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UDS: Use the ToDS and FromDS fields to properly calculate the AAD used during encryption.

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This commit is contained in:
Subv 2017-06-14 16:59:16 -05:00
parent 1f1739d366
commit 2eb174713b
1 changed files with 32 additions and 15 deletions
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47
src/core/hle/service/nwm/uds_data.cpp
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@ -103,7 +103,8 @@ static std::array<u8, CryptoPP::AES::BLOCKSIZE> GenerateDataCCMPKey(
* 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) {
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)
@ -113,20 +114,34 @@ static std::vector<u8> GenerateCCMPAAD(const MacAddress& sender, const MacAddres
// Control field are masked to 0.
struct {
u16_be FC; // MPDU Frame Control field
MacAddress receiver;
MacAddress transmitter;
MacAddress destination;
MacAddress A1;
MacAddress A2;
MacAddress A3;
u16_be SC; // MPDU Sequence Control field
} aad_struct{};
// Default FC value of DataFrame | Protected | ToDS
constexpr u16 DefaultFrameControl = 0x0841;
aad_struct.FC = DefaultFrameControl;
constexpr u16 AADFrameControlMask = 0x8FC7;
aad_struct.FC = frame_control & AADFrameControlMask;
aad_struct.SC = 0;
aad_struct.transmitter = sender;
aad_struct.receiver = receiver;
aad_struct.destination = receiver;
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));
@ -141,11 +156,12 @@ static std::vector<u8> GenerateCCMPAAD(const MacAddress& sender, const MacAddres
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,
u16 sequence_number) {
const MacAddress& bssid, u16 sequence_number,
u16 frame_control) {
// Reference: IEEE 802.11-2007
std::vector<u8> aad = GenerateCCMPAAD(sender, receiver);
std::vector<u8> aad = GenerateCCMPAAD(sender, receiver, bssid, frame_control);
std::vector<u8> packet_number{0,
0,
@ -200,10 +216,11 @@ static std::vector<u8> DecryptDataFrame(const std::vector<u8>& 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,
u16 sequence_number) {
const MacAddress& bssid, u16 sequence_number,
u16 frame_control) {
// Reference: IEEE 802.11-2007
std::vector<u8> aad = GenerateCCMPAAD(sender, receiver);
std::vector<u8> aad = GenerateCCMPAAD(sender, receiver, bssid, frame_control);
std::vector<u8> packet_number{0,
0,