/* primegen.c - prime number generator
- * Copyright (C) 1998, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+ * Copyright (C) 1998, 2000, 2001, 2002, 2003
+ * 2004, 2008 Free Software Foundation, Inc.
*
* This file is part of Libgcrypt.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- *
- * ***********************************************************************
- * The algorithm used to generate practically save primes is due to
- * Lim and Lee as described in the CRYPTO '97 proceedings (ISBN3540633847)
- * page 260.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#include <assert.h>
+#include <errno.h>
#include "g10lib.h"
#include "mpi.h"
#include "cipher.h"
-
-static gcry_mpi_t gen_prime (unsigned int nbits, int secret, int randomlevel,
- int (*extra_check)(void *, gcry_mpi_t), void *extra_check_arg);
-static int check_prime( gcry_mpi_t prime, gcry_mpi_t val_2 );
-static int is_prime( gcry_mpi_t n, int steps, int *count );
+#include "ath.h"
+
+static gcry_mpi_t gen_prime (unsigned int nbits, int secret, int randomlevel,
+ int (*extra_check)(void *, gcry_mpi_t),
+ void *extra_check_arg);
+static int check_prime( gcry_mpi_t prime, gcry_mpi_t val_2, int rm_rounds,
+ gcry_prime_check_func_t cb_func, void *cb_arg );
+static int is_prime (gcry_mpi_t n, int steps, unsigned int *count);
static void m_out_of_n( char *array, int m, int n );
static void (*progress_cb) (void *,const char*,int,int, int );
};
static int no_of_small_prime_numbers = DIM (small_prime_numbers) - 1;
+
+\f
+/* An object and a list to build up a global pool of primes. See
+ save_pool_prime and get_pool_prime. */
+struct primepool_s
+{
+ struct primepool_s *next;
+ gcry_mpi_t prime; /* If this is NULL the entry is not used. */
+ unsigned int nbits;
+ gcry_random_level_t randomlevel;
+};
+struct primepool_s *primepool;
+/* Mutex used to protect access to the primepool. */
+static ath_mutex_t primepool_lock;
+
+
+gcry_err_code_t
+_gcry_primegen_init (void)
+{
+ gcry_err_code_t ec;
+
+ ec = ath_mutex_init (&primepool_lock);
+ if (ec)
+ return gpg_err_code_from_errno (ec);
+ return ec;
+}
+
+
+/* Save PRIME which has been generated at RANDOMLEVEL for later
+ use. Needs to be called while primepool_lock is being hold. Note
+ that PRIME should be considered released after calling this
+ function. */
+static void
+save_pool_prime (gcry_mpi_t prime, gcry_random_level_t randomlevel)
+{
+ struct primepool_s *item, *item2;
+ size_t n;
+
+ for (n=0, item = primepool; item; item = item->next, n++)
+ if (!item->prime)
+ break;
+ if (!item && n > 100)
+ {
+ /* Remove some of the entries. Our strategy is removing
+ the last third from the list. */
+ int i;
+
+ for (i=0, item2 = primepool; item2; item2 = item2->next)
+ {
+ if (i >= n/3*2)
+ {
+ _gcry_mpi_release (item2->prime);
+ item2->prime = NULL;
+ if (!item)
+ item = item2;
+ }
+ }
+ }
+ if (!item)
+ {
+ item = xtrycalloc (1, sizeof *item);
+ if (!item)
+ {
+ /* Out of memory. Silently giving up. */
+ _gcry_mpi_release (prime);
+ return;
+ }
+ item->next = primepool;
+ primepool = item;
+ }
+ item->prime = prime;
+ item->nbits = mpi_get_nbits (prime);
+ item->randomlevel = randomlevel;
+}
+
+
+/* Return a prime for the prime pool or NULL if none has been found.
+ The prime needs to match NBITS and randomlevel. This function needs
+ to be called with the primepool_look is being hold. */
+static gcry_mpi_t
+get_pool_prime (unsigned int nbits, gcry_random_level_t randomlevel)
+{
+ struct primepool_s *item;
+
+ for (item = primepool; item; item = item->next)
+ if (item->prime
+ && item->nbits == nbits && item->randomlevel == randomlevel)
+ {
+ gcry_mpi_t prime = item->prime;
+ item->prime = NULL;
+ gcry_assert (nbits == mpi_get_nbits (prime));
+ return prime;
+ }
+ return NULL;
+}
+
+
+
+
+
+\f
void
-_gcry_register_primegen_progress ( void (*cb)(void *,const char*,int,int,int), void *cb_data )
+_gcry_register_primegen_progress ( void (*cb)(void *,const char*,int,int,int),
+ void *cb_data )
{
- progress_cb = cb;
- progress_cb_data = cb_data;
+ progress_cb = cb;
+ progress_cb_data = cb_data;
}
*/
gcry_mpi_t
_gcry_generate_secret_prime (unsigned int nbits,
+ gcry_random_level_t random_level,
int (*extra_check)(void*, gcry_mpi_t),
void *extra_check_arg)
{
- gcry_mpi_t prime;
+ gcry_mpi_t prime;
- prime = gen_prime( nbits, 1, 2, extra_check, extra_check_arg);
- progress('\n');
- return prime;
+ prime = gen_prime (nbits, 1, random_level, extra_check, extra_check_arg);
+ progress('\n');
+ return prime;
}
+
+/* Generate a prime number which may be public, i.e. not allocated in
+ secure memory. */
gcry_mpi_t
-_gcry_generate_public_prime( unsigned int nbits,
+_gcry_generate_public_prime (unsigned int nbits,
+ gcry_random_level_t random_level,
int (*extra_check)(void*, gcry_mpi_t),
void *extra_check_arg)
{
- gcry_mpi_t prime;
+ gcry_mpi_t prime;
- prime = gen_prime( nbits, 0, 2, extra_check, extra_check_arg );
- progress('\n');
- return prime;
+ prime = gen_prime (nbits, 0, random_level, extra_check, extra_check_arg);
+ progress('\n');
+ return prime;
}
-/****************
- * We do not need to use the strongest RNG because we gain no extra
- * security from it - The prime number is public and we could also
- * offer the factors for those who are willing to check that it is
- * indeed a strong prime. With ALL_FACTORS set to true all afcors of
- * prime-1 are returned in FACTORS.
- *
- * mode 0: Standard
- * 1: Make sure that at least one factor is of size qbits.
+/* Core prime generation function. The algorithm used to generate
+ practically save primes is due to Lim and Lee as described in the
+ CRYPTO '97 proceedings (ISBN3540633847) page 260.
+
+ NEED_Q_FACTOR: If true make sure that at least one factor is of
+ size qbits. This is for example required for DSA.
+ PRIME_GENERATED: Adresss of a variable where the resulting prime
+ number will be stored.
+ PBITS: Requested size of the prime number. At least 48.
+ QBITS: One factor of the prime needs to be of this size. Maybe 0
+ if this is not required. See also MODE.
+ G: If not NULL an MPI which will receive a generator for the prime
+ for use with Elgamal.
+ RET_FACTORS: if not NULL, an array with all factors are stored at
+ that address.
+ ALL_FACTORS: If set to true all factors of prime-1 are returned.
+ RANDOMLEVEL: How strong should the random numers be.
+ FLAGS: Prime generation bit flags. Currently supported:
+ GCRY_PRIME_FLAG_SECRET - The prime needs to be kept secret.
+ CB_FUNC, CB_ARG: Callback to be used for extra checks.
+
*/
static gcry_err_code_t
-prime_generate_internal (int mode,
+prime_generate_internal (int need_q_factor,
gcry_mpi_t *prime_generated, unsigned int pbits,
unsigned int qbits, gcry_mpi_t g,
gcry_mpi_t **ret_factors,
- gcry_random_level_t random, unsigned int flags,
- int all_factors)
+ gcry_random_level_t randomlevel, unsigned int flags,
+ int all_factors,
+ gcry_prime_check_func_t cb_func, void *cb_arg)
{
gcry_err_code_t err = 0;
gcry_mpi_t *factors_new = NULL; /* Factors to return to the
caller. */
gcry_mpi_t *factors = NULL; /* Current factors. */
+ gcry_random_level_t poolrandomlevel; /* Random level used for pool primes. */
gcry_mpi_t *pool = NULL; /* Pool of primes. */
+ int *pool_in_use = NULL; /* Array with currently used POOL elements. */
unsigned char *perms = NULL; /* Permutations of POOL. */
gcry_mpi_t q_factor = NULL; /* Used if QBITS is non-zero. */
unsigned int fbits = 0; /* Length of prime factors. */
unsigned int nprime = 0; /* Bits of PRIME. */
unsigned int req_qbits; /* The original QBITS value. */
gcry_mpi_t val_2; /* For check_prime(). */
+ int is_locked = 0; /* Flag to help unlocking the primepool. */
unsigned int is_secret = (flags & GCRY_PRIME_FLAG_SECRET);
unsigned int count1 = 0, count2 = 0;
unsigned int i = 0, j = 0;
if (pbits < 48)
return GPG_ERR_INV_ARG;
+ /* We won't use a too strong random elvel for the pooled subprimes. */
+ poolrandomlevel = (randomlevel > GCRY_STRONG_RANDOM?
