1 /* crypto/asn1/a_int.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
61 #include <openssl/asn1.h>
62 #include <openssl/bn.h>
64 ASN1_INTEGER *ASN1_INTEGER_dup(const ASN1_INTEGER *x)
66 return M_ASN1_INTEGER_dup(x);
69 int ASN1_INTEGER_cmp(const ASN1_INTEGER *x, const ASN1_INTEGER *y)
73 neg = x->type & V_ASN1_NEG;
74 if (neg != (y->type & V_ASN1_NEG)) {
81 ret = ASN1_STRING_cmp(x, y);
90 * This converts an ASN1 INTEGER into its content encoding.
91 * The internal representation is an ASN1_STRING whose data is a big endian
92 * representation of the value, ignoring the sign. The sign is determined by
93 * the type: V_ASN1_INTEGER for positive and V_ASN1_NEG_INTEGER for negative.
95 * Positive integers are no problem: they are almost the same as the DER
96 * encoding, except if the first byte is >= 0x80 we need to add a zero pad.
98 * Negative integers are a bit trickier...
99 * The DER representation of negative integers is in 2s complement form.
100 * The internal form is converted by complementing each octet and finally
101 * adding one to the result. This can be done less messily with a little trick.
102 * If the internal form has trailing zeroes then they will become FF by the
103 * complement and 0 by the add one (due to carry) so just copy as many trailing
104 * zeros to the destination as there are in the source. The carry will add one
105 * to the last none zero octet: so complement this octet and add one and finally
106 * complement any left over until you get to the start of the string.
108 * Padding is a little trickier too. If the first bytes is > 0x80 then we pad
109 * with 0xff. However if the first byte is 0x80 and one of the following bytes
110 * is non-zero we pad with 0xff. The reason for this distinction is that 0x80
111 * followed by optional zeros isn't padded.
114 int i2c_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp)
116 int pad = 0, ret, i, neg;
117 unsigned char *p, *n, pb = 0;
121 neg = a->type & V_ASN1_NEG;
127 if (!neg && (i > 127)) {
134 } else if (i == 128) {
136 * Special case: if any other bytes non zero we pad:
137 * otherwise we don't.
139 for (i = 1; i < a->length; i++)
158 memcpy(p, a->data, (unsigned int)a->length);
160 /* Begin at the end of the encoding */
161 n = a->data + a->length - 1;
164 /* Copy zeros to destination as long as source is zero */
170 /* Complement and increment next octet */
171 *(p--) = ((*(n--)) ^ 0xff) + 1;
173 /* Complement any octets left */
175 *(p--) = *(n--) ^ 0xff;
182 /* Convert just ASN1 INTEGER content octets to ASN1_INTEGER structure */
184 ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **a, const unsigned char **pp,
187 ASN1_INTEGER *ret = NULL;
188 const unsigned char *p, *pend;
189 unsigned char *to, *s;
192 if ((a == NULL) || ((*a) == NULL)) {
193 if ((ret = M_ASN1_INTEGER_new()) == NULL)
195 ret->type = V_ASN1_INTEGER;
203 * We must OPENSSL_malloc stuff, even for 0 bytes otherwise it signifies
204 * a missing NULL parameter.
206 s = (unsigned char *)OPENSSL_malloc((int)len + 1);
208 i = ERR_R_MALLOC_FAILURE;
214 * Strictly speaking this is an illegal INTEGER but we tolerate it.
216 ret->type = V_ASN1_INTEGER;
217 } else if (*p & 0x80) { /* a negative number */
218 ret->type = V_ASN1_NEG_INTEGER;
219 if ((*p == 0xff) && (len != 1)) {
232 * Special case: if all zeros then the number will be of the form FF
233 * followed by n zero bytes: this corresponds to 1 followed by n zero
234 * bytes. We've already written n zeros so we just append an extra
235 * one and set the first byte to a 1. This is treated separately
236 * because it is the only case where the number of bytes is larger
244 *(to--) = (*(p--) ^ 0xff) + 1;
247 *(to--) = *(p--) ^ 0xff;
250 ret->type = V_ASN1_INTEGER;
251 if ((*p == 0) && (len != 1)) {
255 memcpy(s, p, (int)len);
258 if (ret->data != NULL)
259 OPENSSL_free(ret->data);
261 ret->length = (int)len;
267 ASN1err(ASN1_F_C2I_ASN1_INTEGER, i);
268 if ((ret != NULL) && ((a == NULL) || (*a != ret)))
269 M_ASN1_INTEGER_free(ret);
274 * This is a version of d2i_ASN1_INTEGER that ignores the sign bit of ASN1
275 * integers: some broken software can encode a positive INTEGER with its MSB
276 * set as negative (it doesn't add a padding zero).
