Get AWS Cognito user from ID Token retrieved from Token Endpoint - react-native

Question

I am building a React Native app using Expo and AWS Cognito with AWS Amplify, and I am trying to enable signing in with Facebook, Google, etc. using AWS
I can create a user and sign in using Cognito APIs without any issue.
Using third-parties, though, requires using the Expo AuthSession functionality.
The functionality itself works fine, and I am able to get all the way to retrieving the proper tokens from my /oauth2/token endpoint.
However, as far as Amplify is concerned (and I am aware), the user is not signed in, so when I try to get Auth.currentAuthenticatedUser(), null is returned.
// Open URL in a browser
openURL = async (url) => {
let result = await AuthSession.startAsync({ authUrl: url })
this.getTokenbyCode(result.params.code)
};
getTokenbyCode = async (code) => {
const details = {
grant_type: 'authorization_code',
code,
client_id: '10eavoe3ufj2d70m5m3m2hl4pl',
redirect_uri: AuthSession.getRedirectUrl()
}
const formBody = Object.keys(details)
.map(
key => `${encodeURIComponent(key)}=${encodeURIComponent(details[key])}`
)
.join("&");
await fetch(
'https://presentor.auth.us-west-2.amazoncognito.com/oauth2/token',
{
method: "POST",
headers: {
'Content-type': 'application/x-www-form-urlencoded;charset=UTF-8'
},
body: formBody
}
)
.then(async (res) => {
console.log('res: ', res);
let resJSON = await res.json();
let idToken = await resJSON.id_token;
let decodedToken = jwt(idToken);
let userData = {
Username : decodedToken["cognito:username"],
Pool : Auth.userPool
}
})
.catch(error => {
console.log('error: ', error);
});
}
When I decode the token, I see the payload as I expect, but if I want to, for example, utilize the APIs to refresh the token if it expires, I have to workaround manually (check for expiration and retrieve a new token if it's expired).
Am I missing something basic?

Answer 1

Ok, I figured it out. Not sure if this is the right path, but it's pretty clean and it works, so I'm good with it.
Create CognitoIdToken, CognitoAccessToken, and CognitoRefreshToken objects using amazon-cognito-identity-js
Create a user session from those tokens
Create a user from that user session
await fetch(
'TOKEN ENDPOINT',
{
method: "POST",
headers: {
'Content-type': 'application/x-www-form-urlencoded;charset=UTF-8'
},
body: formBody
}
)
.then(async (res) => {
const IdToken = new CognitoIdToken({ IdToken: tokenRequestJson.id_token });
const AccessToken = new CognitoAccessToken({ AccessToken: tokenRequestJson.access_token });
const RefreshToken = new CognitoRefreshToken({ RefreshToken: tokenRequestJson.refresh_token })
try {
let userSession = new CognitoUserSession({ IdToken, AccessToken, RefreshToken });
console.log('userSession: ', userSession);
const userData = {
Username: userSession.idToken.payload.email,
Pool: userPool
};
console.log('userData: ', userData);
cognitoUser = new CognitoUser(userData);
cognitoUser.setSignInUserSession(userSession);
cognitoUser.getSession((err, session) => { // You must run this to verify that session (internally)
if (session.isValid()) {
console.log('session is valid');
this.setState({user: cognitoUser})
this.props.navigation.navigate('AuthLoading')
} else {
console.log('session is not valid: ', session);
}
})
}
catch (FBSignInError) {
console.log('FBSignInError: ', FBSignInError)
}
})
.catch(fetchError => console.log('fetchError: ', fetchError))