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 (5.8 kb)"
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.
51 * Note: space should not be trimmed, some encoders use it instead of "`"
52 * for padding of last incomplete 4-char block.
53 */
54 str_len = line_len;
55 while (--str_len >= 0
56 && (line[str_len] == '\n' || line[str_len] == '\r')
57 ) {
58 line[str_len] = '\0';
59 }
60
61 if (strcmp(line, "end") == 0) {
62 return; /* the only non-error exit */
63 }
64
65 line_ptr = line;
66 while (*line_ptr) {
67 *line_ptr = (*line_ptr - 0x20) & 0x3f;
68 line_ptr++;
69 }
70 str_len = line_ptr - line;
71
72 encoded_len = line[0] * 4 / 3;
73 /* Check that line is not too short. (we tolerate
74 * overly _long_ line to accommodate possible extra "`").
75 * Empty line case is also caught here. */
76 if (str_len <= encoded_len) {
77 break; /* go to bb_error_msg_and_die("short file"); */
78 }
79 if (encoded_len <= 0) {
80 /* Ignore the "`\n" line, why is it even in the encode file ? */
81 free(line);
82 continue;
83 }
84 if (encoded_len > 60) {
85 bb_simple_error_msg_and_die("line too long");
86 }
87
88 dst = line;
89 line_ptr = line + 1;
90 do {
91 /* Merge four 6 bit chars to three 8 bit chars */
92 *dst++ = line_ptr[0] << 2 | line_ptr[1] >> 4;
93 encoded_len--;
94 if (encoded_len == 0) {
95 break;
96 }
97
98 *dst++ = line_ptr[1] << 4 | line_ptr[2] >> 2;
99 encoded_len--;
100 if (encoded_len == 0) {
101 break;
102 }
103
104 *dst++ = line_ptr[2] << 6 | line_ptr[3];
105 line_ptr += 4;
106 encoded_len -= 2;
107 } while (encoded_len > 0);
108 fwrite(line, 1, dst - line, dst_stream);
109 free(line);
110 }
111 bb_simple_error_msg_and_die("short file");
112 }
113
114 int uudecode_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
uudecode_main(int argc UNUSED_PARAM,char ** argv)115 int uudecode_main(int argc UNUSED_PARAM, char **argv)
116 {
117 FILE *src_stream;
118 char *outname = NULL;
119 char *line;
120
121 getopt32(argv, "^" "o:" "\0" "?1"/* 1 arg max*/, &outname);
122 argv += optind;
123
124 if (!argv[0])
125 *--argv = (char*)"-";
126 src_stream = xfopen_stdin(argv[0]);
127
128 /* Search for the start of the encoding */
129 while ((line = xmalloc_fgetline(src_stream)) != NULL) {
130 void FAST_FUNC (*decode_fn_ptr)(FILE *src, FILE *dst, int flags);
131 char *line_ptr;
132 FILE *dst_stream;
133 int mode;
134
135 if (is_prefixed_with(line, "begin-base64 ")) {
136 line_ptr = line + 13;
137 decode_fn_ptr = read_base64;
138 } else if (is_prefixed_with(line, "begin ")) {
139 line_ptr = line + 6;
140 decode_fn_ptr = read_stduu;
141 } else {
142 free(line);
143 continue;
144 }
145
146 /* begin line found. decode and exit */
147 mode = bb_strtou(line_ptr, NULL, 8);
148 if (outname == NULL) {
149 outname = strchr(line_ptr, ' ');
150 if (!outname)
151 break;
152 outname++;
153 trim(outname); /* remove trailing space (and '\r' for DOS text) */
154 if (!outname[0])
155 break;
156 }
157 dst_stream = stdout;
158 if (NOT_LONE_DASH(outname)
159 /* https://pubs.opengroup.org/onlinepubs/9699919799/utilities/uudecode.html
160 * https://pubs.opengroup.org/onlinepubs/9699919799/utilities/uuencode.html
161 * The above says that output file name specified in input file
162 * or overridden by -o OUTFILE can be special "/dev/stdout" string.
163 * This usually works "implicitly": many systems have /dev/stdout.
