Swiftpack.co - Package - krzyzanowskim/CryptoSwift

Platform Swift support CocoaPods Compatible Carthage compatible Swift Package Manager compatible Twitter


Crypto related functions and helpers for Swift implemented in Swift. (#PureSwift)

Table of Contents


Good mood


  • Easy to use
  • Convenient extensions for String and Data
  • Support for incremental updates (stream, ...)
  • iOS, macOS, AppleTV, watchOS, Linux support


paypal to make the CryptoSwift awesome! Thank you.

Hash (Digest)

Cyclic Redundancy Check (CRC)


Message authenticators

Cipher block mode

  • Electronic codebook (ECB)
  • Cipher-block chaining (CBC)
  • Propagating Cipher Block Chaining (PCBC)
  • Cipher feedback (CFB)
  • Output Feedback (OFB)
  • Counter (CTR)

Password-Based Key Derivation Function

  • PBKDF1 (Password-Based Key Derivation Function 1)
  • PBKDF2 (Password-Based Key Derivation Function 2)
  • HKDF (HMAC-based Extract-and-Expand Key Derivation Function)

Data padding


Why? Because I can.


For the latest version, please check develop branch. Changes from this branch will be merged into the master branch at some point.


To install CryptoSwift, add it as a submodule to your project (on the top level project directory):

git submodule add https://github.com/krzyzanowskim/CryptoSwift.git

It is recommended to enable Whole-Module Optimization to gain better performance. Non-optimized build results in significantly worse performance.

Embedded Framework

Embedded frameworks require a minimum deployment target of iOS 8 or OS X Mavericks (10.9). Drag the CryptoSwift.xcodeproj file into your Xcode project, and add appropriate framework as a dependency to your target. Now select your App and choose the General tab for the app target. Find Embedded Binaries and press "+", then select CryptoSwift.framework (iOS, OS X, watchOS or tvOS)

Sometimes "embedded framework" option is not available. In that case, you have to add new build phase for the target

iOS, macOS, watchOS, tvOS

In the project, you'll find single scheme for all platforms:

  • CryptoSwift

Swift versions support

  • Swift 1.2: branch swift12 version <= 0.0.13
  • Swift 2.1: branch swift21 version <= 0.2.3
  • Swift 2.2, 2.3: branch swift2 version <= 0.5.2
  • Swift 3.1, branch swift3 version <= 0.6.9
  • Swift 3.2, branch swift32 version = 0.7.0
  • Swift 4.0, branch master version >= 0.7.1


You can use CocoaPods.

platform :ios, '8.0'

target 'MyApp' do
  pod 'CryptoSwift'

or for newest version from specified branch of code:

pod 'CryptoSwift', :git => "https://github.com/krzyzanowskim/CryptoSwift", :branch => "master"

Bear in mind that CocoaPods will build CryptoSwift without Whole-Module Optimization that my impact performance. You can change it manually after installation, or use cocoapods-wholemodule plugin.


You can use Carthage. Specify in Cartfile:

github "krzyzanowskim/CryptoSwift"

Run carthage to build the framework and drag the built CryptoSwift.framework into your Xcode project. Follow build instructions. Common issues.

Swift Package Manager

You can use Swift Package Manager and specify dependency in Package.swift by adding this:

dependencies: [
    .package(url: "https://github.com/krzyzanowskim/CryptoSwift.git", .upToNextMinor(from: "0.8.0"))

or more strict

dependencies: [
    .package(url: "https://github.com/krzyzanowskim/CryptoSwift.git", .exact("0.8.0"))

See: Package.swift - manual


also check Playground

import CryptoSwift

CryptoSwift uses array of bytes aka Array<UInt8> as a base type for all operations. Every data may be converted to a stream of bytes. You will find convenience functions that accept String or Data, and it will be internally converted to the array of bytes.

Data types conversion

For you convenience CryptoSwift provides two functions to easily convert array of bytes to Data and another way around:

Data from bytes:

let data = Data(bytes: [0x01, 0x02, 0x03])

Data to Array<UInt8>

let bytes = data.bytes                     // [1,2,3]

Hexadecimal encoding:

let bytes = Array<UInt8>(hex: "0x010203")  // [1,2,3]
let hex   = bytes.toHexString()            // "010203"

Build bytes out of String

let bytes: Array<UInt8> = "password".bytes  // Array("password".utf8)

Also... check out helpers that work with Base64 encoded data:

Calculate Digest

Hashing a data or array of bytes (aka Array<UInt8>)

/* Hash struct usage */
let bytes:Array<UInt8> = [0x01, 0x02, 0x03]
let digest = input.md5()
let digest = Digest.md5(bytes)
let data = Data(bytes: [0x01, 0x02, 0x03])

let hash = data.md5()
let hash = data.sha1()
let hash = data.sha224()
let hash = data.sha256()
let hash = data.sha384()
let hash = data.sha512()    
do {
    var digest = MD5()
    let partial1 = try digest.update(withBytes: [0x31, 0x32])
    let partial2 = try digest.update(withBytes: [0x33])
    let result = try digest.finish()
} catch { }

Hashing a String and printing result

let hash = "123".md5() // "123".bytes.md5()
Calculate CRC

Message authenticators
// Calculate Message Authentication Code (MAC) for message
let key:Array<UInt8> = [1,2,3,4,5,6,7,8,9,10,...]

try Poly1305(key: key).authenticate(bytes)
try HMAC(key: key, variant: .sha256).authenticate(bytes)
Password-Based Key Derivation Functions
let password: Array<UInt8> = Array("s33krit".utf8)
let salt: Array<UInt8> = Array("nacllcan".utf8)

try PKCS5.PBKDF2(password: password, salt: salt, iterations: 4096, variant: .sha256).calculate()
HMAC-based Key Derivation Function
let password: Array<UInt8> = Array("s33krit".utf8)
let salt: Array<UInt8> = Array("nacllcan".utf8)

try HKDF(password: password, salt: salt, variant: .sha256).calculate()
Data Padding

Some content-encryption algorithms assume the input length is a multiple of k octets, where k is greater than one. For such algorithms, the input shall be padded.

