[PATCH v4 00/14] qemu: arm64: Add support for uefi capsule update on qemu arm platform
The capsule update feature is supported on a platform configuration booting in a non-secure mode, i.e with -machine virt,secure=off option set. This results in the platform booting u-boot directly without the presence of trusted firmware(tf-a). Steps that need to be followed for using this feature have been provided as part of the documentation.
Support has also been added for enabling the capsule authentication feature. Capsule authentication, as defined by the uefi specification is very much on similar lines to the logic used for variable authentication. As a result, most of the signature verification code already in use for variable authentication has been used for capsule authentication.
Storage of the public key certificate, needed for the signature verification process is in form of the efi signature list(esl) structure. This public key is stored on an overlay which is then merged with the platform's base fdt at runtime. The public key esl file can be embedded into the overlay dtb using the mkeficapsule utility that has been added as part of the capsule update support series by Takahiro Akashi. Steps needed for enabling capsule authentication have been provided as part of the documentation.
This patch series needs to be applied on top of the capsule update support patch series from Takahiro Akashi on the next branch.
Changes since V3: * Move the selection of SYS_MTDPARTS_RUNTIME config to the board's Kconfig from lib/efi_loader/Kconfig, using imply. * Move the selection of SET_DFU_ALT_INFO config to the board's Kconfig from lib/efi_loader/Kconfig, using imply.
Changes since V2: * Enable building of board_late_init for both of the Qemu arm and arm64 variants * Move the selection the CONFIG_BOARD_LATE_INIT to mach-qemu Kconfig file * Move the functions to populate the mtdparts under board/emulation/common for allowing subsequent re-use by other Qemu arch based platforms * Move the functions to populate the dfu_alt_info variable under board/emulation/common for allowing subsequent re-use by other Qemu arch based platforms * Move the function for fetching the public key certficate from the platform's dtb under board/emulation/common directory. * Move the function for checking the capsule_authentication_enabled env variable under board/emulation/common directory. * Moved the capsule update related documentation for the Qemu platform to a new file under doc/board/emulation/ directory. * Incorporated all typo review comments from Heinrich * Put in a skeletal overlay dts file for reference, as was suggested by Heinrich
Changes since V1: * Added support for embedding the public key cert in an overlay using the -O option * The earlier patch was adding a call to pci_init in board_init. Moved the virtio_init call to board_late_init * Change MTDPARTS_NOR[01] as config options instead of defining them in the qemu-arm.h config header. * Enable CONFIG_SYS_MTDPARTS_RUNTIME with CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT * Build set_dfu_alt_info and board_get_alt_info functions only if CONFIG_SET_DFU_ALT_INFO is defined * Enable CONFIG_SET_DFU_ALT_INFO with CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT * Detect the presence of the FMP Payload header at runtime instead of using a Kconfig option, as was suggested by Heinrich * Change the documentation to reflect the usage of overlays for embedding the public key certs at runtime * Fix the build for 'make htmldocs'
Sughosh Ganu (14): mkeficapsule: Add support for embedding public key in a dtb qemu: arm: Initialise virtio devices in board_late_init crypto: Fix the logic to calculate hash with authattributes set qemu: common: Add support for dynamic mtdparts for the platform qemu: common: Set dfu_alt_info variable for the platform fsp: Move and rename fsp_types.h file efi_loader: Add logic to parse EDKII specific fmp payload header dfu_mtd: Add provision to unlock mtd device efi_loader: Make the pkcs7 header parsing function an extern efi_loader: Re-factor code to build the signature store from efi signature list efi: capsule: Add support for uefi capsule authentication efi_loader: Enable uefi capsule authentication efidebug: capsule: Add a command to update capsule on disk qemu: arm64: Add documentation for capsule update
arch/arm/mach-qemu/Kconfig | 2 + arch/x86/include/asm/fsp/fsp_support.h | 3 +- board/emulation/common/Kconfig | 15 ++ board/emulation/common/Makefile | 5 + board/emulation/common/qemu_capsule.c | 48 ++++ board/emulation/common/qemu_dfu.c | 68 +++++ board/emulation/common/qemu_mtdparts.c | 82 ++++++ board/emulation/qemu-arm/Kconfig | 8 + board/emulation/qemu-arm/qemu-arm.c | 5 + cmd/efidebug.c | 14 ++ doc/board/emulation/index.rst | 1 + doc/board/emulation/qemu_capsule_update.rst | 210 ++++++++++++++++ drivers/dfu/dfu_mtd.c | 20 +- include/efi_api.h | 18 ++ include/efi_loader.h | 12 + .../fsp/fsp_types.h => include/signatures.h | 6 +- lib/crypto/pkcs7_verify.c | 37 ++- lib/efi_loader/Kconfig | 17 ++ lib/efi_loader/efi_capsule.c | 122 +++++++++ lib/efi_loader/efi_firmware.c | 77 +++++- lib/efi_loader/efi_signature.c | 192 +++++++++++---- lib/efi_loader/efi_variable.c | 93 +------ tools/Makefile | 1 + tools/mkeficapsule.c | 233 +++++++++++++++++- 24 files changed, 1125 insertions(+), 164 deletions(-) create mode 100644 board/emulation/common/Kconfig create mode 100644 board/emulation/common/Makefile create mode 100644 board/emulation/common/qemu_capsule.c create mode 100644 board/emulation/common/qemu_dfu.c create mode 100644 board/emulation/common/qemu_mtdparts.c create mode 100644 doc/board/emulation/qemu_capsule_update.rst rename arch/x86/include/asm/fsp/fsp_types.h => include/signatures.h (95%)
Add options for embedding the public key esl(efi signature list) file to the platform's dtb. The esl file is then retrieved and used for authenticating the capsule to be used for updating firmare components on the platform.
The esl file can now be embedded in the dtb by invoking the following command mkeficapsule -K <pub_key.esl> -D <dtb>
In the scenario where the esl file is to be embedded in an overlay, this can be done through the following command mkeficapsule -O -K <pub_key.esl> -D <dtb>
This will create a node named 'signature' in the dtb, and the esl file will be stored as 'capsule-key'
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
tools/Makefile | 1 + tools/mkeficapsule.c | 233 ++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 222 insertions(+), 12 deletions(-)
diff --git a/tools/Makefile b/tools/Makefile index 66d9376803..6d7b48fb57 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -218,6 +218,7 @@ hostprogs-$(CONFIG_MIPS) += mips-relocs hostprogs-$(CONFIG_ASN1_COMPILER) += asn1_compiler HOSTCFLAGS_asn1_compiler.o = -idirafter $(srctree)/include
+mkeficapsule-objs := mkeficapsule.o $(LIBFDT_OBJS) hostprogs-$(CONFIG_EFI_HAVE_CAPSULE_SUPPORT) += mkeficapsule
# We build some files with extra pedantic flags to try to minimize things diff --git a/tools/mkeficapsule.c b/tools/mkeficapsule.c index 3f8bc7009b..270943fc90 100644 --- a/tools/mkeficapsule.c +++ b/tools/mkeficapsule.c @@ -4,16 +4,22 @@ * Author: AKASHI Takahiro */
+#include <errno.h> #include <getopt.h> #include <malloc.h> #include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <string.h> +#include <unistd.h> #include <linux/types.h> + +#include <sys/mman.h> #include <sys/stat.h> #include <sys/types.h>
+#include "fdt_host.h" + typedef __u8 u8; typedef __u16 u16; typedef __u32 u32; @@ -23,6 +29,9 @@ typedef __s32 s32;
#define aligned_u64 __aligned_u64
+#define SIGNATURE_NODENAME "signature" +#define OVERLAY_NODENAME "__overlay__" + #ifndef __packed #define __packed __attribute__((packed)) #endif @@ -43,6 +52,9 @@ static struct option options[] = { {"raw", required_argument, NULL, 'r'}, {"index", required_argument, NULL, 'i'}, {"instance", required_argument, NULL, 'I'}, + {"dtb", required_argument, NULL, 'D'}, + {"public key", required_argument, NULL, 'K'}, + {"overlay", no_argument, NULL, 'O'}, {"help", no_argument, NULL, 'h'}, {NULL, 0, NULL, 0}, }; @@ -51,14 +63,183 @@ static void print_usage(void) { printf("Usage: %s [options] <output file>\n" "Options:\n" - "\t--fit <fit image> new FIT image file\n" - "\t--raw <raw image> new raw image file\n" - "\t--index <index> update image index\n" - "\t--instance <instance> update hardware instance\n" - "\t--help print a help message\n", + + "\t--fit <fit image> new FIT image file\n" + "\t--raw <raw image> new raw image file\n" + "\t--index <index> update image index\n" + "\t--instance <instance> update hardware instance\n" + "\t--public-key <key file> public key esl file\n" + "\t--dtb <dtb file> dtb file\n" + "\t--overlay the dtb file is an overlay\n" + "\t--help print a help message\n", tool_name); }
+static int fdt_add_pub_key_data(void *sptr, void *dptr, size_t key_size, + bool overlay) +{ + int parent; + int ov_node; + int frag_node; + int ret = 0; + + if (overlay) { + /* + * The signature would be stored in the + * first fragment node of the overlay + */ + frag_node = fdt_first_subnode(dptr, 0); + if (frag_node == -FDT_ERR_NOTFOUND) { + fprintf(stderr, + "Couldn't find the fragment node: %s\n", + fdt_strerror(frag_node)); + goto done; + } + + ov_node = fdt_subnode_offset(dptr, frag_node, OVERLAY_NODENAME); + if (ov_node == -FDT_ERR_NOTFOUND) { + fprintf(stderr, + "Couldn't find the __overlay__ node: %s\n", + fdt_strerror(ov_node)); + goto done; + } + } else { + ov_node = 0; + } + + parent = fdt_subnode_offset(dptr, ov_node, SIGNATURE_NODENAME); + if (parent == -FDT_ERR_NOTFOUND) { + parent = fdt_add_subnode(dptr, ov_node, SIGNATURE_NODENAME); + if (parent < 0) { + ret = parent; + if (ret != -FDT_ERR_NOSPACE) { + fprintf(stderr, + "Couldn't create signature node: %s\n", + fdt_strerror(parent)); + } + } + } + if (ret) + goto done; + + /* Write the key to the FDT node */ + ret = fdt_setprop(dptr, parent, "capsule-key", + sptr, key_size); + +done: + if (ret) + ret = ret == -FDT_ERR_NOSPACE ? -ENOSPC : -EIO; + + return ret; +} + +static int add_public_key(const char *pkey_file, const char *dtb_file, + bool overlay) +{ + int ret; + int srcfd = 0; + int destfd = 0; + void *sptr = NULL; + void *dptr = NULL; + off_t src_size; + struct stat pub_key; + struct stat dtb; + + /* Find out the size of the public key */ + srcfd = open(pkey_file, O_RDONLY); + if (srcfd == -1) { + fprintf(stderr, "%s: Can't open %s: %s\n", + __func__, pkey_file, strerror(errno)); + goto err; + } + + ret = fstat(srcfd, &pub_key); + if (ret == -1) { + fprintf(stderr, "%s: Can't stat %s: %s\n", + __func__, pkey_file, strerror(errno)); + goto err; + } + + src_size = pub_key.st_size; + + /* mmap the public key esl file */ + sptr = mmap(0, src_size, PROT_READ, MAP_SHARED, srcfd, 0); + if ((sptr == MAP_FAILED) || (errno != 0)) { + fprintf(stderr, "%s: Failed to mmap %s:%s\n", + __func__, pkey_file, strerror(errno)); + goto err; + } + + /* Open the dest FDT */ + destfd = open(dtb_file, O_RDWR); + if (destfd == -1) { + fprintf(stderr, "%s: Can't open %s: %s\n", + __func__, dtb_file, strerror(errno)); + goto err; + } + + ret = fstat(destfd, &dtb); + if (ret == -1) { + fprintf(stderr, "%s: Can't stat %s: %s\n", + __func__, dtb_file, strerror(errno)); + goto err; + } + + dtb.st_size += src_size + 0x30; + if (ftruncate(destfd, dtb.st_size)) { + fprintf(stderr, "%s: Can't expand %s: %s\n", + __func__, dtb_file, strerror(errno)); + goto err;; + } + + errno = 0; + /* mmap the dtb file */ + dptr = mmap(0, dtb.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, + destfd, 0); + if ((dptr == MAP_FAILED) || (errno != 0)) { + fprintf(stderr, "%s: Failed to mmap %s:%s\n", + __func__, dtb_file, strerror(errno)); + goto err; + } + + if (fdt_check_header(dptr)) { + fprintf(stderr, "%s: Invalid FDT header\n", __func__); + goto err; + } + + ret = fdt_open_into(dptr, dptr, dtb.st_size); + if (ret) { + fprintf(stderr, "%s: Cannot expand FDT: %s\n", + __func__, fdt_strerror(ret)); + goto err; + } + + /* Copy the esl file to the expanded FDT */ + ret = fdt_add_pub_key_data(sptr, dptr, src_size, overlay); + if (ret < 0) { + fprintf(stderr, "%s: Unable to add public key to the FDT\n", + __func__); + goto err; + } + + return 0; + +err: + if (sptr) + munmap(sptr, src_size); + + if (dptr) + munmap(dptr, dtb.st_size); + + if (srcfd >= 0) + close(srcfd); + + if (destfd >= 0) + close(destfd); + + return -1; +} + static int create_fwbin(char *path, char *bin, efi_guid_t *guid, unsigned long index, unsigned long instance) { @@ -173,16 +354,22 @@ err_1: int main(int argc, char **argv) { char *file; + char *pkey_file; + char *dtb_file; efi_guid_t *guid; unsigned long index, instance; int c, idx; + int ret; + bool overlay = false;
file = NULL; + pkey_file = NULL; + dtb_file = NULL; guid = NULL; index = 0; instance = 0; for (;;) { - c = getopt_long(argc, argv, "f:r:i:I:v:h", options, &idx); + c = getopt_long(argc, argv, "f:r:i:I:v:D:K:Oh", options, &idx); if (c == -1) break;
@@ -209,22 +396,44 @@ int main(int argc, char **argv) case 'I': instance = strtoul(optarg, NULL, 0); break; + case 'K': + if (pkey_file) { + printf("Public Key already specified\n"); + return -1; + } + pkey_file = optarg; + break; + case 'D': + if (dtb_file) { + printf("DTB file already specified\n"); + return -1; + } + dtb_file = optarg; + break; + case 'O': + overlay = true; + break; case 'h': print_usage(); return 0; } }
- /* need a output file */ - if (argc != optind + 1) { + /* need a fit image file or raw image file */ + if (!file && !pkey_file && !dtb_file) { + printf("%s: %d\n", __func__, __LINE__); print_usage(); return -1; }
- /* need a fit image file or raw image file */ - if (!file) { - print_usage(); - return -1; + if (pkey_file && dtb_file) { + ret = add_public_key(pkey_file, dtb_file, overlay); + if (ret == -1) { + printf("Adding public key to the dtb failed\n"); + return -1; + } else { + return 0; + } }
if (create_fwbin(argv[optind], file, guid, index, instance)
On the qemu arm platform, the virtio devices are initialised in the board_init function, which gets called before the initr_pci. With this sequence, the virtio block devices on the pci bus are not initialised. Move the initialisation of the virtio devices to board_late_init which gets called after the call to initr_pci.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
arch/arm/mach-qemu/Kconfig | 2 ++ board/emulation/qemu-arm/qemu-arm.c | 5 +++++ 2 files changed, 7 insertions(+)
diff --git a/arch/arm/mach-qemu/Kconfig b/arch/arm/mach-qemu/Kconfig index 588d2d3102..186c3582eb 100644 --- a/arch/arm/mach-qemu/Kconfig +++ b/arch/arm/mach-qemu/Kconfig @@ -16,12 +16,14 @@ choice config TARGET_QEMU_ARM_32BIT bool "ARMv7-A, 32bit" select ARCH_SUPPORT_PSCI + select BOARD_LATE_INIT select CPU_V7A select SYS_ARCH_TIMER
config TARGET_QEMU_ARM_64BIT bool "ARMv8, 64bit" select ARM64 + select BOARD_LATE_INIT
endchoice
diff --git a/board/emulation/qemu-arm/qemu-arm.c b/board/emulation/qemu-arm/qemu-arm.c index f18f2ed7da..aa68bef469 100644 --- a/board/emulation/qemu-arm/qemu-arm.c +++ b/board/emulation/qemu-arm/qemu-arm.c @@ -64,6 +64,11 @@ struct mm_region *mem_map = qemu_arm64_mem_map; #endif
int board_init(void) +{ + return 0; +} + +int board_late_init(void) { /* * Make sure virtio bus is enumerated so that peripherals
RFC 2315 Section 9.3 describes the message digesting process. The digest calculated depends on whether the authenticated attributes are present. In case of a scenario where the authenticated attributes are present, the message digest that gets signed and is part of the pkcs7 message is computed from the auth attributes rather than the contents field.
