1 /*	$NetBSD: tommath.h,v 1.2 2017/01/28 21:31:47 christos Exp $	*/
2 
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
4  *
5  * LibTomMath is a library that provides multiple-precision
6  * integer arithmetic as well as number theoretic functionality.
7  *
8  * The library was designed directly after the MPI library by
9  * Michael Fromberger but has been written from scratch with
10  * additional optimizations in place.
11  *
12  * The library is free for all purposes without any express
13  * guarantee it works.
14  *
15  * Tom St Denis, tomstdenis@gmail.com, http://math.libtomcrypt.com
16  */
17 #ifndef BN_H_
18 #define BN_H_
19 
20 #include <stdio.h>
21 #include <string.h>
22 #include <stdlib.h>
23 #include <ctype.h>
24 #include <limits.h>
25 
26 #include <tommath_class.h>
27 
28 #ifndef MIN
29    #define MIN(x,y) ((x)<(y)?(x):(y))
30 #endif
31 
32 #ifndef MAX
33    #define MAX(x,y) ((x)>(y)?(x):(y))
34 #endif
35 
36 #ifdef __cplusplus
37 extern "C" {
38 
39 /* C++ compilers don't like assigning void * to mp_digit * */
40 #define  OPT_CAST(x)  (x *)
41 
42 #else
43 
44 /* C on the other hand doesn't care */
45 #define  OPT_CAST(x)
46 
47 #endif
48 
49 
50 /* detect 64-bit mode if possible */
51 #if defined(__x86_64__) && !defined(__ILP32__)
52    #if !(defined(MP_64BIT) && defined(MP_16BIT) && defined(MP_8BIT))
53       #define MP_64BIT
54    #endif
55 #endif
56 
57 /* some default configurations.
58  *
59  * A "mp_digit" must be able to hold DIGIT_BIT + 1 bits
60  * A "mp_word" must be able to hold 2*DIGIT_BIT + 1 bits
61  *
62  * At the very least a mp_digit must be able to hold 7 bits
63  * [any size beyond that is ok provided it doesn't overflow the data type]
64  */
65 #ifdef MP_8BIT
66    typedef unsigned char      mp_digit;
67    typedef unsigned short     mp_word;
68 #elif defined(MP_16BIT)
69    typedef unsigned short     mp_digit;
70    typedef unsigned long      mp_word;
71 #elif defined(MP_64BIT)
72    /* for GCC only on supported platforms */
73 #ifndef CRYPT
74    typedef unsigned long long ulong64;
75    typedef signed long long   long64;
76 #endif
77 
78    typedef unsigned long      mp_digit;
79    typedef unsigned long      mp_word __attribute__ ((mode(TI)));
80 
81    #define DIGIT_BIT          60
82 #else
83    /* this is the default case, 28-bit digits */
84 
85    /* this is to make porting into LibTomCrypt easier :-) */
86 #ifndef CRYPT
87    #if defined(_MSC_VER) || defined(__BORLANDC__)
88       typedef unsigned __int64   ulong64;
89       typedef signed __int64     long64;
90    #else
91       typedef unsigned long long ulong64;
92       typedef signed long long   long64;
93    #endif
94 #endif
95 
96    typedef unsigned long      mp_digit;
97    typedef ulong64            mp_word;
98 
99 #ifdef MP_31BIT
100    /* this is an extension that uses 31-bit digits */
101    #define DIGIT_BIT          31
102 #else
103    /* default case is 28-bit digits, defines MP_28BIT as a handy macro to test */
104    #define DIGIT_BIT          28
105    #define MP_28BIT
106 #endif
107 #endif
108 
109 /* define heap macros */
110 #ifndef CRYPT
