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 tarball for details. 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 15#include "libbb.h" 16 17static void read_stduu(FILE *src_stream, FILE *dst_stream) 18{ 19 char *line; 20 21 while ((line = xmalloc_fgetline(src_stream)) != NULL) { 22 int encoded_len, str_len; 23 char *line_ptr, *dst; 24 25 if (strcmp(line, "end") == 0) { 26 return; /* the only non-error exit */ 27 } 28 29 line_ptr = line; 30 while (*line_ptr) { 31 *line_ptr = (*line_ptr - 0x20) & 0x3f; 32 line_ptr++; 33 } 34 str_len = line_ptr - line; 35 36 encoded_len = line[0] * 4 / 3; 37 /* Check that line is not too short. (we tolerate 38 * overly _long_ line to accomodate possible extra '`'). 39 * Empty line case is also caught here. */ 40 if (str_len <= encoded_len) { 41 break; /* go to bb_error_msg_and_die("short file"); */ 42 } 43 if (encoded_len <= 0) { 44 /* Ignore the "`\n" line, why is it even in the encode file ? */ 45 free(line); 46 continue; 47 } 48 if (encoded_len > 60) { 49 bb_error_msg_and_die("line too long"); 50 } 51 52 dst = line; 53 line_ptr = line + 1; 54 do { 55 /* Merge four 6 bit chars to three 8 bit chars */ 56 *dst++ = line_ptr[0] << 2 | line_ptr[1] >> 4; 57 encoded_len--; 58 if (encoded_len == 0) { 59 break; 60 } 61 62 *dst++ = line_ptr[1] << 4 | line_ptr[2] >> 2; 63 encoded_len--; 64 if (encoded_len == 0) { 65 break; 66 } 67 68 *dst++ = line_ptr[2] << 6 | line_ptr[3]; 69 line_ptr += 4; 70 encoded_len -= 2; 71 } while (encoded_len > 0); 72 fwrite(line, 1, dst - line, dst_stream); 73 free(line); 74 } 75 bb_error_msg_and_die("short file"); 76} 77 78static void read_base64(FILE *src_stream, FILE *dst_stream) 79{ 80 int term_count = 1; 81 82 while (1) { 83 char translated[4]; 84 int count = 0; 85 86 while (count < 4) { 87 char *table_ptr; 88 int ch; 89 90 /* Get next _valid_ character. 91 * global vector bb_uuenc_tbl_base64[] contains this string: 92 * "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n" 93 */ 94 do { 95 ch = fgetc(src_stream); 96 if (ch == EOF) { 97 bb_error_msg_and_die("short file"); 98 } 99 table_ptr = strchr(bb_uuenc_tbl_base64, ch); 100 } while (table_ptr == NULL); 101 102 /* Convert encoded character to decimal */ 103 ch = table_ptr - bb_uuenc_tbl_base64; 104 105 if (*table_ptr == '=') { 106 if (term_count == 0) { 107 translated[count] = '\0'; 108 break; 109 } 110 term_count++; 111 } else if (*table_ptr == '\n') { 112 /* Check for terminating line */ 113 if (term_count == 5) { 114 return; 115 } 116 term_count = 1; 117 continue; 118 } else { 119 translated[count] = ch; 120 count++; 121 term_count = 0; 122 } 123 } 124 125 /* Merge 6 bit chars to 8 bit */ 126 if (count > 1) { 127 fputc(translated[0] << 2 | translated[1] >> 4, dst_stream); 128 } 129 if (count > 2) { 130 fputc(translated[1] << 4 | translated[2] >> 2, dst_stream); 131 } 132 if (count > 3) { 133 fputc(translated[2] << 6 | translated[3], dst_stream); 134 } 135 } 136} 137 138int uudecode_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 139int uudecode_main(int argc UNUSED_PARAM, char **argv) 140{ 141 FILE *src_stream; 142 char *outname = NULL; 143 char *line; 144 145 opt_complementary = "?1"; /* 1 argument max */ 146 getopt32(argv, "o:", &outname); 147 argv += optind; 148 149 if (!*argv) 150 *--argv = (char*)"-"; 151 src_stream = xfopen_stdin(*argv); 152 153 /* Search for the start of the encoding */ 154 while ((line = xmalloc_fgetline(src_stream)) != NULL) { 155 void (*decode_fn_ptr)(FILE *src, FILE *dst); 156 char *line_ptr; 157 FILE *dst_stream; 158 int mode; 159 160 if (strncmp(line, "begin-base64 ", 13) == 0) { 161 line_ptr = line + 13; 162 decode_fn_ptr = read_base64; 163 } else if (strncmp(line, "begin ", 6) == 0) { 164 line_ptr = line + 6; 165 decode_fn_ptr = read_stduu; 166 } else { 167 free(line); 168 continue; 169 } 170 171 /* begin line found. decode and exit */ 172 mode = bb_strtou(line_ptr, NULL, 8); 173 if (outname == NULL) { 174 outname = strchr(line_ptr, ' '); 175 if ((outname == NULL) || (*outname == '\0')) { 176 break; 177 } 178 outname++; 179 } 180 dst_stream = stdout; 181 if (NOT_LONE_DASH(outname)) { 182 dst_stream = xfopen_for_write(outname); 183 fchmod(fileno(dst_stream), mode & (S_IRWXU | S_IRWXG | S_IRWXO)); 184 } 185 free(line); 186 decode_fn_ptr(src_stream, dst_stream); 187 /* fclose_if_not_stdin(src_stream); - redundant */ 188 return EXIT_SUCCESS; 189 } 190 bb_error_msg_and_die("no 'begin' line"); 191} 192 193/* Test script. 194Put this into an empty dir with busybox binary, an run. 195 196#!/bin/sh 197test -x busybox || { echo "No ./busybox?"; exit; } 198ln -sf busybox uudecode 199ln -sf busybox uuencode 200>A_null 201echo -n A >A 202echo -n AB >AB 203echo -n ABC >ABC 204echo -n ABCD >ABCD 205echo -n ABCDE >ABCDE 206echo -n ABCDEF >ABCDEF 207cat busybox >A_bbox 208for f in A*; do 209 echo uuencode $f 210 ./uuencode $f <$f >u_$f 211 ./uuencode -m $f <$f >m_$f 212done 213mkdir unpk_u unpk_m 2>/dev/null 214for f in u_*; do 215 ./uudecode <$f -o unpk_u/${f:2} 216 diff -a ${f:2} unpk_u/${f:2} >/dev/null 2>&1 217 echo uudecode $f: $? 218done 219for f in m_*; do 220 ./uudecode <$f -o unpk_m/${f:2} 221 diff -a ${f:2} unpk_m/${f:2} >/dev/null 2>&1 222 echo uudecode $f: $? 223done 224*/ 225