Botan  2.1.0
Crypto and TLS for C++11
clmul.cpp
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1 /*
2 * CLMUL hook
3 * (C) 2013 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7 
8 #include <botan/internal/clmul.h>
9 #include <immintrin.h>
10 #include <wmmintrin.h>
11 
12 namespace Botan {
13 
14 BOTAN_FUNC_ISA("pclmul,ssse3")
15 void gcm_multiply_clmul(uint8_t x[16], const uint8_t H[16])
16  {
17  /*
18  * Algorithms 1 and 5 from Intel's CLMUL guide
19  */
20  const __m128i BSWAP_MASK = _mm_set_epi8(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15);
21 
22  __m128i a = _mm_loadu_si128(reinterpret_cast<const __m128i*>(x));
23  __m128i b = _mm_loadu_si128(reinterpret_cast<const __m128i*>(H));
24 
25  a = _mm_shuffle_epi8(a, BSWAP_MASK);
26  b = _mm_shuffle_epi8(b, BSWAP_MASK);
27 
28  __m128i T0, T1, T2, T3, T4, T5;
29 
30  T0 = _mm_clmulepi64_si128(a, b, 0x00);
31  T1 = _mm_clmulepi64_si128(a, b, 0x01);
32  T2 = _mm_clmulepi64_si128(a, b, 0x10);
33  T3 = _mm_clmulepi64_si128(a, b, 0x11);
34 
35  T1 = _mm_xor_si128(T1, T2);
36  T2 = _mm_slli_si128(T1, 8);
37  T1 = _mm_srli_si128(T1, 8);
38  T0 = _mm_xor_si128(T0, T2);
39  T3 = _mm_xor_si128(T3, T1);
40 
41  T4 = _mm_srli_epi32(T0, 31);
42  T0 = _mm_slli_epi32(T0, 1);
43 
44  T5 = _mm_srli_epi32(T3, 31);
45  T3 = _mm_slli_epi32(T3, 1);
46 
47  T2 = _mm_srli_si128(T4, 12);
48  T5 = _mm_slli_si128(T5, 4);
49  T4 = _mm_slli_si128(T4, 4);
50  T0 = _mm_or_si128(T0, T4);
51  T3 = _mm_or_si128(T3, T5);
52  T3 = _mm_or_si128(T3, T2);
53 
54  T4 = _mm_slli_epi32(T0, 31);
55  T5 = _mm_slli_epi32(T0, 30);
56  T2 = _mm_slli_epi32(T0, 25);
57 
58  T4 = _mm_xor_si128(T4, T5);
59  T4 = _mm_xor_si128(T4, T2);
60  T5 = _mm_srli_si128(T4, 4);
61  T3 = _mm_xor_si128(T3, T5);
62  T4 = _mm_slli_si128(T4, 12);
63  T0 = _mm_xor_si128(T0, T4);
64  T3 = _mm_xor_si128(T3, T0);
65 
66  T4 = _mm_srli_epi32(T0, 1);
67  T1 = _mm_srli_epi32(T0, 2);
68  T2 = _mm_srli_epi32(T0, 7);
69  T3 = _mm_xor_si128(T3, T1);
70  T3 = _mm_xor_si128(T3, T2);
71  T3 = _mm_xor_si128(T3, T4);
72 
73  T3 = _mm_shuffle_epi8(T3, BSWAP_MASK);
74 
75  _mm_storeu_si128(reinterpret_cast<__m128i*>(x), T3);
76  }
77 
78 }
void gcm_multiply_clmul(uint8_t x[16], const uint8_t H[16])
Definition: clmul.cpp:15
#define BOTAN_FUNC_ISA(isa)
Definition: compiler.h:48
Definition: alg_id.cpp:13