111    /* default to libc stuff */
112    #ifndef XMALLOC
113        #define XMALLOC  malloc
114        #define XFREE    free
115        #define XREALLOC realloc
116        #define XCALLOC  calloc
117    #else
118       /* prototypes for our heap functions */
119       extern void *XMALLOC(size_t n);
120       extern void *XREALLOC(void *p, size_t n);
121       extern void *XCALLOC(size_t n, size_t s);
122       extern void XFREE(void *p);
123    #endif
124 #endif
125 
126 
127 /* otherwise the bits per digit is calculated automatically from the size of a mp_digit */
128 #ifndef DIGIT_BIT
129    #define DIGIT_BIT     ((int)((CHAR_BIT * sizeof(mp_digit) - 1)))  /* bits per digit */
130 #endif
131 
132 #define MP_DIGIT_BIT     DIGIT_BIT
133 #define MP_MASK          ((((mp_digit)1)<<((mp_digit)DIGIT_BIT))-((mp_digit)1))
134 #define MP_DIGIT_MAX     MP_MASK
135 
136 /* equalities */
137 #define MP_LT        -1   /* less than */
138 #define MP_EQ         0   /* equal to */
139 #define MP_GT         1   /* greater than */
140 
141 #define MP_ZPOS       0   /* positive integer */
142 #define MP_NEG        1   /* negative */
143 
144 #define MP_OKAY       0   /* ok result */
145 #define MP_MEM        -2  /* out of mem */
146 #define MP_VAL        -3  /* invalid input */
147 #define MP_RANGE      MP_VAL
148 
149 #define MP_YES        1   /* yes response */
150 #define MP_NO         0   /* no response */
151 
152 /* Primality generation flags */
153 #define LTM_PRIME_BBS      0x0001 /* BBS style prime */
154 #define LTM_PRIME_SAFE     0x0002 /* Safe prime (p-1)/2 == prime */
155 #define LTM_PRIME_2MSB_ON  0x0008 /* force 2nd MSB to 1 */
156 
157 typedef int           mp_err;
158 
159 /* you'll have to tune these... */
160 extern int KARATSUBA_MUL_CUTOFF,
161            KARATSUBA_SQR_CUTOFF,
162            TOOM_MUL_CUTOFF,
163            TOOM_SQR_CUTOFF;
164 
165 /* define this to use lower memory usage routines (exptmods mostly) */
166 /* #define MP_LOW_MEM */
167 
168 /* default precision */
169 #ifndef MP_PREC
170    #ifndef MP_LOW_MEM
171       #define MP_PREC                 32     /* default digits of precision */
172    #else
173       #define MP_PREC                 8      /* default digits of precision */
174    #endif
175 #endif
176 
177 /* size of comba arrays, should be at least 2 * 2**(BITS_PER_WORD - BITS_PER_DIGIT*2) */
178 #define MP_WARRAY               (1 << (sizeof(mp_word) * CHAR_BIT - 2 * DIGIT_BIT + 1))
179 
180 /* the infamous mp_int structure */
181 typedef struct  {
182     int used, alloc, sign;
183     mp_digit *dp;
184 } mp_int;
185 
186 /* callback for mp_prime_random, should fill dst with random bytes and return how many read [upto len] */
187 typedef int ltm_prime_callback(unsigned char *dst, int len, void *dat);
188 
189 
190 #define USED(m)    ((m)->used)
191 #define DIGIT(m,k) ((m)->dp[(k)])
192 #define SIGN(m)    ((m)->sign)
193 
194 /* error code to const char* string */
195 const char *mp_error_to_string(int code);
196 
197 /* ---> init and deinit bignum functions <--- */
198 /* init a bignum */
199 int mp_init(mp_int *a);
