[PATCH v6 3/6] tpm: Support boot measurements
Eddie James
eajames at linux.ibm.com
Thu Feb 23 18:52:53 CET 2023
On 2/23/23 03:47, Ilias Apalodimas wrote:
> On Thu, 23 Feb 2023 at 11:30, Ilias Apalodimas
> <ilias.apalodimas at linaro.org> wrote:
>> On Thu, 23 Feb 2023 at 11:02, Ilias Apalodimas
>> <ilias.apalodimas at linaro.org> wrote:
>>> Hi Eddie,
>>>
>>> final_event->number_of_events++;
>>>> @@ -350,66 +142,6 @@ static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type,
>>>> return ret;
>>>> }
>>>>
>>>> -/**
>>>> - * platform_get_tpm_device() - retrieve TPM device
>>>> - *
>>>> - * This function retrieves the udevice implementing a TPM
>>>> - *
>>>> - * This function may be overridden if special initialization is needed.
>>>> - *
>>>> - * @dev: udevice
>>>> - * Return: status code
>>>> - */
>>>> -__weak efi_status_t platform_get_tpm2_device(struct udevice **dev)
>>>> -{
>>>> - for_each_tpm_device(*dev) {
>>>> - /* Only support TPMv2 devices */
>>>> - if (tpm_get_version(*dev) == TPM_V2)
>>>> - return EFI_SUCCESS;
>>>> - }
>>>> -
>>>> - return EFI_NOT_FOUND;
>>>> -}
>>>> -
>>>> -/**
>>>> - * platform_get_eventlog() - retrieve the eventlog address and size
>>>> - *
>>>> - * This function retrieves the eventlog address and size if the underlying
>>>> - * firmware has done some measurements and passed them.
>>>> - *
>>>> - * This function may be overridden based on platform specific method of
>>>> - * passing the eventlog address and size.
>>>> - *
>>>> - * @dev: udevice
>>>> - * @addr: eventlog address
>>>> - * @sz: eventlog size
>>>> - * Return: status code
>>>> - */
>>>> -__weak efi_status_t platform_get_eventlog(struct udevice *dev, u64 *addr,
>>>> - u32 *sz)
>>>> -{
>>>> - const u64 *basep;
>>>> - const u32 *sizep;
>>>> -
>>>> - basep = dev_read_prop(dev, "tpm_event_log_addr", NULL);
>>>> - if (!basep)
>>>> - return EFI_NOT_FOUND;
>>>> -
>>>> - *addr = be64_to_cpup((__force __be64 *)basep);
>>>> -
>>>> - sizep = dev_read_prop(dev, "tpm_event_log_size", NULL);
>>>> - if (!sizep)
>>>> - return EFI_NOT_FOUND;
>>>> -
>>>> - *sz = be32_to_cpup((__force __be32 *)sizep);
>>>> - if (*sz == 0) {
>>>> - log_debug("event log empty\n");
>>>> - return EFI_NOT_FOUND;
>>>> - }
>>>> -
>>>> - return EFI_SUCCESS;
>>>> -}
>>>> -
>>>> /**
>>>> * tpm2_get_max_command_size() - get the supported max command size
>>>> *
>>>> @@ -485,239 +217,6 @@ static int tpm2_get_manufacturer_id(struct udevice *dev, u32 *manufacturer_id)
>>>> return 0;
>>>> }
>>>>
>>>> -/**
>>>> - * tpm2_get_num_pcr() - get the number of PCRs
>>>> - *
>>>> - * @dev: TPM device
>>>> - * @manufacturer_id: output buffer for the number
>>>> - *
>>>> - * Return: 0 on success, -1 on error
>>>> - */
>>>> -static int tpm2_get_num_pcr(struct udevice *dev, u32 *num_pcr)
>>>> -{
>>>> - u8 response[TPM2_RESPONSE_BUFFER_SIZE];
>>>> - u32 ret;
>>>> -
>>>> - memset(response, 0, sizeof(response));
>>>> - ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES,
>>>> - TPM2_PT_PCR_COUNT, response, 1);
>>>> - if (ret)
>>>> - return -1;
>>>> -
>>>> - *num_pcr = get_unaligned_be32(response + properties_offset);
>>>> - if (*num_pcr > TPM2_MAX_PCRS)
>>>> - return -1;
>>>> -
>>>> - return 0;
>>>> -}
>>>> -
>>>> -/**
>>>> - * is_active_pcr() - Check if a supported algorithm is active
>>>> - *
>>>> - * @dev: TPM device
>>>> - * @selection: struct of PCR information
>>>> - *
>>>> - * Return: true if PCR is active
>>>> - */
>>>> -static bool is_active_pcr(struct tpms_pcr_selection *selection)
>>>> -{
>>>> - int i;
>>>> - /*
>>>> - * check the pcr_select. If at least one of the PCRs supports the
>>>> - * algorithm add it on the active ones
>>>> - */
>>>> - for (i = 0; i < selection->size_of_select; i++) {
>>>> - if (selection->pcr_select[i])
>>>> - return true;
>>>> - }
>>>> -
>>>> - return false;
>>>> -}
>>>> -
>>>> -/**
>>>> - * tpm2_get_pcr_info() - get the supported, active PCRs and number of banks
