Add support for hmac related request signing

Author: mheap

src/Client.php

@@ -157,7 +157,7 @@ public static function signRequest(RequestInterface $request, SignatureSecret $c
                 $content = $body->getContents();
                 $params = json_decode($content, true);
                 $params['api_key'] = $credentials['api_key'];
-                $signature = new Signature($params, $credentials['signature_secret']);
+                $signature = new Signature($params, $credentials['signature_secret'], $credentials['signature_method']);
                 $body->rewind();
                 $body->write(json_encode($signature->getSignedParams()));
                 break;
@@ -168,7 +168,7 @@ public static function signRequest(RequestInterface $request, SignatureSecret $c
                 $params = [];
                 parse_str($content, $params);
                 $params['api_key'] = $credentials['api_key'];
-                $signature = new Signature($params, $credentials['signature_secret']);
+                $signature = new Signature($params, $credentials['signature_secret'], $credentials['signature_method']);
                 $params = $signature->getSignedParams();
                 $body->rewind();
                 $body->write(http_build_query($params, null, '&'));
@@ -177,7 +177,7 @@ public static function signRequest(RequestInterface $request, SignatureSecret $c
                 $query = [];
                 parse_str($request->getUri()->getQuery(), $query);
                 $query['api_key'] = $credentials['api_key'];
-                $signature = new Signature($query, $credentials['signature_secret']);
+                $signature = new Signature($query, $credentials['signature_secret'], $credentials['signature_method']);
                 $request = $request->withUri($request->getUri()->withQuery(http_build_query($signature->getSignedParams())));
                 break;
         }

src/Client/Credentials/SignatureSecret.php

@@ -16,9 +16,10 @@ class SignatureSecret extends AbstractCredentials implements CredentialsInterfac
      * @param string $key    API Key
      * @param string $signature_secret Signature Secret
      */
-    public function __construct($key, $signature_secret)
+    public function __construct($key, $signature_secret, $method='md5hash')
     {
         $this->credentials['api_key'] = $key;
         $this->credentials['signature_secret'] = $signature_secret;
+        $this->credentials['signature_method'] = $method;
     }
 }

src/Client/Signature.php

@@ -8,6 +8,8 @@
 
 namespace Nexmo\Client;
 
+use Nexmo\Client\Exception\Exception;
+
 class Signature
 {
     /**
@@ -28,7 +30,7 @@ class Signature
      * @param array $params
      * @param $secret
      */
-    public function __construct(array $params, $secret)
+    public function __construct(array $params, $secret, $signatureMethod)
     {
         $this->params = $params;
         $this->signed = $params;
@@ -51,11 +53,25 @@ public function __construct(array $params, $secret)
         //create base string
         $base = '&'.urldecode(http_build_query($signed));
 
-        //append the secret
-        $base .= $secret;
+        $this->signed['sig'] = $this->sign($signatureMethod, $base, $secret);
+    }
 
-        //create hash
-        $this->signed['sig'] = md5($base);
+    protected function sign($signatureMethod, $data, $secret) {
+       switch($signatureMethod) {
+            case 'md5hash':
+                // md5hash needs the secret appended
+                $data .= $secret;
+                return md5($data);
+                break;
+            case 'md5':
+            case 'sha1':
+            case 'sha256':
+            case 'sha512':
+                return hash_hmac($signatureMethod, $data, $secret);
+                break;
+            default:
+                throw new Exception('Unknown signature algorithm: '.$signatureMethod.'. Expected: md5hash, md5, sha1, sha256, or sha512');
+        }
     }
 
     /**
@@ -117,4 +133,4 @@ public function __toString()
     {
         return $this->getSignature();
     }
-}
+}

test/Client/SignatureTest.php

@@ -10,10 +10,46 @@
 
 use Nexmo\Client\Signature;
 use PHPUnit\Framework\TestCase;
+use Nexmo\Client\Exception\Exception;
 
 
 class SignatureTest extends TestCase
 {
+    public function testInvalidSignatureMethod() {
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('Unknown signature algorithm: fake_algo. Expected: md5hash, md5, sha1, sha256, or sha512');
+        $signature = new Signature(['foo' => 'bar'], 'sig_secret', 'fake_algo');
+    }
+
+    /**
+     * @dataProvider hmacSignatureProvider
+     */
+    public function testHmacSignature($algorithm, $expected){
+        $data = [
+            'api_key' => 'fake_api_key',
+            'to' => '14155550100',
+            'from' => 'AcmeInc',
+            'text' => 'Test From Nexmo',
+            'type' => 'text',
+            'timestamp' => '1540924779'
+        ];
+        $secret = '71efab63122f1d179f51c46bac838fb5';
+        $signature = new Signature($data, $secret, $algorithm);
+
+        $this->assertEquals($expected, $signature->getSignature());
+    }
+
+    public function hmacSignatureProvider() {
+        $data = [];
+
+        $data['md5'] = ['md5', '51cdafebb4bbce9525b195c1617cb8d2'];
+        $data['sha1'] = ['sha1', '0162aec64bc183b2e1256545951fe5639dc98020'];
+        $data['sha256'] = ['sha256', '9fec5ef6d0f2b3d2bb7558b6e4042569823cab9ea0dd30503472b7b304601975'];
+        $data['sha512'] = ['sha512', '40bd12b9a4b6000ad1138eefd24ffe9fbd72aee13c3fa04b32bb69dbc256ad0a04a463b1a9af6660d10f6e1e769ee14b9cff6a635502e93afcd0bfab29f38f87'];
+
+        return $data;
+    }
+
     /**
      * @dataProvider signatures
      * @param $sig
@@ -23,7 +59,7 @@ class SignatureTest extends TestCase
     public function testSignature($sig, $params, $secret)
     {
         //a signature is created from a set of parameters and a secret
-        $signature = new Signature($params, $secret);
+        $signature = new Signature($params, $secret, 'md5hash');
 
         //the parameters should ne be changed
         $this->assertEquals($params, $signature->getParams());

test/ClientTest.php

@@ -569,7 +569,7 @@ public static function assertValidSignature($array, $secret)
         self::assertArrayHasKey('api_key', $array);
 
         //params should be correctly signed
-        $signature = new Signature($array, $secret);
+        $signature = new Signature($array, $secret, 'md5hash');
         self::assertTrue($signature->check($array));
     }
 }