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 Acked-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- tools/Makefile | 4 + tools/eficapsule.h | 115 +++++++++++++ tools/mkeficapsule.c | 398 +++++++++++++++++++++++++++++++++++++++---- 3 files changed, 487 insertions(+), 30 deletions(-) create mode 100644 tools/eficapsule.h
diff --git a/tools/Makefile b/tools/Makefile index 766c0674f4a0..afca08e2941a 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -238,6 +238,10 @@ hostprogs-$(CONFIG_MIPS) += mips-relocs hostprogs-$(CONFIG_ASN1_COMPILER) += asn1_compiler HOSTCFLAGS_asn1_compiler.o = -idirafter $(srctree)/include
+ifeq ($(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 diff --git a/tools/eficapsule.h b/tools/eficapsule.h new file mode 100644 index 000000000000..8c1560bb0671 --- /dev/null +++ b/tools/eficapsule.h @@ -0,0 +1,115 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright 2021 Linaro Limited + * Author: AKASHI Takahiro + * + * derived from efi.h and efi_api.h to make the file POSIX-compliant + */ + +#ifndef _EFI_CAPSULE_H +#define _EFI_CAPSULE_H + +#include <stdint.h> +#include <pe.h> /* WIN_CERTIFICATE */ + +/* + * Gcc's predefined attributes are not recognized by clang. + */ +#ifndef __packed +#define __packed __attribute__((__packed__)) +#endif + +#ifndef __aligned +#define __aligned(x) __attribute__((__aligned__(x))) +#endif + +typedef struct { + uint8_t b[16]; +} efi_guid_t __aligned(8); + +#define EFI_GUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) \ + {{ (a) & 0xff, ((a) >> 8) & 0xff, ((a) >> 16) & 0xff, \ + ((a) >> 24) & 0xff, \ + (b) & 0xff, ((b) >> 8) & 0xff, \ + (c) & 0xff, ((c) >> 8) & 0xff, \ + (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) } } + +#define EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID \ + EFI_GUID(0x6dcbd5ed, 0xe82d, 0x4c44, 0xbd, 0xa1, \ + 0x71, 0x94, 0x19, 0x9a, 0xd9, 0x2a) + +#define EFI_FIRMWARE_IMAGE_TYPE_UBOOT_FIT_GUID \ + EFI_GUID(0xae13ff2d, 0x9ad4, 0x4e25, 0x9a, 0xc8, \ + 0x6d, 0x80, 0xb3, 0xb2, 0x21, 0x47) + +#define EFI_FIRMWARE_IMAGE_TYPE_UBOOT_RAW_GUID \ + EFI_GUID(0xe2bb9c06, 0x70e9, 0x4b14, 0x97, 0xa3, \ + 0x5a, 0x79, 0x13, 0x17, 0x6e, 0x3f) + +#define EFI_CERT_TYPE_PKCS7_GUID \ + EFI_GUID(0x4aafd29d, 0x68df, 0x49ee, 0x8a, 0xa9, \ + 0x34, 0x7d, 0x37, 0x56, 0x65, 0xa7) + +/* flags */ +#define CAPSULE_FLAGS_PERSIST_ACROSS_RESET 0x00010000 + +struct efi_capsule_header { + efi_guid_t capsule_guid; + uint32_t header_size; + uint32_t flags; + uint32_t capsule_image_size; +} __packed; + +struct efi_firmware_management_capsule_header { + uint32_t version; + uint16_t embedded_driver_count; + uint16_t payload_item_count; + uint32_t item_offset_list[]; +} __packed; + +/* image_capsule_support */ +#define CAPSULE_SUPPORT_AUTHENTICATION 0x0000000000000001 + +struct efi_firmware_management_capsule_image_header { + uint32_t version; + efi_guid_t update_image_type_id; + uint8_t update_image_index; + uint8_t reserved[3]; + uint32_t update_image_size; + uint32_t update_vendor_code_size; + uint64_t update_hardware_instance; + uint64_t image_capsule_support; +} __packed; + +/** + * win_certificate_uefi_guid - A certificate that encapsulates + * a GUID-specific signature + * + * @hdr: Windows certificate header + * @cert_type: Certificate type + * @cert_data: Certificate data + */ +struct win_certificate_uefi_guid { + WIN_CERTIFICATE hdr; + efi_guid_t cert_type; + uint8_t cert_data[]; +} __packed; + +/** + * efi_firmware_image_authentication - Capsule authentication method + * descriptor + * + * This structure describes an authentication information for + * a capsule with IMAGE_ATTRIBUTE_AUTHENTICATION_REQUIRED set + * and should be included as part of the capsule. + * Only EFI_CERT_TYPE_PKCS7_GUID is accepted. + * + * @monotonic_count: Count to prevent replay + * @auth_info: Authentication info + */ +struct efi_firmware_image_authentication { + uint64_t monotonic_count; + struct win_certificate_uefi_guid auth_info; +} __packed; + +#endif /* _EFI_CAPSULE_H */ diff --git a/tools/mkeficapsule.c b/tools/mkeficapsule.c index ee3e489c0b30..66dc2ee20912 100644 --- a/tools/mkeficapsule.c +++ b/tools/mkeficapsule.c @@ -16,21 +16,17 @@ #include <sys/stat.h> #include <sys/types.h>
