/* ====================================================================
 * Copyright (c) 2001-2011 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 <string.h>

#include <openssl_grpc/aead.h>
#include <openssl_grpc/aes.h>
#include <openssl_grpc/cipher.h>
#include <openssl_grpc/cpu.h>
#include <openssl_grpc/err.h>
#include <openssl_grpc/mem.h>
#include <openssl_grpc/nid.h>
#include <openssl_grpc/rand.h>

#include "internal.h"
#include "../../internal.h"
#include "../aes/internal.h"
#include "../modes/internal.h"
#include "../delocate.h"

#if defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)
#include <openssl_grpc/arm_arch.h>
#endif


OPENSSL_MSVC_PRAGMA(warning(disable: 4702))  // Unreachable code.

typedef struct {
  union {
    double align;
    AES_KEY ks;
  } ks;
  block128_f block;
  union {
    cbc128_f cbc;
    ctr128_f ctr;
  } stream;
} EVP_AES_KEY;

typedef struct {
  union {
    double align;
    AES_KEY ks;
  } ks;         // AES key schedule to use
  int key_set;  // Set if key initialised
  int iv_set;   // Set if an iv is set
  GCM128_CONTEXT gcm;
  uint8_t *iv;  // Temporary IV store
  int ivlen;         // IV length
  int taglen;
  int iv_gen;      // It is OK to generate IVs
  ctr128_f ctr;
} EVP_AES_GCM_CTX;

#if !defined(OPENSSL_NO_ASM) && \
    (defined(OPENSSL_X86_64) || defined(OPENSSL_X86))
#define VPAES
static char vpaes_capable(void) {
  return (OPENSSL_ia32cap_P[1] & (1 << (41 - 32))) != 0;
}

#if defined(OPENSSL_X86_64)
#define BSAES
static char bsaes_capable(void) {
  return vpaes_capable();
}
#endif

#elif !defined(OPENSSL_NO_ASM) && \
    (defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64))

#if defined(OPENSSL_ARM) && __ARM_MAX_ARCH__ >= 7
#define BSAES
static char bsaes_capable(void) {
  return CRYPTO_is_NEON_capable();
}
#endif

#endif


#if defined(BSAES)
// On platforms where BSAES gets defined (just above), then these functions are
// provided by asm.
void bsaes_cbc_encrypt(const uint8_t *in, uint8_t *out, size_t length,
                       const AES_KEY *key, uint8_t ivec[16], int enc);
void bsaes_ctr32_encrypt_blocks(const uint8_t *in, uint8_t *out, size_t len,
                                const AES_KEY *key, const uint8_t ivec[16]);
#else
static char bsaes_capable(void) {
  return 0;
}

// On other platforms, bsaes_capable() will always return false and so the
// following will never be called.
static void bsaes_cbc_encrypt(const uint8_t *in, uint8_t *out, size_t length,
                              const AES_KEY *key, uint8_t ivec[16], int enc) {
  abort();
}

static void bsaes_ctr32_encrypt_blocks(const uint8_t *in, uint8_t *out,
                                       size_t len, const AES_KEY *key,
                                       const uint8_t ivec[16]) {
  abort();
}
#endif

#if defined(VPAES)
// On platforms where VPAES gets defined (just above), then these functions are
// provided by asm.
int vpaes_set_encrypt_key(const uint8_t *userKey, int bits, AES_KEY *key);
int vpaes_set_decrypt_key(const uint8_t *userKey, int bits, AES_KEY *key);

void vpaes_encrypt(const uint8_t *in, uint8_t *out, const AES_KEY *key);
void vpaes_decrypt(const uint8_t *in, uint8_t *out, const AES_KEY *key);

void vpaes_cbc_encrypt(const uint8_t *in, uint8_t *out, size_t length,
                       const AES_KEY *key, uint8_t *ivec, int enc);
#else
static char vpaes_capable(void) {
  return 0;
}

// On other platforms, vpaes_capable() will always return false and so the
// following will never be called.
static int vpaes_set_encrypt_key(const uint8_t *userKey, int bits,
                                 AES_KEY *key) {
  abort();
}
static int vpaes_set_decrypt_key(const uint8_t *userKey, int bits,
                                 AES_KEY *key) {
  abort();
}
static void vpaes_encrypt(const uint8_t *in, uint8_t *out, const AES_KEY *key) {
  abort();
}
static void vpaes_decrypt(const uint8_t *in, uint8_t *out, const AES_KEY *key) {
  abort();
}
static void vpaes_cbc_encrypt(const uint8_t *in, uint8_t *out, size_t length,
                              const AES_KEY *key, uint8_t *ivec, int enc) {
  abort();
}
#endif

#if !defined(OPENSSL_NO_ASM) && \
    (defined(OPENSSL_X86_64) || defined(OPENSSL_X86))
int aesni_set_encrypt_key(const uint8_t *userKey, int bits, AES_KEY *key);
int aesni_set_decrypt_key(const uint8_t *userKey, int bits, AES_KEY *key);

void aesni_encrypt(const uint8_t *in, uint8_t *out, const AES_KEY *key);
void aesni_decrypt(const uint8_t *in, uint8_t *out, const AES_KEY *key);

void aesni_ecb_encrypt(const uint8_t *in, uint8_t *out, size_t length,
                       const AES_KEY *key, int enc);
void aesni_cbc_encrypt(const uint8_t *in, uint8_t *out, size_t length,
                       const AES_KEY *key, uint8_t *ivec, int enc);

