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
25 #include "d0_bignum.h"
36 static gmp_randstate_t RANDSTATE;
37 static d0_bignum_t temp;
42 void d0_bignum_INITIALIZE(void)
45 unsigned char buf[256];
46 d0_bignum_init(&temp);
47 gmp_randinit_mt(RANDSTATE);
48 gmp_randseed_ui(RANDSTATE, time(NULL));
49 * (time_t *) (&buf[0]) = time(0); // if everything else fails, we use the current time + uninitialized data
52 HCRYPTPROV hCryptProv;
53 if(CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
55 if(!CryptGenRandom(hCryptProv, sizeof(buf), (PBYTE) &buf[0]))
56 fprintf(stderr, "WARNING: could not initialize random number generator (CryptGenRandom failed)\n");
59 fprintf(stderr, "WARNING: could not initialize random number generator (CryptAcquireContext failed)\n");
62 f = fopen("/dev/urandom", "rb");
64 f = fopen("/dev/random", "rb");
68 if(fread(buf, sizeof(buf), 1, f) != 1)
69 fprintf(stderr, "WARNING: could not initialize random number generator (read from random device failed)\n");
73 fprintf(stderr, "WARNING: could not initialize random number generator (no random device found)\n");
76 mpz_import(temp.z, sizeof(buf), 1, 1, 0, 0, buf);
77 gmp_randseed(RANDSTATE, temp.z);
80 void d0_bignum_SHUTDOWN(void)
82 d0_bignum_clear(&temp);
83 gmp_randclear(RANDSTATE);
86 BOOL d0_iobuf_write_bignum(d0_iobuf_t *buf, const d0_bignum_t *bignum)
88 static unsigned char numbuf[65536];
90 numbuf[0] = mpz_sgn(bignum->z) & 3;
91 if((numbuf[0] & 3) != 0) // nonzero
93 count = (mpz_sizeinbase(bignum->z, 2) + 7) / 8;
94 if(count > sizeof(numbuf) - 1)
96 mpz_export(numbuf+1, &count, 1, 1, 0, 0, bignum->z);
98 return d0_iobuf_write_packet(buf, numbuf, count + 1);
101 d0_bignum_t *d0_iobuf_read_bignum(d0_iobuf_t *buf, d0_bignum_t *bignum)
103 static unsigned char numbuf[65536];
104 size_t count = sizeof(numbuf);
105 if(!d0_iobuf_read_packet(buf, numbuf, &count))
109 if(!bignum) bignum = d0_bignum_new(); if(!bignum) return NULL;
110 if(numbuf[0] & 3) // nonzero
112 mpz_import(bignum->z, count-1, 1, 1, 0, 0, numbuf+1);
113 if(numbuf[0] & 2) // negative
114 mpz_neg(bignum->z, bignum->z);
118 mpz_set_ui(bignum->z, 0);
123 ssize_t d0_bignum_export_unsigned(const d0_bignum_t *bignum, void *buf, size_t bufsize)
126 count = (mpz_sizeinbase(bignum->z, 2) + 7) / 8;
131 // pad from left (big endian numbers!)
