[PATCH 35/37] imx8: Add DEK blob encapsulation

25 Mar 2021

From: Clement Faure clement.faure@nxp.com
Add DEK encapsulation support for imx8. The DEK blob is generated by the
SECO through the SCFW API.
Signed-off-by: Clement Faure clement.faure@nxp.com
Signed-off-by: Peng Fan peng.fan@nxp.com
---
 arch/arm/include/asm/arch-imx8/image.h |  11 ++
 arch/arm/mach-imx/Kconfig              |   7 ++
 arch/arm/mach-imx/cmd_dek.c            | 152 +++++++++++++++++++++++++
 arch/arm/mach-imx/imx8/Kconfig         |   1 +
 4 files changed, 171 insertions(+)

diff --git a/arch/arm/include/asm/arch-imx8/image.h b/arch/arm/include/asm/arch-imx8/image.h
index c1e5700859..547beeb986 100644
--- a/arch/arm/include/asm/arch-imx8/image.h
+++ b/arch/arm/include/asm/arch-imx8/image.h
@@ -53,4 +53,15 @@ struct signature_block_hdr {
    u16 signature_offset;
    u32 reserved;
 } __packed;
+
+struct generate_key_blob_hdr {
+	u8 version;
+	u8 length_lsb;
+	u8 length_msb;
+	u8 tag;
+	u8 flags;
+	u8 size;
+	u8 algorithm;
+	u8 mode;
+} __packed;
 #endif
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 3bcfced8f0..26bfc5ccc4 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -77,6 +77,7 @@ config CMD_DEKBLOB
    bool "Support the 'dek_blob' command"
    select IMX_CAAM_DEK_ENCAP if ARCH_MX6 || ARCH_MX7 || ARCH_MX7ULP
    select IMX_OPTEE_DEK_ENCAP if ARCH_IMX8M
+	select IMX_SECO_DEK_ENCAP if ARCH_IMX8
    help
      This enables the 'dek_blob' command which is used with the
      Freescale secure boot mechanism. This command encapsulates and
@@ -98,6 +99,12 @@ config IMX_OPTEE_DEK_ENCAP
      with OP-TEE is done through a SMC call and OP-TEE shared memory. This
      option is available on imx8mm.
+config IMX_SECO_DEK_ENCAP
+	bool "Support the DEK blob encapsulation with SECO"
+	help
+	  This enabled the DEK blob encapsulation with the SECO API. This option
+	  is only available on imx8.
+
 config CMD_PRIBLOB
    bool "Support the set_priblob_bitfield command"
    depends on HAS_CAAM && IMX_HAB
diff --git a/arch/arm/mach-imx/cmd_dek.c b/arch/arm/mach-imx/cmd_dek.c
index 75aec2cef0..b10ead1942 100644
--- a/arch/arm/mach-imx/cmd_dek.c
+++ b/arch/arm/mach-imx/cmd_dek.c
@@ -15,6 +15,11 @@
 #include <asm/arch/clock.h>
 #include <mapmem.h>
 #include <tee.h>
+#ifdef CONFIG_IMX_SECO_DEK_ENCAP
+#include <asm/arch/sci/sci.h>
+#include <asm/arch/image.h>
+#endif
+#include <cpu_func.h>
/**
 * blob_dek() - Encapsulate the DEK as a blob using CAM's Key
@@ -129,6 +134,153 @@ error:
    return ret;
 }
 #endif /* CONFIG_IMX_OPTEE_DEK_ENCAP */
+#ifdef CONFIG_IMX_SECO_DEK_ENCAP
+
+#define DEK_BLOB_KEY_ID				0x0
+
+#define AHAB_PRIVATE_KEY			0x81
+#define AHAB_VERSION				0x00
+#define AHAB_MODE_CBC				0x67
+#define AHAB_ALG_AES				0x55
+#define AHAB_128_AES_KEY			0x10
+#define AHAB_192_AES_KEY			0x18
+#define AHAB_256_AES_KEY			0x20
+#define AHAB_FLAG_KEK				0x80
+#define AHAB_DEK_BLOB				0x01
+
+#define DEK_BLOB_HDR_SIZE			8
+#define SECO_PT					2U
+
+static int blob_encap_dek(u32 src_addr, u32 dst_addr, u32 len)
+{
+	sc_err_t err;
+	sc_rm_mr_t mr_input, mr_output;
+	struct generate_key_blob_hdr hdr;
+	u8 in_size, out_size;
+	u8 *src_ptr, *dst_ptr;
+	int ret = 0;
+	int i;
+
+	/* Set sizes */
+	in_size = sizeof(struct generate_key_blob_hdr) + len / 8;
+	out_size = BLOB_SIZE(len / 8) + DEK_BLOB_HDR_SIZE;
+
+	/* Get src and dst virtual addresses */
+	src_ptr = map_sysmem(src_addr, in_size);
+	dst_ptr = map_sysmem(dst_addr, out_size);
+
+	/* Check addr input */
+	if (!(src_ptr && dst_ptr)) {
