@@ -56,4 +56,5 @@ # Build Artifacts
 .cache/
 build/
 flake.lock
-compile_commands.json+compile_commands.json
+.vscode/

@@ -0,0 +1,48 @@
+#include "memory.h"
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+bool
+circe_memory_equal (const uint8_t *a, const uint8_t *b, size_t len)
+{
+  uint8_t acc = 0x0;
+  for (size_t i = 0; i < len; ++i)
+    {
+      acc |= a[i] ^ b[i];
+    }
+  return acc == 0x0;
+}
+
+void
+circe_memory_copy (const uint8_t *restrict src, uint8_t *restrict dst,
+                   size_t len)
+{
+  for (size_t i = 0; i < len; ++i)
+    {
+      dst[i] = src[i];
+    }
+}
+
+void
+circe_memory_set (uint8_t *dst, uint8_t value, size_t n)
+{
+  for (size_t i = 0; i < n; ++i)
+    {
+      dst[i] = value;
+    }
+}
+
+void *
+circe_memset (void *dest, int value, size_t count)
+{
+  circe_memory_set ((uint8_t *)dest, (uint8_t)value, count);
+  return dest;
+}
+
+void *
+circe_memcpy (void *restrict dest, const void *restrict src, size_t n)
+{
+  circe_memory_copy ((const uint8_t *restrict)src, (uint8_t *restrict)dest, n);
+  return dest;
+}

@@ -0,0 +1,21 @@
+#ifndef CIRCE_COMMON_MEMORY_H
+#define CIRCE_COMMON_MEMORY_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+bool circe_memory_equal (const uint8_t *a, const uint8_t *b, size_t len);
+
+void circe_memory_copy (const uint8_t *restrict src, uint8_t *restrict dst,
+                        size_t len);
+
+void circe_memory_set (uint8_t *dst, uint8_t value, size_t n);
+
+/* COMPATIBILITY FUNCTIONS */
+
+void *circe_memset (void *dest, int value, size_t count);
+
+void *circe_memcpy (void *restrict dest, const void *restrict src, size_t n);
+
+#endif

