Add 'ciphersuites=' method to allow setting of TLSv1.3 cipher suites along with some unit tests (#493)

Add OpenSSL::SSL::SSLContext#ciphersuites= method along with unit tests.

Author: kmdz1

ext/openssl/extconf.rb

@@ -169,6 +169,7 @@ def find_openssl_library
 
 # added in 1.1.1
 have_func("EVP_PKEY_check")
+have_func("SSL_CTX_set_ciphersuites")
 
 # added in 3.0.0
 have_func("SSL_set0_tmp_dh_pkey")

ext/openssl/ossl_ssl.c

@@ -959,27 +959,13 @@ ossl_sslctx_get_ciphers(VALUE self)
     return ary;
 }
 
-/*
- * call-seq:
- *    ctx.ciphers = "cipher1:cipher2:..."
- *    ctx.ciphers = [name, ...]
- *    ctx.ciphers = [[name, version, bits, alg_bits], ...]
- *
- * Sets the list of available cipher suites for this context.  Note in a server
- * context some ciphers require the appropriate certificates.  For example, an
- * RSA cipher suite can only be chosen when an RSA certificate is available.
- */
 static VALUE
-ossl_sslctx_set_ciphers(VALUE self, VALUE v)
+build_cipher_string(VALUE v)
 {
-    SSL_CTX *ctx;
     VALUE str, elem;
     int i;
 
-    rb_check_frozen(self);
-    if (NIL_P(v))
-	return v;
-    else if (RB_TYPE_P(v, T_ARRAY)) {
+    if (RB_TYPE_P(v, T_ARRAY)) {
         str = rb_str_new(0, 0);
         for (i = 0; i < RARRAY_LEN(v); i++) {
             elem = rb_ary_entry(v, i);
@@ -993,14 +979,67 @@ ossl_sslctx_set_ciphers(VALUE self, VALUE v)
         StringValue(str);
     }
 
+    return str;
+}
+
+/*
+ * call-seq:
+ *    ctx.ciphers = "cipher1:cipher2:..."
+ *    ctx.ciphers = [name, ...]
+ *    ctx.ciphers = [[name, version, bits, alg_bits], ...]
+ *
+ * Sets the list of available cipher suites for this context.  Note in a server
+ * context some ciphers require the appropriate certificates.  For example, an
+ * RSA cipher suite can only be chosen when an RSA certificate is available.
+ */
+static VALUE
+ossl_sslctx_set_ciphers(VALUE self, VALUE v)
+{
+    SSL_CTX *ctx;
+    VALUE str;
+
+    rb_check_frozen(self);
+    if (NIL_P(v))
+        return v;
+
+    str = build_cipher_string(v);
+
     GetSSLCTX(self, ctx);
-    if (!SSL_CTX_set_cipher_list(ctx, StringValueCStr(str))) {
+    if (!SSL_CTX_set_cipher_list(ctx, StringValueCStr(str)))
         ossl_raise(eSSLError, "SSL_CTX_set_cipher_list");
-    }
 
     return v;
 }
 
+#ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
+/*
+ * call-seq:
+ *    ctx.ciphersuites = "cipher1:cipher2:..."
+ *    ctx.ciphersuites = [name, ...]
+ *    ctx.ciphersuites = [[name, version, bits, alg_bits], ...]
+ *
+ * Sets the list of available TLSv1.3 cipher suites for this context.
+ */
+static VALUE
+ossl_sslctx_set_ciphersuites(VALUE self, VALUE v)
+{
+    SSL_CTX *ctx;
+    VALUE str;
+
+    rb_check_frozen(self);
+    if (NIL_P(v))
+        return v;
+
+    str = build_cipher_string(v);
+
+    GetSSLCTX(self, ctx);
+    if (!SSL_CTX_set_ciphersuites(ctx, StringValueCStr(str)))
+        ossl_raise(eSSLError, "SSL_CTX_set_ciphersuites");
+
+    return v;
+}
+#endif
+
 #ifndef OPENSSL_NO_DH
 /*
  * call-seq:
@@ -2703,6 +2742,9 @@ Init_ossl_ssl(void)
 			     ossl_sslctx_set_minmax_proto_version, 2);
     rb_define_method(cSSLContext, "ciphers",     ossl_sslctx_get_ciphers, 0);
     rb_define_method(cSSLContext, "ciphers=",    ossl_sslctx_set_ciphers, 1);
+#ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
+    rb_define_method(cSSLContext, "ciphersuites=", ossl_sslctx_set_ciphersuites, 1);
+#endif
 #ifndef OPENSSL_NO_DH
     rb_define_method(cSSLContext, "tmp_dh=", ossl_sslctx_set_tmp_dh, 1);
 #endif

