1 files changed, 76 insertions, 0 deletions
diff --git a/lib/modes/aead/gcm/clmul/clmul.cpp b/lib/modes/aead/gcm/clmul/clmul.cpp
new file mode 100644
index 000000000..cc6d581e3
--- /dev/null
+++ b/lib/modes/aead/gcm/clmul/clmul.cpp
@@ -0,0 +1,76 @@
+/*
+* CLMUL hook
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/internal/clmul.h>
+#include <immintrin.h>
+
+namespace Botan {
+
+void gcm_multiply_clmul(byte x[16], const byte H[16])
+   {
+   /*
+   * Algorithms 1 and 5 from Intel's CLMUL guide
+   */
+   const __m128i BSWAP_MASK = _mm_set_epi8(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15);
+
+   __m128i a = _mm_loadu_si128(reinterpret_cast<const __m128i*>(&x[0]));
+   __m128i b = _mm_loadu_si128(reinterpret_cast<const __m128i*>(&H[0]));
+
+   a = _mm_shuffle_epi8(a, BSWAP_MASK);
+   b = _mm_shuffle_epi8(b, BSWAP_MASK);
+
+   __m128i T0, T1, T2, T3, T4, T5;
+
+   T0 = _mm_clmulepi64_si128(a, b, 0x00);
+   T1 = _mm_clmulepi64_si128(a, b, 0x01);
+   T2 = _mm_clmulepi64_si128(a, b, 0x10);
+   T3 = _mm_clmulepi64_si128(a, b, 0x11);
+
+   T1 = _mm_xor_si128(T1, T2);
+   T2 = _mm_slli_si128(T1, 8);
+   T1 = _mm_srli_si128(T1, 8);
+   T0 = _mm_xor_si128(T0, T2);
+   T3 = _mm_xor_si128(T3, T1);
+
+   T4 = _mm_srli_epi32(T0, 31);
+   T0 = _mm_slli_epi32(T0, 1);
+
+   T5 = _mm_srli_epi32(T3, 31);
+   T3 = _mm_slli_epi32(T3, 1);
+
+   T2 = _mm_srli_si128(T4, 12);
+   T5 = _mm_slli_si128(T5, 4);
+   T4 = _mm_slli_si128(T4, 4);
+   T0 = _mm_or_si128(T0, T4);
+   T3 = _mm_or_si128(T3, T5);
+   T3 = _mm_or_si128(T3, T2);
+
+   T4 = _mm_slli_epi32(T0, 31);
+   T5 = _mm_slli_epi32(T0, 30);
+   T2 = _mm_slli_epi32(T0, 25);
+
+   T4 = _mm_xor_si128(T4, T5);
+   T4 = _mm_xor_si128(T4, T2);
+   T5 = _mm_srli_si128(T4, 4);
+   T3 = _mm_xor_si128(T3, T5);
+   T4 = _mm_slli_si128(T4, 12);
+   T0 = _mm_xor_si128(T0, T4);
+   T3 = _mm_xor_si128(T3, T0);
+
+   T4 = _mm_srli_epi32(T0, 1);
+   T1 = _mm_srli_epi32(T0, 2);
+   T2 = _mm_srli_epi32(T0, 7);
+   T3 = _mm_xor_si128(T3, T1);
+   T3 = _mm_xor_si128(T3, T2);
+   T3 = _mm_xor_si128(T3, T4);
+
+   T3 = _mm_shuffle_epi8(T3, BSWAP_MASK);
+
+   _mm_storeu_si128(reinterpret_cast<__m128i*>(&x[0]), T3);
+   }
+
+}