/* $OpenBSD: gcm128.c,v 1.22 2018/01/24 23:03:37 kettenis Exp $ */

/* ====================================================================

 * Copyright (c) 2010 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@openssl.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 */

#define OPENSSL_FIPSAPI

#include <openssl/crypto.h>

#include "modes_lcl.h"

#include <string.h>

#ifndef MODES_DEBUG

# ifndef NDEBUG

#  define NDEBUG

# endif

#endif

#if defined(BSWAP4) && defined(__STRICT_ALIGNMENT)

/* redefine, because alignment is ensured */

#undef  GETU32

#define GETU32(p) BSWAP4(*(const u32 *)(p))

#undef  PUTU32

#define PUTU32(p,v) *(u32 *)(p) = BSWAP4(v)

#endif

#define PACK(s)   ((size_t)(s)<<(sizeof(size_t)*8-16))

#define REDUCE1BIT(V) \

  do { \

    if (sizeof(size_t)==8) { \

      u64 T = U64(0xe100000000000000) & (0-(V.lo&1)); \

      V.lo  = (V.hi<<63)|(V.lo>>1); \

      V.hi  = (V.hi>>1 )^T; \

    } else { \

      u32 T = 0xe1000000U & (0-(u32)(V.lo&1)); \

      V.lo  = (V.hi<<63)|(V.lo>>1); \

      V.hi  = (V.hi>>1 )^((u64)T<<32); \

    } \

  } while(0)

/*

 * Even though permitted values for TABLE_BITS are 8, 4 and 1, it should

 * never be set to 8. 8 is effectively reserved for testing purposes.

 * TABLE_BITS>1 are lookup-table-driven implementations referred to as

 * "Shoup's" in GCM specification. In other words OpenSSL does not cover

 * whole spectrum of possible table driven implementations. Why? In

 * non-"Shoup's" case memory access pattern is segmented in such manner,

 * that it's trivial to see that cache timing information can reveal

 * fair portion of intermediate hash value. Given that ciphertext is

 * always available to attacker, it's possible for him to attempt to

 * deduce secret parameter H and if successful, tamper with messages

 * [which is nothing but trivial in CTR mode]. In "Shoup's" case it's

 * not as trivial, but there is no reason to believe that it's resistant

 * to cache-timing attack. And the thing about "8-bit" implementation is

 * that it consumes 16 (sixteen) times more memory, 4KB per individual

 * key + 1KB shared. Well, on pros side it should be twice as fast as

 * "4-bit" version. And for gcc-generated x86[_64] code, "8-bit" version

 * was observed to run ~75% faster, closer to 100% for commercial

 * compilers... Yet "4-bit" procedure is preferred, because it's

 * believed to provide better security-performance balance and adequate

 * all-round performance. "All-round" refers to things like:

 *

 * - shorter setup time effectively improves overall timing for

 *   handling short messages;

 * - larger table allocation can become unbearable because of VM

 *   subsystem penalties (for example on Windows large enough free

 *   results in VM working set trimming, meaning that consequent

 *   malloc would immediately incur working set expansion);

 * - larger table has larger cache footprint, which can affect

 *   performance of other code paths (not necessarily even from same

 *   thread in Hyper-Threading world);

 *

 * Value of 1 is not appropriate for performance reasons.

 */

#if TABLE_BITS==8

static void gcm_init_8bit(u128 Htable[256], u64 H[2])

{

  int  i, j;

  u128 V;

  Htable[0].hi = 0;

  Htable[0].lo = 0;

  V.hi = H[0];

  V.lo = H[1];

  for (Htable[128]=V, i=64; i>0; i>>=1) {

    REDUCE1BIT(V);

    Htable[i] = V;

  }

  for (i=2; i<256; i<<=1) {

    u128 *Hi = Htable+i, H0 = *Hi;

    for (j=1; j<i; ++j) {

      Hi[j].hi = H0.hi^Htable[j].hi;

      Hi[j].lo = H0.lo^Htable[j].lo;

    }

  }

}

static void gcm_gmult_8bit(u64 Xi[2], const u128 Htable[256])

{

  u128 Z = { 0, 0};

  const u8 *xi = (const u8 *)Xi+15;

  size_t rem, n = *xi;

