busybox/coreutils/uuencode.c

135 lines
3.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Copyright (C) 2000 by Glenn McGrath
*
* based on the function base64_encode from http.c in wget v1.6
* Copyright (C) 1995, 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "busybox.h"
/* Conversion table. for base 64 */
static const char tbl_base64[65] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/',
'=' /* termination character */
};
static const char tbl_std[65] = {
'`', '!', '"', '#', '$', '%', '&', '\'',
'(', ')', '*', '+', ',', '-', '.', '/',
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', ':', ';', '<', '=', '>', '?',
'@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
'X', 'Y', 'Z', '[', '\\', ']', '^', '_',
'`' /* termination character */
};
/*
* Encode the string S of length LENGTH to base64 format and place it
* to STORE. STORE will be 0-terminated, and must point to a writable
* buffer of at least 1+BASE64_LENGTH(length) bytes.
* where BASE64_LENGTH(len) = (4 * ((LENGTH + 2) / 3))
*/
static void uuencode (const unsigned char *s, char *store, const int length, const char *tbl)
{
int i;
char *p = store;
/* Transform the 3x8 bits to 4x6 bits, as required by base64. */
for (i = 0; i < length; i += 3) {
*p++ = tbl[s[0] >> 2];
*p++ = tbl[((s[0] & 3) << 4) + (s[1] >> 4)];
*p++ = tbl[((s[1] & 0xf) << 2) + (s[2] >> 6)];
*p++ = tbl[s[2] & 0x3f];
s += 3;
}
/* Pad the result if necessary... */
if (i == length + 1) {
*(p - 1) = tbl[64];
}
else if (i == length + 2) {
*(p - 1) = *(p - 2) = tbl[64];
}
/* ...and zero-terminate it. */
*p = '\0';
}
#define SRC_BUF_SIZE 45 // This *MUST* be a multiple of 3
#define DST_BUF_SIZE 4 * ((SRC_BUF_SIZE + 2) / 3)
int uuencode_main(int argc, char **argv)
{
const size_t src_buf_size = SRC_BUF_SIZE;
const size_t dst_buf_size = DST_BUF_SIZE;
size_t write_size = dst_buf_size;
struct stat stat_buf;
FILE *src_stream = stdin;
const char *tbl;
size_t size;
mode_t mode;
RESERVE_CONFIG_BUFFER(src_buf, SRC_BUF_SIZE + 1);
RESERVE_CONFIG_BUFFER(dst_buf, DST_BUF_SIZE + 1);
tbl = tbl_std;
if (bb_getopt_ulflags(argc, argv, "m") & 1) {
tbl = tbl_base64;
}
switch (argc - optind) {
case 2:
src_stream = bb_xfopen(argv[optind], "r");
xstat(argv[optind], &stat_buf);
mode = stat_buf.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO);
if (src_stream == stdout) {
puts("NULL");
}
break;
case 1:
mode = 0666 & ~umask(0666);
break;
default:
bb_show_usage();
}
bb_printf("begin%s %o %s", tbl == tbl_std ? "" : "-base64", mode, argv[argc - 1]);
while ((size = fread(src_buf, 1, src_buf_size, src_stream)) > 0) {
if (size != src_buf_size) {
/* write_size is always 60 until the last line */
write_size=(4 * ((size + 2) / 3));
/* pad with 0s so we can just encode extra bits */
memset(&src_buf[size], 0, src_buf_size - size);
}
/* Encode the buffer we just read in */
uuencode((unsigned char*)src_buf, dst_buf, size, tbl);
putchar('\n');
if (tbl == tbl_std) {
putchar(tbl[size]);
}
if (fwrite(dst_buf, 1, write_size, stdout) != write_size) {
bb_perror_msg_and_die(bb_msg_write_error);
}
}
bb_printf(tbl == tbl_std ? "\n`\nend\n" : "\n====\n");
bb_xferror(src_stream, "source"); /* TODO - Fix this! */
bb_fflush_stdout_and_exit(EXIT_SUCCESS);
}