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-rw-r--r--crypto/bn/bn_prime.c745
1 files changed, 383 insertions, 362 deletions
diff --git a/crypto/bn/bn_prime.c b/crypto/bn/bn_prime.c
index 7b25979dd1c4..1d256874c9d2 100644
--- a/crypto/bn/bn_prime.c
+++ b/crypto/bn/bn_prime.c
@@ -5,21 +5,21 @@
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
- *
+ *
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
+ *
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
- *
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
@@ -34,10 +34,10 @@
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
+ * 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
+ *
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
@@ -49,7 +49,7 @@
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
- *
+ *
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
@@ -63,7 +63,7 @@
* are met:
*
* 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
+ * notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
@@ -115,380 +115,401 @@
#include "bn_lcl.h"
#include <openssl/rand.h>
-/* NB: these functions have been "upgraded", the deprecated versions (which are
- * compatibility wrappers using these functions) are in bn_depr.c.
- * - Geoff
+/*
+ * NB: these functions have been "upgraded", the deprecated versions (which
+ * are compatibility wrappers using these functions) are in bn_depr.c. -
+ * Geoff
*/
-/* The quick sieve algorithm approach to weeding out primes is
- * Philip Zimmermann's, as implemented in PGP. I have had a read of
- * his comments and implemented my own version.
+/*
+ * The quick sieve algorithm approach to weeding out primes is Philip
+ * Zimmermann's, as implemented in PGP. I have had a read of his comments
+ * and implemented my own version.
*/
#include "bn_prime.h"
static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1,
- const BIGNUM *a1_odd, int k, BN_CTX *ctx, BN_MONT_CTX *mont);
+ const BIGNUM *a1_odd, int k, BN_CTX *ctx,
+ BN_MONT_CTX *mont);
static int probable_prime(BIGNUM *rnd, int bits);
static int probable_prime_dh(BIGNUM *rnd, int bits,
- const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx);
-static int probable_prime_dh_safe(BIGNUM *rnd, int bits,
- const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx);
+ const BIGNUM *add, const BIGNUM *rem,
+ BN_CTX *ctx);
+static int probable_prime_dh_safe(BIGNUM *rnd, int bits, const BIGNUM *add,
+ const BIGNUM *rem, BN_CTX *ctx);
int BN_GENCB_call(BN_GENCB *cb, int a, int b)
- {
- /* No callback means continue */
- if(!cb) return 1;
- switch(cb->ver)
- {
- case 1:
- /* Deprecated-style callbacks */
- if(!cb->cb.cb_1)
- return 1;
- cb->cb.cb_1(a, b, cb->arg);
- return 1;
- case 2:
- /* New-style callbacks */
- return cb->cb.cb_2(a, b, cb);
- default:
- break;
- }
- /* Unrecognised callback type */
- return 0;
- }
+{
+ /* No callback means continue */
+ if (!cb)
+ return 1;
+ switch (cb->ver) {
+ case 1:
+ /* Deprecated-style callbacks */
+ if (!cb->cb.cb_1)
+ return 1;
+ cb->cb.cb_1(a, b, cb->arg);
+ return 1;
+ case 2:
+ /* New-style callbacks */
+ return cb->cb.cb_2(a, b, cb);
+ default:
+ break;
+ }
+ /* Unrecognised callback type */
+ return 0;
+}
int BN_generate_prime_ex(BIGNUM *ret, int bits, int safe,
- const BIGNUM *add, const BIGNUM *rem, BN_GENCB *cb)
- {
- BIGNUM *t;
- int found=0;
- int i,j,c1=0;
- BN_CTX *ctx;
- int checks = BN_prime_checks_for_size(bits);
-
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
- BN_CTX_start(ctx);
- t = BN_CTX_get(ctx);
- if(!t) goto err;
-loop:
- /* make a random number and set the top and bottom bits */
- if (add == NULL)
- {
- if (!probable_prime(ret,bits)) goto err;
- }
- else
- {
- if (safe)
- {
- if (!probable_prime_dh_safe(ret,bits,add,rem,ctx))
- goto err;
- }
- else
- {
- if (!probable_prime_dh(ret,bits,add,rem,ctx))
- goto err;
- }
- }
- /* if (BN_mod_word(ret,(BN_ULONG)3) == 1) goto loop; */
- if(!BN_GENCB_call(cb, 0, c1++))
- /* aborted */
- goto err;
-
- if (!safe)
- {
- i=BN_is_prime_fasttest_ex(ret,checks,ctx,0,cb);
- if (i == -1) goto err;
- if (i == 0) goto loop;
- }
- else
- {
- /* for "safe prime" generation,
- * check that (p-1)/2 is prime.