  static const size_t rem_8bit[256] = {

    PACK(0x0000), PACK(0x01C2), PACK(0x0384), PACK(0x0246),

    PACK(0x0708), PACK(0x06CA), PACK(0x048C), PACK(0x054E),

    PACK(0x0E10), PACK(0x0FD2), PACK(0x0D94), PACK(0x0C56),

    PACK(0x0918), PACK(0x08DA), PACK(0x0A9C), PACK(0x0B5E),

    PACK(0x1C20), PACK(0x1DE2), PACK(0x1FA4), PACK(0x1E66),

    PACK(0x1B28), PACK(0x1AEA), PACK(0x18AC), PACK(0x196E),

    PACK(0x1230), PACK(0x13F2), PACK(0x11B4), PACK(0x1076),

    PACK(0x1538), PACK(0x14FA), PACK(0x16BC), PACK(0x177E),

    PACK(0x3840), PACK(0x3982), PACK(0x3BC4), PACK(0x3A06),

    PACK(0x3F48), PACK(0x3E8A), PACK(0x3CCC), PACK(0x3D0E),

    PACK(0x3650), PACK(0x3792), PACK(0x35D4), PACK(0x3416),

    PACK(0x3158), PACK(0x309A), PACK(0x32DC), PACK(0x331E),

    PACK(0x2460), PACK(0x25A2), PACK(0x27E4), PACK(0x2626),

    PACK(0x2368), PACK(0x22AA), PACK(0x20EC), PACK(0x212E),

    PACK(0x2A70), PACK(0x2BB2), PACK(0x29F4), PACK(0x2836),

    PACK(0x2D78), PACK(0x2CBA), PACK(0x2EFC), PACK(0x2F3E),

    PACK(0x7080), PACK(0x7142), PACK(0x7304), PACK(0x72C6),

    PACK(0x7788), PACK(0x764A), PACK(0x740C), PACK(0x75CE),

    PACK(0x7E90), PACK(0x7F52), PACK(0x7D14), PACK(0x7CD6),

    PACK(0x7998), PACK(0x785A), PACK(0x7A1C), PACK(0x7BDE),

    PACK(0x6CA0), PACK(0x6D62), PACK(0x6F24), PACK(0x6EE6),

    PACK(0x6BA8), PACK(0x6A6A), PACK(0x682C), PACK(0x69EE),

    PACK(0x62B0), PACK(0x6372), PACK(0x6134), PACK(0x60F6),

    PACK(0x65B8), PACK(0x647A), PACK(0x663C), PACK(0x67FE),

    PACK(0x48C0), PACK(0x4902), PACK(0x4B44), PACK(0x4A86),

    PACK(0x4FC8), PACK(0x4E0A), PACK(0x4C4C), PACK(0x4D8E),

    PACK(0x46D0), PACK(0x4712), PACK(0x4554), PACK(0x4496),

    PACK(0x41D8), PACK(0x401A), PACK(0x425C), PACK(0x439E),

    PACK(0x54E0), PACK(0x5522), PACK(0x5764), PACK(0x56A6),

    PACK(0x53E8), PACK(0x522A), PACK(0x506C), PACK(0x51AE),

    PACK(0x5AF0), PACK(0x5B32), PACK(0x5974), PACK(0x58B6),

    PACK(0x5DF8), PACK(0x5C3A), PACK(0x5E7C), PACK(0x5FBE),

    PACK(0xE100), PACK(0xE0C2), PACK(0xE284), PACK(0xE346),

    PACK(0xE608), PACK(0xE7CA), PACK(0xE58C), PACK(0xE44E),

    PACK(0xEF10), PACK(0xEED2), PACK(0xEC94), PACK(0xED56),

    PACK(0xE818), PACK(0xE9DA), PACK(0xEB9C), PACK(0xEA5E),

    PACK(0xFD20), PACK(0xFCE2), PACK(0xFEA4), PACK(0xFF66),

    PACK(0xFA28), PACK(0xFBEA), PACK(0xF9AC), PACK(0xF86E),

    PACK(0xF330), PACK(0xF2F2), PACK(0xF0B4), PACK(0xF176),

    PACK(0xF438), PACK(0xF5FA), PACK(0xF7BC), PACK(0xF67E),

    PACK(0xD940), PACK(0xD882), PACK(0xDAC4), PACK(0xDB06),

    PACK(0xDE48), PACK(0xDF8A), PACK(0xDDCC), PACK(0xDC0E),

    PACK(0xD750), PACK(0xD692), PACK(0xD4D4), PACK(0xD516),

    PACK(0xD058), PACK(0xD19A), PACK(0xD3DC), PACK(0xD21E),

    PACK(0xC560), PACK(0xC4A2), PACK(0xC6E4), PACK(0xC726),

    PACK(0xC268), PACK(0xC3AA), PACK(0xC1EC), PACK(0xC02E),

    PACK(0xCB70), PACK(0xCAB2), PACK(0xC8F4), PACK(0xC936),

    PACK(0xCC78), PACK(0xCDBA), PACK(0xCFFC), PACK(0xCE3E),

    PACK(0x9180), PACK(0x9042), PACK(0x9204), PACK(0x93C6),

    PACK(0x9688), PACK(0x974A), PACK(0x950C), PACK(0x94CE),

    PACK(0x9F90), PACK(0x9E52), PACK(0x9C14), PACK(0x9DD6),

