"TCG PC Client Platform Firmware Profile Specification" requires to measure every attempt to load and execute a OS Loader(a UEFI application) into PCR[4]. This commit adds the PE/COFF image measurement, extends PCR, and appends measurement into Event Log.
Signed-off-by: Masahisa Kojima masahisa.kojima@linaro.org ---
(no changes since v2)
Changes in v2: - Remove duplicate <efi.h> include - Remove unnecessary __packed attribute - Add all EV_EFI_* event definition - Create common function to prepare 8-byte aligned image - Add measurement for EV_EFI_BOOT_SERVICES_DRIVER and EV_EFI_RUNTIME_SERVICES_DRIVER - Use efi_search_protocol() to get device_path - Add function comment
include/efi_loader.h | 6 + include/efi_tcg2.h | 9 ++ include/tpm-v2.h | 18 +++ lib/efi_loader/efi_image_loader.c | 59 +++++++-- lib/efi_loader/efi_tcg2.c | 207 ++++++++++++++++++++++++++++-- 5 files changed, 275 insertions(+), 24 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h index de1a496a97..9f2854a255 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -426,6 +426,10 @@ efi_status_t efi_disk_register(void); efi_status_t efi_rng_register(void); /* Called by efi_init_obj_list() to install EFI_TCG2_PROTOCOL */ efi_status_t efi_tcg2_register(void); +/* measure the pe-coff image, extend PCR and add Event Log */ +efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size, + struct efi_loaded_image_obj *handle, + struct efi_loaded_image *loaded_image_info); /* Create handles and protocols for the partitions of a block device */ int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc, const char *if_typename, int diskid, @@ -847,6 +851,8 @@ bool efi_secure_boot_enabled(void);
bool efi_capsule_auth_enabled(void);
+void *efi_prepare_aligned_image(void *efi, u64 *efi_size, void **new_efi); + bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp, WIN_CERTIFICATE **auth, size_t *auth_len);
diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h index 40e241ce31..bcfb98168a 100644 --- a/include/efi_tcg2.h +++ b/include/efi_tcg2.h @@ -9,6 +9,7 @@ #if !defined _EFI_TCG2_PROTOCOL_H_ #define _EFI_TCG2_PROTOCOL_H_
+#include <efi_api.h> #include <tpm-v2.h>
#define EFI_TCG2_PROTOCOL_GUID \ @@ -53,6 +54,14 @@ struct efi_tcg2_event { u8 event[]; } __packed;
+struct uefi_image_load_event { + efi_physical_addr_t image_location_in_memory; + u64 image_length_in_memory; + u64 image_link_time_address; + u64 length_of_device_path; + struct efi_device_path device_path[]; +}; + struct efi_tcg2_boot_service_capability { u8 size; struct efi_tcg2_version structure_version; diff --git a/include/tpm-v2.h b/include/tpm-v2.h index df67a196cf..6e812c017c 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -62,6 +62,24 @@ struct udevice; #define EV_CPU_MICROCODE ((u32)0x00000009) #define EV_TABLE_OF_DEVICES ((u32)0x0000000B)
+/* + * event types, cf. + * "TCG PC Client Platform Firmware Profile Specification", Family "2.0" + * rev 1.04, June 3, 2019 + */ +#define EV_EFI_EVENT_BASE ((u32)0x80000000) +#define EV_EFI_VARIABLE_DRIVER_CONFIG ((u32)0x80000001) +#define EV_EFI_VARIABLE_BOOT ((u32)0x80000002) +#define EV_EFI_BOOT_SERVICES_APPLICATION ((u32)0x80000003) +#define EV_EFI_BOOT_SERVICES_DRIVER ((u32)0x80000004) +#define EV_EFI_RUNTIME_SERVICES_DRIVER ((u32)0x80000005) +#define EV_EFI_GPT_EVENT ((u32)0x80000006) +#define EV_EFI_ACTION ((u32)0x80000007) +#define EV_EFI_PLATFORM_FIRMWARE_BLOB ((u32)0x80000008) +#define EV_EFI_HANDOFF_TABLES ((u32)0x80000009) +#define EV_EFI_HCRTM_EVENT ((u32)0x80000010) +#define EV_EFI_VARIABLE_AUTHORITY ((u32)0x800000E0) + /* TPMS_TAGGED_PROPERTY Structure */ struct tpms_tagged_property { u32 property; diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c index b8a790bcb9..cc548e1b88 100644 --- a/lib/efi_loader/efi_image_loader.c +++ b/lib/efi_loader/efi_image_loader.c @@ -302,6 +302,40 @@ static int cmp_pe_section(const void *arg1, const void *arg2) return 1; }
