| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * EFI image loader |
| * |
| * based partly on wine code |
| * |
| * Copyright (c) 2016 Alexander Graf |
| */ |
| |
| #define LOG_CATEGORY LOGC_EFI |
| |
| #include <common.h> |
| #include <cpu_func.h> |
| #include <efi_loader.h> |
| #include <log.h> |
| #include <malloc.h> |
| #include <pe.h> |
| #include <sort.h> |
| #include <crypto/mscode.h> |
| #include <crypto/pkcs7_parser.h> |
| #include <linux/err.h> |
| |
| const efi_guid_t efi_global_variable_guid = EFI_GLOBAL_VARIABLE_GUID; |
| const efi_guid_t efi_guid_device_path = EFI_DEVICE_PATH_PROTOCOL_GUID; |
| const efi_guid_t efi_guid_loaded_image = EFI_LOADED_IMAGE_PROTOCOL_GUID; |
| const efi_guid_t efi_guid_loaded_image_device_path = |
| EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID; |
| const efi_guid_t efi_simple_file_system_protocol_guid = |
| EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID; |
| const efi_guid_t efi_file_info_guid = EFI_FILE_INFO_GUID; |
| |
| static int machines[] = { |
| #if defined(__aarch64__) |
| IMAGE_FILE_MACHINE_ARM64, |
| #elif defined(__arm__) |
| IMAGE_FILE_MACHINE_ARM, |
| IMAGE_FILE_MACHINE_THUMB, |
| IMAGE_FILE_MACHINE_ARMNT, |
| #endif |
| |
| #if defined(__x86_64__) |
| IMAGE_FILE_MACHINE_AMD64, |
| #elif defined(__i386__) |
| IMAGE_FILE_MACHINE_I386, |
| #endif |
| |
| #if defined(__riscv) && (__riscv_xlen == 32) |
| IMAGE_FILE_MACHINE_RISCV32, |
| #endif |
| |
| #if defined(__riscv) && (__riscv_xlen == 64) |
| IMAGE_FILE_MACHINE_RISCV64, |
| #endif |
| 0 }; |
| |
| /** |
| * efi_print_image_info() - print information about a loaded image |
| * |
| * If the program counter is located within the image the offset to the base |
| * address is shown. |
| * |
| * @obj: EFI object |
| * @image: loaded image |
| * @pc: program counter (use NULL to suppress offset output) |
| * Return: status code |
| */ |
| static efi_status_t efi_print_image_info(struct efi_loaded_image_obj *obj, |
| struct efi_loaded_image *image, |
| void *pc) |
| { |
| printf("UEFI image"); |
| printf(" [0x%p:0x%p]", |
| image->image_base, image->image_base + image->image_size - 1); |
| if (pc && pc >= image->image_base && |
| pc < image->image_base + image->image_size) |
| printf(" pc=0x%zx", pc - image->image_base); |
| if (image->file_path) |
| printf(" '%pD'", image->file_path); |
| printf("\n"); |
| return EFI_SUCCESS; |
| } |
| |
| /** |
| * efi_print_image_infos() - print information about all loaded images |
| * |
| * @pc: program counter (use NULL to suppress offset output) |
| */ |
| void efi_print_image_infos(void *pc) |
| { |
| struct efi_object *efiobj; |
| struct efi_handler *handler; |
| |
| list_for_each_entry(efiobj, &efi_obj_list, link) { |
| list_for_each_entry(handler, &efiobj->protocols, link) { |
| if (!guidcmp(&handler->guid, &efi_guid_loaded_image)) { |
| efi_print_image_info( |
| (struct efi_loaded_image_obj *)efiobj, |
| handler->protocol_interface, pc); |
| } |
| } |
| } |
| } |
| |
| /** |
| * efi_loader_relocate() - relocate UEFI binary |
| * |
| * @rel: pointer to the relocation table |
| * @rel_size: size of the relocation table in bytes |
| * @efi_reloc: actual load address of the image |
| * @pref_address: preferred load address of the image |
| * Return: status code |
| */ |
| static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel, |
| unsigned long rel_size, void *efi_reloc, |
| unsigned long pref_address) |
| { |
| unsigned long delta = (unsigned long)efi_reloc - pref_address; |
| const IMAGE_BASE_RELOCATION *end; |
| int i; |
| |
| if (delta == 0) |
| return EFI_SUCCESS; |
| |
| end = (const IMAGE_BASE_RELOCATION *)((const char *)rel + rel_size); |
| while (rel < end && rel->SizeOfBlock) { |
