+++ /dev/null
-/* crypto/bn/bn_exp.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) 1998-2000 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 "cryptlib.h"
-#include "bn_lcl.h"
-#ifdef ATALLA
-# include <alloca.h>
-# include <atasi.h>
-# include <assert.h>
-# include <dlfcn.h>
-#endif
-
-
-#define TABLE_SIZE 32
-
-/* slow but works */
-int BN_mod_mul(BIGNUM *ret, BIGNUM *a, BIGNUM *b, const BIGNUM *m, BN_CTX *ctx)
- {
- BIGNUM *t;
- int r=0;
-
- bn_check_top(a);
- bn_check_top(b);
- bn_check_top(m);
-
- BN_CTX_start(ctx);
- if ((t = BN_CTX_get(ctx)) == NULL) goto err;
- if (a == b)
- { if (!BN_sqr(t,a,ctx)) goto err; }
- else
- { if (!BN_mul(t,a,b,ctx)) goto err; }
- if (!BN_mod(ret,t,m,ctx)) goto err;
- r=1;
-err:
- BN_CTX_end(ctx);
- return(r);
- }
-
-
-/* this one works - simple but works */
-int BN_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx)
- {
- int i,bits,ret=0;
- BIGNUM *v,*rr;
-
- BN_CTX_start(ctx);
- if ((r == a) || (r == p))
- rr = BN_CTX_get(ctx);
- else
- rr = r;
- if ((v = BN_CTX_get(ctx)) == NULL) goto err;
-
- if (BN_copy(v,a) == NULL) goto err;
- bits=BN_num_bits(p);
-
- if (BN_is_odd(p))
- { if (BN_copy(rr,a) == NULL) goto err; }
- else { if (!BN_one(rr)) goto err; }
-
- for (i=1; i<bits; i++)
- {
- if (!BN_sqr(v,v,ctx)) goto err;
- if (BN_is_bit_set(p,i))
- {
- if (!BN_mul(rr,rr,v,ctx)) goto err;
- }
- }
- ret=1;
-err:
- if (r != rr) BN_copy(r,rr);
- BN_CTX_end(ctx);
- return(ret);
- }
-
-
-#ifdef ATALLA
-
-/*
- * This routine will dynamically check for the existance of an Atalla AXL-200
- * SSL accelerator module. If one is found, the variable
- * asi_accelerator_present is set to 1 and the function pointers
- * ptr_ASI_xxxxxx above will be initialized to corresponding ASI API calls.
- */
-typedef int tfnASI_GetPerformanceStatistics(int reset_flag,
- unsigned int *ret_buf);
-typedef int tfnASI_GetHardwareConfig(long card_num, unsigned int *ret_buf);
-typedef int tfnASI_RSAPrivateKeyOpFn(RSAPrivateKey * rsaKey,
- unsigned char *output,
- unsigned char *input,
- unsigned int modulus_len);
-
-static tfnASI_GetHardwareConfig *ptr_ASI_GetHardwareConfig;
-static tfnASI_RSAPrivateKeyOpFn *ptr_ASI_RSAPrivateKeyOpFn;
-static tfnASI_GetPerformanceStatistics *ptr_ASI_GetPerformanceStatistics;
-static int asi_accelerator_present;
-static int tried_atalla;
-
-void atalla_initialize_accelerator_handle(void)
- {
- void *dl_handle;
- int status;
- unsigned int config_buf[1024];
- static int tested;
-
- if(tested)
- return;
-
- tested=1;
-
- bzero((void *)config_buf, 1024);
-
- /*
- * Check to see if the library is present on the system
- */
- dl_handle = dlopen("atasi.so", RTLD_NOW);
- if (dl_handle == (void *) NULL)
- {
-/* printf("atasi.so library is not present on the system\n");
- printf("No HW acceleration available\n");*/
- return;
- }
-
- /*
- * The library is present. Now we'll check to insure that the
- * LDM is up and running. First we'll get the address of the
- * function in the atasi library that we need to see if the
- * LDM is operating.
