1  /*
2  * "streamable kanji code filter and converter"
3  * Copyright (c) 1998-2002 HappySize, Inc. All rights reserved.
4  *
5  * LICENSE NOTICES
6  *
7  * This file is part of "streamable kanji code filter and converter",
8  * which is distributed under the terms of GNU Lesser General Public
9  * License (version 2) as published by the Free Software Foundation.
10  *
11  * This software is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with "streamable kanji code filter and converter";
18  * if not, write to the Free Software Foundation, Inc., 59 Temple Place,
19  * Suite 330, Boston, MA  02111-1307  USA
20  *
21  * The author of this file:
22  *
23  */
24 /*
25  * The source code included in this files was separated from mbfilter.c
26  * by Moriyoshi Koizumi <moriyoshi@php.net> on 4 Dec 2002. The file
27  * mbfilter.c is included in this package .
28  *
29  */
30 
31 #ifdef HAVE_CONFIG_H
32 #include "config.h"
33 #endif
34 
35 #include "mbfilter.h"
36 #include "mbfilter_base64.h"
37 
38 const mbfl_encoding mbfl_encoding_base64 = {
39 	mbfl_no_encoding_base64,
40 	"BASE64",
41 	"BASE64",
42 	NULL,
43 	NULL,
44 	MBFL_ENCTYPE_ENC_STRM | MBFL_ENCTYPE_GL_UNSAFE,
45 	NULL,
46 	NULL
47 };
48 
49 const struct mbfl_convert_vtbl vtbl_8bit_b64 = {
50 	mbfl_no_encoding_8bit,
51 	mbfl_no_encoding_base64,
52 	mbfl_filt_conv_common_ctor,
53 	mbfl_filt_conv_common_dtor,
54 	mbfl_filt_conv_base64enc,
55 	mbfl_filt_conv_base64enc_flush
56 };
57 
58 const struct mbfl_convert_vtbl vtbl_b64_8bit = {
59 	mbfl_no_encoding_base64,
60 	mbfl_no_encoding_8bit,
61 	mbfl_filt_conv_common_ctor,
62 	mbfl_filt_conv_common_dtor,
63 	mbfl_filt_conv_base64dec,
64 	mbfl_filt_conv_base64dec_flush
65 };
66 
67 
68 #define CK(statement)	do { if ((statement) < 0) return (-1); } while (0)
69 
70 /*
71  * any => BASE64
72  */
73 static const unsigned char mbfl_base64_table[] = {
74  /* 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', */
75    0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x4b,0x4c,0x4d,
76  /* 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', */
77    0x4e,0x4f,0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,
78  /* 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', */
79    0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6c,0x6d,
80  /* 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', */
81    0x6e,0x6f,0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,
82  /* '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/', '\0' */
83    0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x2b,0x2f,0x00
84 };
85 
mbfl_filt_conv_base64enc(int c,mbfl_convert_filter * filter)86 int mbfl_filt_conv_base64enc(int c, mbfl_convert_filter *filter)
87 {
88 	int n;
89 
90 	n = (filter->status & 0xff);
91 	if (n == 0) {
92 		filter->status++;
93 		filter->cache = (c & 0xff) << 16;
94 	} else if (n == 1) {
95 		filter->status++;
96 		filter->cache |= (c & 0xff) << 8;
97 	} else {
98 		filter->status &= ~0xff;
99 		if ((filter->status & MBFL_BASE64_STS_MIME_HEADER) == 0) {
100 			n = (filter->status & 0xff00) >> 8;
101 			if (n > 72) {
102 				CK((*filter->output_function)(0x0d, filter->data));		/* CR */
103 				CK((*filter->output_function)(0x0a, filter->data));		/* LF */
104 				filter->status &= ~0xff00;
105 			}
106 			filter->status += 0x400;
107 		}
108 		n = filter->cache | (c & 0xff);
