private void ProcessCryption()
{
if (IsEncrypted == CryptMethods.Unknown)
{
if (info?.name?.StartsWith(Config.CarotDAV_CryptNameHeader) ?? false)
{
IsEncrypted = CryptMethods.Method2_CBC_CarotDAV;
}
else if (Regex.IsMatch(info?.name ?? "", ".*?\\.[a-z0-9]{8}\\.enc$"))
{
IsEncrypted = CryptMethods.Method1_CTR;
_DisplayName = Path.GetFileNameWithoutExtension(Path.GetFileNameWithoutExtension(info.name));
return;
}
else if (Regex.IsMatch(info?.name ?? "", "^[\u2800-\u28ff]+$"))
{
IsEncrypted = CryptMethods.Method1_CTR;
var decodename = DriveData.DecryptFilename(info);
if (decodename != null)
{
IsEncrypted = CryptMethods.Method1_CTR;
_DisplayName = Path.GetFileNameWithoutExtension(decodename);
return;
}
_DisplayName = info?.name;
CryptError = true;
}
else
{
IsEncrypted = CryptMethods.Method0_Plain;
}
}
switch (IsEncrypted)
{
case CryptMethods.Method0_Plain:
_DisplayName = info?.name;
break;
case CryptMethods.Method1_CTR:
if (Regex.IsMatch(info?.name ?? "", ".*?\\.[a-z0-9]{8}\\.enc$"))
{
_DisplayName = Path.GetFileNameWithoutExtension(Path.GetFileNameWithoutExtension(info.name));
CryptError = false;
}
else if (Regex.IsMatch(info?.name ?? "", "^[\u2800-\u28ff]+$"))
{
var decodename = DriveData.DecryptFilename(info);
if (decodename != null)
{
_DisplayName = Path.GetFileNameWithoutExtension(decodename);
CryptError = false;
}
else
{
_DisplayName = info?.name;
CryptError = true;
}
}
else
{
IsEncrypted = CryptMethods.Method0_Plain;
_DisplayName = info?.name;
}
break;
case CryptMethods.Method2_CBC_CarotDAV:
{
var decodename = CryptCarotDAV.DecryptFilename(info?.name);
if (decodename != null)
{
_DisplayName = decodename;
CryptError = false;
}
else
{
_DisplayName = info?.name;
CryptError = true;
}
}
break;
}
}
public async Task <Stream> downloadFile(FileMetadata_Info target, long?from = null, long?to = null, string enckey = null, bool autodecrypt = true, CancellationToken ct = default(CancellationToken))
{
string id = target.id;
string filename = target.name;
CryptMethods Encrypted = CryptMethods.Method0_Plain;
if (enckey != null)
{
Encrypted = CryptMethods.Method1_CTR;
}
else
{
if (filename.StartsWith(Config.CarotDAV_CryptNameHeader))
{
Encrypted = CryptMethods.Method2_CBC_CarotDAV;
enckey = "";
}
else if (Regex.IsMatch(filename, ".*?\\.[a-z0-9]{8}\\.enc$"))
{
Encrypted = CryptMethods.Method1_CTR;
enckey = Path.GetFileNameWithoutExtension(filename);
}
else if (Regex.IsMatch(filename, "^[\u2800-\u28ff]+$"))
{
enckey = DriveData.DecryptFilename(target);
if (enckey != null)
{
Encrypted = CryptMethods.Method1_CTR;
}
}
if (enckey == null)
{
Encrypted = CryptMethods.Method0_Plain;
}
}
if (!autodecrypt)
{
Encrypted = CryptMethods.Method0_Plain;
}
Config.Log.LogOut("\t[downloadFile] " + id);
string error_str = "";
var client = new HttpClient();
client.Timeout = TimeSpan.FromDays(1);
try
{
long?fix_from = from, fix_to = to;
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", Authkey.access_token);
if (from != null || to != null)
{
if (Encrypted == CryptMethods.Method2_CBC_CarotDAV)
{
if (fix_from != null)
{
// ひとつ前のブロックから要求する
fix_from -= CryptCarotDAV.BlockSizeByte;
if (fix_from < CryptCarotDAV.BlockSizeByte)
{
// 先頭ブロックを取得するときはファイルの先頭から
fix_from = 0;
}
else
{
// ブロックにアライメントを合わせる
fix_from -= ((fix_from - 1) % CryptCarotDAV.BlockSizeByte + 1);
// 途中のブロックを要求された場合は、ヘッダをスキップ
fix_from += CryptCarotDAV.CryptHeaderByte;
}
}
if (fix_to != null)
{
if (fix_to >= target.OrignalLength)
{
// 末尾まで読み込むときは、ハッシュチェックのために最後まで読み込む
fix_to = null;
}
else
{
// オリジナルの位置を、暗号化済みの位置に変更
fix_to += CryptCarotDAV.CryptHeaderByte;
}
}
if (fix_from != null || fix_to != null)
{
client.DefaultRequestHeaders.Range = new RangeHeaderValue(fix_from, fix_to);
}
}
else
{
client.DefaultRequestHeaders.Range = new RangeHeaderValue(from, to);
}
}
string url = Config.contentUrl + "nodes/" + id + "/content?download=false";
var response = await client.GetAsync(
url,
HttpCompletionOption.ResponseHeadersRead,
ct).ConfigureAwait(false);
response.EnsureSuccessStatusCode();
if (Encrypted == CryptMethods.Method1_CTR)
{
return(new CryptCTR.AES256CTR_CryptStream(new ThrottleDownloadStream(new HashStream(await response.Content.ReadAsStreamAsync().ConfigureAwait(false), new MD5CryptoServiceProvider()), ct),
enckey,
from ?? 0));
}
else if (Encrypted == CryptMethods.Method2_CBC_CarotDAV)
{
return(new CryptCarotDAV.CryptCarotDAV_DecryptStream(new ThrottleDownloadStream(new HashStream(await response.Content.ReadAsStreamAsync().ConfigureAwait(false), new MD5CryptoServiceProvider()), ct),
from ?? 0,
fix_from ?? 0,
target.contentProperties?.size ?? -1
));
}
else
{
return(new ThrottleDownloadStream(new HashStream(await response.Content.ReadAsStreamAsync().ConfigureAwait(false), new MD5CryptoServiceProvider()), ct));
}
}
catch (HttpRequestException ex)
{
error_str = ex.Message;
Config.Log.LogOut("\t[downloadFile] " + error_str);
throw;
}
catch (OperationCanceledException)
{
throw;
}
catch (Exception ex)
{
error_str = ex.ToString();
Config.Log.LogOut("\t[downloadFile] " + error_str);
throw;
}
throw new SystemException("fileDownload failed. " + error_str);
}