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Diffstat (limited to 'plugins/VNLib.Plugins.Essentials.SocialOauth/src/SocialOauthBase.cs')
| -rw-r--r-- | plugins/VNLib.Plugins.Essentials.SocialOauth/src/SocialOauthBase.cs | 617 |
1 files changed, 617 insertions, 0 deletions
diff --git a/plugins/VNLib.Plugins.Essentials.SocialOauth/src/SocialOauthBase.cs b/plugins/VNLib.Plugins.Essentials.SocialOauth/src/SocialOauthBase.cs new file mode 100644 index 0000000..6815bf3 --- /dev/null +++ b/plugins/VNLib.Plugins.Essentials.SocialOauth/src/SocialOauthBase.cs @@ -0,0 +1,617 @@ +/* +* Copyright (c) 2022 Vaughn Nugent +* +* Library: VNLib +* Package: VNLib.Plugins.Essentials.SocialOauth +* File: SocialOauthBase.cs +* +* SocialOauthBase.cs is part of VNLib.Plugins.Essentials.SocialOauth which is part of the larger +* VNLib collection of libraries and utilities. +* +* VNLib.Plugins.Essentials.SocialOauth is free software: you can redistribute it and/or modify +* it under the terms of the GNU Affero General Public License as +* published by the Free Software Foundation, either version 3 of the +* License, or (at your option) any later version. +* +* VNLib.Plugins.Essentials.SocialOauth is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU Affero General Public License for more details. +* +* You should have received a copy of the GNU Affero General Public License +* along with this program. If not, see https://www.gnu.org/licenses/. +*/ + +using System; +using System.Net; +using System.Text; +using System.Text.Json; +using System.Threading; +using System.Threading.Tasks; +using System.Collections.Generic; +using System.Security.Cryptography; +using System.Text.Json.Serialization; +using System.Runtime.InteropServices; + +using FluentValidation; + +using RestSharp; +using VNLib.Net.Http; +using VNLib.Net.Rest.Client; +using VNLib.Hashing; +using VNLib.Utils; +using VNLib.Utils.Memory; +using VNLib.Utils.Logging; +using VNLib.Utils.Extensions; +using VNLib.Utils.Memory.Caching; +using VNLib.Plugins.Essentials.Users; +using VNLib.Plugins.Essentials.Accounts; +using VNLib.Plugins.Essentials.Endpoints; +using VNLib.Plugins.Essentials.Extensions; +using VNLib.Plugins.Extensions.Validation; +using VNLib.Plugins.Essentials.SocialOauth.Validators; + +namespace VNLib.Plugins.Essentials.SocialOauth +{ + + /// <summary> + /// Provides a base class for derriving commong OAuth2 implicit authentication + /// </summary> + public abstract class SocialOauthBase : UnprotectedWebEndpoint + { + const string AUTH_ERROR_MESSAGE = "You have no pending authentication requests."; + + const string AUTH_GRANT_SESSION_NAME = "auth"; + + /// <summary> + /// The client configuration struct passed during base class construction + /// </summary> + protected abstract OauthClientConfig Config { get; } + + ///<inheritdoc/> + protected override ProtectionSettings EndpointProtectionSettings { get; } = new() + { + /* + * Disable cross site checking because the OAuth2 flow requires + * cross site when redirecting the client back + */ + DisableCrossSiteDenied = true + }; + + /// <summary> + /// The resst client connection pool + /// </summary> + protected RestClientPool ClientPool { get; } + + private readonly Dictionary<string, LoginClaim> ClaimStore; + private readonly Dictionary<string, OAuthAccessState> AuthorizationStore; + private readonly IValidator<LoginClaim> ClaimValidator; + private readonly IValidator<string> NonceValidator; + private readonly IValidator<AccountData> AccountDataValidator; + + protected SocialOauthBase() + { + ClaimStore = new(StringComparer.OrdinalIgnoreCase); + AuthorizationStore = new(StringComparer.OrdinalIgnoreCase); + ClaimValidator = GetClaimValidator(); + NonceValidator = GetNonceValidator(); + AccountDataValidator = new AccountDataValidator(); + + RestClientOptions poolOptions = new() + { + MaxTimeout = 5000, + AutomaticDecompression = DecompressionMethods.All, + Encoding = Encoding.UTF8, + //disable redirects, api should not redirect + FollowRedirects = false, + }; + + //Configure rest client to comunications to main discord api + ClientPool = new(10, poolOptions, StaticClientPoolInitializer); + } + + private static IValidator<LoginClaim> GetClaimValidator() + { + InlineValidator<LoginClaim> val = new(); + val.RuleFor(static s => s.ClientId) + .Length(10, 100) + .WithMessage("Request