* ext/openssl/ossl_ssl.c: Allow disabling client-side renegotiation.

* test/openssl/test_ssl.rb: Simple tests for this.

  Client-side renegotiation is still considered problematic, even
  when used in the context of secure renegotiation (RI, RFC 5746).
  The changes allow users to either completely disable client
  renegotiation on the server, or to specify a maximum number of
  handshakes allowed in total. The number of total handshakes is
  counted in a callback set as SSL_set_info_callback. If the
  maximum number of handshakes is exceeded an error will be raised
  We do not support renegotiation in the OpenSSL extension, therefore
  this feature can only be tested externally.
  The feature is opt-in, the default setting will be to allow
  unlimited client renegotiation, as was the case before.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35797 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 114 insertions, 35 deletions

diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index d375b0ff67..0eaa3c8f4b 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -29,41 +29,43 @@ VALUE eSSLError;
 VALUE cSSLContext;
 VALUE cSSLSocket;
 
-#define ossl_sslctx_set_cert(o,v)        rb_iv_set((o),"@cert",(v))
-#define ossl_sslctx_set_key(o,v)         rb_iv_set((o),"@key",(v))
-#define ossl_sslctx_set_client_ca(o,v)   rb_iv_set((o),"@client_ca",(v))
-#define ossl_sslctx_set_ca_file(o,v)     rb_iv_set((o),"@ca_file",(v))
-#define ossl_sslctx_set_ca_path(o,v)     rb_iv_set((o),"@ca_path",(v))
-#define ossl_sslctx_set_timeout(o,v)     rb_iv_set((o),"@timeout",(v))
-#define ossl_sslctx_set_verify_mode(o,v) rb_iv_set((o),"@verify_mode",(v))
-#define ossl_sslctx_set_verify_dep(o,v)  rb_iv_set((o),"@verify_depth",(v))
-#define ossl_sslctx_set_verify_cb(o,v)   rb_iv_set((o),"@verify_callback",(v))
-#define ossl_sslctx_set_options(o,v)     rb_iv_set((o),"@options",(v))
-#define ossl_sslctx_set_cert_store(o,v)  rb_iv_set((o),"@cert_store",(v))
-#define ossl_sslctx_set_extra_cert(o,v)  rb_iv_set((o),"@extra_chain_cert",(v))
-#define ossl_sslctx_set_client_cert_cb(o,v) rb_iv_set((o),"@client_cert_cb",(v))
-#define ossl_sslctx_set_tmp_dh_cb(o,v)   rb_iv_set((o),"@tmp_dh_callback",(v))
-#define ossl_sslctx_set_sess_id_ctx(o, v) rb_iv_get((o),"@session_id_context"(v))
-
-#define ossl_sslctx_get_cert(o)          rb_iv_get((o),"@cert")
-#define ossl_sslctx_get_key(o)           rb_iv_get((o),"@key")
-#define ossl_sslctx_get_client_ca(o)     rb_iv_get((o),"@client_ca")
-#define ossl_sslctx_get_ca_file(o)       rb_iv_get((o),"@ca_file")
-#define ossl_sslctx_get_ca_path(o)       rb_iv_get((o),"@ca_path")
-#define ossl_sslctx_get_timeout(o)       rb_iv_get((o),"@timeout")
-#define ossl_sslctx_get_verify_mode(o)   rb_iv_get((o),"@verify_mode")
-#define ossl_sslctx_get_verify_dep(o)    rb_iv_get((o),"@verify_depth")
-#define ossl_sslctx_get_verify_cb(o)     rb_iv_get((o),"@verify_callback")
-#define ossl_sslctx_get_options(o)       rb_iv_get((o),"@options")
-#define ossl_sslctx_get_cert_store(o)    rb_iv_get((o),"@cert_store")
-#define ossl_sslctx_get_extra_cert(o)    rb_iv_get((o),"@extra_chain_cert")
-#define ossl_sslctx_get_client_cert_cb(o) rb_iv_get((o),"@client_cert_cb")
-#define ossl_sslctx_get_tmp_dh_cb(o)     rb_iv_get((o),"@tmp_dh_callback")
-#define ossl_sslctx_get_sess_id_ctx(o)   rb_iv_get((o),"@session_id_context")
+#define ossl_sslctx_set_cert(o,v)        	rb_iv_set((o),"@cert",(v))
+#define ossl_sslctx_set_key(o,v)         	rb_iv_set((o),"@key",(v))
+#define ossl_sslctx_set_client_ca(o,v)   	rb_iv_set((o),"@client_ca",(v))
+#define ossl_sslctx_set_ca_file(o,v)     	rb_iv_set((o),"@ca_file",(v))
+#define ossl_sslctx_set_ca_path(o,v)     	rb_iv_set((o),"@ca_path",(v))
+#define ossl_sslctx_set_timeout(o,v)     	rb_iv_set((o),"@timeout",(v))
+#define ossl_sslctx_set_verify_mode(o,v) 	rb_iv_set((o),"@verify_mode",(v))
+#define ossl_sslctx_set_verify_dep(o,v)  	rb_iv_set((o),"@verify_depth",(v))
+#define ossl_sslctx_set_verify_cb(o,v)   	rb_iv_set((o),"@verify_callback",(v))
+#define ossl_sslctx_set_options(o,v)     	rb_iv_set((o),"@options",(v))
+#define ossl_sslctx_set_cert_store(o,v)  	rb_iv_set((o),"@cert_store",(v))
+#define ossl_sslctx_set_extra_cert(o,v)  	rb_iv_set((o),"@extra_chain_cert",(v))
+#define ossl_sslctx_set_client_cert_cb(o,v) 	rb_iv_set((o),"@client_cert_cb",(v))
+#define ossl_sslctx_set_tmp_dh_cb(o,v)   	rb_iv_set((o),"@tmp_dh_callback",(v))
+#define ossl_sslctx_set_sess_id_ctx(o, v) 	rb_iv_set((o),"@session_id_context",(v))
+#define ossl_sslctx_set_max_handshake(o, v)  	rb_iv_set((o),"@max_handshake",(v))
+
+#define ossl_sslctx_get_cert(o)          	rb_iv_get((o),"@cert")
+#define ossl_sslctx_get_key(o)           	rb_iv_get((o),"@key")
+#define ossl_sslctx_get_client_ca(o)     	rb_iv_get((o),"@client_ca")
+#define ossl_sslctx_get_ca_file(o)       	rb_iv_get((o),"@ca_file")
+#define ossl_sslctx_get_ca_path(o)       	rb_iv_get((o),"@ca_path")
+#define ossl_sslctx_get_timeout(o)       	rb_iv_get((o),"@timeout")
+#define ossl_sslctx_get_verify_mode(o)   	rb_iv_get((o),"@verify_mode")
+#define ossl_sslctx_get_verify_dep(o)    	rb_iv_get((o),"@verify_depth")
+#define ossl_sslctx_get_verify_cb(o)     	rb_iv_get((o),"@verify_callback")
+#define ossl_sslctx_get_options(o)       	rb_iv_get((o),"@options")
+#define ossl_sslctx_get_cert_store(o)    	rb_iv_get((o),"@cert_store")
+#define ossl_sslctx_get_extra_cert(o)    	rb_iv_get((o),"@extra_chain_cert")
+#define ossl_sslctx_get_client_cert_cb(o) 	rb_iv_get((o),"@client_cert_cb")
+#define ossl_sslctx_get_tmp_dh_cb(o)     	rb_iv_get((o),"@tmp_dh_callback")
+#define ossl_sslctx_get_sess_id_ctx(o)   	rb_iv_get((o),"@session_id_context")
+#define ossl_sslctx_get_max_handshake(o)     	rb_iv_get((o),"@max_handshake")
 
