aes-gcm: Baseline implementation from BoringSSL

Copied over from upstream BoringSSL at commit
859679518d3433cdd0dd6cf534bd7bdb2a32dd60 .

cp boringssl/crypto/fipsmodule/modes/gcm.c \
   third_party/boringssl/common/gcm.c
cp crypto/fipsmodule/modes/internal.h \
   third_party/boringssl/include/aes-gcm.h
 => Remove non-GCM definitions
perl boringssl/crypto/fipsmodule/modes/asm/ghash-armv4.pl \
    > third_party/boringssl/core/cortex-m/ghash.S

BRANCH=none
BUG=b:111160949
TEST=none

Change-Id: I34702ff315c8c44e6f4868243058700aaf026099
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1141445
Reviewed-by: Adam Langley <agl@chromium.org>

1 files changed, 1063 insertions, 0 deletions

diff --git a/third_party/boringssl/common/aes-gcm.c b/third_party/boringssl/common/aes-gcm.c
new file mode 100644
index 0000000000..99d0e15e83
--- /dev/null
+++ b/third_party/boringssl/common/aes-gcm.c
@@ -0,0 +1,1063 @@
+/* ====================================================================
+ * Copyright (c) 2008 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.
+ * ==================================================================== */
+
+#include <openssl/base.h>
+
+#include <assert.h>
+#include <string.h>
+
+#include <openssl/mem.h>
+#include <openssl/cpu.h>
+
+#include "internal.h"
+#include "../../internal.h"
+
+#if !defined(OPENSSL_NO_ASM) &&                         \
+    (defined(OPENSSL_X86) || defined(OPENSSL_X86_64) || \
+     defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64) || \
+     defined(OPENSSL_PPC64LE))
+#define GHASH_ASM
+#endif
+
+#define PACK(s) ((size_t)(s) << (sizeof(size_t) * 8 - 16))
+#define REDUCE1BIT(V)                                                 \
+  do {                                                                \
+    if (sizeof(size_t) == 8) {                                        \
+      uint64_t T = UINT64_C(0xe100000000000000) & (0 - ((V).lo & 1)); \
+      (V).lo = ((V).hi << 63) | ((V).lo >> 1);                        \
+      (V).hi = ((V).hi >> 1) ^ T;                                     \
+    } else {                                                          \
+      uint32_t T = 0xe1000000U & (0 - (uint32_t)((V).lo & 1));        \
+      (V).lo = ((V).hi << 63) | ((V).lo >> 1);                        \
+      (V).hi = ((V).hi >> 1) ^ ((uint64_t)T << 32);                   \
+    }                                                                 \
+  } while (0)
+
+// kSizeTWithoutLower4Bits is a mask that can be used to zero the lower four
+// bits of a |size_t|.
+static const size_t kSizeTWithoutLower4Bits = (size_t) -16;
+
+static void gcm_init_4bit(u128 Htable[16], uint64_t H[2]) {
+  u128 V;
+
+  Htable[0].hi = 0;
+  Htable[0].lo = 0;
+  V.hi = H[0];
+  V.lo = H[1];
+
+  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;
+
+#if defined(GHASH_ASM) && defined(OPENSSL_ARM)
+  for (int j = 0; j < 16; ++j) {
+    V = Htable[j];
+    Htable[j].hi = V.lo;
+    Htable[j].lo = V.hi;
+  }
+#endif
+}
+
+#if !defined(GHASH_ASM) || defined(OPENSSL_AARCH64) || defined(OPENSSL_PPC64LE)
+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(uint64_t Xi[2], const u128 Htable[16]) {
+  u128 Z;
+  int cnt = 15;
+  size_t rem, nlo, nhi;
+
+  nlo = ((const uint8_t *)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 (sizeof(size_t) == 8) {
+      Z.hi ^= rem_4bit[rem];
+    } else {
+      Z.hi ^= (uint64_t)rem_4bit[rem] << 32;
+    }
+
+    Z.hi ^= Htable[nhi].hi;
