unit-tests: Seed chunk_hash() only once, but before creating any hashtables

Due to the removal of pthread_once, we manually create the seed for
chunk_hash(). With the new testable functions interface, this won't work for
the hashtable initiated using __attribute__((constructor)). Enforce seeding
before creating that hashtable.

src/libstrongswan/library.c

@@ -243,7 +243,6 @@ bool library_init(char *settings, const char *namespace)
 {
 	private_library_t *this;
 	printf_hook_t *pfh;
-	static bool seeded = FALSE;
 
 	if (lib)
 	{	/* already initialized, increase refcount */
@@ -252,13 +251,7 @@ bool library_init(char *settings, const char *namespace)
 		return !this->integrity_failed;
 	}
 
-	if (!seeded)
-	{
-		/* we do this just once to allow hash table lifetimes longer than
-		 * one init/deinit cycle. */
-		seeded = TRUE;
-		chunk_hash_seed();
-	}
+	chunk_hash_seed();
 
 	INIT(this,
 		.public = {

src/libstrongswan/tests/test_runner.c

@@ -44,6 +44,9 @@ void testable_functions_create()
 {
 	if (!testable_functions)
 	{
+		/* as this is executed before chunk_hash() seed initialization used
+		 * by hashtables, we enforce seeding it here. */
+		chunk_hash_seed();
 		testable_functions = hashtable_create(hashtable_hash_str,
 											  hashtable_equals_str, 8);
 	}

src/libstrongswan/utils/chunk.c

@@ -917,10 +917,17 @@ static u_char static_key[] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
  */
 void chunk_hash_seed()
 {
+	static bool seeded = FALSE;
 	ssize_t len;
 	size_t done = 0;
 	int fd;
 
+	if (seeded)
+	{
+		/* just once to have the same seed during the whole process lifetimes */
+		return;
+	}
+
 	fd = open("/dev/urandom", O_RDONLY);
 	if (fd >= 0)
 	{
@@ -944,6 +951,7 @@ void chunk_hash_seed()
 			key[done] = (u_char)random();
 		}
 	}
+	seeded = TRUE;
 }
 
 /**

src/libstrongswan/utils/chunk.h

@@ -343,7 +343,8 @@ bool chunk_printable(chunk_t chunk, chunk_t *sane, char replace);
  * Seed initial key for chunk_hash().
  *
  * This call should get invoked once during startup. This is usually done
- * by calling library_init().
+ * by calling library_init(). Calling it multiple times is safe, it gets
+ * executed just once.
  */
 void chunk_hash_seed();