 static const char *ossl_sslctx_attrs[] = {
     "cert", "key", "client_ca", "ca_file", "ca_path",
-    "timeout", "verify_mode", "verify_depth",
+    "timeout", "verify_mode", "verify_depth", "max_handshake",
     "verify_callback", "options", "cert_store", "extra_chain_cert",
     "client_cert_cb", "tmp_dh_callback", "session_id_context",
     "session_get_cb", "session_new_cb", "session_remove_cb",
@@ -78,6 +80,7 @@ static const char *ossl_sslctx_attrs[] = {
 #define ossl_ssl_get_x509(o)         rb_iv_get((o),"@x509")
 #define ossl_ssl_get_key(o)          rb_iv_get((o),"@key")
 #define ossl_ssl_get_tmp_dh(o)       rb_iv_get((o),"@tmp_dh")
+#define ossl_ssl_get_handshake(o)    rb_iv_get((o),"@handshake")
 
 #define ossl_ssl_set_io(o,v)         rb_iv_set((o),"@io",(v))
 #define ossl_ssl_set_ctx(o,v)        rb_iv_set((o),"@context",(v))
@@ -85,6 +88,7 @@ static const char *ossl_sslctx_attrs[] = {
 #define ossl_ssl_set_x509(o,v)       rb_iv_set((o),"@x509",(v))
 #define ossl_ssl_set_key(o,v)        rb_iv_set((o),"@key",(v))
 #define ossl_ssl_set_tmp_dh(o,v)     rb_iv_set((o),"@tmp_dh",(v))
+#define ossl_ssl_set_handshake(o,v)  rb_iv_set((o),"@handshake",(v))
 
 static const char *ossl_ssl_attr_readers[] = { "io", "context", };
 static const char *ossl_ssl_attrs[] = {
@@ -542,6 +546,33 @@ ssl_servername_cb(SSL *ssl, int *ad, void *arg)
 }
 #endif
 
+static int
+ssl_get_max_handshake(VALUE ssl)
+{
+    VALUE rb_ctx = ossl_ssl_get_ctx(ssl);
+    VALUE max_handshake = ossl_sslctx_get_max_handshake(rb_ctx);
+    return NIL_P(max_handshake) ? -1 : NUM2INT(max_handshake);
+}
+
+static void
+ssl_renegotiation_cb(const SSL *ssl, int where, int val)
+{
+    int state = SSL_state(ssl);
+
+    /* Count handshakes on the server */
+    if ((where & SSL_CB_HANDSHAKE_START) && 
+	(state & SSL_ST_ACCEPT)) {
+	VALUE rb_ssl = (VALUE)SSL_get_ex_data(ssl, ossl_ssl_ex_ptr_idx);
+	int max = ssl_get_max_handshake(rb_ssl);
+	int cur = NUM2INT(ossl_ssl_get_handshake(rb_ssl));
+
+	if (max != -1 && cur == max)
+	    ossl_raise(eSSLError, "Client renegotations exceeded maximum");
+
+	ossl_ssl_set_handshake(rb_ssl, INT2NUM(cur + 1));
+    }
+}
+
 /*
  * call-seq:
  *    ctx.setup => Qtrue # first time
@@ -792,7 +823,6 @@ ossl_sslctx_set_ciphers(VALUE self, VALUE v)
     return v;
 }
 
-
 /*
  *  call-seq:
  *     ctx.session_add(session) -> true | false
@@ -980,6 +1010,51 @@ ossl_sslctx_flush_sessions(int argc, VALUE *argv, VALUE self)
 }
 