| const uint16_t *relocs = (const uint16_t *)(rel + 1); |
| i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t); |
| while (i--) { |
| uint32_t offset = (uint32_t)(*relocs & 0xfff) + |
| rel->VirtualAddress; |
| int type = *relocs >> EFI_PAGE_SHIFT; |
| uint64_t *x64 = efi_reloc + offset; |
| uint32_t *x32 = efi_reloc + offset; |
| uint16_t *x16 = efi_reloc + offset; |
| |
| switch (type) { |
| case IMAGE_REL_BASED_ABSOLUTE: |
| break; |
| case IMAGE_REL_BASED_HIGH: |
| *x16 += ((uint32_t)delta) >> 16; |
| break; |
| case IMAGE_REL_BASED_LOW: |
| *x16 += (uint16_t)delta; |
| break; |
| case IMAGE_REL_BASED_HIGHLOW: |
| *x32 += (uint32_t)delta; |
| break; |
| case IMAGE_REL_BASED_DIR64: |
| *x64 += (uint64_t)delta; |
| break; |
| #ifdef __riscv |
| case IMAGE_REL_BASED_RISCV_HI20: |
| *x32 = ((*x32 & 0xfffff000) + (uint32_t)delta) | |
| (*x32 & 0x00000fff); |
| break; |
| case IMAGE_REL_BASED_RISCV_LOW12I: |
| case IMAGE_REL_BASED_RISCV_LOW12S: |
| /* We know that we're 4k aligned */ |
| if (delta & 0xfff) { |
| log_err("Unsupported reloc offset\n"); |
| return EFI_LOAD_ERROR; |
| } |
| break; |
| #endif |
| default: |
| log_err("Unknown Relocation off %x type %x\n", |
| offset, type); |
| return EFI_LOAD_ERROR; |
| } |
| relocs++; |
| } |
| rel = (const IMAGE_BASE_RELOCATION *)relocs; |
| } |
| return EFI_SUCCESS; |
| } |
| |
| void __weak invalidate_icache_all(void) |
| { |
| /* If the system doesn't support icache_all flush, cross our fingers */ |
| } |
| |
| /** |
| * efi_set_code_and_data_type() - determine the memory types to be used for code |
| * and data. |
| * |
| * @loaded_image_info: image descriptor |
| * @image_type: field Subsystem of the optional header for |
| * Windows specific field |
| */ |
| static void efi_set_code_and_data_type( |
| struct efi_loaded_image *loaded_image_info, |
| uint16_t image_type) |
| { |
| switch (image_type) { |
| case IMAGE_SUBSYSTEM_EFI_APPLICATION: |
| loaded_image_info->image_code_type = EFI_LOADER_CODE; |
| loaded_image_info->image_data_type = EFI_LOADER_DATA; |
| break; |
| case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER: |
| loaded_image_info->image_code_type = EFI_BOOT_SERVICES_CODE; |
| loaded_image_info->image_data_type = EFI_BOOT_SERVICES_DATA; |
| break; |
| case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER: |
| case IMAGE_SUBSYSTEM_EFI_ROM: |
| loaded_image_info->image_code_type = EFI_RUNTIME_SERVICES_CODE; |
| loaded_image_info->image_data_type = EFI_RUNTIME_SERVICES_DATA; |
| break; |
| default: |
| log_err("invalid image type: %u\n", image_type); |
| /* Let's assume it is an application */ |
| loaded_image_info->image_code_type = EFI_LOADER_CODE; |
| loaded_image_info->image_data_type = EFI_LOADER_DATA; |
| break; |
| } |
| } |
| |
| /** |
| * efi_image_region_add() - add an entry of region |
| * @regs: Pointer to array of regions |
| * @start: Start address of region (included) |
| * @end: End address of region (excluded) |
| * @nocheck: flag against overlapped regions |
| * |
| * Take one entry of region \[@start, @end\[ and insert it into the list. |
| * |
| * * If @nocheck is false, the list will be sorted ascending by address. |
| * Overlapping entries will not be allowed. |
| * |
| * * If @nocheck is true, the list will be sorted ascending by sequence |
| * of adding the entries. Overlapping is allowed. |
| * |
| * Return: status code |
| */ |
| efi_status_t efi_image_region_add(struct efi_image_regions *regs, |
| const void *start, const void *end, |
| int nocheck) |
| { |
| struct image_region *reg; |
| int i, j; |
| |
| if (regs->num >= regs->max) { |
| log_err("%s: no more room for regions\n", __func__); |
| return EFI_OUT_OF_RESOURCES; |
| } |
| |
| if (end < start) |
| return EFI_INVALID_PARAMETER; |
