imx: imx7 Support for Manufacturing Protection

This code was originally developed by Raul Cardenas <[email protected]>
and modified to be applied in U-Boot imx_v2017.03.

More information about the initial submission can be seen
in the link below:
https://lists.denx.de/pipermail/u-boot/2016-February/245273.html

i.MX7D has an a protection feature for Manufacturing process.
This feature uses asymmetric encryption to sign and verify
authenticated software handled between parties. This command
enables the use of such feature.

The private key is unique and generated once per device.
And it is stored in secure memory and only accessible by CAAM.
Therefore, the public key generation and signature functions
are the only functions available for the user.

The manufacturing-protection authentication process can be used to
authenticate the chip to the OEM's server.

Command usage:

Print the public key for the device.
- mfgprot pubk

Generates Signature over given data.
- mfgprot sign <data_address> <data_size>

Signed-off-by: Raul Ulises Cardenas <[email protected]>
Signed-off-by: Breno Lima <[email protected]>
Reviewed-by: Fabio Estevam <[email protected]>
Reviewed-by: Ye Li <[email protected]>
Signed-off-by: Peng Fan <[email protected]>

arch/arm/mach-imx/Kconfig

@@ -99,6 +99,15 @@ config CMD_NANDBCB
 	  This is similar to kobs-ng, which is used in Linux as separate
 	  rootfs package.
 
+config FSL_MFGPROT
+	bool "Support the 'mfgprot' command"
+	depends on IMX_HAB && ARCH_MX7
+	help
+	  This option enables the manufacturing protection command
+	  which can be used has a protection feature for Manufacturing
+	  process. With this tool is possible to authenticate the
+	  chip to the OEM's server.
+
 config NXP_BOARD_REVISION
 	bool "Read NXP board revision from fuses"
 	depends on ARCH_MX6 || ARCH_MX7

arch/arm/mach-imx/Makefile

@@ -35,6 +35,7 @@ ifeq ($(SOC),$(filter $(SOC),mx7))
 obj-y 	+= cpu.o
 obj-$(CONFIG_SYS_I2C_MXC) += i2c-mxv7.o
 obj-$(CONFIG_ENV_IS_IN_MMC) += mmc_env.o
+obj-$(CONFIG_FSL_MFGPROT) += cmd_mfgprot.o
 endif
 ifeq ($(SOC),$(filter $(SOC),mx5 mx6 mx7))
 obj-$(CONFIG_IMX_VIDEO_SKIP) += video.o