Check if the auth attributes are present, and if set, use the auth attributes to compute the hash that would be compared with the encrypted hash on the pkcs7 message.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
lib/crypto/pkcs7_verify.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/lib/crypto/pkcs7_verify.c b/lib/crypto/pkcs7_verify.c index 320ba49f79..58683ef614 100644 --- a/lib/crypto/pkcs7_verify.c +++ b/lib/crypto/pkcs7_verify.c @@ -50,8 +50,15 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, struct image_region regions[2]; int ret = 0;
- /* The digest was calculated already. */ - if (sig->digest) + /* + * [RFC2315 9.3] + * If the authenticated attributes are present, + * the message-digest is calculated on the + * attributes present in the + * authenticatedAttributes field and not just + * the contents field + */ + if (!sinfo->authattrs && sig->digest) return 0;
if (!sinfo->sig->hash_algo) @@ -63,17 +70,25 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, else return -ENOPKG;
- sig->digest = calloc(1, sig->digest_size); - if (!sig->digest) { - pr_warn("Sig %u: Out of memory\n", sinfo->index); - return -ENOMEM; - } + /* + * Calculate the hash only if the data is present. + * In case of authenticated variable and capsule, + * the hash has already been calculated on the + * efi_image_regions and populated + */ + if (pkcs7->data) { + sig->digest = calloc(1, sig->digest_size); + if (!sig->digest) { + pr_warn("Sig %u: Out of memory\n", sinfo->index); + return -ENOMEM; + }
- regions[0].data = pkcs7->data; - regions[0].size = pkcs7->data_len; + regions[0].data = pkcs7->data; + regions[0].size = pkcs7->data_len;
- /* Digest the message [RFC2315 9.3] */ - hash_calculate(sinfo->sig->hash_algo, regions, 1, sig->digest); + /* Digest the message [RFC2315 9.3] */ + hash_calculate(sinfo->sig->hash_algo, regions, 1, sig->digest); + }
/* However, if there are authenticated attributes, there must be a * message digest attribute amongst them which corresponds to the
Add support for setting the default values for mtd partitions on the platform. This would be used for updating the firmware image using uefi capsule update with the dfu mtd backend driver.
Currently, values have been defined for the qemu arm64 platform, with default values defined for the mtd partitions based on the NOR flash. This can be subsequently extended for other qemu architectures which need mtdparts set.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since v3: * Move the selection of SYS_MTDPARTS_RUNTIME config to the board's Kconfig from lib/efi_loader/Kconfig, using imply.
board/emulation/common/Kconfig | 15 +++++ board/emulation/common/Makefile | 3 + board/emulation/common/qemu_mtdparts.c | 82 ++++++++++++++++++++++++++ board/emulation/qemu-arm/Kconfig | 7 +++ 4 files changed, 107 insertions(+) create mode 100644 board/emulation/common/Kconfig create mode 100644 board/emulation/common/Makefile create mode 100644 board/emulation/common/qemu_mtdparts.c
diff --git a/board/emulation/common/Kconfig b/board/emulation/common/Kconfig new file mode 100644 index 0000000000..4c15c8bcb8 --- /dev/null +++ b/board/emulation/common/Kconfig @@ -0,0 +1,15 @@ +config MTDPARTS_NOR0 + string "mtd boot partition for nor0" + default "64m(u-boot)" if TARGET_QEMU_ARM_64BIT && !TFABOOT + depends on SYS_MTDPARTS_RUNTIME + help + This define the partition of nor0 used to build mtparts dynamically + for boot from nor0. + +config MTDPARTS_NOR1 + string "mtd u-boot env partition for nor1" + default "64m(u-boot-env)" if TARGET_QEMU_ARM_64BIT && !TFABOOT + depends on SYS_MTDPARTS_RUNTIME + help + This define the partition of nor1 used to build mtparts dynamically + for the u-boot env stored on nor1. diff --git a/board/emulation/common/Makefile b/board/emulation/common/Makefile new file mode 100644 index 0000000000..de5c8d0c2a --- /dev/null +++ b/board/emulation/common/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0+ + +obj-$(CONFIG_SYS_MTDPARTS_RUNTIME) += qemu_mtdparts.o diff --git a/board/emulation/common/qemu_mtdparts.c b/board/emulation/common/qemu_mtdparts.c new file mode 100644 index 0000000000..60212e97ac --- /dev/null +++ b/board/emulation/common/qemu_mtdparts.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2020 Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <mtd.h> + +#include <linux/string.h> + +#define MTDPARTS_LEN 256 +#define MTDIDS_LEN 128 + +static void board_get_mtdparts(const char *dev, const char *partition, + char *mtdids, char *mtdparts) +{ + /* mtdids: "<dev>=<dev>, ...." */ + if (mtdids[0] != '\0') + strcat(mtdids, ","); + strcat(mtdids, dev); + strcat(mtdids, "="); + strcat(mtdids, dev); + + /* mtdparts: "mtdparts=<dev>:<mtdparts_<dev>>;..." */ + if (mtdparts[0] != '\0') + strncat(mtdparts, ";", MTDPARTS_LEN); + else + strcat(mtdparts, "mtdparts="); + + strncat(mtdparts, dev, MTDPARTS_LEN); + strncat(mtdparts, ":", MTDPARTS_LEN); + strncat(mtdparts, partition, MTDPARTS_LEN); +} + +void board_mtdparts_default(const char **mtdids, const char **mtdparts) +{ + struct mtd_info *mtd; + struct udevice *dev; + const char *mtd_partition; + static char parts[3 * MTDPARTS_LEN + 1]; + static char ids[MTDIDS_LEN + 1]; + static bool mtd_initialized; + + if (mtd_initialized) { + *mtdids = ids; + *mtdparts = parts; + return; + } + + memset(parts, 0, sizeof(parts)); + memset(ids, 0, sizeof(ids)); + + /* Currently mtdparts is needed on Qemu ARM64 for capsule updates */ + if (IS_ENABLED(CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT) && + IS_ENABLED(CONFIG_TARGET_QEMU_ARM_64BIT)) { + /* probe all MTD devices */ + for (uclass_first_device(UCLASS_MTD, &dev); dev; + uclass_next_device(&dev)) { + debug("mtd device = %s\n", dev->name); + } + + mtd = get_mtd_device_nm("nor0"); + if (!IS_ERR_OR_NULL(mtd)) { + mtd_partition = CONFIG_MTDPARTS_NOR0; + board_get_mtdparts("nor0", mtd_partition, ids, parts); + put_mtd_device(mtd); + } + + mtd = get_mtd_device_nm("nor1"); + if (!IS_ERR_OR_NULL(mtd)) { + mtd_partition = CONFIG_MTDPARTS_NOR1; + board_get_mtdparts("nor1", mtd_partition, ids, parts); + put_mtd_device(mtd); + } + } + + mtd_initialized = true; + *mtdids = ids; + *mtdparts = parts; + debug("%s:mtdids=%s & mtdparts=%s\n", __func__, ids, parts); +} diff --git a/board/emulation/qemu-arm/Kconfig b/board/emulation/qemu-arm/Kconfig index 02ae4d9884..0108efebd3 100644 --- a/board/emulation/qemu-arm/Kconfig +++ b/board/emulation/qemu-arm/Kconfig @@ -11,3 +11,10 @@ config BOARD_SPECIFIC_OPTIONS # dummy imply VIRTIO_BLK
endif + +if TARGET_QEMU_ARM_64BIT && !TFABOOT +config BOARD_SPECIFIC_OPTIONS + imply SYS_MTDPARTS_RUNTIME + +source "board/emulation/common/Kconfig" +endif
The dfu framework uses the dfu_alt_info environment variable to get information that is needed for performing the firmware update. Add logic to set the dfu_alt_info for the qemu arm64 platform to reflect the two mtd partitions created for the u-boot env and the firmware image. This can be subsequently extended for other qemu architectures which need this variable set.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: * Move the selection of SET_DFU_ALT_INFO config to the board's Kconfig from lib/efi_loader/Kconfig, using imply.
board/emulation/common/Makefile | 1 + board/emulation/common/qemu_dfu.c | 68 +++++++++++++++++++++++++++++++ board/emulation/qemu-arm/Kconfig | 1 + 3 files changed, 70 insertions(+) create mode 100644 board/emulation/common/qemu_dfu.c
diff --git a/board/emulation/common/Makefile b/board/emulation/common/Makefile index de5c8d0c2a..c5b452e7e3 100644 --- a/board/emulation/common/Makefile +++ b/board/emulation/common/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0+
obj-$(CONFIG_SYS_MTDPARTS_RUNTIME) += qemu_mtdparts.o +obj-$(CONFIG_SET_DFU_ALT_INFO) += qemu_dfu.o diff --git a/board/emulation/common/qemu_dfu.c b/board/emulation/common/qemu_dfu.c new file mode 100644 index 0000000000..62234a7647 --- /dev/null +++ b/board/emulation/common/qemu_dfu.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2020 Linaro Limited + */ + +#include <common.h> +#include <dfu.h> +#include <env.h> +#include <memalign.h> +#include <mtd.h> + +#define DFU_ALT_BUF_LEN SZ_1K + +static void board_get_alt_info(struct mtd_info *mtd, char *buf) +{ + struct mtd_info *part; + bool first = true; + const char *name; + int len, partnum = 0; + + name = mtd->name; + len = strlen(buf); + + if (buf[0] != '\0') + len += snprintf(buf + len, DFU_ALT_BUF_LEN - len, "&"); + len += snprintf(buf + len, DFU_ALT_BUF_LEN - len, + "mtd %s=", name); + + list_for_each_entry(part, &mtd->partitions, node) { + partnum++; + if (!first) + len += snprintf(buf + len, DFU_ALT_BUF_LEN - len, ";"); + first = false; + + len += snprintf(buf + len, DFU_ALT_BUF_LEN - len, + "%s part %d", + part->name, partnum); + } +} + +void set_dfu_alt_info(char *interface, char *devstr) +{ + struct mtd_info *mtd; + + ALLOC_CACHE_ALIGN_BUFFER(char, buf, DFU_ALT_BUF_LEN); + + if (env_get("dfu_alt_info")) + return; + + memset(buf, 0, sizeof(buf)); + + /* + * Currently dfu_alt_info is needed on Qemu ARM64 for + * capsule updates + */ + if (IS_ENABLED(CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT) && + IS_ENABLED(CONFIG_TARGET_QEMU_ARM_64BIT)) { + /* probe all MTD devices */ + mtd_probe_devices(); + + mtd = get_mtd_device_nm("nor0"); + if (!IS_ERR_OR_NULL(mtd)) + board_get_alt_info(mtd, buf); + } + + env_set("dfu_alt_info", buf); + printf("dfu_alt_info set\n"); +} diff --git a/board/emulation/qemu-arm/Kconfig b/board/emulation/qemu-arm/Kconfig index 0108efebd3..fb8d38f5b8 100644 --- a/board/emulation/qemu-arm/Kconfig +++ b/board/emulation/qemu-arm/Kconfig @@ -15,6 +15,7 @@ endif if TARGET_QEMU_ARM_64BIT && !TFABOOT config BOARD_SPECIFIC_OPTIONS imply SYS_MTDPARTS_RUNTIME + imply SET_DFU_ALT_INFO
source "board/emulation/common/Kconfig" endif
The fsp_types.h header file contains macros for building signatures of different widths. These signature macros are architecture agnostic, and can be used in all places which use signatures in a data structure. Move and rename the fsp_types.h under the common include header.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org Reviewed-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com ---
Changes since V3: None
This patch had been sent to the mailing list separately[1] and has been reviewed by Simon Glass and Bin Meng and merged on the x86 tree.
