AWS Nitro Enclaves Python demo

WARNING: This project is just proof-of-concept, not production-ready, use at your own risk.

This project showcase how we can use Python socket package to establish communication between EC2 instance and Nitro Enclave. And use a proxy to make HTTPS call from inside the enclave as usual.

Architecture

See Architecture diagram

Installation guide

Create an EC2 instance with Nitro Enclave enabled in ap-northeast-1. See AWS documentation for steps and requirement.

Amazon Linux 2 AMI is recommended.
Create a new IAM role for the instance, attach AWSKeyManagementServicePowerUser policy to the role.

See AWS Documentation for more detail

SSH into the instance. Install nitro-cli

sudo amazon-linux-extras install aws-nitro-enclaves-cli  
sudo yum install aws-nitro-enclaves-cli-devel -y  
sudo usermod -aG ne ec2-user  
sudo systemctl start nitro-enclaves-allocator.service && sudo systemctl enable nitro-enclaves-allocator.service  
sudo amazon-linux-extras install docker  
sudo systemctl start docker  
sudo systemctl enable docker  
sudo usermod -a -G docker ec2-user  
sudo systemctl start docker && sudo systemctl enable docker  
sudo amazon-linux-extras enable aws-nitro-enclaves-cli  
sudo yum install -y aws-nitro-enclaves-cli aws-nitro-enclaves-cli-devel

Modify the preallocated memory for the enclave to 3000 MB.

Modify the file /etc/nitro_enclaves/allocator.yaml, change the following line:
```
# memory_mib: 512
memory_mib: 3000
```

Enable Docker and Nitro Enclaves Allocator

$ sudo systemctl start nitro-enclaves-allocator.service && sudo systemctl enable nitro-enclaves-allocator.service
$ sudo systemctl start docker && sudo systemctl enable docker

Reboot the instance

Loggin to the instance, clone the repository

sudo yum install git 
git clone https://github.com/hyoer0423/encr_enclave.git

run again

  sudo usermod -aG ne ec2-user  
  sudo systemctl start nitro-enclaves-allocator.service && sudo systemctl enable nitro-enclaves-allocator.service  
  sudo systemctl start docker  
  sudo systemctl enable docker  
  sudo usermod -a -G docker ec2-user  
  sudo systemctl start docker && sudo systemctl enable docker  
  sudo amazon-linux-extras enable aws-nitro-enclaves-cli

Use the build script to build and run the enclave image

$  cd encr_enclave/server
$ chmod +x build.sh
$ ./build.sh

After the enclave has launched, you can find the CID of it.

Find the following line, and take note the enclave-cid value and PCR0

   Enclave Image successfully created.  
   {
  "Measurements": {
    "HashAlgorithm": "Sha384 { ... }",
    "PCR0": "fdd6b3c0e70ee927046ab974521362a7534a629fdccb195abc69147a133b27b8233ff9153b376af2dccf9503cb43246e",
    "PCR1": "c35e620586e91ed40ca5ce360eedf77ba673719135951e293121cb3931220b00f87b5a15e94e25c01fecd08fc9139342",
    "PCR2": "951c4c27d03d0777288f7de339abdd0640da15d454e0efbe8e29bac74a8e8ea06edda8401b6bb672b1b71d32b9bf6751"
  }
} 
Start allocating memory...
Started enclave with enclave-cid: 16, memory: 2600 MiB, cpu-ids: [1, 17]
{
  "EnclaveID": "i-097a9a35e16a8962c-enc17a99614bf41bf8",
  "ProcessID": 7194,
  "EnclaveCID": 16,
  "NumberOfCPUs": 2,
  "CPUIDs": [
    1,
    17
  ],
  "MemoryMiB": 2600
}

creat a KMS key INSTANCE_ROLE_ARN is the same as the instance of your EC2instance KMS_ADMINISTRATOR_ROLE allows you to manage the KMS key's Role PCR0_VALUE_FROM_EIF_BUILD previously recorded PCR0 value Policy like :

