2 * Copyright 2014 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
26 #include <openssl/ssl.h>
27 #include <openssl/tls1.h>
29 #include <sys/socket.h>
30 #include <netinet/in.h>
32 #include <glog/logging.h>
34 #ifndef FOLLY_NO_CONFIG
35 #include <folly/folly-config.h>
41 * Override the default password collector.
43 class PasswordCollector {
45 virtual ~PasswordCollector() {}
47 * Interface for customizing how to collect private key password.
49 * By default, OpenSSL prints a prompt on screen and request for password
50 * while loading private key. To implement a custom password collector,
51 * implement this interface and register it with TSSLSocketFactory.
53 * @param password Pass collected password back to OpenSSL
54 * @param size Maximum length of password including nullptr character
56 virtual void getPassword(std::string& password, int size) = 0;
59 * Return a description of this collector for logging purposes
61 virtual std::string describe() const = 0;
65 * Wrap OpenSSL SSL_CTX into a class.
76 enum SSLVerifyPeerEnum{
79 VERIFY_REQ_CLIENT_CERT,
83 struct NextProtocolsItem {
85 std::list<std::string> protocols;
88 struct AdvertisedNextProtocolsItem {
89 unsigned char *protocols;
95 * Convenience function to call getErrors() with the current errno value.
97 * Make sure that you only call this when there was no intervening operation
98 * since the last OpenSSL error that may have changed the current errno value.
100 static std::string getErrors() {
101 return getErrors(errno);
107 * @param version The lowest or oldest SSL version to support.
109 explicit SSLContext(SSLVersion version = TLSv1);
110 virtual ~SSLContext();
113 * Set default ciphers to be used in SSL handshake process.
115 * @param ciphers A list of ciphers to use for TLSv1.0
117 virtual void ciphers(const std::string& ciphers);
120 * Low-level method that attempts to set the provided ciphers on the
121 * SSL_CTX object, and throws if something goes wrong.
123 virtual void setCiphersOrThrow(const std::string& ciphers);
126 * Method to set verification option in the context object.
128 * @param verifyPeer SSLVerifyPeerEnum indicating the verification
131 virtual void setVerificationOption(const SSLVerifyPeerEnum& verifyPeer);
134 * Method to check if peer verfication is set.
136 * @return true if peer verification is required.
139 virtual bool needsPeerVerification() {
140 return (verifyPeer_ == SSLVerifyPeerEnum::VERIFY ||
141 verifyPeer_ == SSLVerifyPeerEnum::VERIFY_REQ_CLIENT_CERT);
145 * Method to fetch Verification mode for a SSLVerifyPeerEnum.
146 * verifyPeer cannot be SSLVerifyPeerEnum::USE_CTX since there is no
149 * @param verifyPeer SSLVerifyPeerEnum for which the flags need to
152 * @return mode flags that can be used with SSL_set_verify
154 static int getVerificationMode(const SSLVerifyPeerEnum& verifyPeer);
157 * Method to fetch Verification mode determined by the options
158 * set using setVerificationOption.
160 * @return mode flags that can be used with SSL_set_verify
162 virtual int getVerificationMode();
165 * Enable/Disable authentication. Peer name validation can only be done
166 * if checkPeerCert is true.
168 * @param checkPeerCert If true, require peer to present valid certificate
169 * @param checkPeerName If true, validate that the certificate common name
170 * or alternate name(s) of peer matches the hostname
172 * @param peerName If non-empty, validate that the certificate common
173 * name of peer matches the given string (altername
174 * name(s) are not used in this case).
176 virtual void authenticate(bool checkPeerCert, bool checkPeerName,
177 const std::string& peerName = std::string());
179 * Load server certificate.
181 * @param path Path to the certificate file
182 * @param format Certificate file format
184 virtual void loadCertificate(const char* path, const char* format = "PEM");
188 * @param path Path to the private key file
189 * @param format Private key file format
191 virtual void loadPrivateKey(const char* path, const char* format = "PEM");
193 * Load trusted certificates from specified file.
195 * @param path Path to trusted certificate file
197 virtual void loadTrustedCertificates(const char* path);
199 * Load trusted certificates from specified X509 certificate store.
201 * @param store X509 certificate store.
203 virtual void loadTrustedCertificates(X509_STORE* store);
205 * Load a client CA list for validating clients
207 virtual void loadClientCAList(const char* path);
209 * Override default OpenSSL password collector.
211 * @param collector Instance of user defined password collector
213 virtual void passwordCollector(std::shared_ptr<PasswordCollector> collector);
215 * Obtain password collector.
217 * @return User defined password collector
219 virtual std::shared_ptr<PasswordCollector> passwordCollector() {
222 #if OPENSSL_VERSION_NUMBER >= 0x1000105fL && !defined(OPENSSL_NO_TLSEXT)
224 * Provide SNI support
226 enum ServerNameCallbackResult {
228 SERVER_NAME_NOT_FOUND,
229 SERVER_NAME_NOT_FOUND_ALERT_FATAL,
232 * Callback function from openssl to give the application a
233 * chance to check the tlsext_hostname just right after parsing
234 * the Client Hello or Server Hello message.
