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;
315 if (words > (INT_MAX/(4*BN_BITS2)))
317 BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_TOO_LARGE);
322 if (BN_get_flags(b,BN_FLG_STATIC_DATA))
324 BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
327 a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*(words+1));
330 BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE);
335 /* Check if the previous number needs to be copied */
338 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
341 * The fact that the loop is unrolled
342 * 4-wise is a tribute to Intel. It's
343 * the one that doesn't have enough
344 * registers to accomodate more data.
345 * I'd unroll it 8-wise otherwise:-)
347 * <appro@fy.chalmers.se>
349 BN_ULONG a0,a1,a2,a3;
350 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
351 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
358 case 0: /* workaround for ultrix cc: without 'case 0', the optimizer does
359 * the switch table by doing a=top&3; a--; goto jump_table[a];
360 * which fails for top== 0 */
365 /* Now need to zero any data between b->top and b->max */
369 for (i=(words - b->top)>>3; i>0; i--,A+=8)
371 A[0]=0; A[1]=0; A[2]=0; A[3]=0;
372 A[4]=0; A[5]=0; A[6]=0; A[7]=0;
374 for (i=(words - b->top)&7; i>0; i--,A++)
377 memset(A,0,sizeof(BN_ULONG)*(words+1));
378 memcpy(A,b->d,sizeof(b->d[0])*b->top);
384 /* This is an internal function that can be used instead of bn_expand2()
385 * when there is a need to copy BIGNUMs instead of only expanding the
386 * data part, while still expanding them.
387 * Especially useful when needing to expand BIGNUMs that are declared
388 * 'const' and should therefore not be changed.
389 * The reason to use this instead of a BN_dup() followed by a bn_expand2()
390 * is memory allocation overhead. A BN_dup() followed by a bn_expand2()
391 * will allocate new memory for the BIGNUM data twice, and free it once,
392 * while bn_dup_expand() makes sure allocation is made only once.
395 BIGNUM *bn_dup_expand(const BIGNUM *b, int words)
401 BN_ULONG *a = bn_expand_internal(b, words);
415 /* r == NULL, BN_new failure */
419 /* If a == NULL, there was an error in allocation in
420 bn_expand_internal(), and NULL should be returned */
430 /* This is an internal function that should not be used in applications.
431 * It ensures that 'b' has enough room for a 'words' word number number.
432 * It is mostly used by the various BIGNUM routines. If there is an error,
433 * NULL is returned. If not, 'b' is returned. */
435 BIGNUM *bn_expand2(BIGNUM *b, int words)
439 BN_ULONG *a = bn_expand_internal(b, words);
454 BIGNUM *BN_dup(const BIGNUM *a)
458 if (a == NULL) return NULL;
463 if (t == NULL) return(NULL);
465 /* now r == t || r == NULL */
471 BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
479 if (a == b) return(a);
480 if (bn_wexpand(a,b->top) == NULL) return(NULL);
485 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
487 BN_ULONG a0,a1,a2,a3;
488 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
489 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
496 case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */
499 memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
502 /* memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/
504 if ((a->top == 0) && (a->d != NULL))
510 void BN_swap(BIGNUM *a, BIGNUM *b)
512 int flags_old_a, flags_old_b;
514 int tmp_top, tmp_dmax, tmp_neg;
516 flags_old_a = a->flags;
517 flags_old_b = b->flags;
534 a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA);
535 b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA);
539 void BN_clear(BIGNUM *a)
542 memset(a->d,0,a->dmax*sizeof(a->d[0]));
547 BN_ULONG BN_get_word(const BIGNUM *a)
553 if (n > sizeof(BN_ULONG))
555 for (i=a->top-1; i>=0; i--)
557 #ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
558 ret<<=BN_BITS4; /* stops the compiler complaining */
568 int BN_set_word(BIGNUM *a, BN_ULONG w)
571 if (bn_expand(a,sizeof(BN_ULONG)*8) == NULL) return(0);
573 n=sizeof(BN_ULONG)/BN_BYTES;
576 a->d[0]=(BN_ULONG)w&BN_MASK2;
577 if (a->d[0] != 0) a->top=1;
580 /* the following is done instead of
581 * w>>=BN_BITS2 so compilers don't complain
582 * on builds where sizeof(long) == BN_TYPES */
583 #ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
589 a->d[i]=(BN_ULONG)w&BN_MASK2;
590 if (a->d[i] != 0) a->top=i+1;
595 BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret)
601 if (ret == NULL) ret=BN_new();
602 if (ret == NULL) return(NULL);
610 if (bn_expand(ret,(int)(n+2)*8) == NULL)
612 i=((n-1)/BN_BYTES)+1;
613 m=((n-1)%(BN_BYTES));
626 /* need to call this due to clear byte at top if avoiding
627 * having the top bit set (-ve number) */
632 /* ignore negative */
633 int BN_bn2bin(const BIGNUM *a, unsigned char *to)
642 *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff;
647 int BN_ucmp(const BIGNUM *a, const BIGNUM *b)
650 BN_ULONG t1,t2,*ap,*bp;
656 if (i != 0) return(i);
659 for (i=a->top-1; i>=0; i--)
664 return(t1 > t2?1:-1);
669 int BN_cmp(const BIGNUM *a, const BIGNUM *b)
675 if ((a == NULL) || (b == NULL))
688 if (a->neg != b->neg)
696 else { gt= -1; lt=1; }
698 if (a->top > b->top) return(gt);
699 if (a->top < b->top) return(lt);
700 for (i=a->top-1; i>=0; i--)
704 if (t1 > t2) return(gt);
705 if (t1 < t2) return(lt);
710 int BN_set_bit(BIGNUM *a, int n)
718 if (bn_wexpand(a,i+1) == NULL) return(0);
719 for(k=a->top; k<i+1; k++)
724 a->d[i]|=(((BN_ULONG)1)<<j);
728 int BN_clear_bit(BIGNUM *a, int n)
734 if (a->top <= i) return(0);
736 a->d[i]&=(~(((BN_ULONG)1)<<j));
741 int BN_is_bit_set(const BIGNUM *a, int n)
745 if (n < 0) return(0);
748 if (a->top <= i) return(0);
749 return((a->d[i]&(((BN_ULONG)1)<<j))?1:0);
752 int BN_mask_bits(BIGNUM *a, int n)
758 if (w >= a->top) return(0);
764 a->d[w]&= ~(BN_MASK2<<b);
770 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n)
777 if (aa != bb) return((aa > bb)?1:-1);
778 for (i=n-2; i>=0; i--)
782 if (aa != bb) return((aa > bb)?1:-1);
787 /* Here follows a specialised variants of bn_cmp_words(). It has the
788 property of performing the operation on arrays of different sizes.
789 The sizes of those arrays is expressed through cl, which is the
790 common length ( basicall, min(len(a),len(b)) ), and dl, which is the
791 delta between the two lengths, calculated as len(a)-len(b).
792 All lengths are the number of BN_ULONGs... */
794 int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b,
805 return -1; /* a < b */
813 return 1; /* a > b */
816 return bn_cmp_words(a,b,cl);