Padding.pkcs7.add(to: bytes, blockSize: AES.blockSize)

Working with Ciphers

let encrypted = try ChaCha20(key: key, iv: iv).encrypt(message)
let decrypted = try ChaCha20(key: key, iv: iv).decrypt(encrypted)
let encrypted = try Rabbit(key: key, iv: iv).encrypt(message)
let decrypted = try Rabbit(key: key, iv: iv).decrypt(encrypted)
let encrypted = try Blowfish(key: key, blockMode: .CBC(iv: iv), padding: .pkcs7).encrypt(message)
let decrypted = try Blowfish(key: key, blockMode: .CBC(iv: iv), padding: .pkcs7).decrypt(encrypted)

Notice regarding padding: Manual padding of data is optional, and CryptoSwift is using PKCS7 padding by default. If you need manually disable/enable padding, you can do this by setting parameter for AES class

Variant of AES encryption (AES-128, AES-192, AES-256) depends on given key length:

  • AES-128 = 16 bytes
  • AES-192 = 24 bytes
  • AES-256 = 32 bytes

AES-256 example

try AES(key: [1,2,3,...,32], blockMode: .CBC(iv: [1,2,3,...,16]), padding: .pkcs7)
All at once
do {
    let aes = try AES(key: "passwordpassword", iv: "drowssapdrowssap") // aes128
    let ciphertext = try aes.encrypt(Array("Nullam quis risus eget urna mollis ornare vel eu leo.".utf8))
} catch { }
Incremental updates

Incremental operations use instance of Cryptor and encrypt/decrypt one part at a time, this way you can save on memory for large files.

do {
    var encryptor = try AES(key: "passwordpassword", iv: "drowssapdrowssap").makeEncryptor()

    var ciphertext = Array<UInt8>()
    // aggregate partial results
    ciphertext += try encryptor.update(withBytes: Array("Nullam quis risus ".utf8))
    ciphertext += try encryptor.update(withBytes: Array("eget urna mollis ".utf8))
    ciphertext += try encryptor.update(withBytes: Array("ornare vel eu leo.".utf8))
    // finish at the end
    ciphertext += try encryptor.finish()

} catch {

See Playground for sample code that work with stream.

AES Advanced usage
let input: Array<UInt8> = [0,1,2,3,4,5,6,7,8,9]

let key: Array<UInt8> = [0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00]
let iv: Array<UInt8> = AES.randomIV(AES.blockSize)

do {
    let encrypted = try AES(key: key, blockMode: .CBC(iv: iv), padding: .pkcs7).encrypt(input)
    let decrypted = try AES(key: key, blockMode: .CBC(iv: iv), padding: .pkcs7).decrypt(encrypted)
} catch {

AES without data padding

let input: Array<UInt8> = [0,1,2,3,4,5,6,7,8,9]
let encrypted: Array<UInt8> = try! AES(key: Array("secret0key000000".utf8), blockMode: .CBC(iv: Array("0123456789012345".utf8)), padding: .noPadding).encrypt(input)

Using convenience extensions

let plain = Data(bytes: [0x01, 0x02, 0x03])
let encrypted = try! plain.encrypt(ChaCha20(key: key, iv: iv))
let decrypted = try! encrypted.decrypt(ChaCha20(key: key, iv: iv))


CryptoSwift is owned and maintained by Marcin Krzy┼╝anowski

You can follow me on Twitter at @krzyzanowskim for project updates and releases.


Copyright (C) 2014-2017 Marcin Krzy┼╝anowski marcin@krzyzanowskim.com This software is provided 'as-is', without any express or implied warranty.

In no event will the authors be held liable for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

  • The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation is required.
  • Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
  • This notice may not be removed or altered from any source or binary distribution.
  • Redistributions of any form whatsoever must retain the following acknowledgment: 'This product includes software developed by the "Marcin Krzyzanowski" (http://krzyzanowskim.com/).'




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0.8.2 - Feb 22, 2018

  • Fix SHA3 partial updates calculations.
  • Make ChaCha20 processing faster again.

0.8.3 - Feb 22, 2018

  • Fix SHA3 padding.
  • Fix Carthage builds.

0.8.1 - Jan 11, 2018

  • Adds Data(hex:) helper.
  • Adds HKDF (HMAC-based Extract-and-Expand Key Derivation Function)
  • Prevent ChaCha overflow error

0.8.0 - Oct 15, 2017

  • Adds SHA3 Keccak variants
  • Adds String.bytes helper to convert String to array of bytes
  • Improves AES performance
  • Speeds up compilation times with Swift 4
  • Fixes: Blowfish minimum key size is 5
  • Removes Ciphers "iv" parameter (value moved to BlockMode)
  • BlockMode uses associated value for IV value where apply e.g. .CBC(iv: ivbytes)
  • Refactors internal hacks no longer needed with Swift 4

0.7.1 - Sep 21, 2017


  • Swift 4.0 compatibility release