#else

// On other platforms, aesni_capable() will always return false and so the
// following will never be called.
static void aesni_encrypt(const uint8_t *in, uint8_t *out, const AES_KEY *key) {
  abort();
}
static int aesni_set_encrypt_key(const uint8_t *userKey, int bits,
                                 AES_KEY *key) {
  abort();
}
static void aesni_ctr32_encrypt_blocks(const uint8_t *in, uint8_t *out,
                                       size_t blocks, const void *key,
                                       const uint8_t *ivec) {
  abort();
}

#endif

static int aes_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,
                        const uint8_t *iv, int enc) {
  int ret, mode;
  EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;

  mode = ctx->cipher->flags & EVP_CIPH_MODE_MASK;
  if ((mode == EVP_CIPH_ECB_MODE || mode == EVP_CIPH_CBC_MODE) && !enc) {
    if (hwaes_capable()) {
      ret = aes_hw_set_decrypt_key(key, ctx->key_len * 8, &dat->ks.ks);
      dat->block = (block128_f)aes_hw_decrypt;
      dat->stream.cbc = NULL;
      if (mode == EVP_CIPH_CBC_MODE) {
        dat->stream.cbc = (cbc128_f)aes_hw_cbc_encrypt;
      }
    } else if (bsaes_capable() && mode == EVP_CIPH_CBC_MODE) {
      ret = AES_set_decrypt_key(key, ctx->key_len * 8, &dat->ks.ks);
      dat->block = (block128_f)AES_decrypt;
      dat->stream.cbc = (cbc128_f)bsaes_cbc_encrypt;
    } else if (vpaes_capable()) {
      ret = vpaes_set_decrypt_key(key, ctx->key_len * 8, &dat->ks.ks);
      dat->block = (block128_f)vpaes_decrypt;
      dat->stream.cbc =
          mode == EVP_CIPH_CBC_MODE ? (cbc128_f)vpaes_cbc_encrypt : NULL;
    } else {
      ret = AES_set_decrypt_key(key, ctx->key_len * 8, &dat->ks.ks);
      dat->block = (block128_f)AES_decrypt;
      dat->stream.cbc =
          mode == EVP_CIPH_CBC_MODE ? (cbc128_f)AES_cbc_encrypt : NULL;
    }
  } else if (hwaes_capable()) {
    ret = aes_hw_set_encrypt_key(key, ctx->key_len * 8, &dat->ks.ks);
    dat->block = (block128_f)aes_hw_encrypt;
    dat->stream.cbc = NULL;
    if (mode == EVP_CIPH_CBC_MODE) {
      dat->stream.cbc = (cbc128_f)aes_hw_cbc_encrypt;
    } else if (mode == EVP_CIPH_CTR_MODE) {
      dat->stream.ctr = (ctr128_f)aes_hw_ctr32_encrypt_blocks;
    }
  } else if (bsaes_capable() && mode == EVP_CIPH_CTR_MODE) {
    ret = AES_set_encrypt_key(key, ctx->key_len * 8, &dat->ks.ks);
    dat->block = (block128_f)AES_encrypt;
    dat->stream.ctr = (ctr128_f)bsaes_ctr32_encrypt_blocks;
  } else if (vpaes_capable()) {
    ret = vpaes_set_encrypt_key(key, ctx->key_len * 8, &dat->ks.ks);
    dat->block = (block128_f)vpaes_encrypt;
    dat->stream.cbc =
        mode == EVP_CIPH_CBC_MODE ? (cbc128_f)vpaes_cbc_encrypt : NULL;
  } else {
    ret = AES_set_encrypt_key(key, ctx->key_len * 8, &dat->ks.ks);
    dat->block = (block128_f)AES_encrypt;
    dat->stream.cbc =
        mode == EVP_CIPH_CBC_MODE ? (cbc128_f)AES_cbc_encrypt : NULL;
  }

  if (ret < 0) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_AES_KEY_SETUP_FAILED);
    return 0;
  }

  return 1;
}

static int aes_cbc_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out, const uint8_t *in,
                          size_t len) {
  EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;

  if (dat->stream.cbc) {
    (*dat->stream.cbc)(in, out, len, &dat->ks, ctx->iv, ctx->encrypt);
  } else if (ctx->encrypt) {
    CRYPTO_cbc128_encrypt(in, out, len, &dat->ks, ctx->iv, dat->block);
  } else {
    CRYPTO_cbc128_decrypt(in, out, len, &dat->ks, ctx->iv, dat->block);
  }

  return 1;
}

static int aes_ecb_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out, const uint8_t *in,
                          size_t len) {
  size_t bl = ctx->cipher->block_size;
  EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;

  if (len < bl) {
    return 1;
  }

  len -= bl;
  for (size_t i = 0; i <= len; i += bl) {
    (*dat->block)(in + i, out + i, &dat->ks);
  }

  return 1;
}

static int aes_ctr_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out, const uint8_t *in,
                          size_t len) {
  EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;

  if (dat->stream.ctr) {
    CRYPTO_ctr128_encrypt_ctr32(in, out, len, &dat->ks, ctx->iv, ctx->buf,
                                &ctx->num, dat->stream.ctr);
  } else {
    CRYPTO_ctr128_encrypt(in, out, len, &dat->ks, ctx->iv, ctx->buf, &ctx->num,
                          dat->block);
  }
  return 1;
}

static int aes_ofb_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out, const uint8_t *in,
                          size_t len) {
  EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;

