xref: /aosp_15_r20/external/webrtc/rtc_base/openssl_session_cache.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright 2018 The WebRTC Project Authors. All rights reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef RTC_BASE_OPENSSL_SESSION_CACHE_H_
12 #define RTC_BASE_OPENSSL_SESSION_CACHE_H_
13 
14 #include <openssl/ossl_typ.h>
15 
16 #include <map>
17 #include <string>
18 
19 #include "absl/strings/string_view.h"
20 #include "rtc_base/ssl_stream_adapter.h"
21 #include "rtc_base/string_utils.h"
22 
23 #ifndef OPENSSL_IS_BORINGSSL
24 typedef struct ssl_session_st SSL_SESSION;
25 #endif
26 
27 namespace rtc {
28 
29 // The OpenSSLSessionCache maps hostnames to SSL_SESSIONS. This cache is
30 // owned by the OpenSSLAdapterFactory and is passed down to each OpenSSLAdapter
31 // created with the factory.
32 class OpenSSLSessionCache final {
33  public:
34   // Creates a new OpenSSLSessionCache using the provided the SSL_CTX and
35   // the ssl_mode. The SSL_CTX will be up_refed. ssl_ctx cannot be nullptr,
36   // the constructor immediately dchecks this.
37   OpenSSLSessionCache(SSLMode ssl_mode, SSL_CTX* ssl_ctx);
38   // Frees the cached SSL_SESSIONS and then frees the SSL_CTX.
39   ~OpenSSLSessionCache();
40 
41   OpenSSLSessionCache(const OpenSSLSessionCache&) = delete;
42   OpenSSLSessionCache& operator=(const OpenSSLSessionCache&) = delete;
43 
44   // Looks up a session by hostname. The returned SSL_SESSION is not up_refed.
45   SSL_SESSION* LookupSession(absl::string_view hostname) const;
46   // Adds a session to the cache, and up_refs it. Any existing session with the
47   // same hostname is replaced.
48   void AddSession(absl::string_view hostname, SSL_SESSION* session);
49   // Returns the true underlying SSL Context that holds these cached sessions.
50   SSL_CTX* GetSSLContext() const;
51   // The SSL Mode tht the OpenSSLSessionCache was constructed with. This cannot
52   // be changed after launch.
53   SSLMode GetSSLMode() const;
54 
55  private:
56   // Holds the SSL Mode that the OpenSSLCache was initialized with. This is
57   // immutable after creation and cannot change.
58   const SSLMode ssl_mode_;
59   /// SSL Context for all shared cached sessions. This SSL_CTX is initialized
60   //  with SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_CLIENT); Meaning
61   //  all client sessions will be added to the cache internal to the context.
62   SSL_CTX* ssl_ctx_ = nullptr;
63   // Map of hostnames to SSL_SESSIONs; holds references to the SSL_SESSIONs,
64   // which are cleaned up when the factory is destroyed.
65   // TODO(juberti): Add LRU eviction to keep the cache from growing forever.
66   std::map<std::string, SSL_SESSION*, rtc::AbslStringViewCmp> sessions_;
67   // The cache should never be copied or assigned directly.
68 };
69 
70 }  // namespace rtc
71 
72 #endif  // RTC_BASE_OPENSSL_SESSION_CACHE_H_
73