[tor-commits] [tor/master] Unit tests for crypto_force_rand_ssleay().

[nickm at torproject.org]

commit d7c841f4679521d423eb029d7307f10e15dbe133
Author: Nick Mathewson <nickm at torproject.org>
Date:   Wed Dec 23 09:58:08 2015 -0500

    Unit tests for crypto_force_rand_ssleay().
    
    Part of 16794.
---
 src/common/crypto.c    |    2 +-
 src/common/crypto.h    |    4 ++++
 src/test/test_crypto.c |   29 +++++++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/common/crypto.c b/src/common/crypto.c
index 251bbbf..22d938f 100644
--- a/src/common/crypto.c
+++ b/src/common/crypto.c
@@ -252,7 +252,7 @@ crypto_openssl_get_header_version_str(void)
 
 /** Make sure that openssl is using its default PRNG. Return 1 if we had to
  * adjust it; 0 otherwise. */
-static int
+STATIC int
 crypto_force_rand_ssleay(void)
 {
   RAND_METHOD *default_method;
diff --git a/src/common/crypto.h b/src/common/crypto.h
index cf7b9ee..ad779f5 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -314,5 +314,9 @@ struct dh_st *crypto_dh_get_dh_(crypto_dh_t *dh);
 
 void crypto_add_spaces_to_fp(char *out, size_t outlen, const char *in);
 
+#ifdef CRYPTO_PRIVATE
+STATIC int crypto_force_rand_ssleay(void);
+#endif
+
 #endif
 
diff --git a/src/test/test_crypto.c b/src/test/test_crypto.c
index b57aaf6..b3e0e1b 100644
--- a/src/test/test_crypto.c
+++ b/src/test/test_crypto.c
@@ -5,6 +5,7 @@
 
 #include "orconfig.h"
 #define CRYPTO_CURVE25519_PRIVATE
+#define CRYPTO_PRIVATE
 #include "or.h"
 #include "test.h"
 #include "aes.h"
@@ -15,6 +16,7 @@
 #include "ed25519_vectors.inc"
 
 #include <openssl/evp.h>
+#include <openssl/rand.h>
 
 extern const char AUTHORITY_SIGNKEY_3[];
 extern const char AUTHORITY_SIGNKEY_A_DIGEST[];
@@ -131,6 +133,32 @@ test_crypto_rng_range(void *arg)
   ;
 }
 
+/* Test for rectifying openssl RAND engine. */
+static void
+test_crypto_rng_engine(void *arg)
+{
+  (void)arg;
+  RAND_METHOD dummy_method;
+  memset(&dummy_method, 0, sizeof(dummy_method));
+
+  /* We should be a no-op if we're already on RAND_OpenSSL */
+  tt_int_op(0, ==, crypto_force_rand_ssleay());
+  tt_assert(RAND_get_rand_method() == RAND_OpenSSL());
+
+  /* We should correct the method if it's a dummy. */
+  RAND_set_rand_method(&dummy_method);
+  tt_assert(RAND_get_rand_method() == &dummy_method);
+  tt_int_op(1, ==, crypto_force_rand_ssleay());
+  tt_assert(RAND_get_rand_method() == RAND_OpenSSL());
+
+  /* Make sure we aren't calling dummy_method */
+  crypto_rand((void *) &dummy_method, sizeof(dummy_method));
+  crypto_rand((void *) &dummy_method, sizeof(dummy_method));
+
+ done:
+  ;
+}
+
 /** Run unit tests for our AES functionality */
 static void
 test_crypto_aes(void *arg)
@@ -2358,6 +2386,7 @@ struct testcase_t crypto_tests[] = {
   CRYPTO_LEGACY(formats),
   CRYPTO_LEGACY(rng),
   { "rng_range", test_crypto_rng_range, 0, NULL, NULL },
+  { "rng_engine", test_crypto_rng_engine, TT_FORK, NULL, NULL },
   { "aes_AES", test_crypto_aes, TT_FORK, &passthrough_setup, (void*)"aes" },
   { "aes_EVP", test_crypto_aes, TT_FORK, &passthrough_setup, (void*)"evp" },
   CRYPTO_LEGACY(sha),