private void InitKeyAndReadDictionary(PdfDictionary encryptionDictionary, byte[] password)
{
try {
if (password == null)
{
password = new byte[0];
}
else
{
if (password.Length > 127)
{
password = JavaUtil.ArraysCopyOf(password, 127);
}
}
isPdf2 = encryptionDictionary.GetAsNumber(PdfName.R).GetValue() == 6;
byte[] oValue = GetIsoBytes(encryptionDictionary.GetAsString(PdfName.O));
byte[] uValue = GetIsoBytes(encryptionDictionary.GetAsString(PdfName.U));
byte[] oeValue = GetIsoBytes(encryptionDictionary.GetAsString(PdfName.OE));
byte[] ueValue = GetIsoBytes(encryptionDictionary.GetAsString(PdfName.UE));
byte[] perms = GetIsoBytes(encryptionDictionary.GetAsString(PdfName.Perms));
PdfNumber pValue = (PdfNumber)encryptionDictionary.Get(PdfName.P);
this.permissions = pValue.LongValue();
byte[] hash;
hash = ComputeHash(password, oValue, VALIDATION_SALT_OFFSET, SALT_LENGTH, uValue);
usedOwnerPassword = CompareArray(hash, oValue, 32);
if (usedOwnerPassword)
{
hash = ComputeHash(password, oValue, KEY_SALT_OFFSET, SALT_LENGTH, uValue);
AESCipherCBCnoPad ac = new AESCipherCBCnoPad(false, hash);
nextObjectKey = ac.ProcessBlock(oeValue, 0, oeValue.Length);
}
else
{
hash = ComputeHash(password, uValue, VALIDATION_SALT_OFFSET, SALT_LENGTH);
if (!CompareArray(hash, uValue, 32))
{
throw new BadPasswordException(PdfException.BadUserPassword);
}
hash = ComputeHash(password, uValue, KEY_SALT_OFFSET, SALT_LENGTH);
AESCipherCBCnoPad ac = new AESCipherCBCnoPad(false, hash);
nextObjectKey = ac.ProcessBlock(ueValue, 0, ueValue.Length);
}
nextObjectKeySize = 32;
AESCipherCBCnoPad ac_1 = new AESCipherCBCnoPad(false, nextObjectKey);
byte[] decPerms = ac_1.ProcessBlock(perms, 0, perms.Length);
if (decPerms[9] != (byte)'a' || decPerms[10] != (byte)'d' || decPerms[11] != (byte)'b')
{
throw new BadPasswordException(PdfException.BadUserPassword);
}
int permissionsDecoded = (decPerms[0] & 0xff) | ((decPerms[1] & 0xff) << 8) | ((decPerms[2] & 0xff) << 16)
| ((decPerms[3] & 0xff) << 24);
bool encryptMetadata = decPerms[8] == (byte)'T';
bool?encryptMetadataEntry = encryptionDictionary.GetAsBool(PdfName.EncryptMetadata);
if (permissionsDecoded != permissions || encryptMetadataEntry != null && encryptMetadata != encryptMetadataEntry
)
{
ILog logger = LogManager.GetLogger(typeof(iText.Kernel.Crypto.Securityhandler.StandardHandlerUsingAes256));
logger.Error(iText.IO.LogMessageConstant.ENCRYPTION_ENTRIES_P_AND_ENCRYPT_METADATA_NOT_CORRESPOND_PERMS_ENTRY
);
}
this.permissions = permissionsDecoded;
this.encryptMetadata = encryptMetadata;
}
catch (BadPasswordException ex) {
throw;
}
catch (Exception ex) {
throw new PdfException(PdfException.PdfEncryption, ex);
}
}
