/// <summary>
/// Changes the user password.<para> </para>
/// Remember that <paramref name="requestBody"/>'s field
/// <see cref="EpistleRequestBody.Body"/> should be the <see cref="UserChangePasswordRequestDto"/>
/// instance serialized into JSON and then compressed!
/// </summary>
/// <param name="requestBody">Request parameters DTO wrapped into an <see cref="EpistleRequestBody"/>.</param>
/// <returns><c>bool</c> indicating whether the change was successful or not.</returns>
public async Task <bool> ChangeUserPassword(EpistleRequestBody requestBody)
{
var request = EpistleRequest(requestBody, "users/change-pw", Method.Put);
RestResponse response = await restClient.ExecuteAsync(request).ConfigureAwait(false);
return(response?.StatusCode == HttpStatusCode.OK);
}
/// <summary>
/// Deletes a user irreversibly from the backend's db.<para> </para>
/// <paramref name="requestBody.Body"/> should directly be the unprocessed <see cref="User.PasswordSHA512"/>.
/// </summary>
/// <param name="requestBody">Request parameters DTO wrapped into an <see cref="EpistleRequestBody"/>.</param>
/// <returns>Whether deletion was successful or not.</returns>
public async Task <bool> DeleteUser(EpistleRequestBody requestBody)
{
var request = EpistleRequest(requestBody, "users/delete");
RestResponse response = await restClient.ExecuteAsync(request).ConfigureAwait(false);
return(response?.StatusCode == HttpStatusCode.NoContent);
}
/// <summary>
/// Kick a user from a conversation.
/// </summary>
/// <param name="requestBody">Request parameters.</param>
/// <returns>Whether the user was kicked out successfully or not.</returns>
public async Task <bool> KickUser(EpistleRequestBody requestBody)
{
var request = EpistleRequest(requestBody, "convos/kick", Method.Put);
RestResponse response = await restClient.ExecuteAsync(request);
return(response.IsSuccessful);
}
/// <summary>
/// Creates a new convo on the server.<para> </para>
/// "<paramref name="requestBody.Body"/>" should be the <see cref="ConvoCreationRequestDto"/> serialized into JSON and compressed.
/// </summary>
/// <param name="requestBody">Request body containing the parameters (auth, etc...).</param>
/// <returns><c>null</c> if creation failed; the created <see cref="Convo"/>'s unique id.</returns>
public async Task <string> CreateConvo(EpistleRequestBody requestBody)
{
var request = EpistleRequest(requestBody, "convos/create");
RestResponse response = await restClient.ExecuteAsync(request).ConfigureAwait(false);
return(response.IsSuccessful ? response.Content : null);
}
/// <summary>
/// Changes a convo's metadata (description, title, etc...).<para> </para>
/// The user making the request needs to be the <see cref="Convo"/>'s admin (Creator).<para> </para>
/// If you're assigning a new admin, he needs to be a participant of the <see cref="Convo"/>, else you'll get a bad request returned from the web api.
/// </summary>
/// <param name="requestBody">Request body containing the authentication parameters + the data that needs to be changed (<c>null</c> fields will be ignored; fields with values will be updated and persisted into the server's db)..</param>
/// <returns>Whether the convo's metadata was changed successfully or not.</returns>
public async Task <bool> ChangeConvoMetadata(EpistleRequestBody requestBody)
{
var request = EpistleRequest(requestBody, "convos/metadata", Method.Put);
RestResponse response = await restClient.ExecuteAsync(request);
return(response.IsSuccessful);
}
/// <summary>
/// Join a <see cref="Convo" />.
/// </summary>
/// <param name="requestBody">Request body containing the convo join parameters.</param>
/// <returns>Whether the <see cref="Convo" /> was joined successfully or not.</returns>
public async Task <bool> JoinConvo(EpistleRequestBody requestBody)
{
var request = EpistleRequest(requestBody, "convos/join", Method.Put);
RestResponse response = await restClient.ExecuteAsync(request).ConfigureAwait(false);
return(response.IsSuccessful);
}
/// <summary>
/// Posts a message to a <see cref="Convo" />.
/// </summary>
/// <param name="requestBody">Request body containing the message post parameters.</param>
/// <returns>Whether the message was posted successfully or not.</returns>
public async Task <bool> PostMessage(EpistleRequestBody requestBody)
{
var request = EpistleRequest(requestBody, "convos/post");
RestResponse response = await restClient.ExecuteAsync(request);
return(response.IsSuccessful);
}
#pragma warning restore 1591
/// <summary>
/// Changes an Epistle <see cref="User"/>'s password.