    PACK(0x9898), PACK(0x995A), PACK(0x9B1C), PACK(0x9ADE),

    PACK(0x8DA0), PACK(0x8C62), PACK(0x8E24), PACK(0x8FE6),

    PACK(0x8AA8), PACK(0x8B6A), PACK(0x892C), PACK(0x88EE),

    PACK(0x83B0), PACK(0x8272), PACK(0x8034), PACK(0x81F6),

    PACK(0x84B8), PACK(0x857A), PACK(0x873C), PACK(0x86FE),

    PACK(0xA9C0), PACK(0xA802), PACK(0xAA44), PACK(0xAB86),

    PACK(0xAEC8), PACK(0xAF0A), PACK(0xAD4C), PACK(0xAC8E),

    PACK(0xA7D0), PACK(0xA612), PACK(0xA454), PACK(0xA596),

    PACK(0xA0D8), PACK(0xA11A), PACK(0xA35C), PACK(0xA29E),

    PACK(0xB5E0), PACK(0xB422), PACK(0xB664), PACK(0xB7A6),

    PACK(0xB2E8), PACK(0xB32A), PACK(0xB16C), PACK(0xB0AE),

    PACK(0xBBF0), PACK(0xBA32), PACK(0xB874), PACK(0xB9B6),

    PACK(0xBCF8), PACK(0xBD3A), PACK(0xBF7C), PACK(0xBEBE) };

  while (1) {

    Z.hi ^= Htable[n].hi;

    Z.lo ^= Htable[n].lo;

    if ((u8 *)Xi==xi) break;

    n = *(--xi);

    rem  = (size_t)Z.lo&0xff;

    Z.lo = (Z.hi<<56)|(Z.lo>>8);

    Z.hi = (Z.hi>>8);

#if SIZE_MAX == 0xffffffffffffffff

    Z.hi ^= rem_8bit[rem];

#else

    Z.hi ^= (u64)rem_8bit[rem]<<32;

#endif

  }

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP8

  Xi[0] = BSWAP8(Z.hi);

  Xi[1] = BSWAP8(Z.lo);

#else

  u8 *p = (u8 *)Xi;

  u32 v;

  v = (u32)(Z.hi>>32);  PUTU32(p,v);

  v = (u32)(Z.hi);  PUTU32(p+4,v);

  v = (u32)(Z.lo>>32);  PUTU32(p+8,v);

  v = (u32)(Z.lo);  PUTU32(p+12,v);

#endif

#else /* BIG_ENDIAN */

  Xi[0] = Z.hi;

  Xi[1] = Z.lo;

#endif

}

#define GCM_MUL(ctx,Xi)   gcm_gmult_8bit(ctx->Xi.u,ctx->Htable)

#elif TABLE_BITS==4

static void gcm_init_4bit(u128 Htable[16], u64 H[2])

{

  u128 V;

#if defined(OPENSSL_SMALL_FOOTPRINT)

  int  i;

#endif

  Htable[0].hi = 0;

  Htable[0].lo = 0;

  V.hi = H[0];

  V.lo = H[1];

#if defined(OPENSSL_SMALL_FOOTPRINT)

  for (Htable[8]=V, i=4; i>0; i>>=1) {

    REDUCE1BIT(V);

    Htable[i] = V;

  }

  for (i=2; i<16; i<<=1) {

    u128 *Hi = Htable+i;

    int   j;

    for (V=*Hi, j=1; j<i; ++j) {

      Hi[j].hi = V.hi^Htable[j].hi;

      Hi[j].lo = V.lo^Htable[j].lo;

    }

  }

#else

  Htable[8] = V;

  REDUCE1BIT(V);

  Htable[4] = V;

  REDUCE1BIT(V);

  Htable[2] = V;

  REDUCE1BIT(V);

  Htable[1] = V;

  Htable[3].hi  = V.hi^Htable[2].hi, Htable[3].lo  = V.lo^Htable[2].lo;

  V=Htable[4];

  Htable[5].hi  = V.hi^Htable[1].hi, Htable[5].lo  = V.lo^Htable[1].lo;

  Htable[6].hi  = V.hi^Htable[2].hi, Htable[6].lo  = V.lo^Htable[2].lo;

  Htable[7].hi  = V.hi^Htable[3].hi, Htable[7].lo  = V.lo^Htable[3].lo;

  V=Htable[8];

  Htable[9].hi  = V.hi^Htable[1].hi, Htable[9].lo  = V.lo^Htable[1].lo;

  Htable[10].hi = V.hi^Htable[2].hi, Htable[10].lo = V.lo^Htable[2].lo;

  Htable[11].hi = V.hi^Htable[3].hi, Htable[11].lo = V.lo^Htable[3].lo;

  Htable[12].hi = V.hi^Htable[4].hi, Htable[12].lo = V.lo^Htable[4].lo;

  Htable[13].hi = V.hi^Htable[5].hi, Htable[13].lo = V.lo^Htable[5].lo;

  Htable[14].hi = V.hi^Htable[6].hi, Htable[14].lo = V.lo^Htable[6].lo;

  Htable[15].hi = V.hi^Htable[7].hi, Htable[15].lo = V.lo^Htable[7].lo;

#endif

#if defined(GHASH_ASM) && (defined(__arm__) || defined(__arm))

  /*

   * ARM assembler expects specific dword order in Htable.

