TBB: Add an IO abstraction layer to load encrypted firmwares
TBBR spec advocates for optional encryption of firmwares (see optional
requirement: R060_TBBR_FUNCTION). So add an IO abstaction layer to
support firmware decryption that can be stacked above any underlying IO/
packaging layer like FIP etc. It aims to provide a framework to load any
encrypted IO payload.
Also, add plat_get_enc_key_info() to be implemented in a platform
specific manner as handling of encryption key may vary from one platform
to another.
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Change-Id: I9892e0ddf00ebecb8981301dbfa41ea23e078b03
diff --git a/include/tools_share/firmware_encrypted.h b/include/tools_share/firmware_encrypted.h
new file mode 100644
index 0000000..7ca634f
--- /dev/null
+++ b/include/tools_share/firmware_encrypted.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2020, Linaro Limited. All rights reserved.
+ * Author: Sumit Garg <sumit.garg@linaro.org>
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef FIRMWARE_ENCRYPTED_H
+#define FIRMWARE_ENCRYPTED_H
+
+#include <stdint.h>
+
+/* This is used as a signature to validate the encryption header */
+#define ENC_HEADER_MAGIC 0xAA640001U
+
+/* Firmware encryption status flag mask */
+#define FW_ENC_STATUS_FLAG_MASK 0x1
+
+/*
+ * SSK: Secret Symmetric Key
+ * BSSK: Binding Secret Symmetric Key
+ */
+enum fw_enc_status_t {
+ FW_ENC_WITH_SSK = 0,
+ FW_ENC_WITH_BSSK = 1,
+};
+
+#define ENC_MAX_IV_SIZE 16U
+#define ENC_MAX_TAG_SIZE 16U
+#define ENC_MAX_KEY_SIZE 32U
+
+struct fw_enc_hdr {
+ uint32_t magic;
+ uint16_t dec_algo;
+ uint16_t flags;
+ uint16_t iv_len;
+ uint16_t tag_len;
+ uint8_t iv[ENC_MAX_IV_SIZE];
+ uint8_t tag[ENC_MAX_TAG_SIZE];
+};
+
+#endif /* FIRMWARE_ENCRYPTED_H */