is not valid"); + + val.RuleFor(static s => s.PublicKey) + .Length(50, 1024) + .WithMessage("Request is not valid"); + + return val; + } + private static IValidator<string> GetNonceValidator() + { + InlineValidator<string> val = new(); + val.RuleFor(static s => s) + .Length(10, 200) + //Nonces are base32, so only alpha num + .AlphaNumeric(); + return val; + } + + protected override ERRNO PreProccess(HttpEntity entity) + { + if (!base.PreProccess(entity)) + { + return false; + } + /* + * Cross site checking is disabled because we need to allow cross site + * for OAuth2 redirect flows + */ + if (entity.Server.Method != HttpMethod.GET && entity.Server.IsCrossSite()) + { + return false; + } + //Make sure the user is not logged in + if(entity.LoginCookieMatches() || entity.TokenMatches()) + { + return false; + } + return true; + } + + /// <summary> + /// Invoked by the constructor during rest client initlialization + /// </summary> + /// <param name="client">The new client to be configured</param> + protected virtual void StaticClientPoolInitializer(RestClient client) + { + client.AddDefaultHeader("accept", HttpHelpers.GetContentTypeString(ContentType.Json)); + client.UseSerializer<RestSharp.Serializers.Json.SystemTextJsonSerializer>(); + } + + protected virtual void OnBeforeGetToken(HttpEntity entity, string code, RestRequest state) { } + + /// <summary> + /// When derrived in a child class, exchanges an OAuth2 code grant type + /// for an OAuth2 access token to make api requests + /// </summary> + /// <param name="ev"></param> + /// <param name="code">The raw code from the remote OAuth2 granting server</param> + /// <param name="cancellationToken">A token to cancel the operation</param> + /// <returns> + /// A task the resolves the <see cref="OAuthAccessState"/> that includes all relavent + /// authorization data. Result may be null if authorzation is invalid or not granted + /// </returns> + /// <param name="cancellationToken"></param> + protected async Task<OAuthAccessState?> ExchangeCodeForTokenAsync(HttpEntity ev, string code, CancellationToken cancellationToken) + { + //valid response, time to get the actual authorization from gh for client + RestRequest request = new(Config.AccessTokenUrl, Method.Post); + + //Add required params url-encoded + request.AddParameter("client_id", Config.ClientID, ParameterType.GetOrPost); + request.AddParameter("client_secret", Config.ClientSecret, ParameterType.GetOrPost); + request.AddParameter("grant_type", "authorization_code", ParameterType.GetOrPost); + request.AddParameter("code", code, ParameterType.GetOrPost); + request.AddParameter("redirect_uri", $"{ev.Server.RequestUri.Scheme}://{ev.Server.RequestUri.Authority}{Path}", ParameterType.GetOrPost); + + //Allow reconfiguration + OnBeforeGetToken(ev, code, request); + + //Get client from pool + using ClientContract client = ClientPool.Lease(); + //Execute request and attempt to recover the authorization response + RestResponse<OAuthAccessState> response = await client.Resource.ExecuteAsync<OAuthAccessState>(request, cancellationToken: cancellationToken); + //Make sure successfull, if so return the access token to store + return response.IsSuccessful && response.Data != null ? response.Data : null; + } + + /// <summary> + /// Gets an object that represents the user's account data from the OAuth provider when + /// creating a new user for the current platform + /// </summary> + /// <param name="clientAccess">The access state from the code/token exchange</param> + /// <param name="cancellationToken">A token to cancel the operation</param> + /// <returns>The user's account data, null if not account exsits on the remote site, and process cannot continue</returns> + /// <param name="cancellationToken"></param> + protected abstract Task<AccountData?> GetAccountDataAsync(IOAuthAccessState clientAccess, CancellationToken cancellationToken); + /// <summary> + /// Gets an object that represents the required information for logging-in a user (namley unique user-id) + /// </summary> + /// <param name="clientAccess">The authorization information granted from the OAuth2 authorization server</param> + /// <param name="cancellation">A token to cancel the operation</param> + /// <returns></returns> + protected abstract Task<UserLoginData?