1 files changed, 60 insertions, 0 deletions
diff --git a/src/Crypto/Sha2Intel.c b/src/Crypto/Sha2Intel.c
index c926f76a..943115bf 100644
--- a/src/Crypto/Sha2Intel.c
+++ b/src/Crypto/Sha2Intel.c
@@ -1,53 +1,113 @@
 /*
 * Support for SHA-256 x86 instrinsic
 * Based on public domain code by Sean Gulley
 *    (https://github.com/mitls/hacl-star/tree/master/experimental/hash)
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
 /* November 10th 2024: Modified for VeraCrypt */
 
 #include "Sha2.h"
 #include "Common/Endian.h"
 #include "cpu.h"
 #include "misc.h"
 
 #if defined(_UEFI) || defined(CRYPTOPP_DISABLE_ASM)
 #define NO_OPTIMIZED_VERSIONS
 #endif
 
 #ifndef NO_OPTIMIZED_VERSIONS
 
 #if CRYPTOPP_SHANI_AVAILABLE
 
+#ifndef _MSC_VER
+#include <signal.h>
+#include <setjmp.h>
+
+typedef void (*SigHandler)(int);
+
+static jmp_buf s_jmpNoSHA;
+static void SigIllHandlerSHA(int p)
+{
+	longjmp(s_jmpNoSHA, 1);
+}
+#endif
+
+int TrySHA256()
+{
+    volatile int result = 0;
+#ifdef _MSC_VER
+    __try
+#else
+    SigHandler oldHandler = signal(SIGILL, SigIllHandlerSHA);
+    if (oldHandler == SIG_ERR)
+        return 0;
+    if (setjmp(s_jmpNoSHA))
+        result = 0;
+    else
+#endif
+    {
+        // Known input message block
+        __m128i msg0 = _mm_setr_epi32(0x12345678, 0x9ABCDEF0, 0x87654321, 0x0FEDCBA9);
+        __m128i msg1 = _mm_setr_epi32(0x11111111, 0x22222222, 0x33333333, 0x44444444);
+        
+        // SHA256 message schedule update
+        __m128i tmp = _mm_sha256msg1_epu32(msg0, msg1);
+        
+        // Verify result - these values were pre-computed for the given input
+#ifdef _MSC_VER
+        if (tmp.m128i_u32[0] == 0xD8131B44 &&
+            tmp.m128i_u32[1] == 0x9DE6E22B &&
+            tmp.m128i_u32[2] == 0xA86D643A &&
+            tmp.m128i_u32[3] == 0x74320FED)
+#else
+        if (((uint32_t*)(&tmp))[0] == 0xD8131B44 &&
+            ((uint32_t*)(&tmp))[1] == 0x9DE6E22B &&
+            ((uint32_t*)(&tmp))[2] == 0xA86D643A &&
+            ((uint32_t*)(&tmp))[3] == 0x74320FED)
+#endif
+            result = 1;
+    }
+#ifdef _MSC_VER
+    __except (EXCEPTION_EXECUTE_HANDLER)
+    {
+        // ignore error if SHA instructions not supported
+    }
+#else
+    signal(SIGILL, oldHandler);
+#endif
+
+    return result;
+}
+
 //
 void sha256_intel(void *mp, uint_32t state[8], uint_64t num_blks) 
 {
     // Constants table - align for better performance
     CRYPTOPP_ALIGN_DATA(64) 
     static const uint_32t K[64] = {
         0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, 0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5,
         0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3, 0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174,
         0xE49B69C1, 0xEFBE4786, 0x0FC19DC6, 0x240CA1CC, 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA,
         0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, 0xC6E00BF3, 0xD5A79147, 0x06CA6351, 0x14292967,
         0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13, 0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85,
         0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3, 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070,
         0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, 0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3,
         0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208, 0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2,
     };
 
     const __m128i* K_mm = (const __m128i*)K;
     const __m128i* input_mm = (const __m128i*)mp;
     
     // Create byte shuffle mask for big-endian to little-endian conversion
     const __m128i MASK = _mm_set_epi64x(0x0c0d0e0f08090a0b, 0x0405060700010203);
 
     // Load initial values
     __m128i STATE0 = _mm_loadu_si128((__m128i*)&state[0]);
     __m128i STATE1 = _mm_loadu_si128((__m128i*)&state[4]);
 
     // Adjust byte ordering
     STATE0 = _mm_shuffle_epi32(STATE0, 0xB1);  // CDAB
     STATE1 = _mm_shuffle_epi32(STATE1, 0x1B);  // EFGH