From 5b76a31644419b562ee2768d2976c53dcdb3d545 Mon Sep 17 00:00:00 2001
From: Josiah Baldwin <josiah.baldwin@intel.com>
Date: Sun, 4 Aug 2024 16:02:22 -0700
Subject: [PATCH] Changed database file encryption to pbkdf2 for key derivation
 and aes-256-gcm for encryption (#6296)

* Added pbkdf2 and aes-256-gcm options for database file encryption

* Added dbCipherAlgorithm option

* Changed pbkdf2 to default

Maintains backward compatibility, but will require a manual repush to update to the new version

* Removed dbkeyderivationiterations option, as this branch is to be more opinionated
---
 db.js | 58 ++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 48 insertions(+), 10 deletions(-)

diff --git a/db.js b/db.js
index 10bcf59285..524e89bb0b 100644
--- a/db.js
+++ b/db.js
@@ -417,34 +417,72 @@ module.exports.CreateDB = function (parent, func) {
     };
 
     // Get encryption key
-    obj.getEncryptDataKey = function (password) {
+    obj.getEncryptDataKey = function (password, salt, iterations) {
+        if (typeof password != 'string') return null;
+        let key;
+        try {
+            key = parent.crypto.pbkdf2Sync(password, salt, iterations, 32, 'sha384');
+        } catch (e) {
+            // If this previous call fails, it's probably because older pbkdf2 did not specify the hashing function, just use the default.
+            key = parent.crypto.pbkdf2Sync(password, salt, iterations, 32);
+        }
+        return key
+    }
+
+    obj.oldGetEncryptDataKey = function (password) {
         if (typeof password != 'string') return null;
         return parent.crypto.createHash('sha384').update(password).digest("raw").slice(0, 32);
     }
 
     // Encrypt data 
     obj.encryptData = function (password, plaintext) {
-        var key = obj.getEncryptDataKey(password);
-        if (key == null) return null;
+        let encryptionVersion = 0x1;
+        let iterations = 100000
         const iv = parent.crypto.randomBytes(16);
-        const aes = parent.crypto.createCipheriv('aes-256-cbc', key, iv);
+        var key = obj.getEncryptDataKey(password, iv, iterations);
+        if (key == null) return null;
+        const aes = parent.crypto.createCipheriv("aes-256-gcm", key, iv);
         var ciphertext = aes.update(plaintext);
-        ciphertext = Buffer.concat([iv, ciphertext, aes.final()]);
+        let versionbuf = Buffer.allocUnsafe(2);
+        versionbuf.writeUInt16BE(encryptionVersion);
+        let iterbuf = Buffer.allocUnsafe(4);
+        iterbuf.writeUInt32BE(iterations);
+        let encryptedBuf = aes.final();
+        ciphertext = Buffer.concat([versionbuf, iterbuf, aes.getAuthTag(), iv, ciphertext, encryptedBuf]);
         return ciphertext.toString('base64');
     }
 
     // Decrypt data 
     obj.decryptData = function (password, ciphertext) {
+        let ciphertextBytes = Buffer.from(ciphertext, 'base64');
         try {
-            var key = obj.getEncryptDataKey(password);
-            if (key == null) return null;
-            const ciphertextBytes = Buffer.from(ciphertext, 'base64');
             const iv = ciphertextBytes.slice(0, 16);
             const data = ciphertextBytes.slice(16);
-            const aes = parent.crypto.createDecipheriv('aes-256-cbc', key, iv);
-            var plaintextBytes = Buffer.from(aes.update(data));
+            let key = obj.oldGetEncryptDataKey(password);
+            const aes = parent.crypto.createDecipheriv("aes-256-cbc", key, iv);
+            let plaintextBytes = Buffer.from(aes.update(data));
             plaintextBytes = Buffer.concat([plaintextBytes, aes.final()]);
             return plaintextBytes;
+        } catch (e) {}
+        // Adding an encryption version lets us avoid try catching in the future
+        let encryptionVersion = ciphertextBytes.readUInt16BE(0);
+        try {
+            switch (encryptionVersion) {
+                case 0x1:
+                    let iterations = ciphertextBytes.readUInt32BE(2);
+                    let authTag = ciphertextBytes.slice(6, 22);
+                    const iv = ciphertextBytes.slice(22, 38);
+                    const data = ciphertextBytes.slice(38);
+                    let key = obj.getEncryptDataKey(password, iv, iterations);
+                    if (key == null) return null;
+                    const aes = parent.crypto.createDecipheriv("aes-256-gcm", key, iv);
+                    aes.setAuthTag(authTag);
+                    let plaintextBytes = Buffer.from(aes.update(data));
+                    plaintextBytes = Buffer.concat([plaintextBytes, aes.final()]);
+                    return plaintextBytes;
+                default:
+                    return null;
+            }
         } catch (ex) { return null; }
     }