   */

  {

    int j;

#if BYTE_ORDER == LITTLE_ENDIAN

    for (j=0;j<16;++j) {

      V = Htable[j];

      Htable[j].hi = V.lo;

      Htable[j].lo = V.hi;

    }

#else /* BIG_ENDIAN */

    for (j=0;j<16;++j) {

      V = Htable[j];

      Htable[j].hi = V.lo<<32|V.lo>>32;

      Htable[j].lo = V.hi<<32|V.hi>>32;

    }

#endif

  }

#endif

}

#ifndef GHASH_ASM

static const size_t rem_4bit[16] = {

  PACK(0x0000), PACK(0x1C20), PACK(0x3840), PACK(0x2460),

  PACK(0x7080), PACK(0x6CA0), PACK(0x48C0), PACK(0x54E0),

  PACK(0xE100), PACK(0xFD20), PACK(0xD940), PACK(0xC560),

  PACK(0x9180), PACK(0x8DA0), PACK(0xA9C0), PACK(0xB5E0) };

static void gcm_gmult_4bit(u64 Xi[2], const u128 Htable[16])

{

  u128 Z;

  int cnt = 15;

  size_t rem, nlo, nhi;

  nlo  = ((const u8 *)Xi)[15];

  nhi  = nlo>>4;

  nlo &= 0xf;

  Z.hi = Htable[nlo].hi;

  Z.lo = Htable[nlo].lo;

  while (1) {

    rem  = (size_t)Z.lo&0xf;

    Z.lo = (Z.hi<<60)|(Z.lo>>4);

    Z.hi = (Z.hi>>4);

#if SIZE_MAX == 0xffffffffffffffff

    Z.hi ^= rem_4bit[rem];

#else

    Z.hi ^= (u64)rem_4bit[rem]<<32;

#endif

    Z.hi ^= Htable[nhi].hi;

    Z.lo ^= Htable[nhi].lo;

    if (--cnt<0)    break;

    nlo  = ((const u8 *)Xi)[cnt];

    nhi  = nlo>>4;

    nlo &= 0xf;

    rem  = (size_t)Z.lo&0xf;

    Z.lo = (Z.hi<<60)|(Z.lo>>4);

    Z.hi = (Z.hi>>4);

#if SIZE_MAX == 0xffffffffffffffff

    Z.hi ^= rem_4bit[rem];

#else

    Z.hi ^= (u64)rem_4bit[rem]<<32;

#endif

    Z.hi ^= Htable[nlo].hi;

    Z.lo ^= Htable[nlo].lo;

  }

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP8

  Xi[0] = BSWAP8(Z.hi);

  Xi[1] = BSWAP8(Z.lo);

#else

  u8 *p = (u8 *)Xi;

  u32 v;

  v = (u32)(Z.hi>>32);  PUTU32(p,v);

  v = (u32)(Z.hi);  PUTU32(p+4,v);

  v = (u32)(Z.lo>>32);  PUTU32(p+8,v);

  v = (u32)(Z.lo);  PUTU32(p+12,v);

#endif

#else /* BIG_ENDIAN */

  Xi[0] = Z.hi;

  Xi[1] = Z.lo;

#endif

}

#if !defined(OPENSSL_SMALL_FOOTPRINT)

/*

 * Streamed gcm_mult_4bit, see CRYPTO_gcm128_[en|de]crypt for

 * details... Compiler-generated code doesn't seem to give any

 * performance improvement, at least not on x86[_64]. It's here

 * mostly as reference and a placeholder for possible future

 * non-trivial optimization[s]...

 */

static void gcm_ghash_4bit(u64 Xi[2],const u128 Htable[16],

        const u8 *inp,size_t len)

{

    u128 Z;

    int cnt;

    size_t rem, nlo, nhi;

#if 1

    do {

  cnt  = 15;

  nlo  = ((const u8 *)Xi)[15];

  nlo ^= inp[15];

  nhi  = nlo>>4;

  nlo &= 0xf;

  Z.hi = Htable[nlo].hi;

  Z.lo = Htable[nlo].lo;

  while (1) {

    rem  = (size_t)Z.lo&0xf;

    Z.lo = (Z.hi<<60)|(Z.lo>>4);

    Z.hi = (Z.hi>>4);