236 * It is for the server to switch the SSL to another SSL_CTX
237 * to continue the handshake. (i.e. Server Name Indication, SNI, in RFC6066).
239 * If the ServerNameCallback returns:
241 * server: Send a tlsext_hostname in the Server Hello
243 * SERVER_NAME_NOT_FOUND:
244 * server: Does not send a tlsext_hostname in Server Hello
245 * and continue the handshake.
247 * SERVER_NAME_NOT_FOUND_ALERT_FATAL:
248 * server and client: Send fatal TLS1_AD_UNRECOGNIZED_NAME alert to
251 * Quote from RFC 6066:
253 * If the server understood the ClientHello extension but
254 * does not recognize the server name, the server SHOULD take one of two
255 * actions: either abort the handshake by sending a fatal-level
256 * unrecognized_name(112) alert or continue the handshake. It is NOT
257 * RECOMMENDED to send a warning-level unrecognized_name(112) alert,
258 * because the client's behavior in response to warning-level alerts is
264 * Set the ServerNameCallback
266 typedef std::function<ServerNameCallbackResult(SSL* ssl)> ServerNameCallback;
267 virtual void setServerNameCallback(const ServerNameCallback& cb);
270 * Generic callbacks that are run after we get the Client Hello (right
271 * before we run the ServerNameCallback)
273 typedef std::function<void(SSL* ssl)> ClientHelloCallback;
274 virtual void addClientHelloCallback(const ClientHelloCallback& cb);
278 * Create an SSL object from this context.
280 SSL* createSSL() const;
283 * Set the options on the SSL_CTX object.
285 void setOptions(long options);
287 #ifdef OPENSSL_NPN_NEGOTIATED
289 * Set the list of protocols that this SSL context supports. In server
290 * mode, this is the list of protocols that will be advertised for Next
291 * Protocol Negotiation (NPN). In client mode, the first protocol
292 * advertised by the server that is also on this list is
293 * chosen. Invoking this function with a list of length zero causes NPN
296 * @param protocols List of protocol names. This method makes a copy,
297 * so the caller needn't keep the list in scope after
298 * the call completes. The list must have at least
299 * one element to enable NPN. Each element must have
300 * a string length < 256.
301 * @return true if NPN has been activated. False if NPN is disabled.
303 bool setAdvertisedNextProtocols(const std::list<std::string>& protocols);
305 * Set weighted list of lists of protocols that this SSL context supports.
306 * In server mode, each element of the list contains a list of protocols that
307 * could be advertised for Next Protocol Negotiation (NPN). The list of
308 * protocols that will be advertised to a client is selected randomly, based
309 * on weights of elements. Client mode doesn't support randomized NPN, so
310 * this list should contain only 1 element. The first protocol advertised
311 * by the server that is also on the list of protocols of this element is
312 * chosen. Invoking this function with a list of length zero causes NPN
315 * @param items List of NextProtocolsItems, Each item contains a list of
316 * protocol names and weight. After the call of this fucntion
317 * each non-empty list of protocols will be advertised with
318 * probability weight/sum_of_weights. This method makes a copy,
319 * so the caller needn't keep the list in scope after the call
320 * completes. The list must have at least one element with
321 * non-zero weight and non-empty protocols list to enable NPN.
322 * Each name of the protocol must have a string length < 256.
323 * @return true if NPN has been activated. False if NPN is disabled.
325 bool setRandomizedAdvertisedNextProtocols(
326 const std::list<NextProtocolsItem>& items);
329 * Disables NPN on this SSL context.
331 void unsetNextProtocols();
332 void deleteNextProtocolsStrings();
334 #if defined(SSL_MODE_HANDSHAKE_CUTTHROUGH) && \
335 FOLLY_SSLCONTEXT_USE_TLS_FALSE_START
336 bool canUseFalseStartWithCipher(const SSL_CIPHER *cipher);
338 #endif // OPENSSL_NPN_NEGOTIATED
341 * Gets the underlying SSL_CTX for advanced usage
343 SSL_CTX *getSSLCtx() const {
354 * Set preferences for how to treat locks in OpenSSL. This must be
355 * called before the instantiation of any SSLContext objects, otherwise
356 * the defaults will be used.
358 * OpenSSL has a lock for each module rather than for each object or
359 * data that needs locking. Some locks protect only refcounts, and
360 * might be better as spinlocks rather than mutexes. Other locks
361 * may be totally unnecessary if the objects being protected are not
362 * shared between threads in the application.
364 * By default, all locks are initialized as mutexes. OpenSSL's lock usage
365 * may change from version to version and you should know what you are doing
366 * before disabling any locks entirely.
