(Swift 3,4,5...) Compute JWK Thumbprint for RSA and EC Private Keys

Demonstrates how to compute a JSON Web Key thumbprint for a private key (RSA or ECC).

Note: This example requires Chilkat v9.5.0.66 or greater.

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func chilkatTest() {
    let privKey = CkoPrivateKey()!

    // A private key can be loaded from any format (binary DER, PEM, etc.)
    // This example will load the private keys from PEM format, 
    // and will then compute the JWK thumbprint.

    // First do it for this RSA private key...

    let sbPem = CkoStringBuilder()!
    var bCrlf: Bool = true
    sbPem.appendLine("-----BEGIN RSA PRIVATE KEY-----", crlf: bCrlf)
    sbPem.appendLine("Proc-Type: 4,ENCRYPTED", crlf: bCrlf)
    sbPem.appendLine("DEK-Info: DES-EDE3-CBC,2E65118E6C7B5207", crlf: bCrlf)
    sbPem.appendLine("", crlf: bCrlf)
    sbPem.appendLine("7cYUTW4ZBdmVZ4ILB08hcTdm5ib0E0zcy+I7pHpNQfJHtI7BJ4omys5S19ufJPBJ", crlf: bCrlf)
    sbPem.appendLine("IzYjeO7oTVqI37F6EUmjZqG4WVE2UQbQDkosZbZN82O4Ipu1lFAPEbwjqePMKufz", crlf: bCrlf)
    sbPem.appendLine("snSQHKfnbyyDPEVNlJbs19NXC8v6g+pQay5rH/I6N2iBxgsTmuemZ54EhNQMZyEN", crlf: bCrlf)
    sbPem.appendLine("R/CiheArWEH9H8/4hd2gc9Tb2s0MwGHILL4kbbNm5tp3xw4ik7OYWNrj3m+nG6Xb", crlf: bCrlf)
    sbPem.appendLine("vKXh2xEanAZAyMXTqDJTHdn7/CEqusQPJjZGV+Mf1kjKu7p4qcXFnIXP5ILnTW7b", crlf: bCrlf)
    sbPem.appendLine("lHoWC4eweDzKOMRzXmbABEVSUvx2SmPl4TcoC5L1SCAHEmZaKbaY7S5l53u6gl0f", crlf: bCrlf)
    sbPem.appendLine("ULuQbt7Hr3THznlNFKkGT1/yVNt2QOm1emZd55LaNe8E7XsNSlhl0grYQ+Ue8Jba", crlf: bCrlf)
    sbPem.appendLine("x85OapltVjxM9wVCwbgFyi04ihdKHo9e+uYKeTGKv0hU5O7HEH1ev6t/s2u/UG6h", crlf: bCrlf)
    sbPem.appendLine("TqEsYrVp0CMHpt5uAF6nZyK6GZ/CHTxh/rz1hADMofem59+e6tVtjnPGA3EjnJT8", crlf: bCrlf)
    sbPem.appendLine("BMOw/D2QIDxjxj2GUzz+YJp50ENhWrL9oSDkG2nzv4NVL77QIy+T/2/f4PgokUDO", crlf: bCrlf)
    sbPem.appendLine("QJjIfxPWE40cHGHpnQtZvEPoxP0H3T0YhmEVwuJxX3uaWOY/8Fa1c7Ln0SwWdfV5", crlf: bCrlf)
    sbPem.appendLine("gYvJV8o6c3sumcq1O3agPDlHC5O4IxG7AZQ8CHRDyASogzfkY6P579ZOGYaO4al7", crlf: bCrlf)
    sbPem.appendLine("WA1YIpsHs3/1f4SByMuWe0NVkFfvXckjpqGrBQpTmqQzk6baa0VQ0cwU3XlkwHac", crlf: bCrlf)
    sbPem.appendLine("WB/fQ4jylwFzZDcp5JAo53n6aU72zgNvDlGTNKwdXXZI5U3JPocH0AiZgFFWYJLd", crlf: bCrlf)
    sbPem.appendLine("63PJLDnjyE3i6XMVlxifXKkXVv0RYSz+ByS7Oz9aCgnQhNU8ycv+UxtfkPQih5zE", crlf: bCrlf)
    sbPem.appendLine("/0Y2EEFknajmFJpNXczzF8OEzaswmR0AOjcCiklZKRf61rf5faJxJhhqKEEBJuL6", crlf: bCrlf)
    sbPem.appendLine("oodDVRk3OGU1yQSBazT8nK3V+e6FMo3tWkra2BXFCD+pKxTy014Cp59S1w6F1Fjt", crlf: bCrlf)
    sbPem.appendLine("WX7eMWSLWfQ56j2kLMBHq5gb2arqlqH3fsYOTD3TNjCYF3Sgx309kVPuOK5vw61P", crlf: bCrlf)
    sbPem.appendLine("pnL/LN3iGY42WR+9lfAyNN2qj9zvwKwscyYs5+DPQoPmcPcVGc3v/u66bLcOGbEU", crlf: bCrlf)
    sbPem.appendLine("OlGa/6gdD4GCp5E4fP/7GbnEY/PW2abquFhGB+pVdl3/4+1U/8kItlfWNZoG4FhE", crlf: bCrlf)
    sbPem.appendLine("gjMd7glmrdFiNJFFpf5ks1lVXGqJ4mZxqtEZrxUEwciZjm4V27a+E2KyV9NnksZ6", crlf: bCrlf)
    sbPem.appendLine("xF4tGPKIPsvNTV5o8ZqjiacxgbYmr2ywqDXKCgpU/RWSh1sLapqSQqbH/w0MquUj", crlf: bCrlf)
    sbPem.appendLine("VhVX0RMYH/foKtjagZf/KO1/mnCITl86treIdachGgR4wr/qqMjrpPUaPLCRY3JQ", crlf: bCrlf)
    sbPem.appendLine("00XUP1Mu6YPE0SnMYAVxZheqKHly3a1pg4Xp7YWlM671oUORs3+VENfnbIxgr+2D", crlf: bCrlf)
    sbPem.appendLine("TiJT9PxwpfK53Oh7RBSWHJZRuAdLUXE8DG+bl0N/QkJM6pFUxTI1AQ==", crlf: bCrlf)
    sbPem.appendLine("-----END RSA PRIVATE KEY-----", crlf: bCrlf)

