MIME S/MIME Encryption Algorithm Properties

See more MIME Examples

Demonstrates the properties that control S/MIME encryption: Pkcs7CryptAlg (the symmetric content-encryption algorithm), Pkcs7KeyLength (the content-encryption key length in bits), OaepPadding (whether RSAES-OAEP key transport is used instead of RSAES-PKCS1-v1_5), and the OAEP hash settings OaepHash and OaepMgfHash. The properties are configured before calling Encrypt.

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

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

    const mime = try chilkat.Mime.init();
    defer mime.deinit();
    mime.setBodyFromPlainText("This message will be encrypted.") catch {
        std.debug.print("{s}\n", .{try mime.getLastErrorText(alloc)});
        return;
    };

    // Pkcs7CryptAlg is the symmetric content-encryption algorithm.  Supported values are aes, aes-gcm,
    // des, 3des, and rc2.  The default is aes.
    mime.setPkcs7CryptAlg("aes");

    // Pkcs7KeyLength is the content-encryption key length in bits.  The default is 128.
    mime.setPkcs7KeyLength(256);

    // OaepPadding selects the RSA key-transport padding.  The default is false (RSAES-PKCS1-v1_5).
    // Set true to use RSAES-OAEP, in which case the OAEP hash settings apply.
    mime.setOaepPadding(true);
    mime.setOaepHash("sha256");
    mime.setOaepMgfHash("sha256");

    // Load the recipient certificate (public key is sufficient for encrypting).
    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.loadFromFile("qa_data/recipient.cer") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    // Encrypt using the algorithm settings configured above.
    mime.encrypt(cert) catch {
        std.debug.print("{s}\n", .{try mime.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("Encrypted with {s} {d}-bit key.\n", .{ try mime.getPkcs7CryptAlg(alloc), mime.getPkcs7KeyLength() });
}