C++

Remove All S/MIME Security Layers (UnwrapSecurity)

Demonstrates the Chilkat Mime.UnwrapSecurity method, which removes supported S/MIME security layers and restores the underlying MIME content. It takes no arguments and handles both layer orders: signed-then-encrypted and encrypted-then-signed.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: A message can be both signed and encrypted, in either order, producing nested S/MIME wrappers. UnwrapSecurity peels them all off in one call — verifying signatures and decrypting as it goes — so you do not have to detect the layering and call Verify and Decrypt in the right sequence yourself. Decryption still requires the recipient's certificate and private key to be configured.

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C++

#include <CkMime.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the Mime.UnwrapSecurity method, which removes supported S/MIME security layers and
    //  restores the underlying MIME content.  It takes no arguments and handles both layer orders
    //  (signed-then-encrypted and encrypted-then-signed).

    CkMime mime;
    success = mime.LoadMimeFile("qa_data/secured.eml");
    if (success == false) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    //  A single call peels off the signature and/or encryption layers.  (Decryption requires the
    //  appropriate certificate/private key to be configured first.)
    success = mime.UnwrapSecurity();
    if (success == false) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Security layers removed. Content-Type is now: " << mime.contentType() << "\r\n";
    }