 /*
+ *  call-seq:
+ *     ctx.disable_client_renegotiation -> self
+ *
+ * Completely disables client-side renegotiation. Will only affect the
+ * behavior of a server. A server with client renegotation disabled
+ * will reject any client-side attempts to renegotiate the session.
+ */
+static VALUE
+ossl_sslctx_disable_client_renegotation(VALUE self)
+{
+    ossl_sslctx_set_max_handshake(self, INT2NUM(1));
+    return self;
+}
+
+/*
+ *  call-seq:
+ *     ctx.allow_client_renegotiation[(num_handshakes)] -> self
+ *
+ * Affects only server connections. If no argument is provided, there is no
+ * restriction on the number of client-side renegotiation attempts, which is
+ * also the default setting. If an Integer +num_handshakes+ is provided, this
+ * specifies the maximum number of total handshakes that are allowed before
+ * further attempts will be rejected. So to allow exactly one renegotiation,
+ * an argument of 2 would be needed (the initial handshake plus one
+ * renegotiation attempt). An ArgumentError will be raised for negative
+ * arguments or a value of 0.
+ */
+static VALUE
+ossl_sslctx_allow_client_renegotiation(int argc, VALUE *argv, VALUE self)
+{
+    VALUE max = Qnil;
+
+    rb_scan_args(argc, argv, "01", &max);
+
+    if (NIL_P(max)) {
+	ossl_sslctx_set_max_handshake(self, INT2NUM(-1));
+    } else {
+	if (NUM2INT(max) <= 0)
+	    ossl_raise(rb_eArgError, "Maximum handshakes must be positive and non-zero");
+	ossl_sslctx_set_max_handshake(self, max);
+    }
+    return self;
+}
+
+/*
  * SSLSocket class
  */
 static void
@@ -998,8 +1073,8 @@ ossl_ssl_shutdown(SSL *ssl)
 	    if (rc = SSL_shutdown(ssl))
 		break;
 	}
-	ERR_clear_error();
 	SSL_clear(ssl);
+	ERR_clear_error();
     }
 }
 
@@ -1045,6 +1120,7 @@ ossl_ssl_initialize(int argc, VALUE *argv, VALUE self)
     ossl_ssl_set_io(self, io);
     ossl_ssl_set_ctx(self, ctx);
     ossl_ssl_set_sync_close(self, Qfalse);
+    ossl_ssl_set_handshake(self, INT2NUM(0));
     ossl_sslctx_setup(ctx);
 
     rb_iv_set(self, "@hostname", Qnil);
@@ -1095,6 +1171,7 @@ ossl_ssl_setup(VALUE self)
 	SSL_set_ex_data(ssl, ossl_ssl_ex_client_cert_cb_idx, (void*)cb);
 	cb = ossl_sslctx_get_tmp_dh_cb(v_ctx);
 	SSL_set_ex_data(ssl, ossl_ssl_ex_tmp_dh_callback_idx, (void*)cb);
+	SSL_set_info_callback(ssl, ssl_renegotiation_cb);
     }
 
     return Qtrue;
@@ -1305,7 +1382,6 @@ ossl_ssl_read_internal(int argc, VALUE *argv, VALUE self, int nonblock)
     return str;
 }
 
-
 /*
  * call-seq:
  *    ssl.sysread(length) => string
@@ -1415,6 +1491,7 @@ ossl_ssl_close(VALUE self)
 {
     SSL *ssl;
 
+    ossl_ssl_set_handshake(self, INT2NUM(0));
     Data_Get_Struct(self, SSL, ssl);
     ossl_ssl_shutdown(ssl);
     if (RTEST(ossl_ssl_get_sync_close(self)))
@@ -1894,6 +1971,8 @@ Init_ossl_ssl()
     rb_define_method(cSSLContext, "ssl_version=", ossl_sslctx_set_ssl_version, 1);
     rb_define_method(cSSLContext, "ciphers",     ossl_sslctx_get_ciphers, 0);
     rb_define_method(cSSLContext, "ciphers=",    ossl_sslctx_set_ciphers, 1);
+    rb_define_method(cSSLContext, "disable_client_renegotiation", ossl_sslctx_disable_client_renegotation, 0);
+    rb_define_method(cSSLContext, "allow_client_renegotiation", ossl_sslctx_allow_client_renegotiation, -1);
 
     rb_define_method(cSSLContext, "setup", ossl_sslctx_setup, 0);