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UDS: Stub SendTo to generate the unencrypted data frame with the right headers.

This commit is contained in:
Subv 2017-06-13 16:30:17 -05:00
parent ac168eeb5d
commit 7efb64132d
4 changed files with 261 additions and 1 deletions
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2
src/core/CMakeLists.txt
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@ -144,6 +144,7 @@ set(SRCS
hle/service/nwm/nwm_tst.cpp
hle/service/nwm/nwm_uds.cpp
hle/service/nwm/uds_beacon.cpp
hle/service/nwm/uds_data.cpp
hle/service/pm_app.cpp
hle/service/ptm/ptm.cpp
hle/service/ptm/ptm_gets.cpp
@ -341,6 +342,7 @@ set(HEADERS
hle/service/nwm/nwm_tst.h
hle/service/nwm/nwm_uds.h
hle/service/nwm/uds_beacon.h
hle/service/nwm/uds_data.h
hle/service/pm_app.h
hle/service/ptm/ptm.h
hle/service/ptm/ptm_gets.h

68
src/core/hle/service/nwm/nwm_uds.cpp
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@ -15,6 +15,7 @@
#include "core/hle/result.h"
#include "core/hle/service/nwm/nwm_uds.h"
#include "core/hle/service/nwm/uds_beacon.h"
#include "core/hle/service/nwm/uds_data.h"
#include "core/memory.h"
namespace Service {
@ -372,6 +373,71 @@ static void DestroyNetwork(Interface* self) {
LOG_WARNING(Service_NWM, "called");
}
/**
* NWM_UDS::SendTo service function.
* Sends a data frame to the UDS network we're connected to.
* Inputs:
* 0 : Command header.
* 1 : Unknown.
* 2 : u16 Destination network node id.
* 3 : u8 Data channel.
* 4 : Buffer size >> 2
* 5 : Data size
* 6 : Flags
* 7 : Input buffer descriptor
* 8 : Input buffer address
* Outputs:
* 0 : Return header
* 1 : Result of function, 0 on success, otherwise error code
*/
static void SendTo(Interface* self) {
IPC::RequestParser rp(Kernel::GetCommandBuffer(), 0x17, 6, 2);
rp.Skip(1, false);
u16 dest_node_id = rp.Pop<u16>();
u8 data_channel = rp.Pop<u8>();
rp.Skip(1, false);
u32 data_size = rp.Pop<u32>();
u32 flags = rp.Pop<u32>();
size_t desc_size;
const VAddr input_address = rp.PopStaticBuffer(&desc_size, false);
ASSERT(desc_size == data_size);
// TODO(Subv): Figure out the error if this is called while not connected to a network.
if (connection_status.status == static_cast<u32>(NetworkStatus::ConnectedAsClient) ||
connection_status.status == static_cast<u32>(NetworkStatus::ConnectedAsHost)) {
ASSERT_MSG(false, "Not connected to a network (unimplemented)");
}
// TODO(Subv): Do something with the flags.
IPC::RequestBuilder rb = rp.MakeBuilder(1, 0);
constexpr size_t MaxSize = 0x5C6;
if (data_size > MaxSize) {
rb.Push(ResultCode(ErrorDescription::TooLarge, ErrorModule::UDS,
ErrorSummary::WrongArgument, ErrorLevel::Usage));
return;
}
std::vector<u8> data(data_size);
Memory::ReadBlock(input_address, data.data(), data.size());
// TODO(Subv): Increment the sequence number after each sent packet.
u16 sequence_number = 0;
std::vector<u8> data_frame = GenerateDataFrame(data, data_channel, dest_node_id,
connection_status.network_node_id,
sequence_number);
// TODO(Subv): Send the frame.
rb.Push(RESULT_SUCCESS);
LOG_WARNING(Service_NWM, "(STUB) called dest_node_id=%u size=%u flags=%u channel=%u",
static_cast<u32>(dest_node_id), data_size, flags, static_cast<u32>(data_channel));
}
/**
* NWM_UDS::GetChannel service function.
