passepartoutvpn
/
tunnelkit
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
tunnelkit/TunnelKit/Sources/Core/DataPath.m

374 lines
15 KiB
Objective-C
Raw Blame History

//
// DataPath.m
// TunnelKit
//
// Created by Davide De Rosa on 3/2/17.
// Copyright (c) 2019 Davide De Rosa. All rights reserved.
//
// https://github.com/passepartoutvpn
//
// This file is part of TunnelKit.
//
// TunnelKit is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// TunnelKit 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with TunnelKit. If not, see <http://www.gnu.org/licenses/>.
//
// This file incorporates work covered by the following copyright and
// permission notice:
//
// Copyright (c) 2018-Present Private Internet Access
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
#import <arpa/inet.h>
#import "DataPath.h"
#import "DataPathCrypto.h"
#import "MSS.h"
#import "ReplayProtector.h"
#import "LZO.h"
#import "Allocation.h"
#import "Errors.h"
#define DataPathByteAlignment 16
@interface DataPath ()
@property (nonatomic, strong) id<DataPathEncrypter> encrypter;
@property (nonatomic, strong) id<DataPathDecrypter> decrypter;
@property (nonatomic, assign) int packetCapacity;
// outbound -> UDP
@property (nonatomic, strong) NSMutableArray *outPackets;
@property (nonatomic, assign) uint32_t outPacketId;
@property (nonatomic, unsafe_unretained) uint8_t *encBuffer;
@property (nonatomic, assign) int encBufferCapacity;
// inbound -> TUN
@property (nonatomic, strong) NSMutableArray *inPackets;
@property (nonatomic, unsafe_unretained) uint8_t *decBuffer;
@property (nonatomic, assign) int decBufferCapacity;
@property (nonatomic, strong) ReplayProtector *inReplay;
@property (nonatomic, copy) DataPathAssembleBlock assemblePayloadBlock;
@property (nonatomic, copy) DataPathParseBlock parsePayloadBlock;
@property (nonatomic, strong) id<LZO> lzo;
@end
@implementation DataPath
+ (uint8_t *)alignedPointer:(uint8_t *)pointer
{
uint8_t *stack = pointer;
uintptr_t addr = (uintptr_t)stack;
if (addr % DataPathByteAlignment != 0) {
addr += DataPathByteAlignment - addr % DataPathByteAlignment;
}
return (uint8_t *)addr;
}
- (instancetype)initWithEncrypter:(id<DataPathEncrypter>)encrypter
decrypter:(id<DataPathDecrypter>)decrypter
peerId:(uint32_t)peerId
compressionFraming:(CompressionFramingNative)compressionFraming
compressionAlgorithm:(CompressionAlgorithmNative)compressionAlgorithm
maxPackets:(NSInteger)maxPackets
usesReplayProtection:(BOOL)usesReplayProtection
{
NSParameterAssert(encrypter);
NSParameterAssert(decrypter);
NSParameterAssert(maxPackets > 0);
peerId &= 0xffffff;
if ((self = [super init])) {
self.encrypter = encrypter;
self.decrypter = decrypter;
self.maxPacketId = UINT32_MAX - 10000;
self.outPackets = [[NSMutableArray alloc] initWithCapacity:maxPackets];
self.outPacketId = 0;
self.encBufferCapacity = 65000;
self.encBuffer = allocate_safely(self.encBufferCapacity);
self.inPackets = [[NSMutableArray alloc] initWithCapacity:maxPackets];
self.decBufferCapacity = 65000;
self.decBuffer = allocate_safely(self.decBufferCapacity);
if (usesReplayProtection) {
self.inReplay = [[ReplayProtector alloc] init];
}
[self.encrypter setPeerId:peerId];
[self.decrypter setPeerId:peerId];
[self setCompressionFraming:compressionFraming];
if (LZOIsSupported() && (compressionAlgorithm == CompressionAlgorithmNativeLZO)) {
self.lzo = LZOCreate();
}
}
return self;
}
- (void)dealloc
{
bzero(self.encBuffer, self.encBufferCapacity);
bzero(self.decBuffer, self.decBufferCapacity);
