Cobra ODE User Manual v2.0
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Example:
01 02 0C 0B 00 00 01
Configuration excerpt 5.14: Extended COBRA.NFO format (with quick eject byte).
5.4.3
Information about DISC.ISO post-processing
While the disc is encrypted, the COBRA ODE will instruct the PS3 to decrypt the
encrypted sectors from the disc automatically while being read. However, the PS3 uses the
sector LBA as the initialization vector for decrypting the sectors. Since the sectors of the
DISC.ISO file are positioned on the manager disc on a different sector than the original
disc is, the decryption will use the wrong initialization vector. It is therefore needed to
XOR the first 16 bytes of every encrypted sector with the appropriate value to recover the
original decrypted data. The LBA sector of the DISC.ISO is provided in the COBRA.NFO
file since MCU firmware v1.3.
The first 16 bytes of every encrypted sector must first be XORed with the disc's LBA +
sector in the file to retrieve the AES decrypted block, then XORed with the original sector
to get the AES-CBC decrypted block. All other blocks use the cipher data as IV so they
will be decrypted correctly.
The third-party library can be used to do it automatically, or can be used as reference for
the post-processing algorithm.
