WebSocket00.h

//
//  WebSocket00.h
//  UnittWebSocketClient
//
//  Created by Josh Morris on 5/3/11.
//  Copyright 2011 UnitT Software. All rights reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
//  use this file except in compliance with the License. You may obtain a copy of
//  the License at
// 
//  http://www.apache.org/licenses/LICENSE-2.0
// 
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
//  License for the specific language governing permissions and limitations under
//  the License.
//

#import <Foundation/Foundation.h>
#import "AsyncSocket.h"
#import <Security/Security.h>
#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonCryptor.h>
#import "NSData+Base64.h"


enum 
{
    WebSocketReadyStateConnecting = 0, //The connection has not yet been established.
    WebSocketReadyStateOpen = 1, //The WebSocket connection is established and communication is possible.
    WebSocketReadyStateClosing = 2, //The connection is going through the closing handshake.
    WebSocketReadyStateClosed = 3 //The connection has been closed or could not be opened
};
typedef NSUInteger WebSocketReadyState;


@protocol WebSocket00Delegate <NSObject>

/**
 * Called when the web socket connects and is ready for reading and writing.
 **/
- (void) didOpen;

/**
 * Called when the web socket closes. aError will be nil if it closes cleanly.
 **/
- (void) didClose: (NSError*) aError;

/**
 * Called when the web socket receives an error. Such an error can result in the
 socket being closed.
 **/
- (void) didReceiveError: (NSError*) aError;

/**
 * Called when the web socket receives a message.
 **/
- (void) didReceiveMessage: (NSString*) aMessage;

@end


@interface WebSocket00 : NSObject 
{
@private
    id<WebSocket00Delegate> delegate;
    WebSocketReadyState readystate;
    BOOL isSecure;
    NSTimeInterval timeout;
    NSString* serverProtocol;
    NSString* key1;
    NSString* key2;
    NSData* key3;
    BOOL verifyHandshake;
}


/**
 * Callback delegate for websocket events.
 **/
@property(nonatomic,assign) id<WebSocket00Delegate> delegate;

@property (nonatomic, retain) NSError *closingError;
@property (nonatomic, retain) NSData *serverHandshake;

@property (nonatomic, retain) AsyncSocket *socket;

/**
 * Timeout used for sending messages, not establishing the socket connection. A
 * value of -1 will result in no timeouts being applied.
 **/
@property(nonatomic,assign) NSTimeInterval timeout;

/**
 * URL of the websocket
 **/
@property (nonatomic, retain) NSURL *url;

/**
 * Origin is used more in a browser setting, but it is intended to prevent cross-site scripting. If
 * nil, the client will fill this in using the url provided by the websocket.
 **/
@property (nonatomic, copy) NSString *origin;

/**
 * Represents the state of the connection. It can have the following values:
 * - WebSocketReadyStateConnecting: The connection has not yet been established.
 * - WebSocketReadyStateOpen: The WebSocket connection is established and communication is possible.
 * - WebSocketReadyStateClosing: The connection is going through the closing handshake.
 * - WebSocketReadyStateClosed: The connection has been closed or could not be opened.
 **/
@property(nonatomic,readonly) WebSocketReadyState readystate;


/**
 * Settings for securing the connection using SSL/TLS.
 * 
 * The possible keys and values for the TLS settings are well documented.
 * Some possible keys are:
 * - kCFStreamSSLLevel
 * - kCFStreamSSLAllowsExpiredCertificates
 * - kCFStreamSSLAllowsExpiredRoots
 * - kCFStreamSSLAllowsAnyRoot
 * - kCFStreamSSLValidatesCertificateChain
 * - kCFStreamSSLPeerName
 * - kCFStreamSSLCertificates
 * - kCFStreamSSLIsServer
 * 
 * Please refer to Apple's documentation for associated values, as well as other possible keys.
 * 
 * If the value is nil or an empty dictionary, then the websocket cannot be secured.
 **/
@property (nonatomic, retain) NSDictionary *tlsSettings;

/**
 * The subprotocols supported by the client. Each subprotocol is represented by an NSString.
 **/
@property(nonatomic,retain) NSArray* protocols;

/**
 * True if the client should verify the handshake values sent by the server. Since many of
 * the web socket servers may not have been updated to support this, set to false to ignore
 * and simply accept the connection to the server.
 **/
@property(nonatomic,readonly) BOOL verifyHandshake; 

/**
 * The subprotocol selected by the server, nil if none was selected
 **/
@property(nonatomic,copy) NSString* serverProtocol;


+ (id) webSocketWithURLString:(NSString*) aUrlString delegate:(id<WebSocket00Delegate>) aDelegate origin:(NSString*) aOrigin protocols:(NSArray*) aProtocols tlsSettings:(NSDictionary*) aTlsSettings verifyHandshake:(BOOL) aVerifyHandshake;
- (id) initWithURLString:(NSString *) aUrlString delegate:(id<WebSocket00Delegate>) aDelegate origin:(NSString*) aOrigin protocols:(NSArray*) aProtocols tlsSettings:(NSDictionary*) aTlsSettings verifyHandshake:(BOOL) aVerifyHandshake;


/**
 * Connect the websocket and prepare it for reading and writing.
 **/
- (void)open;

/**
 * Finish all reads/writes and close the websocket.
 **/
- (void)close;

/**
 * Write a UTF-8 encoded NSString message to the websocket.
 **/
- (void)send:(NSString*)message;


extern NSString *const WebSocket00Exception;
extern NSString *const WebSocket00ErrorDomain;

@end