[Openvpn-devel,v4,2/2] Add unit tests for engine keys

Message ID 1518303011.3072.4.camel@HansenPartnership.com
State New
Headers show
Series
  • add engine keys keys
Related show

Commit Message

James Bottomley Feb. 10, 2018, 10:50 p.m.
Testing engines is problematic, so one of the prerequisites built for
the tests is a simple openssl engine that reads a non-standard PEM
guarded key.  The test is simply can we run a client/server
configuration with the usual sample key replaced by an engine key.
The trivial engine prints out some operations and we check for these
in the log to make sure the engine was used to load the key and that
it correctly got the password.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

---
v4: add OPENSSL_config(NULL) so debian checks will work
v3: added this patch
---
 configure.ac                                     |   2 +
 src/openvpn/crypto_openssl.c                     |   1 +
 tests/unit_tests/Makefile.am                     |   6 +-
 tests/unit_tests/engine-key/Makefile.am          |  14 ++++
 tests/unit_tests/engine-key/check_engine_keys.sh |  30 +++++++
 tests/unit_tests/engine-key/libtestengine.c      | 102 +++++++++++++++++++++++
 tests/unit_tests/engine-key/openssl.cnf          |  12 +++
 7 files changed, 166 insertions(+), 1 deletion(-)
 create mode 100644 tests/unit_tests/engine-key/Makefile.am
 create mode 100755 tests/unit_tests/engine-key/check_engine_keys.sh
 create mode 100644 tests/unit_tests/engine-key/libtestengine.c
 create mode 100644 tests/unit_tests/engine-key/openssl.cnf

Patch

diff --git a/configure.ac b/configure.ac
index 2cbf3358..2f7ef8a0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1360,6 +1360,7 @@  AM_CONDITIONAL([GIT_CHECKOUT], [test "${GIT_CHECKOUT}" = "yes"])
 AM_CONDITIONAL([ENABLE_PLUGIN_AUTH_PAM], [test "${enable_plugin_auth_pam}" = "yes"])
 AM_CONDITIONAL([ENABLE_PLUGIN_DOWN_ROOT], [test "${enable_plugin_down_root}" = "yes"])
 AM_CONDITIONAL([HAVE_LD_WRAP_SUPPORT], [test "${have_ld_wrap_support}" = "yes"])
+AM_CONDITIONAL([OPENSSL_ENGINE], [test "${have_openssl_engine}" = "yes"])
 
 sampledir="\$(docdir)/sample"
 AC_SUBST([plugindir])
@@ -1424,6 +1425,7 @@  AC_CONFIG_FILES([
         tests/unit_tests/openvpn/Makefile
         tests/unit_tests/plugins/Makefile
         tests/unit_tests/plugins/auth-pam/Makefile
+	tests/unit_tests/engine-key/Makefile
         vendor/Makefile
 	sample/Makefile
 ])
diff --git a/src/openvpn/crypto_openssl.c b/src/openvpn/crypto_openssl.c
index 936cbb0d..558fdb46 100644
--- a/src/openvpn/crypto_openssl.c
+++ b/src/openvpn/crypto_openssl.c
@@ -92,6 +92,7 @@  setup_engine(const char *engine)
 {
     ENGINE *e = NULL;
 
+    OPENSSL_config(NULL);
     ENGINE_load_builtin_engines();
 
     if (engine)
diff --git a/tests/unit_tests/Makefile.am b/tests/unit_tests/Makefile.am
index 31d37b89..648bd7a8 100644
--- a/tests/unit_tests/Makefile.am
+++ b/tests/unit_tests/Makefile.am
@@ -1,5 +1,9 @@ 
 AUTOMAKE_OPTIONS = foreign
 
