Example





In This Topic
GdPicture14 Namespace / GdPicturePDF Class / GetEncryptionScheme Method

GetEncryptionScheme Method (GdPicturePDF)

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Returns the encryption algorithm which has been used to encrypt the currently loaded PDF document.

The PDF specification defines different algorithms to be used to encrypt and/or decrypt a PDF document's content: RC4 40 bits, RC4 128 bits, AES 128 bits, AES 256 bits.

Syntax
'Declaration

 


Public Function GetEncryptionScheme() As PdfEncryption
public PdfEncryption GetEncryptionScheme()
public function GetEncryptionScheme(): PdfEncryption; 
public function GetEncryptionScheme() : PdfEncryption;
public: PdfEncryption GetEncryptionScheme(); 
public:

PdfEncryption GetEncryptionScheme();

Return Value

A member of the PdfEncryption enumeration. The GdPicturePDF.GetStat method can be subsequently used to determine if this method has been successful.
Remarks
You should apply this method on a decrypted PDF document only (see the example below).

You need to decrypt the PDF document at first using the GdPicturePDF.SetPassword method with specifyting either the correct user password or the owner password.

Example
How to correctly find out the encryption algorithm that has been used to encrypt the PDF document. 
Dim caption As String = "Example: GetEncryptionScheme"

Dim gdpicturePDF As New GdPicturePDF()

'Please see the example in the SetPassword method for creating this file.

Dim status As GdPictureStatus = gdpicturePDF.LoadFromFile("encrypted.pdf", False)

If status = GdPictureStatus.OK Then

    Dim encryption As PdfEncryption = PdfEncryption.PdfEncryptionUnknown

    Dim encrypted As Boolean = gdpicturePDF.IsEncrypted()

    status = gdpicturePDF.GetStat()

    If status = GdPictureStatus.OK Then

        If encrypted Then

            'This is incorrect usage.

            encryption = gdpicturePDF.GetEncryptionScheme()

            If gdpicturePDF.GetStat() = GdPictureStatus.OK Then

                MessageBox.Show("This PDF document is encrypted, the encryption scheme is: " + encryption.ToString() + vbCrLf + "Please use SetPassword to decrypt your document.", caption)

            End If

            

            'You need to provide the correct password here.

            status = gdpicturePDF.SetPassword("user")

            If status = GdPictureStatus.OK Then

                'The correct usage.

                encryption = gdpicturePDF.GetEncryptionScheme() ' correct use

                If gdpicturePDF.GetStat() = GdPictureStatus.OK Then

                    MessageBox.Show("This PDF document is decrypted, the encryption scheme is: " + encryption.ToString(), caption)

                End If

            Else

                MessageBox.Show("The SetPassword() method has failed with the status: " + status.ToString(), caption)

            End If

        Else

            encryption = gdpicturePDF.GetEncryptionScheme()

            If gdpicturePDF.GetStat() = GdPictureStatus.OK Then

                MessageBox.Show("The PDF document is not encrypted, the encryption scheme is: " + encryption.ToString(), caption)

            End If

        End If

    Else

        MessageBox.Show("The IsEncrypted() method has failed with the status: " + status.ToString(), caption)

    End If

Else

    MessageBox.Show("The file can't be loaded.", caption)

End If

gdpicturePDF.Dispose()
string caption = "Example: GetEncryptionScheme";

GdPicturePDF gdpicturePDF = new GdPicturePDF();

//Please see the example in the SetPassword method for creating this file.

GdPictureStatus status = gdpicturePDF.LoadFromFile("encrypted.pdf", false);

if (status == GdPictureStatus.OK)

{

    PdfEncryption encryption = PdfEncryption.PdfEncryptionUnknown;

    bool encrypted = gdpicturePDF.IsEncrypted();

    status = gdpicturePDF.GetStat();

    if (status == GdPictureStatus.OK)

    {

        if (encrypted)

        {

            //This is incorrect usage.

            encryption = gdpicturePDF.GetEncryptionScheme();

            if (gdpicturePDF.GetStat() == GdPictureStatus.OK)

                MessageBox.Show("This PDF document is encrypted, the encryption scheme is: " + encryption.ToString() + "\nPlease use SetPassword to decrypt your document.", caption);

            

            //You need to provide the correct password here.

            status = gdpicturePDF.SetPassword("user");

            if (status == GdPictureStatus.OK)

            {

                 //The correct usage.

                encryption = gdpicturePDF.GetEncryptionScheme();

                if (gdpicturePDF.GetStat() == GdPictureStatus.OK)

                    MessageBox.Show("This PDF document is decrypted, the encryption scheme is: " + encryption.ToString(), caption);

            }

            else

            {

                MessageBox.Show("The SetPassword() method has failed with the status: " + status.ToString(), caption);

