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 */
70 const char *BN_version="Big Number" OPENSSL_VERSION_PTEXT;
72 /* For a 32 bit machine
81 static int bn_limit_bits=0;
82 static int bn_limit_num=8; /* (1<<bn_limit_bits) */
83 static int bn_limit_bits_low=0;
84 static int bn_limit_num_low=8; /* (1<<bn_limit_bits_low) */
85 static int bn_limit_bits_high=0;
86 static int bn_limit_num_high=8; /* (1<<bn_limit_bits_high) */
87 static int bn_limit_bits_mont=0;
88 static int bn_limit_num_mont=8; /* (1<<bn_limit_bits_mont) */
90 void BN_set_params(int mult, int high, int low, int mont)
94 if (mult > (sizeof(int)*8)-1)
101 if (high > (sizeof(int)*8)-1)
102 high=sizeof(int)*8-1;
103 bn_limit_bits_high=high;
104 bn_limit_num_high=1<<high;
108 if (low > (sizeof(int)*8)-1)
110 bn_limit_bits_low=low;
111 bn_limit_num_low=1<<low;
115 if (mont > (sizeof(int)*8)-1)
116 mont=sizeof(int)*8-1;
117 bn_limit_bits_mont=mont;
118 bn_limit_num_mont=1<<mont;
122 int BN_get_params(int which)
124 if (which == 0) return(bn_limit_bits);
125 else if (which == 1) return(bn_limit_bits_high);
126 else if (which == 2) return(bn_limit_bits_low);
127 else if (which == 3) return(bn_limit_bits_mont);
131 const BIGNUM *BN_value_one(void)
133 static BN_ULONG data_one=1L;
134 static BIGNUM const_one={&data_one,1,1,0};
139 char *BN_options(void)
142 static char data[16];
148 sprintf(data,"bn(%d,%d)",(int)sizeof(BN_ULLONG)*8,
149 (int)sizeof(BN_ULONG)*8);
151 sprintf(data,"bn(%d,%d)",(int)sizeof(BN_ULONG)*8,
152 (int)sizeof(BN_ULONG)*8);
158 int BN_num_bits_word(BN_ULONG l)
160 static const char bits[256]={
161 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,
162 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
163 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
164 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
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 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
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,
176 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
179 #if defined(SIXTY_FOUR_BIT_LONG)
180 if (l & 0xffffffff00000000L)
182 if (l & 0xffff000000000000L)
184 if (l & 0xff00000000000000L)
186 return(bits[(int)(l>>56)]+56);
188 else return(bits[(int)(l>>48)]+48);
192 if (l & 0x0000ff0000000000L)
194 return(bits[(int)(l>>40)]+40);
196 else return(bits[(int)(l>>32)]+32);
201 #ifdef SIXTY_FOUR_BIT
202 if (l & 0xffffffff00000000LL)
204 if (l & 0xffff000000000000LL)
206 if (l & 0xff00000000000000LL)
208 return(bits[(int)(l>>56)]+56);
210 else return(bits[(int)(l>>48)]+48);
214 if (l & 0x0000ff0000000000LL)
216 return(bits[(int)(l>>40)]+40);
218 else return(bits[(int)(l>>32)]+32);
225 #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
229 return(bits[(int)(l>>24L)]+24);
230 else return(bits[(int)(l>>16L)]+16);
235 #if defined(SIXTEEN_BIT) || defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
237 return(bits[(int)(l>>8)]+8);
240 return(bits[(int)(l )] );
245 int BN_num_bits(const BIGNUM *a)
252 if (a->top == 0) return(0);
255 i=(a->top-1)*BN_BITS2;
256 return(i+BN_num_bits_word(l));
259 void BN_clear_free(BIGNUM *a)
263 if (a == NULL) return;
266 memset(a->d,0,a->dmax*sizeof(a->d[0]));
267 if (!(BN_get_flags(a,BN_FLG_STATIC_DATA)))
270 i=BN_get_flags(a,BN_FLG_MALLOCED);
271 memset(a,0,sizeof(BIGNUM));
276 void BN_free(BIGNUM *a)
278 if (a == NULL) return;
279 if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))
281 a->flags|=BN_FLG_FREE; /* REMOVE? */
282 if (a->flags & BN_FLG_MALLOCED)
286 void BN_init(BIGNUM *a)
288 memset(a,0,sizeof(BIGNUM));
295 if ((ret=(BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL)
297 BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE);
300 ret->flags=BN_FLG_MALLOCED;
308 /* This is used both by bn_expand2() and bn_dup_expand() */
309 /* The caller MUST check that words > b->dmax before calling this */
310 static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
312 BN_ULONG *A,*a = NULL;
316 if (words > (INT_MAX/(4*BN_BITS2)))
318 BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_BIGNUM_TOO_LONG);
323 if (BN_get_flags(b,BN_FLG_STATIC_DATA))
325 BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
328 a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*(words+1));
331 BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE);
336 /* Check if the previous number needs to be copied */
339 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
342 * The fact that the loop is unrolled
343 * 4-wise is a tribute to Intel. It's
344 * the one that doesn't have enough
345 * registers to accomodate more data.
