/// <summary>
/// Encrypt a file message and send it to the given recipient.
/// The thumbnailMessagePath can be null.
/// </summary>
/// <param name="threemaId">target Threema ID</param>
/// <param name="fileMessageFile">the file to be sent</param>
/// <param name="thumbnailMessageFile">file for thumbnail; if not set, no thumbnail will be sent</param>
/// <returns>generated message ID</returns>
public string SendFileMessage(string threemaId, FileInfo fileMessageFile, FileInfo thumbnailMessageFile)
{
//fetch public key
byte[] publicKey = this.apiConnector.LookupKey(threemaId);
if (publicKey == null)
{
throw new InvalidKeyException("invalid threema id");
}
//check capability of a key
CapabilityResult capabilityResult = this.apiConnector.LookupKeyCapability(threemaId);
if (capabilityResult == null || !capabilityResult.CanImage)
{
throw new NotAllowedException();
}
if (fileMessageFile == null)
{
throw new ArgumentException("fileMessageFile must not be null.");
}
if (!fileMessageFile.Exists)
{
throw new FileNotFoundException(fileMessageFile.FullName);
}
byte[] fileData;
using (Stream stream = File.OpenRead(fileMessageFile.FullName))
{
fileData = new byte[stream.Length];
stream.Read(fileData, 0, (int)stream.Length);
stream.Close();
}
if (fileData == null)
{
throw new IOException("invalid file");
}
//encrypt the image
EncryptResult encryptResult = CryptTool.EncryptFileData(fileData);
//upload the image
UploadResult uploadResult = apiConnector.UploadFile(encryptResult);
if (!uploadResult.IsSuccess)
{
throw new IOException("could not upload file (upload response " + uploadResult.ResponseCode + ")");
}
UploadResult uploadResultThumbnail = null;
if (thumbnailMessageFile != null && thumbnailMessageFile.Exists)
{
byte[] thumbnailData;
using (Stream stream = File.OpenRead(thumbnailMessageFile.FullName))
{
thumbnailData = new byte[stream.Length];
stream.Read(thumbnailData, 0, (int)stream.Length);
stream.Close();
}
if (thumbnailData == null)
{
throw new IOException("invalid thumbnail file");
}
//encrypt the thumbnail
EncryptResult encryptResultThumbnail = CryptTool.encryptFileThumbnailData(fileData, encryptResult.Secret);
//upload the thumbnail
uploadResultThumbnail = this.apiConnector.UploadFile(encryptResultThumbnail);
}
//send it
EncryptResult fileMessage = CryptTool.EncryptFileMessage(
encryptResult,
uploadResult,
GetMIMEType(fileMessageFile),
fileMessageFile.Name,
(int)fileMessageFile.Length,
uploadResultThumbnail,
privateKey, publicKey);
return(this.apiConnector.SendE2EMessage(
threemaId,
fileMessage.Nonce,
fileMessage.Result));
}