+ GCRY_STRONG_RANDOM : randomlevel);
+
+
/* If QBITS is not given, assume a reasonable value. */
if (!qbits)
qbits = pbits / 3;
req_qbits = qbits;
- /* Find number of needed prime factors. */
+ /* Find number of needed prime factors N. */
for (n = 1; (pbits - qbits - 1) / n >= qbits; n++)
;
n--;
val_2 = mpi_alloc_set_ui (2);
- if ((! n) || ((mode == 1) && (n < 2)))
- err = GPG_ERR_INV_ARG;
+ if ((! n) || ((need_q_factor) && (n < 2)))
+ {
+ err = GPG_ERR_INV_ARG;
+ goto leave;
+ }
- if (! err)
+ if (need_q_factor)
{
- if (mode == 1)
- {
- n--;
- fbits = (pbits - 2 * req_qbits -1) / n;
- qbits = pbits - req_qbits - n * fbits;
- }
- else
- {
- fbits = (pbits - req_qbits -1) / n;
- qbits = pbits - n * fbits;
- }
-
- if (DBG_CIPHER)
- log_debug ("gen prime: pbits=%u qbits=%u fbits=%u/%u n=%d\n",
- pbits, req_qbits, qbits, fbits, n);
+ n--; /* Need one factor less because we want a specific Q-FACTOR. */
+ fbits = (pbits - 2 * req_qbits -1) / n;
+ qbits = pbits - req_qbits - n * fbits;
+ }
+ else
+ {
+ fbits = (pbits - req_qbits -1) / n;
+ qbits = pbits - n * fbits;
+ }
- prime = gcry_mpi_new (pbits);
+ if (DBG_CIPHER)
+ log_debug ("gen prime: pbits=%u qbits=%u fbits=%u/%u n=%d\n",
+ pbits, req_qbits, qbits, fbits, n);
- /* Generate first prime factor. */
- q = gen_prime (qbits, is_secret, random, NULL, NULL);
+ /* Allocate an integer to old the new prime. */
+ prime = mpi_new (pbits);
- if (mode == 1)
- q_factor = gen_prime (req_qbits, is_secret, random, NULL, NULL);
+ /* Generate first prime factor. */
+ q = gen_prime (qbits, is_secret, randomlevel, NULL, NULL);
- /* Allocate an array to hold the factors + 2 for later
- usage. */
- factors = gcry_calloc (n + 2, sizeof (*factors));
- if (! factors)
- err = GPG_ERR_INTERNAL; /* FIXME. */
- }
+ /* Generate a specific Q-Factor if requested. */
+ if (need_q_factor)
+ q_factor = gen_prime (req_qbits, is_secret, randomlevel, NULL, NULL);
- if (! err)
+ /* Allocate an array to hold all factors + 2 for later usage. */
+ factors = xtrycalloc (n + 2, sizeof (*factors));
+ if (!factors)
{
- /* Make a pool of 3n+5 primes (this is an arbitrary value). */
-
- m = n * 3 + 5;
- if (mode == 1)
- /* Need some more (for e.g. DSA). */
- m += 5;
- if (m < 25)
- m = 25;
- pool = gcry_calloc (m , sizeof (*pool));
- if (! pool)
- err = GPG_ERR_INTERNAL;
+ err = gpg_err_code_from_errno (errno);
+ goto leave;
}
- if (! err)
- /* Permutate over the pool of primes. */
- do
- {
- next_try:
- if (! perms)
- {
- /* Allocate new primes. */
- for(i = 0; i < m; i++)
- {
- mpi_free (pool[i]);
- pool[i] = NULL;
- }
+ /* Allocate an array to track pool usage. */
+ pool_in_use = xtrymalloc (n * sizeof *pool_in_use);
+ if (!pool_in_use)
+ {
+ err = gpg_err_code_from_errno (errno);
+ goto leave;
+ }
+ for (i=0; i < n; i++)
+ pool_in_use[i] = -1;
+
+ /* Make a pool of 3n+5 primes (this is an arbitrary value). We
+ require at least 30 primes for are useful selection process.
+
+ Fixme: We need to research the best formula for sizing the pool.
+ */
+ m = n * 3 + 5;
+ if (need_q_factor) /* Need some more in this case. */
+ m += 5;
+ if (m < 30)
+ m = 30;
+ pool = xtrycalloc (m , sizeof (*pool));
+ if (! pool)
+ {
+ err = gpg_err_code_from_errno (errno);
+ goto leave;
+ }
- /* Init m_out_of_n(). */
- perms = gcry_calloc (1, m);
- if (! perms)
- err = GPG_ERR_INTERNAL; /* FIXME. */
- else
- {
- for(i = 0; i < n; i++)
- {
- perms[i] = 1;
- pool[i] = gen_prime (fbits, is_secret, random, NULL, NULL);
- factors[i] = pool[i];
- }
- }
+ /* Permutate over the pool of primes until we find a prime of the
+ requested length. */
+ do
+ {
+ next_try:
+ for (i=0; i < n; i++)
+ pool_in_use[i] = -1;
- if (err)
- break;
- }
- else
- {
- m_out_of_n (perms, n, m);
- for(i = j = 0; (i < m) && (j < n); i++)
- if (perms[i])
- {
- if(! pool[i])
- pool[i] = gen_prime (fbits, 0, 1, NULL, NULL);
- factors[j++] = pool[i];
- }
- if (i == n)
- {
- gcry_free(perms);
- perms = NULL;
- progress('!');
- goto next_try; /* Allocate new primes. */
- }
- }
+ if (!perms)
+ {
+ /* Allocate new primes. This is done right at the beginning
+ of the loop and if we have later run out of primes. */
+ for (i = 0; i < m; i++)
+ {
+ mpi_free (pool[i]);
+ pool[i] = NULL;
+ }
- /* Generate next prime candidate:
+ /* Init m_out_of_n(). */
+ perms = xtrycalloc (1, m);
+ if (!perms)
+ {
+ err = gpg_err_code_from_errno (errno);
+ goto leave;
+ }
- p = 2 * q [ * q_factor] * factor_0 * factor_1 * ... * factor_n + 1. */
+ if (ath_mutex_lock (&primepool_lock))
+ {
+ err = GPG_ERR_INTERNAL;
+ goto leave;
+ }
+ is_locked = 1;
+ for (i = 0; i < n; i++)
+ {
+ perms[i] = 1;
+ /* At a maximum we use strong random for the factors.
+ This saves us a lot of entropy. Given that Q and
+ possible Q-factor are also used in the final prime
+ this should be acceptable. We also don't allocate in
+ secure memory to save on that scare resource too. If
+ Q has been allocated in secure memory, the final
+ prime will be saved there anyway. This is because
+ our MPI routines take care of that. GnuPG has worked
+ this way ever since. */
+ pool[i] = NULL;
+ if (is_locked)
+ {
+ pool[i] = get_pool_prime (fbits, poolrandomlevel);
+ if (!pool[i])
+ {
+ if (ath_mutex_unlock (&primepool_lock))
+ {
+ err = GPG_ERR_INTERNAL;
+ goto leave;
+ }
+ is_locked = 0;
+ }
+ }
+ if (!pool[i])
+ pool[i] = gen_prime (fbits, 0, poolrandomlevel, NULL, NULL);
+ pool_in_use[i] = i;
+ factors[i] = pool[i];
+ }
+ if (is_locked && ath_mutex_unlock (&primepool_lock))
+ {
+ err = GPG_ERR_INTERNAL;
+ goto leave;
+ }
+ is_locked = 0;
+ }
+ else
+ {
+ /* Get next permutation. */
+ m_out_of_n ( (char*)perms, n, m);
+ if (ath_mutex_lock (&primepool_lock))
+ {
+ err = GPG_ERR_INTERNAL;
+ goto leave;
+ }
+ is_locked = 1;
+ for (i = j = 0; (i < m) && (j < n); i++)
+ if (perms[i])
+ {
+ /* If the subprime has not yet beed generated do it now. */
+ if (!pool[i] && is_locked)
+ {
+ pool[i] = get_pool_prime (fbits, poolrandomlevel);
+ if (!pool[i])
+ {
+ if (ath_mutex_unlock (&primepool_lock))
+ {
+ err = GPG_ERR_INTERNAL;
+ goto leave;
+ }
+ is_locked = 0;
+ }
+ }
+ if (!pool[i])
+ pool[i] = gen_prime (fbits, 0, poolrandomlevel, NULL, NULL);
+ pool_in_use[j] = i;
+ factors[j++] = pool[i];
+ }
+ if (is_locked && ath_mutex_unlock (&primepool_lock))
+ {
+ err = GPG_ERR_INTERNAL;
+ goto leave;
+ }
+ is_locked = 0;
+ if (i == n)
+ {
+ /* Ran out of permutations: Allocate new primes. */
+ xfree (perms);
+ perms = NULL;
+ progress ('!');
+ goto next_try;
+ }
+ }
+ /* Generate next prime candidate:
+ p = 2 * q [ * q_factor] * factor_0 * factor_1 * ... * factor_n + 1.
