Return password reference at the time of setting

Simplifies app/extension IPC.

Demo/Demo/iOS/ViewController.swift

@@ -98,12 +98,11 @@ class ViewController: UIViewController, URLSessionDataDelegate {
 
         let credentials = OpenVPN.Credentials(textUsername.text!, textPassword.text!)
         let cfg = Configuration.make(hostname: hostname, port: port, socketType: socketType)
-        try? keychain.set(password: credentials.password, for: credentials.username, context: tunnelIdentifier)
         let proto = try! cfg.generatedTunnelProtocol(
             withBundleIdentifier: tunnelIdentifier,
             appGroup: appGroup,
             context: tunnelIdentifier,
-            username: credentials.username
+            credentials: credentials
         )
         let neCfg = NetworkExtensionVPNConfiguration(title: "BasicTunnel", protocolConfiguration: proto, onDemandRules: [])
         vpn.reconnect(configuration: neCfg) { (error) in
@@ -147,15 +146,11 @@ class ViewController: UIViewController, URLSessionDataDelegate {
         let username = "foo"
         let password = "bar"
         
-        guard let _ = try? keychain.set(password: password, for: username, context: tunnelIdentifier) else {
+        guard let ref = try? keychain.set(password: password, for: username, context: tunnelIdentifier) else {
             print("Couldn't set password")
             return
         }
-        guard let passwordReference = try? keychain.passwordReference(for: username, context: tunnelIdentifier) else {
+        guard let fetchedPassword = try? Keychain.password(forReference: ref) else {
-            print("Couldn't get password reference")
-            return
-        }
-        guard let fetchedPassword = try? keychain.password(for: username, reference: passwordReference, context: tunnelIdentifier) else {
             print("Couldn't fetch password")
             return
         }

Demo/Demo/macOS/ViewController.swift

@@ -89,12 +89,11 @@ class ViewController: NSViewController {
 
         let credentials = OpenVPN.Credentials(textUsername.stringValue, textPassword.stringValue)
         let cfg = Configuration.make(hostname: hostname, port: port, socketType: .udp)
-        try? keychain.set(password: credentials.password, for: credentials.username, context: tunnelIdentifier)
         let proto = try! cfg.generatedTunnelProtocol(
             withBundleIdentifier: tunnelIdentifier,
             appGroup: appGroup,
             context: tunnelIdentifier,
-            username: credentials.username
+            credentials: credentials
         )
         let neCfg = NetworkExtensionVPNConfiguration(title: "BasicTunnel", protocolConfiguration: proto, onDemandRules: [])
         vpn.reconnect(configuration: neCfg) { (error) in
@@ -132,15 +131,11 @@ class ViewController: NSViewController {
         let username = "foo"
         let password = "bar"
 
-        guard let _ = try? keychain.set(password: password, for: username, context: tunnelIdentifier) else {
+        guard let ref = try? keychain.set(password: password, for: username, context: tunnelIdentifier) else {
             print("Couldn't set password")
             return
         }
-        guard let passwordReference = try? keychain.passwordReference(for: username, context: tunnelIdentifier) else {
+        guard let fetchedPassword = try? Keychain.password(forReference: ref) else {
-            print("Couldn't get password reference")
-            return
-        }
-        guard let fetchedPassword = try? keychain.password(for: username, reference: passwordReference, context: tunnelIdentifier) else {
             print("Couldn't fetch password")
             return
         }

Sources/TunnelKitManager/Keychain.swift

@@ -74,13 +74,15 @@ public class Keychain {
      - Parameter password: The password to set.
      - Parameter username: The username to set the password for.
      - Parameter context: An optional context.
+     - Returns: The reference to the password.
      - Throws: `KeychainError.add` if unable to add the password to the keychain.
      **/
-    public func set(password: String, for username: String, context: String? = nil) throws {
+    @discardableResult
+    public func set(password: String, for username: String, context: String? = nil) throws -> Data {
         do {
             let currentPassword = try self.password(for: username, context: context)
             guard password != currentPassword else {
-                return
+                return try passwordReference(for: username, context: context)
             }
             removePassword(for: username, context: context)
         } catch let e as KeychainError {
@@ -99,11 +101,14 @@ public class Keychain {
         query[kSecAttrAccount as String] = username
         query[kSecAttrAccessible as String] = kSecAttrAccessibleAfterFirstUnlock
         query[kSecValueData as String] = password.data(using: .utf8)
+        query[kSecReturnPersistentRef as String] = true
 
-        let status = SecItemAdd(query as CFDictionary, nil)
+        var ref: CFTypeRef?
-        guard status == errSecSuccess else {
+        let status = SecItemAdd(query as CFDictionary, &ref)
+        guard status == errSecSuccess, let refData = ref as? Data else {
             throw KeychainError.add
         }
+        return refData
     }
     
     /**
@@ -195,18 +200,13 @@ public class Keychain {
     /**
      Gets a password associated with a password reference.
 
