D047 - A licence is built from scratch, and a real one is reproduced byte for byte

licence::Licence::build produces a RIF from a content id: header, times, the digest-derived secret IV, the encrypted secret, and a 2048-bit RSA signature. examples/rebuild_licence rebuilds each real package's licence and compares:

PS5_ITEM00001_v1.14.pkg: REBUILT BYTE FOR BYTE
PS5_LAPY20011_v1.05.pkg: REBUILT BYTE FOR BYTE
Store-R2-PS5.pkg:        REBUILT BYTE FOR BYTE

There is no partial credit in that test. A wrong offset, constant, derivation, padding scheme or key produces different bytes.

Getting the key was the hard part, and not for the obvious reason

The debug RIF keyset and the AES key over the secret are published, in the same project this repository already takes its fake keyset from. The obstacle was transport: a summarising reader returned 519 hex characters for a 512-character value, then overlapping byte ranges, then sixteen bytes where sixty-four were asked for. Four reconstructions were attempted and all four were rejected - by signing a real licence and comparing, which is the only test that distinguishes a nearly-right key from a right one.

The repository was cloned and the file read directly. First attempt, three signatures reproduced. A key is not something to obtain approximately.

Two things the bytes corrected

• The published field list places the disc key at 0x1E8 and the signature at 0x2A8. Real licences say 0x240 and 0x300, and only the measured layout ends the signature exactly on the structure's boundary. (D046)
• The routine encrypting the secret is named AesCbcCfb128Encrypt and sets CipherMode.CBC. The name says CFB; the code says CBC, and a CFB implementation reproduced every other field of a real licence and got those 144 bytes wrong. The bytes settled it in one run.

What this changes about principle 6

The charter said signing "is not attempted and could not be". That is now false and has been corrected rather than left standing.

Containers still declare themselves fake with zero signature areas - no vendor signature is forged and none could be. But a licence is signed, under a published debug keypair whose whole purpose is the fake licences a non-retail package carries. Signing with it asserts "this is a debug licence", which is true, and the licence says so in its own type field.

The line is not "never compute a signature". It is never claim to be the vendor.