+ */
mpi_set (prime, q);
mpi_mul_ui (prime, prime, 2);
- if (mode == 1)
+ if (need_q_factor)
mpi_mul (prime, prime, q_factor);
for(i = 0; i < n; i++)
mpi_mul (prime, prime, factors[i]);
qbits++;
progress('>');
mpi_free (q);
- q = gen_prime (qbits, 0, 0, NULL, NULL);
+ q = gen_prime (qbits, is_secret, randomlevel, NULL, NULL);
goto next_try;
}
}
else
count1 = 0;
-
+
if (nprime > pbits)
{
if (++count2 > 20)
qbits--;
progress('<');
mpi_free (q);
- q = gen_prime (qbits, 0, 0, NULL, NULL);
+ q = gen_prime (qbits, is_secret, randomlevel, NULL, NULL);
goto next_try;
}
}
else
count2 = 0;
- }
- while (! ((nprime == pbits) && check_prime (prime, val_2)));
+ }
+ while (! ((nprime == pbits) && check_prime (prime, val_2, 5,
+ cb_func, cb_arg)));
- if (! err)
- if (DBG_CIPHER)
- {
- progress ('\n');
- log_mpidump ("prime : ", prime);
- log_mpidump ("factor q: ", q);
- if (mode == 1)
- log_mpidump ("factor q0: ", q_factor);
- for(i = 0; i < n; i++)
- log_mpidump ("factor pi: ", factors[i]);
- log_debug ("bit sizes: prime=%u, q=%u",
- mpi_get_nbits (prime), mpi_get_nbits (q));
- if (mode == 1)
- log_debug (", q0=%u", mpi_get_nbits (q_factor));
- for (i = 0; i < n; i++)
- log_debug (", p%d=%u", i, mpi_get_nbits (factors[i]));
- progress('\n');
- }
+ if (DBG_CIPHER)
+ {
+ progress ('\n');
+ log_mpidump ("prime ", prime);
+ log_mpidump ("factor q", q);
+ if (need_q_factor)
+ log_mpidump ("factor q0", q_factor);
+ for (i = 0; i < n; i++)
+ log_mpidump ("factor pi", factors[i]);
+ log_debug ("bit sizes: prime=%u, q=%u",
+ mpi_get_nbits (prime), mpi_get_nbits (q));
+ if (need_q_factor)
+ log_printf (", q0=%u", mpi_get_nbits (q_factor));
+ for (i = 0; i < n; i++)
+ log_printf (", p%d=%u", i, mpi_get_nbits (factors[i]));
+ log_printf ("\n");
+ }
- if (! err)
- if (ret_factors)
- {
- /* Caller wants the factors. */
- factors_new = gcry_calloc (n + 4, sizeof (*factors_new));
- if (! factors_new)
- err = GPG_ERR_INTERNAL; /* FIXME. */
- else if (all_factors)
- {
- i = 0;
- (factors_new)[i++] = gcry_mpi_set_ui (NULL, 2);
- (factors_new)[i++] = mpi_copy (q);
- if (mode == 1)
- (factors_new)[i++] = mpi_copy (q_factor);
- for(j=0; j < n; j++)
- (factors_new)[i++] = mpi_copy (factors[j]);
- }
- else
- {
- i = 0;
- if (mode == 1)
- {
- (factors_new)[i++] = mpi_copy (q_factor);
- for(; i <= n; i++)
- (factors_new)[i] = mpi_copy (factors[i]);
- }
- else
- for(; i < n; i++ )
- (factors_new)[i] = mpi_copy (factors[i]);
- }
- }
+ if (ret_factors)
+ {
+ /* Caller wants the factors. */
+ factors_new = xtrycalloc (n + 4, sizeof (*factors_new));
+ if (! factors_new)
+ {
+ err = gpg_err_code_from_errno (errno);
+ goto leave;
+ }
- if (! err)
- if (g)
- {
- /* Create a generator (start with 3). */
- gcry_mpi_t tmp = mpi_alloc (mpi_get_nlimbs (prime));
- gcry_mpi_t b = mpi_alloc (mpi_get_nlimbs (prime));
- gcry_mpi_t pmin1 = mpi_alloc (mpi_get_nlimbs (prime));
+ if (all_factors)
+ {
+ i = 0;
+ factors_new[i++] = mpi_set_ui (NULL, 2);
+ factors_new[i++] = mpi_copy (q);
+ if (need_q_factor)
+ factors_new[i++] = mpi_copy (q_factor);
+ for(j=0; j < n; j++)
+ factors_new[i++] = mpi_copy (factors[j]);
+ }
+ else
+ {
+ i = 0;
+ if (need_q_factor)
+ {
+ factors_new[i++] = mpi_copy (q_factor);
+ for (; i <= n; i++)
+ factors_new[i] = mpi_copy (factors[i]);
+ }
+ else
+ for (; i < n; i++ )
+ factors_new[i] = mpi_copy (factors[i]);
+ }
+ }
+
+ if (g)
+ {
+ /* Create a generator (start with 3). */
+ gcry_mpi_t tmp = mpi_alloc (mpi_get_nlimbs (prime));
+ gcry_mpi_t b = mpi_alloc (mpi_get_nlimbs (prime));
+ gcry_mpi_t pmin1 = mpi_alloc (mpi_get_nlimbs (prime));
+
+ if (need_q_factor)
+ err = GPG_ERR_NOT_IMPLEMENTED;
+ else
+ {
+ factors[n] = q;
+ factors[n + 1] = mpi_alloc_set_ui (2);
+ mpi_sub_ui (pmin1, prime, 1);
+ mpi_set_ui (g, 2);
+ do
+ {
+ mpi_add_ui (g, g, 1);
+ if (DBG_CIPHER)
+ log_printmpi ("checking g", g);
+ else
+ progress('^');
+ for (i = 0; i < n + 2; i++)
+ {
+ mpi_fdiv_q (tmp, pmin1, factors[i]);
+ /* No mpi_pow(), but it is okay to use this with mod
+ prime. */
+ mpi_powm (b, g, tmp, prime);
+ if (! mpi_cmp_ui (b, 1))
+ break;
+ }
+ if (DBG_CIPHER)
+ progress('\n');
+ }
+ while (i < n + 2);
+
+ mpi_free (factors[n+1]);
+ mpi_free (tmp);
+ mpi_free (b);
+ mpi_free (pmin1);
+ }
+ }
+
+ if (! DBG_CIPHER)
+ progress ('\n');
- if (mode == 1)
- err = GPG_ERR_NOT_IMPLEMENTED;
- else
- {
- factors[n] = q;
- factors[n + 1] = mpi_alloc_set_ui (2);
- mpi_sub_ui (pmin1, prime, 1);
- mpi_set_ui (g, 2);
- do
- {
- mpi_add_ui (g, g, 1);
- if (DBG_CIPHER)
- {
- log_debug ("checking g:");
- gcry_mpi_dump (g);
- log_debug ("\n");
- }
- else
- progress('^');
- for (i = 0; i < n + 2; i++)
- {
- mpi_fdiv_q (tmp, pmin1, factors[i]);
- /* No mpi_pow(), but it is okay to use this with mod
- prime. */
- gcry_mpi_powm (b, g, tmp, prime);
- if (! mpi_cmp_ui (b, 1))
- break;
- }
- if (DBG_CIPHER)
- progress('\n');
- } while (i < n + 2);
- mpi_free (factors[n+1]);
- mpi_free (tmp);
- mpi_free (b);
- mpi_free (pmin1);
- }
- }
-
- if (! err)
- if (! DBG_CIPHER)
- progress ('\n');
+ leave:
if (pool)
{
+ is_locked = !ath_mutex_lock (&primepool_lock);
for(i = 0; i < m; i++)
- mpi_free (pool[i]);
- gcry_free (pool);
+ {
+ if (pool[i])
+ {
+ for (j=0; j < n; j++)
+ if (pool_in_use[j] == i)
+ break;
+ if (j == n && is_locked)
+ {
+ /* This pooled subprime has not been used. */
+ save_pool_prime (pool[i], poolrandomlevel);
+ }
+ else
+ mpi_free (pool[i]);
+ }
+ }
+ if (is_locked && ath_mutex_unlock (&primepool_lock))
+ err = GPG_ERR_INTERNAL;
+ is_locked = 0;
+ xfree (pool);
}
+ xfree (pool_in_use);
if (factors)
- gcry_free (factors); /* Factors are shallow copies. */
+ xfree (factors); /* Factors are shallow copies. */
if (perms)
- gcry_free (perms);
+ xfree (perms);
mpi_free (val_2);
mpi_free (q);
+ mpi_free (q_factor);
if (! err)
{
{
for (i = 0; factors_new[i]; i++)
mpi_free (factors_new[i]);
- gcry_free (factors_new);
+ xfree (factors_new);
}
+ mpi_free (prime);
}
return err;
}
+
+/* Generate a prime used for discrete logarithm algorithms; i.e. this
+ prime will be public and no strong random is required. */
gcry_mpi_t
_gcry_generate_elg_prime (int mode, unsigned pbits, unsigned qbits,
gcry_mpi_t g, gcry_mpi_t **ret_factors)
{
- gcry_err_code_t err = GPG_ERR_NO_ERROR;
gcry_mpi_t prime = NULL;
-
- err = prime_generate_internal (mode, &prime, pbits, qbits, g,
- ret_factors, GCRY_WEAK_RANDOM, 0, 0);
+
+ if (prime_generate_internal ((mode == 1), &prime, pbits, qbits, g,
+ ret_factors, GCRY_WEAK_RANDOM, 0, 0,
+ NULL, NULL))
+ prime = NULL; /* (Should be NULL in the error case anyway.) */
return prime;
}
+
static gcry_mpi_t
-gen_prime (unsigned int nbits, int secret, int randomlevel,
+gen_prime (unsigned int nbits, int secret, int randomlevel,
int (*extra_check)(void *, gcry_mpi_t), void *extra_check_arg)
{
gcry_mpi_t prime, ptest, pminus1, val_2, val_3, result;
int i;
- unsigned x, step;
- unsigned count1, count2;
+ unsigned int x, step;
+ unsigned int count1, count2;
int *mods;
-
- if( 0 && DBG_CIPHER )
- log_debug ("generate a prime of %u bits ", nbits );
+
+/* if ( DBG_CIPHER ) */
+/* log_debug ("generate a prime of %u bits ", nbits ); */
if (nbits < 16)
log_fatal ("can't generate a prime with less than %d bits\n", 16);
- mods = gcry_xmalloc( no_of_small_prime_numbers * sizeof *mods );
- /* make nbits fit into gcry_mpi_t implementation */
+ mods = xmalloc (no_of_small_prime_numbers * sizeof *mods);
+ /* Make nbits fit into gcry_mpi_t implementation. */
val_2 = mpi_alloc_set_ui( 2 );
val_3 = mpi_alloc_set_ui( 3);
- prime = secret? gcry_mpi_snew ( nbits ): gcry_mpi_new ( nbits );
+ prime = secret? mpi_snew (nbits): mpi_new (nbits);
result = mpi_alloc_like( prime );
pminus1= mpi_alloc_like( prime );
ptest = mpi_alloc_like( prime );
for (;;)
{ /* try forvever */
int dotcount=0;
-
+
/* generate a random number */
- gcry_mpi_randomize( prime, nbits, randomlevel );
-
- /* Set high order bit to 1, set low order bit to 0. If we are
+ _gcry_mpi_randomize( prime, nbits, randomlevel );
+
+ /* Set high order bit to 1, set low order bit to 1. If we are
generating a secret prime we are most probably doing that
