Added Ibadinov's socks parsing code, modified to build without warnings/errors

on more systems.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@36828 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,15 @@
+2013-07-04  Ibadinov Marat <ibadinov@me.com>
+
+        * GSSocksParser/GSSocks5Parser.m:
+        * GSSocksParser/GSSocks5Parser.h:
+        * GSSocksParser/GSSocksParserPrivate.h:
+        * GSSocksParser/GSSocksParser.m:
+        * GSSocksParser/GSSocksParserPrivate.m:
+        * GSSocksParser/GSSocksParser.h:
+        * GSSocksParser/GSSocks4Parser.m:
+        * GSSocksParser/GSSocks4Parser.h:
+        Parsing code for SOCKS versions 4 and 5.
+
 2013-07-03  Sebastian Reitenbach <sebastia@l00-bugdead-prods.de>
 
 	* Source/Additions/GSMime.m

Source/GNUmakefile

@@ -174,6 +174,10 @@ GSString.m \
 GSTimSort.m \
 GSTLS.m \
 GSValue.m \
+GSSocksParser/GSSocksParser.m \
+GSSocksParser/GSSocksParserPrivate.m \
+GSSocksParser/GSSocks4Parser.m \
+GSSocksParser/GSSocks5Parser.m \
 NSAffineTransform.m \
 NSArchiver.m \
 NSArray.m \

Source/GSSocksParser/GSSocks4Parser.h

@@ -0,0 +1,34 @@
+/*
+ * Parsers of SOCKS protocol messages
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * Written by Marat Ibadinov <ibadinov@me.com>
+ * Date: 2013
+ *
+ * This file is part of the GNUstep Base Library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110 USA.
+ *
+ * $Date$ $Revision$
+ */
+
+#import "GSSocksParser.h"
+
+@interface GSSocks4Parser : GSSocksParser {
+}
+
+@end
+