  CRYPTO_ofb128_encrypt(in, out, len, &dat->ks, ctx->iv, &ctx->num, dat->block);
  return 1;
}

static char aesni_capable(void);

ctr128_f aes_ctr_set_key(AES_KEY *aes_key, GCM128_CONTEXT *gcm_ctx,
                         block128_f *out_block, const uint8_t *key,
                         size_t key_bytes) {
  if (aesni_capable()) {
    aesni_set_encrypt_key(key, key_bytes * 8, aes_key);
    if (gcm_ctx != NULL) {
      CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)aesni_encrypt, 1);
    }
    if (out_block) {
      *out_block = (block128_f) aesni_encrypt;
    }
    return (ctr128_f)aesni_ctr32_encrypt_blocks;
  }

  if (hwaes_capable()) {
    aes_hw_set_encrypt_key(key, key_bytes * 8, aes_key);
    if (gcm_ctx != NULL) {
      CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)aes_hw_encrypt, 0);
    }
    if (out_block) {
      *out_block = (block128_f) aes_hw_encrypt;
    }
    return (ctr128_f)aes_hw_ctr32_encrypt_blocks;
  }

  if (bsaes_capable()) {
    AES_set_encrypt_key(key, key_bytes * 8, aes_key);
    if (gcm_ctx != NULL) {
      CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)AES_encrypt, 0);
    }
    if (out_block) {
      *out_block = (block128_f) AES_encrypt;
    }
    return (ctr128_f)bsaes_ctr32_encrypt_blocks;
  }

  if (vpaes_capable()) {
    vpaes_set_encrypt_key(key, key_bytes * 8, aes_key);
    if (out_block) {
      *out_block = (block128_f) vpaes_encrypt;
    }
    if (gcm_ctx != NULL) {
      CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)vpaes_encrypt, 0);
    }
    return NULL;
  }

  AES_set_encrypt_key(key, key_bytes * 8, aes_key);
  if (gcm_ctx != NULL) {
    CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)AES_encrypt, 0);
  }
  if (out_block) {
    *out_block = (block128_f) AES_encrypt;
  }
  return NULL;
}

static int aes_gcm_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,
                            const uint8_t *iv, int enc) {
  EVP_AES_GCM_CTX *gctx = ctx->cipher_data;
  if (!iv && !key) {
    return 1;
  }
  if (key) {
    gctx->ctr =
        aes_ctr_set_key(&gctx->ks.ks, &gctx->gcm, NULL, key, ctx->key_len);
    // If we have an iv can set it directly, otherwise use saved IV.
    if (iv == NULL && gctx->iv_set) {
      iv = gctx->iv;
    }
    if (iv) {
      CRYPTO_gcm128_setiv(&gctx->gcm, &gctx->ks.ks, iv, gctx->ivlen);
      gctx->iv_set = 1;
    }
    gctx->key_set = 1;
  } else {
    // If key set use IV, otherwise copy
    if (gctx->key_set) {
      CRYPTO_gcm128_setiv(&gctx->gcm, &gctx->ks.ks, iv, gctx->ivlen);
    } else {
      OPENSSL_memcpy(gctx->iv, iv, gctx->ivlen);
    }
    gctx->iv_set = 1;
    gctx->iv_gen = 0;
  }
  return 1;
}

static void aes_gcm_cleanup(EVP_CIPHER_CTX *c) {
  EVP_AES_GCM_CTX *gctx = c->cipher_data;
  OPENSSL_cleanse(&gctx->gcm, sizeof(gctx->gcm));
  if (gctx->iv != c->iv) {
    OPENSSL_free(gctx->iv);
  }
}

// increment counter (64-bit int) by 1
static void ctr64_inc(uint8_t *counter) {
  int n = 8;
  uint8_t c;

  do {
    --n;
    c = counter[n];
    ++c;
    counter[n] = c;
    if (c) {
      return;
    }
  } while (n);
}

static int aes_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr) {
  EVP_AES_GCM_CTX *gctx = c->cipher_data;
  switch (type) {
    case EVP_CTRL_INIT:
      gctx->key_set = 0;
      gctx->iv_set = 0;
      gctx->ivlen = c->cipher->iv_len;
      gctx->iv = c->iv;
      gctx->taglen = -1;
      gctx->iv_gen = 0;
      return 1;

    case EVP_CTRL_GCM_SET_IVLEN:
      if (arg <= 0) {
        return 0;
      }

      // Allocate memory for IV if needed
      if (arg > EVP_MAX_IV_LENGTH && arg > gctx->ivlen) {
        if (gctx->iv != c->iv) {
          OPENSSL_free(gctx->iv);
        }
        gctx->iv = OPENSSL_malloc(arg);
        if (!gctx->iv) {
          return 0;
        }
      }
      gctx->ivlen = arg;
      return 1;

    case EVP_CTRL_GCM_SET_TAG:
      if (arg <= 0 || arg > 16 || c->encrypt) {
        return 0;
      }
      OPENSSL_memcpy(c->buf, ptr, arg);
      gctx->taglen = arg;
      return 1;

    case EVP_CTRL_GCM_GET_TAG:
      if (arg <= 0 || arg > 16 || !c->encrypt || gctx->taglen < 0) {
        return 0;
      }
      OPENSSL_memcpy(ptr, c->buf, arg);
      return 1;

    case EVP_CTRL_GCM_SET_IV_FIXED:
      // Special case: -1 length restores whole IV
      if (arg == -1) {
        OPENSSL_memcpy(gctx->iv, ptr, gctx->ivlen);
        gctx->iv_gen = 1;
        return 1;
      }
      // Fixed field must be at least 4 bytes and invocation field
      // at least 8.
      if (arg < 4 || (gctx->ivlen - arg) < 8) {
        return 0;
      }
      if (arg) {
        OPENSSL_memcpy(gctx->iv, ptr, arg);
      }
      if (c->encrypt && !RAND_bytes(gctx->iv + arg, gctx->ivlen - arg)) {
        return 0;
      }
      gctx->iv_gen = 1;
      return 1;

