1 files changed, 644 insertions, 0 deletions
diff --git a/src/contrib/libngtcp2/ngtcp2/crypto/gnutls.c b/src/contrib/libngtcp2/ngtcp2/crypto/gnutls.c
new file mode 100644
index 0000000..73ea0c1
--- /dev/null
+++ b/src/contrib/libngtcp2/ngtcp2/crypto/gnutls.c
@@ -0,0 +1,644 @@
+/*
+ * ngtcp2
+ *
+ * Copyright (c) 2020 ngtcp2 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <assert.h>
+
+#include <ngtcp2/ngtcp2_crypto.h>
+#include <ngtcp2/ngtcp2_crypto_gnutls.h>
+
+#include <gnutls/gnutls.h>
+#include <gnutls/crypto.h>
+#include <string.h>
+
+#include "shared.h"
+
+ngtcp2_crypto_aead *ngtcp2_crypto_aead_aes_128_gcm(ngtcp2_crypto_aead *aead) {
+  return ngtcp2_crypto_aead_init(aead, (void *)GNUTLS_CIPHER_AES_128_GCM);
+}
+
+ngtcp2_crypto_md *ngtcp2_crypto_md_sha256(ngtcp2_crypto_md *md) {
+  md->native_handle = (void *)GNUTLS_DIG_SHA256;
+  return md;
+}
+
+ngtcp2_crypto_ctx *ngtcp2_crypto_ctx_initial(ngtcp2_crypto_ctx *ctx) {
+  ngtcp2_crypto_aead_init(&ctx->aead, (void *)GNUTLS_CIPHER_AES_128_GCM);
+  ctx->md.native_handle = (void *)GNUTLS_DIG_SHA256;
+  ctx->hp.native_handle = (void *)GNUTLS_CIPHER_AES_128_CBC;
+  ctx->max_encryption = 0;
+  ctx->max_decryption_failure = 0;
+  return ctx;
+}
+
+ngtcp2_crypto_aead *ngtcp2_crypto_aead_init(ngtcp2_crypto_aead *aead,
+                                            void *aead_native_handle) {
+  aead->native_handle = aead_native_handle;
+  aead->max_overhead = gnutls_cipher_get_tag_size(
+      (gnutls_cipher_algorithm_t)(intptr_t)aead_native_handle);
+  return aead;
+}
+
+ngtcp2_crypto_aead *ngtcp2_crypto_aead_retry(ngtcp2_crypto_aead *aead) {
+  return ngtcp2_crypto_aead_init(aead, (void *)GNUTLS_CIPHER_AES_128_GCM);
+}
+
+static gnutls_cipher_algorithm_t
+crypto_get_hp(gnutls_cipher_algorithm_t cipher) {
+  switch (cipher) {
+  case GNUTLS_CIPHER_AES_128_GCM:
+  case GNUTLS_CIPHER_AES_128_CCM:
+    return GNUTLS_CIPHER_AES_128_CBC;
+  case GNUTLS_CIPHER_AES_256_GCM:
+  case GNUTLS_CIPHER_AES_256_CCM:
+    return GNUTLS_CIPHER_AES_256_CBC;
+  case GNUTLS_CIPHER_CHACHA20_POLY1305:
+    return GNUTLS_CIPHER_CHACHA20_32;
+  default:
+    return GNUTLS_CIPHER_UNKNOWN;
+  }
+}
+
+static uint64_t
+crypto_get_aead_max_encryption(gnutls_cipher_algorithm_t cipher) {
+  switch (cipher) {
+  case GNUTLS_CIPHER_AES_128_GCM:
+  case GNUTLS_CIPHER_AES_256_GCM:
+    return NGTCP2_CRYPTO_MAX_ENCRYPTION_AES_GCM;
+  case GNUTLS_CIPHER_CHACHA20_POLY1305:
+    return NGTCP2_CRYPTO_MAX_ENCRYPTION_CHACHA20_POLY1305;
+  case GNUTLS_CIPHER_AES_128_CCM:
+  case GNUTLS_CIPHER_AES_256_CCM:
+    return NGTCP2_CRYPTO_MAX_ENCRYPTION_AES_CCM;
+  default:
+    return 0;
+  }
+}
+
+static uint64_t
+crypto_get_aead_max_decryption_failure(gnutls_cipher_algorithm_t cipher) {
+  switch (cipher) {
+  case GNUTLS_CIPHER_AES_128_GCM:
+  case GNUTLS_CIPHER_AES_256_GCM:
+    return NGTCP2_CRYPTO_MAX_DECRYPTION_FAILURE_AES_GCM;
+  case GNUTLS_CIPHER_CHACHA20_POLY1305:
+    return NGTCP2_CRYPTO_MAX_DECRYPTION_FAILURE_CHACHA20_POLY1305;
+  case GNUTLS_CIPHER_AES_128_CCM:
+  case GNUTLS_CIPHER_AES_256_CCM:
+    return NGTCP2_CRYPTO_MAX_DECRYPTION_FAILURE_AES_CCM;
+  default:
+    return 0;
+  }
+}
+
+ngtcp2_crypto_ctx *ngtcp2_crypto_ctx_tls(ngtcp2_crypto_ctx *ctx,
+                                         void *tls_native_handle) {
+  gnutls_session_t session = tls_native_handle;
