Skip to content

Commit

Permalink
Browse files Browse the repository at this point in the history
[base16] Add generic base16 encoding and decoding routines
Base16 encoding is currently implemented in both iSCSI and SRP.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
  • Loading branch information
mcb30 committed May 28, 2010
1 parent 97ea628 commit bc83e4b
Show file tree
Hide file tree
Showing 3 changed files with 145 additions and 0 deletions.
106 changes: 106 additions & 0 deletions src/core/base16.c
@@ -0,0 +1,106 @@
/*
* 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., 675 Mass Ave, Cambridge, MA 02139, 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 );
}
38 changes: 38 additions & 0 deletions src/include/ipxe/base16.h
@@ -0,0 +1,38 @@
#ifndef _IPXE_BASE16_H
#define _IPXE_BASE16_H

/** @file
*
* Base16 encoding
*
*/

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <string.h>

/**
* Calculate length of base16-encoded data
*
* @v raw_len Raw data length
* @ret encoded_len Encoded string length (excluding NUL)
*/
static inline size_t base16_encoded_len ( size_t raw_len ) {
return ( 2 * raw_len );
}

/**
* Calculate maximum length of base16-decoded string
*
* @v encoded Encoded string
* @v max_raw_len Maximum length of raw data
*/
static inline size_t base16_decoded_max_len ( const char *encoded ) {
return ( ( strlen ( encoded ) + 1 ) / 2 );
}

extern void base16_encode ( const uint8_t *raw, size_t len, char *encoded );
extern int base16_decode ( const char *encoded, uint8_t *raw );

#endif /* _IPXE_BASE16_H */
1 change: 1 addition & 0 deletions src/include/ipxe/errfile.h
Expand Up @@ -54,6 +54,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
#define ERRFILE_xfer ( ERRFILE_CORE | 0x000e0000 )
#define ERRFILE_bitmap ( ERRFILE_CORE | 0x000f0000 )
#define ERRFILE_base64 ( ERRFILE_CORE | 0x00100000 )
#define ERRFILE_base16 ( ERRFILE_CORE | 0x00110000 )

#define ERRFILE_eisa ( ERRFILE_DRIVER | 0x00000000 )
#define ERRFILE_isa ( ERRFILE_DRIVER | 0x00010000 )
Expand Down

0 comments on commit bc83e4b

Please sign in to comment.