Lib: separate peer & hostname SSL cert validationssl_verify

Add amqp_ssl_socket_set_verify_peer which controls peer certificate validation,
and amqp_ssl_socket_set_verify_hostname which controls hostname validation in
the certificate. Additionally this deprecates amqp_ssl_socket_set_verify.

Fixes #180, #279, #303

2 files changed, 65 insertions, 11 deletions

diff --git a/librabbitmq/amqp_openssl.c b/librabbitmq/amqp_openssl.c
index bb28ddb..727f48c 100644
--- a/librabbitmq/amqp_openssl.c
+++ b/librabbitmq/amqp_openssl.c
@@ -70,7 +70,8 @@ struct amqp_ssl_socket_t {
   SSL_CTX *ctx;
   int sockfd;
   SSL *ssl;
-  amqp_boolean_t verify;
+  amqp_boolean_t verify_peer;
+  amqp_boolean_t verify_hostname;
   int internal_error;
 };
 
@@ -312,13 +313,15 @@ start_connect:
     goto error_out2;
   }
 
-  result = SSL_get_verify_result(self->ssl);
-  if (X509_V_OK != result) {
-    self->internal_error = result;
-    status = AMQP_STATUS_SSL_PEER_VERIFY_FAILED;
-    goto error_out3;
+  if (self->verify_peer) {
+    result = SSL_get_verify_result(self->ssl);
+    if (X509_V_OK != result) {
+      self->internal_error = result;
+      status = AMQP_STATUS_SSL_PEER_VERIFY_FAILED;
+      goto error_out3;
+    }
   }
-  if (self->verify) {
+  if (self->verify_hostname) {
     int verify_status = amqp_ssl_socket_verify_hostname(self, host);
     if (verify_status) {
       self->internal_error = 0;
@@ -425,7 +428,8 @@ amqp_ssl_socket_new(amqp_connection_state_t state)
 
   self->sockfd = -1;
   self->klass = &amqp_ssl_socket_class;
-  self->verify = 1;
+  self->verify_peer = 1;
+  self->verify_hostname = 1;
 
   status = initialize_openssl();
   if (status) {
@@ -555,12 +559,28 @@ void
 amqp_ssl_socket_set_verify(amqp_socket_t *base,
                            amqp_boolean_t verify)
 {
+  amqp_ssl_socket_set_verify_peer(base, verify);
+  amqp_ssl_socket_set_verify_hostname(base, verify);
+}
+
+void amqp_ssl_socket_set_verify_peer(amqp_socket_t *base,
+                                     amqp_boolean_t verify) {
+  struct amqp_ssl_socket_t *self;
+  if (base->klass != &amqp_ssl_socket_class) {
+    amqp_abort("<%p> is not of type amqp_ssl_socket_t", base);
+  }
+  self = (struct amqp_ssl_socket_t *)base;
+  self->verify_peer = verify;
+}
+
+void amqp_ssl_socket_set_verify_hostname(amqp_socket_t *base,
+                                         amqp_boolean_t verify) {
   struct amqp_ssl_socket_t *self;
   if (base->klass != &amqp_ssl_socket_class) {
     amqp_abort("<%p> is not of type amqp_ssl_socket_t", base);
   }
   self = (struct amqp_ssl_socket_t *)base;
-  self->verify = verify;
+  self->verify_hostname = verify;
 }
 
 void
diff --git a/librabbitmq/amqp_ssl_socket.h b/librabbitmq/amqp_ssl_socket.h
index 21a346a..47b5ad1 100644
--- a/librabbitmq/amqp_ssl_socket.h
+++ b/librabbitmq/amqp_ssl_socket.h
@@ -119,6 +119,9 @@ amqp_ssl_socket_set_key_buffer(amqp_socket_t *self,
 /**
  * Enable or disable peer verification.
  *
+ * \deprecated use \amqp_ssl_socket_set_verify_peer and
+ * \amqp_ssl_socket_set_verify_hostname instead.
+ *
  * If peer verification is enabled then the common name in the server
  * certificate must match the server name. Peer verification is enabled by
  * default.
@@ -128,11 +131,42 @@ amqp_ssl_socket_set_key_buffer(amqp_socket_t *self,
  *
  * \since v0.4.0
  */
+AMQP_DEPRECATED(
+    AMQP_PUBLIC_FUNCTION
+    void
+    AMQP_CALL
+    amqp_ssl_socket_set_verify(amqp_socket_t *self, amqp_boolean_t verify)
+);
+
+/**
+ * Enable or disable peer verification.
+ *
+ * Peer verification validates the certificate chain that is sent by the broker.
+ * Hostname validation is controlled by \amqp_ssl_socket_set_verify_peer.
+ *
+ * \param [in,out] self An SSL/TLS socket object.
+ * \param [in] verify enable or disable peer validation
+ *
+ * \since v0.8.0
+ */
+AMQP_PUBLIC_FUNCTION
+void
+AMQP_CALL
+amqp_ssl_socket_set_verify_peer(amqp_socket_t *self, amqp_boolean_t verify);
+
+/**
+ * Enable or disable hostname verification.
+ *
+ * Hostname verification checks the broker cert for a CN or SAN that matches the
+ * hostname that amqp_socket_open() is presented. Peer verification is
+ * controlled by \amqp_ssl_socket_set_verify_peer
+ *
+ * \since v0.8.0
+ */
 AMQP_PUBLIC_FUNCTION
 void
 AMQP_CALL
-amqp_ssl_socket_set_verify(amqp_socket_t *self,
-                           amqp_boolean_t verify);
+amqp_ssl_socket_set_verify_hostname(amqp_socket_t *self, amqp_boolean_t verify);
 
 /**
  * Sets whether rabbitmq-c initializes the underlying SSL library.