free(self.encBuffer);
free(self.decBuffer);
}
- (void)adjustEncBufferToPacketSize:(int)size
{
const int neededCapacity = DataPathByteAlignment + (int)[self.encrypter encryptionCapacityWithLength:size];
if (self.encBufferCapacity >= neededCapacity) {
return;
}
bzero(self.encBuffer, self.encBufferCapacity);
free(self.encBuffer);
self.encBufferCapacity = neededCapacity;
self.encBuffer = allocate_safely(self.encBufferCapacity);
}
- (void)adjustDecBufferToPacketSize:(int)size
{
const int neededCapacity = DataPathByteAlignment + (int)[self.decrypter encryptionCapacityWithLength:size];
if (self.decBufferCapacity >= neededCapacity) {
return;
}
bzero(self.decBuffer, self.decBufferCapacity);
free(self.decBuffer);
self.decBufferCapacity = neededCapacity;
self.decBuffer = allocate_safely(self.decBufferCapacity);
}
- (uint8_t *)encBufferAligned
{
return [[self class] alignedPointer:self.encBuffer];
}
- (uint8_t *)decBufferAligned
{
return [[self class] alignedPointer:self.decBuffer];
}
- (void)setCompressionFraming:(CompressionFramingNative)compressionFraming
{
__weak DataPath *weakSelf = self;
DataPathParseBlock parseCompressedBlock = ^BOOL(uint8_t * _Nonnull payload, NSInteger * _Nonnull payloadOffset, uint8_t * _Nonnull compressionHeader, NSInteger * _Nonnull headerLength, const uint8_t * _Nonnull packet, NSInteger packetLength, NSError * _Nullable __autoreleasing * _Nullable error) {
*compressionHeader = payload[0];
*headerLength = 1;
switch (*compressionHeader) {
case DataPacketNoCompress:
*payloadOffset = 1;
break;
case DataPacketNoCompressSwap:
payload[0] = packet[packetLength - 1];
*payloadOffset = 0;
break;
case DataPacketLZOCompress:
if (!weakSelf.lzo) { // compressed packet unexpected
if (error) {
*error = TunnelKitErrorWithCode(TunnelKitErrorCodeDataPathCompression);
}
return NO;
}
*payloadOffset = 1;
break;
default:
// @"Expected NO_COMPRESS (found %X != %X)", payload[0], DataPacketNoCompress);
if (error) {
*error = TunnelKitErrorWithCode(TunnelKitErrorCodeDataPathCompression);
}
return NO;
}
return YES;
};
switch (compressionFraming) {
case CompressionFramingNativeDisabled: {
self.assemblePayloadBlock = ^(uint8_t * packetDest, NSInteger * packetLengthOffset, NSData * payload) {
memcpy(packetDest, payload.bytes, payload.length);
*packetLengthOffset = 0;
};
self.parsePayloadBlock = ^BOOL(uint8_t * _Nonnull payload, NSInteger * _Nonnull payloadOffset, uint8_t * _Nonnull compressionHeader, NSInteger * _Nonnull headerLength, const uint8_t * _Nonnull packet, NSInteger packetLength, NSError * _Nullable __autoreleasing * _Nullable error) {
*payloadOffset = 0;
*compressionHeader = 0x00;
*headerLength = 0;
return YES;
};
break;
}
case CompressionFramingNativeCompress: {
self.assemblePayloadBlock = ^(uint8_t * packetDest, NSInteger * packetLengthOffset, NSData * payload) {
NSData *compressedPayload = [weakSelf.lzo compressedDataWithData:payload error:NULL];
if (compressedPayload) {
packetDest[0] = DataPacketLZOCompress;
*packetLengthOffset = 1 - (payload.length - compressedPayload.length);
payload = compressedPayload;
memcpy(packetDest + 1, payload.bytes, payload.length);
} else {
*packetLengthOffset = 1;
// do not byte swap if compression enabled
if (weakSelf.lzo) {
packetDest[0] = DataPacketNoCompress;
memcpy(packetDest + 1, payload.bytes, payload.length);
} else {
memcpy(packetDest, payload.bytes, payload.length);
packetDest[payload.length] = packetDest[0];
packetDest[0] = DataPacketNoCompressSwap;
}
}
};
