summaryrefslogtreecommitdiff
path: root/coreutils/uudecode.c
blob: 6ecfe6ceffa076e028fe1dcae30848533bb74df7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
/* vi: set sw=4 ts=4: */
/*
 * Copyright 2003, Glenn McGrath
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 *
 * Based on specification from
 * http://www.opengroup.org/onlinepubs/007904975/utilities/uuencode.html
 *
 * Bugs: the spec doesn't mention anything about "`\n`\n" prior to the
 * "end" line
 */

//usage:#define uudecode_trivial_usage
//usage:       "[-o OUTFILE] [INFILE]"
//usage:#define uudecode_full_usage "\n\n"
//usage:       "Uudecode a file\n"
//usage:       "Finds outfile name in uuencoded source unless -o is given"
//usage:
//usage:#define uudecode_example_usage
//usage:       "$ uudecode -o busybox busybox.uu\n"
//usage:       "$ ls -l busybox\n"
//usage:       "-rwxr-xr-x   1 ams      ams        245264 Jun  7 21:35 busybox\n"

#include "libbb.h"

#if ENABLE_UUDECODE
static void FAST_FUNC read_stduu(FILE *src_stream, FILE *dst_stream, int flags UNUSED_PARAM)
{
	char *line;

	while ((line = xmalloc_fgetline(src_stream)) != NULL) {
		int encoded_len, str_len;
		char *line_ptr, *dst;

		if (strcmp(line, "end") == 0) {
			return; /* the only non-error exit */
		}

		line_ptr = line;
		while (*line_ptr) {
			*line_ptr = (*line_ptr - 0x20) & 0x3f;
			line_ptr++;
		}
		str_len = line_ptr - line;

		encoded_len = line[0] * 4 / 3;
		/* Check that line is not too short. (we tolerate
		 * overly _long_ line to accomodate possible extra '`').
		 * Empty line case is also caught here. */
		if (str_len <= encoded_len) {
			break; /* go to bb_error_msg_and_die("short file"); */
		}
		if (encoded_len <= 0) {
			/* Ignore the "`\n" line, why is it even in the encode file ? */
			free(line);
			continue;
		}
		if (encoded_len > 60) {
			bb_error_msg_and_die("line too long");
		}

		dst = line;
		line_ptr = line + 1;
		do {
			/* Merge four 6 bit chars to three 8 bit chars */
			*dst++ = line_ptr[0] << 2 | line_ptr[1] >> 4;
			encoded_len--;
			if (encoded_len == 0) {
				break;
			}

			*dst++ = line_ptr[1] << 4 | line_ptr[2] >> 2;
			encoded_len--;
			if (encoded_len == 0) {
				break;
			}

			*dst++ = line_ptr[2] << 6 | line_ptr[3];
			line_ptr += 4;
			encoded_len -= 2;
		} while (encoded_len > 0);
		fwrite(line, 1, dst - line, dst_stream);
		free(line);
	}
	bb_error_msg_and_die("short file");
}
#endif

#if ENABLE_UUDECODE
int uudecode_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int uudecode_main(int argc UNUSED_PARAM, char **argv)
{
	FILE *src_stream;
	char *outname = NULL;
	char *line;

	opt_complementary = "?1"; /* 1 argument max */
	getopt32(argv, "o:", &outname);
	argv += optind;

	if (!argv[0])
		*--argv = (char*)"-";
	src_stream = xfopen_stdin(argv[0]);

	/* Search for the start of the encoding */
	while ((line = xmalloc_fgetline(src_stream)) != NULL) {
		void FAST_FUNC (*decode_fn_ptr)(FILE *src, FILE *dst, int flags);
		char *line_ptr;
		FILE *dst_stream;
		int mode;

		if (strncmp(line, "begin-base64 ", 13) == 0) {
			line_ptr = line + 13;
			decode_fn_ptr = read_base64;
		} else if (strncmp(line, "begin ", 6) == 0) {
			line_ptr = line + 6;
			decode_fn_ptr = read_stduu;
		} else {
			free(line);
			continue;
		}

