From e747f4d41885efa200b8fafa67cd81c52223cd31 Mon Sep 17 00:00:00 2001 From: Andy Polyakov Date: Wed, 26 May 2010 21:36:36 +0000 Subject: [PATCH] gcm128.c: P.-M. Hager has tipped about possibility to fold reductions in gcm_ghash_4bit. Taking the idea a step further I've added extra 256+16 bytes of per-key storage, so that one can speak about 3rd variant in addition to "256B" and "4KB": "528B" one. Commonly it should be ~50% faster than "256B" implementation or ~25% slower than "4KB" one. --- crypto/modes/gcm128.c | 112 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) diff --git a/crypto/modes/gcm128.c b/crypto/modes/gcm128.c index 132c7892bc..8b1880cf5d 100644 --- a/crypto/modes/gcm128.c +++ b/crypto/modes/gcm128.c @@ -413,6 +413,7 @@ static void gcm_ghash_4bit(u64 Xi[2],const u128 Htable[16], size_t rem, nlo, nhi; const union { long one; char little; } is_endian = {1}; +#if 1 do { cnt = 15; nlo = ((const u8 *)Xi)[15]; @@ -453,6 +454,117 @@ static void gcm_ghash_4bit(u64 Xi[2],const u128 Htable[16], Z.hi ^= Htable[nlo].hi; Z.lo ^= Htable[nlo].lo; } +#else + /* + * Extra 256+16 bytes per-key plus 512 bytes shared tables + * [should] give ~50% improvement... One could have PACK()-ed + * the rem_8bit even here, but priority is to minimize memory + * usage... + */ + u128 Hshr4[16]; /* Htable shifted right by 4 bits */ + u8 Hshl4[16]; /* Htable shifted left by 4 bits */ + static const unsigned short rem_8bit[256] = { + 0x0000, 0x01C2, 0x0384, 0x0246, 0x0708, 0x06CA, 0x048C, 0x054E, + 0x0E10, 0x0FD2, 0x0D94, 0x0C56, 0x0918, 0x08DA, 0x0A9C, 0x0B5E, + 0x1C20, 0x1DE2, 0x1FA4, 0x1E66, 0x1B28, 0x1AEA, 0x18AC, 0x196E, + 0x1230, 0x13F2, 0x11B4, 0x1076, 0x1538, 0x14FA, 0x16BC, 0x177E, + 0x3840, 0x3982, 0x3BC4, 0x3A06, 0x3F48, 0x3E8A, 0x3CCC, 0x3D0E, + 0x3650, 0x3792, 0x35D4, 0x3416, 0x3158, 0x309A, 0x32DC, 0x331E, + 0x2460, 0x25A2, 0x27E4, 0x2626, 0x2368, 0x22AA, 0x20EC, 0x212E, + 0x2A70, 0x2BB2, 0x29F4, 0x2836, 0x2D78, 0x2CBA, 0x2EFC, 0x2F3E, + 0x7080, 0x7142, 0x7304, 0x72C6, 0x7788, 0x764A, 0x740C, 0x75CE, + 0x7E90, 0x7F52, 0x7D14, 0x7CD6, 0x7998, 0x785A, 0x7A1C, 0x7BDE, + 0x6CA0, 0x6D62, 0x6F24, 0x6EE6, 0x6BA8, 0x6A6A, 0x682C, 0x69EE, + 0x62B0, 0x6372, 0x6134, 0x60F6, 0x65B8, 0x647A, 0x663C, 0x67FE, + 0x48C0, 0x4902, 0x4B44, 0x4A86, 0x4FC8, 0x4E0A, 0x4C4C, 0x4D8E, + 0x46D0, 0x4712, 0x4554, 0x4496, 0x41D8, 0x401A, 0x425C, 0x439E, + 0x54E0, 0x5522, 0x5764, 0x56A6, 0x53E8, 0x522A, 0x506C, 0x51AE, + 0x5AF0, 0x5B32, 0x5974, 0x58B6, 0x5DF8, 0x5C3A, 0x5E7C, 0x5FBE, + 0xE100, 0xE0C2, 0xE284, 