+    Z.lo ^= Htable[nhi].lo;
+
+    if (--cnt < 0) {
+      break;
+    }
+
+    nlo = ((const uint8_t *)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 (sizeof(size_t) == 8) {
+      Z.hi ^= rem_4bit[rem];
+    } else {
+      Z.hi ^= (uint64_t)rem_4bit[rem] << 32;
+    }
+
+    Z.hi ^= Htable[nlo].hi;
+    Z.lo ^= Htable[nlo].lo;
+  }
+
+  Xi[0] = CRYPTO_bswap8(Z.hi);
+  Xi[1] = CRYPTO_bswap8(Z.lo);
+}
+
+// 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(uint64_t Xi[2], const u128 Htable[16],
+                           const uint8_t *inp, size_t len) {
+  u128 Z;
+  int cnt;
+  size_t rem, nlo, nhi;
+
+  do {
+    cnt = 15;
+    nlo = ((const uint8_t *)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 (sizeof(size_t) == 8) {
+        Z.hi ^= rem_4bit[rem];
+      } else {
+        Z.hi ^= (uint64_t)rem_4bit[rem] << 32;
+      }
+
+      Z.hi ^= Htable[nhi].hi;
+      Z.lo ^= Htable[nhi].lo;
+
+      if (--cnt < 0) {
+        break;
+      }
+
+      nlo = ((const uint8_t *)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 (sizeof(size_t) == 8) {
+        Z.hi ^= rem_4bit[rem];
+      } else {
+        Z.hi ^= (uint64_t)rem_4bit[rem] << 32;
+      }
+
+      Z.hi ^= Htable[nlo].hi;
+      Z.lo ^= Htable[nlo].lo;
+    }
+
+    Xi[0] = CRYPTO_bswap8(Z.hi);
+    Xi[1] = CRYPTO_bswap8(Z.lo);
+  } while (inp += 16, len -= 16);
+}
+#else  // GHASH_ASM
+void gcm_gmult_4bit(uint64_t Xi[2], const u128 Htable[16]);
+void gcm_ghash_4bit(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                    size_t len);
+#endif
+
+#define GCM_MUL(ctx, Xi) gcm_gmult_4bit((ctx)->Xi.u, (ctx)->Htable)
+#if defined(GHASH_ASM)
+#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
+
+
+#if defined(GHASH_ASM)
+
+#if defined(OPENSSL_X86) || defined(OPENSSL_X86_64)
+#define GCM_FUNCREF_4BIT
+void gcm_init_clmul(u128 Htable[16], const uint64_t Xi[2]);
+void gcm_gmult_clmul(uint64_t Xi[2], const u128 Htable[16]);
+void gcm_ghash_clmul(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                     size_t len);
+
+#if defined(OPENSSL_X86_64)
+#define GHASH_ASM_X86_64
+void gcm_init_avx(u128 Htable[16], const uint64_t Xi[2]);
+void gcm_gmult_avx(uint64_t Xi[2], const u128 Htable[16]);
+void gcm_ghash_avx(uint64_t Xi[2], const u128 Htable[16], const uint8_t *in,
+                   size_t len);
+#define AESNI_GCM
+size_t aesni_gcm_encrypt(const uint8_t *in, uint8_t *out, size_t len,
+                         const void *key, uint8_t ivec[16], uint64_t *Xi);
+size_t aesni_gcm_decrypt(const uint8_t *in, uint8_t *out, size_t len,
+                         const void *key, uint8_t ivec[16], uint64_t *Xi);
+#endif
+
+#if defined(OPENSSL_X86)
+#define GHASH_ASM_X86
+void gcm_gmult_4bit_mmx(uint64_t Xi[2], const u128 Htable[16]);
+void gcm_ghash_4bit_mmx(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                        size_t len);
+#endif
+
+#elif defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)
+#include <openssl/arm_arch.h>
+#if __ARM_ARCH__ >= 7
+#define GHASH_ASM_ARM
+#define GCM_FUNCREF_4BIT
+
+static int pmull_capable(void) {
+  return CRYPTO_is_ARMv8_PMULL_capable();
+}
+
+void gcm_init_v8(u128 Htable[16], const uint64_t Xi[2]);
+void gcm_gmult_v8(uint64_t Xi[2], const u128 Htable[16]);
+void gcm_ghash_v8(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                  size_t len);
+
+#if defined(OPENSSL_ARM)
+// 32-bit ARM also has support for doing GCM with NEON instructions.