    case EVP_CTRL_GCM_IV_GEN:
      if (gctx->iv_gen == 0 || gctx->key_set == 0) {
        return 0;
      }
      CRYPTO_gcm128_setiv(&gctx->gcm, &gctx->ks.ks, gctx->iv, gctx->ivlen);
      if (arg <= 0 || arg > gctx->ivlen) {
        arg = gctx->ivlen;
      }
      OPENSSL_memcpy(ptr, gctx->iv + gctx->ivlen - arg, arg);
      // Invocation field will be at least 8 bytes in size and
      // so no need to check wrap around or increment more than
      // last 8 bytes.
      ctr64_inc(gctx->iv + gctx->ivlen - 8);
      gctx->iv_set = 1;
      return 1;

    case EVP_CTRL_GCM_SET_IV_INV:
      if (gctx->iv_gen == 0 || gctx->key_set == 0 || c->encrypt) {
        return 0;
      }
      OPENSSL_memcpy(gctx->iv + gctx->ivlen - arg, ptr, arg);
      CRYPTO_gcm128_setiv(&gctx->gcm, &gctx->ks.ks, gctx->iv, gctx->ivlen);
      gctx->iv_set = 1;
      return 1;

    case EVP_CTRL_COPY: {
      EVP_CIPHER_CTX *out = ptr;
      EVP_AES_GCM_CTX *gctx_out = out->cipher_data;
      if (gctx->iv == c->iv) {
        gctx_out->iv = out->iv;
      } else {
        gctx_out->iv = OPENSSL_malloc(gctx->ivlen);
        if (!gctx_out->iv) {
          return 0;
        }
        OPENSSL_memcpy(gctx_out->iv, gctx->iv, gctx->ivlen);
      }
      return 1;
    }

    default:
      return -1;
  }
}

static int aes_gcm_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out, const uint8_t *in,
                          size_t len) {
  EVP_AES_GCM_CTX *gctx = ctx->cipher_data;

  // If not set up, return error
  if (!gctx->key_set) {
    return -1;
  }
  if (!gctx->iv_set) {
    return -1;
  }

  if (in) {
    if (out == NULL) {
      if (!CRYPTO_gcm128_aad(&gctx->gcm, in, len)) {
        return -1;
      }
    } else if (ctx->encrypt) {
      if (gctx->ctr) {
        if (!CRYPTO_gcm128_encrypt_ctr32(&gctx->gcm, &gctx->ks.ks, in, out, len,
                                         gctx->ctr)) {
          return -1;
        }
      } else {
        if (!CRYPTO_gcm128_encrypt(&gctx->gcm, &gctx->ks.ks, in, out, len)) {
          return -1;
        }
      }
    } else {
      if (gctx->ctr) {
        if (!CRYPTO_gcm128_decrypt_ctr32(&gctx->gcm, &gctx->ks.ks, in, out, len,
                                         gctx->ctr)) {
          return -1;
        }
      } else {
        if (!CRYPTO_gcm128_decrypt(&gctx->gcm, &gctx->ks.ks, in, out, len)) {
          return -1;
        }
      }
    }
    return len;
  } else {
    if (!ctx->encrypt) {
      if (gctx->taglen < 0 ||
          !CRYPTO_gcm128_finish(&gctx->gcm, ctx->buf, gctx->taglen)) {
        return -1;
      }
      gctx->iv_set = 0;
      return 0;
    }
    CRYPTO_gcm128_tag(&gctx->gcm, ctx->buf, 16);
    gctx->taglen = 16;
    // Don't reuse the IV
    gctx->iv_set = 0;
    return 0;
  }
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_128_cbc_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_cbc;
  out->block_size = 16;
  out->key_len = 16;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CBC_MODE;
  out->init = aes_init_key;
  out->cipher = aes_cbc_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_128_ctr_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_ctr;
  out->block_size = 1;
  out->key_len = 16;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CTR_MODE;
  out->init = aes_init_key;
  out->cipher = aes_ctr_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_128_ecb_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_ecb;
  out->block_size = 16;
  out->key_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_ECB_MODE;
  out->init = aes_init_key;
  out->cipher = aes_ecb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_128_ofb_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_ofb128;
  out->block_size = 1;
  out->key_len = 16;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_OFB_MODE;
  out->init = aes_init_key;
  out->cipher = aes_ofb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_128_gcm_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_gcm;
  out->block_size = 1;
  out->key_len = 16;
  out->iv_len = 12;
  out->ctx_size = sizeof(EVP_AES_GCM_CTX);
  out->flags = EVP_CIPH_GCM_MODE | EVP_CIPH_CUSTOM_IV |
               EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT |
               EVP_CIPH_CTRL_INIT | EVP_CIPH_FLAG_AEAD_CIPHER;
  out->init = aes_gcm_init_key;
  out->cipher = aes_gcm_cipher;
  out->cleanup = aes_gcm_cleanup;
  out->ctrl = aes_gcm_ctrl;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_192_cbc_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_192_cbc;
  out->block_size = 16;
  out->key_len = 24;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CBC_MODE;
  out->init = aes_init_key;
  out->cipher = aes_cbc_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_192_ctr_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_192_ctr;
  out->block_size = 1;
  out->key_len = 24;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CTR_MODE;
  out->init = aes_init_key;
  out->cipher = aes_ctr_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_192_ecb_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_192_ecb;
  out->block_size = 16;
  out->key_len = 24;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_ECB_MODE;
  out->init = aes_init_key;
  out->cipher = aes_ecb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_192_gcm_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_192_gcm;
  out->block_size = 1;
  out->key_len = 24;
  out->iv_len = 12;
  out->ctx_size = sizeof(EVP_AES_GCM_CTX);
  out->flags = EVP_CIPH_GCM_MODE | EVP_CIPH_CUSTOM_IV |
               EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT |
               EVP_CIPH_CTRL_INIT | EVP_CIPH_FLAG_AEAD_CIPHER;
  out->init = aes_gcm_init_key;
  out->cipher = aes_gcm_cipher;
  out->cleanup = aes_gcm_cleanup;
  out->ctrl = aes_gcm_ctrl;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_256_cbc_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_cbc;
  out->block_size = 16;
  out->key_len = 32;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CBC_MODE;
  out->init = aes_init_key;
  out->cipher = aes_cbc_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_256_ctr_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_ctr;
  out->block_size = 1;
  out->key_len = 32;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CTR_MODE;
  out->init = aes_init_key;
  out->cipher = aes_ctr_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_256_ecb_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_ecb;
  out->block_size = 16;
  out->key_len = 32;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_ECB_MODE;
  out->init = aes_init_key;
  out->cipher = aes_ecb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_256_ofb_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_ofb128;
  out->block_size = 1;
  out->key_len = 32;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_OFB_MODE;
  out->init = aes_init_key;
  out->cipher = aes_ofb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aes_256_gcm_generic) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_gcm;
  out->block_size = 1;
  out->key_len = 32;
  out->iv_len = 12;
  out->ctx_size = sizeof(EVP_AES_GCM_CTX);
  out->flags = EVP_CIPH_GCM_MODE | EVP_CIPH_CUSTOM_IV |
               EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT |
               EVP_CIPH_CTRL_INIT | EVP_CIPH_FLAG_AEAD_CIPHER;
  out->init = aes_gcm_init_key;
  out->cipher = aes_gcm_cipher;
  out->cleanup = aes_gcm_cleanup;
  out->ctrl = aes_gcm_ctrl;
}

