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>
master
Raul Cardenas
9 years ago
committed by
Stefano Babic
parent
b5cd10b911
commit
0200020bc2
@ -0,0 +1,91 @@ |
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/*
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* Copyright 2008-2015 Freescale Semiconductor, Inc. |
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* |
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* SPDX-License-Identifier: GPL-2.0+ |
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* |
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* Command for encapsulating DEK blob |
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*/ |
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#include <common.h> |
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#include <command.h> |
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#include <environment.h> |
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#include <malloc.h> |
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#include <asm/byteorder.h> |
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#include <linux/compiler.h> |
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#include <fsl_sec.h> |
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#include <asm/arch/clock.h> |
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DECLARE_GLOBAL_DATA_PTR; |
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/**
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* blob_dek() - Encapsulate the DEK as a blob using CAM's Key |
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* @src: - Address of data to be encapsulated |
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* @dst: - Desination address of encapsulated data |
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* @len: - Size of data to be encapsulated |
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* |
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* Returns zero on success,and negative on error. |
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*/ |
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static int blob_encap_dek(const u8 *src, u8 *dst, u32 len) |
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{ |
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int ret = 0; |
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u32 jr_size = 4; |
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u32 out_jr_size = sec_in32(CONFIG_SYS_FSL_JR0_ADDR + 0x102c); |
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if (out_jr_size != jr_size) { |
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hab_caam_clock_enable(1); |
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sec_init(); |
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} |
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if (!((len == 128) | (len == 192) | (len == 256))) { |
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debug("Invalid DEK size. Valid sizes are 128, 192 and 256b\n"); |
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return -1; |
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} |
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len /= 8; |
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ret = blob_dek(src, dst, len); |
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return ret; |
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} |
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/**
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* do_dek_blob() - Handle the "dek_blob" command-line command |
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* @cmdtp: Command data struct pointer |
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* @flag: Command flag |
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* @argc: Command-line argument count |
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* @argv: Array of command-line arguments |
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* |
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* Returns zero on success, CMD_RET_USAGE in case of misuse and negative |
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* on error. |
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*/ |
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static int do_dek_blob(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) |
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{ |
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uint32_t src_addr, dst_addr, len; |
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uint8_t *src_ptr, *dst_ptr; |
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int ret = 0; |
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if (argc != 4) |
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return CMD_RET_USAGE; |
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src_addr = simple_strtoul(argv[1], NULL, 16); |
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dst_addr = simple_strtoul(argv[2], NULL, 16); |
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len = simple_strtoul(argv[3], NULL, 10); |
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src_ptr = map_sysmem(src_addr, len/8); |
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dst_ptr = map_sysmem(dst_addr, BLOB_SIZE(len/8)); |
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ret = blob_encap_dek(src_ptr, dst_ptr, len); |
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return ret; |
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} |
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/***************************************************/ |
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static char dek_blob_help_text[] = |
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"src dst len - Encapsulate and create blob of data\n" |
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" $len bits long at address $src and\n" |
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" store the result at address $dst.\n"; |
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U_BOOT_CMD( |
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dek_blob, 4, 1, do_dek_blob, |
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"Data Encryption Key blob encapsulation", |
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dek_blob_help_text |
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); |
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