Possible FCC unlock for L680/xmm7360 modems and friends

Can someone confirm?

> at+gtfcclockgen
< 0x12345678 (a challenge, some eight-digit hex string)

Compute sha256 of that challenge in little endian plus a salt, where

• 8086:7560: "\xbb\x23\xbe\x7f"
• 8086:4d75: "\x74\xde\xbb\xa9"
• Lenovo perhaps also: "\xcc\xa6\x1d\xdf"

Send the first four octets in little endian, in decimal. For 8086:7560:

sha256("\x78\x56\x34\x12" + "\xbb\x23\xbe\x7f") = ffcbe872f585...

0x72e8cbff = 1927859199

> at+gtfcclockver=1927859199
< OK

> at+gtfcclockmodeunlock
< OK

> at+cfun=1
< OK

> at+gtfcclockstate
< 1
<
< OK

Have a lot of fun ...