(Swift) RSA Sign utf-8 Bytes of String to get Base64 RSA Signature

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Demonstrates how RSA sign the utf-8 byte representation of a string to get the signature in base64 format.

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

func chilkatTest() {
    // Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
    // this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

    // Chilkat automatically detects and determines the way in which the HSM is used,
    // which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

    let cert = CkoCert()!

    // Set the token/smartcard PIN prior to loading.
    cert.smartCardPin = "123456"

    // Specify the certificate by its common name.
    var success: Bool = cert.load(fromSmartcard: "cn=chilkat-rsa-2048")
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    print("Signing with cert: \(cert.subjectCN!)")

    // Create a string to be hashed and signed.
    let sb = CkoStringBuilder()!
    var crlfLineEnding: Bool = true
    var i: Int
    for i = 0; i <= 10; i++ {
        sb.appendLine("This is a test.", crlf: crlfLineEnding)
    }

    let rsa = CkoRsa()!

    // Use the certificate's private key for signing.
    success = rsa.setX509Cert(cert, usePrivateKey: true)
    if success == false {
        print("\(rsa.lastErrorText!)")
        return
    }

    // Sign the SHA-256 hash of the utf-8 byte representation of the contents of sb
    // Return the signature in base64 format.
    rsa.encodingMode = "base64"
    rsa.charset = "utf-8"
    var stringToSign: String? = sb.getAsString()
    var sigBase64: String? = rsa.signStringENC(stringToSign, hashAlg: "sha256")
    if rsa.lastMethodSuccess == false {
        print("\(rsa.lastErrorText!)")
        return
    }

    print("RSA signature as base64: \(sigBase64!)")

}