+  gnutls_cipher_algorithm_t cipher;
+  gnutls_digest_algorithm_t hash;
+  gnutls_cipher_algorithm_t hp_cipher;
+
+  cipher = gnutls_cipher_get(session);
+  if (cipher != GNUTLS_CIPHER_UNKNOWN && cipher != GNUTLS_CIPHER_NULL) {
+    ngtcp2_crypto_aead_init(&ctx->aead, (void *)cipher);
+  }
+
+  hash = gnutls_prf_hash_get(session);
+  if (hash != GNUTLS_DIG_UNKNOWN && hash != GNUTLS_DIG_NULL) {
+    ctx->md.native_handle = (void *)hash;
+  }
+
+  hp_cipher = crypto_get_hp(cipher);
+  if (hp_cipher != GNUTLS_CIPHER_UNKNOWN) {
+    ctx->hp.native_handle = (void *)hp_cipher;
+  }
+
+  ctx->max_encryption = crypto_get_aead_max_encryption(cipher);
+  ctx->max_decryption_failure = crypto_get_aead_max_decryption_failure(cipher);
+
+  return ctx;
+}
+
+ngtcp2_crypto_ctx *ngtcp2_crypto_ctx_tls_early(ngtcp2_crypto_ctx *ctx,
+                                               void *tls_native_handle) {
+  gnutls_session_t session = tls_native_handle;
+  gnutls_cipher_algorithm_t cipher;
+  gnutls_digest_algorithm_t hash;
+  gnutls_cipher_algorithm_t hp_cipher;
+
+  cipher = gnutls_early_cipher_get(session);
+  if (cipher != GNUTLS_CIPHER_UNKNOWN && cipher != GNUTLS_CIPHER_NULL) {
+    ngtcp2_crypto_aead_init(&ctx->aead, (void *)cipher);
+  }
+
+  hash = gnutls_early_prf_hash_get(session);
+  if (hash != GNUTLS_DIG_UNKNOWN && hash != GNUTLS_DIG_NULL) {
+    ctx->md.native_handle = (void *)hash;
+  }
+
+  hp_cipher = crypto_get_hp(cipher);
+  if (hp_cipher != GNUTLS_CIPHER_UNKNOWN) {
+    ctx->hp.native_handle = (void *)hp_cipher;
+  }
+
+  ctx->max_encryption = crypto_get_aead_max_encryption(cipher);
+  ctx->max_decryption_failure = crypto_get_aead_max_decryption_failure(cipher);
+
+  return ctx;
+}
+
+size_t ngtcp2_crypto_md_hashlen(const ngtcp2_crypto_md *md) {
+  return gnutls_hash_get_len(
+      (gnutls_digest_algorithm_t)(intptr_t)md->native_handle);
+}
+
+size_t ngtcp2_crypto_aead_keylen(const ngtcp2_crypto_aead *aead) {
+  return gnutls_cipher_get_key_size(
+      (gnutls_cipher_algorithm_t)(intptr_t)aead->native_handle);
+}
+
+size_t ngtcp2_crypto_aead_noncelen(const ngtcp2_crypto_aead *aead) {
+  return gnutls_cipher_get_iv_size(
+      (gnutls_cipher_algorithm_t)(intptr_t)aead->native_handle);
+}
+
+int ngtcp2_crypto_aead_ctx_encrypt_init(ngtcp2_crypto_aead_ctx *aead_ctx,
+                                        const ngtcp2_crypto_aead *aead,
+                                        const uint8_t *key, size_t noncelen) {
+  gnutls_cipher_algorithm_t cipher =
+      (gnutls_cipher_algorithm_t)(intptr_t)aead->native_handle;
+  gnutls_aead_cipher_hd_t hd;
+  gnutls_datum_t _key;
+
+  (void)noncelen;
+
+  _key.data = (void *)key;
+  _key.size = (unsigned int)ngtcp2_crypto_aead_keylen(aead);
+
+  if (gnutls_aead_cipher_init(&hd, cipher, &_key) != 0) {
+    return -1;
+  }
+
+  aead_ctx->native_handle = hd;
+
+  return 0;
+}
+
+int ngtcp2_crypto_aead_ctx_decrypt_init(ngtcp2_crypto_aead_ctx *aead_ctx,
+                                        const ngtcp2_crypto_aead *aead,
+                                        const uint8_t *key, size_t noncelen) {
+  gnutls_cipher_algorithm_t cipher =
+      (gnutls_cipher_algorithm_t)(intptr_t)aead->native_handle;
+  gnutls_aead_cipher_hd_t hd;
+  gnutls_datum_t _key;
+
+  (void)noncelen;
+
+  _key.data = (void *)key;
+  _key.size = (unsigned int)ngtcp2_crypto_aead_keylen(aead);
