xref: /freebsd/crypto/heimdal/lib/asn1/der_length.c (revision eacee0ff7ec955b32e09515246bd97b6edcd2b0f)
1 /*
2  * Copyright (c) 1997 - 2001 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "der_locl.h"
35 
36 RCSID("$Id: der_length.c,v 1.12 2001/09/25 13:39:26 assar Exp $");
37 
38 static size_t
39 len_unsigned (unsigned val)
40 {
41   size_t ret = 0;
42 
43   do {
44     ++ret;
45     val /= 256;
46   } while (val);
47   return ret;
48 }
49 
50 static size_t
51 len_int (int val)
52 {
53   size_t ret = 0;
54 
55   if (val == 0)
56     return 1;
57   while (val > 255 || val < -255) {
58     ++ret;
59     val /= 256;
60   }
61   if (val != 0) {
62     ++ret;
63     if ((signed char)val != val)
64       ++ret;
65     val /= 256;
66   }
67   return ret;
68 }
69 
70 static size_t
71 len_oid (const oid *oid)
72 {
73     size_t ret = 1;
74     int n;
75 
76     for (n = 2; n < oid->length; ++n) {
77 	unsigned u = oid->components[n];
78 
79 	++ret;
80 	u /= 128;
81 	while (u > 0) {
82 	    ++ret;
83 	    u /= 128;
84 	}
85     }
86     return ret;
87 }
88 
89 size_t
90 length_len (size_t len)
91 {
92   if (len < 128)
93     return 1;
94   else
95     return len_unsigned (len) + 1;
96 }
97 
98 size_t
99 length_integer (const int *data)
100 {
101   size_t len = len_int (*data);
102 
103   return 1 + length_len(len) + len;
104 }
105 
106 size_t
107 length_unsigned (const unsigned *data)
108 {
109   size_t len = len_unsigned (*data);
110 
111   return 1 + length_len(len) + len;
112 }
113 
114 size_t
115 length_enumerated (const unsigned *data)
116 {
117   size_t len = len_int (*data);
118 
119   return 1 + length_len(len) + len;
120 }
121 
122 size_t
123 length_general_string (const general_string *data)
124 {
125   char *str = *data;
126   size_t len = strlen(str);
127   return 1 + length_len(len) + len;
128 }
129 
130 size_t
131 length_octet_string (const octet_string *k)
132 {
133   return 1 + length_len(k->length) + k->length;
134 }
135 
136 size_t
137 length_oid (const oid *k)
138 {
139   size_t len = len_oid (k);
140 
141   return 1 + length_len(len) + len;
142 }
143 
144 size_t
145 length_generalized_time (const time_t *t)
146 {
147   octet_string k;
148   size_t ret;
149 
150   time2generalizedtime (*t, &k);
151   ret = 1 + length_len(k.length) + k.length;
152   free (k.data);
153   return ret;
154 }
155