#if SIZE_MAX == 0xffffffffffffffff

    Z.hi ^= rem_4bit[rem];

#else

    Z.hi ^= (u64)rem_4bit[rem]<<32;

#endif

    Z.hi ^= Htable[nhi].hi;

    Z.lo ^= Htable[nhi].lo;

    if (--cnt<0)    break;

    nlo  = ((const u8 *)Xi)[cnt];

    nlo ^= inp[cnt];

    nhi  = nlo>>4;

    nlo &= 0xf;

    rem  = (size_t)Z.lo&0xf;

    Z.lo = (Z.hi<<60)|(Z.lo>>4);

    Z.hi = (Z.hi>>4);

#if SIZE_MAX == 0xffffffffffffffff

    Z.hi ^= rem_4bit[rem];

#else

    Z.hi ^= (u64)rem_4bit[rem]<<32;

#endif

    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 the priority is to minimize

     * cache footprint...

     */

    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 {

  for (Z.lo=0, Z.hi=0, cnt=15; cnt; --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 BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP8

  Xi[0] = BSWAP8(Z.hi);

  Xi[1] = BSWAP8(Z.lo);

#else

  u8 *p = (u8 *)Xi;

  u32 v;

  v = (u32)(Z.hi>>32);  PUTU32(p,v);

  v = (u32)(Z.hi);  PUTU32(p+4,v);

  v = (u32)(Z.lo>>32);  PUTU32(p+8,v);

  v = (u32)(Z.lo);  PUTU32(p+12,v);

#endif

#else /* BIG_ENDIAN */

  Xi[0] = Z.hi;

  Xi[1] = Z.lo;

#endif

    } while (inp+=16, len-=16);

}

#endif

#else

void gcm_gmult_4bit(u64 Xi[2],const u128 Htable[16]);

void gcm_ghash_4bit(u64 Xi[2],const u128 Htable[16],const u8 *inp,size_t len);

#endif

#define GCM_MUL(ctx,Xi)   gcm_gmult_4bit(ctx->Xi.u,ctx->Htable)

#if defined(GHASH_ASM) || !defined(OPENSSL_SMALL_FOOTPRINT)

#define GHASH(ctx,in,len) gcm_ghash_4bit((ctx)->Xi.u,(ctx)->Htable,in,len)

/* GHASH_CHUNK is "stride parameter" missioned to mitigate cache

 * trashing effect. In other words idea is to hash data while it's

 * still in L1 cache after encryption pass... */

#define GHASH_CHUNK       (3*1024)

#endif

#else /* TABLE_BITS */

static void gcm_gmult_1bit(u64 Xi[2],const u64 H[2])

{

  u128 V,Z = { 0,0 };

  long X;

  int  i,j;

  const long *xi = (const long *)Xi;

  V.hi = H[0];  /* H is in host byte order, no byte swapping */

  V.lo = H[1];

  for (j=0; j<16/sizeof(long); ++j) {

#if BYTE_ORDER == LITTLE_ENDIAN

#if SIZE_MAX == 0xffffffffffffffff

#ifdef BSWAP8

      X = (long)(BSWAP8(xi[j]));

#else

      const u8 *p = (const u8 *)(xi+j);

      X = (long)((u64)GETU32(p)<<32|GETU32(p+4));

#endif

#else

      const u8 *p = (const u8 *)(xi+j);

      X = (long)GETU32(p);

#endif

#else /* BIG_ENDIAN */

    X = xi[j];

#endif

    for (i=0; i<8*sizeof(long); ++i, X<<=1) {

      u64 M = (u64)(X>>(8*sizeof(long)-1));

      Z.hi ^= V.hi&M;

      Z.lo ^= V.lo&M;

      REDUCE1BIT(V);

    }

  }

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP8

  Xi[0] = BSWAP8(Z.hi);

  Xi[1] = BSWAP8(Z.lo);

#else

  u8 *p = (u8 *)Xi;

  u32 v;

  v = (u32)(Z.hi>>32);  PUTU32(p,v);

  v = (u32)(Z.hi);  PUTU32(p+4,v);

  v = (u32)(Z.lo>>32);  PUTU32(p+8,v);

  v = (u32)(Z.lo);  PUTU32(p+12,v);

#endif

#else /* BIG_ENDIAN */

  Xi[0] = Z.hi;

  Xi[1] = Z.lo;

#endif

}

#define GCM_MUL(ctx,Xi)   gcm_gmult_1bit(ctx->Xi.u,ctx->H.u)

#endif

#if defined(GHASH_ASM) && \

  (defined(__i386)  || defined(__i386__)  || \

   defined(__x86_64)  || defined(__x86_64__)  || \

   defined(_M_IX86) || defined(_M_AMD64)  || defined(_M_X64))

#include "x86_arch.h"

#endif

#if TABLE_BITS==4 && defined(GHASH_ASM)

