Add ARM64 crypto as NEON C intrinsics for MSVC (WOLFSSL_ARMASM_INTRINSICS)

CMakeLists.txt

@@ -2386,6 +2386,28 @@ if (WOLFSSL_ARMASM_INLINE)
     list(APPEND WOLFSSL_DEFINITIONS "-DWOLFSSL_ARMASM_INLINE")
 endif()
 
+# ARM64 crypto kernels as NEON C intrinsics instead of assembly. Intended for
+# MSVC on Windows ARM64: cl.exe compiles no ARM64 inline assembly, and the
+# Microsoft-syntax .asm files need a separate armasm64.exe step that is only
+# wired up through MSBuild (.vcxproj), not CMake. The intrinsics are ordinary C,
+# so they need no assembler and no per-source target-feature flag (MSVC enables
+# NEON crypto unconditionally on ARM64).
+#
+# Mutually exclusive with the assembly forms - it supplies the same *_AARCH64
+# symbols - hence a separate opt-in rather than an automatic fallback.
+add_option("WOLFSSL_ARMASM_INTRINSICS"
+    "Use NEON C intrinsics for ARM64 crypto instead of assembly, for MSVC \
+(default: disabled)"
+    "no" "yes;no")
+
+if (WOLFSSL_ARMASM_INTRINSICS)
+    if (NOT MSVC)
+        message(FATAL_ERROR "WOLFSSL_ARMASM_INTRINSICS is only supported with "
+            "MSVC on ARM64; other toolchains should use the assembly path.")
+    endif()
+    list(APPEND WOLFSSL_DEFINITIONS "-DWOLFSSL_ARMASM_INTRINSICS")
+endif()
+
 # TODO:
 #       - CRL monitor
 #       - User crypto

cmake/functions.cmake

@@ -278,6 +278,7 @@ function(generate_build_flags)
     endif()
     set(BUILD_INLINE ${WOLFSSL_INLINE} PARENT_SCOPE)
     set(BUILD_ARMASM_INLINE ${WOLFSSL_ARMASM_INLINE} PARENT_SCOPE)
+    set(BUILD_ARMASM_INTRINSICS ${WOLFSSL_ARMASM_INTRINSICS} PARENT_SCOPE)
     set(BUILD_ARM_THUMB ${WOLFSSL_ARMASM_THUMB2} PARENT_SCOPE)
     if(WOLFSSL_OCSP OR WOLFSSL_USER_SETTINGS)
         set(BUILD_OCSP "yes" PARENT_SCOPE)
@@ -1345,6 +1346,20 @@ function(generate_lib_src_list LIB_SOURCES)
         list(APPEND LIB_SOURCES wolfcrypt/src/puf.c)
     endif()
 
+    # ARM64 crypto kernels as NEON C intrinsics (MSVC on Windows ARM64).
+    # Supplies the same *_AARCH64 symbols as the assembly forms, so it is an
+    # alternative to them rather than an addition - see WOLFSSL_ARMASM_INTRINSICS
+    # in CMakeLists.txt. Each file is self-guarding on the macro, so listing them
+    # unconditionally would also work; they are gated here to keep the compile
+    # command clean and to avoid listing sources no other toolchain can use.
+    if(BUILD_ARMASM_INTRINSICS)
+        list(APPEND LIB_SOURCES
+            wolfcrypt/src/port/arm/armv8-aes-intrinsics-msvc.c
+            wolfcrypt/src/port/arm/armv8-sha-intrinsics-msvc.c
+            wolfcrypt/src/port/arm/armv8-poly1305-intrinsics-msvc.c
+            wolfcrypt/src/port/arm/armv8-chacha-intrinsics-msvc.c)
+    endif()
+
     set(LIB_SOURCES ${LIB_SOURCES} PARENT_SCOPE)
 endfunction()
 

wolfcrypt/src/include.am

@@ -37,6 +37,13 @@ EXTRA_DIST += wolfcrypt/src/port/arm/armv8-poly1305-asm.asm
 EXTRA_DIST += wolfcrypt/src/port/arm/armv8-sha256-asm.asm
 EXTRA_DIST += wolfcrypt/src/port/arm/armv8-sha3-asm.asm
 EXTRA_DIST += wolfcrypt/src/port/arm/armv8-sha512-asm.asm
+# ARM64 crypto as NEON C intrinsics, for MSVC on Windows ARM64 (built via CMake
+# with WOLFSSL_ARMASM_INTRINSICS, or the MSVC project files). Not built by
+# autotools, which targets GCC/Clang where the assembly path applies.
+EXTRA_DIST += wolfcrypt/src/port/arm/armv8-aes-intrinsics-msvc.c
+EXTRA_DIST += wolfcrypt/src/port/arm/armv8-sha-intrinsics-msvc.c
+EXTRA_DIST += wolfcrypt/src/port/arm/armv8-poly1305-intrinsics-msvc.c
+EXTRA_DIST += wolfcrypt/src/port/arm/armv8-chacha-intrinsics-msvc.c
 EXTRA_DIST += wolfcrypt/src/wc_dsp.c
 EXTRA_DIST += wolfcrypt/src/sp_dsp32.c
 EXTRA_DIST += wolfcrypt/src/sp_x86_64_asm.asm