[1] - https://lists.denx.de/pipermail/u-boot/2020-December/434849.html
arch/x86/include/asm/fsp/fsp_support.h | 3 ++- .../x86/include/asm/fsp/fsp_types.h => include/signatures.h | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-) rename arch/x86/include/asm/fsp/fsp_types.h => include/signatures.h (95%)
diff --git a/arch/x86/include/asm/fsp/fsp_support.h b/arch/x86/include/asm/fsp/fsp_support.h index 29e511415c..3cd3e4fcf5 100644 --- a/arch/x86/include/asm/fsp/fsp_support.h +++ b/arch/x86/include/asm/fsp/fsp_support.h @@ -7,11 +7,12 @@ #ifndef __FSP_SUPPORT_H__ #define __FSP_SUPPORT_H__
+#include <signatures.h> + #include <asm/fsp/fsp_bootmode.h> #include <asm/fsp/fsp_fv.h> #include <asm/fsp/fsp_hob.h> #include <asm/fsp/fsp_infoheader.h> -#include <asm/fsp/fsp_types.h> #include <asm/fsp_arch.h> #include <asm/fsp/fsp_azalia.h>
diff --git a/arch/x86/include/asm/fsp/fsp_types.h b/include/signatures.h similarity index 95% rename from arch/x86/include/asm/fsp/fsp_types.h rename to include/signatures.h index 3d5b17ecf1..4042db1e00 100644 --- a/arch/x86/include/asm/fsp/fsp_types.h +++ b/include/signatures.h @@ -4,8 +4,8 @@ * Copyright (C) 2014, Bin Meng bmeng.cn@gmail.com */
-#ifndef __FSP_TYPES_H__ -#define __FSP_TYPES_H__ +#ifndef __SIGNATURES_H__ +#define __SIGNATURES_H__
/** * Returns a 16-bit signature built from 2 ASCII characters. @@ -59,4 +59,4 @@ #define SIGNATURE_64(A, B, C, D, E, F, G, H) \ (SIGNATURE_32(A, B, C, D) | ((u64)(SIGNATURE_32(E, F, G, H)) << 32))
-#endif +#endif /* __SIGNATURES_H__ */
When building the capsule using scripts in edk2, a fmp header is added on top of the binary payload. Add logic to detect presence of the header. When present, the pointer to the image needs to be adjusted as per the size of the header to point to the actual binary payload.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
lib/efi_loader/efi_firmware.c | 41 +++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+)
diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c index 72c560dbc2..5d2ecde2f1 100644 --- a/lib/efi_loader/efi_firmware.c +++ b/lib/efi_loader/efi_firmware.c @@ -11,8 +11,30 @@ #include <dfu.h> #include <efi_loader.h> #include <image.h> +#include <signatures.h> + #include <linux/list.h>
+#define FMP_PAYLOAD_HDR_SIGNATURE SIGNATURE_32('M', 'S', 'S', '1') + +/** + * struct fmp_payload_header - EDK2 header for the FMP payload + * + * This structure describes the header which is preprended to the + * FMP payload by the edk2 capsule generation scripts. + * + * @signature: Header signature used to identify the header + * @header_size: Size of the structure + * @fw_version: Firmware versions used + * @lowest_supported_version: Lowest supported version + */ +struct fmp_payload_header { + u32 signature; + u32 header_size; + u32 fw_version; + u32 lowest_supported_version; +}; + /* Place holder; not supported */ static efi_status_t EFIAPI efi_firmware_get_image_unsupported( @@ -379,12 +401,31 @@ efi_status_t EFIAPI efi_firmware_raw_set_image( efi_status_t (*progress)(efi_uintn_t completion), u16 **abort_reason) { + u32 fmp_hdr_signature; + struct fmp_payload_header *header; + EFI_ENTRY("%p %d %p %ld %p %p %p\n", this, image_index, image, image_size, vendor_code, progress, abort_reason);
if (!image) return EFI_EXIT(EFI_INVALID_PARAMETER);
+ fmp_hdr_signature = FMP_PAYLOAD_HDR_SIGNATURE; + header = (void *)image; + + if (!memcmp(&header->signature, &fmp_hdr_signature, + sizeof(fmp_hdr_signature))) { + /* + * When building the capsule with the scripts in + * edk2, a FMP header is inserted above the capsule + * payload. Compensate for this header to get the + * actual payload that is to be updated. + */ + image += header->header_size; + image_size -= header->header_size; + + } + if (dfu_write_by_alt(image_index - 1, (void *)image, image_size, NULL, NULL)) return EFI_EXIT(EFI_DEVICE_ERROR);
Prior to writing to an mtd device, mtd_erase is called. This call fails in case the sector being erased is locked. Call mtd_unlock to unlock the region which is to be erased and later written to. Lock the region once the write to the region has completed.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
drivers/dfu/dfu_mtd.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/dfu/dfu_mtd.c b/drivers/dfu/dfu_mtd.c index 36cd4e945b..b34975dbb0 100644 --- a/drivers/dfu/dfu_mtd.c +++ b/drivers/dfu/dfu_mtd.c @@ -21,7 +21,7 @@ static bool mtd_is_aligned_with_block_size(struct mtd_info *mtd, u64 size) static int mtd_block_op(enum dfu_op op, struct dfu_entity *dfu, u64 offset, void *buf, long *len) { - u64 off, lim, remaining; + u64 off, lim, remaining, lock_ofs, lock_len; struct mtd_info *mtd = dfu->data.mtd.info; struct mtd_oob_ops io_op = {}; int ret = 0; @@ -34,7 +34,7 @@ static int mtd_block_op(enum dfu_op op, struct dfu_entity *dfu, return 0; }
- off = dfu->data.mtd.start + offset + dfu->bad_skip; + off = lock_ofs = dfu->data.mtd.start + offset + dfu->bad_skip; lim = dfu->data.mtd.start + dfu->data.mtd.size;
if (off >= lim) { @@ -56,12 +56,19 @@ static int mtd_block_op(enum dfu_op op, struct dfu_entity *dfu, if (op == DFU_OP_WRITE) { struct erase_info erase_op = {};
- remaining = round_up(*len, mtd->erasesize); + remaining = lock_len = round_up(*len, mtd->erasesize); erase_op.mtd = mtd; erase_op.addr = off; erase_op.len = mtd->erasesize; erase_op.scrub = 0;
+ debug("Unlocking the mtd device\n"); + ret = mtd_unlock(mtd, lock_ofs, lock_len); + if (ret && ret != -EOPNOTSUPP) { + printf("MTD device unlock failed\n"); + return 0; + } + while (remaining) { if (erase_op.addr + remaining > lim) { printf("Limit reached 0x%llx while erasing at offset 0x%llx\n", @@ -139,6 +146,13 @@ static int mtd_block_op(enum dfu_op op, struct dfu_entity *dfu, io_op.len = mtd->writesize; }
+ if (op == DFU_OP_WRITE) { + /* Write done, lock again */ + debug("Locking the mtd device\n"); + ret = mtd_lock(mtd, lock_ofs, lock_len); + if (ret && ret != -EOPNOTSUPP) + printf("MTD device lock failed\n"); + } return ret; }
The pkcs7 header parsing functionality is pretty generic, and can be used by other features like capsule authentication. Make the function an extern, also changing it's name to efi_parse_pkcs7_header
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
include/efi_loader.h | 4 ++ lib/efi_loader/efi_signature.c | 85 +++++++++++++++++++++++++++++++ lib/efi_loader/efi_variable.c | 93 ++-------------------------------- 3 files changed, 93 insertions(+), 89 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h index 365f3d01dc..8807fcd913 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -818,6 +818,10 @@ bool efi_secure_boot_enabled(void); bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp, WIN_CERTIFICATE **auth, size_t *auth_len);
+struct pkcs7_message *efi_parse_pkcs7_header(const void *buf, + size_t buflen, + u8 **tmpbuf); + /* runtime implementation of memcpy() */ void efi_memcpy_runtime(void *dest, const void *src, size_t n);
diff --git a/lib/efi_loader/efi_signature.c b/lib/efi_loader/efi_signature.c index 79dee27421..9ab071b611 100644 --- a/lib/efi_loader/efi_signature.c +++ b/lib/efi_loader/efi_signature.c @@ -27,6 +27,91 @@ const efi_guid_t efi_guid_cert_x509_sha256 = EFI_CERT_X509_SHA256_GUID; const efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID;
#ifdef CONFIG_EFI_SECURE_BOOT +static u8 pkcs7_hdr[] = { + /* SEQUENCE */ + 0x30, 0x82, 0x05, 0xc7, + /* OID: pkcs7-signedData */ + 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x07, 0x02, + /* Context Structured? */ + 0xa0, 0x82, 0x05, 0xb8, +}; + +/** + * efi_parse_pkcs7_header - parse a signature in payload + * @buf: Pointer to payload's value + * @buflen: Length of @buf + * @tmpbuf: Pointer to temporary buffer + * + * Parse a signature embedded in payload's value and instantiate + * a pkcs7_message structure. Since pkcs7_parse_message() accepts only + * pkcs7's signedData, some header needed be prepended for correctly + * parsing authentication data + * A temporary buffer will be allocated if needed, and it should be + * kept valid during the authentication because some data in the buffer + * will be referenced by efi_signature_verify(). + * + * Return: Pointer to pkcs7_message structure on success, NULL on error + */ +struct pkcs7_message *efi_parse_pkcs7_header(const void *buf, + size_t buflen, + u8 **tmpbuf) +{ + u8 *ebuf; + size_t ebuflen, len; + struct pkcs7_message *msg; + + /* + * This is the best assumption to check if the binary is + * already in a form of pkcs7's signedData. + */ + if (buflen > sizeof(pkcs7_hdr) && + !memcmp(&((u8 *)buf)[4], &pkcs7_hdr[4], 11)) { + msg = pkcs7_parse_message(buf, buflen); + if (IS_ERR(msg)) + return NULL; + return msg; + } + + /* + * Otherwise, we should add a dummy prefix sequence for pkcs7 + * message parser to be able to process. + * NOTE: EDK2 also uses similar hack in WrapPkcs7Data() + * in CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyCommon.c + * TODO: + * The header should be composed in a more refined manner. + */ + EFI_PRINT("Makeshift prefix added to authentication data\n"); + ebuflen = sizeof(pkcs7_hdr) + buflen; + if (ebuflen <= 0x7f) { + EFI_PRINT("Data is too short\n"); + return NULL; + } + + ebuf = malloc(ebuflen); + if (!ebuf) { + EFI_PRINT("Out of memory\n"); + return NULL; + } + + memcpy(ebuf, pkcs7_hdr, sizeof(pkcs7_hdr)); + memcpy(ebuf + sizeof(pkcs7_hdr), buf, buflen); + len = ebuflen - 4; + ebuf[2] = (len >> 8) & 0xff; + ebuf[3] = len & 0xff; + len = ebuflen - 0x13; + ebuf[0x11] = (len >> 8) & 0xff; + ebuf[0x12] = len & 0xff; + + msg = pkcs7_parse_message(ebuf, ebuflen); + + if (IS_ERR(msg)) { + free(ebuf); + return NULL; + } + + *tmpbuf = ebuf; + return msg; +}
/** * efi_hash_regions - calculate a hash value diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c index 0c689cfb47..ba0874e9e7 100644 --- a/lib/efi_loader/efi_variable.c +++ b/lib/efi_loader/efi_variable.c @@ -24,91 +24,6 @@ #include <asm/sections.h>
#ifdef CONFIG_EFI_SECURE_BOOT -static u8 pkcs7_hdr[] = { - /* SEQUENCE */ - 0x30, 0x82, 0x05, 0xc7, - /* OID: pkcs7-signedData */ - 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x07, 0x02, - /* Context Structured? */ - 0xa0, 0x82, 0x05, 0xb8, -}; - -/** - * efi_variable_parse_signature - parse a signature in variable - * @buf: Pointer to variable's value - * @buflen: Length of @buf - * @tmpbuf: Pointer to temporary buffer - * - * Parse a signature embedded in variable's value and instantiate - * a pkcs7_message structure. Since pkcs7_parse_message() accepts only - * pkcs7's signedData, some header needed be prepended for correctly - * parsing authentication data, particularly for variable's. - * A temporary buffer will be allocated if needed, and it should be - * kept valid during the authentication because some data in the buffer - * will be referenced by efi_signature_verify(). - * - * Return: Pointer to pkcs7_message structure on success, NULL on error - */ -static struct pkcs7_message *efi_variable_parse_signature(const void *buf, - size_t buflen, - u8 **tmpbuf) -{ - u8 *ebuf; - size_t ebuflen, len; - struct pkcs7_message *msg; - - /* - * This is the best assumption to check if the binary is - * already in a form of pkcs7's signedData. - */ - if (buflen > sizeof(pkcs7_hdr) && - !memcmp(&((u8 *)buf)[4], &pkcs7_hdr[4], 11)) { - msg = pkcs7_parse_message(buf, buflen); - if (IS_ERR(msg)) - return NULL; - return msg; - } - - /* - * Otherwise, we should add a dummy prefix sequence for pkcs7 - * message parser to be able to process. - * NOTE: EDK2 also uses similar hack in WrapPkcs7Data() - * in CryptoPkg/Library/BaseCryptLib/Pk/CryptPkcs7VerifyCommon.c - * TODO: - * The header should be composed in a more refined manner. - */ - EFI_PRINT("Makeshift prefix added to authentication data\n"); - ebuflen = sizeof(pkcs7_hdr) + buflen; - if (ebuflen <= 0x7f) { - EFI_PRINT("Data is too short\n"); - return NULL; - } - - ebuf = malloc(ebuflen); - if (!ebuf) { - EFI_PRINT("Out of memory\n"); - return NULL; - } - - memcpy(ebuf, pkcs7_hdr, sizeof(pkcs7_hdr)); - memcpy(ebuf + sizeof(pkcs7_hdr), buf, buflen); - len = ebuflen - 4; - ebuf[2] = (len >> 8) & 0xff; - ebuf[3] = len & 0xff; - len = ebuflen - 0x13; - ebuf[0x11] = (len >> 8) & 0xff; - ebuf[0x12] = len & 0xff; - - msg = pkcs7_parse_message(ebuf, ebuflen); - - if (IS_ERR(msg)) { - free(ebuf); - return NULL; - } - - *tmpbuf = ebuf; - return msg; -}
/** * efi_variable_authenticate - authenticate a variable @@ -215,10 +130,10 @@ static efi_status_t efi_variable_authenticate(u16 *variable, goto err;
/* ebuf should be kept valid during the authentication */ - var_sig = efi_variable_parse_signature(auth->auth_info.cert_data, - auth->auth_info.hdr.dwLength - - sizeof(auth->auth_info), - &ebuf); + var_sig = efi_parse_pkcs7_header(auth->auth_info.cert_data, + auth->auth_info.hdr.dwLength + - sizeof(auth->auth_info), + &ebuf); if (!var_sig) { EFI_PRINT("Parsing variable's signature failed\n"); goto err;
The efi_sigstore_parse_sigdb function reads the uefi authenticated variable, stored in the signature database format and builds the signature store structure. Factor out the code for building the signature store. This can then be used by the capsule authentication routine to build the signature store even when the signature database is not stored as an uefi authenticated variable
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
include/efi_loader.h | 2 + lib/efi_loader/efi_signature.c | 103 +++++++++++++++++++-------------- 2 files changed, 63 insertions(+), 42 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h index 8807fcd913..73c3c4b85a 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -811,6 +811,8 @@ efi_status_t efi_image_region_add(struct efi_image_regions *regs, int nocheck);
void efi_sigstore_free(struct efi_signature_store *sigstore); +struct efi_signature_store *efi_build_signature_store(void *sig_list, + efi_uintn_t size); struct efi_signature_store *efi_sigstore_parse_sigdb(u16 *name);
bool efi_secure_boot_enabled(void); diff --git a/lib/efi_loader/efi_signature.c b/lib/efi_loader/efi_signature.c index 9ab071b611..87525bdc80 100644 --- a/lib/efi_loader/efi_signature.c +++ b/lib/efi_loader/efi_signature.c @@ -736,6 +736,63 @@ err: return NULL; }
+/** + * efi_sigstore_parse_sigdb - parse the signature list and populate + * the signature store + * + * @sig_list: Pointer to the signature list + * @size: Size of the signature list + * + * Parse the efi signature list and instantiate a signature store + * structure. + * + * Return: Pointer to signature store on success, NULL on error + */ +struct efi_signature_store *efi_build_signature_store(void *sig_list, + efi_uintn_t size) +{ + struct efi_signature_list *esl; + struct efi_signature_store *sigstore = NULL, *siglist; + + esl = sig_list; + while (size > 0) { + /* List must exist if there is remaining data. */ + if (size < sizeof(*esl)) { + EFI_PRINT("Signature list in wrong format\n"); + goto err; + } + + if (size < esl->signature_list_size) { + EFI_PRINT("Signature list in wrong format\n"); + goto err; + } + + /* Parse a single siglist. */ + siglist = efi_sigstore_parse_siglist(esl); + if (!siglist) { + EFI_PRINT("Parsing of signature list of failed\n"); + goto err; + } + + /* Append siglist */ + siglist->next = sigstore; + sigstore = siglist; + + /* Next */ + size -= esl->signature_list_size; + esl = (void *)esl + esl->signature_list_size; + } + free(sig_list); + + return sigstore; + +err: + efi_sigstore_free(sigstore); + free(sig_list); + + return NULL; +} + /** * efi_sigstore_parse_sigdb - parse a signature database variable * @name: Variable's name @@ -747,8 +804,7 @@ err: */ struct efi_signature_store *efi_sigstore_parse_sigdb(u16 *name) { - struct efi_signature_store *sigstore = NULL, *siglist; - struct efi_signature_list *esl; + struct efi_signature_store *sigstore = NULL; const efi_guid_t *vendor; void *db; efi_uintn_t db_size; @@ -784,47 +840,10 @@ struct efi_signature_store *efi_sigstore_parse_sigdb(u16 *name) ret = EFI_CALL(efi_get_variable(name, vendor, NULL, &db_size, db)); if (ret != EFI_SUCCESS) { EFI_PRINT("Getting variable, %ls, failed\n", name); - goto err; - } - - /* Parse siglist list */ - esl = db; - while (db_size > 0) { - /* List must exist if there is remaining data. */ - if (db_size < sizeof(*esl)) { - EFI_PRINT("variable, %ls, in wrong format\n", name); - goto err; - } - - if (db_size < esl->signature_list_size) { - EFI_PRINT("variable, %ls, in wrong format\n", name); - goto err; - } - - /* Parse a single siglist. */ - siglist = efi_sigstore_parse_siglist(esl); - if (!siglist) { - EFI_PRINT("Parsing signature list of %ls failed\n", - name); - goto err; - } - - /* Append siglist */ - siglist->next = sigstore; - sigstore = siglist; - - /* Next */ - db_size -= esl->signature_list_size; - esl = (void *)esl + esl->signature_list_size; + free(db); + return NULL; } - free(db); - - return sigstore;
-err: - efi_sigstore_free(sigstore); - free(db); - - return NULL; + return efi_build_signature_store(db, db_size); } #endif /* CONFIG_EFI_SECURE_BOOT */
Add support for authenticating uefi capsules. Most of the signature verification functionality is shared with the uefi secure boot feature.