arch/arm/mach-imx/cmd_mfgprot.c

@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2016 Freescale Semiconductor, Inc.
+ * Copyright 2017 NXP
+ *
+ * These commands enable the use of the CAAM MPPubK-generation and MPSign
+ * functions in supported i.MX devices.
+ */
+
+#include <asm/byteorder.h>
+#include <asm/arch/clock.h>
+#include <linux/compiler.h>
+#include <command.h>
+#include <common.h>
+#include <environment.h>
+#include <fsl_sec.h>
+#include <mapmem.h>
+#include <memalign.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * do_mfgprot() - Handle the "mfgprot" 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_mfgprot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	u8 *m_ptr, *dgst_ptr, *c_ptr, *d_ptr, *dst_ptr;
+	char *pubk, *sign, *sel;
+	int m_size, i, ret;
+	u32 m_addr;
+
+	pubk = "pubk";
+	sign = "sign";
+	sel = argv[1];
+
+	/* Enable HAB clock */
+	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 (strcmp(sel, pubk) == 0) {
+		dst_ptr = malloc_cache_aligned(FSL_CAAM_MP_PUBK_BYTES);
+		if (!dst_ptr)
+			return -ENOMEM;
+
+		ret = gen_mppubk(dst_ptr);
+		if (ret) {
+			free(dst_ptr);
+			return ret;
+		}
+
+		/* Output results */
+		puts("Public key:\n");
+		for (i = 0; i < FSL_CAAM_MP_PUBK_BYTES; i++)
+			printf("%02X", (dst_ptr)[i]);
+		puts("\n");
+		free(dst_ptr);
+
+	} else if (strcmp(sel, sign) == 0) {
+		if (argc != 4)
+			return CMD_RET_USAGE;
+
+		m_addr = simple_strtoul(argv[2], NULL, 16);
+		m_size = simple_strtoul(argv[3], NULL, 10);
+		m_ptr = map_physmem(m_addr, m_size, MAP_NOCACHE);
+		if (!m_ptr)
+			return -ENOMEM;
+
+		dgst_ptr = malloc_cache_aligned(FSL_CAAM_MP_MES_DGST_BYTES);
+		if (!dgst_ptr) {
+			ret = -ENOMEM;
+			goto free_m;
+		}
+
+		c_ptr = malloc_cache_aligned(FSL_CAAM_MP_PRVK_BYTES);
+		if (!c_ptr) {
+			ret = -ENOMEM;
+			goto free_dgst;
+		}
+
+		d_ptr = malloc_cache_aligned(FSL_CAAM_MP_PRVK_BYTES);
+		if (!d_ptr) {
+			ret = -ENOMEM;
+			goto free_c;
+		}
+
+		ret = sign_mppubk(m_ptr, m_size, dgst_ptr, c_ptr, d_ptr);
+		if (ret)
+			goto free_d;
+
+		/* Output results */
+		puts("Message: ");
+		for (i = 0; i < m_size; i++)
+			printf("%02X ", (m_ptr)[i]);
+		puts("\n");
+
+		puts("Message Representative Digest(SHA-256):\n");
+		for (i = 0; i < FSL_CAAM_MP_MES_DGST_BYTES; i++)
+			printf("%02X", (dgst_ptr)[i]);
+		puts("\n");
+
+		puts("Signature:\n");
+		puts("C:\n");
+		for (i = 0; i < FSL_CAAM_MP_PRVK_BYTES; i++)
+			printf("%02X", (c_ptr)[i]);
+		puts("\n");
+
+		puts("d:\n");
+		for (i = 0; i < FSL_CAAM_MP_PRVK_BYTES; i++)
+			printf("%02X", (d_ptr)[i]);
+		puts("\n");
+free_d:
+	free(d_ptr);
+free_c:
+	free(c_ptr);
+free_dgst:
+	free(dgst_ptr);
+free_m:
+	unmap_sysmem(m_ptr);
+
+	} else {
+		return CMD_RET_USAGE;
+	}
+	return ret;
+}
+
+/***************************************************/
+static char mfgprot_help_text[] =
+	"Usage:\n"
+	 "Print the public key for Manufacturing Protection\n"
+	 "\tmfgprot pubk\n"
+	 "Generates a Manufacturing Protection signature\n"
+	 "\tmfgprot sign <data_addr> <size>";
+
+U_BOOT_CMD(
+	mfgprot, 4, 1, do_mfgprot,
+	"Manufacturing Protection\n",
+	mfgprot_help_text
+);

drivers/crypto/fsl/Makefile

@@ -8,3 +8,4 @@ obj-$(CONFIG_CMD_BLOB) += fsl_blob.o
 obj-$(CONFIG_CMD_DEKBLOB) += fsl_blob.o
 obj-$(CONFIG_RSA_FREESCALE_EXP) += fsl_rsa.o
 obj-$(CONFIG_FSL_CAAM_RNG) += rng.o
+obj-$(CONFIG_FSL_MFGPROT) += fsl_mfgprot.o

drivers/crypto/fsl/desc.h

@@ -740,6 +740,7 @@ struct __packed pdb_mp_sign {
 };
 