* Returns the WiFi channel in which the network we're connected to is transmitting.
@ -564,7 +630,7 @@ const Interface::FunctionInfo FunctionTable[] = {
{0x00130040, nullptr, "Unbind"},
{0x001400C0, nullptr, "PullPacket"},
{0x00150080, nullptr, "SetMaxSendDelay"},
{0x00170182, nullptr, "SendTo"},
{0x00170182, SendTo, "SendTo"},
{0x001A0000, GetChannel, "GetChannel"},
{0x001B0302, InitializeWithVersion, "InitializeWithVersion"},
{0x001D0044, BeginHostingNetwork, "BeginHostingNetwork"},

112
src/core/hle/service/nwm/uds_data.cpp Normal file
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@ -0,0 +1,112 @@
// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <cstring>
#include "core/hle/service/nwm/nwm_uds.h"
#include "core/hle/service/nwm/uds_data.h"
#include "core/hw/aes/key.h"
#include <cryptopp/aes.h>
#include <cryptopp/md5.h>
#include <cryptopp/modes.h>
namespace Service {
namespace NWM {
// AES Keyslot used to generate the UDS data frame CCMP key.
constexpr size_t UDSDataCryptoAESKeySlot = 0x2D;
/*
* Generates a SNAP-enabled 802.2 LLC header for the specified protocol.
* @returns a buffer with the bytes of the generated header.
*/
static std::vector<u8> GenerateLLCHeader(EtherType protocol) {
LLCHeader header{};
header.protocol = static_cast<u16>(protocol);
std::vector<u8> buffer(sizeof(header));
memcpy(buffer.data(), &header, sizeof(header));
return buffer;
}
/*
* Generates a Nintendo UDS SecureData header with the specified parameters.
* @returns a buffer with the bytes of the generated header.
*/
static std::vector<u8> GenerateSecureDataHeader(u16 data_size, u8 channel, u16 dest_node_id,
u16 src_node_id, u16 sequence_number) {
SecureDataHeader header{};
header.protocol_size = data_size + sizeof(SecureDataHeader);
// TODO(Subv): It is likely that the first 4 bytes of this header are actually a decorator for another protocol.
header.securedata_size = data_size + sizeof(SecureDataHeader) - 4;
header.is_management = 0; // Frames sent by the emulated application are never UDS management frames
header.data_channel = channel;
header.sequence_number = sequence_number;
header.dest_node_id = dest_node_id;
header.src_node_id = src_node_id;
std::vector<u8> buffer(sizeof(header));
memcpy(buffer.data(), &header, sizeof(header));
return buffer;
}
/*
* Calculates the CTR used for the AES-CTR process that calculates
* the CCMP crypto key for data frames.
* @returns The CTR used for data frames crypto key generation.
*/
static std::array<u8, CryptoPP::MD5::DIGESTSIZE> GetDataCryptoCTR(const NetworkInfo& network_info) {
DataFrameCryptoCTR data{};
data.host_mac = network_info.host_mac_address;
data.wlan_comm_id = network_info.wlan_comm_id;
data.id = network_info.id;
data.network_id = network_info.network_id;
std::array<u8, CryptoPP::MD5::DIGESTSIZE> hash;
CryptoPP::MD5().CalculateDigest(hash.data(), reinterpret_cast<u8*>(&data), sizeof(data));
return hash;
}
/*
* Generates the key used for encrypting the 802.11 data frames generated by UDS.
* @returns The key used for data frames crypto.
