Thanks Emil. The reason I asked is that I am researching ways to provide that "minimum entropy required", and I was not able to find details about the number generation. Best regards, Alexandre Giron Em seg, 25 de mar de 2019 às 09:23, Emil Lenngren <emil.lenngren@xxxxxxxxx> escreveu: > > Hi Alexandre, > > Den mån 25 mars 2019 kl 13:03 skrev Alexandre Augusto > <alexandre.a.giron@xxxxxxxxx>: > > > > Hello, > > > > I would like to know, if possible, information about the bluez LE Rand > > command (ocf 0x0018) at HCI code. How does it generate the number? Is > > it vendor-specific (or secret)? > > According to the Bluetooth core specification, it shall be a "A pseudo > random number generator compliant with [FIPS PUB 140-2] > (http://csrc.nist.gov/publications/fips/fips140-2/fips1402annexc.pdf)" > which shall be seeded "with at least the minimum entropy required by > the pseudo random number generator". What algorithm each Bluetooth > controller actually uses is therefore vendor specific. I guess most > controllers will use some SHA-based or AES-based algorithm. Note that > it is not the host (BlueZ) that generates the number; it just asks the > controller to generate it for the host. > > /Emil -- Alexandre Augusto Giron Professor da UTFPR
