Use new configuration architecture for crypto options

This is a comparatively simple change.

5 files changed, 131 insertions, 0 deletions

diff --git a/src/lib/crypt_ops/.may_include b/src/lib/crypt_ops/.may_include
index 0739699686..810e777271 100644
--- a/src/lib/crypt_ops/.may_include
+++ b/src/lib/crypt_ops/.may_include
@@ -1,6 +1,7 @@
 orconfig.h
 lib/arch/*.h
 lib/cc/*.h
+lib/conf/*.h
 lib/container/*.h
 lib/crypt_ops/*.h
 lib/ctime/*.h
@@ -17,6 +18,8 @@ lib/testsupport/*.h
 lib/thread/*.h
 lib/log/*.h
 
+lib/crypt_ops/*.inc
+
 trunnel/pwbox.h
 
 keccak-tiny/*.h
diff --git a/src/lib/crypt_ops/crypto_init.c b/src/lib/crypt_ops/crypto_init.c
index a16bf4e11a..999eac75f5 100644
--- a/src/lib/crypt_ops/crypto_init.c
+++ b/src/lib/crypt_ops/crypto_init.c
@@ -23,6 +23,9 @@
 #include "lib/crypt_ops/crypto_nss_mgt.h"
 #include "lib/crypt_ops/crypto_rand.h"
 #include "lib/crypt_ops/crypto_sys.h"
+#include "lib/crypt_ops/crypto_options_st.h"
+#include "lib/conf/conftypes.h"
+#include "lib/log/util_bug.h"
 
 #include "lib/subsys/subsys.h"
 
@@ -252,6 +255,84 @@ subsys_crypto_thread_cleanup(void)
   crypto_thread_cleanup();
 }
 
