| Message ID | 20210831024659.53464-2-takahiro.akashi@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | efi_loader: capsule: improve capsule authentication support | expand |
On 8/31/21 4:46 AM, 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: nits %s/need/need to/ > -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 %s/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 | 435 +++++++++++++++++++++++++++++++++++++++---- > 3 files changed, 416 insertions(+), 34 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" Having different versions of efimkcapsule with different capabilities is very confusing for users. Please, add select TOOLS_LIBCRYPTO > + 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 4a86321f6467..6ea3033dbfb8 100644 > --- a/tools/Makefile > +++ b/tools/Makefile > @@ -237,8 +237,12 @@ 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..090fb02de68d 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 If I get you right, you ideentified two use cases: * unsigned capsules * signed capsules Should it be allowable to have unsigned capsules with some board configurations then mkeficapsule compiled with CONFIG_TOOLS_LIBCRYPTO=y must be able to produce unsigned capsules. > {"help", no_argument, NULL, 'h'}, > {NULL, 0, NULL, 0}, > }; > @@ -57,16 +80,280 @@ 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 > + > +/** > + * create_fwbin - create an uefi capsule file > + * @path: Path to a created capsule file > + * @bin: Path to a firmware binary to encapsulate > + * @guid: GUID of related FMP driver > + * @index: Index number in capsule > + * @instance: Instance number in capsule > + * @mcount: Monolitic count in authentication information > + * @private_file: Path to a private key file > + * @cert_file: Path to a certificate file > + * > + * This function actually does the job of creating an uefi capsule file. > + * All the arguments must be supplied. > + * If either @private_file ror @cert_file is NULL, the capsule file > + * won't be signed. > + * > + * Return: > + * * 0 - on success > + * * -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, *g; > struct stat bin_stat; > u8 *data; > @@ -76,8 +363,9 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, > #ifdef DEBUG > 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; > > g = fopen(bin, "r"); > if (!g) { > @@ -93,11 +381,34 @@ 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 +417,20 @@ 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 +439,13 @@ 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 +455,53 @@ 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 +510,37 @@ err_1: > return -1; > } > > -/* > - * 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; > > @@ -214,29 +567,47 @@ 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) { > - print_usage(); > - exit(EXIT_FAILURE); > - } > - > - /* need a fit image file or raw image file */ > - if (!file) { > + /* check necessary parameters */ > + if ((argc != optind + 1) || !file || This needs to be changed to support signed and unsigned capsules. > + ((privkey_file && !cert_file) || > + (!privkey_file && cert_file))) { > print_usage(); > - exit(EXIT_SUCCESS); > + return -1; Please use EXIT_FALURE. > } > > - 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); > + return -1; return EXIT_FAILURE; > } > > - exit(EXIT_SUCCESS); > + return 0; In main, please, use return EXIT_SUCCESS; Best regards Heinrich > } >
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 4a86321f6467..6ea3033dbfb8 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -237,8 +237,12 @@ 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..090fb02de68d 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 +80,280 @@ 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 + +/** + * create_fwbin - create an uefi capsule file + * @path: Path to a created capsule file + * @bin: Path to a firmware binary to encapsulate + * @guid: GUID of related FMP driver + * @index: Index number in capsule + * @instance: Instance number in capsule + * @mcount: Monolitic count in authentication information + * @private_file: Path to a private key file + * @cert_file: Path to a certificate file + * + * This function actually does the job of creating an uefi capsule file. + * All the arguments must be supplied. + * If either @private_file ror @cert_file is NULL, the capsule file + * won't be signed. + * + * Return: + * * 0 - on success + * * -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, *g; struct stat bin_stat; u8 *data; @@ -76,8 +363,9 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, #ifdef DEBUG 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; g = fopen(bin, "r"); if (!g) { @@ -93,11 +381,34 @@ 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 +417,20 @@ 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 +439,13 @@ 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 +455,53 @@ 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 +510,37 @@ err_1: return -1; } -/* - * 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; @@ -214,29 +567,47 @@ 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) { - print_usage(); - exit(EXIT_FAILURE); - } - - /* need a fit image file or raw image file */ - if (!file) { + /* check necessary parameters */ + if ((argc != optind + 1) || !file || + ((privkey_file && !cert_file) || + (!privkey_file && cert_file))) { print_usage(); - exit(EXIT_SUCCESS); + return -1; } - 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); + return -1; } - exit(EXIT_SUCCESS); + return 0; }
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 | 435 +++++++++++++++++++++++++++++++++++++++---- 3 files changed, 416 insertions(+), 34 deletions(-) -- 2.33.0