-     - Parameter username: The username to get the password for.
      - Parameter reference: The password reference.
-     - Parameter context: An optional context.
+     - Returns: The password for the input reference.
-     - Returns: The password for the input username and reference.
      - Throws: `KeychainError.notFound` if unable to find the password in the keychain.
      **/
-    public func password(for username: String, reference: Data, context: String? = nil) throws -> String {
+    public static func password(forReference reference: Data) throws -> String {
         var query = [String: Any]()
-        setScope(query: &query, context: context)
+        query[kSecValuePersistentRef as String] = reference
-        query[kSecClass as String] = kSecClassGenericPassword
-        query[kSecAttrAccount as String] = username
-        query[kSecMatchItemList as String] = [reference]
         query[kSecReturnData as String] = true
         
         var result: AnyObject?

Sources/TunnelKitOpenVPNAppExtension/OpenVPNTunnelProvider.swift

@@ -217,9 +217,8 @@ open class OpenVPNTunnelProvider: NEPacketTunnelProvider {
         // optional credentials
         let credentials: OpenVPN.Credentials?
         if let username = protocolConfiguration.username, let passwordReference = protocolConfiguration.passwordReference {
-            let keychain = Keychain(group: appGroup)
+            guard let password = try? Keychain.password(forReference: passwordReference) else {
-            guard let password = try? keychain.password(for: username, reference: passwordReference) else {
+                completionHandler(OpenVPNProviderConfigurationError.credentials(details: "Keychain.password(forReference:)"))
-                completionHandler(OpenVPNProviderConfigurationError.credentials(details: "keychain.password(for:, reference:)"))
                 return
             }
             credentials = OpenVPN.Credentials(username, password)

Sources/TunnelKitOpenVPNManager/OpenVPNProvider+Configuration.swift

@@ -276,7 +276,7 @@ extension OpenVPNProvider {
          - Parameter bundleIdentifier: The provider bundle identifier required to locate the tunnel extension.
          - Parameter appGroup: The name of the app group in which the tunnel extension lives in.
          - Parameter context: The keychain context where to look for the password reference.
-         - Parameter username: The username to authenticate with.
+         - Parameter credentials: The credentials to authenticate with.
          - Returns: The generated `NETunnelProviderProtocol` object.
          - Throws: `OpenVPNProviderError.credentials` if unable to store `credentials.password` to the `appGroup` keychain.
          */
@@ -284,16 +284,18 @@ extension OpenVPNProvider {
             withBundleIdentifier bundleIdentifier: String,
             appGroup: String,
             context: String,
-            username: String?) throws -> NETunnelProviderProtocol {
+            credentials: OpenVPN.Credentials?) throws -> NETunnelProviderProtocol {
             
             let protocolConfiguration = NETunnelProviderProtocol()
             let keychain = Keychain(group: appGroup)
 
             protocolConfiguration.providerBundleIdentifier = bundleIdentifier
             protocolConfiguration.serverAddress = sessionConfiguration.hostname ?? resolvedAddresses?.first
-            if let username = username {
+            if let username = credentials?.username {
                 protocolConfiguration.username = username
-                protocolConfiguration.passwordReference = try? keychain.passwordReference(for: username, context: context)
+                if let password = credentials?.password {
+                    protocolConfiguration.passwordReference = try? keychain.set(password: password, for: username, context: context)
+                }
             }
             protocolConfiguration.providerConfiguration = generatedProviderConfiguration(appGroup: appGroup)
             

Tests/TunnelKitOpenVPNTests/AppExtensionTests.swift

@@ -81,7 +81,7 @@ class AppExtensionTests: XCTestCase {
             withBundleIdentifier: identifier,
             appGroup: appGroup,
             context: context,
-            username: credentials.username
+            credentials: credentials
         )
         XCTAssertNotNil(proto)