+
+  if (gnutls_aead_cipher_init(&hd, cipher, &_key) != 0) {
+    return -1;
+  }
+
+  aead_ctx->native_handle = hd;
+
+  return 0;
+}
+
+void ngtcp2_crypto_aead_ctx_free(ngtcp2_crypto_aead_ctx *aead_ctx) {
+  if (aead_ctx->native_handle) {
+    gnutls_aead_cipher_deinit(aead_ctx->native_handle);
+  }
+}
+
+int ngtcp2_crypto_cipher_ctx_encrypt_init(ngtcp2_crypto_cipher_ctx *cipher_ctx,
+                                          const ngtcp2_crypto_cipher *cipher,
+                                          const uint8_t *key) {
+  gnutls_cipher_algorithm_t _cipher =
+      (gnutls_cipher_algorithm_t)(intptr_t)cipher->native_handle;
+  gnutls_cipher_hd_t hd;
+  gnutls_datum_t _key;
+
+  _key.data = (void *)key;
+  _key.size = (unsigned int)gnutls_cipher_get_key_size(_cipher);
+
+  if (gnutls_cipher_init(&hd, _cipher, &_key, NULL) != 0) {
+    return -1;
+  }
+
+  cipher_ctx->native_handle = hd;
+
+  return 0;
+}
+
+void ngtcp2_crypto_cipher_ctx_free(ngtcp2_crypto_cipher_ctx *cipher_ctx) {
+  if (cipher_ctx->native_handle) {
+    gnutls_cipher_deinit(cipher_ctx->native_handle);
+  }
+}
+
+int ngtcp2_crypto_hkdf_extract(uint8_t *dest, const ngtcp2_crypto_md *md,
+                               const uint8_t *secret, size_t secretlen,
+                               const uint8_t *salt, size_t saltlen) {
+  gnutls_mac_algorithm_t prf =
+      (gnutls_mac_algorithm_t)(intptr_t)md->native_handle;
+  gnutls_datum_t _secret = {(void *)secret, (unsigned int)secretlen};
+  gnutls_datum_t _salt = {(void *)salt, (unsigned int)saltlen};
+
+  if (gnutls_hkdf_extract(prf, &_secret, &_salt, dest) != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+int ngtcp2_crypto_hkdf_expand(uint8_t *dest, size_t destlen,
+                              const ngtcp2_crypto_md *md, const uint8_t *secret,
+                              size_t secretlen, const uint8_t *info,
+                              size_t infolen) {
+  gnutls_mac_algorithm_t prf =
+      (gnutls_mac_algorithm_t)(intptr_t)md->native_handle;
+  gnutls_datum_t _secret = {(void *)secret, (unsigned int)secretlen};
+  gnutls_datum_t _info = {(void *)info, (unsigned int)infolen};
+
+  if (gnutls_hkdf_expand(prf, &_secret, &_info, dest, destlen) != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+int ngtcp2_crypto_hkdf(uint8_t *dest, size_t destlen,
+                       const ngtcp2_crypto_md *md, const uint8_t *secret,
+                       size_t secretlen, const uint8_t *salt, size_t saltlen,
+                       const uint8_t *info, size_t infolen) {
+  gnutls_mac_algorithm_t prf =
+      (gnutls_mac_algorithm_t)(intptr_t)md->native_handle;
+  size_t keylen = ngtcp2_crypto_md_hashlen(md);
+  uint8_t key[64];
+  gnutls_datum_t _secret = {(void *)secret, (unsigned int)secretlen};
+  gnutls_datum_t _key = {(void *)key, (unsigned int)keylen};
+  gnutls_datum_t _salt = {(void *)salt, (unsigned int)saltlen};
+  gnutls_datum_t _info = {(void *)info, (unsigned int)infolen};
+
+  assert(keylen <= sizeof(key));
+
+  if (gnutls_hkdf_extract(prf, &_secret, &_salt, key) != 0) {
+    return -1;
+  }
+
+  if (gnutls_hkdf_expand(prf, &_key, &_info, dest, destlen) != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+int ngtcp2_crypto_encrypt(uint8_t *dest, const ngtcp2_crypto_aead *aead,