+static int neon_capable(void) {
+  return CRYPTO_is_NEON_capable();
+}
+
+void gcm_init_neon(u128 Htable[16], const uint64_t Xi[2]);
+void gcm_gmult_neon(uint64_t Xi[2], const u128 Htable[16]);
+void gcm_ghash_neon(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                    size_t len);
+#else
+// AArch64 only has the ARMv8 versions of functions.
+static int neon_capable(void) {
+  return 0;
+}
+static void gcm_init_neon(u128 Htable[16], const uint64_t Xi[2]) {
+  abort();
+}
+static void gcm_gmult_neon(uint64_t Xi[2], const u128 Htable[16]) {
+  abort();
+}
+static void gcm_ghash_neon(uint64_t Xi[2], const u128 Htable[16],
+                           const uint8_t *inp, size_t len) {
+  abort();
+}
+#endif
+
+#endif
+#elif defined(OPENSSL_PPC64LE)
+#define GHASH_ASM_PPC64LE
+#define GCM_FUNCREF_4BIT
+void gcm_init_p8(u128 Htable[16], const uint64_t Xi[2]);
+void gcm_gmult_p8(uint64_t Xi[2], const u128 Htable[16]);
+void gcm_ghash_p8(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                  size_t len);
+#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_ghash_init(gmult_func *out_mult, ghash_func *out_hash,
+                       u128 *out_key, u128 out_table[16],
+                       int *out_is_avx,
+                       const uint8_t *gcm_key) {
+  *out_is_avx = 0;
+
+  union {
+    uint64_t u[2];
+    uint8_t c[16];
+  } H;
+
+  OPENSSL_memcpy(H.c, gcm_key, 16);
+
+  // H is stored in host byte order
+  H.u[0] = CRYPTO_bswap8(H.u[0]);
+  H.u[1] = CRYPTO_bswap8(H.u[1]);
+
+  OPENSSL_memcpy(out_key, H.c, 16);
+
+#if defined(GHASH_ASM_X86_64)
+  if (crypto_gcm_clmul_enabled()) {
+    if (((OPENSSL_ia32cap_get()[1] >> 22) & 0x41) == 0x41) {  // AVX+MOVBE
+      gcm_init_avx(out_table, H.u);
+      *out_mult = gcm_gmult_avx;
+      *out_hash = gcm_ghash_avx;
+      *out_is_avx = 1;
+      return;
+    }
+    gcm_init_clmul(out_table, H.u);
+    *out_mult = gcm_gmult_clmul;
+    *out_hash = gcm_ghash_clmul;
+    return;
+  }
+#elif defined(GHASH_ASM_X86)
+  if (crypto_gcm_clmul_enabled()) {
+    gcm_init_clmul(out_table, H.u);
+    *out_mult = gcm_gmult_clmul;
+    *out_hash = gcm_ghash_clmul;
+    return;
+  }
+#elif defined(GHASH_ASM_ARM)
+  if (pmull_capable()) {
+    gcm_init_v8(out_table, H.u);
+    *out_mult = gcm_gmult_v8;
+    *out_hash = gcm_ghash_v8;
+    return;
+  }
+
+  if (neon_capable()) {
+    gcm_init_neon(out_table, H.u);
+    *out_mult = gcm_gmult_neon;
+    *out_hash = gcm_ghash_neon;
+    return;
+  }
+#elif defined(GHASH_ASM_PPC64LE)
+  if (CRYPTO_is_PPC64LE_vcrypto_capable()) {
+    gcm_init_p8(out_table, H.u);
+    *out_mult = gcm_gmult_p8;
+    *out_hash = gcm_ghash_p8;
+    return;
+  }
+#endif
+
