readme

vc_net.zip 网络通信开发包vc源码 一套易用的网络通信包

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The software distributed with this README file removes content
protection from any Windows Media Audio file (.wma file) that uses DRM
version 2 (as implemented in Windows Media Player version 7).  It has
been tested under Windows 98, so may or may not work with other Media
Player/OS combinations.  Also be aware that many "protected content"
files out there are actually DRM version 1, especially if they are
older files.  This software will not do anything to unprotect version
1 files.

There is another piece of software, called "unfuck", which similarly
removes protections, but there is a fundamental difference in how
these two pieces of software work.  Unfuck works by allowing the
player to unprotect and uncompress the audio, and then captures the
audio samples on the way to the sound card.  This software attacks the
problem directly: it simply removes the encryption from the protected
file, leaving everything else exactly the same.  Because of this,
there is no loss of quality due to uncompressing and re-compressing
the content -- what you're left with is exactly the original content,
just not protected.  It's also much faster.

Please be aware that this software is "proof-of-concept" or
"demonstration" level, not production level.  While every effort has
been made to make sure that it works properly, it may fail in
unforeseen situations -- it has NOT been thoroughly tested!  There
isn't much chance that this program will screw up your system, but use
at your own risk!

   WARNING!!!!!  I have just learned that the new Microsoft Media
   Player EULA includes a clause that says they can *automatically*
   modify the software on your system, without any confirmation from
   you required!  In other words, they can disable your software, or
   force an upgrade so that FreeMe won't work, just because they feel
   like it.  Be careful out there!


CONTENTS:
  README - This file
  LICENSE - Yes, a license!  Read it!
  Technical - Full technical description of how MS DRMv2 works
  Philosophy - My philosophy on why I released this, and what's wrong
               with the DMCA
  FreeMe.exe - The actual program
  src/ - The source code

  The first 4 files can possibly be widely re-distributed and mirrored
  without much fear of real legal worries -- however, you will almost
  certainly be harassed by several big and powerful companies, so keep
  that in mind.  The last two files (the program) cause more problems:
  distributing these in the U.S. is almost certainly a violation of
  the DMCA.  However, outside the U.S. should be mostly ok -- so
  mirror these on as many foreign sites as possible!  Again, you may
  be harassed by big and powerful companies, and might get threatening
  letters from lawyers, so be prepared for that.


INSTALLATION:
  There's just a single executable file "FreeMe.exe" to install.  You
  can copy it so that it's in your executable PATH (for example, copy
  to directory C:\WINDOWS\COMMAND), or you can put a shortcut to it on
  your desktop -- see below.


USAGE:
  This is a command-line program, and the best way to run it is from
  the command line.  If it is installed, and the executable is in your
  PATH, all you have to do is type "freeme x.wma" at a DOS prompt in
  order to unprotect the file "x.wma".  There is a verbose flag that
  you can invoke to have it print out all sorts of information as it
  discovers it (your public/private key pairs, KID of the file you're
  unprotecting, content key, etc.).  For example, typing "freeme -v
  x.wma" unprotects the file as above, but in verbose mode.  The
  output file will be called "Freed-x.wma", where "x.wma" is the
  original filename.

  One problem with this being a command line utility is that many
  audio files have very long file names, so you'll have to put the
  filename in quotes in order for this to work, like so:
    Prompt> freeme "Billy and the Boingers - The RIAA Stole My Soul.wma"

  As an alternative, you can put a shortcut to the FreeMe.exe
  executable on your desktop, and then can simply drag files from the
  file explorer to FreeMe.  However, there is one big problem with
  this:  the filename given to FreeMe is actually the short filename,
  so if you did this with the file above, you'd end up with an output
  file named something like "Freed-BILLYA~1.WMA"  Unfortunately, I
  don't know how to fix this -- maybe someone else out there does.


SOURCE CODE:
  The full source code is included in the src/ directory, but you will
  need a Win32 version of the OpenSSL package (and crypto library) in
  order to compile it.

