2 * Copyright (C) 2009 Michael Brown <mbrown@fensystems.co.uk>.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
31 #include <ipxe/base64.h>
39 static const char base64[64] =
40 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
46 * @v raw_len Length of raw data
48 * @v len Length of buffer
49 * @ret len Encoded length
51 size_t base64_encode ( const void *raw, size_t raw_len, char *data,
53 const uint8_t *raw_bytes = ( ( const uint8_t * ) raw );
54 size_t raw_bit_len = ( 8 * raw_len );
61 for ( bit = 0 ; bit < raw_bit_len ; bit += 6, used++ ) {
64 tmp = ( raw_bytes[byte] << shift );
65 if ( ( byte + 1 ) < raw_len )
66 tmp |= ( raw_bytes[ byte + 1 ] >> ( 8 - shift ) );
67 tmp = ( ( tmp >> 2 ) & 0x3f );
69 data[used] = base64[tmp];
71 for ( ; ( bit % 8 ) != 0 ; bit += 6, used++ ) {
78 data[ len - 1 ] = '\0'; /* Ensure terminator exists */
84 * Base64-decode string
86 * @v encoded Encoded string
88 * @v len Length of buffer
89 * @ret len Length of data, or negative error
91 int base64_decode ( const char *encoded, void *data, size_t len ) {
92 const char *in = encoded;
98 unsigned int pad_count = 0;
101 /* Zero the output buffer */
102 memset ( data, 0, len );
105 while ( ( in_char = *(in++) ) ) {
107 /* Ignore whitespace characters */
108 if ( isspace ( in_char ) )
111 /* Process pad characters */
112 if ( in_char == '=' ) {
113 if ( pad_count >= 2 ) {
114 DBG ( "Base64-encoded string \"%s\" has too "
115 "many pad characters\n", encoded );
119 bit -= 2; /* unused_bits = ( 2 * pad_count ) */
123 DBG ( "Base64-encoded string \"%s\" has invalid pad "
124 "sequence\n", encoded );
128 /* Process normal characters */
129 match = strchr ( base64, in_char );
131 DBG ( "Base64-encoded string \"%s\" contains invalid "
132 "character '%c'\n", encoded, in_char );
135 in_bits = ( match - base64 );
137 /* Add to raw data */
139 offset = ( bit / 8 );
141 out[offset] |= ( in_bits >> ( bit % 8 ) );
144 out[offset] |= ( in_bits << ( 8 - ( bit % 8 ) ) );
148 /* Check that we decoded a whole number of bytes */
149 if ( ( bit % 8 ) != 0 ) {
150 DBG ( "Base64-encoded string \"%s\" has invalid bit length "
151 "%d\n", encoded, bit );
155 /* Return length in bytes */