+  gcm_init_4bit(out_table, H.u);
+#if defined(GHASH_ASM_X86)
+  *out_mult = gcm_gmult_4bit_mmx;
+  *out_hash = gcm_ghash_4bit_mmx;
+#else
+  *out_mult = gcm_gmult_4bit;
+  *out_hash = gcm_ghash_4bit;
+#endif
+}
+
+void CRYPTO_gcm128_init(GCM128_CONTEXT *ctx, const void *aes_key,
+                        block128_f block, int block_is_hwaes) {
+  OPENSSL_memset(ctx, 0, sizeof(*ctx));
+  ctx->block = block;
+
+  uint8_t gcm_key[16];
+  OPENSSL_memset(gcm_key, 0, sizeof(gcm_key));
+  (*block)(gcm_key, gcm_key, aes_key);
+
+  int is_avx;
+  CRYPTO_ghash_init(&ctx->gmult, &ctx->ghash, &ctx->H, ctx->Htable, &is_avx,
+                    gcm_key);
+
+  ctx->use_aesni_gcm_crypt = (is_avx && block_is_hwaes) ? 1 : 0;
+}
+
+void CRYPTO_gcm128_setiv(GCM128_CONTEXT *ctx, const void *key,
+                         const uint8_t *iv, size_t len) {
+  unsigned int ctr;
+#ifdef GCM_FUNCREF_4BIT
+  void (*gcm_gmult_p)(uint64_t 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) {
+    OPENSSL_memcpy(ctx->Yi.c, iv, 12);
+    ctx->Yi.c[15] = 1;
+    ctr = 1;
+  } else {
+    uint64_t len0 = len;
+
+    while (len >= 16) {
+      for (size_t i = 0; i < 16; ++i) {
+        ctx->Yi.c[i] ^= iv[i];
+      }
+      GCM_MUL(ctx, Yi);
+      iv += 16;
+      len -= 16;
+    }
+    if (len) {
+      for (size_t i = 0; i < len; ++i) {
+        ctx->Yi.c[i] ^= iv[i];
+      }
+      GCM_MUL(ctx, Yi);
+    }
+    len0 <<= 3;
+    ctx->Yi.u[1] ^= CRYPTO_bswap8(len0);
+
+    GCM_MUL(ctx, Yi);
+    ctr = CRYPTO_bswap4(ctx->Yi.d[3]);
+  }
+
+  (*ctx->block)(ctx->Yi.c, ctx->EK0.c, key);
+  ++ctr;
+  ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+}
+
+int CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx, const uint8_t *aad, size_t len) {
+  unsigned int n;
+  uint64_t alen = ctx->len.u[0];
+#ifdef GCM_FUNCREF_4BIT
+  void (*gcm_gmult_p)(uint64_t Xi[2], const u128 Htable[16]) = ctx->gmult;
+#ifdef GHASH
+  void (*gcm_ghash_p)(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                      size_t len) = ctx->ghash;
+#endif
+#endif
+
+  if (ctx->len.u[1]) {
+    return 0;
+  }
+
+  alen += len;
+  if (alen > (UINT64_C(1) << 61) || (sizeof(len) == 8 && alen < len)) {
+    return 0;
+  }
+  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 1;
+    }
+  }
+
+  // Process a whole number of blocks.
+#ifdef GHASH
+  size_t len_blocks = len & kSizeTWithoutLower4Bits;
+  if (len_blocks != 0) {
+    GHASH(ctx, aad, len_blocks);
+    aad += len_blocks;
+    len -= len_blocks;
+  }
+#else
+  while (len >= 16) {
+    for (size_t i = 0; i < 16; ++i) {
+      ctx->Xi.c[i] ^= aad[i];
+    }
+    GCM_MUL(ctx, Xi);
+    aad += 16;
+    len -= 16;
+  }
+#endif
+
+  // Process the remainder.
