(Swift) RSA Sign an Encoded Hash

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Demonstrates signing a hash (e.g., SHA256) provided as an encoded string (e.g., base64 or hex).

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 the private key for this cert: \(cert.subjectCN!)")

    // Create data to be hashed and signed.
    let bd = CkoBinData()!
    var i: Int
    for i = 0; i <= 100; i++ {
        bd.appendEncoded("000102030405060708090A0B0C0D0E0F", encoding: "hex")
    }

    let rsa = CkoRsa()!

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

    // We'll first compute the hash and then pass the encoded hash to be signed.
    var sha256_base64: String? = bd.getHash("sha256", encoding: "base64")
    print("sha256 hash in base64 format: \(sha256_base64!)")

    // Pass in the base64 hash and return a base64 signature.
    rsa.encodingMode = "base64"
    var rsaSig_base64: String? = rsa.signHashENC(sha256_base64, hashAlg: "sha256")
    if success == false {
        print("\(rsa.lastErrorText!)")
        return
    }

    print("RSA signature as base64: \(rsaSig_base64!)")

}