AES256.swift

import CommonCrypto;

@objc(AES256) class AES256 : CDVPlugin {

    private static let SECURE_KEY_LENGTH = 16;
    private static let SECURE_IV_LENGTH = 8;
    private static let PBKDF2_ITERATION_COUNT = 1001;
    private static let aes256Queue = DispatchQueue(label: "AESQUEUE", qos: DispatchQoS.background, attributes: .concurrent)

    // Encrypts the plain text using aes256 encryption alogrithm
    @objc(encrypt:) func encrypt(_ command: CDVInvokedUrlCommand) {
        AES256.aes256Queue.async {
            var pluginResult = CDVPluginResult(
                status: CDVCommandStatus_ERROR,
                messageAs: "Error occurred while performing Encryption"
            )
            let secureKey = command.arguments[0] as? String ?? ""
            let iv = command.arguments[1] as? String ?? ""
            let value = command.arguments[2] as? String ?? ""
            let encrypted = AES256CBC.encryptString(value, password: secureKey, iv: iv)
            pluginResult = CDVPluginResult(status: CDVCommandStatus_OK, messageAs: encrypted)
            self.commandDelegate!.send(
                pluginResult,
                callbackId: command.callbackId
            )
        }
    }

    // Decrypts the aes256 encoded string into plain text
    @objc(decrypt:) func decrypt(_ command: CDVInvokedUrlCommand) {
        AES256.aes256Queue.async {
            var pluginResult = CDVPluginResult(
              status: CDVCommandStatus_ERROR,
              messageAs: "Error occurred while performing Decryption"
            )
            let secureKey = command.arguments[0] as? String ?? ""
            let iv = command.arguments[1] as? String ?? ""
            let value = command.arguments[2] as? String ?? ""
            let decrypted = AES256CBC.decryptString(value, password: secureKey, iv: iv)
            pluginResult = CDVPluginResult(status: CDVCommandStatus_OK, messageAs: decrypted)
            self.commandDelegate!.send(
              pluginResult,
              callbackId: command.callbackId
            )
        }
    }

    // Generates the secure key from the given password
    @objc(generateSecureKey:) func generateSecureKey(_ command: CDVInvokedUrlCommand) {
      AES256.aes256Queue.async {
        var pluginResult = CDVPluginResult(
            status: CDVCommandStatus_ERROR,
            messageAs: "Error occurred while generating secure key"
        )
        let password = command.arguments[0] as? String ?? ""
        let secureKey:String? = PBKDF2.pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA1), password:password, salt:AES256CBC.generateSalt(), keyByteCount:AES256.SECURE_KEY_LENGTH, rounds:AES256.PBKDF2_ITERATION_COUNT)
        pluginResult = CDVPluginResult(status: CDVCommandStatus_OK, messageAs: secureKey)
        self.commandDelegate!.send(
            pluginResult,
            callbackId: command.callbackId
        )
      }
    }

    // Generates the IV from the given password
    @objc(generateSecureIV:) func generateSecureIV(_ command: CDVInvokedUrlCommand) {
      AES256.aes256Queue.async {
        var pluginResult = CDVPluginResult(
            status: CDVCommandStatus_ERROR,
            messageAs: "Error occurred while generating secure IV"
        )
        let password = command.arguments[0] as? String ?? ""
        let secureIV:String? = PBKDF2.pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA1), password:password, salt:AES256CBC.generateSalt(), keyByteCount:AES256.SECURE_IV_LENGTH, rounds:AES256.PBKDF2_ITERATION_COUNT)
        pluginResult = CDVPluginResult(status: CDVCommandStatus_OK, messageAs: secureIV)
        self.commandDelegate!.send(
            pluginResult,
            callbackId: command.callbackId
        )
      }
    }
}