+  if (len != 0) {
+    n = (unsigned int)len;
+    for (size_t i = 0; i < len; ++i) {
+      ctx->Xi.c[i] ^= aad[i];
+    }
+  }
+
+  ctx->ares = n;
+  return 1;
+}
+
+int CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx, const void *key,
+                          const uint8_t *in, uint8_t *out, size_t len) {
+  unsigned int n, ctr;
+  uint64_t mlen = ctx->len.u[1];
+  block128_f block = ctx->block;
+#ifdef GCM_FUNCREF_4BIT
+  void (*gcm_gmult_p)(uint64_t Xi[2], const u128 Htable[16]) = ctx->gmult;
+#ifdef GHASH
+  void (*gcm_ghash_p)(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                      size_t len) = ctx->ghash;
+#endif
+#endif
+
+  mlen += len;
+  if (mlen > ((UINT64_C(1) << 36) - 32) ||
+      (sizeof(len) == 8 && mlen < len)) {
+    return 0;
+  }
+  ctx->len.u[1] = mlen;
+
+  if (ctx->ares) {
+    // First call to encrypt finalizes GHASH(AAD)
+    GCM_MUL(ctx, Xi);
+    ctx->ares = 0;
+  }
+
+  ctr = CRYPTO_bswap4(ctx->Yi.d[3]);
+
+  n = ctx->mres;
+  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 1;
+    }
+  }
+  if (STRICT_ALIGNMENT &&
+      ((uintptr_t)in | (uintptr_t)out) % sizeof(size_t) != 0) {
+    for (size_t i = 0; i < len; ++i) {
+      if (n == 0) {
+        (*block)(ctx->Yi.c, ctx->EKi.c, key);
+        ++ctr;
+        ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+      }
+      ctx->Xi.c[n] ^= out[i] = in[i] ^ ctx->EKi.c[n];
+      n = (n + 1) % 16;
+      if (n == 0) {
+        GCM_MUL(ctx, Xi);
+      }
+    }
+
+    ctx->mres = n;
+    return 1;
+  }
+#if defined(GHASH) && defined(GHASH_CHUNK)
+  while (len >= GHASH_CHUNK) {
+    size_t j = GHASH_CHUNK;
+
+    while (j) {
+      (*block)(ctx->Yi.c, ctx->EKi.c, key);
+      ++ctr;
+      ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+      for (size_t i = 0; i < 16; i += sizeof(size_t)) {
+        store_word_le(out + i,
+                      load_word_le(in + i) ^ ctx->EKi.t[i / sizeof(size_t)]);
+      }
+      out += 16;
+      in += 16;
+      j -= 16;
+    }
+    GHASH(ctx, out - GHASH_CHUNK, GHASH_CHUNK);
+    len -= GHASH_CHUNK;
+  }
+  size_t len_blocks = len & kSizeTWithoutLower4Bits;
+  if (len_blocks != 0) {
+    while (len >= 16) {
+      (*block)(ctx->Yi.c, ctx->EKi.c, key);
+      ++ctr;
+      ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+      for (size_t i = 0; i < 16; i += sizeof(size_t)) {
+        store_word_le(out + i,
+                      load_word_le(in + i) ^ ctx->EKi.t[i / sizeof(size_t)]);
+      }
+      out += 16;
+      in += 16;
+      len -= 16;
+    }
+    GHASH(ctx, out - len_blocks, len_blocks);
+  }
+#else
+  while (len >= 16) {
+    (*block)(ctx->Yi.c, ctx->EKi.c, key);
+    ++ctr;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    for (size_t i = 0; i < 16; i += sizeof(size_t)) {
+      size_t tmp = load_word_le(in + i) ^ ctx->EKi.t[i / sizeof(size_t)];
+      store_word_le(out + i, tmp);
+      ctx->Xi.t[i / sizeof(size_t)] ^= tmp;
+    }
+    GCM_MUL(ctx, Xi);
+    out += 16;
+    in += 16;
+    len -= 16;
+  }
+#endif
+  if (len) {
+    (*block)(ctx->Yi.c, ctx->EKi.c, key);
+    ++ctr;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    while (len--) {
+      ctx->Xi.c[n] ^= out[n] = in[n] ^ ctx->EKi.c[n];
+      ++n;
+    }
+  }
+
+  ctx->mres = n;
+  return 1;
+}
+
+int CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx, const void *key,
+                          const unsigned char *in, unsigned char *out,
+                          size_t len) {
+  unsigned int n, ctr;
+  uint64_t mlen = ctx->len.u[1];
+  block128_f block = ctx->block;
+#ifdef GCM_FUNCREF_4BIT
+  void (*gcm_gmult_p)(uint64_t Xi[2], const u128 Htable[16]) = ctx->gmult;
+#ifdef GHASH
+  void (*gcm_ghash_p)(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                      size_t len) = ctx->ghash;
+#endif
+#endif
+
+  mlen += len;
+  if (mlen > ((UINT64_C(1) << 36) - 32) ||