- */
-
- ptr_ASI_GetHardwareConfig =
- (tfnASI_GetHardwareConfig *)dlsym(dl_handle,"ASI_GetHardwareConfig");
-
- if (ptr_ASI_GetHardwareConfig)
- {
- /*
- * We found the call, now we'll get our config
- * status. If we get a non 0 result, the LDM is not
- * running and we cannot use the Atalla ASI *
- * library.
- */
- status = (*ptr_ASI_GetHardwareConfig)(0L, config_buf);
- if (status != 0)
- {
- printf("atasi.so library is present but not initialized\n");
- printf("No HW acceleration available\n");
- return;
- }
- }
- else
- {
-/* printf("We found the library, but not the function. Very Strange!\n");*/
- return ;
- }
-
- /*
- * It looks like we have acceleration capabilities. Load up the
- * pointers to our ASI API calls.
- */
- ptr_ASI_RSAPrivateKeyOpFn=
- (tfnASI_RSAPrivateKeyOpFn *)dlsym(dl_handle, "ASI_RSAPrivateKeyOpFn");
- if (ptr_ASI_RSAPrivateKeyOpFn == NULL)
- {
-/* printf("We found the library, but no RSA function. Very Strange!\n");*/
- return;
- }
-
- ptr_ASI_GetPerformanceStatistics =
- (tfnASI_GetPerformanceStatistics *)dlsym(dl_handle, "ASI_GetPerformanceStatistics");
- if (ptr_ASI_GetPerformanceStatistics == NULL)
- {
-/* printf("We found the library, but no stat function. Very Strange!\n");*/
- return;
- }
-
- /*
- * Indicate that acceleration is available
- */
- asi_accelerator_present = 1;
-
-/* printf("This system has acceleration!\n");*/
-
- return;
- }
-
-/* make sure this only gets called once when bn_mod_exp calls bn_mod_exp_mont */
-int BN_mod_exp_atalla(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m)
- {
- unsigned char *abin;
- unsigned char *pbin;
- unsigned char *mbin;
- unsigned char *rbin;
- int an,pn,mn,ret;
- RSAPrivateKey keydata;
-
- atalla_initialize_accelerator_handle();
- if(!asi_accelerator_present)
- return 0;
-
-
-/* We should be able to run without size testing */
-# define ASIZE 128
- an=BN_num_bytes(a);
- pn=BN_num_bytes(p);
- mn=BN_num_bytes(m);
-
- if(an <= ASIZE && pn <= ASIZE && mn <= ASIZE)
- {
- int size=mn;
-
- assert(an <= mn);
- abin=alloca(size);
- memset(abin,'\0',mn);
- BN_bn2bin(a,abin+size-an);
-
- pbin=alloca(pn);
- BN_bn2bin(p,pbin);
-
- mbin=alloca(size);
- memset(mbin,'\0',mn);
- BN_bn2bin(m,mbin+size-mn);
-
- rbin=alloca(size);
-
- memset(&keydata,'\0',sizeof keydata);
- keydata.privateExponent.data=pbin;
- keydata.privateExponent.len=pn;
- keydata.modulus.data=mbin;
- keydata.modulus.len=size;
-
- ret=(*ptr_ASI_RSAPrivateKeyOpFn)(&keydata,rbin,abin,keydata.modulus.len);
-/*fprintf(stderr,"!%s\n",BN_bn2hex(a));*/
- if(!ret)
- {
- BN_bin2bn(rbin,keydata.modulus.len,r);
-/*fprintf(stderr,"?%s\n",BN_bn2hex(r));*/
- return 1;
- }
- }
- return 0;
- }
-#endif /* def ATALLA */
-
-
-int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
- BN_CTX *ctx)
- {
- int ret;
-