| |
| for (i = 0; i < regs->num; i++) { |
| reg = ®s->reg[i]; |
| if (nocheck) |
| continue; |
| |
| /* new data after registered region */ |
| if (start >= reg->data + reg->size) |
| continue; |
| |
| /* new data preceding registered region */ |
| if (end <= reg->data) { |
| for (j = regs->num - 1; j >= i; j--) |
| memcpy(®s->reg[j + 1], ®s->reg[j], |
| sizeof(*reg)); |
| break; |
| } |
| |
| /* new data overlapping registered region */ |
| log_err("%s: new region already part of another\n", __func__); |
| return EFI_INVALID_PARAMETER; |
| } |
| |
| reg = ®s->reg[i]; |
| reg->data = start; |
| reg->size = end - start; |
| regs->num++; |
| |
| return EFI_SUCCESS; |
| } |
| |
| /** |
| * cmp_pe_section() - compare virtual addresses of two PE image sections |
| * @arg1: pointer to pointer to first section header |
| * @arg2: pointer to pointer to second section header |
| * |
| * Compare the virtual addresses of two sections of an portable executable. |
| * The arguments are defined as const void * to allow usage with qsort(). |
| * |
| * Return: -1 if the virtual address of arg1 is less than that of arg2, |
| * 0 if the virtual addresses are equal, 1 if the virtual address |
| * of arg1 is greater than that of arg2. |
| */ |
| static int cmp_pe_section(const void *arg1, const void *arg2) |
| { |
| const IMAGE_SECTION_HEADER *section1, *section2; |
| |
| section1 = *((const IMAGE_SECTION_HEADER **)arg1); |
| section2 = *((const IMAGE_SECTION_HEADER **)arg2); |
| |
| if (section1->VirtualAddress < section2->VirtualAddress) |
| return -1; |
| else if (section1->VirtualAddress == section2->VirtualAddress) |
| return 0; |
| else |
| return 1; |
| } |
| |
| /** |
| * efi_prepare_aligned_image() - prepare 8-byte aligned image |
| * @efi: pointer to the EFI binary |
| * @efi_size: size of @efi binary |
| * |
| * If @efi is not 8-byte aligned, this function newly allocates |
| * the image buffer. |
| * |
| * Return: valid pointer to a image, return NULL if allocation fails. |
| */ |
| void *efi_prepare_aligned_image(void *efi, u64 *efi_size) |
| { |
| size_t new_efi_size; |
| void *new_efi; |
| |
| /* |
| * Size must be 8-byte aligned and the trailing bytes must be |
| * zero'ed. Otherwise hash value may be incorrect. |
| */ |
| if (!IS_ALIGNED(*efi_size, 8)) { |
| new_efi_size = ALIGN(*efi_size, 8); |
| new_efi = calloc(new_efi_size, 1); |
| if (!new_efi) |
| return NULL; |
| memcpy(new_efi, efi, *efi_size); |
| *efi_size = new_efi_size; |
| return new_efi; |
| } else { |
| return efi; |
| } |
| } |
| |
| /** |
| * efi_image_parse() - parse a PE image |
| * @efi: Pointer to image |
| * @len: Size of @efi |
| * @regp: Pointer to a list of regions |
| * @auth: Pointer to a pointer to authentication data in PE |
| * @auth_len: Size of @auth |
| * |
| * Parse image binary in PE32(+) format, assuming that sanity of PE image |
| * has been checked by a caller. |
| * On success, an address of authentication data in @efi and its size will |
| * be returned in @auth and @auth_len, respectively. |
| * |
| * Return: true on success, false on error |
| */ |
| bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp, |
| WIN_CERTIFICATE **auth, size_t *auth_len) |
| { |
| struct efi_image_regions *regs; |
| IMAGE_DOS_HEADER *dos; |
| IMAGE_NT_HEADERS32 *nt; |
| IMAGE_SECTION_HEADER *sections, **sorted; |
| int num_regions, num_sections, i; |
| int ctidx = IMAGE_DIRECTORY_ENTRY_SECURITY; |
| u32 align, size, authsz, authoff; |
| size_t bytes_hashed; |
| |
| dos = (void *)efi; |
| nt = (void *)(efi + dos->e_lfanew); |
| authoff = 0; |
| authsz = 0; |
| |
| /* |
| * Count maximum number of regions to be digested. |
| * We don't have to have an exact number here. |
| * See efi_image_region_add()'s in parsing below. |