    // The actual password for the above PEM is "passwd".
    var success: Bool = privKey.loadEncryptedPem(sbPem.getAsString(), password: "passwd")
    if success != true {
        print("\(privKey.lastErrorText!)")
        return
    }

    // Generate the JWK thumbprint:
    print("JWK thumbprint: \(privKey.getJwkThumbprint("SHA256")!)")

    // Output:
    // JWK thumbprint: QzUpUAW1Y5iksGxq3r1o3JMROR6D7FLwvRlHmDQVg0I

    // --------------------------------------------------------------
    // Now let's do an EC private key.  The following is an unencrypted PEM containing a 384-bit EC key..
    sbPem.clear()
    sbPem.appendLine("-----BEGIN PRIVATE KEY-----", crlf: bCrlf)
    sbPem.appendLine("MIG2AgEAMBAGByqGSM49AgEGBSuBBAAiBIGeMIGbAgEBBDAamStb0Xep3y3sWw2u", crlf: bCrlf)
    sbPem.appendLine("SSAdUPkgQ9Rvhlnx8XEVOYy2teh69T0on77ja02m03n8t8WhZANiAARUNSar38Rz", crlf: bCrlf)
    sbPem.appendLine("lKPyZFsNSGUanzpNRth0C+MikVEH8FAlDHMMpAs34dyF4IK0uxgbiEe9bQ+ieLrl", crlf: bCrlf)
    sbPem.appendLine("6xwFR0yaTivuwoyXC+ScGUnwnpaXmid6UUgw4ypbneHsaKuZ9JLdMAo=", crlf: bCrlf)
    sbPem.appendLine("-----END PRIVATE KEY-----", crlf: bCrlf)

    success = privKey.loadPem(sbPem.getAsString())
    if success != true {
        print("\(privKey.lastErrorText!)")
        return
    }

    // Generate the JWK thumbprint:
    print("JWK thumbprint: \(privKey.getJwkThumbprint("SHA256")!)")

    // Output:
    // JWK thumbprint: ABAUUfNSONFsZYvZ_o_0bsPT3qeG3jttXB09VC_ETWQ

}