/// </summary>
/// <param name="oldPw">The old <see cref="User"/> password (NOT its SHA512!).</param>
/// <param name="newPw">The new, better and safer password (NOT its SHA512!).</param>
/// <param name="totp">Request authentication token.</param>
/// <returns>Whether the password change request was successful or not.</returns>
/// <exception cref="ApplicationException">Thrown if the <see cref="User.PrivateKeyPem"/> is <c>null</c> or empty.</exception>
public async Task <bool> ChangePassword(string oldPw, string newPw, string totp)
{
if (oldPw == newPw)
{
return(false);
}
if (user.PrivateKeyPem.NullOrEmpty())
{
string msg = "The user's in-memory private key seems to be null or empty; can't change passwords without re-encrypting a new copy of the user key!";
logger?.LogError(msg);
throw new ApplicationException(msg);
}
var dto = new UserChangePasswordRequestDto
{
Totp = totp,
OldPwSHA512 = oldPw.SHA512(),
NewPwSHA512 = newPw.SHA512(),
NewPrivateKey = await keyExchange.EncryptAndCompressPrivateKeyAsync(user.PrivateKeyPem, newPw).ConfigureAwait(false)
};
var requestBody = new EpistleRequestBody
{
UserId = user.Id,
Auth = user.Token.Item2,
Body = await compressionUtility.Compress(JsonSerializer.Serialize(dto)).ConfigureAwait(false)
};
bool success = await userService.ChangeUserPassword(requestBody.Sign(crypto, user.PrivateKeyPem)).ConfigureAwait(false);
return(success);
}
/// <summary>
/// Uploads a new profile picture to the server.
/// </summary>
/// <param name="totp">2FA Token.</param>
/// <param name="pic">The profile picture (base64-encoded). Can be <c>null</c>.</param>
/// <returns>Whether the update was accepted or failed.</returns>
public async Task <bool> UpdateUserProfilePicture(string totp, string pic)
{
try
{
if (user is null || pic.Length > 512 * 512 || user.Id.NullOrEmpty() || user.Token is null || user.Token.Item2.NullOrEmpty() || totp.NullOrEmpty())
{
return(false);
}
var dto = new UserChangeProfilePictureRequestDto
{
Totp = totp,
ProfilePicture = pic,
PasswordSHA512 = user.PasswordSHA512
};
var requestBody = new EpistleRequestBody
{
UserId = user.Id,
Auth = user.Token?.Item2,
Body = JsonSerializer.Serialize(dto)
};
var request = EpistleRequest(requestBody.Sign(rsa, user.PrivateKeyPem), "users/pic", Method.Put);
RestResponse response = await restClient.ExecuteAsync(request).ConfigureAwait(false);
return(response?.StatusCode == HttpStatusCode.OK);
}
catch
{
return(false);
}
}
private async void TryJoinConvos()
{
if (!appSettings["SaveConvoPasswords", true])
{
return;
}
var userConvos = (await userService.GetConvos(user.Id, user.Token.Item2))
.Select(c => (Convo)c)
.Distinct()
.Where(convo => !convo.IsExpired()).ToArray();
foreach (var convo in userConvos)
{
string cachedPwSHA512 = convoPasswordProvider.GetPasswordSHA512(convo.Id);
if (cachedPwSHA512.NullOrEmpty())
{
cachedPwSHA512 = await SecureStorage.GetAsync($"convo:{convo.Id}_pw:SHA512");
}
if (cachedPwSHA512.NotNullNotEmpty())
{
var dto = new ConvoJoinRequestDto
{
ConvoId = convo.Id,
ConvoPasswordSHA512 = cachedPwSHA512
};
var body = new EpistleRequestBody
{
UserId = user.Id,
Auth = user.Token.Item2,
Body = JsonSerializer.Serialize(dto)
};
if (await convoService.JoinConvo(body.Sign(crypto, user.PrivateKeyPem)))
{
convoPasswordProvider.SetPasswordSHA512(convo.Id, cachedPwSHA512);
ConvoMetadataDto metadata = await convoService.GetConvoMetadata(convo.Id, cachedPwSHA512, user.Id, user.Token.Item2);
if (metadata != null)
{
var viewModel = viewModelFactory.Create <ActiveConvoViewModel>();
viewModel.ActiveConvo = convo;
viewModel.OnAppearing();
activeConvos[convo.Id] = viewModel;
}
}
}
}
eventAggregator.GetEvent <TriggerUpdateConvosListEvent>().Publish();
}
/// <summary>
/// Creates a <see cref="RestRequest"/> using the provided <paramref name="requestBody"/>, <paramref name="endpoint"/> and <paramref name="method"/>.<para> </para>
/// The <paramref name="requestBody"/> is serialized to JSON and added to the HTTP request body.<para> </para>
/// Please only add bodies to POST, and maybe PUT requests...
