(MFC) Send Encrypted Email using RSAES-OAEP with AES-128 CBC and SHA256

Demonstrates how to send encrypted email using RSAES-OAEP with SHA256 and AES-128 content encryption.

Note: This example requires Chilkat v9.5.0.67 or greater.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkCert.h>
#include <CkEmail.h>
#include <CkMailMan.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    // Load an RSA-based certificate.
    // (Encrypting an email only requires the public key.  Decrypting an email requires the private key.)
    CkCert cert;
    bool success = cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem");
    if (success != true) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkEmail email;

    // Create a simple email.
    email.put_Subject("Sample RSAES-OAEP Encrypted Email");
    email.put_Body("Sample RSAES-OAEP Encrypted Email");
    email.put_From("support@chilkatsoft.com");

    // Add a recipient.
    // (The email is encrypted using the recipient's certificate.
    // If sending to multiple recipients, then the AddEncryptCert method would
    // need to be called once for each recipient's certificate.)
    email.AddTo("Chilkat GMail","chilkat.support@gmail.com");

    // Set the email object properties to indicate the desired encryption.
    email.put_Pkcs7CryptAlg("aes");
    // If AES-256 is desired, set the following property to 256.
    email.put_Pkcs7KeyLength(128);
    email.put_OaepPadding(true);
    // Other choices for the OAEP hash algorithm are "sha1", "sha384", and "sha512"
    email.put_OaepHash("sha256");

    // Provide the certificate to be used for encryption
    email.AddEncryptCert(cert);

    // Don't forget to indicate that the email should be encrypted when sent..
    email.put_SendEncrypted(true);

    // The mailman object will do the RSAES-OAEP encryption when sending.
    CkMailMan mailman;

    // Set the SMTP settings for your email account on your mail server.
    mailman.put_SmtpUsername("SMTP_LOGIN");
    mailman.put_SmtpPassword("SMTP_PASSWORD");
    mailman.put_SmtpHost("MY_SMTP_DOMAIN_OR_IP");
    mailman.put_SmtpPort(587);
    mailman.put_StartTLS(true);

    // Send the email.  The mailman will encrypt the email as directed by the 
    // property settings of the email object.
    success = mailman.SendEmail(email);
    if (success != true) {
        strOut.append(mailman.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    success = mailman.CloseSmtpConnection();
    if (success != true) {
        strOut.append("Connection to SMTP server not closed cleanly.");
        strOut.append("\r\n");
    }

    strOut.append("Mail Sent!");
    strOut.append("\r\n");

    // -----------------------------------------------------------
    // This is an example of an RSAES-OAEP encrypted email
    // -----------------------------------------------------------

    // MIME-Version: 1.0
    // Date: Thu, 27 Apr 2017 08:43:32 -0500
    // Message-ID: <772DC039F0259C474BAC60240EA2BA2272402308@CHILKAT13>
    // Content-Type: application/pkcs7-mime; name="smime.p7m"; smime-type="enveloped-data"
    // Content-Transfer-Encoding: base64
    // X-Priority: 3 (Normal)
    // Subject: Sample RSAES-OAEP Encrypted Email
    // From: support@chilkatsoft.com
    // To: "Chilkat GMail" <chilkat.support@gmail.com>
    // Content-Disposition: attachment; filename="smime.p7m"
    // 
    // MIICWQYJKoZIhvcNAQcDoIICSjCCAkYCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
    // CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
    // dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
    // oA0wCwYJYIZIAWUDBAIBBIIBABr0E1dKJjK0FAYRz/NCtJmBeB0nUxgcuBnhGPI/UeyGub3cCo+K
    // G5F4/iVTBJqVvYIF5+fvBnyTginwv7OiUiFWLyihiFC3NIyZJO22+XMHpNatCffTPZk10WswkTgk
    // G3ApnRvGQAaldnFD0Hs8drPU4vBvY9QsjT7YDGa6u2NMX+sr1ewEZArqU0mNfJ6RsEYd5FQbFEVF
    // qLmnz8Dt+yhoJlUtfUd8TXIeqHRJ7RxKOTSzlBZaAdTv2QX4oL9IcAgZeTg5iw+yRPkSAwWyg+I/
    // 7fybLsUpRGDHTGUU+AvHvP0kYKa1mkvccBVEC/+4hEyhpS1tWIR5ByY6vM76Z+8wgZwGCSqGSIb3
    // DQEHATAdBglghkgBZQMEAQIEEKqD0YDHX1NsVDaV32UczpeAcLteQyRPTV4hATjwcPiVelPfeWNs
    // xZKRGaEBqLM8+Y+V4ciCFoOlgJuOcP4m1PTHyilfzd+SCsKz5l1C7+sfPf36n2aacX6IWga59Bz5
    // QbWrOHDUT7O5PnGwKVgQFw3Cj4GrdPGWKcoqxB0HuKnj3WA=


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }