FIPS_186_1_A5_TEST memset(hit->data, 0, hit->len); hit->data[hit->len-1] = 0x02; #else rv = RNG_GenerateGlobalRandomBytes(hit->data, hit->len); #endif if (rv) return SECFailure; err = mp_read_unsigned_octets(H, hit->data, hit->len); if (err) { MP_TO_SEC_ERROR(err); return SECFailure; } return SECSuccess; } static SECStatus addToSeed(const SECItem * seed, unsigned long addend, int seedlen, /* g in 186-1 */ SECItem * seedout) { mp_int s, sum, modulus, tmp; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; MP_DIGITS(&s) = 0; MP_DIGITS(&sum) = 0; MP_DIGITS(&modulus) = 0; MP_DIGITS(&tmp) = 0; CHECK_MPI_OK( mp_init(&s) ); CHECK_MPI_OK( mp_init(&sum) ); CHECK_MPI_OK( mp_init(&modulus) ); SECITEM_TO_MPINT(*seed, &s); /* s = seed */ /* seed += addend */ if (addend < MP_DIGIT_MAX) { CHECK_MPI_OK( mp_add_d(&s, (mp_digit)addend, &s) ); } else { CHECK_MPI_OK( mp_init(&tmp) ); CHECK_MPI_OK( mp_set_ulong(&tmp, addend) ); CHECK_MPI_OK( mp_add(&s, &tmp, &s) ); } /*sum = s mod 2**seedlen */ CHECK_MPI_OK( mp_div_2d(&s, (mp_digit)seedlen, NULL, &sum) ); if (seedout->data != NULL) { SECITEM_ZfreeItem(seedout, PR_FALSE); } MPINT_TO_SECITEM(&sum, seedout, NULL); cleanup: mp_clear(&s); mp_clear(&sum); mp_clear(&modulus); mp_clear(&tmp); if (err) { MP_TO_SEC_ERROR(err); return SECFailure; } return rv; } /* Compute Hash[(SEED + addend) mod 2**g] ** Result is placed in shaOutBuf. ** This computation is used in steps 2 and 7 of FIPS 186 Appendix 2.2 and ** step 11.2 of FIPS 186-3 Appendix A.1.1.2 . */ static SECStatus addToSeedThenHash(HASH_HashType hashtype, const SECItem * seed, unsigned long addend, int seedlen, /* g in 186-1 */ unsigned char * hashOutBuf) { SECItem str = { 0, 0, 0 }; SECStatus rv; rv = addToSeed(seed, addend, seedlen, &str); if (rv != SECSuccess) { return rv; } rv = HASH_HashBuf(hashtype, hashOutBuf, str.data, str.len);/* hash result */ if (str.data) SECITEM_ZfreeItem(&str, PR_FALSE); return rv; } /* ** Perform steps 2 and 3 of FIPS 186-1, appendix 2.2. ** Generate Q from seed. */ static SECStatus makeQfromSeed( unsigned int g, /* input. Length of seed in bits. */ const SECItem * seed, /* input. */ mp_int * Q) /* output. */ { unsigned char sha1[SHA1_LENGTH]; unsigned char sha2[SHA1_LENGTH]; unsigned char U[SHA1_LENGTH]; SECStatus rv = SECSuccess; mp_err err = MP_OKAY; int i; /* ****************************************************************** ** Step 2. ** "Compute U = SHA[SEED] XOR SHA[(SEED+1) mod 2**g]." **/ CHECK_SEC_OK( SHA1_HashBuf(sha1, seed->data, seed->len) ); CHECK_SEC_OK( addToSeedThenHash(HASH_AlgSHA1, seed, 1, g, sha2) ); for (i=0; idata, seed->len) ); /* mod 2**N . Step 7 will explicitly set the top bit to 1, so no need * to handle mod 2**N-1 */ if (hashLen > N_bytes) { offset = hashLen - N_bytes; } /* ****************************************************************** ** Step 7. ** computed_q = 2**(N-1) + U + 1 - (U mod 2) ** ** This is the same as: ** computed_q = 2**(N-1) | U | 1; */ U[offset] |= 0x80; /* U is MSB first */ U[hashLen-1] |= 0x01; err = mp_read_unsigned_octets(Q, &U[offset], N_bytes); cleanup: memset(U, 0, HASH_LENGTH_MAX); if (err) { MP_TO_SEC_ERROR(err); return SECFailure; } return rv; } /* ** Perform steps from FIPS 186-3, Appendix A.1.2.1 and Appendix C.6 ** ** This generates a provable prime from two smaller prime. The resulting ** prime p will have q0 as a multiple of p-1. q0 can be 1. ** ** This implments steps 4 thorough 22 of FIPS 186-3 A.1.2.1 and ** steps 16 through 34 of FIPS 186-2 C.6 */ #define MAX_ST_SEED_BITS (HASH_LENGTH_MAX*PR_BITS_PER_BYTE) SECStatus makePrimefromPrimesShaweTaylor( HASH_HashType hashtype, /* selected Hashing algorithm */ unsigned int length, /* input. Length of prime in bits. */ mp_int * c0, /* seed prime */ mp_int * q, /* sub prime, can be 1 */ mp_int * prime, /* output. */ SECItem * prime_seed, /* input/output. */ unsigned int *prime_gen_counter) /* input/output. */ { mp_int c; mp_int c0_2; mp_int t; mp_int a; mp_int z; mp_int two_length_minus_1; SECStatus rv = SECFailure; int hashlen = HASH_ResultLen(hashtype); int outlen = hashlen*PR_BITS_PER_BYTE; int offset; unsigned char bit, mask; /* x needs to hold roundup(L/outlen)*outlen. * This can be no larger than L+outlen-1, So we set it's size to * our max L + max outlen and know we are safe */ unsigned char x[DSA_MAX_P_BITS/8+HASH_LENGTH_MAX]; mp_err err = MP_OKAY; int i; int iterations; int old_counter; MP_DIGITS(&c) = 0; MP_DIGITS(&c0_2) = 0; MP_DIGITS(&t) = 0; MP_DIGITS(&a) = 0; MP_DIGITS(&z) = 0; MP_DIGITS(&two_length_minus_1) = 0; CHECK_MPI_OK( mp_init(&c) ); CHECK_MPI_OK( mp_init(&c0_2) ); CHECK_MPI_OK( mp_init(&t) ); CHECK_MPI_OK( mp_init(&a) ); CHECK_MPI_OK( mp_init(&z) ); CHECK_MPI_OK( mp_init(&two_length_minus_1) ); /* ** There is a slight mapping of variable names depending on which ** FIPS 186 steps are being carried out. The mapping is as follows: ** variable A.1.2.1 C.6 ** c0 p0 c0 ** q q 1 ** c p c ** c0_2 2*p0*q 2*c0 ** length L length ** prime_seed pseed prime_seed ** prime_gen_counter pgen_counter prime_gen_counter ** ** Also note: or iterations variable is actually iterations+1, since ** iterations+1 works better in C. */ /* Step 4/16 iterations = ceiling(length/outlen)-1 */ iterations = (length+outlen-1)/outlen; /* NOTE: iterations +1 */ /* Step 5/17 old_counter = prime_gen_counter */ old_counter = *prime_gen_counter; /* ** Comment: Generate a pseudorandom integer x in the interval ** [2**(lenght-1), 2**length]. ** ** Step 6/18 x = 0 */ PORT_Memset(x, 0, sizeof(x)); /* ** Step 7/19 for i = 0 to iterations do ** x = x + (HASH(prime_seed + i) * 2^(i*outlen)) */ for (i=0; i < iterations; i++) { /* is bigger than prime_seed should get to */ CHECK_SEC_OK( addToSeedThenHash(hashtype, prime_seed, i, MAX_ST_SEED_BITS,&x[(iterations - i - 1)*hashlen])); } /* Step 8/20 prime_seed = prime_seed + iterations + 1 */ CHECK_SEC_OK(addToSeed(prime_seed, iterations, MAX_ST_SEED_BITS, prime_seed)); /* ** Step 9/21 x = 2 ** (length-1) + x mod 2 ** (length-1) ** ** This step mathematically sets the high bit and clears out ** all the other bits higher than length. 