Source/GSSocksParser/GSSocks4Parser.m

@@ -0,0 +1,170 @@
+/*
+ * Parsers of SOCKS protocol messages
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * Written by Marat Ibadinov <ibadinov@me.com>
+ * Date: 2013
+ *
+ * This file is part of the GNUstep Base Library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110 USA.
+ *
+ * $Date$ $Revision$
+ */
+
+#import "GSSocks4Parser.h"
+#import "GSSocksParserPrivate.h"
+#import <arpa/inet.h>
+
+typedef enum GSSocks4InternalError {
+  GSSocks4InternalErrorIPv6 = 0x4a
+} GSSocks4InternalError;
+
+typedef enum GSSocks4ResponseStatus {
+  GSSocks4ResponseStatusAccessGranted     = 0x5a,
+  GSSocks4ResponseStatusRequestRejected   = 0x5b,
+  GSSocks4ResponseStatusIdentdFailed      = 0x5c,
+  GSSocks4ResponseStatusUserNotConfirmed  = 0x5d,
+} GSSocks4ResponseStatus;
+
+#ifdef  __clang__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-align"
+#endif
+
+@implementation GSSocks4Parser
+
+- (id) initWithConfiguration: (NSDictionary *)aConfiguration
+                     address: (NSString *)anAddress
+                        port: (NSUInteger)aPort
+{
+  if (nil != (self = [super init]))
+    {
+      configuration = [aConfiguration retain];
+      address = [anAddress retain];
+      port = aPort;
+    }
+  return self;
+}
+
+- (void) start
+{
+  NSMutableData *data;
+  uint8_t *bytes;
+  uint8_t zero;
+  NSString *user;
+  GSSocksAddressType addressType;
+
+  addressType = [self addressType];
+  if (addressType == GSSocksAddressTypeIPv6)
+    {
+      NSError *error;
+
+      error = [self errorWithCode: GSSocks4InternalErrorIPv6
+        description: @"IPv6 addresses are not supported by SOCKS4 proxies"];
+      [delegate parser: self encounteredError: error];
+      return;
+    }
+  
+  data = [NSMutableData dataWithLength: 8];
+  bytes = [data mutableBytes];
+  bytes[0] = 0x4;
+  bytes[1] = 0x1;
+  *(uint16_t *)(bytes + 2) = htons((uint16_t)port);
+  if (addressType == GSSocksAddressTypeDomain)
+    {
+      bytes[4] = bytes[5] = bytes[6] = 0;
+      bytes[7] = 1;
+    }
+  else
+    {
+      const uint32_t *addressBytes = [[self addressData] bytes];
+
+      *(uint32_t *)(bytes + 4) = htonl(*addressBytes);
+    }
+  zero = 0x0;
+  user = [configuration objectForKey: NSStreamSOCKSProxyUserKey];
+  if (user)
+    {
+      [data appendData: [user dataUsingEncoding: NSUTF8StringEncoding]];
+      [data appendBytes: &zero length: 1];
+    }
+  if (addressType == GSSocksAddressTypeDomain)
+    {
+      [data appendData: [address dataUsingEncoding: NSUTF8StringEncoding]];
+      [data appendBytes: &zero length: 1];
+    }
+  
+  [delegate parser: self formedRequest: data];
+  [delegate parser: self needsMoreBytes: 8];
+}
+
+- (NSError *) errorWithResponseStatus: (NSInteger)aStatus
+{
+  NSString *description;
+
+  switch ((GSSocks4ResponseStatus)aStatus)
+    {
+      case GSSocks4ResponseStatusRequestRejected:
+        description = @"request was rejected or the server failed to fulfil it";
+        break;
+      case GSSocks4ResponseStatusIdentdFailed:
+        description = @"identd is not running or not reachable from the server";
+        break;
+      case GSSocks4ResponseStatusUserNotConfirmed:
+        description = @"identd could not confirm the user ID string in the request";
+        break;
+      default:
+        description = @"unknown";
+        break;
+  }
+  description = [NSString stringWithFormat:
+    @"SOCKS4 connnection failed, reason: %@", description];
+  return [self errorWithCode: aStatus description: description];
+}
+
+- (void) parseNextChunk: (NSData *)aChunk
+{
+  NSUInteger  bndPort;
+  uint32_t    addressBytes;
+  NSData      *addressData;
+  NSString    *bndAddress;
+  const uint8_t *bytes;
+
+  bytes = [aChunk bytes];
+  if (bytes[1] != GSSocks4ResponseStatusAccessGranted)
+    {
+      NSError *error = [self errorWithResponseStatus:bytes[1]];
+      [delegate parser:self encounteredError:error];
+      return;
+    }
+  
+  bndPort = ntohs(*(uint16_t *)(bytes + 2));
+  addressBytes = ntohl(*(uint32_t *)(bytes + 4));
+  addressData = [NSData dataWithBytesNoCopy: &addressBytes
+                                     length: 4
+                               freeWhenDone: NO];
+  bndAddress = [self addressFromData: addressData
+                            withType :GSSocksAddressTypeIPv4];
+  
+  [delegate parser: self finishedWithAddress: bndAddress port: bndPort];
+}
+
+@end
+
+#ifdef  __clang__
+#pragma GCC diagnostic pop
+#endif

Source/GSSocksParser/GSSocks5Parser.h

@@ -0,0 +1,38 @@
+/*
+ * Parsers of SOCKS protocol messages
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * Written by Marat Ibadinov <ibadinov@me.com>
+ * Date: 2013
+ *
+ * This file is part of the GNUstep Base Library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110 USA.
+ *
+ * $Date$ $Revision$
+ */
+
+#import "GSSocksParser.h"
+
+@interface GSSocks5Parser : GSSocksParser {
+  NSUInteger  state;
+  NSUInteger  addressSize;
+  uint8_t     addressType;
+  BOOL        stopped;
+}
+
+@end
+