- bn_check_top(a);
- bn_check_top(p);
- bn_check_top(m);
-
-#ifdef ATALLA
- if(BN_mod_exp_atalla(r,a,p,m))
- return 1;
-/* If it fails, try the other methods (but don't try atalla again) */
- tried_atalla=1;
-#endif
-
-#ifdef MONT_MUL_MOD
- /* I have finally been able to take out this pre-condition of
- * the top bit being set. It was caused by an error in BN_div
- * with negatives. There was also another problem when for a^b%m
- * a >= m. eay 07-May-97 */
-/* if ((m->d[m->top-1]&BN_TBIT) && BN_is_odd(m)) */
-
- if (BN_is_odd(m))
- {
- if (a->top == 1)
- {
- BN_ULONG A = a->d[0];
- ret=BN_mod_exp_mont_word(r,A,p,m,ctx,NULL);
- }
- else
- ret=BN_mod_exp_mont(r,a,p,m,ctx,NULL);
- }
- else
-#endif
-#ifdef RECP_MUL_MOD
- { ret=BN_mod_exp_recp(r,a,p,m,ctx); }
-#else
- { ret=BN_mod_exp_simple(r,a,p,m,ctx); }
-#endif
-
-#ifdef ATALLA
- tried_atalla=0;
-#endif
-
- return(ret);
- }
-
-
-int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
- const BIGNUM *m, BN_CTX *ctx)
- {
- int i,j,bits,ret=0,wstart,wend,window,wvalue;
- int start=1,ts=0;
- BIGNUM *aa;
- BIGNUM val[TABLE_SIZE];
- BN_RECP_CTX recp;
-
- bits=BN_num_bits(p);
-
- if (bits == 0)
- {
- BN_one(r);
- return(1);
- }
-
- BN_CTX_start(ctx);
- if ((aa = BN_CTX_get(ctx)) == NULL) goto err;
-
- BN_RECP_CTX_init(&recp);
- if (BN_RECP_CTX_set(&recp,m,ctx) <= 0) goto err;
-
- BN_init(&(val[0]));
- ts=1;
-
- if (!BN_mod(&(val[0]),a,m,ctx)) goto err; /* 1 */
-
- window = BN_window_bits_for_exponent_size(bits);
- if (window > 1)
- {
- if (!BN_mod_mul_reciprocal(aa,&(val[0]),&(val[0]),&recp,ctx))
- goto err; /* 2 */
- j=1<<(window-1);
- for (i=1; i<j; i++)
- {
- BN_init(&val[i]);
- if (!BN_mod_mul_reciprocal(&(val[i]),&(val[i-1]),aa,&recp,ctx))
- goto err;
- }
- ts=i;
- }
-
- start=1; /* This is used to avoid multiplication etc
- * when there is only the value '1' in the
- * buffer. */
- wvalue=0; /* The 'value' of the window */
- wstart=bits-1; /* The top bit of the window */
- wend=0; /* The bottom bit of the window */
-
- if (!BN_one(r)) goto err;
-
- for (;;)
- {
- if (BN_is_bit_set(p,wstart) == 0)
- {
- if (!start)
- if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
- goto err;
- if (wstart == 0) break;
- wstart--;
- continue;
- }
- /* We now have wstart on a 'set' bit, we now need to work out
- * how bit a window to do. To do this we need to scan
- * forward until the last set bit before the end of the
- * window */
- j=wstart;
- wvalue=1;
- wend=0;
- for (i=1; i<window; i++)
- {
- if (wstart-i < 0) break;
- if (BN_is_bit_set(p,wstart-i))
- {
- wvalue<<=(i-wend);
- wvalue|=1;
- wend=i;
- }
- }
-
- /* wend is the size of the current window */
- j=wend+1;
- /* add the 'bytes above' */
- if (!start)
- for (i=0; i<j; i++)
- {
- if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
- goto err;
