/*
* Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <ipxe/base16.h>
/** @file
*
* Base16 encoding
*
*/
/**
* Base16-encode data
*
* @v raw Raw data
* @v len Length of raw data
* @v encoded Buffer for encoded string
*
* The buffer must be the correct length for the encoded string. Use
* something like
*
* char buf[ base16_encoded_len ( len ) + 1 ];
*
* (the +1 is for the terminating NUL) to provide a buffer of the
* correct size.
*/
void base16_encode ( const uint8_t *raw, size_t len, char *encoded ) {
const uint8_t *raw_bytes = raw;
char *encoded_bytes = encoded;
size_t remaining = len;
for ( ; remaining-- ; encoded_bytes += 2 ) {
sprintf ( encoded_bytes, "%02x", *(raw_bytes++) );
}
DBG ( "Base16-encoded to \"%s\":\n", encoded );
DBG_HDA ( 0, raw, len );
assert ( strlen ( encoded ) == base16_encoded_len ( len ) );
}
/**
* Base16-decode data
*
* @v encoded Encoded string
* @v raw Raw data
* @ret len Length of raw data, or negative error
*
* The buffer must be large enough to contain the decoded data. Use
* something like
*
* char buf[ base16_decoded_max_len ( encoded ) ];
*
* to provide a buffer of the correct size.
*/
int base16_decode ( const char *encoded, uint8_t *raw ) {
const char *encoded_bytes = encoded;
uint8_t *raw_bytes = raw;
char buf[3];
char *endp;
size_t len;
while ( encoded_bytes[0] ) {
if ( ! encoded_bytes[1] ) {
DBG ( "Base16-encoded string \"%s\" has invalid "
"length\n", encoded );
return -EINVAL;
}
memcpy ( buf, encoded_bytes, 2 );
buf[2] = '\0';
*(raw_bytes++) = strtoul ( buf, &endp, 16 );
if ( *endp != '\0' ) {
DBG ( "Base16-encoded string \"%s\" has invalid "
"byte \"%s\"\n", encoded, buf );
return -EINVAL;
}
encoded_bytes += 2;
}
len = ( raw_bytes - raw );
DBG ( "Base16-decoded \"%s\" to:\n", encoded );
DBG_HDA ( 0, raw, len );
assert ( len <= base16_decoded_max_len ( encoded ) );
return ( len );
}