346 * I'd unroll it 8-wise otherwise:-)
348 * <appro@fy.chalmers.se>
350 BN_ULONG a0,a1,a2,a3;
351 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
352 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
359 case 0: /* workaround for ultrix cc: without 'case 0', the optimizer does
360 * the switch table by doing a=top&3; a--; goto jump_table[a];
361 * which fails for top== 0 */
367 memset(A,0,sizeof(BN_ULONG)*(words+1));
368 memcpy(A,b->d,sizeof(b->d[0])*b->top);
374 /* This is an internal function that can be used instead of bn_expand2()
375 * when there is a need to copy BIGNUMs instead of only expanding the
376 * data part, while still expanding them.
377 * Especially useful when needing to expand BIGNUMs that are declared
378 * 'const' and should therefore not be changed.
379 * The reason to use this instead of a BN_dup() followed by a bn_expand2()
380 * is memory allocation overhead. A BN_dup() followed by a bn_expand2()
381 * will allocate new memory for the BIGNUM data twice, and free it once,
382 * while bn_dup_expand() makes sure allocation is made only once.
385 BIGNUM *bn_dup_expand(const BIGNUM *b, int words)
389 /* This function does not work if
390 * words <= b->dmax && top < words
391 * because BN_dup() does not preserve 'dmax'!
392 * (But bn_dup_expand() is not used anywhere yet.)
397 BN_ULONG *a = bn_expand_internal(b, words);
411 /* r == NULL, BN_new failure */
415 /* If a == NULL, there was an error in allocation in
416 bn_expand_internal(), and NULL should be returned */
426 /* This is an internal function that should not be used in applications.
427 * It ensures that 'b' has enough room for a 'words' word number
428 * and initialises any unused part of b->d with leading zeros.
429 * It is mostly used by the various BIGNUM routines. If there is an error,
430 * NULL is returned. If not, 'b' is returned. */
432 BIGNUM *bn_expand2(BIGNUM *b, int words)
439 BN_ULONG *a = bn_expand_internal(b, words);
452 /* NB: bn_wexpand() calls this only if the BIGNUM really has to grow */
453 if ((b != NULL) && (b->top < b->dmax))
456 for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8)
458 A[0]=0; A[1]=0; A[2]=0; A[3]=0;
459 A[4]=0; A[5]=0; A[6]=0; A[7]=0;
461 for (i=(b->dmax - b->top)&7; i>0; i--,A++)
463 assert(A == &(b->d[b->dmax]));
469 BIGNUM *BN_dup(const BIGNUM *a)
473 if (a == NULL) return NULL;
478 if (t == NULL) return(NULL);
480 /* now r == t || r == NULL */
486 BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
494 if (a == b) return(a);
495 if (bn_wexpand(a,b->top) == NULL) return(NULL);
500 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
502 BN_ULONG a0,a1,a2,a3;
503 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
504 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
511 case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */
514 memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
517 /* memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/
519 if ((a->top == 0) && (a->d != NULL))
525 void BN_swap(BIGNUM *a, BIGNUM *b)
527 int flags_old_a, flags_old_b;
529 int tmp_top, tmp_dmax, tmp_neg;
