Rewrite session cache in OpenSSL ports.

net/ssl/ssl_client_session_cache_openssl_unittest.cc

+// Copyright 2015 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/ssl/ssl_client_session_cache_openssl.h"
+
+#include <openssl/ssl.h>
+
+#include "base/strings/string_number_conversions.h"
+#include "base/test/simple_test_clock.h"
+#include "net/ssl/scoped_openssl_types.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+// Test basic insertion and lookup operations.
+TEST(SSLClientSessionCacheOpenSSLTest, Basic) {
+  SSLClientSessionCacheOpenSSL::Config config;
+  SSLClientSessionCacheOpenSSL cache(config);
+
+  ScopedSSL_SESSION session1(SSL_SESSION_new());
+  ScopedSSL_SESSION session2(SSL_SESSION_new());
+  ScopedSSL_SESSION session3(SSL_SESSION_new());
+  EXPECT_EQ(1, session1->references);
+  EXPECT_EQ(1, session2->references);
+  EXPECT_EQ(1, session3->references);
+
+  EXPECT_EQ(nullptr, cache.Lookup("key1"));
+  EXPECT_EQ(nullptr, cache.Lookup("key2"));
+  EXPECT_EQ(0u, cache.size());
+
+  cache.Insert("key1", session1.get());
+  EXPECT_EQ(session1.get(), cache.Lookup("key1"));
+  EXPECT_EQ(nullptr, cache.Lookup("key2"));
+  EXPECT_EQ(1u, cache.size());
+
+  cache.Insert("key2", session2.get());
+  EXPECT_EQ(session1.get(), cache.Lookup("key1"));
+  EXPECT_EQ(session2.get(), cache.Lookup("key2"));
+  EXPECT_EQ(2u, cache.size());
+
+  EXPECT_EQ(2, session1->references);
+  EXPECT_EQ(2, session2->references);
+
+  cache.Insert("key1", session3.get());
+  EXPECT_EQ(session3.get(), cache.Lookup("key1"));

[Ryan Sleevi, 2015/04/02 20:00:14]

EXPECT_NEQ(session3.get(), session1.get()) ?

[davidben, 2015/04/03 00:37:11]

Er. That's just asserting that SSL_SESSION_new returns different pointers each
time, no?

[Ryan Sleevi, 2015/04/03 00:59:02]

Well, and that no one accidentally stores a pointer to session3.get in the
interim of the test.

[davidben, 2015/04/07 18:35:36]

But that can be determined trivially by inspection of this function. It's not a
property of BoringSSL or SSLClientSessionCacheOpenSSL. session3.get() is a local
variable.

It's also implied by lines 50 and 52.

+  EXPECT_EQ(session2.get(), cache.Lookup("key2"));
+  EXPECT_EQ(2u, cache.size());
+
+  EXPECT_EQ(1, session1->references);
+  EXPECT_EQ(2, session2->references);
+  EXPECT_EQ(2, session3->references);
+
+  cache.Flush();
+  EXPECT_EQ(nullptr, cache.Lookup("key1"));
+  EXPECT_EQ(nullptr, cache.Lookup("key2"));
+  EXPECT_EQ(nullptr, cache.Lookup("key3"));
+  EXPECT_EQ(0u, cache.size());
+
+  EXPECT_EQ(1, session1->references);
+  EXPECT_EQ(1, session2->references);
+  EXPECT_EQ(1, session3->references);
+}
+
+// Test that a session may be inserted at two different keys. This should never
+// be necessary, but the API doesn't prohibit it.
+TEST(SSLClientSessionCacheOpenSSLTest, DoubleInsert) {
+  SSLClientSessionCacheOpenSSL::Config config;
+  SSLClientSessionCacheOpenSSL cache(config);
+
+  ScopedSSL_SESSION session(SSL_SESSION_new());
+  EXPECT_EQ(1, session->references);
+
+  EXPECT_EQ(nullptr, cache.Lookup("key1"));
+  EXPECT_EQ(nullptr, cache.Lookup("key2"));
+  EXPECT_EQ(0u, cache.size());
+
+  cache.Insert("key1", session.get());
+  EXPECT_EQ(session.get(), cache.Lookup("key1"));
+  EXPECT_EQ(nullptr, cache.Lookup("key2"));
+  EXPECT_EQ(1u, cache.size());
+
+  EXPECT_EQ(2, session->references);
+
+  cache.Insert("key2", session.get());
+  EXPECT_EQ(session.get(), cache.Lookup("key1"));
+  EXPECT_EQ(session.get(), cache.Lookup("key2"));
+  EXPECT_EQ(2u, cache.size());
+
+  EXPECT_EQ(3, session->references);
+
+  cache.Flush();
+  EXPECT_EQ(nullptr, cache.Lookup("key1"));
+  EXPECT_EQ(nullptr, cache.Lookup("key2"));
+  EXPECT_EQ(0u, cache.size());
+
+  EXPECT_EQ(1, session->references);
+}
+
+// Tests that the session cache's size is correctly bounded.
+TEST(SSLClientSessionCacheOpenSSLTest, MaxEntries) {
+  SSLClientSessionCacheOpenSSL::Config config;
+  config.max_entries = 3;
+  SSLClientSessionCacheOpenSSL cache(config);
+  base::SimpleTestClock* clock = new base::SimpleTestClock;

[Ryan Sleevi, 2015/04/02 20:00:14]

Why store the naked pointer? It's unused.

[davidben, 2015/04/03 00:37:11]

Copy-pasta. Removed.

