From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masahisa Kojima Date: Thu, 22 Apr 2021 14:25:21 +0900 Subject: [PATCH 2/2] efi_loader: add PE/COFF image measurement In-Reply-To: <343a05e6-7a47-6c66-c1e1-f55451e6f65f@gmx.de> References: <20210415133020.29175-1-masahisa.kojima@linaro.org> <20210415133020.29175-3-masahisa.kojima@linaro.org> <343a05e6-7a47-6c66-c1e1-f55451e6f65f@gmx.de> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Heinrich, Thank you very much for your review comments. > > + ret = efi_check_pe(efi, efi_size, (void **)&nt); > Why are you calling this function? It is already called in efi_load_pe(). This is for the case that tcg2_hash_pe_image() is called from efi_tcg2_hash_log_extend_event(). Anyway, I will move efi_check_pe() call inside of efi_tcg2_hash_log_extend_event(). > > + if (!(active & alg_to_mask(hash_alg))) > > + continue; > > + switch (hash_alg) { > > + case TPM2_ALG_SHA1: > > SHA1 is known to be unsafe. Why would we support it? Basically I agree with removing SHA1 support. This efi_tcg2.c implementation aims to support TCG v2, so there is no reason to keep SHA1. Anyway, SHA1 is supported in tcg2_create_digest() for the measurement other than PE/COFF image. Do we also remove SHA1 from tcg2_create_digest()? For other comments, I will modify the code and send v2 patch. Thanks, Masahisa On Wed, 21 Apr 2021 at 19:57, Heinrich Schuchardt wrote: > > On 4/15/21 3:30 PM, Masahisa Kojima wrote: > > "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 > > --- > > include/efi_loader.h | 4 + > > include/efi_tcg2.h | 10 ++ > > include/tpm-v2.h | 1 + > > lib/efi_loader/efi_image_loader.c | 7 ++ > > lib/efi_loader/efi_tcg2.c | 187 ++++++++++++++++++++++++++++-- > > 5 files changed, 199 insertions(+), 10 deletions(-) > > > > diff --git a/include/efi_loader.h b/include/efi_loader.h > > index de1a496a97..b02bc93c8e 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, > > diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h > > index 40e241ce31..f8d46c5fd2 100644 > > --- a/include/efi_tcg2.h > > +++ b/include/efi_tcg2.h > > @@ -9,6 +9,8 @@ > > #if !defined _EFI_TCG2_PROTOCOL_H_ > > #define _EFI_TCG2_PROTOCOL_H_ > > > > +#include > > This include is already included in efi_api.h. > > > +#include > > #include > > > > #define EFI_TCG2_PROTOCOL_GUID \ > > @@ -53,6 +55,14 @@ 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[]; > > A device path is not an array of struct efi_device_path. But the first > element is of this type. So ok. > > > +} __packed; > > Why should this be __packed? You don't use arrays of this structure and > it is naturally packed. > > > + > > 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..ab9c04dc0a 100644 > > --- a/include/tpm-v2.h > > +++ b/include/tpm-v2.h > > @@ -61,6 +61,7 @@ struct udevice; > > #define EV_S_CRTM_VERSION ((u32)0x00000008) > > #define EV_CPU_MICROCODE ((u32)0x00000009) > > #define EV_TABLE_OF_DEVICES ((u32)0x0000000B) > > Please, add a comment here that the following values are defined in the > "TCG EFI Platform Specification". > > > +#define EV_EFI_BOOT_SERVICES_APPLICATION ((u32)0x80000003) > > Please, add all EV_EFI_* constants. > > > > > /* TPMS_TAGGED_PROPERTY Structure */ > > struct tpms_tagged_property { > > diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c > > index 2c35cb5651..b032ec5dd8 100644 > > --- a/lib/efi_loader/efi_image_loader.c > > +++ b/lib/efi_loader/efi_image_loader.c > > @@ -829,6 +829,13 @@ 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 ed86a220fb..9fab07605f 100644 > > --- a/lib/efi_loader/efi_tcg2.c > > +++ b/lib/efi_loader/efi_tcg2.c > > @@ -13,8 +13,10 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -709,6 +711,172 @@ out: > > return