--- /dev/null
+/* crypto/bn/bn_prime.c */
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * 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:
+ * 1. Redistributions of source code must retain the 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 acknowledgement:
+ * "This product includes cryptographic software written by
+ * 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
+ * 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
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR 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.
+ *
+ * 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
+ * [including the GNU Public Licence.]
+ */
+/* ====================================================================
+ * Copyright (c) 1998-2001 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>
+#include "cryptlib.h"
+#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
+ */
+
+/* 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);
+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);
+
+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;
+ }
+
+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);
+ }
+
+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);
+ }
+
+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;
+ }
+
+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);
+ }
+
+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);
+ }
+
+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);
+ }
projects / cassiopeia.git / blobdiff