+		debug("src_addr or dst_addr invalid\n");
+		return -1;
+	}
+
+	/* Build key header */
+	hdr.version = AHAB_VERSION;
+	hdr.length_lsb = sizeof(struct generate_key_blob_hdr) + len / 8;
+	hdr.length_msb = 0x00;
+	hdr.tag = AHAB_PRIVATE_KEY;
+	hdr.flags = AHAB_DEK_BLOB;
+	hdr.algorithm = AHAB_ALG_AES;
+	hdr.mode = AHAB_MODE_CBC;
+
+	switch (len) {
+	case 128:
+		hdr.size = AHAB_128_AES_KEY;
+		break;
+	case 192:
+		hdr.size = AHAB_192_AES_KEY;
+		break;
+	case 256:
+		hdr.size = AHAB_256_AES_KEY;
+		break;
+	default:
+		/* Not supported */
+		debug("Invalid DEK size. Valid sizes are 128, 192 and 256b\n");
+		return -1;
+	}
+
+	/* Build input message */
+	memmove((void *)(src_ptr + sizeof(struct generate_key_blob_hdr)),
+		(void *)src_ptr, len / 8);
+	memcpy((void *)src_ptr, (void *)&hdr,
+	       sizeof(struct generate_key_blob_hdr));
+
+	/* Flush the cache before triggering the CAAM DMA */
+	flush_dcache_range(src_addr, src_addr + in_size);
+
+	/* Find input memory region */
+	err = sc_rm_find_memreg((-1), &mr_input, src_addr & ~(CONFIG_SYS_CACHELINE_SIZE - 1),
+				ALIGN(src_addr + in_size, CONFIG_SYS_CACHELINE_SIZE));
+	if (err) {
+		printf("Error: find memory region 0x%X\n", src_addr);
+		return -ENOMEM;
+	}
+
+	/* Find output memory region */
+	err = sc_rm_find_memreg((-1), &mr_output, dst_addr & ~(CONFIG_SYS_CACHELINE_SIZE - 1),
+				ALIGN(dst_addr + out_size, CONFIG_SYS_CACHELINE_SIZE));
+	if (err) {
+		printf("Error: find memory region 0x%X\n", dst_addr);
+		return -ENOMEM;
+	}
+
+	/* Set memory region permissions for SECO */
+	err = sc_rm_set_memreg_permissions(-1, mr_input, SECO_PT,
+					   SC_RM_PERM_FULL);
+	if (err) {
+		printf("Set permission failed for input memory region\n");
+		ret = -EPERM;
+		goto error;
+	}
+
+	err = sc_rm_set_memreg_permissions(-1, mr_output, SECO_PT,
+					   SC_RM_PERM_FULL);
+	if (err) {
+		printf("Set permission failed for output memory region\n");
+		ret = -EPERM;
+		goto error;
+	}
+
+	/* Flush output data before SECO operation */
+	flush_dcache_range((ulong)dst_ptr, (ulong)(dst_ptr +
+			roundup(out_size, ARCH_DMA_MINALIGN)));
+
+	/* Generate DEK blob */
+	err = sc_seco_gen_key_blob((-1), 0x0, src_addr, dst_addr, out_size);
+	if (err) {
+		ret = -EPERM;
+		goto error;
+	}
+
+	/* Invalidate output buffer */
+	invalidate_dcache_range((ulong)dst_ptr, (ulong)(dst_ptr +
+			roundup(out_size, ARCH_DMA_MINALIGN)));
+
+	printf("DEK Blob\n");
+	for (i = 0; i < DEK_BLOB_HDR_SIZE + BLOB_SIZE(len / 8); i++)
+		printf("%02X", dst_ptr[i]);
+	printf("\n");
+
+error:
+	/* Remove memory region permission to SECO */
+	err = sc_rm_set_memreg_permissions(-1, mr_input, SECO_PT,
+					   SC_RM_PERM_NONE);
+	if (err) {
+		printf("Error: remove permission failed for input\n");
+		ret = -EPERM;
+	}
+
+	err = sc_rm_set_memreg_permissions(-1, mr_output, SECO_PT,
+					   SC_RM_PERM_NONE);
+	if (err) {
+		printf("Error: remove permission failed for output\n");
+		ret = -EPERM;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_IMX_SECO_DEK_ENCAP */
/**
  * do_dek_blob() - Handle the "dek_blob" command-line command
diff --git a/arch/arm/mach-imx/imx8/Kconfig b/arch/arm/mach-imx/imx8/Kconfig
index 04b9729109..4e76612d05 100644
--- a/arch/arm/mach-imx/imx8/Kconfig
+++ b/arch/arm/mach-imx/imx8/Kconfig
@@ -2,6 +2,7 @@ if ARCH_IMX8
config AHAB_BOOT
    bool "Support i.MX8 AHAB features"
+	imply CMD_DEKBLOB
    help
      This option enables the support for AHAB secure boot.
-- 
2.25.1


    

[PATCH 35/37] imx8: Add DEK blob encapsulation

Peng Fan (OSS)