Thank you for evaluating the artifact for TEEKAP. This document will get you started with our prototype implementation. If you encounter any technial difficulties, we will do our best to resolve them as soon as possible. Please contact us at [email protected] (Mingyuan Gao), [email protected] (Hung Dang) or [email protected] (Ee-Chien Chang).

Since deploying TEEKAP requires that 1) most machines feature Intel SGX with Flexible Launch Control (FLC) support, and 2) a DCAP (Data Center Attestation Primitive)-based attestation service for Intel SGX has been setup, we have deployed TEEKAP in the SGX cluster at our school. We have sent the login credentials to the Artifact Evaluation Chairs for the reviewers to access our TEEKAP deployment. We also uploaded recordings of terminal sessions to asciinema.org for your reference!

1. Overview of the TEEKAP Platform

Our platform mainly consists of three parts, namely, API library for Data Owners (libDataOwner), Access Committee JURY (a cluster of nodes), and API library for Data Users (libDataUser). The storage server is optional, and its source code is also provided. Specifically, the specification for all APIs in libDataOwner is described in data_ower/api_specification.md. The specification for all APIs in libDataUser is described in data_user/api_specification.md.

The platform has been prototyped on Ubuntu Linux, and the remote attestation for SGX enclaves uses the DCAP-based scheme, rather than the EPID-based Intel Attestation Service.

2. Setting up TEEKAP

2.0 Setting up DCAP Attestation Service for Intel SGX

Please refer to the following links on how to setup the DCAP Attestation Service in your own data center, and how to provision your SGX platforms to this service.

• Intel SGX DCAP Quick Install Guide

• Setting up Open Enclave to use DCAP

2.1 Setting up JURY machines

Each JURY node is required to feature Intel SGX with FLC support. In addition, the Open Enclave runtime and some dependent libraries like Boost are required to be installed. In the scripts folder, there are three bash scripts for installing these dependencies, that is, setup_openenclave_with_dcap_support.sh, setup_boost.sh, and setup_raft.sh.

2.2 Setting up Data Owner's machine

Data Owner's machine is not required to feature Intel SGX. In addition to the libDataOwner library, we also need to install some dependent libraries like Boost, OpenSSL, and the secret-sharing lib. In the scripts folder, there are two bash scripts for installing these libraries, that is, setup_boost.sh and setup_openssl.sh.

2.3 Setting up Data User's machine

Data User's machine is required to feature Intel SGX. In addition to the libDataUser library, we also need to install the Open Enclave runtime and some dependent libraries like Boost, OpenSSL, and the secret-sharing lib. In the scripts folder, there are three bash scripts for installing these libraries, that is, setup_openenclave_with_dcap_support.sh, setup_boost.sh and setup_openssl.sh.

3. Workflow in TEEKAP

3.1 Negociation between Data Owner and Data User

To use Data Owner's Data, Data User needs to pass his code (in the form of enclave code) to Data Owner for inspection. After inspecting the code without any issues like explicitly leaking raw data, Data Owner creates a data capsule for Data User.

When creating a data capsule, the Data Owner needs to obtain the "MRENCLAVE" value of the Data User's enclave. Many tools are availale for this, and we will use the built-in tool (i.e., oesign) from Open Enclave.

$ oesign dump --enclave-image DataUserEnclave.signed

The above command will dump many metadata about the enclave, one of them is the "MRENCLAVE" value.

3.2 Data Owner Creates the Data Capsule

To create a data capsule, the DataOwner first creates a file named "enclave_policy.json" with the "MRENCLAVE" value obtained above.

$ cat enclave_policy.json

{ "mrenclave":"5dabe838af1a6300036bb9e55ccec129448729beaa339279123c56baee2edd1b"}

Second, the DataOwner runs the program data_owner_client in the directory data_owner to create the data capsule. The program will promote for inputting the expiry conditions.

$ ./data_owner_client input_file access_committee_leader_ip http_port enclave_policy_file storage_server_ip port

When the data capsule is successfully created, a metadata file will be created.

