1/*
2 * Copyright (c) 1995-2001 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 <stdlib.h>
35#include <string.h>
36
37#include "dma.h"
38
39static char base64_chars[] =
40    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
41
42static int
43pos(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
53int
54base64_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
93static unsigned int
94token_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
115int
116base64_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