Source/GSSocksParser/GSSocks5Parser.m

@@ -0,0 +1,283 @@
+/*
+ * Parsers of SOCKS protocol messages
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * Written by Marat Ibadinov <ibadinov@me.com>
+ * Date: 2013
+ *
+ * This file is part of the GNUstep Base Library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110 USA.
+ *
+ * $Date$ $Revision$
+ */
+
+#import "GSSocks5Parser.h"
+#import "GSSocksParserPrivate.h"
+#import <arpa/inet.h>
+
+typedef enum GSSocks5ParserState {
+  GSSocks5ParserStateHandshake,
+  GSSocks5ParserStateAuthenticationRequest,
+  GSSocks5ParserStateAuthenticationResponse,
+  GSSocks5ParserStateRequest,
+  GSSocks5ParserStateResponse,
+  GSSocks5ParserStateResponseAddressLength,
+  GSSocks5ParserStateResponseAddressAndPort,
+} GSSocks5ParserState;
+
+typedef enum GSSocks5AuthenticationMethod {
+  GSSocks5AuthenticationMethodNone                = 0x00,
+  GSSocks5AuthenticationMethodGSSAPI              = 0x01,
+  GSSocks5AuthenticationMethodPassword            = 0x02,
+  GSSocks5AuthenticationMethodNoAcceptable        = 0xFF,
+} GSSocks5AuthenticationMethod;
+
+typedef enum GSSocks5ResponseStatus {
+  GSSocks5ResponseStatusSuccess                   = 0x0,
+  GSSocks5ResponseStatusGeneralFailure            = 0x1,
+  GSSocks5ResponseStatusConnectionNotAllowed      = 0x2,
+  GSSocks5ResponseStatusNetworkUnreachable        = 0x3,
+  GSSocks5ResponseStatusHostUnreachable           = 0x4,
+  GSSocks5ResponseStatusConnectionRefused         = 0x5,
+  GSSocks5ResponseStatusTTLExpired                = 0x6,
+  GSSocks5ResponseStatusCommandNotSupported       = 0x7,
+  GSSocks5ResponseStatusAddressTypeNotSupported   = 0x8,
+} GSSocks5ResponseStatus;
+
+#ifdef __clang__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-align"
+#endif
+
+@implementation GSSocks5Parser
+
+- (id) initWithConfiguration: (NSDictionary *)aConfiguration
+                     address: (NSString *)anAddress
+                        port: (NSUInteger)aPort
+{
+  if (nil != (self = [super init]))
+    {
+      configuration = [aConfiguration retain];
+      address = [anAddress retain];
+      port = aPort;
+      stopped = YES;
+    }
+  return self;
+}
+
+- (void) start
+{
+  uint8_t bytes[3] = {0x5, 0x1, GSSocks5AuthenticationMethodNone};
+
+  state = GSSocks5ParserStateHandshake;
+  stopped = NO;
+  
+  if ([configuration objectForKey: NSStreamSOCKSProxyUserKey])
+    {
+      bytes[2] = GSSocks5AuthenticationMethodPassword;
+    }
+  
+  [delegate parser: self
+     formedRequest: [NSData dataWithBytes: bytes length: 3]];
+  [delegate parser: self needsMoreBytes: 2];
+}
+
+- (NSError *) errorWithResponseStatus: (NSInteger)aStatus
+{
+  NSString *description;
+
+  switch ((GSSocks5ResponseStatus)aStatus)
+    {
+      case GSSocks5ResponseStatusGeneralFailure:
+        description = @"general server failure";
+        break;
+      case GSSocks5ResponseStatusConnectionNotAllowed:
+        description = @"connection is not allowed by a ruleset";
+        break;
+      case GSSocks5ResponseStatusNetworkUnreachable:
+        description = @"destination network is unreachable";
+        break;
+      case GSSocks5ResponseStatusHostUnreachable:
+        description = @"destination host is unreachable";
+        break;
+      case GSSocks5ResponseStatusConnectionRefused:
+        description = @"connection has been refused";
+        break;
+      case GSSocks5ResponseStatusTTLExpired:
+        description = @"connection has timed out";
+        break;
+      case GSSocks5ResponseStatusCommandNotSupported:
+        description = @"command is not supported";
+        break;
+      case GSSocks5ResponseStatusAddressTypeNotSupported:
+        description = @"address type is not supported";
+        break;
+      default:
+        description = @"unkown";
+        break;
+    }
+  description = [NSString stringWithFormat:
+    @"SOCKS5 server failed to fulfil request, reason: %@", description];
+  return [self errorWithCode: aStatus description: description];
+}
+
+- (void) reportError: (NSError *)anError
+{
+  stopped = YES;
+  [delegate parser: self encounteredError: anError];
+}
+
+- (void) parseNextChunk: (NSData *)aChunk
+{
+  const uint8_t *bytes;
+  if (stopped)
+    {
+      return;
+    }
+  bytes = [aChunk bytes];
+  switch ((GSSocks5ParserState)state)
+    {
+      case GSSocks5ParserStateHandshake:
+        {
+          if (bytes[1] == GSSocks5AuthenticationMethodNoAcceptable)
+            {
+              NSError *error;
+
+              error = [self
+                errorWithCode: GSSocks5AuthenticationMethodNoAcceptable
