With this enhancement, mkeficapsule will be able to create a capsule file with a signature which will be verified later by FMP's SetImage().
We will have to specify addtional command parameters: -monotonic-cout <count> : monotonic count -private-key <private key file> : private key file -certificate <certificate file> : certificate file Only when those parameters are given, a signature will be added to a capsule file.
Users are expected to maintain the monotonic count for each firmware image.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- tools/Makefile | 4 + tools/mkeficapsule.c | 324 +++++++++++++++++++++++++++++++++++++++---- 2 files changed, 303 insertions(+), 25 deletions(-)
diff --git a/tools/Makefile b/tools/Makefile index d020c55d6644..02eae0286e20 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -231,6 +231,10 @@ hostprogs-$(CONFIG_MIPS) += mips-relocs hostprogs-$(CONFIG_ASN1_COMPILER) += asn1_compiler HOSTCFLAGS_asn1_compiler.o = -idirafter $(srctree)/include
+ifneq ($(CONFIG_EFI_CAPSULE_AUTHENTICATE),) +HOSTLDLIBS_mkeficapsule += \ + $(shell pkg-config --libs libssl libcrypto 2> /dev/null || echo "-lssl -lcrypto") +endif mkeficapsule-objs := mkeficapsule.o $(LIBFDT_OBJS) hostprogs-$(CONFIG_EFI_HAVE_CAPSULE_SUPPORT) += mkeficapsule
diff --git a/tools/mkeficapsule.c b/tools/mkeficapsule.c index de0a62898886..34ff1bdd82eb 100644 --- a/tools/mkeficapsule.c +++ b/tools/mkeficapsule.c @@ -18,7 +18,17 @@ #include <sys/stat.h> #include <sys/types.h>
-#include "fdt_host.h" +#include <linux/kconfig.h> +#if IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) +#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 + +#include <linux/libfdt.h>
typedef __u8 u8; typedef __u16 u16; @@ -46,6 +56,13 @@ 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; + +#if IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) +static const char *opts_short = "f:r:i:I:v:D:K:P:C:m:dOh"; +#else +static const char *opts_short = "f:r:i:I:v:D:K:Oh"; +#endif
static struct option options[] = { {"fit", required_argument, NULL, 'f'}, @@ -54,6 +71,12 @@ static struct option options[] = { {"instance", required_argument, NULL, 'I'}, {"dtb", required_argument, NULL, 'D'}, {"public key", required_argument, NULL, 'K'}, +#if IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) + {"private-key", required_argument, NULL, 'P'}, + {"certificate", required_argument, NULL, 'C'}, + {"monotonic-count", required_argument, NULL, 'm'}, + {"dump-sig", no_argument, NULL, 'd'}, +#endif {"overlay", no_argument, NULL, 'O'}, {"help", no_argument, NULL, 'h'}, {NULL, 0, NULL, 0}, @@ -70,6 +93,12 @@ static void print_usage(void) "\t-I, --instance <instance> update hardware instance\n" "\t-K, --public-key <key file> public key esl file\n" "\t-D, --dtb <dtb file> dtb file\n" +#if IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) + "\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-O, --overlay the dtb file is an overlay\n" "\t-h, --help print a help message\n", tool_name); @@ -249,12 +278,167 @@ err: return ret; }
+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; + +#if IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) +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; +} +#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; @@ -266,6 +450,7 @@ 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) { @@ -281,11 +466,36 @@ 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 IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) + 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; + } + } +#endif + header.capsule_guid = efi_guid_fm_capsule; header.header_size = sizeof(header); /* TODO: The current implementation ignores flags */ @@ -294,11 +504,20 @@ 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; @@ -307,13 +526,13 @@ 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; @@ -323,34 +542,61 @@ 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 IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) + 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; + } } +#endif + 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); +#if IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) + if (auth_context.sig_size) + OPENSSL_free(auth_context.sig_data); +#endif
return 0;
-err_3: +err_4: fclose(f); +err_3: +#if IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) + if (auth_context.sig_size) + OPENSSL_free(auth_context.sig_data); +#endif err_2: free(data); err_1: @@ -359,10 +605,6 @@ err_1: return -1; }
-/* - * Usage: - * $ mkeficapsule -f <firmware binary> <output file> - */ int main(int argc, char **argv) { char *file; @@ -370,6 +612,8 @@ int main(int argc, char **argv) char *dtb_file; efi_guid_t *guid; unsigned long index, instance; + uint64_t mcount; + char *privkey_file, *cert_file; int c, idx; int ret; bool overlay = false; @@ -380,8 +624,12 @@ int main(int argc, char **argv) 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:D:K:Oh", options, &idx); + c = getopt_long(argc, argv, opts_short, options, &idx); if (c == -1) break;
@@ -422,6 +670,28 @@ int main(int argc, char **argv) } dtb_file = optarg; break; +#if IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) + 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 case 'O': overlay = true; break; @@ -431,8 +701,12 @@ int main(int argc, char **argv) } }
- /* need a fit image file or raw image file */ - if (!file && !pkey_file && !dtb_file) { + /* check necessary parameters */ + if ((file && (!(optind < argc) || + (privkey_file && !cert_file) || + (!privkey_file && cert_file))) || + ((pkey_file && !dtb_file) || + (!pkey_file && dtb_file))) { print_usage(); exit(EXIT_FAILURE); } @@ -442,12 +716,12 @@ int main(int argc, char **argv) if (ret == -1) { printf("Adding public key to the dtb failed\n"); exit(EXIT_FAILURE); - } else { - exit(EXIT_SUCCESS); } }
- if (create_fwbin(argv[optind], file, guid, index, instance) + if (optind < argc && + create_fwbin(argv[optind], file, guid, index, instance, + mcount, privkey_file, cert_file) < 0) { printf("Creating firmware capsule failed\n"); exit(EXIT_FAILURE);