- * Since a prime is odd, We just
- * need to divide by 2 */
- if (!BN_rshift1(t,ret)) goto err;
-
- for (i=0; i<checks; i++)
- {
- j=BN_is_prime_fasttest_ex(ret,1,ctx,0,cb);
- if (j == -1) goto err;
- if (j == 0) goto loop;
-
- j=BN_is_prime_fasttest_ex(t,1,ctx,0,cb);
- if (j == -1) goto err;
- if (j == 0) goto loop;
-
- if(!BN_GENCB_call(cb, 2, c1-1))
- goto err;
- /* We have a safe prime test pass */
- }
- }
- /* we have a prime :-) */
- found = 1;
-err:
- if (ctx != NULL)
- {
- BN_CTX_end(ctx);
- BN_CTX_free(ctx);
- }
- bn_check_top(ret);
- return found;
- }
-
-int BN_is_prime_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, BN_GENCB *cb)
- {
- return BN_is_prime_fasttest_ex(a, checks, ctx_passed, 0, cb);
- }
+ const BIGNUM *add, const BIGNUM *rem, BN_GENCB *cb)
+{
+ BIGNUM *t;
+ int found = 0;
+ int i, j, c1 = 0;
+ BN_CTX *ctx;
+ int checks = BN_prime_checks_for_size(bits);
+
+ ctx = BN_CTX_new();
+ if (ctx == NULL)
+ goto err;
+ BN_CTX_start(ctx);
+ t = BN_CTX_get(ctx);
+ if (!t)
+ goto err;
+ loop:
+ /* make a random number and set the top and bottom bits */
+ if (add == NULL) {
+ if (!probable_prime(ret, bits))
+ goto err;
+ } else {
+ if (safe) {
+ if (!probable_prime_dh_safe(ret, bits, add, rem, ctx))
+ goto err;
+ } else {
+ if (!probable_prime_dh(ret, bits, add, rem, ctx))
+ goto err;
+ }
+ }
+ /* if (BN_mod_word(ret,(BN_ULONG)3) == 1) goto loop; */
+ if (!BN_GENCB_call(cb, 0, c1++))
+ /* aborted */
+ goto err;
+
+ if (!safe) {
+ i = BN_is_prime_fasttest_ex(ret, checks, ctx, 0, cb);
+ if (i == -1)
+ goto err;
+ if (i == 0)
+ goto loop;
+ } else {
+ /*
+ * for "safe prime" generation, check that (p-1)/2 is prime. Since a
+ * prime is odd, We just need to divide by 2
+ */
+ if (!BN_rshift1(t, ret))
+ goto err;
+
+ for (i = 0; i < checks; i++) {
+ j = BN_is_prime_fasttest_ex(ret, 1, ctx, 0, cb);
+ if (j == -1)
+ goto err;
+ if (j == 0)
+ goto loop;
+
+ j = BN_is_prime_fasttest_ex(t, 1, ctx, 0, cb);
+ if (j == -1)
+ goto err;
+ if (j == 0)
+ goto loop;
+
+ if (!BN_GENCB_call(cb, 2, c1 - 1))
+ goto err;
+ /* We have a safe prime test pass */
+ }
+ }
+ /* we have a prime :-) */
+ found = 1;
+ err:
+ if (ctx != NULL) {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
+ bn_check_top(ret);
+ return found;
+}
+
+int BN_is_prime_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,
+ BN_GENCB *cb)
+{
+ return BN_is_prime_fasttest_ex(a, checks, ctx_passed, 0, cb);
+}
int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,
- int do_trial_division, BN_GENCB *cb)
- {
- int i, j, ret = -1;
- int k;
- BN_CTX *ctx = NULL;
- BIGNUM *A1, *A1_odd, *check; /* taken from ctx */
- BN_MONT_CTX *mont = NULL;
