Using Core Kit SFA Android SDK

After successfully installing and initializing SingleFactorAuth, you can use it to authenticate your users and obtain their private and public keys.

The SingleFactorAuth instance natively provides the following functions:

• getKey() - Returns the torus key using the verifier, verifierId & idToken.

getKey()

getKey()

To obtain a user's Torus key using the Web3Auth SFA Android SDK, you can call the getKey() function.

Variable	Description
loginParams	Parameters for the login. It takes LoginParams as the value.
context?	Android activity context
sessionTime	sessionTime parameter is used for session management. The default value is 1 day ~ 86400, and max value is 7 days. It takes Long as a value.

Returns

public CompletableFuture<TorusKey> getKey(loginParams: LoginParams, context: Context? = null, sessionTime: Long = 86400)`

On a successful call, the getKey() function returns a CompletableFuture instance.

LoginParams

getKey(loginParams: LoginParams, context: Context? = null, sessionTime: Long = 86400)

Table

Parameter	Description
verifier	The verifier obtained from the Web3Auth Dashboard. It's a mandatory field and takes String as a value.
verifierId	The verifierId used for the verification. It takes String as a value.
idToken	The idToken of the user obtained from the login provider. It takes String as a value.
subVerifierInfoArray?	Sub verifier info. Usually used during the aggregate verifier. It takes Array<TorusSubVerifierInfo> as a value.

Type

class LoginParams {
    val verifier: String
    val verifierId: String
    val idToken: String
    var subVerifierInfoArray: Array<TorusSubVerifierInfo>? = null

    constructor(verifier: String, verifierId: String, idToken: String) {
        this.verifier = verifier
        this.verifierId = verifierId
        this.idToken = idToken
    }

    constructor(
        verifier: String,
        verifierId: String,
        idToken: String,
        subVerifierInfoArray: Array<TorusSubVerifierInfo>
    ) {
        this.verifier = verifier
        this.verifierId = verifierId
        this.idToken = idToken
        this.subVerifierInfoArray = subVerifierInfoArray
    }
}

Usage

loginParams = LoginParams("YOUR_VERIFIER_NAME", "YOUR_VERIFIER_ID_VALUE", "YOUR_ID_TOKEN");
torusKey = singleFactorAuth.getKey(loginParams).get();

Note

Web3Auth SFA Android SDK only works for users who have not enabled MFA.

MFA enabled users

For MFA enabled users, you'll see an Error message.

Example

import android.widget.Button
import android.os.Bundle
import com.github.web3auth.singlefactorauth.SingleFactorAuth
import com.github.web3auth.singlefactorauth.types.SingleFactorAuthArgs
import com.github.web3auth.singlefactorauth.types.LoginParams
import com.github.web3auth.singlefactorauth.types.TorusKey
import org.torusresearch.fetchnodedetails.types.TorusNetwork
import com.auth0.android.jwt.JWT

class MainActivity : AppCompatActivity() {
  // ...
  private lateinit var singleFactorAuth: SingleFactorAuth
  private lateinit var singleFactorAuthArgs: SingleFactorAuthArgs
  private lateinit var loginParams: LoginParams
  private var torusKey: TorusKey? = null

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    singleFactorAuthArgs = SingleFactorAuthArgs(TorusNetwork.TESTNET)
    singleFactorAuth = SingleFactorAuth(singleFactorAuthArgs)

    // Setup UI and event handlers
    val signInButton = findViewById<Button>(R.id.signIn)
    signInButton.setOnClickListener { signIn() }
  }

  private fun signIn() {
    val jwt = JWT(idToken) // idToken is the JWT token obtained from auth provider or your custom JWT provider
    val sub = jwt.getClaim("sub").asString() // get sub claims
    loginParams = LoginParams("web3auth-firebase-examples", "$sub", "$idToken")
    try {
        torusKey = singleFactorAuth.getKey(loginParams).get()
    } catch (e: ExecutionException) {
        e.printStackTrace()
    } catch (e: InterruptedException) {
        e.printStackTrace()
    }
    println("""Private Key: ${torusKey!!.privateKey.toString(16)}""".trimIndent())
    println("""Public Address: ${torusKey!!.publicAddress}""".trimIndent())
  }
  //...
}

Example

You can have a look at the this example made on top of this SDK and try it out yourself.