164 * If ENABLE_DESKTOP, support that explicitly:
165 */
166 && (!ENABLE_DESKTOP || strcmp(outname, "/dev/stdout") != 0)
167 ) {
168 dst_stream = xfopen_for_write(outname);
169 fchmod(fileno(dst_stream), mode & (S_IRWXU | S_IRWXG | S_IRWXO));
170 }
171 free(line);
172 decode_fn_ptr(src_stream, dst_stream, /*flags:*/ BASE64_FLAG_UU_STOP + BASE64_FLAG_NO_STOP_CHAR);
173 /* fclose_if_not_stdin(src_stream); - redundant */
174 return EXIT_SUCCESS;
175 }
176 bb_simple_error_msg_and_die("no 'begin' line");
177 }
178 #endif
179
180 //config:config BASE32
181 //config: bool "base32 (4.9 kb)"
182 //config: default y
183 //config: help
184 //config: Base32 encode and decode
185
186 //config:config BASE64
187 //config: bool "base64 (4.9 kb)"
188 //config: default y
189 //config: help
190 //config: Base64 encode and decode
191
192 //usage:#define base32_trivial_usage
193 //usage: "[-d] [-w COL] [FILE]"
194 //usage:#define base32_full_usage "\n\n"
195 //usage: "Base32 encode or decode FILE to standard output\n"
196 //usage: "\n -d Decode data"
197 //usage: "\n -w COL Wrap lines at COL (default 76, 0 disables)"
198 ////usage: "\n -i When decoding, ignore non-alphabet characters"
199
200 //usage:#define base64_trivial_usage
201 //usage: "[-d] [-w COL] [FILE]"
202 //usage:#define base64_full_usage "\n\n"
203 //usage: "Base64 encode or decode FILE to standard output\n"
204 //usage: "\n -d Decode data"
205 //usage: "\n -w COL Wrap lines at COL (default 76, 0 disables)"
206 ///////: "\n -i When decoding, ignore non-alphabet characters"
207 // -i is accepted but has no effect: currently, decode_base32/64() functions
208 // (called via read_base64()) skip invalid chars unconditionally.
209
210 // APPLET_ODDNAME:name main location suid_type help
211 //applet:IF_BASE32(APPLET_ODDNAME(base32, baseNUM, BB_DIR_BIN, BB_SUID_DROP, base32))
212 //applet:IF_BASE64(APPLET_ODDNAME(base64, baseNUM, BB_DIR_BIN, BB_SUID_DROP, base64))
213
214 //kbuild:lib-$(CONFIG_BASE64) += uudecode.o
215 //kbuild:lib-$(CONFIG_BASE32) += uudecode.o
216
217 #if ENABLE_BASE32 || ENABLE_BASE64
218
219 # if ENABLE_BASE32
bb_b32encode(char * p,const void * src,int length)220 static void bb_b32encode(char *p, const void *src, int length)
221 {
222 #define tbl bb_uuenc_tbl_base32
223 const unsigned char *s = src;
224
225 /* Transform 5x8 bits to 8x5 bits */
226 while (length > 0) {
227 unsigned cur, next;
228
229 length--;
230 cur = *s++;
231 *p++ = tbl[cur >> 3]; // xxxxx--- -------- -------- -------- --------
232 cur &= 7;
233
234 next = 0;
235 if (--length >= 0)
236 next = *s++;
237 *p++ = tbl[(cur << 2) + (next >> 6)]; // -----xxx xx------ -------- -------- --------
238 cur = next & 0x3f;
239
240 *p++ = tbl[cur >> 1]; // -------- --xxxxx- -------- -------- --------
241 cur &= 1;
242
243 next = 0;
244 if (--length >= 0)
245 next = *s++;
246 *p++ = tbl[(cur << 4) + (next >> 4)]; // -------- -------x xxxx---- -------- --------
247 cur = next & 0xf;
248
249 next = 0;
250 if (--length >= 0)
251 next = *s++;
252 *p++ = tbl[(cur << 1) + (next >> 7)]; // -------- -------- ----xxxx x------- --------
253 cur = next & 0x7f;
254
255 *p++ = tbl[cur >> 2]; // -------- -------- -------- -xxxxx-- --------
256 cur &= 3;
257
258 next = 0;
259 if (--length >= 0)
260 next = *s++;
261 *p++ = tbl[(cur << 3) + (next >> 5)]; // -------- -------- -------- ------xx xxx-----
262 cur = next & 0x1f;
263
264 *p++ = tbl[cur]; // -------- -------- -------- -------- ---xxxxx