@@ -0,0 +1,93 @@
+/*
+ * Circe configuration for mldsa-native.
+ *
+ * Selected instead of contrib/mldsa-native/mldsa/mldsa_native_config.h by
+ * building with -DMLD_CONFIG_FILE="circe_mldsa_config.h" (see
+ * contrib/meson.build).
+ *
+ * Circe only needs ML-DSA-44 with the randomized (randombytes) API.
+ */
+
+#ifndef MLD_CONFIG_H
+#define MLD_CONFIG_H
+
+/* ML-DSA-44. */
+#define MLD_CONFIG_PARAMETER_SET 44
+
+/* Namespace prefix for exported symbols (matches the upstream default for 44).
+ */
+#define MLD_CONFIG_NAMESPACE_PREFIX PQCP_MLDSA_NATIVE_MLDSA44
+
+/*
+ * Randomized API.
+ *
+ * We deliberately leave MLD_CONFIG_NO_RANDOMIZED_API and
+ * MLD_CONFIG_CUSTOM_RANDOMBYTES *unset*: mldsa-native keeps the randomized
+ * signing API and expects the consumer to provide
+ *
+ *     int randombytes(uint8_t *out, size_t outlen);   // 0 on success
+ *
+ * No deterministic/derand-only build.
+ */
+
+/*
+ * Implementation-only options.
+ *
+ * MLD_BUILD_INTERNAL is defined by the library's src/common.h before this file
+ * is included, so these only affect the library build, not consumers that
+ * merely include mldsa_native.h.
+ */
+#if defined(MLD_BUILD_INTERNAL)
+
+/*
+ * Use the optimized native backends on AArch64 and x86-64, and the portable C
+ * backends everywhere else. The architecture is detected from the compiler's
+ * predefined macros, matching mldsa-native's own src/sys.h; the actual backend
+ * (NEON / AVX2, and the SHA3/Keccak accelerator) is then selected
+ * automatically from the -march flags passed by contrib/meson.build.
+ */
+#if defined(__aarch64__) || defined(__x86_64__)
+#define MLD_CONFIG_USE_NATIVE_BACKEND_ARITH
+#define MLD_CONFIG_ARITH_BACKEND_FILE "native/meta.h"
+#define MLD_CONFIG_USE_NATIVE_BACKEND_FIPS202
+#define MLD_CONFIG_FIPS202_BACKEND_FILE "fips202/native/auto.h"
+#endif
+
+/*
+ * Freestanding build: no libc is linked, so route mldsa-native's memcpy /
+ * memset / stack-zeroization through Circe's portable implementations in
+ * common/memory.c. This drops the library's <string.h> includes and leaves no
+ * unresolved libc symbols.
+ */
+#define MLD_CONFIG_CUSTOM_MEMCPY
+#define MLD_CONFIG_CUSTOM_MEMSET
+#define MLD_CONFIG_CUSTOM_ZEROIZE
+#if !defined(__ASSEMBLER__)
+#include "src/sys.h" /* for MLD_INLINE */
+#include <stddef.h>
+#include <stdint.h>
+
+/* Defined in common/memory.c */
+void *circe_memcpy (void *restrict dest, const void *restrict src, size_t n);
+void *circe_memset (void *dest, int value, size_t count);
+
+static MLD_INLINE void *
+mld_memcpy (void *dest, const void *src, size_t n)
+{
+  return circe_memcpy (dest, src, n);
+}
+static MLD_INLINE void *
+mld_memset (void *s, int c, size_t n)
+{
+  return circe_memset (s, c, n);
+}
+static MLD_INLINE void
+mld_zeroize (void *ptr, size_t len)
+{
+  circe_memset (ptr, 0, len);
+}
+#endif /* !__ASSEMBLER__ */
+
+#endif /* MLD_BUILD_INTERNAL */
+
+#endif /* MLD_CONFIG_H */