# if  (defined(__i386)  || defined(__i386__)  || \

   defined(__x86_64)  || defined(__x86_64__)  || \

   defined(_M_IX86) || defined(_M_AMD64)  || defined(_M_X64))

#  define GHASH_ASM_X86_OR_64

#  define GCM_FUNCREF_4BIT

void gcm_init_clmul(u128 Htable[16],const u64 Xi[2]);

void gcm_gmult_clmul(u64 Xi[2],const u128 Htable[16]);

void gcm_ghash_clmul(u64 Xi[2],const u128 Htable[16],const u8 *inp,size_t len);

#  if defined(__i386) || defined(__i386__) || defined(_M_IX86)

#   define GHASH_ASM_X86

void gcm_gmult_4bit_mmx(u64 Xi[2],const u128 Htable[16]);

void gcm_ghash_4bit_mmx(u64 Xi[2],const u128 Htable[16],const u8 *inp,size_t len);

void gcm_gmult_4bit_x86(u64 Xi[2],const u128 Htable[16]);

void gcm_ghash_4bit_x86(u64 Xi[2],const u128 Htable[16],const u8 *inp,size_t len);

#  endif

# elif defined(__arm__) || defined(__arm)

#  include "arm_arch.h"

#  if __ARM_ARCH__>=7 && !defined(__STRICT_ALIGNMENT)

#   define GHASH_ASM_ARM

#   define GCM_FUNCREF_4BIT

void gcm_gmult_neon(u64 Xi[2],const u128 Htable[16]);

void gcm_ghash_neon(u64 Xi[2],const u128 Htable[16],const u8 *inp,size_t len);

#  endif

# endif

#endif

#ifdef GCM_FUNCREF_4BIT

# undef  GCM_MUL

# define GCM_MUL(ctx,Xi)  (*gcm_gmult_p)(ctx->Xi.u,ctx->Htable)

# ifdef GHASH

#  undef  GHASH

#  define GHASH(ctx,in,len) (*gcm_ghash_p)(ctx->Xi.u,ctx->Htable,in,len)

# endif

#endif

void CRYPTO_gcm128_init(GCM128_CONTEXT *ctx,void *key,block128_f block)

{

  memset(ctx,0,sizeof(*ctx));

  ctx->block = block;

  ctx->key   = key;

  (*block)(ctx->H.c,ctx->H.c,key);

#if BYTE_ORDER == LITTLE_ENDIAN

  /* H is stored in host byte order */

#ifdef BSWAP8

  ctx->H.u[0] = BSWAP8(ctx->H.u[0]);

  ctx->H.u[1] = BSWAP8(ctx->H.u[1]);

#else

  u8 *p = ctx->H.c;

  u64 hi,lo;

  hi = (u64)GETU32(p)  <<32|GETU32(p+4);

  lo = (u64)GETU32(p+8)<<32|GETU32(p+12);

  ctx->H.u[0] = hi;

  ctx->H.u[1] = lo;

#endif

#endif

#if TABLE_BITS==8

  gcm_init_8bit(ctx->Htable,ctx->H.u);

#elif  TABLE_BITS==4

# if  defined(GHASH_ASM_X86_OR_64)

#  if !defined(GHASH_ASM_X86) || defined(OPENSSL_IA32_SSE2)

  /* check FXSR and PCLMULQDQ bits */

  if ((OPENSSL_cpu_caps() & (CPUCAP_MASK_FXSR | CPUCAP_MASK_PCLMUL)) ==

      (CPUCAP_MASK_FXSR | CPUCAP_MASK_PCLMUL)) {

    gcm_init_clmul(ctx->Htable,ctx->H.u);

    ctx->gmult = gcm_gmult_clmul;

    ctx->ghash = gcm_ghash_clmul;

    return;

  }

#  endif

  gcm_init_4bit(ctx->Htable,ctx->H.u);

#  if defined(GHASH_ASM_X86)      /* x86 only */

#   if  defined(OPENSSL_IA32_SSE2)

  if (OPENSSL_cpu_caps() & CPUCAP_MASK_SSE) { /* check SSE bit */

#   else

  if (OPENSSL_cpu_caps() & CPUCAP_MASK_MMX) { /* check MMX bit */

#   endif

    ctx->gmult = gcm_gmult_4bit_mmx;

    ctx->ghash = gcm_ghash_4bit_mmx;

  } else {

    ctx->gmult = gcm_gmult_4bit_x86;

    ctx->ghash = gcm_ghash_4bit_x86;

  }

#  else

  ctx->gmult = gcm_gmult_4bit;

  ctx->ghash = gcm_ghash_4bit;

#  endif

# elif  defined(GHASH_ASM_ARM)

  if (OPENSSL_armcap_P & ARMV7_NEON) {

    ctx->gmult = gcm_gmult_neon;

    ctx->ghash = gcm_ghash_neon;