+      (sizeof(len) == 8 && mlen < len)) {
+    return 0;
+  }
+  ctx->len.u[1] = mlen;
+
+  if (ctx->ares) {
+    // First call to decrypt finalizes GHASH(AAD)
+    GCM_MUL(ctx, Xi);
+    ctx->ares = 0;
+  }
+
+  ctr = CRYPTO_bswap4(ctx->Yi.d[3]);
+
+  n = ctx->mres;
+  if (n) {
+    while (n && len) {
+      uint8_t c = *(in++);
+      *(out++) = c ^ ctx->EKi.c[n];
+      ctx->Xi.c[n] ^= c;
+      --len;
+      n = (n + 1) % 16;
+    }
+    if (n == 0) {
+      GCM_MUL(ctx, Xi);
+    } else {
+      ctx->mres = n;
+      return 1;
+    }
+  }
+  if (STRICT_ALIGNMENT &&
+      ((uintptr_t)in | (uintptr_t)out) % sizeof(size_t) != 0) {
+    for (size_t i = 0; i < len; ++i) {
+      uint8_t c;
+      if (n == 0) {
+        (*block)(ctx->Yi.c, ctx->EKi.c, key);
+        ++ctr;
+        ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+      }
+      c = in[i];
+      out[i] = c ^ ctx->EKi.c[n];
+      ctx->Xi.c[n] ^= c;
+      n = (n + 1) % 16;
+      if (n == 0) {
+        GCM_MUL(ctx, Xi);
+      }
+    }
+
+    ctx->mres = n;
+    return 1;
+  }
+#if defined(GHASH) && defined(GHASH_CHUNK)
+  while (len >= GHASH_CHUNK) {
+    size_t j = GHASH_CHUNK;
+
+    GHASH(ctx, in, GHASH_CHUNK);
+    while (j) {
+      (*block)(ctx->Yi.c, ctx->EKi.c, key);
+      ++ctr;
+      ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+      for (size_t i = 0; i < 16; i += sizeof(size_t)) {
+        store_word_le(out + i,
+                      load_word_le(in + i) ^ ctx->EKi.t[i / sizeof(size_t)]);
+      }
+      out += 16;
+      in += 16;
+      j -= 16;
+    }
+    len -= GHASH_CHUNK;
+  }
+  size_t len_blocks = len & kSizeTWithoutLower4Bits;
+  if (len_blocks != 0) {
+    GHASH(ctx, in, len_blocks);
+    while (len >= 16) {
+      (*block)(ctx->Yi.c, ctx->EKi.c, key);
+      ++ctr;
+      ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+      for (size_t i = 0; i < 16; i += sizeof(size_t)) {
+        store_word_le(out + i,
+                      load_word_le(in + i) ^ ctx->EKi.t[i / sizeof(size_t)]);
+      }
+      out += 16;
+      in += 16;
+      len -= 16;
+    }
+  }
+#else
+  while (len >= 16) {
+    (*block)(ctx->Yi.c, ctx->EKi.c, key);
+    ++ctr;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    for (size_t i = 0; i < 16; i += sizeof(size_t)) {
+      size_t c = load_word_le(in + i);
+      store_word_le(out + i, c ^ ctx->EKi.t[i / sizeof(size_t)]);
+      ctx->Xi.t[i / sizeof(size_t)] ^= c;
+    }
+    GCM_MUL(ctx, Xi);
+    out += 16;
+    in += 16;
+    len -= 16;
+  }
+#endif
+  if (len) {
+    (*block)(ctx->Yi.c, ctx->EKi.c, key);
+    ++ctr;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    while (len--) {
+      uint8_t c = in[n];
+      ctx->Xi.c[n] ^= c;
+      out[n] = c ^ ctx->EKi.c[n];
+      ++n;
+    }
+  }
+
+  ctx->mres = n;
+  return 1;
+}
+
+int CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx, const void *key,
+                                const uint8_t *in, uint8_t *out, size_t len,
+                                ctr128_f stream) {
+  unsigned int n, ctr;
+  uint64_t mlen = ctx->len.u[1];
+#ifdef GCM_FUNCREF_4BIT
+  void (*gcm_gmult_p)(uint64_t Xi[2], const u128 Htable[16]) = ctx->gmult;
+#ifdef GHASH
+  void (*gcm_ghash_p)(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                      size_t len) = ctx->ghash;
+#endif
+#endif
+
+  mlen += len;
+  if (mlen > ((UINT64_C(1) << 36) - 32) ||
+      (sizeof(len) == 8 && mlen < len)) {
+    return 0;
+  }
+  ctx->len.u[1] = mlen;
+
+  if (ctx->ares) {
+    // First call to encrypt finalizes GHASH(AAD)
+    GCM_MUL(ctx, Xi);
+    ctx->ares = 0;
+  }
+
+  n = ctx->mres;
+  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 1;
+    }
+  }
+
+#if defined(AESNI_GCM)
+  if (ctx->use_aesni_gcm_crypt) {
+    // |aesni_gcm_encrypt| may not process all the input given to it. It may
+    // not process *any* of its input if it is deemed too small.