		/* begin line found. decode and exit */
		mode = bb_strtou(line_ptr, NULL, 8);
		if (outname == NULL) {
			outname = strchr(line_ptr, ' ');
			if ((outname == NULL) || (*outname == '\0')) {
				break;
			}
			outname++;
		}
		dst_stream = stdout;
		if (NOT_LONE_DASH(outname)) {
			dst_stream = xfopen_for_write(outname);
			fchmod(fileno(dst_stream), mode & (S_IRWXU | S_IRWXG | S_IRWXO));
		}
		free(line);
		decode_fn_ptr(src_stream, dst_stream, /*flags:*/ BASE64_FLAG_UU_STOP + BASE64_FLAG_NO_STOP_CHAR);
		/* fclose_if_not_stdin(src_stream); - redundant */
		return EXIT_SUCCESS;
	}
	bb_error_msg_and_die("no 'begin' line");
}
#endif

//applet:IF_BASE64(APPLET(base64, BB_DIR_BIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_BASE64) += uudecode.o

//config:config BASE64
//config:	bool "base64"
//config:	default y
//config:	help
//config:	  Base64 encode and decode

//usage:#define base64_trivial_usage
//usage:	"[-d] [FILE]"
//usage:#define base64_full_usage "\n\n"
//usage:       "Base64 encode or decode FILE to standard output"
//usage:     "\n	-d	Decode data"
////usage:     "\n	-w COL	Wrap lines at COL (default 76, 0 disables)"
////usage:     "\n	-i	When decoding, ignore non-alphabet characters"

#if ENABLE_BASE64
int base64_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int base64_main(int argc UNUSED_PARAM, char **argv)
{
	FILE *src_stream;
	unsigned opts;

	opt_complementary = "?1"; /* 1 argument max */
	opts = getopt32(argv, "d");
	argv += optind;

	if (!argv[0])
		*--argv = (char*)"-";
	src_stream = xfopen_stdin(argv[0]);
	if (opts) {
		read_base64(src_stream, stdout, /*flags:*/ (char)EOF);
	} else {
		enum {
			SRC_BUF_SIZE = 76/4*3,  /* This *MUST* be a multiple of 3 */
			DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
		};
		char src_buf[SRC_BUF_SIZE];
		char dst_buf[DST_BUF_SIZE + 1];
		int src_fd = fileno(src_stream);
		while (1) {
			size_t size = full_read(src_fd, src_buf, SRC_BUF_SIZE);
			if (!size)
				break;
			if ((ssize_t)size < 0)
				bb_perror_msg_and_die(bb_msg_read_error);
			/* Encode the buffer we just read in */
			bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
			xwrite(STDOUT_FILENO, dst_buf, 4 * ((size + 2) / 3));
			bb_putchar('\n');
			fflush(stdout);
		}
	}

	fflush_stdout_and_exit(EXIT_SUCCESS);
}
#endif

/* Test script.
Put this into an empty dir with busybox binary, an run.

#!/bin/sh
test -x busybox || { echo "No ./busybox?"; exit; }
ln -sf busybox uudecode
ln -sf busybox uuencode
>A_null
echo -n A >A
echo -n AB >AB
echo -n ABC >ABC
echo -n ABCD >ABCD
echo -n ABCDE >ABCDE
echo -n ABCDEF >ABCDEF
cat busybox >A_bbox
for f in A*; do
    echo uuencode $f
    ./uuencode    $f <$f >u_$f
    ./uuencode -m $f <$f >m_$f
done
mkdir unpk_u unpk_m 2>/dev/null
for f in u_*; do
    ./uudecode <$f -o unpk_u/${f:2}
    diff -a ${f:2} unpk_u/${f:2} >/dev/null 2>&1
    echo uudecode $f: $?
done
for f in m_*; do
    ./uudecode <$f -o unpk_m/${f:2}
    diff -a ${f:2} unpk_m/${f:2} >/dev/null 2>&1
    echo uudecode $f: $?
done
*/