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Merge pull request #2778 from Subv/uds_more

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Services/UDS: Stub SendTo to generate the unencrypted data frames with the right headers
This commit is contained in:
Sebastian Valle
2017-06-26 19:35:52 -05:00
committed by GitHub
parent d1e414d813 2eb174713b
commit fa53ccc74b
5 changed files with 436 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

77
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 +373,80 @@ 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);
IPC::RequestBuilder rb = rp.MakeBuilder(1, 0);
if (connection_status.status != static_cast<u32>(NetworkStatus::ConnectedAsClient) &&
connection_status.status != static_cast<u32>(NetworkStatus::ConnectedAsHost)) {
rb.Push(ResultCode(ErrorDescription::NotAuthorized, ErrorModule::UDS,
ErrorSummary::InvalidState, ErrorLevel::Status));
return;
}
if (dest_node_id == connection_status.network_node_id) {
rb.Push(ResultCode(ErrorDescription::NotFound, ErrorModule::UDS,
ErrorSummary::WrongArgument, ErrorLevel::Status));
return;
}
// TODO(Subv): Do something with the flags.
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_payload = GenerateDataPayload(
data, data_channel, dest_node_id, connection_status.network_node_id, sequence_number);
// TODO(Subv): Retrieve the MAC address of the dest_node_id and our own to encrypt
// and encapsulate the payload.
// 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.
@@ -600,7 +675,7 @@ 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"},

