Implemented HMAC-SHA256 signature support to OAuth1.

src/OAuth/OAuth1/Service/AbstractService.php

@@ -23,6 +23,9 @@ abstract class AbstractService extends BaseAbstractService implements ServiceInt
     /** @var null|UriInterface */
     protected $baseApiUri;
 
+    /** @var string */
+    protected $signatureMethod = 'HMAC-SHA1';
+
     /**
      * {@inheritdoc}
      */
@@ -274,17 +277,18 @@ protected function generateNonce($length = 32)
      */
     protected function getSignatureMethod()
     {
-        return 'HMAC-SHA1';
+        return $this->signatureMethod;
     }
 
     /**
-     * This returns the version used in the authorization header of the requests.
+     * Set the signature method.
+     * Currently supported: 'HMAC-SHA1' and 'HMAC-SHA256'
      *
-     * @return string
+     * @param string $method
      */
-    protected function getVersion()
+    protected function setSignatureMethod($method)
     {
-        return '1.0';
+        $this->signatureMethod = (string) $method;
     }
 
     /**

src/OAuth/OAuth1/Signature/Signature.php

@@ -114,6 +114,8 @@ protected function hash($data)
         switch (strtoupper($this->algorithm)) {
             case 'HMAC-SHA1':
                 return hash_hmac('sha1', $data, $this->getSigningKey(), true);
+            case 'HMAC-SHA256':
+                return hash_hmac('sha256', $data, $this->getSigningKey(), true);
             default:
                 throw new UnsupportedHashAlgorithmException(
                     'Unsupported hashing algorithm (' . $this->algorithm . ') used.'