265 }
266 #undef tbl
267 /* Zero-terminate */
268 *p = '\0';
269 /* Pad as necessary */
270 length = ((-length) * 3) >> 1; /* -4 => 6 pad chars, -3 => 4, -2 => 3, -1 => 1 */
271 while (length--) {
272 *--p = '=';
273 }
274 }
275 # else
276 void bb_b32encode(char *p, const void *src, int length); /* undefined */
277 # endif
278
279 int baseNUM_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
baseNUM_main(int argc UNUSED_PARAM,char ** argv)280 int baseNUM_main(int argc UNUSED_PARAM, char **argv)
281 {
282 FILE *src_stream;
283 unsigned opts;
284 unsigned col = 76;
285
286 opts = getopt32(argv, "^" "diw:+" "\0" "?1"/* 1 arg max*/, &col);
287 argv += optind;
288
289 if (!argv[0])
290 *--argv = (char*)"-";
291 src_stream = xfopen_stdin(argv[0]);
292 if (opts & 1) {
293 /* -d: decode */
294 int flags = (unsigned char)EOF;
295 if (ENABLE_BASE32 && (!ENABLE_BASE64 || applet_name[4] == '3'))
296 flags = ((unsigned char)EOF) | BASE64_32;
297 read_base64(src_stream, stdout, flags);
298 } else {
299 enum {
300 SRC_BUF_SIZE = 3 * 5 * 32, /* this *MUST* be a multiple of 3 and 5 */
301 DST_BUF_SIZE = 8 * ((SRC_BUF_SIZE + 4) / 5), /* max growth on encode (base32 case) */
302 };
303 /* Use one buffer for both input and output:
304 * encoding reads input "left-to-right",
305 * it's safe to place source at the end of the buffer and
306 * overwrite it while encoding, just be careful to have a gap.
307 */
308 char dst_buf[((DST_BUF_SIZE + /*gap:*/ 16) /*round up to 16:*/ | 0xf) + 1];
309 #define src_buf (dst_buf + sizeof(dst_buf) - SRC_BUF_SIZE)
310 int src_fd, rem;
311
312 src_fd = fileno(src_stream);
313 rem = 0;
314 while (1) {
315 size_t size = full_read(src_fd, src_buf, SRC_BUF_SIZE);
316 if ((ssize_t)size < 0)
317 bb_simple_perror_msg_and_die(bb_msg_read_error);
318 if (size == 0) {
319 if (rem != 0) bb_putchar('\n');
320 break;
321 }
322
323 /* Encode the buffer we just read in */
324 if (ENABLE_BASE32 && (!ENABLE_BASE64 || applet_name[4] == '3')) {
325 bb_b32encode(dst_buf, src_buf, size);
326 size = 8 * ((size + 4) / 5);
327 } else {
328 bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
329 size = 4 * ((size + 2) / 3);
330 }
331
332 if (col == 0) {
333 fputs_stdout(dst_buf);
334 } else {
335 char *result = dst_buf;
336 if (rem == 0)
337 rem = col;
338 while (1) {
339 int out = size < rem ? size : rem;
340 rem -= out;
341 printf(rem != 0 ? "%.*s" : "%.*s\n", out, result);
342 if (rem != 0)
343 break;
344 size -= out;
345 if (size == 0)
346 break;
347 result += out;
348 rem = col;
349 }
350 }
351 }
352 #undef src_buf
353 }
354
355 fflush_stdout_and_exit(EXIT_SUCCESS);
356 }
357 #endif
358
359 /* Test script.
360 Put this into an empty dir with busybox binary, an run.
361
362 #!/bin/sh
363 test -x busybox || { echo "No ./busybox?"; exit; }
364 ln -sf busybox uudecode
365 ln -sf busybox uuencode
366 >A_null
367 echo -n A >A
368 echo -n AB >AB
369 echo -n ABC >ABC
370 echo -n ABCD >ABCD
371 echo -n ABCDE >ABCDE
372 echo -n ABCDEF >ABCDEF
373 cat busybox >A_bbox
374 for f in A*; do
375 echo uuencode $f
376 ./uuencode $f <$f >u_$f
377 ./uuencode -m $f <$f >m_$f
378 done
379 mkdir unpk_u unpk_m 2>/dev/null
380 for f in u_*; do
381 ./uudecode <$f -o unpk_u/${f:2}
382 diff -a ${f:2} unpk_u/${f:2} >/dev/null 2>&1
383 echo uudecode $f: $?
384 done
385 for f in m_*; do
386 ./uudecode <$f -o unpk_m/${f:2}
387 diff -a ${f:2} unpk_m/${f:2} >/dev/null 2>&1
388 echo uudecode $f: $?
389 done
390 */
391