The fdt_add_pubkey tool is used for adding a public key to the devicetree, which is then used for verifying the FIT signatures. Add a function for embedding the public key in the form of an EFI Signature List(ESL) file as a property under the signature node of the device tree.
Unlike the public key added for FIT signature verification, the ESL file contents are added as a whole, as a property under the signature node in the DTB.
The public key in the ESL form is used by the capsule authentication feature for authenticating the capsules, prior to update.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org --- Changes since V1: * New patch * Use fdt_add_pubkey tool for adding the ESL into the dtb instead of using the shell script used in the earlier version.
tools/Makefile | 2 +- tools/fdt_add_pubkey.c | 16 +++++-- tools/fdt_add_pubkey_esl.c | 98 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 112 insertions(+), 4 deletions(-) create mode 100644 tools/fdt_add_pubkey_esl.c
diff --git a/tools/Makefile b/tools/Makefile index d793cf3bec..a5558eeb4d 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -152,7 +152,7 @@ dumpimage-objs := $(dumpimage-mkimage-objs) dumpimage.o mkimage-objs := $(dumpimage-mkimage-objs) mkimage.o fit_info-objs := $(dumpimage-mkimage-objs) fit_info.o fit_check_sign-objs := $(dumpimage-mkimage-objs) fit_check_sign.o -fdt_add_pubkey-objs := $(dumpimage-mkimage-objs) fdt_add_pubkey.o +fdt_add_pubkey-objs := $(dumpimage-mkimage-objs) fdt_add_pubkey.o fdt_add_pubkey_esl.o file2include-objs := file2include.o
ifneq ($(CONFIG_MX23)$(CONFIG_MX28)$(CONFIG_TOOLS_LIBCRYPTO),) diff --git a/tools/fdt_add_pubkey.c b/tools/fdt_add_pubkey.c index 5582d7a8ef..f536ab543b 100644 --- a/tools/fdt_add_pubkey.c +++ b/tools/fdt_add_pubkey.c @@ -2,18 +2,21 @@ #include <image.h> #include "fit_common.h"
+extern int fdt_embed_esl(const char *esl_file, void *keydest); + static const char *cmdname;
static const char *algo_name = "sha1,rsa2048"; /* -a <algo> */ static const char *keydir = "."; /* -k <keydir> */ static const char *keyname = "key"; /* -n <keyname> */ static const char *require_keys; /* -r <conf|image> */ +static const char *esl_file; /* -e <esl file> */ static const char *keydest; /* argv[n] */
static void __attribute__((__noreturn__)) print_usage(const char *msg) { fprintf(stderr, "Error: %s\n", msg); - fprintf(stderr, "Usage: %s [-a <algo>] [-k <keydir>] [-n <keyname>] [-r <conf|image>]" + fprintf(stderr, "Usage: %s [-a <algo>] [-e <esl file>] [-k <keydir>] [-n <keyname>] [-r <conf|image>]" " <fdt blob>\n", cmdname); fprintf(stderr, "Help information: %s [-h]\n", cmdname); exit(EXIT_FAILURE); @@ -23,6 +26,7 @@ static void __attribute__((__noreturn__)) print_help(void) { fprintf(stderr, "Options:\n" "\t-a <algo> Cryptographic algorithm. Optional parameter, default value: sha1,rsa2048\n" + "\t-e <esl file> EFI Signature List(ESL) file to embed into the FDT\n" "\t-k <keydir> Directory with public key. Optional parameter, default value: .\n" "\t-n <keyname> Public key name. Optional parameter, default value: key\n" "\t-r <conf|image> Required: If present this indicates that the key must be verified for the image / configuration to be considered valid.\n" @@ -34,7 +38,7 @@ static void process_args(int argc, char *argv[]) { int opt;
- while ((opt = getopt(argc, argv, "a:k:n:r:h")) != -1) { + while ((opt = getopt(argc, argv, "a:e:k:n:r:h")) != -1) { switch (opt) { case 'k': keydir = optarg; @@ -48,6 +52,9 @@ static void process_args(int argc, char *argv[]) case 'r': require_keys = optarg; break; + case 'e': + esl_file = optarg; + break; case 'h': print_help(); default: @@ -106,7 +113,10 @@ static int add_pubkey(struct image_sign_info *info) if (destfd < 0) exit(EXIT_FAILURE);
- ret = info->crypto->add_verify_data(info, dest_blob); + + ret = esl_file ? fdt_embed_esl(esl_file, dest_blob) : + info->crypto->add_verify_data(info, dest_blob); + if (ret == -ENOSPC) continue; else if (ret < 0) diff --git a/tools/fdt_add_pubkey_esl.c b/tools/fdt_add_pubkey_esl.c new file mode 100644 index 0000000000..de6ee41535 --- /dev/null +++ b/tools/fdt_add_pubkey_esl.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2023 Linaro Limited + * + */ + +#include <fcntl.h> +#include <stdio.h> +#include <unistd.h> + +#include <linux/libfdt.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/types.h> + +#include "mkimage.h" + +#define ESL_SIG_NODENAME "signature" + +static int get_esl_pub_key(const char *esl_file, void **key_ptr, int *key_fd, + off_t *key_size) +{ + int ret; + struct stat pub_key; + + debug("%s: esl file => %s\n", __func__, esl_file); + *key_fd = open(esl_file, O_RDONLY); + if (*key_fd == -1) { + fprintf(stderr, "Unable to open %s: %s\n", + esl_file, strerror(errno)); + return -EACCES; + } + + ret = fstat(*key_fd, &pub_key); + if (ret == -1) { + fprintf(stderr, "Can't stat %s: %s\n", + esl_file, strerror(errno)); + ret = errno; + goto err; + } + *key_size = pub_key.st_size; + + /* mmap the public key esl file */ + *key_ptr = mmap(0, *key_size, PROT_READ, MAP_SHARED, *key_fd, 0); + if ((*key_ptr == MAP_FAILED) || (errno != 0)) { + fprintf(stderr, "Failed to mmap %s:%s\n", + esl_file, strerror(errno)); + ret = errno; + goto err; + } + + return 0; +err: + close(*key_fd); + + return ret; +} + +int fdt_embed_esl(const char *esl_file, void *keydest) +{ + int ret, key_fd; + off_t key_size = 0; + void *key_ptr = NULL; + int parent; + + ret = get_esl_pub_key(esl_file, &key_ptr, &key_fd, &key_size); + if (ret) { + debug("Unable to open the public key esl file\n"); + goto out; + } + + parent = fdt_subnode_offset(keydest, 0, ESL_SIG_NODENAME); + if (parent == -FDT_ERR_NOTFOUND) { + parent = fdt_add_subnode(keydest, 0, ESL_SIG_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 out; + + ret = fdt_setprop(keydest, parent, "capsule-key", + key_ptr, key_size); + +out: + close(key_fd); + munmap(key_ptr, key_size); + + if (ret) + return ret == -FDT_ERR_NOSPACE ? -ENOSPC : -EIO; + + return ret; +}