*/
static std::array<u8, CryptoPP::AES::BLOCKSIZE> GenerateDataCCMPKey(const std::vector<u8>& passphrase,
const NetworkInfo& network_info) {
// Calculate the MD5 hash of the input passphrase.
std::array<u8, CryptoPP::MD5::DIGESTSIZE> passphrase_hash;
CryptoPP::MD5().CalculateDigest(passphrase_hash.data(), passphrase.data(), passphrase.size());
std::array<u8, CryptoPP::AES::BLOCKSIZE> ccmp_key;
// The CCMP key is the result of encrypting the MD5 hash of the passphrase with AES-CTR using keyslot 0x2D.
using CryptoPP::AES;
std::array<u8, CryptoPP::MD5::DIGESTSIZE> counter = GetDataCryptoCTR(network_info);
std::array<u8, AES::BLOCKSIZE> key = HW::AES::GetNormalKey(UDSDataCryptoAESKeySlot);
CryptoPP::CTR_Mode<AES>::Encryption aes;
aes.SetKeyWithIV(key.data(), AES::BLOCKSIZE, counter.data());
aes.ProcessData(ccmp_key.data(), passphrase_hash.data(), passphrase_hash.size());
return ccmp_key;
}
std::vector<u8> GenerateDataFrame(const std::vector<u8>& data, u8 channel, u16 dest_node, u16 src_node, u16 sequence_number) {
std::vector<u8> buffer = GenerateLLCHeader(EtherType::SecureData);
std::vector<u8> securedata_header = GenerateSecureDataHeader(data.size(), channel, dest_node, src_node, sequence_number);
buffer.insert(buffer.end(), securedata_header.begin(), securedata_header.end());
buffer.insert(buffer.end(), data.begin(), data.end());
// TODO(Subv): Encrypt the frame.
// TODO(Subv): Prepend CCMP initialization vector (sequence_number).
// TODO(Subv): Encapsulate the frame in an 802.11 data frame.
return buffer;
}
} // namespace NWM
} // namespace Service

80
src/core/hle/service/nwm/uds_data.h Normal file
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@ -0,0 +1,80 @@
// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include "common/common_types.h"
#include "common/swap.h"
#include "core/hle/service/service.h"
namespace Service {
namespace NWM {
enum class SAP : u8 {
SNAPExtensionUsed = 0xAA
};
enum class PDUControl : u8 {
UnnumberedInformation = 3
};
enum class EtherType : u16 {
SecureData = 0x876D,
EAPoL = 0x888E
};
/*
* 802.2 header, UDS packets always use SNAP for these headers,
* which means the dsap and ssap are always SNAPExtensionUsed (0xAA)
* and the OUI is always 0.
*/
struct LLCHeader {
u8 dsap = static_cast<u8>(SAP::SNAPExtensionUsed);
u8 ssap = static_cast<u8>(SAP::SNAPExtensionUsed);
u8 control = static_cast<u8>(PDUControl::UnnumberedInformation);
std::array<u8, 3> OUI = {};
u16_be protocol;
};
static_assert(sizeof(LLCHeader) == 8, "LLCHeader has the wrong size");
/*
* Nintendo SecureData header, every UDS packet contains one,
* it is used to store metadata about the transmission such as
* the source and destination network node ids.
*/
struct SecureDataHeader {
u16_be protocol_size;
INSERT_PADDING_BYTES(2);
u16_be securedata_size;
u8 is_management;
u8 data_channel;
u16_be sequence_number;
u16_be dest_node_id;
u16_be src_node_id;
};
static_assert(sizeof(SecureDataHeader) == 14, "SecureDataHeader has the wrong size");
/*
* The raw bytes of this structure are the CTR used in the encryption (AES-CTR)
* process used to generate the CCMP key for data frame encryption.
*/
struct DataFrameCryptoCTR {
u32_le wlan_comm_id;
u32_le network_id;
std::array<u8, 6> host_mac;
u16_le id;
};
static_assert(sizeof(DataFrameCryptoCTR) == 16, "DataFrameCryptoCTR has the wrong size");
/**
* Generates an encrypted 802.11 data frame starting at the CCMP IV.
* @returns The generated frame.
*/
std::vector<u8> GenerateDataFrame(const std::vector<u8>& data, u8 channel, u16 dest_node, u16 src_node, u16 sequence_number);
} // namespace NWM
} // namespace Service