The root certificate containing the public key used for the signature verification is stored as part of the device tree blob. The root certificate is stored as an efi signature list(esl) file -- this file contains the x509 certificate which is the root certificate.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
board/emulation/common/Makefile | 1 + board/emulation/common/qemu_capsule.c | 48 ++++++++++ include/efi_api.h | 18 ++++ include/efi_loader.h | 6 ++ lib/efi_loader/Kconfig | 17 ++++ lib/efi_loader/efi_capsule.c | 122 ++++++++++++++++++++++++++ lib/efi_loader/efi_signature.c | 4 +- 7 files changed, 214 insertions(+), 2 deletions(-) create mode 100644 board/emulation/common/qemu_capsule.c
diff --git a/board/emulation/common/Makefile b/board/emulation/common/Makefile index c5b452e7e3..7ed447a69d 100644 --- a/board/emulation/common/Makefile +++ b/board/emulation/common/Makefile @@ -2,3 +2,4 @@
obj-$(CONFIG_SYS_MTDPARTS_RUNTIME) += qemu_mtdparts.o obj-$(CONFIG_SET_DFU_ALT_INFO) += qemu_dfu.o +obj-$(CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT) += qemu_capsule.o diff --git a/board/emulation/common/qemu_capsule.c b/board/emulation/common/qemu_capsule.c new file mode 100644 index 0000000000..f1d403501a --- /dev/null +++ b/board/emulation/common/qemu_capsule.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2020 Linaro Limited + */ + +#include <common.h> +#include <efi_api.h> +#include <efi_loader.h> +#include <env.h> +#include <fdtdec.h> + +DECLARE_GLOBAL_DATA_PTR; + +int efi_get_public_key_data(void **pkey, efi_uintn_t *pkey_len) +{ + const void *fdt_blob = gd->fdt_blob; + const void *blob; + const char *cnode_name = "capsule-key"; + const char *snode_name = "signature"; + int sig_node; + int len; + + sig_node = fdt_subnode_offset(fdt_blob, 0, snode_name); + if (sig_node < 0) { + EFI_PRINT("Unable to get signature node offset\n"); + return -FDT_ERR_NOTFOUND; + } + + blob = fdt_getprop(fdt_blob, sig_node, cnode_name, &len); + + if (!blob || len < 0) { + EFI_PRINT("Unable to get capsule-key value\n"); + *pkey = NULL; + *pkey_len = 0; + return -FDT_ERR_NOTFOUND; + } + + *pkey = (void *)blob; + *pkey_len = len; + + return 0; +} + +bool efi_capsule_auth_enabled(void) +{ + return env_get("capsule_authentication_enabled") != NULL ? + true : false; +} diff --git a/include/efi_api.h b/include/efi_api.h index e82d4ca9ff..ecb43a0607 100644 --- a/include/efi_api.h +++ b/include/efi_api.h @@ -1812,6 +1812,24 @@ struct efi_variable_authentication_2 { struct win_certificate_uefi_guid auth_info; } __attribute__((__packed__));
+/** + * efi_firmware_image_authentication - Capsule authentication method + * descriptor + * + * This structure describes an authentication information for + * a capsule with IMAGE_ATTRIBUTE_AUTHENTICATION_REQUIRED set + * and should be included as part of the capsule. + * Only EFI_CERT_TYPE_PKCS7_GUID is accepted. + * + * @monotonic_count: Count to prevent replay + * @auth_info: Authentication info + */ +struct efi_firmware_image_authentication { + uint64_t monotonic_count; + struct win_certificate_uefi_guid auth_info; +} __attribute__((__packed__)); + + /** * efi_signature_data - A format of signature * diff --git a/include/efi_loader.h b/include/efi_loader.h index 73c3c4b85a..fb3e974aa1 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -817,6 +817,8 @@ struct efi_signature_store *efi_sigstore_parse_sigdb(u16 *name);
bool efi_secure_boot_enabled(void);
+bool efi_capsule_auth_enabled(void); + bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp, WIN_CERTIFICATE **auth, size_t *auth_len);
@@ -844,6 +846,10 @@ efi_status_t EFIAPI efi_query_capsule_caps( u64 *maximum_capsule_size, u32 *reset_type);
+efi_status_t efi_capsule_authenticate(const void *capsule, + efi_uintn_t capsule_size, + void **image, efi_uintn_t *image_size); + #define EFI_CAPSULE_DIR L"\EFI\UpdateCapsule\"
/* Hook at initialization */ diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index 073d90c802..297b2a2a7d 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -139,6 +139,23 @@ config EFI_CAPSULE_FIRMWARE_MANAGEMENT Select this option if you want to enable capsule-based firmware update using Firmware Management Protocol.
+config EFI_CAPSULE_AUTHENTICATE + bool "Update Capsule authentication" + depends on EFI_CAPSULE_FIRMWARE + depends on EFI_CAPSULE_ON_DISK + depends on EFI_CAPSULE_FIRMWARE_MANAGEMENT + select SHA256 + select RSA + select RSA_VERIFY + select RSA_VERIFY_WITH_PKEY + select X509_CERTIFICATE_PARSER + select PKCS7_MESSAGE_PARSER + select PKCS7_VERIFY + default n + help + Select this option if you want to enable capsule + authentication + config EFI_CAPSULE_FIRMWARE_FIT bool "FMP driver for FIT image" depends on EFI_CAPSULE_FIRMWARE_MANAGEMENT diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c index ea22ee7968..d9a7bbd509 100644 --- a/lib/efi_loader/efi_capsule.c +++ b/lib/efi_loader/efi_capsule.c @@ -14,6 +14,10 @@ #include <mapmem.h> #include <sort.h>
+#include <crypto/pkcs7.h> +#include <crypto/pkcs7_parser.h> +#include <linux/err.h> + const efi_guid_t efi_guid_capsule_report = EFI_CAPSULE_REPORT_GUID; static const efi_guid_t efi_guid_firmware_management_capsule_id = EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID; @@ -191,6 +195,124 @@ skip: return NULL; }
+#if defined(CONFIG_EFI_CAPSULE_AUTHENTICATE) + +const efi_guid_t efi_guid_capsule_root_cert_guid = + EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID; + +__weak int efi_get_public_key_data(void **pkey, efi_uintn_t *pkey_len) +{ + /* The platform is supposed to provide + * a method for getting the public key + * stored in the form of efi signature + * list + */ + return 0; +} + +efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_size, + void **image, efi_uintn_t *image_size) +{ + u8 *buf; + int ret; + void *fdt_pkey, *pkey; + efi_uintn_t pkey_len; + uint64_t monotonic_count; + struct efi_signature_store *truststore; + struct pkcs7_message *capsule_sig; + struct efi_image_regions *regs; + struct efi_firmware_image_authentication *auth_hdr; + efi_status_t status; + + status = EFI_SECURITY_VIOLATION; + capsule_sig = NULL; + truststore = NULL; + regs = NULL; + + /* Sanity checks */ + if (capsule == NULL || capsule_size == 0) + goto out; + + auth_hdr = (struct efi_firmware_image_authentication *)capsule; + if (capsule_size < sizeof(*auth_hdr)) + goto out; + + if (auth_hdr->auth_info.hdr.dwLength <= + offsetof(struct win_certificate_uefi_guid, cert_data)) + goto out; + + if (guidcmp(&auth_hdr->auth_info.cert_type, &efi_guid_cert_type_pkcs7)) + goto out; + + *image = (uint8_t *)capsule + sizeof(auth_hdr->monotonic_count) + + auth_hdr->auth_info.hdr.dwLength; + *image_size = capsule_size - auth_hdr->auth_info.hdr.dwLength - + sizeof(auth_hdr->monotonic_count); + memcpy(&monotonic_count, &auth_hdr->monotonic_count, + sizeof(monotonic_count)); + + /* data to be digested */ + regs = calloc(sizeof(*regs) + sizeof(struct image_region) * 2, 1); + if (!regs) + goto out; + + regs->max = 2; + efi_image_region_add(regs, (uint8_t *)*image, + (uint8_t *)*image + *image_size, 1); + + efi_image_region_add(regs, (uint8_t *)&monotonic_count, + (uint8_t *)&monotonic_count + sizeof(monotonic_count), + 1); + + capsule_sig = efi_parse_pkcs7_header(auth_hdr->auth_info.cert_data, + auth_hdr->auth_info.hdr.dwLength + - sizeof(auth_hdr->auth_info), + &buf); + if (IS_ERR(capsule_sig)) { + debug("Parsing variable's pkcs7 header failed\n"); + capsule_sig = NULL; + goto out; + } + + ret = efi_get_public_key_data(&fdt_pkey, &pkey_len); + if (ret < 0) + goto out; + + pkey = malloc(pkey_len); + if (!pkey) + goto out; + + memcpy(pkey, fdt_pkey, pkey_len); + truststore = efi_build_signature_store(pkey, pkey_len); + if (!truststore) + goto out; + + /* verify signature */ + if (efi_signature_verify(regs, capsule_sig, truststore, NULL)) { + debug("Verified\n"); + } else { + debug("Verifying variable's signature failed\n"); + goto out; + } + + status = EFI_SUCCESS; + +out: + efi_sigstore_free(truststore); + pkcs7_free_message(capsule_sig); + free(regs); + + return status; +} +#else +efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_size, + void **image, efi_uintn_t *image_size) +{ + return EFI_UNSUPPORTED; +} +#endif /* CONFIG_EFI_CAPSULE_AUTHENTICATE */ + + /** * efi_capsule_update_firmware - update firmware from capsule * @capsule_data: Capsule diff --git a/lib/efi_loader/efi_signature.c b/lib/efi_loader/efi_signature.c index 87525bdc80..c7ec275414 100644 --- a/lib/efi_loader/efi_signature.c +++ b/lib/efi_loader/efi_signature.c @@ -26,7 +26,7 @@ const efi_guid_t efi_guid_cert_x509 = EFI_CERT_X509_GUID; const efi_guid_t efi_guid_cert_x509_sha256 = EFI_CERT_X509_SHA256_GUID; const efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID;
-#ifdef CONFIG_EFI_SECURE_BOOT +#if defined(CONFIG_EFI_SECURE_BOOT) || defined(CONFIG_EFI_CAPSULE_AUTHENTICATE) static u8 pkcs7_hdr[] = { /* SEQUENCE */ 0x30, 0x82, 0x05, 0xc7, @@ -846,4 +846,4 @@ struct efi_signature_store *efi_sigstore_parse_sigdb(u16 *name)
return efi_build_signature_store(db, db_size); } -#endif /* CONFIG_EFI_SECURE_BOOT */ +#endif /* CONFIG_EFI_SECURE_BOOT || CONFIG_EFI_CAPSULE_AUTHENTICATE */
Add support for enabling uefi capsule authentication. This feature is enabled by setting the environment variable "capsule_authentication_enabled".
The following configs are needed for enabling uefi capsule update and capsule authentication features on the platform.
CONFIG_EFI_HAVE_CAPSULE_SUPPORT=y CONFIG_EFI_CAPSULE_ON_DISK=y CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y CONFIG_EFI_CAPSULE_FIRMWARE=y CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y CONFIG_EFI_CAPSULE_AUTHENTICATE=y
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
lib/efi_loader/efi_firmware.c | 36 ++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-)
diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c index 5d2ecde2f1..5e401bbca2 100644 --- a/lib/efi_loader/efi_firmware.c +++ b/lib/efi_loader/efi_firmware.c @@ -184,9 +184,16 @@ static efi_status_t efi_get_dfu_info( image_info[i].version_name = NULL; /* not supported */ image_info[i].size = 0; image_info[i].attributes_supported = - IMAGE_ATTRIBUTE_IMAGE_UPDATABLE; + IMAGE_ATTRIBUTE_IMAGE_UPDATABLE | + IMAGE_ATTRIBUTE_AUTHENTICATION_REQUIRED; image_info[i].attributes_setting = IMAGE_ATTRIBUTE_IMAGE_UPDATABLE; + + /* Check if the capsule authentication is enabled */ + if (env_get("capsule_authentication_enabled")) + image_info[0].attributes_setting |= + IMAGE_ATTRIBUTE_AUTHENTICATION_REQUIRED; + image_info[i].lowest_supported_image_version = 0; image_info[i].last_attempt_version = 0; image_info[i].last_attempt_status = LAST_ATTEMPT_STATUS_SUCCESS; @@ -403,6 +410,9 @@ efi_status_t EFIAPI efi_firmware_raw_set_image( { u32 fmp_hdr_signature; struct fmp_payload_header *header; + void *capsule_payload; + efi_status_t status; + efi_uintn_t capsule_payload_size;
EFI_ENTRY("%p %d %p %ld %p %p %p\n", this, image_index, image, image_size, vendor_code, progress, abort_reason); @@ -410,6 +420,30 @@ efi_status_t EFIAPI efi_firmware_raw_set_image( if (!image) return EFI_EXIT(EFI_INVALID_PARAMETER);
+ /* Authenticate the capsule if authentication enabled */ + if (IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) && + env_get("capsule_authentication_enabled")) { + capsule_payload = NULL; + capsule_payload_size = 0; + status = efi_capsule_authenticate(image, image_size, + &capsule_payload, + &capsule_payload_size); + + if (status == EFI_SECURITY_VIOLATION) { + printf("Capsule authentication check failed. Aborting update\n"); + return EFI_EXIT(status); + } else if (status != EFI_SUCCESS) { + return EFI_EXIT(status); + } + + debug("Capsule authentication successfull\n"); + image = capsule_payload; + image_size = capsule_payload_size; + } else { + debug("Capsule authentication disabled. "); + debug("Updating capsule without authenticating.\n"); + } + fmp_hdr_signature = FMP_PAYLOAD_HDR_SIGNATURE; header = (void *)image;
Add a efidebug subcommand to initiate a firmware update using the efi firmware management protocol(fmp) set_image routine.