278
src/core/hle/service/nwm/uds_data.cpp Normal file
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@@ -0,0 +1,278 @@
// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <cstring>
#include <cryptopp/aes.h>
#include <cryptopp/ccm.h>
#include <cryptopp/filters.h>
#include <cryptopp/md5.h>
#include <cryptopp/modes.h>
#include "core/hle/service/nwm/nwm_uds.h"
#include "core/hle/service/nwm/uds_data.h"
#include "core/hw/aes/key.h"
namespace Service {
namespace NWM {
using MacAddress = std::array<u8, 6>;
/*
* 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);
// Note: This size includes everything except the first 4 bytes of the structure,
// reinforcing the hypotheses that the first 4 bytes are actually the header of
// another container protocol.
header.securedata_size = data_size + sizeof(SecureDataHeader) - 4;
// Frames sent by the emulated application are never UDS management frames
header.is_management = 0;
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(HW::AES::KeySlotID::UDSDataKey);
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;
}
/*
* Generates the Additional Authenticated Data (AAD) for an UDS 802.11 encrypted data frame.
* @returns a buffer with the bytes of the AAD.
*/
static std::vector<u8> GenerateCCMPAAD(const MacAddress& sender, const MacAddress& receiver,
const MacAddress& bssid, u16 frame_control) {
// Reference: IEEE 802.11-2007
// 8.3.3.3.2 Construct AAD (22-30 bytes)
// The AAD is constructed from the MPDU header. The AAD does not include the header Duration
// field, because the Duration field value can change due to normal IEEE 802.11 operation (e.g.,
// a rate change during retransmission). For similar reasons, several subfields in the Frame
// Control field are masked to 0.
struct {
u16_be FC; // MPDU Frame Control field
MacAddress A1;
MacAddress A2;
MacAddress A3;
u16_be SC; // MPDU Sequence Control field
} aad_struct{};
constexpr u16 AADFrameControlMask = 0x8FC7;
aad_struct.FC = frame_control & AADFrameControlMask;
aad_struct.SC = 0;
bool to_ds = (frame_control & (1 << 0)) != 0;
bool from_ds = (frame_control & (1 << 1)) != 0;
// In the 802.11 standard, ToDS = 1 and FromDS = 1 is a valid configuration,
// however, the 3DS doesn't seem to transmit frames with such combination.
ASSERT_MSG(to_ds != from_ds, "Invalid combination");
// The meaning of the address fields depends on the ToDS and FromDS fields.
if (from_ds) {
aad_struct.A1 = receiver;
aad_struct.A2 = bssid;
aad_struct.A3 = sender;
}
if (to_ds) {
aad_struct.A1 = bssid;
aad_struct.A2 = sender;
aad_struct.A3 = receiver;
}
std::vector<u8> aad(sizeof(aad_struct));
std::memcpy(aad.data(), &aad_struct, sizeof(aad_struct));
return aad;
}
/*
* Decrypts the payload of an encrypted 802.11 data frame using the specified key.
* @returns The decrypted payload.
*/
static std::vector<u8> DecryptDataFrame(const std::vector<u8>& encrypted_payload,
const std::array<u8, CryptoPP::AES::BLOCKSIZE>& ccmp_key,
const MacAddress& sender, const MacAddress& receiver,
const MacAddress& bssid, u16 sequence_number,
u16 frame_control) {
// Reference: IEEE 802.11-2007
std::vector<u8> aad = GenerateCCMPAAD(sender, receiver, bssid, frame_control);
std::vector<u8> packet_number{0,
0,
0,
0,
static_cast<u8>((sequence_number >> 8) & 0xFF),
static_cast<u8>(sequence_number & 0xFF)};
// 8.3.3.3.3 Construct CCM nonce (13 bytes)
std::vector<u8> nonce;
nonce.push_back(0); // priority
nonce.insert(nonce.end(), sender.begin(), sender.end()); // Address 2
nonce.insert(nonce.end(), packet_number.begin(), packet_number.end()); // PN
try {
CryptoPP::CCM<CryptoPP::AES, 8>::Decryption d;
d.SetKeyWithIV(ccmp_key.data(), ccmp_key.size(), nonce.data(), nonce.size());
d.SpecifyDataLengths(aad.size(), encrypted_payload.size() - 8, 0);
CryptoPP::AuthenticatedDecryptionFilter df(
d, nullptr, CryptoPP::AuthenticatedDecryptionFilter::MAC_AT_END |
CryptoPP::AuthenticatedDecryptionFilter::THROW_EXCEPTION);
// put aad
df.ChannelPut(CryptoPP::AAD_CHANNEL, aad.data(), aad.size());
// put cipher with mac
df.ChannelPut(CryptoPP::DEFAULT_CHANNEL, encrypted_payload.data(),
encrypted_payload.size() - 8);
df.ChannelPut(CryptoPP::DEFAULT_CHANNEL,
encrypted_payload.data() + encrypted_payload.size() - 8, 8);
df.ChannelMessageEnd(CryptoPP::AAD_CHANNEL);
df.ChannelMessageEnd(CryptoPP::DEFAULT_CHANNEL);
df.SetRetrievalChannel(CryptoPP::DEFAULT_CHANNEL);
int size = df.MaxRetrievable();
std::vector<u8> pdata(size);
df.Get(pdata.data(), size);
return pdata;
} catch (CryptoPP::Exception&) {
LOG_ERROR(Service_NWM, "failed to decrypt");
}
return {};
}
/*
* Encrypts the payload of an 802.11 data frame using the specified key.
* @returns The encrypted payload.
*/
static std::vector<u8> EncryptDataFrame(const std::vector<u8>& payload,
const std::array<u8, CryptoPP::AES::BLOCKSIZE>& ccmp_key,
const MacAddress& sender, const MacAddress& receiver,
const MacAddress& bssid, u16 sequence_number,
u16 frame_control) {
// Reference: IEEE 802.11-2007
std::vector<u8> aad = GenerateCCMPAAD(sender, receiver, bssid, frame_control);
std::vector<u8> packet_number{0,
0,
0,
0,
static_cast<u8>((sequence_number >> 8) & 0xFF),
static_cast<u8>(sequence_number & 0xFF)};
// 8.3.3.3.3 Construct CCM nonce (13 bytes)
std::vector<u8> nonce;
nonce.push_back(0); // priority
nonce.insert(nonce.end(), sender.begin(), sender.end()); // Address 2
nonce.insert(nonce.end(), packet_number.begin(), packet_number.end()); // PN
try {
CryptoPP::CCM<CryptoPP::AES, 8>::Encryption d;
d.SetKeyWithIV(ccmp_key.data(), ccmp_key.size(), nonce.data(), nonce.size());
d.SpecifyDataLengths(aad.size(), payload.size(), 0);
CryptoPP::AuthenticatedEncryptionFilter df(d);
// put aad
df.ChannelPut(CryptoPP::AAD_CHANNEL, aad.data(), aad.size());
df.ChannelMessageEnd(CryptoPP::AAD_CHANNEL);
// put plaintext
df.ChannelPut(CryptoPP::DEFAULT_CHANNEL, payload.data(), payload.size());
df.ChannelMessageEnd(CryptoPP::DEFAULT_CHANNEL);
df.SetRetrievalChannel(CryptoPP::DEFAULT_CHANNEL);
int size = df.MaxRetrievable();
std::vector<u8> cipher(size);
df.Get(cipher.data(), size);
return cipher;
} catch (CryptoPP::Exception&) {
LOG_ERROR(Service_NWM, "failed to encrypt");
}
return {};
}
std::vector<u8> GenerateDataPayload(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());
return buffer;
}
} // namespace NWM
} // namespace Service

78
src/core/hle/service/nwm/uds_data.h Normal file
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@@ -0,0 +1,78 @@
// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <array>
#include <vector>
#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 {
// TODO(Subv): It is likely that the first 4 bytes of this header are
// actually part of another container protocol.
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 unencrypted 802.11 data payload.
* @returns The generated frame payload.
*/
std::vector<u8> GenerateDataPayload(const std::vector<u8>& data, u8 channel, u16 dest_node,
u16 src_node, u16 sequence_number);
} // namespace NWM
} // namespace Service

2
src/core/hw/aes/key.h
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@@ -12,6 +12,8 @@ namespace HW {
namespace AES {
enum KeySlotID : size_t {
// AES Keyslot used to generate the UDS data frame CCMP key.
UDSDataKey = 0x2D,
APTWrap = 0x31,
MaxKeySlotID = 0x40,