+/** + * efi_prepare_aligned_image() - prepare 8-byte aligned image + * @efi: pointer to the EFI binary + * @efi_size: size of @efi binary + * @new_efi: pointer to the newly allocated image + * + * If @efi is not 8-byte aligned, this function newly allocates + * the image buffer and updates @efi_size. + * + * Return: valid pointer to a image, return NULL if allocation fails. + */ +void *efi_prepare_aligned_image(void *efi, u64 *efi_size, void **new_efi) +{ + size_t new_efi_size; + void *p; + + /* + * 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); + p = calloc(new_efi_size, 1); + if (!p) + return NULL; + memcpy(p, efi, *efi_size); + *efi_size = new_efi_size; + *new_efi = p; + return p; + } else { + return efi; + } +} + /** * efi_image_parse() - parse a PE image * @efi: Pointer to image @@ -560,7 +594,7 @@ static bool efi_image_authenticate(void *efi, size_t efi_size) struct efi_signature_store *db = NULL, *dbx = NULL; void *new_efi = NULL; u8 *auth, *wincerts_end; - size_t new_efi_size, auth_size; + size_t auth_size; bool ret = false;
EFI_PRINT("%s: Enter, %d\n", __func__, ret); @@ -571,19 +605,9 @@ static bool efi_image_authenticate(void *efi, size_t efi_size) if (!efi_secure_boot_enabled()) return true;
- /* - * Size must be 8-byte aligned and the trailing bytes must be - * zero'ed. Otherwise hash value may be incorrect. - */ - if (efi_size & 0x7) { - new_efi_size = (efi_size + 0x7) & ~0x7ULL; - new_efi = calloc(new_efi_size, 1); - if (!new_efi) - return false; - memcpy(new_efi, efi, efi_size); - efi = new_efi; - efi_size = new_efi_size; - } + efi = efi_prepare_aligned_image(efi, (u64 *)&efi_size, &new_efi); + if (!efi) + return false;
if (!efi_image_parse(efi, efi_size, ®s, &wincerts, &wincerts_len)) { @@ -886,6 +910,13 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, goto err; }
+#if CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL) + /* Measure an PE/COFF image */ + if (tcg2_measure_pe_image(efi, efi_size, handle, + loaded_image_info)) + log_err("PE image measurement failed\n"); +#endif + /* Copy PE headers */ memcpy(efi_reloc, efi, sizeof(*dos) diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 94e8f22bbb..7ad9cb2b89 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -13,8 +13,10 @@ #include <efi_loader.h> #include <efi_tcg2.h> #include <log.h> +#include <malloc.h> #include <version.h> #include <tpm-v2.h> +#include <u-boot/rsa.h> #include <u-boot/sha1.h> #include <u-boot/sha256.h> #include <u-boot/sha512.h> @@ -706,6 +708,183 @@ out: return EFI_EXIT(ret); }
+/** + * tcg2_hash_pe_image() - calculate PE/COFF image hash + * + * @efi: pointer to the EFI binary + * @efi_size: size of @efi binary + * @digest_list: list of digest algorithms to extend + * + * Return: status code + */ +static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size, + struct tpml_digest_values *digest_list) +{ + WIN_CERTIFICATE *wincerts = NULL; + size_t wincerts_len; + struct efi_image_regions *regs = NULL; + void *new_efi = NULL; + u8 hash[TPM2_SHA512_DIGEST_SIZE]; + efi_status_t ret; + u32 active; + int i; + + efi = efi_prepare_aligned_image(efi, &efi_size, &new_efi); + if (!efi) + return EFI_OUT_OF_RESOURCES; + + if (!efi_image_parse(efi, efi_size, ®s, &wincerts, + &wincerts_len)) { + log_err("Parsing PE executable image failed\n"); + ret = EFI_INVALID_PARAMETER; + goto out; + } + + ret = __get_active_pcr_banks(&active); + if (ret != EFI_SUCCESS) { + ret = EFI_DEVICE_ERROR; + goto out; + } + + digest_list->count = 0; + for (i = 0; i < MAX_HASH_COUNT; i++) { + u16 hash_alg = hash_algo_list[i].hash_alg; + + if (!(active & alg_to_mask(hash_alg))) + continue; + switch (hash_alg) { + case TPM2_ALG_SHA1: + hash_calculate("sha1", regs->reg, regs->num, hash); + break; + case TPM2_ALG_SHA256: + hash_calculate("sha256", regs->reg, regs->num, hash); + break; + case TPM2_ALG_SHA384: + hash_calculate("sha384", regs->reg, regs->num, hash); + break; + case TPM2_ALG_SHA512: + hash_calculate("sha512", regs->reg, regs->num, hash); + break; + default: + EFI_PRINT("Unsupported algorithm %x\n", hash_alg); + return EFI_INVALID_PARAMETER; + } + digest_list->digests[i].hash_alg = hash_alg; + memcpy(&digest_list->digests[i].digest, hash, (u32)alg_to_len(hash_alg)); + digest_list->count++; + } + +out: + free(new_efi); + free(regs); + + return ret; +} + +/** + * tcg2_measure_pe_image() - measure PE/COFF image + * + * @efi: pointer to the EFI binary + * @efi_size: size of @efi binary + * @handle: loaded image handle + * @loaded_image: loaded