Maintain separate server and client TLS contexts.

Fixes bug #988.

2 files changed, 88 insertions, 15 deletions

diff --git a/src/common/tortls.c b/src/common/tortls.c
index b49f9e3e4f..1bb3b8b356 100644
--- a/src/common/tortls.c
+++ b/src/common/tortls.c
@@ -190,12 +190,16 @@ static X509* tor_tls_create_certificate(crypto_pk_env_t *rsa,
                                         const char *cname_sign,
                                         unsigned int lifetime);
 static void tor_tls_unblock_renegotiation(tor_tls_t *tls);
+static int tor_tls_context_init_one(tor_tls_context_t **ppcontext,
+                                    crypto_pk_env_t *identity,
+                                    unsigned int key_lifetime);
 static tor_tls_context_t *tor_tls_context_new(crypto_pk_env_t *identity,
                                               unsigned int key_lifetime);
 
-/** Global tls context. We keep it here because nobody else needs to
- * touch it. */
-static tor_tls_context_t *global_tls_context = NULL;
+/** Global TLS contexts. We keep them here because nobody else needs
+ * to touch them. */
+static tor_tls_context_t *server_tls_context = NULL;
+static tor_tls_context_t *client_tls_context = NULL;
 /** True iff tor_tls_init() has been called. */
 static int tls_library_is_initialized = 0;
 
@@ -431,9 +435,15 @@ tor_tls_init(void)
 void
 tor_tls_free_all(void)
 {
-  if (global_tls_context) {
-    tor_tls_context_decref(global_tls_context);
-    global_tls_context = NULL;
+  if (server_tls_context) {
+    tor_tls_context_t *ctx = server_tls_context;
+    server_tls_context = NULL;
+    tor_tls_context_decref(ctx);
+  }
+  if (client_tls_context) {
+    tor_tls_context_t *ctx = client_tls_context;
+    client_tls_context = NULL;
+    tor_tls_context_decref(ctx);
   }
   if (!HT_EMPTY(&tlsmap_root)) {
     log_warn(LD_MM, "Still have entries in the tlsmap at shutdown.");
@@ -620,21 +630,80 @@ tor_tls_context_incref(tor_tls_context_t *ctx)
   ++ctx->refcnt;
 }
 
+/** Create new global client and server TLS contexts.
+ *
+ * If <b>server_identity</b> is NULL, this will not generate a server
+ * TLS context. If <b>is_public_server</b> is non-zero, this will use
+ * the same TLS context for incoming and outgoing connections, and
+ * ignore <b>client_identity</b>. */
+int
+tor_tls_context_init(int is_public_server,
+                     crypto_pk_env_t *client_identity,
+                     crypto_pk_env_t *server_identity,
+                     unsigned int key_lifetime)
+{
+  int rv1 = 0;
+  int rv2 = 0;
+
+  if (is_public_server) {
+    tor_tls_context_t *new_ctx;
+    tor_tls_context_t *old_ctx;
+
+    tor_assert(server_identity != NULL);
+
+    rv1 = tor_tls_context_init_one(&server_tls_context,
+                                   server_identity,
+                                   key_lifetime);
+
+    if (rv1 >= 0) {
+      new_ctx = server_tls_context;
+      tor_tls_context_incref(new_ctx);
+      old_ctx = client_tls_context;
+      client_tls_context = new_ctx;
+
+      if (old_ctx != NULL) {
+        tor_tls_context_decref(old_ctx);
+      }
+    }
+  } else {
+    if (server_identity != NULL) {
+      rv1 = tor_tls_context_init_one(&server_tls_context,
+                                     server_identity,
+                                     key_lifetime);
+    } else {
+      tor_tls_context_t *old_ctx = server_tls_context;
+      server_tls_context = NULL;
+
+      if (old_ctx != NULL) {
+        tor_tls_context_decref(old_ctx);
+      }
+    }
+
+    rv2 = tor_tls_context_init_one(&client_tls_context,
+                                   client_identity,
+                                   key_lifetime);
+  }
+
+  return MIN(rv1, rv2);
+}
+
 /** Create a new global TLS context.
  *
  * You can call this function multiple times.  Each time you call it,
  * it generates new certificates; all new connections will use
  * the new SSL context.
  */
-int
-tor_tls_context_init(crypto_pk_env_t *identity, unsigned int key_lifetime)
+static int
+tor_tls_context_init_one(tor_tls_context_t **ppcontext,
+                         crypto_pk_env_t *identity,
+                         unsigned int key_lifetime)
 {
   tor_tls_context_t *new_ctx = tor_tls_context_new(identity,
                                                    key_lifetime);
-  tor_tls_context_t *old_ctx = global_tls_context;
+  tor_tls_context_t *old_ctx = *ppcontext;
 
   if (new_ctx != NULL) {
-    global_tls_context = new_ctx;
+    *ppcontext = new_ctx;
 
     /* Free the old context if one existed. */
     if (old_ctx != NULL) {
@@ -946,9 +1015,11 @@ tor_tls_new(int sock, int isServer)
 {
   BIO *bio = NULL;
   tor_tls_t *result = tor_malloc_zero(sizeof(tor_tls_t));
+  tor_tls_context_t *context = isServer ? server_tls_context :
+    client_tls_context;
 
-  tor_assert(global_tls_context); /* make sure somebody made it first */
-  if (!(result->ssl = SSL_new(global_tls_context->ctx))) {
+  tor_assert(context); /* make sure somebody made it first */
+  if (!(result->ssl = SSL_new(context->ctx))) {
     tls_log_errors(NULL, LOG_WARN, LD_NET, "creating SSL object");
     tor_free(result);
     return NULL;
@@ -988,8 +1059,8 @@ tor_tls_new(int sock, int isServer)
   }
   HT_INSERT(tlsmap, &tlsmap_root, result);
   SSL_set_bio(result->ssl, bio, bio);
-  tor_tls_context_incref(global_tls_context);
-  result->context = global_tls_context;
+  tor_tls_context_incref(context);
+  result->context = context;
   result->state = TOR_TLS_ST_HANDSHAKE;
   result->isServer = isServer;
   result->wantwrite_n = 0;
diff --git a/src/common/tortls.h b/src/common/tortls.h
index 40382667bf..955027ba35 100644
--- a/src/common/tortls.h
+++ b/src/common/tortls.h
@@ -50,7 +50,9 @@ typedef struct tor_tls_t tor_tls_t;
 const char *tor_tls_err_to_string(int err);
 
 void tor_tls_free_all(void);
-int tor_tls_context_init(crypto_pk_env_t *identity,
+int tor_tls_context_init(int is_public_server,
+                         crypto_pk_env_t *client_identity,
+                         crypto_pk_env_t *server_identity,
                          unsigned int key_lifetime);
 tor_tls_t *tor_tls_new(int sock, int is_server);
 void tor_tls_set_logged_address(tor_tls_t *tls, const char *address);