x_long.c revision 296465 
1/* x_long.c */
2/*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
4 * 2000.
5 */
6/* ====================================================================
7 * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#include <stdio.h>
61#include "cryptlib.h"
62#include <openssl/asn1t.h>
63#include <openssl/bn.h>
64
65/*
66 * Custom primitive type for long handling. This converts between an
67 * ASN1_INTEGER and a long directly.
68 */
69
70static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it);
71static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it);
72
73static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype,
74                    const ASN1_ITEM *it);
75static int long_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
76                    int utype, char *free_cont, const ASN1_ITEM *it);
77
78static ASN1_PRIMITIVE_FUNCS long_pf = {
79    NULL, 0,
80    long_new,
81    long_free,
82    long_free,                  /* Clear should set to initial value */
83    long_c2i,
84    long_i2c
85};
86
87ASN1_ITEM_start(LONG)
88        ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, ASN1_LONG_UNDEF, "LONG"
89ASN1_ITEM_end(LONG)
90
91ASN1_ITEM_start(ZLONG)
92        ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, 0, "ZLONG"
93ASN1_ITEM_end(ZLONG)
94
95static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
96{
97    *(long *)pval = it->size;
98    return 1;
99}
100
101static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
102{
103    *(long *)pval = it->size;
104}
105
106static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype,
107                    const ASN1_ITEM *it)
108{
109    long ltmp;
110    unsigned long utmp;
111    int clen, pad, i;
112    /* this exists to bypass broken gcc optimization */
113    char *cp = (char *)pval;
114
115    /* use memcpy, because we may not be long aligned */
116    memcpy(&ltmp, cp, sizeof(long));
117
118    if (ltmp == it->size)
119        return -1;
120    /*
121     * Convert the long to positive: we subtract one if negative so we can
122     * cleanly handle the padding if only the MSB of the leading octet is
123     * set.
124     */
125    if (ltmp < 0)
126        utmp = -ltmp - 1;
127    else
128        utmp = ltmp;
129    clen = BN_num_bits_word(utmp);
130    /* If MSB of leading octet set we need to pad */
131    if (!(clen & 0x7))
132        pad = 1;
133    else
134        pad = 0;
135
136    /* Convert number of bits to number of octets */
137    clen = (clen + 7) >> 3;
138
139    if (cont) {
140        if (pad)
141            *cont++ = (ltmp < 0) ? 0xff : 0;
142        for (i = clen - 1; i >= 0; i--) {
143            cont[i] = (unsigned char)(utmp & 0xff);
144            if (ltmp < 0)
145                cont[i] ^= 0xff;
146            utmp >>= 8;
147        }
148    }
149    return clen + pad;
150}
151
152static int long_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
153                    int utype, char *free_cont, const ASN1_ITEM *it)
154{
155    int neg, i;
156    long ltmp;
157    unsigned long utmp = 0;
158    char *cp = (char *)pval;
159    if (len > (int)sizeof(long)) {
160        ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
161        return 0;
162    }
163    /* Is it negative? */
164    if (len && (cont[0] & 0x80))
165        neg = 1;
166    else
167        neg = 0;
168    utmp = 0;
169    for (i = 0; i < len; i++) {
170        utmp <<= 8;
171        if (neg)
172            utmp |= cont[i] ^ 0xff;
173        else
174            utmp |= cont[i];
175    }
176    ltmp = (long)utmp;
177    if (neg) {
178        ltmp++;
179        ltmp = -ltmp;
180    }
181    if (ltmp == it->size) {
182        ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
183        return 0;
184    }
185    memcpy(cp, &ltmp, sizeof(long));
186    return 1;
187}
188