200 
201 /* free a bignum */
202 void mp_clear(mp_int *a);
203 
204 /* init a null terminated series of arguments */
205 int mp_init_multi(mp_int *mp, ...);
206 
207 /* clear a null terminated series of arguments */
208 void mp_clear_multi(mp_int *mp, ...);
209 
210 /* exchange two ints */
211 void mp_exch(mp_int *a, mp_int *b);
212 
213 /* shrink ram required for a bignum */
214 int mp_shrink(mp_int *a);
215 
216 /* grow an int to a given size */
217 int mp_grow(mp_int *a, int size);
218 
219 /* init to a given number of digits */
220 int mp_init_size(mp_int *a, int size);
221 
222 /* ---> Basic Manipulations <--- */
223 #define mp_iszero(a) (((a)->used == 0) ? MP_YES : MP_NO)
224 #define mp_iseven(a) (((a)->used > 0 && (((a)->dp[0] & 1) == 0)) ? MP_YES : MP_NO)
225 #define mp_isodd(a)  (((a)->used > 0 && (((a)->dp[0] & 1) == 1)) ? MP_YES : MP_NO)
226 #define mp_isneg(a)  (((a)->sign) ? MP_YES : MP_NO)
227 
228 /* set to zero */
229 void mp_zero(mp_int *a);
230 
231 /* set to zero, multi */
232 void mp_zero_multi(mp_int *a, ...);
233 
234 /* set to a digit */
235 void mp_set(mp_int *a, mp_digit b);
236 
237 /* set a 32-bit const */
238 int mp_set_int(mp_int *a, unsigned long b);
239 
240 /* get a 32-bit value */
241 unsigned long mp_get_int(mp_int * a);
242 
243 /* initialize and set a digit */
244 int mp_init_set (mp_int * a, mp_digit b);
245 
246 /* initialize and set 32-bit value */
247 int mp_init_set_int (mp_int * a, unsigned long b);
248 
249 /* copy, b = a */
250 int mp_copy(mp_int *a, mp_int *b);
251 
252 /* inits and copies, a = b */
253 int mp_init_copy(mp_int *a, mp_int *b);
254 
255 /* trim unused digits */
256 void mp_clamp(mp_int *a);
257 
258 /* ---> digit manipulation <--- */
259 
260 /* right shift by "b" digits */
261 void mp_rshd(mp_int *a, int b);
262 
263 /* left shift by "b" digits */
264 int mp_lshd(mp_int *a, int b);
265 
266 /* c = a / 2**b */
267 int mp_div_2d(mp_int *a, int b, mp_int *c, mp_int *d);
268 
269 /* b = a/2 */
270 int mp_div_2(mp_int *a, mp_int *b);
271 
272 /* c = a * 2**b */
273 int mp_mul_2d(mp_int *a, int b, mp_int *c);
274 
275 /* b = a*2 */
276 int mp_mul_2(mp_int *a, mp_int *b);
277 
278 /* c = a mod 2**d */
279 int mp_mod_2d(mp_int *a, int b, mp_int *c);
280 
281 /* computes a = 2**b */
282 int mp_2expt(mp_int *a, int b);
283 
284 /* Counts the number of lsbs which are zero before the first zero bit */
285 int mp_cnt_lsb(mp_int *a);
286 
287 /* I Love Earth! */
288 
289 /* makes a pseudo-random int of a given size */
290 int mp_rand(mp_int *a, int digits);
291 
292 /* ---> binary operations <--- */
293 /* c = a XOR b  */
294 int mp_xor(mp_int *a, mp_int *b, mp_int *c);
295 
296 /* c = a OR b */
297 int mp_or(mp_int *a, mp_int *b, mp_int *c);
298 
299 /* c = a AND b */
300 int mp_and(mp_int *a, mp_int *b, mp_int *c);
301 
302 /* ---> Basic arithmetic <--- */
303 
304 /* b = -a */
305 int mp_neg(mp_int *a, mp_int *b);
306 
307 /* b = |a| */
308 int mp_abs(mp_int *a, mp_int *b);
309 
310 /* compare a to b */
311 int mp_cmp(mp_int *a, mp_int *b);
312 
313 /* compare |a| to |b| */
314 int mp_cmp_mag(mp_int *a, mp_int *b);