+                          const ngtcp2_crypto_aead_ctx *aead_ctx,
+                          const uint8_t *plaintext, size_t plaintextlen,
+                          const uint8_t *nonce, size_t noncelen,
+                          const uint8_t *aad, size_t aadlen) {
+  gnutls_cipher_algorithm_t cipher =
+      (gnutls_cipher_algorithm_t)(intptr_t)aead->native_handle;
+  gnutls_aead_cipher_hd_t hd = aead_ctx->native_handle;
+  size_t taglen = gnutls_cipher_get_tag_size(cipher);
+  size_t ciphertextlen = plaintextlen + taglen;
+
+  if (gnutls_aead_cipher_encrypt(hd, nonce, noncelen, aad, aadlen, taglen,
+                                 plaintext, plaintextlen, dest,
+                                 &ciphertextlen) != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+int ngtcp2_crypto_decrypt(uint8_t *dest, const ngtcp2_crypto_aead *aead,
+                          const ngtcp2_crypto_aead_ctx *aead_ctx,
+                          const uint8_t *ciphertext, size_t ciphertextlen,
+                          const uint8_t *nonce, size_t noncelen,
+                          const uint8_t *aad, size_t aadlen) {
+  gnutls_cipher_algorithm_t cipher =
+      (gnutls_cipher_algorithm_t)(intptr_t)aead->native_handle;
+  gnutls_aead_cipher_hd_t hd = aead_ctx->native_handle;
+  size_t taglen = gnutls_cipher_get_tag_size(cipher);
+  size_t plaintextlen;
+
+  if (taglen > ciphertextlen) {
+    return -1;
+  }
+
+  plaintextlen = ciphertextlen - taglen;
+
+  if (gnutls_aead_cipher_decrypt(hd, nonce, noncelen, aad, aadlen, taglen,
+                                 ciphertext, ciphertextlen, dest,
+                                 &plaintextlen) != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+int ngtcp2_crypto_hp_mask(uint8_t *dest, const ngtcp2_crypto_cipher *hp,
+                          const ngtcp2_crypto_cipher_ctx *hp_ctx,
+                          const uint8_t *sample) {
+  gnutls_cipher_algorithm_t cipher =
+      (gnutls_cipher_algorithm_t)(intptr_t)hp->native_handle;
+  gnutls_cipher_hd_t hd = hp_ctx->native_handle;
+
+  switch (cipher) {
+  case GNUTLS_CIPHER_AES_128_CBC:
+  case GNUTLS_CIPHER_AES_256_CBC: {
+    uint8_t iv[16];
+    uint8_t buf[16];
+
+    /* Emulate one block AES-ECB by invalidating the effect of IV */
+    memset(iv, 0, sizeof(iv));
+
+    gnutls_cipher_set_iv(hd, iv, sizeof(iv));
+
+    if (gnutls_cipher_encrypt2(hd, sample, 16, buf, sizeof(buf)) != 0) {
+      return -1;
+    }
+
+    memcpy(dest, buf, 5);
+  } break;
+
+  case GNUTLS_CIPHER_CHACHA20_32: {
+    static const uint8_t PLAINTEXT[] = "\x00\x00\x00\x00\x00";
+    uint8_t buf[5 + 16];
+    size_t buflen = sizeof(buf);
+
+    gnutls_cipher_set_iv(hd, (void *)sample, 16);
+
+    if (gnutls_cipher_encrypt2(hd, PLAINTEXT, sizeof(PLAINTEXT) - 1, buf,
+                               buflen) != 0) {
+      return -1;
+    }
+
+    memcpy(dest, buf, 5);
+  } break;
+  default:
+    assert(0);
+  }
+
+  return 0;
+}
+
+ngtcp2_crypto_level ngtcp2_crypto_gnutls_from_gnutls_record_encryption_level(
+    gnutls_record_encryption_level_t gtls_level) {
+  switch (gtls_level) {
+  case GNUTLS_ENCRYPTION_LEVEL_INITIAL:
+    return NGTCP2_CRYPTO_LEVEL_INITIAL;
+  case GNUTLS_ENCRYPTION_LEVEL_HANDSHAKE:
+    return NGTCP2_CRYPTO_LEVEL_HANDSHAKE;
+  case GNUTLS_ENCRYPTION_LEVEL_APPLICATION:
+    return NGTCP2_CRYPTO_LEVEL_APPLICATION;
