From 3b773da8bc3f079d4ae9c3b59d50176d3f221023 Mon Sep 17 00:00:00 2001
From: Adam Ierymenko <adam.ierymenko@zerotier.com>
Date: Wed, 29 Jul 2020 21:52:07 -0700
Subject: [PATCH] Add separate accelerated() function for AES::GMAC.

---
 core/AES.cpp   |  2 +-
 core/AES.hpp   | 16 ++++++++++++++++
 core/Tests.cpp |  2 +-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/core/AES.cpp b/core/AES.cpp
index 745940b4f..d605c0a66 100644
--- a/core/AES.cpp
+++ b/core/AES.cpp
@@ -47,7 +47,7 @@ ZT_INLINE uint8x16_t s_clmul_armneon_crypto(uint8x16_t a8, const uint8x16_t y, c
 	return vrbitq_u8(veorq_u8(r0, t0));
 }
 
-#endif
+#endif // ZT_AES_NEON
 
 #ifdef ZT_HAVE_UINT128
 
diff --git a/core/AES.hpp b/core/AES.hpp
index 8a2ef811f..056be7892 100644
--- a/core/AES.hpp
+++ b/core/AES.hpp
@@ -149,6 +149,22 @@ public:
 		friend class GMACSIVDecryptor;
 
 	public:
+		/**
+		 * @return True if this system has hardware GMAC acceleration
+		 */
+		static ZT_INLINE bool accelerated()
+		{
+#ifdef ZT_AES_AESNI
+			return Utils::CPUID.aes;
+#else
+#ifdef ZT_AES_NEON
+			return Utils::ARMCAP.pmull;
+#else
+			return false;
+#endif
+#endif
+		}
+
 		/**
 		 * Create a new instance of GMAC (must be initialized with init() before use)
 		 *
diff --git a/core/Tests.cpp b/core/Tests.cpp
index a5c569739..ad01c5c29 100644
--- a/core/Tests.cpp
+++ b/core/Tests.cpp
@@ -1115,7 +1115,7 @@ extern "C" const char *ZTT_crypto()
 
 		{
 			uint8_t tag[16];
-			ZT_T_PRINTF("[crypto] Testing AES-GMAC (hardware acceleration: %s)... ", AES::accelerated() ? "enabled" : "disabled");
+			ZT_T_PRINTF("[crypto] Testing AES-GMAC (hardware acceleration: %s)... ", AES::GMAC::accelerated() ? "enabled" : "disabled");
 			{
 				AES aes(AES_GMAC_VECTOR_0_KEY);
 				AES::GMAC gmac(aes);