A Pure Rust Implementation of an Elliptic Curve Keypair Generator in an Intel SGX Enclave

✒️ Notes:

More specifically, an Secp256k1 key pair generator & message signer where both the enclave and the app are written in pure Rust. Made possible by the fantastic Rust SGX Software Developer Kit by Baidux Labs: https://github.com/baidu/rust-sgx-sdk

 

📃 CLI Usage:

      Intel SGX Ethereum Key Management CLI.
          Copyright: 2018 Oraclize.it
          Questions: [email protected]

      Usage:  ethkeysgx generate                                  [--keyfile=<path>]
              ethkeysgx show public                               [--keyfile=<path>]
              ethkeysgx show secret                               [--keyfile=<path>]
              ethkeysgx show address                              [--keyfile=<path>] 
              ethkeysgx sign <message>                            [--keyfile=<path>] [-n | --noprefix]
              ethkeysgx verify <address> <message> <signature>    [--keyfile=<path>] [-n | --noprefix]
              ethkeysgx [-h | --help]

      Options:
          -h, --help          ❍ Show this usage message.
          --keyfile=<path>    ❍ Path to desired encrypted keyfile. [default: ./encrypted_keypair]
          -n, --noprefix      ❍ Does not add the ethereum message prefix when signing or verifying 
                              a signed message. Messages signed with no prefix are NOT ECRecoverable!

      Commands:
          generate            ❍ Generates an secp256k1 keypair inside an SGX enclave, encrypts
                              them & saves to disk as either ./encrypted_keypair.txt in the
                              current directory, or at the passed in path.
          show public         ❍ Log the public key from the given encrypted keypair to the console.
          show secret         ❍ Log the private key from the given encrypted keypair to the console.
          sign                ❍ Signs a passed in message using key pair provided, otherwise uses
                              default keypair if it exists. Defaults to using the ethereum message
                              prefix and ∴ signatures are ECRecoverable.
          verify              ❍ Verify a given address signed a given message with a given signature.

 

🔧 Build it Yourself:

❍ Pull requisite files:

Pull the Rust SGX SDK Docker image

❍ sgx-nuc@~$ docker pull baiduxlab/sgx-rust

Clone this Repo

❍ sgx-nuc@~$ git clone https://gitlab.com/gskapka/secp256k1-enclave-rust.git

 

❍ Prepare the Docker Container:

If using SIMULATION mode:

❍ sgx-nuc@~$ sudo docker run -v /path/to/secp256k1-enclave-rust:/root/keygen -ti baiduxlab/sgx-rust

Else if using HARDWARE mode:

❍ sgx-nuc@~$ sudo docker run -v/path/to/secp256k1-enclave-rust:/root/keygen -ti --device /dev/isgx baiduxlab/sgx-rust

Rebuild the tool chain:

❍ sgx-nuc-docker@~# rustup default nightly-2018-10-01-x86_64-unknown-linux-gnu

Add required components:

❍ sgx-nuc-docker@~# rustup component add rust-src

Finally, if using HARDWARE mode, import the service:_

❍ sgx-nuc-docker@~# /opt/intel/libsgx-enclave-common/aesm/aesm_service &

 

❍ Prepare the keygen:

In the ❍ sgx-nuc-docker@~/keygen directory inside the docker, first ensure the desired mode (SW or HW) is set correctly inside the Makefile:

    // ... Beginning of file ...

    ######## SGX SDK Settings ########

    SGX_SDK ?= /opt/intel/sgxsdk
    SGX_MODE ?= HW                // <-- This option. HW for Hardware or SW for software.
    SGX_ARCH ?= x64

    // ... Remainder of file ...

Next, set the environment variable inside the docker to the desired mode:

❍ sgx-nuc-docker@~/keygen# export SGX_MODE=HW

Then build the project:

❍ sgx-nuc-docker@~/keygen# make

And finally run it to see the usage notes:

❍ sgx-nuc-docker@~/keygen# cd bin && ./ethkeysgx

 

📋 To Do List:

✅ Refactor to lib crate.

✅ Test on real nuc in HW mode.

✅ Make CLI with Docopt.

🔲 Remotely attest!

✅ Make ECRecoverable sigs.

🔲 Stream to the enc. to allow file encryption.

🔲 Add rudimentary password protection.

🔲 Use mister enclave instead of mister signer!

🔲 Make threaded to have vanity addresses (can limit tried?)

🔲 Abstract out generic enclave funcs (mem. allocing etc)

✅ Separate the app from the SDK repo enclave to make it lean and mean.

🔲 Add transaction signing.

🔲 Make a stand alone binary for D/L.

🔲 Add a monotonic counter to the key accesses.

🔲 Add a monotonic counter to tx signing events.

 

📚 Resources:

❍ Here's some stuff about the EDL file

❍ Here's some stuff about the Makefile syntax: