File Coverage

src/ldns/compat/b64_ntop.c
Criterion Covered Total %
statement 0 41 0.0
branch 0 18 0.0
condition n/a
subroutine n/a
pod n/a
total 0 59 0.0


line stmt bran cond sub pod time code
1             /*
2             * Copyright (c) 1996, 1998 by Internet Software Consortium.
3             *
4             * Permission to use, copy, modify, and distribute this software for any
5             * purpose with or without fee is hereby granted, provided that the above
6             * copyright notice and this permission notice appear in all copies.
7             *
8             * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
9             * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10             * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11             * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12             * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13             * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14             * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
15             * SOFTWARE.
16             */
17              
18             /*
19             * Portions Copyright (c) 1995 by International Business Machines, Inc.
20             *
21             * International Business Machines, Inc. (hereinafter called IBM) grants
22             * permission under its copyrights to use, copy, modify, and distribute this
23             * Software with or without fee, provided that the above copyright notice and
24             * all paragraphs of this notice appear in all copies, and that the name of IBM
25             * not be used in connection with the marketing of any product incorporating
26             * the Software or modifications thereof, without specific, written prior
27             * permission.
28             *
29             * To the extent it has a right to do so, IBM grants an immunity from suit
30             * under its patents, if any, for the use, sale or manufacture of products to
31             * the extent that such products are used for performing Domain Name System
32             * dynamic updates in TCP/IP networks by means of the Software. No immunity is
33             * granted for any product per se or for any other function of any product.
34             *
35             * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
36             * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
37             * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
38             * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
39             * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
40             * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
41             */
42             #include
43             #include
44             #include
45             #include
46              
47             static const char Base64[] =
48             "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
49             static const char Pad64 = '=';
50              
51             /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
52             The following encoding technique is taken from RFC 1521 by Borenstein
53             and Freed. It is reproduced here in a slightly edited form for
54             convenience.
55              
56             A 65-character subset of US-ASCII is used, enabling 6 bits to be
57             represented per printable character. (The extra 65th character, "=",
58             is used to signify a special processing function.)
59              
60             The encoding process represents 24-bit groups of input bits as output
61             strings of 4 encoded characters. Proceeding from left to right, a
62             24-bit input group is formed by concatenating 3 8-bit input groups.
63             These 24 bits are then treated as 4 concatenated 6-bit groups, each
64             of which is translated into a single digit in the base64 alphabet.
65              
66             Each 6-bit group is used as an index into an array of 64 printable
67             characters. The character referenced by the index is placed in the
68             output string.
69              
70             Table 1: The Base64 Alphabet
71              
72             Value Encoding Value Encoding Value Encoding Value Encoding
73             0 A 17 R 34 i 51 z
74             1 B 18 S 35 j 52 0
75             2 C 19 T 36 k 53 1
76             3 D 20 U 37 l 54 2
77             4 E 21 V 38 m 55 3
78             5 F 22 W 39 n 56 4
79             6 G 23 X 40 o 57 5
80             7 H 24 Y 41 p 58 6
81             8 I 25 Z 42 q 59 7
82             9 J 26 a 43 r 60 8
83             10 K 27 b 44 s 61 9
84             11 L 28 c 45 t 62 +
85             12 M 29 d 46 u 63 /
86             13 N 30 e 47 v
87             14 O 31 f 48 w (pad) =
88             15 P 32 g 49 x
89             16 Q 33 h 50 y
90              
91             Special processing is performed if fewer than 24 bits are available
92             at the end of the data being encoded. A full encoding quantum is
93             always completed at the end of a quantity. When fewer than 24 input
94             bits are available in an input group, zero bits are added (on the
95             right) to form an integral number of 6-bit groups. Padding at the
96             end of the data is performed using the '=' character.
97              
98             Since all base64 input is an integral number of octets, only the
99             -------------------------------------------------
100             following cases can arise:
101            
102             (1) the final quantum of encoding input is an integral
103             multiple of 24 bits; here, the final unit of encoded
104             output will be an integral multiple of 4 characters
105             with no "=" padding,
106             (2) the final quantum of encoding input is exactly 8 bits;
107             here, the final unit of encoded output will be two
108             characters followed by two "=" padding characters, or
109             (3) the final quantum of encoding input is exactly 16 bits;
110             here, the final unit of encoded output will be three
111             characters followed by one "=" padding character.
112             */
113              
114             int
115 0           ldns_b64_ntop(uint8_t const *src, size_t srclength, char *target, size_t targsize) {
116 0           size_t datalength = 0;
117             uint8_t input[3];
118             uint8_t output[4];
119             size_t i;
120            
121 0 0         if (srclength == 0) {
122 0 0         if (targsize > 0) {
123 0           target[0] = '\0';
124 0           return 0;
125             } else {
126 0           return -1;
127             }
128             }
129              
130 0 0         while (2 < srclength) {
131 0           input[0] = *src++;
132 0           input[1] = *src++;
133 0           input[2] = *src++;
134 0           srclength -= 3;
135              
136 0           output[0] = input[0] >> 2;
137 0           output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
138 0           output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
139 0           output[3] = input[2] & 0x3f;
140             assert(output[0] < 64);
141             assert(output[1] < 64);
142             assert(output[2] < 64);
143             assert(output[3] < 64);
144              
145 0 0         if (datalength + 4 > targsize) {
146 0           return (-1);
147             }
148 0           target[datalength++] = Base64[output[0]];
149 0           target[datalength++] = Base64[output[1]];
150 0           target[datalength++] = Base64[output[2]];
151 0           target[datalength++] = Base64[output[3]];
152             }
153            
154             /* Now we worry about padding. */
155 0 0         if (0 != srclength) {
156             /* Get what's left. */
157 0           input[0] = input[1] = input[2] = (uint8_t) '\0';
158 0 0         for (i = 0; i < srclength; i++)
159 0           input[i] = *src++;
160            
161 0           output[0] = input[0] >> 2;
162 0           output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
163 0           output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
164             assert(output[0] < 64);
165             assert(output[1] < 64);
166             assert(output[2] < 64);
167              
168 0 0         if (datalength + 4 > targsize) {
169 0           return (-2);
170             }
171 0           target[datalength++] = Base64[output[0]];
172 0           target[datalength++] = Base64[output[1]];
173 0 0         if (srclength == 1) {
174 0           target[datalength++] = Pad64;
175             } else {
176 0           target[datalength++] = Base64[output[2]];
177             }
178 0           target[datalength++] = Pad64;
179             }
180 0 0         if (datalength >= targsize) {
181 0           return (-3);
182             }
183 0           target[datalength] = '\0'; /* Returned value doesn't count \0. */
184 0           return (int) (datalength);
185             }