@@ -0,0 +1,94 @@
+/*
+ * Circe configuration for mlkem-native.
+ *
+ * Selected instead of contrib/mlkem-native/mlkem/mlkem_native_config.h by
+ * building with -DMLK_CONFIG_FILE="circe_mlkem_config.h" (see
+ * contrib/meson.build).
+ *
+ * Circe only needs ML-KEM-768 with the randomized (randombytes) API.
+ */
+
+#ifndef MLK_CONFIG_H
+#define MLK_CONFIG_H
+
+/* ML-KEM-768. */
+#define MLK_CONFIG_PARAMETER_SET 768
+
+/* Namespace prefix for exported symbols (matches the upstream default for
+ * 768). */
+#define MLK_CONFIG_NAMESPACE_PREFIX PQCP_MLKEM_NATIVE_MLKEM768
+
+/*
+ * Randomized API.
+ *
+ * We deliberately leave MLK_CONFIG_NO_RANDOMIZED_API and
+ * MLK_CONFIG_CUSTOM_RANDOMBYTES *unset*: mlkem-native keeps
+ * crypto_kem_keypair() and crypto_kem_enc() and expects the consumer to
+ * provide
+ *
+ *     int randombytes(uint8_t *out, size_t outlen);   // 0 on success
+ *
+ * No deterministic/derand-only build.
+ */
+
+/*
+ * Implementation-only options.
+ *
+ * MLK_BUILD_INTERNAL is defined by the library's src/common.h before this file
+ * is included, so these only affect the library build, not consumers that
+ * merely include mlkem_native.h.
+ */
+#if defined(MLK_BUILD_INTERNAL)
+
+/*
+ * Use the optimized native backends on AArch64 and x86-64, and the portable C
+ * backends everywhere else. The architecture is detected from the compiler's
+ * predefined macros, matching mlkem-native's own src/sys.h; the actual backend
+ * (NEON / AVX2, and the SHA3/Keccak accelerator) is then selected
+ * automatically from the -march flags passed by contrib/meson.build.
+ */
+#if defined(__aarch64__) || defined(__x86_64__)
+#define MLK_CONFIG_USE_NATIVE_BACKEND_ARITH
+#define MLK_CONFIG_ARITH_BACKEND_FILE "native/meta.h"
+#define MLK_CONFIG_USE_NATIVE_BACKEND_FIPS202
+#define MLK_CONFIG_FIPS202_BACKEND_FILE "fips202/native/auto.h"
+#endif
+
+/*
+ * Freestanding build: no libc is linked, so route mlkem-native's memcpy /
+ * memset / stack-zeroization through Circe's portable implementations in
+ * common/memory.c. This drops the library's <string.h> includes and leaves no
+ * unresolved libc symbols.
+ */
+#define MLK_CONFIG_CUSTOM_MEMCPY
+#define MLK_CONFIG_CUSTOM_MEMSET
+#define MLK_CONFIG_CUSTOM_ZEROIZE
+#if !defined(__ASSEMBLER__)
+#include "src/sys.h" /* for MLK_INLINE */
+#include <stddef.h>
+#include <stdint.h>
+
+/* Defined in common/memory.c */
+void *circe_memcpy (void *restrict dest, const void *restrict src, size_t n);
+void *circe_memset (void *dest, int value, size_t count);
+
+static MLK_INLINE void *
+mlk_memcpy (void *dest, const void *src, size_t n)
+{
+  return circe_memcpy (dest, src, n);
+}
+static MLK_INLINE void *
+mlk_memset (void *s, int c, size_t n)
+{
+  return circe_memset (s, c, n);
+}
+static MLK_INLINE void
+mlk_zeroize (void *ptr, size_t len)
+{
+  circe_memset (ptr, 0, len);
+}
+#endif /* !__ASSEMBLER__ */
+
+#endif /* MLK_BUILD_INTERNAL */
+
+#endif /* MLK_CONFIG_H */