self.parsePayloadBlock = parseCompressedBlock;
break;
}
case CompressionFramingNativeCompLZO: {
self.assemblePayloadBlock = ^(uint8_t * packetDest, NSInteger * packetLengthOffset, NSData * payload) {
NSData *compressedPayload = [weakSelf.lzo compressedDataWithData:payload error:NULL];
if (compressedPayload) {
packetDest[0] = DataPacketLZOCompress;
*packetLengthOffset = 1 - (payload.length - compressedPayload.length);
payload = compressedPayload;
} else {
packetDest[0] = DataPacketNoCompress;
*packetLengthOffset = 1;
}
memcpy(packetDest + 1, payload.bytes, payload.length);
};
self.parsePayloadBlock = parseCompressedBlock;
break;
}
}
}
#pragma mark DataPath
- (NSArray<NSData *> *)encryptPackets:(NSArray<NSData *> *)packets key:(uint8_t)key error:(NSError *__autoreleasing *)error
{
// NSAssert(self.encrypter.peerId == self.decrypter.peerId, @"Peer-id mismatch in DataPath encrypter/decrypter");
if (self.outPacketId > self.maxPacketId) {
if (error) {
*error = TunnelKitErrorWithCode(TunnelKitErrorCodeDataPathOverflow);
}
return nil;
}
[self.outPackets removeAllObjects];
for (NSData *payload in packets) {
self.outPacketId += 1;
// may resize encBuffer to hold encrypted payload
[self adjustEncBufferToPacketSize:(int)payload.length];
uint8_t *dataPacketBytes = self.encBufferAligned;
NSInteger dataPacketLength;
[self.encrypter assembleDataPacketWithBlock:self.assemblePayloadBlock
packetId:self.outPacketId
payload:payload
into:dataPacketBytes
length:&dataPacketLength];
MSSFix(dataPacketBytes, dataPacketLength);
NSData *encryptedDataPacket = [self.encrypter encryptedDataPacketWithKey:key
packetId:self.outPacketId
packetBytes:dataPacketBytes
packetLength:dataPacketLength
error:error];
if (!encryptedDataPacket) {
return nil;
}
[self.outPackets addObject:encryptedDataPacket];
}
return self.outPackets;
}
- (NSArray<NSData *> *)decryptPackets:(NSArray<NSData *> *)packets keepAlive:(bool *)keepAlive error:(NSError *__autoreleasing *)error
{
// NSAssert(self.encrypter.peerId == self.decrypter.peerId, @"Peer-id mismatch in DataPath encrypter/decrypter");
[self.inPackets removeAllObjects];
for (NSData *encryptedDataPacket in packets) {
// may resize decBuffer to encryptedPacket.length
[self adjustDecBufferToPacketSize:(int)encryptedDataPacket.length];
uint8_t *dataPacketBytes = self.decBufferAligned;
NSInteger dataPacketLength = INT_MAX;
uint32_t packetId;
const BOOL success = [self.decrypter decryptDataPacket:encryptedDataPacket
into:dataPacketBytes
length:&dataPacketLength
packetId:&packetId
error:error];
if (!success) {
return nil;
}
if (packetId > self.maxPacketId) {
if (error) {
*error = TunnelKitErrorWithCode(TunnelKitErrorCodeDataPathOverflow);
}
return nil;
}
if (self.inReplay && [self.inReplay isReplayedPacketId:packetId]) {
continue;
}
uint8_t compressionHeader;
NSData *payload = [self.decrypter parsePayloadWithBlock:self.parsePayloadBlock
compressionHeader:&compressionHeader
packetBytes:dataPacketBytes
packetLength:dataPacketLength
error:error];
if (!payload) {
return nil;
}
if (compressionHeader == DataPacketLZOCompress) {
payload = [self.lzo decompressedDataWithData:payload error:error];
if (!payload) {
return nil;
}
}
if ((payload.length == sizeof(DataPacketPingData)) && !memcmp(payload.bytes, DataPacketPingData, payload.length)) {
if (keepAlive) {
*keepAlive = true;
}
continue;
}
// MSSFix(payloadBytes, payloadLength);
[self.inPackets addObject:payload];
}
return self.inPackets;
}
@end
Reference in New Issue View Git Blame Copy Permalink