xref: /openbsd-src/lib/libcrypto/asn1/x_long.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /* $OpenBSD: x_long.c,v 1.9 2014/07/11 08:44:47 jsing Exp $ */
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 <string.h>
61 
62 #include <openssl/asn1t.h>
63 #include <openssl/bn.h>
64 #include <openssl/err.h>
65 
66 /* Custom primitive type for long handling. This converts between an ASN1_INTEGER
67  * and a long directly.
68  */
69 
70 
71 static int long_new(ASN1_VALUE **pval, const ASN1_ITEM *it);
72 static void long_free(ASN1_VALUE **pval, const ASN1_ITEM *it);
73 
74 static int long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it);
75 static int long_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it);
76 static int long_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it, int indent, const ASN1_PCTX *pctx);
77 
78 static 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 	long_print
86 };
87 
88 ASN1_ITEM_start(LONG)
89 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, ASN1_LONG_UNDEF, "LONG"
90 ASN1_ITEM_end(LONG)
91 
92 ASN1_ITEM_start(ZLONG)
93 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &long_pf, 0, "ZLONG"
94 ASN1_ITEM_end(ZLONG)
95 
96 static int
97 long_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
98 {
99 	*(long *)pval = it->size;
100 	return 1;
101 }
102 
103 static void
104 long_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
105 {
106 	*(long *)pval = it->size;
107 }
108 
109 static int
110 long_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype,
111     const ASN1_ITEM *it)
112 {
113 	long ltmp;
114 	unsigned long utmp;
115 	int clen, pad, i;
116 	/* this exists to bypass broken gcc optimization */
117 	char *cp = (char *)pval;
118 
119 	/* use memcpy, because we may not be long aligned */
120 	memcpy(&ltmp, cp, sizeof(long));
121 
122 	if (ltmp == it->size)
123 		return -1;
124 	/* Convert the long to positive: we subtract one if negative so
125 	 * we can cleanly handle the padding if only the MSB of the leading
126 	 * octet is set.
127 	 */
128 	if (ltmp < 0)
129 		utmp = -ltmp - 1;
130 	else
131 		utmp = ltmp;
132 	clen = BN_num_bits_word(utmp);
133 	/* If MSB of leading octet set we need to pad */
134 	if (!(clen & 0x7))
135 		pad = 1;
136 	else
137 		pad = 0;
138 
139 	/* Convert number of bits to number of octets */
140 	clen = (clen + 7) >> 3;
141 
142 	if (cont) {
143 		if (pad)
144 			*cont++ = (ltmp < 0) ? 0xff : 0;
145 		for (i = clen - 1; i >= 0; i--) {
146 			cont[i] = (unsigned char)(utmp & 0xff);
147 			if (ltmp < 0)
148 				cont[i] ^= 0xff;
149 			utmp >>= 8;
150 		}
151 	}
152 	return clen + pad;
153 }
154 
155 static int
156 long_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype,
157     char *free_cont, const ASN1_ITEM *it)
158 {
159 	int neg, i;
160 	long ltmp;
161 	unsigned long utmp = 0;
162 	char *cp = (char *)pval;
163 	if (len > (int)sizeof(long)) {
164 		ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
165 		return 0;
166 	}
167 	/* Is it negative? */
168 	if (len && (cont[0] & 0x80))
169 		neg = 1;
170 	else
171 		neg = 0;
172 	utmp = 0;
173 	for (i = 0; i < len; i++) {
174 		utmp <<= 8;
175 		if (neg)
176 			utmp |= cont[i] ^ 0xff;
177 		else
178 			utmp |= cont[i];
179 	}
180 	ltmp = (long)utmp;
181 	if (neg) {
182 		ltmp++;
183 		ltmp = -ltmp;
184 	}
185 	if (ltmp == it->size) {
186 		ASN1err(ASN1_F_LONG_C2I, ASN1_R_INTEGER_TOO_LARGE_FOR_LONG);
187 		return 0;
188 	}
189 	memcpy(cp, &ltmp, sizeof(long));
190 	return 1;
191 }
192 
193 static int
194 long_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it, int indent,
195     const ASN1_PCTX *pctx)
196 {
197 	return BIO_printf(out, "%ld\n", *(long *)pval);
198 }
199