server-ts: protected_session.js -> ts

src/services/protected_session.ts

@@ -0,0 +1,82 @@
+"use strict";
+
+import log = require('./log');
+import dataEncryptionService = require('./encryption/data_encryption');
+
+let dataKey: Buffer | null = null;
+
+function setDataKey(decryptedDataKey: Buffer) {
+    dataKey = Buffer.from(decryptedDataKey);
+}
+
+function getDataKey() {
+    return dataKey;
+}
+
+function resetDataKey() {
+    dataKey = null;
+}
+
+function isProtectedSessionAvailable() {
+    return !!dataKey;
+}
+
+function encrypt(plainText: string | Buffer) {
+    const dataKey = getDataKey();
+    if (plainText === null || dataKey === null) {
+        return null;
+    }
+
+    return dataEncryptionService.encrypt(dataKey, plainText);
+}
+
+function decrypt(cipherText: string | Buffer) {
+    const dataKey = getDataKey();
+    if (cipherText === null || dataKey === null) {
+        return null;
+    }
+
+    return dataEncryptionService.decrypt(dataKey, cipherText);
+}
+
+function decryptString(cipherText: string) {
+    const dataKey = getDataKey();
+    if (dataKey === null) {
+        return null;
+    }
+    return dataEncryptionService.decryptString(dataKey, cipherText);
+}
+
+let lastProtectedSessionOperationDate: number | null = null;
+
+function touchProtectedSession() {
+    if (isProtectedSessionAvailable()) {
+        lastProtectedSessionOperationDate = Date.now();
+    }
+}
+
+function checkProtectedSessionExpiration() {
+    const options = require('./options.js');
+    const protectedSessionTimeout = options.getOptionInt('protectedSessionTimeout');
+    if (isProtectedSessionAvailable()
+        && lastProtectedSessionOperationDate
+        && Date.now() - lastProtectedSessionOperationDate > protectedSessionTimeout * 1000) {
+
+        resetDataKey();
+
+        log.info("Expiring protected session");
+
+        require('./ws.js').reloadFrontend("leaving protected session");
+    }
+}
+
+module.exports = {
+    setDataKey,
+    resetDataKey,
+    isProtectedSessionAvailable,
+    encrypt,
+    decrypt,
+    decryptString,
+    touchProtectedSession,
+    checkProtectedSessionExpiration
+};