Add pristine AES sources from MbedTLS 3.6.2 to a new subdirectory

Next commit will amend them and add Makefiles, replacing our older AES-NI
aware code that didn't "just work" with all and any format.

src/mbedtls/aesce.h

@@ -0,0 +1,136 @@
+/**
+ * \file aesce.h
+ *
+ * \brief Support hardware AES acceleration on Armv8-A processors with
+ *        the Armv8-A Cryptographic Extension.
+ *
+ * \warning These functions are only for internal use by other library
+ *          functions; you must not call them directly.
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+#ifndef MBEDTLS_AESCE_H
+#define MBEDTLS_AESCE_H
+
+#include "mbedtls/build_info.h"
+#include "common.h"
+
+#include "mbedtls/aes.h"
+
+
+#if defined(MBEDTLS_AESCE_C) \
+    && defined(MBEDTLS_ARCH_IS_ARMV8_A) && defined(MBEDTLS_HAVE_NEON_INTRINSICS) \
+    && (defined(MBEDTLS_COMPILER_IS_GCC) || defined(__clang__) || defined(MSC_VER))
+
+/* MBEDTLS_AESCE_HAVE_CODE is defined if we have a suitable target platform, and a
+ * potentially suitable compiler (compiler version & flags are not checked when defining
+ * this). */
+#define MBEDTLS_AESCE_HAVE_CODE
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(__linux__) && !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
+
+extern signed char mbedtls_aesce_has_support_result;
+
+/**
+ * \brief          Internal function to detect the crypto extension in CPUs.
+ *
+ * \return         1 if CPU has support for the feature, 0 otherwise
+ */
+int mbedtls_aesce_has_support_impl(void);
+
+#define MBEDTLS_AESCE_HAS_SUPPORT() (mbedtls_aesce_has_support_result == -1 ? \
+                                     mbedtls_aesce_has_support_impl() : \
+                                     mbedtls_aesce_has_support_result)
+
+#else /* defined(__linux__) && !defined(MBEDTLS_AES_USE_HARDWARE_ONLY) */
+
+/* If we are not on Linux, we can't detect support so assume that it's supported.
+ * Similarly, assume support if MBEDTLS_AES_USE_HARDWARE_ONLY is set.
+ */
+#define MBEDTLS_AESCE_HAS_SUPPORT() 1
+
+#endif /* defined(__linux__) && !defined(MBEDTLS_AES_USE_HARDWARE_ONLY) */
+
+/**
+ * \brief          Internal AES-ECB block encryption and decryption
+ *
+ * \warning        This assumes that the context specifies either 10, 12 or 14
+ *                 rounds and will behave incorrectly if this is not the case.
+ *
+ * \param ctx      AES context
+ * \param mode     MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
+ * \param input    16-byte input block
+ * \param output   16-byte output block
+ *
+ * \return         0 on success (cannot fail)
+ */
+int mbedtls_aesce_crypt_ecb(mbedtls_aes_context *ctx,
+                            int mode,
+                            const unsigned char input[16],
+                            unsigned char output[16]);
+
+/**
+ * \brief          Internal GCM multiplication: c = a * b in GF(2^128)
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
+ *
+ * \param c        Result
+ * \param a        First operand
+ * \param b        Second operand
+ *
+ * \note           Both operands and result are bit strings interpreted as
+ *                 elements of GF(2^128) as per the GCM spec.
+ */
+void mbedtls_aesce_gcm_mult(unsigned char c[16],
+                            const unsigned char a[16],
+                            const unsigned char b[16]);
+
+
+#if !defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
+/**
+ * \brief           Internal round key inversion. This function computes
+ *                  decryption round keys from the encryption round keys.
+ *
+ * \param invkey    Round keys for the equivalent inverse cipher
+ * \param fwdkey    Original round keys (for encryption)
+ * \param nr        Number of rounds (that is, number of round keys minus one)
+ */
+void mbedtls_aesce_inverse_key(unsigned char *invkey,
+                               const unsigned char *fwdkey,
+                               int nr);
+#endif /* !MBEDTLS_BLOCK_CIPHER_NO_DECRYPT */
+
+/**
+ * \brief           Internal key expansion for encryption
+ *
+ * \param rk        Destination buffer where the round keys are written
+ * \param key       Encryption key
+ * \param bits      Key size in bits (must be 128, 192 or 256)
+ *
+ * \return          0 if successful, or MBEDTLS_ERR_AES_INVALID_KEY_LENGTH
+ */
+int mbedtls_aesce_setkey_enc(unsigned char *rk,
+                             const unsigned char *key,
+                             size_t bits);
+
+#ifdef __cplusplus
+}
+#endif
+
+#else
+
+#if defined(MBEDTLS_AES_USE_HARDWARE_ONLY) && defined(MBEDTLS_ARCH_IS_ARMV8_A)
+#error "AES hardware acceleration not supported on this platform / compiler"
+#endif
+
+#endif /* MBEDTLS_AESCE_C && MBEDTLS_ARCH_IS_ARMV8_A && MBEDTLS_HAVE_NEON_INTRINSICS &&
+          (MBEDTLS_COMPILER_IS_GCC || __clang__ || MSC_VER) */
+
+#endif /* MBEDTLS_AESCE_H */