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Duplicate OpensSSL to Create Signature using Cert and Key Files

See more OpenSSL Examples

This example duplicates the following:

openssl smime –sign -in something.xml -out something.der -signer mycert.crt -inkey cert.key -outform der –nodetach

Note: Although "smime" is the OpenSSL command, it's not actually producing S/MIME. The arguments "-outform der -binary" indicates that the output is binary DER (i.e. the PKCS7 binary signature). The input can be any type of file: XML, PDF, JPG, ... *anything*...

Zig

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

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

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

    const crypt = try chilkat.Crypt2.init();
    defer crypt.deinit();

    // Load the cert and private key from separate files.
    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.loadFromFile("myCert.crt") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    const bd = try chilkat.BinData.init();
    defer bd.deinit();
    try bd.loadFile("cert.key");
    const privkey = try chilkat.PrivateKey.init();
    defer privkey.deinit();
    // Load from any format private key.
    // If the file does not need a password, the 2nd arg is ignored.
    privkey.loadAnyFormat(bd, "password_if_needed") catch {
        std.debug.print("{s}\n", .{try privkey.getLastErrorText(alloc)});
        return;
    };

    crypt.setSigningCert2(cert, privkey) catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

    // Create the opaque signature (PKCS7 binary DER that contains both the signature and original file data).
    crypt.createP7M("qa_data/infile.anything", "qa_output/outfile.der") catch {
        std.debug.print("{s}\n", .{try crypt.getLastErrorText(alloc)});
        return;
    };

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