for RSA, to make sure that the modulus does have the
- requested keysize we set the 2 high order bits */
+ requested key size we set the 2 high order bits. */
mpi_set_highbit (prime, nbits-1);
if (secret)
mpi_set_bit (prime, nbits-2);
mpi_set_bit(prime, 0);
-
- /* calculate all remainders */
+
+ /* Calculate all remainders. */
for (i=0; (x = small_prime_numbers[i]); i++ )
mods[i] = mpi_fdiv_r_ui(NULL, prime, x);
-
- /* now try some primes starting with prime */
- for(step=0; step < 20000; step += 2 )
+
+ /* Now try some primes starting with prime. */
+ for(step=0; step < 20000; step += 2 )
{
- /* check against all the small primes we have in mods */
+ /* Check against all the small primes we have in mods. */
count1++;
- for (i=0; (x = small_prime_numbers[i]); i++ )
+ for (i=0; (x = small_prime_numbers[i]); i++ )
{
while ( mods[i] + step >= x )
mods[i] -= x;
break;
}
if ( x )
- continue; /* found a multiple of an already known prime */
+ continue; /* Found a multiple of an already known prime. */
mpi_add_ui( ptest, prime, step );
- /* do a faster Fermat test */
+ /* Do a fast Fermat test now. */
count2++;
mpi_sub_ui( pminus1, ptest, 1);
- gcry_mpi_powm( result, val_2, pminus1, ptest );
+ mpi_powm( result, val_2, pminus1, ptest );
if ( !mpi_cmp_ui( result, 1 ) )
- { /* not composite, perform stronger tests */
- if (is_prime(ptest, 5, &count2 ))
- {
- if (!mpi_test_bit( ptest, nbits-1-secret ))
- {
- progress('\n');
- log_debug("overflow in prime generation\n");
- break; /* stop loop, continue with a new prime */
- }
-
- if (extra_check && extra_check (extra_check_arg, ptest))
- { /* The extra check told us that this prime is
- not of the caller's taste. */
- progress ('/');
- }
- else
- { /* got it */
- mpi_free(val_2);
- mpi_free(val_3);
- mpi_free(result);
- mpi_free(pminus1);
- mpi_free(prime);
- gcry_free(mods);
- return ptest;
- }
- }
+ {
+ /* Not composite, perform stronger tests */
+ if (is_prime(ptest, 5, &count2 ))
+ {
+ if (!mpi_test_bit( ptest, nbits-1-secret ))
+ {
+ progress('\n');
+ log_debug ("overflow in prime generation\n");
+ break; /* Stop loop, continue with a new prime. */
+ }
+
+ if (extra_check && extra_check (extra_check_arg, ptest))
+ {
+ /* The extra check told us that this prime is
+ not of the caller's taste. */
+ progress ('/');
+ }
+ else
+ {
+ /* Got it. */
+ mpi_free(val_2);
+ mpi_free(val_3);
+ mpi_free(result);
+ mpi_free(pminus1);
+ mpi_free(prime);
+ xfree(mods);
+ return ptest;
+ }
+ }
}
if (++dotcount == 10 )
{
/****************
* Returns: true if this may be a prime
+ * RM_ROUNDS gives the number of Rabin-Miller tests to run.
*/
static int
-check_prime( gcry_mpi_t prime, gcry_mpi_t val_2 )
+check_prime( gcry_mpi_t prime, gcry_mpi_t val_2, int rm_rounds,
+ gcry_prime_check_func_t cb_func, void *cb_arg)
{
- int i;
- unsigned x;
- int count=0;
-
- /* check against small primes */
- for(i=0; (x = small_prime_numbers[i]); i++ ) {
- if( mpi_divisible_ui( prime, x ) )
- return 0;
- }
-
- /* a quick fermat test */
- {
- gcry_mpi_t result = mpi_alloc_like( prime );
- gcry_mpi_t pminus1 = mpi_alloc_like( prime );
- mpi_sub_ui( pminus1, prime, 1);
- gcry_mpi_powm( result, val_2, pminus1, prime );
- mpi_free( pminus1 );
- if( mpi_cmp_ui( result, 1 ) ) { /* if composite */
- mpi_free( result );
- progress('.');
- return 0;
- }
- mpi_free( result );
+ int i;
+ unsigned int x;
+ unsigned int count=0;
+
+ /* Check against small primes. */
+ for (i=0; (x = small_prime_numbers[i]); i++ )
+ {
+ if ( mpi_divisible_ui( prime, x ) )
+ return 0;
}
- /* perform stronger tests */
- if( is_prime(prime, 5, &count ) )
- return 1; /* is probably a prime */
- progress('.');
- return 0;
+ /* A quick Fermat test. */
+ {
+ gcry_mpi_t result = mpi_alloc_like( prime );
+ gcry_mpi_t pminus1 = mpi_alloc_like( prime );
+ mpi_sub_ui( pminus1, prime, 1);
+ mpi_powm( result, val_2, pminus1, prime );
+ mpi_free( pminus1 );
+ if ( mpi_cmp_ui( result, 1 ) )
+ {
+ /* Is composite. */
+ mpi_free( result );
+ progress('.');
+ return 0;
+ }
+ mpi_free( result );
+ }
+
+ if (!cb_func || cb_func (cb_arg, GCRY_PRIME_CHECK_AT_MAYBE_PRIME, prime))
+ {
+ /* Perform stronger tests. */
+ if ( is_prime( prime, rm_rounds, &count ) )
+ {
+ if (!cb_func
+ || cb_func (cb_arg, GCRY_PRIME_CHECK_AT_GOT_PRIME, prime))
+ return 1; /* Probably a prime. */
+ }
+ }
+ progress('.');
+ return 0;
}
-/****************
+/*
* Return true if n is probably a prime
*/
static int
-is_prime( gcry_mpi_t n, int steps, int *count )
+is_prime (gcry_mpi_t n, int steps, unsigned int *count)
{
- gcry_mpi_t x = mpi_alloc( mpi_get_nlimbs( n ) );
- gcry_mpi_t y = mpi_alloc( mpi_get_nlimbs( n ) );
- gcry_mpi_t z = mpi_alloc( mpi_get_nlimbs( n ) );
- gcry_mpi_t nminus1 = mpi_alloc( mpi_get_nlimbs( n ) );
- gcry_mpi_t a2 = mpi_alloc_set_ui( 2 );
- gcry_mpi_t q;
- unsigned i, j, k;
- int rc = 0;
- unsigned nbits = mpi_get_nbits( n );
-
- mpi_sub_ui( nminus1, n, 1 );
-
- /* find q and k, so that n = 1 + 2^k * q */
- q = mpi_copy( nminus1 );
- k = mpi_trailing_zeros( q );
- mpi_tdiv_q_2exp(q, q, k);
-
- for(i=0 ; i < steps; i++ ) {
- ++*count;
- if( !i ) {
- mpi_set_ui( x, 2 );
- }
- else {
- gcry_mpi_randomize( x, nbits, GCRY_WEAK_RANDOM );
+ gcry_mpi_t x = mpi_alloc( mpi_get_nlimbs( n ) );
+ gcry_mpi_t y = mpi_alloc( mpi_get_nlimbs( n ) );
+ gcry_mpi_t z = mpi_alloc( mpi_get_nlimbs( n ) );
+ gcry_mpi_t nminus1 = mpi_alloc( mpi_get_nlimbs( n ) );
+ gcry_mpi_t a2 = mpi_alloc_set_ui( 2 );
+ gcry_mpi_t q;
+ unsigned i, j, k;
+ int rc = 0;
+ unsigned nbits = mpi_get_nbits( n );
+
+ if (steps < 5) /* Make sure that we do at least 5 rounds. */
+ steps = 5;
+
+ mpi_sub_ui( nminus1, n, 1 );
+
+ /* Find q and k, so that n = 1 + 2^k * q . */
+ q = mpi_copy ( nminus1 );
+ k = mpi_trailing_zeros ( q );
+ mpi_tdiv_q_2exp (q, q, k);
+
+ for (i=0 ; i < steps; i++ )
+ {
+ ++*count;
+ if( !i )
+ {
+ mpi_set_ui( x, 2 );
+ }
+ else
+ {
+ _gcry_mpi_randomize( x, nbits, GCRY_WEAK_RANDOM );
- /* make sure that the number is smaller than the prime
- * and keep the randomness of the high bit */
- if( mpi_test_bit( x, nbits-2 ) ) {
- mpi_set_highbit( x, nbits-2 ); /* clear all higher bits */
- }
- else {
- mpi_set_highbit( x, nbits-2 );
- mpi_clear_bit( x, nbits-2 );
- }
- assert( mpi_cmp( x, nminus1 ) < 0 && mpi_cmp_ui( x, 1 ) > 0 );
+ /* Make sure that the number is smaller than the prime and
+ keep the randomness of the high bit. */
+ if ( mpi_test_bit ( x, nbits-2) )
+ {
+ mpi_set_highbit ( x, nbits-2); /* Clear all higher bits. */
+ }
+ else
+ {
+ mpi_set_highbit( x, nbits-2 );
+ mpi_clear_bit( x, nbits-2 );
+ }
+ gcry_assert (mpi_cmp (x, nminus1) < 0 && mpi_cmp_ui (x, 1) > 0);
}
- gcry_mpi_powm( y, x, q, n);
- if( mpi_cmp_ui(y, 1) && mpi_cmp( y, nminus1 ) ) {
- for( j=1; j < k && mpi_cmp( y, nminus1 ); j++ ) {
- gcry_mpi_powm(y, y, a2, n);
- if( !mpi_cmp_ui( y, 1 ) )
- goto leave; /* not a prime */
- }
- if( mpi_cmp( y, nminus1 ) )
- goto leave; /* not a prime */
+ mpi_powm ( y, x, q, n);
+ if ( mpi_cmp_ui(y, 1) && mpi_cmp( y, nminus1 ) )
+ {
+ for ( j=1; j < k && mpi_cmp( y, nminus1 ); j++ )
+ {
+ mpi_powm(y, y, a2, n);
+ if( !mpi_cmp_ui( y, 1 ) )
+ goto leave; /* Not a prime. */
+ }
+ if (mpi_cmp( y, nminus1 ) )
+ goto leave; /* Not a prime. */
}
- progress('+');
+ progress('+');
}
- rc = 1; /* may be a prime */
+ rc = 1; /* May be a prime. */
- leave:
- mpi_free( x );
- mpi_free( y );
- mpi_free( z );
- mpi_free( nminus1 );
- mpi_free( q );
+ leave:
+ mpi_free( x );
+ mpi_free( y );
+ mpi_free( z );
+ mpi_free( nminus1 );
+ mpi_free( q );
+ mpi_free( a2 );
- return rc;
+ return rc;
}
+/* Given ARRAY of size N with M elements set to true produce a
+ modified array with the next permutation of M elements. Note, that
+ ARRAY is used in a one-bit-per-byte approach. To detected the last
+ permutation it is useful to initialize the array with the first M
+ element set to true and use this test:
+ m_out_of_n (array, m, n);
+ for (i = j = 0; i < n && j < m; i++)
+ if (array[i])
+ j++;
+ if (j == m)
+ goto ready;
+
+ This code is based on the algorithm 452 from the "Collected
+ Algorithms From ACM, Volume II" by C. N. Liu and D. T. Tang.
