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)
DiffieHellman 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")
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:

Make sure CocoaPods is installed.

Update your Podfile to include the following:
pod 'SwCrypt'

Run
pod install
.
Swift Package Manager
SPM is built into new versions of Xcode. To install SwCrypt with SPM:

Open your project in Xcode

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

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

Click "Next" > "Next" > "Finish"
Inspired from
 http://blog.flirble.org/2011/01/05/rsapublickeyopensslios/
 https://github.com/lancy/RSADemo
 https://github.com/TakeScoop/SwiftyRSA
 https://github.com/henrinormak/Heimdall
 https://github.com/btnguyen2k/swiftrsautils
License
This project is copyrighted under the MIT license.