/*
* Off-the-Record Messaging library
* Copyright (C) 2004-2012 Ian Goldberg, Chris Alexander, Willy Lew,
* Nikita Borisov
* <otr@cypherpunks.ca>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of version 2.1 of the GNU Lesser General
* Public License as published by the Free Software Foundation.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __B64_H__
#define __B64_H__
#include <stdlib.h>
/* Base64 encodes blocks of this many bytes: */
#define OTRL_B64_DECODED_LEN 3
/* into blocks of this many bytes: */
#define OTRL_B64_ENCODED_LEN 4
/* An encoded block of length encoded_len can turn into a maximum of
* this many decoded bytes: */
#define OTRL_B64_MAX_DECODED_SIZE(encoded_len) \
(((encoded_len + OTRL_B64_ENCODED_LEN - 1) / OTRL_B64_ENCODED_LEN) \
* OTRL_B64_DECODED_LEN)
/*
* base64 encode data. Insert no linebreaks or whitespace.
*
* The buffer base64data must contain at least ((datalen+2)/3)*4 bytes of
* space. This function will return the number of bytes actually used.
*/
size_t otrl_base64_encode(char *base64data, const unsigned char *data,
size_t datalen);
/*
* base64 decode data. Skip non-base64 chars, and terminate at the
* first '=', or the end of the buffer.
*
* The buffer data must contain at least ((base64len+3) / 4) * 3 bytes
* of space. This function will return the number of bytes actually
* used.
*/
size_t otrl_base64_decode(unsigned char *data, const char *base64data,
size_t base64len);
/*
* Base64-encode a block of data, stick "?OTR:" and "." around it, and
* return the result, or NULL in the event of a memory error.
*/
char *otrl_base64_otr_encode(const unsigned char *buf, size_t buflen);
/*
* Base64-decode the portion of the given message between "?OTR:" and
* ".". Set *bufp to the decoded data, and set *lenp to its length.
* The caller must free() the result. Return 0 on success, -1 on a
* memory error, or -2 on invalid input.
*/
int otrl_base64_otr_decode(const char *msg, unsigned char **bufp,
size_t *lenp);
#endif
