1 files changed, 46 insertions, 0 deletions
diff --git a/data/extensions/jsr@javascriptrestrictor/session_hash.js b/data/extensions/jsr@javascriptrestrictor/session_hash.js
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+++ b/data/extensions/jsr@javascriptrestrictor/session_hash.js
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+/** \file
+ * \brief A cache for session and domain hashes, used for Farbling
+ *
+ *  \author Copyright (C) 2021  Matus Svancar
+ *  \author Copyright (C) 2021  Giorgio Maone
+ *
+ *  \license SPDX-License-Identifier: GPL-3.0-or-later
+ */
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+
+/**
+ * Object for generating and caching domain/session hashes
+ * getFor method used to get domain hashes from given url
+ *
+ * \note cached visited domains with related keys are only deleted after end of the session
+ */
+var Hashes = {
+  sessionHash : gen_random64().toString(),
+  visitedDomains : {},
+  getFor(url){
+		let site = getSiteForURL(url);
+	  let domainHash = this.visitedDomains[site];
+	  if (!domainHash) {
+		  let hmac = sha256.hmac.create(this.sessionHash);
+		  hmac.update(site);
+		  domainHash = hmac.hex();
+		  this.visitedDomains[site] = domainHash;
+	  }
+    return {
+      domainHash
+    };
+  }
+};