- const BIGNUM *A = NULL;
-
- if (BN_cmp(a, BN_value_one()) <= 0)
- return 0;
-
- if (checks == BN_prime_checks)
- checks = BN_prime_checks_for_size(BN_num_bits(a));
-
- /* first look for small factors */
- if (!BN_is_odd(a))
- /* a is even => a is prime if and only if a == 2 */
- return BN_is_word(a, 2);
- if (do_trial_division)
- {
- for (i = 1; i < NUMPRIMES; i++)
- if (BN_mod_word(a, primes[i]) == 0)
- return 0;
- if(!BN_GENCB_call(cb, 1, -1))
- goto err;
- }
-
- if (ctx_passed != NULL)
- ctx = ctx_passed;
- else
- if ((ctx=BN_CTX_new()) == NULL)
- goto err;
- BN_CTX_start(ctx);
-
- /* A := abs(a) */
- if (a->neg)
- {
- BIGNUM *t;
- if ((t = BN_CTX_get(ctx)) == NULL) goto err;
- BN_copy(t, a);
- t->neg = 0;
- A = t;
- }
- else
- A = a;
- A1 = BN_CTX_get(ctx);
- A1_odd = BN_CTX_get(ctx);
- check = BN_CTX_get(ctx);
- if (check == NULL) goto err;
-
- /* compute A1 := A - 1 */
- if (!BN_copy(A1, A))
- goto err;
- if (!BN_sub_word(A1, 1))
- goto err;
- if (BN_is_zero(A1))
- {
- ret = 0;
- goto err;
- }
-
- /* write A1 as A1_odd * 2^k */
- k = 1;
- while (!BN_is_bit_set(A1, k))
- k++;
- if (!BN_rshift(A1_odd, A1, k))
- goto err;
-
- /* Montgomery setup for computations mod A */
- mont = BN_MONT_CTX_new();
- if (mont == NULL)
- goto err;
- if (!BN_MONT_CTX_set(mont, A, ctx))
- goto err;
-
- for (i = 0; i < checks; i++)
- {
- if (!BN_pseudo_rand_range(check, A1))
- goto err;
- if (!BN_add_word(check, 1))
- goto err;
- /* now 1 <= check < A */
-
- j = witness(check, A, A1, A1_odd, k, ctx, mont);
- if (j == -1) goto err;
- if (j)
- {
- ret=0;
- goto err;
- }
- if(!BN_GENCB_call(cb, 1, i))
- goto err;
- }
- ret=1;
-err:
- if (ctx != NULL)
- {
- BN_CTX_end(ctx);
- if (ctx_passed == NULL)
- BN_CTX_free(ctx);
- }
- if (mont != NULL)
- BN_MONT_CTX_free(mont);
-
- return(ret);
- }
+ int do_trial_division, BN_GENCB *cb)
+{
+ int i, j, ret = -1;
+ int k;
+ BN_CTX *ctx = NULL;
+ BIGNUM *A1, *A1_odd, *check; /* taken from ctx */
+ BN_MONT_CTX *mont = NULL;
+ const BIGNUM *A = NULL;
+
+ if (BN_cmp(a, BN_value_one()) <= 0)
+ return 0;
+
+ if (checks == BN_prime_checks)
+ checks = BN_prime_checks_for_size(BN_num_bits(a));
+
+ /* first look for small factors */
+ if (!BN_is_odd(a))
+ /* a is even => a is prime if and only if a == 2 */
+ return BN_is_word(a, 2);
+ if (do_trial_division) {
+ for (i = 1; i < NUMPRIMES; i++)
+ if (BN_mod_word(a, primes[i]) == 0)
+ return 0;
+ if (!BN_GENCB_call(cb, 1, -1))
+ goto err;
+ }
+
+ if (ctx_passed != NULL)
+ ctx = ctx_passed;
+ else if ((ctx = BN_CTX_new()) == NULL)
+ goto err;
+ BN_CTX_start(ctx);
+
+ /* A := abs(a) */
+ if (a->neg) {
+ BIGNUM *t;
+ if ((t = BN_CTX_get(ctx)) == NULL)