+  case GNUTLS_ENCRYPTION_LEVEL_EARLY:
+    return NGTCP2_CRYPTO_LEVEL_EARLY;
+  default:
+    assert(0);
+    abort();
+  }
+}
+
+gnutls_record_encryption_level_t
+ngtcp2_crypto_gnutls_from_ngtcp2_level(ngtcp2_crypto_level crypto_level) {
+  switch (crypto_level) {
+  case NGTCP2_CRYPTO_LEVEL_INITIAL:
+    return GNUTLS_ENCRYPTION_LEVEL_INITIAL;
+  case NGTCP2_CRYPTO_LEVEL_HANDSHAKE:
+    return GNUTLS_ENCRYPTION_LEVEL_HANDSHAKE;
+  case NGTCP2_CRYPTO_LEVEL_APPLICATION:
+    return GNUTLS_ENCRYPTION_LEVEL_APPLICATION;
+  case NGTCP2_CRYPTO_LEVEL_EARLY:
+    return GNUTLS_ENCRYPTION_LEVEL_EARLY;
+  default:
+    assert(0);
+    abort();
+  }
+}
+
+int ngtcp2_crypto_read_write_crypto_data(ngtcp2_conn *conn,
+                                         ngtcp2_crypto_level crypto_level,
+                                         const uint8_t *data, size_t datalen) {
+  gnutls_session_t session = ngtcp2_conn_get_tls_native_handle(conn);
+  int rv;
+
+  if (datalen > 0) {
+    rv = gnutls_handshake_write(
+        session, ngtcp2_crypto_gnutls_from_ngtcp2_level(crypto_level), data,
+        datalen);
+    if (rv != 0) {
+      if (!gnutls_error_is_fatal(rv)) {
+        return 0;
+      }
+      gnutls_alert_send_appropriate(session, rv);
+      return -1;
+    }
+  }
+
+  if (!ngtcp2_conn_get_handshake_completed(conn)) {
+    rv = gnutls_handshake(session);
+    if (rv < 0) {
+      if (!gnutls_error_is_fatal(rv)) {
+        return 0;
+      }
+      gnutls_alert_send_appropriate(session, rv);
+      return -1;
+    }
+
+    ngtcp2_conn_handshake_completed(conn);
+  }
+
+  return 0;
+}
+
+int ngtcp2_crypto_set_remote_transport_params(ngtcp2_conn *conn, void *tls) {
+  (void)conn;
+  (void)tls;
+  /* Nothing to do; GnuTLS applications are supposed to register the
+     quic_transport_parameters extension with
+     gnutls_session_ext_register. */
+  return 0;
+}
+
+int ngtcp2_crypto_set_local_transport_params(void *tls, const uint8_t *buf,
+                                             size_t len) {
+  (void)tls;
+  (void)buf;
+  (void)len;
+  /* Nothing to do; GnuTLS applications are supposed to register the
+     quic_transport_parameters extension with
+     gnutls_session_ext_register. */
+  return 0;
+}
+
+int ngtcp2_crypto_get_path_challenge_data_cb(ngtcp2_conn *conn, uint8_t *data,
+                                             void *user_data) {
+  (void)conn;
+  (void)user_data;
+
+  if (gnutls_rnd(GNUTLS_RND_RANDOM, data, NGTCP2_PATH_CHALLENGE_DATALEN) != 0) {
+    return NGTCP2_ERR_CALLBACK_FAILURE;
+  }
+
+  return 0;
+}
+
+int ngtcp2_crypto_random(uint8_t *data, size_t datalen) {
+  if (gnutls_rnd(GNUTLS_RND_RANDOM, data, datalen) != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+static int secret_func(gnutls_session_t session,
+                       gnutls_record_encryption_level_t gtls_level,
+                       const void *rx_secret, const void *tx_secret,
+                       size_t secretlen) {
+  ngtcp2_crypto_conn_ref *conn_ref = gnutls_session_get_ptr(session);
+  ngtcp2_conn *conn = conn_ref->get_conn(conn_ref);
+  ngtcp2_crypto_level level =
+      ngtcp2_crypto_gnutls_from_gnutls_record_encryption_level(gtls_level);
+
+  if (rx_secret &&
+      ngtcp2_crypto_derive_and_install_rx_key(conn, NULL, NULL, NULL, level,
