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- /*
- * 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 <stdio.h>
- #include <errno.h>
- #include <assert.h>
- #include <ipxe/string.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;
-
- /* Encode each byte */
- for ( ; remaining-- ; encoded_bytes += 2 ) {
- sprintf ( encoded_bytes, "%02x", *(raw_bytes++) );
- }
-
- /* Ensure terminating NUL exists even if length was zero */
- *encoded_bytes = '\0';
-
- DBG ( "Base16-encoded to \"%s\":\n", encoded );
- DBG_HDA ( 0, raw, len );
- assert ( strlen ( encoded ) == base16_encoded_len ( len ) );
- }
-
- /**
- * Decode hexadecimal string
- *
- * @v encoded Encoded string
- * @v separator Byte separator character, or 0 for no separator
- * @v data Buffer
- * @v len Length of buffer
- * @ret len Length of data, or negative error
- */
- int hex_decode ( const char *encoded, char separator, void *data, size_t len ) {
- uint8_t *out = data;
- unsigned int count = 0;
- unsigned int sixteens;
- unsigned int units;
-
- while ( *encoded ) {
-
- /* Check separator, if applicable */
- if ( count && separator && ( ( *(encoded++) != separator ) ) )
- return -EINVAL;
-
- /* Extract digits. Note that either digit may be NUL,
- * which would be interpreted as an invalid value by
- * digit_value(); there is therefore no need for an
- * explicit end-of-string check.
- */
- sixteens = digit_value ( *(encoded++) );
- if ( sixteens >= 16 )
- return -EINVAL;
- units = digit_value ( *(encoded++) );
- if ( units >= 16 )
- return -EINVAL;
-
- /* Store result */
- if ( count < len )
- out[count] = ( ( sixteens << 4 ) | units );
- count++;
-
- }
- return count;
- }
-
- /**
- * 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 ) {
- int len;
-
- len = hex_decode ( encoded, 0, raw, -1UL );
- if ( len < 0 )
- return len;
-
- DBG ( "Base16-decoded \"%s\" to:\n", encoded );
- DBG_HDA ( 0, raw, len );
- assert ( len <= ( int ) base16_decoded_max_len ( encoded ) );
-
- return len;
- }
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