fpc-validation.puml

/'
Copyright 2020 Intel Corporation
Copyright IBM Corp. All Rights Reserved.

SPDX-License-Identifier: Apache-2.0
'/

@startuml

'- force wrapping of longer text
'skinparam wrapWidth 400

!pragma teoz true

hide footbox
title Foot Box removed

title Fabric Private Chaincode - Transaction validation using FPC validation plugin

actor "User Org1" as User1 order 9
participant "Peer_CLI/\nClient SDK" as CLI order 10

participant "Peer Org1" as Peer1 order 25
participant "Peer Org2" as Peer2 order 60
participant "Peer Org3" as Peer3 order 70

entity Orderer order 100

ref over User1, Orderer
    install, approve, commit chaincode definition (ECC_MR)
    see fpc-lifecycle-v2.puml
end ref

ref over User1, Orderer
    register enclaves and key-dist
    see fpc-registration.puml and fpc-key-dist.puml
end ref

group endorsement
    activate CLI

    User1 -> CLI : send proposal
    ref over CLI, Peer1, Peer2, Peer3
        invoke chaincode enclave and collect enough enclave endorsements { proposal-response }
        and corresponding results { ccrsp_msg } to satisfy enclave endorsement policy
        see fpc-cc-invocation.puml
    end ref

    alt FPC Lite
        group enclave endorsement validation transaction
            CLI -> Peer1 ++: invoke "validateEnclaveEndorsement" ({ ccrsp_msg })
                create participant "FPC_stub" as ECC1 order 26
                Peer1 -> ECC1 ++:
                    group enclave endorsement validation
                        ECC1 -> ECC1 : <ECC_result, read/writeset, proposal, Sig_Enclave, Enclave_Id> <- extract from  ccrsp_msg
    
                        create participant ERCC order 30
                        ECC1 -> ERCC++ : queryEnclaveCredentials(CC_Id, Enclave_Id)
                            note right
                                If FPC enclave is registered, ERCC will
                                return the corresponding Credentials,
                                otherwise Credentials is empty and validation will abort.
                            end note
                        return Credentials
                        ECC1 -> ECC1 : extract Enclave_VK from Credentials.attesated_data
                        ECC1 -> ECC1 : verify Sig_Enclave over <proposal, read/writeset, ECC_result> with Enclave_VK
                        ECC1 -> ECC1 : extract CC_Params from Credentials.AttestedData
                        ECC1 -> ECC1 : check CC_Params matches own chaincode definition
                        note right of ECC1
                            All these check validate for FPC Lite the implicitly defined "designated enclave" 
                            enclave endorsement policy, the only enclave endorsement policy supported in MVP.
                        end note
                    end group
                    group transaction replay
                        ECC1 -> ECC1 : re-create reads and writes based on read/writeset from input proposal
                    end group
                    note right of ECC1
                        any validation or replay failure results in a transaction abort
                    end note
                return
            return validation-proposal-response
        end group
        loop for all/"enough" enclave endorsers
            note right CLI
                Invoke at enough endorsing peers to satisfy validation endorsement policy
                and collect { validation-proposal-response }.
            end note
            ref over CLI,Peer2,Peer3
                enclave endorsementt validation transaction
            end ref
        end
    end

end group

group transaction submission
    CLI -> CLI : form transaction from { validation-proposal-response } (FPC Lite) or from { proposal-response } (otherwise)

    CLI -> Orderer++ : send transaction
    deactivate CLI
    ...
    Orderer -> Orderer : form block
end group

Orderer -> Peer1+ : broadcast
& Orderer -> Peer2+ : broadcast
& Orderer -> Peer3+ : broadcast
deactivate Orderer

group validation & commit
    Peer1 -> Peer1 : validate block signature
    loop for each tx in block

        note over Peer1
            For every FPC transaction, we first perform
            default validation and then FPC validation
        end note

        group default validation
            Peer1 -> Peer1 : perform default validation
            Peer1 -> Peer1 : validate tx (client) signature
            Peer1 -> Peer1 : MVCC check
            Peer1 -> Peer1 : validate endorsements
        end group

        alt "Full" FPC (Post-MVP)
            group fpc-vscc
                /'
                    Note that i dropped here the old MVP version which would have had signature in ccrsp_msg.
                    The corresponding validation would essentially be replacing below with content of
                    group enclave endorsement validation, but read/write-set extracted from ledger rather 
                    than from ccrsp_msg.
                '/
                note over Peer1
                    fpc-vscc is a validation plugin associated with each FPC Chaincode.
                    Any failure below will result in an invalidation of the transaction.
                end note
                note right of Peer1
                    The enclave's signature was already verified against the (enclave's) PeerCertificate.
                    Similarly, the enclave endorsement policy is encoded in the (fabric) endorsement policy
                    and already validate.
                    The only step required to verify is that the endorsement comes from a correctly
                    registered enclave for that chaincode
                end note

                Peer1 -> ERCC++ : queryEnclaveCredentials(CC_Id, Hash(PeerCertificate.Public_key))
                return Credentials
		note right of Peer1
                    fail if no credential is returned
                end note
                /' 
                    we could also verify ..
                     Credentials.Attesteddata.HostParams.Certificate == PeerCertificate
                    .. but that doesn't seem to be strictly necessary
                '/
            end group
        end
    end loop

    loop for each tx in block
        Peer1 -> Peer1 : apply valid tx writeset
    end loop

    Peer1 -> Peer1 : append block to ledger

    alt "Full" FPC (Post-MVP)
        create "Ledger_enclave Peer_Org1" as TLCC1 order 31 #99FF99
        Peer1 -> TLCC1 : new block
        deactivate Peer1
        |||
        ref over TLCC1
            validation & commit
        end ref
        note over TLCC1
            Ledger enclave performs the same
            validation steps as the peer does.
            This is necessary to let the ledger
            enclave establish its own trusted
            view of the ledger.
        end note

        TLCC1 -> TLCC1 : compute and store integrity-metadata for the invoked FPC chaincode's writeset
        |||
        deactivate TLCC1
        |||
    end

end group /' validation & commit '/

ref over Peer2
    validation & commit
end ref
|||
deactivate Peer2

ref over Peer3
    validation & commit
end ref
|||
deactivate Peer3


@enduml