1 files changed, 198 insertions, 180 deletions

diff --git a/src/lib/libcrypto/bn/bn_prime.c b/src/lib/libcrypto/bn/bn_prime.c
index 6fa0f9be1e..a5f01b92eb 100644
--- a/src/lib/libcrypto/bn/bn_prime.c
+++ b/src/lib/libcrypto/bn/bn_prime.c
@@ -55,6 +55,59 @@
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    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
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT 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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
 
 #include <stdio.h>
 #include <time.h>
@@ -62,26 +115,29 @@
 #include "bn_lcl.h"
 #include <openssl/rand.h>
 
-/* The quick seive algorithm approach to weeding out primes is
+/* 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 *a, BIGNUM *n, BN_CTX *ctx,BN_CTX *ctx2,
-        BN_MONT_CTX *mont);
+static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1,
+        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,
         BIGNUM *add, BIGNUM *rem, BN_CTX *ctx);
-static int probable_prime_dh_strong(BIGNUM *rnd, int bits,
+static int probable_prime_dh_safe(BIGNUM *rnd, int bits,
         BIGNUM *add, BIGNUM *rem, BN_CTX *ctx);
-BIGNUM *BN_generate_prime(BIGNUM *ret, int bits, int strong, BIGNUM *add,
+
+BIGNUM *BN_generate_prime(BIGNUM *ret, int bits, int safe, BIGNUM *add,
              BIGNUM *rem, void (*callback)(int,int,void *), void *cb_arg)
         {
         BIGNUM *rnd=NULL;
         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;
@@ -100,9 +156,9 @@ loop:
                 }
         else
                 {
-                if (strong)
+                if (safe)
                         {
-                        if (!probable_prime_dh_strong(rnd,bits,add,rem,ctx))
+                        if (!probable_prime_dh_safe(rnd,bits,add,rem,ctx))
                                  goto err;
                         }
                 else
@@ -114,160 +170,185 @@ loop:
         /* if (BN_mod_word(rnd,(BN_ULONG)3) == 1) goto loop; */
         if (callback != NULL) callback(0,c1++,cb_arg);
 
-        if (!strong)
+        if (!safe)
                 {
-                i=BN_is_prime(rnd,BN_prime_checks,callback,ctx,cb_arg);
+                i=BN_is_prime_fasttest(rnd,checks,callback,ctx,cb_arg,0);
                 if (i == -1) goto err;
                 if (i == 0) goto loop;
                 }
         else
                 {
-                /* for a strong prime generation,
+                /* 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,rnd)) goto err;
 
-                for (i=0; i<BN_prime_checks; i++)
+                for (i=0; i<checks; i++)
                         {
-                        j=BN_is_prime(rnd,1,callback,ctx,cb_arg);
+                        j=BN_is_prime_fasttest(rnd,1,callback,ctx,cb_arg,0);
                         if (j == -1) goto err;
                         if (j == 0) goto loop;
 
-                        j=BN_is_prime(&t,1,callback,ctx,cb_arg);
+                        j=BN_is_prime_fasttest(&t,1,callback,ctx,cb_arg,0);
                         if (j == -1) goto err;
                         if (j == 0) goto loop;
 
                         if (callback != NULL) callback(2,c1-1,cb_arg);
-                        /* We have a strong prime test pass */
+                        /* We have a safe prime test pass */
                         }
                 }
         /* we have a prime :-) */
-        ret=rnd;
+        found = 1;
 err:
-        if ((ret == NULL) && (rnd != NULL)) BN_free(rnd);
+        if (!found && (ret == NULL) && (rnd != NULL)) BN_free(rnd);
         BN_free(&t);
         if (ctx != NULL) BN_CTX_free(ctx);
-        return(ret);
+        return(found ? rnd : NULL);
         }
 
-int BN_is_prime(BIGNUM *a, int checks, void (*callback)(int,int,void *),
-             BN_CTX *ctx_passed, void *cb_arg)
+int BN_is_prime(const BIGNUM *a, int checks, void (*callback)(int,int,void *),
+        BN_CTX *ctx_passed, void *cb_arg)
         {
-        int i,j,c2=0,ret= -1;
-        BIGNUM *check;
-        BN_CTX *ctx=NULL,*ctx2=NULL;
-        BN_MONT_CTX *mont=NULL;
+        return BN_is_prime_fasttest(a, checks, callback, ctx_passed, cb_arg, 0);
+        }
 