> GetLoginDataAsync(IOAuthAccessState clientAccess, CancellationToken cancellation); + + class LoginClaim : ICacheable, INonce + { + [JsonPropertyName("public_key")] + public string? PublicKey { get; set; } + [JsonPropertyName("browser_id")] + public string? ClientId { get; set; } + + /// <summary> + /// The raw OAuth flow state parameter the client must decrypt before + /// navigating to remote authentication source + /// </summary> + [JsonIgnore] + public ReadOnlyMemory<byte> RawNonce { get; private set; } + [JsonIgnore] + DateTime ICacheable.Expires { get; set; } + bool IEquatable<ICacheable>.Equals(ICacheable? other) => Equals(other); + void ICacheable.Evicted() + { + //Erase nonce + Memory.UnsafeZeroMemory(RawNonce); + } + + public override bool Equals(object? obj) + { + return obj is LoginClaim otherClaim && this.PublicKey!.Equals(otherClaim.PublicKey, StringComparison.Ordinal); + } + public override int GetHashCode() => PublicKey!.GetHashCode(); + + void INonce.ComputeNonce(Span<byte> buffer) + { + RandomHash.GetRandomBytes(buffer); + //Store copy + RawNonce = buffer.ToArray(); + } + + bool INonce.VerifyNonce(ReadOnlySpan<byte> nonceBytes) + { + return CryptographicOperations.FixedTimeEquals(RawNonce.Span, nonceBytes); + } + } + + /* + * Get method is invoked when the remote OAuth2 control has been passed back + * to this server. If successfull should include a code that grants authorization + * and include a state variable that the client decrypted from an initial claim + * to prove its identity + */ + + protected override async ValueTask<VfReturnType> GetAsync(HttpEntity entity) + { + //Make sure state and code parameters are available + if (entity.QueryArgs.TryGetNonEmptyValue("state", out string? state) && entity.QueryArgs.TryGetNonEmptyValue("code", out string? code)) + { + //Disable refer headers when nonce is set + entity.Server.Headers["Referrer-Policy"] = "no-referrer"; + + //Check for security navigation headers. This should be a browser redirect, + if (!entity.Server.IsNavigation() || !entity.Server.IsUserInvoked()) + { + //The connection was not a browser redirect + entity.Redirect(RedirectType.Temporary, $"{Path}?result=bad_sec"); + return VfReturnType.VirtualSkip; + } + //Try to get the claim from the state parameter + if (ClaimStore.TryGetOrEvictRecord(state, out LoginClaim? claim) < 1) + { + entity.Redirect(RedirectType.Temporary, $"{Path}?result=expired"); + return VfReturnType.VirtualSkip; + } + //Lock on the claim to prevent replay + lock (claim) + { + bool isValid = claim.VerifyNonce(state); + //Evict the record inside the lock, also wipes nonce contents + ClaimStore.EvictRecord(state); + + //Compare binary values of nonce incase of dicionary collision + if (!isValid) + { + entity.Redirect(RedirectType.Temporary, $"{Path}?result=invalid"); + return VfReturnType.VirtualSkip; + } + } + //Exchange the OAuth code for a token (application specific) + OAuthAccessState? token = await ExchangeCodeForTokenAsync(entity, code, entity.EventCancellation); + //Token may be null + if(token == null) + { + entity.Redirect(RedirectType.Temporary, $"{Path}?result=invalid"); + return VfReturnType.VirtualSkip; + } + //Store claim info + token.PublicKey = claim.PublicKey; + token.ClientId = claim.ClientId; + //Generate the new nonce + string nonce = token.ComputeNonce((int)Config.NonceByteSize); + //Collect expired records + AuthorizationStore.CollectRecords(); + //Register the access token + AuthorizationStore.StoreRecord(nonce, token, Config.LoginNonceLifetime); + //Prepare redirect + entity.Redirect(RedirectType.Temporary, $"{Path}?result=authorized&nonce={nonce}"); + return VfReturnType.VirtualSkip; + } + //Check to see if there was an error code set + if (entity.QueryArgs.TryGetNonEmptyValue("error", out string? errorCode)) + { + Log.Debug("{Type} error {err}:{des}", Config.AccountOrigin, errorCode, entity.QueryArgs["error_description"]); + entity.Redirect(RedirectType.Temporary, $"{Path}?result=error"); + return VfReturnType.VirtualSkip; + } + return VfReturnType.ProcessAsFile; + } + + /* + * Post messages finalize a login from a nonce + */ + + protected override async ValueTask<VfReturnType> PostAsync(HttpEntity entity) + { + ValErrWebMessage webm = new(); + //Get the finalization message + using JsonDocument? request = await entity.GetJsonFromFileAsync(); + if (webm.Assert(request != null, "Request message is