image protocol + * + * Return: status code + */ +efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size, + struct efi_loaded_image_obj *handle, + struct efi_loaded_image *loaded_image) +{ + struct tpml_digest_values digest_list; + efi_status_t ret; + struct udevice *dev; + u32 pcr_index, event_type, event_size; + struct uefi_image_load_event *image_load_event; + struct efi_device_path *device_path; + u32 device_path_length; + IMAGE_DOS_HEADER *dos; + IMAGE_NT_HEADERS32 *nt; + struct efi_handler *handler; + + ret = platform_get_tpm2_device(&dev); + if (ret != EFI_SUCCESS) + return ret; + + switch (handle->image_type) { + case IMAGE_SUBSYSTEM_EFI_APPLICATION: + pcr_index = 4; + event_type = EV_EFI_BOOT_SERVICES_APPLICATION; + break; + case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER: + pcr_index = 2; + event_type = EV_EFI_BOOT_SERVICES_DRIVER; + break; + case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER: + pcr_index = 2; + event_type = EV_EFI_RUNTIME_SERVICES_DRIVER; + break; + default: + return EFI_UNSUPPORTED; + } + + ret = tcg2_hash_pe_image(efi, efi_size, &digest_list); + if (ret != EFI_SUCCESS) + return ret; + + ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); + if (ret != EFI_SUCCESS) + return ret; + + ret = EFI_CALL(efi_search_protocol(&handle->header, + &efi_guid_loaded_image_device_path, + &handler)); + if (ret != EFI_SUCCESS) + return ret; + + device_path = EFI_CALL(handler->protocol_interface); + device_path_length = efi_dp_size(device_path); + if (device_path_length > 0) { + /* add end node size */ + device_path_length += sizeof(struct efi_device_path); + } + event_size = sizeof(struct uefi_image_load_event) + device_path_length; + image_load_event = (struct uefi_image_load_event *)malloc(event_size); + if (!image_load_event) + return EFI_OUT_OF_RESOURCES; + + image_load_event->image_location_in_memory = (efi_physical_addr_t)efi; + image_load_event->image_length_in_memory = efi_size; + image_load_event->length_of_device_path = device_path_length; + + dos = (IMAGE_DOS_HEADER *)efi; + nt = (IMAGE_NT_HEADERS32 *)(efi + dos->e_lfanew); + if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) { + IMAGE_NT_HEADERS64 *nt64 = (IMAGE_NT_HEADERS64 *)nt; + + image_load_event->image_link_time_address = + nt64->OptionalHeader.ImageBase; + } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) { + image_load_event->image_link_time_address = + nt->OptionalHeader.ImageBase; + } else { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + if (device_path_length > 0) { + memcpy(image_load_event->device_path, device_path, + device_path_length); + } + + ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list, + event_size, (u8 *)image_load_event); + +out: + free(image_load_event); + + return ret; +} + /** * efi_tcg2_hash_log_extend_event() - extend and optionally log events * @@ -758,24 +937,32 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags, /* * if PE_COFF_IMAGE is set we need to make sure the image is not * corrupted, verify it and hash the PE/COFF image in accordance with - * the procedure specified in "Calculating the PE Image Hash" - * section of the "Windows Authenticode Portable Executable Signature + * the procedure specified in "Calculating the PE Image Hash" + * section of the "Windows Authenticode Portable Executable Signature * Format" - * Not supported for now */ if (flags & PE_COFF_IMAGE) { - ret = EFI_UNSUPPORTED; - goto out; - } + IMAGE_NT_HEADERS32 *nt;
- pcr_index = efi_tcg_event->header.pcr_index; - event_type = efi_tcg_event->header.event_type; + ret = efi_check_pe((void *)data_to_hash, data_to_hash_len, + (void **)&nt); + if (ret != EFI_SUCCESS) { + log_err("Not a valid PE-COFF file\n"); + goto out; + }
- ret = tcg2_create_digest((u8 *)data_to_hash, data_to_hash_len, - &digest_list); + ret = tcg2_hash_pe_image((void *)data_to_hash, data_to_hash_len, + &digest_list); + } else { + ret = tcg2_create_digest((u8 *)data_to_hash, data_to_hash_len, + &digest_list); + } if (ret != EFI_SUCCESS) goto out;
+ pcr_index = efi_tcg_event->header.pcr_index; + event_type = efi_tcg_event->header.event_type; + ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); if (ret != EFI_SUCCESS) goto out;