/// <summary>
/// Convert the file trailer dictionary into a <see cref="DocumentInformation"/> instance.
/// </summary>
public static DocumentInformation Create(IPdfTokenScanner pdfTokenScanner, TrailerDictionary trailer, bool isLenientParsing)
{
if (!trailer.Info.HasValue)
{
return(DocumentInformation.Default);
}
var token = DirectObjectFinder.Get <IToken>(trailer.Info.Value, pdfTokenScanner);
if (token is DictionaryToken infoParsed)
{
var title = GetEntryOrDefault(infoParsed, NameToken.Title);
var author = GetEntryOrDefault(infoParsed, NameToken.Author);
var subject = GetEntryOrDefault(infoParsed, NameToken.Subject);
var keywords = GetEntryOrDefault(infoParsed, NameToken.Keywords);
var creator = GetEntryOrDefault(infoParsed, NameToken.Creator);
var producer = GetEntryOrDefault(infoParsed, NameToken.Producer);
var creationDate = GetEntryOrDefault(infoParsed, NameToken.CreationDate);
var modifiedDate = GetEntryOrDefault(infoParsed, NameToken.ModDate);
return(new DocumentInformation(infoParsed, title, author, subject,
keywords, creator, producer, creationDate, modifiedDate));
}
if (token is StreamToken streamToken)
{
var streamDictionary = streamToken.StreamDictionary;
if (!streamDictionary.TryGet(NameToken.Type, out NameToken typeNameToken) || typeNameToken != "Metadata")
{
throw new PdfDocumentFormatException("Unknown document metadata type was found");
}
if (!streamDictionary.TryGet(NameToken.Subtype, out NameToken subtypeToken) || subtypeToken != "XML")
{
throw new PdfDocumentFormatException("Unknown document metadata subtype was found");
}
// We are not fully supporting XMP Stream so we let the user fully deserialize the stream
return(DocumentInformation.Default);
}
if (isLenientParsing)
{
return(DocumentInformation.Default);
}
throw new PdfDocumentFormatException($"Unknown document information token was found {token.GetType().Name}");
}
public DocumentInformation Create(IPdfTokenScanner pdfTokenScanner, TrailerDictionary trailer)
{
if (!trailer.Info.HasValue)
{
return(DocumentInformation.Default);
}
var infoParsed = DirectObjectFinder.Get <DictionaryToken>(trailer.Info.Value, pdfTokenScanner);
var title = GetEntryOrDefault(infoParsed, NameToken.Title);
var author = GetEntryOrDefault(infoParsed, NameToken.Author);
var subject = GetEntryOrDefault(infoParsed, NameToken.Subject);
var keywords = GetEntryOrDefault(infoParsed, NameToken.Keywords);
var creator = GetEntryOrDefault(infoParsed, NameToken.Creator);
var producer = GetEntryOrDefault(infoParsed, NameToken.Producer);
return(new DocumentInformation(infoParsed, title, author, subject,
keywords, creator, producer));
}
public EncryptionHandler(EncryptionDictionary encryptionDictionary, TrailerDictionary trailerDictionary, IReadOnlyList <string> passwords)
{
this.encryptionDictionary = encryptionDictionary;
passwords = passwords ?? new[] { string.Empty };
if (!passwords.Contains(string.Empty))
{
passwords = new List <string>(passwords)
{
string.Empty
};
}
byte[] documentIdBytes;
if (trailerDictionary.Identifier != null && trailerDictionary.Identifier.Count == 2)
{
var token = trailerDictionary.Identifier[0];
switch (token)
{
case HexToken hex:
documentIdBytes = hex.Bytes.ToArray();
break;
default:
documentIdBytes = OtherEncodings.StringAsLatin1Bytes(token.Data);
break;
}
}
else
{
documentIdBytes = EmptyArray <byte> .Instance;
}
if (encryptionDictionary == null)
{
return;
}
useAes = false;
if (encryptionDictionary.EncryptionAlgorithmCode == EncryptionAlgorithmCode.SecurityHandlerInDocument ||
encryptionDictionary.EncryptionAlgorithmCode == EncryptionAlgorithmCode.SecurityHandlerInDocument256)
{
if (!encryptionDictionary.TryGetCryptHandler(out var cryptHandlerLocal))
{
throw new PdfDocumentEncryptedException("Document encrypted with security handler in document but no crypt dictionary found.", encryptionDictionary);
}
