Protect

Tag Info
Tag Number: 
24
Tag Type: 
Define
Tag Flash Version: 
2
Unknown SWF Tag: 
This tag is defined by the Flash documentation by Adobe
Brief Description: 

Disable edition capabilities of the given SWF file. Though this doesn't need to be enforced by an SWF editor, it marks the file as being copyrighted in a way.

WARNING: this tag is only valid in Flash V2.x, V3.x, and V4.x, use the EnableDebugger instead in V5.x and EnableDebugger2 in V6.x and newer movies.

Tag Structure: 
struct swf_protect {
	swf_tag			f_tag;		/* 24, 58 or 64  */
	if(version >= 5) {
		if(tag == ProtectDebug2) {
			unsigned short	f_reserved;1
		}
		/* the password is optional when tag == Protect */
		string		f_md5_password;
	}
};
  • 1. f_reserved must be set to zero.
See Also: 
EnableDebugger
EnableDebugger2

The protection tag is totally useless. The SWF format is an open format, otherwise how would you have so many players and tools to work with SWF movies? Thus, you can pretend to protect your movies, but anyone with a simple binary editor can transform the tag and make it another which has no such effect. Also, swf_dump and some other tools (such as flasm) can read your movie anyway.

For the sake of defining what you have in each tag, there are the protection tags fully described.

According to Macromedia, you can find some free implementation of the MD5 algorithm by Poul-Henning Kamp in FreeBSD in the file src/lib/libcrypt/crypt-md5.c. For your convenience, there is an implementation of that MD5 sum in the SSWF library.

IMPORTANT

Version 2, 3, 4 must use Protect.

Version 5 must use EnableDebugger.

Version 6 and over must use EnableDebugger2.