1 /* vi: set sw=4 ts=4: */
2 /*
3  * Copyright 2003, Glenn McGrath
4  *
5  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
6  *
7  * Based on specification from
8  * http://www.opengroup.org/onlinepubs/007904975/utilities/uuencode.html
9  *
10  * Bugs: the spec doesn't mention anything about "`\n`\n" prior to the
11  * "end" line
12  */
13 //config:config UUDECODE
14 //config:	bool "uudecode"
15 //config:	default y
16 //config:	help
17 //config:	  uudecode is used to decode a uuencoded file.
18 
19 //applet:IF_UUDECODE(APPLET(uudecode, BB_DIR_USR_BIN, BB_SUID_DROP))
20 
21 //kbuild:lib-$(CONFIG_UUDECODE) += uudecode.o
22 
23 //usage:#define uudecode_trivial_usage
24 //usage:       "[-o OUTFILE] [INFILE]"
25 //usage:#define uudecode_full_usage "\n\n"
26 //usage:       "Uudecode a file\n"
27 //usage:       "Finds OUTFILE in uuencoded source unless -o is given"
28 //usage:
29 //usage:#define uudecode_example_usage
30 //usage:       "$ uudecode -o busybox busybox.uu\n"
31 //usage:       "$ ls -l busybox\n"
32 //usage:       "-rwxr-xr-x   1 ams      ams        245264 Jun  7 21:35 busybox\n"
33 
34 #include "libbb.h"
35 
36 #if ENABLE_UUDECODE
read_stduu(FILE * src_stream,FILE * dst_stream,int flags UNUSED_PARAM)37 static void FAST_FUNC read_stduu(FILE *src_stream, FILE *dst_stream, int flags UNUSED_PARAM)
38 {
39 	char *line;
40 
41 	for (;;) {
42 		int encoded_len, str_len;
43 		char *line_ptr, *dst;
44 		size_t line_len;
45 
46 		line_len = 64 * 1024;
47 		line = xmalloc_fgets_str_len(src_stream, "\n", &line_len);
48 		if (!line)
49 			break;
50 		/* Handle both Unix and MSDOS text, and stray trailing spaces */
51 		str_len = line_len;
52 		while (--str_len >= 0 && isspace(line[str_len]))
53 			line[str_len] = '\0';
54 
55 		if (strcmp(line, "end") == 0) {
56 			return; /* the only non-error exit */
57 		}
58 
59 		line_ptr = line;
60 		while (*line_ptr) {
61 			*line_ptr = (*line_ptr - 0x20) & 0x3f;
62 			line_ptr++;
63 		}
64 		str_len = line_ptr - line;
65 
66 		encoded_len = line[0] * 4 / 3;
67 		/* Check that line is not too short. (we tolerate
68 		 * overly _long_ line to accommodate possible extra '`').
69 		 * Empty line case is also caught here. */
70 		if (str_len <= encoded_len) {
71 			break; /* go to bb_error_msg_and_die("short file"); */
72 		}
73 		if (encoded_len <= 0) {
74 			/* Ignore the "`\n" line, why is it even in the encode file ? */
75 			free(line);
76 			continue;
77 		}
78 		if (encoded_len > 60) {
79 			bb_error_msg_and_die("line too long");
80 		}
81 
82 		dst = line;
83 		line_ptr = line + 1;
84 		do {
85 			/* Merge four 6 bit chars to three 8 bit chars */
86 			*dst++ = line_ptr[0] << 2 | line_ptr[1] >> 4;
87 			encoded_len--;
88 			if (encoded_len == 0) {
89 				break;
90 			}
91 
92 			*dst++ = line_ptr[1] << 4 | line_ptr[2] >> 2;
93 			encoded_len--;
94 			if (encoded_len == 0) {
95 				break;
96 			}
97 
98 			*dst++ = line_ptr[2] << 6 | line_ptr[3];
99 			line_ptr += 4;
100 			encoded_len -= 2;
101 		} while (encoded_len > 0);
102 		fwrite(line, 1, dst - line, dst_stream);
103 		free(line);
104 	}
105 	bb_error_msg_and_die("short file");
106 }
107 #endif
108 
109 #if ENABLE_UUDECODE
110 int uudecode_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
uudecode_main(int argc UNUSED_PARAM,char ** argv)111 int uudecode_main(int argc UNUSED_PARAM, char **argv)
112 {
113 	FILE *src_stream;
114 	char *outname = NULL;
115 	char *line;
116 
117 	opt_complementary = "?1"; /* 1 argument max */
118 	getopt32(argv, "o:", &outname);
119 	argv += optind;
120 
121 	if (!argv[0])
122 		*--argv = (char*)"-";
123 	src_stream = xfopen_stdin(argv[0]);
124 
125 	/* Search for the start of the encoding */
126 	while ((line = xmalloc_fgetline(src_stream)) != NULL) {
127 		void FAST_FUNC (*decode_fn_ptr)(FILE *src, FILE *dst, int flags);
128 		char *line_ptr;
129 		FILE *dst_stream;
130 		int mode;
131 
