paulo@0: /*
paulo@0:  * $Id: url.c,v 1.1 2004/03/24 06:34:36 hipnod Exp $
paulo@0:  *
paulo@0:  * Copyright (C) 2001-2003 giFT project (gift.sourceforge.net)
paulo@0:  *
paulo@0:  * This program is free software; you can redistribute it and/or modify it
paulo@0:  * under the terms of the GNU General Public License as published by the
paulo@0:  * Free Software Foundation; either version 2, or (at your option) any
paulo@0:  * later version.
paulo@0:  *
paulo@0:  * This program is distributed in the hope that it will be useful, but
paulo@0:  * WITHOUT ANY WARRANTY; without even the implied warranty of
paulo@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
paulo@0:  * General Public License for more details.
paulo@0:  */
paulo@0: 
paulo@0: #include "gt_gnutella.h"
paulo@0: #include "encoding/url.h"
paulo@0: 
paulo@0: #include <ctype.h>
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: /* url decode/encode helpers */
paulo@0: 
paulo@0: static int oct_value_from_hex (char hex_char)
paulo@0: {
paulo@0: 	if (!isxdigit (hex_char))
paulo@0: 		return 0;
paulo@0: 
paulo@0: 	if (hex_char >= '0' && hex_char <= '9')
paulo@0: 		return (hex_char - '0');
paulo@0: 
paulo@0: 	hex_char = toupper (hex_char);
paulo@0: 
paulo@0: 	return ((hex_char - 'A') + 10);
paulo@0: }
paulo@0: 
paulo@0: char *gt_url_decode (const char *encoded)
paulo@0: {
paulo@0: 	char *decoded, *ptr;
paulo@0: 
paulo@0: 	if (!encoded)
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	/* make sure we are using our own memory here ... */
paulo@0: 	ptr = strdup (encoded);
paulo@0: 
paulo@0: 	/* save the head */
paulo@0: 	decoded = ptr;
paulo@0: 
paulo@0: 	/* convert '+' -> ' ' and %2x -> char value */
paulo@0: 	while (*ptr)
paulo@0: 	{
paulo@0: 		switch (*ptr)
paulo@0: 		{
paulo@0: 		 case '+':
paulo@0: 			*ptr = ' ';
paulo@0: 			break;
paulo@0: 		 case '%':
paulo@0: 			if (isxdigit (ptr[1]) && isxdigit (ptr[2]))
paulo@0: 			{
paulo@0: 				int oct_val;
paulo@0: 
paulo@0: 				oct_val =  oct_value_from_hex (ptr[1]) * 16;
paulo@0: 				oct_val += oct_value_from_hex (ptr[2]);
paulo@0: 
paulo@0: 				*ptr = (char) oct_val;
paulo@0: 
paulo@0: 				string_move (ptr + 1, ptr + 3);
paulo@0: 			}
paulo@0: 			break;
paulo@0: 		 default:
paulo@0: 			break;
paulo@0: 		}
paulo@0: 
paulo@0: 		ptr++;
paulo@0: 	}
paulo@0: 
paulo@0: 	return decoded;
paulo@0: }
paulo@0: 
paulo@0: static char *gt_url_encode_char (char *stream, unsigned char c)
paulo@0: {
paulo@0: 	const char hex_alpha[] = "0123456789abcdef";
paulo@0: 
paulo@0: 	*stream++ = '%';
paulo@0: 
paulo@0: 	*stream++ = hex_alpha[(c & 0xf0) >> 4];
paulo@0: 	*stream++ = hex_alpha[(c & 0x0f)];
paulo@0: 
paulo@0: 	return stream;
paulo@0: }
paulo@0: 
paulo@0: /*
paulo@0:  * This is a bit overzealous about what to encode..hopefully that's ok.  This
paulo@0:  * escapes path components ('/').
paulo@0:  */
paulo@0: static BOOL is_safe_char (unsigned char c)
paulo@0: {
paulo@0: 	if (c >= 'A' && c <= 'Z')
paulo@0: 		return TRUE;
paulo@0: 
paulo@0: 	if (c >= 'a' && c <= 'z')
paulo@0: 		return TRUE;
paulo@0: 
paulo@0: 	if (c >= '0' && c <= '9')
paulo@0: 		return TRUE;
paulo@0: 
paulo@0: 	switch (c)
paulo@0: 	{
paulo@0: 	 case '-':
paulo@0: 	 case '.':
paulo@0: 	 case '_':
paulo@0: 		return TRUE;
paulo@0: 	 default:
paulo@0: 		return FALSE;
paulo@0: 	}
paulo@0: 
paulo@0: 	return FALSE;
paulo@0: }
paulo@0: 
paulo@0: char *gt_url_encode (const char *decoded)
paulo@0: {
paulo@0: 	char         *encoded, *ptr;
paulo@0: 	unsigned char chr;
paulo@0: 
paulo@0: 	if (!decoded)
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	/* allocate a large enough buffer for all cases */
paulo@0: 	encoded = ptr = malloc ((strlen (decoded) * 3) + 1);
paulo@0: 
paulo@0: 	while ((chr = *decoded) != 0)
paulo@0: 	{
paulo@0: 		if (is_safe_char (chr))
paulo@0: 			*ptr++ = chr;
paulo@0: 		else
paulo@0: 			ptr = gt_url_encode_char (ptr, chr);
paulo@0: 
paulo@0: 		decoded++;
paulo@0: 	}
paulo@0: 
paulo@0: 	*ptr = 0;
paulo@0: 
paulo@0: 	return encoded;
paulo@0: }
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: #if 0
paulo@0: int main (int argc, char **argv)
paulo@0: {
paulo@0: 	int i;
paulo@0: 
paulo@0: 	for (i = 1; i < argc; i++)
paulo@0: 	{
paulo@0: 		char *enc, *dec;
paulo@0: 
paulo@0: 		enc = gt_url_encode (argv[i]);
paulo@0: 		dec = gt_url_decode (enc);
paulo@0: 
paulo@0: 		printf ("%s\n%s\n%s\n", argv[i], enc, dec);
paulo@0: 
paulo@0: 		assert (strcmp (argv[i], dec) == 0);
paulo@0: 	}
paulo@0: 
paulo@0: 	return 0;
paulo@0: }
paulo@0: #endif