[ElastiCache] Add Auth Token Generator for ElastiCache IAM authentication

.changes/nextrelease/elasticache-auth-token-generator.json

@@ -0,0 +1,7 @@
+[
+    {
+        "type": "feature",
+        "category": "ElastiCache",
+        "description": "Add Aws\\ElastiCache\\AuthTokenGenerator class to generate IAM authentication tokens for ElastiCache for Redis."
+    }
+]

src/ElastiCache/AuthTokenGenerator.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace Aws\ElastiCache;
+
+use Aws;
+use Aws\Credentials\Credentials;
+use Aws\Credentials\CredentialsInterface;
+use Aws\Signature\SignatureV4;
+use GuzzleHttp\Promise;
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\Psr7\Uri;
+
+/**
+ * Generates auth tokens for use with IAM authentication.
+ */
+class AuthTokenGenerator
+{
+    private $credentialProvider;
+
+    /**
+     * The constructor takes an instance of Credentials or a CredentialProvider.
+     *
+     * @param callable|Credentials $creds
+     */
+    public function __construct($creds)
+    {
+        if ($creds instanceof CredentialsInterface) {
+            $promise = new Promise\FulfilledPromise($creds);
+            $this->credentialProvider = Aws\constantly($promise);
+        } else {
+            $this->credentialProvider = $creds;
+        }
+    }
+
+    /**
+     * Create the token for ElastiCache login.
+     *
+     * @param string $replication_group_id The replication group id
+     * @param string $region The region where the ElastiCache cluster is located
+     * @param string $username The username to login as
+     * @param int $lifetime The lifetime of the token in minutes
+     *
+     * @return string Token generated
+     */
+    public function createToken($replication_group_id, $region, $username, $lifetime = 15)
+    {
+        if (! is_numeric($lifetime) || $lifetime > 15 || $lifetime <= 0) {
+            throw new \InvalidArgumentException(
+                "Lifetime must be a positive number less than or equal to 15, was {$lifetime}",
+                null
+            );
+        }
+
+        $uri = new Uri();
+        $uri = $uri->withHost($replication_group_id);
+        $uri = $uri->withPath('/');
+        $uri = $uri->withQuery('Action=connect&User='.$username);
+
+        $request = new Request('GET', $uri);
+        $signer = new SignatureV4('elasticache', $region);
+        $provider = $this->credentialProvider;
+
+        $url = (string) $signer->presign(
+            $request,
+            $provider()->wait(),
+            '+'.$lifetime.' minutes'
+        )->getUri();
+
+        // Remove 2 extra slash from the presigned url result
+        return substr($url, 2);
+    }
+}

tests/ElastiCache/AuthTokenGeneratorTest.php

@@ -0,0 +1,125 @@
+<?php
+namespace Aws\Test\ElastiCache;
+
+use Aws\Credentials\Credentials;
+use Aws\ElastiCache\AuthTokenGenerator;
+use GuzzleHttp\Promise;
+use Yoast\PHPUnitPolyfills\TestCases\TestCase;
+
+/**
+ * @covers Aws\ElastiCache\AuthTokenGenerator
+ */
+class AuthTokenGeneratorTest extends TestCase
+{
+    public function testCanCreateAuthTokenWthCredentialInstance()
+    {
+        $creds = new Credentials('foo', 'bar', 'baz');
+        $connect = new AuthTokenGenerator($creds);
+        $token = $connect->createToken(
+            'my-replication-group',
+            'us-west-2',
+            'myRedisUser'
+        );
+
+        $this->assertStringContainsString('my-replication-group', $token);
+        $this->assertStringContainsString('us-west-2', $token);
+        $this->assertStringContainsString('X-Amz-Credential=foo', $token);
+        $this->assertStringContainsString('X-Amz-Expires=900', $token);
+        $this->assertStringContainsString('X-Amz-SignedHeaders=host', $token);
+        $this->assertStringContainsString('User=myRedisUser', $token);
+        $this->assertStringContainsString('Action=connect', $token);
+    }
+
+    public function testCanCreateAuthTokenWthCredentialProvider()
+    {
+        $accessKeyId = 'AKID';
+        $secretKeyId = 'SECRET';
+        $provider = function () use ($accessKeyId, $secretKeyId) {
+            return Promise\Create::promiseFor(
+                new Credentials($accessKeyId, $secretKeyId)
+            );
+        };
+
+        $connect = new AuthTokenGenerator($provider);
+        $token = $connect->createToken(
+            'my-replication-group',
+            'us-west-2',
+            'myRedisUser'
+        );
+
+        $this->assertStringContainsString('my-replication-group', $token);
+        $this->assertStringContainsString('us-west-2', $token);
+        $this->assertStringContainsString('X-Amz-Credential=AKID', $token);
+        $this->assertStringContainsString('X-Amz-Expires=900', $token);
+        $this->assertStringContainsString('X-Amz-SignedHeaders=host', $token);
+        $this->assertStringContainsString('User=myRedisUser', $token);
+        $this->assertStringContainsString('Action=connect', $token);
+    }
+
+    public function lifetimeProvider()
+    {
+        return [
+            [1],
+            [14],
+            ['14'],
+            [15],
+        ];
+    }
+
+    /**
+     * @dataProvider lifetimeProvider
+     *
+     * @param $lifetime
+     */
+    public function testCanCreateAuthTokenWthNonDefaultLifetime($lifetime)
+    {
+        $creds = new Credentials('foo', 'bar', 'baz');
+        $connect = new AuthTokenGenerator($creds);
+        $token = $connect->createToken(
+            'my-replication-group',
+            'us-west-2',
+            'myRedisUser',
+            $lifetime
+        );
+        $lifetimeInSeconds = $lifetime * 60;
+        $this->assertStringContainsString('my-replication-group', $token);
+        $this->assertStringContainsString('us-west-2', $token);
+        $this->assertStringContainsString('X-Amz-Credential=foo', $token);
+        $this->assertStringContainsString("X-Amz-Expires={$lifetimeInSeconds}", $token);
+        $this->assertStringContainsString('X-Amz-SignedHeaders=host', $token);
+        $this->assertStringContainsString('User=myRedisUser', $token);
+        $this->assertStringContainsString('Action=connect', $token);
+    }
+
+    public function lifetimeFailureProvider()
+    {
+        return [
+            [0],
+            ['0'],
+            [''],
+            [16],
+            ['16'],
+            [10000],
+            [null],
+        ];
+    }
+
+    /**
+     * @dataProvider lifetimeFailureProvider
+     *
+     * @param $lifetime
+     */
+    public function testThrowsExceptionWithInvalidLifetime($lifetime)
+    {
+        $this->expectExceptionMessage("Lifetime must be a positive number less than or equal to 15, was");
+        $this->expectException(\InvalidArgumentException::class);
+        $creds = new Credentials('foo', 'bar', 'baz');
+        $connect = new AuthTokenGenerator($creds);
+        $connect->createToken(
+            'my-replication-group',
+            'us-west-2',
+            'myRedisUser',
+            $lifetime
+        );
+    }
+}