expo-secure-environment

Cryptographic operations using the devices Secure Environment (HSM,SE,etc.) locked behind biometric authentication

Currently Android API 30+ is supported and the minimum supported version of iOS for Expo.

Supported cryptographic algorithms

key algorithm: Secp256r1

signature algorithm: ECDSA with SHA256

Create a key pair

import { generateKeypair } from "@animo-id/expo-secure-environment";

const myId = "keypair-id";

// Make sure it is backed by biometrics
generateKeypair(myId, true);

Get the public bytes by the id

Returns the compressed form of a P-256 public key (and not the DER-encoded SubjectPublicKeyInfo)

import {
    generateKeypair,
    getPublicBytesForKeyId,
} from "@animo-id/expo-secure-environment";

const myId = "keypair-id";

// Make sure it is backed by biometrics
generateKeypair(myId, true);

const publicBytes: Uint8Array = getPublicBytesForKeyId(myId);

Sign data

Returns the raw signature (and not a DER-Encoded ECDA-Sig-Value)

import {
    generateKeypair,
    sign
} from "@animo-id/expo-secure-environment";

const myId = "keypair-id";

// Make sure it is backed by biometrics
generateKeypair(myId, true);

// Make sure that when we sign we pass the third argument as true to indicate we would like to use biometrics
const signature = sign(myId, new Uint8Array(10).fill(7), true);