#if !defined(OPENSSL_NO_ASM) && \
    (defined(OPENSSL_X86_64) || defined(OPENSSL_X86))

// AES-NI section.

static char aesni_capable(void) {
  return (OPENSSL_ia32cap_P[1] & (1 << (57 - 32))) != 0;
}

static int aesni_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,
                          const uint8_t *iv, int enc) {
  int ret, mode;
  EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;

  mode = ctx->cipher->flags & EVP_CIPH_MODE_MASK;
  if ((mode == EVP_CIPH_ECB_MODE || mode == EVP_CIPH_CBC_MODE) && !enc) {
    ret = aesni_set_decrypt_key(key, ctx->key_len * 8, ctx->cipher_data);
    dat->block = (block128_f)aesni_decrypt;
    dat->stream.cbc =
        mode == EVP_CIPH_CBC_MODE ? (cbc128_f)aesni_cbc_encrypt : NULL;
  } else {
    ret = aesni_set_encrypt_key(key, ctx->key_len * 8, ctx->cipher_data);
    dat->block = (block128_f)aesni_encrypt;
    if (mode == EVP_CIPH_CBC_MODE) {
      dat->stream.cbc = (cbc128_f)aesni_cbc_encrypt;
    } else if (mode == EVP_CIPH_CTR_MODE) {
      dat->stream.ctr = (ctr128_f)aesni_ctr32_encrypt_blocks;
    } else {
      dat->stream.cbc = NULL;
    }
  }

  if (ret < 0) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_AES_KEY_SETUP_FAILED);
    return 0;
  }

  return 1;
}

static int aesni_cbc_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out,
                            const uint8_t *in, size_t len) {
  aesni_cbc_encrypt(in, out, len, ctx->cipher_data, ctx->iv, ctx->encrypt);

  return 1;
}

static int aesni_ecb_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out,
                            const uint8_t *in, size_t len) {
  size_t bl = ctx->cipher->block_size;

  if (len < bl) {
    return 1;
  }

  aesni_ecb_encrypt(in, out, len, ctx->cipher_data, ctx->encrypt);

