Re: [PATCH v6 03/12] tools: mkeficapsule: add firmwware image signing

On 11/2/21 01:55, AKASHI Takahiro wrote:

With this enhancement, mkeficapsule will be able to sign a capsule file when it is created. A signature added will be used later in the verification at FMP's SetImage() call.

To do that, We need specify additional command parameters: -monotonic-cout <count> : monotonic count -private-key <private key file> : private key file -certificate <certificate file> : certificate file Only when all of those parameters are given, a signature will be added to a capsule file.

Users are expected to maintain and increment the monotonic count at every time of the update for each firmware image.

Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org Reviewed-by: Simon Glass sjg@chromium.org

You licensed tools/mkeficapsule.c under GPL-2.0 which is imcompatible with OpenSSL (https://www.gnu.org/licenses/license-list.html#OpenSSL).

Either agree with all contributors of the tool to use a more liberal license or use another library.

---

tools/Kconfig | 8 + tools/Makefile | 8 +- tools/mkeficapsule.c | 382 ++++++++++++++++++++++++++++++++++++++++--- 3 files changed, 376 insertions(+), 22 deletions(-)

diff --git a/tools/Kconfig b/tools/Kconfig index 91ce8ae3e516..117c921da3fe 100644 --- a/tools/Kconfig +++ b/tools/Kconfig @@ -90,4 +90,12 @@ config TOOLS_SHA512 help Enable SHA512 support in the tools builds

+config TOOLS_MKEFICAPSULE

• bool "Build efimkcapsule command"
• default y if EFI_CAPSULE_ON_DISK
• help

•  This command allows users to create a UEFI capsule file and,
  

•  optionally sign that file. If you want to enable UEFI capsule
  

•  update feature on your target, you certainly need this.
  

• endmenu

diff --git a/tools/Makefile b/tools/Makefile index b45219e2c30c..5a73cc4b363d 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -238,8 +238,12 @@ 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 +HOSTLDLIBS_mkeficapsule += -luuid +ifeq ($(CONFIG_TOOLS_LIBCRYPTO),y) +HOSTLDLIBS_mkeficapsule += \

• $(shell pkg-config --libs libssl libcrypto 2> /dev/null || echo "-lssl -lcrypto")

+endif +hostprogs-$(CONFIG_TOOLS_MKEFICAPSULE) += mkeficapsule

# We build some files with extra pedantic flags to try to minimize things # that won't build on some weird host compiler -- though there are lots of diff --git a/tools/mkeficapsule.c b/tools/mkeficapsule.c index 8427fedd941c..086757ee8ad7 100644 --- a/tools/mkeficapsule.c +++ b/tools/mkeficapsule.c @@ -15,6 +15,16 @@ #include <sys/stat.h> #include <sys/types.h>

+#include <linux/kconfig.h> +#ifdef CONFIG_TOOLS_LIBCRYPTO +#include <openssl/asn1.h> +#include <openssl/bio.h> +#include <openssl/evp.h> +#include <openssl/err.h> +#include <openssl/pem.h> +#include <openssl/pkcs7.h> +#endif

• typedef __u8 u8; typedef __u16 u16; typedef __u32 u32;

@@ -38,12 +48,25 @@ efi_guid_t efi_guid_image_type_uboot_fit = EFI_FIRMWARE_IMAGE_TYPE_UBOOT_FIT_GUID; efi_guid_t efi_guid_image_type_uboot_raw = EFI_FIRMWARE_IMAGE_TYPE_UBOOT_RAW_GUID; +efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID;

+#ifdef CONFIG_TOOLS_LIBCRYPTO +static const char *opts_short = "f:r:i:I:v:p:c:m:dh"; +#else +static const char *opts_short = "f:r:i:I:v:h"; +#endif

static struct option options[] = { {"fit", required_argument, NULL, 'f'}, {"raw", required_argument, NULL, 'r'}, {"index", required_argument, NULL, 'i'}, {"instance", required_argument, NULL, 'I'}, +#ifdef CONFIG_TOOLS_LIBCRYPTO

• {"private-key", required_argument, NULL, 'p'},
• {"certificate", required_argument, NULL, 'c'},
• {"monotonic-count", required_argument, NULL, 'm'},
• {"dump-sig", no_argument, NULL, 'd'},

+#endif {"help", no_argument, NULL, 'h'}, {NULL, 0, NULL, 0}, }; @@ -57,10 +80,252 @@ static void print_usage(void) "\t-r, --raw <raw image> new raw image file\n" "\t-i, --index <index> update image index\n" "\t-I, --instance <instance> update hardware instance\n" +#ifdef CONFIG_TOOLS_LIBCRYPTO

•       "\t-p, --private-key <privkey file>  private key file\n"
  

