Merge branch 'openssl-providers'

Optionally load the legacy provider in OpenSSL 3 (enabled, by default) to
make algorithms like MD4 and DES available, which we require for
EAP-MSCHAPv2.  Allow explicitly loading the fips provider via existing
fips_mode option.  The loaded providers, whether influenced by the above
options or not, are logged.

Closes strongswan/strongswan#759

conf/plugins/openssl.opt

@@ -3,3 +3,16 @@ charon.plugins.openssl.engine_id = pkcs11
 
 charon.plugins.openssl.fips_mode = 0
 	Set OpenSSL FIPS mode: disabled(0), enabled(1), Suite B enabled(2).
+
+	Set OpenSSL FIPS mode.  With OpenSSL before 3.0, the supported values are
+	disabled(0), enabled(1) and Suite B enabled(2).  With OpenSSL 3+, any value
+	other than 0 will explicitly load the fips and base providers (_load_legacy_
+	will be ignored). The latter still requires the config in fipsmodule.cnf
+	(e.g. for the module's MAC), but allows explicitly loading the provider if
+	it's not activated in that config.
+
+charon.plugins.openssl.load_legacy = yes
+	Load the legacy provider in OpenSSL 3+ for algorithms like MD4, DES, or
+	Blowfish (the first two are required for EAP-MSCHAPv2). If disabled, the
+	default provider is loaded, or those configured in the OpenSSL config (e.g.
+	the fips provider).

src/libstrongswan/plugins/openssl/openssl_plugin.c

@@ -16,6 +16,7 @@
 
 #include <library.h>
 #include <utils/debug.h>
+#include <collections/array.h>
 #include <threading/thread.h>
 #include <threading/mutex.h>
 #include <threading/thread_value.h>
@@ -31,6 +32,9 @@
 #ifndef OPENSSL_NO_ECDH
 #include <openssl/ec.h>
 #endif
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+#include <openssl/provider.h>
+#endif
 
 #include "openssl_plugin.h"
 #include "openssl_util.h"
@@ -70,6 +74,13 @@ struct private_openssl_plugin_t {
 	 * public functions
 	 */
 	openssl_plugin_t public;
+
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+	/**
+	 * Loaded providers
+	 */
+	array_t *providers;
+#endif
 };
 
 /**
@@ -876,6 +887,15 @@ METHOD(plugin_t, get_features, int,
 METHOD(plugin_t, destroy, void,
 	private_openssl_plugin_t *this)
 {
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+	OSSL_PROVIDER *provider;
+	while (array_remove(this->providers, ARRAY_TAIL, &provider))
+	{
+		OSSL_PROVIDER_unload(provider);
+	}
+	array_destroy(this->providers);
+#endif /* OPENSSL_VERSION_NUMBER */
+
 /* OpenSSL 1.1.0 cleans up itself at exit and while OPENSSL_cleanup() exists we
  * can't call it as we couldn't re-initialize the library (as required by the
  * unit tests and the Android app) */
@@ -896,6 +916,31 @@ METHOD(plugin_t, destroy, void,
 	free(this);
 }
 
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+typedef struct {
+	char names[BUF_LEN];
+	int len;
+} ossl_provider_names_t;
+
+/**
+ * Callback to produce a list of the names of loaded providers
+ */
+static int concat_ossl_providers(OSSL_PROVIDER *provider, void *cbdata)
+{
+	ossl_provider_names_t *data = cbdata;
+	int len;
+
+	len = snprintf(&data->names[data->len], sizeof(data->names) - data->len,
+				   " %s", OSSL_PROVIDER_get0_name(provider));
+	if (len < (sizeof(data->names) - data->len))
+	{
+		data->len += len;
+		return 1;
+	}
+	return 0;
+}
+#endif
+
 /*
  * see header file
  */
@@ -911,15 +956,16 @@ plugin_t *openssl_plugin_create()
 	{
 		if (FIPS_mode() != fips_mode && !FIPS_mode_set(fips_mode))
 		{
-			DBG1(DBG_LIB, "unable to set openssl FIPS mode(%d) from (%d)",
+			DBG1(DBG_LIB, "unable to set OpenSSL FIPS mode(%d) from (%d)",
 				 fips_mode, FIPS_mode());
 			return NULL;
 		}
 	}
-#else
+#elif OPENSSL_VERSION_NUMBER < 0x30000000L
+	/* OpenSSL 3.0+ is handled below */
 	if (fips_mode)
 	{
-		DBG1(DBG_LIB, "openssl FIPS mode(%d) unavailable", fips_mode);
+		DBG1(DBG_LIB, "OpenSSL FIPS mode(%d) unavailable", fips_mode);
 		return NULL;
 	}
 #endif
@@ -952,11 +998,43 @@ plugin_t *openssl_plugin_create()
 #endif /* OPENSSL_NO_ENGINE */
 #endif /* OPENSSL_VERSION_NUMBER */
 
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+	if (fips_mode)
+	{
+		OSSL_PROVIDER *fips;
+
+		fips = OSSL_PROVIDER_load(NULL, "fips");
+		if (!fips)
+		{
+			DBG1(DBG_LIB, "unable to load OpenSSL FIPS provider");
+			return NULL;
+		}
+		array_insert_create(&this->providers, ARRAY_TAIL, fips);
+		/* explicitly load the base provider containing encoding functions */
+		array_insert_create(&this->providers, ARRAY_TAIL,
+							OSSL_PROVIDER_load(NULL, "base"));
+	}
+	else if (lib->settings->get_bool(lib->settings, "%s.plugins.openssl.load_legacy",
+									 TRUE, lib->ns))
+	{
+		/* load the legacy provider for algorithms like MD4, DES, BF etc. */
+		array_insert_create(&this->providers, ARRAY_TAIL,
+							OSSL_PROVIDER_load(NULL, "legacy"));
+		/* explicitly load the default provider, as mentioned by crypto(7) */
+		array_insert_create(&this->providers, ARRAY_TAIL,
+							OSSL_PROVIDER_load(NULL, "default"));
+	}
+	ossl_provider_names_t data = {};
+	OSSL_PROVIDER_do_all(NULL, concat_ossl_providers, &data);
+	dbg(DBG_LIB, strpfx(lib->ns, "charon") ? 1 : 2,
+		"providers loaded by OpenSSL:%s", data.names);
+#endif /* OPENSSL_VERSION_NUMBER */
+
 #ifdef OPENSSL_FIPS
 	/* we do this here as it may have been enabled via openssl.conf */
 	fips_mode = FIPS_mode();
 	dbg(DBG_LIB, strpfx(lib->ns, "charon") ? 1 : 2,
-		"openssl FIPS mode(%d) - %sabled ", fips_mode, fips_mode ? "en" : "dis");
+		"OpenSSL FIPS mode(%d) - %sabled ", fips_mode, fips_mode ? "en" : "dis");
 #endif /* OPENSSL_FIPS */
 
 #if OPENSSL_VERSION_NUMBER < 0x1010100fL