EncryptedPackageEnvelope.CreateFromPackage Method (Stream, Stream, PublishLicense, CryptoProvider)

 

Creates and returns an EncryptedPackageEnvelope (on the specified stream) that uses the specified unencrypted package as its content.

Namespace:   System.IO.Packaging
Assembly:  WindowsBase (in WindowsBase.dll)

public static EncryptedPackageEnvelope CreateFromPackage(
	Stream envelopeStream,
	Stream packageStream,
	PublishLicense publishLicense,
	CryptoProvider cryptoProvider
)

Parameters

envelopeStream
Type: System.IO.Stream

The stream on which to create the file.

packageStream
Type: System.IO.Stream

The stream representing the existing unencrypted package.

publishLicense
Type: System.Security.RightsManagement.PublishLicense

The publish license that is embedded in the compound file.

cryptoProvider
Type: System.Security.RightsManagement.CryptoProvider

An object that determines what operations the current user is allowed to perform on the encrypted content.

Exception Condition
ArgumentNullException

envelopeStream or packageStream is null.

NotSupportedException

envelopeStream does not provide read/write access.

The current user has read/write access to the new file.

The following example shows how to use the CreateFromPackage method to instantiate an EncryptedPackageEnvelope.

WriteStatus("   Signing the UnsignedPublishLicense\n" +
            "       to build the PublishLicense.");
UseLicense authorsUseLicense;
PublishLicense publishLicense =
    unsignedLicense.Sign(_secureEnv, out authorsUseLicense);

WriteStatus("   Binding the author's UseLicense and");
WriteStatus("       obtaining the CryptoProvider.");
CryptoProvider cryptoProvider = authorsUseLicense.Bind(_secureEnv);

WriteStatus("   Creating the EncryptedPackage.");
Stream packageStream = File.OpenRead(packageFile);
EncryptedPackageEnvelope ePackage =
    EncryptedPackageEnvelope.CreateFromPackage(encryptedFile,
        packageStream, publishLicense, cryptoProvider);

WriteStatus("   Adding an author's UseLicense.");
RightsManagementInformation rmi =
    ePackage.RightsManagementInformation;
rmi.SaveUseLicense(author, authorsUseLicense);

ePackage.Close();
WriteStatus("   Done - Package encryption complete.");

WriteStatus("Verifying package encryption.");
if (EncryptedPackageEnvelope.IsEncryptedPackageEnvelope(encryptedFile))
{
    WriteStatus("   Confirmed - '" + encryptedFilename +
                "' is encrypted.");
}
else
{
    MessageBox.Show("ERROR: '" + encryptedFilename +
        "' is NOT ENCRYPTED.", "Encryption Error",
        MessageBoxButton.OK, MessageBoxImage.Error);
    WriteStatus("ERROR: '" + encryptedFilename +
                "' is NOT ENCRYPTED.\n");
    return false;
}

.NET Framework
Available since 3.0
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