Fix request headers being overwritten

lib/auth/auth.js

@@ -32,6 +32,15 @@ function setAuthHandler(handler) {
     return auth;
 }
 
+function decodeHeader(value) {
+    // extract string after 'x-amz-meta-scality-rewritten-'
+    let tail = value.slice(29);
+    tail = tail.replace(/\|/g, '/');
+    tail = tail.replace(/-/g, '=');
+    tail = Buffer.from(tail, 'base64').toString();
+    return `x-amz-meta-${tail}`;
+}
+
 /**
  * This function will check validity of request parameters to authenticate
  *
@@ -51,7 +60,22 @@ function setAuthHandler(handler) {
  */
 function extractParams(request, log, awsService, data) {
     log.trace('entered', { method: 'Arsenal.auth.server.extractParams' });
-    const authHeader = request.headers.authorization;
+    const modifiedRequest = Object.assign({}, request);
+    modifiedRequest.headers = {};
+    Object.keys(request.headers).forEach(headerName => {
+        modifiedRequest.headers[headerName] = request.headers[headerName];
+    });
+    for (let i = 0; i < modifiedRequest.rawHeaders.length; i += 2) {
+        const headerName = modifiedRequest.rawHeaders[i];
+        const lowerCaseHeaderName = headerName.toLowerCase();
+        if (lowerCaseHeaderName.startsWith('x-amz-meta-scality-rewritten-')) {
+            const decodedHeader = decodeHeader(headerName);
+            modifiedRequest.headers[decodedHeader.toLowerCase()] =
+                request.headers[lowerCaseHeaderName];
+            delete modifiedRequest.headers[lowerCaseHeaderName];
+        }
+    }
+    const authHeader = modifiedRequest.headers.authorization;
     let version = null;
     let method = null;
 
@@ -85,7 +109,8 @@ function extractParams(request, log, awsService, data) {
             return { err: errors.NotImplemented };
         }
         log.trace('identified auth method', { version, authMethod: method });
-        return checkFunctions[version][method](request, log, data, awsService);
+        return checkFunctions[version][method](modifiedRequest, log,
+            data, awsService);
     }
 
     // no auth info identified

tests/unit/auth/v2/publicAccess.js

@@ -19,6 +19,7 @@ describe('Public Access', () => {
         const request = {
             method: 'GET',
             headers: { host: 's3.amazonaws.com' },
+            rawHeaders: [],
             url: '/bucket',
             query: {},
         };
@@ -46,6 +47,7 @@ describe('Public Access', () => {
                 host: 's3.amazonaws.com',
                 authorization: 'noAuth',
             },
+            rawHeaders: ['authorization', 'noAuth'],
             url: '/bucket',
             query: {},
         };