On 26.05.21 05:09, 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.
>
> Acked-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
> Tested-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
> Signed-off-by: Masahisa Kojima <masahisa.koj...@linaro.org>
> ---
>
> Changes in v9:
> - use original return code from __get_active_pcr_banks()
> - return EFI_UNSUPPORTED instead of EFI_INVALID_PARAMETER
> if efi_image_parse() fails, it complies with TCG spec
> - remove **new_efi parameter from efi_prepare_aligned_image()
> to improve the readability
>
> (no changes since v7)
>
> Changes in v7:
> - include hash-checksum.h instead of rsa.h
> - select HASH_CALCULATE in Kconfig, not to update lib/Makefile
> - rebased the base code
>
> Changes in v6:
> - update lib/Makefile to add hash-checksum.c as a compilation target
>
> (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/Kconfig | 1 +
> lib/efi_loader/efi_image_loader.c | 62 ++++++---
> lib/efi_loader/efi_tcg2.c | 207 ++++++++++++++++++++++++++++--
> 6 files changed, 277 insertions(+), 26 deletions(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 522696d635..0a9c82a257 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,
> @@ -886,6 +890,8 @@ bool efi_secure_boot_enabled(void);
>
> bool efi_capsule_auth_enabled(void);
>
> +void *efi_prepare_aligned_image(void *efi, u64 *efi_size);
> +
> 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 7de7d6a57d..247b386967 100644
> --- a/include/tpm-v2.h
> +++ b/include/tpm-v2.h
> @@ -70,6 +70,24 @@ struct udevice;
> #define EV_TABLE_OF_DEVICES ((u32)0x0000000B)
> #define EV_COMPACT_HASH ((u32)0x0000000C)
>
> +/*
> + * 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/Kconfig b/lib/efi_loader/Kconfig
> index 98845b8ba3..0e6200fa25 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -309,6 +309,7 @@ config EFI_TCG2_PROTOCOL
> select SHA512_ALGO
> select SHA384
> select SHA512
> + select HASH_CALCULATE
> help
> Provide a EFI_TCG2_PROTOCOL implementation using the TPM hardware
> of the platform.
> diff --git a/lib/efi_loader/efi_image_loader.c
> b/lib/efi_loader/efi_image_loader.c
> index fe1ee198e2..bcd57f7fcc 100644
> --- a/lib/efi_loader/efi_image_loader.c
> +++ b/lib/efi_loader/efi_image_loader.c
> @@ -302,6 +302,38 @@ 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
> + *
> + * 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
> @@ -561,7 +593,7 @@ 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);
> @@ -569,21 +601,11 @@ 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;
> - }
> + new_efi = efi_prepare_aligned_image(efi, (u64 *)&efi_size);
> + if (!new_efi)
> + return false;
>
> - if (!efi_image_parse(efi, efi_size, ®s, &wincerts,
> + if (!efi_image_parse(new_efi, efi_size, ®s, &wincerts,
> &wincerts_len)) {
> EFI_PRINT("Parsing PE executable image failed\n");
> goto err;
> @@ -725,7 +747,8 @@ err:
> efi_sigstore_free(dbx);
> pkcs7_free_message(msg);
> free(regs);
> - free(new_efi);
> + if (new_efi != efi)
> + free(new_efi);
>
> EFI_PRINT("%s: Exit, %d\n", __func__, ret);
> return ret;
> @@ -891,6 +914,13 @@ 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 39074f7547..3dd417aa27 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/hash-checksum.h>
> #include <u-boot/sha1.h>
> #include <u-boot/sha256.h>
> #include <u-boot/sha512.h>
> @@ -707,6 +709,183 @@ 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;
> +
> + new_efi = efi_prepare_aligned_image(efi, &efi_size);
> + if (!new_efi)
> + return EFI_OUT_OF_RESOURCES;
> +
> + if (!efi_image_parse(new_efi, efi_size, ®s, &wincerts,
> + &wincerts_len)) {
> + log_err("Parsing PE executable image failed\n");
> + ret = EFI_UNSUPPORTED;
> + goto out;
> + }
> +
> + ret = __get_active_pcr_banks(&active);
> + if (ret != EFI_SUCCESS) {
> + 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:
> + if (new_efi != efi)
> + 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_hash_pe_image((void *)data_to_hash, data_to_hash_len,
> + &digest_list);
Compiling on a 32bit system fails:
https://source.denx.de/u-boot/custodians/u-boot-efi/-/jobs/273092
I hope the following applied on top catches all the reported issues:
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 3dd417aa27..47bc371477 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -853,7 +853,7 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64
efi_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_location_in_memory = (uintptr_t)efi;
image_load_event->image_length_in_memory = efi_size;
image_load_event->length_of_device_path = device_path_length;
@@ -944,14 +944,14 @@ efi_tcg2_hash_log_extend_event(struct
efi_tcg2_protocol *this, u64 flags,
if (flags & PE_COFF_IMAGE) {
IMAGE_NT_HEADERS32 *nt;
- ret = efi_check_pe((void *)data_to_hash, data_to_hash_len,
- (void **)&nt);
+ ret = efi_check_pe((void *)(uintptr_t)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_hash_pe_image((void *)data_to_hash,
data_to_hash_len,
- &digest_list);
+ ret = tcg2_hash_pe_image((void *)(uintptr_t)data_to_hash,
+ data_to_hash_len, &digest_list);
} else {
ret = tcg2_create_digest((u8 *)(uintptr_t)data_to_hash,
data_to_hash_len, &digest_list);
Best regards
Heinrich
> + } else {
> + ret = tcg2_create_digest((u8 *)(uintptr_t)data_to_hash,
> + data_to_hash_len, &digest_list);
> + }
>
> - ret = tcg2_create_digest((u8 *)(uintptr_t)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;
>