+/** Magic number for crypto_options_t. */
+#define CRYPTO_OPTIONS_MAGIC 0x68757368
+
+/** Invoked before validating crypto options: makes sure that if
+ * AccelName is set, HardwareAccel is turned on.
+ **/
+static int
+crypto_options_prenormalize(void *arg, char **msg_out)
+{
+  crypto_options_t *opt = arg;
+  tor_assert(opt->magic == CRYPTO_OPTIONS_MAGIC);
+  (void)msg_out;
+
+  // TODO: It would be cleaner to remove this code, but right now the
+  // tests depend on it.
+  if (opt->AccelName && !opt->HardwareAccel)
+    opt->HardwareAccel = 1;
+
+  return 0;
+}
+
+/**
+ * Return 0 if <b>arg</b> is a valid crypto_options_t.  Otherwise return -1
+ * and set *<b>msg_out</b> to a freshly allocated error string.
+ **/
+static int
+crypto_options_validate(const void *arg, char **msg_out)
+{
+  const crypto_options_t *opt = arg;
+  tor_assert(opt->magic == CRYPTO_OPTIONS_MAGIC);
+  tor_assert(msg_out);
+
+  if (opt->AccelDir && !opt->AccelName) {
+    *msg_out = tor_strdup("Can't use hardware crypto accelerator dir "
+                          "without engine name.");
+    return -1;
+  }
+
+  return 0;
+}
+
+/* Declare the options field table for crypto_options */
+#define CONF_CONTEXT LL_TABLE
+#include "lib/crypt_ops/crypto_options.inc"
+#undef CONF_CONTEXT
+
+/**
+ * Declares the configuration options for this module.
+ **/
+static const config_format_t crypto_options_fmt = {
+  .size = sizeof(crypto_options_t),
+  .magic = { "crypto_options_t",
+             CRYPTO_OPTIONS_MAGIC,
+             offsetof(crypto_options_t, magic) },
+  .vars = crypto_options_t_vars,
+  .pre_normalize_fn = crypto_options_prenormalize,
+  .validate_fn = crypto_options_validate,
+  .config_suite_offset = -1,
+};
+
+/**
+ * Invoked from subsysmgr.c when a new set of options arrives.
+ **/
+static int
+crypto_set_options(void *arg)
+{
+  const crypto_options_t *options = arg;
+  // This call already checks for crypto_global_initialized_, so it
+  // will only initialize the subsystem the first time it's called.
+  if (crypto_global_init(options->HardwareAccel,
+                         options->AccelName,
+                         options->AccelDir)) {
+    log_err(LD_BUG, "Unable to initialize the crypto subsystem. Exiting.");
+    return -1;
+  }
+  return 0;
+}
+
 const struct subsys_fns_t sys_crypto = {
   .name = "crypto",
   .supported = true,
@@ -261,4 +342,7 @@ const struct subsys_fns_t sys_crypto = {
   .prefork = subsys_crypto_prefork,
   .postfork = subsys_crypto_postfork,
   .thread_cleanup = subsys_crypto_thread_cleanup,
+
+  .options_format = &crypto_options_fmt,
+  .set_options = crypto_set_options,
 };
diff --git a/src/lib/crypt_ops/crypto_options.inc b/src/lib/crypt_ops/crypto_options.inc
new file mode 100644
index 0000000000..5bee0daacd
--- /dev/null
+++ b/src/lib/crypt_ops/crypto_options.inc
@@ -0,0 +1,19 @@
+
+/**
+ * @file crypto_options.inc
+ * @brief Declare configuration options for the crypto_ops module.
+ **/
+
+/** Holds configuration about our cryptography options. */
+BEGIN_CONF_STRUCT(crypto_options_t)
+
+/** Should we enable extra OpenSSL hardware acceleration (where available)?  */
+CONF_VAR(HardwareAccel, BOOL, CFLG_IMMUTABLE, "0")
+
+/** Optional OpenSSL hardware-acceleration engine name */
+CONF_VAR(AccelName, STRING, CFLG_IMMUTABLE, NULL)
+
+/** Optional OpenSSL hardware-acceleration engine search directory. */
+CONF_VAR(AccelDir, FILENAME, CFLG_IMMUTABLE, NULL)
+
+END_CONF_STRUCT(crypto_options_t)
diff --git a/src/lib/crypt_ops/crypto_options_st.h b/src/lib/crypt_ops/crypto_options_st.h
new file mode 100644
index 0000000000..8127b41eec
--- /dev/null
+++ b/src/lib/crypt_ops/crypto_options_st.h
@@ -0,0 +1,23 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * @file crypto_options_st.h
+ * @brief Header for lib/crypt_ops/crypto_options_st.c
+ **/
+
+#ifndef TOR_LIB_CRYPT_OPS_CRYPTO_OPTIONS_ST_H
+#define TOR_LIB_CRYPT_OPS_CRYPTO_OPTIONS_ST_H
+
+#include "lib/conf/confdecl.h"
+
+#define CONF_CONTEXT STRUCT
+#include "lib/crypt_ops/crypto_options.inc"
+#undef CONF_CONTEXT
+
+typedef struct crypto_options_t crypto_options_t;
+
+#endif /* !defined(TOR_LIB_CRYPT_OPS_CRYPTO_OPTIONS_ST_H) */
diff --git a/src/lib/crypt_ops/include.am b/src/lib/crypt_ops/include.am
index 1f58a33d38..7644cab412 100644
--- a/src/lib/crypt_ops/include.am
+++ b/src/lib/crypt_ops/include.am
@@ -68,6 +68,8 @@ noinst_HEADERS +=					\
 	src/lib/crypt_ops/crypto_nss_mgt.h		\
 	src/lib/crypt_ops/crypto_openssl_mgt.h		\
 	src/lib/crypt_ops/crypto_ope.h          	\
+	src/lib/crypt_ops/crypto_options.inc		\
+	src/lib/crypt_ops/crypto_options_st.h		\
 	src/lib/crypt_ops/crypto_pwbox.h		\
 	src/lib/crypt_ops/crypto_rand.h			\
 	src/lib/crypt_ops/crypto_rsa.h			\