+ goto err;
+ BN_copy(t, a);
+ t->neg = 0;
+ A = t;
+ } else
+ A = a;
+ A1 = BN_CTX_get(ctx);
+ A1_odd = BN_CTX_get(ctx);
+ check = BN_CTX_get(ctx);
+ if (check == NULL)
+ goto err;
+
+ /* compute A1 := A - 1 */
+ if (!BN_copy(A1, A))
+ goto err;
+ if (!BN_sub_word(A1, 1))
+ goto err;
+ if (BN_is_zero(A1)) {
+ ret = 0;
+ goto err;
+ }
+
+ /* write A1 as A1_odd * 2^k */
+ k = 1;
+ while (!BN_is_bit_set(A1, k))
+ k++;
+ if (!BN_rshift(A1_odd, A1, k))
+ goto err;
+
+ /* Montgomery setup for computations mod A */
+ mont = BN_MONT_CTX_new();
+ if (mont == NULL)
+ goto err;
+ if (!BN_MONT_CTX_set(mont, A, ctx))
+ goto err;
+
+ for (i = 0; i < checks; i++) {
+ if (!BN_pseudo_rand_range(check, A1))
+ goto err;
+ if (!BN_add_word(check, 1))
+ goto err;
+ /* now 1 <= check < A */
+
+ j = witness(check, A, A1, A1_odd, k, ctx, mont);
+ if (j == -1)
+ goto err;
+ if (j) {
+ ret = 0;
+ goto err;
+ }
+ if (!BN_GENCB_call(cb, 1, i))
+ goto err;
+ }
+ ret = 1;
+ err:
+ if (ctx != NULL) {
+ BN_CTX_end(ctx);
+ if (ctx_passed == NULL)
+ BN_CTX_free(ctx);
+ }
+ if (mont != NULL)
+ BN_MONT_CTX_free(mont);
+
+ return (ret);
+}
static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1,
- const BIGNUM *a1_odd, int k, BN_CTX *ctx, BN_MONT_CTX *mont)
- {
- if (!BN_mod_exp_mont(w, w, a1_odd, a, ctx, mont)) /* w := w^a1_odd mod a */
- return -1;
- if (BN_is_one(w))
- return 0; /* probably prime */
- if (BN_cmp(w, a1) == 0)
- return 0; /* w == -1 (mod a), 'a' is probably prime */
- while (--k)
- {
- if (!BN_mod_mul(w, w, w, a, ctx)) /* w := w^2 mod a */
- return -1;
- if (BN_is_one(w))
- return 1; /* 'a' is composite, otherwise a previous 'w' would
- * have been == -1 (mod 'a') */
- if (BN_cmp(w, a1) == 0)
- return 0; /* w == -1 (mod a), 'a' is probably prime */
- }
- /* If we get here, 'w' is the (a-1)/2-th power of the original 'w',
- * and it is neither -1 nor +1 -- so 'a' cannot be prime */
- bn_check_top(w);
- return 1;
- }
+ const BIGNUM *a1_odd, int k, BN_CTX *ctx,
+ BN_MONT_CTX *mont)
+{
+ if (!BN_mod_exp_mont(w, w, a1_odd, a, ctx, mont)) /* w := w^a1_odd mod a */
+ return -1;
+ if (BN_is_one(w))
+ return 0; /* probably prime */
+ if (BN_cmp(w, a1) == 0)
+ return 0; /* w == -1 (mod a), 'a' is probably prime */
+ while (--k) {
+ if (!BN_mod_mul(w, w, w, a, ctx)) /* w := w^2 mod a */
+ return -1;
+ if (BN_is_one(w))
+ return 1; /* 'a' is composite, otherwise a previous 'w'
+ * would have been == -1 (mod 'a') */
+ if (BN_cmp(w, a1) == 0)
+ return 0; /* w == -1 (mod a), 'a' is probably prime */
+ }
+ /*
+ * If we get here, 'w' is the (a-1)/2-th power of the original 'w', and
+ * it is neither -1 nor +1 -- so 'a' cannot be prime
