(Swift) Generate ECDSA Key and Get Details as XML

Demonstrates how to generate an ECC key and gets the parts as XML.

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

func chilkatTest() {
    //  This requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    let ecc = CkoEcc()

    //  Generate a random ECC private key on the secp256k1 curve.
    //  Chilkat also supports other curves, such as secp384r1, secp521r1, and secp256r1.

    //  Create a Fortuna PRNG and seed it with system entropy.
    //  This will be our source of random data for generating the ECC private key.
    let fortuna = CkoPrng()
    var entropy: String? = fortuna.GetEntropy(32, encoding: "base64")
    var success: Bool = fortuna.AddEntropy(entropy, encoding: "base64")

    var privKey: CkoPrivateKey? = ecc.GenEccKey("secp256k1", prng: fortuna)
    if ecc.LastMethodSuccess != true {
        print("\(ecc.LastErrorText)")
        return
    }

    //  An EC private key has this ASN.1
    //  ECPrivateKey ::= SEQUENCE {
    //      version        INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
    //      privateKey     OCTET STRING,
    //      parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
    //      publicKey  [1] BIT STRING OPTIONAL (This is the ANSI X9.63 public key format.)

    let asn = CkoAsn()
    success = asn.LoadEncoded(privKey!.GetPkcs1ENC("base64"), encoding: "base64")
    if success != true {
        print("\(asn.LastErrorText)")
        return
    }

    let xml = CkoXml()
    xml.LoadXml(asn.AsnToXml())

    print("\(xml.GetXml())")

    //  The XML looks like this:
    //  <?xml version="1.0" encoding="utf-8" ?>
    //  <sequence>
    //      <int>01</int>
    //      <octets>JgJvBG+3wletkJab8iXAkpz0O8/AgWZSpkYVcB7SpnU=</octets>
    //      <contextSpecific tag="0" constructed="1">
    //          <oid>1.3.132.0.10</oid>
    //      </contextSpecific>
    //  </sequence>

    //  The 32-byte private key is in the octets..
    //  Get it as hex.
    let crypt = CkoCrypt2()
    var privKeyHex: String? = crypt.ReEncode(xml.GetChildContent("octets"), fromEncoding: "base64", toEncoding: "hex")

    print("EC private key as hex = \(privKeyHex!)")

    privKey = nil

}