Zig

Convert Java KeyStore to PKCS12 / PFX

See more Java KeyStore (JKS) Examples

Loads a Java keystore file and saves it as a PKCS12 / PFX. A Java keystore (JKS) can contain two types of entries: (1) trusted root certificates or (2) private keys + cert chains. Usually a JKS will contain all entries of one type or another (and thus a particular JKS serves one purpose or another; meaning that a JKS containing trusted roots is used as a source for verifying pre-trusted roots, and a JKS containing private keys (and cert chains) is used as a secure, encrypted store for private keys).

A PKCS12 / PFX typically contains one or more private keys, along with each private key's certificate chain. Therefore, it typically makes sense to only write the private key entries to a PKCS12 (and the associated certificate chains). If a JKS contains trusted root certificates, it makes more sense to conver it to a PEM file (such as the CA cert bundle in PEM format from mozilla.org).

Zig

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

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

    var success: bool = false;

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

    const jks = try chilkat.JavaKeyStore.init();
    defer jks.deinit();

    const jks_password = "myJksPassword";

    // Load the Java keystore from a file.  The JKS file password is used
    // to verify the keyed digest that is found at the very end of the keystore.
    // It verifies that the keystore has not been modified.
    success = if (jks.loadFile(jks_password, "/someDir/keyStore.jks")) true else |_| false;
    if (!success) {
        std.debug.print("{s}\n", .{try jks.getLastErrorText(alloc)});
        return;
    }

    // To convert, we'll access the private key entries
    // from the JKS, add each to the PKCS12, and then save the PKCS12.
    const pkcs12 = try chilkat.Pfx.init();
    defer pkcs12.deinit();

    const num_private_keys = jks.getNumPrivateKeys();
    var i: i32 = 0;

    // For each private key entry, get the private key and
    // the associated certificate chain.
    // Each private key is password protected.  Usually it is the same
    // password as used for the keyed digest of the entire JKS.
    // However, this does not have to be.  The password is passed
    // here to handle the possibility of each private key requiring
    // a different password.
    i = 0;
    while (i < num_private_keys) {
ERROR: Method not in the Zig package: JavaKeyStore.GetPrivateKey
ERROR: Method not in the Zig package: JavaKeyStore.GetPrivateKey
        const priv_key = jks.ERROR();
        std.debug.print("{s}\n", .{try jks.getPrivateKeyAlias(alloc, i)});
ERROR: Method not in the Zig package: JavaKeyStore.GetCertChain
ERROR: Method not in the Zig package: JavaKeyStore.GetCertChain
        const cert_chain = jks.ERROR();

        // Add the private key and it's associated certificate chain to the PKCS12.
        success = if (pkcs12.addPrivateKey(priv_key, cert_chain)) true else |_| false;
        if (!success) {
            std.debug.print("{s}\n", .{try pkcs12.getLastErrorText(alloc)});

            return;
        }

        i = i + 1;
    }

    // Save the PKCS12 / PFX to a file.
    // The password can be the same as the JKS password, or something new.
    // (With the PKCS12 format, there is a single password for the entire contents
    // of the file.  With the JKS format, there is flexibility in allowing each private key
    // to have it's own password.)
    const pkcs12_password = "myNewPassword";
    success = if (pkcs12.toFile(pkcs12_password, "/pkcs12_files/myPfx.p12")) true else |_| false;
    if (!success) {
        std.debug.print("{s}\n", .{try pkcs12.getLastErrorText(alloc)});
    } else {
        std.debug.print("Successfully saved to PKCS12 format.\n", .{});
    }
}