+ */
+ bn_check_top(w);
+ return 1;
+}
static int probable_prime(BIGNUM *rnd, int bits)
- {
- int i;
- prime_t mods[NUMPRIMES];
- BN_ULONG delta,maxdelta;
-
-again:
- if (!BN_rand(rnd,bits,1,1)) return(0);
- /* we now have a random number 'rand' to test. */
- for (i=1; i<NUMPRIMES; i++)
- mods[i]=(prime_t)BN_mod_word(rnd,(BN_ULONG)primes[i]);
- maxdelta=BN_MASK2 - primes[NUMPRIMES-1];
- delta=0;
- loop: for (i=1; i<NUMPRIMES; i++)
- {
- /* check that rnd is not a prime and also
- * that gcd(rnd-1,primes) == 1 (except for 2) */
- if (((mods[i]+delta)%primes[i]) <= 1)
- {
- delta+=2;
- if (delta > maxdelta) goto again;
- goto loop;
- }
- }
- if (!BN_add_word(rnd,delta)) return(0);
- bn_check_top(rnd);
- return(1);
- }
+{
+ int i;
+ prime_t mods[NUMPRIMES];
+ BN_ULONG delta, maxdelta;
+
+ again:
+ if (!BN_rand(rnd, bits, 1, 1))
+ return (0);
+ /* we now have a random number 'rand' to test. */
+ for (i = 1; i < NUMPRIMES; i++)
+ mods[i] = (prime_t) BN_mod_word(rnd, (BN_ULONG)primes[i]);
+ maxdelta = BN_MASK2 - primes[NUMPRIMES - 1];
+ delta = 0;
+ loop:for (i = 1; i < NUMPRIMES; i++) {
+ /*
+ * check that rnd is not a prime and also that gcd(rnd-1,primes) == 1
+ * (except for 2)
+ */
+ if (((mods[i] + delta) % primes[i]) <= 1) {
+ delta += 2;
+ if (delta > maxdelta)
+ goto again;
+ goto loop;
+ }
+ }
+ if (!BN_add_word(rnd, delta))
+ return (0);
+ bn_check_top(rnd);
+ return (1);
+}
static int probable_prime_dh(BIGNUM *rnd, int bits,
- const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx)
- {
- int i,ret=0;
- BIGNUM *t1;
-
- BN_CTX_start(ctx);
- if ((t1 = BN_CTX_get(ctx)) == NULL) goto err;
-
- if (!BN_rand(rnd,bits,0,1)) goto err;
-
- /* we need ((rnd-rem) % add) == 0 */
-
- if (!BN_mod(t1,rnd,add,ctx)) goto err;
- if (!BN_sub(rnd,rnd,t1)) goto err;
- if (rem == NULL)
- { if (!BN_add_word(rnd,1)) goto err; }
- else
- { if (!BN_add(rnd,rnd,rem)) goto err; }
-
- /* we now have a random number 'rand' to test. */
-
- loop: for (i=1; i<NUMPRIMES; i++)
- {
- /* check that rnd is a prime */
- if (BN_mod_word(rnd,(BN_ULONG)primes[i]) <= 1)
- {
- if (!BN_add(rnd,rnd,add)) goto err;
- goto loop;
- }
- }
- ret=1;
-err:
- BN_CTX_end(ctx);
- bn_check_top(rnd);
- return(ret);
- }
+ const BIGNUM *add, const BIGNUM *rem,
+ BN_CTX *ctx)
+{
+ int i, ret = 0;
+ BIGNUM *t1;
+
+ BN_CTX_start(ctx);
+ if ((t1 = BN_CTX_get(ctx)) == NULL)
+ goto err;
+
+ if (!BN_rand(rnd, bits, 0, 1))
+ goto err;
+
+ /* we need ((rnd-rem) % add) == 0 */
+
+ if (!BN_mod(t1, rnd, add, ctx))
+ goto err;
+ if (!BN_sub(rnd, rnd, t1))
+ goto err;
+ if (rem == NULL) {
+ if (!BN_add_word(rnd, 1))
+ goto err;
+ } else {
+ if (!BN_add(rnd, rnd, rem))
