TBB: add authentication module interface

This patch provides an API to access the authentication module that
will be used to verify the authenticity of the images loaded into
memory as part of the Trusted Board Boot process.

To include the authentication module as part of the build, set the
boolean build option TRUSTED_BOARD_BOOT. One single authentication
module must be registered at build time by setting the build option
AUTH_MOD=<mod_name>. All authentication modules will be located in
'common/auth/<mod_name>' and must present the <mod_name>.mk file that
will be included by the build system to compile the module sources.

To create an authentication module, an instance of auth_mod_t called
'auth_mod' must be declared in the module sources. The initialization
and verification functions provided by the module will be exported
through the function pointers specified when declaring this instance.

If an authentication module includes third party sources that do not
adhere to the C99 standard, the -pedantic option may be removed from
the build options by setting the flag DISABLE_PEDANTIC in the module
file <mod_name>.mk.

Change-Id: I080bb04bd421029bcdf22ec2c63807afbf061dcd

1 files changed, 61 insertions, 0 deletions

diff --git a/common/auth.c b/common/auth.c
new file mode 100644
index 00000000..37234b8e
--- /dev/null
+++ b/common/auth.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <auth.h>
+#include <debug.h>
+
+/*
+ * Initialize the authentication module
+ */
+void auth_init(void)
+{
+	assert(auth_mod.name);
+	assert(auth_mod.init);
+	assert(auth_mod.verify);
+
+	INFO("Using authentication module '%s'\n", auth_mod.name);
+	if (auth_mod.init() != 0)
+		assert(0);
+}
+
+/*
+ * Authenticate a certificate/image
+ *
+ * Return: 0 = success, Otherwise = error
+ */
+int auth_verify_obj(unsigned int obj_id, uintptr_t obj_buf, size_t len)
+{
+	assert(obj_id < AUTH_NUM_OBJ);
+	assert(obj_buf != 0);
+	assert(auth_mod.verify);
+
+	return auth_mod.verify(obj_id, obj_buf, len);
+}