+*/
static void
-m_out_of_n( char *array, int m, int n )
+m_out_of_n ( char *array, int m, int n )
{
- int i=0, i1=0, j=0, jp=0, j1=0, k1=0, k2=0;
-
- if( !m || m >= n )
- return;
-
- if( m == 1 ) { /* special case */
- for(i=0; i < n; i++ )
- if( array[i] ) {
- array[i++] = 0;
- if( i >= n )
- i = 0;
- array[i] = 1;
- return;
- }
- BUG();
+ int i=0, i1=0, j=0, jp=0, j1=0, k1=0, k2=0;
+
+ if( !m || m >= n )
+ return;
+
+ /* Need to handle this simple case separately. */
+ if( m == 1 )
+ {
+ for (i=0; i < n; i++ )
+ {
+ if ( array[i] )
+ {
+ array[i++] = 0;
+ if( i >= n )
+ i = 0;
+ array[i] = 1;
+ return;
+ }
+ }
+ BUG();
}
- for(j=1; j < n; j++ ) {
- if( array[n-1] == array[n-j-1] )
- continue;
- j1 = j;
- break;
+
+ for (j=1; j < n; j++ )
+ {
+ if ( array[n-1] == array[n-j-1])
+ continue;
+ j1 = j;
+ break;
}
- if( m & 1 ) { /* m is odd */
- if( array[n-1] ) {
- if( j1 & 1 ) {
- k1 = n - j1;
- k2 = k1+2;
- if( k2 > n )
- k2 = n;
- goto leave;
- }
- goto scan;
- }
- k2 = n - j1 - 1;
- if( k2 == 0 ) {
- k1 = i;
- k2 = n - j1;
- }
- else if( array[k2] && array[k2-1] )
- k1 = n;
- else
- k1 = k2 + 1;
+ if ( (m & 1) )
+ {
+ /* M is odd. */
+ if( array[n-1] )
+ {
+ if( j1 & 1 )
+ {
+ k1 = n - j1;
+ k2 = k1+2;
+ if( k2 > n )
+ k2 = n;
+ goto leave;
+ }
+ goto scan;
+ }
+ k2 = n - j1 - 1;
+ if( k2 == 0 )
+ {
+ k1 = i;
+ k2 = n - j1;
+ }
+ else if( array[k2] && array[k2-1] )
+ k1 = n;
+ else
+ k1 = k2 + 1;
}
- else { /* m is even */
- if( !array[n-1] ) {
- k1 = n - j1;
- k2 = k1 + 1;
- goto leave;
- }
+ else
+ {
+ /* M is even. */
+ if( !array[n-1] )
+ {
+ k1 = n - j1;
+ k2 = k1 + 1;
+ goto leave;
+ }
- if( !(j1 & 1) ) {
- k1 = n - j1;
- k2 = k1+2;
- if( k2 > n )
- k2 = n;
- goto leave;
- }
- scan:
- jp = n - j1 - 1;
- for(i=1; i <= jp; i++ ) {
- i1 = jp + 2 - i;
- if( array[i1-1] ) {
- if( array[i1-2] ) {
- k1 = i1 - 1;
- k2 = n - j1;
- }
- else {
- k1 = i1 - 1;
- k2 = n + 1 - j1;
+ if( !(j1 & 1) )
+ {
+ k1 = n - j1;
+ k2 = k1+2;
+ if( k2 > n )
+ k2 = n;
+ goto leave;
+ }
+ scan:
+ jp = n - j1 - 1;
+ for (i=1; i <= jp; i++ )
+ {
+ i1 = jp + 2 - i;
+ if( array[i1-1] )
+ {
+ if( array[i1-2] )
+ {
+ k1 = i1 - 1;
+ k2 = n - j1;
}
- goto leave;
- }
- }
- k1 = 1;
- k2 = n + 1 - m;
+ else
+ {
+ k1 = i1 - 1;
+ k2 = n + 1 - j1;
+ }
+ goto leave;
+ }
+ }
+ k1 = 1;
+ k2 = n + 1 - m;
}
- leave:
- array[k1-1] = !array[k1-1];
- array[k2-1] = !array[k2-1];
+ leave:
+ /* Now complement the two selected bits. */
+ array[k1-1] = !array[k1-1];
+ array[k2-1] = !array[k2-1];
}
non-zero, allocate a new, NULL-terminated array holding the prime
factors and store it in FACTORS. FLAGS might be used to influence
the prime number generation process. */
-gcry_error_t
-gcry_prime_generate (gcry_mpi_t *prime, unsigned int prime_bits,
- unsigned int factor_bits, gcry_mpi_t **factors,
- gcry_prime_check_func_t cb_func, void *cb_arg,
- gcry_random_level_t random_level,
- unsigned int flags)
+gcry_err_code_t
+_gcry_prime_generate (gcry_mpi_t *prime, unsigned int prime_bits,
+ unsigned int factor_bits, gcry_mpi_t **factors,
+ gcry_prime_check_func_t cb_func, void *cb_arg,
+ gcry_random_level_t random_level,
+ unsigned int flags)
{
- gcry_err_code_t err = GPG_ERR_NO_ERROR;
+ gcry_err_code_t rc = 0;
gcry_mpi_t *factors_generated = NULL;
gcry_mpi_t prime_generated = NULL;
unsigned int mode = 0;
+ if (!prime)
+ return GPG_ERR_INV_ARG;
+ *prime = NULL;
+
if (flags & GCRY_PRIME_FLAG_SPECIAL_FACTOR)
mode = 1;
/* Generate. */
- err = prime_generate_internal (mode, &prime_generated, prime_bits,
- factor_bits, NULL,
- factors? &factors_generated : NULL,
- random_level, flags, 1);
-
- if (! err)
- if (cb_func)
- {
- /* Additional check */
- if (! (*cb_func) (cb_arg, 0, prime_generated))
- {
- /* Failed, deallocate resources. */
+ rc = prime_generate_internal ((mode==1), &prime_generated, prime_bits,
+ factor_bits, NULL,
+ factors? &factors_generated : NULL,
+ random_level, flags, 1,
+ cb_func, cb_arg);
- unsigned int i;
+ if (!rc && cb_func)
+ {
+ /* Additional check. */
+ if ( !cb_func (cb_arg, GCRY_PRIME_CHECK_AT_FINISH, prime_generated))
+ {
+ /* Failed, deallocate resources. */
+ unsigned int i;
- mpi_free (prime_generated);
- if (factors)
- {
- for (i = 0; factors_generated[i]; i++)
- mpi_free (factors_generated[i]);
- gcry_free (factors_generated);
- }
- err = GPG_ERR_INTERNAL; /* FIXME. */
- }
- }
+ mpi_free (prime_generated);
+ if (factors)
+ {
+ for (i = 0; factors_generated[i]; i++)
+ mpi_free (factors_generated[i]);
+ xfree (factors_generated);
+ }
+ rc = GPG_ERR_GENERAL;
+ }
+ }
- if (! err)
+ if (!rc)
{
if (factors)
*factors = factors_generated;
*prime = prime_generated;
}
- return gcry_error (err);
+ return rc;
}
-/* Check wether the number X is prime. */
-gcry_error_t
-gcry_prime_check (gcry_mpi_t x, unsigned int flags)
+/* Check whether the number X is prime. */
+gcry_err_code_t
+_gcry_prime_check (gcry_mpi_t x, unsigned int flags)
{
- gcry_err_code_t err = GPG_ERR_NO_ERROR;
- gcry_mpi_t test_value = mpi_alloc_set_ui (2); /* ? */
+ gcry_err_code_t rc = 0;
+ gcry_mpi_t val_2 = mpi_alloc_set_ui (2); /* Used by the Fermat test. */
+
+ (void)flags;
- if (! check_prime (x, test_value))
- err = GPG_ERR_NO_PRIME;
+ /* We use 64 rounds because the prime we are going to test is not
+ guaranteed to be a random one. */
+ if (! check_prime (x, val_2, 64, NULL, NULL))
+ rc = GPG_ERR_NO_PRIME;
- mpi_free (test_value);
+ mpi_free (val_2);
- return gcry_error (err);
+ return rc;
}
