encfs/base/base64.h

79 lines
2.6 KiB
C++

/*****************************************************************************
* Author: Valient Gough <vgough@pobox.com>
*
*****************************************************************************
* Copyright (c) 2002-2003, Valient Gough
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at your
* option) 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _base64_incl_
#define _base64_incl_
#include "base/types.h"
namespace encfs {
inline int B64ToB256Bytes(int numB64Bytes) {
return (numB64Bytes * 6) / 8; // round down
}
inline int B32ToB256Bytes(int numB32Bytes) {
return (numB32Bytes * 5) / 8; // round down
}
inline int B256ToB64Bytes(int numB256Bytes) {
return (numB256Bytes * 8 + 5) / 6; // round up
}
inline int B256ToB32Bytes(int numB256Bytes) {
return (numB256Bytes * 8 + 4) / 5; // round up
}
/*
convert data between different bases - each being a power of 2.
*/
void changeBase2(byte *src, int srcLength, int srcPow2, byte *dst,
int dstLength, int dstPow2);
/*
same as changeBase2, but writes output over the top of input data.
*/
void changeBase2Inline(byte *buf, int srcLength, int srcPow2, int dst2Pow,
bool outputPartialLastByte);
// inplace translation from values [0,2^6] => base64 ASCII
// This is a nonstandard B64 encoding, which uses ',' and '-' as
// non-alphanumeric chars.
void B64ToAscii(byte *buf, int length);
// inplace translation from values [0,2^5] => base32 ASCII
void B32ToAscii(byte *buf, int length);
// inplace translation from values base64 ASCII => [0,2^6]
// This is a nonstandard B64 encoding, which uses ',' and '-' as
// non-alphanumeric chars.
void AsciiToB64(byte *buf, int length);
// inplace translation from values base32 ASCII => [0,2^5]
void AsciiToB32(byte *buf, int length);
// Decode standard B64 into the output array.
// Used only to decode legacy Boost XML serialized config format.
// The output size must be at least B64ToB256Bytes(inputLen).
bool B64StandardDecode(byte *out, const byte *in, int inputLen);
} // namespace encfs
#endif