Unicode C

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

See more SMTP Examples

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.

Unicode C

#include <C_CkCertW.h>
#include <C_CkEmailW.h>
#include <C_CkMailManW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCertW cert;
    HCkEmailW email;
    HCkMailManW mailman;

    success = FALSE;

    //  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.)
    cert = CkCertW_Create();
    success = CkCertW_LoadFromFile(cert,L"qa_data/rsaes-oaep/cert.pem");
    if (success != TRUE) {
        wprintf(L"%s\n",CkCertW_lastErrorText(cert));
        CkCertW_Dispose(cert);
        return;
    }

    email = CkEmailW_Create();

    //  Create a simple email.
    CkEmailW_putSubject(email,L"Sample RSAES-OAEP Encrypted Email");
    CkEmailW_putBody(email,L"Sample RSAES-OAEP Encrypted Email");
    CkEmailW_putFrom(email,L"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.)
    CkEmailW_AddTo(email,L"Chilkat GMail",L"chilkat.support@gmail.com");

    //  Set the email object properties to indicate the desired encryption.
    CkEmailW_putPkcs7CryptAlg(email,L"aes");
    //  If AES-256 is desired, set the following property to 256.
    CkEmailW_putPkcs7KeyLength(email,128);
    CkEmailW_putOaepPadding(email,TRUE);
    //  Other choices for the OAEP hash algorithm are "sha1", "sha384", and "sha512"
    CkEmailW_putOaepHash(email,L"sha256");

    //  Provide the certificate to be used for encryption
    CkEmailW_AddEncryptCert(email,cert);

    //  Don't forget to indicate that the email should be encrypted when sent..
    CkEmailW_putSendEncrypted(email,TRUE);

    //  The mailman object will do the RSAES-OAEP encryption when sending.
    mailman = CkMailManW_Create();

    //  Set the SMTP settings for your email account on your mail server.
    CkMailManW_putSmtpUsername(mailman,L"SMTP_LOGIN");
    CkMailManW_putSmtpPassword(mailman,L"SMTP_PASSWORD");
    CkMailManW_putSmtpHost(mailman,L"MY_SMTP_DOMAIN_OR_IP");
    CkMailManW_putSmtpPort(mailman,587);
    CkMailManW_putStartTLS(mailman,TRUE);

    //  Send the email.  The mailman will encrypt the email as directed by the 
    //  property settings of the email object.
    success = CkMailManW_SendEmail(mailman,email);
    if (success != TRUE) {
        wprintf(L"%s\n",CkMailManW_lastErrorText(mailman));
        CkCertW_Dispose(cert);
        CkEmailW_Dispose(email);
        CkMailManW_Dispose(mailman);
        return;
    }

    success = CkMailManW_CloseSmtpConnection(mailman);
    if (success != TRUE) {
        wprintf(L"Connection to SMTP server not closed cleanly.\n");
    }

    wprintf(L"Mail Sent!\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=


    CkCertW_Dispose(cert);
    CkEmailW_Dispose(email);
    CkMailManW_Dispose(mailman);

    }