+    size_t bulk = aesni_gcm_encrypt(in, out, len, key, ctx->Yi.c, ctx->Xi.u);
+    in += bulk;
+    out += bulk;
+    len -= bulk;
+  }
+#endif
+
+  ctr = CRYPTO_bswap4(ctx->Yi.d[3]);
+
+#if defined(GHASH)
+  while (len >= GHASH_CHUNK) {
+    (*stream)(in, out, GHASH_CHUNK / 16, key, ctx->Yi.c);
+    ctr += GHASH_CHUNK / 16;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    GHASH(ctx, out, GHASH_CHUNK);
+    out += GHASH_CHUNK;
+    in += GHASH_CHUNK;
+    len -= GHASH_CHUNK;
+  }
+#endif
+  size_t i = len & kSizeTWithoutLower4Bits;
+  if (i != 0) {
+    size_t j = i / 16;
+
+    (*stream)(in, out, j, key, ctx->Yi.c);
+    ctr += (unsigned int)j;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    in += i;
+    len -= i;
+#if defined(GHASH)
+    GHASH(ctx, out, i);
+    out += i;
+#else
+    while (j--) {
+      for (i = 0; i < 16; ++i) {
+        ctx->Xi.c[i] ^= out[i];
+      }
+      GCM_MUL(ctx, Xi);
+      out += 16;
+    }
+#endif
+  }
+  if (len) {
+    (*ctx->block)(ctx->Yi.c, ctx->EKi.c, key);
+    ++ctr;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    while (len--) {
+      ctx->Xi.c[n] ^= out[n] = in[n] ^ ctx->EKi.c[n];
+      ++n;
+    }
+  }
+
+  ctx->mres = n;
+  return 1;
+}
+
+int CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx, const void *key,
+                                const uint8_t *in, uint8_t *out, size_t len,
+                                ctr128_f stream) {
+  unsigned int n, ctr;
+  uint64_t mlen = ctx->len.u[1];
+#ifdef GCM_FUNCREF_4BIT
+  void (*gcm_gmult_p)(uint64_t Xi[2], const u128 Htable[16]) = ctx->gmult;
+#ifdef GHASH
+  void (*gcm_ghash_p)(uint64_t Xi[2], const u128 Htable[16], const uint8_t *inp,
+                      size_t len) = ctx->ghash;
+#endif
+#endif
+
+  mlen += len;
+  if (mlen > ((UINT64_C(1) << 36) - 32) ||
+      (sizeof(len) == 8 && mlen < len)) {
+    return 0;
+  }
+  ctx->len.u[1] = mlen;
+
+  if (ctx->ares) {
+    // First call to decrypt finalizes GHASH(AAD)
+    GCM_MUL(ctx, Xi);
+    ctx->ares = 0;
+  }
+
+  n = ctx->mres;
+  if (n) {
+    while (n && len) {
+      uint8_t c = *(in++);
+      *(out++) = c ^ ctx->EKi.c[n];
+      ctx->Xi.c[n] ^= c;
+      --len;
+      n = (n + 1) % 16;
+    }
+    if (n == 0) {
+      GCM_MUL(ctx, Xi);
+    } else {
+      ctx->mres = n;
+      return 1;
+    }
+  }
+
+#if defined(AESNI_GCM)
+  if (ctx->use_aesni_gcm_crypt) {
+    // |aesni_gcm_decrypt| may not process all the input given to it. It may
+    // not process *any* of its input if it is deemed too small.