-typedef __u8 u8; -typedef __u16 u16; -typedef __u32 u32; -typedef __u64 u64; -typedef __s16 s16; -typedef __s32 s32; - -#define aligned_u64 __aligned_u64 - -#ifndef __packed -#define __packed __attribute__((packed)) +#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
-#include <efi.h> -#include <efi_api.h> +#include "eficapsule.h"
static const char *tool_name = "mkeficapsule";
@@ -39,12 +35,25 @@ 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}, }; @@ -58,10 +67,253 @@ 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; + uint8_t *image_data; + size_t image_size; + struct efi_firmware_image_authentication auth; + uint8_t *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) { + fprintf(stderr, "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) { + fprintf(stderr, "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, uint8_t *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, uint8_t *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 @@ -168,23 +420,25 @@ 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; - u64 offset; + uint64_t offset; int ret;
#ifdef DEBUG fprintf(stderr, "For output: %s\n", path); fprintf(stderr, "\tbin: %s\n\ttype: %pUl\n", bin, guid); - fprintf(stderr, "\tindex: %ld\n\tinstance: %ld\n", index, instance); + fprintf(stderr, "\tindex: %lu\n\tinstance: %lu\n", index, instance); #endif - + auth_context.sig_size = 0; f = NULL; data = NULL; ret = -1; @@ -195,6 +449,27 @@ 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)) { + fprintf(stderr, "Signing firmware image failed\n"); + goto err; + } + + if (dump_sig && + dump_signature(path, auth_context.sig_data, + auth_context.sig_size)) { + fprintf(stderr, "Creating signature file failed\n"); + goto err; + } + } + /* * write a capsule file */ @@ -212,9 +487,12 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, /* TODO: The current implementation ignores flags */ header.flags = CAPSULE_FLAGS_PERSIST_ACROSS_RESET; header.capsule_image_size = sizeof(header) - + sizeof(capsule) + sizeof(u64) + + sizeof(capsule) + sizeof(uint64_t) + 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; @@ -230,7 +508,7 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, "Firmware capsule header")) goto err;
- offset = sizeof(capsule) + sizeof(u64); + offset = sizeof(capsule) + sizeof(uint64_t); if (write_capsule_file(f, &offset, sizeof(offset), "Offset to capsule image")) goto err; @@ -245,13 +523,32 @@ 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 */ @@ -262,28 +559,43 @@ static int create_fwbin(char *path, char *bin, efi_guid_t *guid, err: if (f) fclose(f); + free_sig_data(&auth_context); free(data);
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;
@@ -291,7 +603,7 @@ int main(int argc, char **argv) case 'f': if (file) { fprintf(stderr, "Image already specified\n"); - return -1; + exit(EXIT_FAILURE); } file = optarg; guid = &efi_guid_image_type_uboot_fit; @@ -299,7 +611,7 @@ int main(int argc, char **argv) case 'r': if (file) { fprintf(stderr, "Image already specified\n"); - return -1; + exit(EXIT_FAILURE); } file = optarg; guid = &efi_guid_image_type_uboot_raw; @@ -310,14 +622,40 @@ int main(int argc, char **argv) case 'I': instance = strtoul(optarg, NULL, 0); break; +#ifdef CONFIG_TOOLS_LIBCRYPTO + case 'p': + if (privkey_file) { + fprintf(stderr, + "Private Key already specified\n"); + exit(EXIT_FAILURE); + } + privkey_file = optarg; + break; + case 'c': + if (cert_file) { + fprintf(stderr, + "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); } @@ -328,8 +666,8 @@ int main(int argc, char **argv) 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) { fprintf(stderr, "Creating firmware capsule failed\n"); exit(EXIT_FAILURE); }