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
73 const char BN_version[]="Big Number" OPENSSL_VERSION_PTEXT;
75 /* This stuff appears to be completely unused, so is deprecated */
76 #ifndef OPENSSL_NO_DEPRECATED
77 /* For a 32 bit machine
86 static int bn_limit_bits=0;
87 static int bn_limit_num=8; /* (1<<bn_limit_bits) */
88 static int bn_limit_bits_low=0;
89 static int bn_limit_num_low=8; /* (1<<bn_limit_bits_low) */
90 static int bn_limit_bits_high=0;
91 static int bn_limit_num_high=8; /* (1<<bn_limit_bits_high) */
92 static int bn_limit_bits_mont=0;
93 static int bn_limit_num_mont=8; /* (1<<bn_limit_bits_mont) */
95 void BN_set_params(int mult, int high, int low, int mont)
99 if (mult > (int)(sizeof(int)*8)-1)
100 mult=sizeof(int)*8-1;
102 bn_limit_num=1<<mult;
106 if (high > (int)(sizeof(int)*8)-1)
107 high=sizeof(int)*8-1;
108 bn_limit_bits_high=high;
109 bn_limit_num_high=1<<high;
113 if (low > (int)(sizeof(int)*8)-1)
115 bn_limit_bits_low=low;
116 bn_limit_num_low=1<<low;
120 if (mont > (int)(sizeof(int)*8)-1)
121 mont=sizeof(int)*8-1;
122 bn_limit_bits_mont=mont;
123 bn_limit_num_mont=1<<mont;
127 int BN_get_params(int which)
129 if (which == 0) return(bn_limit_bits);
130 else if (which == 1) return(bn_limit_bits_high);
131 else if (which == 2) return(bn_limit_bits_low);
132 else if (which == 3) return(bn_limit_bits_mont);
137 const BIGNUM *BN_value_one(void)
139 static const BN_ULONG data_one=1L;
140 static const BIGNUM const_one={(BN_ULONG *)&data_one,1,1,0,BN_FLG_STATIC_DATA};
145 int BN_num_bits_word(BN_ULONG l)
148 static const unsigned char bits[256]={
149 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,
150 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
151 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
152 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
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 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
156 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
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,
163 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
164 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
167 #if defined(SIXTY_FOUR_BIT_LONG)
168 if (l & 0xffffffff00000000L)
170 if (l & 0xffff000000000000L)
172 if (l & 0xff00000000000000L)
174 return(bits[(int)(l>>56)]+56);
176 else return(bits[(int)(l>>48)]+48);
180 if (l & 0x0000ff0000000000L)
182 return(bits[(int)(l>>40)]+40);
184 else return(bits[(int)(l>>32)]+32);
189 #ifdef SIXTY_FOUR_BIT
190 if (l & 0xffffffff00000000LL)
192 if (l & 0xffff000000000000LL)
194 if (l & 0xff00000000000000LL)
196 return(bits[(int)(l>>56)]+56);
198 else return(bits[(int)(l>>48)]+48);
202 if (l & 0x0000ff0000000000LL)
204 return(bits[(int)(l>>40)]+40);
206 else return(bits[(int)(l>>32)]+32);
213 #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
217 return(bits[(int)(l>>24L)]+24);
218 else return(bits[(int)(l>>16L)]+16);
223 #if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
225 return(bits[(int)(l>>8)]+8);
228 return(bits[(int)(l )] );
233 int BN_num_bits(const BIGNUM *a)
238 if (BN_is_zero(a)) return 0;
239 return ((i*BN_BITS2) + BN_num_bits_word(a->d[i]));
242 void BN_clear_free(BIGNUM *a)
246 if (a == NULL) return;
250 OPENSSL_cleanse(a->d,a->dmax*sizeof(a->d[0]));
251 if (!(BN_get_flags(a,BN_FLG_STATIC_DATA)))
254 i=BN_get_flags(a,BN_FLG_MALLOCED);
255 OPENSSL_cleanse(a,sizeof(BIGNUM));
260 void BN_free(BIGNUM *a)
262 if (a == NULL) return;
264 if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))
266 if (a->flags & BN_FLG_MALLOCED)
270 #ifndef OPENSSL_NO_DEPRECATED
271 a->flags|=BN_FLG_FREE;
277 void BN_init(BIGNUM *a)
279 memset(a,0,sizeof(BIGNUM));
287 if ((ret=(BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL)
289 BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE);
292 ret->flags=BN_FLG_MALLOCED;
301 /* This is used both by bn_expand2() and bn_dup_expand() */
302 /* The caller MUST check that words > b->dmax before calling this */
303 static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
305 BN_ULONG *A,*a = NULL;
311 if (words > (INT_MAX/(4*BN_BITS2)))
313 BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_BIGNUM_TOO_LONG);
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);
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 */
360 memset(A,0,sizeof(BN_ULONG)*words);
361 memcpy(A,b->d,sizeof(b->d[0])*b->top);
367 /* This is an internal function that can be used instead of bn_expand2()
368 * when there is a need to copy BIGNUMs instead of only expanding the
369 * data part, while still expanding them.
370 * Especially useful when needing to expand BIGNUMs that are declared
371 * 'const' and should therefore not be changed.
372 * The reason to use this instead of a BN_dup() followed by a bn_expand2()
373 * is memory allocation overhead. A BN_dup() followed by a bn_expand2()
374 * will allocate new memory for the BIGNUM data twice, and free it once,
375 * while bn_dup_expand() makes sure allocation is made only once.