   {
    "Version": "2012-10-17",
    "Id": "key-consolepolicy-3",
    "Statement": [
        {
            "Sid": "Enable IAM User Permissions",
            "Effect": "Allow",
            "Principal": {
                "AWS": KMS_ADMINISTRATOR_ROLE
            },
            "Action": "kms:*",
            "Resource": "*"
        },
        {
            "Sid": "Allow access for Key Administrators",
            "Effect": "Allow",
            "Principal": {
                "AWS": INSTANCE_ROLE_ARN
            },
            "Action": [
                "kms:Create*",
                "kms:Describe*",
                "kms:Enable*",
                "kms:List*",
                "kms:Put*",
                "kms:Update*",
                "kms:Revoke*",
                "kms:Disable*",
                "kms:Get*",
                "kms:Delete*",
                "kms:TagResource",
                "kms:UntagResource",
                "kms:ScheduleKeyDeletion",
                "kms:CancelKeyDeletion"
            ],
            "Resource": "*"
        },
        {
            "Sid": "Enable decrypt from enclave",
            "Effect": "Allow",
            "Principal": {
                "AWS": INSTANCE_ROLE_ARN
            },
            "Action": "kms:Decrypt",
            "Resource": "*",
            "Condition": {
                "StringEqualsIgnoreCase": {
                    "kms:RecipientAttestation:ImageSha384": PCR0_VALUE_FROM_EIF_BUILD
                }
            }
        },
        {
            "Sid": "Enable encrypt from instance",
            "Effect": "Allow",
            "Principal": {
                "AWS": INSTANCE_ROLE_ARN
            },
            "Action": "kms:Encrypt",
            "Resource": "*"
        }
    ]
   }

Open a new SSH session, run the vsock-proxy tool

$ vsock-proxy 8000 kms.ap-northeast-1.amazonaws.com 443

Open another SSH session, install python3 and the necessary packages for running client app

   $ yum install python3 -y
   $ cd encr_enclave/client
   $ python3 -m venv venv
   $ source venv/bin/activate
   $ pip install -r requirements.txt

Run the client app, replace <cid> with the enclave CID you get in step 11
```
$ python3 client.py <cid> <key_arn>
```
output should be like:

   {'Plaintext': b'811505', 'Ciphertext': b"\x01\x02\x02\x00x\xae\x83ysZ\xfch%\x1a\x0b\x1d,%`\xec\x7f\x1a\x08>\xcfO\x9f\x98\xcah\xa9\xd9\xacb\xa6\x8e\x8e\x01\xe8xR<9.\xa3\xed\xcb\xd8PX0!W\xa4\x00\x00\x00d0b\x06\t*\x86H\x86\xf7\r\x01\x07\x06\xa0U0S\x02\x01\x000N\x06\t*\x86H\x86\xf7\r\x01\x07\x010\x1e\x06\t`\x86H\x01e\x03\x04\x01.0\x11\x04\x0c\xdc2\x15o\x9c\x0fq\x050\x8eW\xf0\x02\x01\x10\x80!w\xadV\xa6<7O\xf5o\xf3\xd1\x96\xc45\xa0\xf2n~gX'>B#\xf8\xf1o@f.X\x0e\xd6", 'Decryptedtext': '811505'}

If everthing is OK, you will see the the key ID and key state are shown on the screen.

File structure

client/

This directory contains the code running on parent EC2 instance. Use requirements.txt to install necessary pip package
server/Dockerfile

This file is to build the eif file required to run on the Nitro Enclave.
server/server.py

This is the main server app
server/traffic-forwarder.py

This is a background app running on Nitro Enclave to forward HTTP traffic between parent instance and enclave via the vsock
server/run.sh

This is the bootstrap shell script. It first modify the Nitro Enclave netwrok config to assign an IP address 127.0.0.1 to local loopback. Then start the traffic forwarder and the main server app

Todos

Add implementation of attestation

License

Apache License, Version 2.0