Add support for MongoDB authentication (digest).

source/vibe/db/mongo/auth.d

@@ -0,0 +1,98 @@
+/**
+	MongoDB authentication adapter
+
+	Copyright: © 2012 RejectedSoftware e.K.
+	License: Subject to the terms of the MIT license, as written in the included LICENSE.txt file.
+	Authors: Sönke Ludwig, Christian Schneider
+*/
+module vibe.db.mongo.auth;
+import
+  std.string,
+  std.digest.md,
+  vibe.data.bson,
+  vibe.db.mongo.client,
+  vibe.db.mongo.database
+;
+
+class MongoAuth
+{
+  private
+  {
+    MongoClient m_client;
+  }
+
+  /**
+    Initialize adapter.
+
+    Examples:
+      ---
+      auto ma = new MongoAuth(mongo);
+      bool ok = ma.auth("admin", "guru", "secret");
+      ---
+   */
+
+  this(MongoClient client)
+  {
+    m_client = client;
+  }
+
+  /**
+    Initialize adapter and authenticate this connection.
+
+    Throws:
+      Exception if not successfully authenticated.
+
+    Examples:
+      ---
+      auto ma = new MongoAuth(mongo, "admin", "guru", "secret");
+      ---
+   */
+  this(MongoClient client, string dbname, string username, string password)
+  {
+    m_client = mongo;
+    bool res = auth(dbname, username, password);
+    if (!res) throw new Exception("MongoAuth failed.");
+  }
+
+  /**
+    Authenticate this connection.
+
+    Examples:
+      ---
+      auto ma = new MongoAuth(mongo);
+      bool ok = ma.auth("admin", "guru", "secret");
+      logInfo("auth: %s", ok);
+      ---
+   */
+  bool auth(string dbname, string username, string password)
+  {
+    auto db = m_client.getDatabase(dbname);
+    string nonce = getNonce(db);
+    string key = getKey(nonce, username, password);
+    Bson cmd = Bson.EmptyObject;
+    cmd["authenticate"] = Bson(1);
+    cmd["nonce"] = Bson(nonce);
+    cmd["user"] = Bson(username);
+    cmd["key"] = Bson(key);
+    auto res = db.runCommand(cmd);
+    if (res["ok"].get!double == 1.0)
+      return true;
+    return false;
+  }
+
+  package string getNonce(MongoDatabase db)
+  {
+    auto res = db.runCommand(Bson(["getnonce":Bson(1)]));
+    return res["nonce"].get!string;
+  }
+
+  package string getKey(string nonce, string username, string password)
+  {
+    return toLower(toHexString(md5Of(nonce ~ username ~ createPasswordDigest(username, password))).idup);
+  }
+
+  package string createPasswordDigest(string username, string password)
+  {
+    return toLower(toHexString(md5Of(username ~ ":mongo:" ~ password)).idup);
+  }
+}