/// </summary>
/// <param name="requestBody">The <see cref="EpistleRequestBody"/> to serialize into JSON and add to the HTTP POST (or PUT) request's body.</param>
/// <param name="endpoint">The API endpoint (relative path).</param>
/// <param name="method">The HTTP method to use. Should be either POST or PUT if you use the request body.</param>
/// <returns>The <see cref="RestRequest"/>, ready to be submitted.</returns>
protected RestRequest EpistleRequest(EpistleRequestBody requestBody, string endpoint, Method method = Method.Post)
{
if (method != Method.Post && method != Method.Put)
{
throw new ArgumentException($"{nameof(EpistleWebApiService)}::{nameof(EpistleRequest)}: Non-PUT or POST HTTP method passed. Please only add request bodies to POST and PUT requests!");
}
var request = new RestRequest(
method: method,
resource: new Uri(endpoint, UriKind.Relative)
);
request.AddStringBody(JsonSerializer.Serialize(requestBody), "application/json");
return(request);
}
/// <summary>
/// Deletes a convo server-side.
/// </summary>
/// <param name="requestBody">Request body containing the convo deletion parameters (auth, etc...).</param>
/// <returns>Whether deletion was successful or not.</returns>
public async Task <bool> DeleteConvo(EpistleRequestBody requestBody)
{
RestResponse response = await restClient.ExecuteAsync(EpistleRequest(requestBody, "convos/delete"));
return(response.IsSuccessful);
}
/// <summary>
/// Submits a message to a <see cref="Convo"/>.
/// </summary>
/// <param name="convo">The <see cref="Convo"/> to post the message into.</param>
/// <param name="messageType">The type of message (e.g. "TEXT=UTF8", "FILE=example.png", etc...).</param>
/// <param name="message">The message body to encrypt and post.</param>
/// <returns>Whether the message could be submitted successfully or not.</returns>
private async Task <bool> PostMessageToConvo(Convo convo, string messageType, byte[] message)
{
if (message.NullOrEmpty())
{
return(false);
}
Task <IDictionary <string, string> > publicKeys = userService.GetUserPublicKeys(user.Id, convo.GetParticipantIdsCommaSeparated(), user.Token.Item2);
byte[] compressedMessage = await compressionUtility.Compress(message, CompressionSettings.Default).ConfigureAwait(false);
using var encryptionResult = await aes.EncryptAsync(compressedMessage).ConfigureAwait(false);
byte[] key = new byte[48];
for (int i = 0; i < 32; i++)
{
key[i] = encryptionResult.Key[i];
}
for (int i = 0; i < 16; i++)
{
key[i + 32] = encryptionResult.IV[i];
}
// Encrypt the message decryption key for every convo participant individually.
var encryptedKeys = new ConcurrentBag <string>();
Parallel.ForEach(await publicKeys.ConfigureAwait(false), kvp =>
{
(string userId, string userPublicKey) = kvp;
if (userId.NotNullNotEmpty() && userPublicKey.NotNullNotEmpty())
{
string decompressedPublicKey = keyExchange.DecompressPublicKey(userPublicKey);
encryptedKeys.Add(userId + ':' + Convert.ToBase64String(rsa.Encrypt(key, decompressedPublicKey)));
}
});
try
{
var postParamsDto = new PostMessageParamsDto
{
Type = messageType,
SenderName = userSettings.Username,
ConvoId = convo.Id,
ConvoPasswordSHA512 = convoPasswordProvider.GetPasswordSHA512(convo.Id),
EncryptedKeys = encryptedKeys.ToCommaSeparatedString(),
EncryptedBody = Convert.ToBase64String(encryptionResult.EncryptedData)
};
var body = new EpistleRequestBody
{
UserId = user.Id,
Auth = user.Token.Item2,
Body = JsonSerializer.Serialize(postParamsDto)
};
return(await convoService.PostMessage(body.Sign(rsa, user.PrivateKeyPem)).ConfigureAwait(false));
}
catch
{
return(false);
}
}