AMQP_STATUS_SSL_PEER_VERIFY_FAILED with Letsencrypt certificate

[tschoonj]

Hi,

I am trying to connect to my rabbitmq server which has SSL enabled using Letsencrypt generated certificates, which are currently valid.

I can use the rabbitmq server with pika over SSL without any additional configuration.

However with rabbitmq-c, on the same machine, I run into AMQP_STATUS_SSL_PEER_VERIFY_FAILED. Any thoughts on why this is? The root and intermediate certificates are all present and in the openssl search path.

[tschoonj]

I can make the problem go away by forcing openssl to load the default certificates:

diff --git a/librabbitmq/amqp_openssl.c b/librabbitmq/amqp_openssl.c
index 0a37fe0..9086c9f 100644
--- a/librabbitmq/amqp_openssl.c
+++ b/librabbitmq/amqp_openssl.c
@@ -365,6 +365,8 @@ amqp_socket_t *amqp_ssl_socket_new(amqp_connection_state_t state) {
    * logic not behave as expected, so turn this back off */
   SSL_CTX_clear_mode(self->ctx, SSL_MODE_AUTO_RETRY);
 
+  SSL_CTX_set_default_verify_paths(self->ctx);
+
   amqp_set_socket(state, (amqp_socket_t *)self);
 
   return (amqp_socket_t *)self;

@alanxz Would you accept a PR that introduces this change?