2 Blind-ID library for user identification using RSA blind signatures
3 Copyright (C) 2010 Rudolf Polzer
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with this library; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #include "d0_bignum.h"
30 static gmp_randstate_t RANDSTATE;
31 static d0_bignum_t temp;
35 void d0_bignum_INITIALIZE(void)
38 d0_bignum_init(&temp);
39 gmp_randinit_mt(RANDSTATE);
40 gmp_randseed_ui(RANDSTATE, time(NULL));
41 f = fopen("/dev/urandom", "rb");
43 f = fopen("/dev/random", "rb");
46 unsigned char buf[256];
48 if(fread(buf, sizeof(buf), 1, f) == 1)
50 mpz_import(temp.z, sizeof(buf), 1, 1, 0, 0, buf);
51 gmp_randseed(RANDSTATE, temp.z);
57 void d0_bignum_SHUTDOWN(void)
59 d0_bignum_clear(&temp);
60 gmp_randclear(RANDSTATE);
63 BOOL d0_iobuf_write_bignum(d0_iobuf_t *buf, const d0_bignum_t *bignum)
65 static unsigned char numbuf[65536];
67 numbuf[0] = mpz_sgn(bignum->z) & 3;
68 if((numbuf[0] & 3) != 0) // nonzero
70 count = (mpz_sizeinbase(bignum->z, 2) + 7) / 8;
71 if(count > sizeof(numbuf) - 1)
73 mpz_export(numbuf+1, &count, 1, 1, 0, 0, bignum->z);
75 return d0_iobuf_write_packet(buf, numbuf, count + 1);
78 d0_bignum_t *d0_iobuf_read_bignum(d0_iobuf_t *buf, d0_bignum_t *bignum)
80 static unsigned char numbuf[65536];
81 size_t count = sizeof(numbuf);
82 if(!d0_iobuf_read_packet(buf, numbuf, &count))
86 if(!bignum) bignum = d0_bignum_new(); if(!bignum) return NULL;
87 if(numbuf[0] & 3) // nonzero
89 mpz_import(bignum->z, count-1, 1, 1, 0, 0, numbuf+1);
90 if(numbuf[0] & 2) // negative
91 mpz_neg(bignum->z, bignum->z);
95 mpz_set_ui(bignum->z, 0);
100 ssize_t d0_bignum_export_unsigned(const d0_bignum_t *bignum, void *buf, size_t bufsize)
103 count = (mpz_sizeinbase(bignum->z, 2) + 7) / 8;
108 // pad from left (big endian numbers!)
109 memset(buf, 0, bufsize - count);
110 buf += bufsize - count;
113 mpz_export(buf, &bufsize, 1, 1, 0, 0, bignum->z);
117 // mpz_sizeinbase lied to us
119 // there is no sane way whatsoever to handle this
125 // mpz_sizeinbase lied to us
129 memset(buf, 0, count);
133 memmove(buf + count - bufsize, buf, bufsize);
134 memset(buf, 0, count - bufsize);
140 d0_bignum_t *d0_bignum_import_unsigned(d0_bignum_t *bignum, const void *buf, size_t bufsize)
143 if(!bignum) bignum = d0_bignum_new(); if(!bignum) return NULL;
144 mpz_import(bignum->z, bufsize, 1, 1, 0, 0, buf);
148 d0_bignum_t *d0_bignum_new(void)
150 d0_bignum_t *b = d0_malloc(sizeof(d0_bignum_t));
155 void d0_bignum_free(d0_bignum_t *a)
161 void d0_bignum_init(d0_bignum_t *b)
166 void d0_bignum_clear(d0_bignum_t *a)
171 size_t d0_bignum_size(const d0_bignum_t *r)
173 return mpz_sizeinbase(r->z, 2);
176 int d0_bignum_cmp(const d0_bignum_t *a, const d0_bignum_t *b)
178 return mpz_cmp(a->z, b->z);
181 d0_bignum_t *d0_bignum_rand_range(d0_bignum_t *r, const d0_bignum_t *min, const d0_bignum_t *max)
183 if(!r) r = d0_bignum_new(); if(!r) return NULL;
184 mpz_sub(temp.z, max->z, min->z);
185 mpz_urandomm(r->z, RANDSTATE, temp.z);
186 mpz_add(r->z, r->z, min->z);
