SwCrypt

RSA public/private key generation, RSA, AES encryption/decryption, RSA sign/verify in Swift with CommonCrypto in iOS and OS X

Code Quality Rank: L3

Programming language: Swift

License: MIT License

Tags: Security    

Latest version: v5.1.4

README

SwCrypt

Create public and private RSA keys in DER format

let (privateKey, publicKey) = try! CC.RSA.generateKeyPair(2048)

Convert them to PEM format

let privateKeyPEM = try SwKeyConvert.PrivateKey.derToPKCS1PEM(privateKey)
let publicKeyPEM = SwKeyConvert.PublicKey.derToPKCS8PEM(publicKey)

Or read them from strings with PEM data

let privateKeyDER = SwKeyConvert.PrivateKey.pemToPKCS1DER(privateKeyPEM)
let publicKeyDER = SwKeyConvert.PublicKey.pemToPKCS1DER(publicKeyPEM)

Or encrypt, decrypt the private key (OpenSSL compatible)

try SwKeyConvert.PrivateKey.encryptPEM(privateKeyPEM, passphrase: "longpassword", mode: .aes256CBC)
try SwKeyConvert.PrivateKey.decryptPEM(privEncrypted, passphrase: "longpassword")

Get public key from private keys in DER format

let publicKeyDER = try? CC.RSA.getPublicKeyFromPrivateKey(privateKeyDER!)

Encrypt, decrypt data with RSA

try CC.RSA.encrypt(data, derKey: publicKey, tag: tag, padding: .oaep, digest: .sha1)
try CC.RSA.decrypt(data, derKey: privateKey, tag: tag, padding: .oaep, digest: .sha1)

Sign, verify data with RSA

let sign = try? CC.RSA.sign(testMessage, derKey: privKey, padding: .pss, 
 digest: .sha256, saltLen: 16)
let verified = try? CC.RSA.verify(testMessage, derKey: pubKey, padding: .pss,
 digest: .sha256, saltLen: 16, signedData: sign!)

Elliptic curve functions

let keys = try? CC.EC.generateKeyPair(384)
let signed = try? CC.EC.signHash(keys!.0, hash: hash)
let verified = try? CC.EC.verifyHash(keys!.1, hash: hash, signedData: signed!)

let shared = try? CC.EC.computeSharedSecret(keys!.0, publicKey: partnerPubKey)

let privComponents = try? CC.EC.getPrivateKeyComponents(keys!.0)
let pubComponents = try? CC.EC.getPublicKeyComponents(keys!.1)

let pubKey = try? CC.EC.createFromData(keySize, x, y)
let pubKey = try? CC.EC.getPublicKeyFromPrivateKey(keys!.0)

Diffie-Hellman functions

let dh = try CC.DH.DH(dhParam: .rfc3526Group5)
let myPubKey = try dh.generateKey()
let commonKey = try dh.computeKey(partnerPubKey!)

Encrypt, decrypt data with symmetric ciphers

try CC.crypt(.encrypt, blockMode: .cbc, algorithm: .aes, padding: .pkcs7Padding, data: data, key: aesKey, iv: iv)
try CC.crypt(.decrypt, blockMode: .cfb, algorithm: .aes, padding: .pkcs7Padding, data: data, key: aesKey, iv: iv)

Encrypt, decrypt data with symmetric authenticating ciphers

try CC.cryptAuth(.encrypt, blockMode: .gcm, algorithm: .aes, data: data, aData: aData, key: aesKey, iv: iv, tagLength: tagLength)
try CC.cryptAuth(.decrypt, blockMode: .ccm, algorithm: .aes, data: data, aData: aData, key: aesKey, iv: iv, tagLength: tagLength)

Digest functions

CC.digest(data, alg: .md5)
CC.digest(data, alg: .sha256)
CC.digest(data, alg: .sha512)

HMAC function

CC.HMAC(data, alg: .sha512, key: key)

CMAC function

CC.CMAC.AESCMAC(input, key: key)

CRC function

let output = try? CC.CRC.crc(input, mode: .crc32)

KeyDerivation

CC.KeyDerivation.PBKDF2(password, salt: salt, prf: .sha256, rounds: 4096)

Symmetric Key Wrapping

try CC.KeyWrap.SymmetricKeyWrap(CC.KeyWrap.rfc3394IV, kek: kek, rawKey: rawKey)
try CC.KeyWrap.SymmetricKeyUnwrap(CC.KeyWrap.rfc3394IV, kek: kek, wrappedKey: wrappedKey)

Upsert, get, delete keys from KeyStore

try SwKeyStore.upsertKey(privateKeyPEM, keyTag: "priv", options: [kSecAttrAccessible:kSecAttrAccessibleWhenUnlockedThisDeviceOnly])
try SwKeyStore.getKey("priv")
try SwKeyStore.delKey("priv")

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Check availability

SwCrypt uses dlopen and dlsym to load the CommonCrypto's functions, because not all of them are available in public header files. You have to check the availability before using them.

let digestAvailable : Bool = CC.digestAvailable()
let ramdomAvailable : Bool = CC.randomAvailable(()
let hmacAvailable : Bool = CC.hmacAvailable()
let cryptorAvailable : Bool = CC.cryptorAvailable
let keyDerivationAvailable : Bool = CC.KeyDerivation.available()
let keyWrapAvailable : Bool = CC.KeyWrap.available()
let rsaAvailable : Bool = CC.RSA.available()
let dhAvailable : Bool = CC.DH.available()
let ecAvailable : Bool = CC.EC.available()
let crcAvailable : Bool = CC.CRC.available()
let cmacAvailable : Bool = CC.CMAC.available()
let gcmAvailable : Bool = CC.GCM.available()
let ccmAvailable : Bool = CC.CCM.available()

or all in one turn:
let ccAvailable : Bool = CC.available()

Install

Just copy SwCrypt.swift to your project or use the Carthage dependency manager.

CocoaPods

CocoaPods is a dependency manager for Cocoa projects. To install SwCrypt with CocoaPods:

1. Make sure CocoaPods is installed.

2. Update your Podfile to include the following:

   pod 'SwCrypt'
   

3. Run pod install.

Swift Package Manager

SPM is built into new versions of Xcode. To install SwCrypt with SPM:

1. Open your project in Xcode

2. Click "File" -> "Swift Packages" -> "Add Package Dependency..."

3. Paste the following URL: https://github.com/soyersoyer/SwCrypt

4. Click "Next" -> "Next" -> "Finish"

Inspired from

• http://blog.flirble.org/2011/01/05/rsa-public-key-openssl-ios/
• https://github.com/lancy/RSADemo
• https://github.com/TakeScoop/SwiftyRSA
• https://github.com/henrinormak/Heimdall
• https://github.com/btnguyen2k/swift-rsautils

License

This project is copyrighted under the MIT license.