Add m-esr52 at 52.6.0

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(&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);
+    }
+}