The firmware update can be initiated through
'efidebug capsule disk-update'
This would locate the efi capsule file on the efi system partition, and call the platform's set_image fmp routine to initiate the firmware update.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
cmd/efidebug.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/cmd/efidebug.c b/cmd/efidebug.c index fa9d7fe757..5fb7b1e3c6 100644 --- a/cmd/efidebug.c +++ b/cmd/efidebug.c @@ -79,6 +79,16 @@ static int do_efi_capsule_update(struct cmd_tbl *cmdtp, int flag, return CMD_RET_SUCCESS; }
+static int do_efi_capsule_on_disk_update(struct cmd_tbl *cmdtp, int flag, + int argc, char * const argv[]) +{ + efi_status_t ret; + + ret = efi_launch_capsules(); + + return ret == EFI_SUCCESS ? CMD_RET_SUCCESS : CMD_RET_FAILURE; +} + /** * do_efi_capsule_show() - show capsule information * @@ -207,6 +217,8 @@ static struct cmd_tbl cmd_efidebug_capsule_sub[] = { "", ""), U_BOOT_CMD_MKENT(show, CONFIG_SYS_MAXARGS, 1, do_efi_capsule_show, "", ""), + U_BOOT_CMD_MKENT(disk-update, 0, 0, do_efi_capsule_on_disk_update, + "", ""), U_BOOT_CMD_MKENT(result, CONFIG_SYS_MAXARGS, 1, do_efi_capsule_res, "", ""), }; @@ -1544,6 +1556,8 @@ static char efidebug_help_text[] = #ifdef CONFIG_EFI_HAVE_CAPSULE_SUPPORT "efidebug capsule update [-v] <capsule address>\n" " - process a capsule\n" + "efidebug capsule disk-update\n" + " - update a capsule from disk\n" "efidebug capsule show <capsule address>\n" " - show capsule information\n" "efidebug capsule result [<capsule result var>]\n"
Add documentation highlighting the steps for using the uefi capsule update feature for updating the u-boot firmware image.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org ---
Changes since V3: None
doc/board/emulation/index.rst | 1 + doc/board/emulation/qemu_capsule_update.rst | 210 ++++++++++++++++++++ 2 files changed, 211 insertions(+) create mode 100644 doc/board/emulation/qemu_capsule_update.rst
diff --git a/doc/board/emulation/index.rst b/doc/board/emulation/index.rst index 1adefee155..a09ead1c35 100644 --- a/doc/board/emulation/index.rst +++ b/doc/board/emulation/index.rst @@ -10,3 +10,4 @@ Emulation qemu-mips qemu-riscv qemu-x86 + qemu_capsule_update diff --git a/doc/board/emulation/qemu_capsule_update.rst b/doc/board/emulation/qemu_capsule_update.rst new file mode 100644 index 0000000000..9fec75f8f1 --- /dev/null +++ b/doc/board/emulation/qemu_capsule_update.rst @@ -0,0 +1,210 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright (C) 2020, Linaro Limited + +Enabling UEFI Capsule Update feature +------------------------------------ + +Support has been added for the UEFI capsule update feature which +enables updating the U-Boot image using the UEFI firmware management +protocol (fmp). The capsules are not passed to the firmware through +the UpdateCapsule runtime service. Instead, capsule-on-disk +functionality is used for fetching the capsule from the EFI System +Partition (ESP) by placing the capsule file under the +\EFI\UpdateCapsule directory. + +Currently, support has been added on the QEMU ARM64 virt platform for +updating the U-Boot binary as a raw image when the platform is booted +in non-secure mode, i.e. with CONFIG_TFABOOT disabled. For this +configuration, the QEMU platform needs to be booted with +'secure=off'. The U-Boot binary placed on the first bank of the NOR +flash at offset 0x0. The U-Boot environment is placed on the second +NOR flash bank at offset 0x4000000. + +The capsule update feature is enabled with the following configuration +settings:: + + CONFIG_MTD=y + CONFIG_FLASH_CFI_MTD=y + CONFIG_CMD_MTDPARTS=y + CONFIG_CMD_DFU=y + CONFIG_DFU_MTD=y + CONFIG_PCI_INIT_R=y + CONFIG_EFI_CAPSULE_ON_DISK=y + CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y + CONFIG_EFI_CAPSULE_FIRMWARE=y + CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y + CONFIG_EFI_CAPSULE_FMP_HEADER=y + +In addition, the following config needs to be disabled(QEMU ARM specific):: + + CONFIG_TFABOOT + +The capsule file can be generated by using the GenerateCapsule.py +script in EDKII:: + + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ + <capsule_file_name> --fw-version <val> --lsv <val> --guid \ + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose --update-image-index \ + <val> --verbose <u-boot.bin> + +The above is a wrapper script(GenerateCapsule) which eventually calls +the actual GenerateCapsule.py script. + +As per the UEFI specification, the capsule file needs to be placed on +the EFI System Partition, under the \EFI\UpdateCapsule directory. The +EFI System Partition can be a virtio-blk-device. + +Before initiating the firmware update, the efi variables BootNext, +BootXXXX and OsIndications need to be set. The BootXXXX variable needs +to be pointing to the EFI System Partition which contains the capsule +file. The BootNext, BootXXXX and OsIndications variables can be set +using the following commands:: + + => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name> + => efidebug boot next 0 + => setenv -e -nv -bs -rt -v OsIndications =0x04 + => saveenv + +Finally, the capsule update can be initiated with the following +command:: + + => efidebug capsule disk-update + +The updated U-Boot image will be booted on subsequent boot. + +Enabling Capsule Authentication +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The UEFI specification defines a way of authenticating the capsule to +be updated by verifying the capsule signature. The capsule signature +is computed and prepended to the capsule payload at the time of +capsule generation. This signature is then verified by using the +public key stored as part of the X509 certificate. This certificate is +in the form of an efi signature list (esl) file, which is embedded as +part of the platform's device tree blob using the mkeficapsule +utility. + +On the QEMU virt platforms, the device-tree is generated on the fly +based on the devices configured. This device tree is then passed on to +the various software components booting on the platform, including +U-Boot. Therefore, on the QEMU virt platform, the signatute is +embedded on an overlay. This overlay is then applied at runtime to the +base platform device-tree. Steps needed for embedding the esl file in +the overlay are highlighted below. + +The capsule authentication feature can be enabled through the +following config, in addition to the configs listed above for capsule +update:: + + CONFIG_EFI_CAPSULE_AUTHENTICATE=y + +The public and private keys used for the signing process are generated +and used by the steps highlighted below:: + + 1. Install utility commands on your host + * OPENSSL + * efitools + + 2. Create signing keys and certificate files on your host + + $ openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=CRT/ \ + -keyout CRT.key -out CRT.crt -nodes -days 365 + $ cert-to-efi-sig-list CRT.crt CRT.esl + + $ openssl x509 -in CRT.crt -out CRT.cer -outform DER + $ openssl x509 -inform DER -in CRT.cer -outform PEM -out CRT.pub.pem + + $ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in CRT.crt + $ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem + +The capsule file can be generated by using the GenerateCapsule.py +script in EDKII:: + + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ + <capsule_file_name> --monotonic-count <val> --fw-version \ + <val> --lsv <val> --guid \ + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \ + --update-image-index <val> --signer-private-cert \ + /path/to/CRT.pem --trusted-public-cert \ + /path/to/CRT.pub.pem --other-public-cert /path/to/CRT.pub.pem \ + <u-boot.bin> + +Place the capsule generated in the above step on the EFI System +Partition under the EFI/UpdateCapsule directory + +For embedding the public key certificate, the following steps need to +be followed:: + + 1. Generate a skeleton overlay dts file, with a single fragment + node and an empty __overlay__ node + + A typical skeleton overlay file will look like this + + /dts-v1/; + /plugin/; + + / { + fragment@0 { + target-path = "/"; + __overlay__ { + }; + }; + }; + + + 2. Convert the dts to a corresponding dtb with the following + command + ./scripts/dtc/dtc -@ -I dts -O dtb -o <ov_dtb_file_name> \ + <dts_file> + + 3. Run the dtb file generated above through the mkeficapsule tool + in U-Boot + ./tools/mkeficapsule -O <pub_key.esl> -D <ov_dtb> + +Running the above command results in the creation of a 'signature' +node in the dtb, under which the public key is stored as a +'capsule-key' property. The '-O' option is to be used since the +public key certificate(esl) file is being embedded in an overlay. + +The dtb file embedded with the certificate is now to be placed on an +EFI System Partition. This would then be loaded and "merged" with the +base platform flattened device-tree(dtb) at runtime. + +Build U-Boot with the following steps(QEMU ARM64):: + + $ make qemu_arm64_defconfig + $ make menuconfig + Disable CONFIG_TFABOOT + Enable CONFIG_EFI_CAPSULE_AUTHENTICATE + Enable all configs needed for capsule update(listed above) + $ make all + +Boot the platform and perform the following steps on the U-Boot +command line:: + + 1. Enable capsule authentication by setting the following env + variable + + => setenv capsule_authentication_enabled 1 + => saveenv + + 2. Load the overlay dtb to memory and merge it with the base fdt + + => fatload virtio 0:1 <$fdtovaddr> EFI/<ov_dtb_file> + => fdt addr $fdtcontroladdr + => fdt resize <size_of_ov_dtb_file> + => fdt apply <$fdtovaddr> + + 3. Set the following environment and UEFI boot variables + + => setenv -e -nv -bs -rt -v OsIndications =0x04 + => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name> + => efidebug boot next 0 + => saveenv + + 4. Finally, the capsule update can be initiated with the following + command + + => efidebug capsule disk-update + +On subsequent reboot, the platform should boot the updated U-Boot binary.
On 30.12.20 14:57, Sughosh Ganu wrote:
Add documentation highlighting the steps for using the uefi capsule update feature for updating the u-boot firmware image.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org
Changes since V3: None
doc/board/emulation/index.rst | 1 + doc/board/emulation/qemu_capsule_update.rst | 210 ++++++++++++++++++++ 2 files changed, 211 insertions(+) create mode 100644 doc/board/emulation/qemu_capsule_update.rst
diff --git a/doc/board/emulation/index.rst b/doc/board/emulation/index.rst index 1adefee155..a09ead1c35 100644 --- a/doc/board/emulation/index.rst +++ b/doc/board/emulation/index.rst @@ -10,3 +10,4 @@ Emulation qemu-mips qemu-riscv qemu-x86
- qemu_capsule_update
diff --git a/doc/board/emulation/qemu_capsule_update.rst b/doc/board/emulation/qemu_capsule_update.rst new file mode 100644 index 0000000000..9fec75f8f1 --- /dev/null +++ b/doc/board/emulation/qemu_capsule_update.rst @@ -0,0 +1,210 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright (C) 2020, Linaro Limited
+Enabling UEFI Capsule Update feature +------------------------------------
+Support has been added for the UEFI capsule update feature which +enables updating the U-Boot image using the UEFI firmware management +protocol (fmp). The capsules are not passed to the firmware through +the UpdateCapsule runtime service. Instead, capsule-on-disk +functionality is used for fetching the capsule from the EFI System +Partition (ESP) by placing the capsule file under the +\EFI\UpdateCapsule directory.
+Currently, support has been added on the QEMU ARM64 virt platform for +updating the U-Boot binary as a raw image when the platform is booted +in non-secure mode, i.e. with CONFIG_TFABOOT disabled. For this +configuration, the QEMU platform needs to be booted with +'secure=off'. The U-Boot binary placed on the first bank of the NOR +flash at offset 0x0. The U-Boot environment is placed on the second +NOR flash bank at offset 0x4000000.
+The capsule update feature is enabled with the following configuration +settings::
- CONFIG_MTD=y
- CONFIG_FLASH_CFI_MTD=y
- CONFIG_CMD_MTDPARTS=y
- CONFIG_CMD_DFU=y
- CONFIG_DFU_MTD=y
- CONFIG_PCI_INIT_R=y
- CONFIG_EFI_CAPSULE_ON_DISK=y
- CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y
- CONFIG_EFI_CAPSULE_FIRMWARE=y
- CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y
- CONFIG_EFI_CAPSULE_FMP_HEADER=y
+In addition, the following config needs to be disabled(QEMU ARM specific)::
- CONFIG_TFABOOT
+The capsule file can be generated by using the GenerateCapsule.py +script in EDKII::
- $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \
- <capsule_file_name> --fw-version <val> --lsv <val> --guid \
- e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose --update-image-index \
- <val> --verbose <u-boot.bin>
+The above is a wrapper script(GenerateCapsule) which eventually calls +the actual GenerateCapsule.py script.
+As per the UEFI specification, the capsule file needs to be placed on +the EFI System Partition, under the \EFI\UpdateCapsule directory. The +EFI System Partition can be a virtio-blk-device.
+Before initiating the firmware update, the efi variables BootNext, +BootXXXX and OsIndications need to be set. The BootXXXX variable needs +to be pointing to the EFI System Partition which contains the capsule +file. The BootNext, BootXXXX and OsIndications variables can be set +using the following commands::
- => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name>
- => efidebug boot next 0
- => setenv -e -nv -bs -rt -v OsIndications =0x04
- => saveenv
+Finally, the capsule update can be initiated with the following +command::
- => efidebug capsule disk-update
+The updated U-Boot image will be booted on subsequent boot.
+Enabling Capsule Authentication +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The UEFI specification defines a way of authenticating the capsule to +be updated by verifying the capsule signature. The capsule signature +is computed and prepended to the capsule payload at the time of +capsule generation. This signature is then verified by using the +public key stored as part of the X509 certificate. This certificate is +in the form of an efi signature list (esl) file, which is embedded as +part of the platform's device tree blob using the mkeficapsule +utility.
+On the QEMU virt platforms, the device-tree is generated on the fly +based on the devices configured. This device tree is then passed on to +the various software components booting on the platform, including +U-Boot. Therefore, on the QEMU virt platform, the signatute is +embedded on an overlay. This overlay is then applied at runtime to the +base platform device-tree. Steps needed for embedding the esl file in +the overlay are highlighted below.
+The capsule authentication feature can be enabled through the +following config, in addition to the configs listed above for capsule +update::
- CONFIG_EFI_CAPSULE_AUTHENTICATE=y
+The public and private keys used for the signing process are generated +and used by the steps highlighted below::
- Install utility commands on your host
* OPENSSL* efitools
- Create signing keys and certificate files on your host
$ openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=CRT/ \-keyout CRT.key -out CRT.crt -nodes -days 365$ cert-to-efi-sig-list CRT.crt CRT.esl$ openssl x509 -in CRT.crt -out CRT.cer -outform DER$ openssl x509 -inform DER -in CRT.cer -outform PEM -out CRT.pub.pem$ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in CRT.crt$ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem+The capsule file can be generated by using the GenerateCapsule.py +script in EDKII::
- $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \
<capsule_file_name> --monotonic-count <val> --fw-version \<val> --lsv <val> --guid \e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \--update-image-index <val> --signer-private-cert \/path/to/CRT.pem --trusted-public-cert \/path/to/CRT.pub.pem --other-public-cert /path/to/CRT.pub.pem \<u-boot.bin>+Place the capsule generated in the above step on the EFI System +Partition under the EFI/UpdateCapsule directory
+For embedding the public key certificate, the following steps need to +be followed::
- Generate a skeleton overlay dts file, with a single fragment
node and an empty __overlay__ nodeA typical skeleton overlay file will look like this/dts-v1/;/plugin/;/ {fragment@0 {target-path = "/";__overlay__ {};};};
- Convert the dts to a corresponding dtb with the following
Shouldn't this be dtbo?
command./scripts/dtc/dtc -@ -I dts -O dtb -o <ov_dtb_file_name> \<dts_file>
- Run the dtb file generated above through the mkeficapsule tool
in U-Boot./tools/mkeficapsule -O <pub_key.esl> -D <ov_dtb>+Running the above command results in the creation of a 'signature' +node in the dtb, under which the public key is stored as a +'capsule-key' property. The '-O' option is to be used since the +public key certificate(esl) file is being embedded in an overlay.
+The dtb file embedded with the certificate is now to be placed on an +EFI System Partition. This would then be loaded and "merged" with the +base platform flattened device-tree(dtb) at runtime.
+Build U-Boot with the following steps(QEMU ARM64)::
- $ make qemu_arm64_defconfig
- $ make menuconfig
Disable CONFIG_TFABOOTEnable CONFIG_EFI_CAPSULE_AUTHENTICATEEnable all configs needed for capsule update(listed above)- $ make all
+Boot the platform and perform the following steps on the U-Boot +command line::
- Enable capsule authentication by setting the following env
variable=> setenv capsule_authentication_enabled 1=> saveenv
- Load the overlay dtb to memory and merge it with the base fdt
=> fatload virtio 0:1 <$fdtovaddr> EFI/<ov_dtb_file>=> fdt addr $fdtcontroladdr=> fdt resize <size_of_ov_dtb_file>=> fdt apply <$fdtovaddr>
Having the public key on the disk means that any public key can be placed here and we get zero security.
We need to build the public key into U-Boot.
Could you, please, investigate how we can adjust the build process accordingly.
Best regards
Heinrich
- Set the following environment and UEFI boot variables
=> setenv -e -nv -bs -rt -v OsIndications =0x04=> efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name>=> efidebug boot next 0=> saveenv
- Finally, the capsule update can be initiated with the following
command=> efidebug capsule disk-update+On subsequent reboot, the platform should boot the updated U-Boot binary.
hi Heinrich,
On Tue, 2 Mar 2021 at 16:45, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 30.12.20 14:57, Sughosh Ganu wrote:
Add documentation highlighting the steps for using the uefi capsule update feature for updating the u-boot firmware image.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org
Changes since V3: None
doc/board/emulation/index.rst | 1 + doc/board/emulation/qemu_capsule_update.rst | 210 ++++++++++++++++++++ 2 files changed, 211 insertions(+) create mode 100644 doc/board/emulation/qemu_capsule_update.rst
diff --git a/doc/board/emulation/index.rst
b/doc/board/emulation/index.rst
index 1adefee155..a09ead1c35 100644 --- a/doc/board/emulation/index.rst +++ b/doc/board/emulation/index.rst @@ -10,3 +10,4 @@ Emulation qemu-mips qemu-riscv qemu-x86
- qemu_capsule_update
diff --git a/doc/board/emulation/qemu_capsule_update.rst
b/doc/board/emulation/qemu_capsule_update.rst
new file mode 100644 index 0000000000..9fec75f8f1 --- /dev/null +++ b/doc/board/emulation/qemu_capsule_update.rst @@ -0,0 +1,210 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright (C) 2020, Linaro Limited
+Enabling UEFI Capsule Update feature +------------------------------------
+Support has been added for the UEFI capsule update feature which +enables updating the U-Boot image using the UEFI firmware management +protocol (fmp). The capsules are not passed to the firmware through +the UpdateCapsule runtime service. Instead, capsule-on-disk +functionality is used for fetching the capsule from the EFI System +Partition (ESP) by placing the capsule file under the +\EFI\UpdateCapsule directory.
+Currently, support has been added on the QEMU ARM64 virt platform for +updating the U-Boot binary as a raw image when the platform is booted +in non-secure mode, i.e. with CONFIG_TFABOOT disabled. For this +configuration, the QEMU platform needs to be booted with +'secure=off'. The U-Boot binary placed on the first bank of the NOR +flash at offset 0x0. The U-Boot environment is placed on the second +NOR flash bank at offset 0x4000000.
+The capsule update feature is enabled with the following configuration +settings::
- CONFIG_MTD=y
- CONFIG_FLASH_CFI_MTD=y
- CONFIG_CMD_MTDPARTS=y
- CONFIG_CMD_DFU=y
- CONFIG_DFU_MTD=y
- CONFIG_PCI_INIT_R=y
- CONFIG_EFI_CAPSULE_ON_DISK=y
- CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y
- CONFIG_EFI_CAPSULE_FIRMWARE=y
- CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y
- CONFIG_EFI_CAPSULE_FMP_HEADER=y
+In addition, the following config needs to be disabled(QEMU ARM
specific)::
- CONFIG_TFABOOT
+The capsule file can be generated by using the GenerateCapsule.py +script in EDKII::
- $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \
- <capsule_file_name> --fw-version <val> --lsv <val> --guid \
- e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose --update-image-index
\
- <val> --verbose <u-boot.bin>
+The above is a wrapper script(GenerateCapsule) which eventually calls +the actual GenerateCapsule.py script.
+As per the UEFI specification, the capsule file needs to be placed on +the EFI System Partition, under the \EFI\UpdateCapsule directory. The +EFI System Partition can be a virtio-blk-device.