 #define PDB_MP_CSEL_SHIFT	17
+#define PDB_MP_CSEL_WIDTH	4
 #define PDB_MP_CSEL_P256	0x3 << PDB_MP_CSEL_SHIFT	/* P-256 */
 #define PDB_MP_CSEL_P384	0x4 << PDB_MP_CSEL_SHIFT	/* P-384 */
 #define PDB_MP_CSEL_P521	0x5 << PDB_MP_CSEL_SHIFT	/* P-521 */

drivers/crypto/fsl/fsl_mfgprot.c

@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2014-2016 Freescale Semiconductor, Inc.
+ * Copyright 2017 NXP
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <fsl_sec.h>
+#include <memalign.h>
+#include "desc.h"
+#include "desc_constr.h"
+#include "jobdesc.h"
+#include "jr.h"
+
+/* Size of MFG descriptor */
+#define MFG_PUBK_DSC_WORDS 4
+#define MFG_SIGN_DSC_WORDS 8
+
+static void mfg_build_sign_dsc(u32 *dsc_ptr, const u8 *m, int size,
+			       u8 *dgst, u8 *c, u8 *d)
+{
+	u32 *dsc = dsc_ptr;
+	struct pdb_mp_sign *pdb;
+
+	init_job_desc_pdb(dsc, 0, sizeof(struct pdb_mp_sign));
+
+	pdb = (struct pdb_mp_sign *)desc_pdb(dsc);
+
+	/* Curve */
+	pdb->pdb_hdr = (PDB_MP_CSEL_P256);
+
+	/* Message Pointer */
+	pdb_add_ptr(&pdb->dma_addr_msg, virt_to_phys((void *)m));
+
+	/* mes-resp Pointer */
+	pdb_add_ptr(&pdb->dma_addr_hash, virt_to_phys((void *)dgst));
+
+	/* C Pointer */
+	pdb_add_ptr(&pdb->dma_addr_c_sig, virt_to_phys((void *)c));
+
+	/* d Pointer */
+	pdb_add_ptr(&pdb->dma_addr_d_sig, virt_to_phys((void *)d));
+
+	/* Message Size */
+	pdb->img_size = size;
+
+	/* MP PubK generate key command */
+	append_cmd(dsc, (CMD_OPERATION | OP_TYPE_DECAP_PROTOCOL |
+			 OP_PCLID_MP_SIGN));
+}
+
+static void mfg_build_pubk_dsc(u32 *dsc_ptr, u8 *dst)
+{
+	u32 *dsc = dsc_ptr;
+	struct pdb_mp_pub_k *pdb;
+
+	init_job_desc_pdb(dsc, 0, sizeof(struct pdb_mp_pub_k));
+
+	pdb = (struct pdb_mp_pub_k *)desc_pdb(dsc);
+
+	/* Curve */
+	pdb->pdb_hdr = (PDB_MP_CSEL_P256);
+
+	/* Message Pointer */
+	pdb_add_ptr(&pdb->dma_pkey, virt_to_phys((void *)dst));
+
+	/* MP Sign key command */
+	append_cmd(dsc, (CMD_OPERATION | OP_TYPE_DECAP_PROTOCOL |
+			 OP_PCLID_MP_PUB_KEY));
+}
+
+int gen_mppubk(u8 *dst)
+{
+	int size, ret;
+	u32 *dsc;
+
+	/* Job Descriptor initialization */
+	dsc = memalign(ARCH_DMA_MINALIGN,
+		       sizeof(uint32_t) * MFG_PUBK_DSC_WORDS);
+	if (!dsc) {
+		debug("Not enough memory for descriptor allocation\n");
+		return -ENOMEM;
+	}
+
+	mfg_build_pubk_dsc(dsc, dst);
+
+	size = roundup(sizeof(uint32_t) * MFG_PUBK_DSC_WORDS,
+		       ARCH_DMA_MINALIGN);
+	flush_dcache_range((unsigned long)dsc, (unsigned long)dsc + size);
+
+	size = roundup(FSL_CAAM_MP_PUBK_BYTES, ARCH_DMA_MINALIGN);
+	flush_dcache_range((unsigned long)dst, (unsigned long)dst + size);
