(PureBasic) 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 PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkCert.pb"
IncludeFile "CkEmail.pb"
IncludeFile "CkMailMan.pb"

Procedure ChilkatExample()

    ; 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.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i = CkCert::ckLoadFromFile(cert,"qa_data/rsaes-oaep/cert.pem")
    If success <> 1
        Debug CkCert::ckLastErrorText(cert)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    email.i = CkEmail::ckCreate()
    If email.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Create a simple email.
    CkEmail::setCkSubject(email, "Sample RSAES-OAEP Encrypted Email")
    CkEmail::setCkBody(email, "Sample RSAES-OAEP Encrypted Email")
    CkEmail::setCkFrom(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::ckAddTo(email,"Chilkat GMail","chilkat.support@gmail.com")

    ; Set the email object properties to indicate the desired encryption.
    CkEmail::setCkPkcs7CryptAlg(email, "aes")
    ; If AES-256 is desired, set the following property to 256.
    CkEmail::setCkPkcs7KeyLength(email, 128)
    CkEmail::setCkOaepPadding(email, 1)
    ; Other choices for the OAEP hash algorithm are "sha1", "sha384", and "sha512"
    CkEmail::setCkOaepHash(email, "sha256")

    ; Provide the certificate to be used for encryption
    CkEmail::ckAddEncryptCert(email,cert)

    ; Don't forget to indicate that the email should be encrypted when sent..
    CkEmail::setCkSendEncrypted(email, 1)

    ; The mailman object will do the RSAES-OAEP encryption when sending.
    mailman.i = CkMailMan::ckCreate()
    If mailman.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Set the SMTP settings for your email account on your mail server.
    CkMailMan::setCkSmtpUsername(mailman, "SMTP_LOGIN")
    CkMailMan::setCkSmtpPassword(mailman, "SMTP_PASSWORD")
    CkMailMan::setCkSmtpHost(mailman, "MY_SMTP_DOMAIN_OR_IP")
    CkMailMan::setCkSmtpPort(mailman, 587)
    CkMailMan::setCkStartTLS(mailman, 1)

    ; Send the email.  The mailman will encrypt the email as directed by the 
    ; property settings of the email object.
    success = CkMailMan::ckSendEmail(mailman,email)
    If success <> 1
        Debug CkMailMan::ckLastErrorText(mailman)
        CkCert::ckDispose(cert)
        CkEmail::ckDispose(email)
        CkMailMan::ckDispose(mailman)
        ProcedureReturn
    EndIf

    success = CkMailMan::ckCloseSmtpConnection(mailman)
    If success <> 1
        Debug "Connection to SMTP server not closed cleanly."
    EndIf

    Debug "Mail Sent!"

    ; -----------------------------------------------------------
    ; 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::ckDispose(cert)
    CkEmail::ckDispose(email)
    CkMailMan::ckDispose(mailman)


    ProcedureReturn
EndProcedure