+  cache.SetClockForTesting(make_scoped_ptr(clock));
+
+  ScopedSSL_SESSION session1(SSL_SESSION_new());
+  ScopedSSL_SESSION session2(SSL_SESSION_new());
+  ScopedSSL_SESSION session3(SSL_SESSION_new());
+  ScopedSSL_SESSION session4(SSL_SESSION_new());
+
+  // Insert three entries.
+  cache.Insert("key1", session1.get());
+  cache.Insert("key2", session2.get());
+  cache.Insert("key3", session3.get());
+  EXPECT_EQ(session1.get(), cache.Lookup("key1"));
+  EXPECT_EQ(session2.get(), cache.Lookup("key2"));
+  EXPECT_EQ(session3.get(), cache.Lookup("key3"));
+  EXPECT_EQ(3u, cache.size());
+
+  // On insertion of a fourth, the first is removed.
+  cache.Insert("key4", session4.get());
+  EXPECT_EQ(nullptr, cache.Lookup("key1"));
+  EXPECT_EQ(session4.get(), cache.Lookup("key4"));
+  EXPECT_EQ(session3.get(), cache.Lookup("key3"));
+  EXPECT_EQ(session2.get(), cache.Lookup("key2"));
+  EXPECT_EQ(3u, cache.size());
+
+  // Despite being newest, the next to be removed is session4 as it was accessed
+  // least. recently.
+  cache.Insert("key1", session1.get());
+  EXPECT_EQ(session1.get(), cache.Lookup("key1"));
+  EXPECT_EQ(session2.get(), cache.Lookup("key2"));
+  EXPECT_EQ(session3.get(), cache.Lookup("key3"));
+  EXPECT_EQ(nullptr, cache.Lookup("key4"));
+  EXPECT_EQ(3u, cache.size());
+}
+
+// Tests that session expiration works properly.
+TEST(SSLClientSessionCacheOpenSSLTest, Expiration) {
+  const size_t kNumEntries = 20;
+  const size_t kExpirationCheckCount = 10;
+  const base::TimeDelta kTimeout = base::TimeDelta::FromSeconds(1000);
+
+  SSLClientSessionCacheOpenSSL::Config config;
+  config.expiration_check_count = kExpirationCheckCount;
+  config.timeout = kTimeout;
+  SSLClientSessionCacheOpenSSL cache(config);
+  base::SimpleTestClock* clock = new base::SimpleTestClock;
+  cache.SetClockForTesting(make_scoped_ptr(clock));
+
+  // Add |kNumEntries - 1| entries.
+  for (size_t i = 0; i < kNumEntries - 1; i++) {
+    ScopedSSL_SESSION session(SSL_SESSION_new());
+    cache.Insert(base::SizeTToString(i), session.get());
+  }
+  EXPECT_EQ(kNumEntries - 1, cache.size());
+
+  // Expire all the previous entries and insert one more entry.
+  clock->Advance(kTimeout * 2);
+  ScopedSSL_SESSION session(SSL_SESSION_new());
+  cache.Insert("key", session.get());
+
+  // All entries are still in the cache.
+  EXPECT_EQ(kNumEntries, cache.size());
+
+  // Perform one fewer lookup than needed to trigger the expiration check. This
+  // shall not expire any session.
+  for (size_t i = 0; i < kExpirationCheckCount - 1; i++)
+    cache.Lookup("key");
+
+  // All entries are still in the cache.
+  EXPECT_EQ(kNumEntries, cache.size());
+
+  // Perform one more lookup. This will expire all sessions but the last one.
+  cache.Lookup("key");
+  EXPECT_EQ(1u, cache.size());
+  EXPECT_EQ(session.get(), cache.Lookup("key"));
+  for (size_t i = 0; i < kNumEntries - 1; i++) {
+    SCOPED_TRACE(i);
+    EXPECT_EQ(nullptr, cache.Lookup(base::SizeTToString(i)));
+  }
+}
+
+// Tests that Lookup performs an expiration check before returning a cached
+// session.
+TEST(SSLClientSessionCacheOpenSSLTest, LookupExpirationCheck) {
+  // kExpirationCheckCount is set to a suitably large number so the automated
+  // pruning never triggers.
+  const size_t kExpirationCheckCount = 1000;
+  const base::TimeDelta kTimeout = base::TimeDelta::FromSeconds(1000);
+
+  SSLClientSessionCacheOpenSSL::Config config;
+  config.expiration_check_count = kExpirationCheckCount;
+  config.timeout = kTimeout;
+  SSLClientSessionCacheOpenSSL cache(config);
+  base::SimpleTestClock* clock = new base::SimpleTestClock;
+  cache.SetClockForTesting(make_scoped_ptr(clock));
+
+  // Insert an entry into the session cache.
+  ScopedSSL_SESSION session(SSL_SESSION_new());
+  cache.Insert("key", session.get());
+  EXPECT_EQ(session.get(), cache.Lookup("key"));
+  EXPECT_EQ(1u, cache.size());
+
+  // Expire the session.
+  clock->Advance(kTimeout * 2);
+
+  // The entry has not been removed yet.
+  EXPECT_EQ(1u, cache.size());
+
+  // But it will not be returned on lookup and gets pruned at that point.
+  EXPECT_EQ(nullptr, cache.Lookup("key"));
+  EXPECT_EQ(0u, cache.size());
+
+  // Sessions also are treated as expired if the clock rewinds.
+  cache.Insert("key", session.get());
+  EXPECT_EQ(session.get(), cache.Lookup("key"));
+  EXPECT_EQ(1u, cache.size());
+
+  clock->Advance(-kTimeout * 2);
+
+  EXPECT_EQ(nullptr, cache.Lookup("key"));
+  EXPECT_EQ(0u, cache.size());
+}
+
+}  // namespace net