+
+	/* Execute Job Descriptor */
+	puts("\nGenerating Manufacturing Protection Public Key\n");
+
+	ret = run_descriptor_jr(dsc);
+	if (ret) {
+		debug("Error in public key generation %d\n", ret);
+		goto err;
+	}
+
+	size = roundup(FSL_CAAM_MP_PUBK_BYTES, ARCH_DMA_MINALIGN);
+	invalidate_dcache_range((unsigned long)dst, (unsigned long)dst + size);
+err:
+	free(dsc);
+	return ret;
+}
+
+int sign_mppubk(const u8 *m, int data_size, u8 *dgst, u8 *c, u8 *d)
+{
+	int size, ret;
+	u32 *dsc;
+
+	/* Job Descriptor initialization */
+	dsc = memalign(ARCH_DMA_MINALIGN,
+		       sizeof(uint32_t) * MFG_SIGN_DSC_WORDS);
+	if (!dsc) {
+		debug("Not enough memory for descriptor allocation\n");
+		return -ENOMEM;
+	}
+
+	mfg_build_sign_dsc(dsc, m, data_size, dgst, c, d);
+
+	size = roundup(sizeof(uint32_t) * MFG_SIGN_DSC_WORDS,
+		       ARCH_DMA_MINALIGN);
+	flush_dcache_range((unsigned long)dsc, (unsigned long)dsc + size);
+
+	size = roundup(data_size, ARCH_DMA_MINALIGN);
+	flush_dcache_range((unsigned long)m, (unsigned long)m + size);
+
+	size = roundup(FSL_CAAM_MP_MES_DGST_BYTES, ARCH_DMA_MINALIGN);
+	flush_dcache_range((unsigned long)dgst, (unsigned long)dgst + size);
+
+	size = roundup(FSL_CAAM_MP_PRVK_BYTES, ARCH_DMA_MINALIGN);
+	flush_dcache_range((unsigned long)c, (unsigned long)c + size);
+	flush_dcache_range((unsigned long)d, (unsigned long)d + size);
+
+	/* Execute Job Descriptor */
+	puts("\nSigning message with Manufacturing Protection Public Key\n");
+
+	ret = run_descriptor_jr(dsc);
+	if (ret) {
+		debug("Error in public key generation %d\n", ret);
+		goto err;
+	}
+
+	size = roundup(FSL_CAAM_MP_MES_DGST_BYTES, ARCH_DMA_MINALIGN);
+	invalidate_dcache_range((unsigned long)dgst,
+				(unsigned long)dgst + size);
+
+	size = roundup(FSL_CAAM_MP_PRVK_BYTES, ARCH_DMA_MINALIGN);
+	invalidate_dcache_range((unsigned long)c, (unsigned long)c + size);
+	invalidate_dcache_range((unsigned long)d, (unsigned long)d + size);
+
+err:
+	free(dsc);
+	return ret;
+}

include/fsl_sec.h

@@ -340,6 +340,10 @@ struct sg_entry {
 
 #endif
 
+#define FSL_CAAM_MP_PUBK_BYTES		    64
+#define FSL_CAAM_MP_PRVK_BYTES		    32
+#define FSL_CAAM_MP_MES_DGST_BYTES	    32
+
 /* blob_dek:
  * Encapsulates the src in a secure blob and stores it dst
  * @src: reference to the plaintext
@@ -349,6 +353,10 @@ struct sg_entry {
  */
 int blob_dek(const u8 *src, u8 *dst, u8 len);
 
+int gen_mppubk(u8 *dst);
+
+int sign_mppubk(const u8 *m, int data_size, u8 *dgst, u8 *c, u8 *d);
+
 #if defined(CONFIG_ARCH_C29X)
 int sec_init_idx(uint8_t);
 #endif