diff options
Diffstat (limited to 'security/nss/lib/freebl/pqg.c')
| -rw-r--r-- | security/nss/lib/freebl/pqg.c | 1878 |
1 files changed, 1878 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/pqg.c b/security/nss/lib/freebl/pqg.c new file mode 100644 index 000000000..2f24afd24 --- /dev/null +++ b/security/nss/lib/freebl/pqg.c @@ -0,0 +1,1878 @@ +/* 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. + */ +static 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 */ +static 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); + PORT_Assert(hash_obj != NULL); + if (hash_obj == NULL) { + /* type is always a valid HashType. Thus a null hash_obj must be a bug */ + PORT_SetError(SEC_ERROR_LIBRARY_FAILURE); + return 0; + } + PORT_Assert(hash_obj->length != 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; i < SHA1_LENGTH; ++i) + U[i] = sha1[i] ^ sha2[i]; + /* ****************************************************************** + ** Step 3. + ** "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." + */ + U[0] |= 0x80; /* U is MSB first */ + U[SHA1_LENGTH - 1] |= 0x01; + err = mp_read_unsigned_octets(Q, U, SHA1_LENGTH); +cleanup: + memset(U, 0, SHA1_LENGTH); + memset(sha1, 0, SHA1_LENGTH); + memset(sha2, 0, SHA1_LENGTH); + if (err) { + MP_TO_SEC_ERROR(err); + return SECFailure; + } + return rv; +} + +/* +** Perform steps 6 and 7 of FIPS 186-3, appendix A.1.1.2. +** Generate Q from seed. +*/ +static SECStatus +makeQ2fromSeed( + HASH_HashType hashtype, /* selected Hashing algorithm */ + unsigned int N, /* input. Length of q in bits. */ + const SECItem *seed, /* input. */ + mp_int *Q) /* output. */ +{ + unsigned char U[HASH_LENGTH_MAX]; + SECStatus rv = SECSuccess; + mp_err err = MP_OKAY; + int N_bytes = N / PR_BITS_PER_BYTE; /* length of N in bytes rather than bits */ + int hashLen = HASH_ResultLen(hashtype); + int offset = 0; + + /* ****************************************************************** + ** Step 6. + ** "Compute U = hash[SEED] mod 2**N-1]." + **/ + CHECK_SEC_OK(HASH_HashBuf(hashtype, U, seed->data, 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) +static 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); + PORT_Memset(x, 0, sizeof(x)); + 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 +*/ +static 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); + PORT_Memset(x, 0, sizeof(x)); + 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 < n; ++j) { /* Do the first n terms of V_j */ + /* Do step 11.1 for iteration j. + ** V_j = HASH[(seed + offset + j) mod 2**g] + */ + CHECK_SEC_OK(addToSeedThenHash(hashtype, seed, offset + j, seedlen, V_j)); + /* Do step 11.2 for iteration j. + ** W += V_j * 2**(j*outlen) + */ + OCTETS_TO_MPINT(V_j, &tmp, hashlen); /* get bignum V_j */ + CHECK_MPI_OK(mpl_lsh(&tmp, &tmp, j * outlen)); /* tmp=V_j << j*outlen */ + CHECK_MPI_OK(mp_add(&W, &tmp, &W)); /* W += tmp */ + } + /* Step 11.2, continued. + ** [W += ((V_n mod 2**b) * 2**(n*outlen))] + */ + CHECK_SEC_OK(addToSeedThenHash(hashtype, seed, offset + n, seedlen, V_j)); + OCTETS_TO_MPINT(V_j, &V_n, hashlen); /* get bignum V_n */ + CHECK_MPI_OK(mp_div_2d(&V_n, b, NULL, &tmp)); /* tmp = V_n mod 2**b */ + CHECK_MPI_OK(mpl_lsh(&tmp, &tmp, n * outlen)); /* tmp = tmp << n*outlen */ + CHECK_MPI_OK(mp_add(&W, &tmp, &W)); /* W += tmp */ + /* 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." + */ + CHECK_MPI_OK(mpl_set_bit(&X, (mp_size)(L - 1), 1)); /* X = 2**(L-1) */ + CHECK_MPI_OK(mp_add(&X, &W, &X)); /* X += W */ + /************************************************************* + ** Step 11.4. (Step 9 in 186-1) + ** "c = X mod 2q" + */ + CHECK_MPI_OK(mp_mul_2(Q, &twoQ)); /* 2q */ + CHECK_MPI_OK(mp_mod(&X, &twoQ, &c)); /* 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_MPI_OK(mp_sub_d(&c, 1, &c)); /* c -= 1 */ + CHECK_MPI_OK(mp_sub(&X, &c, P)); /* P = X - c */ +cleanup: + mp_clear(&W); + mp_clear(&X); + mp_clear(&c); + mp_clear(&twoQ); + mp_clear(&V_n); + mp_clear(&tmp); + if (err) { + MP_TO_SEC_ERROR(err); + return SECFailure; + } + return rv; +} + +/* +** Generate G from h, P, and Q. +*/ +static SECStatus +makeGfromH(const mp_int *P, /* input. */ + const mp_int *Q, /* input. */ + mp_int *H, /* input and output. */ + mp_int *G, /* output. */ + PRBool *passed) +{ + mp_int exp, pm1; + mp_err err = MP_OKAY; + SECStatus rv = SECSuccess; + *passed = PR_FALSE; + MP_DIGITS(&exp) = 0; + MP_DIGITS(&pm1) = 0; + CHECK_MPI_OK(mp_init(&exp)); + CHECK_MPI_OK(mp_init(&pm1)); + CHECK_MPI_OK(mp_sub_d(P, 1, &pm1)); /* P - 1 */ + if (mp_cmp(H, &pm1) >= 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 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)); + + /* parameters have been passed in, only generate G */ + if (*pParams != NULL) { + /* we only support G index generation if generating separate from PQ */ + if ((*pVfy == NULL) || (type == FIPS186_1_TYPE) || + ((*pVfy)->h.len != 1) || ((*pVfy)->h.data == NULL) || + ((*pVfy)->seed.data == NULL) || ((*pVfy)->seed.len == 0)) { + PORT_SetError(SEC_ERROR_INVALID_ARGS); + return SECFailure; + } + params = *pParams; + verify = *pVfy; + + /* fill in P Q, */ + SECITEM_TO_MPINT((*pParams)->prime, &P); + SECITEM_TO_MPINT((*pParams)->subPrime, &Q); + hashtype = getFirstHash(L, N); + CHECK_SEC_OK(makeGfromIndex(hashtype, &P, &Q, &(*pVfy)->seed, + (*pVfy)->h.data[0], &G)); + MPINT_TO_SECITEM(&G, &(*pParams)->base, (*pParams)->arena); + goto cleanup; + } + /* 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; + + /* 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<h<p-1 and (h**[(p-1)/q])mod p > 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) { + if (params) { + PORT_FreeArena(params->arena, PR_TRUE); + } + if (verify) { + 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); + } +} |