Stream CreateAndInitEncryptionStream(Stream baseStream, ZipEntry entry)
{
CryptoStream result = null;
if ( (entry.Version < ZipConstants.VersionStrongEncryption)
|| (entry.Flags & (int)GeneralBitFlags.StrongEncryption) == 0) {
PkzipClassicManaged classicManaged = new PkzipClassicManaged();
OnKeysRequired(entry.Name);
if (HaveKeys == false) {
throw new ZipException("No password available for encrypted stream");
}
// Closing a CryptoStream will close the base stream as well so wrap it in an UncompressedStream
// which doesnt do this.
result = new CryptoStream(new UncompressedStream(baseStream),
classicManaged.CreateEncryptor(key, null), CryptoStreamMode.Write);
if ( (entry.Crc < 0) || (entry.Flags & 8) != 0) {
WriteEncryptionHeader(result, entry.DosTime << 16);
}
else {
WriteEncryptionHeader(result, entry.Crc);
}
}
return result;
}
