Merge pull request #37 from scality/FT/authV4-2

Implement authentication V4 signature verification route

lib/IAMClient.js

@@ -188,6 +188,43 @@ class IAMClient {
         this.request('GET', '/auth/v2', callback, data);
     }
 
+    /**
+     * Verify AWS request signature using V4 auth (contrary to v2, hash is
+     * always sha256)
+     *
+     * @param {string} stringToSign - string to sign as built from the request
+     * @param {string} signature - the user-computed signature as provided by
+     *                             the request, base64-encoded
+     * @param {string} accessKey - the id of the key as provided by the request
+     * @param {string} region - the region where the user wants authentication
+     * @param {string} scopeDate - the date from which the signature is valid
+     * @param {string} [options.reqUid] - the request UID
+     * @param {IAMClient~requestCallback} callback - callback
+     * @returns {undefined}
+     */
+    verifySignatureV4(stringToSign, signature, accessKey, region, scopeDate,
+                        options, callback) {
+        assert(typeof stringToSign === 'string' && stringToSign !== '',
+               'stringToSign is required');
+        assert(typeof signature === 'string' && signature !== '',
+               'signature is required');
+        assert(typeof accessKey === 'string' && accessKey !== '',
+               'accessKey is required');
+        assert(typeof region === 'string' && region !== '',
+               'region is required');
+        assert(typeof scopeDate === 'string' && scopeDate !== '',
+               'scopeDate is required');
+        const data = { additionaldata: { stringToSign,
+                                         signatureFromRequest: signature,
+                                         accessKey,
+                                         region,
+                                         scopeDate } };
+        if (options.reqUid !== undefined) {
+            data[requestUidKey] = options.reqUid;
+        }
+        this.request('GET', '/auth/v4', callback, data);
+    }
+
     /**
      * @param {string} method - CRUD method chosen for the request
      * @param {string} path - RESTful URL for the request