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+/* 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(&params->prime) * PR_BITS_PER_BYTE;
+ N = PQG_GetLength(&params->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(&params->prime) * PR_BITS_PER_BYTE;
+ N = PQG_GetLength(&params->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, &params->prime, params->arena);
+ MPINT_TO_SECITEM(&Q, &params->subPrime, params->arena);
+ MPINT_TO_SECITEM(&G, &params->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(&params->prime, PR_FALSE); /* don't free prime */
+ SECITEM_FreeItem(&params->subPrime, PR_FALSE); /* don't free subPrime */
+ SECITEM_FreeItem(&params->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);
+ }
+}