378 #ifndef OPENSSL_NO_DEPRECATED
379 BIGNUM *bn_dup_expand(const BIGNUM *b, int words)
385 /* This function does not work if
386 * words <= b->dmax && top < words
387 * because BN_dup() does not preserve 'dmax'!
388 * (But bn_dup_expand() is not used anywhere yet.)
393 BN_ULONG *a = bn_expand_internal(b, words);
407 /* r == NULL, BN_new failure */
411 /* If a == NULL, there was an error in allocation in
412 bn_expand_internal(), and NULL should be returned */
424 /* This is an internal function that should not be used in applications.
425 * It ensures that 'b' has enough room for a 'words' word number
426 * and initialises any unused part of b->d with leading zeros.
427 * It is mostly used by the various BIGNUM routines. If there is an error,
428 * NULL is returned. If not, 'b' is returned. */
430 BIGNUM *bn_expand2(BIGNUM *b, int words)
436 BN_ULONG *a = bn_expand_internal(b, words);
438 if(b->d) OPENSSL_free(b->d);
443 /* None of this should be necessary because of what b->top means! */
445 /* NB: bn_wexpand() calls this only if the BIGNUM really has to grow */
446 if (b->top < b->dmax)
449 BN_ULONG *A = &(b->d[b->top]);
450 for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8)
452 A[0]=0; A[1]=0; A[2]=0; A[3]=0;
453 A[4]=0; A[5]=0; A[6]=0; A[7]=0;
455 for (i=(b->dmax - b->top)&7; i>0; i--,A++)
457 assert(A == &(b->d[b->dmax]));
464 BIGNUM *BN_dup(const BIGNUM *a)
468 if (a == NULL) return NULL;
472 if (t == NULL) return NULL;
482 BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
490 if (a == b) return(a);
491 if (bn_wexpand(a,b->top) == NULL) return(NULL);
496 for (i=b->top>>2; i>0; i--,A+=4,B+=4)
498 BN_ULONG a0,a1,a2,a3;
499 a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
500 A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
507 case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */
510 memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
519 void BN_swap(BIGNUM *a, BIGNUM *b)
521 int flags_old_a, flags_old_b;
523 int tmp_top, tmp_dmax, tmp_neg;
528 flags_old_a = a->flags;
529 flags_old_b = b->flags;
546 a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA);
547 b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA);
552 void BN_clear(BIGNUM *a)
556 memset(a->d,0,a->dmax*sizeof(a->d[0]));
561 BN_ULONG BN_get_word(const BIGNUM *a)
565 else if (a->top == 1)
571 int BN_set_word(BIGNUM *a, BN_ULONG w)
574 if (bn_expand(a,(int)sizeof(BN_ULONG)*8) == NULL) return(0);
577 a->top = (w ? 1 : 0);
582 BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret)
591 if (ret == NULL) return(NULL);
600 i=((n-1)/BN_BYTES)+1;
601 m=((n-1)%(BN_BYTES));
602 if (bn_wexpand(ret, (int)i) == NULL)
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)
636 *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff;
641 int BN_ucmp(const BIGNUM *a, const BIGNUM *b)
644 BN_ULONG t1,t2,*ap,*bp;
650 if (i != 0) return(i);
653 for (i=a->top-1; i>=0; i--)
658 return((t1 > t2) ? 1 : -1);
663 int BN_cmp(const BIGNUM *a, const BIGNUM *b)
669 if ((a == NULL) || (b == NULL))
682 if (a->neg != b->neg)
690 else { gt= -1; lt=1; }
692 if (a->top > b->top) return(gt);
693 if (a->top < b->top) return(lt);
694 for (i=a->top-1; i>=0; i--)
698 if (t1 > t2) return(gt);
699 if (t1 < t2) return(lt);
704 int BN_set_bit(BIGNUM *a, int n)
715 if (bn_wexpand(a,i+1) == NULL) return(0);
716 for(k=a->top; k<i+1; k++)
721 a->d[i]|=(((BN_ULONG)1)<<j);
726 int BN_clear_bit(BIGNUM *a, int n)
735 if (a->top <= i) return(0);
737 a->d[i]&=(~(((BN_ULONG)1)<<j));
742 int BN_is_bit_set(const BIGNUM *a, int n)
750 if (a->top <= i) return 0;
751 return (int)(((a->d[i])>>j)&((BN_ULONG)1));
754 int BN_mask_bits(BIGNUM *a, int n)
763 if (w >= a->top) return 0;
769 a->d[w]&= ~(BN_MASK2<<b);
775 void BN_set_negative(BIGNUM *a, int b)
777 if (b && !BN_is_zero(a))
783 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n)
790 if (aa != bb) return((aa > bb)?1:-1);
791 for (i=n-2; i>=0; i--)
795 if (aa != bb) return((aa > bb)?1:-1);
800 /* Here follows a specialised variants of bn_cmp_words(). It has the
801 property of performing the operation on arrays of different sizes.
802 The sizes of those arrays is expressed through cl, which is the
803 common length ( basicall, min(len(a),len(b)) ), and dl, which is the
804 delta between the two lengths, calculated as len(a)-len(b).
805 All lengths are the number of BN_ULONGs... */
807 int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b,
818 return -1; /* a < b */
826 return 1; /* a > b */
829 return bn_cmp_words(a,b,cl);