PureBasic

Set the Decryption Certificate and Private Key

Demonstrates the Chilkat Email.SetDecryptCert2 method, which explicitly provides a certificate and its corresponding private key as separate objects for decrypting a received encrypted email. Set them before loading the encrypted message. This example loads a .cer certificate and a PEM private key, sets both, then loads an encrypted email.

Background: Sometimes the certificate and its private key are stored separately — a public .cer file plus a PEM (or other format) key file — rather than combined in a PFX. SetDecryptCert2 accepts the two objects individually, which is the natural fit for that arrangement. It is the two-object counterpart to SetDecryptCert, which takes a single certificate that already carries its private key.

Chilkat PureBasic Downloads

Download Chilkat for PureBasic

PureBasic

IncludeFile "CkCert.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkEmail.pb"

Procedure ChilkatExample()

    success.i = 0

    ;  Demonstrates the SetDecryptCert2 method, which explicitly provides a certificate and its
    ;  corresponding private key (as separate objects) for decrypting a received encrypted
    ;  email.  Set them before loading the encrypted email.

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

    ;  Load the certificate (public) and the matching private key from separate files.
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkCert::ckLoadFromFile(cert,"qa_data/certs/recipient.cer")
    If success = 0
        Debug CkCert::ckLastErrorText(cert)
        CkEmail::ckDispose(email)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

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

    success = CkPrivateKey::ckLoadPemFile(privKey,"qa_data/certs/recipient_privkey.pem")
    If success = 0
        Debug CkPrivateKey::ckLastErrorText(privKey)
        CkEmail::ckDispose(email)
        CkCert::ckDispose(cert)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

    ;  Provide the certificate and private key to use for decryption.
    success = CkEmail::ckSetDecryptCert2(email,cert,privKey)
    If success = 0
        Debug CkEmail::ckLastErrorText(email)
        CkEmail::ckDispose(email)
        CkCert::ckDispose(cert)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

    ;  Load the encrypted email; Chilkat decrypts it using the certificate and key.
    success = CkEmail::ckLoadEml(email,"qa_data/eml/encrypted.eml")
    If success = 0
        Debug CkEmail::ckLastErrorText(email)
        CkEmail::ckDispose(email)
        CkCert::ckDispose(cert)
        CkPrivateKey::ckDispose(privKey)
        ProcedureReturn
    EndIf

    Debug "Decrypted = " + Str(CkEmail::ckDecrypted(email))

    ;  Note: Paths such as "qa_data/..." are relative local filesystem paths,
    ;  relative to the current working directory of the running application.


    CkEmail::ckDispose(email)
    CkCert::ckDispose(cert)
    CkPrivateKey::ckDispose(privKey)


    ProcedureReturn
EndProcedure