  There are some definite problems with this code, which I would
  suggest to people interested in improving what I've distributed:
  First off, a lot of things in Windows seem to be designed to be
  easier in C++ than in C; unfortunately, I don't know a lot about
  Windows programming, and never have learned or used C++ at all, so
  some of my code may be a little strange in its approach.  Secondly,
  my .asf/.wma file format processing is hopelessly naive.  Surely
  there are better ways to do this, or existing libraries to do it.
  Also, I don't really do XML parsing, but just a very simplistic
  scanning.  This seems to work for every license I've seen, but using
  a real XML parser would make this much more robust.  Finally, a nice
  pretty GUI would be good, but wasn't necessary for my
  "proof-of-concept" code, so I didn't include it.

  Finally, you know that Microsoft is going to make some changes that
  will render my software useless.  You've got the source code, so use
  that as a starting point to change with them.


HOW TO CONTACT ME:
  Being anonymous, it's hard to give a way to contact me.  However, if
  you have something very important to tell me, post to the sci.crypt
  Usenet newsgroup with a subject that includes the phrase "To Beale
  Screamer".  My PGP key is given in this distribution, in case you
  need it (and I will always sign anything I distribute).

  Please don't inundate the poor people in sci.crypt with a bunch of
  pointless comments.  But I did want to give people some avenue for
  contacting me if absolutely necessary.


MESSAGES:
  I have included messages below for specific groups of people.

  Users: Please respect the uses I have intended this software for.  I
      want to make a point with this software, and if you use it for
      purposes of violating copyrights, the message stands a very good
      chance of getting lost.  Also, Microsoft is obviously going to
      release patches to their media player in order to get around the
      exploit in my software -- I think you'll be safe it you refuse
      to upgrade from your current version of the Windows Media Player
      (but see the warning above about "forced upgrades").  Unless they
      want to sacrifice backward compatibility, you will at least be
      able to work with your current (legally obtained) media files
      for the near future.

  Microsoft: You guys have put together a pretty good piece of
      software.  Really.  The only real technical flaw is that
      licenses can't be examined for their restrictions once they are
      obtained.  My real beef is with the media publishers' use of this
      software, not the technology itself.  However, it's easy to see
      where software bloat and inefficiency comes from when this code
      is examined: every main DLL has a separate copy of the elliptic
      curve and other basic crypto routines, and parameters passed
      back and forth between modules are encrypted giving unnecessary
      overhead, not to mention all the checks of the code integrity,
      checks for a debugger running, code encryption and decryption.
      Perhaps you felt this was necessary for the "security through
      obscurity" aspect, but I've got to tell you that this really
      doesn't make a bit of difference.  Make lean and mean code,
      because the obscurity doesn't work as well as you think it does.
      Also read the message below to the Justice Department!

  Justice Department: Maybe this should really be addressed to the
      state officials, since it looks like the current U.S.
      administration doesn't care too much about monopoly powers being
      abused.  But for whoever is interested, there is a very serious
      anti-competitive measure in this software.  In particular, for
      various modules of the software to be used, you must supply a
      certified public key for communication.  Guess who controls the
      certification of public keys?  Microsoft.  So if someone wants
      to make a competing product, which integrates well with the
      Windows OS, you will need to get Microsoft's permission and
      obtain a certificate from them.  I don't know what their policy
      is on this, so don't know if this power will be abused or not.
      However, it has the potential for being a weapon Microsoft can
      use to knock out any competition to their products.

  Artists: Don't fear new distribution methods -- embrace them.
      Technology is providing you the means to get your art directly
      to consumers, avoiding the big record companies.  They want a
      piece of the action for YOUR creativity, and you don't need to
      let them in on it any more.  Your fans will treat you nicely,
      unless you treat your fans poorly (take note of that Lars).  Bo
      Diddley didn't have anything to fear from his fans, but a lot to
      fear from Leonard Chess.  Think about that.

  Publishers: Give us more options, not fewer.  If you try to take
      away our current rights, and dictate to us what we may or may
      not do, you're going to get a lot of resistance.  You better
      find a way to play nicely soon, because technology is making it
      possible for artists to make do without you at all.  Try getting
      some progressive thinkers into management -- current people
      don't seem to be able to cope with the new environment that is
      emerging.

- - --

Original Distribution Date:  October 18, 2001
by "Beale Screamer"


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