fpc-cc-execution.puml

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

    SPDX-License-Identifier: Apache-2.0
'/

@startuml

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!pragma teoz true

hide footbox
title Foot Box removed

title Fabric Private Chaincode - Chaincode execution

participant "FPC_stub_enclave" as Enclave1 order 10 #99FF99
participant "FPC_chaincode" as Chaincode order 30 #99FF99

participant "FPC_stub" as ECC1 order 31

database "Peer_state" as storage1 order 40
participant "Ledger_enclave" as TLCC1 order 41 #99FF99

activate Enclave1

ref over Enclave1, TLCC1
    see fpc-cc-invocation.puml
end

note over TLCC1
  "Full" FPC only (Post-MVP)
end note


Enclave1 -> Chaincode : invoke (args, CTX)
activate Chaincode
note right
    FPC_stub_enclave calls invoke of the FPC_chaincode,
    which implements the actual application logic.

    Context (CTX) is used to retrieve state and the
    corresponding integrity-metadata from the same view.
end note

loop
  note over Chaincode
    This loop denotes the application logic as it
    may perform multiple getState and putState operations.
    Note that these operations are over the secure channel,
    see fpc-cc-invocation.puml for its establishment.
  end note

  alt getState
    Chaincode -> Enclave1 ++ : getState(key, CTX)
      Enclave1 -> Enclave1 : update readset
      Enclave1 -> ECC1 ++ : getState(key, CTX)
        ECC1 -> storage1 ++ : getState(key, CTX)
        return value_enc
        return value_enc
      alt "Full" FPC (Post-MVP)
        Enclave1 -> TLCC1 ++ : getMetadata(key, CTX)
          note over Enclave1: this request is via the enclave-tlcc secure channel
          return integrity-metadata
        Enclave1 -> Enclave1 : check value_enc using integrity-data
      end

      Enclave1 -> Enclave1 : value <- decrypt value_enc with SEK
      Enclave1 -> Enclave1 : update readset
      return value
    note right
        Application logic can now use value for
        some computation; the value is in clear
        and validated with the help of Ledger_enclave.
    end note

  else putState
    Chaincode -> Enclave1 ++ : putState(key, value, CTX)
      Enclave1 -> Enclave1 : value_enc <- encrypt value with SEK
      Enclave1 -> ECC1 ++: putState(key, value_enc, CTX)
        note right
          NOTE that with putState operations, only encrypted
          data leaves the enclave.
        end note
        ECC1 -> ECC1 : putState(key, value_enc, CTX)
        return
      Enclave1 -> Enclave1 : update writeset
      return
  end
end

Chaincode -> Chaincode : compute some result
note right
    The application logic may also return some result
end note

Chaincode --> Enclave1 : return result
deactivate Chaincode

@enduml