/* Copyright (c) 2014, Google Inc.

 *

 * Permission to use, copy, modify, and/or distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY

 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION

 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN

 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

#include <assert.h>

#include <limits.h>

#include <string.h>

#include <openssl/aead.h>

#include <openssl/cipher.h>

#include <openssl/err.h>

#include <openssl/hmac.h>

#include <openssl/md5.h>

#include <openssl/mem.h>

#include <openssl/sha.h>

#include "../fipsmodule/cipher/internal.h"

#include "../internal.h"

#include "internal.h"

typedef struct {

  EVP_CIPHER_CTX cipher_ctx;

  HMAC_CTX hmac_ctx;

  // mac_key is the portion of the key used for the MAC. It is retained

  // separately for the constant-time CBC code.

  uint8_t mac_key[EVP_MAX_MD_SIZE];

  uint8_t mac_key_len;

  // implicit_iv is one iff this is a pre-TLS-1.1 CBC cipher without an explicit

  // IV.

  char implicit_iv;

} AEAD_TLS_CTX;

static_assert(EVP_MAX_MD_SIZE < 256, "mac_key_len does not fit in uint8_t");

static_assert(sizeof(((EVP_AEAD_CTX *)NULL)->state) >= sizeof(AEAD_TLS_CTX),

              "AEAD state is too small");

static_assert(alignof(union evp_aead_ctx_st_state) >= alignof(AEAD_TLS_CTX),

              "AEAD state has insufficient alignment");

static void aead_tls_cleanup(EVP_AEAD_CTX *ctx) {

  AEAD_TLS_CTX *tls_ctx = (AEAD_TLS_CTX *)&ctx->state;

  EVP_CIPHER_CTX_cleanup(&tls_ctx->cipher_ctx);

  HMAC_CTX_cleanup(&tls_ctx->hmac_ctx);

}

static int aead_tls_init(EVP_AEAD_CTX *ctx, const uint8_t *key, size_t key_len,

                         size_t tag_len, enum evp_aead_direction_t dir,

                         const EVP_CIPHER *cipher, const EVP_MD *md,

                         char implicit_iv) {

  if (tag_len != EVP_AEAD_DEFAULT_TAG_LENGTH &&

      tag_len != EVP_MD_size(md)) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_TAG_SIZE);

    return 0;

  }

  if (key_len != EVP_AEAD_key_length(ctx->aead)) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_KEY_LENGTH);

    return 0;

  }

  size_t mac_key_len = EVP_MD_size(md);

  size_t enc_key_len = EVP_CIPHER_key_length(cipher);

  assert(mac_key_len + enc_key_len +

         (implicit_iv ? EVP_CIPHER_iv_length(cipher) : 0) == key_len);

  AEAD_TLS_CTX *tls_ctx = (AEAD_TLS_CTX *)&ctx->state;

  EVP_CIPHER_CTX_init(&tls_ctx->cipher_ctx);

  HMAC_CTX_init(&tls_ctx->hmac_ctx);

  assert(mac_key_len <= EVP_MAX_MD_SIZE);

  OPENSSL_memcpy(tls_ctx->mac_key, key, mac_key_len);

  tls_ctx->mac_key_len = (uint8_t)mac_key_len;

  tls_ctx->implicit_iv = implicit_iv;

  if (!EVP_CipherInit_ex(&tls_ctx->cipher_ctx, cipher, NULL, &key[mac_key_len],

                         implicit_iv ? &key[mac_key_len + enc_key_len] : NULL,

                         dir == evp_aead_seal) ||

      !HMAC_Init_ex(&tls_ctx->hmac_ctx, key, mac_key_len, md, NULL)) {

    aead_tls_cleanup(ctx);

    return 0;

  }

  EVP_CIPHER_CTX_set_padding(&tls_ctx->cipher_ctx, 0);

  return 1;

}

static size_t aead_tls_tag_len(const EVP_AEAD_CTX *ctx, const size_t in_len,

                               const size_t extra_in_len) {

  assert(extra_in_len == 0);

  const AEAD_TLS_CTX *tls_ctx = (AEAD_TLS_CTX *)&ctx->state;

  const size_t hmac_len = HMAC_size(&tls_ctx->hmac_ctx);

  if (EVP_CIPHER_CTX_mode(&tls_ctx->cipher_ctx) != EVP_CIPH_CBC_MODE) {

    // The NULL cipher.

