PureBasic

Set the Decryption Certificate for an Email

Demonstrates the Chilkat Email.SetDecryptCert method, which explicitly provides a certificate (with access to its private key) for decrypting a received encrypted email. Set the certificate before loading the encrypted message so Chilkat can decrypt it automatically. This example loads the certificate from a PFX, sets it, and then loads an encrypted email.

Background: Decrypting S/MIME email requires the recipient's private key. On Windows and macOS, Chilkat can find an installed certificate automatically, but when the key lives in a standalone PFX file you provide it explicitly with SetDecryptCert. A PFX (PKCS#12) bundles the certificate and its private key in one password-protected file. If the certificate and key are in separate files, use SetDecryptCert2 instead.

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

Procedure ChilkatExample()

    success.i = 0

    ;  Demonstrates the SetDecryptCert method, which explicitly provides a certificate (with
    ;  access to its private key) for decrypting a received encrypted email.  Set the cert
    ;  before loading the encrypted email so it can be decrypted automatically.

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

    ;  Load a certificate together with its private key from a PFX file.
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkCert::ckLoadPfxFile(cert,"qa_data/certs/decryption.pfx","pfx_password")
    If success = 0
        Debug CkCert::ckLastErrorText(cert)
        CkEmail::ckDispose(email)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ;  Provide the certificate to use for decryption.
    success = CkEmail::ckSetDecryptCert(email,cert)
    If success = 0
        Debug CkEmail::ckLastErrorText(email)
        CkEmail::ckDispose(email)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

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

    Debug "ReceivedEncrypted = " + Str(CkEmail::ckReceivedEncrypted(email))
    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)


    ProcedureReturn
EndProcedure