2020-08-11 18:35:11
PUBLISHED
An improperly initialized migrationAuth value in Googles go-tpm TPM1.2 library versions prior to 0.3.0 can lead an eavesdropping attacker to discover the auth value for a key created with CreateWrapKey. An attacker listening in on the channel can collect both encUsageAuth and encMigrationAuth, and then can calculate usageAuth ^ encMigrationAuth as the migrationAuth can be guessed for all keys created with CreateWrapKey. TPM2.0 is not impacted by this. We recommend updating your library to 0.3.0 or later, or, if you cannot update, to call CreateWrapKey with a random 20-byte value for migrationAuth.