Asymmetric and symmetric cryptography (RSA and AES) made easy for Swift

by iOS Example

Simple Swift Crypto

I needed a simple way of doing both symmetric and asymmetric crypto without the headache. I also didn’t need to store it in the Keychain. So I made this.

Works on MacOS, iOS, WatchOS and TvOS.

Example Usage

AES Symmetric Encryption and Decryption

let testString: String = "Hello World!"
let testData: Data = testString.data(using: .utf8)!

let aesPrivateKey: AES256Key = SimpleSwiftCrypto.generateRandomAES256Key()!
let encryptedData: Data = aesPrivateKey.encrypt(data: testData)!

let decryptedData: Data = aesPrivateKey.decrypt(data: encryptedData)!
let decryptedString: String = String(data: decryptedData, encoding: .utf8)! // "Hello World!"

RSA Asymmetric Encryption and Decryption

let testString: String = "Hello World!"
let testData: Data = testString.data(using: .utf8)!

let rsaPrivateKey: RSAKeyPair = SimpleSwiftCrypto.generateRandomRSAKeyPair()!
let rsaPublicKey: RSAPublicKey = rsaPrivateKey.extractPublicKey()
let encryptedData: Data = rsaPublicKey.encrypt(data: testData)!

let decryptedData: Data = rsaPrivateKey.decrypt(data: encryptedData)!
let decryptedString: String = String(data: decryptedData, encoding: .utf8)! // "Hello World!"

Exporting and Loading AES Secret Key

let aesPrivateKey: AES256Key = SimpleSwiftCrypto.generateRandomAES256Key()!
let aesPrivateKeyAsData: Data = aesPrivateKey.exportIvAndPrivateAES256Key()

// send `aesPrivateKeyAsData` to another device securely, then...  
let sameAesPrivateKeyFromData: AES256Key = .loadIvAndPrivateAES256Key(ivAndPrivateAES256Key: aesPrivateKeyAsData)!

Exporting and Loading RSA Public Key

let rsaPrivateKey: RSAKeyPair = SimpleSwiftCrypto.generateRandomRSAKeyPair()!
let rsaPublicKey: RSAPublicKey = rsaPrivateKey.extractPublicKey()
let rsaPublicKeyAsData: Data = rsaPublicKey.export()!


// send `rsaPublicKeyAsData` to another device, then...  
let sameRsaPublicKeyFromData: RSAPublicKey = .load(rsaPublicKeyData: rsaPublicKeyAsData)!

Add as Swift Package

// swift-tools-version:5.5
import PackageDescription

let package = Package(
    name: "Example",
    dependencies: [
        .package(name: "SimpleSwiftCrypto", url: "https://github.com/joehinkle11/SimpleSwiftCrypto.git", from: "1.0.0"),
    ],
    targets: [
        "SimpleSwiftCrypto"
    ]
)

Why did I make this?

I’m working on an IDE for iPad/iOS called App Maker Professional. A new feature I’m adding is multiplayer, and I don’t want to have my users’ files on the server. So I made this to be able to encrypt their files locally on device so the server can’t read them.

Contributions

If someone wants to add Keychain support, that’d be great. I’ll take a look at a PR.

License

MIT

Sources

GitHub

View Github