  return 1;
}

static int aesni_gcm_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,
                              const uint8_t *iv, int enc) {
  EVP_AES_GCM_CTX *gctx = ctx->cipher_data;
  if (!iv && !key) {
    return 1;
  }
  if (key) {
    aesni_set_encrypt_key(key, ctx->key_len * 8, &gctx->ks.ks);
    CRYPTO_gcm128_init(&gctx->gcm, &gctx->ks, (block128_f)aesni_encrypt, 1);
    gctx->ctr = (ctr128_f)aesni_ctr32_encrypt_blocks;
    // If we have an iv can set it directly, otherwise use
    // saved IV.
    if (iv == NULL && gctx->iv_set) {
      iv = gctx->iv;
    }
    if (iv) {
      CRYPTO_gcm128_setiv(&gctx->gcm, &gctx->ks.ks, iv, gctx->ivlen);
      gctx->iv_set = 1;
    }
    gctx->key_set = 1;
  } else {
    // If key set use IV, otherwise copy
    if (gctx->key_set) {
      CRYPTO_gcm128_setiv(&gctx->gcm, &gctx->ks.ks, iv, gctx->ivlen);
    } else {
      OPENSSL_memcpy(gctx->iv, iv, gctx->ivlen);
    }
    gctx->iv_set = 1;
    gctx->iv_gen = 0;
  }
  return 1;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_128_cbc) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_cbc;
  out->block_size = 16;
  out->key_len = 16;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CBC_MODE;
  out->init = aesni_init_key;
  out->cipher = aesni_cbc_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_128_ctr) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_ctr;
  out->block_size = 1;
  out->key_len = 16;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CTR_MODE;
  out->init = aesni_init_key;
  out->cipher = aes_ctr_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_128_ecb) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_ecb;
  out->block_size = 16;
  out->key_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_ECB_MODE;
  out->init = aesni_init_key;
  out->cipher = aesni_ecb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_128_ofb) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_ofb128;
  out->block_size = 1;
  out->key_len = 16;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_OFB_MODE;
  out->init = aesni_init_key;
  out->cipher = aes_ofb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_128_gcm) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_128_gcm;
  out->block_size = 1;
  out->key_len = 16;
  out->iv_len = 12;
  out->ctx_size = sizeof(EVP_AES_GCM_CTX);
  out->flags = EVP_CIPH_GCM_MODE | EVP_CIPH_CUSTOM_IV |
               EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT |
               EVP_CIPH_CTRL_INIT | EVP_CIPH_FLAG_AEAD_CIPHER;
  out->init = aesni_gcm_init_key;
  out->cipher = aes_gcm_cipher;
  out->cleanup = aes_gcm_cleanup;
  out->ctrl = aes_gcm_ctrl;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_192_cbc) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_192_cbc;
  out->block_size = 16;
  out->key_len = 24;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CBC_MODE;
  out->init = aesni_init_key;
  out->cipher = aesni_cbc_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_192_ctr) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_192_ctr;
  out->block_size = 1;
  out->key_len = 24;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CTR_MODE;
  out->init = aesni_init_key;
  out->cipher = aes_ctr_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_192_ecb) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_192_ecb;
  out->block_size = 16;
  out->key_len = 24;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_ECB_MODE;
  out->init = aesni_init_key;
  out->cipher = aesni_ecb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_192_gcm) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_192_gcm;
  out->block_size = 1;
  out->key_len = 24;
  out->iv_len = 12;
  out->ctx_size = sizeof(EVP_AES_GCM_CTX);
  out->flags = EVP_CIPH_GCM_MODE | EVP_CIPH_CUSTOM_IV |
               EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT |
               EVP_CIPH_CTRL_INIT | EVP_CIPH_FLAG_AEAD_CIPHER;
  out->init = aesni_gcm_init_key;
  out->cipher = aes_gcm_cipher;
  out->cleanup = aes_gcm_cleanup;
  out->ctrl = aes_gcm_ctrl;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_256_cbc) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_cbc;
  out->block_size = 16;
  out->key_len = 32;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CBC_MODE;
  out->init = aesni_init_key;
  out->cipher = aesni_cbc_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_256_ctr) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_ctr;
  out->block_size = 1;
  out->key_len = 32;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_CTR_MODE;
  out->init = aesni_init_key;
  out->cipher = aes_ctr_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_256_ecb) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_ecb;
  out->block_size = 16;
  out->key_len = 32;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_ECB_MODE;
  out->init = aesni_init_key;
  out->cipher = aesni_ecb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_256_ofb) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_ofb128;
  out->block_size = 1;
  out->key_len = 32;
  out->iv_len = 16;
  out->ctx_size = sizeof(EVP_AES_KEY);
  out->flags = EVP_CIPH_OFB_MODE;
  out->init = aesni_init_key;
  out->cipher = aes_ofb_cipher;
}

DEFINE_LOCAL_DATA(EVP_CIPHER, aesni_256_gcm) {
  memset(out, 0, sizeof(EVP_CIPHER));

  out->nid = NID_aes_256_gcm;
  out->block_size = 1;
  out->key_len = 32;
  out->iv_len = 12;
  out->ctx_size = sizeof(EVP_AES_GCM_CTX);
  out->flags = EVP_CIPH_GCM_MODE | EVP_CIPH_CUSTOM_IV |
               EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT |
               EVP_CIPH_CTRL_INIT | EVP_CIPH_CUSTOM_COPY |
               EVP_CIPH_FLAG_AEAD_CIPHER;
  out->init = aesni_gcm_init_key;
  out->cipher = aes_gcm_cipher;
  out->cleanup = aes_gcm_cleanup;
  out->ctrl = aes_gcm_ctrl;
}

#define EVP_CIPHER_FUNCTION(keybits, mode)             \
  const EVP_CIPHER *EVP_aes_##keybits##_##mode(void) { \
    if (aesni_capable()) {                             \
      return aesni_##keybits##_##mode();               \
    } else {                                           \
      return aes_##keybits##_##mode##_generic();       \
    }                                                  \
  }

#else  // ^^^  OPENSSL_X86_64 || OPENSSL_X86

static char aesni_capable(void) {
  return 0;
}

#define EVP_CIPHER_FUNCTION(keybits, mode)             \
  const EVP_CIPHER *EVP_aes_##keybits##_##mode(void) { \
    return aes_##keybits##_##mode##_generic();         \
  }

#endif

EVP_CIPHER_FUNCTION(128, cbc)
EVP_CIPHER_FUNCTION(128, ctr)
EVP_CIPHER_FUNCTION(128, ecb)
EVP_CIPHER_FUNCTION(128, ofb)
EVP_CIPHER_FUNCTION(128, gcm)

EVP_CIPHER_FUNCTION(192, cbc)
EVP_CIPHER_FUNCTION(192, ctr)
EVP_CIPHER_FUNCTION(192, ecb)
EVP_CIPHER_FUNCTION(192, gcm)

EVP_CIPHER_FUNCTION(256, cbc)
EVP_CIPHER_FUNCTION(256, ctr)
EVP_CIPHER_FUNCTION(256, ecb)
EVP_CIPHER_FUNCTION(256, ofb)
EVP_CIPHER_FUNCTION(256, gcm)