- }
-
- /* wvalue will be an odd number < 2^window */
- if (!BN_mod_mul_reciprocal(r,r,&(val[wvalue>>1]),&recp,ctx))
- goto err;
-
- /* move the 'window' down further */
- wstart-=wend+1;
- wvalue=0;
- start=0;
- if (wstart < 0) break;
- }
- ret=1;
-err:
- BN_CTX_end(ctx);
- for (i=0; i<ts; i++)
- BN_clear_free(&(val[i]));
- BN_RECP_CTX_free(&recp);
- return(ret);
- }
-
-
-int BN_mod_exp_mont(BIGNUM *rr, BIGNUM *a, const BIGNUM *p,
- const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
- {
- int i,j,bits,ret=0,wstart,wend,window,wvalue;
- int start=1,ts=0;
- BIGNUM *d,*r;
- BIGNUM *aa;
- BIGNUM val[TABLE_SIZE];
- BN_MONT_CTX *mont=NULL;
-
- bn_check_top(a);
- bn_check_top(p);
- bn_check_top(m);
-
-#ifdef ATALLA
- if(!tried_atalla && BN_mod_exp_atalla(rr,a,p,m))
- return 1;
-/* If it fails, try the other methods */
-#endif
-
- if (!(m->d[0] & 1))
- {
- BNerr(BN_F_BN_MOD_EXP_MONT,BN_R_CALLED_WITH_EVEN_MODULUS);
- return(0);
- }
- bits=BN_num_bits(p);
- if (bits == 0)
- {
- BN_one(rr);
- return(1);
- }
- BN_CTX_start(ctx);
- d = BN_CTX_get(ctx);
- r = BN_CTX_get(ctx);
- if (d == NULL || r == NULL) goto err;
-
- /* If this is not done, things will break in the montgomery
- * part */
-
- if (in_mont != NULL)
- mont=in_mont;
- else
- {
- if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
- if (!BN_MONT_CTX_set(mont,m,ctx)) goto err;
- }
-
- BN_init(&val[0]);
- ts=1;
- if (BN_ucmp(a,m) >= 0)
- {
- if (!BN_mod(&(val[0]),a,m,ctx))
- goto err;
- aa= &(val[0]);
- }
- else
- aa=a;
- if (!BN_to_montgomery(&(val[0]),aa,mont,ctx)) goto err; /* 1 */
-
- window = BN_window_bits_for_exponent_size(bits);
- if (window > 1)
- {
- if (!BN_mod_mul_montgomery(d,&(val[0]),&(val[0]),mont,ctx)) goto err; /* 2 */
- j=1<<(window-1);
- for (i=1; i<j; i++)
- {
- BN_init(&(val[i]));
- if (!BN_mod_mul_montgomery(&(val[i]),&(val[i-1]),d,mont,ctx))
- goto err;
- }
- ts=i;
- }
-
- start=1; /* This is used to avoid multiplication etc
- * when there is only the value '1' in the
- * buffer. */
- wvalue=0; /* The 'value' of the window */
- wstart=bits-1; /* The top bit of the window */
- wend=0; /* The bottom bit of the window */
-
- if (!BN_to_montgomery(r,BN_value_one(),mont,ctx)) goto err;
- for (;;)
- {
- if (BN_is_bit_set(p,wstart) == 0)
- {
- if (!start)
- {
- if (!BN_mod_mul_montgomery(r,r,r,mont,ctx))
- goto err;
- }
- if (wstart == 0) break;
- wstart--;
- continue;
- }
- /* We now have wstart on a 'set' bit, we now need to work out
- * how bit a window to do. To do this we need to scan
- * forward until the last set bit before the end of the
- * window */
- j=wstart;
- wvalue=1;
- wend=0;
- for (i=1; i<window; i++)
- {
- if (wstart-i < 0) break;
- if (BN_is_bit_set(p,wstart-i))
- {
- wvalue<<=(i-wend);
- wvalue|=1;
- wend=i;
- }
- }
-
- /* wend is the size of the current window */