| */ |
| num_regions = 3; /* for header */ |
| num_regions += nt->FileHeader.NumberOfSections; |
| num_regions++; /* for extra */ |
| |
| regs = calloc(sizeof(*regs) + sizeof(struct image_region) * num_regions, |
| 1); |
| if (!regs) |
| goto err; |
| regs->max = num_regions; |
| |
| /* |
| * Collect data regions for hash calculation |
| * 1. File headers |
| */ |
| if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) { |
| IMAGE_NT_HEADERS64 *nt64 = (void *)nt; |
| IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader; |
| |
| /* Skip CheckSum */ |
| efi_image_region_add(regs, efi, &opt->CheckSum, 0); |
| if (nt64->OptionalHeader.NumberOfRvaAndSizes <= ctidx) { |
| efi_image_region_add(regs, |
| &opt->Subsystem, |
| efi + opt->SizeOfHeaders, 0); |
| } else { |
| /* Skip Certificates Table */ |
| efi_image_region_add(regs, |
| &opt->Subsystem, |
| &opt->DataDirectory[ctidx], 0); |
| efi_image_region_add(regs, |
| &opt->DataDirectory[ctidx] + 1, |
| efi + opt->SizeOfHeaders, 0); |
| |
| authoff = opt->DataDirectory[ctidx].VirtualAddress; |
| authsz = opt->DataDirectory[ctidx].Size; |
| } |
| |
| bytes_hashed = opt->SizeOfHeaders; |
| align = opt->FileAlignment; |
| } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) { |
| IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader; |
| |
| /* Skip CheckSum */ |
| efi_image_region_add(regs, efi, &opt->CheckSum, 0); |
| if (nt->OptionalHeader.NumberOfRvaAndSizes <= ctidx) { |
| efi_image_region_add(regs, |
| &opt->Subsystem, |
| efi + opt->SizeOfHeaders, 0); |
| } else { |
| /* Skip Certificates Table */ |
| efi_image_region_add(regs, &opt->Subsystem, |
| &opt->DataDirectory[ctidx], 0); |
| efi_image_region_add(regs, |
| &opt->DataDirectory[ctidx] + 1, |
| efi + opt->SizeOfHeaders, 0); |
| |
| authoff = opt->DataDirectory[ctidx].VirtualAddress; |
| authsz = opt->DataDirectory[ctidx].Size; |
| } |
| |
| bytes_hashed = opt->SizeOfHeaders; |
| align = opt->FileAlignment; |
| } else { |
| log_err("%s: Invalid optional header magic %x\n", __func__, |
| nt->OptionalHeader.Magic); |
| goto err; |
| } |
| |
| /* 2. Sections */ |
| num_sections = nt->FileHeader.NumberOfSections; |
| sections = (void *)((uint8_t *)&nt->OptionalHeader + |
| nt->FileHeader.SizeOfOptionalHeader); |
| sorted = calloc(sizeof(IMAGE_SECTION_HEADER *), num_sections); |
| if (!sorted) { |
| log_err("%s: Out of memory\n", __func__); |
| goto err; |
| } |
| |
| /* |
| * Make sure the section list is in ascending order. |
| */ |
| for (i = 0; i < num_sections; i++) |
| sorted[i] = §ions[i]; |
| qsort(sorted, num_sections, sizeof(sorted[0]), cmp_pe_section); |
| |
| for (i = 0; i < num_sections; i++) { |
| if (!sorted[i]->SizeOfRawData) |
| continue; |
| |
| size = (sorted[i]->SizeOfRawData + align - 1) & ~(align - 1); |
| efi_image_region_add(regs, efi + sorted[i]->PointerToRawData, |
| efi + sorted[i]->PointerToRawData + size, |
| 0); |
| log_debug("section[%d](%s): raw: 0x%x-0x%x, virt: %x-%x\n", |
| i, sorted[i]->Name, |
| sorted[i]->PointerToRawData, |
| sorted[i]->PointerToRawData + size, |
| sorted[i]->VirtualAddress, |
| sorted[i]->VirtualAddress |
| + sorted[i]->Misc.VirtualSize); |
| |
| bytes_hashed += size; |
| } |
| free(sorted); |
| |
| /* 3. Extra data excluding Certificates Table */ |
| if (bytes_hashed + authsz < len) { |
| log_debug("extra data for hash: %zu\n", |
| len - (bytes_hashed + authsz)); |
| efi_image_region_add(regs, efi + bytes_hashed, |
| efi + len - authsz, 0); |
| } |
| |
| /* Return Certificates Table */ |
| if (authsz) { |
| if (len < authoff + authsz) { |
| log_err("%s: Size for auth too large: %u >= %zu\n", |
| __func__, authsz, len - authoff); |
| goto err; |
| } |
| if (authsz < sizeof(*auth)) { |