#define EVP_AEAD_AES_GCM_TAG_LEN 16

struct aead_aes_gcm_ctx {
  union {
    double align;
    AES_KEY ks;
  } ks;
  GCM128_CONTEXT gcm;
  ctr128_f ctr;
};

struct aead_aes_gcm_tls12_ctx {
  struct aead_aes_gcm_ctx gcm_ctx;
  uint64_t min_next_nonce;
};

static int aead_aes_gcm_init_impl(struct aead_aes_gcm_ctx *gcm_ctx,
                                  size_t *out_tag_len, const uint8_t *key,
                                  size_t key_len, size_t tag_len) {
  const size_t key_bits = key_len * 8;

  if (key_bits != 128 && key_bits != 256) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_KEY_LENGTH);
    return 0;  // EVP_AEAD_CTX_init should catch this.
  }

  if (tag_len == EVP_AEAD_DEFAULT_TAG_LENGTH) {
    tag_len = EVP_AEAD_AES_GCM_TAG_LEN;
  }

  if (tag_len > EVP_AEAD_AES_GCM_TAG_LEN) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TAG_TOO_LARGE);
    return 0;
  }

  gcm_ctx->ctr =
      aes_ctr_set_key(&gcm_ctx->ks.ks, &gcm_ctx->gcm, NULL, key, key_len);
  *out_tag_len = tag_len;
  return 1;
}

static int aead_aes_gcm_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
                             size_t key_len, size_t requested_tag_len) {
  struct aead_aes_gcm_ctx *gcm_ctx;
  gcm_ctx = OPENSSL_malloc(sizeof(struct aead_aes_gcm_ctx));
  if (gcm_ctx == NULL) {
    return 0;
  }

  size_t actual_tag_len;
  if (!aead_aes_gcm_init_impl(gcm_ctx, &actual_tag_len, key, key_len,
                              requested_tag_len)) {
    OPENSSL_free(gcm_ctx);
    return 0;
  }

  ctx->aead_state = gcm_ctx;
  ctx->tag_len = actual_tag_len;
  return 1;
}

static void aead_aes_gcm_cleanup(EVP_AEAD_CTX *ctx) {
  OPENSSL_free(ctx->aead_state);
}

static int aead_aes_gcm_seal_scatter(const EVP_AEAD_CTX *ctx, uint8_t *out,
                                     uint8_t *out_tag, size_t *out_tag_len,
                                     size_t max_out_tag_len,
                                     const uint8_t *nonce, size_t nonce_len,
                                     const uint8_t *in, size_t in_len,
                                     const uint8_t *extra_in,
                                     size_t extra_in_len,
                                     const uint8_t *ad, size_t ad_len) {
  const struct aead_aes_gcm_ctx *gcm_ctx = ctx->aead_state;
  GCM128_CONTEXT gcm;

  if (extra_in_len + ctx->tag_len < ctx->tag_len) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);
    return 0;
  }
  if (max_out_tag_len < extra_in_len + ctx->tag_len) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
    return 0;
  }
  if (nonce_len == 0) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_NONCE_SIZE);
    return 0;
  }

  const AES_KEY *key = &gcm_ctx->ks.ks;

  OPENSSL_memcpy(&gcm, &gcm_ctx->gcm, sizeof(gcm));
  CRYPTO_gcm128_setiv(&gcm, key, nonce, nonce_len);

  if (ad_len > 0 && !CRYPTO_gcm128_aad(&gcm, ad, ad_len)) {
    return 0;
  }

  if (gcm_ctx->ctr) {
    if (!CRYPTO_gcm128_encrypt_ctr32(&gcm, key, in, out, in_len,
                                     gcm_ctx->ctr)) {
      return 0;
    }
  } else {
    if (!CRYPTO_gcm128_encrypt(&gcm, key, in, out, in_len)) {
      return 0;
    }
  }

  if (extra_in_len) {
    if (gcm_ctx->ctr) {
      if (!CRYPTO_gcm128_encrypt_ctr32(&gcm, key, extra_in, out_tag,
                                       extra_in_len, gcm_ctx->ctr)) {
        return 0;
      }
    } else {
      if (!CRYPTO_gcm128_encrypt(&gcm, key, extra_in, out_tag, extra_in_len)) {
        return 0;
      }
    }
  }

  CRYPTO_gcm128_tag(&gcm, out_tag + extra_in_len, ctx->tag_len);
  *out_tag_len = ctx->tag_len + extra_in_len;

  return 1;
}

static int aead_aes_gcm_open_gather(const EVP_AEAD_CTX *ctx, uint8_t *out,
                                    const uint8_t *nonce, size_t nonce_len,
                                    const uint8_t *in, size_t in_len,
                                    const uint8_t *in_tag, size_t in_tag_len,
                                    const uint8_t *ad, size_t ad_len) {
  const struct aead_aes_gcm_ctx *gcm_ctx = ctx->aead_state;
  uint8_t tag[EVP_AEAD_AES_GCM_TAG_LEN];
  GCM128_CONTEXT gcm;

  if (nonce_len == 0) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_NONCE_SIZE);
    return 0;
  }

  if (in_tag_len != ctx->tag_len) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
    return 0;
  }

  const AES_KEY *key = &gcm_ctx->ks.ks;

  OPENSSL_memcpy(&gcm, &gcm_ctx->gcm, sizeof(gcm));
  CRYPTO_gcm128_setiv(&gcm, key, nonce, nonce_len);

  if (!CRYPTO_gcm128_aad(&gcm, ad, ad_len)) {
    return 0;
  }

  if (gcm_ctx->ctr) {
    if (!CRYPTO_gcm128_decrypt_ctr32(&gcm, key, in, out, in_len,
                                     gcm_ctx->ctr)) {
      return 0;
    }
  } else {
    if (!CRYPTO_gcm128_decrypt(&gcm, key, in, out, in_len)) {
      return 0;
    }
  }