EFI_EXIT(ret); > > } > > > > +static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size, > > + struct tpml_digest_values *digest_list) > > +{ > > + IMAGE_NT_HEADERS32 *nt; > > + WIN_CERTIFICATE *wincerts = NULL; > > + size_t wincerts_len; > > + struct efi_image_regions *regs = NULL; > > + void *new_efi = NULL; > > + size_t new_efi_size; > > + u8 hash[TPM2_SHA512_DIGEST_SIZE]; > > + efi_status_t ret; > > + u32 active; > > + int i; > > + > > + ret = efi_check_pe(efi, efi_size, (void **)&nt); > Why are you calling this function? It is already called in efi_load_pe(). > > > + if (ret != EFI_SUCCESS) { > > + log_err("Not a valid PE-COFF file\n"); > > + return EFI_INVALID_PARAMETER; > > + } > > + > > + /* > > + * 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 EFI_OUT_OF_RESOURCES; > > + memcpy(new_efi, efi, efi_size); > > + efi = new_efi; > > + efi_size = new_efi_size; > > + } > > + > > + 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; > > + } > > Please, don't duplicate code from efi_image_authenticate(). Extract a > common function instead. > > > + > > + 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: > > SHA1 is known to be unsafe. Why would we support it? > > > + hash_calculate("sha1", regs->reg, regs->num, hash); > > + digest_list->count++; > > Why do you repeat this line in every case of the switch statement? > Please, put it below. > > > + break; > > + case TPM2_ALG_SHA256: > > + hash_calculate("sha256", regs->reg, regs->num, hash); > > + digest_list->count++; > > + break; > > + case TPM2_ALG_SHA384: > > + hash_calculate("sha384", regs->reg, regs->num, hash); > > + digest_list->count++; > > + break; > > + case TPM2_ALG_SHA512: > > + hash_calculate("sha512", regs->reg, regs->num, hash); > > + digest_list->count++; > > + 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)); > > + } > > + > > +out: > > + free(new_efi); > > + free(regs); > > + > > + return ret; > > +} > > + > > +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; > > + u8 *event; > > The variable event is not needed. You can use image_load_event directly. > > > + struct efi_device_path *device_path; > > + u32 device_path_length; > > + IMAGE_DOS_HEADER *dos; > > + IMAGE_NT_HEADERS32 *nt; > > + > > + ret = platform_get_tpm2_device(&dev); > > + if (ret != EFI_SUCCESS) > > + return ret; > > + > > + if (handle->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) { > > We should measure drivers too. Cf. > EV_EFI_BOOT_SERVICES_DRIVER, EV_EFI_RUNTIME_SERVICES_DRIVER. > > > + pcr_index = 4; > > + event_type = EV_EFI_BOOT_SERVICES_APPLICATION; > > + } else { > > + 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; > > + > > + loaded_image->system_table->boottime->handle_protocol(&handle->header, > > + &efi_guid_loaded_image_device_path, > > + (void **)&device_path); > > You would have to use EFI_CALL() here. > > Please, use efi_search_protocol() instead of all this indirection. > > Best regards > > Heinrich > > > + 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; > > + event = malloc(event_size); > > + if (!event) > > + return EFI_OUT_OF_RESOURCES; > > + > > + image_load_event = (struct uefi_image_load_event *)event; > > + 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, event); > > + > > +out: > > + free(event); > > + > > + return ret; > > +} > > + > > /** > > * efi_tcg2_hash_log_extend_event() - extend and optionally log events > > * > > @@ -761,24 +929,23 @@ 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; > > + 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_create_digest((u8 *)data_to_hash, data_to_hash_len, > > - &digest_list); > > - if (ret != EFI_SUCCESS) > > - goto out; > > - > > ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); > > if (ret != EFI_SUCCESS) > > goto out; > > >