| log_err("%s: Size for auth too small: %u < %zu\n", |
| __func__, authsz, sizeof(*auth)); |
| goto err; |
| } |
| *auth = efi + authoff; |
| *auth_len = authsz; |
| log_debug("WIN_CERTIFICATE: 0x%x, size: 0x%x\n", authoff, |
| authsz); |
| } else { |
| *auth = NULL; |
| *auth_len = 0; |
| } |
| |
| *regp = regs; |
| |
| return true; |
| |
| err: |
| free(regs); |
| |
| return false; |
| } |
| |
| #ifdef CONFIG_EFI_SECURE_BOOT |
| /** |
| * efi_image_verify_digest - verify image's message digest |
| * @regs: Array of memory regions to digest |
| * @msg: Signature in pkcs7 structure |
| * |
| * @regs contains all the data in a PE image to digest. Calculate |
| * a hash value based on @regs and compare it with a messaged digest |
| * in the content (SpcPeImageData) of @msg's contentInfo. |
| * |
| * Return: true if verified, false if not |
| */ |
| static bool efi_image_verify_digest(struct efi_image_regions *regs, |
| struct pkcs7_message *msg) |
| { |
| struct pefile_context ctx; |
| void *hash; |
| int hash_len, ret; |
| |
| const void *data; |
| size_t data_len; |
| size_t asn1hdrlen; |
| |
| /* get pkcs7's contentInfo */ |
| ret = pkcs7_get_content_data(msg, &data, &data_len, &asn1hdrlen); |
| if (ret < 0 || !data) |
| return false; |
| |
| /* parse data and retrieve a message digest into ctx */ |
| ret = mscode_parse(&ctx, data, data_len, asn1hdrlen); |
| if (ret < 0) |
| return false; |
| |
| /* calculate a hash value of PE image */ |
| hash = NULL; |
| if (!efi_hash_regions(regs->reg, regs->num, &hash, ctx.digest_algo, |
| &hash_len)) |
| return false; |
| |
| /* match the digest */ |
| if (ctx.digest_len != hash_len || memcmp(ctx.digest, hash, hash_len)) |
| return false; |
| |
| return true; |
| } |
| |
| /** |
| * efi_image_authenticate() - verify a signature of signed image |
| * @efi: Pointer to image |
| * @efi_size: Size of @efi |
| * |
| * A signed image should have its signature stored in a table of its PE header. |
| * So if an image is signed and only if if its signature is verified using |
| * signature databases, an image is authenticated. |
| * If an image is not signed, its validity is checked by using |
| * efi_image_unsigned_authenticated(). |
| * TODO: |
| * When AuditMode==0, if the image's signature is not found in |
| * the authorized database, or is found in the forbidden database, |
| * the image will not be started and instead, information about it |
| * will be placed in this table. |
| * When AuditMode==1, an EFI_IMAGE_EXECUTION_INFO element is created |
| * in the EFI_IMAGE_EXECUTION_INFO_TABLE for every certificate found |
| * in the certificate table of every image that is validated. |
| * |
| * Return: true if authenticated, false if not |
| */ |
| static bool efi_image_authenticate(void *efi, size_t efi_size) |
| { |
| struct efi_image_regions *regs = NULL; |
| WIN_CERTIFICATE *wincerts = NULL, *wincert; |
| size_t wincerts_len; |
| struct pkcs7_message *msg = NULL; |
| struct efi_signature_store *db = NULL, *dbx = NULL; |
| void *new_efi = NULL; |
| u8 *auth, *wincerts_end; |
| size_t auth_size; |
| bool ret = false; |
| |
| log_debug("%s: Enter, %d\n", __func__, ret); |
| |
| if (!efi_secure_boot_enabled()) |
| return true; |
| |
| new_efi = efi_prepare_aligned_image(efi, (u64 *)&efi_size); |
| if (!new_efi) |
| return false; |
| |
| if (!efi_image_parse(new_efi, efi_size, ®s, &wincerts, |
| &wincerts_len)) { |
| log_err("Parsing PE executable image failed\n"); |
| goto out; |
| } |
| |
| /* |
| * verify signature using db and dbx |
| */ |
| db = efi_sigstore_parse_sigdb(u"db"); |
| if (!db) { |
| log_err("Getting signature database(db) failed\n"); |
| goto out; |
| } |
| |
| dbx = efi_sigstore_parse_sigdb(u"dbx"); |
| if (!dbx) { |
