Zig Requires Chilkat v11.0.0+

Convert RSA Private Key to Public Key

See more RSA Examples

Demonstrates how to get a public RSA key from a private RSA key. Zig

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

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

    const priv_key = try chilkat.PrivateKey.init();
    defer priv_key.deinit();

    // Step 1: Load the private key from a source.
    // (Chilkat can load private keys from all types of formats, and from in-memory bytes or encoded strings.
    // see the online reference documentation for more options.)
    priv_key.loadPemFile("qa_data/pem/VP_Private.pem") catch {
        std.debug.print("{s}\n", .{try priv_key.getLastErrorText(alloc)});
        return;
    };

    // Step 2: Get the public key object from the private key object.
    const pub_key = try chilkat.PublicKey.init();
    defer pub_key.deinit();
    priv_key.toPublicKey(pub_key) catch {};

    // Step 3: Save the public key in a desired format.
    // (Chilkat can load or save public and private keys in many different formats.  See
    // the online reference documentation for more options.)

    // Saves to a PKCS8 PEM file.
    const b_prefer_pkcs1 = false;
    pub_key.savePemFile(b_prefer_pkcs1, "qa_data/pem/VP_Public.pem") catch {
        std.debug.print("{s}\n", .{try pub_key.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("Extracted and saved public key from private key.\n", .{});
}