- j=wend+1;
- /* add the 'bytes above' */
- if (!start)
- for (i=0; i<j; i++)
- {
- if (!BN_mod_mul_montgomery(r,r,r,mont,ctx))
- goto err;
- }
-
- /* wvalue will be an odd number < 2^window */
- if (!BN_mod_mul_montgomery(r,r,&(val[wvalue>>1]),mont,ctx))
- goto err;
-
- /* move the 'window' down further */
- wstart-=wend+1;
- wvalue=0;
- start=0;
- if (wstart < 0) break;
- }
- if (!BN_from_montgomery(rr,r,mont,ctx)) goto err;
- ret=1;
-err:
- if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
- BN_CTX_end(ctx);
- for (i=0; i<ts; i++)
- BN_clear_free(&(val[i]));
- return(ret);
- }
-
-int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p,
- const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
- {
- BN_MONT_CTX *mont = NULL;
- int b, bits, ret=0;
- int r_is_one;
- BN_ULONG w, next_w;
- BIGNUM *d, *r, *t;
- BIGNUM *swap_tmp;
-#define BN_MOD_MUL_WORD(r, w, m) \
- (BN_mul_word(r, (w)) && \
- (/* BN_ucmp(r, (m)) < 0 ? 1 :*/ \
- (BN_mod(t, r, m, ctx) && (swap_tmp = r, r = t, t = swap_tmp, 1))))
- /* BN_MOD_MUL_WORD is only used with 'w' large,
- * so the BN_ucmp test is probably more overhead
- * than always using BN_mod (which uses BN_copy if
- * a similar test returns true). */
-#define BN_TO_MONTGOMERY_WORD(r, w, mont) \
- (BN_set_word(r, (w)) && BN_to_montgomery(r, r, (mont), ctx))
-
- bn_check_top(p);
- bn_check_top(m);
-
- if (!(m->d[0] & 1))
- {
- BNerr(BN_F_BN_MOD_EXP_MONT_WORD,BN_R_CALLED_WITH_EVEN_MODULUS);
- return(0);
- }
- bits = BN_num_bits(p);
- if (bits == 0)
- {
- BN_one(rr);
- return(1);
- }
- BN_CTX_start(ctx);
- d = BN_CTX_get(ctx);
- r = BN_CTX_get(ctx);
- t = BN_CTX_get(ctx);
- if (d == NULL || r == NULL || t == NULL) goto err;
-
-#ifdef ATALLA
- if (!tried_atalla)
- {
- BN_set_word(t, a);
- if (BN_mod_exp_atalla(rr, t, p, m))
- {
- BN_CTX_end(ctx);
- return 1;
- }
- }
-/* If it fails, try the other methods */
-#endif
-
- if (in_mont != NULL)
- mont=in_mont;
- else
- {
- if ((mont = BN_MONT_CTX_new()) == NULL) goto err;
- if (!BN_MONT_CTX_set(mont, m, ctx)) goto err;
- }
-
- r_is_one = 1; /* except for Montgomery factor */
-
- /* bits-1 >= 0 */
-
- /* The result is accumulated in the product r*w. */
- w = a; /* bit 'bits-1' of 'p' is always set */
- for (b = bits-2; b >= 0; b--)
- {
- /* First, square r*w. */
- next_w = w*w;
- if ((next_w/w) != w) /* overflow */
- {
- if (r_is_one)
- {
- if (!BN_TO_MONTGOMERY_WORD(r, w, mont)) goto err;
- r_is_one = 0;
- }
- else
- {
- if (!BN_MOD_MUL_WORD(r, w, m)) goto err;
- }
- next_w = 1;
- }
- w = next_w;
- if (!r_is_one)
- {
- if (!BN_mod_mul_montgomery(r, r, r, mont, ctx)) goto err;
- }
-
- /* Second, multiply r*w by 'a' if exponent bit is set. */
- if (BN_is_bit_set(p, b))
- {
- next_w = w*a;
- if ((next_w/a) != w) /* overflow */
- {
- if (r_is_one)