'x' is stored ** in the x array, MSB first. The above formula gives us an 'x' ** which is length bytes long and has the high bit set. We also know ** that length <= iterations*outlen since ** iterations=ceiling(length/outlen). First we find the offset in ** bytes into the array where the high bit is. */ offset = (outlen*iterations - length)/PR_BITS_PER_BYTE; /* now we want to set the 'high bit', since length may not be a * multiple of 8,*/ bit = 1 << ((length-1) & 0x7); /* select the proper bit in the byte */ /* we need to zero out the rest of the bits in the byte above */ mask = (bit-1); /* now we set it */ x[offset] = (mask & x[offset]) | bit; /* ** Comment: Generate a candidate prime c in the interval ** [2**(lenght-1), 2**length]. ** ** Step 10 t = ceiling(x/(2q(p0))) ** Step 22 t = ceiling(x/(2(c0))) */ CHECK_MPI_OK( mp_read_unsigned_octets(&t, &x[offset], hashlen*iterations - offset ) ); /* t = x */ CHECK_MPI_OK( mp_mul(c0, q, &c0_2) ); /* c0_2 is now c0*q */ CHECK_MPI_OK( mp_add(&c0_2, &c0_2, &c0_2) ); /* c0_2 is now 2*q*c0 */ CHECK_MPI_OK( mp_add(&t, &c0_2, &t) ); /* t = x+2*q*c0 */ CHECK_MPI_OK( mp_sub_d(&t, (mp_digit) 1, &t) ); /* t = x+2*q*c0 -1 */ /* t = floor((x+2qc0-1)/2qc0) = ceil(x/2qc0) */ CHECK_MPI_OK( mp_div(&t, &c0_2, &t, NULL) ); /* ** step 11: if (2tqp0 +1 > 2**length), then t = ceiling(2**(length-1)/2qp0) ** step 12: t = 2tqp0 +1. ** ** step 23: if (2tc0 +1 > 2**length), then t = ceiling(2**(length-1)/2c0) ** step 24: t = 2tc0 +1. */ CHECK_MPI_OK( mp_2expt(&two_length_minus_1, length-1) ); step_23: CHECK_MPI_OK( mp_mul(&t, &c0_2, &c) ); /* c = t*2qc0 */ CHECK_MPI_OK( mp_add_d(&c, (mp_digit)1, &c) ); /* c= 2tqc0 + 1*/ if (mpl_significant_bits(&c) > length) { /* if c > 2**length */ CHECK_MPI_OK( mp_sub_d(&c0_2, (mp_digit) 1, &t) ); /* t = 2qc0-1 */ /* t = 2**(length-1) + 2qc0 -1 */ CHECK_MPI_OK( mp_add(&two_length_minus_1,&t, &t) ); /* t = floor((2**(length-1)+2qc0 -1)/2qco) * = ceil(2**(lenght-2)/2qc0) */ CHECK_MPI_OK( mp_div(&t, &c0_2, &t, NULL) ); CHECK_MPI_OK( mp_mul(&t, &c0_2, &c) ); CHECK_MPI_OK( mp_add_d(&c, (mp_digit)1, &c) ); /* c= 2tqc0 + 1*/ } /* Step 13/25 prime_gen_counter = prime_gen_counter + 1*/ (*prime_gen_counter)++; /* ** Comment: Test the candidate prime c for primality; first pick an ** integer a between 2 and c-2. ** ** Step 14/26 a=0 */ PORT_Memset(x, 0, sizeof(x)); /* use x for a */ /* ** Step 15/27 for i = 0 to iterations do ** a = a + (HASH(prime_seed + i) * 2^(i*outlen)) ** ** NOTE: we reuse the x array for 'a' initially. */ for (i=0; i < iterations; i++) { /* MAX_ST_SEED_BITS is bigger than prime_seed should get to */ CHECK_SEC_OK(addToSeedThenHash(hashtype, prime_seed, i, MAX_ST_SEED_BITS,&x[(iterations - i - 1)*hashlen])); } /* Step 16/28 prime_seed = prime_seed + iterations + 1 */ CHECK_SEC_OK(addToSeed(prime_seed, iterations, MAX_ST_SEED_BITS, prime_seed)); /* Step 17/29 a = 2 + (a mod (c-3)). */ CHECK_MPI_OK( mp_read_unsigned_octets(&a, x, iterations*hashlen) ); CHECK_MPI_OK( mp_sub_d(&c, (mp_digit) 3, &z) ); /* z = c -3 */ CHECK_MPI_OK( mp_mod(&a, &z, &a) ); /* a = a mod c -3 */ CHECK_MPI_OK( mp_add_d(&a, (mp_digit) 2, &a) ); /* a = 2 + a mod c -3 */ /* ** Step 18 z = a**(2tq) mod p. ** Step 30 z = a**(2t) mod c. */ CHECK_MPI_OK( mp_mul(&t, q, &z) ); /* z = tq */ CHECK_MPI_OK( mp_add(&z, &z, &z) ); /* z = 2tq */ CHECK_MPI_OK( mp_exptmod(&a, &z, &c, &z) ); /* z = a**(2tq) mod c */ /* ** Step 19 if (( 1 == GCD(z-1,p)) and ( 1 == z**p0 mod p )), then ** Step 31 if (( 1 == GCD(z-1,c)) and ( 1 == z**c0 mod c )), then */ CHECK_MPI_OK( mp_sub_d(&z, (mp_digit) 1, &a) ); CHECK_MPI_OK( mp_gcd(&a,&c,&a )); if (mp_cmp_d(&a, (mp_digit)1) == 0) { CHECK_MPI_OK( mp_exptmod(&z, c0, &c, &a) ); if (mp_cmp_d(&a, (mp_digit)1) == 0) { /* Step 31.1 prime = c */ CHECK_MPI_OK( mp_copy(&c, prime) ); /* ** Step 31.2 return Success, prime, prime_seed, ** prime_gen_counter */ rv = SECSuccess; goto cleanup; } } /* ** Step 20/32 If (prime_gen_counter > 4 * length + old_counter then ** return (FAILURE, 0, 0, 0). ** NOTE: the test is reversed, so we fall through on failure to the ** cleanup routine */ if (*prime_gen_counter < (4*length + old_counter)) { /* Step 21/33 t = t + 1 */ CHECK_MPI_OK( mp_add_d(&t, (mp_digit) 1, &t) ); /* Step 22/34 Go to step 23/11 */ goto step_23; } /* if (prime_gencont > (4*length + old_counter), fall through to failure */ rv = SECFailure; /* really is already set, but paranoia is good */ cleanup: mp_clear(&c); mp_clear(&c0_2); mp_clear(&t); mp_clear(&a); mp_clear(&z); mp_clear(&two_length_minus_1); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } if (rv == SECFailure) { mp_zero(prime); if (prime_seed->data) { SECITEM_FreeItem(prime_seed, PR_FALSE); } *prime_gen_counter = 0; } return rv; } /* ** Perform steps from FIPS 186-3, Appendix C.6 ** ** This generates a provable prime from a seed */ SECStatus makePrimefromSeedShaweTaylor( HASH_HashType hashtype, /* selected Hashing algorithm */ unsigned int length, /* input. Length of prime in bits. */ const SECItem * input_seed, /* input. */ mp_int * prime, /* output. */ SECItem * prime_seed, /* output. */ unsigned int *prime_gen_counter) /* output. */ { mp_int c; mp_int c0; mp_int one; SECStatus rv = SECFailure; int hashlen = HASH_ResultLen(hashtype); int outlen = hashlen*PR_BITS_PER_BYTE; int offset; unsigned char bit, mask; unsigned char x[HASH_LENGTH_MAX*2]; mp_digit dummy; mp_err err = MP_OKAY; int i; MP_DIGITS(&c) = 0; MP_DIGITS(&c0) = 0; MP_DIGITS(&one) = 0; CHECK_MPI_OK( mp_init(&c) ); CHECK_MPI_OK( mp_init(&c0) ); CHECK_MPI_OK( mp_init(&one) ); /* Step 1. if length < 2 then return (FAILURE, 0, 0, 0) */ if (length < 2) { rv = SECFailure; goto cleanup; } /* Step 2. if length >= 33 then goto step 14 */ if (length >= 33) { mp_zero(&one); CHECK_MPI_OK( mp_add_d(&one, (mp_digit) 1, &one) ); /* Step 14 (status, c0, prime_seed, prime_gen_counter) = ** (ST_Random_Prime((ceil(length/2)+1, input_seed) */ rv = makePrimefromSeedShaweTaylor(hashtype, (length+1)/2+1, input_seed, &c0, prime_seed, prime_gen_counter); /* Step 15 if FAILURE is returned, return (FAILURE, 0, 0, 0). */ if (rv != SECSuccess) { goto cleanup; } /* Steps 16-34 */ rv = makePrimefromPrimesShaweTaylor(hashtype,length, &c0, &one, prime, prime_seed, prime_gen_counter); goto cleanup; /* we're done, one way or the other */ } /* Step 3 prime_seed = input_seed */ CHECK_SEC_OK(SECITEM_CopyItem(NULL, prime_seed, input_seed)); /* Step 4 prime_gen_count = 0 */ *prime_gen_counter = 0; step_5: /* Step 5 c = Hash(prime_seed) xor Hash(prime_seed+1). */ CHECK_SEC_OK(HASH_HashBuf(hashtype, x, prime_seed->data, prime_seed->len) ); CHECK_SEC_OK(addToSeedThenHash(hashtype, prime_seed, 1, MAX_ST_SEED_BITS, &x[hashlen]) ); for (i=0; i < hashlen; i++) { x[i] = x[i] ^ x[i+hashlen]; } /* Step 6 c = 2**length-1 + c mod 2**length-1 */ /* This step mathematically sets the high bit and clears out ** all the other bits higher than length. Right now c is stored ** in the x array, MSB first. The above formula gives us a c which ** is length bytes long and has the high bit set. We also know that ** length < outlen since the smallest outlen is 160 bits and the largest ** length at this point is 32 bits. So first we find the offset in bytes ** into the array where the high bit is. */ offset = (outlen - length)/PR_BITS_PER_BYTE; /* now we want to set the 'high bit'. We have to calculate this since * length may not be a multiple of 8.*/ bit = 1 << ((length-1) & 0x7); /* select the proper bit in the byte */ /* we need to zero out the rest of the bits in the byte above */ mask = (bit-1); /* now we set it */ x[offset] = (mask & x[offset]) | bit; /* Step 7 c = c*floor(c/2) + 1 */ /* set the low bit. much easier to find (the end of the array) */ x[hashlen-1] |= 1; /* now that we've set our bits, we can create our candidate "c" */ CHECK_MPI_OK( mp_read_unsigned_octets(&c, &x[offset], hashlen-offset) ); /* Step 8 prime_gen_counter = prime_gen_counter + 1 */ (*prime_gen_counter)++; /* Step 9 prime_seed = prime_seed + 2 */ CHECK_SEC_OK(addToSeed(prime_seed, 2, MAX_ST_SEED_BITS, prime_seed)); /* Step 10 Perform deterministic primality test on c. For example, since ** c is small, it's primality can be tested by trial division, See ** See Appendic C.7. ** ** We in fact test with trial division. mpi has a built int trial divider ** that divides all divisors up to 2^16. */ if (prime_tab[prime_tab_size-1] < 0xFFF1) { /* we aren't testing all the primes between 0 and 2^16, we really * can't use this construction. Just fail. */ rv = SECFailure; goto cleanup; } dummy = prime_tab_size; err = mpp_divis_primes(&c, &dummy); /* Step 11 if c is prime then */ if (err == MP_NO) { /* Step 11.1 prime = c */ CHECK_MPI_OK( mp_copy(&c, prime) ); /* Step 11.2 return SUCCESS prime, prime_seed, prime_gen_counter */ err = MP_OKAY; rv = SECSuccess; goto cleanup; } else if (err != MP_YES) { goto cleanup; /* function failed, bail out */ } else { /* reset mp_err */ err = MP_OKAY; } /* ** Step 12 if (prime_gen_counter > (4*len)) ** then return (FAILURE, 0, 0, 0)) ** Step 13 goto step 5 */ if (*prime_gen_counter <= (4*length)) { goto step_5; } /* if (prime_gencont > 4*length), fall through to failure */ rv = SECFailure; /* really is already set, but paranoia is good */ cleanup: mp_clear(&c); mp_clear(&c0); mp_clear(&one); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } if (rv == SECFailure) { mp_zero(prime); if (prime_seed->data) { SECITEM_FreeItem(prime_seed, PR_FALSE); } *prime_gen_counter = 0; } return rv; } /* * Find a Q and algorithm from Seed. */ static SECStatus findQfromSeed( unsigned int L, /* input. Length of p in bits. */ unsigned int N, /* input. Length of q in bits. */ unsigned int g, /* input. Length of seed in bits. */ const SECItem * seed, /* input. */ mp_int * Q, /* input. */ mp_int * Q_, /* output. */ unsigned int *qseed_len, /* output */ HASH_HashType *hashtypePtr, /* output. Hash uses */ pqgGenType *typePtr) /* output. Generation Type used */ { HASH_HashType hashtype; SECItem firstseed = { 0, 0, 0 }; SECItem qseed = { 0, 0, 0 }; SECStatus rv; *qseed_len = 0; /* only set if FIPS186_3_ST_TYPE */ /* handle legacy small DSA first can only be FIPS186_1_TYPE */ if (L < 1024) { rv =makeQfromSeed(g,seed,Q_); if ((rv == SECSuccess) && (mp_cmp(Q,Q_) == 0)) { *hashtypePtr = HASH_AlgSHA1; *typePtr = FIPS186_1_TYPE; return SECSuccess; } return SECFailure; } /* 1024 could use FIPS186_1 or FIPS186_3 algorithms, we need to try * them both */ if (L == 1024) { rv = makeQfromSeed(g,seed,Q_); if (rv == SECSuccess) { if (mp_cmp(Q,Q_) == 0) { *hashtypePtr = HASH_AlgSHA1; *typePtr = FIPS186_1_TYPE; return SECSuccess; } } /* fall through for FIPS186_3 types */ } /* at this point we know we aren't using FIPS186_1, start trying FIPS186_3 * with appropriate hash types */ for (hashtype = getFirstHash(L,N); hashtype != HASH_AlgTOTAL; hashtype=getNextHash(hashtype)) { rv = makeQ2fromSeed(hashtype, N, seed, Q_); if (rv != SECSuccess) { continue; } if (mp_cmp(Q,Q_) == 0) { *hashtypePtr = hashtype; *typePtr = FIPS186_3_TYPE; return SECSuccess; } } /* * OK finally try FIPS186_3 Shawe-Taylor */ firstseed = *seed; firstseed.len = seed->len/3; for (hashtype = getFirstHash(L,N); hashtype != HASH_AlgTOTAL; hashtype=getNextHash(hashtype)) { unsigned int count; rv = makePrimefromSeedShaweTaylor(hashtype, N, &firstseed, Q_, &qseed, &count); if (rv != SECSuccess) { continue; } if (mp_cmp(Q,Q_) == 0) { /* check qseed as well... */ int offset = seed->len - qseed.len; if ((offset < 0) || (PORT_Memcmp(&seed->data[offset],qseed.data,qseed.len) != 0)) { /* we found q, but the seeds don't match. This isn't an * accident, someone has been tweeking with the seeds, just * fail a this point. */ SECITEM_FreeItem(&qseed,PR_FALSE); return SECFailure; } *qseed_len = qseed.len; *hashtypePtr = hashtype; *typePtr = FIPS186_3_ST_TYPE; SECITEM_FreeItem(&qseed, PR_FALSE); return SECSuccess; } SECITEM_FreeItem(&qseed, PR_FALSE); } /* no hash algorithms found which match seed to Q, fail */ return SECFailure; } /* ** Perform steps 7, 8 and 9 of FIPS 186, appendix 2.2. ** which are the same as steps 11.1-11.5 of FIPS 186-2, App A.1.1.2 ** Generate P from Q, seed, L, and offset. */ static SECStatus makePfromQandSeed( HASH_HashType hashtype, /* selected Hashing algorithm */ unsigned int L, /* Length of P in bits. Per FIPS 186. */ unsigned int N, /* Length of Q in bits. Per FIPS 186. */ unsigned int offset, /* Per FIPS 186, App 2.2. & 186-3 App A.1.1.2 */ unsigned int seedlen, /* input. Length of seed in bits. (g in 186-1)*/ const SECItem * seed, /* input. */ const mp_int * Q, /* input. */ mp_int * P) /* output. */ { unsigned int j; /* Per FIPS 186-3 App. A.1.1.2 (k in 186-1)*/ unsigned int n; /* Per FIPS 186, appendix 2.2. */ mp_digit b; /* Per FIPS 186, appendix 2.2. */ unsigned int outlen; /* Per FIPS 186-3 App. A.1.1.2 */ unsigned int hashlen; /* outlen in bytes */ unsigned char V_j[HASH_LENGTH_MAX]; mp_int W, X, c, twoQ, V_n, tmp; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; /* Initialize bignums */ MP_DIGITS(&W) = 0; MP_DIGITS(&X) = 0; MP_DIGITS(&c) = 0; MP_DIGITS(&twoQ) = 0; MP_DIGITS(&V_n) = 0; MP_DIGITS(&tmp) = 0; CHECK_MPI_OK( mp_init(&W) ); CHECK_MPI_OK( mp_init(&X) ); CHECK_MPI_OK( mp_init(&c) ); CHECK_MPI_OK( mp_init(&twoQ) ); CHECK_MPI_OK( mp_init(&tmp) ); CHECK_MPI_OK( mp_init(&V_n) ); hashlen = HASH_ResultLen(hashtype); outlen = hashlen*PR_BITS_PER_BYTE; /* L - 1 = n*outlen + b */ n = (L - 1) / outlen; b = (L - 1) % outlen; /* ****************************************************************** ** Step 11.1 (Step 7 in 186-1) ** "for j = 0 ... n let ** V_j = SHA[(SEED + offset + j) mod 2**seedlen]." ** ** Step 11.2 (Step 8 in 186-1) ** "W = V_0 + (V_1 * 2**outlen) + ... + (V_n-1 * 2**((n-1)*outlen)) ** + ((V_n mod 2**b) * 2**(n*outlen)) */ for (j=0; j= 0) /* H >= P-1 */ CHECK_MPI_OK( mp_sub(H, &pm1, H) ); /* H = H mod (P-1) */ /* Let b = 2**n (smallest power of 2 greater than P). ** Since P-1 >= b/2, and H < b, quotient(H/(P-1)) = 0 or 1 ** so the above operation safely computes H mod (P-1) */ /* Check for H = to 0 or 1. Regen H if so. (Regen means return error). */ if (mp_cmp_d(H, 1) <= 0) { rv = SECFailure; goto cleanup; } /* Compute G, according to the equation G = (H ** ((P-1)/Q)) mod P */ CHECK_MPI_OK( mp_div(&pm1, Q, &exp, NULL) ); /* exp = (P-1)/Q */ CHECK_MPI_OK( mp_exptmod(H, &exp, P, G) ); /* G = H ** exp mod P */ /* Check for G == 0 or G == 1, return error if so. */ if (mp_cmp_d(G, 1) <= 0) { rv = SECFailure; goto cleanup; } *passed = PR_TRUE; cleanup: mp_clear(&exp); mp_clear(&pm1); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } /* ** Generate G from seed, index, P, and Q. */ static SECStatus makeGfromIndex(HASH_HashType hashtype, const mp_int *P, /* input. */ const mp_int *Q, /* input. */ const SECItem *seed, /* input. */ unsigned char index, /* input. */ mp_int *G) /* input/output */ { mp_int e, pm1, W; unsigned int count; unsigned char data[HASH_LENGTH_MAX]; unsigned int len; mp_err err = MP_OKAY; SECStatus rv = SECSuccess; const SECHashObject *hashobj = NULL; void *hashcx = NULL; MP_DIGITS(&e) = 0; MP_DIGITS(&pm1) = 0; MP_DIGITS(&W) = 0; CHECK_MPI_OK( mp_init(&e) ); CHECK_MPI_OK( mp_init(&pm1) ); CHECK_MPI_OK( mp_init(&W) ); /* initialize our hash stuff */ hashobj = HASH_GetRawHashObject(hashtype); if (hashobj == NULL) { /* shouldn't happen */ PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); rv = SECFailure; goto cleanup; } hashcx = hashobj->create(); if (hashcx == NULL) { rv = SECFailure; goto cleanup; } CHECK_MPI_OK( mp_sub_d(P, 1, &pm1) ); /* P - 1 */ /* Step 3 e = (p-1)/q */ CHECK_MPI_OK( mp_div(&pm1, Q, &e, NULL) ); /* e = (P-1)/Q */ /* Steps 4, 5, and 6 */ /* count is a 16 bit value in the spec. We actually represent count * as more than 16 bits so we can easily detect the 16 bit overflow */ #define MAX_COUNT 0x10000 for (count = 1; count < MAX_COUNT; count++) { /* step 7 * U = domain_param_seed || "ggen" || index || count * step 8 * W = HASH(U) */ hashobj->begin(hashcx); hashobj->update(hashcx,seed->data,seed->len); hashobj->update(hashcx, (unsigned char *)"ggen", 4); hashobj->update(hashcx,&index, 1); data[0] = (count >> 8) & 0xff; data[1] = count & 0xff; hashobj->update(hashcx, data, 2); hashobj->end(hashcx, data, &len, sizeof(data)); OCTETS_TO_MPINT(data, &W, len); /* step 9. g = W**e mod p */ CHECK_MPI_OK( mp_exptmod(&W, &e, P, G) ); /* step 10. if (g < 2) then goto step 5 */ /* NOTE: this weird construct is to keep the flow according to the spec. * the continue puts us back to step 5 of the for loop */ if (mp_cmp_d(G, 2) < 0) { continue; } break; /* step 11 follows step 10 if the test condition is false */ } if (count >= MAX_COUNT) { rv = SECFailure; /* last part of step 6 */ } /* step 11. * return valid G */ cleanup: PORT_Memset(data, 0, sizeof(data)); if (hashcx) { hashobj->destroy(hashcx, PR_TRUE); } mp_clear(&e); mp_clear(&pm1); mp_clear(&W); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } /* This code uses labels and gotos, so that it can follow the numbered ** steps in the algorithms from FIPS 186-3 appendix A.1.1.2 very closely, ** and so that the correctness of this code can be easily verified. ** So, please forgive the ugly c code. **/ static SECStatus pqg_ParamGen(unsigned int L, unsigned int N, pqgGenType type, unsigned int seedBytes, PQGParams **pParams, PQGVerify **pVfy) { unsigned int n; /* Per FIPS 186, app 2.2. 186-3 app A.1.1.2 */ unsigned int seedlen; /* Per FIPS 186-3 app A.1.1.2 (was 'g' 186-1)*/ unsigned int counter; /* Per FIPS 186, app 2.2. 186-3 app A.1.1.2 */ unsigned int offset; /* Per FIPS 186, app 2.2. 186-3 app A.1.1.2 */ unsigned int outlen; /* Per FIPS 186-3, appendix A.1.1.2. */ unsigned int maxCount; HASH_HashType hashtype; SECItem *seed; /* Per FIPS 186, app 2.2. 186-3 app A.1.1.2 */ PLArenaPool *arena = NULL; PQGParams *params = NULL; PQGVerify *verify = NULL; PRBool passed; SECItem hit = { 0, 0, 0 }; SECItem firstseed = { 0, 0, 0 }; SECItem qseed = { 0, 0, 0 }; SECItem pseed = { 0, 0, 0 }; mp_int P, Q, G, H, l, p0; mp_err err = MP_OKAY; SECStatus rv = SECFailure; int iterations = 0; /* Step 1. L and N already checked by caller*/ /* Step 2. if (seedlen < N) return INVALID; */ if (seedBytes < N/PR_BITS_PER_BYTE || !pParams || !pVfy) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } /* Initialize an arena for the params. */ arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE); if (!arena) { PORT_SetError(SEC_ERROR_NO_MEMORY); return SECFailure; } params = (PQGParams *)PORT_ArenaZAlloc(arena, sizeof(PQGParams)); if (!params) { PORT_SetError(SEC_ERROR_NO_MEMORY); PORT_FreeArena(arena, PR_TRUE); return SECFailure; } params->arena = arena; /* Initialize an arena for the verify. */ arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE); if (!arena) { PORT_SetError(SEC_ERROR_NO_MEMORY); PORT_FreeArena(params->arena, PR_TRUE); return SECFailure; } verify = (PQGVerify *)PORT_ArenaZAlloc(arena, sizeof(PQGVerify)); if (!verify) { PORT_SetError(SEC_ERROR_NO_MEMORY); PORT_FreeArena(arena, PR_TRUE); PORT_FreeArena(params->arena, PR_TRUE); return SECFailure; } verify->arena = arena; seed = &verify->seed; arena = NULL; /* Initialize bignums */ MP_DIGITS(&P) = 0; MP_DIGITS(&Q) = 0; MP_DIGITS(&G) = 0; MP_DIGITS(&H) = 0; MP_DIGITS(&l) = 0; MP_DIGITS(&p0) = 0; CHECK_MPI_OK( mp_init(&P) ); CHECK_MPI_OK( mp_init(&Q) ); CHECK_MPI_OK( mp_init(&G) ); CHECK_MPI_OK( mp_init(&H) ); CHECK_MPI_OK( mp_init(&l) ); CHECK_MPI_OK( mp_init(&p0) ); /* Select Hash and Compute lengths. */ /* getFirstHash gives us the smallest acceptable hash for this key * strength */ hashtype = getFirstHash(L,N); outlen = HASH_ResultLen(hashtype)*PR_BITS_PER_BYTE; /* Step 3: n = Ceil(L/outlen)-1; (same as n = Floor((L-1)/outlen)) */ n = (L - 1) / outlen; /* Step 4: (skipped since we don't use b): b = L -1 - (n*outlen); */ seedlen = seedBytes * PR_BITS_PER_BYTE; /* bits in seed */ step_5: /* ****************************************************************** ** Step 5. (Step 1 in 186-1) ** "Choose an abitrary sequence of at least N bits and call it SEED. ** Let g be the length of SEED in bits." */ if (++iterations > MAX_ITERATIONS) { /* give up after a while */ PORT_SetError(SEC_ERROR_NEED_RANDOM); goto cleanup; } seed->len = seedBytes; CHECK_SEC_OK( getPQseed(seed, verify->arena) ); /* ****************************************************************** ** Step 6. (Step 2 in 186-1) ** ** "Compute U = SHA[SEED] XOR SHA[(SEED+1) mod 2**g]. (186-1)" ** "Compute U = HASH[SEED] 2**(N-1). (186-3)" ** ** Step 7. (Step 3 in 186-1) ** "Form Q from U by setting the most