109 		CK((*filter->output_function)(mbfl_base64_table[(n >> 18) & 0x3f], filter->data));
110 		CK((*filter->output_function)(mbfl_base64_table[(n >> 12) & 0x3f], filter->data));
111 		CK((*filter->output_function)(mbfl_base64_table[(n >> 6) & 0x3f], filter->data));
112 		CK((*filter->output_function)(mbfl_base64_table[n & 0x3f], filter->data));
113 	}
114 
115 	return c;
116 }
117 
mbfl_filt_conv_base64enc_flush(mbfl_convert_filter * filter)118 int mbfl_filt_conv_base64enc_flush(mbfl_convert_filter *filter)
119 {
120 	int status, cache, len;
121 
122 	status = filter->status & 0xff;
123 	cache = filter->cache;
124 	len = (filter->status & 0xff00) >> 8;
125 	filter->status &= ~0xffff;
126 	filter->cache = 0;
127 	/* flush fragments */
128 	if (status >= 1) {
129 		if ((filter->status & MBFL_BASE64_STS_MIME_HEADER) == 0) {
130 			if (len > 72){
131 				CK((*filter->output_function)(0x0d, filter->data));		/* CR */
132 				CK((*filter->output_function)(0x0a, filter->data));		/* LF */
133 			}
134 		}
135 		CK((*filter->output_function)(mbfl_base64_table[(cache >> 18) & 0x3f], filter->data));
136 		CK((*filter->output_function)(mbfl_base64_table[(cache >> 12) & 0x3f], filter->data));
137 		if (status == 1) {
138 			CK((*filter->output_function)(0x3d, filter->data));		/* '=' */
139 			CK((*filter->output_function)(0x3d, filter->data));		/* '=' */
140 		} else {
141 			CK((*filter->output_function)(mbfl_base64_table[(cache >> 6) & 0x3f], filter->data));
142 			CK((*filter->output_function)(0x3d, filter->data));		/* '=' */
143 		}
144 	}
145 	return 0;
146 }
147 
148 /*
149  * BASE64 => any
150  */
mbfl_filt_conv_base64dec(int c,mbfl_convert_filter * filter)151 int mbfl_filt_conv_base64dec(int c, mbfl_convert_filter *filter)
152 {
153 	int n;
154 
155 	if (c == 0x0d || c == 0x0a || c == 0x20 || c == 0x09 || c == 0x3d) {	/* CR or LF or SPACE or HTAB or '=' */
156 		return c;
157 	}
158 
159 	n = 0;
160 	if (c >= 0x41 && c <= 0x5a) {		/* A - Z */
161 		n = c - 65;
162 	} else if (c >= 0x61 && c <= 0x7a) {	/* a - z */
163 		n = c - 71;
164 	} else if (c >= 0x30 && c <= 0x39) {	/* 0 - 9 */
165 		n = c + 4;
166 	} else if (c == 0x2b) {			/* '+' */
167 		n = 62;
168 	} else if (c == 0x2f) {			/* '/' */
169 		n = 63;
170 	}
171 	n &= 0x3f;
172 
173 	switch (filter->status) {
174 	case 0:
175 		filter->status = 1;
176 		filter->cache = n << 18;
177 		break;
178 	case 1:
179 		filter->status = 2;
180 		filter->cache |= n << 12;
181 		break;
182 	case 2:
183 		filter->status = 3;
184 		filter->cache |= n << 6;
185 		break;
186 	default:
187 		filter->status = 0;
188 		n |= filter->cache;
189 		CK((*filter->output_function)((n >> 16) & 0xff, filter->data));
190 		CK((*filter->output_function)((n >> 8) & 0xff, filter->data));
191 		CK((*filter->output_function)(n & 0xff, filter->data));
192 		break;
193 	}
194 
195 	return c;
196 }
197 
mbfl_filt_conv_base64dec_flush(mbfl_convert_filter * filter)198 int mbfl_filt_conv_base64dec_flush(mbfl_convert_filter *filter)
199 {
200 	int status, cache;
201 
202 	status = filter->status;
203 	cache = filter->cache;
204 	filter->status = 0;
205 	filter->cache = 0;
206 	/* flush fragments */
207 	if (status >= 2) {
208 		CK((*filter->output_function)((cache >> 16) & 0xff, filter->data));
209 		if (status >= 3) {
210 			CK((*filter->output_function)((cache >> 8) & 0xff, filter->data));
211 		}
212 	}
213 	return 0;
214 }
215