Implement master key for wrapping keys in the keystore.

The KEK (Key Encryption Key) is first fetched from the FPGA that gets it
from the volatile Master Key Memory (that in theory has tamper*kek_len =
len protection with wiping), and secondly from flash.

The flash option is meant for development/evaluation use using an Alpha
board where the Master Key Memory is not battery backed. For any serious
use of an Alpha, an option is to enter the master key into the volatile
MKM on each power-on as a way to unlock the keystore.

1 files changed, 53 insertions, 0 deletions

diff --git a/masterkey.h b/masterkey.h
new file mode 100644
index 0000000..8b47409
--- /dev/null
+++ b/masterkey.h
@@ -0,0 +1,53 @@
+/*
+ * masterkey.h
+ * -----------
+ * Code to handle the Master Key that wraps all the keys in the keystore.
+ *
+ * Copyright (c) 2016, NORDUnet A/S 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 the NORDUnet 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.
+ */
+
+#ifndef __STM32_HSM_MASTERKEY_H
+#define __STM32_HSM_MASTERKEY_H
+
+typedef enum {
+    HSM_MASTERKEY_FAIL,
+    HSM_MASTERKEY_OK,
+    HSM_MASTERKEY_SET,
+    HSM_MASTERKEY_NOT_SET,
+} masterkey_status_t;
+
+extern masterkey_status_t masterkey_volatile_read(uint8_t *buf, size_t len);
+extern masterkey_status_t masterkey_volatile_write(uint8_t *buf, size_t len);
+extern masterkey_status_t masterkey_volatile_erase(size_t len);
+
+extern masterkey_status_t masterkey_flash_read(uint8_t *buf, size_t len);
+extern masterkey_status_t masterkey_flash_write(uint8_t *buf, size_t len);
+extern masterkey_status_t masterkey_flash_erase(size_t len);
+
+#endif /* __STM32_HSM_MASTERKEY_H */