cmake: add find_package(lux-gpu-kernels) discovery hook

.gitignore

@@ -14,3 +14,12 @@ QWEN.md
 build-local/
 docs-site/.next/
 docs-site/node_modules/
+
+# Symlinks created at configure-time by the lux-gpu-kernels discovery hook
+# (top-level CMakeLists.txt). Each <scheme>/gpu/<backend> is a symlink into
+# the lux-gpu-kernels install prefix when the private repo is found;
+# absent on CPU-only builds. Never committed.
+*/gpu/cuda
+*/gpu/metal
+*/gpu/wgsl
+math/ntt/cuda

README.md

@@ -1,12 +1,17 @@
 # luxcpp/crypto
 
 Canonical native cryptographic primitives for the Lux / Hanzo / Zoo
-ecosystem. CPU + GPU implementations live here and only here.
-
-* CPU: portable C++17 / C++20, no third-party crypto libraries
-* GPU: CUDA, Metal, WGSL kernels with byte-equal CPU↔GPU output
+ecosystem. Public surface ships CPU implementations only.
+
+* CPU: portable C++17 / C++20, no third-party crypto libraries (this repo)
+* GPU: CUDA, Metal, WGSL kernels — **proprietary**, distributed via
+  `lux-private/gpu-kernels`. Public CMake build auto-detects via
+  `find_package(lux-gpu-kernels CONFIG QUIET)` and disables Metal/CUDA/WGSL
+  drivers when absent (CPU-only fallback). Commercial license:
+  licensing@lux.network
 * C ABI: `include/lux/crypto/<alg>.h`, callable from Go (cgo) and
-  Rust (bindgen / lux-crypto-sys)
+  Rust (bindgen / lux-crypto-sys) — identical surface whether the GPU
+  kernels are linked or not
 
 The Go entry point is `github.com/luxfi/crypto`; the GPU device router
 is `github.com/luxfi/accel`.

aead/CMakeLists.txt

@@ -39,28 +39,21 @@ endif()
 # =============================================================================
 # CUDA drivers + determinism test.
 #
-# The .cu files compile only when CRYPTO_ENABLE_CUDA is ON (NVCC required).
-# The host driver compiles on every host: with LUX_AEAD_HAVE_CUDA defined it
-# launches the kernels; without, it returns -1 from every entry point so the
-# determinism test prints a "build-only" banner on Apple.
+# Built only when CRYPTO_ENABLE_CUDA=ON (lux-gpu-kernels found + NVCC). The
+# host driver and .cu kernels live in lux-private/gpu-kernels; consumer tests
+# at the top-level CMakeLists are gated on the same flag.
 # =============================================================================
-
-# Always build the host driver (stub or real). On Apple this gives us the
-# build-only path (compiles, links, returns -1). On Linux+CUDA CI we set
-# CRYPTO_ENABLE_CUDA=ON which flips the driver into real-dispatch mode
-# and additionally compiles the .cu kernels.
-
-add_library(aead_cuda_driver STATIC gpu/cuda/aead_driver_cuda.cpp)
-target_include_directories(aead_cuda_driver
-    PUBLIC
-        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/gpu/cuda>
-        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/cpp>
-)
-target_compile_features(aead_cuda_driver PUBLIC cxx_std_20)
-set_target_properties(aead_cuda_driver PROPERTIES POSITION_INDEPENDENT_CODE ON)
-
 if(CRYPTO_ENABLE_CUDA)
     enable_language(CUDA)
+    add_library(aead_cuda_driver STATIC gpu/cuda/aead_driver_cuda.cpp)
+    target_include_directories(aead_cuda_driver
+        PUBLIC
+            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/gpu/cuda>
+            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/cpp>
+    )
+    target_compile_features(aead_cuda_driver PUBLIC cxx_std_20)
+    set_target_properties(aead_cuda_driver PROPERTIES POSITION_INDEPENDENT_CODE ON)
+
     add_library(aead_cuda_kernels STATIC
         gpu/cuda/chacha20_poly1305.cu
         gpu/cuda/aes_gcm.cu)
@@ -76,60 +69,53 @@ if(CRYPTO_ENABLE_CUDA)
     target_link_libraries(aead_cuda_driver PUBLIC CUDA::cudart)
 endif()
 
-# Test executables are added at the top-level CMakeLists.txt where
-# enable_testing() has been called before us. The library targets above
-# are sufficient for the parent to wire test binaries.
-
 # =============================================================================
 # WGSL driver (compiles WGSL via wgpu-native or Dawn; outputs bound through
-# C ABI). On Apple, byte-equality is enforced if wgpu-native is on the system;
-# otherwise the test self-skips. On Linux/CI, same behavior with Dawn.
+# C ABI). Built only when CRYPTO_ENABLE_WGSL=ON.
 # =============================================================================
+if(CRYPTO_ENABLE_WGSL)
+    # Concatenate WGSL sources into a header that the host driver embeds.
+    set(AEAD_WGSL_DIR    "${CMAKE_CURRENT_SOURCE_DIR}/gpu/wgsl")
+    set(AEAD_WGSL_HEADER "${CMAKE_CURRENT_BINARY_DIR}/aead_wgsl_sources.h")
+    file(WRITE "${AEAD_WGSL_HEADER}" "// Auto-generated. Do not edit.\n#pragma once\n\n")
+    foreach(_SRC chacha20_poly1305.wgsl aes_gcm.wgsl)
+        get_filename_component(_NAME ${_SRC} NAME_WE)
+        string(REGEX REPLACE "^chacha20_poly1305$" "ChaCha20Poly1305" _SHORT "${_NAME}")
+        string(REGEX REPLACE "^aes_gcm$"           "AesGcm"           _SHORT "${_SHORT}")
+        file(READ "${AEAD_WGSL_DIR}/${_SRC}" _CONTENT)
+        file(APPEND "${AEAD_WGSL_HEADER}"
+            "// ---- ${_SRC} ----\n"
+            "static constexpr char kAEAD_WGSL_${_SHORT}[] = R\"AEADWGSL(\n${_CONTENT}\n)AEADWGSL\";\n\n")
+    endforeach()
 