            }

        }

        else

        {

            encryption = gdpicturePDF.GetEncryptionScheme();

            if (gdpicturePDF.GetStat() == GdPictureStatus.OK)

                MessageBox.Show("The PDF document is not encrypted, the encryption scheme is: " + encryption.ToString(), caption);

        }

    }

    else

    {

        MessageBox.Show("The IsEncrypted() method has failed with the status: " + status.ToString(), caption);

    }

}

else

{

    MessageBox.Show("The file can't be loaded.", caption);

}

gdpicturePDF.Dispose();
Example
How to correctly find out the encryption algorithm that has been used to encrypt the PDF document. Dim caption As String = "Example: GetEncryptionScheme" Dim gdpicturePDF As New GdPicturePDF() 'Please see the example in the SetPassword method for creating this file. Dim status As GdPictureStatus = gdpicturePDF.LoadFromFile("encrypted.pdf", False) If status = GdPictureStatus.OK Then Dim encryption As PdfEncryption = PdfEncryption.PdfEncryptionUnknown Dim encrypted As Boolean = gdpicturePDF.IsEncrypted() status = gdpicturePDF.GetStat() If status = GdPictureStatus.OK Then If encrypted Then 'This is incorrect usage. encryption = gdpicturePDF.GetEncryptionScheme() If gdpicturePDF.GetStat() = GdPictureStatus.OK Then MessageBox.Show("This PDF document is encrypted, the encryption scheme is: " + encryption.ToString() + vbCrLf + "Please use SetPassword to decrypt your document.", caption) End If 'You need to provide the correct password here. status = gdpicturePDF.SetPassword("user") If status = GdPictureStatus.OK Then 'The correct usage. encryption = gdpicturePDF.GetEncryptionScheme() ' correct use If gdpicturePDF.GetStat() = GdPictureStatus.OK Then MessageBox.Show("This PDF document is decrypted, the encryption scheme is: " + encryption.ToString(), caption) End If Else MessageBox.Show("The SetPassword() method has failed with the status: " + status.ToString(), caption) End If Else encryption = gdpicturePDF.GetEncryptionScheme() If gdpicturePDF.GetStat() = GdPictureStatus.OK Then MessageBox.Show("The PDF document is not encrypted, the encryption scheme is: " + encryption.ToString(), caption) End If End If Else MessageBox.Show("The IsEncrypted() method has failed with the status: " + status.ToString(), caption) End If Else MessageBox.Show("The file can't be loaded.", caption) End If gdpicturePDF.Dispose() string caption = "Example: GetEncryptionScheme"; GdPicturePDF gdpicturePDF = new GdPicturePDF(); //Please see the example in the SetPassword method for creating this file. GdPictureStatus status = gdpicturePDF.LoadFromFile("encrypted.pdf", false); if (status == GdPictureStatus.OK) { PdfEncryption encryption = PdfEncryption.PdfEncryptionUnknown; bool encrypted = gdpicturePDF.IsEncrypted(); status = gdpicturePDF.GetStat(); if (status == GdPictureStatus.OK) { if (encrypted) { //This is incorrect usage. encryption = gdpicturePDF.GetEncryptionScheme(); if (gdpicturePDF.GetStat() == GdPictureStatus.OK) MessageBox.Show("This PDF document is encrypted, the encryption scheme is: " + encryption.ToString() + "\nPlease use SetPassword to decrypt your document.", caption); //You need to provide the correct password here. status = gdpicturePDF.SetPassword("user"); if (status == GdPictureStatus.OK) { //The correct usage. encryption = gdpicturePDF.GetEncryptionScheme(); if (gdpicturePDF.GetStat() == GdPictureStatus.OK) MessageBox.Show("This PDF document is decrypted, the encryption scheme is: " + encryption.ToString(), caption); } else { MessageBox.Show("The SetPassword() method has failed with the status: " + status.ToString(), caption); } } else { encryption = gdpicturePDF.GetEncryptionScheme(); if (gdpicturePDF.GetStat() == GdPictureStatus.OK) MessageBox.Show("The PDF document is not encrypted, the encryption scheme is: " + encryption.ToString(), caption); } } else { MessageBox.Show("The IsEncrypted() method has failed with the status: " + status.ToString(), caption); } } else { MessageBox.Show("The file can't be loaded.", caption); } gdpicturePDF.Dispose();
See Also

Reference

GdPicturePDF Class
GdPicturePDF Members
SetPassword Method
GetStat Method
IsEncrypted Method
SetPassword Method
IsOwnerPassword Method
GetEncryptionMode Method
GetRight Method
LoadFromFile Method
SaveToFile(String) Method
LoadFromStream Method
SaveToStream(Stream) Method