1 /* crypto/bn/bn_lib.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.]
60 # undef NDEBUG /* avoid conflicting definitions */
69 const char *BN_version="Big Number" OPENSSL_VERSION_PTEXT;
71 /* For a 32 bit machine
80 static int bn_limit_bits=0;
81 static int bn_limit_num=8; /* (1<<bn_limit_bits) */
82 static int bn_limit_bits_low=0;
83 static int bn_limit_num_low=8; /* (1<<bn_limit_bits_low) */
84 static int bn_limit_bits_high=0;
85 static int bn_limit_num_high=8; /* (1<<bn_limit_bits_high) */
86 static int bn_limit_bits_mont=0;
87 static int bn_limit_num_mont=8; /* (1<<bn_limit_bits_mont) */
89 void BN_set_params(int mult, int high, int low, int mont)
93 if (mult > (sizeof(int)*8)-1)
100 if (high > (sizeof(int)*8)-1)
101 high=sizeof(int)*8-1;
102 bn_limit_bits_high=high;
103 bn_limit_num_high=1<<high;
107 if (low > (sizeof(int)*8)-1)
109 bn_limit_bits_low=low;
110 bn_limit_num_low=1<<low;
114 if (mont > (sizeof(int)*8)-1)
115 mont=sizeof(int)*8-1;
116 bn_limit_bits_mont=mont;
117 bn_limit_num_mont=1<<mont;
121 int BN_get_params(int which)
123 if (which == 0) return(bn_limit_bits);
124 else if (which == 1) return(bn_limit_bits_high);
125 else if (which == 2) return(bn_limit_bits_low);
126 else if (which == 3) return(bn_limit_bits_mont);
130 BIGNUM *BN_value_one(void)
132 static BN_ULONG data_one=1L;
133 static BIGNUM const_one={&data_one,1,1,0};
138 char *BN_options(void)
141 static char data[16];
147 sprintf(data,"bn(%d,%d)",(int)sizeof(BN_ULLONG)*8,
148 (int)sizeof(BN_ULONG)*8);
150 sprintf(data,"bn(%d,%d)",(int)sizeof(BN_ULONG)*8,
151 (int)sizeof(BN_ULONG)*8);
157 int BN_num_bits_word(BN_ULONG l)
159 static const char bits[256]={
160 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,
161 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
162 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
163 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
164 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
165 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
166 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
167 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
168 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
169 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
170 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
171 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
172 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
173 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
174 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
175 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
178 #if defined(SIXTY_FOUR_BIT_LONG)
179 if (l & 0xffffffff00000000L)
181 if (l & 0xffff000000000000L)
183 if (l & 0xff00000000000000L)
185 return(bits[(int)(l>>56)]+56);
187 else return(bits[(int)(l>>48)]+48);
191 if (l & 0x0000ff0000000000L)
193 return(bits[(int)(l>>40)]+40);
195 else return(bits[(int)(l>>32)]+32);
200 #ifdef SIXTY_FOUR_BIT
201 if (l & 0xffffffff00000000LL)
203 if (l & 0xffff000000000000LL)
205 if (l & 0xff00000000000000LL)
207 return(bits[(int)(l>>56)]+56);
209 else return(bits[(int)(l>>48)]+48);
213 if (l & 0x0000ff0000000000LL)
215 return(bits[(int)(l>>40)]+40);
217 else return(bits[(int)(l>>32)]+32);
224 #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
228 return(bits[(int)(l>>24L)]+24);
229 else return(bits[(int)(l>>16L)]+16);
234 #if defined(SIXTEEN_BIT) || defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
236 return(bits[(int)(l>>8)]+8);
239 return(bits[(int)(l )] );
244 int BN_num_bits(const BIGNUM *a)
251 if (a->top == 0) return(0);
254 i=(a->top-1)*BN_BITS2;
255 return(i+BN_num_bits_word(l));
258 void BN_clear_free(BIGNUM *a)
262 if (a == NULL) return;
265 memset(a->d,0,a->dmax*sizeof(a->d[0]));
266 if (!(BN_get_flags(a,BN_FLG_STATIC_DATA)))
269 i=BN_get_flags(a,BN_FLG_MALLOCED);
270 memset(a,0,sizeof(BIGNUM));
275 void BN_free(BIGNUM *a)
277 if (a == NULL) return;
278 if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))
280 a->flags|=BN_FLG_FREE; /* REMOVE? */
281 if (a->flags & BN_FLG_MALLOCED)
285 void BN_init(BIGNUM *a)
287 memset(a,0,sizeof(BIGNUM));
294 if ((ret=(BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL)
296 BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE);
299 ret->flags=BN_FLG_MALLOCED;
307 /* This is used both by bn_expand2() and bn_dup_expand() */
308 /* The caller MUST check that words > b->dmax before calling this */
309 static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
311 BN_ULONG *A,*a = NULL;
316 if (BN_get_flags(b,BN_FLG_STATIC_DATA))
318 BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
321 a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*(words+1));
324 BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE);
329 /* Check if the previous number needs to be copied */
332 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
335 * The fact that the loop is unrolled
336 * 4-wise is a tribute to Intel. It's
337 * the one that doesn't have enough
338 * registers to accomodate more data.