    return hmac_len;

  }

  const size_t block_size = EVP_CIPHER_CTX_block_size(&tls_ctx->cipher_ctx);

  // An overflow of |in_len + hmac_len| doesn't affect the result mod

  // |block_size|, provided that |block_size| is a smaller power of two.

  assert(block_size != 0 && (block_size & (block_size - 1)) == 0);

  const size_t pad_len = block_size - (in_len + hmac_len) % block_size;

  return hmac_len + pad_len;

}

static int aead_tls_seal_scatter(const EVP_AEAD_CTX *ctx, uint8_t *out,

                                 uint8_t *out_tag, size_t *out_tag_len,

                                 const size_t max_out_tag_len,

                                 const uint8_t *nonce, const size_t nonce_len,

                                 const uint8_t *in, const size_t in_len,

                                 const uint8_t *extra_in,

                                 const size_t extra_in_len, const uint8_t *ad,

                                 const size_t ad_len) {

  AEAD_TLS_CTX *tls_ctx = (AEAD_TLS_CTX *)&ctx->state;

  if (!tls_ctx->cipher_ctx.encrypt) {

    // Unlike a normal AEAD, a TLS AEAD may only be used in one direction.

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_OPERATION);

    return 0;

  }

  if (in_len > INT_MAX) {

    // EVP_CIPHER takes int as input.

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);

    return 0;

  }

  if (max_out_tag_len < aead_tls_tag_len(ctx, in_len, extra_in_len)) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);

    return 0;

  }

  if (nonce_len != EVP_AEAD_nonce_length(ctx->aead)) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_NONCE_SIZE);

    return 0;

  }

  if (ad_len != 13 - 2 /* length bytes */) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_AD_SIZE);

    return 0;

  }

  // To allow for CBC mode which changes cipher length, |ad| doesn't include the

  // length for legacy ciphers.

  uint8_t ad_extra[2];

  ad_extra[0] = (uint8_t)(in_len >> 8);

  ad_extra[1] = (uint8_t)(in_len & 0xff);

  // Compute the MAC. This must be first in case the operation is being done

  // in-place.

  uint8_t mac[EVP_MAX_MD_SIZE];

  unsigned mac_len;

  if (!HMAC_Init_ex(&tls_ctx->hmac_ctx, NULL, 0, NULL, NULL) ||

      !HMAC_Update(&tls_ctx->hmac_ctx, ad, ad_len) ||

      !HMAC_Update(&tls_ctx->hmac_ctx, ad_extra, sizeof(ad_extra)) ||

      !HMAC_Update(&tls_ctx->hmac_ctx, in, in_len) ||

      !HMAC_Final(&tls_ctx->hmac_ctx, mac, &mac_len)) {

    return 0;

  }

  // Configure the explicit IV.

  if (EVP_CIPHER_CTX_mode(&tls_ctx->cipher_ctx) == EVP_CIPH_CBC_MODE &&

      !tls_ctx->implicit_iv &&

      !EVP_EncryptInit_ex(&tls_ctx->cipher_ctx, NULL, NULL, NULL, nonce)) {

    return 0;

  }

  // Encrypt the input.

  int len;

  if (!EVP_EncryptUpdate(&tls_ctx->cipher_ctx, out, &len, in, (int)in_len)) {

    return 0;

  }

  unsigned block_size = EVP_CIPHER_CTX_block_size(&tls_ctx->cipher_ctx);

  // Feed the MAC into the cipher in two steps. First complete the final partial

  // block from encrypting the input and split the result between |out| and

  // |out_tag|. Then feed the rest.

  const size_t early_mac_len = (block_size - (in_len % block_size)) % block_size;

  if (early_mac_len != 0) {

    assert(len + block_size - early_mac_len == in_len);

    uint8_t buf[EVP_MAX_BLOCK_LENGTH];

    int buf_len;

    if (!EVP_EncryptUpdate(&tls_ctx->cipher_ctx, buf, &buf_len, mac,

                           (int)early_mac_len)) {

      return 0;

    }

    assert(buf_len == (int)block_size);

    OPENSSL_memcpy(out + len, buf, block_size - early_mac_len);

    OPENSSL_memcpy(out_tag, buf + block_size - early_mac_len, early_mac_len);