132 		if (is_prefixed_with(line, "begin-base64 ")) {
133 			line_ptr = line + 13;
134 			decode_fn_ptr = read_base64;
135 		} else if (is_prefixed_with(line, "begin ")) {
136 			line_ptr = line + 6;
137 			decode_fn_ptr = read_stduu;
138 		} else {
139 			free(line);
140 			continue;
141 		}
142 
143 		/* begin line found. decode and exit */
144 		mode = bb_strtou(line_ptr, NULL, 8);
145 		if (outname == NULL) {
146 			outname = strchr(line_ptr, ' ');
147 			if (!outname)
148 				break;
149 			outname++;
150 			trim(outname); /* remove trailing space (and '\r' for DOS text) */
151 			if (!outname[0])
152 				break;
153 		}
154 		dst_stream = stdout;
155 		if (NOT_LONE_DASH(outname)) {
156 			dst_stream = xfopen_for_write(outname);
157 			fchmod(fileno(dst_stream), mode & (S_IRWXU | S_IRWXG | S_IRWXO));
158 		}
159 		free(line);
160 		decode_fn_ptr(src_stream, dst_stream, /*flags:*/ BASE64_FLAG_UU_STOP + BASE64_FLAG_NO_STOP_CHAR);
161 		/* fclose_if_not_stdin(src_stream); - redundant */
162 		return EXIT_SUCCESS;
163 	}
164 	bb_error_msg_and_die("no 'begin' line");
165 }
166 #endif
167 
168 //applet:IF_BASE64(APPLET(base64, BB_DIR_BIN, BB_SUID_DROP))
169 
170 //kbuild:lib-$(CONFIG_BASE64) += uudecode.o
171 
172 //config:config BASE64
173 //config:	bool "base64"
174 //config:	default y
175 //config:	help
176 //config:	  Base64 encode and decode
177 
178 //usage:#define base64_trivial_usage
179 //usage:	"[-d] [FILE]"
180 //usage:#define base64_full_usage "\n\n"
181 //usage:       "Base64 encode or decode FILE to standard output"
182 //usage:     "\n	-d	Decode data"
183 ////usage:     "\n	-w COL	Wrap lines at COL (default 76, 0 disables)"
184 ////usage:     "\n	-i	When decoding, ignore non-alphabet characters"
185 
186 #if ENABLE_BASE64
187 int base64_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
base64_main(int argc UNUSED_PARAM,char ** argv)188 int base64_main(int argc UNUSED_PARAM, char **argv)
189 {
190 	FILE *src_stream;
191 	unsigned opts;
192 
193 	opt_complementary = "?1"; /* 1 argument max */
194 	opts = getopt32(argv, "d");
195 	argv += optind;
196 
197 	if (!argv[0])
198 		*--argv = (char*)"-";
199 	src_stream = xfopen_stdin(argv[0]);
200 	if (opts) {
201 		read_base64(src_stream, stdout, /*flags:*/ (char)EOF);
202 	} else {
203 		enum {
204 			SRC_BUF_SIZE = 76/4*3,  /* This *MUST* be a multiple of 3 */
205 			DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
206 		};
207 		char src_buf[SRC_BUF_SIZE];
208 		char dst_buf[DST_BUF_SIZE + 1];
209 		int src_fd = fileno(src_stream);
210 		while (1) {
211 			size_t size = full_read(src_fd, src_buf, SRC_BUF_SIZE);
212 			if (!size)
213 				break;
214 			if ((ssize_t)size < 0)
215 				bb_perror_msg_and_die(bb_msg_read_error);
216 			/* Encode the buffer we just read in */
217 			bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
218 			xwrite(STDOUT_FILENO, dst_buf, 4 * ((size + 2) / 3));
219 			bb_putchar('\n');
220 			fflush(stdout);
221 		}
222 	}
223 
224 	fflush_stdout_and_exit(EXIT_SUCCESS);
225 }
226 #endif
227 
228 /* Test script.
229 Put this into an empty dir with busybox binary, an run.
230 
231 #!/bin/sh
232 test -x busybox || { echo "No ./busybox?"; exit; }
233 ln -sf busybox uudecode
234 ln -sf busybox uuencode
235 >A_null
236 echo -n A >A
237 echo -n AB >AB
238 echo -n ABC >ABC
239 echo -n ABCD >ABCD
240 echo -n ABCDE >ABCDE
241 echo -n ABCDEF >ABCDEF
242 cat busybox >A_bbox
243 for f in A*; do
244     echo uuencode $f
245     ./uuencode    $f <$f >u_$f
246     ./uuencode -m $f <$f >m_$f
247 done
248 mkdir unpk_u unpk_m 2>/dev/null
249 for f in u_*; do
250     ./uudecode <$f -o unpk_u/${f:2}
251     diff -a ${f:2} unpk_u/${f:2} >/dev/null 2>&1
252     echo uudecode $f: $?
253 done
254 for f in m_*; do
255     ./uudecode <$f -o unpk_m/${f:2}
256     diff -a ${f:2} unpk_m/${f:2} >/dev/null 2>&1
257     echo uudecode $f: $?
258 done
259 */
260