315 
316 /* c = a + b */
317 int mp_add(mp_int *a, mp_int *b, mp_int *c);
318 
319 /* c = a - b */
320 int mp_sub(mp_int *a, mp_int *b, mp_int *c);
321 
322 /* c = a * b */
323 int mp_mul(mp_int *a, mp_int *b, mp_int *c);
324 
325 /* b = a*a  */
326 int mp_sqr(mp_int *a, mp_int *b);
327 
328 /* a/b => cb + d == a */
329 int mp_div(mp_int *a, mp_int *b, mp_int *c, mp_int *d);
330 
331 /* c = a mod b, 0 <= c < b  */
332 int mp_mod(mp_int *a, mp_int *b, mp_int *c);
333 
334 /* ---> single digit functions <--- */
335 
336 /* compare against a single digit */
337 int mp_cmp_d(mp_int *a, mp_digit b);
338 
339 /* c = a + b */
340 int mp_add_d(mp_int *a, mp_digit b, mp_int *c);
341 
342 /* c = a - b */
343 int mp_sub_d(mp_int *a, mp_digit b, mp_int *c);
344 
345 /* c = a * b */
346 int mp_mul_d(mp_int *a, mp_digit b, mp_int *c);
347 
348 /* a/b => cb + d == a */
349 int mp_div_d(mp_int *a, mp_digit b, mp_int *c, mp_digit *d);
350 
351 /* a/3 => 3c + d == a */
352 int mp_div_3(mp_int *a, mp_int *c, mp_digit *d);
353 
354 /* c = a**b */
355 int mp_expt_d(mp_int *a, mp_digit b, mp_int *c);
356 
357 /* c = a mod b, 0 <= c < b  */
358 int mp_mod_d(mp_int *a, mp_digit b, mp_digit *c);
359 
360 /* ---> number theory <--- */
361 
362 /* d = a + b (mod c) */
363 int mp_addmod(mp_int *a, mp_int *b, mp_int *c, mp_int *d);
364 
365 /* d = a - b (mod c) */
366 int mp_submod(mp_int *a, mp_int *b, mp_int *c, mp_int *d);
367 
368 /* d = a * b (mod c) */
369 int mp_mulmod(mp_int *a, mp_int *b, mp_int *c, mp_int *d);
370 
371 /* c = a * a (mod b) */
372 int mp_sqrmod(mp_int *a, mp_int *b, mp_int *c);
373 
374 /* c = 1/a (mod b) */
375 int mp_invmod(mp_int *a, mp_int *b, mp_int *c);
376 
377 /* c = (a, b) */
378 int mp_gcd(mp_int *a, mp_int *b, mp_int *c);
379 
380 /* produces value such that U1*a + U2*b = U3 */
381 int mp_exteuclid(mp_int *a, mp_int *b, mp_int *U1, mp_int *U2, mp_int *U3);
382 
383 /* c = [a, b] or (a*b)/(a, b) */
384 int mp_lcm(mp_int *a, mp_int *b, mp_int *c);
385 
386 /* finds one of the b'th root of a, such that |c|**b <= |a|
387  *
388  * returns error if a < 0 and b is even
389  */
390 int mp_n_root(mp_int *a, mp_digit b, mp_int *c);
391 
392 /* special sqrt algo */
393 int mp_sqrt(mp_int *arg, mp_int *ret);
394 
395 /* is number a square? */
396 int mp_is_square(mp_int *arg, int *ret);
397 
398 /* computes the jacobi c = (a | n) (or Legendre if b is prime)  */
399 int mp_jacobi(mp_int *a, mp_int *n, int *c);
400 
401 /* used to setup the Barrett reduction for a given modulus b */
402 int mp_reduce_setup(mp_int *a, mp_int *b);
403 
404 /* Barrett Reduction, computes a (mod b) with a precomputed value c
405  *
406  * Assumes that 0 < a <= b*b, note if 0 > a > -(b*b) then you can merely
407  * compute the reduction as -1 * mp_reduce(mp_abs(a)) [pseudo code].
408  */
409 int mp_reduce(mp_int *a, mp_int *b, mp_int *c);
410 
411 /* setups the montgomery reduction */
412 int mp_montgomery_setup(mp_int *a, mp_digit *mp);
413 
414 /* computes a = B**n mod b without division or multiplication useful for
415  * normalizing numbers in a Montgomery system.