+int BN_is_prime_fasttest(const BIGNUM *a, int checks,
+                void (*callback)(int,int,void *),
+                BN_CTX *ctx_passed, void *cb_arg,
+                int do_trial_division)
+        {
+        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 (checks == BN_prime_checks)
+                checks = BN_prime_checks_for_size(BN_num_bits(a));
+
+        /* first look for small factors */
         if (!BN_is_odd(a))
                 return(0);
+        if (do_trial_division)
+                {
+                for (i = 1; i < NUMPRIMES; i++)
+                        if (BN_mod_word(a, primes[i]) == 0) 
+                                return 0;
+                if (callback != NULL) callback(1, -1, cb_arg);
+                }
+
         if (ctx_passed != NULL)
-                ctx=ctx_passed;
+                ctx = ctx_passed;
         else
-                if ((ctx=BN_CTX_new()) == NULL) goto err;
-
-        if ((ctx2=BN_CTX_new()) == NULL) goto err;
-        if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
-
-        check= &(ctx->bn[ctx->tos++]);
+                if ((ctx=BN_CTX_new()) == NULL)
+                        goto err;
+        BN_CTX_start(ctx);
 
-        /* Setup the montgomery structure */
-        if (!BN_MONT_CTX_set(mont,a,ctx2)) goto err;
+        /* 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;
+                }
 
-        for (i=0; i<checks; i++)
+        /* 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_rand(check,BN_num_bits(a)-1,0,0)) goto err;
-                j=witness(check,a,ctx,ctx2,mont);
+                if (!BN_pseudo_rand(check, BN_num_bits(A1), 0, 0))
+                        goto err;
+                if (BN_cmp(check, A1) >= 0)
+                        if (!BN_sub(check, 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 (callback != NULL) callback(1,c2++,cb_arg);
+                if (callback != NULL) callback(1,i,cb_arg);
                 }
         ret=1;
 err:
-        ctx->tos--;
-        if ((ctx_passed == NULL) && (ctx != NULL))
-                BN_CTX_free(ctx);
-        if (ctx2 != NULL)
-                BN_CTX_free(ctx2);
-        if (mont != NULL) BN_MONT_CTX_free(mont);
-                
+        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);
         }
 
-#define RECP_MUL_MOD
-
-static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx, BN_CTX *ctx2,
-             BN_MONT_CTX *mont)
+static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1,
+        const BIGNUM *a1_odd, int k, BN_CTX *ctx, BN_MONT_CTX *mont)
         {
-        int k,i,ret= -1,good;
-        BIGNUM *d,*dd,*tmp,*d1,*d2,*n1;
-        BIGNUM *mont_one,*mont_n1,*mont_a;
-
-        d1= &(ctx->bn[ctx->tos]);
-        d2= &(ctx->bn[ctx->tos+1]);
-        n1= &(ctx->bn[ctx->tos+2]);
-        ctx->tos+=3;
-
-        mont_one= &(ctx2->bn[ctx2->tos]);
-        mont_n1= &(ctx2->bn[ctx2->tos+1]);
-        mont_a= &(ctx2->bn[ctx2->tos+2]);
-        ctx2->tos+=3;
-
-        d=d1;
-        dd=d2;
-        if (!BN_one(d)) goto err;
-        if (!BN_sub(n1,n,d)) goto err; /* n1=n-1; */
-        k=BN_num_bits(n1);
-
-        if (!BN_to_montgomery(mont_one,BN_value_one(),mont,ctx2)) goto err;
-        if (!BN_to_montgomery(mont_n1,n1,mont,ctx2)) goto err;
-        if (!BN_to_montgomery(mont_a,a,mont,ctx2)) goto err;
-
-        BN_copy(d,mont_one);
-        for (i=k-1; i>=0; i--)
+        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_cmp(d,mont_one) != 0) &&
-                        (BN_cmp(d,mont_n1) != 0))
-                        good=1;
-                else
-                        good=0;
-
-                BN_mod_mul_montgomery(dd,d,d,mont,ctx2);
-
-                if (good && (BN_cmp(dd,mont_one) == 0))
-                        {
-                        ret=1;
-                        goto err;
-                        }
-                if (BN_is_bit_set(n1,i))
-                        {
-                        BN_mod_mul_montgomery(d,dd,mont_a,mont,ctx2);
-                        }
-                else
-                        {
-                        tmp=d;
-                        d=dd;
-                        dd=tmp;
-                        }
+                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 (BN_cmp(d,mont_one) == 0)
-                i=0;
-        else    i=1;
-        ret=i;
-err:
-        ctx->tos-=3;
-        ctx2->tos-=3;
-        return(ret);
+        /* 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 */
+        return 1;
         }
 