+                description: @"SOCKS server does not support"
+                  @" requested authentication method"];
+              [self reportError:error];
+              break;
+            }
+          if (![configuration objectForKey: NSStreamSOCKSProxyUserKey])
+            {
+              state = GSSocks5ParserStateRequest;
+              goto GSSocks5ParserStateRequest;
+            }
+          state = GSSocks5ParserStateAuthenticationRequest;
+        }
+      case GSSocks5ParserStateAuthenticationRequest:
+        {
+          NSString *username
+            = [configuration objectForKey: NSStreamSOCKSProxyUserKey];
+          NSString *password
+            = [configuration objectForKey: NSStreamSOCKSProxyPasswordKey];
+          uint8_t bytes[3] = {
+            0x5, (uint8_t)[username length], (uint8_t)[password length]};
+          NSMutableData *request
+            = [NSMutableData dataWithCapacity:bytes[1] + bytes[2] + 3];
+
+          [request appendBytes: bytes length: 2];
+          [request appendBytes: [username UTF8String] length: bytes[1]];
+          [request appendBytes: &bytes[2] length: 1];
+          [request appendBytes: [password UTF8String] length: bytes[2]];
+          
+          state = GSSocks5ParserStateAuthenticationResponse;
+          [delegate parser: self formedRequest: request];
+          [delegate parser: self needsMoreBytes: 2];
+          break;
+        }
+      case GSSocks5ParserStateAuthenticationResponse:
+        {
+          if (bytes[1])
+            {
+              NSError *error;
+
+              error = [self errorWithCode: 0xFF + bytes[1]
+                              description: @"SOCKS authentication failed"];
+              [self reportError: error];
+              break;
+            }
+          state = GSSocks5ParserStateRequest;
+        }
+        GSSocks5ParserStateRequest:
+      case GSSocks5ParserStateRequest:
+        {
+          GSSocksAddressType type = [self addressType];
+          uint8_t request[4] = {
+              0x5, 0x1, 0x0, type
+          };
+          uint16_t portWithNetworkEndianness;
+          NSMutableData *data = [NSMutableData dataWithBytes:request length:4];
+          NSData *addressData = [self addressData];
+
+          if (type == GSSocksAddressTypeDomain)
+            {
+              uint8_t length = (uint8_t)[addressData length];
+              [data appendBytes: &length length: 1];
+            }
+          [data appendData: addressData];
+          portWithNetworkEndianness = htons((uint16_t)port);
+          [data appendBytes: &portWithNetworkEndianness length: 2];
+          
+          state = GSSocks5ParserStateResponse;
+          [delegate parser: self formedRequest: data];
+          [delegate parser: self needsMoreBytes: 4];
+          break;
+        }
+      case GSSocks5ParserStateResponse:
+        {
+          if (bytes[1] != GSSocks5ResponseStatusSuccess)
+            {
+              NSError *error = [self errorWithResponseStatus: bytes[1]];
+              [self reportError: error];
+              break;
+            }
+          addressType = bytes[3]; /* addess type */
+          if (addressType == GSSocksAddressTypeDomain)
+            {
+              state = GSSocks5ParserStateResponseAddressLength;
+              [delegate parser: self needsMoreBytes: 1];
+            }
+          else
+            {
+              state = GSSocks5ParserStateResponseAddressAndPort;
+              addressSize = addressType == GSSocksAddressTypeIPv4 ? 4 :  16;
+              [delegate parser: self needsMoreBytes: addressSize + 2];
+            }
+          break;
+        }
+      case GSSocks5ParserStateResponseAddressLength:
+        {
+          addressSize = bytes[0];
+          state = GSSocks5ParserStateResponseAddressAndPort;
+          [delegate parser: self needsMoreBytes: addressSize + 2];
+          break;
+        }
+      case GSSocks5ParserStateResponseAddressAndPort:
+        {
+          NSString    *bndAddress;
+          NSUInteger  bndPort;
+          NSData      *data;
+
+          data = [NSData dataWithBytes: [aChunk bytes]
+                                length: addressSize];
+          bndAddress = [self addressFromData: data
+                                    withType: addressType];
+          bndPort = ntohs(*(uint16_t *)(bytes + addressSize));
+          [delegate parser: self finishedWithAddress: bndAddress port: bndPort];
+          break;
+        }
+    }
+}
+
+@end
+
+#ifdef  __clang__
+#pragma GCC diagnostic pop
+#endif