required")) + { + entity.CloseResponseJson(HttpStatusCode.BadRequest, webm); + return VfReturnType.VirtualSkip; + } + //Recover the nonce + string? base32Nonce = request.RootElement.GetPropString("nonce"); + if(webm.Assert(base32Nonce != null, message: "Nonce parameter is required")) + { + entity.CloseResponseJson(HttpStatusCode.UnprocessableEntity, webm); + return VfReturnType.VirtualSkip; + } + //Validate nonce + if (!NonceValidator.Validate(base32Nonce, webm)) + { + entity.CloseResponseJson(HttpStatusCode.UnprocessableEntity, webm); + return VfReturnType.VirtualSkip; + } + //Recover the access token + if (AuthorizationStore.TryGetOrEvictRecord(base32Nonce!, out OAuthAccessState? token) < 1) + { + webm.Result = AUTH_ERROR_MESSAGE; + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + bool valid; + //Valid token, now verify the nonce within the locked context + lock (token) + { + valid = token.VerifyNonce(base32Nonce); + //Evict (wipes nonce) + AuthorizationStore.EvictRecord(base32Nonce!); + } + if (webm.Assert(valid, AUTH_ERROR_MESSAGE)) + { + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + + //get the user's login information (ie userid) + UserLoginData? userLogin = await GetLoginDataAsync(token, entity.EventCancellation); + + if(webm.Assert(userLogin?.UserId != null, AUTH_ERROR_MESSAGE)) + { + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + + //Fetch the user from the database + IUser? user = await Config.Users.GetUserFromIDAsync(userLogin.UserId, entity.EventCancellation); + + if(user == null) + { + //Get the clients personal info to being login process + AccountData? userAccount = await GetAccountDataAsync(token, entity.EventCancellation); + + if (webm.Assert(userAccount != null, AUTH_ERROR_MESSAGE)) + { + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + + //Validate the account data + if (webm.Assert(AccountDataValidator.Validate(userAccount).IsValid, AUTH_ERROR_MESSAGE)) + { + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + + //make sure registration is enabled + if (webm.Assert(Config.AllowRegistration, AUTH_ERROR_MESSAGE)) + { + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + //Create new user, create random passwords + byte[] randomPass = RandomHash.GetRandomBytes(Config.RandomPasswordSize); + //Generate a new random passowrd incase the user wants to use a local account to log in sometime in the future + PrivateString passhash = Config.Passwords.Hash(randomPass); + //overwite the password bytes + Memory.InitializeBlock(randomPass.AsSpan()); + try + { + //Create the user with the specified email address, minimum privilage level, and an empty password + user = await Config.Users.CreateUserAsync(userLogin.UserId!, userAccount.EmailAddress, AccountManager.MINIMUM_LEVEL, passhash, entity.EventCancellation); + //Set active status + user.Status = UserStatus.Active; + //Store the new profile + user.SetProfile(userAccount); + //Set the account creation origin + user.SetAccountOrigin(Config.AccountOrigin); + } + catch(UserCreationFailedException) + { + Log.Warn("Failed to create new user from new OAuth2 login, because a creation exception occured"); + webm.Result = "Please try again later"; + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + finally + { + passhash.Dispose(); + } + } + else + { + //Check for local only + if (webm.Assert(!user.LocalOnly, AUTH_ERROR_MESSAGE)) + { + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + //Make sure local accounts are allowed + if (webm.Assert(!user.IsLocalAccount() || Config.AllowForLocalAccounts, AUTH_ERROR_MESSAGE)) + { + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + //Reactivate inactive accounts + if(user.Status == UserStatus.Inactive) + { + user.Status = UserStatus.Active; + } + + //Make sure the account is active + if(webm.Assert(user.Status == UserStatus.Active, AUTH_ERROR_MESSAGE)) + { + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + } + //Finalze login + try + { + //Generate authoization + webm.Token = entity.GenerateAuthorization(token.PublicKey!, token.ClientId!, user); + //Store the user current oauth information in the current session for others to digest + entity.Session.SetObject($"{Config.AccountOrigin}.