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.

C

#include <C_CkCert.h>
#include <C_CkEmail.h>
#include <C_CkMailMan.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCert cert;
    HCkEmail email;
    HCkMailMan 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 = CkCert_Create();
    success = CkCert_LoadFromFile(cert,"qa_data/rsaes-oaep/cert.pem");
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCert_Dispose(cert);
        return;
    }

    email = CkEmail_Create();

    // Create a simple email.
    CkEmail_putSubject(email,"Sample RSAES-OAEP Encrypted Email");
    CkEmail_putBody(email,"Sample RSAES-OAEP Encrypted Email");
    CkEmail_putFrom(email,"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.)
    CkEmail_AddTo(email,"Chilkat GMail","chilkat.support@gmail.com");

    // Set the email object properties to indicate the desired encryption.
    CkEmail_putPkcs7CryptAlg(email,"aes");
    // If AES-256 is desired, set the following property to 256.
    CkEmail_putPkcs7KeyLength(email,128);
    CkEmail_putOaepPadding(email,TRUE);
    // Other choices for the OAEP hash algorithm are "sha1", "sha384", and "sha512"
    CkEmail_putOaepHash(email,"sha256");

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

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

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

    // Set the SMTP settings for your email account on your mail server.
    CkMailMan_putSmtpUsername(mailman,"SMTP_LOGIN");
    CkMailMan_putSmtpPassword(mailman,"SMTP_PASSWORD");
    CkMailMan_putSmtpHost(mailman,"MY_SMTP_DOMAIN_OR_IP");
    CkMailMan_putSmtpPort(mailman,587);
    CkMailMan_putStartTLS(mailman,TRUE);

    // Send the email.  The mailman will encrypt the email as directed by the 
    // property settings of the email object.
    success = CkMailMan_SendEmail(mailman,email);
    if (success != TRUE) {
        printf("%s\n",CkMailMan_lastErrorText(mailman));
        CkCert_Dispose(cert);
        CkEmail_Dispose(email);
        CkMailMan_Dispose(mailman);
        return;
    }

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

    printf("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=


    CkCert_Dispose(cert);
    CkEmail_Dispose(email);
    CkMailMan_Dispose(mailman);

    }