Xbase++ Requires Chilkat v11.7.0+

Choose the PDF Encryption Algorithm: AES-256, AES-128 or RC4

Demonstrates the algorithmChoice option of the encrypt operation. aes-256 is the default and the one to use unless an older reader must open the file. aes-128 is for readers that predate AES-256. rc4-128 and rc4-40 are broken ciphers kept only for very old readers. Each algorithm needs a minimum PDF version, and the file header is raised to it when the PDF is saved, never lowered. A PDF saved with RC4 is written with a classic cross-reference table so that those old readers can parse it.

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LOCAL nSuccess
LOCAL oJson
LOCAL oJsonOut
LOCAL oInfo
LOCAL oPdf1
LOCAL oPdf2
LOCAL oPdf3

nSuccess := 0

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

//  The PDF used in this example is available at two_page_memo.pdf

oJson := CreateObject("Chilkat.JsonObject")
oJsonOut := CreateObject("Chilkat.JsonObject")
oInfo := CreateObject("Chilkat.JsonObject")

//  AES-256, the default.  Saved as PDF 1.7 with Adobe extension level 8.
oPdf1 := CreateObject("Chilkat.Pdf")
nSuccess := oPdf1:LoadFile("qa_data/pdf/two_page_memo.pdf")
IF (nSuccess == 0)
    ? oPdf1:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    RETURN
ENDIF

oPdf1:UserPassword := "user-secret"
oPdf1:OwnerPassword := "owner-secret"
oJson:UpdateString("algorithmChoice", "aes-256")
nSuccess := oPdf1:Protection("encrypt", oJson, oJsonOut)
IF (nSuccess == 0)
    ? oPdf1:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    RETURN
ENDIF

? "aes-256 will be saved as PDF " + oJsonOut:StringOf("pending.pdfVersion") + ", Adobe extension level " + Str(oJsonOut:IntOf("pending.adobeExtensionLevel"))
nSuccess := oPdf1:WriteFile("qa_output/memo_aes256.pdf")
IF (nSuccess == 0)
    ? oPdf1:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    RETURN
ENDIF

nSuccess := oPdf1:PreLoadCheck("qa_output/memo_aes256.pdf", oInfo)
IF (nSuccess == 0)
    ? oPdf1:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    RETURN
ENDIF

? "  saved file: " + oInfo:StringOf("algorithm") + ", PDF " + oInfo:StringOf("pdfVersion")

//  AES-128, for readers that predate AES-256.  Saved as PDF 1.6.
oPdf2 := CreateObject("Chilkat.Pdf")
nSuccess := oPdf2:LoadFile("qa_data/pdf/two_page_memo.pdf")
IF (nSuccess == 0)
    ? oPdf2:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    oPdf2:destroy()
    RETURN
ENDIF

oPdf2:UserPassword := "user-secret"
oPdf2:OwnerPassword := "owner-secret"
oJson:UpdateString("algorithmChoice", "aes-128")
nSuccess := oPdf2:Protection("encrypt", oJson, oJsonOut)
IF (nSuccess == 0)
    ? oPdf2:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    oPdf2:destroy()
    RETURN
ENDIF

? "aes-128 will be saved as PDF " + oJsonOut:StringOf("pending.pdfVersion")
nSuccess := oPdf2:WriteFile("qa_output/memo_aes128.pdf")
IF (nSuccess == 0)
    ? oPdf2:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    oPdf2:destroy()
    RETURN
ENDIF

nSuccess := oPdf2:PreLoadCheck("qa_output/memo_aes128.pdf", oInfo)
IF (nSuccess == 0)
    ? oPdf2:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    oPdf2:destroy()
    RETURN
ENDIF

? "  saved file: " + oInfo:StringOf("algorithm") + ", PDF " + oInfo:StringOf("pdfVersion")

//  RC4-128, a broken cipher, only for readers too old for AES.  Saved as PDF 1.4.
oPdf3 := CreateObject("Chilkat.Pdf")
nSuccess := oPdf3:LoadFile("qa_data/pdf/two_page_memo.pdf")
IF (nSuccess == 0)
    ? oPdf3:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    oPdf2:destroy()
    oPdf3:destroy()
    RETURN
ENDIF

oPdf3:UserPassword := "user-secret"
oPdf3:OwnerPassword := "owner-secret"
oJson:UpdateString("algorithmChoice", "rc4-128")
nSuccess := oPdf3:Protection("encrypt", oJson, oJsonOut)
IF (nSuccess == 0)
    ? oPdf3:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    oPdf2:destroy()
    oPdf3:destroy()
    RETURN
ENDIF

? "rc4-128 will be saved as PDF " + oJsonOut:StringOf("pending.pdfVersion")
nSuccess := oPdf3:WriteFile("qa_output/memo_rc4_128.pdf")
IF (nSuccess == 0)
    ? oPdf3:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    oPdf2:destroy()
    oPdf3:destroy()
    RETURN
ENDIF

nSuccess := oPdf3:PreLoadCheck("qa_output/memo_rc4_128.pdf", oInfo)
IF (nSuccess == 0)
    ? oPdf3:LastErrorText
    oJson:destroy()
    oJsonOut:destroy()
    oInfo:destroy()
    oPdf1:destroy()
    oPdf2:destroy()
    oPdf3:destroy()
    RETURN
ENDIF

? "  saved file: " + oInfo:StringOf("algorithm") + ", PDF " + oInfo:StringOf("pdfVersion")

//  Sample output:

//  aes-256 will be saved as PDF 1.7, Adobe extension level 8
//    saved file: aes-256, PDF 1.7
//  aes-128 will be saved as PDF 1.6
//    saved file: aes-128, PDF 1.6
//  rc4-128 will be saved as PDF 1.4
//    saved file: rc4-128, PDF 1.4

oJson:destroy()
oJsonOut:destroy()
oInfo:destroy()
oPdf1:destroy()
oPdf2:destroy()
oPdf3:destroy()