  }

  size_t tag_len = early_mac_len;

  if (!EVP_EncryptUpdate(&tls_ctx->cipher_ctx, out_tag + tag_len, &len,

                         mac + tag_len, mac_len - tag_len)) {

    return 0;

  }

  tag_len += len;

  if (block_size > 1) {

    assert(block_size <= 256);

    assert(EVP_CIPHER_CTX_mode(&tls_ctx->cipher_ctx) == EVP_CIPH_CBC_MODE);

    // Compute padding and feed that into the cipher.

    uint8_t padding[256];

    unsigned padding_len = block_size - ((in_len + mac_len) % block_size);

    OPENSSL_memset(padding, padding_len - 1, padding_len);

    if (!EVP_EncryptUpdate(&tls_ctx->cipher_ctx, out_tag + tag_len, &len,

                           padding, (int)padding_len)) {

      return 0;

    }

    tag_len += len;

  }

  if (!EVP_EncryptFinal_ex(&tls_ctx->cipher_ctx, out_tag + tag_len, &len)) {

    return 0;

  }

  assert(len == 0);  // Padding is explicit.

  assert(tag_len == aead_tls_tag_len(ctx, in_len, extra_in_len));

  *out_tag_len = tag_len;

  return 1;

}

static int aead_tls_open(const EVP_AEAD_CTX *ctx, uint8_t *out, size_t *out_len,

                         size_t max_out_len, const uint8_t *nonce,

                         size_t nonce_len, const uint8_t *in, size_t in_len,

                         const uint8_t *ad, size_t ad_len) {

  AEAD_TLS_CTX *tls_ctx = (AEAD_TLS_CTX *)&ctx->state;

  if (tls_ctx->cipher_ctx.encrypt) {

    // Unlike a normal AEAD, a TLS AEAD may only be used in one direction.

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_OPERATION);

    return 0;

  }

  if (in_len < HMAC_size(&tls_ctx->hmac_ctx)) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);

    return 0;

  }

  if (max_out_len < in_len) {

    // This requires that the caller provide space for the MAC, even though it

    // will always be removed on return.

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);

    return 0;

  }

  if (nonce_len != EVP_AEAD_nonce_length(ctx->aead)) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_NONCE_SIZE);

    return 0;

  }

  if (ad_len != 13 - 2 /* length bytes */) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_AD_SIZE);

    return 0;

  }

  if (in_len > INT_MAX) {

    // EVP_CIPHER takes int as input.

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);

    return 0;

  }

  // Configure the explicit IV.

  if (EVP_CIPHER_CTX_mode(&tls_ctx->cipher_ctx) == EVP_CIPH_CBC_MODE &&

      !tls_ctx->implicit_iv &&

      !EVP_DecryptInit_ex(&tls_ctx->cipher_ctx, NULL, NULL, NULL, nonce)) {

    return 0;

  }

  // Decrypt to get the plaintext + MAC + padding.

  size_t total = 0;

  int len;

  if (!EVP_DecryptUpdate(&tls_ctx->cipher_ctx, out, &len, in, (int)in_len)) {

    return 0;

  }

  total += len;

  if (!EVP_DecryptFinal_ex(&tls_ctx->cipher_ctx, out + total, &len)) {

    return 0;

  }

  total += len;

  assert(total == in_len);

  CONSTTIME_SECRET(out, total);

  // Remove CBC padding. Code from here on is timing-sensitive with respect to

  // |padding_ok| and |data_plus_mac_len| for CBC ciphers.

  size_t data_plus_mac_len;

  crypto_word_t padding_ok;

  if (EVP_CIPHER_CTX_mode(&tls_ctx->cipher_ctx) == EVP_CIPH_CBC_MODE) {

    if (!EVP_tls_cbc_remove_padding(

            &padding_ok, &data_plus_mac_len, out, total,

            EVP_CIPHER_CTX_block_size(&tls_ctx->cipher_ctx),

            HMAC_size(&tls_ctx->hmac_ctx))) {

      // Publicly invalid. This can be rejected in non-constant time.

      OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);

      return 0;

    }

  } else {

    padding_ok = CONSTTIME_TRUE_W;

    data_plus_mac_len = total;

    // |data_plus_mac_len| = |total| = |in_len| at this point. |in_len| has

    // already been checked against the MAC size at the top of the function.

    assert(data_plus_mac_len >= HMAC_size(&tls_ctx->hmac_ctx));

  }

  size_t data_len = data_plus_mac_len - HMAC_size(&tls_ctx->hmac_ctx);

  // At this point, if the padding is valid, the first |data_plus_mac_len| bytes

  // after |out| are the plaintext and MAC. Otherwise, |data_plus_mac_len| is

  // still large enough to extract a MAC, but it will be irrelevant.

  // To allow for CBC mode which changes cipher length, |ad| doesn't include the

  // length for legacy ciphers.

  uint8_t ad_fixed[13];

  OPENSSL_memcpy(ad_fixed, ad, 11);

  ad_fixed[11] = (uint8_t)(data_len >> 8);

  ad_fixed[12] = (uint8_t)(data_len & 0xff);

  ad_len += 2;

  // Compute the MAC and extract the one in the record.

  uint8_t mac[EVP_MAX_MD_SIZE];

  size_t mac_len;

  uint8_t record_mac_tmp[EVP_MAX_MD_SIZE];

  uint8_t *record_mac;

  if (EVP_CIPHER_CTX_mode(&tls_ctx->cipher_ctx) == EVP_CIPH_CBC_MODE &&

      EVP_tls_cbc_record_digest_supported(tls_ctx->hmac_ctx.md)) {

    if (!EVP_tls_cbc_digest_record(tls_ctx->hmac_ctx.md, mac, &mac_len,

                                   ad_fixed, out, data_len, total,

                                   tls_ctx->mac_key, tls_ctx->mac_key_len)) {

      OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);

      return 0;

    }

    assert(mac_len == HMAC_size(&tls_ctx->hmac_ctx));

    record_mac = record_mac_tmp;

    EVP_tls_cbc_copy_mac(record_mac, mac_len, out, data_plus_mac_len, total);

  } else {

    // We should support the constant-time path for all CBC-mode ciphers

    // implemented.

    assert(EVP_CIPHER_CTX_mode(&tls_ctx->cipher_ctx) != EVP_CIPH_CBC_MODE);

    unsigned mac_len_u;

    if (!HMAC_Init_ex(&tls_ctx->hmac_ctx, NULL, 0, NULL, NULL) ||

        !HMAC_Update(&tls_ctx->hmac_ctx, ad_fixed, ad_len) ||

        !HMAC_Update(&tls_ctx->hmac_ctx, out, data_len) ||

        !HMAC_Final(&tls_ctx->hmac_ctx, mac, &mac_len_u)) {

      return 0;

    }

    mac_len = mac_len_u;

    assert(mac_len == HMAC_size(&tls_ctx->hmac_ctx));

    record_mac = &out[data_len];

  }

  // Perform the MAC check and the padding check in constant-time. It should be

  // safe to simply perform the padding check first, but it would not be under a

  // different choice of MAC location on padding failure. See

  // EVP_tls_cbc_remove_padding.

  crypto_word_t good =

      constant_time_eq_int(CRYPTO_memcmp(record_mac, mac, mac_len), 0);

  good &= padding_ok;

  CONSTTIME_DECLASSIFY(&good, sizeof(good));

  if (!good) {

    OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);

    return 0;

  }

  CONSTTIME_DECLASSIFY(&data_len, sizeof(data_len));

  CONSTTIME_DECLASSIFY(out, data_len);

  // End of timing-sensitive code.

  *out_len = data_len;

  return 1;

}

static int aead_aes_128_cbc_sha1_tls_init(EVP_AEAD_CTX *ctx, const uint8_t *key,

                                          size_t key_len, size_t tag_len,

                                          enum evp_aead_direction_t dir) {

  return aead_tls_init(ctx, key, key_len, tag_len, dir, EVP_aes_128_cbc(),

                       EVP_sha1(), 0);

}

static int aead_aes_128_cbc_sha1_tls_implicit_iv_init(

    EVP_AEAD_CTX *ctx, const uint8_t *key, size_t key_len, size_t tag_len,

    enum evp_aead_direction_t dir) {

  return aead_tls_init(ctx, key, key_len, tag_len, dir, EVP_aes_128_cbc(),

                       EVP_sha1(), 1);

