Add ability to set TLS 1.3 ciphersuites in SSLContext

Summary: Add support for Openssl's TLS 1.3 ciphersuites API. SSL_CTX_set_ciphersuites was added in OpenSSL 1.1.1, so guard it with a prereq.

Reviewed By: yfeldblum, mingtaoy

Differential Revision: D24542765

fbshipit-source-id: d281bb2262cd456823da1896c0c77c3ba4ab78ce

folly/io/async/SSLContext.cpp

@@ -771,6 +771,15 @@ void SSLContext::setSessionLifecycleCallbacks(
   sessionLifecycleCallbacks_ = std::move(cb);
 }
 
+#if FOLLY_OPENSSL_PREREQ(1, 1, 1)
+void SSLContext::setCiphersuitesOrThrow(const std::string& ciphersuites) {
+  auto rc = SSL_CTX_set_ciphersuites(ctx_, ciphersuites.c_str());
+  if (rc == 0) {
+    throw std::runtime_error("SSL_CTX_set_ciphersuites: " + getErrors());
+  }
+}
+#endif // FOLLY_OPENSSL_PREREQ(1, 1, 1)
+
 std::ostream& operator<<(std::ostream& os, const PasswordCollector& collector) {
   os << collector.describe();
   return os;

folly/io/async/SSLContext.h

@@ -151,20 +151,21 @@ class SSLContext {
   virtual ~SSLContext();
 
   /**
-   * Set default ciphers to be used in SSL handshake process.
+   * Set default TLS 1.2 and below ciphers to be used in SSL handshake process.
    *
    * @param ciphers A list of ciphers to use for TLSv1.0
    */
   virtual void ciphers(const std::string& ciphers);
 
   /**
-   * Low-level method that attempts to set the provided ciphers on the
-   * SSL_CTX object, and throws if something goes wrong.
+   * Low-level method that attempts to set the provided TLS 1.2
+   * and below ciphers on the SSL_CTX object,
+   * and throws if something goes wrong.
    */
   virtual void setCiphersOrThrow(const std::string& ciphers);
 
   /**
-   * Set default ciphers to be used in SSL handshake process.
+   * Set default TLS 1.2 and below ciphers to be used in SSL handshake process.
    */
   template <typename Iterator>
   void setCipherList(Iterator ibegin, Iterator iend) {
@@ -559,6 +560,15 @@ class SSLContext {
   void setSessionLifecycleCallbacks(
       std::unique_ptr<SessionLifecycleCallbacks> cb);
 
+#if FOLLY_OPENSSL_PREREQ(1, 1, 1)
+  /**
+   * Set the TLS 1.3 ciphersuites to be used in the SSL handshake, in
+   * order of preference.
+   * Throws if unsuccessful.
+   */
+  void setCiphersuitesOrThrow(const std::string& ciphersuites);
+#endif
+
   [[deprecated("Use folly::ssl::init")]] static void initializeOpenSSL();
 
  protected:

folly/io/async/test/SSLContextTest.cpp

@@ -29,6 +29,7 @@ class SSLContextTest : public testing::Test {
  public:
   SSLContext ctx;
   void verifySSLCipherList(const vector<string>& ciphers);
+  void verifySSLCiphersuites(const vector<string>& ciphersuites);
 };
 
 void SSLContextTest::verifySSLCipherList(const vector<string>& ciphers) {
@@ -36,6 +37,11 @@ void SSLContextTest::verifySSLCipherList(const vector<string>& ciphers) {
   EXPECT_EQ(ciphers, test::getNonTLS13CipherList(ssl.get()));
 }
 
+void SSLContextTest::verifySSLCiphersuites(const vector<string>& ciphersuites) {
+  ssl::SSLUniquePtr ssl(ctx.createSSL());
+  EXPECT_EQ(ciphersuites, test::getTLS13Ciphersuites(ssl.get()));
+}
+
 TEST_F(SSLContextTest, TestSetCipherString) {
   ctx.ciphers("AES128-SHA:ECDHE-RSA-AES256-SHA384");
   verifySSLCipherList({"AES128-SHA", "ECDHE-RSA-AES256-SHA384"});
@@ -205,4 +211,24 @@ TEST_F(SSLContextTest, TestInvalidSigAlgThrows) {
   }
 }
 #endif
+
+#if FOLLY_OPENSSL_PREREQ(1, 1, 1)
+TEST_F(SSLContextTest, TestSetCiphersuites) {
+  std::vector<std::string> ciphersuitesList{
+      "TLS_AES_128_CCM_SHA256",
+      "TLS_AES_128_GCM_SHA256",
+  };
+  std::string ciphersuites;
+  folly::join(":", ciphersuitesList, ciphersuites);
+  ctx.setCiphersuitesOrThrow(ciphersuites);
+
+  verifySSLCiphersuites(ciphersuitesList);
+}
+
+TEST_F(SSLContextTest, TestSetInvalidCiphersuite) {
+  EXPECT_THROW(
+      ctx.setCiphersuitesOrThrow("ECDHE-ECDSA-AES256-GCM-SHA384"),
+      std::runtime_error);
+}
+#endif // FOLLY_OPENSSL_PREREQ(1, 1, 1)
 } // namespace folly

folly/io/async/test/SSLUtil.cpp

@@ -71,5 +71,18 @@ std::vector<std::string> getNonTLS13CipherList(SSL* s) {
   return ciphers;
 }
 
+std::vector<std::string> getTLS13Ciphersuites(SSL* s) {
+  auto ciphers = getCiphersFromSSL(s);
+  ciphers.erase(
+      std::remove_if(
+          begin(ciphers),
+          end(ciphers),
+          [](const std::string& cipher) {
+            return suitesFor13.count(cipher) == 0;
+          }),
+      end(ciphers));
+  return ciphers;
+}
+
 } // namespace test
 } // namespace folly

folly/io/async/test/SSLUtil.h

@@ -30,5 +30,7 @@ std::vector<std::string> getCiphersFromSSL(SSL* s);
 
 std::vector<std::string> getNonTLS13CipherList(SSL* s);
 
+std::vector<std::string> getTLS13Ciphersuites(SSL* s);
+
 } // namespace test
 } // namespace folly