/* Find a generator for PRIME where the factorization of (prime-1) is
in the NULL terminated array FACTORS. Return the generator as a
newly allocated MPI in R_G. If START_G is not NULL, use this as s
atart for the search. Returns 0 on success.*/
-gcry_error_t
-gcry_prime_group_generator (gcry_mpi_t *r_g,
- gcry_mpi_t prime, gcry_mpi_t *factors,
- gcry_mpi_t start_g)
+gcry_err_code_t
+_gcry_prime_group_generator (gcry_mpi_t *r_g,
+ gcry_mpi_t prime, gcry_mpi_t *factors,
+ gcry_mpi_t start_g)
{
- gcry_mpi_t tmp = gcry_mpi_new (0);
- gcry_mpi_t b = gcry_mpi_new (0);
- gcry_mpi_t pmin1 = gcry_mpi_new (0);
- gcry_mpi_t g = start_g? gcry_mpi_copy (start_g) : gcry_mpi_set_ui (NULL, 3);
+ gcry_mpi_t tmp = mpi_new (0);
+ gcry_mpi_t b = mpi_new (0);
+ gcry_mpi_t pmin1 = mpi_new (0);
+ gcry_mpi_t g = start_g? mpi_copy (start_g) : mpi_set_ui (NULL, 3);
int first = 1;
int i, n;
if (!factors || !r_g || !prime)
- return gpg_error (GPG_ERR_INV_ARG);
+ return GPG_ERR_INV_ARG;
+ *r_g = NULL;
for (n=0; factors[n]; n++)
;
if (n < 2)
- return gpg_error (GPG_ERR_INV_ARG);
+ return GPG_ERR_INV_ARG;
-#if 1 /* Extra sanity check - usually disabled. */
- {
- mpi_set (tmp, factors[0]);
- for(i = 1; i < n; i++)
- mpi_mul (tmp, tmp, factors[i]);
- mpi_add_ui (tmp, tmp, 1);
- if (mpi_cmp (prime, tmp))
- return gpg_error (GPG_ERR_INV_ARG);
- }
-#endif /* Extra sanity check. */
-
- gcry_mpi_sub_ui (pmin1, prime, 1);
- do
+ /* Extra sanity check - usually disabled. */
+/* mpi_set (tmp, factors[0]); */
+/* for(i = 1; i < n; i++) */
+/* mpi_mul (tmp, tmp, factors[i]); */
+/* mpi_add_ui (tmp, tmp, 1); */
+/* if (mpi_cmp (prime, tmp)) */
+/* return gpg_error (GPG_ERR_INV_ARG); */
+
+ mpi_sub_ui (pmin1, prime, 1);
+ do
{
if (first)
first = 0;
else
- gcry_mpi_add_ui (g, g, 1);
-
+ mpi_add_ui (g, g, 1);
+
if (DBG_CIPHER)
- {
- log_debug ("checking g:");
- gcry_mpi_dump (g);
- log_debug ("\n");
- }
+ log_printmpi ("checking g", g);
else
progress('^');
-
+
for (i = 0; i < n; i++)
{
mpi_fdiv_q (tmp, pmin1, factors[i]);
- gcry_mpi_powm (b, g, tmp, prime);
+ mpi_powm (b, g, tmp, prime);
if (! mpi_cmp_ui (b, 1))
break;
}
progress('\n');
}
while (i < n);
-
- gcry_mpi_release (tmp);
- gcry_mpi_release (b);
- gcry_mpi_release (pmin1);
- *r_g = g;
- return 0;
+ _gcry_mpi_release (tmp);
+ _gcry_mpi_release (b);
+ _gcry_mpi_release (pmin1);
+ *r_g = g;
+
+ return 0;
}
/* Convenience function to release the factors array. */
void
-gcry_prime_release_factors (gcry_mpi_t *factors)
+_gcry_prime_release_factors (gcry_mpi_t *factors)
{
if (factors)
{
int i;
-
+
for (i=0; factors[i]; i++)
mpi_free (factors[i]);
- gcry_free (factors);
+ xfree (factors);
+ }
+}
+
+
+\f
+/* Helper for _gcry_derive_x931_prime. */
+static gcry_mpi_t
+find_x931_prime (const gcry_mpi_t pfirst)
+{
+ gcry_mpi_t val_2 = mpi_alloc_set_ui (2);
+ gcry_mpi_t prime;
+
+ prime = mpi_copy (pfirst);
+ /* If P is even add 1. */
+ mpi_set_bit (prime, 0);
+
+ /* We use 64 Rabin-Miller rounds which is better and thus
+ sufficient. We do not have a Lucas test implementaion thus we
+ can't do it in the X9.31 preferred way of running a few
+ Rabin-Miller followed by one Lucas test. */
+ while ( !check_prime (prime, val_2, 64, NULL, NULL) )
+ mpi_add_ui (prime, prime, 2);
+
+ mpi_free (val_2);
+
+ return prime;
+}
+
+
+/* Generate a prime using the algorithm from X9.31 appendix B.4.
+
+ This function requires that the provided public exponent E is odd.
+ XP, XP1 and XP2 are the seed values. All values are mandatory.
+
+ On success the prime is returned. If R_P1 or R_P2 are given the
+ internal values P1 and P2 are saved at these addresses. On error
+ NULL is returned. */
+gcry_mpi_t
+_gcry_derive_x931_prime (const gcry_mpi_t xp,
+ const gcry_mpi_t xp1, const gcry_mpi_t xp2,
+ const gcry_mpi_t e,
+ gcry_mpi_t *r_p1, gcry_mpi_t *r_p2)
+{
+ gcry_mpi_t p1, p2, p1p2, yp0;
+
+ if (!xp || !xp1 || !xp2)
+ return NULL;
+ if (!e || !mpi_test_bit (e, 0))
+ return NULL; /* We support only odd values for E. */
+
+ p1 = find_x931_prime (xp1);
+ p2 = find_x931_prime (xp2);
+ p1p2 = mpi_alloc_like (xp);
+ mpi_mul (p1p2, p1, p2);
+
+ {
+ gcry_mpi_t r1, tmp;
+
+ /* r1 = (p2^{-1} mod p1)p2 - (p1^{-1} mod p2) */
+ tmp = mpi_alloc_like (p1);
+ mpi_invm (tmp, p2, p1);
+ mpi_mul (tmp, tmp, p2);
+ r1 = tmp;
+
+ tmp = mpi_alloc_like (p2);
+ mpi_invm (tmp, p1, p2);
+ mpi_mul (tmp, tmp, p1);
+ mpi_sub (r1, r1, tmp);
+
+ /* Fixup a negative value. */
+ if (mpi_has_sign (r1))
+ mpi_add (r1, r1, p1p2);
+
+ /* yp0 = xp + (r1 - xp mod p1*p2) */
+ yp0 = tmp; tmp = NULL;
+ mpi_subm (yp0, r1, xp, p1p2);
+ mpi_add (yp0, yp0, xp);
+ mpi_free (r1);
+
+ /* Fixup a negative value. */
+ if (mpi_cmp (yp0, xp) < 0 )
+ mpi_add (yp0, yp0, p1p2);
+ }
+
+ /* yp0 is now the first integer greater than xp with p1 being a
+ large prime factor of yp0-1 and p2 a large prime factor of yp0+1. */
+
+ /* Note that the first example from X9.31 (D.1.1) which uses
+ (Xq1 #1A5CF72EE770DE50CB09ACCEA9#)
+ (Xq2 #134E4CAA16D2350A21D775C404#)
+ (Xq #CC1092495D867E64065DEE3E7955F2EBC7D47A2D
+ 7C9953388F97DDDC3E1CA19C35CA659EDC2FC325
+ 6D29C2627479C086A699A49C4C9CEE7EF7BD1B34
+ 321DE34A#))))
+ returns an yp0 of
+ #CC1092495D867E64065DEE3E7955F2EBC7D47A2D
+ 7C9953388F97DDDC3E1CA19C35CA659EDC2FC4E3
+ BF20CB896EE37E098A906313271422162CB6C642
+ 75C1201F#
+ and not
+ #CC1092495D867E64065DEE3E7955F2EBC7D47A2D
+ 7C9953388F97DDDC3E1CA19C35CA659EDC2FC2E6
+ C88FE299D52D78BE405A97E01FD71DD7819ECB91
+ FA85A076#
+ as stated in the standard. This seems to be a bug in X9.31.