Source/GSSocksParser/GSSocksParser.h

@@ -0,0 +1,73 @@
+/*
+ * Parsers of SOCKS protocol messages
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * Written by Marat Ibadinov <ibadinov@me.com>
+ * Date: 2013
+ *
+ * This file is part of the GNUstep Base Library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110 USA.
+ *
+ * $Date$ $Revision$
+ */
+
+#import <Foundation/NSData.h>
+#import <Foundation/NSDictionary.h>
+#import <Foundation/NSError.h>
+#import <Foundation/NSStream.h>
+#import <Foundation/NSString.h>
+
+@class GSSocksParser;
+
+@protocol GSSocksParserDelegate <NSObject>
+
+- (void) parser: (GSSocksParser *)aParser
+ needsMoreBytes: (NSUInteger)aLength;
+- (void) parser: (GSSocksParser *)aParser
+  formedRequest: (NSData *)aRequest;
+- (void) parser: (GSSocksParser *)aParser
+finishedWithAddress: (NSString *)anAddress
+port: (NSUInteger)aPort;
+
+- (void) parser: (GSSocksParser *)aParser
+encounteredError: (NSError *)anError;
+
+@end
+
+@interface GSSocksParser : NSObject
+{
+  NSDictionary                *configuration;
+  NSString                    *address;
+  id<GSSocksParserDelegate>   delegate;
+  NSUInteger                  port;
+}
+
+- (id) initWithConfiguration: (NSDictionary *)aConfiguration
+                     address: (NSString *)anAddress
+                        port: (NSUInteger)aPort;
+
+- (id<GSSocksParserDelegate>) delegate;
+- (void) setDelegate: (id<GSSocksParserDelegate>)aDelegate;
+
+- (NSString *) address;
+- (NSUInteger) port;
+
+- (void) start;
+- (void) parseNextChunk: (NSData *)aChunk;
+
+@end
+

Source/GSSocksParser/GSSocksParser.m

@@ -0,0 +1,121 @@
+/*
+ * Parsers of SOCKS protocol messages
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * Written by Marat Ibadinov <ibadinov@me.com>
+ * Date: 2013
+ *
+ * This file is part of the GNUstep Base Library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110 USA.
+ *
+ * $Date$ $Revision$
+ */
+
+#import "GSSocksParser.h"
+#import "GSSocks4Parser.h"
+#import "GSSocks5Parser.h"
+#import "Foundation/NSException.h"
+
+@interface NSObject (SubclassResponsibility)
+- (id) subclassResponsibility: (SEL)aSelector;
+@end
+
+@implementation GSSocksParser
+
+- (id) init
+{
+  if (nil != (self = [super init]))
+    {
+      configuration = nil;
+      address = nil;
+      delegate = nil;
+      port = 0;
+    }
+  return self;
+}
+
+- (id) initWithConfiguration: (NSDictionary *)aConfiguration
+                     address: (NSString *)anAddress
+                        port: (NSUInteger)aPort
+{
+  NSString *version;
+  Class concreteClass;
+
+  version = [aConfiguration objectForKey: NSStreamSOCKSProxyVersionKey];
+  version = version ? version : NSStreamSOCKSProxyVersion5;
+  
+  [self release];
+  
+  if ([version isEqualToString: NSStreamSOCKSProxyVersion5])
+    {
+      concreteClass = [GSSocks5Parser class];
+    }
+  else if ([version isEqualToString: NSStreamSOCKSProxyVersion4])
+    {
+      concreteClass = [GSSocks4Parser class];
+    }
+  else
+    {
+      [NSException raise: NSInternalInconsistencyException
+                  format: @"Unsupported socks verion: %@", version];
+    }
+  return [[concreteClass alloc] initWithConfiguration: aConfiguration
+                                              address: anAddress 
+                                                 port: aPort];
+}
+
+- (void) dealloc
+{
+  [delegate release];
+  [address release];
+  [configuration release];
+  [super dealloc];
+}
+
+- (id<GSSocksParserDelegate>) delegate
+{
+  return delegate;
+}
+
+- (void) setDelegate: (id<GSSocksParserDelegate>)aDelegate
+{
+  id previous = delegate;
+  delegate = [aDelegate retain];
+  [previous release];
+}
+
+- (NSString *) address
+{
+  return address;
+}
+
+- (NSUInteger) port
+{
+  return port;
+}
+
+- (void) start
+{
+  [self subclassResponsibility:_cmd];
+}
+
+- (void) parseNextChunk: (NSData *)aChunk
+{
+  [self subclassResponsibility: _cmd];
+}
+
+@end

