Zig Requires Chilkat v11.0.0+

IMAP Download and Verify Signed MIME

See more IMAP Examples

Downloads the original MIME of a digitally signed email and saves the .p7s signature along with other MIME parts. It then imports the email into a Chilkat email object to unwrap the S/MIME and verify the signature, and subsequently saves the attachments if they haven't been saved already. 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 example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    const imap = try chilkat.Imap.init();
    defer imap.deinit();

    // Connect to an IMAP server.
    // Use TLS
    imap.setSsl(true);
    imap.setPort(993);
    success = if (imap.connect("imap.example.com")) true else |_| false;
    if (!success) {
        std.debug.print("{s}\n", .{try imap.getLastErrorText(alloc)});
        return;
    }

    success = if (imap.login("myLogin", "myPassword")) true else |_| false;
    if (!success) {
        std.debug.print("{s}\n", .{try imap.getLastErrorText(alloc)});
        return;
    }

    // Select an IMAP mailbox
    success = if (imap.selectMailbox("Inbox")) true else |_| false;
    if (!success) {
        std.debug.print("{s}\n", .{try imap.getLastErrorText(alloc)});
        return;
    }

    // Download the 1st email (as MIME) in the Inbox by sequence number.
    const sb_mime = try chilkat.StringBuilder.init();
    defer sb_mime.deinit();
    success = if (imap.fetchSingleAsMimeSb(1, false, sb_mime)) true else |_| false;
    if (!success) {
        std.debug.print("{s}\n", .{try imap.getLastErrorText(alloc)});
        return;
    }

    // Load it into a MIME object and check to see if it is signed
    const mime = try chilkat.Mime.init();
    defer mime.deinit();
    mime.loadMimeSb(sb_mime) catch {};
    var already_saved_parts: bool = false;
    if (mime.containsSignedParts()) {
        // This will save the .p7s and other parts...
        const st = try chilkat.StringTable.init();
        defer st.deinit();
        success = if (mime.partsToFiles("c:/temp/qa_output", st)) true else |_| false;
        if (success) {
            const num_files = st.getCount();
            var i: i32 = 0;
            while (i < num_files) {
                std.debug.print("Created: {s}\n", .{try st.stringAt(alloc, i)});
                i = i + 1;
            }

            already_saved_parts = true;
        }
    }

    // Load the MIME into an Email object.  This unwraps the security layers and verifies signatures.
    const email = try chilkat.Email.init();
    defer email.deinit();
    email.setFromMimeSb(sb_mime) catch {};

    if (email.getReceivedSigned()) {
        std.debug.print("This email was signed.\n", .{});

        // Check to see if the signatures were verified.
        if (email.getSignaturesValid()) {
            std.debug.print("Digital signature(s) verified.\n", .{});
            std.debug.print("Signer: {s}\n", .{try email.getSignedBy(alloc)});

            // The certificate used for signing may be obtained
            // by calling email.LastSignerCert.  Index 0 is the first signer.
            const cert = try chilkat.Cert.init();
            defer cert.deinit();
            success = if (email.lastSignerCert(0, cert)) true else |_| false;
            if (!success) {
                std.debug.print("Failed to get signing certificate object.\n", .{});
            } else {
                std.debug.print("Signing cert: {s}\n", .{try cert.getSubjectCN(alloc)});
            }
        } else {
            std.debug.print("Digital signature verification failed.\n", .{});
        }
    } else {
        std.debug.print("This email was not signed.\n", .{});
    }

    if (!already_saved_parts) {
        email.saveAllAttachments("c:/temp/qa_output") catch {};
    }
}