+                                              rx_secret, secretlen) != 0) {
+    return -1;
+  }
+
+  if (tx_secret &&
+      ngtcp2_crypto_derive_and_install_tx_key(conn, NULL, NULL, NULL, level,
+                                              tx_secret, secretlen) != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+static int read_func(gnutls_session_t session,
+                     gnutls_record_encryption_level_t gtls_level,
+                     gnutls_handshake_description_t htype, const void *data,
+                     size_t datalen) {
+  ngtcp2_crypto_conn_ref *conn_ref = gnutls_session_get_ptr(session);
+  ngtcp2_conn *conn = conn_ref->get_conn(conn_ref);
+  ngtcp2_crypto_level level =
+      ngtcp2_crypto_gnutls_from_gnutls_record_encryption_level(gtls_level);
+  int rv;
+
+  if (htype == GNUTLS_HANDSHAKE_CHANGE_CIPHER_SPEC) {
+    return 0;
+  }
+
+  rv = ngtcp2_conn_submit_crypto_data(conn, level, data, datalen);
+  if (rv != 0) {
+    ngtcp2_conn_set_tls_error(conn, rv);
+    return -1;
+  }
+
+  return 0;
+}
+
+static int alert_read_func(gnutls_session_t session,
+                           gnutls_record_encryption_level_t gtls_level,
+                           gnutls_alert_level_t alert_level,
+                           gnutls_alert_description_t alert_desc) {
+  ngtcp2_crypto_conn_ref *conn_ref = gnutls_session_get_ptr(session);
+  ngtcp2_conn *conn = conn_ref->get_conn(conn_ref);
+  (void)gtls_level;
+  (void)alert_level;
+
+  ngtcp2_conn_set_tls_alert(conn, (uint8_t)alert_desc);
+
+  return 0;
+}
+
+static int tp_recv_func(gnutls_session_t session, const uint8_t *data,
+                        size_t datalen) {
+  ngtcp2_crypto_conn_ref *conn_ref = gnutls_session_get_ptr(session);
+  ngtcp2_conn *conn = conn_ref->get_conn(conn_ref);
+  int rv;
+
+  rv = ngtcp2_conn_decode_remote_transport_params(conn, data, datalen);
+  if (rv != 0) {
+    ngtcp2_conn_set_tls_error(conn, rv);
+    return -1;
+  }
+
+  return 0;
+}
+
+static int tp_send_func(gnutls_session_t session, gnutls_buffer_t extdata) {
+  ngtcp2_crypto_conn_ref *conn_ref = gnutls_session_get_ptr(session);
+  ngtcp2_conn *conn = conn_ref->get_conn(conn_ref);
+  uint8_t buf[256];
+  ngtcp2_ssize nwrite;
+  int rv;
+
+  nwrite = ngtcp2_conn_encode_local_transport_params(conn, buf, sizeof(buf));
+  if (nwrite < 0) {
+    return -1;
+  }
+
+  rv = gnutls_buffer_append_data(extdata, buf, (size_t)nwrite);
+  if (rv != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+static int crypto_gnutls_configure_session(gnutls_session_t session) {
+  int rv;
+
+  gnutls_handshake_set_secret_function(session, secret_func);
+  gnutls_handshake_set_read_function(session, read_func);
+  gnutls_alert_set_read_function(session, alert_read_func);
+
+  rv = gnutls_session_ext_register(
+      session, "QUIC Transport Parameters",
+      NGTCP2_TLSEXT_QUIC_TRANSPORT_PARAMETERS_V1, GNUTLS_EXT_TLS, tp_recv_func,
+      tp_send_func, NULL, NULL, NULL,
+      GNUTLS_EXT_FLAG_TLS | GNUTLS_EXT_FLAG_CLIENT_HELLO | GNUTLS_EXT_FLAG_EE);
+  if (rv != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
+int ngtcp2_crypto_gnutls_configure_server_session(gnutls_session_t session) {
+  return crypto_gnutls_configure_session(session);
+}
+
+int ngtcp2_crypto_gnutls_configure_client_session(gnutls_session_t session) {
+  return crypto_gnutls_configure_session(session);
+}