+Before initiating the firmware update, the efi variables BootNext, +BootXXXX and OsIndications need to be set. The BootXXXX variable needs +to be pointing to the EFI System Partition which contains the capsule +file. The BootNext, BootXXXX and OsIndications variables can be set +using the following commands::
- => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name>
- => efidebug boot next 0
- => setenv -e -nv -bs -rt -v OsIndications =0x04
- => saveenv
+Finally, the capsule update can be initiated with the following +command::
- => efidebug capsule disk-update
+The updated U-Boot image will be booted on subsequent boot.
+Enabling Capsule Authentication +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The UEFI specification defines a way of authenticating the capsule to +be updated by verifying the capsule signature. The capsule signature +is computed and prepended to the capsule payload at the time of +capsule generation. This signature is then verified by using the +public key stored as part of the X509 certificate. This certificate is +in the form of an efi signature list (esl) file, which is embedded as +part of the platform's device tree blob using the mkeficapsule +utility.
+On the QEMU virt platforms, the device-tree is generated on the fly +based on the devices configured. This device tree is then passed on to +the various software components booting on the platform, including +U-Boot. Therefore, on the QEMU virt platform, the signatute is +embedded on an overlay. This overlay is then applied at runtime to the +base platform device-tree. Steps needed for embedding the esl file in +the overlay are highlighted below.
+The capsule authentication feature can be enabled through the +following config, in addition to the configs listed above for capsule +update::
- CONFIG_EFI_CAPSULE_AUTHENTICATE=y
+The public and private keys used for the signing process are generated +and used by the steps highlighted below::
- Install utility commands on your host
* OPENSSL* efitools
- Create signing keys and certificate files on your host
$ openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=CRT/ \-keyout CRT.key -out CRT.crt -nodes -days 365$ cert-to-efi-sig-list CRT.crt CRT.esl$ openssl x509 -in CRT.crt -out CRT.cer -outform DER$ openssl x509 -inform DER -in CRT.cer -outform PEM -outCRT.pub.pem
$ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in CRT.crt$ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem+The capsule file can be generated by using the GenerateCapsule.py +script in EDKII::
- $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \
<capsule_file_name> --monotonic-count <val> --fw-version \<val> --lsv <val> --guid \e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \--update-image-index <val> --signer-private-cert \/path/to/CRT.pem --trusted-public-cert \/path/to/CRT.pub.pem --other-public-cert /path/to/CRT.pub.pem \<u-boot.bin>+Place the capsule generated in the above step on the EFI System +Partition under the EFI/UpdateCapsule directory
+For embedding the public key certificate, the following steps need to +be followed::
- Generate a skeleton overlay dts file, with a single fragment
node and an empty __overlay__ nodeA typical skeleton overlay file will look like this/dts-v1/;/plugin/;/ {fragment@0 {target-path = "/";__overlay__ {};};};
- Convert the dts to a corresponding dtb with the following
Shouldn't this be dtbo?
command./scripts/dtc/dtc -@ -I dts -O dtb -o <ov_dtb_file_name> \<dts_file>
- Run the dtb file generated above through the mkeficapsule tool
in U-Boot./tools/mkeficapsule -O <pub_key.esl> -D <ov_dtb>+Running the above command results in the creation of a 'signature' +node in the dtb, under which the public key is stored as a +'capsule-key' property. The '-O' option is to be used since the +public key certificate(esl) file is being embedded in an overlay.
+The dtb file embedded with the certificate is now to be placed on an +EFI System Partition. This would then be loaded and "merged" with the +base platform flattened device-tree(dtb) at runtime.
+Build U-Boot with the following steps(QEMU ARM64)::
- $ make qemu_arm64_defconfig
- $ make menuconfig
Disable CONFIG_TFABOOTEnable CONFIG_EFI_CAPSULE_AUTHENTICATEEnable all configs needed for capsule update(listed above)- $ make all
+Boot the platform and perform the following steps on the U-Boot +command line::
- Enable capsule authentication by setting the following env
variable=> setenv capsule_authentication_enabled 1=> saveenv
- Load the overlay dtb to memory and merge it with the base fdt
=> fatload virtio 0:1 <$fdtovaddr> EFI/<ov_dtb_file>=> fdt addr $fdtcontroladdr=> fdt resize <size_of_ov_dtb_file>=> fdt apply <$fdtovaddr>Having the public key on the disk means that any public key can be placed here and we get zero security.
But that does not mean the authentication will succeed unless the private key is compromised. Deleting or tampering the public key on the disk can result in a denial of service attack, as the capsule authentication would fail, but that is true even when the public key is embedded in u-boot -- the public key or the u-boot image can be tampered with, resulting in a board brick. For countering this kind of denial of service attack, the public key needs to be placed on a secure storage device, which cannot be modified or removed from the normal world. Moreover, how is this different to the placement of the signature database used for the uefi secure boot as part of the uefi authenticated variables on a storage device that can be accessed from the normal world.
-sughosh
We need to build the public key into U-Boot.
Could you, please, investigate how we can adjust the build process accordingly.
Best regards
Heinrich
- Set the following environment and UEFI boot variables
=> setenv -e -nv -bs -rt -v OsIndications =0x04=> efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name>=> efidebug boot next 0=> saveenv
- Finally, the capsule update can be initiated with the following
command=> efidebug capsule disk-update+On subsequent reboot, the platform should boot the updated U-Boot
binary.
On 02.03.21 15:48, Sughosh Ganu wrote:
hi Heinrich,
On Tue, 2 Mar 2021 at 16:45, Heinrich Schuchardt <xypron.glpk@gmx.de mailto:xypron.glpk@gmx.de> wrote:
On 30.12.20 14:57, Sughosh Ganu wrote: > Add documentation highlighting the steps for using the uefi capsule > update feature for updating the u-boot firmware image. > > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org <mailto:sughosh.ganu@linaro.org>> > --- > > Changes since V3: None > > doc/board/emulation/index.rst | 1 + > doc/board/emulation/qemu_capsule_update.rst | 210 ++++++++++++++++++++ > 2 files changed, 211 insertions(+) > create mode 100644 doc/board/emulation/qemu_capsule_update.rst > > diff --git a/doc/board/emulation/index.rst b/doc/board/emulation/index.rst > index 1adefee155..a09ead1c35 100644 > --- a/doc/board/emulation/index.rst > +++ b/doc/board/emulation/index.rst > @@ -10,3 +10,4 @@ Emulation > qemu-mips > qemu-riscv > qemu-x86 > + qemu_capsule_update > diff --git a/doc/board/emulation/qemu_capsule_update.rst b/doc/board/emulation/qemu_capsule_update.rst > new file mode 100644 > index 0000000000..9fec75f8f1 > --- /dev/null > +++ b/doc/board/emulation/qemu_capsule_update.rst > @@ -0,0 +1,210 @@ > +.. SPDX-License-Identifier: GPL-2.0+ > +.. Copyright (C) 2020, Linaro Limited > + > +Enabling UEFI Capsule Update feature > +------------------------------------ > + > +Support has been added for the UEFI capsule update feature which > +enables updating the U-Boot image using the UEFI firmware management > +protocol (fmp). The capsules are not passed to the firmware through > +the UpdateCapsule runtime service. Instead, capsule-on-disk > +functionality is used for fetching the capsule from the EFI System > +Partition (ESP) by placing the capsule file under the > +\EFI\UpdateCapsule directory. > + > +Currently, support has been added on the QEMU ARM64 virt platform for > +updating the U-Boot binary as a raw image when the platform is booted > +in non-secure mode, i.e. with CONFIG_TFABOOT disabled. For this > +configuration, the QEMU platform needs to be booted with > +'secure=off'. The U-Boot binary placed on the first bank of the NOR > +flash at offset 0x0. The U-Boot environment is placed on the second > +NOR flash bank at offset 0x4000000. > + > +The capsule update feature is enabled with the following configuration > +settings:: > + > + CONFIG_MTD=y > + CONFIG_FLASH_CFI_MTD=y > + CONFIG_CMD_MTDPARTS=y > + CONFIG_CMD_DFU=y > + CONFIG_DFU_MTD=y > + CONFIG_PCI_INIT_R=y > + CONFIG_EFI_CAPSULE_ON_DISK=y > + CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y > + CONFIG_EFI_CAPSULE_FIRMWARE=y > + CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y > + CONFIG_EFI_CAPSULE_FMP_HEADER=y > + > +In addition, the following config needs to be disabled(QEMU ARM specific):: > + > + CONFIG_TFABOOT > + > +The capsule file can be generated by using the GenerateCapsule.py > +script in EDKII:: > + > + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ > + <capsule_file_name> --fw-version <val> --lsv <val> --guid \ > + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose --update-image-index \ > + <val> --verbose <u-boot.bin> > + > +The above is a wrapper script(GenerateCapsule) which eventually calls > +the actual GenerateCapsule.py script. > + > +As per the UEFI specification, the capsule file needs to be placed on > +the EFI System Partition, under the \EFI\UpdateCapsule directory. The > +EFI System Partition can be a virtio-blk-device. > + > +Before initiating the firmware update, the efi variables BootNext, > +BootXXXX and OsIndications need to be set. The BootXXXX variable needs > +to be pointing to the EFI System Partition which contains the capsule > +file. The BootNext, BootXXXX and OsIndications variables can be set > +using the following commands:: > + > + => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name> > + => efidebug boot next 0 > + => setenv -e -nv -bs -rt -v OsIndications =0x04 > + => saveenv > + > +Finally, the capsule update can be initiated with the following > +command:: > + > + => efidebug capsule disk-update > + > +The updated U-Boot image will be booted on subsequent boot. > + > +Enabling Capsule Authentication > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > + > +The UEFI specification defines a way of authenticating the capsule to > +be updated by verifying the capsule signature. The capsule signature > +is computed and prepended to the capsule payload at the time of > +capsule generation. This signature is then verified by using the > +public key stored as part of the X509 certificate. This certificate is > +in the form of an efi signature list (esl) file, which is embedded as > +part of the platform's device tree blob using the mkeficapsule > +utility. > + > +On the QEMU virt platforms, the device-tree is generated on the fly > +based on the devices configured. This device tree is then passed on to > +the various software components booting on the platform, including > +U-Boot. Therefore, on the QEMU virt platform, the signatute is > +embedded on an overlay. This overlay is then applied at runtime to the > +base platform device-tree. Steps needed for embedding the esl file in > +the overlay are highlighted below. > + > +The capsule authentication feature can be enabled through the > +following config, in addition to the configs listed above for capsule > +update:: > + > + CONFIG_EFI_CAPSULE_AUTHENTICATE=y > + > +The public and private keys used for the signing process are generated > +and used by the steps highlighted below:: > + > + 1. Install utility commands on your host > + * OPENSSL > + * efitools > + > + 2. Create signing keys and certificate files on your host > + > + $ openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=CRT/ \ > + -keyout CRT.key -out CRT.crt -nodes -days 365 > + $ cert-to-efi-sig-list CRT.crt CRT.esl > + > + $ openssl x509 -in CRT.crt -out CRT.cer -outform DER > + $ openssl x509 -inform DER -in CRT.cer -outform PEM -out CRT.pub.pem > + > + $ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in CRT.crt > + $ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem > + > +The capsule file can be generated by using the GenerateCapsule.py > +script in EDKII:: > + > + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ > + <capsule_file_name> --monotonic-count <val> --fw-version \ > + <val> --lsv <val> --guid \ > + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \ > + --update-image-index <val> --signer-private-cert \ > + /path/to/CRT.pem --trusted-public-cert \ > + /path/to/CRT.pub.pem --other-public-cert /path/to/CRT.pub.pem \ > + <u-boot.bin> > + > +Place the capsule generated in the above step on the EFI System > +Partition under the EFI/UpdateCapsule directory > + > +For embedding the public key certificate, the following steps need to > +be followed:: > + > + 1. Generate a skeleton overlay dts file, with a single fragment > + node and an empty __overlay__ node > + > + A typical skeleton overlay file will look like this > + > + /dts-v1/; > + /plugin/; > + > + / { > + fragment@0 { > + target-path = "/"; > + __overlay__ { > + }; > + }; > + }; > + > + > + 2. Convert the dts to a corresponding dtb with the following Shouldn't this be dtbo? > + command > + ./scripts/dtc/dtc -@ -I dts -O dtb -o <ov_dtb_file_name> \ > + <dts_file> > + > + 3. Run the dtb file generated above through the mkeficapsule tool > + in U-Boot > + ./tools/mkeficapsule -O <pub_key.esl> -D <ov_dtb> > + > +Running the above command results in the creation of a 'signature' > +node in the dtb, under which the public key is stored as a > +'capsule-key' property. The '-O' option is to be used since the > +public key certificate(esl) file is being embedded in an overlay. > + > +The dtb file embedded with the certificate is now to be placed on an > +EFI System Partition. This would then be loaded and "merged" with the > +base platform flattened device-tree(dtb) at runtime. > + > +Build U-Boot with the following steps(QEMU ARM64):: > + > + $ make qemu_arm64_defconfig > + $ make menuconfig > + Disable CONFIG_TFABOOT > + Enable CONFIG_EFI_CAPSULE_AUTHENTICATE > + Enable all configs needed for capsule update(listed above) > + $ make all > + > +Boot the platform and perform the following steps on the U-Boot > +command line:: > + > + 1. Enable capsule authentication by setting the following env > + variable > + > + => setenv capsule_authentication_enabled 1 > + => saveenv > + > + 2. Load the overlay dtb to memory and merge it with the base fdt > + > + => fatload virtio 0:1 <$fdtovaddr> EFI/<ov_dtb_file> > + => fdt addr $fdtcontroladdr > + => fdt resize <size_of_ov_dtb_file> > + => fdt apply <$fdtovaddr> Having the public key on the disk means that any public key can be placed here and we get zero security.But that does not mean the authentication will succeed unless the private key is compromised. Deleting or tampering the public key on the disk can result in a denial of service attack, as the capsule authentication would fail, but that is true even when the public key is embedded in u-boot -- the public key or the u-boot image can be tampered with, resulting in a board brick. For countering this kind of denial of service attack, the public key needs to be placed on a secure storage device, which cannot be modified or removed from the normal world. Moreover, how is this different to the placement of the signature database used for the uefi secure boot as part of the uefi authenticated variables on a storage device that can be accessed from the normal world.
The public key is what you use to verify that a capsule was signed by an authorized party. Who controls the public keys used for capsule checking can crack the device:
I just have to create a public/private key pair to sign my malware and place both the public key and the malware capsule on the disk.
We should not allow public keys for capsules to be on disk.
TF-A checks BL33 (U-Boot). If the public key is part of BL33 then only capsules signed with this trusted key can be installed.
An attacker can still change U-Boot in a way that TF-A will not load it leading to a denial of service. But he cannot launch malware via capsules.
