1 /* crypto/bn/bn_exp.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
73 int BN_mod_mul(BIGNUM *ret, BIGNUM *a, BIGNUM *b, const BIGNUM *m, BN_CTX *ctx)
83 if ((t = BN_CTX_get(ctx)) == NULL) goto err;
85 { if (!BN_sqr(t,a,ctx)) goto err; }
87 { if (!BN_mul(t,a,b,ctx)) goto err; }
88 if (!BN_mod(ret,t,m,ctx)) goto err;
96 /* this one works - simple but works */
97 int BN_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx)
103 if ((r == a) || (r == p))
104 rr = BN_CTX_get(ctx);
107 if ((v = BN_CTX_get(ctx)) == NULL) goto err;
109 if (BN_copy(v,a) == NULL) goto err;
113 { if (BN_copy(rr,a) == NULL) goto err; }
114 else { if (!BN_one(rr)) goto err; }
116 for (i=1; i<bits; i++)
118 if (!BN_sqr(v,v,ctx)) goto err;
119 if (BN_is_bit_set(p,i))
121 if (!BN_mul(rr,rr,v,ctx)) goto err;
126 if (r != rr) BN_copy(r,rr);
135 * This routine will dynamically check for the existance of an Atalla AXL-200
136 * SSL accelerator module. If one is found, the variable
137 * asi_accelerator_present is set to 1 and the function pointers
138 * ptr_ASI_xxxxxx above will be initialized to corresponding ASI API calls.
140 typedef int tfnASI_GetPerformanceStatistics(int reset_flag,
141 unsigned int *ret_buf);
142 typedef int tfnASI_GetHardwareConfig(long card_num, unsigned int *ret_buf);
143 typedef int tfnASI_RSAPrivateKeyOpFn(RSAPrivateKey * rsaKey,
144 unsigned char *output,
145 unsigned char *input,
146 unsigned int modulus_len);
148 static tfnASI_GetHardwareConfig *ptr_ASI_GetHardwareConfig;
149 static tfnASI_RSAPrivateKeyOpFn *ptr_ASI_RSAPrivateKeyOpFn;
150 static tfnASI_GetPerformanceStatistics *ptr_ASI_GetPerformanceStatistics;
151 static int asi_accelerator_present;
152 static int tried_atalla;
154 void atalla_initialize_accelerator_handle(void)
158 unsigned int config_buf[1024];
166 bzero((void *)config_buf, 1024);
169 * Check to see if the library is present on the system
171 dl_handle = dlopen("atasi.so", RTLD_NOW);
172 if (dl_handle == (void *) NULL)
174 /* printf("atasi.so library is not present on the system\n");
175 printf("No HW acceleration available\n");*/
180 * The library is present. Now we'll check to insure that the
181 * LDM is up and running. First we'll get the address of the
182 * function in the atasi library that we need to see if the
186 ptr_ASI_GetHardwareConfig =
187 (tfnASI_GetHardwareConfig *)dlsym(dl_handle,"ASI_GetHardwareConfig");
189 if (ptr_ASI_GetHardwareConfig)
192 * We found the call, now we'll get our config
193 * status. If we get a non 0 result, the LDM is not
194 * running and we cannot use the Atalla ASI *
197 status = (*ptr_ASI_GetHardwareConfig)(0L, config_buf);
200 printf("atasi.so library is present but not initialized\n");
201 printf("No HW acceleration available\n");
207 /* printf("We found the library, but not the function. Very Strange!\n");*/
212 * It looks like we have acceleration capabilities. Load up the
213 * pointers to our ASI API calls.