  } else {

    gcm_init_4bit(ctx->Htable,ctx->H.u);

    ctx->gmult = gcm_gmult_4bit;

    ctx->ghash = gcm_ghash_4bit;

  }

# else

  gcm_init_4bit(ctx->Htable,ctx->H.u);

# endif

#endif

}

void CRYPTO_gcm128_setiv(GCM128_CONTEXT *ctx,const unsigned char *iv,size_t len)

{

  unsigned int ctr;

#ifdef GCM_FUNCREF_4BIT

  void (*gcm_gmult_p)(u64 Xi[2],const u128 Htable[16])  = ctx->gmult;

#endif

  ctx->Yi.u[0]  = 0;

  ctx->Yi.u[1]  = 0;

  ctx->Xi.u[0]  = 0;

  ctx->Xi.u[1]  = 0;

  ctx->len.u[0] = 0;  /* AAD length */

  ctx->len.u[1] = 0;  /* message length */

  ctx->ares = 0;

  ctx->mres = 0;

  if (len==12) {

    memcpy(ctx->Yi.c,iv,12);

    ctx->Yi.c[15]=1;

    ctr=1;

  }

  else {

    size_t i;

    u64 len0 = len;

    while (len>=16) {

      for (i=0; i<16; ++i) ctx->Yi.c[i] ^= iv[i];

      GCM_MUL(ctx,Yi);

      iv += 16;

      len -= 16;

    }

    if (len) {

      for (i=0; i<len; ++i) ctx->Yi.c[i] ^= iv[i];

      GCM_MUL(ctx,Yi);

    }

    len0 <<= 3;

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP8

    ctx->Yi.u[1]  ^= BSWAP8(len0);

#else

    ctx->Yi.c[8]  ^= (u8)(len0>>56);

    ctx->Yi.c[9]  ^= (u8)(len0>>48);

    ctx->Yi.c[10] ^= (u8)(len0>>40);

    ctx->Yi.c[11] ^= (u8)(len0>>32);

    ctx->Yi.c[12] ^= (u8)(len0>>24);

    ctx->Yi.c[13] ^= (u8)(len0>>16);

    ctx->Yi.c[14] ^= (u8)(len0>>8);

    ctx->Yi.c[15] ^= (u8)(len0);

#endif

#else /* BIG_ENDIAN */

    ctx->Yi.u[1]  ^= len0;

#endif

    GCM_MUL(ctx,Yi);

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP4

    ctr = BSWAP4(ctx->Yi.d[3]);

#else

    ctr = GETU32(ctx->Yi.c+12);

#endif

#else /* BIG_ENDIAN */

    ctr = ctx->Yi.d[3];

#endif

  }

  (*ctx->block)(ctx->Yi.c,ctx->EK0.c,ctx->key);

  ++ctr;

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP4

  ctx->Yi.d[3] = BSWAP4(ctr);

#else

  PUTU32(ctx->Yi.c+12,ctr);

#endif

#else /* BIG_ENDIAN */

  ctx->Yi.d[3] = ctr;

#endif

}

int CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx,const unsigned char *aad,size_t len)

{

  size_t i;

  unsigned int n;

  u64 alen = ctx->len.u[0];

#ifdef GCM_FUNCREF_4BIT

  void (*gcm_gmult_p)(u64 Xi[2],const u128 Htable[16])  = ctx->gmult;

# ifdef GHASH

  void (*gcm_ghash_p)(u64 Xi[2],const u128 Htable[16],

        const u8 *inp,size_t len) = ctx->ghash;

# endif

#endif

  if (ctx->len.u[1]) return -2;

  alen += len;

  if (alen>(U64(1)<<61) || (sizeof(len)==8 && alen<len))

    return -1;

  ctx->len.u[0] = alen;

  n = ctx->ares;

  if (n) {

    while (n && len) {

      ctx->Xi.c[n] ^= *(aad++);

      --len;

      n = (n+1)%16;

    }

    if (n==0) GCM_MUL(ctx,Xi);

    else {

      ctx->ares = n;

      return 0;

    }

  }

#ifdef GHASH

  if ((i = (len&(size_t)-16))) {

    GHASH(ctx,aad,i);

    aad += i;

    len -= i;

  }

#else

  while (len>=16) {

    for (i=0; i<16; ++i) ctx->Xi.c[i] ^= aad[i];

    GCM_MUL(ctx,Xi);

    aad += 16;

    len -= 16;

  }

#endif

  if (len) {

    n = (unsigned int)len;

    for (i=0; i<len; ++i) ctx->Xi.c[i] ^= aad[i];

  }

  ctx->ares = n;

  return 0;

}

int CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx,

    const unsigned char *in, unsigned char *out,

    size_t len)