339 * I'd unroll it 8-wise otherwise:-)
341 * <appro@fy.chalmers.se>
343 BN_ULONG a0,a1,a2,a3;
344 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
345 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
352 case 0: /* workaround for ultrix cc: without 'case 0', the optimizer does
353 * the switch table by doing a=top&3; a--; goto jump_table[a];
354 * which fails for top== 0 */
359 /* Now need to zero any data between b->top and b->max */
362 for (i=(words - b->top)>>3; i>0; i--,A+=8)
364 A[0]=0; A[1]=0; A[2]=0; A[3]=0;
365 A[4]=0; A[5]=0; A[6]=0; A[7]=0;
367 for (i=(words - b->top)&7; i>0; i--,A++)
370 memset(A,0,sizeof(BN_ULONG)*(words+1));
371 memcpy(A,b->d,sizeof(b->d[0])*b->top);
377 /* This is an internal function that can be used instead of bn_expand2()
378 * when there is a need to copy BIGNUMs instead of only expanding the
379 * data part, while still expanding them.
380 * Especially useful when needing to expand BIGNUMs that are declared
381 * 'const' and should therefore not be changed.
382 * The reason to use this instead of a BN_dup() followed by a bn_expand2()
383 * is memory allocation overhead. A BN_dup() followed by a bn_expand2()
384 * will allocate new memory for the BIGNUM data twice, and free it once,
385 * while bn_dup_expand() makes sure allocation is made only once.
388 BIGNUM *bn_dup_expand(const BIGNUM *b, int words)
394 BN_ULONG *a = bn_expand_internal(b, words);
408 /* r == NULL, BN_new failure */
412 /* If a == NULL, there was an error in allocation in
413 bn_expand_internal(), and NULL should be returned */
423 /* This is an internal function that should not be used in applications.
424 * It ensures that 'b' has enough room for a 'words' word number number.
425 * It is mostly used by the various BIGNUM routines. If there is an error,
426 * NULL is returned. If not, 'b' is returned. */
428 BIGNUM *bn_expand2(BIGNUM *b, int words)
432 BN_ULONG *a = bn_expand_internal(b, words);
447 BIGNUM *BN_dup(const BIGNUM *a)
451 if (a == NULL) return NULL;
456 if (t == NULL) return(NULL);
458 /* now r == t || r == NULL */
464 BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
472 if (a == b) return(a);
473 if (bn_wexpand(a,b->top) == NULL) return(NULL);
478 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
480 BN_ULONG a0,a1,a2,a3;
481 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
482 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
489 case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */
492 memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
495 /* memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/
497 if ((a->top == 0) && (a->d != NULL))
503 void BN_swap(BIGNUM *a, BIGNUM *b)
505 int flags_old_a, flags_old_b;
507 int tmp_top, tmp_dmax, tmp_neg;
509 flags_old_a = a->flags;
510 flags_old_b = b->flags;
527 a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA);
528 b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA);
532 void BN_clear(BIGNUM *a)
535 memset(a->d,0,a->dmax*sizeof(a->d[0]));
540 BN_ULONG BN_get_word(const BIGNUM *a)
546 if (n > sizeof(BN_ULONG))
548 for (i=a->top-1; i>=0; i--)
550 #ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
551 ret<<=BN_BITS4; /* stops the compiler complaining */
561 int BN_set_word(BIGNUM *a, BN_ULONG w)
564 if (bn_expand(a,sizeof(BN_ULONG)*8) == NULL) return(0);
566 n=sizeof(BN_ULONG)/BN_BYTES;
569 a->d[0]=(BN_ULONG)w&BN_MASK2;
570 if (a->d[0] != 0) a->top=1;
573 /* the following is done instead of
574 * w>>=BN_BITS2 so compilers don't complain
575 * on builds where sizeof(long) == BN_TYPES */
576 #ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
582 a->d[i]=(BN_ULONG)w&BN_MASK2;
583 if (a->d[i] != 0) a->top=i+1;
588 BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret)
594 if (ret == NULL) ret=BN_new();
595 if (ret == NULL) return(NULL);
603 if (bn_expand(ret,(int)(n+2)*8) == NULL)
605 i=((n-1)/BN_BYTES)+1;
606 m=((n-1)%(BN_BYTES));
619 /* need to call this due to clear byte at top if avoiding
620 * having the top bit set (-ve number) */
625 /* ignore negative */
626 int BN_bn2bin(const BIGNUM *a, unsigned char *to)
635 *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff;
640 int BN_ucmp(const BIGNUM *a, const BIGNUM *b)
643 BN_ULONG t1,t2,*ap,*bp;
649 if (i != 0) return(i);
652 for (i=a->top-1; i>=0; i--)
657 return(t1 > t2?1:-1);
662 int BN_cmp(const BIGNUM *a, const BIGNUM *b)
668 if ((a == NULL) || (b == NULL))
681 if (a->neg != b->neg)
689 else { gt= -1; lt=1; }
691 if (a->top > b->top) return(gt);
692 if (a->top < b->top) return(lt);
693 for (i=a->top-1; i>=0; i--)
697 if (t1 > t2) return(gt);
698 if (t1 < t2) return(lt);
703 int BN_set_bit(BIGNUM *a, int n)
711 if (bn_wexpand(a,i+1) == NULL) return(0);
712 for(k=a->top; k<i+1; k++)
717 a->d[i]|=(((BN_ULONG)1)<<j);
721 int BN_clear_bit(BIGNUM *a, int n)
727 if (a->top <= i) return(0);
729 a->d[i]&=(~(((BN_ULONG)1)<<j));
734 int BN_is_bit_set(const BIGNUM *a, int n)
738 if (n < 0) return(0);
741 if (a->top <= i) return(0);
742 return((a->d[i]&(((BN_ULONG)1)<<j))?1:0);
745 int BN_mask_bits(BIGNUM *a, int n)
751 if (w >= a->top) return(0);
757 a->d[w]&= ~(BN_MASK2<<b);
763 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n)
770 if (aa != bb) return((aa > bb)?1:-1);
771 for (i=n-2; i>=0; i--)
775 if (aa != bb) return((aa > bb)?1:-1);