hush/libbb/uuencode.c

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/* vi: set sw=4 ts=4: */
/*
* Copyright 2006 Rob Landley <rob@landley.net>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
/* Conversion table. for base 64 */
const char bb_uuenc_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 */
};
const char bb_uuenc_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))
*/
void bb_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';
}