diff options
Diffstat (limited to 'src/VBox/Devices/PC/ipxe/src/core/base64.c')
| -rw-r--r-- | src/VBox/Devices/PC/ipxe/src/core/base64.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/src/VBox/Devices/PC/ipxe/src/core/base64.c b/src/VBox/Devices/PC/ipxe/src/core/base64.c new file mode 100644 index 00000000..e452f7d4 --- /dev/null +++ b/src/VBox/Devices/PC/ipxe/src/core/base64.c @@ -0,0 +1,157 @@ +/* + * Copyright (C) 2009 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. + * + * You can also choose to distribute this program under the terms of + * the Unmodified Binary Distribution Licence (as given in the file + * COPYING.UBDL), provided that you have satisfied its requirements. + */ + +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); + +#include <stdint.h> +#include <string.h> +#include <ctype.h> +#include <errno.h> +#include <assert.h> +#include <ipxe/base64.h> + +/** @file + * + * Base64 encoding + * + */ + +static const char base64[64] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +/** + * Base64-encode data + * + * @v raw Raw data + * @v raw_len Length of raw data + * @v data Buffer + * @v len Length of buffer + * @ret len Encoded length + */ +size_t base64_encode ( const void *raw, size_t raw_len, char *data, + size_t len ) { + const uint8_t *raw_bytes = ( ( const uint8_t * ) raw ); + size_t raw_bit_len = ( 8 * raw_len ); + size_t used = 0; + unsigned int bit; + unsigned int byte; + unsigned int shift; + unsigned int tmp; + + for ( bit = 0 ; bit < raw_bit_len ; bit += 6, used++ ) { + byte = ( bit / 8 ); + shift = ( bit % 8 ); + tmp = ( raw_bytes[byte] << shift ); + if ( ( byte + 1 ) < raw_len ) + tmp |= ( raw_bytes[ byte + 1 ] >> ( 8 - shift ) ); + tmp = ( ( tmp >> 2 ) & 0x3f ); + if ( used < len ) + data[used] = base64[tmp]; + } + for ( ; ( bit % 8 ) != 0 ; bit += 6, used++ ) { + if ( used < len ) + data[used] = '='; + } + if ( used < len ) + data[used] = '\0'; + if ( len ) + data[ len - 1 ] = '\0'; /* Ensure terminator exists */ + + return used; +} + +/** + * Base64-decode string + * + * @v encoded Encoded string + * @v data Buffer + * @v len Length of buffer + * @ret len Length of data, or negative error + */ +int base64_decode ( const char *encoded, void *data, size_t len ) { + const char *in = encoded; + uint8_t *out = data; + uint8_t in_char; + char *match; + int in_bits; + unsigned int bit = 0; + unsigned int pad_count = 0; + size_t offset; + + /* Zero the output buffer */ + memset ( data, 0, len ); + + /* Decode string */ + while ( ( in_char = *(in++) ) ) { + + /* Ignore whitespace characters */ + if ( isspace ( in_char ) ) + continue; + + /* Process pad characters */ + if ( in_char == '=' ) { + if ( pad_count >= 2 ) { + DBG ( "Base64-encoded string \"%s\" has too " + "many pad characters\n", encoded ); + return -EINVAL; + } + pad_count++; + bit -= 2; /* unused_bits = ( 2 * pad_count ) */ + continue; + } + if ( pad_count ) { + DBG ( "Base64-encoded string \"%s\" has invalid pad " + "sequence\n", encoded ); + return -EINVAL; + } + + /* Process normal characters */ + match = strchr ( base64, in_char ); + if ( ! match ) { + DBG ( "Base64-encoded string \"%s\" contains invalid " + "character '%c'\n", encoded, in_char ); + return -EINVAL; + } + in_bits = ( match - base64 ); + + /* Add to raw data */ + in_bits <<= 2; + offset = ( bit / 8 ); + if ( offset < len ) + out[offset] |= ( in_bits >> ( bit % 8 ) ); + offset++; + if ( offset < len ) + out[offset] |= ( in_bits << ( 8 - ( bit % 8 ) ) ); + bit += 6; + } + + /* Check that we decoded a whole number of bytes */ + if ( ( bit % 8 ) != 0 ) { + DBG ( "Base64-encoded string \"%s\" has invalid bit length " + "%d\n", encoded, bit ); + return -EINVAL; + } + + /* Return length in bytes */ + return ( bit / 8 ); +} |