diff --git a/quic/core/tls_handshaker.cc b/quic/core/tls_handshaker.cc
new file mode 100644
index 0000000..d6207bb
--- /dev/null
+++ b/quic/core/tls_handshaker.cc
@@ -0,0 +1,241 @@
+// Copyright (c) 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/third_party/quiche/src/quic/core/tls_handshaker.h"
+
+#include "third_party/boringssl/src/include/openssl/crypto.h"
+#include "third_party/boringssl/src/include/openssl/ssl.h"
+#include "net/third_party/quiche/src/quic/core/quic_crypto_stream.h"
+#include "net/third_party/quiche/src/quic/core/tls_client_handshaker.h"
+#include "net/third_party/quiche/src/quic/platform/api/quic_arraysize.h"
+#include "net/third_party/quiche/src/quic/platform/api/quic_bug_tracker.h"
+
+namespace quic {
+
+namespace {
+
+class SslIndexSingleton {
+ public:
+  static SslIndexSingleton* GetInstance() {
+    static SslIndexSingleton* instance = new SslIndexSingleton();
+    return instance;
+  }
+
+  int HandshakerIndex() const { return ssl_ex_data_index_handshaker_; }
+
+ private:
+  SslIndexSingleton() {
+    CRYPTO_library_init();
+    ssl_ex_data_index_handshaker_ =
+        SSL_get_ex_new_index(0, nullptr, nullptr, nullptr, nullptr);
+    CHECK_LE(0, ssl_ex_data_index_handshaker_);
+  }
+
+  SslIndexSingleton(const SslIndexSingleton&) = delete;
+  SslIndexSingleton& operator=(const SslIndexSingleton&) = delete;
+
+  int ssl_ex_data_index_handshaker_;
+};
+
+}  // namespace
+
+TlsHandshaker::TlsHandshaker(QuicCryptoStream* stream,
+                             QuicSession* session,
+                             SSL_CTX* ssl_ctx)
+    : stream_(stream), session_(session) {
+  ssl_.reset(SSL_new(ssl_ctx));
+  SSL_set_ex_data(ssl(), SslIndexSingleton::GetInstance()->HandshakerIndex(),
+                  this);
+}
+
+TlsHandshaker::~TlsHandshaker() {}
+
+bool TlsHandshaker::ProcessInput(QuicStringPiece input, EncryptionLevel level) {
+  if (parser_error_ != QUIC_NO_ERROR) {
+    return false;
+  }
+  // TODO(nharper): Call SSL_quic_read_level(ssl()) and check whether the
+  // encryption level BoringSSL expects matches the encryption level that we
+  // just received input at. If they mismatch, should ProcessInput return true
+  // or false? If data is for a future encryption level, it should be queued for
+  // later?
+  if (SSL_provide_quic_data(ssl(), BoringEncryptionLevel(level),
+                            reinterpret_cast<const uint8_t*>(input.data()),
+                            input.size()) != 1) {
+    // SSL_provide_quic_data can fail for 3 reasons:
+    // - API misuse (calling it before SSL_set_custom_quic_method, which we
+    //   call in the TlsHandshaker c'tor)
+    // - Memory exhaustion when appending data to its buffer
+    // - Data provided at the wrong encryption level
+    //
+    // Of these, the only sensible error to handle is data provided at the wrong
+    // encryption level.
+    //
+    // Note: the error provided below has a good-sounding enum value, although
+    // it doesn't match the description as it's a QUIC Crypto specific error.
+    parser_error_ = QUIC_INVALID_CRYPTO_MESSAGE_TYPE;
+    parser_error_detail_ = "TLS stack failed to receive data";
+    return false;
+  }
+  AdvanceHandshake();
+  return true;
+}
+
+// static
+bssl::UniquePtr<SSL_CTX> TlsHandshaker::CreateSslCtx() {
+  CRYPTO_library_init();
+  bssl::UniquePtr<SSL_CTX> ssl_ctx(SSL_CTX_new(TLS_with_buffers_method()));
+  SSL_CTX_set_min_proto_version(ssl_ctx.get(), TLS1_3_VERSION);
+  SSL_CTX_set_max_proto_version(ssl_ctx.get(), TLS1_3_VERSION);
+  SSL_CTX_set_quic_method(ssl_ctx.get(), &kSslQuicMethod);
+  return ssl_ctx;
+}
+
+// static
+TlsHandshaker* TlsHandshaker::HandshakerFromSsl(const SSL* ssl) {
+  return reinterpret_cast<TlsHandshaker*>(SSL_get_ex_data(
+      ssl, SslIndexSingleton::GetInstance()->HandshakerIndex()));
+}
+
+// static
+EncryptionLevel TlsHandshaker::QuicEncryptionLevel(
+    enum ssl_encryption_level_t level) {
+  switch (level) {
+    case ssl_encryption_initial:
+      return ENCRYPTION_NONE;
+    case ssl_encryption_early_data:
+    case ssl_encryption_handshake:
+      return ENCRYPTION_ZERO_RTT;
+    case ssl_encryption_application:
+      return ENCRYPTION_FORWARD_SECURE;
+  }
+}
+
+// static
+enum ssl_encryption_level_t TlsHandshaker::BoringEncryptionLevel(
+    EncryptionLevel level) {
+  switch (level) {
+    case ENCRYPTION_NONE:
+      return ssl_encryption_initial;
+    case ENCRYPTION_ZERO_RTT:
+      return ssl_encryption_handshake;
+    case ENCRYPTION_FORWARD_SECURE:
+      return ssl_encryption_application;
+    default:
+      QUIC_BUG << "Invalid encryption level " << level;