{AUTH_GRANT_SESSION_NAME}", token); + //Send the username back to the client + webm.Result = new AccountData() + { + EmailAddress = user.EmailAddress, + }; + //Set the success flag + webm.Success = true; + //Write to log + Log.Debug("Successful login for user {uid}... from {ip}", user.UserID[..8], entity.TrustedRemoteIp); + //release the user + await user.ReleaseAsync(); + } + catch (CryptographicException ce) + { + Log.Debug("Failed to generate authorization for {user}, error {err}", user.UserID, ce.Message); + webm.Result = AUTH_ERROR_MESSAGE; + } + catch (OutOfMemoryException) + { + Log.Debug("Out of buffer space for token data encryption, for user {usr}, from ip {ip}", user.UserID, entity.TrustedRemoteIp); + webm.Result = AUTH_ERROR_MESSAGE; + } + catch(UserUpdateException uue) + { + webm.Token = null; + webm.Result = AUTH_ERROR_MESSAGE; + webm.Success = false; + entity.InvalidateLogin(); + Log.Error(uue); + } + finally + { + user.Dispose(); + } + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + + /* + * Claims are considered indempodent because they require no previous state + * and will return a new secret authentication "token" (url + nonce) that + * uniquely identifies the claim and authorization upgrade later + */ + + protected override async ValueTask<VfReturnType> PutAsync(HttpEntity entity) + { + ValErrWebMessage webm = new(); + + //Get the login message + LoginClaim? claim = await entity.GetJsonFromFileAsync<LoginClaim>(); + + if (webm.Assert(claim != null, "Emtpy message body")) + { + entity.CloseResponseJson(HttpStatusCode.BadRequest, webm); + return VfReturnType.VirtualSkip; + } + + //Validate the message + if (!ClaimValidator.Validate(claim, webm)) + { + entity.CloseResponseJson(HttpStatusCode.UnprocessableEntity, webm); + return VfReturnType.VirtualSkip; + } + + //Cleanup old records + ClaimStore.CollectRecords(); + //Set nonce + string base32Nonce = claim.ComputeNonce((int)Config.NonceByteSize); + //build the redirect url + webm.Result = BuildUrl(base32Nonce, claim.PublicKey!, entity.IsSecure ? "https" : "http", entity.Server.RequestUri.Authority, entity.Server.Encoding); + //Store the claim + ClaimStore.StoreRecord(base32Nonce, claim, Config.LoginNonceLifetime); + webm.Success = true; + //Response + entity.CloseResponse(webm); + return VfReturnType.VirtualSkip; + } + + /* + * Construct the client's redirect url based on their login claim, which contains + * a public key which can be used to encrypt the url so that only the client + * private-key holder can decrypt the url and redirect themselves to the + * target OAuth website. + * + * The result is an encrypted nonce that should guard against replay attacks and MITM + */ + + private string BuildUrl(string base32Nonce, string pubKey, ReadOnlySpan<char> scheme, ReadOnlySpan<char> redirectAuthority, Encoding enc) + { + //Char buffer for base32 and url building + using UnsafeMemoryHandle<byte> buffer = Memory.UnsafeAlloc<byte>(8192, true); + //get bin buffer slice + Span<byte> binBuffer = buffer.Span[1024..]; + + ReadOnlySpan<char> url; + { + //Get char buffer slice and cast to char + Span<char> charBuf = MemoryMarshal.Cast<byte, char>(buffer.Span[..1024]); + //buffer writer for easier syntax + ForwardOnlyWriter<char> writer = new(charBuf); + //first build the redirect url to re-encode it + writer.Append(scheme); + writer.Append("://"); + //Create redirect url (current page, default action is to authorize the client) + writer.Append(redirectAuthority); + writer.Append(Path); + //url encode the redirect path and save it for later + string redirectFiltered = Uri.EscapeDataString(writer.ToString()); + //reset the writer again to begin building the path + writer.Reset(); + //Append the config redirect path + writer.Append(Config.AccessCodeUrl.OriginalString); + //begin query arguments + writer.Append("&client_id="); + writer.Append(Config.ClientID); + //add the redirect url + writer.Append("&redirect_uri="); + writer.Append(redirectFiltered); + //Append the state parameter + writer.Append("&state="); + writer.Append(base32Nonce); + url = writer.AsSpan(); + } + //Separate buffers + Span<byte> encryptionBuffer = binBuffer[1024..]; + Span<byte> encodingBuffer = binBuffer[..1024]; + //Encode the url to binary + int byteCount = enc.GetBytes(url, encodingBuffer); + //Encrypt the binary + ERRNO count = AccountManager.TryEncryptClientData(pubKey, encodingBuffer[..byteCount], in encryptionBuffer); + //base64 encode the encrypted + return Convert.ToBase64String(encryptionBuffer[0..(int)count]); + } + } +} |