Zig Requires Chilkat v11.0.0+

Generate ECDSA Key and Get Details as XML

See more ECC Examples

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

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

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

    const ecc = try chilkat.Ecc.init();
    defer ecc.deinit();

    // 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.
    const fortuna = try chilkat.Prng.init();
    defer fortuna.deinit();
    const entropy = try fortuna.getEntropy(alloc, 32, "base64");
    try fortuna.addEntropy(entropy, "base64");

    const priv_key = try chilkat.PrivateKey.init();
    defer priv_key.deinit();
    ecc.genKey("secp256k1", fortuna, priv_key) catch {
        std.debug.print("{s}\n", .{try ecc.getLastErrorText(alloc)});
        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.)

    const asn = try chilkat.Asn.init();
    defer asn.deinit();
    asn.loadEncoded(try priv_key.getPkcs1ENC(alloc, "base64"), "base64") catch {
        std.debug.print("{s}\n", .{try asn.getLastErrorText(alloc)});
        return;
    };

    const xml = try chilkat.Xml.init();
    defer xml.deinit();
    xml.loadXml(try asn.asnToXml(alloc)) catch {};

    std.debug.print("{s}\n", .{try xml.getXml(alloc)});

    // 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.
    const crypt = try chilkat.Crypt2.init();
    defer crypt.deinit();
    const priv_key_hex = try crypt.reEncode(alloc, try xml.getChildContent(alloc, "octets"), "base64", "hex");

    std.debug.print("EC private key as hex = {s}\n", .{priv_key_hex});
}