Source/GSSocksParser/GSSocksParserPrivate.h

@@ -0,0 +1,49 @@
+/*
+ * Parsers of SOCKS protocol messages
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * Written by Marat Ibadinov <ibadinov@me.com>
+ * Date: 2013
+ *
+ * This file is part of the GNUstep Base Library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110 USA.
+ *
+ * $Date$ $Revision$
+ */
+
+#import "GSSocksParser.h"
+
+typedef enum GSSocksAddressType {
+  GSSocksAddressTypeIPv4     = 0x1,
+  GSSocksAddressTypeIPv6     = 0x4,
+  GSSocksAddressTypeDomain   = 0x3,
+} GSSocksAddressType;
+
+@interface GSSocksParser (Private)
+
+- (NSError *) errorWithCode: (NSInteger)aCode
+                description: (NSString *)aDescription;
+
+
+- (GSSocksAddressType) addressType;
+
+- (NSData *) addressData;
+- (NSString *) addressFromData: (NSData *)aData
+                      withType: (GSSocksAddressType)anAddressType;
+
+@end
+

Source/GSSocksParser/GSSocksParserPrivate.m

@@ -0,0 +1,219 @@
+/*
+ * Parsers of SOCKS protocol messages
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * Written by Marat Ibadinov <ibadinov@me.com>
+ * Date: 2013
+ *
+ * This file is part of the GNUstep Base Library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110 USA.
+ *
+ * $Date$ $Revision$
+ */
+
+#import "GSSocksParserPrivate.h"
+#import "Foundation/NSArray.h"
+#import "Foundation/NSBundle.h"
+#import "Foundation/NSCharacterSet.h"
+#import "Foundation/NSException.h"
+#import <stdio.h>
+
+@interface NSString (GSSocksParser)
+- (NSString *) stringByRepeatingCurrentString: (NSUInteger)times;
+@end
+
+@implementation NSString (GSSocksParser)
+
+- (NSString *) stringByRepeatingCurrentString: (NSUInteger)times
+{
+  return [@"" stringByPaddingToLength: times * [self length]
+                           withString: self
+                      startingAtIndex: 0];
+}
+
+@end
+
+@implementation GSSocksParser (Private)
+
+- (NSError *) errorWithCode: (NSInteger)aCode
+                description: (NSString *)aDescription
+{
+    NSDictionary *userInfo;
+
+    aDescription = NSLocalizedString(aDescription, @"");
+    userInfo = [NSDictionary dictionaryWithObject: aDescription
+                                           forKey: NSLocalizedDescriptionKey];
+    return [NSError errorWithDomain: NSStreamSOCKSErrorDomain
+                               code: aCode
+                           userInfo: userInfo];
+}
+
+- (GSSocksAddressType) addressType
+{
+  const char *cAddress;
+  NSUInteger index;
+  BOOL hasAlpha;
+  BOOL hasDot;
+  char character;
+
+  if ([address length] > 16)
+    {
+      return GSSocksAddressTypeDomain;
+    }
+  cAddress = [address UTF8String];
+  index = 0;
+  hasAlpha = NO;
+  hasDot = NO;
+
+  while (0 != (character = cAddress[index]))
+    {
+      BOOL isAlpha = character >= 'a' && character <= 'f';
+
+      if (!(character >= '0' && character <= '9')
+        && !isAlpha && character != '.' && character != ':')
+        {
+          return GSSocksAddressTypeDomain;
+        }
+      hasAlpha    = hasAlpha  || isAlpha;
+      hasDot      = hasDot    || character == '.';
+      ++index;
+    }
+  return hasAlpha && hasDot ? GSSocksAddressTypeDomain
+    : (hasDot ? GSSocksAddressTypeIPv4 : GSSocksAddressTypeIPv6);
+}
+
+- (NSData *) addressData
+{
+  switch ([self addressType])
+    {
+      case GSSocksAddressTypeIPv4:
+        {
+          NSMutableData *result = [NSMutableData dataWithLength: 4];
+          const char *cString = [address UTF8String];
+          uint8_t *bytes = [result mutableBytes];
+
+          sscanf(cString, "%hhu.%hhu.%hhu.%hhu",
+            &bytes[0], &bytes[1], &bytes[2], &bytes[3]);
+          return result;
+        }
+      case GSSocksAddressTypeIPv6:
+        {