cryptHandler = cryptHandlerLocal;
useAes = cryptHandlerLocal?.StreamDictionary?.Name == CryptDictionary.Method.AesV2 ||
cryptHandlerLocal?.StreamDictionary?.Name == CryptDictionary.Method.AesV3;
}
var charset = OtherEncodings.Iso88591;
if (encryptionDictionary.Revision == 5 || encryptionDictionary.Revision == 6)
{
// ReSharper disable once RedundantAssignment
charset = Encoding.UTF8;
}
var length = encryptionDictionary.EncryptionAlgorithmCode == EncryptionAlgorithmCode.Rc4OrAes40BitKey
? 5
: encryptionDictionary.KeyLength.GetValueOrDefault() / 8;
var foundPassword = false;
foreach (var password in passwords)
{
var passwordBytes = charset.GetBytes(password);
var isUserPassword = false;
byte[] decryptionPasswordBytes;
if (IsOwnerPassword(passwordBytes, encryptionDictionary, length, documentIdBytes, out var userPassBytes))
{
if (encryptionDictionary.Revision == 5 || encryptionDictionary.Revision == 6)
{
decryptionPasswordBytes = passwordBytes;
}
else
{
decryptionPasswordBytes = userPassBytes;
}
}
else if (IsUserPassword(passwordBytes, encryptionDictionary, length, documentIdBytes))
{
decryptionPasswordBytes = passwordBytes;
isUserPassword = true;
}
else
{
continue;
}
encryptionKey = CalculateEncryptionKey(decryptionPasswordBytes, encryptionDictionary,
length,
documentIdBytes,
isUserPassword);
foundPassword = true;
break;
}
if (!foundPassword)
{
throw new PdfDocumentEncryptedException("The document was encrypted and none of the provided passwords were the user or owner password.",
encryptionDictionary);
}
}
public EncryptionHandler(EncryptionDictionary encryptionDictionary, TrailerDictionary trailerDictionary, string password)
{
this.encryptionDictionary = encryptionDictionary;
var documentIdBytes = trailerDictionary.Identifier != null && trailerDictionary.Identifier.Count == 2 ?
OtherEncodings.StringAsLatin1Bytes(trailerDictionary.Identifier[0])
: EmptyArray <byte> .Instance;
password = password ?? string.Empty;
if (encryptionDictionary == null)
{
return;
}
useAes = false;
if (encryptionDictionary.EncryptionAlgorithmCode == EncryptionAlgorithmCode.SecurityHandlerInDocument ||
encryptionDictionary.EncryptionAlgorithmCode == EncryptionAlgorithmCode.SecurityHandlerInDocument256)
{
if (!encryptionDictionary.TryGetCryptHandler(out var cryptHandlerLocal))
{
throw new PdfDocumentEncryptedException("Document encrypted with security handler in document but no crypt dictionary found.", encryptionDictionary);
}
cryptHandler = cryptHandlerLocal;
useAes = cryptHandlerLocal?.StreamDictionary?.Name == CryptDictionary.Method.AesV2 ||
cryptHandlerLocal?.StreamDictionary?.Name == CryptDictionary.Method.AesV3;
}
var charset = OtherEncodings.Iso88591;
if (encryptionDictionary.Revision == 5 || encryptionDictionary.Revision == 6)
{
// ReSharper disable once RedundantAssignment
charset = Encoding.UTF8;
}
var passwordBytes = charset.GetBytes(password);
byte[] decryptionPasswordBytes;
var length = encryptionDictionary.EncryptionAlgorithmCode == EncryptionAlgorithmCode.Rc4OrAes40BitKey
? 5
: encryptionDictionary.KeyLength.GetValueOrDefault() / 8;
var isUserPassword = false;
if (IsOwnerPassword(passwordBytes, encryptionDictionary, length, documentIdBytes, out var userPassBytes))
{
if (encryptionDictionary.Revision == 5 || encryptionDictionary.Revision == 6)
{
decryptionPasswordBytes = passwordBytes;
}
else
{
decryptionPasswordBytes = userPassBytes;
}
}
else if (IsUserPassword(passwordBytes, encryptionDictionary, length, documentIdBytes))
{
decryptionPasswordBytes = passwordBytes;
isUserPassword = true;
}
else
{
throw new PdfDocumentEncryptedException("The document was encrypted and the provided password was neither the user or owner password.", encryptionDictionary);
}
encryptionKey = CalculateEncryptionKey(decryptionPasswordBytes, encryptionDictionary,
length,
documentIdBytes,
isUserPassword);
}
