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Code Issues Releases Wiki Activity

Prevent overflow when reading/converting strings from the torrent metainfo.

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This commit is contained in:
Josh Elsasser 2006-10-13 00:26:35 +00:00
parent d202bc4f1e
commit 4f3adfc8d7
1 changed files with 11 additions and 2 deletions
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13
libtransmission/metainfo.c
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@ -29,7 +29,8 @@
/***********************************************************************
* Local prototypes
**********************************************************************/
static void strcatUTF8( char *, char * );
#define strcatUTF8( dst, src) _strcatUTF8( (dst), sizeof( dst ), (src) )
static void _strcatUTF8( char *, int, char * );
/***********************************************************************
* tr_metainfoParse
@ -300,7 +301,9 @@ void tr_metainfoRemoveSaved( const char * hashString )
* non-compliant torrents around... If we encounter an invalid UTF-8
* character, we assume it is ISO 8859-1 and convert it to UTF-8.
**********************************************************************/
static void strcatUTF8( char * s, char * append )
#define WANTBYTES( want, got ) \
if( (want) > (got) ) { return; } else { (got) -= (want); }
static void _strcatUTF8( char * s, int len, char * append )
{
char * p;
@ -308,6 +311,7 @@ static void strcatUTF8( char * s, char * append )
while( s[0] )
{
s++;
len--;
}
/* Now start appending, converting on the fly if necessary */
@ -316,6 +320,7 @@ static void strcatUTF8( char * s, char * append )
if( !( p[0] & 0x80 ) )
{
/* ASCII character */
WANTBYTES( 1, len );
*(s++) = *(p++);
continue;
}
@ -323,6 +328,7 @@ static void strcatUTF8( char * s, char * append )
if( ( p[0] & 0xE0 ) == 0xC0 && ( p[1] & 0xC0 ) == 0x80 )
{
/* 2-bytes UTF-8 character */
WANTBYTES( 2, len );
*(s++) = *(p++); *(s++) = *(p++);
continue;
}
@ -331,6 +337,7 @@ static void strcatUTF8( char * s, char * append )
( p[2] & 0xC0 ) == 0x80 )
{
/* 3-bytes UTF-8 character */
WANTBYTES( 3, len );
*(s++) = *(p++); *(s++) = *(p++);
*(s++) = *(p++);
continue;
@ -340,12 +347,14 @@ static void strcatUTF8( char * s, char * append )
( p[2] & 0xC0 ) == 0x80 && ( p[3] & 0xC0 ) == 0x80 )
{
/* 4-bytes UTF-8 character */
WANTBYTES( 4, len );
*(s++) = *(p++); *(s++) = *(p++);
*(s++) = *(p++); *(s++) = *(p++);
continue;
}
/* ISO 8859-1 -> UTF-8 conversion */
WANTBYTES( 2, len );
*(s++) = 0xC0 | ( ( *p & 0xFF ) >> 6 );
*(s++) = 0x80 | ( *(p++) & 0x3F );
}