2 * Copyright (c) 2006 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 RCSID("$Id: bn.c 22261 2007-12-09 06:24:18Z lha $");
45 #include <krb5-types.h>
46 #include <rfc2459_asn1.h> /* XXX */
57 hi = calloc(1, sizeof(*hi));
71 heim_integer *hi = (heim_integer *)bn;
73 memset(hi->data, 0, hi->length);
76 memset(hi, 0, sizeof(*hi));
80 BN_clear_free(BIGNUM *bn)
86 BN_dup(const BIGNUM *bn)
89 if (der_copy_heim_integer((const heim_integer *)bn, (heim_integer *)b)) {
97 * If the caller really want to know the number of bits used, subtract
98 * one from the length, multiply by 8, and then lookup in the table
99 * how many bits the hightest byte uses.
102 BN_num_bits(const BIGNUM *bn)
104 static unsigned char num2bits[256] = {
105 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4, 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
106 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
107 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
108 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
109 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
110 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
111 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
112 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
114 const heim_integer *i = (const void *)bn;
117 return (i->length - 1) * 8 + num2bits[((unsigned char *)i->data)[0]];
121 BN_num_bytes(const BIGNUM *bn)
123 return ((const heim_integer *)bn)->length;
127 * Ignore negative flag.
131 BN_bin2bn(const void *s, int len, BIGNUM *bn)
133 heim_integer *hi = (void *)bn;
139 hi = (heim_integer *)BN_new();
144 BN_clear((BIGNUM *)hi);
146 hi->data = malloc(len);
147 if (hi->data == NULL && len != 0) {
149 BN_free((BIGNUM *)hi);
153 memcpy(hi->data, s, len);
158 BN_bn2bin(const BIGNUM *bn, void *to)
160 const heim_integer *hi = (const void *)bn;
161 memcpy(to, hi->data, hi->length);
166 BN_hex2bn(BIGNUM **bnp, const char *in)
184 ret = hex_decode(in, data, len);
190 *bnp = BN_bin2bn(data, ret, NULL);
194 BN_set_negative(*bnp, negative);
199 BN_bn2hex(const BIGNUM *bn)
206 len = BN_num_bytes(bn);
211 len = BN_bn2bin(bn, data);
213 ret = hex_encode(data, len, &str);
222 BN_cmp(const BIGNUM *bn1, const BIGNUM *bn2)
224 return der_heim_integer_cmp((const heim_integer *)bn1,
225 (const heim_integer *)bn2);
229 BN_set_negative(BIGNUM *bn, int flag)
231 ((heim_integer *)bn)->negative = (flag ? 1 : 0);
235 BN_is_negative(const BIGNUM *bn)
237 return ((const heim_integer *)bn)->negative ? 1 : 0;
240 static const unsigned char is_set[8] = { 1, 2, 4, 8, 16, 32, 64, 128 };
243 BN_is_bit_set(const BIGNUM *bn, int bit)
245 heim_integer *hi = (heim_integer *)bn;
246 unsigned char *p = hi->data;
248 if ((bit / 8) > hi->length || hi->length == 0)
251 return p[hi->length - 1 - (bit / 8)] & is_set[bit % 8];
255 BN_set_bit(BIGNUM *bn, int bit)
257 heim_integer *hi = (heim_integer *)bn;
260 if ((bit / 8) > hi->length || hi->length == 0) {
261 size_t len = (bit + 7) / 8;
262 void *d = realloc(hi->data, len);
267 memset(&p[hi->length], 0, len);
272 p[hi->length - 1 - (bit / 8)] |= is_set[bit % 8];
277 BN_clear_bit(BIGNUM *bn, int bit)
279 heim_integer *hi = (heim_integer *)bn;
280 unsigned char *p = hi->data;
282 if ((bit / 8) > hi->length || hi->length == 0)
285 p[hi->length - 1 - (bit / 8)] &= (unsigned char)(~(is_set[bit % 8]));
291 BN_set_word(BIGNUM *bn, unsigned long num)
293 unsigned char p[sizeof(num)];
297 for (num2 = num, i = 0; num2 > 0; i++)
302 p[i - 1] = (num & 0xff);
306 bn = BN_bin2bn(p, len + 1, bn);
311 BN_get_word(const BIGNUM *bn)
313 heim_integer *hi = (heim_integer *)bn;
314 unsigned long num = 0;
317 if (hi->negative || hi->length > sizeof(num))
320 for (i = 0; i < hi->length; i++)
321 num = ((unsigned char *)hi->data)[i] | (num << 8);
326 BN_rand(BIGNUM *bn, int bits, int top, int bottom)
328 size_t len = (bits + 7) / 8;
329 heim_integer *i = (heim_integer *)bn;
334 i->data = malloc(len);
335 if (i->data == NULL && len != 0)
339 if (RAND_bytes(i->data, i->length) != 1) {
348 BN_clear_bit(bn, j - 1);
355 } else if (top == 0 && bits > 0) {
356 BN_set_bit(bn, bits - 1);
357 } else if (top == 1 && bits > 1) {
358 BN_set_bit(bn, bits - 1);
359 BN_set_bit(bn, bits - 2);
365 if (bottom && bits > 0)
376 BN_uadd(BIGNUM *res, const BIGNUM *a, const BIGNUM *b)
378 const heim_integer *ai = (const heim_integer *)a;
379 const heim_integer *bi = (const heim_integer *)b;
380 const unsigned char *ap, *bp;
386 if (ai->negative && bi->negative)
388 if (ai->length < bi->length) {
389 const heim_integer *si = bi;
394 ci.length = ai->length + 1;
395 ci.data = malloc(ci.length);
399 ap = &((const unsigned char *)ai->data)[ai->length - 1];
400 bp = &((const unsigned char *)bi->data)[bi->length - 1];
401 cp = &((unsigned char *)ci.data)[ci.length - 1];
403 for (len = bi->length; len > 0; len--) {
404 carry = *ap + *bp + carry;
406 carry = (carry & ~0xff) ? 1 : 0;
409 for (len = ai->length - bi->length; len > 0; len--) {
412 carry = (carry & ~0xff) ? 1 : 0;
416 memmove(cp, cp + 1, --ci.length);
421 *((heim_integer *)res) = ci;
428 * Callback when doing slow generation of numbers, like primes.
432 BN_GENCB_set(BN_GENCB *gencb, int (*cb_2)(int, int, BN_GENCB *), void *ctx)
435 gencb->cb.cb_2 = cb_2;
440 BN_GENCB_call(BN_GENCB *cb, int a, int b)
442 if (cb == NULL || cb->cb.cb_2 == NULL)
444 return cb->cb.cb_2(a, b, cb);