(Swift 3,4,5...) RSA Encrypt RSA/ECB/OAEPWithSHA1AndMGF1Padding

Demonstrates how to RSA encrypt using RSA/ECB/OAEPWithSHA1AndMGF1Padding. Also demonstrates RSA/ECB/OAEPWithSHA-256AndMGF1Padding. Both of these terms are from Java's JCE. Note: In this context, "ECB" doesn't actually mean anything. It's a symmetric cipher mode that doesn't apply (or make sense) in this context.

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    let rsa = CkoRsa()!

    // First load a public key object with a public key.
    // In this case, we'll load it from a file.
    let pubkey = CkoPublicKey()!
    var success: Bool = pubkey.load(fromFile: "qa_data/pem/rsa_public.pem")
    if success != true {
        print("\(pubkey.lastErrorText!)")
        return
    }

    // RSA encryption is limited to small amounts of data. The limit
    // is typically a few hundred bytes and is based on the key size and
    // padding (OAEP vs. PKCS1_5).  RSA encryption is typically used for
    // encrypting hashes or symmetric (bulk encryption algorithm) secret keys.
    var plainText: String? = "Time is an illusion. Lunchtime doubly so."

    // Import the public key to be used for encrypting.
    success = rsa.importPublicKeyObj(pubkey)

    // To get OAEP padding, set the OaepPadding property:
    rsa.oaepPadding = true

    // To use SHA1 or SHA-256, set the OaepHash property
    rsa.oaepHash = "sha256"
    // for SHA1 --
    rsa.oaepHash = "sha1"

    // Indicate we'll want hex output
    rsa.encodingMode = "hex"

    // Encrypt..
    var usePrivateKey: Bool = false
    var encryptedStr: String? = rsa.encryptStringENC(plainText, bUsePrivateKey: usePrivateKey)
    print("\(encryptedStr!)")

    // -------------------------------------------------
    // Now decrypt with the matching private key.
    let rsa2 = CkoRsa()!

    let privKey = CkoPrivateKey()!
    success = privKey.loadEncryptedPem("qa_data/pem/rsa_passwd.pem", password: "passwd")
    if success != true {
        print("\(privKey.lastErrorText!)")
        return
    }

    success = rsa2.importPrivateKeyObj(privKey)

    // Make sure we have the same settings used for encryption.
    rsa2.oaepPadding = true
    rsa2.encodingMode = "hex"
    rsa2.oaepHash = "sha1"

    var originalStr: String? = rsa2.decryptStringENC(encryptedStr, bUsePrivateKey: true)

    print("\(originalStr!)")

}