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 */
64 #define OPENSSL_FIPSAPI
72 const char BN_version[]="Big Number" OPENSSL_VERSION_PTEXT;
74 /* This stuff appears to be completely unused, so is deprecated */
75 #ifndef OPENSSL_NO_DEPRECATED
76 /* For a 32 bit machine
85 static int bn_limit_bits=0;
86 static int bn_limit_num=8; /* (1<<bn_limit_bits) */
87 static int bn_limit_bits_low=0;
88 static int bn_limit_num_low=8; /* (1<<bn_limit_bits_low) */
89 static int bn_limit_bits_high=0;
90 static int bn_limit_num_high=8; /* (1<<bn_limit_bits_high) */
91 static int bn_limit_bits_mont=0;
92 static int bn_limit_num_mont=8; /* (1<<bn_limit_bits_mont) */
94 void BN_set_params(int mult, int high, int low, int mont)
98 if (mult > (int)(sizeof(int)*8)-1)
101 bn_limit_num=1<<mult;
105 if (high > (int)(sizeof(int)*8)-1)
106 high=sizeof(int)*8-1;
107 bn_limit_bits_high=high;
108 bn_limit_num_high=1<<high;
112 if (low > (int)(sizeof(int)*8)-1)
114 bn_limit_bits_low=low;
115 bn_limit_num_low=1<<low;
119 if (mont > (int)(sizeof(int)*8)-1)
120 mont=sizeof(int)*8-1;
121 bn_limit_bits_mont=mont;
122 bn_limit_num_mont=1<<mont;
126 int BN_get_params(int which)
128 if (which == 0) return(bn_limit_bits);
129 else if (which == 1) return(bn_limit_bits_high);
130 else if (which == 2) return(bn_limit_bits_low);
131 else if (which == 3) return(bn_limit_bits_mont);
136 const BIGNUM *BN_value_one(void)
138 static const BN_ULONG data_one=1L;
139 static const BIGNUM const_one={(BN_ULONG *)&data_one,1,1,0,BN_FLG_STATIC_DATA};
144 int BN_num_bits_word(BN_ULONG l)
146 static const unsigned char bits[256]={
147 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,
148 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
149 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
150 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
151 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
152 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
153 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
154 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
155 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
156 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
157 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
158 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
159 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
160 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
161 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
162 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
165 #if defined(SIXTY_FOUR_BIT_LONG)
166 if (l & 0xffffffff00000000L)
168 if (l & 0xffff000000000000L)
170 if (l & 0xff00000000000000L)
172 return(bits[(int)(l>>56)]+56);
174 else return(bits[(int)(l>>48)]+48);
178 if (l & 0x0000ff0000000000L)
180 return(bits[(int)(l>>40)]+40);
182 else return(bits[(int)(l>>32)]+32);
187 #ifdef SIXTY_FOUR_BIT
188 if (l & 0xffffffff00000000LL)
190 if (l & 0xffff000000000000LL)
192 if (l & 0xff00000000000000LL)
194 return(bits[(int)(l>>56)]+56);
196 else return(bits[(int)(l>>48)]+48);
200 if (l & 0x0000ff0000000000LL)
202 return(bits[(int)(l>>40)]+40);
204 else return(bits[(int)(l>>32)]+32);
211 #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
215 return(bits[(int)(l>>24L)]+24);
216 else return(bits[(int)(l>>16L)]+16);
221 #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
223 return(bits[(int)(l>>8)]+8);
226 return(bits[(int)(l )] );
231 int BN_num_bits(const BIGNUM *a)
236 if (BN_is_zero(a)) return 0;
237 return ((i*BN_BITS2) + BN_num_bits_word(a->d[i]));
240 void BN_clear_free(BIGNUM *a)
244 if (a == NULL) return;
248 OPENSSL_cleanse(a->d,a->dmax*sizeof(a->d[0]));
249 if (!(BN_get_flags(a,BN_FLG_STATIC_DATA)))
252 i=BN_get_flags(a,BN_FLG_MALLOCED);
253 OPENSSL_cleanse(a,sizeof(BIGNUM));
258 void BN_free(BIGNUM *a)
260 if (a == NULL) return;
262 if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))
264 if (a->flags & BN_FLG_MALLOCED)
268 #ifndef OPENSSL_NO_DEPRECATED
269 a->flags|=BN_FLG_FREE;
275 void BN_init(BIGNUM *a)
277 memset(a,0,sizeof(BIGNUM));
285 if ((ret=(BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL)
287 BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE);
290 ret->flags=BN_FLG_MALLOCED;
299 /* This is used both by bn_expand2() and bn_dup_expand() */
300 /* The caller MUST check that words > b->dmax before calling this */
301 static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
303 BN_ULONG *A,*a = NULL;
309 if (words > (INT_MAX/(4*BN_BITS2)))
311 BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_BIGNUM_TOO_LONG);
314 if (BN_get_flags(b,BN_FLG_STATIC_DATA))
316 BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
319 a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*words);
322 BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE);
327 /* Check if the previous number needs to be copied */
330 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
333 * The fact that the loop is unrolled
334 * 4-wise is a tribute to Intel. It's
335 * the one that doesn't have enough
336 * registers to accomodate more data.
337 * I'd unroll it 8-wise otherwise:-)
339 * <appro@fy.chalmers.se>
341 BN_ULONG a0,a1,a2,a3;
342 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
343 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
350 case 0: /* workaround for ultrix cc: without 'case 0', the optimizer does
351 * the switch table by doing a=top&3; a--; goto jump_table[a];
352 * which fails for top== 0 */
358 memset(A,0,sizeof(BN_ULONG)*words);
359 memcpy(A,b->d,sizeof(b->d[0])*b->top);
365 /* This is an internal function that can be used instead of bn_expand2()
366 * when there is a need to copy BIGNUMs instead of only expanding the
367 * data part, while still expanding them.