+          NSArray *components = [address componentsSeparatedByString: @"::"];
+          NSMutableData *result;
+          uint16_t *bytes;
+            
+          if ([components count] == 2)
+            {
+              NSString *leading;
+              NSString *trailing;
+              NSCharacterSet *charset;
+              NSArray   *separated;
+              NSUInteger leadingCount;
+              NSUInteger trailingCount;
+
+              leading = [components objectAtIndex: 0];
+              trailing = [components objectAtIndex: 1];
+              charset
+                = [NSCharacterSet characterSetWithCharactersInString: @":"];
+              separated
+                = [leading componentsSeparatedByCharactersInSet: charset];
+              leadingCount = [leading length] ? [separated count] : 0;
+/* FIXME ... do we need to add this following statement?
+              separated
+                = [trailing componentsSeparatedByCharactersInSet: charset];
+*/
+              trailingCount = [trailing length] ? [separated count] : 0;
+              
+              if (leadingCount && trailingCount)
+                {
+                  NSString *middle;
+
+                  middle = [@"0:" stringByRepeatingCurrentString:
+                    8 - leadingCount - trailingCount];
+                  address = [[[leading stringByAppendingString: @":"]
+                    stringByAppendingString: middle]
+                      stringByAppendingString: trailing];
+                }
+              else if (!leadingCount)
+                {
+                  NSString *start;
+
+                  start = [@"0:" stringByRepeatingCurrentString:
+                    8 - trailingCount];
+                  address = [start stringByAppendingString: trailing];
+                }
+              else
+                {
+                  NSString *end;
+
+                  end = [@":0" stringByRepeatingCurrentString:
+                    8 - leadingCount];
+                  address = [leading stringByAppendingString: end];        
+              }
+          }
+            
+          result = [NSMutableData dataWithLength:16];
+          bytes = [result mutableBytes];
+          sscanf([address UTF8String], "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
+            &bytes[0], &bytes[1], &bytes[2], &bytes[3],
+            &bytes[4], &bytes[5], &bytes[6], &bytes[7]);
+          return result;
+        }
+      case GSSocksAddressTypeDomain:
+        {
+          return [address dataUsingEncoding:NSUTF8StringEncoding];
+        }
+      default:
+        [NSException raise: NSInternalInconsistencyException
+                    format: @"Unknown address type"];
+        return nil;
+    }
+}
+
+- (NSString *) addressFromData: (NSData *)aData
+                      withType: (GSSocksAddressType)anAddressType
+{
+  switch (anAddressType)
+    {
+      case GSSocksAddressTypeIPv4:
+        {
+          const uint8_t *bytes = [aData bytes];
+
+          return [NSString stringWithFormat: @"%hhu.%hhu.%hhu.%hhu",
+            bytes[0], bytes[1], bytes[2], bytes[3]];
+        }
+      case GSSocksAddressTypeIPv6:
+        {
+          const uint16_t *bytes = [aData bytes];
+
+          return [NSString stringWithFormat: @"%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
+            bytes[0], bytes[1], bytes[2], bytes[3],
+            bytes[4], bytes[5], bytes[6], bytes[7]];
+        }
+      case GSSocksAddressTypeDomain:
+        {
+          return [[[NSString alloc] initWithData: aData
+            encoding: NSUTF8StringEncoding] autorelease];
+        }
+      default:
+        [NSException raise: NSInternalInconsistencyException
+                    format: @"Unknown address type"];
+        return nil;
+    }
+}
+
+@end