1 /*
2 * Copyright (c) 1995-2001 Kungliga Tekniska Högskolan
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 <stdlib.h>
35 #include <string.h>
36
37 #include "dma.h"
38
39 static char base64_chars[] =
40 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
41
42 static int
pos(char c)43 pos(char c)
44 {
45 char *p;
46 for (p = base64_chars; *p; p++)
47 if (*p == c)
48 return p - base64_chars;
49 return -1;
50 }
51
52
53 int
base64_encode(const void * data,int size,char ** str)54 base64_encode(const void *data, int size, char **str)
55 {
56 char *s, *p;
57 int i;
58 int c;
59 const unsigned char *q;
60
61 p = s = (char *) malloc(size * 4 / 3 + 4);
62 if (p == NULL)
63 return -1;
64 q = (const unsigned char *) data;
65 i = 0;
66 for (i = 0; i < size;) {
67 c = q[i++];
68 c *= 256;
69 if (i < size)
70 c += q[i];
71 i++;
72 c *= 256;
73 if (i < size)
74 c += q[i];
75 i++;
76 p[0] = base64_chars[(c & 0x00fc0000) >> 18];
77 p[1] = base64_chars[(c & 0x0003f000) >> 12];
78 p[2] = base64_chars[(c & 0x00000fc0) >> 6];
79 p[3] = base64_chars[(c & 0x0000003f) >> 0];
80 if (i > size)
81 p[3] = '=';
82 if (i > size + 1)
83 p[2] = '=';
84 p += 4;
85 }
86 *p = 0;
87 *str = s;
88 return strlen(s);
89 }
90
91 #define DECODE_ERROR 0xffffffff
92
93 static unsigned int
token_decode(const char * token)94 token_decode(const char *token)
95 {
96 int i;
97 unsigned int val = 0;
98 int marker = 0;
99 if (strlen(token) < 4)
100 return DECODE_ERROR;
101 for (i = 0; i < 4; i++) {
102 val *= 64;
103 if (token[i] == '=')
104 marker++;
105 else if (marker > 0)
106 return DECODE_ERROR;
107 else
108 val += pos(token[i]);
109 }
110 if (marker > 2)
111 return DECODE_ERROR;
112 return (marker << 24) | val;
113 }
114
115 int
base64_decode(const char * str,void * data)116 base64_decode(const char *str, void *data)
117 {
118 const char *p;
119 unsigned char *q;
120
121 q = data;
122 for (p = str; *p && (*p == '=' || strchr(base64_chars, *p)); p += 4) {
123 unsigned int val = token_decode(p);
124 unsigned int marker = (val >> 24) & 0xff;
125 if (val == DECODE_ERROR)
126 return -1;
127 *q++ = (val >> 16) & 0xff;
128 if (marker < 2)
129 *q++ = (val >> 8) & 0xff;
130 if (marker < 1)
131 *q++ = val & 0xff;
132 }
133 return q - (unsigned char *) data;
134 }
135
136