0xE346, 0xE608, 0xE7CA, 0xE58C, 0xE44E, + 0xEF10, 0xEED2, 0xEC94, 0xED56, 0xE818, 0xE9DA, 0xEB9C, 0xEA5E, + 0xFD20, 0xFCE2, 0xFEA4, 0xFF66, 0xFA28, 0xFBEA, 0xF9AC, 0xF86E, + 0xF330, 0xF2F2, 0xF0B4, 0xF176, 0xF438, 0xF5FA, 0xF7BC, 0xF67E, + 0xD940, 0xD882, 0xDAC4, 0xDB06, 0xDE48, 0xDF8A, 0xDDCC, 0xDC0E, + 0xD750, 0xD692, 0xD4D4, 0xD516, 0xD058, 0xD19A, 0xD3DC, 0xD21E, + 0xC560, 0xC4A2, 0xC6E4, 0xC726, 0xC268, 0xC3AA, 0xC1EC, 0xC02E, + 0xCB70, 0xCAB2, 0xC8F4, 0xC936, 0xCC78, 0xCDBA, 0xCFFC, 0xCE3E, + 0x9180, 0x9042, 0x9204, 0x93C6, 0x9688, 0x974A, 0x950C, 0x94CE, + 0x9F90, 0x9E52, 0x9C14, 0x9DD6, 0x9898, 0x995A, 0x9B1C, 0x9ADE, + 0x8DA0, 0x8C62, 0x8E24, 0x8FE6, 0x8AA8, 0x8B6A, 0x892C, 0x88EE, + 0x83B0, 0x8272, 0x8034, 0x81F6, 0x84B8, 0x857A, 0x873C, 0x86FE, + 0xA9C0, 0xA802, 0xAA44, 0xAB86, 0xAEC8, 0xAF0A, 0xAD4C, 0xAC8E, + 0xA7D0, 0xA612, 0xA454, 0xA596, 0xA0D8, 0xA11A, 0xA35C, 0xA29E, + 0xB5E0, 0xB422, 0xB664, 0xB7A6, 0xB2E8, 0xB32A, 0xB16C, 0xB0AE, + 0xBBF0, 0xBA32, 0xB874, 0xB9B6, 0xBCF8, 0xBD3A, 0xBF7C, 0xBEBE }; + + /* + * This pre-processing phase slows down procedure by approximately + * same time as it makes each loop spin faster. In other words + * single block performance is approximately same as straightforward + * "4-bit" implementation, and then it goes only faster... + */ + for (cnt=0; cnt<16; ++cnt) { + Z.hi = Htable[cnt].hi; + Z.lo = Htable[cnt].lo; + Hshr4[cnt].lo = (Z.hi<<60)|(Z.lo>>4); + Hshr4[cnt].hi = (Z.hi>>4); + Hshl4[cnt] = (u8)(Z.lo<<4); + } + + do { + nlo = ((const u8 *)Xi)[15]; + nlo ^= inp[15]; + nhi = nlo>>4; + nlo &= 0xf; + + Z.hi = Htable[nlo].hi; + Z.lo = Htable[nlo].lo; + + rem = (size_t)Z.lo&0xff; + + Z.lo = (Z.hi<<56)|(Z.lo>>8); + Z.hi = (Z.hi>>8); + + Z.hi ^= Hshr4[nhi].hi; + Z.lo ^= Hshr4[nhi].lo; + Z.hi ^= (u64)rem_8bit[rem^Hshl4[nhi]]<<48; + + for (cnt=14; cnt>0; --cnt) { + nlo = ((const u8 *)Xi)[cnt]; + nlo ^= inp[cnt]; + nhi = nlo>>4; + nlo &= 0xf; + + Z.hi ^= Htable[nlo].hi; + Z.lo ^= Htable[nlo].lo; + + rem = (size_t)Z.lo&0xff; + + Z.lo = (Z.hi<<56)|(Z.lo>>8); + Z.hi = (Z.hi>>8); + + Z.hi ^= Hshr4[nhi].hi; + Z.lo ^= Hshr4[nhi].lo; + Z.hi ^= (u64)rem_8bit[rem^Hshl4[nhi]]<<48; + } + + nlo = ((const u8 *)Xi)[0]; + nlo ^= inp[0]; + nhi = nlo>>4; + nlo &= 0xf; + + Z.hi ^= Htable[nlo].hi; + Z.lo ^= Htable[nlo].lo; + + rem = (size_t)Z.lo&0xf; + + Z.lo = (Z.hi<<60)|(Z.lo>>4); + Z.hi = (Z.hi>>4); + + Z.hi ^= Htable[nhi].hi; + Z.lo ^= Htable[nhi].lo; + Z.hi ^= ((u64)rem_8bit[rem<<4])<<48; +#endif if (is_endian.little) { #ifdef BSWAP8 -- 2.25.1