Rediger

CryptoProvider Class

Definition

Namespace:
System.Security.RightsManagement
Assembly:
WindowsBase.dll

Provides digital rights management services for encrypting and decrypting protected content.

public ref class CryptoProvider : IDisposable
public class CryptoProvider : IDisposable
type CryptoProvider = class
    interface IDisposable
Public Class CryptoProvider
Implements IDisposable
Inheritance
Object
CryptoProvider
Implements
IDisposable

Examples

The following example shows how to use the CryptoProvider class to create 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;
}

WriteStatus("   Signing the UnsignedPublishLicense" & vbLf & "       to build the PublishLicense.")
Dim authorsUseLicense As UseLicense = Nothing
Dim publishLicense As PublishLicense = unsignedLicense.Sign(_secureEnv, authorsUseLicense)

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

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

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

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

WriteStatus("Verifying package encryption.")
If EncryptedPackageEnvelope.IsEncryptedPackageEnvelope(encryptedFile) Then
    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." & vbLf)
    Return False
End If

Remarks

CryptoProvider is created as a result of the Bind method when binding a rights managed UseLicense to a SecureEnvironment.

As with other System.Security.RightsManagement types, CryptoProvider is only usable in full trust applications.

Properties

Name Description
BlockSize

Gets the cipher block size, in bytes.
BoundGrants

Gets a collection listing the rights that passed verification and that are granted to the user.
CanDecrypt

Gets a value that indicates whether the user has rights to decrypt.
CanEncrypt

Gets a value that indicates whether the user has rights to encrypt.
CanMergeBlocks

Gets a value that indicates whether Encrypt(Byte[]) and Decrypt(Byte[]) can accept buffers that are different block sizes in length.

Methods

Name Description
Decrypt(Byte[])

Decrypts cipher text to clear text.
Dispose()

Releases all resources used by the CryptoProvider.
Dispose(Boolean)

Releases the unmanaged resources used by the CryptoProvider and optionally releases the managed resources.
Encrypt(Byte[])

Encrypts clear text to cipher text.
Finalize()

Frees resources and performs internal cleanup before the instance is reclaimed by garbage collection.

Applies to

See also