PHP Extension

Azure OpenID Connect Step 2 -- Get id_token and Validate

See more OIDC Examples

After getting the endpoints by querying the Azure's OIDC well-known discovery document (OpenID Configuration document), we use the authorization_endpoint to get the id_token, and then validate it.. PHP Extension

<?php

include("chilkat.php");

$success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// In our previous example (Azure Fetch OpenID Connect metadata document) we fetched
// the OpenID configuration document which is JSON which contains an entry for authorization_endpoint.

$authorization_endpoint = 'https://login.microsoftonline.com/{tenant}/oauth2/v2.0/authorize';

// The OpenID Connect metadata document also contained a jwks_uri entry.  This is the JSON Web Key Set (JWKS),
// which is a set of keys containing the public keys used to verify any JSON Web Token (JWT) (in this case the id_token)
// issued by the authorization server and signed using the RS256 signing algorithm. 
$jwks_uri = 'https://login.microsoftonline.com/{tenant}/discovery/v2.0/keys';

// We're going to send the following GET request, but it will be sent through an interactive web browser (not by Chilkat).
// The following code will form the URL that is to be programmatically loaded and sent in a browser.

// GET https://login.microsoftonline.com/{tenant}/oauth2/v2.0/authorize?
// client_id=6731de76-14a6-49ae-97bc-6eba6914391e
// &response_type=id_token
// &redirect_uri=http%3A%2F%2Flocalhost%2Fmyapp%2F
// &response_mode=form_post
// &scope=openid
// &state=12345
// &nonce=678910

// Use this object to set params and then get the URL-encoded query params string 
$req = new CkHttpRequest();
$req->AddParam('client_id','{client_id}');
$req->AddParam('response_type','id_token');
$req->AddParam('redirect_uri','http://localhost:3017/');
$req->AddParam('response_mode','form_post');
$req->AddParam('scope','openid');
$prng = new CkPrng();
$req->AddParam('state',$prng->genRandom(3,'decimal'));
$req->AddParam('nonce',$prng->genRandom(4,'decimal'));

$encodedParams = $req->getUrlEncodedParams();
print $encodedParams . "\n";

// Sample URL encoded params:
// client_id=6731de76-14a6-49ae-97bc-6eba6914391e&redirect_uri=http%3A%2F%2Flocalhost%3A3017%2F&response_mode=form_post&scope=openid&state=3572902&nonce=57352474

// This is the URL to be programmatically loaded and sent in an interactive web browser..
$sbUrl = new CkStringBuilder();
$sbUrl->Append($authorization_endpoint);
$sbUrl->Append('?');
$sbUrl->Append($encodedParams);
$url = $sbUrl->getAsString();

// Before we launch the browser with the contents of sbUrl, create a socket to listen for the eventual callback..

$listenSock = new CkSocket();

// This is the connection received from the browser.
$browserSock = new CkSocket();

// Listen at the port indicated by the redirect_uri above.
$backLog = 5;
$success = $listenSock->BindAndListen(3017,$backLog);
if ($success == false) {
    print $listenSock->lastErrorText() . "\n";
    exit;
}

// Wait for the browser's connection in a background thread.
// (We'll send load the URL into the browser following this..)
// Wait a max of 60 seconds before giving up.
$maxWaitMs = 30000;
// task is a CkTask
$task = $listenSock->AcceptNextAsync($maxWaitMs,$browserSock);
$task->Run();

// -------------------------------------------------------------------
// At this point, your application should load the URL in a browser.
$oauth2 = new CkOAuth2();
$success = $oauth2->LaunchBrowser($url);
if ($success == false) {
    print $oauth2->lastErrorText() . "\n";
    exit;
}

// -------------------------------------------------------------------

// Wait for the listenSock's task to complete.
$success = $task->Wait($maxWaitMs);
if (!$success or ($task->get_StatusInt() != 7) or ($task->get_TaskSuccess() != true)) {
    if (!$success) {
        // The task.LastErrorText applies to the Wait method call.
        print $task->lastErrorText() . "\n";
    }
    else {
        // The ResultErrorText applies to the underlying task method call (i.e. the AcceptNextConnection)
        print $task->status() . "\n";
        print $task->resultErrorText() . "\n";
    }

    exit;
}

// If we get to this point, a connection on listenSock was accepted, and the redirected POST
// is waiting to be read on the connected socket.
// The POST we are going to read contains the following:

// POST /myapp/ HTTP/1.1
// Host: localhost
// Content-Type: application/x-www-form-urlencoded
// 
// id_token=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1dCI6Ik1uQ19WWmNB...&state=12345

