Allow specific libtls hostname validation errors to propagate.

Remove direct calls to printf from the tls_check_hostname() path. This allows
NUL byte error messages to bubble up to the caller, to be logged in a
program-appropriate way. It also removes non-portable calls to getprogname().

The semantics of tls_error() are changed slightly: the last error message is
not necessarily preserved between subsequent calls into the library.
When the previous call to libtls succeeds, client programs should treat the
return value of tls_error() as undefined.

ok tedu@

1 files changed, 6 insertions, 4 deletions

diff --git a/src/lib/libtls/tls_client.c b/src/lib/libtls/tls_client.c
index a4528b9b87..c5849a6897 100644
--- a/src/lib/libtls/tls_client.c
+++ b/src/lib/libtls/tls_client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls_client.c,v 1.2 2014/11/02 14:45:05 jsing Exp $ */
+/* $OpenBSD: tls_client.c,v 1.3 2014/12/07 15:00:32 bcook Exp $ */
 /*
  * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
  *
@@ -209,9 +209,11 @@ tls_connect_fds(struct tls *ctx, int fd_read, int fd_write,
                         tls_set_error(ctx, "no server certificate");
                         goto err;
                 }
-                if (tls_check_hostname(cert, hostname) != 0) {
-                        tls_set_error(ctx, "host `%s' not present in"
-                            " server certificate", hostname);
+                tls_clear_error(ctx);
+                if (tls_check_hostname(ctx, cert, hostname) != 0) {
+                        if (tls_error(ctx) == NULL)
+                                tls_set_error(ctx, "host `%s' not present in"
+                                    " server certificate", hostname);
                         goto err;
                 }
         }