-# Concatenate WGSL sources into a header that the host driver embeds.
-set(AEAD_WGSL_DIR    "${CMAKE_CURRENT_SOURCE_DIR}/gpu/wgsl")
-set(AEAD_WGSL_HEADER "${CMAKE_CURRENT_BINARY_DIR}/aead_wgsl_sources.h")
-file(WRITE "${AEAD_WGSL_HEADER}" "// Auto-generated. Do not edit.\n#pragma once\n\n")
-foreach(_SRC chacha20_poly1305.wgsl aes_gcm.wgsl)
-    get_filename_component(_NAME ${_SRC} NAME_WE)
-    string(REGEX REPLACE "^chacha20_poly1305$" "ChaCha20Poly1305" _SHORT "${_NAME}")
-    string(REGEX REPLACE "^aes_gcm$"           "AesGcm"           _SHORT "${_SHORT}")
-    file(READ "${AEAD_WGSL_DIR}/${_SRC}" _CONTENT)
-    file(APPEND "${AEAD_WGSL_HEADER}"
-        "// ---- ${_SRC} ----\n"
-        "static constexpr char kAEAD_WGSL_${_SHORT}[] = R\"AEADWGSL(\n${_CONTENT}\n)AEADWGSL\";\n\n")
-endforeach()
-
-# Locate wgpu-native (Homebrew) or Dawn.
-set(_AEAD_WGPU_FOUND FALSE)
-find_path(_AEAD_WGPU_INCLUDE webgpu.h
-    HINTS /opt/homebrew/include /usr/local/include /usr/include)
-find_library(_AEAD_WGPU_LIB NAMES wgpu_native wgpu
-    HINTS /opt/homebrew/lib /usr/local/lib /usr/lib)
-if(_AEAD_WGPU_INCLUDE AND _AEAD_WGPU_LIB)
-    set(_AEAD_WGPU_FOUND TRUE)
-endif()
+    # Locate wgpu-native (Homebrew) or Dawn.
+    set(_AEAD_WGPU_FOUND FALSE)
+    find_path(_AEAD_WGPU_INCLUDE webgpu.h
+        HINTS /opt/homebrew/include /usr/local/include /usr/include)
+    find_library(_AEAD_WGPU_LIB NAMES wgpu_native wgpu
+        HINTS /opt/homebrew/lib /usr/local/lib /usr/lib)
+    if(_AEAD_WGPU_INCLUDE AND _AEAD_WGPU_LIB)
+        set(_AEAD_WGPU_FOUND TRUE)
+    endif()
 
-add_library(aead_wgpu_driver STATIC gpu/wgsl/aead_driver_wgpu.cpp)
-target_include_directories(aead_wgpu_driver
-    PRIVATE
-        "${CMAKE_CURRENT_BINARY_DIR}"
-        "${CMAKE_CURRENT_SOURCE_DIR}/gpu/wgsl"
-        "${CMAKE_CURRENT_SOURCE_DIR}/cpp"
-)
-target_compile_features(aead_wgpu_driver PUBLIC cxx_std_20)
-set_target_properties(aead_wgpu_driver PROPERTIES POSITION_INDEPENDENT_CODE ON)
+    add_library(aead_wgpu_driver STATIC gpu/wgsl/aead_driver_wgpu.cpp)
+    target_include_directories(aead_wgpu_driver
+        PRIVATE
+            "${CMAKE_CURRENT_BINARY_DIR}"
+            "${CMAKE_CURRENT_SOURCE_DIR}/gpu/wgsl"
+            "${CMAKE_CURRENT_SOURCE_DIR}/cpp"
+    )
+    target_compile_features(aead_wgpu_driver PUBLIC cxx_std_20)
+    set_target_properties(aead_wgpu_driver PROPERTIES POSITION_INDEPENDENT_CODE ON)
 
-if(_AEAD_WGPU_FOUND)
-    target_include_directories(aead_wgpu_driver PRIVATE ${_AEAD_WGPU_INCLUDE})
-    target_link_libraries(aead_wgpu_driver PUBLIC ${_AEAD_WGPU_LIB})
-    target_compile_definitions(aead_wgpu_driver PRIVATE
-        LUX_AEAD_HAS_WEBGPU=1
-        LUX_AEAD_HAS_WGPU_NATIVE=1)
-    message(STATUS "[aead-wgsl] wgpu-native: ${_AEAD_WGPU_LIB}")
-else()
-    message(STATUS "[aead-wgsl] wgpu-native: NOT FOUND (driver compiles to stub)")
+    if(_AEAD_WGPU_FOUND)
+        target_include_directories(aead_wgpu_driver PRIVATE ${_AEAD_WGPU_INCLUDE})
+        target_link_libraries(aead_wgpu_driver PUBLIC ${_AEAD_WGPU_LIB})
+        target_compile_definitions(aead_wgpu_driver PRIVATE
+            LUX_AEAD_HAS_WEBGPU=1
+            LUX_AEAD_HAS_WGPU_NATIVE=1)
+        message(STATUS "[aead-wgsl] wgpu-native: ${_AEAD_WGPU_LIB}")
+    else()
+        message(STATUS "[aead-wgsl] wgpu-native: NOT FOUND (driver compiles to stub)")
+    endif()
 endif()
-
-# See note above: aead_wgsl_determinism_test is added at the top-level
-# CMakeLists.txt after enable_testing() has run.