279 ASN1_INTEGER *d2i_ASN1_UINTEGER(ASN1_INTEGER **a, const unsigned char **pp,
282 ASN1_INTEGER *ret = NULL;
283 const unsigned char *p;
286 int inf, tag, xclass;
289 if ((a == NULL) || ((*a) == NULL)) {
290 if ((ret = M_ASN1_INTEGER_new()) == NULL)
292 ret->type = V_ASN1_INTEGER;
297 inf = ASN1_get_object(&p, &len, &tag, &xclass, length);
299 i = ASN1_R_BAD_OBJECT_HEADER;
303 if (tag != V_ASN1_INTEGER) {
304 i = ASN1_R_EXPECTING_AN_INTEGER;
309 * We must OPENSSL_malloc stuff, even for 0 bytes otherwise it signifies
310 * a missing NULL parameter.
312 s = (unsigned char *)OPENSSL_malloc((int)len + 1);
314 i = ERR_R_MALLOC_FAILURE;
317 ret->type = V_ASN1_INTEGER;
319 if ((*p == 0) && (len != 1)) {
323 memcpy(s, p, (int)len);
327 if (ret->data != NULL)
328 OPENSSL_free(ret->data);
330 ret->length = (int)len;
336 ASN1err(ASN1_F_D2I_ASN1_UINTEGER, i);
337 if ((ret != NULL) && ((a == NULL) || (*a != ret)))
338 M_ASN1_INTEGER_free(ret);
342 int ASN1_INTEGER_set(ASN1_INTEGER *a, long v)
346 unsigned char buf[sizeof(long) + 1];
348 if (a->length < (int)(sizeof(long) + 1)) {
350 OPENSSL_free(a->data);
352 (unsigned char *)OPENSSL_malloc(sizeof(long) + 1)) != NULL)
353 memset((char *)a->data, 0, sizeof(long) + 1);
355 if (a->data == NULL) {
356 ASN1err(ASN1_F_ASN1_INTEGER_SET, ERR_R_MALLOC_FAILURE);
361 a->type = V_ASN1_NEG_INTEGER;
363 a->type = V_ASN1_INTEGER;
365 for (i = 0; i < sizeof(long); i++) {
368 buf[i] = (int)v & 0xff;
372 for (k = i - 1; k >= 0; k--)
373 a->data[j++] = buf[k];
378 long ASN1_INTEGER_get(const ASN1_INTEGER *a)
386 if (i == V_ASN1_NEG_INTEGER)
388 else if (i != V_ASN1_INTEGER)
391 if (a->length > (int)sizeof(long)) {
392 /* hmm... a bit ugly, return all ones */
398 for (i = 0; i < a->length; i++) {
400 r |= (unsigned char)a->data[i];
407 ASN1_INTEGER *BN_to_ASN1_INTEGER(const BIGNUM *bn, ASN1_INTEGER *ai)
413 ret = M_ASN1_INTEGER_new();
417 ASN1err(ASN1_F_BN_TO_ASN1_INTEGER, ERR_R_NESTED_ASN1_ERROR);
420 if (BN_is_negative(bn))
421 ret->type = V_ASN1_NEG_INTEGER;
423 ret->type = V_ASN1_INTEGER;
425 len = ((j == 0) ? 0 : ((j / 8) + 1));
426 if (ret->length < len + 4) {
427 unsigned char *new_data = OPENSSL_realloc(ret->data, len + 4);
429 ASN1err(ASN1_F_BN_TO_ASN1_INTEGER, ERR_R_MALLOC_FAILURE);
432 ret->data = new_data;
434 ret->length = BN_bn2bin(bn, ret->data);
435 /* Correct zero case */
443 M_ASN1_INTEGER_free(ret);
447 BIGNUM *ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn)
451 if ((ret = BN_bin2bn(ai->data, ai->length, bn)) == NULL)
452 ASN1err(ASN1_F_ASN1_INTEGER_TO_BN, ASN1_R_BN_LIB);
453 else if (ai->type == V_ASN1_NEG_INTEGER)
454 BN_set_negative(ret, 1);