signficant bit (the 2**159 bit) ** and the least signficant bit to 1. In terms of boolean operations, ** Q = U OR 2**159 OR 1. Note that 2**159 < Q < 2**160. (186-1)" ** ** "q = 2**(N-1) + U + 1 - (U mod 2) (186-3) ** ** Note: Both formulations are the same for U < 2**(N-1) and N=160 ** ** If using Shawe-Taylor, We do the entire A.1.2.1.2 setps in the block ** FIPS186_3_ST_TYPE. */ if (type == FIPS186_1_TYPE) { CHECK_SEC_OK( makeQfromSeed(seedlen, seed, &Q) ); } else if (type == FIPS186_3_TYPE) { CHECK_SEC_OK( makeQ2fromSeed(hashtype, N, seed, &Q) ); } else { /* FIPS186_3_ST_TYPE */ unsigned int qgen_counter, pgen_counter; /* Step 1 (L,N) already checked for acceptability */ firstseed = *seed; qgen_counter = 0; /* Step 2. Use N and firstseed to generate random prime q * using Apendix C.6 */ CHECK_SEC_OK( makePrimefromSeedShaweTaylor(hashtype, N, &firstseed, &Q, &qseed, &qgen_counter) ); /* Step 3. Use floor(L/2+1) and qseed to generate random prime p0 * using Appendix C.6 */ pgen_counter = 0; CHECK_SEC_OK( makePrimefromSeedShaweTaylor(hashtype, (L+1)/2+1, &qseed, &p0, &pseed, &pgen_counter) ); /* Steps 4-22 FIPS 186-3 appendix A.1.2.1.2 */ CHECK_SEC_OK( makePrimefromPrimesShaweTaylor(hashtype, L, &p0, &Q, &P, &pseed, &pgen_counter) ); /* combine all the seeds */ seed->len = firstseed.len +qseed.len + pseed.len; seed->data = PORT_ArenaZAlloc(verify->arena, seed->len); if (seed->data == NULL) { goto cleanup; } PORT_Memcpy(seed->data, firstseed.data, firstseed.len); PORT_Memcpy(seed->data+firstseed.len, pseed.data, pseed.len); PORT_Memcpy(seed->data+firstseed.len+pseed.len, qseed.data, qseed.len); counter = 0 ; /* (qgen_counter << 16) | pgen_counter; */ /* we've generated both P and Q now, skip to generating G */ goto generate_G; } /* ****************************************************************** ** Step 8. (Step 4 in 186-1) ** "Use a robust primality testing algorithm to test whether q is prime." ** ** Appendix 2.1 states that a Rabin test with at least 50 iterations ** "will give an acceptable probability of error." */ /*CHECK_SEC_OK( prm_RabinTest(&Q, &passed) );*/ err = mpp_pprime(&Q, prime_testcount_q(L,N)); passed = (err == MP_YES) ? SECSuccess : SECFailure; /* ****************************************************************** ** Step 9. (Step 5 in 186-1) "If q is not prime, goto step 5 (1 in 186-1)." */ if (passed != SECSuccess) goto step_5; /* ****************************************************************** ** Step 10. ** offset = 1; **( Step 6b 186-1)"Let counter = 0 and offset = 2." */ offset = (type == FIPS186_1_TYPE) ? 2 : 1; /* ** Step 11. (Step 6a,13a,14 in 186-1) ** For counter - 0 to (4L-1) do ** */ maxCount = L >= 1024 ? (4*L - 1) : 4095; for (counter = 0; counter <= maxCount; counter++) { /* ****************************************************************** ** Step 11.1 (Step 7 in 186-1) ** "for j = 0 ... n let ** V_j = HASH[(SEED + offset + j) mod 2**seedlen]." ** ** Step 11.2 (Step 8 in 186-1) ** "W = V_0 + V_1*2**outlen+...+ V_n-1 * 2**((n-1)*outlen) + ** ((Vn* mod 2**b)*2**(n*outlen))" ** Step 11.3 (Step 8 in 186-1) ** "X = W + 2**(L-1) ** Note that 0 <= W < 2**(L-1) and hence 2**(L-1) <= X < 2**L." ** ** Step 11.4 (Step 9 in 186-1). ** "c = X mod 2q" ** ** Step 11.5 (Step 9 in 186-1). ** " p = X - (c - 1). ** Note that p is congruent to 1 mod 2q." */ CHECK_SEC_OK( makePfromQandSeed(hashtype, L, N, offset, seedlen, seed, &Q, &P) ); /************************************************************* ** Step 11.6. (Step 10 in 186-1) ** "if p < 2**(L-1), then goto step 11.9. (step 13 in 186-1)" */ CHECK_MPI_OK( mpl_set_bit(&l, (mp_size)(L-1), 1) ); /* l = 2**(L-1) */ if (mp_cmp(&P, &l) < 0) goto step_11_9; /************************************************************ ** Step 11.7 (step 11 in 186-1) ** "Perform a robust primality test on p." */ /*CHECK_SEC_OK( prm_RabinTest(&P, &passed) );*/ err = mpp_pprime(&P, prime_testcount_p(L, N)); passed = (err == MP_YES) ? SECSuccess : SECFailure; /* ****************************************************************** ** Step 11.8. "If p is determined to be primed return VALID ** values of p, q, seed and counter." */ if (passed == SECSuccess) break; step_11_9: /* ****************************************************************** ** Step 11.9. "offset = offset + n + 1." */ offset += n + 1; } /* ****************************************************************** ** Step 12. "goto step 5." ** ** NOTE: if counter <= maxCount, then we exited the loop at Step 11.8 ** and now need to return p,q, seed, and counter. */ if (counter > maxCount) goto step_5; generate_G: /* ****************************************************************** ** returning p, q, seed and counter */ if (type == FIPS186_1_TYPE) { /* Generate g, This is called the "Unverifiable Generation of g * in FIPA186-3 Appedix A.2.1. For compatibility we maintain * this version of the code */ SECITEM_AllocItem(NULL, &hit, L/8); /* h is no longer than p */ if (!hit.data) goto cleanup; do { /* loop generate h until 1 1 */ CHECK_SEC_OK( generate_h_candidate(&hit, &H) ); CHECK_SEC_OK( makeGfromH(&P, &Q, &H, &G, &passed) ); } while (passed != PR_TRUE); MPINT_TO_SECITEM(&H, &verify->h, verify->arena); } else { unsigned char index = 1; /* default to 1 */ verify->h.data = (unsigned char *)PORT_ArenaZAlloc(verify->arena, 1); if (verify->h.data == NULL) { goto cleanup; } verify->h.len = 1; verify->h.data[0] = index; /* Generate g, using the FIPS 186-3 Appendix A.23 */ CHECK_SEC_OK(makeGfromIndex(hashtype, &P, &Q, seed, index, &G) ); } /* All generation is done. Now, save the PQG params. */ MPINT_TO_SECITEM(&P, ¶ms->prime, params->arena); MPINT_TO_SECITEM(&Q, ¶ms->subPrime, params->arena); MPINT_TO_SECITEM(&G, ¶ms->base, params->arena); verify->counter = counter; *pParams = params; *pVfy = verify; cleanup: if (pseed.data) { PORT_Free(pseed.data); } if (qseed.data) { PORT_Free(qseed.data); } mp_clear(&P); mp_clear(&Q); mp_clear(&G); mp_clear(&H); mp_clear(&l); mp_clear(&p0); if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } if (rv) { PORT_FreeArena(params->arena, PR_TRUE); PORT_FreeArena(verify->arena, PR_TRUE); } if (hit.data) { SECITEM_FreeItem(&hit, PR_FALSE); } return rv; } SECStatus PQG_ParamGen(unsigned int j, PQGParams **pParams, PQGVerify **pVfy) { unsigned int L; /* Length of P in bits. Per FIPS 186. */ unsigned int seedBytes; if (j > 8 || !pParams || !pVfy) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } L = 512 + (j * 64); /* bits in P */ seedBytes = L/8; return pqg_ParamGen(L, DSA1_Q_BITS, FIPS186_1_TYPE, seedBytes, pParams, pVfy); } SECStatus PQG_ParamGenSeedLen(unsigned int j, unsigned int seedBytes, PQGParams **pParams, PQGVerify **pVfy) { unsigned int L; /* Length of P in bits. Per FIPS 186. */ if (j > 8 || !pParams || !pVfy) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } L = 512 + (j * 64); /* bits in P */ return pqg_ParamGen(L, DSA1_Q_BITS, FIPS186_1_TYPE, seedBytes, pParams, pVfy); } SECStatus PQG_ParamGenV2(unsigned int L, unsigned int N, unsigned int seedBytes, PQGParams **pParams, PQGVerify **pVfy) { if (N == 0) { N = pqg_get_default_N(L); } if (seedBytes == 0) { /* seedBytes == L/8 for probable primes, N/8 for Shawe-Taylor Primes */ seedBytes = N/8; } if (pqg_validate_dsa2(L,N) != SECSuccess) { /* error code already set */ return SECFailure; } return pqg_ParamGen(L, N, FIPS186_3_ST_TYPE, seedBytes, pParams, pVfy); } /* * verify can use vfy structures returned from either FIPS186-1 or * FIPS186-2, and can handle differences in selected Hash functions to * generate the parameters. */ SECStatus PQG_VerifyParams(const PQGParams *params, const PQGVerify *vfy, SECStatus *result) { SECStatus rv = SECSuccess; unsigned int g, n, L, N, offset, outlen; mp_int p0, P, Q, G, P_, Q_, G_, r, h; mp_err err = MP_OKAY; int j; unsigned int counter_max = 0; /* handle legacy L < 1024 */ unsigned int qseed_len; SECItem pseed_ = {0, 0, 0}; HASH_HashType hashtype; pqgGenType type; #define CHECKPARAM(cond) \ if (!(cond)) { \ *result = SECFailure; \ goto cleanup; \ } if (!params || !vfy || !result) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } /* always need at least p, q, and seed for any meaningful check */ if ((params->prime.len == 0) || (params->subPrime.len == 0) || (vfy->seed.len == 0)) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } /* we want to either check PQ or G or both. If we don't have G, make * sure we have count so we can check P. */ if ((params->base.len == 0) && (vfy->counter == -1)) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } MP_DIGITS(&p0) = 0; MP_DIGITS(&P) = 0; MP_DIGITS(&Q) = 0; MP_DIGITS(&G) = 0; MP_DIGITS(&P_) = 0; MP_DIGITS(&Q_) = 0; MP_DIGITS(&G_) = 0; MP_DIGITS(&r) = 0; MP_DIGITS(&h) = 0; CHECK_MPI_OK( mp_init(&p0) ); CHECK_MPI_OK( mp_init(&P) ); CHECK_MPI_OK( mp_init(&Q) ); CHECK_MPI_OK( mp_init(&G) ); CHECK_MPI_OK( mp_init(&P_) ); CHECK_MPI_OK( mp_init(&Q_) ); CHECK_MPI_OK( mp_init(&G_) ); CHECK_MPI_OK( mp_init(&r) ); CHECK_MPI_OK( mp_init(&h) ); *result = SECSuccess; SECITEM_TO_MPINT(params->prime, &P); SECITEM_TO_MPINT(params->subPrime, &Q); /* if G isn't specified, just check P and Q */ if (params->base.len != 0) { SECITEM_TO_MPINT(params->base, &G); } /* 1. Check (L,N) pair */ N = mpl_significant_bits(&Q); L = mpl_significant_bits(&P); if (L < 1024) { /* handle DSA1 pqg parameters with less thatn 1024 bits*/ CHECKPARAM( N == DSA1_Q_BITS ); j = PQG_PBITS_TO_INDEX(L); CHECKPARAM( j >= 0 && j <= 8 ); counter_max = 4096; } else { /* handle DSA2 parameters (includes DSA1, 1024 bits) */ CHECKPARAM(pqg_validate_dsa2(L, N) == SECSuccess); counter_max = 4*L; } /* 3. G < P */ if (params->base.len != 0) { CHECKPARAM( mp_cmp(&G, &P) < 0 ); } /* 4. P % Q == 1 */ CHECK_MPI_OK( mp_mod(&P, &Q, &r) ); CHECKPARAM( mp_cmp_d(&r, 1) == 0 ); /* 5. Q is prime */ CHECKPARAM( mpp_pprime(&Q, prime_testcount_q(L,N)) == MP_YES ); /* 6. P is prime */ CHECKPARAM( mpp_pprime(&P, prime_testcount_p(L,N)) == MP_YES ); /* Steps 7-12 are done only if the optional PQGVerify is supplied. */ /* continue processing P */ /* 7. counter < 4*L */ CHECKPARAM( (vfy->counter == -1) || (vfy->counter < counter_max) ); /* 8. g >= N and g < 2*L (g is length of seed in bits) */ g = vfy->seed.len * 8; CHECKPARAM( g >= N && g < counter_max/2 ); /* 9. Q generated from SEED matches Q in PQGParams. */ /* This function checks all possible hash and generation types to * find a Q_ which matches Q. */ CHECKPARAM( findQfromSeed(L, N, g, &vfy->seed, &Q, &Q_, &qseed_len, &hashtype, &type) == SECSuccess ); CHECKPARAM( mp_cmp(&Q, &Q_) == 0 ); if (type == FIPS186_3_ST_TYPE) { SECItem qseed = { 0, 0, 0 }; SECItem pseed = { 0, 0, 0 }; unsigned int first_seed_len; unsigned