}

static int aead_aes_128_cbc_sha256_tls_init(EVP_AEAD_CTX *ctx,

                                            const uint8_t *key, size_t key_len,

                                            size_t tag_len,

                                            enum evp_aead_direction_t dir) {

  return aead_tls_init(ctx, key, key_len, tag_len, dir, EVP_aes_128_cbc(),

                       EVP_sha256(), 0);

}

static int aead_aes_256_cbc_sha1_tls_init(EVP_AEAD_CTX *ctx, const uint8_t *key,

                                          size_t key_len, size_t tag_len,

                                          enum evp_aead_direction_t dir) {

  return aead_tls_init(ctx, key, key_len, tag_len, dir, EVP_aes_256_cbc(),

                       EVP_sha1(), 0);

}

static int aead_aes_256_cbc_sha1_tls_implicit_iv_init(

    EVP_AEAD_CTX *ctx, const uint8_t *key, size_t key_len, size_t tag_len,

    enum evp_aead_direction_t dir) {

  return aead_tls_init(ctx, key, key_len, tag_len, dir, EVP_aes_256_cbc(),

                       EVP_sha1(), 1);

}

static int aead_des_ede3_cbc_sha1_tls_init(EVP_AEAD_CTX *ctx,

                                           const uint8_t *key, size_t key_len,

                                           size_t tag_len,

                                           enum evp_aead_direction_t dir) {

  return aead_tls_init(ctx, key, key_len, tag_len, dir, EVP_des_ede3_cbc(),

                       EVP_sha1(), 0);

}

static int aead_des_ede3_cbc_sha1_tls_implicit_iv_init(

    EVP_AEAD_CTX *ctx, const uint8_t *key, size_t key_len, size_t tag_len,

    enum evp_aead_direction_t dir) {

  return aead_tls_init(ctx, key, key_len, tag_len, dir, EVP_des_ede3_cbc(),

                       EVP_sha1(), 1);

}

static int aead_tls_get_iv(const EVP_AEAD_CTX *ctx, const uint8_t **out_iv,

                           size_t *out_iv_len) {

  const AEAD_TLS_CTX *tls_ctx = (AEAD_TLS_CTX *)&ctx->state;

  const size_t iv_len = EVP_CIPHER_CTX_iv_length(&tls_ctx->cipher_ctx);

  if (iv_len <= 1) {

    OPENSSL_PUT_ERROR(CIPHER, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);

    return 0;

  }

  *out_iv = tls_ctx->cipher_ctx.iv;

  *out_iv_len = iv_len;

  return 1;

}

static const EVP_AEAD aead_aes_128_cbc_sha1_tls = {

    SHA_DIGEST_LENGTH + 16,  // key len (SHA1 + AES128)

    16,                      // nonce len (IV)

    16 + SHA_DIGEST_LENGTH,  // overhead (padding + SHA1)

    SHA_DIGEST_LENGTH,       // max tag length

    0,                       // seal_scatter_supports_extra_in

    NULL,  // init

    aead_aes_128_cbc_sha1_tls_init,

    aead_tls_cleanup,

    aead_tls_open,

    aead_tls_seal_scatter,

    NULL,  // open_gather

    NULL,  // get_iv

    aead_tls_tag_len,

};

static const EVP_AEAD aead_aes_128_cbc_sha1_tls_implicit_iv = {

    SHA_DIGEST_LENGTH + 16 + 16,  // key len (SHA1 + AES128 + IV)

    0,                            // nonce len

    16 + SHA_DIGEST_LENGTH,       // overhead (padding + SHA1)

    SHA_DIGEST_LENGTH,            // max tag length

    0,                            // seal_scatter_supports_extra_in

    NULL,  // init

    aead_aes_128_cbc_sha1_tls_implicit_iv_init,

    aead_tls_cleanup,

    aead_tls_open,

    aead_tls_seal_scatter,

    NULL,             // open_gather

    aead_tls_get_iv,  // get_iv

    aead_tls_tag_len,

};

static const EVP_AEAD aead_aes_128_cbc_sha256_tls = {

    SHA256_DIGEST_LENGTH + 16,  // key len (SHA256 + AES128)

    16,                         // nonce len (IV)

    16 + SHA256_DIGEST_LENGTH,  // overhead (padding + SHA256)

