(PureBasic) Duplicate OpensSSL Command that Decrypts Binary DER

This example duplicates the following:

openssl smime -decrypt -in INPUT_FILE -inform der -binary -out OUTPUT_FILE -recip PEM_CERT_AND_KEY -passin pass:PRIVKEY_PASSWORD

Note: Although "smime" is the OpenSSL command, we're not really dealing with S/MIME. The arguments "-inform der -binary" indicate that the input is simply the binary DER (i.e. the PKCS7 binary encrypted object). The output can be any type of file (whatever was encrypted).

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkCert.pb"
IncludeFile "CkCrypt2.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkPem.pb"

Procedure ChilkatExample()

    ; This example requires the Chilkat API to have been previously unlocked.
    ; See Global Unlock Sample for sample code.

    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkCrypt2::setCkCryptAlgorithm(crypt, "pki")

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

    success.i = CkPem::ckLoadPemFile(pem,"qa_data/pem/myPem.pem","password")
    If success <> 1
        Debug CkPem::ckLastErrorText(pem)
        CkCrypt2::ckDispose(crypt)
        CkPem::ckDispose(pem)
        ProcedureReturn
    EndIf

    privkey.i = CkPem::ckGetPrivateKey(pem,0)
    If CkPem::ckLastMethodSuccess(pem) <> 1
        Debug CkPem::ckLastErrorText(pem)
        CkCrypt2::ckDispose(crypt)
        CkPem::ckDispose(pem)
        ProcedureReturn
    EndIf

    cert.i = CkPem::ckGetCert(pem,0)
    If CkPem::ckLastMethodSuccess(pem) <> 1
        CkPrivateKey::ckDispose(privkey)

        Debug CkPem::ckLastErrorText(pem)
        CkCrypt2::ckDispose(crypt)
        CkPem::ckDispose(pem)
        ProcedureReturn
    EndIf

    success = CkCrypt2::ckSetDecryptCert2(crypt,cert,privkey)
    If success <> 1
        CkPrivateKey::ckDispose(privkey)

        CkCert::ckDispose(cert)

        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkPem::ckDispose(pem)
        ProcedureReturn
    EndIf

    CkPrivateKey::ckDispose(privkey)

    CkCert::ckDispose(cert)

    success = CkCrypt2::ckCkDecryptFile(crypt,"qa_data/infile.enc","qa_output/outfile.dat")
    If success <> 1
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkPem::ckDispose(pem)
        ProcedureReturn
    EndIf

    Debug "Success."


    CkCrypt2::ckDispose(crypt)
    CkPem::ckDispose(pem)


    ProcedureReturn
EndProcedure