Because that file definitely looks sane, and properly targets the KOA2.
Code:
kindletool convert -k ~/Downloads/update_voice_kindle_all_new_oasis.bin
Bundle SP01 (Signing Envelope)
Cert number 2
Cert file pubprodkey02.pem (Official 2K)
Bundle FB02 (Fullbin [signed?])
Bundle Type Recovery
MD5 Hash cbda910d361d9fba839e60597dc46d0b
Magic 1 2048630901
Magic 2 1897089723
Minor 1
Header Rev 2
Platform Zelda
Board Unspecified
md5sum /home/niluje/Downloads/update_voice_kindle_all_new_oasis_converted.tar.gz
cbda910d361d9fba839e60597dc46d0b /home/niluje/Downloads/update_voice_kindle_all_new_oasis_converted.tar.gz
It just *happens* to be formatted like a factory update package, vs. a full update package.
Code:
Checking update package '/home/niluje/Downloads/update_kindle_all_new_oasis_5.9.5.2.bin'.
Bundle SP01 (Signing Envelope)
Cert number 2
Cert file pubprodkey02.pem (Official 2K)
Bundle FB03 (Fullbin [OTA?, fwo?])
Bundle Type Recovery V2
Target OTA 3301990004
MD5 Hash 8668c5edff9432c39c07a20ce1c0f1c6
Magic 1 2048630901
Magic 2 1897089723
Minor 1
Platform Zelda
Header Rev 0
Board Unspecified
Devices 15
Device Kindle Oasis 2 (2017) (Unknown Variant 0LM)
Device Kindle Oasis 2 (2017) (Unknown Variant 0LN)
Device Kindle Oasis 2 (2017) (Unknown Variant 0LP)
Device Kindle Oasis 2 (2017) (Unknown Variant 0LQ)
Device Kindle Oasis 2 (2017) (Unknown Variant 0P1)
Device Kindle Oasis 2 (2017) (Unknown Variant 0P2)
Device Kindle Oasis 2 (2017) (Unknown Variant 0P6)
Device Kindle Oasis 2 (2017) (Unknown Variant 0P7)
Device Kindle Oasis 2 (2017) WiFi (8GB)
Device Kindle Oasis 2 (2017) WiFi+3G (32GB)
Device Kindle Oasis 2 (2017) (Unknown Variant 0S2)
Device Kindle Oasis 2 (2017) (Unknown Variant 0S3)
Device Kindle Oasis 2 (2017) (Unknown Variant 0S4)
Device Kindle Oasis 2 (2017) (Unknown Variant 0S7)
Device Kindle Oasis 2 (2017) WiFi (32GB)
FB02 vs. FB03
Which means, that, in a delicious bit of irony, Amazon's own anti-downgrade protection is coming back to bite users in the ass.
I'll be in the corner laughing maniacally.