 static int probable_prime(BIGNUM *rnd, int bits)
         {
         int i;
-        MS_STATIC BN_ULONG mods[NUMPRIMES];
+        BN_ULONG mods[NUMPRIMES];
         BN_ULONG delta,d;
 
 again:
@@ -285,7 +366,7 @@ again:
                         d=delta;
                         delta+=2;
                         /* perhaps need to check for overflow of
-                         * delta (but delta can be upto 2^32)
+                         * delta (but delta can be up to 2^32)
                          * 21-May-98 eay - added overflow check */
                         if (delta < d) goto again;
                         goto loop;
@@ -301,7 +382,8 @@ static int probable_prime_dh(BIGNUM *rnd, int bits, BIGNUM *add, BIGNUM *rem,
         int i,ret=0;
         BIGNUM *t1;
 
-        t1= &(ctx->bn[ctx->tos++]);
+        BN_CTX_start(ctx);
+        if ((t1 = BN_CTX_get(ctx)) == NULL) goto err;
 
         if (!BN_rand(rnd,bits,0,1)) goto err;
 
@@ -327,20 +409,22 @@ static int probable_prime_dh(BIGNUM *rnd, int bits, BIGNUM *add, BIGNUM *rem,
                 }
         ret=1;
 err:
-        ctx->tos--;
+        BN_CTX_end(ctx);
         return(ret);
         }
 
-static int probable_prime_dh_strong(BIGNUM *p, int bits, BIGNUM *padd,
+static int probable_prime_dh_safe(BIGNUM *p, int bits, BIGNUM *padd,
              BIGNUM *rem, BN_CTX *ctx)
         {
         int i,ret=0;
-        BIGNUM *t1,*qadd=NULL,*q=NULL;
+        BIGNUM *t1,*qadd,*q;
 
         bits--;
-        t1= &(ctx->bn[ctx->tos++]);
-        q= &(ctx->bn[ctx->tos++]);
-        qadd= &(ctx->bn[ctx->tos++]);
+        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;
                 
@@ -376,72 +460,6 @@ static int probable_prime_dh_strong(BIGNUM *p, int bits, BIGNUM *padd,
                 }
         ret=1;
 err:
-        ctx->tos-=3;
-        return(ret);
-        }
-
-#if 0
-static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx)
-        {
-        int k,i,nb,ret= -1;
-        BIGNUM *d,*dd,*tmp;
-        BIGNUM *d1,*d2,*x,*n1,*inv;
-
-        d1= &(ctx->bn[ctx->tos]);
-        d2= &(ctx->bn[ctx->tos+1]);
-        x=  &(ctx->bn[ctx->tos+2]);
-        n1= &(ctx->bn[ctx->tos+3]);
-        inv=&(ctx->bn[ctx->tos+4]);
-        ctx->tos+=5;
-
-        d=d1;
-        dd=d2;
-        if (!BN_one(d)) goto err;
-        if (!BN_sub(n1,n,d)) goto err; /* n1=n-1; */
-        k=BN_num_bits(n1);
-
-        /* i=BN_num_bits(n); */
-#ifdef RECP_MUL_MOD
-        nb=BN_reciprocal(inv,n,ctx); /**/
-        if (nb == -1) goto err;
-#endif
-
-        for (i=k-1; i>=0; i--)
-                {
-                if (BN_copy(x,d) == NULL) goto err;
-#ifndef RECP_MUL_MOD
-                if (!BN_mod_mul(dd,d,d,n,ctx)) goto err;
-#else
-                if (!BN_mod_mul_reciprocal(dd,d,d,n,inv,nb,ctx)) goto err;
-#endif
-                if (    BN_is_one(dd) &&
-                        !BN_is_one(x) &&
-                        (BN_cmp(x,n1) != 0))
-                        {
-                        ret=1;
-                        goto err;
-                        }
-                if (BN_is_bit_set(n1,i))
-                        {
-#ifndef RECP_MUL_MOD
-                        if (!BN_mod_mul(d,dd,a,n,ctx)) goto err;
-#else
-                        if (!BN_mod_mul_reciprocal(d,dd,a,n,inv,nb,ctx)) goto err; 
-#endif
-                        }
-                else
-                        {
-                        tmp=d;
-                        d=dd;
-                        dd=tmp;
-                        }
-                }
-        if (BN_is_one(d))
-                i=0;
-        else    i=1;
-        ret=i;
-err:
-        ctx->tos-=5;
+        BN_CTX_end(ctx);
         return(ret);
         }
-#endif