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-rw-r--r--GNUmakefile2
-rw-r--r--ks_flash.c13
-rw-r--r--masterkey.c218
-rw-r--r--masterkey.h53
4 files changed, 282 insertions, 4 deletions
diff --git a/GNUmakefile b/GNUmakefile
index 14e94c6..151ce5c 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -118,7 +118,7 @@ ifeq "${KS}" "mmap"
else ifeq "${KS}" "volatile"
KS_OBJ += ks_volatile.o
else ifeq "${KS}" "flash"
- KS_OBJ += ks_flash.o
+ KS_OBJ += ks_flash.o masterkey.o
endif
# RPC_MODE = none | server | client-simple | client-mixed
diff --git a/ks_flash.c b/ks_flash.c
index 09a9847..036e72e 100644
--- a/ks_flash.c
+++ b/ks_flash.c
@@ -40,6 +40,7 @@
#define HAL_OK CMIS_HAL_OK
#include "stm-keystore.h"
+#include "masterkey.h"
#undef HAL_OK
#include <string.h>
@@ -323,10 +324,16 @@ hal_error_t hal_ks_get_kek(uint8_t *kek,
(kek_max < bitsToBytes(256)) ? bitsToBytes(192) :
bitsToBytes(256));
- #warning Faking the Key Encryption Key
- memset(kek, 4, len);
+ if (masterkey_volatile_read(kek, len) == HSM_MASTERKEY_SET) {
+ *kek_len = len;
+ return LIBHAL_OK;
+ }
+ if (masterkey_flash_read(kek, len) == HSM_MASTERKEY_SET) {
+ *kek_len = len;
+ return LIBHAL_OK;
+ }
- return LIBHAL_OK;
+ return HAL_ERROR_KEYSTORE_ACCESS;
}
diff --git a/masterkey.c b/masterkey.c
new file mode 100644
index 0000000..cc9a62f
--- /dev/null
+++ b/masterkey.c
@@ -0,0 +1,218 @@
+/*
+ * masterkey.c
+ * -----------
+ * Masterkey set/get functions.
+ *
+ * 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.
+ */
+
+#define HAL_OK CMIS_HAL_OK
+#include "stm-init.h"
+#include "stm-keystore.h"
+#undef HAL_OK
+
+#define HAL_OK LIBHAL_OK
+#include "hal.h"
+#include "masterkey.h"
+#undef HAL_OK
+
+#include <string.h>
+
+
+static int volatile_init = 0, flash_init = 0;
+static const hal_core_t *core = NULL;
+
+#define MKM_VOLATILE_STATUS_ADDRESS 0
+#define SCLK_DIV 0x20
+#define MKM_FLASH_STATUS_ADDRESS (KEYSTORE_SECTOR_SIZE * (KEYSTORE_NUM_SECTORS - 1))
+#define MKM_FLASH_STATUS_IN_USE 0x0000ffff
+#define KEK_LENGTH (256 / 8)
+
+
+hal_error_t masterkey_volatile_init()
+{
+ hal_error_t err;
+ uint32_t status;
+
+ if (! volatile_init) {
+ if ((core = hal_core_find(MKMIF_NAME, NULL)) == NULL) {
+ return HAL_ERROR_CORE_NOT_FOUND;
+ }
+
+ err =
+ hal_mkmif_set_clockspeed(core, SCLK_DIV) ||
+ hal_mkmif_init(core) ||
+ hal_mkmif_read_word(core, MKM_VOLATILE_STATUS_ADDRESS, &status);
+
+ if (err != LIBHAL_OK) return err;
+
+ if (status != HSM_MASTERKEY_SET &&
+ status != HSM_MASTERKEY_NOT_SET) {
+ if ((err = hal_mkmif_write_word(core, MKM_VOLATILE_STATUS_ADDRESS, HSM_MASTERKEY_NOT_SET)) != LIBHAL_OK) {
+ return err;
+ }
+ }
+
+ volatile_init = 1;
+ }
+ return LIBHAL_OK;
+}
+
+masterkey_status_t masterkey_volatile_read(uint8_t *buf, size_t len)
+{
+ hal_error_t err;
+ uint32_t status;
+
+ err =
+ masterkey_volatile_init() ||
+ hal_mkmif_read_word(core, MKM_VOLATILE_STATUS_ADDRESS, &status);
+
+ if (err != LIBHAL_OK) return HSM_MASTERKEY_FAIL;
+
+ if (buf != NULL && status == HSM_MASTERKEY_SET) {
+ if ((err = hal_mkmif_read(core, MKM_VOLATILE_STATUS_ADDRESS + 4, buf, len)) == LIBHAL_OK) {
+ return HSM_MASTERKEY_SET;
+ }
+ }
+
+ if (status == HSM_MASTERKEY_SET || status == HSM_MASTERKEY_NOT_SET) {
+ return (masterkey_status_t) status;