@@ -0,0 +1,100 @@
+# Builds the external post-quantum primitives Circe depends on:
+#   - mlkem-native  -> ML-KEM-768
+#   - mldsa-native  -> ML-DSA-44
+#
+# Both are compiled as single-compilation-unit (monolithic) builds: one C unit
+# plus one assembly unit per library. The parameter set, namespace and native
+# backend selection live in the config headers under contrib/config/, which are
+# pulled in via -DML{K,D}_CONFIG_FILE.
+#
+# Each consumer of these libraries must still provide a randombytes()
+# implementation:  int randombytes(uint8_t *out, size_t outlen);
+
+cc = meson.get_compiler('c')
+
+# ---------------------------------------------------------------------------
+# Native-backend architecture flags
+#
+# The config headers enable the native backends whenever the compiler targets
+# AArch64 or x86-64. Here we hand the compiler the ISA flags those backends
+# need; on any other architecture we add nothing and the portable C backends
+# are used instead.
+# ---------------------------------------------------------------------------
+native_arch_args = []
+cpu = host_machine.cpu_family()
+
+if cpu == 'x86_64'
+    # AVX2 arithmetic backend + BMI2 for the Keccak/rejection-sampling paths.
+    foreach arg : ['-mavx2', '-mbmi2']
+        if cc.has_argument(arg)
+            native_arch_args += arg
+        endif
+    endforeach
+elif cpu == 'aarch64'
+    # NEON arithmetic backend + the Armv8.4 SHA3 extension for native Keccak.
+    if cc.has_argument('-march=armv8.4-a+sha3')
+        native_arch_args += '-march=armv8.4-a+sha3'
+    endif
+endif
+
+contrib_config_inc = include_directories('config')
+
+# Freestanding, matching the rest of Circe: no libc is linked, and the config
+# headers route the libraries' memcpy/memset/zeroize through common's
+# circe_memcpy/circe_memset (hence the common_dep below).
+pqc_c_args = [
+    '-O3',
+    '-ffreestanding',
+    '-fno-stack-protector', # no libc: don't emit __stack_chk_fail references
+    '-fomit-frame-pointer',
+] + native_arch_args
+
+# ---------------------------------------------------------------------------
+# mlkem-native -> ML-KEM-768
+# ---------------------------------------------------------------------------
+mlkem_inc = include_directories('mlkem-native/mlkem')
+mlkem_config_arg = '-DMLK_CONFIG_FILE="circe_mlkem_config.h"'
+
+mlkem_lib = static_library(
+    'circe-mlkem',
+    [
+        'mlkem-native/mlkem/mlkem_native.c',
+        'mlkem-native/mlkem/mlkem_native_asm.S',
+    ],
+    c_args: pqc_c_args + [mlkem_config_arg],
+    include_directories: [mlkem_inc, contrib_config_inc],
+    dependencies: [common_dep],
+)
+
+mlkem_dep = declare_dependency(
+    link_with: mlkem_lib,
+    include_directories: [mlkem_inc, contrib_config_inc],
+    compile_args: [mlkem_config_arg],
+    dependencies: [common_dep],
+)
+set_variable(meson.project_name() + '_mlkem_dep', mlkem_dep)
+
+# ---------------------------------------------------------------------------
+# mldsa-native -> ML-DSA-44
+# ---------------------------------------------------------------------------
+mldsa_inc = include_directories('mldsa-native/mldsa')
+mldsa_config_arg = '-DMLD_CONFIG_FILE="circe_mldsa_config.h"'
+
+mldsa_lib = static_library(
+    'circe-mldsa',
+    [
+        'mldsa-native/mldsa/mldsa_native.c',
+        'mldsa-native/mldsa/mldsa_native_asm.S',
+    ],
+    c_args: pqc_c_args + [mldsa_config_arg],
+    include_directories: [mldsa_inc, contrib_config_inc],
+    dependencies: [common_dep],
+)
+
+mldsa_dep = declare_dependency(
+    link_with: mldsa_lib,
+    include_directories: [mldsa_inc, contrib_config_inc],
+    compile_args: [mldsa_config_arg],
+    dependencies: [common_dep],
+)
+set_variable(meson.project_name() + '_mldsa_dep', mldsa_dep)

@@ -16,6 +16,7 @@ ]
 
 common_sources = [
     'common/cbor.c',
+    'common/memory.c',
 ]
 
 common_incdir = include_directories('common/')
@@ -30,6 +31,14 @@
 common_dep = declare_dependency(include_directories: common_incdir, link_with: common_target)
 set_variable(meson.project_name() + '_common_dep', common_dep)
 
+# Post-quantum primitives from contrib/ (ML-KEM-768, ML-DSA-44).
+# Built freestanding; they route memcpy/memset/zeroize through common's
+# circe_memcpy/circe_memset, so they depend on common_dep.
+# Exposes <project>_mlkem_dep and <project>_mldsa_dep.
+subdir('contrib')
+mlkem_dependency = get_variable(meson.project_name() + '_mlkem_dep')
+mldsa_dependency = get_variable(meson.project_name() + '_mldsa_dep')
+
 ## LIBCIRCE-CORE
 
 core_build_args = [
@@ -50,7 +59,7 @@ 'circe-core',
     core_sources,
     c_args: core_build_args,
     include_directories: core_incdir,
-    dependencies: [common_dep, tct_dependency],
+    dependencies: [common_dep, tct_dependency, mlkem_dependency, mldsa_dependency],
 )
 
 core_dep = declare_dependency(include_directories: core_incdir, link_with: core_target)
@@ -58,4 +67,4 @@ set_variable(meson.project_name() + '_core_dep', core_dep)
 
 if not meson.is_subproject() and not meson.is_cross_build()
     # Tests go here
-endif+endif