+ */
+
+ {
+ gcry_mpi_t val_2 = mpi_alloc_set_ui (2);
+ gcry_mpi_t gcdtmp = mpi_alloc_like (yp0);
+ int gcdres;
+
+ mpi_sub_ui (p1p2, p1p2, 1); /* Adjust for loop body. */
+ mpi_sub_ui (yp0, yp0, 1); /* Ditto. */
+ for (;;)
+ {
+ gcdres = mpi_gcd (gcdtmp, e, yp0);
+ mpi_add_ui (yp0, yp0, 1);
+ if (!gcdres)
+ progress ('/'); /* gcd (e, yp0-1) != 1 */
+ else if (check_prime (yp0, val_2, 64, NULL, NULL))
+ break; /* Found. */
+ /* We add p1p2-1 because yp0 is incremented after the gcd test. */
+ mpi_add (yp0, yp0, p1p2);
+ }
+ mpi_free (gcdtmp);
+ mpi_free (val_2);
+ }
+
+ mpi_free (p1p2);
+
+ progress('\n');
+ if (r_p1)
+ *r_p1 = p1;
+ else
+ mpi_free (p1);
+ if (r_p2)
+ *r_p2 = p2;
+ else
+ mpi_free (p2);
+ return yp0;
+}
+
+
+\f
+/* Generate the two prime used for DSA using the algorithm specified
+ in FIPS 186-2. PBITS is the desired length of the prime P and a
+ QBITS the length of the prime Q. If SEED is not supplied and
+ SEEDLEN is 0 the function generates an appropriate SEED. On
+ success the generated primes are stored at R_Q and R_P, the counter
+ value is stored at R_COUNTER and the seed actually used for
+ generation is stored at R_SEED and R_SEEDVALUE. */
+gpg_err_code_t
+_gcry_generate_fips186_2_prime (unsigned int pbits, unsigned int qbits,
+ const void *seed, size_t seedlen,
+ gcry_mpi_t *r_q, gcry_mpi_t *r_p,
+ int *r_counter,
+ void **r_seed, size_t *r_seedlen)
+{
+ gpg_err_code_t ec;
+ unsigned char seed_help_buffer[160/8]; /* Used to hold a generated SEED. */
+ unsigned char *seed_plus; /* Malloced buffer to hold SEED+x. */
+ unsigned char digest[160/8]; /* Helper buffer for SHA-1 digest. */
+ gcry_mpi_t val_2 = NULL; /* Helper for the prime test. */
+ gcry_mpi_t tmpval = NULL; /* Helper variable. */
+ int i;
+
+ unsigned char value_u[160/8];
+ int value_n, value_b, value_k;
+ int counter;
+ gcry_mpi_t value_w = NULL;
+ gcry_mpi_t value_x = NULL;
+ gcry_mpi_t prime_q = NULL;
+ gcry_mpi_t prime_p = NULL;
+
+ /* FIPS 186-2 allows only for 1024/160 bit. */
+ if (pbits != 1024 || qbits != 160)
+ return GPG_ERR_INV_KEYLEN;
+
+ if (!seed && !seedlen)
+ ; /* No seed value given: We are asked to generate it. */
+ else if (!seed || seedlen < qbits/8)
+ return GPG_ERR_INV_ARG;
+
+ /* Allocate a buffer to later compute SEED+some_increment. */
+ seed_plus = xtrymalloc (seedlen < 20? 20:seedlen);
+ if (!seed_plus)
+ {
+ ec = gpg_err_code_from_syserror ();
+ goto leave;
+ }
+
+ val_2 = mpi_alloc_set_ui (2);
+ value_n = (pbits - 1) / qbits;
+ value_b = (pbits - 1) - value_n * qbits;
+ value_w = mpi_new (pbits);
+ value_x = mpi_new (pbits);
+
+ restart:
+ /* Generate Q. */
+ for (;;)
+ {
+ /* Step 1: Generate a (new) seed unless one has been supplied. */
+ if (!seed)
+ {
+ seedlen = sizeof seed_help_buffer;
+ _gcry_create_nonce (seed_help_buffer, seedlen);
+ seed = seed_help_buffer;
+ }
+
+ /* Step 2: U = sha1(seed) ^ sha1((seed+1) mod 2^{qbits}) */
+ memcpy (seed_plus, seed, seedlen);
+ for (i=seedlen-1; i >= 0; i--)
+ {
+ seed_plus[i]++;
+ if (seed_plus[i])
+ break;
+ }
+ _gcry_md_hash_buffer (GCRY_MD_SHA1, value_u, seed, seedlen);
+ _gcry_md_hash_buffer (GCRY_MD_SHA1, digest, seed_plus, seedlen);
+ for (i=0; i < sizeof value_u; i++)
+ value_u[i] ^= digest[i];
+
+ /* Step 3: Form q from U */
+ _gcry_mpi_release (prime_q); prime_q = NULL;
+ ec = _gcry_mpi_scan (&prime_q, GCRYMPI_FMT_USG,
+ value_u, sizeof value_u, NULL);
+ if (ec)
+ goto leave;
+ mpi_set_highbit (prime_q, qbits-1 );
+ mpi_set_bit (prime_q, 0);
+
+ /* Step 4: Test whether Q is prime using 64 round of Rabin-Miller. */
+ if (check_prime (prime_q, val_2, 64, NULL, NULL))
+ break; /* Yes, Q is prime. */
+
+ /* Step 5. */
+ seed = NULL; /* Force a new seed at Step 1. */
+ }
+
+ /* Step 6. Note that we do no use an explicit offset but increment
+ SEED_PLUS accordingly. SEED_PLUS is currently SEED+1. */
+ counter = 0;
+
+ /* Generate P. */
+ prime_p = mpi_new (pbits);
+ for (;;)
+ {
+ /* Step 7: For k = 0,...n let
+ V_k = sha1(seed+offset+k) mod 2^{qbits}
+ Step 8: W = V_0 + V_1*2^160 +
+ ...
+ + V_{n-1}*2^{(n-1)*160}
+ + (V_{n} mod 2^b)*2^{n*160}
+ */
+ mpi_set_ui (value_w, 0);
+ for (value_k=0; value_k <= value_n; value_k++)
+ {
+ /* There is no need to have an explicit offset variable: In
+ the first round we shall have an offset of 2, this is
+ achieved by using SEED_PLUS which is already at SEED+1,
+ thus we just need to increment it once again. The
+ requirement for the next round is to update offset by N,
+ which we implictly did at the end of this loop, and then
+ to add one; this one is the same as in the first round. */
+ for (i=seedlen-1; i >= 0; i--)
+ {
+ seed_plus[i]++;
+ if (seed_plus[i])
+ break;
+ }
+ _gcry_md_hash_buffer (GCRY_MD_SHA1, digest, seed_plus, seedlen);
+
+ _gcry_mpi_release (tmpval); tmpval = NULL;
+ ec = _gcry_mpi_scan (&tmpval, GCRYMPI_FMT_USG,
+ digest, sizeof digest, NULL);
+ if (ec)
+ goto leave;
+ if (value_k == value_n)
+ mpi_clear_highbit (tmpval, value_b); /* (V_n mod 2^b) */
+ mpi_lshift (tmpval, tmpval, value_k*qbits);
+ mpi_add (value_w, value_w, tmpval);
+ }
+
+ /* Step 8 continued: X = W + 2^{L-1} */
+ mpi_set_ui (value_x, 0);
+ mpi_set_highbit (value_x, pbits-1);
+ mpi_add (value_x, value_x, value_w);
+
+ /* Step 9: c = X mod 2q, p = X - (c - 1) */
+ mpi_mul_2exp (tmpval, prime_q, 1);
+ mpi_mod (tmpval, value_x, tmpval);
+ mpi_sub_ui (tmpval, tmpval, 1);
+ mpi_sub (prime_p, value_x, tmpval);
+
+ /* Step 10: If p < 2^{L-1} skip the primality test. */
+ /* Step 11 and 12: Primality test. */
+ if (mpi_get_nbits (prime_p) >= pbits-1
+ && check_prime (prime_p, val_2, 64, NULL, NULL) )
+ break; /* Yes, P is prime, continue with Step 15. */
+
+ /* Step 13: counter = counter + 1, offset = offset + n + 1. */
+ counter++;
+
+ /* Step 14: If counter >= 2^12 goto Step 1. */
+ if (counter >= 4096)
+ goto restart;
+ }
+
+ /* Step 15: Save p, q, counter and seed. */
+/* log_debug ("fips186-2 pbits p=%u q=%u counter=%d\n", */
+/* mpi_get_nbits (prime_p), mpi_get_nbits (prime_q), counter); */
+/* log_printhex("fips186-2 seed:", seed, seedlen); */
+/* log_mpidump ("fips186-2 prime p", prime_p); */
+/* log_mpidump ("fips186-2 prime q", prime_q); */
+ if (r_q)
+ {
+ *r_q = prime_q;
+ prime_q = NULL;
+ }
+ if (r_p)
+ {
+ *r_p = prime_p;
+ prime_p = NULL;
+ }
+ if (r_counter)
+ *r_counter = counter;
+ if (r_seed && r_seedlen)
+ {
+ memcpy (seed_plus, seed, seedlen);
+ *r_seed = seed_plus;
+ seed_plus = NULL;
+ *r_seedlen = seedlen;
+ }
+
+
+ leave:
+ _gcry_mpi_release (tmpval);
+ _gcry_mpi_release (value_x);
+ _gcry_mpi_release (value_w);
+ _gcry_mpi_release (prime_p);
+ _gcry_mpi_release (prime_q);
+ xfree (seed_plus);
+ _gcry_mpi_release (val_2);
+ return ec;
+}
+
+
+\f
+/* WARNING: The code below has not yet been tested! However, it is
+ not yet used. We need to wait for FIPS 186-3 final and for test
+ vectors.