+      return ssl_encryption_initial;
+  }
+}
+
+const EVP_MD* TlsHandshaker::Prf() {
+  return EVP_get_digestbynid(
+      SSL_CIPHER_get_prf_nid(SSL_get_pending_cipher(ssl())));
+}
+
+std::unique_ptr<QuicEncrypter> TlsHandshaker::CreateEncrypter(
+    const std::vector<uint8_t>& pp_secret) {
+  std::unique_ptr<QuicEncrypter> encrypter =
+      QuicEncrypter::CreateFromCipherSuite(
+          SSL_CIPHER_get_id(SSL_get_pending_cipher(ssl())));
+  CryptoUtils::SetKeyAndIV(Prf(), pp_secret, encrypter.get());
+  return encrypter;
+}
+
+std::unique_ptr<QuicDecrypter> TlsHandshaker::CreateDecrypter(
+    const std::vector<uint8_t>& pp_secret) {
+  std::unique_ptr<QuicDecrypter> decrypter =
+      QuicDecrypter::CreateFromCipherSuite(
+          SSL_CIPHER_get_id(SSL_get_pending_cipher(ssl())));
+  CryptoUtils::SetKeyAndIV(Prf(), pp_secret, decrypter.get());
+  return decrypter;
+}
+
+const SSL_QUIC_METHOD TlsHandshaker::kSslQuicMethod{
+    TlsHandshaker::SetEncryptionSecretCallback,
+    TlsHandshaker::WriteMessageCallback, TlsHandshaker::FlushFlightCallback,
+    TlsHandshaker::SendAlertCallback};
+
+// static
+int TlsHandshaker::SetEncryptionSecretCallback(
+    SSL* ssl,
+    enum ssl_encryption_level_t level,
+    const uint8_t* read_key,
+    const uint8_t* write_key,
+    size_t secret_len) {
+  // TODO(nharper): replace these vectors and memcpys with spans (which
+  // unfortunately doesn't yet exist in quic/platform/api).
+  std::vector<uint8_t> read_secret(secret_len), write_secret(secret_len);
+  memcpy(read_secret.data(), read_key, secret_len);
+  memcpy(write_secret.data(), write_key, secret_len);
+  HandshakerFromSsl(ssl)->SetEncryptionSecret(QuicEncryptionLevel(level),
+                                              read_secret, write_secret);
+  return 1;
+}
+
+// static
+int TlsHandshaker::WriteMessageCallback(SSL* ssl,
+                                        enum ssl_encryption_level_t level,
+                                        const uint8_t* data,
+                                        size_t len) {
+  HandshakerFromSsl(ssl)->WriteMessage(
+      QuicEncryptionLevel(level),
+      QuicStringPiece(reinterpret_cast<const char*>(data), len));
+  return 1;
+}
+
+// static
+int TlsHandshaker::FlushFlightCallback(SSL* ssl) {
+  HandshakerFromSsl(ssl)->FlushFlight();
+  return 1;
+}
+
+// static
+int TlsHandshaker::SendAlertCallback(SSL* ssl,
+                                     enum ssl_encryption_level_t level,
+                                     uint8_t desc) {
+  HandshakerFromSsl(ssl)->SendAlert(QuicEncryptionLevel(level), desc);
+  return 1;
+}
+
+void TlsHandshaker::SetEncryptionSecret(
+    EncryptionLevel level,
+    const std::vector<uint8_t>& read_secret,
+    const std::vector<uint8_t>& write_secret) {
+  std::unique_ptr<QuicEncrypter> encrypter = CreateEncrypter(write_secret);
+  session()->connection()->SetEncrypter(level, std::move(encrypter));
+  if (level != ENCRYPTION_FORWARD_SECURE) {
+    std::unique_ptr<QuicDecrypter> decrypter = CreateDecrypter(read_secret);
+    session()->connection()->SetDecrypter(level, std::move(decrypter));
+  } else {
+    // When forward-secure read keys are available, they get set as the
+    // alternative decrypter instead of the primary decrypter. One reason for
+    // this is that after the forward secure keys become available, the server
+    // still has crypto handshake messages to read at the handshake encryption
+    // level, meaning that both the ENCRYPTION_ZERO_RTT and
+    // ENCRYPTION_FORWARD_SECURE decrypters need to be available. (Tests also
+    // assume that an alternative decrypter gets set, so at some point we need
+    // to call SetAlternativeDecrypter.)
+    std::unique_ptr<QuicDecrypter> decrypter = CreateDecrypter(read_secret);
+    session()->connection()->SetAlternativeDecrypter(
+        level, std::move(decrypter), /*latch_once_used*/ true);
+  }
+}
+
+void TlsHandshaker::WriteMessage(EncryptionLevel level, QuicStringPiece data) {
+  stream_->WriteCryptoData(level, data);
+}
+
+void TlsHandshaker::FlushFlight() {}
+
+void TlsHandshaker::SendAlert(EncryptionLevel level, uint8_t desc) {
+  // TODO(nharper): Alerts should be sent on the wire as a 16-bit QUIC error
+  // code computed to be 0x100 | desc (draft-ietf-quic-tls-14, section 4.8).
+  // This puts it in the range reserved for CRYPTO_ERROR
+  // (draft-ietf-quic-transport-14, section 11.3). However, according to
+  // quic_error_codes.h, this QUIC implementation only sends 1-byte error codes
+  // right now.
+  CloseConnection(QUIC_HANDSHAKE_FAILED, "TLS handshake failure");
+}
+
+}  // namespace quic