xref: /netbsd-src/sys/dev/iscsi/base64.c (revision e0c33d56947cbef18399ebf4ec5637772bf62a16)
1 /*	$NetBSD: base64.c,v 1.2 2017/04/18 17:28:18 maya Exp $	*/
2 
3 /*-
4  * Copyright (c) 2005,2006,2011 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Wasabi Systems, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 /*
32  * Adapted for kernel mode use with minimal changes from
33  * /usr/src/crypto/dist/heimdal/lib/roken/base64.c
34  *
35  * Original:
36  * Copyright (c) 1995-2001 Kungliga Tekniska H�gskolan
37  * (Royal Institute of Technology, Stockholm, Sweden).
38  * All rights reserved.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  *
44  * 1. Redistributions of source code must retain the above copyright
45  *    notice, this list of conditions and the following disclaimer.
46  *
47  * 2. Redistributions in binary form must reproduce the above copyright
48  *    notice, this list of conditions and the following disclaimer in the
49  *    documentation and/or other materials provided with the distribution.
50  *
51  * 3. Neither the name of the Institute nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  */
67 
68 #include "iscsi_globals.h"
69 #include "base64.h"
70 
71 static char base64_chars[] =
72 	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
73 
74 static int
pos(char c)75 pos(char c)
76 {
77 	char *p;
78 
79 	for (p = base64_chars; *p; p++) {
80 		if (*p == c) {
81 			return (int)(p - base64_chars);
82 		}
83 	}
84 	return -1;
85 }
86 
87 int
base64_encode(const void * data,int size,uint8_t * buffer)88 base64_encode(const void *data, int size, uint8_t * buffer)
89 {
90 	uint8_t *p;
91 	int i;
92 	int c;
93 	const uint8_t *q;
94 
95 	p = buffer;
96 	q = (const uint8_t *) data;
97 	*p++ = '0';
98 	*p++ = 'b';
99 
100 	for (i = 0; i < size;) {
101 		c = q[i++];
102 		c *= 256;
103 		if (i < size) {
104 			c += q[i];
105 		}
106 		i++;
107 		c *= 256;
108 		if (i < size) {
109 			c += q[i];
110 		}
111 		i++;
112 		p[0] = base64_chars[(c & 0x00fc0000) >> 18];
113 		p[1] = base64_chars[(c & 0x0003f000) >> 12];
114 		p[2] = base64_chars[(c & 0x00000fc0) >> 6];
115 		p[3] = base64_chars[(c & 0x0000003f) >> 0];
116 		if (i > size) {
117 			p[3] = '=';
118 		}
119 		if (i > size + 1) {
120 			p[2] = '=';
121 		}
122 		p += 4;
123 	}
124 	*p = 0;
125 	return strlen(buffer);
126 }
127 
128 #define DECODE_ERROR 0xffffffff
129 
130 static uint32_t
token_decode(uint8_t * token)131 token_decode(uint8_t * token)
132 {
133 	int i;
134 	uint32_t val = 0;
135 	int marker = 0;
136 
137 	if (strlen(token) < 4) {
138 		return DECODE_ERROR;
139 	}
140 	for (i = 0; i < 4; i++) {
141 		val *= 64;
142 		if (token[i] == '=') {
143 			marker++;
144 		} else if (marker > 0) {
145 			return DECODE_ERROR;
146 		} else {
147 			val += pos(token[i]);
148 		}
149 	}
150 	if (marker > 2) {
151 		return DECODE_ERROR;
152 	}
153 	return (marker << 24) | val;
154 }
155 
156 
157 uint8_t *
base64_decode(uint8_t * str,void * data,int * datalen)158 base64_decode(uint8_t * str, void *data, int *datalen)
159 {
160 	uint8_t *p, *q;
161 	uint32_t marker = 0;
162 
163 	q = data;
164 	for (p = str; *p; p += 4) {
165 		uint32_t val = token_decode(p);
166 		marker = (val >> 24) & 0xff;
167 		if (val == DECODE_ERROR) {
168 			return NULL;
169 		}
170 		*q++ = (val >> 16) & 0xff;
171 		if (marker < 2) {
172 			*q++ = (val >> 8) & 0xff;
173 		}
174 		if (marker < 1) {
175 			*q++ = val & 0xff;
176 		}
177 	}
178 	*datalen = (int)(q - (uint8_t *) data);
179 
180 	return p - marker + 1;
181 }
182