////////////////////////////////////////////////////////////////////
// Encryption Constructor
////////////////////////////////////////////////////////////////////
internal PdfEncryption
(
PdfDocument Document,
String UserPassword,
String OwnerPassword,
Permission UserPermissions
) : base(Document)
{
// Notes:
// The PDF File Writer library supports AES 128 encryption only.
// The library does not strip leading or trailing white space. They are part of the password.
// EncriptMetadata is assumed to be true (this libraray does not use metadata).
// Embeded Files Only is assumed to be false (this library does not have embeded files).
Dictionary.Add("/Filter", "/Standard");
Dictionary.Add("/R", "4");
Dictionary.Add("/V", "4");
Dictionary.Add("/Length", "128");
// remove all unused bits and add all bits that must be one
Permissions = ((Int32)UserPermissions & (Int32)Permission.All) | PermissionBase;
Dictionary.AddInteger("/P", Permissions);
// convert user string password to byte array
Byte[] UserBinaryPassword = ProcessPassword(UserPassword);
// convert owner string password to byte array
if (String.IsNullOrEmpty(OwnerPassword))
{
OwnerPassword = BitConverter.ToUInt64(PdfDocument.RandomByteArray(8), 0).ToString();
}
Byte[] OwnerBinaryPassword = ProcessPassword(OwnerPassword);
// calculate owner key for crypto dictionary
Byte[] OwnerKey = CreateOwnerKey(UserBinaryPassword, OwnerBinaryPassword);
CreateMasterKey(UserBinaryPassword, OwnerKey);
Byte[] UserKey = CreateUserKey();
Dictionary.Add("/O", Document.ByteArrayToPdfHexString(OwnerKey));
Dictionary.Add("/U", Document.ByteArrayToPdfHexString(UserKey));
Dictionary.Add("/StrF", "/StdCF");
Dictionary.Add("/StmF", "/StdCF");
Dictionary.Add("/CF", "<</StdCF<</Length 16/AuthEvent/DocOpen/CFM/AESV2>>>>");
return;
}
////////////////////////////////////////////////////////////////////
// Encryption Constructor
////////////////////////////////////////////////////////////////////
internal PdfEncryption
(
PdfDocument Document,
string UserPassword,
string OwnerPassword,
Permission UserPermissions,
EncryptionType EncryptionType
) : base(Document)
{
// Notes:
// The PDF File Writer library supports AES 128 encryption and standard 128 encryption.
// The library does not strip leading or trailing white space. They are part of the password.
// EncriptMetadata is assumed to be true (this libraray does not use metadata).
// Embeded Files Only is assumed to be false (this library does not have embeded files).
// remove all unused bits and add all bits that must be one
Permissions = ((int)UserPermissions & (int)Permission.All) | PermissionBase;
Dictionary.AddInteger("/P", Permissions);
// convert user string password to byte array
var UserBinaryPassword = ProcessPassword(UserPassword);
// convert owner string password to byte array
if (string.IsNullOrEmpty(OwnerPassword))
{
OwnerPassword = BitConverter.ToUInt64(PdfDocument.RandomByteArray(8), 0).ToString();
}
var OwnerBinaryPassword = ProcessPassword(OwnerPassword);
// calculate owner key for crypto dictionary
var OwnerKey = CreateOwnerKey(UserBinaryPassword, OwnerBinaryPassword);
// create master key and user key
CreateMasterKey(UserBinaryPassword, OwnerKey);
var UserKey = CreateUserKey();
// build dictionary
Dictionary.Add("/Filter", "/Standard");
Dictionary.Add("/Length", "128");
Dictionary.Add("/O", Document.ByteArrayToPdfHexString(OwnerKey));
Dictionary.Add("/U", Document.ByteArrayToPdfHexString(UserKey));
// encryption type
this.EncryptionType = EncryptionType;
if (EncryptionType == EncryptionType.Aes128)
{
Dictionary.Add("/R", "4");
Dictionary.Add("/V", "4");
Dictionary.Add("/StrF", "/StdCF");
Dictionary.Add("/StmF", "/StdCF");
Dictionary.Add("/CF", "<</StdCF<</Length 16/AuthEvent/DocOpen/CFM/AESV2>>>>");
}
else
{
Dictionary.Add("/R", "3");
Dictionary.Add("/V", "2");
}
// add encryption to trailer dictionary
Document.TrailerDict.AddIndirectReference("/Encrypt", this);
}
