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authorWilmer van der Gaast <wilmer@gaast.net>2008-06-30 00:41:39 +0100
committerWilmer van der Gaast <wilmer@gaast.net>2008-06-30 00:41:39 +0100
commitf5d1b3185140e690a6503b9e68c7ea28655b405e (patch)
treef679a139ecca219aa2c7a07adcaefd3000c8c801 /irc_im.c
parentcd63d5822e76a6126bb3017567c9ce2869a44e0b (diff)
parent913545e54123296fb8229ecad2c77a6e899e0242 (diff)
Merging changes from Jelmer: It's now possible to cross-compile a Windows
version of BitlBee from Linux. No working SSL support yet though!
Diffstat (limited to 'irc_im.c')
0 files changed, 0 insertions, 0 deletions
#n114'>114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153
/***************************************************************************\
*                                                                           *
*  BitlBee - An IRC to IM gateway                                           *
*  Base64 handling functions. encode_real() is mostly based on the y64 en-  *
*  coder from libyahoo2. Moving it to a new file because it's getting big.  *
*                                                                           *
*  Copyright 2006 Wilmer van der Gaast <wilmer@gaast.net>                   *
*                                                                           *
*  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        *
*  (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 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.              *
*                                                                           *
\***************************************************************************/

#include <glib.h>
#include <string.h>
#include "base64.h"

static const char real_b64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

char *tobase64(const char *text)
{
	return base64_encode((const unsigned char *)text, strlen(text));
}

char *base64_encode(const unsigned char *in, int len)
{
	char *out;
	
	out = g_malloc((len + 2)    /* the == padding */
	                    / 3     /* every 3-byte block */
	                    * 4     /* becomes a 4-byte one */
	                    + 1);   /* and of course, ASCIIZ! */
	
	base64_encode_real((unsigned char*) in, len, (unsigned char*) out, real_b64);
	
	return out;
}

int base64_encode_real(const unsigned char *in, int inlen, unsigned char *out, const char *b64digits)
{
	int outlen = 0;
	
	for (; inlen >= 3; inlen -= 3)
	{
		out[outlen++] = b64digits[in[0] >> 2];
		out[outlen++] = b64digits[((in[0]<<4) & 0x30) | (in[1]>>4)];
		out[outlen++] = b64digits[((in[1]<<2) & 0x3c) | (in[2]>>6)];
		out[outlen++] = b64digits[in[2] & 0x3f];
		in += 3;
	}
	if (inlen > 0)
	{
		out[outlen++] = b64digits[in[0] >> 2];
		if (inlen > 1)
		{
			out[outlen++] = b64digits[((in[0]<<4) & 0x30) | (in[1]>>4)];
			out[outlen++] = b64digits[((in[1]<<2) & 0x3c)];
		}
		else
		{
			out[outlen++] = b64digits[((in[0]<<4) & 0x30)];
			out[outlen++] = b64digits[64];
		}
		out[outlen++] = b64digits[64];
	}
	out[outlen] = 0;
	
	return outlen;
}

/* Just a simple wrapper, but usually not very convenient because of zero
   termination. */
char *frombase64(const char *in)
{
	unsigned char *out;
	
	base64_decode(in, &out);
	
	return (char*) out;
}

/* FIXME: Lookup table stuff is not threadsafe! (But for now BitlBee is not threaded.) */
int base64_decode(const char *in, unsigned char **out)
{
	static char b64rev[256] = { 0 };
	int len, i;
	
	/* Create a reverse-lookup for the Base64 sequence. */
	if( b64rev[0] == 0 )
	{
		memset( b64rev, 0xff, 256 );
		for( i = 0; i <= 64; i ++ )
			b64rev[(int)real_b64[i]] = i;
	}
	
	len = strlen( in );
	*out = g_malloc( ( len + 6 ) / 4 * 3 );
	len = base64_decode_real( (unsigned char*) in, *out, b64rev );
	*out = g_realloc( *out, len + 1 );
	out[0][len] = 0;	/* Zero termination can't hurt. */
	
	return len;
}

int base64_decode_real(const unsigned char *in, unsigned char *out, char *b64rev)
{
	int i, outlen = 0;
	
	for( i = 0; in[i] && in[i+1] && in[i+2] && in[i+3]; i += 4 )
	{
		int sx;
		
		sx = b64rev[(int)in[i+0]];
		if( sx >= 64 )
			break;
		out[outlen] = ( sx << 2 ) & 0xfc;
		
		sx = b64rev[(int)in[i+1]];
		if( sx >= 64 )
			break;
		out[outlen] |= ( sx >> 4 ) & 0x03;
		outlen ++;
		out[outlen] = ( sx << 4 ) & 0xf0;
		
		sx = b64rev[(int)in[i+2]];
		if( sx >= 64 )
			break;
		out[outlen] |= ( sx >> 2 ) & 0x0f;
		outlen ++;
		out[outlen] = ( sx << 6 ) & 0xc0;
		
		sx = b64rev[(int)in[i+3]];
		if( sx >= 64 )
			break;
		out[outlen] |= sx;
		outlen ++;
	}
	
	/* If sx > 64 the base64 string was damaged. Should we ignore this? */
	
	return outlen;
}