| log_err("Getting signature database(dbx) failed\n"); |
| goto out; |
| } |
| |
| if (efi_signature_lookup_digest(regs, dbx, true)) { |
| log_debug("Image's digest was found in \"dbx\"\n"); |
| goto out; |
| } |
| |
| /* |
| * go through WIN_CERTIFICATE list |
| * NOTE: |
| * We may have multiple signatures either as WIN_CERTIFICATE's |
| * in PE header, or as pkcs7 SignerInfo's in SignedData. |
| * So the verification policy here is: |
| * - Success if, at least, one of signatures is verified |
| * - unless signature is rejected explicitly with its digest. |
| */ |
| |
| for (wincert = wincerts, wincerts_end = (u8 *)wincerts + wincerts_len; |
| (u8 *)wincert < wincerts_end; |
| wincert = (WIN_CERTIFICATE *) |
| ((u8 *)wincert + ALIGN(wincert->dwLength, 8))) { |
| if ((u8 *)wincert + sizeof(*wincert) >= wincerts_end) |
| break; |
| |
| if (wincert->dwLength <= sizeof(*wincert)) { |
| log_debug("dwLength too small: %u < %zu\n", |
| wincert->dwLength, sizeof(*wincert)); |
| continue; |
| } |
| |
| log_debug("WIN_CERTIFICATE_TYPE: 0x%x\n", |
| wincert->wCertificateType); |
| |
| auth = (u8 *)wincert + sizeof(*wincert); |
| auth_size = wincert->dwLength - sizeof(*wincert); |
| if (wincert->wCertificateType == WIN_CERT_TYPE_EFI_GUID) { |
| if (auth + sizeof(efi_guid_t) >= wincerts_end) |
| break; |
| |
| if (auth_size <= sizeof(efi_guid_t)) { |
| log_debug("dwLength too small: %u < %zu\n", |
| wincert->dwLength, sizeof(*wincert)); |
| continue; |
| } |
| if (guidcmp(auth, &efi_guid_cert_type_pkcs7)) { |
| log_debug("Certificate type not supported: %pUs\n", |
| auth); |
| ret = false; |
| goto out; |
| } |
| |
| auth += sizeof(efi_guid_t); |
| auth_size -= sizeof(efi_guid_t); |
| } else if (wincert->wCertificateType |
| != WIN_CERT_TYPE_PKCS_SIGNED_DATA) { |
| log_debug("Certificate type not supported\n"); |
| ret = false; |
| goto out; |
| } |
| |
| msg = pkcs7_parse_message(auth, auth_size); |
| if (IS_ERR(msg)) { |
| log_err("Parsing image's signature failed\n"); |
| msg = NULL; |
| continue; |
| } |
| |
| /* |
| * verify signatures in pkcs7's signedInfos which are |
| * to authenticate the integrity of pkcs7's contentInfo. |
| * |
| * NOTE: |
| * UEFI specification defines two signature types possible |
| * in signature database: |
| * a. x509 certificate, where a signature in image is |
| * a message digest encrypted by RSA public key |
| * (EFI_CERT_X509_GUID) |
| * b. bare hash value of message digest |
| * (EFI_CERT_SHAxxx_GUID) |
| * |
| * efi_signature_verify() handles case (a), while |
| * efi_signature_lookup_digest() handles case (b). |
| * |
| * There is a third type: |
| * c. message digest of a certificate |
| * (EFI_CERT_X509_SHAAxxx_GUID) |
| * This type of signature is used only in revocation list |
| * (dbx) and handled as part of efi_signatgure_verify(). |
| */ |
| /* try black-list first */ |
| if (efi_signature_verify_one(regs, msg, dbx)) { |
| ret = false; |
| log_debug("Signature was rejected by \"dbx\"\n"); |
| goto out; |
| } |
| |
| if (!efi_signature_check_signers(msg, dbx)) { |
| ret = false; |
| log_debug("Signer(s) in \"dbx\"\n"); |
| goto out; |
| } |
| |
| /* try white-list */ |
| if (!efi_signature_verify(regs, msg, db, dbx)) { |
| log_debug("Signature was not verified by \"db\"\n"); |
| continue; |
| } |
| |
| /* |
| * now calculate an image's hash value and compare it with |
| * a messaged digest embedded in pkcs7's contentInfo |
| */ |
| if (efi_image_verify_digest(regs, msg)) { |
| ret = true; |
| continue; |
| } |
| |
| log_debug("Message digest doesn't match\n"); |
| } |
| |
| |
| /* last resort try the image sha256 hash in db */ |
| if (!ret && efi_signature_lookup_digest(regs, db, false)) |
| ret = true; |
| |
| out: |
| efi_sigstore_free(db); |
