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Codec & Crypto

Namespaces: wknet::codec · wknet::crypto
Headers: wknet/codec/Codec.h · wknet/crypto/Aead.h
(both included by Wknet.h)

Content-coding / EXI / Pack200 decode, and AEAD encrypt/decrypt. HTTP sends can use codec through SendOptions Accept-Encoding / coding materials.

Codec · wknet::codec

Coding / materials

enum class Coding : UCHAR {
    Identity = 0,
    Gzip = 1,
    Deflate = 2,
    Brotli = 3,
    Compress = 4,
    Zstd = 5,
    DictionaryCompressedBrotli = 6,
    DictionaryCompressedZstd = 7,
    Aes128Gcm = 8,
    Exi = 9,
    Pack200Gzip = 10
};

struct ExternalMaterial final {
    Coding CodingKind = Coding::Identity;
    const UCHAR* Dictionary = nullptr;
    SIZE_T DictionaryLength = 0;
    const UCHAR* Aes128GcmKeyingMaterial = nullptr;
    SIZE_T Aes128GcmKeyingMaterialLength = 0;
};

using MaterialCallback = NTSTATUS(*)(
    _In_opt_ void* context,
    Coding coding,
    _Out_ ExternalMaterial* material);

struct DecodeMaterials final {
    const ExternalMaterial* Items = nullptr;
    SIZE_T ItemCount = 0;
    MaterialCallback Callback = nullptr;
    void* CallbackContext = nullptr;
};

struct DecodeBuffers final {
    char* DecodedBody = nullptr;
    SIZE_T DecodedBodyCapacity = 0;
    char* ScratchBody = nullptr;
    SIZE_T ScratchBodyCapacity = 0;
    const DecodeMaterials* Materials = nullptr;
};

struct DecodeResult final {
    const char* Body = nullptr;
    SIZE_T BodyLength = 0;
    bool AppliedCoding = false;
};

Functions

bool DeflateRuntimeAvailable() noexcept;

NTSTATUS DecodeOne(
    Coding coding,
    _In_reads_bytes_(sourceLength) const char* source,
    SIZE_T sourceLength,
    _Out_writes_bytes_(destinationCapacity) char* destination,
    SIZE_T destinationCapacity,
    _Out_ SIZE_T* decodedLength,
    _In_opt_ const DecodeMaterials* materials = nullptr) noexcept;

NTSTATUS DecodeChain(
    _In_reads_(codingCount) const Coding* codings,
    SIZE_T codingCount,
    _In_reads_bytes_(bodyLength) const char* body,
    SIZE_T bodyLength,
    _In_ const DecodeBuffers& buffers,
    _Out_ DecodeResult& result) noexcept;

// Schema-less EXI 1.0 → Infoset-equivalent XML
NTSTATUS DecodeExi(
    _In_reads_bytes_(sourceLength) const UCHAR* source,
    SIZE_T sourceLength,
    _Out_writes_bytes_(destinationCapacity) char* destination,
    SIZE_T destinationCapacity,
    _Out_ SIZE_T* decodedLength) noexcept;

// Pack200 (raw or gzip) → JAR bytes
NTSTATUS DecodePack200(
    _In_reads_bytes_(sourceLength) const UCHAR* source,
    SIZE_T sourceLength,
    _Out_writes_bytes_(destinationCapacity) char* destination,
    SIZE_T destinationCapacity,
    _Out_ SIZE_T* decodedLength) noexcept;
API Notes
DeflateRuntimeAvailable Whether Deflate runtime is available
DecodeOne Single coding into destination
DecodeChain Decode chain in reverse Content-Encoding order
DecodeExi Schema-less EXI 1.0 only; external Schema/strict grammar → STATUS_NOT_SUPPORTED
DecodePack200 Java 5–8 Pack200 150.7/160.1/170.1/171.0; semantic JAR output

HTTP-layer material types are http::CodingDecodeMaterials / http::ContentCoding (see Sync HTTP).

Crypto AEAD · wknet::crypto::Aead

Depends on BufferView / CngProviderCache from CngProvider.h.

enum class AeadAlgorithm : UCHAR {
    Aes128Gcm,
    Aes256Gcm,
    ChaCha20Poly1305,
    Aes128Ccm,
    Aes128Ccm8
};

constexpr SIZE_T AeadMaxKeyLength = 32;
constexpr SIZE_T AeadMaxNonceLength = 12;
constexpr SIZE_T AeadMaxTagLength = 16;
constexpr SIZE_T AeadChaCha20Poly1305KeyLength = 32;
constexpr SIZE_T AeadChaCha20Poly1305NonceLength = 12;
constexpr SIZE_T AeadChaCha20Poly1305TagLength = 16;

struct AeadKey final {
    AeadAlgorithm Algorithm = AeadAlgorithm::Aes128Gcm;
    const UCHAR* Key = nullptr;
    SIZE_T KeyLength = 0;
};

struct AeadParameters final {
    BufferView Nonce = {}; // Data / Length
    BufferView Aad = {};
    BufferView Tag = {};
};

class Aead final {
public:
    Aead() = delete;

    static SIZE_T TagLength(AeadAlgorithm algorithm) noexcept;

    static NTSTATUS Encrypt(
        _In_opt_ const CngProviderCache* cache,
        _In_ const AeadKey& key,
        _In_ const AeadParameters& parameters,
        _In_reads_bytes_opt_(plaintextLength) const UCHAR* plaintext,
        SIZE_T plaintextLength,
        _Out_writes_bytes_(ciphertextLength) UCHAR* ciphertext,
        SIZE_T ciphertextLength,
        _Out_writes_bytes_(tagLength) UCHAR* tag,
        SIZE_T tagLength,
        _Out_opt_ SIZE_T* bytesWritten = nullptr) noexcept;

    static NTSTATUS Decrypt(
        _In_opt_ const CngProviderCache* cache,
        _In_ const AeadKey& key,
        _In_ const AeadParameters& parameters,
        _In_reads_bytes_opt_(ciphertextLength) const UCHAR* ciphertext,
        SIZE_T ciphertextLength,
        _Out_writes_bytes_(plaintextLength) UCHAR* plaintext,
        SIZE_T plaintextLength,
        _Out_opt_ SIZE_T* bytesWritten = nullptr) noexcept;
};
Item Notes
cache Optional CNG provider cache; nullptr opens providers as needed
Encrypt Writes ciphertext and tag
Decrypt Verifies tag then writes plaintext
TagLength Tag size for algorithm

BufferView (CngProvider.h): const UCHAR* Data + SIZE_T Length.

Other crypto headers (Ed25519.h, KeyExchange.h, …) are not aggregated by Wknet.h; include as needed.

See also