531 flags_old_a = a->flags;
532 flags_old_b = b->flags;
549 a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA);
550 b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA);
554 void BN_clear(BIGNUM *a)
557 memset(a->d,0,a->dmax*sizeof(a->d[0]));
562 BN_ULONG BN_get_word(const BIGNUM *a)
568 if (n > sizeof(BN_ULONG))
570 for (i=a->top-1; i>=0; i--)
572 #ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
573 ret<<=BN_BITS4; /* stops the compiler complaining */
583 int BN_set_word(BIGNUM *a, BN_ULONG w)
586 if (bn_expand(a,sizeof(BN_ULONG)*8) == NULL) return(0);
588 n=sizeof(BN_ULONG)/BN_BYTES;
591 a->d[0]=(BN_ULONG)w&BN_MASK2;
592 if (a->d[0] != 0) a->top=1;
595 /* the following is done instead of
596 * w>>=BN_BITS2 so compilers don't complain
597 * on builds where sizeof(long) == BN_TYPES */
598 #ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
604 a->d[i]=(BN_ULONG)w&BN_MASK2;
605 if (a->d[i] != 0) a->top=i+1;
610 BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret)
616 if (ret == NULL) ret=BN_new();
617 if (ret == NULL) return(NULL);
625 if (bn_expand(ret,(int)(n+2)*8) == NULL)
627 i=((n-1)/BN_BYTES)+1;
628 m=((n-1)%(BN_BYTES));
641 /* need to call this due to clear byte at top if avoiding
642 * having the top bit set (-ve number) */
647 /* ignore negative */
648 int BN_bn2bin(const BIGNUM *a, unsigned char *to)
657 *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff;
662 int BN_ucmp(const BIGNUM *a, const BIGNUM *b)
665 BN_ULONG t1,t2,*ap,*bp;
671 if (i != 0) return(i);
674 for (i=a->top-1; i>=0; i--)
679 return(t1 > t2?1:-1);
684 int BN_cmp(const BIGNUM *a, const BIGNUM *b)
690 if ((a == NULL) || (b == NULL))
703 if (a->neg != b->neg)
711 else { gt= -1; lt=1; }
713 if (a->top > b->top) return(gt);
714 if (a->top < b->top) return(lt);
715 for (i=a->top-1; i>=0; i--)
719 if (t1 > t2) return(gt);
720 if (t1 < t2) return(lt);
725 int BN_set_bit(BIGNUM *a, int n)
733 if (bn_wexpand(a,i+1) == NULL) return(0);
734 for(k=a->top; k<i+1; k++)
739 a->d[i]|=(((BN_ULONG)1)<<j);
743 int BN_clear_bit(BIGNUM *a, int n)
749 if (a->top <= i) return(0);
751 a->d[i]&=(~(((BN_ULONG)1)<<j));
756 int BN_is_bit_set(const BIGNUM *a, int n)
760 if (n < 0) return(0);
763 if (a->top <= i) return(0);
764 return((a->d[i]&(((BN_ULONG)1)<<j))?1:0);
767 int BN_mask_bits(BIGNUM *a, int n)
773 if (w >= a->top) return(0);
779 a->d[w]&= ~(BN_MASK2<<b);
785 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n)
792 if (aa != bb) return((aa > bb)?1:-1);
793 for (i=n-2; i>=0; i--)
797 if (aa != bb) return((aa > bb)?1:-1);
802 /* Here follows a specialised variants of bn_cmp_words(). It has the
803 property of performing the operation on arrays of different sizes.
804 The sizes of those arrays is expressed through cl, which is the
805 common length ( basicall, min(len(a),len(b)) ), and dl, which is the
806 delta between the two lengths, calculated as len(a)-len(b).
807 All lengths are the number of BN_ULONGs... */
809 int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b,
820 return -1; /* a < b */
828 return 1; /* a > b */
831 return bn_cmp_words(a,b,cl);