| efi_sigstore_free(dbx); |
| pkcs7_free_message(msg); |
| free(regs); |
| if (new_efi != efi) |
| free(new_efi); |
| |
| log_debug("%s: Exit, %d\n", __func__, ret); |
| return ret; |
| } |
| #else |
| static bool efi_image_authenticate(void *efi, size_t efi_size) |
| { |
| return true; |
| } |
| #endif /* CONFIG_EFI_SECURE_BOOT */ |
| |
| |
| /** |
| * efi_check_pe() - check if a memory buffer contains a PE-COFF image |
| * |
| * @buffer: buffer to check |
| * @size: size of buffer |
| * @nt_header: on return pointer to NT header of PE-COFF image |
| * Return: EFI_SUCCESS if the buffer contains a PE-COFF image |
| */ |
| efi_status_t efi_check_pe(void *buffer, size_t size, void **nt_header) |
| { |
| IMAGE_DOS_HEADER *dos = buffer; |
| IMAGE_NT_HEADERS32 *nt; |
| |
| if (size < sizeof(*dos)) |
| return EFI_INVALID_PARAMETER; |
| |
| /* Check for DOS magix */ |
| if (dos->e_magic != IMAGE_DOS_SIGNATURE) |
| return EFI_INVALID_PARAMETER; |
| |
| /* |
| * Check if the image section header fits into the file. Knowing that at |
| * least one section header follows we only need to check for the length |
| * of the 64bit header which is longer than the 32bit header. |
| */ |
| if (size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS32)) |
| return EFI_INVALID_PARAMETER; |
| nt = (IMAGE_NT_HEADERS32 *)((u8 *)buffer + dos->e_lfanew); |
| |
| /* Check for PE-COFF magic */ |
| if (nt->Signature != IMAGE_NT_SIGNATURE) |
| return EFI_INVALID_PARAMETER; |
| |
| if (nt_header) |
| *nt_header = nt; |
| |
| return EFI_SUCCESS; |
| } |
| |
| /** |
| * section_size() - determine size of section |
| * |
| * The size of a section in memory if normally given by VirtualSize. |
| * If VirtualSize is not provided, use SizeOfRawData. |
| * |
| * @sec: section header |
| * Return: size of section in memory |
| */ |
| static u32 section_size(IMAGE_SECTION_HEADER *sec) |
| { |
| if (sec->Misc.VirtualSize) |
| return sec->Misc.VirtualSize; |
| else |
| return sec->SizeOfRawData; |
| } |
| |
| /** |
| * efi_load_pe() - relocate EFI binary |
| * |
| * This function loads all sections from a PE binary into a newly reserved |
| * piece of memory. On success the entry point is returned as handle->entry. |
| * |
| * @handle: loaded image handle |
| * @efi: pointer to the EFI binary |
| * @efi_size: size of @efi binary |
| * @loaded_image_info: loaded image protocol |
| * Return: status code |
| */ |
| efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, |
| void *efi, size_t efi_size, |
| struct efi_loaded_image *loaded_image_info) |
| { |
| IMAGE_NT_HEADERS32 *nt; |
| IMAGE_DOS_HEADER *dos; |
| IMAGE_SECTION_HEADER *sections; |
| int num_sections; |
| void *efi_reloc; |
| int i; |
| const IMAGE_BASE_RELOCATION *rel; |
| unsigned long rel_size; |
| int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC; |
| uint64_t image_base; |
| unsigned long virt_size = 0; |
| int supported = 0; |
| efi_status_t ret; |
| |
| ret = efi_check_pe(efi, efi_size, (void **)&nt); |
| if (ret != EFI_SUCCESS) { |
| log_err("Not a PE-COFF file\n"); |
| return EFI_LOAD_ERROR; |
| } |
| |
| for (i = 0; machines[i]; i++) |
| if (machines[i] == nt->FileHeader.Machine) { |
| supported = 1; |
| break; |
| } |
| |
| if (!supported) { |
| log_err("Machine type 0x%04x is not supported\n", |
| nt->FileHeader.Machine); |
| return EFI_LOAD_ERROR; |
| } |
| |
| num_sections = nt->FileHeader.NumberOfSections; |
| sections = (void *)&nt->OptionalHeader + |
| nt->FileHeader.SizeOfOptionalHeader; |
| |
| if (efi_size < ((void *)sections + sizeof(sections[0]) * num_sections |
| - efi)) { |
| log_err("Invalid number of sections: %d\n", num_sections); |
| return EFI_LOAD_ERROR; |
| } |
| |
| /* Authenticate an image */ |
| if (efi_image_authenticate(efi, efi_size)) { |
