From b4d0307d9e476cb64899af2905f90a03aa958f3c Mon Sep 17 00:00:00 2001
From: Adam Ierymenko <adam.ierymenko@zerotier.com>
Date: Wed, 29 Jul 2020 13:37:32 -0700
Subject: [PATCH] Some AES NEON reorg.

---
 core/AES.cpp | 13 ++++++++-----
 core/AES.hpp | 23 ++++++++++++++---------
 2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/core/AES.cpp b/core/AES.cpp
index ad87dbc51..aadacd07e 100644
--- a/core/AES.cpp
+++ b/core/AES.cpp
@@ -744,8 +744,8 @@ void AES::CTR::crypt(const void *const input, unsigned int len) noexcept
 	}
 #endif // ZT_AES_AESNI
 
-#ifdef ZT_ARCH_ARM_HAS_NEON
-	if (true) {
+#ifdef ZT_AES_NEON
+	if (s_hasNeonAes) {
 		uint8x16_t dd = vld1q_u8(reinterpret_cast<uint8_t *>(_ctr));
 		const uint32x4_t one = {0,0,0,1};
 
@@ -842,7 +842,7 @@ void AES::CTR::crypt(const void *const input, unsigned int len) noexcept
 		vst1q_u8(reinterpret_cast<uint8_t *>(_ctr), dd);
 		return;
 	}
-#endif // ZT_ARCH_ARM_HAS_NEON
+#endif // ZT_AES_NEON
 
 	uint64_t keyStream[2];
 	uint32_t ctr = Utils::ntoh(reinterpret_cast<uint32_t *>(_ctr)[3]);
@@ -1330,7 +1330,10 @@ void AES::_decrypt_aesni(const void *in, void *out) const noexcept
 
 #endif // ZT_AES_AESNI
 
-#ifdef ZT_ARCH_ARM_HAS_NEON
+#ifdef ZT_AES_NEON
+
+const bool AES::s_hasNeonAes = true;
+const bool AES::s_hasNeonGcm = true;
 
 #define ZT_INIT_ARMNEON_CRYPTO_SUBWORD(w) ((uint32_t)s_sbox[w & 0xffU] + ((uint32_t)s_sbox[(w >> 8U) & 0xffU] << 8U) + ((uint32_t)s_sbox[(w >> 16U) & 0xffU] << 16U) + ((uint32_t)s_sbox[(w >> 24U) & 0xffU] << 24U))
 #define ZT_INIT_ARMNEON_CRYPTO_ROTWORD(w) (((w) << 8U) | ((w) >> 24U))
@@ -1411,6 +1414,6 @@ void AES::_decrypt_armneon_crypto(const void *const in, void *const out) const n
 	vst1q_u8(reinterpret_cast<uint8_t *>(out), tmp);
 }
 
-#endif // ZT_ARCH_ARM_HAS_NEON
+#endif // ZT_AES_NEON
 
 } // namespace ZeroTier
diff --git a/core/AES.hpp b/core/AES.hpp
index 3efeb3daa..4b4d83c90 100644
--- a/core/AES.hpp
+++ b/core/AES.hpp
@@ -21,6 +21,9 @@
 #if !defined(ZT_AES_NO_ACCEL) && defined(ZT_ARCH_X64)
 #define ZT_AES_AESNI 1
 #endif
+#if !defined(ZT_AES_NO_ACCEL) && defined(ZT_ARCH_ARM_HAS_NEON)
+#define ZT_AES_NEON 1
+#endif
 
 namespace ZeroTier {
 
@@ -75,8 +78,8 @@ public:
 			return;
 		}
 #endif
-#ifdef ZT_ARCH_ARM_HAS_NEON
-		if (true) {
+#ifdef ZT_AES_NEON
+		if (s_hasNeonAes) {
 			_init_armneon_crypto(reinterpret_cast<const uint8_t *>(key));
 			return;
 		}
@@ -98,8 +101,8 @@ public:
 			return;
 		}
 #endif
-#ifdef ZT_ARCH_ARM_HAS_NEON
-		if (true) {
+#ifdef ZT_AES_NEON
+		if (s_hasNeonAes) {
 			_encrypt_armneon_crypto(in, out);
 			return;
 		}
@@ -121,8 +124,8 @@ public:
 			return;
 		}
 #endif
-#ifdef ZT_ARCH_ARM_HAS_NEON
-		if (true) {
+#ifdef ZT_AES_NEON
+		if (s_hasNeonAes) {
 			_decrypt_armneon_crypto(in, out);
 			return;
 		}
@@ -521,7 +524,7 @@ private:
 		} ni;
 #endif
 
-#ifdef ZT_ARCH_ARM_HAS_NEON
+#ifdef ZT_AES_NEON
 		struct
 		{
 			uint8x16_t ek[15];
@@ -540,11 +543,13 @@ private:
 
 #ifdef ZT_AES_AESNI
 	void _init_aesni(const uint8_t key[32]) noexcept;
-	void _encrypt_aesni(const void *const in, void *const out) const noexcept;
+	void _encrypt_aesni(const void *in, void *out) const noexcept;
 	void _decrypt_aesni(const void *in, void *out) const noexcept;
 #endif
 
-#ifdef ZT_ARCH_ARM_HAS_NEON
+#ifdef ZT_AES_NEON
+	static const bool s_hasNeonAes;
+	static const bool s_hasNeonGcm;
 	void _init_armneon_crypto(const uint8_t key[32]) noexcept;
 	void _encrypt_armneon_crypto(const void *const in, void *const out) const noexcept;
 	void _decrypt_armneon_crypto(const void *const in, void *const out) const noexcept;