Re: [PATCH v2 1/9] tools: mkeficapsule: add firmwware image signing

Hi,

I've tested this update on the DeveloperBox platform.

Tested-by: Masami Hiramatsu masami.hiramatsu@linaro.org

Thank you,

2021年7月27日(火) 18:12 AKASHI Takahiro takahiro.akashi@linaro.org:

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

tools/Kconfig | 7 + tools/Makefile | 8 +- tools/mkeficapsule.c | 332 +++++++++++++++++++++++++++++++++++++++---- 3 files changed, 316 insertions(+), 31 deletions(-)

diff --git a/tools/Kconfig b/tools/Kconfig index d6f82cd949b5..9a37ed035311 100644 --- a/tools/Kconfig +++ b/tools/Kconfig @@ -20,4 +20,11 @@ config TOOLS_LIBCRYPTO This selection does not affect target features, such as runtime FIT signature verification.

+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 bae3f95c4995..af8536489652 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -245,8 +245,12 @@ 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 4995ba4e0c2a..798706c7b5f7 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}, }; @@ -57,16 +80,195 @@ 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); }

+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 +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;
  

+}

+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;
  

+}

+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;
  

+}

+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;
  

+}

+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

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, *g;
    struct stat bin_stat;
    u8 *data;
  

@@ -78,6 +280,7 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, printf("\tbin: %s\n\ttype: %pUl\n", bin, guid); printf("\tindex: %ld\n\tinstance: %ld\n", index, instance); #endif

•   auth_context.sig_size = 0;
  
    g = fopen(bin, "r");
    if (!g) {
  

@@ -93,11 +296,34 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, printf("cannot allocate memory: %zx\n", (size_t)bin_stat.st_size); goto err_1; }

•   f = fopen(path, "w");
  

•   if (!f) {
  

•           printf("cannot open %s\n", path);
  

•   size = fread(data, 1, bin_stat.st_size, g);
  

•   if (size < bin_stat.st_size) {
  

•           printf("read failed (%zx)\n", size);
            goto err_2;
    }
  

•   /* 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_stat.st_size;
  

•           if (create_auth_data(&auth_context)) {
  

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

•                   goto err_3;
  

•           }
  

•           if (dump_sig &&
  

•               dump_signature(path, auth_context.sig_data,
  

•                              auth_context.sig_size)) {
  

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

•                   goto err_3;
  

•           }
  

•   }
  

•   header.capsule_guid = efi_guid_fm_capsule;
    header.header_size = sizeof(header);
    /* TODO: The current implementation ignores flags */
  

@@ -106,11 +332,20 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, + sizeof(capsule) + sizeof(u64) + sizeof(image) + bin_stat.st_size;

•   if (auth_context.sig_size)
  

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

•                           + auth_context.sig_size;
  

•   f = fopen(path, "w");
  

•   if (!f) {
  

•           printf("cannot open %s\n", path);
  

•           goto err_3;
  

•   }
  
    size = fwrite(&header, 1, sizeof(header), f);
    if (size < sizeof(header)) {
            printf("write failed (%zx)\n", size);
  

•           goto err_3;
  

•           goto err_4;
    }
  
    capsule.version = 0x00000001;
  

@@ -119,13 +354,13 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, size = fwrite(&capsule, 1, sizeof(capsule), f); if (size < (sizeof(capsule))) { printf("write failed (%zx)\n", size);

•           goto err_3;
  

•           goto err_4;
    }
    offset = sizeof(capsule) + sizeof(u64);
    size = fwrite(&offset, 1, sizeof(offset), f);
    if (size < sizeof(offset)) {
            printf("write failed (%zx)\n", size);
  

•           goto err_3;
  

•           goto err_4;
    }
  
    image.version = 0x00000003;
  

@@ -135,34 +370,53 @@ 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_stat.st_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;
  
    size = fwrite(&image, 1, sizeof(image), f);
    if (size < sizeof(image)) {
            printf("write failed (%zx)\n", size);
  

•           goto err_3;
  

•           goto err_4;
    }
  

•   size = fread(data, 1, bin_stat.st_size, g);
  

•   if (size < bin_stat.st_size) {
  

•           printf("read failed (%zx)\n", size);
  

•           goto err_3;
  

•   if (auth_context.sig_size) {
  

•           size = fwrite(&auth_context.auth, 1,
  

•                         sizeof(auth_context.auth), f);
  

•           if (size < sizeof(auth_context.auth)) {
  

•                   printf("write failed (%zx)\n", size);
  

•                   goto err_4;
  

•           }
  

•           size = fwrite(auth_context.sig_data, 1,
  

•                         auth_context.sig_size, f);
  

•           if (size < auth_context.sig_size) {
  

•                   printf("write failed (%zx)\n", size);
  

•                   goto err_4;
  

•           }
    }
  

•   size = fwrite(data, 1, bin_stat.st_size, f);
    if (size < bin_stat.st_size) {
            printf("write failed (%zx)\n", size);
  

•           goto err_3;
  

•           goto err_4;
    }
  
    fclose(f);
    fclose(g);
    free(data);
  

•   free_sig_data(&auth_context);
  
    return 0;
  
  

-err_3: +err_4: fclose(f); +err_3:

•   free_sig_data(&auth_context);
  

err_2: free(data); err_1: @@ -171,23 +425,25 @@ err_1: return -1; }

-/*

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

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;
  
  

@@ -214,26 +470,44 @@ 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");
  

•                           return -1;
  

•                   }
  

•                   privkey_file = optarg;
  

•                   break;
  

•           case 'c':
  

•                   if (cert_file) {
  

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

•                           return -1;
  

•                   }
  

•                   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; } }

•   /* 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);
    }
  

-- 2.31.0