132 memset(buf, 0, bufsize - count);
133 buf += bufsize - count;
136 mpz_export(buf, &bufsize, 1, 1, 0, 0, bignum->z);
140 // mpz_sizeinbase lied to us
142 // there is no sane way whatsoever to handle this
148 // mpz_sizeinbase lied to us
152 memset(buf, 0, count);
156 memmove(buf + count - bufsize, buf, bufsize);
157 memset(buf, 0, count - bufsize);
163 d0_bignum_t *d0_bignum_import_unsigned(d0_bignum_t *bignum, const void *buf, size_t bufsize)
166 if(!bignum) bignum = d0_bignum_new(); if(!bignum) return NULL;
167 mpz_import(bignum->z, bufsize, 1, 1, 0, 0, buf);
171 d0_bignum_t *d0_bignum_new(void)
173 d0_bignum_t *b = d0_malloc(sizeof(d0_bignum_t));
178 void d0_bignum_free(d0_bignum_t *a)
184 void d0_bignum_init(d0_bignum_t *b)
189 void d0_bignum_clear(d0_bignum_t *a)
194 size_t d0_bignum_size(const d0_bignum_t *r)
196 return mpz_sizeinbase(r->z, 2);
199 int d0_bignum_cmp(const d0_bignum_t *a, const d0_bignum_t *b)
201 return mpz_cmp(a->z, b->z);
204 d0_bignum_t *d0_bignum_rand_range(d0_bignum_t *r, const d0_bignum_t *min, const d0_bignum_t *max)
206 if(!r) r = d0_bignum_new(); if(!r) return NULL;
207 mpz_sub(temp.z, max->z, min->z);
208 mpz_urandomm(r->z, RANDSTATE, temp.z);
209 mpz_add(r->z, r->z, min->z);
213 d0_bignum_t *d0_bignum_rand_bit_atmost(d0_bignum_t *r, size_t n)
215 if(!r) r = d0_bignum_new(); if(!r) return NULL;
216 mpz_urandomb(r->z, RANDSTATE, n);
220 d0_bignum_t *d0_bignum_rand_bit_exact(d0_bignum_t *r, size_t n)
222 if(!r) r = d0_bignum_new(); if(!r) return NULL;
223 mpz_urandomb(r->z, RANDSTATE, n-1);
224 mpz_setbit(r->z, n-1);
228 d0_bignum_t *d0_bignum_zero(d0_bignum_t *r)
230 return d0_bignum_int(r, 0);
233 d0_bignum_t *d0_bignum_one(d0_bignum_t *r)
235 return d0_bignum_int(r, 1);
238 d0_bignum_t *d0_bignum_int(d0_bignum_t *r, int n)
240 if(!r) r = d0_bignum_new(); if(!r) return NULL;
245 d0_bignum_t *d0_bignum_mov(d0_bignum_t *r, const d0_bignum_t *a)
249 if(!r) r = d0_bignum_new(); if(!r) return NULL;
254 d0_bignum_t *d0_bignum_neg(d0_bignum_t *r, const d0_bignum_t *a)
256 if(!r) r = d0_bignum_new(); if(!r) return NULL;
261 d0_bignum_t *d0_bignum_shl(d0_bignum_t *r, const d0_bignum_t *a, ssize_t n)
263 if(!r) r = d0_bignum_new(); if(!r) return NULL;
265 mpz_mul_2exp(r->z, a->z, n);
267 mpz_fdiv_q_2exp(r->z, a->z, -n);
273 d0_bignum_t *d0_bignum_add(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
275 if(!r) r = d0_bignum_new(); if(!r) return NULL;
276 mpz_add(r->z, a->z, b->z);
280 d0_bignum_t *d0_bignum_sub(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
282 if(!r) r = d0_bignum_new(); if(!r) return NULL;
283 mpz_sub(r->z, a->z, b->z);
287 d0_bignum_t *d0_bignum_mul(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
289 if(!r) r = d0_bignum_new(); if(!r) return NULL;
290 mpz_mul(r->z, a->z, b->z);
294 d0_bignum_t *d0_bignum_divmod(d0_bignum_t *q, d0_bignum_t *m, const d0_bignum_t *a, const d0_bignum_t *b)
300 mpz_fdiv_qr(q->z, m->z, a->z, b->z);
302 mpz_fdiv_q(q->z, a->z, b->z);
304 mpz_fdiv_r(m->z, a->z, b->z);
311 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)
313 r = d0_bignum_add(r, a, b);
314 mpz_fdiv_r(r->z, r->z, m->z);
318 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)
320 r = d0_bignum_mul(r, a, b);
321 mpz_fdiv_r(r->z, r->z, m->z);
325 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)
327 if(!r) r = d0_bignum_new(); if(!r) return NULL;
328 mpz_powm(r->z, a->z, b->z, m->z);
332 BOOL d0_bignum_mod_inv(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *m)
334 // here, r MUST be set, as otherwise we cannot return error state!
335 return mpz_invert(r->z, a->z, m->z);
338 int d0_bignum_isprime(d0_bignum_t *r, int param)
340 return mpz_probab_prime_p(r->z, param);
343 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)
345 if(!r) r = d0_bignum_new(); if(!r) return NULL;
347 mpz_gcdext(r->z, s->z, t ? t->z : NULL, a->z, b->z);
349 mpz_gcdext(r->z, t->z, NULL, b->z, a->z);
351 mpz_gcd(r->z, a->z, b->z);
355 char *d0_bignum_tostring(const d0_bignum_t *x, unsigned int base)
357 return mpz_get_str(NULL, base, x->z);