368 * Example: if you don't share SSL sessions between threads in your
369 * application, you may be able to do this
371 * setSSLLockTypes({{CRYPTO_LOCK_SSL_SESSION, SSLContext::LOCK_NONE}})
373 static void setSSLLockTypes(std::map<int, SSLLockType> lockTypes);
376 * Examine OpenSSL's error stack, and return a string description of the
379 * This operation removes the errors from OpenSSL's error stack.
381 static std::string getErrors(int errnoCopy);
384 * We want to vary which cipher we'll use based on the client's TLS version.
386 void switchCiphersIfTLS11(
388 const std::string& tls11CipherString
391 bool checkPeerName() { return checkPeerName_; }
392 std::string peerFixedName() { return peerFixedName_; }
395 * Helper to match a hostname versus a pattern.
397 static bool matchName(const char* host, const char* pattern, int size);
400 * Functions for setting up and cleaning up openssl.
401 * They can be invoked during the start of the application.
403 static void initializeOpenSSL();
404 static void cleanupOpenSSL();
407 * Default randomize method.
409 static void randomize();
415 SSLVerifyPeerEnum verifyPeer_{SSLVerifyPeerEnum::NO_VERIFY};
418 std::string peerFixedName_;
419 std::shared_ptr<PasswordCollector> collector_;
420 #if OPENSSL_VERSION_NUMBER >= 0x1000105fL && !defined(OPENSSL_NO_TLSEXT)
421 ServerNameCallback serverNameCb_;
422 std::vector<ClientHelloCallback> clientHelloCbs_;
425 static std::mutex mutex_;
426 static bool initialized_;
428 #ifndef SSLCONTEXT_NO_REFCOUNT
429 static uint64_t count_;
432 #ifdef OPENSSL_NPN_NEGOTIATED
434 * Wire-format list of advertised protocols for use in NPN.
436 std::vector<AdvertisedNextProtocolsItem> advertisedNextProtocols_;
437 static int sNextProtocolsExDataIndex_;
439 static int advertisedNextProtocolCallback(SSL* ssl,
440 const unsigned char** out, unsigned int* outlen, void* data);
441 static int selectNextProtocolCallback(
442 SSL* ssl, unsigned char **out, unsigned char *outlen,
443 const unsigned char *server, unsigned int server_len, void *args);
445 #if defined(SSL_MODE_HANDSHAKE_CUTTHROUGH) && \
446 FOLLY_SSLCONTEXT_USE_TLS_FALSE_START
447 // This class contains all allowed ciphers for SSL false start. Call its
448 // `canUseFalseStartWithCipher` to check for cipher qualification.
449 class SSLFalseStartChecker {
451 SSLFalseStartChecker();
453 bool canUseFalseStartWithCipher(const SSL_CIPHER *cipher);
456 static int compare_ulong(const void *x, const void *y);
458 // All ciphers that are allowed to use false start.
459 unsigned long ciphers_[47];
460 unsigned int length_;
464 SSLFalseStartChecker falseStartChecker_;
467 #endif // OPENSSL_NPN_NEGOTIATED
469 static int passwordCallback(char* password, int size, int, void* data);
471 #if OPENSSL_VERSION_NUMBER >= 0x1000105fL && !defined(OPENSSL_NO_TLSEXT)
473 * The function that will be called directly from openssl
474 * in order for the application to get the tlsext_hostname just after
475 * parsing the Client Hello or Server Hello message. It will then call
476 * the serverNameCb_ function object. Hence, it is sort of a
477 * wrapper/proxy between serverNameCb_ and openssl.
479 * The openssl's primary intention is for SNI support, but we also use it
480 * generically for performing logic after the Client Hello comes in.
482 static int baseServerNameOpenSSLCallback(
484 int* al /* alert (return value) */,
489 std::string providedCiphersString_;
491 // Functions are called when locked by the calling function.
492 static void initializeOpenSSLLocked();
493 static void cleanupOpenSSLLocked();
496 typedef std::shared_ptr<SSLContext> SSLContextPtr;
498 std::ostream& operator<<(std::ostream& os, const folly::PasswordCollector& collector);
503 * Validate that the peer certificate's common name or subject alt names
504 * match what we expect. Currently this only checks for IPs within
505 * subject alt names but it could easily be expanded to check common name
506 * and hostnames as well.
508 * @param cert X509* peer certificate
509 * @param addr sockaddr object containing sockaddr to verify
510 * @param addrLen length of sockaddr as returned by getpeername or accept
511 * @return true iff a subject altname IP matches addr
513 // TODO(agartrell): Add support for things like common name when
515 static bool validatePeerCertNames(X509* cert,
516 const sockaddr* addr,
520 * Get the peer socket address from an X509_STORE_CTX*. Unlike the
521 * accept, getsockname, getpeername, etc family of operations, addrLen's
522 * initial value is ignored and reset.
524 * @param ctx Context from which to retrieve peer sockaddr
525 * @param addrStorage out param for address
526 * @param addrLen out param for length of address
527 * @return true on success, false on failure
529 static bool getPeerAddressFromX509StoreCtx(X509_STORE_CTX* ctx,
530 sockaddr_storage* addrStorage,