215 ptr_ASI_RSAPrivateKeyOpFn=
216 (tfnASI_RSAPrivateKeyOpFn *)dlsym(dl_handle, "ASI_RSAPrivateKeyOpFn");
217 if (ptr_ASI_RSAPrivateKeyOpFn == NULL)
219 /* printf("We found the library, but no RSA function. Very Strange!\n");*/
223 ptr_ASI_GetPerformanceStatistics =
224 (tfnASI_GetPerformanceStatistics *)dlsym(dl_handle, "ASI_GetPerformanceStatistics");
225 if (ptr_ASI_GetPerformanceStatistics == NULL)
227 /* printf("We found the library, but no stat function. Very Strange!\n");*/
232 * Indicate that acceleration is available
234 asi_accelerator_present = 1;
236 /* printf("This system has acceleration!\n");*/
241 /* make sure this only gets called once when bn_mod_exp calls bn_mod_exp_mont */
242 int BN_mod_exp_atalla(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m)
249 RSAPrivateKey keydata;
251 atalla_initialize_accelerator_handle();
252 if(!asi_accelerator_present)
256 /* We should be able to run without size testing */
262 if(an <= ASIZE && pn <= ASIZE && mn <= ASIZE)
268 memset(abin,'\0',mn);
269 BN_bn2bin(a,abin+size-an);
275 memset(mbin,'\0',mn);
276 BN_bn2bin(m,mbin+size-mn);
280 memset(&keydata,'\0',sizeof keydata);
281 keydata.privateExponent.data=pbin;
282 keydata.privateExponent.len=pn;
283 keydata.modulus.data=mbin;
284 keydata.modulus.len=size;
286 ret=(*ptr_ASI_RSAPrivateKeyOpFn)(&keydata,rbin,abin,keydata.modulus.len);
287 /*fprintf(stderr,"!%s\n",BN_bn2hex(a));*/
290 BN_bin2bn(rbin,keydata.modulus.len,r);
291 /*fprintf(stderr,"?%s\n",BN_bn2hex(r));*/
297 #endif /* def ATALLA */
300 int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
310 if(BN_mod_exp_atalla(r,a,p,m))
312 /* If it fails, try the other methods (but don't try atalla again) */
317 /* I have finally been able to take out this pre-condition of
318 * the top bit being set. It was caused by an error in BN_div
319 * with negatives. There was also another problem when for a^b%m
320 * a >= m. eay 07-May-97 */
321 /* if ((m->d[m->top-1]&BN_TBIT) && BN_is_odd(m)) */
327 BN_ULONG A = a->d[0];
328 ret=BN_mod_exp_mont_word(r,A,p,m,ctx,NULL);
331 ret=BN_mod_exp_mont(r,a,p,m,ctx,NULL);
336 { ret=BN_mod_exp_recp(r,a,p,m,ctx); }
338 { ret=BN_mod_exp_simple(r,a,p,m,ctx); }
349 int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
350 const BIGNUM *m, BN_CTX *ctx)
352 int i,j,bits,ret=0,wstart,wend,window,wvalue;
355 BIGNUM val[TABLE_SIZE];
367 if ((aa = BN_CTX_get(ctx)) == NULL) goto err;
369 BN_RECP_CTX_init(&recp);
370 if (BN_RECP_CTX_set(&recp,m,ctx) <= 0) goto err;
375 if (!BN_mod(&(val[0]),a,m,ctx)) goto err; /* 1 */
376 if (!BN_mod_mul_reciprocal(aa,&(val[0]),&(val[0]),&recp,ctx))
379 if (bits <= 17) /* This is probably 3 or 0x10001, so just do singles */
381 else if (bits >= 256)
382 window=5; /* max size of window */
383 else if (bits >= 128)
392 if (!BN_mod_mul_reciprocal(&(val[i]),&(val[i-1]),aa,&recp,ctx))
397 start=1; /* This is used to avoid multiplication etc
398 * when there is only the value '1' in the
400 wvalue=0; /* The 'value' of the window */
401 wstart=bits-1; /* The top bit of the window */
402 wend=0; /* The bottom bit of the window */
404 if (!BN_one(r)) goto err;
408 if (BN_is_bit_set(p,wstart) == 0)
411 if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
413 if (wstart == 0) break;
417 /* We now have wstart on a 'set' bit, we now need to work out
418 * how bit a window to do. To do this we need to scan
419 * forward until the last set bit before the end of the
424 for (i=1; i<window; i++)
426 if (wstart-i < 0) break;
427 if (BN_is_bit_set(p,wstart-i))
435 /* wend is the size of the current window */
437 /* add the 'bytes above' */
441 if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
445 /* wvalue will be an odd number < 2^window */
446 if (!BN_mod_mul_reciprocal(r,r,&(val[wvalue>>1]),&recp,ctx))
449 /* move the 'window' down further */
453 if (wstart < 0) break;
459 BN_clear_free(&(val[i]));
460 BN_RECP_CTX_free(&recp);
465 int BN_mod_exp_mont(BIGNUM *rr, BIGNUM *a, const BIGNUM *p,
466 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
468 int i,j,bits,ret=0,wstart,wend,window,wvalue;
472 BIGNUM val[TABLE_SIZE];
473 BN_MONT_CTX *mont=NULL;
480 if(!tried_atalla && BN_mod_exp_atalla(rr,a,p,m))
482 /* If it fails, try the other methods */
487 BNerr(BN_F_BN_MOD_EXP_MONT,BN_R_CALLED_WITH_EVEN_MODULUS);