$ cat 06acfb1adc43473a5860f1c124d7568f621bab627f6e9b7a499e63c3c28dfa6f.metadata

"access_expiry": 1633718666,
"access_limit": 100,
"dc_file": "06acfb1adc43473a5860f1c124d7568f621bab627f6e9b7a499e63c3c28dfa6f.enc",
"dc_id": "06acfb1adc43473a5860f1c124d7568f621bab627f6e9b7a499e63c3c28dfa6f",
"mrenclave": "bd71c6380ef77c5417e8b2d1ce2d4b6504b9f418e5049342440cfff2443d95bd",
"mrsigner": "bd71c6380ef77c5417e8b2d1ce2d4b6504b9f418e5049342440cfff2443d95bd"

Here, dc_file contains the ciphertext of DataOwner's Data, and dc_id is the data capsule's permanent ID.

3.3 Data User Uses the Data Capsule

To use the data capsule, the DataUser needs to get the dc_id and dc_file for the data capsule. The dc_file can be shared from the DataOwner or downloaded from the Storage Server.

To access the Data stored inside the data capsule, the DataUser runs the program at the directory data_user_client.

$ ./data_user_client enclave_path access_committee_leader_ip http_port data_capsule_id data_capsule_file

4. TEEKAP Deployment at our SGX Cluster

Deploying TEEKAP is non-trivial, since it requires that 1) most machines feature Intel SGX with Flexible Launch Control (FLC) support, and 2) a DCAP (Data Center Attestation Primitive)-based attestation service for Intel SGX has been setup.

To facilitate the evaluation process, we have deployed TEEKAP in the SGX cluster at our school. We have sent the login credentials to the Artifact Evaluation Chairs for the reviewers to access our TEEKAP deployment.

As shown in the above figure, the JURY cluster consists of three machines, i.e., node1, node2, and node3. We provide step-by-step guides on 1) how to deploy JURY, and 2) how to use TEEKAP for Data Owners and Data Users, as well as recordings of the terminal sessions for your reference.

4.0 How to Access our TEEKAP Deployment

We have prepared a machine acsac-gateway for the reviewers to access our SGX cluster.

We have sent the login credentials to this machine.

Here, we assume you have logged into the machine acsac-gateway and opened a Terminal.

4.1 Deploying JURY at a three-node Cluster

NOTE: We have created a script called start_jury_nodes.sh to deploy JURY at a three-node cluster.

$ cd ~/data_capsule/scripts

$ ./start_jury_nodes.sh

Type add_followers in node1's prompt, and the cluster is brought up.

Below is more detailed explanation.

At the directory access_committee, run the make command to compile the source code.

$ make

After the building process is finished, a program called access_committee_node will be generated. A signed enclave image called JuryEnclave.signed is also generated.

Copy access_committee_node, JuryEnclave.signed and run_node.sh to each node.

Log in to each node, and start the access_committee_node program as follows. Record each node's ip_address and server_id.

$ ./run_node.sh server_id

Please refer to the following terminal recording at https://asciinema.org/a/435586 on how to start a node, and how to add other nodes as followers.

We will make node node1 the leader, and nodes node2 and node3 followers. To do this, first, create a file named cluster.config and copy this file to the same directory as run_node.sh on machine node1.

$ cat cluster.config

1 172.27.126.170

2 172.27.73.56

3 172.27.87.233

Then, at node1's "access_committee_node" prompt, issue the add_followers command, as shown in the following figure.

4.2 DataOwner Creates a Data Capsule

NOTE: We use the machine acsac-gateway as the DataOwner's machine

$ cd ~/data_capsule/data_owner

At the directory data_owner, run the make command to compile the source code.

$ make

After the building process is finished, a program called data_owner_client will be generated. An API library file called libDataOwner.a is also generated.

Run the script ./run_data_owner_client.sh to create a data capsule for the secrete data secret_data.txt

$ ./run_data_owner_client.sh

Please refer to the following terminal recording at https://asciinema.org/a/435677 on how to create a data capsule.

4.3 DataUser Uses the Data Capsule

NOTE: We also use the machine acsac-gateway as the DataUser's machine

$ cd ~/data_capsule/data_user

At the directory data_user, run the make command to compile the source code.

$ make

After the building process is finished, a program called data_user_client will be generated. A signed enclave image called DataUserEnclave.signed is also generated.

Run the script ./run_data_user_client.sh data_capsule_id data_capsule_file to use a data capsule

$ ./run_data_user_client.sh data_capsule_id data_capsule_file

Please refer to the following terminal recording at https://asciinema.org/a/435678 on how to use a data capsule.