| handle->auth_status = EFI_IMAGE_AUTH_PASSED; |
| } else { |
| handle->auth_status = EFI_IMAGE_AUTH_FAILED; |
| log_err("Image not authenticated\n"); |
| } |
| |
| /* Calculate upper virtual address boundary */ |
| for (i = num_sections - 1; i >= 0; i--) { |
| IMAGE_SECTION_HEADER *sec = §ions[i]; |
| |
| virt_size = max_t(unsigned long, virt_size, |
| sec->VirtualAddress + section_size(sec)); |
| } |
| |
| /* Read 32/64bit specific header bits */ |
| if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) { |
| IMAGE_NT_HEADERS64 *nt64 = (void *)nt; |
| IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader; |
| image_base = opt->ImageBase; |
| efi_set_code_and_data_type(loaded_image_info, opt->Subsystem); |
| handle->image_type = opt->Subsystem; |
| efi_reloc = efi_alloc_aligned_pages(virt_size, |
| loaded_image_info->image_code_type, |
| opt->SectionAlignment); |
| if (!efi_reloc) { |
| log_err("Out of memory\n"); |
| ret = EFI_OUT_OF_RESOURCES; |
| goto err; |
| } |
| handle->entry = efi_reloc + opt->AddressOfEntryPoint; |
| rel_size = opt->DataDirectory[rel_idx].Size; |
| rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress; |
| } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) { |
| IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader; |
| image_base = opt->ImageBase; |
| efi_set_code_and_data_type(loaded_image_info, opt->Subsystem); |
| handle->image_type = opt->Subsystem; |
| efi_reloc = efi_alloc_aligned_pages(virt_size, |
| loaded_image_info->image_code_type, |
| opt->SectionAlignment); |
| if (!efi_reloc) { |
| log_err("Out of memory\n"); |
| ret = EFI_OUT_OF_RESOURCES; |
| goto err; |
| } |
| handle->entry = efi_reloc + opt->AddressOfEntryPoint; |
| rel_size = opt->DataDirectory[rel_idx].Size; |
| rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress; |
| } else { |
| log_err("Invalid optional header magic %x\n", |
| nt->OptionalHeader.Magic); |
| ret = EFI_LOAD_ERROR; |
| goto err; |
| } |
| |
| #if CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL) |
| /* Measure an PE/COFF image */ |
| ret = tcg2_measure_pe_image(efi, efi_size, handle, loaded_image_info); |
| if (ret == EFI_SECURITY_VIOLATION) { |
| /* |
| * TCG2 Protocol is installed but no TPM device found, |
| * this is not expected. |
| */ |
| log_err("PE image measurement failed, no tpm device found\n"); |
| goto err; |
| } |
| |
| #endif |
| |
| /* Copy PE headers */ |
| memcpy(efi_reloc, efi, |
| sizeof(*dos) |
| + sizeof(*nt) |
| + nt->FileHeader.SizeOfOptionalHeader |
| + num_sections * sizeof(IMAGE_SECTION_HEADER)); |
| |
| /* Load sections into RAM */ |
| for (i = num_sections - 1; i >= 0; i--) { |
| IMAGE_SECTION_HEADER *sec = §ions[i]; |
| u32 copy_size = section_size(sec); |
| |
| if (copy_size > sec->SizeOfRawData) { |
| copy_size = sec->SizeOfRawData; |
| memset(efi_reloc + sec->VirtualAddress, 0, |
| sec->Misc.VirtualSize); |
| } |
| memcpy(efi_reloc + sec->VirtualAddress, |
| efi + sec->PointerToRawData, |
| copy_size); |
| } |
| |
| /* Run through relocations */ |
| if (efi_loader_relocate(rel, rel_size, efi_reloc, |
| (unsigned long)image_base) != EFI_SUCCESS) { |
| efi_free_pages((uintptr_t) efi_reloc, |
| (virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT); |
| ret = EFI_LOAD_ERROR; |
| goto err; |
| } |
| |
| /* Flush cache */ |
| flush_cache((ulong)efi_reloc, |
| ALIGN(virt_size, EFI_CACHELINE_SIZE)); |
| invalidate_icache_all(); |
| |
| /* Populate the loaded image interface bits */ |
| loaded_image_info->image_base = efi_reloc; |
| loaded_image_info->image_size = virt_size; |
| |
| if (handle->auth_status == EFI_IMAGE_AUTH_PASSED) |
| return EFI_SUCCESS; |
| else |
| return EFI_SECURITY_VIOLATION; |
| |
| err: |
| return ret; |
| } |