Wrong block author on Kreivo network #6229
Description
The block 0xbe1686e5…157eec8445e0 has the following information regarding block author:
Header digest logs:
[
{
"type": "preRuntime",
"value": {
"engine": "CMLS",
"payload": "0x01010130"
}
},
{
"type": "preRuntime",
"value": {
"engine": "aura",
"payload": "0x2ec0841100000000"
}
},
{
"type": "consensus",
"value": {
"engine": "RPSR",
"payload": "0x5c488cc6a7b678f955047f7fc075881ade0c6cd0004699252df71165b76e4bba56616507"
}
},
{
"type": "seal",
"value": {
"engine": "aura",
"payload": "0x72908525dd861bb5813aeafe393625576bd29a8ab4b3245e5869adb8d65d421e3eb7a9f4b9f0edf28e2d0d7f86208032648b32761ab7ad41e27905c603807b89"
}
}
]
Session.Validators:
[
0: "D6AS6xwwDBQ89mRPQdUMG9UQnQ7knaNdx1Fk5SUETMwT9DL"
1: "EFuS5c3xEmKPHYJz7KD9ZTXmRqaHggixxUfMPbfvvDvjKGm"
2: "Eymc4KLiiPaSYSYhenT8gxhvBp8wt3ooAiJVzWqf6sDxyhe"
3: "H4V4RJU6735JwQVnpWJ9Ljn9VhoKwCADpiTMD4bU4QqffYL"
4: "H4WVkfa4FAMSQF4G2A9Zmgq8fcmjsCxZjWJ78htkWvLzbJa"
5: "HCnk32t9YScHgdXAaQ4BwgbgBVMqHETfEVA336rm1NFeTg6"
]
Currently, PJS says the author for this block is H4WVkfa4FA…8htkWvLzbJa, index=4. However, looking at the aura preRuntime seal, it has a value of 0x2ec0841100000000, which in u64 is 293912622, which mod amount of validators (6) equals to idx=0, D6AS6xww…UETMwT9DL.
The problem here is that extractAuthor grabs only the first preRuntime log, which in this case is CMLS, not a recognised engine, and it fallsback to consensus RPSR, not an engine either, and then seal aura - But then reads the value of that seal as a u64, as if it were a preRuntime. Then 0x72908525dd861bb5 in u64 is 13050172629611548786, which mod 6 equals to idx=4.
Unless I misunderstood something, this is resulting in wrong block authors for networks that have a CMLS preRuntime seal before the aura one.