+ }
+
+ return HSM_MASTERKEY_FAIL;
+}
+
+masterkey_status_t masterkey_volatile_write(uint8_t *buf, size_t len)
+{
+ hal_error_t err;
+
+ if (len != KEK_LENGTH) return HSM_MASTERKEY_FAIL;
+ if (! buf) return HSM_MASTERKEY_FAIL;
+
+ err =
+ masterkey_volatile_init() ||
+ hal_mkmif_write(core, MKM_VOLATILE_STATUS_ADDRESS + 4, buf, len) ||
+ hal_mkmif_write_word(core, MKM_VOLATILE_STATUS_ADDRESS, HSM_MASTERKEY_SET);
+
+ if (err != LIBHAL_OK) return HSM_MASTERKEY_FAIL;
+
+ return HSM_MASTERKEY_OK;
+}
+
+masterkey_status_t masterkey_volatile_erase(size_t len)
+{
+ uint8_t buf[KEK_LENGTH] = {0};
+ hal_error_t err;
+
+ if (len != KEK_LENGTH) return HSM_MASTERKEY_FAIL;
+
+ err =
+ masterkey_volatile_init() ||
+ hal_mkmif_write(core, MKM_VOLATILE_STATUS_ADDRESS + 4, buf, sizeof(buf)) ||
+ hal_mkmif_write_word(core, MKM_VOLATILE_STATUS_ADDRESS, HSM_MASTERKEY_NOT_SET);
+
+ if (err != LIBHAL_OK) return HSM_MASTERKEY_FAIL;
+
+ return HSM_MASTERKEY_OK;
+}
+
+/* Storing the master key in flash is a pretty Bad Idea, but since the Alpha board
+ * doesn't have a battery mounted (only pin headers for attaching one), it might
+ * help in non-production use where one doesn't have tamper protection anyways.
+ *
+ * For production use on the Alpha, one option is to have the Master Key on paper
+ * and enter it into volatile RAM after each power on.
+ */
+hal_error_t masterkey_flash_init()
+{
+ if (! flash_init) {
+ if (! keystore_check_id()) return HAL_ERROR_IO_UNEXPECTED;
+ flash_init = 1;
+ }
+ return LIBHAL_OK;
+}
+
+masterkey_status_t masterkey_flash_read(uint8_t *buf, size_t len)
+{
+ uint8_t page[KEYSTORE_PAGE_SIZE];
+ uint32_t *status = (uint32_t *) page;
+
+ if (len > sizeof(page) - 4) return HSM_MASTERKEY_FAIL;
+
+ if (masterkey_flash_init() != LIBHAL_OK) return HSM_MASTERKEY_FAIL;
+
+ if (! keystore_read_data(MKM_FLASH_STATUS_ADDRESS, page, sizeof(page))) {
+ memset(page, 0, sizeof(page));
+ return HSM_MASTERKEY_FAIL;
+ }
+
+ if (buf != NULL && len) memcpy(buf, page + 4, len);
+
+ memset(page + 4, 0, sizeof(page) - 4);
+
+ if (*status == MKM_FLASH_STATUS_IN_USE) return HSM_MASTERKEY_SET;
+ if (*status == 0x0 || *status == 0xffffffff) return HSM_MASTERKEY_NOT_SET;
+
+ return HSM_MASTERKEY_FAIL;
+}
+
+masterkey_status_t masterkey_flash_write(uint8_t *buf, size_t len)
+{
+ uint8_t page[KEYSTORE_PAGE_SIZE] = {0xff};
+ uint32_t *status = (uint32_t *) page;
+ int res;
+
+ if (len > sizeof(page) - 4) return HSM_MASTERKEY_FAIL;
+ if (buf == NULL) return HSM_MASTERKEY_FAIL;
+
+ if (masterkey_flash_init() != LIBHAL_OK) return HSM_MASTERKEY_FAIL;
+
+ *status = MKM_FLASH_STATUS_IN_USE;
+ memcpy(page + 4, buf, len);
+
+ res = keystore_write_data(MKM_FLASH_STATUS_ADDRESS, page, sizeof(page));
+ memset(page, 0, sizeof(page));
+ if (res != 1) {
+ return HSM_MASTERKEY_FAIL;
+ }
+
+ return HSM_MASTERKEY_OK;
+}
+
+masterkey_status_t masterkey_flash_erase(size_t len)
+{
+ if (len > KEYSTORE_PAGE_SIZE - 4) return HSM_MASTERKEY_FAIL;
+
+ if (keystore_erase_sectors(MKM_FLASH_STATUS_ADDRESS / KEYSTORE_SECTOR_SIZE,
+ MKM_FLASH_STATUS_ADDRESS / KEYSTORE_SECTOR_SIZE) != 1) {
+ return HSM_MASTERKEY_FAIL;
+ }
+
+ return HSM_MASTERKEY_OK;
+}
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 */