Separate encryption/decryption logic for different frameworks used

passKit/Crypto/PGPAgent.swift

@@ -0,0 +1,64 @@
+//
+//  PGPAgent.swift
+//  passKit
+//
+//  Created by Yishi Lin on 2019/7/17.
+//  Copyright © 2019 Bob Sun. All rights reserved.
+//
+
+public class PGPAgent {
+
+    public static let shared: PGPAgent = PGPAgent()
+
+    private let keyStore: KeyStore
+    private var pgpInterface: PgpInterface?
+
+    public init(keyStore: KeyStore = AppKeychain.shared) {
+        self.keyStore = keyStore
+    }
+
+    public func initKeys() throws {
+        guard let publicKey: String = keyStore.get(for: PgpKey.PUBLIC.getKeychainKey()),
+              let privateKey: String = keyStore.get(for: PgpKey.PRIVATE.getKeychainKey()) else {
+            throw AppError.KeyImport
+        }
+        do {
+            pgpInterface = try GopenPgp(publicArmoredKey: publicKey, privateArmoredKey: privateKey)
+        } catch {
+            pgpInterface = try ObjectivePgp(publicArmoredKey: publicKey, privateArmoredKey: privateKey)
+        }
+    }
+
+    public func uninitKeys() {
+        pgpInterface = nil
+    }
+
+    public var keyId: String? {
+        return pgpInterface?.keyId
+    }
+
+    public func decrypt(encryptedData: Data, requestPGPKeyPassphrase: () -> String) throws -> Data? {
+        try checkAndInit()
+        let passphrase = keyStore.get(for: Globals.pgpKeyPassphrase) ?? requestPGPKeyPassphrase()
+        return try pgpInterface!.decrypt(encryptedData: encryptedData, passphrase: passphrase)
+    }
+
+    public func encrypt(plainData: Data) throws -> Data {
+        try checkAndInit()
+        guard let pgpInterface = pgpInterface else {
+            throw AppError.Encryption
+        }
+        return try pgpInterface.encrypt(plainData: plainData)
+    }
+
+    public var isPrepared: Bool {
+        return keyStore.contains(key: PgpKey.PUBLIC.getKeychainKey())
+            && keyStore.contains(key: PgpKey.PRIVATE.getKeychainKey())
+    }
+
+    private func checkAndInit() throws {
+        if pgpInterface == nil || !keyStore.contains(key: Globals.pgpKeyPassphrase) {
+            try initKeys()
+        }
+    }
+}