Pass hostkey & port to host verify callback

Co-authored-by: Stefan Karpinski <stefan@karpinski.org>

src/libgit2/transports/ssh.c

@@ -651,6 +651,8 @@ static int check_against_known_hosts(
 	return ret;
 }
 
+#define SSH_DEFAULT_PORT 22
+
 /*
  * Perform the check for the session's certificate against known hosts if
  * possible and then ask the user if they have a callback.
@@ -748,9 +750,16 @@ static int check_certificate(
 	if (check_cb != NULL) {
 		git_cert_hostkey *cert_ptr = &cert;
 		git_error_state previous_error = {0};
+		const char *host_ptr = host;
+		git_str host_and_port = GIT_STR_INIT;
+
+		if (port != SSH_DEFAULT_PORT) {
+			git_str_printf(&host_and_port, "%s:%d", host, port);
+			host_ptr = host_and_port.ptr;
+		}
 
 		git_error_state_capture(&previous_error, error);
-		error = check_cb((git_cert *) cert_ptr, cert_valid, host, check_cb_payload);
+		error = check_cb((git_cert *) cert_ptr, cert_valid, host_ptr, check_cb_payload);
 		if (error == GIT_PASSTHROUGH) {
 			error = git_error_state_restore(&previous_error);
 		} else if (error < 0 && !git_error_last()) {
@@ -758,13 +767,12 @@ static int check_certificate(
 		}
 
 		git_error_state_free(&previous_error);
+		git_str_dispose(&host_and_port);
 	}
 
 	return error;
 }
 
-#define SSH_DEFAULT_PORT "22"
-
 static int _git_ssh_setup_conn(
 	ssh_subtransport *t,
 	const char *url,