x_long.c revision 225736 
1/* x_long.c */
2/* Written by Dr Stephen N Henson (steve@openssl.org) 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#include <openssl/bn.h>
63
64/* Custom primitive type for long handling. This converts between an ASN1_INTEGER
65 * and a long directly.
66 */
67
68
69static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it);
70static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it);
71
72static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it);
73static int long_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it);
74
75static ASN1_PRIMITIVE_FUNCS long_pf = {
76	NULL, 0,
77	long_new,
78	long_free,
79	long_free,	/* Clear should set to initial value */
80	long_c2i,
81	long_i2c
82};
83
84ASN1_ITEM_start(LONG)
85	ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, ASN1_LONG_UNDEF, "LONG"
86ASN1_ITEM_end(LONG)
87
88ASN1_ITEM_start(ZLONG)
89	ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, 0, "ZLONG"
90ASN1_ITEM_end(ZLONG)
91
92static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
93{
94	*(long *)pval = it->size;
95	return 1;
96}
97
98static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
99{
100	*(long *)pval = it->size;
101}
102
103static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it)
104{
105	long ltmp;
106	unsigned long utmp;
107	int clen, pad, i;
108	/* this exists to bypass broken gcc optimization */
109	char *cp = (char *)pval;
110
111	/* use memcpy, because we may not be long aligned */
112	memcpy(&ltmp, cp, sizeof(long));
113
114	if(ltmp == it->size) return -1;
115	/* Convert the long to positive: we subtract one if negative so
116	 * we can cleanly handle the padding if only the MSB of the leading
117	 * octet is set.
118	 */
119	if(ltmp < 0) utmp = -ltmp - 1;
120	else utmp = ltmp;
121	clen = BN_num_bits_word(utmp);
122	/* If MSB of leading octet set we need to pad */
123	if(!(clen & 0x7)) pad = 1;
124	else pad = 0;
125
126	/* Convert number of bits to number of octets */
127	clen = (clen + 7) >> 3;
128
129	if(cont) {
130		if(pad) *cont++ = (ltmp < 0) ? 0xff : 0;
131		for(i = clen - 1; i >= 0; i--) {
132			cont[i] = (unsigned char)(utmp & 0xff);
133			if(ltmp < 0) cont[i] ^= 0xff;
134			utmp >>= 8;
135		}
136	}
137	return clen + pad;
138}
139
140static int long_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
141		    int utype, char *free_cont, const ASN1_ITEM *it)
142{
143	int neg, i;
144	long ltmp;
145	unsigned long utmp = 0;
146	char *cp = (char *)pval;
147	if(len > (int)sizeof(long)) {
148		ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
149		return 0;
150	}
151	/* Is it negative? */
152	if(len && (cont[0] & 0x80)) neg = 1;
153	else neg = 0;
154	utmp = 0;
155	for(i = 0; i < len; i++) {
156		utmp <<= 8;
157		if(neg) utmp |= cont[i] ^ 0xff;
158		else utmp |= cont[i];
159	}
160	ltmp = (long)utmp;
161	if(neg) {
162		ltmp++;
163		ltmp = -ltmp;
164	}
165	if(ltmp == it->size) {
166		ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
167		return 0;
168	}
169	memcpy(cp, &ltmp, sizeof(long));
170	return 1;
171}
172