This lab enables Secure Chaincode Execution using Intel SGX for Hyperledger Fabric.
The transparency and resilience gained from blockchain protocols ensure the integrity of blockchain applications and yet contradicts the goal to keep application state confidential and to maintain privacy for its users.
To remedy this problem, this project uses Trusted Execution Environments (TEEs), in particular Intel Software Guard Extensions (SGX), to protect the privacy of chaincode data and computation from potentially untrusted peers.
Intel SGX is the most prominent TEE today and available with commodity CPUs. It establishes trusted execution contexts called enclaves on a CPU, which isolate data and programs from the host operating system in hardware and ensure that outputs are correct.
This lab provides a framework to develop and execute Fabric chaincode within an enclave. Furthermore, Fabric extensions for chaincode enclave registration and transaction verification are provided.
This lab proposes an architecture to enable Secure Chaincode Execution using Intel SGX for Hyperledger Fabric as presented and published in the paper:
- Marcus Brandenburger, Christian Cachin, Rüdiger Kapitza, Alessandro Sorniotti: Blockchain and Trusted Computing: Problems, Pitfalls, and a Solution for Hyperledger Fabric. https://arxiv.org/abs/1805.08541
We provide an initial proof-of-concept implementation of the proposed architecture. Note that the code provided in this repository is prototype code and not meant for production use! The main goal of this lab is to discuss and refine the proposed architecture involving the Hyperledger community.
This lab extends a Fabric peer with the following components: A chaincode enclave that executes a particular chaincode and a ledger enclave that enables all chaincode enclaves to verify the blockchain state integrity; all run inside SGX. In the untrusted part of the peer, an enclave registry maintains the identities of all chaincode enclaves and an enclave transaction validator that is responsible for validating transactions executed by a chaincode enclave before committing them to the ledger.
The following diagram shows the architecture:
The system consists of the following components:
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Chaincode enclave: The chaincode enclave executes one particular chaincode, and thereby isolates it from the peer and from other chaincodes. A chaincode library acts as intermediary between the chaincode in the enclave and the peer. The chaincode enclave exposes the Fabric chaincode interface and extends it with additional support for state encryption, attestation, and secure blockchain state access. This component is devided into two subcomponents:
ecc_enclavecontains the code running inside an enclave andecccontains a wrapper chaincode that invokes the enclave. -
Ledger enclave: The ledger enclave maintains the ledger in an enclave in the form of integrity-specific metadata representing the most recent blockchain state at the peer. It performs the same validation steps as the peer when a new block arrives, but additionally generates a cryptographic hash of each key-value pair of the blockchain state and stores it within the enclave. The ledger enclave exposes an interface to the chaincode enclave for accessing the integrity-specific metadata. This is used to verify the correctness of the data retrieved from the blockchain state. Like the chaincode enclave, the ledger enclave is divided into two subcomponents:
tlccandtlcc_enclave. -
Enclave registry: The enclave registry is a chaincode that runs outside SGX and maintains a list of all existing chaincode enclaves in the network. It performs attestation with the chaincode enclave and stores the attestation result on the blockchain. The attestation demonstrates that a specific chaincode executes in an actual enclave. This enables the peers and the clients to inspect the attestation of a chaincode enclave before invoking chaincode operations or committing state changes. The enclave registry (
ercc) comes with a custom validation plugin (ercc-vscc). -
Enclave transaction validator: The enclave transaction validator (
ecc/vscc) complements the peer’s validation system and is responsible for validating transactions produced by a chaincode enclave. In particular, the enclave transaction validator checks that a transaction contains a valid signature issued by a registered chaincode enclave. If the validation is successful, it marks the transactions as valid and hands it over to the ledger enclave, which crosschecks the decision before it finally commits the transaction to the ledger.
The following steps guide you through the build phase and configuration, for deploying and running an example chaincode.
- CMake 3.5.1 or higher
- Go 1.10 or higher
- Install Fabric v1.2 https://github.com/hyperledger/fabric
- Install the Linux SGX SDK v2.1.3 https://github.com/intel/linux-sgx
- You also need to install Intel SGX SSL https://github.com/intel/intel-sgx-ssl
The the chaincode envlave and the trusted ledger enclave require SGXSSL. See README in project root fore more details. Intel SGX SSL https://github.com/intel/intel-sgx-ssl
After installing the SGX SDK and SGX SSL double check that SGX_SDK and
SGX_SSL is set correctly in cmake/Init.cmake.
Checkout the code and make sure it is on your GOPATH.
$ git clone https://github.com/hyperledger-labs/fabric-secure-chaincode.git
First we need to enable a Fabric peer to excute chaincode using our project. In fabric you find a details described how to patch fabric and build the peer.
In utils/fabric-ccenv-sgx you can find instructions to create a custom fabric-ccenv docker image that is required to execute a chaincode within an enclave.
Next build the chaincode enclave ecc_enclave and the ledgger enclave tlcc_enclave. Follow the instructions in the corresponding directories.
In the next step we need to integrate the enclave code into a Fabric chaincode. Please follow the instructions in ecc for the chaincode enclave and tlcc for the ledger enclave.
In order to run deploy a chaincode enclave we need to build the enclave registry. See ercc.
Now we have a components we need to run the example auction chaincode in an enclave.
- Marcus Brandenburger, Christian Cachin, Rüdiger Kapitza, Alessandro Sorniotti: Blockchain and Trusted Computing: Problems, Pitfalls, and a Solution for Hyperledger Fabric. https://arxiv.org/abs/1805.08541
- Marcus Brandenburger (bur@zurich.ibm.com)
- Christian Cachin (cca@zurich.ibm.com)
- Rüdiger Kapitza (kapitza@ibr.cs.tu-bs.de)
- Alessandro Sorniotti (aso@zurich.ibm.com)
Hyperledger Fabric Secure Chaincode Execution source code files are made available under the Apache License, Version 2.0 (Apache-2.0), located in the LICENSE file.