•       "\t-c, --certificate <cert file>     signer's certificate file\n"
  

•       "\t-m, --monotonic-count <count>     monotonic count\n"
  

•       "\t-d, --dump_sig              dump signature (*.p7)\n"
  

+#endif "\t-h, --help print a help message\n", tool_name); }

+/**

• • auth_context - authentication context
• • @key_file: Path to a private key file
• • @cert_file: Path to a certificate file
• • @image_data: Pointer to firmware data
• • @image_size: Size of firmware data
• • @auth: Authentication header
• • @sig_data: Signature data
• • @sig_size: Size of signature data
• • Data structure used in create_auth_data(). @key_file through
• • @image_size are input parameters. @auth, @sig_data and @sig_size
• • are filled in by create_auth_data().
• */

+struct auth_context {

• char *key_file;
• char *cert_file;
• u8 *image_data;
• size_t image_size;
• struct efi_firmware_image_authentication auth;
• u8 *sig_data;
• size_t sig_size;

+};

+static int dump_sig;

+#ifdef CONFIG_TOOLS_LIBCRYPTO +/**

• • fileio-read_pkey - read out a private key
• • @filename: Path to a private key file
• • Read out a private key file and parse it into "EVP_PKEY" structure.
• • Return:
• • • Pointer to private key structure - on success
• • • NULL - on failure
• */

+static EVP_PKEY *fileio_read_pkey(const char *filename) +{

• EVP_PKEY *key = NULL;
• BIO *bio;
• bio = BIO_new_file(filename, "r");
• if (!bio)

• goto out;
  

• key = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);

+out:

• BIO_free_all(bio);
• if (!key) {

• printf("Can't load key from file '%s'\n", filename);
  

• ERR_print_errors_fp(stderr);
  

• }
• return key;

+}

+/**

• • fileio-read_cert - read out a certificate
• • @filename: Path to a certificate file
• • Read out a certificate file and parse it into "X509" structure.
• • Return:
• • • Pointer to certificate structure - on success
• • • NULL - on failure
• */

+static X509 *fileio_read_cert(const char *filename) +{

• X509 *cert = NULL;
• BIO *bio;
• bio = BIO_new_file(filename, "r");
• if (!bio)

• goto out;
  

• cert = PEM_read_bio_X509(bio, NULL, NULL, NULL);

+out:

• BIO_free_all(bio);
• if (!cert) {

• printf("Can't load certificate from file '%s'\n", filename);
  

• ERR_print_errors_fp(stderr);
  

• }
• return cert;

+}

+/**

• • create_auth_data - compose authentication data in capsule
• • @auth_context: Pointer to authentication context
• • Fill up an authentication header (.auth) and signature data (.sig_data)
• • in @auth_context, using library functions from openssl.
• • All the parameters in @auth_context must be filled in by a caller.
• • Return:
• • • 0 - on success
• • • -1 - on failure
• */

+static int create_auth_data(struct auth_context *ctx) +{

• EVP_PKEY *key = NULL;
• X509 *cert = NULL;
• BIO *data_bio = NULL;
• const EVP_MD *md;
• PKCS7 *p7;
• int flags, ret = -1;
• OpenSSL_add_all_digests();
• OpenSSL_add_all_ciphers();
• ERR_load_crypto_strings();
• key = fileio_read_pkey(ctx->key_file);
• if (!key)

• goto err;
  

• cert = fileio_read_cert(ctx->cert_file);
• if (!cert)

• goto err;
  

• /*

• * create a BIO, containing:
  

• *  * firmware image
  

• *  * monotonic count
  

• * in this order!
  

• * See EDK2's FmpAuthenticatedHandlerRsa2048Sha256()
  

• */
  

• data_bio = BIO_new(BIO_s_mem());
• BIO_write(data_bio, ctx->image_data, ctx->image_size);
• BIO_write(data_bio, &ctx->auth.monotonic_count,

•   sizeof(ctx->auth.monotonic_count));
  

• md = EVP_get_digestbyname("SHA256");
• if (!md)

• goto err;
  

• /* create signature */
• /* TODO: maybe add PKCS7_NOATTR and PKCS7_NOSMIMECAP */
• flags = PKCS7_BINARY | PKCS7_DETACHED;
• p7 = PKCS7_sign(NULL, NULL, NULL, data_bio, flags | PKCS7_PARTIAL);
• if (!p7)

• goto err;
  

• if (!PKCS7_sign_add_signer(p7, cert, key, md, flags))

• goto err;
  

• if (!PKCS7_final(p7, data_bio, flags))

• goto err;
  

• /* convert pkcs7 into DER */
• ctx->sig_data = NULL;
• ctx->sig_size = ASN1_item_i2d((ASN1_VALUE *)p7, &ctx->sig_data,