499 if (d == NULL || r == NULL) goto err;
501 /* If this is not done, things will break in the montgomery
508 if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
509 if (!BN_MONT_CTX_set(mont,m,ctx)) goto err;
514 if (BN_ucmp(a,m) >= 0)
516 if (!BN_mod(&(val[0]),a,m,ctx))
522 if (!BN_to_montgomery(&(val[0]),aa,mont,ctx)) goto err; /* 1 */
523 if (!BN_mod_mul_montgomery(d,&(val[0]),&(val[0]),mont,ctx)) goto err; /* 2 */
525 if (bits <= 20) /* This is probably 3 or 0x10001, so just do singles */
527 else if (bits >= 256)
528 window=5; /* max size of window */
529 else if (bits >= 128)
538 if (!BN_mod_mul_montgomery(&(val[i]),&(val[i-1]),d,mont,ctx))
543 start=1; /* This is used to avoid multiplication etc
544 * when there is only the value '1' in the
546 wvalue=0; /* The 'value' of the window */
547 wstart=bits-1; /* The top bit of the window */
548 wend=0; /* The bottom bit of the window */
550 if (!BN_to_montgomery(r,BN_value_one(),mont,ctx)) goto err;
553 if (BN_is_bit_set(p,wstart) == 0)
557 if (!BN_mod_mul_montgomery(r,r,r,mont,ctx))
560 if (wstart == 0) break;
564 /* We now have wstart on a 'set' bit, we now need to work out
565 * how bit a window to do. To do this we need to scan
566 * forward until the last set bit before the end of the
571 for (i=1; i<window; i++)
573 if (wstart-i < 0) break;
574 if (BN_is_bit_set(p,wstart-i))
582 /* wend is the size of the current window */
584 /* add the 'bytes above' */
588 if (!BN_mod_mul_montgomery(r,r,r,mont,ctx))
592 /* wvalue will be an odd number < 2^window */
593 if (!BN_mod_mul_montgomery(r,r,&(val[wvalue>>1]),mont,ctx))
596 /* move the 'window' down further */
600 if (wstart < 0) break;
602 BN_from_montgomery(rr,r,mont,ctx);
605 if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
608 BN_clear_free(&(val[i]));
612 int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p,
613 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
614 /* if we had BN_mod_exp_mont_2, we could even use windowing in it */
618 BN_MONT_CTX *mont = NULL;
625 BNerr(BN_F_BN_MOD_EXP_MONT_WORD,BN_R_CALLED_WITH_EVEN_MODULUS);
628 bits = BN_num_bits(p);
638 if (d == NULL || r == NULL || t == NULL) goto err;
644 if (BN_mod_exp_word_atalla(rr, t, p, m))
647 /* If it fails, try the other methods */
654 if ((mont = BN_MONT_CTX_new()) == NULL) goto err;
655 if (!BN_MONT_CTX_set(mont, m, ctx)) goto err;
658 if (!BN_to_montgomery(r, BN_value_one(), mont, ctx)) goto err;
659 for (b = bits-1; b >= 0; b--)
661 if (BN_is_bit_set(p, b))
663 if (!BN_mul_word(r, a))
665 if (BN_ucmp(r, m) >= 0)
667 if (!BN_mod(t, r, m, ctx))
669 { BIGNUM *swap_tmp = r; r = t; t = swap_tmp; }
675 if (!BN_mod_mul_montgomery(r, r, r, mont, ctx))
679 BN_from_montgomery(rr, r, mont, ctx);
682 if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
688 /* The old fallback, simple version :-) */
689 int BN_mod_exp_simple(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m,
692 int i,j,bits,ret=0,wstart,wend,window,wvalue,ts=0;
695 BIGNUM val[TABLE_SIZE];
706 if ((d = BN_CTX_get(ctx)) == NULL) goto err;
710 if (!BN_mod(&(val[0]),a,m,ctx)) goto err; /* 1 */
711 if (!BN_mod_mul(d,&(val[0]),&(val[0]),m,ctx))
714 if (bits <= 17) /* This is probably 3 or 0x10001, so just do singles */
716 else if (bits >= 256)
717 window=5; /* max size of window */
718 else if (bits >= 128)
727 if (!BN_mod_mul(&(val[i]),&(val[i-1]),d,m,ctx))
732 start=1; /* This is used to avoid multiplication etc
733 * when there is only the value '1' in the
735 wvalue=0; /* The 'value' of the window */
736 wstart=bits-1; /* The top bit of the window */
737 wend=0; /* The bottom bit of the window */
739 if (!BN_one(r)) goto err;
743 if (BN_is_bit_set(p,wstart) == 0)
746 if (!BN_mod_mul(r,r,r,m,ctx))
748 if (wstart == 0) break;
752 /* We now have wstart on a 'set' bit, we now need to work out
753 * how bit a window to do. To do this we need to scan
754 * forward until the last set bit before the end of the
759 for (i=1; i<window; i++)
761 if (wstart-i < 0) break;
762 if (BN_is_bit_set(p,wstart-i))
770 /* wend is the size of the current window */
772 /* add the 'bytes above' */
776 if (!BN_mod_mul(r,r,r,m,ctx))
780 /* wvalue will be an odd number < 2^window */
781 if (!BN_mod_mul(r,r,&(val[wvalue>>1]),m,ctx))
784 /* move the 'window' down further */
788 if (wstart < 0) break;
794 BN_clear_free(&(val[i]));