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);
458 IMPLEMENT_STACK_OF(ASN1_INTEGER
)
460 IMPLEMENT_ASN1_SET_OF(ASN1_INTEGER
)