50064fc3d0
Minimize target dependency on OpenSSL (easier to drop later). Outside of OpenVPN tunnel extension, OpenSSL is only used to decrypt encrypted private keys in CryptoContainer (found in TunnelKitOpenVPNCore, therefore "temporarily" dependent on CTunnelKitOpenVPNAppExtension for TLSBox/CryptoBox).
102 lines
3.2 KiB
Objective-C
102 lines
3.2 KiB
Objective-C
//
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// PacketStream.m
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// TunnelKit
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//
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// Created by Davide De Rosa on 4/25/19.
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// Copyright (c) 2021 Davide De Rosa. All rights reserved.
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//
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// https://github.com/passepartoutvpn
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//
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// This file is part of TunnelKit.
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//
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// TunnelKit is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// TunnelKit is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with TunnelKit. If not, see <http://www.gnu.org/licenses/>.
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//
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#import "PacketStream.h"
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static const NSInteger PacketStreamHeaderLength = sizeof(uint16_t);
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@implementation PacketStream
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+ (void)memcpyXor:(uint8_t *)dst src:(NSData *)src xorMask:(uint8_t)xorMask
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{
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if (xorMask != 0) {
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for (int i = 0; i < src.length; ++i) {
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dst[i] = ((uint8_t *)(src.bytes))[i] ^ xorMask;
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}
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return;
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}
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memcpy(dst, src.bytes, src.length);
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}
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+ (NSArray<NSData *> *)packetsFromStream:(NSData *)stream until:(NSInteger *)until xorMask:(uint8_t)xorMask
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{
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NSInteger ni = 0;
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NSMutableArray<NSData *> *parsed = [[NSMutableArray alloc] init];
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while (ni + PacketStreamHeaderLength <= stream.length) {
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const NSInteger packlen = CFSwapInt16BigToHost(*(uint16_t *)(stream.bytes + ni));
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const NSInteger start = ni + PacketStreamHeaderLength;
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const NSInteger end = start + packlen;
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if (end > stream.length) {
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break;
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}
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NSData *packet = [stream subdataWithRange:NSMakeRange(start, packlen)];
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uint8_t* packetBytes = (uint8_t*) packet.bytes;
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if (xorMask != 0) {
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for (int i = 0; i < packet.length; i++) {
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packetBytes[i] ^= xorMask;
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}
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}
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[parsed addObject:packet];
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ni = end;
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}
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if (until) {
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*until = ni;
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}
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return parsed;
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}
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+ (NSData *)streamFromPacket:(NSData *)packet xorMask:(uint8_t)xorMask
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{
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NSMutableData *raw = [[NSMutableData alloc] initWithLength:(PacketStreamHeaderLength + packet.length)];
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uint8_t *ptr = raw.mutableBytes;
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*(uint16_t *)ptr = CFSwapInt16HostToBig(packet.length);
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ptr += PacketStreamHeaderLength;
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[PacketStream memcpyXor:ptr src:packet xorMask:xorMask];
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return raw;
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}
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+ (NSData *)streamFromPackets:(NSArray<NSData *> *)packets xorMask:(uint8_t)xorMask
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{
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NSInteger streamLength = 0;
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for (NSData *p in packets) {
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streamLength += PacketStreamHeaderLength + p.length;
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}
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NSMutableData *raw = [[NSMutableData alloc] initWithLength:streamLength];
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uint8_t *ptr = raw.mutableBytes;
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for (NSData *packet in packets) {
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*(uint16_t *)ptr = CFSwapInt16HostToBig(packet.length);
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ptr += PacketStreamHeaderLength;
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[PacketStream memcpyXor:ptr src:packet xorMask:xorMask];
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ptr += packet.length;
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}
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return raw;
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}
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@end
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