416  */
417 int mp_montgomery_calc_normalization(mp_int *a, mp_int *b);
418 
419 /* computes x/R == x (mod N) via Montgomery Reduction */
420 int mp_montgomery_reduce(mp_int *a, mp_int *m, mp_digit mp);
421 
422 /* returns 1 if a is a valid DR modulus */
423 int mp_dr_is_modulus(mp_int *a);
424 
425 /* sets the value of "d" required for mp_dr_reduce */
426 void mp_dr_setup(mp_int *a, mp_digit *d);
427 
428 /* reduces a modulo b using the Diminished Radix method */
429 int mp_dr_reduce(mp_int *a, mp_int *b, mp_digit mp);
430 
431 /* returns true if a can be reduced with mp_reduce_2k */
432 int mp_reduce_is_2k(mp_int *a);
433 
434 /* determines k value for 2k reduction */
435 int mp_reduce_2k_setup(mp_int *a, mp_digit *d);
436 
437 /* reduces a modulo b where b is of the form 2**p - k [0 <= a] */
438 int mp_reduce_2k(mp_int *a, mp_int *n, mp_digit d);
439 
440 /* returns true if a can be reduced with mp_reduce_2k_l */
441 int mp_reduce_is_2k_l(mp_int *a);
442 
443 /* determines k value for 2k reduction */
444 int mp_reduce_2k_setup_l(mp_int *a, mp_int *d);
445 
446 /* reduces a modulo b where b is of the form 2**p - k [0 <= a] */
447 int mp_reduce_2k_l(mp_int *a, mp_int *n, mp_int *d);
448 
449 /* d = a**b (mod c) */
450 int mp_exptmod(mp_int *a, mp_int *b, mp_int *c, mp_int *d);
451 
452 /* ---> Primes <--- */
453 
454 /* number of primes */
455 #ifdef MP_8BIT
456    #define PRIME_SIZE      31
457 #else
458    #define PRIME_SIZE      256
459 #endif
460 
461 /* table of first PRIME_SIZE primes */
462 extern const mp_digit ltm_prime_tab[];
463 
464 /* result=1 if a is divisible by one of the first PRIME_SIZE primes */
465 int mp_prime_is_divisible(mp_int *a, int *result);
466 
467 /* performs one Fermat test of "a" using base "b".
468  * Sets result to 0 if composite or 1 if probable prime
469  */
470 int mp_prime_fermat(mp_int *a, mp_int *b, int *result);
471 
472 /* performs one Miller-Rabin test of "a" using base "b".
473  * Sets result to 0 if composite or 1 if probable prime
474  */
475 int mp_prime_miller_rabin(mp_int *a, mp_int *b, int *result);
476 
477 /* This gives [for a given bit size] the number of trials required
478  * such that Miller-Rabin gives a prob of failure lower than 2^-96
479  */
480 int mp_prime_rabin_miller_trials(int size);
481 
482 /* performs t rounds of Miller-Rabin on "a" using the first
483  * t prime bases.  Also performs an initial sieve of trial
484  * division.  Determines if "a" is prime with probability
485  * of error no more than (1/4)**t.
486  *
487  * Sets result to 1 if probably prime, 0 otherwise
488  */
489 int mp_prime_is_prime(mp_int *a, int t, int *result);
490 
491 /* finds the next prime after the number "a" using "t" trials
492  * of Miller-Rabin.
493  *
494  * bbs_style = 1 means the prime must be congruent to 3 mod 4
495  */
496 int mp_prime_next_prime(mp_int *a, int t, int bbs_style);
497 
498 /* makes a truly random prime of a given size (bytes),
499  * call with bbs = 1 if you want it to be congruent to 3 mod 4
500  *
501  * You have to supply a callback which fills in a buffer with random bytes.  "dat" is a parameter you can
502  * have passed to the callback (e.g. a state or something).  This function doesn't use "dat" itself
503  * so it can be NULL
504  *
505  * The prime generated will be larger than 2^(8*size).
