feat: Add isDatabaseEncrypted utility function to detect encrypted databases

LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015-2018 Protocol Labs Inc.
+Copyright (c) 2018 Haja Networks Oy
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -57,6 +57,42 @@ const db = await orbitdb.open(dbAddress, { encryption })
 
 ```
 
+## Detecting Encrypted Databases
+
+The `isDatabaseEncrypted()` function helps detect if a database is encrypted when it has been opened **without** any encryption options. It currently detects encryption in two main ways:
+
+- **Data-only encryption**: `db.all()` succeeds, entries exist, but their `value` fields are `undefined` (while `hash` is present).
+- **Replication and/or data encryption**: `db.all()` throws a `TypeError` such as `Cannot read properties of undefined (reading 'value')` because OrbitDB cannot decrypt the underlying log entries.
+
+```js
+import SimpleEncryption, { isDatabaseEncrypted } from '@orbitdb/simple-encryption'
+
+// Try opening database without encryption
+const db = await orbitdb.open(address, {})
+
+// Check if it's encrypted
+const isEncrypted = await isDatabaseEncrypted(db)
+
+if (isEncrypted) {
+  // Application-specific flow: ask user for password / config
+  const password = await promptForPassword()
+
+  // Depending on how the DB was created, you may need:
+  // - data encryption only
+  // - replication encryption only
+  // - or both
+  const replication = await SimpleEncryption({ password })
+  const data = await SimpleEncryption({ password })
+
+  await db.close()
+
+  // Example: open with both replication and data encryption
+  const encryptedDb = await orbitdb.open(address, {
+    encryption: { replication, data }
+  })
+}
+```
+
 ## Contributing
 
 **Take a look at our organization-wide [Contributing Guide](https://github.com/orbitdb/welcome/blob/master/contributing.md).** You'll find most of your questions answered there. Some questions may be answered in the [FAQ](FAQ.md), as well.