x_long.c revision 109998 
1/* x_long.c */
2/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
3 * project 2000.
4 */
5/* ====================================================================
6 * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in
17 *    the documentation and/or other materials provided with the
18 *    distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 *    software must display the following acknowledgment:
22 *    "This product includes software developed by the OpenSSL Project
23 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 *    endorse or promote products derived from this software without
27 *    prior written permission. For written permission, please contact
28 *    licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 *    nor may "OpenSSL" appear in their names without prior written
32 *    permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 *    acknowledgment:
36 *    "This product includes software developed by the OpenSSL Project
37 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com).  This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59#include <stdio.h>
60#include "cryptlib.h"
61#include <openssl/asn1t.h>
62
63/* Custom primitive type for long handling. This converts between an ASN1_INTEGER
64 * and a long directly.
65 */
66
67
68static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it);
69static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it);
70
71static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it);
72static int long_c2i(ASN1_VALUE **pval, unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it);
73
74static ASN1_PRIMITIVE_FUNCS long_pf = {
75	NULL, 0,
76	long_new,
77	long_free,
78	long_free,	/* Clear should set to initial value */
79	long_c2i,
80	long_i2c
81};
82
83ASN1_ITEM_start(LONG)
84	ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, ASN1_LONG_UNDEF, "LONG"
85ASN1_ITEM_end(LONG)
86
87ASN1_ITEM_start(ZLONG)
88	ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, 0, "ZLONG"
89ASN1_ITEM_end(ZLONG)
90
91static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
92{
93	*(long *)pval = it->size;
94	return 1;
95}
96
97static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
98{
99	*(long *)pval = it->size;
100}
101
102static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it)
103{
104	long ltmp;
105	unsigned long utmp;
106	int clen, pad, i;
107	ltmp = *(long *)pval;
108	if(ltmp == it->size) return -1;
109	/* Convert the long to positive: we subtract one if negative so
110	 * we can cleanly handle the padding if only the MSB of the leading
111	 * octet is set.
112	 */
113	if(ltmp < 0) utmp = -ltmp - 1;
114	else utmp = ltmp;
115	clen = BN_num_bits_word(utmp);
116	/* If MSB of leading octet set we need to pad */
117	if(!(clen & 0x7)) pad = 1;
118	else pad = 0;
119
120	/* Convert number of bits to number of octets */
121	clen = (clen + 7) >> 3;
122
123	if(cont) {
124		if(pad) *cont++ = (ltmp < 0) ? 0xff : 0;
125		for(i = clen - 1; i >= 0; i--) {
126			cont[i] = (unsigned char)(utmp & 0xff);
127			if(ltmp < 0) cont[i] ^= 0xff;
128			utmp >>= 8;
129		}
130	}
131	return clen + pad;
132}
133
134static int long_c2i(ASN1_VALUE **pval, unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it)
135{
136	int neg, i;
137	long ltmp;
138	unsigned long utmp = 0;
139	if(len > sizeof(long)) {
140		ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
141		return 0;
142	}
143	/* Is it negative? */
144	if(len && (cont[0] & 0x80)) neg = 1;
145	else neg = 0;
146	utmp = 0;
147	for(i = 0; i < len; i++) {
148		utmp <<= 8;
149		if(neg) utmp |= cont[i] ^ 0xff;
150		else utmp |= cont[i];
151	}
152	ltmp = (long)utmp;
153	if(neg) {
154		ltmp++;
155		ltmp = -ltmp;
156	}
157	if(ltmp == it->size) {
158		ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
159		return 0;
160	}
161	*(long *)pval = ltmp;
162	return 1;
163}
164