From ac01277d93636cd7cb9163555e2d929c39849371 Mon Sep 17 00:00:00 2001
From: Jeffrey Walton <noloader@gmail.com>
Date: Wed, 26 Oct 2016 22:35:24 -0400
Subject: [PATCH] Add X86 SHA cpu feature detection

---
 cpu.cpp      |  8 ++++++--
 cpu.h        | 11 +++++++++++
 validat1.cpp |  2 +-
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/cpu.cpp b/cpu.cpp
index 73c8096de..5d0664ad5 100644
--- a/cpu.cpp
+++ b/cpu.cpp
@@ -185,8 +185,8 @@ static bool TrySSE2()
 
 bool CRYPTOPP_SECTION_INIT g_x86DetectionDone = false;
 bool CRYPTOPP_SECTION_INIT g_hasMMX = false, CRYPTOPP_SECTION_INIT g_hasISSE = false, CRYPTOPP_SECTION_INIT g_hasSSE2 = false, CRYPTOPP_SECTION_INIT g_hasSSSE3 = false;
-bool CRYPTOPP_SECTION_INIT g_hasSSE4 = false, CRYPTOPP_SECTION_INIT g_hasAESNI = false, CRYPTOPP_SECTION_INIT g_hasCLMUL = false, CRYPTOPP_SECTION_INIT g_isP4 = false;
-bool CRYPTOPP_SECTION_INIT g_hasRDRAND = false, CRYPTOPP_SECTION_INIT g_hasRDSEED = false;
+bool CRYPTOPP_SECTION_INIT g_hasSSE4 = false, CRYPTOPP_SECTION_INIT g_hasAESNI = false, CRYPTOPP_SECTION_INIT g_hasCLMUL = false, CRYPTOPP_SECTION_INIT g_hasSHA = false;
+bool CRYPTOPP_SECTION_INIT g_hasRDRAND = false, CRYPTOPP_SECTION_INIT g_hasRDSEED = false, CRYPTOPP_SECTION_INIT g_isP4 = false;
 bool CRYPTOPP_SECTION_INIT g_hasPadlockRNG = false, CRYPTOPP_SECTION_INIT g_hasPadlockACE = false, CRYPTOPP_SECTION_INIT g_hasPadlockACE2 = false;
 bool CRYPTOPP_SECTION_INIT g_hasPadlockPHE = false, CRYPTOPP_SECTION_INIT g_hasPadlockPMM = false;
 word32 CRYPTOPP_SECTION_INIT g_cacheLineSize = CRYPTOPP_L1_CACHE_LINE_SIZE;
@@ -254,6 +254,7 @@ void DetectX86Features()
 	{
 		static const unsigned int RDRAND_FLAG = (1 << 30);
 		static const unsigned int RDSEED_FLAG = (1 << 18);
+		static const unsigned int    SHA_FLAG = (1 << 29);
 
 		g_isP4 = ((cpuid1[0] >> 8) & 0xf) == 0xf;
 		g_cacheLineSize = 8 * GETBYTE(cpuid1[1], 1);
@@ -263,7 +264,10 @@ void DetectX86Features()
 		{
 			word32 cpuid3[4];
 			if (CpuId(7, cpuid3))
+			{
 				g_hasRDSEED = !!(cpuid3[1] /*EBX*/ & RDSEED_FLAG);
+				g_hasSHA = !!(cpuid3[1] /*EBX*/ & SHA_FLAG);
+			}
 		}
 	}
 	else if (IsAMD(cpuid))
diff --git a/cpu.h b/cpu.h
index b2e55b30b..6a7e61734 100644
--- a/cpu.h
+++ b/cpu.h
@@ -109,6 +109,7 @@ extern CRYPTOPP_DLL bool g_hasSSSE3;
 extern CRYPTOPP_DLL bool g_hasSSE4;
 extern CRYPTOPP_DLL bool g_hasAESNI;
 extern CRYPTOPP_DLL bool g_hasCLMUL;
+extern CRYPTOPP_DLL bool g_hasSHA;
 extern CRYPTOPP_DLL bool g_isP4;
 extern CRYPTOPP_DLL bool g_hasRDRAND;
 extern CRYPTOPP_DLL bool g_hasRDSEED;
@@ -209,6 +210,16 @@ inline bool HasCLMUL()
 	return g_hasCLMUL;
 }
 
+//! \brief Determines SHA availability
+//! \returns true if SHA is determined to be available, false otherwise
+//! \details HasSHA() is a runtime check performed using CPUID
+inline bool HasSHA()
+{
+	if (!g_x86DetectionDone)
+		DetectX86Features();
+	return g_hasSHA;
+}
+
 //! \brief Determines if the CPU is an Intel P4
 //! \returns true if the CPU is a P4, false otherwise
 //! \details IsP4() is a runtime check performed using CPUID
diff --git a/validat1.cpp b/validat1.cpp
index ea75089fa..6eb1d3f80 100644
--- a/validat1.cpp
+++ b/validat1.cpp
@@ -310,7 +310,7 @@ bool TestSettings()
 
 	cout << "hasMMX == " << hasMMX << ", hasISSE == " << hasISSE << ", hasSSE2 == " << hasSSE2 << ", hasSSSE3 == " << hasSSSE3 << ", hasSSE4 == " << hasSSE4;
 	cout << ", hasAESNI == " << HasAESNI() << ", hasCLMUL == " << HasCLMUL() << ", hasRDRAND == " << HasRDRAND() << ", hasRDSEED == " << HasRDSEED();
-	cout << ", isP4 == " << isP4 << ", cacheLineSize == " << cacheLineSize << endl;
+	cout << ", hasSHA == " << HasSHA() << ", isP4 == " << isP4 << ", cacheLineSize == " << cacheLineSize << endl;
 
 #elif (CRYPTOPP_BOOL_ARM32 || CRYPTOPP_BOOL_ARM64)
 	bool hasNEON = HasNEON();