Access requester secrets

In this tutorial, you will learn how to:

leverage requester secrets by using the following environment variables in your code: IEXEC_REQUESTER_SECRET_1, IEXEC_REQUESTER_SECRET_2, ..., IEXEC_REQUESTER_SECRET_<N>
map your personal secrets to those environment variables when buying an execution on iExec network

Before going any further, make sure you managed to Build your first application with Scone framework.

Prerequisites:

Docker 17.05 or higher on the daemon and client.
iExec SDK 8.0.0 or higher. Install the iExec SDK
Familiarity with the basic concepts of Intel® SGX and SCONE framework.

Trusted Execution Environments offer a huge advantage from a security perspective. They guarantee that the behavior of execution does not change even when launched on an untrusted remote machine. The data inside this type of environment is also protected, which allows its monetization while preventing leakage.

With iExec, it is possible to securely consume requester-provided secrets in the application.

The requester secrets are only exposed to authorized apps inside enclaves and never leave them.

Your secrets are transferred with the SDK from your machine to the SMS over a TLS channel.

Let's see how to do all of that!

Prepare your application

For demo purposes, we omitted some development best practices in these examples.

Make sure to check your field's best practices before going to production.

We will use the API countapi.xyz. This service keeps a count of hit on any couple of namespace/key (ex: https://api.countapi.xyz/hit/foo/bar). In this example, we will use requester secrets to set namespace/key.

Let's create a directory tree for this app in ~/iexec-projects/.

cd ~/iexec-projects
mkdir tee-requester-secrets-app && cd tee-requester-secrets-app
iexec init --skip-wallet
mkdir src
touch Dockerfile
touch sconify.sh
chmod +x sconify.sh

Make sure your chain.json content is correct.

The application use the requester secrets to make a call to a secret endpoint of countapi.xyz and writes the result in a file:

Copy the following content in src/ .

src/app.js

const fsPromises = require("fs").promises;
const axios = require("axios");

(async () => {
  try {
    const iexecOut = process.env.IEXEC_OUT;
    // get the secret endpoint from requester secrets
    const secretNamespace = process.env.IEXEC_REQUESTER_SECRET_1;
    const secretKey = process.env.IEXEC_REQUESTER_SECRET_2;
    if (!secretNamespace) {
      console.log("missing requester secret 1 (namespace)");
      process.exit(1);
    }
    if (!secretKey) {
      console.log("missing requester secret 2 (key)");
      process.exit(1);
    }
    // get the hit count from countapi
    const hitCount = await axios
      .get(`https://api.countapi.xyz/hit/${secretNamespace}/${secretKey}`)
      .then(({ data }) => data.value);

    const result = `endpoint hit ${hitCount} times`;
    console.log(result);
    // write the result
    await fsPromises.writeFile(`${iexecOut}/result.txt`, result);
    // declare everything is computed
    const computedJsonObj = {
      "deterministic-output-path": `${iexecOut}/result.txt`,
    };
    await fsPromises.writeFile(
      `${iexecOut}/computed.json`,
      JSON.stringify(computedJsonObj)
    );
  } catch (e) {
    // do not log anything that could reveal the requester secrets!
    console.log("something went wrong");
    process.exit(1);
  }
})();

src/app.py

import os
import json
import requests

try:
    iexec_out = os.environ["IEXEC_OUT"]

    # get the secret endpoint from requester secrets
    try:
        secret_namespace = os.environ["IEXEC_REQUESTER_SECRET_1"]
    except Exception:
        print("missing requester secret 1 (namespace)")
        exit(1)
    try:
        secret_key = os.environ["IEXEC_REQUESTER_SECRET_2"]
    except Exception:
        print("missing requester secret 2 (key)")
        exit(1)

    # get the hit count from countapi
    response = requests.request("GET", "https://api.countapi.xyz/hit/" + secret_namespace + "/" + secret_key)
    json_response = response.json()
    hit_count = json_response["value"]

    result = "endpoint hit " + str(hit_count) + " times"
    print(result)

    # write the result
    with open(iexec_out + "/result.txt", "w+") as fout:
        fout.write(result)

    # declare everything is computed
    with open(iexec_out + "/computed.json", "w+") as f:
        json.dump({ "deterministic-output-path" : iexec_out + "/result.txt" }, f)

except Exception:
    # do not log anything that could reveal the requester developer secret!
    print("something went wrong")
    exit(1)

Build a Confidential Computing application

Create the Dockerfile

In this section, you will:

Build the native image of the application as described in Build your first application.
Create and execute the sconify.sh script to build the Scone TEE application as we saw in Build Scone app > Prepare your application.

The Dockerfile and the build scripts are similar to the ones we saw previously for a trusted application:

Create the Dockerfile

For a Javascript application:

# Starting from a base image supported by SCONE
FROM node:14-alpine3.11

# install your dependencies
RUN mkdir /app && cd /app && npm install axios

COPY ./src /app

ENTRYPOINT [ "node", "/app/app.js"]

For a Python application:

FROM python:3.7.3-alpine3.10

RUN pip3 install requests

COPY ./src /app

ENTRYPOINT ["python3", "/app/app.py"]

Build the docker image.

docker build . --tag <docker-hub-user>/count-api:1.0.0

Follow the steps described in Build Scone app > Build the TEE docker image.

Update the sconify.sh script with the variables as follow:

# Declare image related variables
IMG_NAME=tee-scone-count-api
IMG_FROM=<docker-hub-user>/count-api:1.0.0
IMG_TO=<docker-hub-user>/${IMG_NAME}:1.0.0-debug

Run the sconify.sh script to build the Scone TEE application:

./sconify.sh

Push the image on Docker Hub

docker push <docker-hub-user>/tee-scone-count-api:1.0.0-debug

Test your app on iExec

At this stage, your application is ready to be tested on iExec with the following steps:

Deploy the TEE app on iExec

Deploy your application

For simplicity, we will use secrets in a TEE-debug app on a debug workerpool. The debug workerpool is connected to a debug Secret Management Service so we will send the requester secrets to this SMS (this is fine for debugging but do not use to store production secrets).

Push some requester secrets to the SMS

iexec requester push-secret my-namespace
iexec requester push-secret my-key

Check secrets availability in the SMS

iexec requester check-secret my-namespace
iexec requester check-secret my-key

Run the TEE app

You are now ready to run the app with requester secrets.

Specify the --secret and --tag tee,scone options in iexec app run command to run a tee app with requester secrets on Scone

iexec app run <appAddress> \
  --tag tee,scone \
  --workerpool debug-v8-bellecour.main.pools.iexec.eth \
  --secret 1=my-namespace \
  --secret 2=my-key \
  --watch

The option --secret <secretMapping...> allow the requester to provision any number of secrets with the mapping syntax <key>=<name>.

example:

--secret 1=foo 3=bar

the secret named foo will be available in IEXEC_REQUESTER_SECRET_1
the secret named bar will be available in IEXEC_REQUESTER_SECRET_3
IEXEC_REQUESTER_SECRET_2 will be skipped

Next step?

Thanks to the explained confidential computing workflow, you now know how to consume requester secrets in a Confidential Computing application.

To go further, check out how to:

PreviousAttach a secret to your app NextAccess a confidential dataset

Last updated 1 month ago