Successfully cracked DRM of DMMVRPlayer, a Japanese VR adult video player

[moco]

This player on Windows is using an executable file called WsLoader.exe, which performs DRM processing. Despite having no prior experience in reverse engineering, I was able to decrypt the license by carefully studying the API behavior and license format. In DRM processing, AES256 CBC and RSA2048 are used.


License before decryption:

RWZzS1ExVmJ6MXcyRGRGdFVrS0N4NmZiNTRXNUJUUzFmNjFsSzdyanZXZzdqdDZ6aldudUlzbnVvdUlIb3d4STJ6b2N3cFljMmRCVg0KTFZpMWJvcVMyb1ZUSnNNWGU3b0FOR0dxT0dVejd3M2I0TmU1cTJzT2FVZXFJK0RiYnJFKzQ4VUJNRElHbmx6cDV2ZXltem84aHhBdw0KQ01DSG1yVDlTM0FnQXM1M3QyKzVjZHpEYkdlRzZDb25OWlJJTHdhYzB2LzBncU5FNWI5TGd5VU51VExmRWpVb0t6eEtEd1BkSi8rVA0KeHQ4Mnh3Wk9aQTJodVQvM3dRYVBab2I5aHJ2UWJ5ditBZEdIOTFpTjRxVk9TMTQ1MkptcS9EQWczQ254aDMrejVJaERoQmxNeDljYg0KVFkxeHdLcWlnd3dPYmxNbHdvSVA0R3ViVFpKT01ibXZrNlkyWWc9PQ0KDQo1bWRGbTRQK3hJM25FWTA1d012djh3U3B2bWt6REtheFppQWdsaUY0MUtteUdJZXg4ajZmb1E3OXh3Wm5ld0hjS1JpdHYvWW85akdvDQo3UjBGRFlNL3BtWFAzTlE4eXVBVGVSaENUOG5tVFB6TXI2dmVyM1pKRWZVazdBSEpFM1RVQzJDUkZHTE1POU40anlybUlCN2xFQTk4DQpjTFdJWUJLRFdPanpBaHNXeEFLbk9YSk9XaFhQYUluOFZOVEloRmI1RUF3eHY0SFl2eStWNU9JMCt4TzdwcU5Xb2RZSG05QUc4Q2NTDQpmNWxkOVdpOUNEMWZ5dnk3MUxPS2xqQkd5alE2TU5BOGFLS1J2SlJZNFRJZ2Vxa2lWRkhJSlNsTHdwWVZxVGFicGhGbW8rVGx4TUtnDQo3a3FGOWtvOHJEUFpRYVdQTzBwSkwwWUFQQU9XYlVITnlNbmdvVUdOZ05nUmsxRE1JK0F2V3l0TVpaZys5ajZTeTVwL2RZREdpM0ZjDQpTRkt6eGZkZHNDTUJCajFKWU9Vdy9BNnU3TkVYU3dUZHdlZlFRL2JyeWNGUUhsVGlTQUdCbjE2N0N0Mzl4cytnY3ozS1puNWpuZXZyDQpGZm90eUVsMnVGc3RlUXJzbDgzR0NDSjFTN01OZjgxbnNFZFcrNkVMYmZWaHNvN1JKdFFYZ1dKTDk4YlBlckhoTzU2UkFOZU53WnozDQpEK2tsRUtDSzdodkNldi91ZVk1OE9kZFN1M0VZVUtUNGtoUEx3d0syN3VYeG5tMkdlYTBwZy82aGhvNmE0SExsdlNWbEE4RW1pT2kzDQo2OG52bjBER0NvM0FzSXMxcFpramt6NmU3ejNYTEhzQ0lpRWx5RWRXNHlxdjE3cFlCQ09MM3M4UXJhS0xycm9iZXNGYkI5ZmRtRWd1DQpCR05kdTJhbTFTdmhPNkdzMXZnY0l2Y2U5RWk1dno4c3RYMDgxZGowQ0E9PQ==

License after decryption:

<rights>
  <context>
    <version>1.0</version>
  </context>
  <agreement>
    <asset>
      <context>
        <uid>urn:uuid:91eb4bb5-a617-4778-91ce-246b8843e843</uid>
      </context>
      <KeyInfo>
        <KeyValue>H7iVlrLEg3JrjpZrCrJpUg==</KeyValue>
      </KeyInfo>
    </asset>
    <permission>
      <play>
        <constraint>
          <datetime>
          </datetime>
          <interval>P14D</interval>
        </constraint>
      </play>
    </permission>
  </agreement>
</rights>

Used video ---> https://www.dmm.co.jp/digital/videoa/-/detail/=/cid=aqust00001/
8K resolution

[[ss]vegeta]

... congratz?

[newuser]

@mono, could you talk though more how you uncovered the decryption key?

[Frieren]

where's the 8k video for research purpose?

[Anonymous84]

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[larley]