Best regards
Heinrich
We need to build the public key into U-Boot. Could you, please, investigate how we can adjust the build process accordingly. Best regards Heinrich > + > + 3. Set the following environment and UEFI boot variables > + > + => setenv -e -nv -bs -rt -v OsIndications =0x04 > + => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name> > + => efidebug boot next 0 > + => saveenv > + > + 4. Finally, the capsule update can be initiated with the following > + command > + > + => efidebug capsule disk-update > + > +On subsequent reboot, the platform should boot the updated U-Boot binary. >
On Tue, 2 Mar 2021 at 21:27, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 02.03.21 15:48, Sughosh Ganu wrote:
hi Heinrich,
On Tue, 2 Mar 2021 at 16:45, Heinrich Schuchardt <xypron.glpk@gmx.de mailto:xypron.glpk@gmx.de> wrote:
On 30.12.20 14:57, Sughosh Ganu wrote: > Add documentation highlighting the steps for using the uefi capsule > update feature for updating the u-boot firmware image. > > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org <mailto:sughosh.ganu@linaro.org>> > --- > > Changes since V3: None > > doc/board/emulation/index.rst | 1 + > doc/board/emulation/qemu_capsule_update.rst | 210 ++++++++++++++++++++ > 2 files changed, 211 insertions(+) > create mode 100644 doc/board/emulation/qemu_capsule_update.rst > > diff --git a/doc/board/emulation/index.rst b/doc/board/emulation/index.rst > index 1adefee155..a09ead1c35 100644 > --- a/doc/board/emulation/index.rst > +++ b/doc/board/emulation/index.rst > @@ -10,3 +10,4 @@ Emulation > qemu-mips > qemu-riscv > qemu-x86 > + qemu_capsule_update > diff --git a/doc/board/emulation/qemu_capsule_update.rst b/doc/board/emulation/qemu_capsule_update.rst > new file mode 100644 > index 0000000000..9fec75f8f1 > --- /dev/null > +++ b/doc/board/emulation/qemu_capsule_update.rst > @@ -0,0 +1,210 @@ > +.. SPDX-License-Identifier: GPL-2.0+ > +.. Copyright (C) 2020, Linaro Limited > + > +Enabling UEFI Capsule Update feature > +------------------------------------ > + > +Support has been added for the UEFI capsule update feature which > +enables updating the U-Boot image using the UEFI firmwaremanagement
> +protocol (fmp). The capsules are not passed to the firmwarethrough
> +the UpdateCapsule runtime service. Instead, capsule-on-disk > +functionality is used for fetching the capsule from the EFI System > +Partition (ESP) by placing the capsule file under the > +\EFI\UpdateCapsule directory. > + > +Currently, support has been added on the QEMU ARM64 virt platformfor
> +updating the U-Boot binary as a raw image when the platform isbooted
> +in non-secure mode, i.e. with CONFIG_TFABOOT disabled. For this > +configuration, the QEMU platform needs to be booted with > +'secure=off'. The U-Boot binary placed on the first bank of theNOR
> +flash at offset 0x0. The U-Boot environment is placed on thesecond
> +NOR flash bank at offset 0x4000000. > + > +The capsule update feature is enabled with the following configuration > +settings:: > + > + CONFIG_MTD=y > + CONFIG_FLASH_CFI_MTD=y > + CONFIG_CMD_MTDPARTS=y > + CONFIG_CMD_DFU=y > + CONFIG_DFU_MTD=y > + CONFIG_PCI_INIT_R=y > + CONFIG_EFI_CAPSULE_ON_DISK=y > + CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y > + CONFIG_EFI_CAPSULE_FIRMWARE=y > + CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y > + CONFIG_EFI_CAPSULE_FMP_HEADER=y > + > +In addition, the following config needs to be disabled(QEMU ARM specific):: > + > + CONFIG_TFABOOT > + > +The capsule file can be generated by using the GenerateCapsule.py > +script in EDKII:: > + > + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ > + <capsule_file_name> --fw-version <val> --lsv <val> --guid \ > + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose --update-image-index \ > + <val> --verbose <u-boot.bin> > + > +The above is a wrapper script(GenerateCapsule) which eventuallycalls
> +the actual GenerateCapsule.py script. > + > +As per the UEFI specification, the capsule file needs to beplaced on
> +the EFI System Partition, under the \EFI\UpdateCapsule directory.The
> +EFI System Partition can be a virtio-blk-device. > + > +Before initiating the firmware update, the efi variables BootNext, > +BootXXXX and OsIndications need to be set. The BootXXXX variable needs > +to be pointing to the EFI System Partition which contains thecapsule
> +file. The BootNext, BootXXXX and OsIndications variables can beset
> +using the following commands:: > + > + => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name> > + => efidebug boot next 0 > + => setenv -e -nv -bs -rt -v OsIndications =0x04 > + => saveenv > + > +Finally, the capsule update can be initiated with the following > +command:: > + > + => efidebug capsule disk-update > + > +The updated U-Boot image will be booted on subsequent boot. > + > +Enabling Capsule Authentication > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > + > +The UEFI specification defines a way of authenticating thecapsule to
> +be updated by verifying the capsule signature. The capsulesignature
> +is computed and prepended to the capsule payload at the time of > +capsule generation. This signature is then verified by using the > +public key stored as part of the X509 certificate. This certificate is > +in the form of an efi signature list (esl) file, which isembedded as
> +part of the platform's device tree blob using the mkeficapsule > +utility. > + > +On the QEMU virt platforms, the device-tree is generated on thefly
> +based on the devices configured. This device tree is then passed on to > +the various software components booting on the platform, including > +U-Boot. Therefore, on the QEMU virt platform, the signatute is > +embedded on an overlay. This overlay is then applied at runtime to the > +base platform device-tree. Steps needed for embedding the eslfile in
> +the overlay are highlighted below. > + > +The capsule authentication feature can be enabled through the > +following config, in addition to the configs listed above forcapsule
> +update:: > + > + CONFIG_EFI_CAPSULE_AUTHENTICATE=y > + > +The public and private keys used for the signing process are generated > +and used by the steps highlighted below:: > + > + 1. Install utility commands on your host > + * OPENSSL > + * efitools > + > + 2. Create signing keys and certificate files on your host > + > + $ openssl req -x509 -sha256 -newkey rsa:2048 -subj/CN=CRT/ \
> + -keyout CRT.key -out CRT.crt -nodes -days 365 > + $ cert-to-efi-sig-list CRT.crt CRT.esl > + > + $ openssl x509 -in CRT.crt -out CRT.cer -outform DER > + $ openssl x509 -inform DER -in CRT.cer -outform PEM -out CRT.pub.pem > + > + $ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in CRT.crt > + $ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem > + > +The capsule file can be generated by using the GenerateCapsule.py > +script in EDKII:: > + > + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ > + <capsule_file_name> --monotonic-count <val> --fw-version \ > + <val> --lsv <val> --guid \ > + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \ > + --update-image-index <val> --signer-private-cert \ > + /path/to/CRT.pem --trusted-public-cert \ > + /path/to/CRT.pub.pem --other-public-cert/path/to/CRT.pub.pem \
> + <u-boot.bin> > + > +Place the capsule generated in the above step on the EFI System > +Partition under the EFI/UpdateCapsule directory > + > +For embedding the public key certificate, the following stepsneed to
> +be followed:: > + > + 1. Generate a skeleton overlay dts file, with a singlefragment
> + node and an empty __overlay__ node > + > + A typical skeleton overlay file will look like this > + > + /dts-v1/; > + /plugin/; > + > + / { > + fragment@0 { > + target-path = "/"; > + __overlay__ { > + }; > + }; > + }; > + > + > + 2. Convert the dts to a corresponding dtb with the following Shouldn't this be dtbo? > + command > + ./scripts/dtc/dtc -@ -I dts -O dtb -o <ov_dtb_file_name> \ > + <dts_file> > + > + 3. Run the dtb file generated above through the mkeficapsuletool
> + in U-Boot > + ./tools/mkeficapsule -O <pub_key.esl> -D <ov_dtb> > + > +Running the above command results in the creation of a 'signature' > +node in the dtb, under which the public key is stored as a > +'capsule-key' property. The '-O' option is to be used since the > +public key certificate(esl) file is being embedded in an overlay. > + > +The dtb file embedded with the certificate is now to be placed onan
> +EFI System Partition. This would then be loaded and "merged" withthe
> +base platform flattened device-tree(dtb) at runtime. > + > +Build U-Boot with the following steps(QEMU ARM64):: > + > + $ make qemu_arm64_defconfig > + $ make menuconfig > + Disable CONFIG_TFABOOT > + Enable CONFIG_EFI_CAPSULE_AUTHENTICATE > + Enable all configs needed for capsule update(listed above) > + $ make all > + > +Boot the platform and perform the following steps on the U-Boot > +command line:: > + > + 1. Enable capsule authentication by setting the following env > + variable > + > + => setenv capsule_authentication_enabled 1 > + => saveenv > + > + 2. Load the overlay dtb to memory and merge it with the basefdt
> + > + => fatload virtio 0:1 <$fdtovaddr> EFI/<ov_dtb_file> > + => fdt addr $fdtcontroladdr > + => fdt resize <size_of_ov_dtb_file> > + => fdt apply <$fdtovaddr> Having the public key on the disk means that any public key can be placed here and we get zero security.But that does not mean the authentication will succeed unless the private key is compromised. Deleting or tampering the public key on the disk can result in a denial of service attack, as the capsule authentication would fail, but that is true even when the public key is embedded in u-boot -- the public key or the u-boot image can be tampered with, resulting in a board brick. For countering this kind of denial of service attack, the public key needs to be placed on a secure storage device, which cannot be modified or removed from the normal world. Moreover, how is this different to the placement of the signature database used for the uefi secure boot as part of the uefi authenticated variables on a storage device that can be accessed from the normal world.
The public key is what you use to verify that a capsule was signed by an authorized party. Who controls the public keys used for capsule checking can crack the device:
I just have to create a public/private key pair to sign my malware and place both the public key and the malware capsule on the disk.
But when tf-a verifies this this BL33 during boot, it would fail authentication and would not boot that BL33 image. So it is the same as denial of service, isn't it.
-sughosh
We should not allow public keys for capsules to be on disk.
TF-A checks BL33 (U-Boot). If the public key is part of BL33 then only capsules signed with this trusted key can be installed.
An attacker can still change U-Boot in a way that TF-A will not load it leading to a denial of service. But he cannot launch malware via capsules.
Best regards
Heinrich
We need to build the public key into U-Boot. Could you, please, investigate how we can adjust the build process accordingly. Best regards Heinrich > + > + 3. Set the following environment and UEFI boot variables > + > + => setenv -e -nv -bs -rt -v OsIndications =0x04 > + => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name> > + => efidebug boot next 0 > + => saveenv > + > + 4. Finally, the capsule update can be initiated with the following > + command > + > + => efidebug capsule disk-update > + > +On subsequent reboot, the platform should boot the updated U-Boot binary. >
On 02.03.21 17:39, Sughosh Ganu wrote:
On Tue, 2 Mar 2021 at 21:27, Heinrich Schuchardt <xypron.glpk@gmx.de mailto:xypron.glpk@gmx.de> wrote:
On 02.03.21 15:48, Sughosh Ganu wrote: > hi Heinrich, > > On Tue, 2 Mar 2021 at 16:45, Heinrich Schuchardt <xypron.glpk@gmx.de <mailto:xypron.glpk@gmx.de> > <mailto:xypron.glpk@gmx.de <mailto:xypron.glpk@gmx.de>>> wrote: > > On 30.12.20 14:57, Sughosh Ganu wrote: > > Add documentation highlighting the steps for using the uefi capsule > > update feature for updating the u-boot firmware image. > > > > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org <mailto:sughosh.ganu@linaro.org> > <mailto:sughosh.ganu@linaro.org <mailto:sughosh.ganu@linaro.org>>> > > --- > > > > Changes since V3: None > > > > doc/board/emulation/index.rst | 1 + > > doc/board/emulation/qemu_capsule_update.rst | 210 > ++++++++++++++++++++ > > 2 files changed, 211 insertions(+) > > create mode 100644 doc/board/emulation/qemu_capsule_update.rst > > > > diff --git a/doc/board/emulation/index.rst > b/doc/board/emulation/index.rst > > index 1adefee155..a09ead1c35 100644 > > --- a/doc/board/emulation/index.rst > > +++ b/doc/board/emulation/index.rst > > @@ -10,3 +10,4 @@ Emulation > > qemu-mips > > qemu-riscv > > qemu-x86 > > + qemu_capsule_update > > diff --git a/doc/board/emulation/qemu_capsule_update.rst > b/doc/board/emulation/qemu_capsule_update.rst > > new file mode 100644 > > index 0000000000..9fec75f8f1 > > --- /dev/null > > +++ b/doc/board/emulation/qemu_capsule_update.rst > > @@ -0,0 +1,210 @@ > > +.. SPDX-License-Identifier: GPL-2.0+ > > +.. Copyright (C) 2020, Linaro Limited > > + > > +Enabling UEFI Capsule Update feature > > +------------------------------------ > > + > > +Support has been added for the UEFI capsule update feature which > > +enables updating the U-Boot image using the UEFI firmware management > > +protocol (fmp). The capsules are not passed to the firmware through > > +the UpdateCapsule runtime service. Instead, capsule-on-disk > > +functionality is used for fetching the capsule from the EFI System > > +Partition (ESP) by placing the capsule file under the > > +\EFI\UpdateCapsule directory. > > + > > +Currently, support has been added on the QEMU ARM64 virt platform for > > +updating the U-Boot binary as a raw image when the platform is booted > > +in non-secure mode, i.e. with CONFIG_TFABOOT disabled. For this > > +configuration, the QEMU platform needs to be booted with > > +'secure=off'. The U-Boot binary placed on the first bank of the NOR > > +flash at offset 0x0. The U-Boot environment is placed on the second > > +NOR flash bank at offset 0x4000000. > > + > > +The capsule update feature is enabled with the following > configuration > > +settings:: > > + > > + CONFIG_MTD=y > > + CONFIG_FLASH_CFI_MTD=y > > + CONFIG_CMD_MTDPARTS=y > > + CONFIG_CMD_DFU=y > > + CONFIG_DFU_MTD=y > > + CONFIG_PCI_INIT_R=y > > + CONFIG_EFI_CAPSULE_ON_DISK=y > > + CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y > > + CONFIG_EFI_CAPSULE_FIRMWARE=y > > + CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y > > + CONFIG_EFI_CAPSULE_FMP_HEADER=y > > + > > +In addition, the following config needs to be disabled(QEMU ARM > specific):: > > + > > + CONFIG_TFABOOT > > + > > +The capsule file can be generated by using the GenerateCapsule.py > > +script in EDKII:: > > + > > + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ > > + <capsule_file_name> --fw-version <val> --lsv <val> --guid \ > > + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose > --update-image-index \ > > + <val> --verbose <u-boot.bin> > > + > > +The above is a wrapper script(GenerateCapsule) which eventually calls > > +the actual GenerateCapsule.py script. > > + > > +As per the UEFI specification, the capsule file needs to be placed on > > +the EFI System Partition, under the \EFI\UpdateCapsule directory. The > > +EFI System Partition can be a virtio-blk-device. > > + > > +Before initiating the firmware update, the efi variables BootNext, > > +BootXXXX and OsIndications need to be set. The BootXXXX variable > needs > > +to be pointing to the EFI System Partition which contains the capsule > > +file. The BootNext, BootXXXX and OsIndications variables can be set > > +using the following commands:: > > + > > + => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name> > > + => efidebug boot next 0 > > + => setenv -e -nv -bs -rt -v OsIndications =0x04 > > + => saveenv > > + > > +Finally, the capsule update can be initiated with the following > > +command:: > > + > > + => efidebug capsule disk-update > > + > > +The updated U-Boot image will be booted on subsequent boot. > > + > > +Enabling Capsule Authentication > > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > + > > +The UEFI specification defines a way of authenticating the capsule to > > +be updated by verifying the capsule signature. The capsule signature > > +is computed and prepended to the capsule payload at the time of > > +capsule generation. This signature is then verified by using the > > +public key stored as part of the X509 certificate. This > certificate is > > +in the form of an efi signature list (esl) file, which is embedded as > > +part of the platform's device tree blob using the mkeficapsule > > +utility. > > + > > +On the QEMU virt platforms, the device-tree is generated on the fly > > +based on the devices configured. This device tree is then passed > on to > > +the various software components booting on the platform, including > > +U-Boot. Therefore, on the QEMU virt platform, the signatute is > > +embedded on an overlay. This overlay is then applied at runtime > to the > > +base platform device-tree. Steps needed for embedding the esl file in > > +the overlay are highlighted below. > > + > > +The capsule authentication feature can be enabled through the > > +following config, in addition to the configs listed above for capsule > > +update:: > > + > > + CONFIG_EFI_CAPSULE_AUTHENTICATE=y > > + > > +The public and private keys used for the signing process are > generated > > +and used by the steps highlighted below:: > > + > > + 1. Install utility commands on your host > > + * OPENSSL > > + * efitools > > + > > + 2. Create signing keys and certificate files on your host > > + > > + $ openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=CRT/ \ > > + -keyout CRT.key -out CRT.crt -nodes -days 365 > > + $ cert-to-efi-sig-list CRT.crt CRT.esl > > + > > + $ openssl x509 -in CRT.crt -out CRT.cer -outform DER > > + $ openssl x509 -inform DER -in CRT.cer -outform PEM -out > CRT.pub.pem > > + > > + $ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in > CRT.crt > > + $ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem > > + > > +The capsule file can be generated by using the GenerateCapsule.py > > +script in EDKII:: > > + > > + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e -o \ > > + <capsule_file_name> --monotonic-count <val> --fw-version \ > > + <val> --lsv <val> --guid \ > > + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \ > > + --update-image-index <val> --signer-private-cert \ > > + /path/to/CRT.pem --trusted-public-cert \ > > + /path/to/CRT.pub.pem --other-public-cert /path/to/CRT.pub.pem \ > > + <u-boot.bin> > > + > > +Place the capsule generated in the above step on the EFI System > > +Partition under the EFI/UpdateCapsule directory > > + > > +For embedding the public key certificate, the following steps need to > > +be followed:: > > + > > + 1. Generate a skeleton overlay dts file, with a single fragment > > + node and an empty __overlay__ node > > + > > + A typical skeleton overlay file will look like this > > + > > + /dts-v1/; > > + /plugin/; > > + > > + / { > > + fragment@0 { > > + target-path = "/"; > > + __overlay__ { > > + }; > > + }; > > + }; > > + > > + > > + 2. Convert the dts to a corresponding dtb with the following > > Shouldn't this be dtbo? > > > + command > > + ./scripts/dtc/dtc -@ -I dts -O dtb -o <ov_dtb_file_name> \ > > + <dts_file> > > + > > + 3. Run the dtb file generated above through the mkeficapsule tool > > + in U-Boot > > + ./tools/mkeficapsule -O <pub_key.esl> -D <ov_dtb> > > + > > +Running the above command results in the creation of a 'signature' > > +node in the dtb, under which the public key is stored as a > > +'capsule-key' property. The '-O' option is to be used since the > > +public key certificate(esl) file is being embedded in an overlay. > > + > > +The dtb file embedded with the certificate is now to be placed on an > > +EFI System Partition. This would then be loaded and "merged" with the > > +base platform flattened device-tree(dtb) at runtime. > > + > > +Build U-Boot with the following steps(QEMU ARM64):: > > + > > + $ make qemu_arm64_defconfig > > + $ make menuconfig > > + Disable CONFIG_TFABOOT > > + Enable CONFIG_EFI_CAPSULE_AUTHENTICATE > > + Enable all configs needed for capsule update(listed above) > > + $ make all > > + > > +Boot the platform and perform the following steps on the U-Boot > > +command line:: > > + > > + 1. Enable capsule authentication by setting the following env > > + variable > > + > > + => setenv capsule_authentication_enabled 1 > > + => saveenv > > + > > + 2. Load the overlay dtb to memory and merge it with the base fdt > > + > > + => fatload virtio 0:1 <$fdtovaddr> EFI/<ov_dtb_file> > > + => fdt addr $fdtcontroladdr > > + => fdt resize <size_of_ov_dtb_file> > > + => fdt apply <$fdtovaddr> > > Having the public key on the disk means that any public key can be > placed here and we get zero security. > > > But that does not mean the authentication will succeed unless the > private key is compromised. Deleting or tampering the public key on the > disk can result in a denial of service attack, as the capsule > authentication would fail, but that is true even when the public key is > embedded in u-boot -- the public key or the u-boot image can be tampered > with, resulting in a board brick. For countering this kind of denial of > service attack, the public key needs to be placed on a secure storage > device, which cannot be modified or removed from the normal world. > Moreover, how is this different to the placement of the signature > database used for the uefi secure boot as part of the uefi authenticated > variables on a storage device that can be accessed from the normal world. The public key is what you use to verify that a capsule was signed by an authorized party. Who controls the public keys used for capsule checking can crack the device: I just have to create a public/private key pair to sign my malware and place both the public key and the malware capsule on the disk.But when tf-a verifies this this BL33 during boot, it would fail authentication and would not boot that BL33 image. So it is the same as denial of service, isn't it.
