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 WARN_UNUSED_RESULT BOOL d0_bignum_INITIALIZE(void)
46 unsigned char buf[256];
47 d0_bignum_init(&temp);
48 gmp_randinit_mt(RANDSTATE);
49 gmp_randseed_ui(RANDSTATE, time(NULL));
50 * (time_t *) (&buf[0]) = time(0); // if everything else fails, we use the current time + uninitialized data
53 HCRYPTPROV hCryptProv;
54 if(CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
56 if(!CryptGenRandom(hCryptProv, sizeof(buf), (PBYTE) &buf[0]))
58 fprintf(stderr, "WARNING: could not initialize random number generator (CryptGenRandom failed)\n");
61 CryptReleaseContext(hCryptProv, 0);
63 else if(CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT | CRYPT_NEWKEYSET))
65 if(!CryptGenRandom(hCryptProv, sizeof(buf), (PBYTE) &buf[0]))
67 fprintf(stderr, "WARNING: could not initialize random number generator (CryptGenRandom failed)\n");
70 CryptReleaseContext(hCryptProv, 0);
74 fprintf(stderr, "WARNING: could not initialize random number generator (CryptAcquireContext failed)\n");
79 f = fopen("/dev/urandom", "rb");
81 f = fopen("/dev/random", "rb");
85 if(fread(buf, sizeof(buf), 1, f) != 1)
87 fprintf(stderr, "WARNING: could not initialize random number generator (read from random device failed)\n");
94 fprintf(stderr, "WARNING: could not initialize random number generator (no random device found)\n");
99 mpz_import(temp.z, sizeof(buf), 1, 1, 0, 0, buf);
100 gmp_randseed(RANDSTATE, temp.z);
105 void d0_bignum_SHUTDOWN(void)
107 d0_bignum_clear(&temp);
108 gmp_randclear(RANDSTATE);
111 BOOL d0_iobuf_write_bignum(d0_iobuf_t *buf, const d0_bignum_t *bignum)
113 static unsigned char numbuf[65536];
115 numbuf[0] = mpz_sgn(bignum->z) & 3;
116 if((numbuf[0] & 3) != 0) // nonzero
118 count = (mpz_sizeinbase(bignum->z, 2) + 7) / 8;
119 if(count > sizeof(numbuf) - 1)
121 mpz_export(numbuf+1, &count, 1, 1, 0, 0, bignum->z);
123 return d0_iobuf_write_packet(buf, numbuf, count + 1);
126 d0_bignum_t *d0_iobuf_read_bignum(d0_iobuf_t *buf, d0_bignum_t *bignum)
128 static unsigned char numbuf[65536];
129 size_t count = sizeof(numbuf);
130 if(!d0_iobuf_read_packet(buf, numbuf, &count))
134 if(!bignum) bignum = d0_bignum_new(); if(!bignum) return NULL;
135 if(numbuf[0] & 3) // nonzero
137 mpz_import(bignum->z, count-1, 1, 1, 0, 0, numbuf+1);
138 if(numbuf[0] & 2) // negative
139 mpz_neg(bignum->z, bignum->z);
143 mpz_set_ui(bignum->z, 0);
148 ssize_t d0_bignum_export_unsigned(const d0_bignum_t *bignum, void *buf, size_t bufsize)
151 count = (mpz_sizeinbase(bignum->z, 2) + 7) / 8;
156 // pad from left (big endian numbers!)