+ goto err;
+ }
+
+ /* we now have a random number 'rand' to test. */
+
+ loop:for (i = 1; i < NUMPRIMES; i++) {
+ /* check that rnd is a prime */
+ if (BN_mod_word(rnd, (BN_ULONG)primes[i]) <= 1) {
+ if (!BN_add(rnd, rnd, add))
+ goto err;
+ goto loop;
+ }
+ }
+ ret = 1;
+ err:
+ BN_CTX_end(ctx);
+ bn_check_top(rnd);
+ return (ret);
+}
static int probable_prime_dh_safe(BIGNUM *p, int bits, const BIGNUM *padd,
- const BIGNUM *rem, BN_CTX *ctx)
- {
- int i,ret=0;
- BIGNUM *t1,*qadd,*q;
-
- bits--;
- BN_CTX_start(ctx);
- t1 = BN_CTX_get(ctx);
- q = BN_CTX_get(ctx);
- qadd = BN_CTX_get(ctx);
- if (qadd == NULL) goto err;
-
- if (!BN_rshift1(qadd,padd)) goto err;
-
- if (!BN_rand(q,bits,0,1)) goto err;
-
- /* we need ((rnd-rem) % add) == 0 */
- if (!BN_mod(t1,q,qadd,ctx)) goto err;
- if (!BN_sub(q,q,t1)) goto err;
- if (rem == NULL)
- { if (!BN_add_word(q,1)) goto err; }
- else
- {
- if (!BN_rshift1(t1,rem)) goto err;
- if (!BN_add(q,q,t1)) goto err;
- }
-
- /* we now have a random number 'rand' to test. */
- if (!BN_lshift1(p,q)) goto err;
- if (!BN_add_word(p,1)) goto err;
-
- loop: for (i=1; i<NUMPRIMES; i++)
- {
- /* check that p and q are prime */
- /* check that for p and q
- * gcd(p-1,primes) == 1 (except for 2) */
- if ( (BN_mod_word(p,(BN_ULONG)primes[i]) == 0) ||
- (BN_mod_word(q,(BN_ULONG)primes[i]) == 0))
- {
- if (!BN_add(p,p,padd)) goto err;
- if (!BN_add(q,q,qadd)) goto err;
- goto loop;
- }
- }
- ret=1;
-err:
- BN_CTX_end(ctx);
- bn_check_top(p);
- return(ret);
- }
+ const BIGNUM *rem, BN_CTX *ctx)
+{
+ int i, ret = 0;
+ BIGNUM *t1, *qadd, *q;
+
+ bits--;
+ BN_CTX_start(ctx);
+ t1 = BN_CTX_get(ctx);
+ q = BN_CTX_get(ctx);
+ qadd = BN_CTX_get(ctx);
+ if (qadd == NULL)
+ goto err;
+
+ if (!BN_rshift1(qadd, padd))
+ goto err;
+
+ if (!BN_rand(q, bits, 0, 1))
+ goto err;
+
+ /* we need ((rnd-rem) % add) == 0 */
+ if (!BN_mod(t1, q, qadd, ctx))
+ goto err;
+ if (!BN_sub(q, q, t1))
+ goto err;
+ if (rem == NULL) {
+ if (!BN_add_word(q, 1))
+ goto err;
+ } else {
+ if (!BN_rshift1(t1, rem))
+ goto err;
+ if (!BN_add(q, q, t1))
+ goto err;
+ }
+
+ /* we now have a random number 'rand' to test. */
+ if (!BN_lshift1(p, q))
+ goto err;
+ if (!BN_add_word(p, 1))
+ goto err;
+
+ loop:for (i = 1; i < NUMPRIMES; i++) {
+ /* check that p and q are prime */
+ /*
+ * check that for p and q gcd(p-1,primes) == 1 (except for 2)
+ */
+ if ((BN_mod_word(p, (BN_ULONG)primes[i]) == 0) ||
+ (BN_mod_word(q, (BN_ULONG)primes[i]) == 0)) {
+ if (!BN_add(p, p, padd))
+ goto err;
+ if (!BN_add(q, q, qadd))
+ goto err;
+ goto loop;
+ }
+ }
+ ret = 1;
+ err:
+ BN_CTX_end(ctx);
+ bn_check_top(p);
+ return (ret);
+}