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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. * Generates the Additional Authenticated Data (AAD) for an UDS 802.11 encrypted data frame.
* @returns a buffer with the bytes of the AAD. * @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 // Reference: IEEE 802.11-2007
// 8.3.3.3.2 Construct AAD (22-30 bytes) // 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. // Control field are masked to 0.
struct { struct {
u16_be FC; // MPDU Frame Control field u16_be FC; // MPDU Frame Control field
MacAddress receiver; MacAddress A1;
MacAddress transmitter; MacAddress A2;
MacAddress destination; MacAddress A3;
u16_be SC; // MPDU Sequence Control field u16_be SC; // MPDU Sequence Control field
} aad_struct{}; } aad_struct{};
// Default FC value of DataFrame | Protected | ToDS constexpr u16 AADFrameControlMask = 0x8FC7;
constexpr u16 DefaultFrameControl = 0x0841; aad_struct.FC = frame_control & AADFrameControlMask;
aad_struct.FC = DefaultFrameControl;
aad_struct.SC = 0; aad_struct.SC = 0;
aad_struct.transmitter = sender;
aad_struct.receiver = receiver; bool to_ds = (frame_control & (1 << 0)) != 0;
aad_struct.destination = receiver; 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::vector<u8> aad(sizeof(aad_struct));
std::memcpy(aad.data(), &aad_struct, 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, static std::vector<u8> DecryptDataFrame(const std::vector<u8>& encrypted_payload,
const std::array<u8, CryptoPP::AES::BLOCKSIZE>& ccmp_key, const std::array<u8, CryptoPP::AES::BLOCKSIZE>& ccmp_key,
const MacAddress& sender, const MacAddress& receiver, const MacAddress& sender, const MacAddress& receiver,
u16 sequence_number) { const MacAddress& bssid, u16 sequence_number,
u16 frame_control) {
// Reference: IEEE 802.11-2007 // 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, std::vector<u8> packet_number{0,
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, static std::vector<u8> EncryptDataFrame(const std::vector<u8>& payload,
const std::array<u8, CryptoPP::AES::BLOCKSIZE>& ccmp_key, const std::array<u8, CryptoPP::AES::BLOCKSIZE>& ccmp_key,
const MacAddress& sender, const MacAddress& receiver, const MacAddress& sender, const MacAddress& receiver,
u16 sequence_number) { const MacAddress& bssid, u16 sequence_number,
u16 frame_control) {
// Reference: IEEE 802.11-2007 // 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, std::vector<u8> packet_number{0,
0, 0,