// But first.. we no longer need the listen socket...
// Stop listening on port 3017.
$listenSock->Close(10);

// We're acting as a temporary web server to receive this one redirected HTTP request..
// Read the start line of the request.. (i.e. the "POST /myapp/ HTTP/1.1")
$startLine = $browserSock->receiveUntilMatch('\r\n');
if ($browserSock->get_LastMethodSuccess() == false) {
    print $browserSock->lastErrorText() . "\n";
    exit;
}

// Read the request header.
$requestHeader = $browserSock->receiveUntilMatch('\r\n\r\n');
if ($browserSock->get_LastMethodSuccess() == false) {
    print $browserSock->lastErrorText() . "\n";
    exit;
}

print $requestHeader . "\n";
print '----' . "\n";

// Read the body.
// The body will contain "id_token= eyJ......"
$sbRequestBody = new CkStringBuilder();
$success = $browserSock->ReceiveSb($sbRequestBody);
if ($success == false) {
    print $browserSock->lastErrorText() . "\n";
    exit;
}

print $sbRequestBody->getAsString() . "\n";

// Given that we're acting as a web server, we must send a response..
// We can now send our HTTP response.
$sbResponseHtml = new CkStringBuilder();
$sbResponseHtml->Append('<html><body><p>Thank you!</b></body</html>');

$sbResponse = new CkStringBuilder();
$sbResponse->Append('HTTP/1.1 200 OK\r\n');
$sbResponse->Append('Content-Length: ');
$sbResponse->AppendInt($sbResponseHtml->get_Length());
$sbResponse->Append('\r\n');
$sbResponse->Append('Content-Type: text/html\r\n');
$sbResponse->Append('\r\n');
$sbResponse->AppendSb($sbResponseHtml);

$browserSock->SendString($sbResponse->getAsString());
$browserSock->Close(50);

// Get the id_token from the sbRequestBody that we just received.
// (Remember, we're acting as the web server, thus we received the redirect request..)
$hashTab = new CkHashtable();
$hashTab->AddQueryParams($sbRequestBody->getAsString());

// See https://docs.microsoft.com/en-us/azure/active-directory/develop/id-tokens#validating-an-id-token
// for more information about ID tokens..
$idToken = $hashTab->lookupStr('id_token');

$jwt = new CkJwt();

// Let's see if the time constraints, if any, are valid.
// The above JWT was created on the afternoon of 16-May-2016, with an expiration of 1 hour.
// If the current system time is before the "nbf" time, or after the "exp" time,
// then IsTimeValid will return false/0.
// Also, we'll allow a leeway of 60 seconds to account for any clock skew.
// Note: If the token has no "nbf" or "exp" claim fields, then IsTimeValid is always true.
$leeway = 60;
$bTimeValid = $jwt->IsTimeValid($idToken,$leeway);
print 'time constraints valid: ' . $bTimeValid . "\n";

// Now let's recover the original claims JSON (the payload).
$payload = $jwt->getPayload($idToken);
// The payload will likely be in compact form:
print $payload . "\n";

// We can format for human viewing by loading it into Chilkat's JSON object
// and emit.
$json = new CkJsonObject();
$success = $json->Load($payload);
$json->put_EmitCompact(false);
print $json->emit() . "\n";

// Sample output:

// {
//   "aud": "f125d695-c50e-456e-a579-a486f06d1213",
//   "iss": "https://login.microsoftonline.com/6d8ddd66-68d1-43b0-af5c-e31b4b7dd5cd/v2.0",
//   "iat": 1626535322,
//   "nbf": 1626535322,
//   "exp": 1626539222,
//   "aio": "AWQAm/8TAAAAHQncmY0VvhgyMIhfleHX3DjsGfmlPM1CopkJ3mPnBUnCxrJ0ubruaACEhwGO7NsoHBhqFEzRzPxOq7MtuGVFsql+qJKZx8vQCszKYEPX9Wb3b5+d5KJTABHCIH48bTFd",
//   "idp": "https://sts.windows.net/9188040d-6c67-4c5b-b112-36a304b66dad/",
//   "nonce": "1519043321",
//   "rh": "0.ARgAZt2NbdFosEOvXOMbS33VzZXWJfEOxW5FpXmkhvBtEhMYALQ.",
//   "sub": "RMIZlHJ7hfsJmL8Qq3h6M0nPi4g-HEavnAFgxzaT2KM",
//   "tid": "6d8ddd66-68d1-43b0-af5c-e31b4b7dd5cd",
//   "uti": "-BXGHxvfREW-r9HI5NBiAA",
//   "ver": "2.0"
// }