157 memset(buf, 0, bufsize - count);
158 buf += bufsize - count;
161 mpz_export(buf, &bufsize, 1, 1, 0, 0, bignum->z);
165 // mpz_sizeinbase lied to us
167 // there is no sane way whatsoever to handle this
173 // mpz_sizeinbase lied to us
177 memset(buf, 0, count);
181 memmove(buf + count - bufsize, buf, bufsize);
182 memset(buf, 0, count - bufsize);
188 d0_bignum_t *d0_bignum_import_unsigned(d0_bignum_t *bignum, const void *buf, size_t bufsize)
191 if(!bignum) bignum = d0_bignum_new(); if(!bignum) return NULL;
192 mpz_import(bignum->z, bufsize, 1, 1, 0, 0, buf);
196 d0_bignum_t *d0_bignum_new(void)
198 d0_bignum_t *b = d0_malloc(sizeof(d0_bignum_t));
203 void d0_bignum_free(d0_bignum_t *a)
209 void d0_bignum_init(d0_bignum_t *b)
214 void d0_bignum_clear(d0_bignum_t *a)
219 size_t d0_bignum_size(const d0_bignum_t *r)
221 return mpz_sizeinbase(r->z, 2);
224 int d0_bignum_cmp(const d0_bignum_t *a, const d0_bignum_t *b)
226 return mpz_cmp(a->z, b->z);
229 d0_bignum_t *d0_bignum_rand_range(d0_bignum_t *r, const d0_bignum_t *min, const d0_bignum_t *max)
231 if(!r) r = d0_bignum_new(); if(!r) return NULL;
232 mpz_sub(temp.z, max->z, min->z);
233 mpz_urandomm(r->z, RANDSTATE, temp.z);
234 mpz_add(r->z, r->z, min->z);
238 d0_bignum_t *d0_bignum_rand_bit_atmost(d0_bignum_t *r, size_t n)
240 if(!r) r = d0_bignum_new(); if(!r) return NULL;
241 mpz_urandomb(r->z, RANDSTATE, n);
245 d0_bignum_t *d0_bignum_rand_bit_exact(d0_bignum_t *r, size_t n)
247 if(!r) r = d0_bignum_new(); if(!r) return NULL;
248 mpz_urandomb(r->z, RANDSTATE, n-1);
249 mpz_setbit(r->z, n-1);
253 d0_bignum_t *d0_bignum_zero(d0_bignum_t *r)
255 return d0_bignum_int(r, 0);
258 d0_bignum_t *d0_bignum_one(d0_bignum_t *r)
260 return d0_bignum_int(r, 1);
263 d0_bignum_t *d0_bignum_int(d0_bignum_t *r, int n)
265 if(!r) r = d0_bignum_new(); if(!r) return NULL;
270 d0_bignum_t *d0_bignum_mov(d0_bignum_t *r, const d0_bignum_t *a)
274 if(!r) r = d0_bignum_new(); if(!r) return NULL;
279 d0_bignum_t *d0_bignum_neg(d0_bignum_t *r, const d0_bignum_t *a)
281 if(!r) r = d0_bignum_new(); if(!r) return NULL;
286 d0_bignum_t *d0_bignum_shl(d0_bignum_t *r, const d0_bignum_t *a, ssize_t n)
288 if(!r) r = d0_bignum_new(); if(!r) return NULL;
290 mpz_mul_2exp(r->z, a->z, n);
292 mpz_fdiv_q_2exp(r->z, a->z, -n);
298 d0_bignum_t *d0_bignum_add(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
300 if(!r) r = d0_bignum_new(); if(!r) return NULL;
301 mpz_add(r->z, a->z, b->z);
305 d0_bignum_t *d0_bignum_sub(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
307 if(!r) r = d0_bignum_new(); if(!r) return NULL;
308 mpz_sub(r->z, a->z, b->z);
312 d0_bignum_t *d0_bignum_mul(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *b)
314 if(!r) r = d0_bignum_new(); if(!r) return NULL;
315 mpz_mul(r->z, a->z, b->z);
319 d0_bignum_t *d0_bignum_divmod(d0_bignum_t *q, d0_bignum_t *m, const d0_bignum_t *a, const d0_bignum_t *b)
325 mpz_fdiv_qr(q->z, m->z, a->z, b->z);
327 mpz_fdiv_q(q->z, a->z, b->z);
329 mpz_fdiv_r(m->z, a->z, b->z);
336 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)
338 r = d0_bignum_add(r, a, b);
339 mpz_fdiv_r(r->z, r->z, m->z);
343 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)
345 r = d0_bignum_mul(r, a, b);
346 mpz_fdiv_r(r->z, r->z, m->z);
350 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)
352 if(!r) r = d0_bignum_new(); if(!r) return NULL;
353 mpz_powm(r->z, a->z, b->z, m->z);
357 BOOL d0_bignum_mod_inv(d0_bignum_t *r, const d0_bignum_t *a, const d0_bignum_t *m)
359 // here, r MUST be set, as otherwise we cannot return error state!
360 return mpz_invert(r->z, a->z, m->z);
363 int d0_bignum_isprime(d0_bignum_t *r, int param)
365 return mpz_probab_prime_p(r->z, param);
368 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)
370 if(!r) r = d0_bignum_new(); if(!r) return NULL;
372 mpz_gcdext(r->z, s->z, t ? t->z : NULL, a->z, b->z);
374 mpz_gcdext(r->z, t->z, NULL, b->z, a->z);
376 mpz_gcd(r->z, a->z, b->z);
380 char *d0_bignum_tostring(const d0_bignum_t *x, unsigned int base)
382 return mpz_get_str(NULL, base, x->z);