190 d0_bignum_t *d0_bignum_rand_bit_atmost(d0_bignum_t *r, size_t n)
192 if(!r) r = d0_bignum_new(); if(!r) return NULL;
193 mpz_urandomb(r->z, RANDSTATE, n);
197 d0_bignum_t *d0_bignum_rand_bit_exact(d0_bignum_t *r, size_t n)
199 if(!r) r = d0_bignum_new(); if(!r) return NULL;
200 mpz_urandomb(r->z, RANDSTATE, n-1);
201 mpz_setbit(r->z, n-1);
205 d0_bignum_t *d0_bignum_zero(d0_bignum_t *r)
207 return d0_bignum_int(r, 0);
210 d0_bignum_t *d0_bignum_one(d0_bignum_t *r)
212 return d0_bignum_int(r, 1);
215 d0_bignum_t *d0_bignum_int(d0_bignum_t *r, int n)
217 if(!r) r = d0_bignum_new(); if(!r) return NULL;
222 d0_bignum_t *d0_bignum_mov(d0_bignum_t *r, const d0_bignum_t *a)
226 if(!r) r = d0_bignum_new(); if(!r) return NULL;
231 d0_bignum_t *d0_bignum_neg(d0_bignum_t *r, const d0_bignum_t *a)
233 if(!r) r = d0_bignum_new(); if(!r) return NULL;
238 d0_bignum_t *d0_bignum_shl(d0_bignum_t *r, const d0_bignum_t *a, ssize_t n)
240 if(!r) r = d0_bignum_new(); if(!r) return NULL;
242 mpz_mul_2exp(r->z, a->z, n);
244 mpz_fdiv_q_2exp(r->z, a->z, -n);
250 d0_bignum_t *d0_bignum_add(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
252 if(!r) r = d0_bignum_new(); if(!r) return NULL;
253 mpz_add(r->z, a->z, b->z);
257 d0_bignum_t *d0_bignum_sub(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
259 if(!r) r = d0_bignum_new(); if(!r) return NULL;
260 mpz_sub(r->z, a->z, b->z);
264 d0_bignum_t *d0_bignum_mul(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
266 if(!r) r = d0_bignum_new(); if(!r) return NULL;
267 mpz_mul(r->z, a->z, b->z);
271 d0_bignum_t *d0_bignum_divmod(d0_bignum_t *q, d0_bignum_t *m, const d0_bignum_t *a, const d0_bignum_t *b)
277 mpz_fdiv_qr(q->z, m->z, a->z, b->z);
279 mpz_fdiv_q(q->z, a->z, b->z);
281 mpz_fdiv_r(m->z, a->z, b->z);
288 d0_bignum_t *d0_bignum_mod_add(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b, const d0_bignum_t *m)
290 r = d0_bignum_add(r, a, b);
291 mpz_fdiv_r(r->z, r->z, m->z);
295 d0_bignum_t *d0_bignum_mod_mul(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b, const d0_bignum_t *m)
297 r = d0_bignum_mul(r, a, b);
298 mpz_fdiv_r(r->z, r->z, m->z);
302 d0_bignum_t *d0_bignum_mod_pow(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b, const d0_bignum_t *m)
304 if(!r) r = d0_bignum_new(); if(!r) return NULL;
305 mpz_powm(r->z, a->z, b->z, m->z);
309 BOOL d0_bignum_mod_inv(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *m)
311 // here, r MUST be set, as otherwise we cannot return error state!
312 return mpz_invert(r->z, a->z, m->z);
315 int d0_bignum_isprime(d0_bignum_t *r, int param)
317 return mpz_probab_prime_p(r->z, param);
320 d0_bignum_t *d0_bignum_gcd(d0_bignum_t *r, d0_bignum_t *s, d0_bignum_t *t, const d0_bignum_t *a, const d0_bignum_t *b)
322 if(!r) r = d0_bignum_new(); if(!r) return NULL;
324 mpz_gcdext(r->z, s->z, t ? t->z : NULL, a->z, b->z);
326 mpz_gcdext(r->z, t->z, NULL, b->z, a->z);
328 mpz_gcd(r->z, a->z, b->z);
332 char *d0_bignum_tostring(const d0_bignum_t *x, unsigned int base)
334 return mpz_get_str(NULL, base, x->z);