506  */
507 #define mp_prime_random(a, t, size, bbs, cb, dat) mp_prime_random_ex(a, t, ((size) * 8) + 1, (bbs==1)?LTM_PRIME_BBS:0, cb, dat)
508 
509 /* makes a truly random prime of a given size (bits),
510  *
511  * Flags are as follows:
512  *
513  *   LTM_PRIME_BBS      - make prime congruent to 3 mod 4
514  *   LTM_PRIME_SAFE     - make sure (p-1)/2 is prime as well (implies LTM_PRIME_BBS)
515  *   LTM_PRIME_2MSB_OFF - make the 2nd highest bit zero
516  *   LTM_PRIME_2MSB_ON  - make the 2nd highest bit one
517  *
518  * You have to supply a callback which fills in a buffer with random bytes.  "dat" is a parameter you can
519  * have passed to the callback (e.g. a state or something).  This function doesn't use "dat" itself
520  * so it can be NULL
521  *
522  */
523 int mp_prime_random_ex(mp_int *a, int t, int size, int flags, ltm_prime_callback cb, void *dat);
524 
525 int mp_find_prime(mp_int *a, int t);
526 
527 /* ---> radix conversion <--- */
528 int mp_count_bits(mp_int *a);
529 
530 int mp_unsigned_bin_size(mp_int *a);
531 int mp_read_unsigned_bin(mp_int *a, const unsigned char *b, int c);
532 int mp_to_unsigned_bin(mp_int *a, unsigned char *b);
533 int mp_to_unsigned_bin_n (mp_int * a, unsigned char *b, unsigned long *outlen);
534 
535 int mp_signed_bin_size(mp_int *a);
536 int mp_read_signed_bin(mp_int *a, const unsigned char *b, int c);
537 int mp_to_signed_bin(mp_int *a,  unsigned char *b);
538 int mp_to_signed_bin_n (mp_int * a, unsigned char *b, unsigned long *outlen);
539 
540 int mp_read_radix(mp_int *a, const char *str, int radix);
541 int mp_toradix(mp_int *a, char *str, int radix);
542 int mp_toradix_n(mp_int * a, char *str, int radix, int maxlen);
543 int mp_radix_size(mp_int *a, int radix, int *size);
544 
545 int mp_fread(mp_int *a, int radix, FILE *stream);
546 int mp_fwrite(mp_int *a, int radix, FILE *stream);
547 
548 #define mp_read_raw(mp, str, len) mp_read_signed_bin((mp), (str), (len))
549 #define mp_raw_size(mp)           mp_signed_bin_size(mp)
550 #define mp_toraw(mp, str)         mp_to_signed_bin((mp), (str))
551 #define mp_read_mag(mp, str, len) mp_read_unsigned_bin((mp), (str), (len))
552 #define mp_mag_size(mp)           mp_unsigned_bin_size(mp)
553 #define mp_tomag(mp, str)         mp_to_unsigned_bin((mp), (str))
554 
555 #define mp_tobinary(M, S)  mp_toradix((M), (S), 2)
556 #define mp_tooctal(M, S)   mp_toradix((M), (S), 8)
557 #define mp_todecimal(M, S) mp_toradix((M), (S), 10)
558 #define mp_tohex(M, S)     mp_toradix((M), (S), 16)
559 
560 /* lowlevel functions, do not call! */
561 int s_mp_add(mp_int *a, mp_int *b, mp_int *c);
562 int s_mp_sub(mp_int *a, mp_int *b, mp_int *c);
563 #define s_mp_mul(a, b, c) s_mp_mul_digs(a, b, c, (a)->used + (b)->used + 1)
564 int fast_s_mp_mul_digs(mp_int *a, mp_int *b, mp_int *c, int digs);
565 int s_mp_mul_digs(mp_int *a, mp_int *b, mp_int *c, int digs);
566 int fast_s_mp_mul_high_digs(mp_int *a, mp_int *b, mp_int *c, int digs);
567 int s_mp_mul_high_digs(mp_int *a, mp_int *b, mp_int *c, int digs);
568 int fast_s_mp_sqr(mp_int *a, mp_int *b);
569 int s_mp_sqr(mp_int *a, mp_int *b);
570 int mp_karatsuba_mul(mp_int *a, mp_int *b, mp_int *c);
571 int mp_toom_mul(mp_int *a, mp_int *b, mp_int *c);
572 int mp_karatsuba_sqr(mp_int *a, mp_int *b);
573 int mp_toom_sqr(mp_int *a, mp_int *b);
574 int fast_mp_invmod(mp_int *a, mp_int *b, mp_int *c);
575 int mp_invmod_slow (mp_int * a, mp_int * b, mp_int * c);
576 int fast_mp_montgomery_reduce(mp_int *a, mp_int *m, mp_digit mp);
577 int mp_exptmod_fast(mp_int *G, mp_int *X, mp_int *P, mp_int *Y, int mode);
578 int s_mp_exptmod (mp_int * G, mp_int * X, mp_int * P, mp_int * Y, int mode);
579 void bn_reverse(unsigned char *s, int len);
580 
581 extern const char *mp_s_rmap;
582 
583 #ifdef __cplusplus
584    }
585 #endif
586 
587 #endif
588 
589 
590 /* Source: /cvs/libtom/libtommath/tommath.h,v  */
591 /* Revision: 1.8  */
592 /* Date: 2006/03/31 14:18:44  */
593