react-native-uport-signer

Getting started

React Native 60.5+

Use version 1.6.0 or higher.

$ yarn add react-native-uport-signer

Autolinking will take care of the rest.

React Native < 60.5

Use version v1.5.2

$ yarn add react-native-uport-signer@1.5.2

Follow the manual linking instructions for v1.5.2

Use with uport-credentials

In order to use uport-credentials in react-native you need to provide a global buffer due to some sub dependencies using it.

$ yarn add uport-credentials

Example creating and sending a verification to the uport app

import { Linking } from 'react-native'
import { RNUportHDSigner, getSignerForHDPath } from 'react-native-uport-signer'
import { Credentials } from 'uport-credentials'

RNUportHDSigner.createSeed().then(seed => {

  const credentialsParams = {}
  // Get Signer function to be used by credentials, address given by RNUportHDSigner
  credentialsParams.signer = getSignerForHDPath(seed.address)
  // set did of the issuer
  credentialsParams.did = `did:ethr:${seed.address}`

  const cred = new Credentials(credentialsParams)

  cred.createVerification({
    sub: subject, //Address of receiver of the verification
    claim: {name: 'John Smith'}
  }).then(verification => {
    const url = `https://id.uport.me/req/${verification}` 
    Linking.openURL(url).catch((err) => console.error('An error occurred', err));
  })
})

General HD Signer Usage

RNUportHDSigner provides a mechanism of importing or creating seeds that can be used to derive keys for signing. Seeds are encrypted using platform specific hardware backed encryption and can be extra protected by fingerprint/keyguard.

Keys are derived every time they are used to sign or to compute addresses.

creating or importing seeds

import { RNUportHDSigner } from 'react-native-uport-signer';

var seedAlias = ""

// Create a new seed
RNUportHDSigner.createSeed('prompt').then( addressObj => {
  //keep a record of it to reference the seed when signing
  seedAlias = addressObj.address
})

// Import a seed using a previously saved phrase
RNUportHDSigner.importSeed(phrase, 'simple').then(addressObj => {
	//keep a record of it to reference the seed when signing
    seedAlias = addressObj.address
})

// Delete seed
RNUportHDSigner.deleteSeed(seedAlias)

Depending on the protection level chosen during seed creation or import, the user may be prompted to use their fingerprint or device PIN to unlock the seed. Relevant methods allow you to provide a message to the user about what it is they are signing.

Protection levels:

'simple' - seeds are encrypted but don't require user auth to be used
'prompt' - seeds are encrypted and need fingerprint or keyguard unlocking.
'singleprompt' - seeds are encrypted and need keyguard to unlock but only once every 30 seconds

The last 2 cases bring up the fingerprint or device keyguard UI every time a seed/key is used.

revealing the recovery phrase

The seed phrase can be revealed (and later used for recovery using importSeed). It is a sequence of 12 words, a commonly used recovery pattern in the crypto space.

// Get the seed phrase
RNUportHDSigner.showSeed(seedAlias, 'Reveal the recovery phrase').then (phrase => {
	// have the user write down the phrase
})

key derivation paths

When signing, you need to specify a derivation path that will be used to generate the key. If you need to know the ethereum address or public key corresponding to that key, it can be revealed using addressForPath(). This needs to be done only once since the address is deterministic.

Some example paths:

m/44'/60'/0'/0/0 - commonly used by ethereum wallet apps (metamask, trezor, jaxx...)
m/7696500'/0'/0'/0' - uport root account path

//Derive another Address
RNUportHDSigner.addressForPath(seedAlias, `m/44'/60'/0'/0/0`, 'Create a new address').then (addressObj => {
	console.log(addressObj.address)
    console.log(addressObj.pubKey)
})

signing

You can sign ethereum transactions and JWT payloads:

// Signing a JWT
RNUportHDSigner.signJwt(seedAlias,
        RNUportHDSigner.UPORT_ROOT_DERIVATION_PATH,
        base64EncodedJwt,
        'Sign a claim'
    ).then( jwtSig => {
			console.log(jwtSig.r)
			console.log(jwtSig.s)
			console.log(jwtSig.v)
		})
		
// Signing an Eth Tx
RNUportHDSigner.signTx(address,
        `m/44'/60'/0'/0/0`,
        base64EncodedTx,
        'Sign an ETH transaction'
    ).then( txSig => {
			console.log(txSig.r)
			console.log(txSig.s)
			console.log(txSig.v)
    })

Basic Signer Usage (DEPRECATED)

Usage of the basic signer is discouraged because recovery of the keys is not possible. Keys can be imported but this is not a secure practice. Any key recovery mechanism is outside the scope of the basic signer (RNUportSigner). Please use the HD signer, RNUportHDSigner

import { RNUportSigner } from 'react-native-uport-signer';

// Create a keypair
RNUportSigner.createKeyPair('simple').then(keypair => {
			console.log(keypair.address)
			console.log(keypar.pubKey)
})

//Sign a JWT
const exampleJwtPayload = { iss: address, aud: address, name: 'test'}

RNUportSigner.signJwt(address,
		exampleJwtPayload.toString('base64'), 
		'Sign a JWT'
).then( jwtSig => {
	console.log(jwtSig.r)
	console.log(jwtSig.s)
	console.log(jwtSig.v)
})

//Sign an Eth tx
RNUportSigner.signTx(address,
        rlpEncodedTx, //RLP Encoded eth transaction
        'Sign an ETH transaction'
).then( txSig => {
	console.log(txSig.r)
	console.log(txSig.s)
	console.log(txSig.v)
})

Contributions welcome

Please run yarn install after checkout to get an up-to-speed dev environment for this library.

Changelog

1.6.1
- [iOS] specify version of UPTEthereumSigner pod
1.6.0
- [iOS] feature - enable autolink ( #40 )
1.5.2
- bugfix #36 - build was not called automatically on prepublish ( #37 )
1.5.1
- [Android] bugfix - changed package name to me.uport.rnsigner thanks to @VMadalin ( #34 )
- support - add simple CI checks (#35)
1.5.0
- [iOS] fix parameter name for deleteSeed
- Adds typescript support
1.4.5
- [Android] bugfix - IllegalStateException when using prompt without fingerprint sensor (#30)
1.4.4
- New method named getSignerForHDPath which returns a signing method to be passed into uport-credentials as a parameter
1.3.4
- [Android] bugfix - duplicate classes error (#22)
1.3.3
- [Android] bugfix - fix silent errors when signing JWT (#20)
1.3.2
- [Android] remove createJSModules override to work with react-native > 0.47
1.3.1
- [iOS] fix search path for valet
1.3.0
- [iOS] replaces usage of CoreEthereum -> EthCore
- [iOS] Adds requiresMainQueueSetup method to get rid of react-native yellowbox warning
- [Android] Correctly scales recovery param for JWT's on android
- [Android] Methods use an activity context when available
v1.2.1
- android build based on kotlin 1.3.30
- expose listSeedAddresses method on android

iwashi1t/react-native-uport-signer