368 * Especially useful when needing to expand BIGNUMs that are declared
369 * 'const' and should therefore not be changed.
370 * The reason to use this instead of a BN_dup() followed by a bn_expand2()
371 * is memory allocation overhead. A BN_dup() followed by a bn_expand2()
372 * will allocate new memory for the BIGNUM data twice, and free it once,
373 * while bn_dup_expand() makes sure allocation is made only once.
376 #ifndef OPENSSL_NO_DEPRECATED
377 BIGNUM *bn_dup_expand(const BIGNUM *b, int words)
383 /* This function does not work if
384 * words <= b->dmax && top < words
385 * because BN_dup() does not preserve 'dmax'!
386 * (But bn_dup_expand() is not used anywhere yet.)
391 BN_ULONG *a = bn_expand_internal(b, words);
405 /* r == NULL, BN_new failure */
409 /* If a == NULL, there was an error in allocation in
410 bn_expand_internal(), and NULL should be returned */
422 /* This is an internal function that should not be used in applications.
423 * It ensures that 'b' has enough room for a 'words' word number
424 * and initialises any unused part of b->d with leading zeros.
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)
434 BN_ULONG *a = bn_expand_internal(b, words);
436 if(b->d) OPENSSL_free(b->d);
441 /* None of this should be necessary because of what b->top means! */
443 /* NB: bn_wexpand() calls this only if the BIGNUM really has to grow */
444 if (b->top < b->dmax)
447 BN_ULONG *A = &(b->d[b->top]);
448 for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8)
450 A[0]=0; A[1]=0; A[2]=0; A[3]=0;
451 A[4]=0; A[5]=0; A[6]=0; A[7]=0;
453 for (i=(b->dmax - b->top)&7; i>0; i--,A++)
455 assert(A == &(b->d[b->dmax]));
462 BIGNUM *BN_dup(const BIGNUM *a)
466 if (a == NULL) return NULL;
470 if (t == NULL) return NULL;
480 BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
488 if (a == b) return(a);
489 if (bn_wexpand(a,b->top) == NULL) return(NULL);
494 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
496 BN_ULONG a0,a1,a2,a3;
497 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
498 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
505 case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */
508 memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
517 void BN_swap(BIGNUM *a, BIGNUM *b)
519 int flags_old_a, flags_old_b;
521 int tmp_top, tmp_dmax, tmp_neg;
526 flags_old_a = a->flags;
527 flags_old_b = b->flags;
544 a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA);
545 b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA);
550 void BN_clear(BIGNUM *a)
554 memset(a->d,0,a->dmax*sizeof(a->d[0]));
559 BN_ULONG BN_get_word(const BIGNUM *a)
563 else if (a->top == 1)
569 int BN_set_word(BIGNUM *a, BN_ULONG w)
572 if (bn_expand(a,(int)sizeof(BN_ULONG)*8) == NULL) return(0);
575 a->top = (w ? 1 : 0);
580 BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret)
589 if (ret == NULL) return(NULL);
598 i=((n-1)/BN_BYTES)+1;
599 m=((n-1)%(BN_BYTES));
600 if (bn_wexpand(ret, (int)i) == NULL)
617 /* need to call this due to clear byte at top if avoiding
618 * having the top bit set (-ve number) */
623 /* ignore negative */
624 int BN_bn2bin(const BIGNUM *a, unsigned char *to)
634 *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff;
639 int BN_ucmp(const BIGNUM *a, const BIGNUM *b)
642 BN_ULONG t1,t2,*ap,*bp;
648 if (i != 0) return(i);
651 for (i=a->top-1; i>=0; i--)
656 return((t1 > t2) ? 1 : -1);
661 int BN_cmp(const BIGNUM *a, const BIGNUM *b)
667 if ((a == NULL) || (b == NULL))
680 if (a->neg != b->neg)
688 else { gt= -1; lt=1; }
690 if (a->top > b->top) return(gt);
691 if (a->top < b->top) return(lt);
692 for (i=a->top-1; i>=0; i--)
696 if (t1 > t2) return(gt);
697 if (t1 < t2) return(lt);
702 int BN_set_bit(BIGNUM *a, int n)
713 if (bn_wexpand(a,i+1) == NULL) return(0);
714 for(k=a->top; k<i+1; k++)
719 a->d[i]|=(((BN_ULONG)1)<<j);
724 int BN_clear_bit(BIGNUM *a, int n)
733 if (a->top <= i) return(0);
735 a->d[i]&=(~(((BN_ULONG)1)<<j));
740 int BN_is_bit_set(const BIGNUM *a, int n)
748 if (a->top <= i) return 0;
749 return (int)(((a->d[i])>>j)&((BN_ULONG)1));
752 int BN_mask_bits(BIGNUM *a, int n)
761 if (w >= a->top) return 0;
767 a->d[w]&= ~(BN_MASK2<<b);
773 void BN_set_negative(BIGNUM *a, int b)
775 if (b && !BN_is_zero(a))
781 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n)
788 if (aa != bb) return((aa > bb)?1:-1);
789 for (i=n-2; i>=0; i--)
793 if (aa != bb) return((aa > bb)?1:-1);
798 /* Here follows a specialised variants of bn_cmp_words(). It has the
799 property of performing the operation on arrays of different sizes.
800 The sizes of those arrays is expressed through cl, which is the
801 common length ( basicall, min(len(a),len(b)) ), and dl, which is the
802 delta between the two lengths, calculated as len(a)-len(b).
803 All lengths are the number of BN_ULONGs... */
805 int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b,
816 return -1; /* a < b */
824 return 1; /* a > b */
827 return bn_cmp_words(a,b,cl);