+    size_t bulk = aesni_gcm_decrypt(in, out, len, key, ctx->Yi.c, ctx->Xi.u);
+    in += bulk;
+    out += bulk;
+    len -= bulk;
+  }
+#endif
+
+  ctr = CRYPTO_bswap4(ctx->Yi.d[3]);
+
+#if defined(GHASH)
+  while (len >= GHASH_CHUNK) {
+    GHASH(ctx, in, GHASH_CHUNK);
+    (*stream)(in, out, GHASH_CHUNK / 16, key, ctx->Yi.c);
+    ctr += GHASH_CHUNK / 16;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    out += GHASH_CHUNK;
+    in += GHASH_CHUNK;
+    len -= GHASH_CHUNK;
+  }
+#endif
+  size_t i = len & kSizeTWithoutLower4Bits;
+  if (i != 0) {
+    size_t j = i / 16;
+
+#if defined(GHASH)
+    GHASH(ctx, in, i);
+#else
+    while (j--) {
+      size_t k;
+      for (k = 0; k < 16; ++k) {
+        ctx->Xi.c[k] ^= in[k];
+      }
+      GCM_MUL(ctx, Xi);
+      in += 16;
+    }
+    j = i / 16;
+    in -= i;
+#endif
+    (*stream)(in, out, j, key, ctx->Yi.c);
+    ctr += (unsigned int)j;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    out += i;
+    in += i;
+    len -= i;
+  }
+  if (len) {
+    (*ctx->block)(ctx->Yi.c, ctx->EKi.c, key);
+    ++ctr;
+    ctx->Yi.d[3] = CRYPTO_bswap4(ctr);
+    while (len--) {
+      uint8_t c = in[n];
+      ctx->Xi.c[n] ^= c;
+      out[n] = c ^ ctx->EKi.c[n];
+      ++n;
+    }
+  }
+
+  ctx->mres = n;
+  return 1;
+}
+
+int CRYPTO_gcm128_finish(GCM128_CONTEXT *ctx, const uint8_t *tag, size_t len) {
+  uint64_t alen = ctx->len.u[0] << 3;
+  uint64_t clen = ctx->len.u[1] << 3;
+#ifdef GCM_FUNCREF_4BIT
+  void (*gcm_gmult_p)(uint64_t Xi[2], const u128 Htable[16]) = ctx->gmult;
+#endif
+
+  if (ctx->mres || ctx->ares) {
+    GCM_MUL(ctx, Xi);
+  }
+
+  alen = CRYPTO_bswap8(alen);
+  clen = CRYPTO_bswap8(clen);
+
+  ctx->Xi.u[0] ^= alen;
+  ctx->Xi.u[1] ^= clen;
+  GCM_MUL(ctx, Xi);
+
+  ctx->Xi.u[0] ^= ctx->EK0.u[0];
+  ctx->Xi.u[1] ^= ctx->EK0.u[1];
+
+  if (tag && len <= sizeof(ctx->Xi)) {
+    return CRYPTO_memcmp(ctx->Xi.c, tag, len) == 0;
+  } else {
+    return 0;
+  }
+}
+
+void CRYPTO_gcm128_tag(GCM128_CONTEXT *ctx, unsigned char *tag, size_t len) {
+  CRYPTO_gcm128_finish(ctx, NULL, 0);
+  OPENSSL_memcpy(tag, ctx->Xi.c,
+                 len <= sizeof(ctx->Xi.c) ? len : sizeof(ctx->Xi.c));
+}
+
+#if defined(OPENSSL_X86) || defined(OPENSSL_X86_64)
+int crypto_gcm_clmul_enabled(void) {
+#ifdef GHASH_ASM
+  const uint32_t *ia32cap = OPENSSL_ia32cap_get();
+  return (ia32cap[0] & (1 << 24)) &&  // check FXSR bit
+         (ia32cap[1] & (1 << 1));     // check PCLMULQDQ bit
+#else
+  return 0;
+#endif
+}
+#endif