• 		      ASN1_ITEM_rptr(PKCS7));
  

• if (!ctx->sig_size)

• goto err;
  

• /* fill auth_info */
• ctx->auth.auth_info.hdr.dwLength = sizeof(ctx->auth.auth_info)

• 				+ ctx->sig_size;
  

• ctx->auth.auth_info.hdr.wRevision = WIN_CERT_REVISION_2_0;
• ctx->auth.auth_info.hdr.wCertificateType = WIN_CERT_TYPE_EFI_GUID;
• memcpy(&ctx->auth.auth_info.cert_type, &efi_guid_cert_type_pkcs7,

•       sizeof(efi_guid_cert_type_pkcs7));
  

• ret = 0;

+err:

• BIO_free_all(data_bio);
• EVP_PKEY_free(key);
• X509_free(cert);
• return ret;

+}

+/**

• • dump_signature - dump out a signature
• • @path: Path to a capsule file
• • @signature: Signature data
• • @sig_size: Size of signature data
• • Signature data pointed to by @signature will be saved into
• • a file whose file name is @path with ".p7" suffix.
• • Return:
• • • 0 - on success
• • • -1 - on failure
• */

+static int dump_signature(const char *path, u8 *signature, size_t sig_size) +{

• char *sig_path;
• FILE *f;
• size_t size;
• int ret = -1;
• sig_path = malloc(strlen(path) + 3 + 1);
• if (!sig_path)

• return ret;
  

• sprintf(sig_path, "%s.p7", path);
• f = fopen(sig_path, "w");
• if (!f)

• goto err;
  

• size = fwrite(signature, 1, sig_size, f);
• if (size == sig_size)

• ret = 0;
  

• fclose(f);

+err:

• free(sig_path);
• return ret;

+}

+/**

• • free_sig_data - free out signature data
• • @ctx: Pointer to authentication context
• • Free signature data allocated in create_auth_data().
• */

+static void free_sig_data(struct auth_context *ctx) +{

• if (ctx->sig_size)

• OPENSSL_free(ctx->sig_data);
  

+} +#else +static int create_auth_data(struct auth_context *ctx) +{

• return 0;

+}

+static int dump_signature(const char *path, u8 *signature, size_t sig_size) +{

• return 0;

+}

+static void free_sig_data(struct auth_context *ctx) {} +#endif

• /**
  • read_bin_file - read a firmware binary file
  • @bin: Path to a firmware binary file

@@ -162,11 +427,13 @@ static int write_capsule_file(FILE *f, void *data, size_t size, const char *msg)

• • -1 - on failure

*/ static int create_fwbin(char *path, char *bin, efi_guid_t *guid,

• 	unsigned long index, unsigned long instance)
  

• 	unsigned long index, unsigned long instance,
  

• 	uint64_t mcount, char *privkey_file, char *cert_file)
  

  { struct efi_capsule_header header; struct efi_firmware_management_capsule_header capsule; struct efi_firmware_management_capsule_image_header image;
• struct auth_context auth_context; FILE *f; void *data; off_t bin_size;

@@ -176,9 +443,9 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, #ifdef DEBUG

scripts/checkpatch.pl gives the following warning for this file:

Use 'if (IS_ENABLED(CONFIG...))' instead of '#if or #ifdef' where possible.

Best regards

Heinrich

printf("For output: %s\n", path); printf("\tbin: %s\n\ttype: %pUl\n", bin, guid);

• printf("\tindex: %ld\n\tinstance: %ld\n", index, instance);

• printf("\tindex: %lu\n\tinstance: %lu\n", index, instance); #endif

• auth_context.sig_size = 0; f = NULL; data = NULL; ret = -1;

@@ -189,6 +456,27 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, if (read_bin_file(bin, &data, &bin_size)) goto err;

• /* first, calculate signature to determine its size */
• if (privkey_file && cert_file) {

• auth_context.key_file = privkey_file;
  

• auth_context.cert_file = cert_file;
  

• auth_context.auth.monotonic_count = mcount;
  

• auth_context.image_data = data;
  

• auth_context.image_size = bin_size;
  

• if (create_auth_data(&auth_context)) {
  

• 	printf("Signing firmware image failed\n");
  

• 	goto err;
  

• }
  

• if (dump_sig &&
  

•     dump_signature(path, auth_context.sig_data,
  

• 		   auth_context.sig_size)) {
  

• 	printf("Creating signature file failed\n");
  

• 	goto err;
  

• }
  

• }
• /*
  • write a capsule file
  */

@@ -209,6 +497,9 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, + sizeof(capsule) + sizeof(u64) + sizeof(image) + bin_size;

• if (auth_context.sig_size)

