Add crypto module as a subsystem.

src/lib/crypt_ops/.may_include

@@ -12,6 +12,7 @@ lib/malloc/*.h
 lib/intmath/*.h
 lib/sandbox/*.h
 lib/string/*.h
+lib/subsys/*.h
 lib/testsupport/testsupport.h
 lib/thread/*.h
 lib/log/*.h

src/lib/crypt_ops/crypto_init.c

@@ -20,6 +20,9 @@
 #include "lib/crypt_ops/crypto_openssl_mgt.h"
 #include "lib/crypt_ops/crypto_nss_mgt.h"
 #include "lib/crypt_ops/crypto_rand.h"
+#include "lib/crypt_ops/crypto_sys.h"
+
+#include "lib/subsys/subsys.h"
 
 #include "siphash.h"
 
@@ -202,3 +205,26 @@ tor_is_using_nss(void)
   return 0;
 #endif
 }
+
+static int
+init_crypto_sys(void)
+{
+  if (crypto_early_init() < 0)
+    return -1;
+  crypto_dh_init();
+  return 0;
+}
+
+static void
+shutdown_crypto_sys(void)
+{
+  crypto_global_cleanup();
+}
+
+const struct subsys_fns_t sys_crypto = {
+  .name = "crypto",
+  .supported = true,
+  .level = -60,
+  .initialize = init_crypto_sys,
+  .shutdown = shutdown_crypto_sys,
+};

src/lib/crypt_ops/crypto_sys.h

@@ -0,0 +1,14 @@
+/* Copyright (c) 2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file log_crypto.h
+ * \brief Declare subsystem object for the crypto module.
+ **/
+
+#ifndef TOR_CRYPTO_SYS_H
+#define TOR_CRYPTO_SYS_H
+
+extern const struct subsys_fns_t sys_crypto;
+
+#endif /* !defined(TOR_CRYPTO_SYS_H) */

src/lib/crypt_ops/include.am

@@ -66,5 +66,6 @@ noinst_HEADERS +=					\
 	src/lib/crypt_ops/crypto_rand.h			\
 	src/lib/crypt_ops/crypto_rsa.h			\
 	src/lib/crypt_ops/crypto_s2k.h			\
+	src/lib/crypt_ops/crypto_sys.h			\
 	src/lib/crypt_ops/crypto_util.h                 \
 	src/lib/crypt_ops/digestset.h