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