  CRYPTO_gcm128_tag(&gcm, tag, ctx->tag_len);
  if (CRYPTO_memcmp(tag, in_tag, ctx->tag_len) != 0) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
    return 0;
  }

  return 1;
}

DEFINE_METHOD_FUNCTION(EVP_AEAD, EVP_aead_aes_128_gcm) {
  memset(out, 0, sizeof(EVP_AEAD));

  out->key_len = 16;
  out->nonce_len = 12;
  out->overhead = EVP_AEAD_AES_GCM_TAG_LEN;
  out->max_tag_len = EVP_AEAD_AES_GCM_TAG_LEN;
  out->seal_scatter_supports_extra_in = 1;

  out->init = aead_aes_gcm_init;
  out->cleanup = aead_aes_gcm_cleanup;
  out->seal_scatter = aead_aes_gcm_seal_scatter;
  out->open_gather = aead_aes_gcm_open_gather;
}

DEFINE_METHOD_FUNCTION(EVP_AEAD, EVP_aead_aes_256_gcm) {
  memset(out, 0, sizeof(EVP_AEAD));

  out->key_len = 32;
  out->nonce_len = 12;
  out->overhead = EVP_AEAD_AES_GCM_TAG_LEN;
  out->max_tag_len = EVP_AEAD_AES_GCM_TAG_LEN;
  out->seal_scatter_supports_extra_in = 1;

  out->init = aead_aes_gcm_init;
  out->cleanup = aead_aes_gcm_cleanup;
  out->seal_scatter = aead_aes_gcm_seal_scatter;
  out->open_gather = aead_aes_gcm_open_gather;
}

static int aead_aes_gcm_tls12_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
                                   size_t key_len, size_t requested_tag_len) {
  struct aead_aes_gcm_tls12_ctx *gcm_ctx;
  gcm_ctx = OPENSSL_malloc(sizeof(struct aead_aes_gcm_tls12_ctx));
  if (gcm_ctx == NULL) {
    return 0;
  }

  gcm_ctx->min_next_nonce = 0;

  size_t actual_tag_len;
  if (!aead_aes_gcm_init_impl(&gcm_ctx->gcm_ctx, &actual_tag_len, key, key_len,
                              requested_tag_len)) {
    OPENSSL_free(gcm_ctx);
    return 0;
  }

  ctx->aead_state = gcm_ctx;
  ctx->tag_len = actual_tag_len;
  return 1;
}

static void aead_aes_gcm_tls12_cleanup(EVP_AEAD_CTX *ctx) {
  OPENSSL_free(ctx->aead_state);
}

static int aead_aes_gcm_tls12_seal_scatter(
    const EVP_AEAD_CTX *ctx, uint8_t *out, uint8_t *out_tag,
    size_t *out_tag_len, size_t max_out_tag_len, const uint8_t *nonce,
    size_t nonce_len, const uint8_t *in, size_t in_len, const uint8_t *extra_in,
    size_t extra_in_len, const uint8_t *ad, size_t ad_len) {
  struct aead_aes_gcm_tls12_ctx *gcm_ctx = ctx->aead_state;
  if (nonce_len != 12) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
    return 0;
  }

  // The given nonces must be strictly monotonically increasing.
  uint64_t given_counter;
  OPENSSL_memcpy(&given_counter, nonce + nonce_len - sizeof(given_counter),
                 sizeof(given_counter));
  given_counter = CRYPTO_bswap8(given_counter);
  if (given_counter == UINT64_MAX ||
      given_counter < gcm_ctx->min_next_nonce) {
    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_NONCE);
    return 0;
  }

  gcm_ctx->min_next_nonce = given_counter + 1;

  return aead_aes_gcm_seal_scatter(ctx, out, out_tag, out_tag_len,
                                   max_out_tag_len, nonce, nonce_len, in,
                                   in_len, extra_in, extra_in_len, ad, ad_len);
}

DEFINE_METHOD_FUNCTION(EVP_AEAD, EVP_aead_aes_128_gcm_tls12) {
  memset(out, 0, sizeof(EVP_AEAD));

  out->key_len = 16;
  out->nonce_len = 12;
  out->overhead = EVP_AEAD_AES_GCM_TAG_LEN;
  out->max_tag_len = EVP_AEAD_AES_GCM_TAG_LEN;
  out->seal_scatter_supports_extra_in = 1;

  out->init = aead_aes_gcm_tls12_init;
  out->cleanup = aead_aes_gcm_tls12_cleanup;
  out->seal_scatter = aead_aes_gcm_tls12_seal_scatter;
  out->open_gather = aead_aes_gcm_open_gather;
}

DEFINE_METHOD_FUNCTION(EVP_AEAD, EVP_aead_aes_256_gcm_tls12) {
  memset(out, 0, sizeof(EVP_AEAD));

  out->key_len = 32;
  out->nonce_len = 12;
  out->overhead = EVP_AEAD_AES_GCM_TAG_LEN;
  out->max_tag_len = EVP_AEAD_AES_GCM_TAG_LEN;
  out->seal_scatter_supports_extra_in = 1;

  out->init = aead_aes_gcm_tls12_init;
  out->cleanup = aead_aes_gcm_tls12_cleanup;
  out->seal_scatter = aead_aes_gcm_tls12_seal_scatter;
  out->open_gather = aead_aes_gcm_open_gather;
}

int EVP_has_aes_hardware(void) {
#if defined(OPENSSL_X86) || defined(OPENSSL_X86_64)
  return aesni_capable() && crypto_gcm_clmul_enabled();
#elif defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)
  return hwaes_capable() && CRYPTO_is_ARMv8_PMULL_capable();
#else
  return 0;
#endif
}
