PureBasic

Sign a File to Create a .p7m File (using a PFX)

See more Encryption Examples

_LANGUAGE_ example to sign a file creating a .p7m file as output. The .p7m contains the signed contents of the original file. It can be verified and restored by calling VerifyP7M. PureBasic

IncludeFile "CkCertStore.pb"
IncludeFile "CkCert.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkCrypt2.pb"

Procedure ChilkatExample()

    success.i = 0

    ; 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

    ; Use a digital certificate and private key from a PFX file (.pfx or .p12).
    signingCertSubject.s = "Acme Inc"
    pfxFilename.s = "/Users/chilkat/testData/pfx/acme.pfx"
    pfxPassword.s = "test123"

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

    success = CkCertStore::ckLoadPfxFile(certStore,pfxFilename,pfxPassword)
    If success <> 1
        Debug CkCertStore::ckLastErrorText(certStore)
        CkCrypt2::ckDispose(crypt)
        CkCertStore::ckDispose(certStore)
        ProcedureReturn
    EndIf

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

    CkJsonObject::ckUpdateString(jsonCN,"CN",signingCertSubject)

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

    success = CkCertStore::ckFindCert(certStore,jsonCN,cert)
    If success = 0
        Debug "Failed to find certificate by subject common name."
        CkCrypt2::ckDispose(crypt)
        CkCertStore::ckDispose(certStore)
        CkJsonObject::ckDispose(jsonCN)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Tell the crypt component to use this cert.
    success = CkCrypt2::ckSetSigningCert(crypt,cert)

    ; We can sign any type of file, creating a .p7m as output:
    inFile.s = "/Users/chilkat/testData/pdf/sample.pdf"
    outputFile.s = "/Users/chilkat/testData/p7m/sample.pdf.p7m"
    success = CkCrypt2::ckCreateP7M(crypt,inFile,outputFile)
    If success = 0
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkCertStore::ckDispose(certStore)
        CkJsonObject::ckDispose(jsonCN)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Verify and restore the original file:
    success = CkCrypt2::ckSetVerifyCert(crypt,cert)

    inFile = outputFile
    outputFile = "/Users/chilkat/testData/pdf/restored.pdf"

    success = CkCrypt2::ckVerifyP7M(crypt,inFile,outputFile)
    If success = 0
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkCertStore::ckDispose(certStore)
        CkJsonObject::ckDispose(jsonCN)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    Debug "Success!"


    CkCrypt2::ckDispose(crypt)
    CkCertStore::ckDispose(certStore)
    CkJsonObject::ckDispose(jsonCN)
    CkCert::ckDispose(cert)


    ProcedureReturn
EndProcedure