You cannot stop denial of service, but you can stop malware.
That is why I don't want the public key used for capsule verification on disk.
Best regards
Heinrich
-sughosh
We should not allow public keys for capsules to be on disk. TF-A checks BL33 (U-Boot). If the public key is part of BL33 then only capsules signed with this trusted key can be installed. An attacker can still change U-Boot in a way that TF-A will not load it leading to a denial of service. But he cannot launch malware via capsules. Best regards Heinrich > > > We need to build the public key into U-Boot. > > Could you, please, investigate how we can adjust the build process > accordingly. > > Best regards > > Heinrich > > > + > > + 3. Set the following environment and UEFI boot variables > > + > > + => setenv -e -nv -bs -rt -v OsIndications =0x04 > > + => efidebug boot add 0 Boot0000 virtio 0:1 > <capsule_file_name> > > + => efidebug boot next 0 > > + => saveenv > > + > > + 4. Finally, the capsule update can be initiated with the > following > > + command > > + > > + => efidebug capsule disk-update > > + > > +On subsequent reboot, the platform should boot the updated U-Boot > binary. > > >
On Tue, 2 Mar 2021 at 22:36, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 02.03.21 17:39, Sughosh Ganu wrote:
On Tue, 2 Mar 2021 at 21:27, Heinrich Schuchardt <xypron.glpk@gmx.de mailto:xypron.glpk@gmx.de> wrote:
On 02.03.21 15:48, Sughosh Ganu wrote: > hi Heinrich, > > On Tue, 2 Mar 2021 at 16:45, Heinrich Schuchardt <xypron.glpk@gmx.de <mailto:xypron.glpk@gmx.de> > <mailto:xypron.glpk@gmx.de <mailto:xypron.glpk@gmx.de>>> wrote: > > On 30.12.20 14:57, Sughosh Ganu wrote: > > Add documentation highlighting the steps for using the uefi capsule > > update feature for updating the u-boot firmware image. > > > > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org <mailto:sughosh.ganu@linaro.org> > <mailto:sughosh.ganu@linaro.org <mailto:sughosh.ganu@linaro.org>>>
> > --- > > > > Changes since V3: None > > > > doc/board/emulation/index.rst | 1 + > > doc/board/emulation/qemu_capsule_update.rst | 210 > ++++++++++++++++++++ > > 2 files changed, 211 insertions(+) > > create mode 100644doc/board/emulation/qemu_capsule_update.rst
> > > > diff --git a/doc/board/emulation/index.rst > b/doc/board/emulation/index.rst > > index 1adefee155..a09ead1c35 100644 > > --- a/doc/board/emulation/index.rst > > +++ b/doc/board/emulation/index.rst > > @@ -10,3 +10,4 @@ Emulation > > qemu-mips > > qemu-riscv > > qemu-x86 > > + qemu_capsule_update > > diff --git a/doc/board/emulation/qemu_capsule_update.rst > b/doc/board/emulation/qemu_capsule_update.rst > > new file mode 100644 > > index 0000000000..9fec75f8f1 > > --- /dev/null > > +++ b/doc/board/emulation/qemu_capsule_update.rst > > @@ -0,0 +1,210 @@ > > +.. SPDX-License-Identifier: GPL-2.0+ > > +.. Copyright (C) 2020, Linaro Limited > > + > > +Enabling UEFI Capsule Update feature > > +------------------------------------ > > + > > +Support has been added for the UEFI capsule update feature which > > +enables updating the U-Boot image using the UEFI firmware management > > +protocol (fmp). The capsules are not passed to the firmware through > > +the UpdateCapsule runtime service. Instead, capsule-on-disk > > +functionality is used for fetching the capsule from the EFI System > > +Partition (ESP) by placing the capsule file under the > > +\EFI\UpdateCapsule directory. > > + > > +Currently, support has been added on the QEMU ARM64 virt platform for > > +updating the U-Boot binary as a raw image when the platform is booted > > +in non-secure mode, i.e. with CONFIG_TFABOOT disabled. Forthis
> > +configuration, the QEMU platform needs to be booted with > > +'secure=off'. The U-Boot binary placed on the first bank of the NOR > > +flash at offset 0x0. The U-Boot environment is placed on the second > > +NOR flash bank at offset 0x4000000. > > + > > +The capsule update feature is enabled with the following > configuration > > +settings:: > > + > > + CONFIG_MTD=y > > + CONFIG_FLASH_CFI_MTD=y > > + CONFIG_CMD_MTDPARTS=y > > + CONFIG_CMD_DFU=y > > + CONFIG_DFU_MTD=y > > + CONFIG_PCI_INIT_R=y > > + CONFIG_EFI_CAPSULE_ON_DISK=y > > + CONFIG_EFI_CAPSULE_FIRMWARE_MANAGEMENT=y > > + CONFIG_EFI_CAPSULE_FIRMWARE=y > > + CONFIG_EFI_CAPSULE_FIRMWARE_RAW=y > > + CONFIG_EFI_CAPSULE_FMP_HEADER=y > > + > > +In addition, the following config needs to be disabled(QEMUARM
> specific):: > > + > > + CONFIG_TFABOOT > > + > > +The capsule file can be generated by using the GenerateCapsule.py > > +script in EDKII:: > > + > > + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e-o \
> > + <capsule_file_name> --fw-version <val> --lsv <val>--guid \
> > + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose > --update-image-index \ > > + <val> --verbose <u-boot.bin> > > + > > +The above is a wrapper script(GenerateCapsule) which eventually calls > > +the actual GenerateCapsule.py script. > > + > > +As per the UEFI specification, the capsule file needs to be placed on > > +the EFI System Partition, under the \EFI\UpdateCapsule directory. The > > +EFI System Partition can be a virtio-blk-device. > > + > > +Before initiating the firmware update, the efi variables BootNext, > > +BootXXXX and OsIndications need to be set. The BootXXXX variable > needs > > +to be pointing to the EFI System Partition which contains the capsule > > +file. The BootNext, BootXXXX and OsIndications variables can be set > > +using the following commands:: > > + > > + => efidebug boot add 0 Boot0000 virtio 0:1 <capsule_file_name> > > + => efidebug boot next 0 > > + => setenv -e -nv -bs -rt -v OsIndications =0x04 > > + => saveenv > > + > > +Finally, the capsule update can be initiated with thefollowing
> > +command:: > > + > > + => efidebug capsule disk-update > > + > > +The updated U-Boot image will be booted on subsequent boot. > > + > > +Enabling Capsule Authentication > > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > + > > +The UEFI specification defines a way of authenticating the capsule to > > +be updated by verifying the capsule signature. The capsule signature > > +is computed and prepended to the capsule payload at thetime of
> > +capsule generation. This signature is then verified by using the > > +public key stored as part of the X509 certificate. This > certificate is > > +in the form of an efi signature list (esl) file, which is embedded as > > +part of the platform's device tree blob using themkeficapsule
> > +utility. > > + > > +On the QEMU virt platforms, the device-tree is generated on the fly > > +based on the devices configured. This device tree is then passed > on to > > +the various software components booting on the platform, including > > +U-Boot. Therefore, on the QEMU virt platform, the signatuteis
> > +embedded on an overlay. This overlay is then applied atruntime
> to the > > +base platform device-tree. Steps needed for embedding the esl file in > > +the overlay are highlighted below. > > + > > +The capsule authentication feature can be enabled throughthe
> > +following config, in addition to the configs listed above for capsule > > +update:: > > + > > + CONFIG_EFI_CAPSULE_AUTHENTICATE=y > > + > > +The public and private keys used for the signing process are > generated > > +and used by the steps highlighted below:: > > + > > + 1. Install utility commands on your host > > + * OPENSSL > > + * efitools > > + > > + 2. Create signing keys and certificate files on yourhost
> > + > > + $ openssl req -x509 -sha256 -newkey rsa:2048 -subj /CN=CRT/ \ > > + -keyout CRT.key -out CRT.crt -nodes -days 365 > > + $ cert-to-efi-sig-list CRT.crt CRT.esl > > + > > + $ openssl x509 -in CRT.crt -out CRT.cer -outform DER > > + $ openssl x509 -inform DER -in CRT.cer -outform PEM -out > CRT.pub.pem > > + > > + $ openssl pkcs12 -export -out CRT.pfx -inkey CRT.key -in > CRT.crt > > + $ openssl pkcs12 -in CRT.pfx -nodes -out CRT.pem > > + > > +The capsule file can be generated by using the GenerateCapsule.py > > +script in EDKII:: > > + > > + $ ./BaseTools/BinWrappers/PosixLike/GenerateCapsule -e-o \
> > + <capsule_file_name> --monotonic-count <val> --fw-version \ > > + <val> --lsv <val> --guid \ > > + e2bb9c06-70e9-4b14-97a3-5a7913176e3f --verbose \ > > + --update-image-index <val> --signer-private-cert \ > > + /path/to/CRT.pem --trusted-public-cert \ > > + /path/to/CRT.pub.pem --other-public-cert /path/to/CRT.pub.pem \ > > + <u-boot.bin> > > + > > +Place the capsule generated in the above step on the EFISystem
> > +Partition under the EFI/UpdateCapsule directory > > + > > +For embedding the public key certificate, the following steps need to > > +be followed:: > > + > > + 1. Generate a skeleton overlay dts file, with a single fragment > > + node and an empty __overlay__ node > > + > > + A typical skeleton overlay file will look like this > > + > > + /dts-v1/; > > + /plugin/; > > + > > + / { > > + fragment@0 { > > + target-path = "/"; > > + __overlay__ { > > + }; > > + }; > > + }; > > + > > + > > + 2. Convert the dts to a corresponding dtb with the following > > Shouldn't this be dtbo? > > > + command > > + ./scripts/dtc/dtc -@ -I dts -O dtb -o <ov_dtb_file_name> \ > > + <dts_file> > > + > > + 3. Run the dtb file generated above through the mkeficapsule tool > > + in U-Boot > > + ./tools/mkeficapsule -O <pub_key.esl> -D <ov_dtb> > > + > > +Running the above command results in the creation of a 'signature' > > +node in the dtb, under which the public key is stored as a > > +'capsule-key' property. The '-O' option is to be used sincethe
> > +public key certificate(esl) file is being embedded in an overlay. > > + > > +The dtb file embedded with the certificate is now to be placed on an > > +EFI System Partition. This would then be loaded and "merged" with the > > +base platform flattened device-tree(dtb) at runtime. > > + > > +Build U-Boot with the following steps(QEMU ARM64):: > > + > > + $ make qemu_arm64_defconfig > > + $ make menuconfig > > + Disable CONFIG_TFABOOT > > + Enable CONFIG_EFI_CAPSULE_AUTHENTICATE > > + Enable all configs needed for capsule update(listed above) > > + $ make all > > + > > +Boot the platform and perform the following steps on theU-Boot
> > +command line:: > > + > > + 1. Enable capsule authentication by setting the following env > > + variable > > + > > + => setenv capsule_authentication_enabled 1 > > + => saveenv > > + > > + 2. Load the overlay dtb to memory and merge it with the base fdt > > + > > + => fatload virtio 0:1 <$fdtovaddr> EFI/<ov_dtb_file> > > + => fdt addr $fdtcontroladdr > > + => fdt resize <size_of_ov_dtb_file> > > + => fdt apply <$fdtovaddr> > > Having the public key on the disk means that any public keycan be
> placed here and we get zero security. > > > But that does not mean the authentication will succeed unless the > private key is compromised. Deleting or tampering the public key on the > disk can result in a denial of service attack, as the capsule > authentication would fail, but that is true even when the public key is > embedded in u-boot -- the public key or the u-boot image can be tampered > with, resulting in a board brick. For countering this kind of denial of > service attack, the public key needs to be placed on a securestorage
> device, which cannot be modified or removed from the normal world. > Moreover, how is this different to the placement of the signature > database used for the uefi secure boot as part of the uefi authenticated > variables on a storage device that can be accessed from the normal world. The public key is what you use to verify that a capsule was signedby an
authorized party. Who controls the public keys used for capsulechecking
can crack the device: I just have to create a public/private key pair to sign my malwareand
place both the public key and the malware capsule on the disk.But when tf-a verifies this this BL33 during boot, it would fail authentication and would not boot that BL33 image. So it is the same as denial of service, isn't it.
You cannot stop denial of service, but you can stop malware.
That is why I don't want the public key used for capsule verification on disk.
If we have a trusted boot flow[1], with tf-a authenticating the BL33(u-boot) image before booting, how do we allow malware to boot on the system.
-sughosh
[1] - https://trustedfirmware-a.readthedocs.io/en/latest/design/trusted-board-boot...
Best regards
Heinrich
-sughosh
We should not allow public keys for capsules to be on disk. TF-A checks BL33 (U-Boot). If the public key is part of BL33 thenonly
capsules signed with this trusted key can be installed. An attacker can still change U-Boot in a way that TF-A will not loadit
leading to a denial of service. But he cannot launch malware via capsules. Best regards Heinrich > > > We need to build the public key into U-Boot. > > Could you, please, investigate how we can adjust the buildprocess
> accordingly. > > Best regards > > Heinrich > > > + > > + 3. Set the following environment and UEFI boot variables > > + > > + => setenv -e -nv -bs -rt -v OsIndications =0x04 > > + => efidebug boot add 0 Boot0000 virtio 0:1 > <capsule_file_name> > > + => efidebug boot next 0 > > + => saveenv > > + > > + 4. Finally, the capsule update can be initiated with the > following > > + command > > + > > + => efidebug capsule disk-update > > + > > +On subsequent reboot, the platform should boot the updated U-Boot > binary. > > >
participants (2)
-
Heinrich Schuchardt -
Sughosh Ganu