(Swift 3,4,5...) RSA Encrypt Hash using SHA256 hash function and SHA1 mask function

Note: This example requires a feature introduced in Chilkat v9.5.0.66

How can this Javascript be duplicated using Chilkat?

function a(e, t) {
                var r = s.pki.publicKeyFromPem(e)
                  , n = r.encrypt(t, "RSA-OAEP", {
                    md: s.md.sha256.create(),
                    mgf1: {
                        md: s.md.sha1.create()
                    }
                });
                return s.util.encode64(n)
            }

Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens, even using the same data and key, the result will be different -- but still valid. One should not expect to get the same output.

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

func chilkatTest() {
    // Note: This example requires a feature introduced in Chilkat v9.5.0.66

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    let pubkey = CkoPublicKey()!

    let sbPem = CkoStringBuilder()!
    var bCrlf: Bool = true
    sbPem.appendLine("-----BEGIN PUBLIC KEY-----", crlf: bCrlf)
    sbPem.appendLine("MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF", crlf: bCrlf)
    sbPem.appendLine("3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA", crlf: bCrlf)
    sbPem.appendLine("04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s", crlf: bCrlf)
    sbPem.appendLine("Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF", crlf: bCrlf)
    sbPem.appendLine("wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE", crlf: bCrlf)
    sbPem.appendLine("f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W", crlf: bCrlf)
    sbPem.appendLine("SwIDAQAB", crlf: bCrlf)
    sbPem.appendLine("-----END PUBLIC KEY-----", crlf: bCrlf)

    // Load the public key object from the PEM. 
    var success: Bool = pubkey.load(from: sbPem.getAsString())
    if success != true {
        print("\(pubkey.lastErrorText!)")
        return
    }

    var originalData: String? = "This is the original data to be SHA-256 hashed and RSA encrypted."

    // First we SHA-256 hash the original data to get the hash in base64 format:
    let crypt = CkoCrypt2()!
    crypt.hashAlgorithm = "SHA-256"
    crypt.encodingMode = "base64"
    var hashBase64: String? = crypt.hashStringENC(originalData)

    // Setup RSA to use OAEP padding with SHA-1 for the mask function.
    let rsa = CkoRsa()!
    rsa.oaepPadding = true
    rsa.oaepHash = "SHA1"
    rsa.importPublicKeyObj(pubkey)
    rsa.encodingMode = "base64"

    // Starting in v9.5.0.66, we can provide a binary encoding mode, such as "base64", "hex", "base64url", etc.
    // for the Charset property.   The Charset property was previously limited to character encodings, such as
    // "utf-8", "iso-8859-1", etc.  If a binary encoding is used, then the string passed in is decoded to the binary
    // bytes as indicated.  (If an actual charset, such as "utf-8" is used, then the input string is converted to the
    // byte representation of the charset, and then encrypted.)

    // Given that a hash is composed of non-text binary bytes, we'll set the Charset property equal to "base64" 
    // (because we have the base64 hash from above).
    rsa.charset = "base64"

    // Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens,
    // even using the same data and key, the result will be different --  but still valid.  One should not expect
    // to get the same output.
    var bUsePrivateKey: Bool = false
    var encryptedStr: String? = rsa.encryptStringENC(hashBase64, bUsePrivateKey: bUsePrivateKey)
    if rsa.lastMethodSuccess != true {
        print("\(rsa.lastErrorText!)")
        return
    }

    print("Base64 RSA encrypted output: \(encryptedStr!)")

}