Removing the simlock is really challenging. I have 2 pairs of (NCK, hash) but I don't know the salt and the hash type. Most likely the hash type is sha256, but there are also some other hash algorithms that generate 32 byte hashes: haval, ripemd256 etc.
The salt used in SGS2 is 8 times chr(0) and it is appended to the NCK. But this rule does not apply to the Xcover. So they've either changed the salt or maybe they are using some undocumented hash algorithm for hashing the NCK.
Now I'm trying to vary the salt, but I'm pretty limited here due to the huge number of possible combinations for an 8 byte salt: 256^8=18,446,744,073,709,551,616.......
Any idea or advice is welcome.