From 72a3327c13b85cb6281ae902c0d35c9f4e34e436 Mon Sep 17 00:00:00 2001
From: Tim Ruffing <crypto@timruffing.de>
Date: Wed, 4 Mar 2020 17:33:28 +0100
Subject: [PATCH] Add constant-time test to `make check` and make Travis fail
 if it fails

Moreover, this changes the way Travis runs the constant-time tests
by adding a `--error-exitcode=1` parameter to valgrind. Without that
parameter, valgrind simply passes the exit code through, even in the
case of valgrind errors. That is, Travis would succeed even if
valgrind found problems.
---
 .gitignore                |  2 ++
 .travis.yml               |  2 +-
 Makefile.am               |  3 ++-
 src/valgrind_ctime_test.c |  2 +-
 valgrind_ctime_test.sh    | 12 ++++++++++++
 5 files changed, 18 insertions(+), 3 deletions(-)
 create mode 100755 valgrind_ctime_test.sh

diff --git a/.gitignore b/.gitignore
index cb4331aa90..c061705f4e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,6 +31,8 @@ libtool
 *.lo
 *.o
 *~
+*.log
+*.trs
 src/libsecp256k1-config.h
 src/libsecp256k1-config.h.in
 src/ecmult_static_context.h
diff --git a/.travis.yml b/.travis.yml
index ff4a6d2bc9..de3ea39d83 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -95,7 +95,7 @@ script:
    travis_wait 30 valgrind --error-exitcode=42 ./exhaustive_tests;
    fi
  - if [ -n "$CTIMETEST" ]; then
-   libtool --mode=execute valgrind  ./valgrind_ctime_test &> valgrind_ctime_test.log;
+   ./valgrind_ctime_test.sh &> valgrind_ctime_test.log;
    fi
 
 after_script:
diff --git a/Makefile.am b/Makefile.am
index e73b1baf38..8fc07ac890 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -96,6 +96,7 @@ tests_CPPFLAGS = -DSECP256K1_BUILD -I$(top_srcdir)/src -I$(top_srcdir)/include $
 if VALGRIND_ENABLED
 tests_CPPFLAGS += -DVALGRIND
 noinst_PROGRAMS += valgrind_ctime_test
+TESTS += valgrind_ctime_test.sh
 valgrind_ctime_test_SOURCES = src/valgrind_ctime_test.c
 valgrind_ctime_test_LDADD = libsecp256k1.la $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB)
 endif
@@ -141,7 +142,7 @@ src/ecmult_static_context.h: $(gen_context_BIN)
 CLEANFILES = $(gen_context_BIN) src/ecmult_static_context.h
 endif
 
-EXTRA_DIST = autogen.sh src/gen_context.c src/basic-config.h
+EXTRA_DIST = autogen.sh valgrind_ctime_test.sh src/gen_context.c src/basic-config.h
 
 if ENABLE_MODULE_ECDH
 include src/modules/ecdh/Makefile.am.include
diff --git a/src/valgrind_ctime_test.c b/src/valgrind_ctime_test.c
index 04c06d498f..24b5887450 100644
--- a/src/valgrind_ctime_test.c
+++ b/src/valgrind_ctime_test.c
@@ -28,7 +28,7 @@ int main(void) {
     if (!RUNNING_ON_VALGRIND) {
         fprintf(stderr, "This test can only usefully be run inside valgrind.\n");
         fprintf(stderr, "Usage: libtool --mode=execute valgrind ./valgrind_ctime_test\n");
-        exit(1);
+        exit(99); /* indicates "ERROR" in make check */
     }
 
     /** In theory, testing with a single secret input should be sufficient:
diff --git a/valgrind_ctime_test.sh b/valgrind_ctime_test.sh
new file mode 100755
index 0000000000..6b90242d2d
--- /dev/null
+++ b/valgrind_ctime_test.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+
+libtool --mode=execute valgrind --error-exitcode=1 ./valgrind_ctime_test "$@"
+
+case $? in
+    127) # "command not found", i.e., either libtool or valgrind not installed
+        exit 77 # map this to "SKIP" (=77) for make check
+        ;;
+    *)
+        exit $?
+        ;;
+esac