• header.capsule_image_size += sizeof(auth_context.auth)
  

• 		+ auth_context.sig_size;
  

  if (write_capsule_file(f, &header, sizeof(header), "Capsule header")) goto err;

@@ -239,13 +530,32 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, image.reserved[1] = 0; image.reserved[2] = 0; image.update_image_size = bin_size;

• if (auth_context.sig_size)

• image.update_image_size += sizeof(auth_context.auth)
  

• 		+ auth_context.sig_size;
  

  image.update_vendor_code_size = 0; /* none */ image.update_hardware_instance = instance; image.image_capsule_support = 0;

• if (auth_context.sig_size)

• image.image_capsule_support |= CAPSULE_SUPPORT_AUTHENTICATION;
  

  if (write_capsule_file(f, &image, sizeof(image), "Firmware capsule image header")) goto err;

• /*

• * signature
  

• */
  

• if (auth_context.sig_size) {

• if (write_capsule_file(f, &auth_context.auth,
  

• 		       sizeof(auth_context.auth),
  

• 		       "Authentication header"))
  

• 	goto err;
  

• if (write_capsule_file(f, auth_context.sig_data,
  

• 		       auth_context.sig_size, "Signature"))
  

• 	goto err;
  

• }

• /*

  • firmware binary

  */

@@ -262,23 +572,37 @@ err: return ret; }

-/*

• • Usage:
• • $ mkeficapsule -f <firmware binary> <output file>

+/**

• • main - main entry function of mkeficapsule
• • @argc: Number of arguments
• • @argv: Array of pointers to arguments
• • Create an uefi capsule file, optionally signing it.
• • Parse all the arguments and pass them on to create_fwbin().
• • Return:
• • • 0 - on success
• • • -1 - on failure

  */ int main(int argc, char **argv) { char *file; efi_guid_t *guid; unsigned long index, instance;

• uint64_t mcount;

• char *privkey_file, *cert_file; int c, idx;

  file = NULL; guid = NULL; index = 0; instance = 0;

• mcount = 0;

• privkey_file = NULL;

• cert_file = NULL;

• dump_sig = 0; for (;;) {

• c = getopt_long(argc, argv, "f:r:i:I:v:h", options, &idx);
  

• c = getopt_long(argc, argv, opts_short, options, &idx);
  

  if (c == -1) break;

@@ -286,7 +610,7 @@ int main(int argc, char **argv) case 'f': if (file) { printf("Image already specified\n");

• 		return -1;
  

• 		exit(EXIT_FAILURE);
  }
  file = optarg;
  guid = &efi_guid_image_type_uboot_fit;
  

@@ -294,7 +618,7 @@ int main(int argc, char **argv) case 'r': if (file) { printf("Image already specified\n");

• 		return -1;
  

• 		exit(EXIT_FAILURE);
  }
  file = optarg;
  guid = &efi_guid_image_type_uboot_raw;
  

@@ -305,26 +629,44 @@ int main(int argc, char **argv) case 'I': instance = strtoul(optarg, NULL, 0); break; +#ifdef CONFIG_TOOLS_LIBCRYPTO

• case 'p':
  

• 	if (privkey_file) {
  

• 		printf("Private Key already specified\n");
  

• 		exit(EXIT_FAILURE);
  

• 	}
  

• 	privkey_file = optarg;
  

• 	break;
  

• case 'c':
  

• 	if (cert_file) {
  

• 		printf("Certificate file already specified\n");
  

• 		exit(EXIT_FAILURE);
  

• 	}
  

• 	cert_file = optarg;
  

• 	break;
  

• case 'm':
  

• 	mcount = strtoul(optarg, NULL, 0);
  

• 	break;
  

• case 'd':
  

• 	dump_sig = 1;
  

• 	break;
  

+#endif /* CONFIG_TOOLS_LIBCRYPTO */ case 'h': print_usage();

• 	return 0;
  

• 	exit(EXIT_SUCCESS);
  

  } }

• /* need an output file */
• if (argc != optind + 1) {

• /* check necessary parameters */
• if ((argc != optind + 1) || !file ||

•    ((privkey_file && !cert_file) ||
  

•     (!privkey_file && cert_file))) {
  

  print_usage(); exit(EXIT_FAILURE); }

• /* need a fit image file or raw image file */
• if (!file) {

• print_usage();
  

• exit(EXIT_SUCCESS);
  

• }
• if (create_fwbin(argv[optind], file, guid, index, instance)

• 	< 0) {
  

• if (create_fwbin(argv[optind], file, guid, index, instance,

• 	 mcount, privkey_file, cert_file) < 0) {
  

  printf("Creating firmware capsule failed\n"); exit(EXIT_FAILURE); }