/// <summary>
/// Prepares the security handler for encrypting the document.
/// Entry point for encryption of a document that is about to be saved.
/// </summary>
public void PrepareEncryption()
{
#if !SILVERLIGHT
Debug.Assert(this._document._securitySettings.DocumentSecurityLevel != PdfDocumentSecurityLevel.None);
int permissions = (int)this.Permission;
bool strongEncryption = this._document._securitySettings.DocumentSecurityLevel >= PdfDocumentSecurityLevel.Encrypted128Bit;
stringEncryptor = EncryptorFactory.InitEncryption(_document, this);
streamEncryptor = stringEncryptor;
// using the AES encryption implies a Pdf Version 1.7 ?
//if (_document._securitySettings.DocumentSecurityLevel >= PdfDocumentSecurityLevel.EncryptedAES256 && _document.Version < 17)
// _document.Version = 17;
// Correct permission bits
permissions |= (int)(strongEncryption ? (uint)0xfffff0c0 : (uint)0xffffffc0);
permissions &= unchecked ((int)0xfffffffc);
PdfInteger pValue = new PdfInteger(permissions);
Elements[Keys.P] = pValue;
#endif
}
/// <summary>
/// Checks the password.
/// Entry point for decrypting a loaded document
/// </summary>
/// <param name="inputPassword">Password or null if no password is provided.</param>
public PasswordValidity ValidatePassword(string inputPassword)
{
if (inputPassword == null)
{
inputPassword = "";
}
EncryptorFactory.InitDecryption(_document, this, out stringEncryptor, out streamEncryptor);
if (stringEncryptor == null && streamEncryptor == null)
{
throw new PdfSharpException("No suitable decryptor available. Send this document to support.");
}
if (streamEncryptor == null && stringEncryptor != null)
{
streamEncryptor = stringEncryptor;
}
else if (stringEncryptor == null)
{
stringEncryptor = streamEncryptor;
}
stringEncryptor.InitEncryptionKey(inputPassword);
streamEncryptor.InitEncryptionKey(inputPassword);
stringEncryptor.ValidatePassword(inputPassword);
if (stringEncryptor.PasswordValid && stringEncryptor.HaveOwnerPermission)
{
return(PasswordValidity.OwnerPassword);
}
if (stringEncryptor.PasswordValid)
{
return(PasswordValidity.UserPassword);
}
return(PasswordValidity.Invalid);
}