imx6: Added DEK blob generator command

Freescale's SEC block has built-in Data Encryption
Key(DEK) Blob Protocol which provides a method for
protecting a DEK for non-secure memory storage.
SEC block protects data in a data structure called
a Secret Key Blob, which provides both confidentiality
and integrity protection.
Every time the blob encapsulation is executed,
a AES-256 key is randomly generated to encrypt the DEK.
This key is encrypted with the OTP Secret key
from SoC. The resulting blob consists of the encrypted
AES-256 key, the encrypted DEK, and a 16-bit MAC.

During decapsulation, the reverse process is performed
to get back the original DEK. A caveat to the blob
decapsulation process,  is that the DEK is decrypted
in secure-memory and can only be read by FSL SEC HW.
The DEK is used to decrypt data during encrypted boot.

Commands added
--------------
  dek_blob - encapsulating DEK as a cryptgraphic blob

Commands Syntax
---------------
  dek_blob src dst len

    Encapsulate and create blob of a len-bits DEK at
    address src and store the result at address dst.

Signed-off-by: Raul Cardenas <Ulises.Cardenas@freescale.com>
Signed-off-by: Nitin Garg <nitin.garg@freescale.com>

Signed-off-by: Ulises Cardenas <ulises.cardenas@freescale.com>

Signed-off-by: Ulises Cardenas-B45798 <Ulises.Cardenas@freescale.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/arch/arm/imx-common/cmd_dek.c b/arch/arm/imx-common/cmd_dek.c
new file mode 100644
index 0000000000..d93d5fb240
--- /dev/null
+++ b/arch/arm/imx-common/cmd_dek.c
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2008-2015 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * Command for encapsulating DEK blob
+ */
+
+#include <common.h>
+#include <command.h>
+#include <environment.h>
+#include <malloc.h>
+#include <asm/byteorder.h>
+#include <linux/compiler.h>
+#include <fsl_sec.h>
+#include <asm/arch/clock.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+* blob_dek() - Encapsulate the DEK as a blob using CAM's Key
+* @src: - Address of data to be encapsulated
+* @dst: - Desination address of encapsulated data
+* @len: - Size of data to be encapsulated
+*
+* Returns zero on success,and negative on error.
+*/
+static int blob_encap_dek(const u8 *src, u8 *dst, u32 len)
+{
+	int ret = 0;
+	u32 jr_size = 4;
+
+	u32 out_jr_size = sec_in32(CONFIG_SYS_FSL_JR0_ADDR + 0x102c);
+	if (out_jr_size != jr_size) {
+		hab_caam_clock_enable(1);
+		sec_init();
+	}
+
+	if (!((len == 128) | (len == 192) | (len == 256))) {
+		debug("Invalid DEK size. Valid sizes are 128, 192 and 256b\n");
+		return -1;
+	}
+
+	len /= 8;
+	ret = blob_dek(src, dst, len);
+
+	return ret;
+}
+
+/**
+ * do_dek_blob() - Handle the "dek_blob" command-line command
+ * @cmdtp:  Command data struct pointer
+ * @flag:   Command flag
+ * @argc:   Command-line argument count
+ * @argv:   Array of command-line arguments
+ *
+ * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
+ * on error.
+ */
+static int do_dek_blob(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	uint32_t src_addr, dst_addr, len;
+	uint8_t *src_ptr, *dst_ptr;
+	int ret = 0;
+
+	if (argc != 4)
+		return CMD_RET_USAGE;
+
+	src_addr = simple_strtoul(argv[1], NULL, 16);
+	dst_addr = simple_strtoul(argv[2], NULL, 16);
+	len = simple_strtoul(argv[3], NULL, 10);
+
+	src_ptr = map_sysmem(src_addr, len/8);
+	dst_ptr = map_sysmem(dst_addr, BLOB_SIZE(len/8));
+
+	ret = blob_encap_dek(src_ptr, dst_ptr, len);
+
+	return ret;
+}
+
+/***************************************************/
+static char dek_blob_help_text[] =
+	"src dst len            - Encapsulate and create blob of data\n"
+	"                         $len bits long at address $src and\n"
+	"                         store the result at address $dst.\n";
+
+U_BOOT_CMD(
+	dek_blob, 4, 1, do_dek_blob,
+	"Data Encryption Key blob encapsulation",
+	dek_blob_help_text
+);