    SHA256_DIGEST_LENGTH,       // max tag length

    0,                          // seal_scatter_supports_extra_in

    NULL,  // init

    aead_aes_128_cbc_sha256_tls_init,

    aead_tls_cleanup,

    aead_tls_open,

    aead_tls_seal_scatter,

    NULL,  // open_gather

    NULL,  // get_iv

    aead_tls_tag_len,

};

static const EVP_AEAD aead_aes_256_cbc_sha1_tls = {

    SHA_DIGEST_LENGTH + 32,  // key len (SHA1 + AES256)

    16,                      // nonce len (IV)

    16 + SHA_DIGEST_LENGTH,  // overhead (padding + SHA1)

    SHA_DIGEST_LENGTH,       // max tag length

    0,                       // seal_scatter_supports_extra_in

    NULL,  // init

    aead_aes_256_cbc_sha1_tls_init,

    aead_tls_cleanup,

    aead_tls_open,

    aead_tls_seal_scatter,

    NULL,  // open_gather

    NULL,  // get_iv

    aead_tls_tag_len,

};

static const EVP_AEAD aead_aes_256_cbc_sha1_tls_implicit_iv = {

    SHA_DIGEST_LENGTH + 32 + 16,  // key len (SHA1 + AES256 + IV)

    0,                            // nonce len

    16 + SHA_DIGEST_LENGTH,       // overhead (padding + SHA1)

    SHA_DIGEST_LENGTH,            // max tag length

    0,                            // seal_scatter_supports_extra_in

    NULL,  // init

    aead_aes_256_cbc_sha1_tls_implicit_iv_init,

    aead_tls_cleanup,

    aead_tls_open,

    aead_tls_seal_scatter,

    NULL,             // open_gather

    aead_tls_get_iv,  // get_iv

    aead_tls_tag_len,

};

static const EVP_AEAD aead_des_ede3_cbc_sha1_tls = {

    SHA_DIGEST_LENGTH + 24,  // key len (SHA1 + 3DES)

    8,                       // nonce len (IV)

    8 + SHA_DIGEST_LENGTH,   // overhead (padding + SHA1)

    SHA_DIGEST_LENGTH,       // max tag length

    0,                       // seal_scatter_supports_extra_in

    NULL,  // init

    aead_des_ede3_cbc_sha1_tls_init,

    aead_tls_cleanup,

    aead_tls_open,

    aead_tls_seal_scatter,

    NULL,  // open_gather

    NULL,  // get_iv

    aead_tls_tag_len,

};

static const EVP_AEAD aead_des_ede3_cbc_sha1_tls_implicit_iv = {

    SHA_DIGEST_LENGTH + 24 + 8,  // key len (SHA1 + 3DES + IV)

    0,                           // nonce len

    8 + SHA_DIGEST_LENGTH,       // overhead (padding + SHA1)

    SHA_DIGEST_LENGTH,           // max tag length

    0,                           // seal_scatter_supports_extra_in

    NULL,  // init

    aead_des_ede3_cbc_sha1_tls_implicit_iv_init,

    aead_tls_cleanup,

    aead_tls_open,

    aead_tls_seal_scatter,

    NULL,             // open_gather

    aead_tls_get_iv,  // get_iv

    aead_tls_tag_len,

};

const EVP_AEAD *EVP_aead_aes_128_cbc_sha1_tls(void) {

  return &aead_aes_128_cbc_sha1_tls;

}

const EVP_AEAD *EVP_aead_aes_128_cbc_sha1_tls_implicit_iv(void) {

  return &aead_aes_128_cbc_sha1_tls_implicit_iv;

}

const EVP_AEAD *EVP_aead_aes_128_cbc_sha256_tls(void) {

  return &aead_aes_128_cbc_sha256_tls;

}

const EVP_AEAD *EVP_aead_aes_256_cbc_sha1_tls(void) {

  return &aead_aes_256_cbc_sha1_tls;

}

const EVP_AEAD *EVP_aead_aes_256_cbc_sha1_tls_implicit_iv(void) {

  return &aead_aes_256_cbc_sha1_tls_implicit_iv;

}

const EVP_AEAD *EVP_aead_des_ede3_cbc_sha1_tls(void) {

  return &aead_des_ede3_cbc_sha1_tls;

}

const EVP_AEAD *EVP_aead_des_ede3_cbc_sha1_tls_implicit_iv(void) {

  return &aead_des_ede3_cbc_sha1_tls_implicit_iv;

}