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• Changes to the WebM Open Source License

  5 juin 2010, par noreply@blogger.com (John Luther)

  You’ll see on the WebM license page and in our source code repositories that we’ve made a small change to our open source license. There were a couple of issues that popped up after we released WebM at Google I/O a couple weeks ago, specifically around how the patent clause was written.

  As it was originally written, if a patent action was brought against Google, the patent license terminated. This provision itself is not unusual in an OSS license, and similar provisions exist in the 2nd Apache License and in version 3 of the GPL. The twist was that ours terminated "any" rights and not just rights to the patents, which made our license GPLv3 and GPLv2 incompatible. Also, in doing this, we effectively created a potentially new open source copyright license, something we are loath to do.

  Using patent language borrowed from both the Apache and GPLv3 patent clauses, in this new iteration of the patent clause we’ve decoupled patents from copyright, thus preserving the pure BSD nature of the copyright license. This means we are no longer creating a new open source copyright license, and the patent grant can exist on its own. Additionally, we have updated the patent grant language to make it clearer that the grant includes the right to modify the code and give it to others. (We’ve updated the licensing FAQ to reflect these changes as well.)

  We’ve also added a definition for the "this implementation" language, to make that more clear.

  Thanks for your patience as we worked through this, and we hope you like, enjoy and (most importantly) use WebM and join with us in creating more freedom online. We had a lot of help on these changes, so thanks to our friends in open source and free software who traded many emails, often at odd hours, with us.

  Chris DiBona is the Open Source Programs Manager at Google.

  

• Changes to the WebM Open Source License

  4 juin 2010, par noreply@blogger.com (John Luther)

  You’ll see on the WebM license page and in our source code repositories that we’ve made a small change to our open source license. There were a couple of issues that popped up after we released WebM at Google I/O a couple weeks ago, specifically around how the patent clause was written.

  As it was originally written, if a patent action was brought against Google, the patent license terminated. This provision itself is not unusual in an OSS license, and similar provisions exist in the 2nd Apache License and in version 3 of the GPL. The twist was that ours terminated "any" rights and not just rights to the patents, which made our license GPLv3 and GPLv2 incompatible. Also, in doing this, we effectively created a potentially new open source copyright license, something we are loath to do.

  Using patent language borrowed from both the Apache and GPLv3 patent clauses, in this new iteration of the patent clause we’ve decoupled patents from copyright, thus preserving the pure BSD nature of the copyright license. This means we are no longer creating a new open source copyright license, and the patent grant can exist on its own. Additionally, we have updated the patent grant language to make it clearer that the grant includes the right to modify the code and give it to others. (We’ve updated the licensing FAQ to reflect these changes as well.)

  We’ve also added a definition for the "this implementation" language, to make that more clear.

  Thanks for your patience as we worked through this, and we hope you like, enjoy and (most importantly) use WebM and join with us in creating more freedom online. We had a lot of help on these changes, so thanks to our friends in open source and free software who traded many emails, often at odd hours, with us.

  Chris DiBona is the Open Source Programs Manager at Google.

  

• Deobfuscation Redux : JavaScript

  20 juin 2011, par Multimedia Mike — Reverse Engineering, deobfuscation, javascript, programming

  Google recently released version 12 of their Chrome browser. This version adds a new feature that automatically allows deobfuscating obfuscated JavaScript source code.

  Before :

  
  
  

  After :

  
  
  

  As a reverse engineering purist, I was a bit annoyed. Not at the feature, just the naming. This is clearly code beautification but not necessarily deobfuscation. The real obfuscation comes not from removing whitespace but from renaming variable and function names to terse 1- and 2-letter identifiers. True automated deobfuscation — which entails recovering the original variable and function identifiers as well as source code comments — is basically impossible.

  Still, it makes me wonder if there is any interest in a JavaScript deobfuscator that operates similar to my Java deobfuscator which was one of the first things I published on this blog. The general idea is automatically replace function names with random English verbs (since functions correspond to actions) and variable names with random animal names (I decided "English nouns" encompassed too broad a category of words). I suspect the day that someone releases a proprietary multimedia codec in a pure (though obfuscated) JavaScript format is that day that I will try to accomplish this, if it hasn’t been done already.

  See also :

  • Success on the Java De-obfuscation Front