Zig Requires Chilkat v11.0.0+

Duplicate openssl pkey -in private.pem -pubout -out pubkey.pem

See more OpenSSL Examples

How to output the public part of a private key: Demonstrates how to duplicate this OpenSSL command:

openssl pkey -in private.pem -pubout -out pubkey.pem

Zig

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

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

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

    // Load the private key from an PEM file:
    pkey.loadPemFile("private.pem") catch {
        std.debug.print("{s}\n", .{try pkey.getLastErrorText(alloc)});
        return;
    };

    const pub_key = try chilkat.PublicKey.init();
    defer pub_key.deinit();
    pkey.toPublicKey(pub_key) catch {};

    pub_key.savePemFile(false, "pubKey.pem") catch {
        std.debug.print("{s}\n", .{try pub_key.getLastErrorText(alloc)});

        return;
    };

    std.debug.print("Success.\n", .{});
}