{

  unsigned int n, ctr;

  size_t i;

  u64        mlen  = ctx->len.u[1];

  block128_f block = ctx->block;

  void      *key   = ctx->key;

#ifdef GCM_FUNCREF_4BIT

  void (*gcm_gmult_p)(u64 Xi[2],const u128 Htable[16])  = ctx->gmult;

# ifdef GHASH

  void (*gcm_ghash_p)(u64 Xi[2],const u128 Htable[16],

        const u8 *inp,size_t len) = ctx->ghash;

# endif

#endif

  mlen += len;

  if (mlen>((U64(1)<<36)-32) || (sizeof(len)==8 && mlen<len))

    return -1;

  ctx->len.u[1] = mlen;

  if (ctx->ares) {

    /* First call to encrypt finalizes GHASH(AAD) */

    GCM_MUL(ctx,Xi);

    ctx->ares = 0;

  }

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP4

  ctr = BSWAP4(ctx->Yi.d[3]);

#else

  ctr = GETU32(ctx->Yi.c+12);

#endif

#else /* BIG_ENDIAN */

  ctr = ctx->Yi.d[3];

#endif

  n = ctx->mres;

#if !defined(OPENSSL_SMALL_FOOTPRINT)

  if (16%sizeof(size_t) == 0) do { /* always true actually */

    if (n) {

      while (n && len) {

        ctx->Xi.c[n] ^= *(out++) = *(in++)^ctx->EKi.c[n];

        --len;

        n = (n+1)%16;

      }

      if (n==0) GCM_MUL(ctx,Xi);

      else {

        ctx->mres = n;

        return 0;

      }

    }

#ifdef __STRICT_ALIGNMENT

    if (((size_t)in|(size_t)out)%sizeof(size_t) != 0)

      break;

#endif

#if defined(GHASH) && defined(GHASH_CHUNK)

    while (len>=GHASH_CHUNK) {

        size_t j=GHASH_CHUNK;

        while (j) {

          size_t *out_t=(size_t *)out;

          const size_t *in_t=(const size_t *)in;

      (*block)(ctx->Yi.c,ctx->EKi.c,key);

      ++ctr;

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP4

      ctx->Yi.d[3] = BSWAP4(ctr);

#else

      PUTU32(ctx->Yi.c+12,ctr);

#endif

#else /* BIG_ENDIAN */

      ctx->Yi.d[3] = ctr;

#endif

      for (i=0; i<16/sizeof(size_t); ++i)

        out_t[i] = in_t[i] ^ ctx->EKi.t[i];

      out += 16;

      in  += 16;

      j   -= 16;

        }

        GHASH(ctx,out-GHASH_CHUNK,GHASH_CHUNK);

        len -= GHASH_CHUNK;

    }

    if ((i = (len&(size_t)-16))) {

        size_t j=i;

        while (len>=16) {

          size_t *out_t=(size_t *)out;

          const size_t *in_t=(const size_t *)in;

      (*block)(ctx->Yi.c,ctx->EKi.c,key);

      ++ctr;

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP4

      ctx->Yi.d[3] = BSWAP4(ctr);

#else

      PUTU32(ctx->Yi.c+12,ctr);

#endif

#else /* BIG_ENDIAN */

      ctx->Yi.d[3] = ctr;

#endif

      for (i=0; i<16/sizeof(size_t); ++i)

        out_t[i] = in_t[i] ^ ctx->EKi.t[i];

      out += 16;

      in  += 16;

      len -= 16;

        }

        GHASH(ctx,out-j,j);

    }

#else

    while (len>=16) {

          size_t *out_t=(size_t *)out;

          const size_t *in_t=(const size_t *)in;

      (*block)(ctx->Yi.c,ctx->EKi.c,key);

      ++ctr;

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP4

      ctx->Yi.d[3] = BSWAP4(ctr);

#else

      PUTU32(ctx->Yi.c+12,ctr);

#endif

#else /* BIG_ENDIAN */

      ctx->Yi.d[3] = ctr;

#endif

      for (i=0; i<16/sizeof(size_t); ++i)

        ctx->Xi.t[i] ^=

        out_t[i] = in_t[i]^ctx->EKi.t[i];

      GCM_MUL(ctx,Xi);

      out += 16;

      in  += 16;

      len -= 16;

    }

#endif

    if (len) {

      (*block)(ctx->Yi.c,ctx->EKi.c,key);

      ++ctr;

#if BYTE_ORDER == LITTLE_ENDIAN

#ifdef BSWAP4

      ctx->Yi.d[3] = BSWAP4(ctr);

#else

      PUTU32(ctx->Yi.c+12,ctr);

#endif

#else /* BIG_ENDIAN */

      ctx->Yi.d[3] = ctr;

#endif

      while (len--) {

        ctx->Xi.c[n] ^= out[n] = in[n]^ctx->EKi.c[n];

        ++n;

      }