// We can recover the original JOSE header in the same way:
$joseHeader = $jwt->getHeader($idToken);
// The payload will likely be in compact form:
print $joseHeader . "\n";

// We can format for human viewing by loading it into Chilkat's JSON object
// and emit.
$jsonJoseHeader = new CkJsonObject();
$success = $jsonJoseHeader->Load($joseHeader);
$jsonJoseHeader->put_EmitCompact(false);
print $jsonJoseHeader->emit() . "\n";

// Sample output:

// {
//   "typ": "JWT",
//   "alg": "RS256",
//   "kid": "nOo3ZDrODXEK1jKWhXslHR_KXEg"
// }

// Finally, we need to fetch the JSON Web Key Sets from the jwks_uri
// and use it to verify the id_token's RSA signature.
$sbJwks = new CkStringBuilder();
$http = new CkHttp();
$success = $http->QuickGetSb($jwks_uri,$sbJwks);
if ($success == false) {
    print $http->lastErrorText() . "\n";
    exit;
}

$jwkset = new CkJsonObject();
$success = $jwkset->LoadSb($sbJwks);
$jwkset->put_EmitCompact(false);
print $jwkset->emit() . "\n";

// A sample jwkset:

// {
//   "keys": [
//     {
//       "kty": "RSA",
//       "use": "sig",
//       "kid": "nOo3ZDrODXEK1jKWhXslHR_KXEg",
//       "x5t": "nOo3ZDrODXEK1jKWhXslHR_KXEg",
//       "n": "oaLLT9hkcSj ... NVrZdUdTBQ",
//       "e": "AQAB",
//       "x5c": [
//         "MIIDBTC ... MRku44Dw7R"
//       ],
//       "issuer": "https://login.microsoftonline.com/6d8ddd66-68d1-43b0-af5c-e31b4b7dd5cd/v2.0"
//     },
//     {
//       "kty": "RSA",
//       "use": "sig",
//       "kid": "l3sQ-50cCH4xBVZLHTGwnSR7680",
//       "x5t": "l3sQ-50cCH4xBVZLHTGwnSR7680",
//       "n": "sfsXMXW ... AYkwb6xUQ",
//       "e": "AQAB",
//       "x5c": [
//         "MIIDBTCCA ... BWrh+/vJ"
//       ],
//       "issuer": "https://login.microsoftonline.com/6d8ddd66-68d1-43b0-af5c-e31b4b7dd5cd/v2.0"
//     },
//     {
//       "kty": "RSA",
//       "use": "sig",
//       "kid": "DqUu8gf-nAgcyjP3-SuplNAXAnc",
//       "x5t": "DqUu8gf-nAgcyjP3-SuplNAXAnc",
//       "n": "1n7-nWSL ... V3pFWhQ",
//       "e": "AQAB",
//       "x5c": [
//         "MIIC8TC ... 9pIcnkPQ=="
//       ],
//       "issuer": "https://login.microsoftonline.com/6d8ddd66-68d1-43b0-af5c-e31b4b7dd5cd/v2.0"
//     },
//     {
//       "kty": "RSA",
//       "use": "sig",
//       "kid": "OzZ5Dbmcso9Qzt2ModGmihg30Bo",
//       "x5t": "OzZ5Dbmcso9Qzt2ModGmihg30Bo",
//       "n": "01re9a2BU ... 5OzQ6Q",
//       "e": "AQAB",
//       "x5c": [
//         "MIIC8TC ... YmwJ6sDdRvQ=="
//       ],
//       "issuer": "https://login.microsoftonline.com/6d8ddd66-68d1-43b0-af5c-e31b4b7dd5cd/v2.0"
//     }
//   ]
// }

// We should have an RSA key with kid matching the kid from the joseHeader..
$kid = $jsonJoseHeader->stringOf('kid');

// Find the RSA key with the specified key id
// jwk is a CkJsonObject
$jwk = $jwkset->FindRecord('keys','kid',$kid,true);
if ($jwkset->get_LastMethodSuccess() == false) {
    print 'Failed to find a matching RSA key in the JWK key set...' . "\n";
    exit;
}

$pubkey = new CkPublicKey();

$success = $pubkey->LoadFromString($jwk->emit());
if ($success == false) {
    print $pubkey->lastErrorText() . "\n";
    print $jwk->emit() . "\n";
}
else {
    $verified = $jwt->VerifyJwtPk($idToken,$pubkey);
    print 'Verified: ' . $verified . "\n";
}


?>