(Go) Get Public Key from CSR

Demonstrates how to get the public key from a CSR.

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

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

    pem := chilkat.NewPem()

    // No password is required.  Pass an empty password string..
    noPassword := ""
    success := pem.LoadPemFile("qa_data/csr/csr2.pem",noPassword)
    if success != true {
        fmt.Println(pem.LastErrorText())
        pem.DisposePem()
        return
    }

    strBase64 := pem.GetEncodedItem("csr","","base64",0)

    asn := chilkat.NewAsn()
    success = asn.LoadEncoded(*strBase64,"base64")
    if success != true {
        fmt.Println(asn.LastErrorText())
        pem.DisposePem()
        asn.DisposeAsn()
        return
    }

    // Convert the ASN.1 to XML.
    xml := chilkat.NewXml()
    success = xml.LoadXml(*asn.AsnToXml())
    fmt.Println(*xml.GetXml())
    fmt.Println("----")

    strModulusHex := xml.GetChildContent("bits")
    fmt.Println("strModulusHex = ", *strModulusHex)
    fmt.Println("----")

    // We need the modulus as base64.
    bd := chilkat.NewBinData()
    bd.AppendEncoded(*strModulusHex,"hex")
    modulus64 := bd.GetEncoded("base64")
    fmt.Println("modulus64 = ", *modulus64)
    fmt.Println("----")

    // Build the XML for the public key.
    xmlPubKey := chilkat.NewXml()
    xmlPubKey.SetTag("RSAPublicKey")
    xmlPubKey.UpdateChildContent("Modulus",*modulus64)
    // The RSA exponent will always be decimal 65537 (base64 = AQAB)
    xmlPubKey.UpdateChildContent("Exponent","AQAB")

    fmt.Println("RSA public key as XML:")
    fmt.Println(*xmlPubKey.GetXml())
    fmt.Println("----")

    // Load the XML into a Chilkat public key object.
    pubkey := chilkat.NewPublicKey()
    success = pubkey.LoadFromString(*xmlPubKey.GetXml())
    if success != true {
        fmt.Println(pubkey.LastErrorText())
        pem.DisposePem()
        asn.DisposeAsn()
        xml.DisposeXml()
        bd.DisposeBinData()
        xmlPubKey.DisposeXml()
        pubkey.DisposePublicKey()
        return
    }

    // Show the public key as PEM.
    preferPkcs1 := true
    fmt.Println(*pubkey.GetPem(preferPkcs1))

    pem.DisposePem()
    asn.DisposeAsn()
    xml.DisposeXml()
    bd.DisposeBinData()
    xmlPubKey.DisposeXml()
    pubkey.DisposePublicKey()