+SUBDIRS =
 if CMOCKA_INITIALIZED
-SUBDIRS = example_test openvpn plugins
+SUBDIRS += example_test openvpn plugins
+endif
+if OPENSSL_ENGINE
+SUBDIRS += engine-key
 endif
diff --git a/tests/unit_tests/engine-key/Makefile.am b/tests/unit_tests/engine-key/Makefile.am
new file mode 100644
index 00000000..f83bf817
--- /dev/null
+++ b/tests/unit_tests/engine-key/Makefile.am
@@ -0,0 +1,14 @@ 
+AUTOMAKE_OPTIONS = foreign
+
+check_LTLIBRARIES = libtestengine.la
+
+TESTS_ENVIRONMENT = srcdir="$(abs_srcdir)"; \
+	top_builddir="$(top_builddir)"; \
+	top_srcdir="$(top_srcdir)"; \
+	export srcdir top_builddir top_srcdir;
+
+TESTS = check_engine_keys.sh
+
+libtestengine_la_SOURCES = libtestengine.c
+libtestengine_la_LDFLAGS = -rpath /lib -avoid-version
+
diff --git a/tests/unit_tests/engine-key/check_engine_keys.sh b/tests/unit_tests/engine-key/check_engine_keys.sh
new file mode 100755
index 00000000..c1ae59e6
--- /dev/null
+++ b/tests/unit_tests/engine-key/check_engine_keys.sh
@@ -0,0 +1,30 @@ 
+#!/bin/sh
+
+OPENSSL_CONF="${srcdir}/openssl.cnf"
+export OPENSSL_CONF
+
+password='AT3S4PASSWD'
+
+key="${srcdir}/client.key"
+pwdfile="${srcdir}/passwd"
+
+# create an engine key for us
+sed 's/PRIVATE KEY/TEST ENGINE KEY/' < ${top_srcdir}/sample/sample-keys/client.key > ${key}
+echo "$password" > $pwdfile
+
+# note here we've induced a mismatch in the client key and the server
+# cert which openvpn should report and die.  Check that it does.  Note
+# also that this mismatch depends on openssl not openvpn, so it is
+# somewhat fragile
+${top_builddir}/src/openvpn/openvpn --cd ${top_srcdir}/sample --config sample-config-files/loopback-server --engine testengine --key ${key} --askpass $pwdfile > log.txt 2>&1
+
+# first off check we died because of a key mismatch.  If this doesn't
+# pass, suspect openssl of returning different messages and update the
+# test accordingly
+grep -q 'X509_check_private_key:key values mismatch' log.txt || { echo "Key mismatch not detected"; exit 1; }
+
+# now look for the engine prints (these are under our control)
+grep -q 'ENGINE: engine_init called' log.txt || { echo "Engine initialization not detected"; exit 1; }
+grep -q 'ENGINE: engine_load_key called' log.txt || { echo "Key was not loaded from engine"; exit 1; }
+grep -q "ENGINE: engine_load_key got password ${password}" log.txt || { echo "Key password was not retrieved by the engine"; exit 1; }
+exit 0
diff --git a/tests/unit_tests/engine-key/libtestengine.c b/tests/unit_tests/engine-key/libtestengine.c
new file mode 100644
index 00000000..4880223d
--- /dev/null
+++ b/tests/unit_tests/engine-key/libtestengine.c
@@ -0,0 +1,102 @@ 
+#include <string.h>
+#include <openssl/engine.h>
+#include <openssl/evp.h>
+#include <openssl/pem.h>
+
+static char *engine_id = "testengine";
+static char *engine_name = "Engine for testing openvpn engine key support";
+
+static int is_initialized = 0;
+
+static int engine_init(ENGINE *e)
+{
+	is_initialized = 1;
+	fprintf(stderr, "ENGINE: engine_init called\n");
+	return 1;
+}
+
+static int engine_finish(ENGINE *e)
+{
+	fprintf(stderr, "ENGINE: engine_finsh called\n");
+	is_initialized = 0;
+	return 1;
+}
+
+static EVP_PKEY *engine_load_key(ENGINE *e, const char *key_id,
+				 UI_METHOD *ui_method, void *cb_data)
+{
+	BIO *b;
+	EVP_PKEY *pkey;
+	PKCS8_PRIV_KEY_INFO *p8inf;
+	UI *ui;
+	char auth[256];
+	int len;
+
+	fprintf(stderr, "ENGINE: engine_load_key called\n");
+
+	if (!is_initialized) {
+		fprintf(stderr, "Load Key called without correct initialization\n");
+		return NULL;
+	}
+	b = BIO_new_file(key_id, "r");
+	if (!b) {
+		fprintf(stderr, "File %s does not exist or cannot be read\n", key_id); 
+		return 0;
+	}
+	/* Basically read an EVP_PKEY private key file with different
+	 * PEM guards --- we are a test engine */
+	p8inf = PEM_ASN1_read_bio((d2i_of_void *)d2i_PKCS8_PRIV_KEY_INFO,
+				 "TEST ENGINE KEY", b,
+				 NULL, NULL, NULL);
+	BIO_free(b);
+	if (!p8inf) {
+		fprintf(stderr, "Failed to read engine private key\n");
+		return NULL;
+	}
+	pkey = EVP_PKCS82PKEY(p8inf);
+
+	/* now we have a private key, pretend it had a password
+	 * this verifies the password makes it through openvpn OK */
+	ui = UI_new();
+
+	if (ui_method)
+		UI_set_method(ui, ui_method);
+
+	UI_add_user_data(ui, cb_data);
+
+	if (UI_add_input_string(ui, "enter test engine key",
+				UI_INPUT_FLAG_DEFAULT_PWD,
+				auth, 0, sizeof(auth)) == 0) {
+		fprintf(stderr, "UI_add_input_string failed\n");
+		goto out;
+	}
+
+	if (UI_process(ui)) {
+		fprintf(stderr, "UI_process failed\n");
+		goto out;
+	}
+
+	fprintf(stderr, "ENGINE: engine_load_key got password %s\n", auth);
+
+ out:
+	UI_free(ui);
+
+	return pkey;
+}
+
+
+static int engine_bind_fn(ENGINE *e, const char *id)
+{
+	if (id && strcmp(id, engine_id) != 0)
+		return 0;
+	if (!ENGINE_set_id(e, engine_id) ||
+	    !ENGINE_set_name(e, engine_name) ||
+	    !ENGINE_set_init_function(e, engine_init) ||
+	    !ENGINE_set_finish_function(e, engine_finish) ||
+	    !ENGINE_set_load_privkey_function(e, engine_load_key))
+		return 0;
+	return 1;
+}
+
+IMPLEMENT_DYNAMIC_CHECK_FN()
+IMPLEMENT_DYNAMIC_BIND_FN(engine_bind_fn)
diff --git a/tests/unit_tests/engine-key/openssl.cnf b/tests/unit_tests/engine-key/openssl.cnf
new file mode 100644
index 00000000..53200c46
--- /dev/null
+++ b/tests/unit_tests/engine-key/openssl.cnf
@@ -0,0 +1,12 @@ 
+HOME		= .
+openssl_conf	= openssl_init
+
+[req]
+[openssl_init]
+engines		= engines_section
+
+[engines_section]
+testengine	= testengine_section
+
+[testengine_section]
+dynamic_path	= $ENV::srcdir/.libs/libtestengine.so