- {
- if (!BN_TO_MONTGOMERY_WORD(r, w, mont)) goto err;
- r_is_one = 0;
- }
- else
- {
- if (!BN_MOD_MUL_WORD(r, w, m)) goto err;
- }
- next_w = a;
- }
- w = next_w;
- }
- }
-
- /* Finally, set r:=r*w. */
- if (w != 1)
- {
- if (r_is_one)
- {
- if (!BN_TO_MONTGOMERY_WORD(r, w, mont)) goto err;
- r_is_one = 0;
- }
- else
- {
- if (!BN_MOD_MUL_WORD(r, w, m)) goto err;
- }
- }
-
- if (r_is_one) /* can happen only if a == 1*/
- {
- if (!BN_one(rr)) goto err;
- }
- else
- {
- if (!BN_from_montgomery(rr, r, mont, ctx)) goto err;
- }
- ret = 1;
-err:
- if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
- BN_CTX_end(ctx);
- return(ret);
- }
-
-
-/* The old fallback, simple version :-) */
-int BN_mod_exp_simple(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m,
- BN_CTX *ctx)
- {
- int i,j,bits,ret=0,wstart,wend,window,wvalue,ts=0;
- int start=1;
- BIGNUM *d;
- BIGNUM val[TABLE_SIZE];
-
- bits=BN_num_bits(p);
-
- if (bits == 0)
- {
- BN_one(r);
- return(1);
- }
-
- BN_CTX_start(ctx);
- if ((d = BN_CTX_get(ctx)) == NULL) goto err;
-
- BN_init(&(val[0]));
- ts=1;
- if (!BN_mod(&(val[0]),a,m,ctx)) goto err; /* 1 */
-
- window = BN_window_bits_for_exponent_size(bits);
- if (window > 1)
- {
- if (!BN_mod_mul(d,&(val[0]),&(val[0]),m,ctx))
- goto err; /* 2 */
- j=1<<(window-1);
- for (i=1; i<j; i++)
- {
- BN_init(&(val[i]));
- if (!BN_mod_mul(&(val[i]),&(val[i-1]),d,m,ctx))
- goto err;
- }
- ts=i;
- }
-
- start=1; /* This is used to avoid multiplication etc
- * when there is only the value '1' in the
- * buffer. */
- wvalue=0; /* The 'value' of the window */
- wstart=bits-1; /* The top bit of the window */
- wend=0; /* The bottom bit of the window */
-
- if (!BN_one(r)) goto err;
-
- for (;;)
- {
- if (BN_is_bit_set(p,wstart) == 0)
- {
- if (!start)
- if (!BN_mod_mul(r,r,r,m,ctx))
- goto err;
- if (wstart == 0) break;
- wstart--;
- continue;
- }
- /* We now have wstart on a 'set' bit, we now need to work out
- * how bit a window to do. To do this we need to scan
- * forward until the last set bit before the end of the
- * window */
- j=wstart;
- wvalue=1;
- wend=0;
- for (i=1; i<window; i++)
- {
- if (wstart-i < 0) break;
- if (BN_is_bit_set(p,wstart-i))
- {
- wvalue<<=(i-wend);
- wvalue|=1;
- wend=i;
- }
- }
-
- /* wend is the size of the current window */
- j=wend+1;
- /* add the 'bytes above' */
- if (!start)
- for (i=0; i<j; i++)
- {
- if (!BN_mod_mul(r,r,r,m,ctx))
- goto err;
- }
-
- /* wvalue will be an odd number < 2^window */
- if (!BN_mod_mul(r,r,&(val[wvalue>>1]),m,ctx))
- goto err;
-
- /* move the 'window' down further */
- wstart-=wend+1;
- wvalue=0;
- start=0;
- if (wstart < 0) break;
- }
- ret=1;
-err:
- BN_CTX_end(ctx);
- for (i=0; i<ts; i++)
- BN_clear_free(&(val[i]));
- return(ret);
- }
-
projects / apple / security.git / blobdiff