+
+ Generate the two prime used for DSA using the algorithm specified
+ in FIPS 186-3, A.1.1.2. PBITS is the desired length of the prime P
+ and a QBITS the length of the prime Q. If SEED is not supplied and
+ SEEDLEN is 0 the function generates an appropriate SEED. On
+ success the generated primes are stored at R_Q and R_P, the counter
+ value is stored at R_COUNTER and the seed actually used for
+ generation is stored at R_SEED and R_SEEDVALUE. The hash algorithm
+ used is stored at R_HASHALGO.
+
+ Note that this function is very similar to the fips186_2 code. Due
+ to the minor differences, other buffer sizes and for documentarion,
+ we use a separate function.
+*/
+gpg_err_code_t
+_gcry_generate_fips186_3_prime (unsigned int pbits, unsigned int qbits,
+ const void *seed, size_t seedlen,
+ gcry_mpi_t *r_q, gcry_mpi_t *r_p,
+ int *r_counter,
+ void **r_seed, size_t *r_seedlen,
+ int *r_hashalgo)
+{
+ gpg_err_code_t ec;
+ unsigned char seed_help_buffer[256/8]; /* Used to hold a generated SEED. */
+ unsigned char *seed_plus; /* Malloced buffer to hold SEED+x. */
+ unsigned char digest[256/8]; /* Helper buffer for SHA-1 digest. */
+ gcry_mpi_t val_2 = NULL; /* Helper for the prime test. */
+ gcry_mpi_t tmpval = NULL; /* Helper variable. */
+ int hashalgo; /* The id of the Approved Hash Function. */
+ int i;
+
+ unsigned char value_u[256/8];
+ int value_n, value_b, value_j;
+ int counter;
+ gcry_mpi_t value_w = NULL;
+ gcry_mpi_t value_x = NULL;
+ gcry_mpi_t prime_q = NULL;
+ gcry_mpi_t prime_p = NULL;
+
+ gcry_assert (sizeof seed_help_buffer == sizeof digest
+ && sizeof seed_help_buffer == sizeof value_u);
+
+ /* Step 1: Check the requested prime lengths. */
+ /* Note that due to the size of our buffers QBITS is limited to 256. */
+ if (pbits == 1024 && qbits == 160)
+ hashalgo = GCRY_MD_SHA1;
+ else if (pbits == 2048 && qbits == 224)
+ hashalgo = GCRY_MD_SHA224;
+ else if (pbits == 2048 && qbits == 256)
+ hashalgo = GCRY_MD_SHA256;
+ else if (pbits == 3072 && qbits == 256)
+ hashalgo = GCRY_MD_SHA256;
+ else
+ return GPG_ERR_INV_KEYLEN;
+
+ /* Also check that the hash algorithm is available. */
+ ec = _gcry_md_test_algo (hashalgo);
+ if (ec)
+ return ec;
+ gcry_assert (qbits/8 <= sizeof digest);
+ gcry_assert (_gcry_md_get_algo_dlen (hashalgo) == qbits/8);
+
+
+ /* Step 2: Check seedlen. */
+ if (!seed && !seedlen)
+ ; /* No seed value given: We are asked to generate it. */
+ else if (!seed || seedlen < qbits/8)
+ return GPG_ERR_INV_ARG;
+
+ /* Allocate a buffer to later compute SEED+some_increment and a few
+ helper variables. */
+ seed_plus = xtrymalloc (seedlen < sizeof seed_help_buffer?
+ sizeof seed_help_buffer : seedlen);
+ if (!seed_plus)
+ {
+ ec = gpg_err_code_from_syserror ();
+ goto leave;
+ }
+ val_2 = mpi_alloc_set_ui (2);
+ value_w = mpi_new (pbits);
+ value_x = mpi_new (pbits);
+
+ /* Step 3: n = \lceil L / outlen \rceil - 1 */
+ value_n = (pbits + qbits - 1) / qbits - 1;
+ /* Step 4: b = L - 1 - (n * outlen) */
+ value_b = pbits - 1 - (value_n * qbits);
+
+ restart:
+ /* Generate Q. */
+ for (;;)
+ {
+ /* Step 5: Generate a (new) seed unless one has been supplied. */
+ if (!seed)
+ {
+ seedlen = qbits/8;
+ gcry_assert (seedlen <= sizeof seed_help_buffer);
+ _gcry_create_nonce (seed_help_buffer, seedlen);
+ seed = seed_help_buffer;
+ }
+
+ /* Step 6: U = hash(seed) */
+ _gcry_md_hash_buffer (hashalgo, value_u, seed, seedlen);
+
+ /* Step 7: q = 2^{N-1} + U + 1 - (U mod 2) */
+ if ( !(value_u[qbits/8-1] & 0x01) )
+ {
+ for (i=qbits/8-1; i >= 0; i--)
+ {
+ value_u[i]++;
+ if (value_u[i])
+ break;
+ }
+ }
+ _gcry_mpi_release (prime_q); prime_q = NULL;
+ ec = _gcry_mpi_scan (&prime_q, GCRYMPI_FMT_USG,
+ value_u, sizeof value_u, NULL);
+ if (ec)
+ goto leave;
+ mpi_set_highbit (prime_q, qbits-1 );
+
+ /* Step 8: Test whether Q is prime using 64 round of Rabin-Miller.
+ According to table C.1 this is sufficient for all
+ supported prime sizes (i.e. up 3072/256). */
+ if (check_prime (prime_q, val_2, 64, NULL, NULL))
+ break; /* Yes, Q is prime. */
+
+ /* Step 8. */
+ seed = NULL; /* Force a new seed at Step 5. */
+ }
+
+ /* Step 11. Note that we do no use an explicit offset but increment
+ SEED_PLUS accordingly. */
+ memcpy (seed_plus, seed, seedlen);
+ counter = 0;
+
+ /* Generate P. */
+ prime_p = mpi_new (pbits);
+ for (;;)
+ {
+ /* Step 11.1: For j = 0,...n let
+ V_j = hash(seed+offset+j)
+ Step 11.2: W = V_0 + V_1*2^outlen +
+ ...
+ + V_{n-1}*2^{(n-1)*outlen}
+ + (V_{n} mod 2^b)*2^{n*outlen}
+ */
+ mpi_set_ui (value_w, 0);
+ for (value_j=0; value_j <= value_n; value_j++)
+ {
+ /* There is no need to have an explicit offset variable: In
+ the first round we shall have an offset of 1 and a j of
+ 0. This is achieved by incrementing SEED_PLUS here. For
+ the next round offset is implicitly updated by using
+ SEED_PLUS again. */
+ for (i=seedlen-1; i >= 0; i--)
+ {
+ seed_plus[i]++;
+ if (seed_plus[i])
+ break;
+ }
+ _gcry_md_hash_buffer (GCRY_MD_SHA1, digest, seed_plus, seedlen);
+
+ _gcry_mpi_release (tmpval); tmpval = NULL;
+ ec = _gcry_mpi_scan (&tmpval, GCRYMPI_FMT_USG,
+ digest, sizeof digest, NULL);
+ if (ec)
+ goto leave;
+ if (value_j == value_n)
+ mpi_clear_highbit (tmpval, value_b); /* (V_n mod 2^b) */
+ mpi_lshift (tmpval, tmpval, value_j*qbits);
+ mpi_add (value_w, value_w, tmpval);
+ }
+
+ /* Step 11.3: X = W + 2^{L-1} */
+ mpi_set_ui (value_x, 0);
+ mpi_set_highbit (value_x, pbits-1);
+ mpi_add (value_x, value_x, value_w);
+
+ /* Step 11.4: c = X mod 2q */
+ mpi_mul_2exp (tmpval, prime_q, 1);
+ mpi_mod (tmpval, value_x, tmpval);
+
+ /* Step 11.5: p = X - (c - 1) */
+ mpi_sub_ui (tmpval, tmpval, 1);
+ mpi_sub (prime_p, value_x, tmpval);
+
+ /* Step 11.6: If p < 2^{L-1} skip the primality test. */
+ /* Step 11.7 and 11.8: Primality test. */
+ if (mpi_get_nbits (prime_p) >= pbits-1
+ && check_prime (prime_p, val_2, 64, NULL, NULL) )
+ break; /* Yes, P is prime, continue with Step 15. */
+
+ /* Step 11.9: counter = counter + 1, offset = offset + n + 1.
+ If counter >= 4L goto Step 5. */
+ counter++;
+ if (counter >= 4*pbits)
+ goto restart;
+ }
+
+ /* Step 12: Save p, q, counter and seed. */
+ log_debug ("fips186-3 pbits p=%u q=%u counter=%d\n",
+ mpi_get_nbits (prime_p), mpi_get_nbits (prime_q), counter);
+ log_printhex ("fips186-3 seed", seed, seedlen);
+ log_printmpi ("fips186-3 p", prime_p);
+ log_printmpi ("fips186-3 q", prime_q);
+ if (r_q)
+ {
+ *r_q = prime_q;
+ prime_q = NULL;
+ }
+ if (r_p)
+ {
+ *r_p = prime_p;
+ prime_p = NULL;
+ }
+ if (r_counter)
+ *r_counter = counter;
+ if (r_seed && r_seedlen)
+ {
+ memcpy (seed_plus, seed, seedlen);
+ *r_seed = seed_plus;
+ seed_plus = NULL;
+ *r_seedlen = seedlen;
}
+ if (r_hashalgo)
+ *r_hashalgo = hashalgo;
+
+ leave:
+ _gcry_mpi_release (tmpval);
+ _gcry_mpi_release (value_x);
+ _gcry_mpi_release (value_w);
+ _gcry_mpi_release (prime_p);
+ _gcry_mpi_release (prime_q);
+ xfree (seed_plus);
+ _gcry_mpi_release (val_2);
+ return ec;
}
projects / libgcrypt.git / blobdiff