diff --git a/quic/test_tools/test_ticket_crypter.cc b/quic/test_tools/test_ticket_crypter.cc
new file mode 100644
index 0000000..4d0d93e
--- /dev/null
+++ b/quic/test_tools/test_ticket_crypter.cc
@@ -0,0 +1,74 @@
+// Copyright (c) 2020 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/test_tools/test_ticket_crypter.h"
+
+#include <cstring>
+
+#include "net/third_party/quiche/src/common/platform/api/quiche_arraysize.h"
+
+namespace quic {
+namespace test {
+
+namespace {
+
+// A TicketCrypter implementation is supposed to encrypt and decrypt session
+// tickets. However, the only requirement that is needed of a test
+// implementation is that calling Decrypt(Encrypt(input), callback) results in
+// callback being called with input. (The output of Encrypt must also not exceed
+// the overhead specified by MaxOverhead.) This test implementation encrypts
+// tickets by prepending kTicketPrefix to generate the ciphertext. The decrypt
+// function checks that the prefix is present and strips it; otherwise it
+// returns an empty vector to signal failure.
+constexpr char kTicketPrefix[] = "TEST TICKET";
+
+}  // namespace
+
+size_t TestTicketCrypter::MaxOverhead() {
+  return QUICHE_ARRAYSIZE(kTicketPrefix);
+}
+
+std::vector<uint8_t> TestTicketCrypter::Encrypt(quiche::QuicheStringPiece in) {
+  size_t prefix_len = QUICHE_ARRAYSIZE(kTicketPrefix);
+  std::vector<uint8_t> out(prefix_len + in.size());
+  memcpy(out.data(), kTicketPrefix, prefix_len);
+  memcpy(out.data() + prefix_len, in.data(), in.size());
+  return out;
+}
+
+std::vector<uint8_t> TestTicketCrypter::Decrypt(quiche::QuicheStringPiece in) {
+  size_t prefix_len = QUICHE_ARRAYSIZE(kTicketPrefix);
+  if (fail_decrypt_ || in.size() < prefix_len ||
+      memcmp(kTicketPrefix, in.data(), prefix_len) != 0) {
+    return std::vector<uint8_t>();
+  }
+  return std::vector<uint8_t>(in.begin() + prefix_len, in.end());
+}
+
+void TestTicketCrypter::Decrypt(
+    quiche::QuicheStringPiece in,
+    std::unique_ptr<ProofSource::DecryptCallback> callback) {
+  auto decrypted_ticket = Decrypt(in);
+  if (run_async_) {
+    pending_callbacks_.push_back({std::move(callback), decrypted_ticket});
+  } else {
+    callback->Run(decrypted_ticket);
+  }
+}
+
+void TestTicketCrypter::SetRunCallbacksAsync(bool run_async) {
+  run_async_ = run_async;
+}
+
+size_t TestTicketCrypter::NumPendingCallbacks() {
+  return pending_callbacks_.size();
+}
+
+void TestTicketCrypter::RunPendingCallback(size_t n) {
+  const PendingCallback& callback = pending_callbacks_[n];
+  callback.callback->Run(callback.decrypted_ticket);
+}
+
+}  // namespace test
+}  // namespace quic