int pgen_counter = 0; /* extract pseed and qseed from domain_parameter_seed, which is * first_seed || pseed || qseed. qseed is first_seed + small_integer * pseed is qseed + small_integer. This means most of the time * first_seed.len == qseed.len == pseed.len. Rarely qseed.len and/or * pseed.len will be one greater than first_seed.len, so we can * depend on the fact that * first_seed.len = floor(domain_parameter_seed.len/3). * findQfromSeed returned qseed.len, so we can calculate pseed.len as * pseed.len = domain_parameter_seed.len - first_seed.len - qseed.len * this is probably over kill, since 99.999% of the time they will all * be equal. * * With the lengths, we can now find the offsets; * first_seed.data = domain_parameter_seed.data + 0 * pseed.data = domain_parameter_seed.data + first_seed.len * qseed.data = domain_parameter_seed.data * + domain_paramter_seed.len - qseed.len * */ first_seed_len = vfy->seed.len/3; CHECKPARAM(qseed_len < vfy->seed.len); CHECKPARAM(first_seed_len*8 > N-1); CHECKPARAM(first_seed_len+qseed_len < vfy->seed.len); qseed.len = qseed_len; qseed.data = vfy->seed.data + vfy->seed.len - qseed.len; pseed.len = vfy->seed.len - (first_seed_len+qseed_len); pseed.data = vfy->seed.data + first_seed_len; /* * now complete FIPS 186-3 A.1.2.1.2. Step 1 was completed * above in our initial checks, Step 2 was completed by * findQfromSeed */ /* Step 3 (status, c0, prime_seed, prime_gen_counter) = ** (ST_Random_Prime((ceil(length/2)+1, input_seed) */ CHECK_SEC_OK( makePrimefromSeedShaweTaylor(hashtype, (L+1)/2+1, &qseed, &p0, &pseed_, &pgen_counter) ); /* Steps 4-22 FIPS 186-3 appendix A.1.2.1.2 */ CHECK_SEC_OK( makePrimefromPrimesShaweTaylor(hashtype, L, &p0, &Q_, &P_, &pseed_, &pgen_counter) ); CHECKPARAM( mp_cmp(&P, &P_) == 0 ); /* make sure pseed wasn't tampered with (since it is part of * calculating G) */ CHECKPARAM( SECITEM_CompareItem(&pseed, &pseed_) == SECEqual ); } else if (vfy->counter == -1) { /* If counter is set to -1, we are really only verifying G, skip * the remainder of the checks for P */ CHECKPARAM(type != FIPS186_1_TYPE); /* we only do this for DSA2 */ } else { /* 10. P generated from (L, counter, g, SEED, Q) matches P * in PQGParams. */ outlen = HASH_ResultLen(hashtype)*PR_BITS_PER_BYTE; n = (L - 1) / outlen; offset = vfy->counter * (n + 1) + ((type == FIPS186_1_TYPE) ? 2 : 1); CHECK_SEC_OK( makePfromQandSeed(hashtype, L, N, offset, g, &vfy->seed, &Q, &P_) ); CHECKPARAM( mp_cmp(&P, &P_) == 0 ); } /* now check G, skip if don't have a g */ if (params->base.len == 0) goto cleanup; /* first Always check that G is OK FIPS186-3 A.2.2 & A.2.4*/ /* 1. 2 < G < P-1 */ /* P is prime, p-1 == zero 1st bit */ CHECK_MPI_OK( mpl_set_bit(&P, 0, 0) ); CHECKPARAM( mp_cmp_d(&G, 2) > 0 && mp_cmp(&G, &P) < 0 ); CHECK_MPI_OK( mpl_set_bit(&P, 0, 1) ); /* set it back */ /* 2. verify g**q mod p == 1 */ CHECK_MPI_OK( mp_exptmod(&G, &Q, &P, &h) ); /* h = G ** Q mod P */ CHECKPARAM(mp_cmp_d(&h, 1) == 0); /* no h, the above is the best we can do */ if (vfy->h.len == 0) { if (type != FIPS186_1_TYPE) { *result = SECWouldBlock; } goto cleanup; } /* * If h is one byte and FIPS186-3 was used to generate Q (we've verified * Q was generated from seed already, then we assume that FIPS 186-3 * appendix A.2.3 was used to generate G. Otherwise we assume A.2.1 was * used to generate G. */ if ((vfy->h.len == 1) && (type != FIPS186_1_TYPE)) { /* A.2.3 */ CHECK_SEC_OK(makeGfromIndex(hashtype, &P, &Q, &vfy->seed, vfy->h.data[0], &G_) ); CHECKPARAM( mp_cmp(&G, &G_) == 0 ); } else { int passed; /* A.2.1 */ SECITEM_TO_MPINT(vfy->h, &h); /* 11. 1 < h < P-1 */ /* P is prime, p-1 == zero 1st bit */ CHECK_MPI_OK( mpl_set_bit(&P, 0, 0) ); CHECKPARAM( mp_cmp_d(&G, 2) > 0 && mp_cmp(&G, &P) ); CHECK_MPI_OK( mpl_set_bit(&P, 0, 1) ); /* set it back */ /* 12. G generated from h matches G in PQGParams. */ CHECK_SEC_OK( makeGfromH(&P, &Q, &h, &G_, &passed) ); CHECKPARAM( passed && mp_cmp(&G, &G_) == 0 ); } cleanup: mp_clear(&p0); mp_clear(&P); mp_clear(&Q); mp_clear(&G); mp_clear(&P_); mp_clear(&Q_); mp_clear(&G_); mp_clear(&r); mp_clear(&h); if (pseed_.data) { SECITEM_FreeItem(&pseed_,PR_FALSE); } if (err) { MP_TO_SEC_ERROR(err); rv = SECFailure; } return rv; } /************************************************************************** * Free the PQGParams struct and the things it points to. * **************************************************************************/ void PQG_DestroyParams(PQGParams *params) { if (params == NULL) return; if (params->arena != NULL) { PORT_FreeArena(params->arena, PR_FALSE); /* don't zero it */ } else { SECITEM_FreeItem(¶ms->prime, PR_FALSE); /* don't free prime */ SECITEM_FreeItem(¶ms->subPrime, PR_FALSE); /* don't free subPrime */ SECITEM_FreeItem(¶ms->base, PR_FALSE); /* don't free base */ PORT_Free(params); } } /************************************************************************** * Free the PQGVerify struct and the things it points to. * **************************************************************************/ void PQG_DestroyVerify(PQGVerify *vfy) { if (vfy == NULL) return; if (vfy->arena != NULL) { PORT_FreeArena(vfy->arena, PR_FALSE); /* don't zero it */ } else { SECITEM_FreeItem(&vfy->seed, PR_FALSE); /* don't free seed */ SECITEM_FreeItem(&vfy->h, PR_FALSE); /* don't free h */ PORT_Free(vfy); } }