From 42f4a88ed1cb505550d1b26334ad1677024694f5 Mon Sep 17 00:00:00 2001
From: Robert Escriva <robert@rescrv.net>
Date: Thu, 3 Mar 2016 10:16:48 -0500
Subject: [PATCH] A test shim in testing that removes randomness

This means that added caveats will be deterministic, and thus testable, without
having to alter the underlying code.
---
 Makefile.am | 10 ++++++++--
 port.c      |  2 +-
 shim.c      | 43 +++++++++++++++++++++++++++++++++++++++++++
 test/env.sh |  1 +
 4 files changed, 53 insertions(+), 3 deletions(-)
 create mode 100644 shim.c

diff --git a/Makefile.am b/Makefile.am
index 578dbd5..4d7cdb5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,4 @@
-# Copyright (c) 2014, Robert Escriva
+# Copyright (c) 2014-2016, Robert Escriva
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -65,9 +65,15 @@ EXTRA_DIST += test/python-hmac-sanity-check
 EXTRA_DIST += test/python-hmac-sanity-check.sh
 EXTRA_DIST += test/readme.sh
 
+check_LTLIBRARIES = libmacaroons-shim.la
+
+libmacaroons_shim_la_SOURCES = shim.c
+libmacaroons_shim_la_LIBADD =  $(SODIUM_LIBS)
+libmacaroons_shim_la_LDFLAGS = -module -avoid-version -rpath /evil/libtool/hack/to/force/shared/lib/creation
+
 TESTS  =
 TESTS += test/python-hmac-sanity-check.sh
-#TESTS += test/readme.sh
+TESTS += test/readme.sh
 
 #################################### Python ####################################
 
diff --git a/port.c b/port.c
index 4fef7fa..138682a 100644
--- a/port.c
+++ b/port.c
@@ -126,7 +126,7 @@ macaroon_secretbox_open(const unsigned char* enc_key,
 void
 macaroon_bin2hex(const unsigned char* bin, size_t bin_sz, char* hex)
 {
-    void* ptr = sodium_bin2hex(hex, bin_sz * 2, bin, bin_sz);
+    void* ptr = sodium_bin2hex(hex, bin_sz * 2 + 1, bin, bin_sz);
     assert(ptr == hex);
 }
 
diff --git a/shim.c b/shim.c
new file mode 100644
index 0000000..95cb9af
--- /dev/null
+++ b/shim.c
@@ -0,0 +1,43 @@
+/* Copyright (c) 2016, Robert Escriva
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *     * Redistributions of source code must retain the above copyright notice,
+ *       this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of this project nor the names of its contributors may
+ *       be used to endorse or promote products derived from this software
+ *       without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* C */
+#include <stdlib.h>
+
+/* sodium */
+#include <sodium/utils.h>
+
+__attribute__ ((visibility ("default")))
+void randombytes_buf(void * const buf, const size_t size)
+{
+    sodium_memzero(buf, size);
+}
diff --git a/test/env.sh b/test/env.sh
index 2b47c5d..3264020 100644
--- a/test/env.sh
+++ b/test/env.sh
@@ -2,4 +2,5 @@ export MACAROONS_SRCDIR="$1"
 export MACAROONS_BUILDDIR="$2"
 export MACAROONS_VERSION="$3"
 
+export LD_PRELOAD="${MACAROONS_BUILDDIR}/.libs/libmacaroons-shim.so"
 export PYTHONPATH="${MACAROONS_BUILDDIR}"/bindings/python/.libs:${PYTHONPATH}