test/openssl/test_ssl.rb

@@ -1569,6 +1569,95 @@ def test_tmp_dh_callback
     end
   end
 
+  def test_ciphersuites_method_tls_connection
+    ssl_ctx = OpenSSL::SSL::SSLContext.new
+    if !tls13_supported? || !ssl_ctx.respond_to?(:ciphersuites=)
+      pend 'TLS 1.3 not supported'
+    end
+
+    csuite = ['TLS_AES_128_GCM_SHA256', 'TLSv1.3', 128, 128]
+    inputs = [csuite[0], [csuite[0]], [csuite]]
+
+    start_server do |port|
+      inputs.each do |input|
+        cli_ctx = OpenSSL::SSL::SSLContext.new
+        cli_ctx.min_version = cli_ctx.max_version = OpenSSL::SSL::TLS1_3_VERSION
+        cli_ctx.ciphersuites = input
+
+        server_connect(port, cli_ctx) do |ssl|
+          assert_equal('TLSv1.3', ssl.ssl_version)
+          assert_equal(csuite[0], ssl.cipher[0])
+          ssl.puts('abc'); assert_equal("abc\n", ssl.gets)
+        end
+      end
+    end
+  end
+
+  def test_ciphersuites_method_nil_argument
+    ssl_ctx = OpenSSL::SSL::SSLContext.new
+    pend 'ciphersuites= method is missing' unless ssl_ctx.respond_to?(:ciphersuites=)
+
+    assert_nothing_raised { ssl_ctx.ciphersuites = nil }
+  end
+
+  def test_ciphersuites_method_frozen_object
+    ssl_ctx = OpenSSL::SSL::SSLContext.new
+    pend 'ciphersuites= method is missing' unless ssl_ctx.respond_to?(:ciphersuites=)
+
+    ssl_ctx.freeze
+    assert_raise(FrozenError) { ssl_ctx.ciphersuites = 'TLS_AES_256_GCM_SHA384' }
+  end
+
+  def test_ciphersuites_method_bogus_csuite
+    ssl_ctx = OpenSSL::SSL::SSLContext.new
+    pend 'ciphersuites= method is missing' unless ssl_ctx.respond_to?(:ciphersuites=)
+
+    assert_raise_with_message(
+      OpenSSL::SSL::SSLError,
+      /SSL_CTX_set_ciphersuites: no cipher match/i
+    ) { ssl_ctx.ciphersuites = 'BOGUS' }
+  end
+
+  def test_ciphers_method_tls_connection
+    csuite = ['ECDHE-RSA-AES256-GCM-SHA384', 'TLSv1.2', 256, 256]
+    inputs = [csuite[0], [csuite[0]], [csuite]]
+
+    start_server do |port|
+      inputs.each do |input|
+        cli_ctx = OpenSSL::SSL::SSLContext.new
+        cli_ctx.min_version = cli_ctx.max_version = OpenSSL::SSL::TLS1_2_VERSION
+        cli_ctx.ciphers = input
+
+        server_connect(port, cli_ctx) do |ssl|
+          assert_equal('TLSv1.2', ssl.ssl_version)
+          assert_equal(csuite[0], ssl.cipher[0])
+          ssl.puts('abc'); assert_equal("abc\n", ssl.gets)
+        end
+      end
+    end
+  end
+
+  def test_ciphers_method_nil_argument
+    ssl_ctx = OpenSSL::SSL::SSLContext.new
+    assert_nothing_raised { ssl_ctx.ciphers = nil }
+  end
+
+  def test_ciphers_method_frozen_object
+    ssl_ctx = OpenSSL::SSL::SSLContext.new
+
+    ssl_ctx.freeze
+    assert_raise(FrozenError) { ssl_ctx.ciphers = 'ECDHE-RSA-AES128-SHA' }
+  end
+
+  def test_ciphers_method_bogus_csuite
+    ssl_ctx = OpenSSL::SSL::SSLContext.new
+
+    assert_raise_with_message(
+      OpenSSL::SSL::SSLError,
+      /SSL_CTX_set_cipher_list: no cipher match/i
+    ) { ssl_ctx.ciphers = 'BOGUS' }
+  end
+
   def test_connect_works_when_setting_dh_callback_to_nil
     ctx_proc = -> ctx {
       ctx.max_version = :TLS1_2