View source for 4DIS - FileEncryption

== '''File encryption''' ==

[[4D IS]] - Back


FileEncryption is a class to encrypt files or strings.

'''Functions :'''

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FileEncryption.Encrypt ( "...text...", key as int ) : String;
FileEncryption.EncryptFile ( "...url...", key as int );

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'''You need ...'''

[[4DIS - IO]]

'''... and ...'''

FileEncryption.js

<syntaxhighlight lang="javascript">

class FileEncryption
{
	public static function GetCharList ( string : String )
	{
		var s : String = "";
		
		for ( var i : int = 0; i < string.length; i++ )
			if ( s.IndexOf ( string [ i ] ) == -1 )
				s += string [ i ];
		
		return s;
	}
	
	public static function GetNewChar ( c : char, list : String, key : int )
	{
		var oi : int = list.length - list.IndexOf ( c ) - 1 + key;
		
		while ( oi >= list.length )
			oi -= list.length;
		
		while ( oi < 0 )
			oi += list.length;
		
		return list [ oi ];
	}
	
	public static function Encrypt ( string : String, key : int )
	{
		var list : String = GetCharList ( string );
		var rs : String = "";
		
		for ( var i : int = 0; i < string.length; i++ )
			rs += GetNewChar ( string [ i ], list, key );
		
		return rs;
	}
	
	public static function EncryptFile ( url : String, key : int )
	{
		if ( ! IO.ExistsFile ( url ) )
			return null;
		
		IO.WriteFile ( url, Encrypt ( IO.ReadFile ( url ), key ) );
	}
}

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