Zig Requires Chilkat v11.0.0+

POP3 Read S/MIME Encrypted Email

Read S/MIME encrypted email. Zig

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

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

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

    // The mailman object is used for receiving (POP3)
    // and sending (SMTP) email.
    const mailman = try chilkat.MailMan.init();
    defer mailman.deinit();

    // Set the POP3 server's hostname
    mailman.setMailHost("pop.example.com");

    // Set the POP3 login/password.
    mailman.setPopUsername("myLogin");
    mailman.setPopPassword("myPassword");

    // If running on Microsoft Windows, the Chilkat mailman
    // will automatically search the registry-based certificate stores
    // for matching certificates and private keys required for
    // decryption.  However, on Linux, MAX OS X, and other
    // operating systems, no such thing exists.  Therefore, you'll
    // need to specify one or more PFX (.p12 / .pfx) files as
    // sources for locating the certs required for decyrption.
    mailman.addPfxSourceFile("/pfxFiles/certs_and_keys_1.pfx", "pfxPassword1") catch {
        std.debug.print("{s}\n", .{try mailman.getLastErrorText(alloc)});
        return;
    };

    mailman.addPfxSourceFile("/pfxFiles/certs_and_keys_2.pfx", "pfxPassword2") catch {
        std.debug.print("{s}\n", .{try mailman.getLastErrorText(alloc)});
        return;
    };

    // ...
    // Note: On MS Windows, it is not required to provide PFX sources
    // if the needed certs and private keys are already installed
    // on the system (in the registry-based certificate stores).

    // Copy the all email from the user's POP3 mailbox
    // into a bundle object.  The email remains on the server.
    const bundle = try chilkat.EmailBundle.init();
    defer bundle.deinit();
    const keep_on_server = true;
    const headers_only = false;
    // Irrelevent because we are NOT downloading headers-only
    const num_body_lines = 0;
    mailman.fetchAll(keep_on_server, headers_only, num_body_lines, bundle) catch {
        std.debug.print("{s}\n", .{try mailman.getLastErrorText(alloc)});
        return;
    };

    // S/MIME security envelopes are automatically "unwrapped"
    // when a message is retrieved from the server. Signed emails are automatically verified, and
    // encrypted emails are automatically decrypted, restoring the email to the original state before
    // signing and/or encrypting. Information about the signing and encrypting certificates can be
    // retrieved from the Email object (methods: GetSignedByCert, GetEncryptedByCert;
    // properties: SignedBy, EncryptedBy, SignaturesValid, Decrypted, ReceivedSigned,
    // ReceivedEncrypted).

    // Loop over the bundle
    const email = try chilkat.Email.init();
    defer email.deinit();
    var i: i32 = 0;
    while (i < bundle.getMessageCount()) {
        bundle.emailAt(i, email) catch {};

        std.debug.print("{s}\n", .{try email.getFrom(alloc)});
        std.debug.print("{s}\n", .{try email.getSubject(alloc)});

        // At this point, if the email was signed and/or encrypted, it is already "unwrapped", i.e.
        // the email is already decrypted and in a state as if it were never signed or encrypted.
        // You may check to see if the email was received encrypted or signed, and if so,
        // whether it was successfully unwrapped and who signed or encrypted it:
        if (email.getReceivedEncrypted()) {
            std.debug.print("This email was encrypted when received.\n", .{});
            if (email.getDecrypted()) {
                std.debug.print("This email was successfully decrypted.  It was encrypted by:\n", .{});
                std.debug.print("{s}\n", .{try email.getEncryptedBy(alloc)});
            } else {
                std.debug.print("This email was not decrypted.\n", .{});
            }
        }

        if (email.getReceivedSigned()) {
            std.debug.print("This email was signed when received.\n", .{});
            if (email.getSignaturesValid()) {
                std.debug.print("The signature was verified.  It was signed by:\n", .{});
                std.debug.print("{s}\n", .{try email.getSignedBy(alloc)});
            } else {
                std.debug.print("The signature verification failed.\n", .{});
            }
        }

        // The email's body, HTML body, attachments, etc.
        // are decrypted and available just like any non-encrypted email.

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

        i = i + 1;
    }
}