release/src/router/busybox/coreutils/uudecode.c

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