>>>> - *
>>>> - * @dev: TPM device
>>>> - * @supported_pcr: bitmask with the algorithms supported
>>>> - * @active_pcr: bitmask with the active algorithms
>>>> - * @pcr_banks: number of PCR banks
>>>> - *
>>>> - * Return: 0 on success, -1 on error
>>>> - */
>>>> -static int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr,
>>>> - u32 *active_pcr, u32 *pcr_banks)
>>>> -{
>>>> - u8 response[TPM2_RESPONSE_BUFFER_SIZE];
>>>> - struct tpml_pcr_selection pcrs;
>>>> - u32 ret, num_pcr;
>>>> - size_t i;
>>>> - int tpm_ret;
>>>> -
>>>> - *supported_pcr = 0;
>>>> - *active_pcr = 0;
>>>> - *pcr_banks = 0;
>>>> - memset(response, 0, sizeof(response));
>>>> - ret = tpm2_get_capability(dev, TPM2_CAP_PCRS, 0, response, 1);
>>>> - if (ret)
>>>> - goto out;
>>>> -
>>>> - pcrs.count = get_unaligned_be32(response);
>>>> - /*
>>>> - * We only support 5 algorithms for now so check against that
>>>> - * instead of TPM2_NUM_PCR_BANKS
>>>> - */
>>>> - if (pcrs.count > MAX_HASH_COUNT || pcrs.count < 1)
>>>> - goto out;
>>>> -
>>>> - tpm_ret = tpm2_get_num_pcr(dev, &num_pcr);
>>>> - if (tpm_ret)
>>>> - goto out;
>>>> -
>>>> - for (i = 0; i < pcrs.count; i++) {
>>>> - /*
>>>> - * Definition of TPMS_PCR_SELECTION Structure
>>>> - * hash: u16
>>>> - * size_of_select: u8
>>>> - * pcr_select: u8 array
>>>> - *
>>>> - * The offsets depend on the number of the device PCRs
>>>> - * so we have to calculate them based on that
>>>> - */
>>>> - u32 hash_offset = offsetof(struct tpml_pcr_selection, selection) +
>>>> - i * offsetof(struct tpms_pcr_selection, pcr_select) +
>>>> - i * ((num_pcr + 7) / 8);
>>>> - u32 size_select_offset =
>>>> - hash_offset + offsetof(struct tpms_pcr_selection,
>>>> - size_of_select);
>>>> - u32 pcr_select_offset =
>>>> - hash_offset + offsetof(struct tpms_pcr_selection,
>>>> - pcr_select);
>>>> -
>>>> - pcrs.selection[i].hash =
>>>> - get_unaligned_be16(response + hash_offset);
>>>> - pcrs.selection[i].size_of_select =
>>>> - __get_unaligned_be(response + size_select_offset);
>>>> - if (pcrs.selection[i].size_of_select > TPM2_PCR_SELECT_MAX)
>>>> - goto out;
>>>> - /* copy the array of pcr_select */
>>>> - memcpy(pcrs.selection[i].pcr_select, response + pcr_select_offset,
>>>> - pcrs.selection[i].size_of_select);
>>>> - }
>>>> -
>>>> - for (i = 0; i < pcrs.count; i++) {
>>>> - u32 hash_mask = alg_to_mask(pcrs.selection[i].hash);
>>>> -
>>>> - if (hash_mask) {
>>>> - *supported_pcr |= hash_mask;
>>>> - if (is_active_pcr(&pcrs.selection[i]))
>>>> - *active_pcr |= hash_mask;
>>>> - } else {
>>>> - EFI_PRINT("Unknown algorithm %x\n", pcrs.selection[i].hash);
>>>> - }
>>>> - }
>>>> -
>>>> - *pcr_banks = pcrs.count;
>>>> -
>>>> - return 0;
>>>> -out:
>>>> - return -1;
>>>> -}
>>>> -
>>>> -/**
>>>> - * __get_active_pcr_banks() - returns the currently active PCR banks
>>>> - *
>>>> - * @active_pcr_banks: pointer for receiving the bitmap of currently
>>>> - * active PCR banks
>>>> - *
>>>> - * Return: status code
>>>> - */
>>>> -static efi_status_t __get_active_pcr_banks(u32 *active_pcr_banks)
>>>> -{
>>>> - struct udevice *dev;
>>>> - u32 active = 0, supported = 0, pcr_banks = 0;
>>>> - efi_status_t ret;
>>>> - int err;
>>>> -
>>>> - ret = platform_get_tpm2_device(&dev);
>>>> - if (ret != EFI_SUCCESS)
>>>> - goto out;
>>>> -
>>>> - err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks);
>>>> - if (err) {
>>>> - ret = EFI_DEVICE_ERROR;
>>>> - goto out;
>>>> - }
>>>> -
>>>> - *active_pcr_banks = active;
>>>> -
>>>> -out:
>>>> - return ret;
>>>> -}
>>>> -
>>>> -/* tcg2_create_digest - create a list of digests of the supported PCR banks
>>>> - * for a given memory range
>>>> - *
>>>> - * @input: input memory
>>>> - * @length: length of buffer to calculate the digest
>>>> - * @digest_list: list of digests to fill in
>>>> - *
>>>> - * Return: status code
>>>> - */
>>>> -static efi_status_t tcg2_create_digest(const u8 *input, u32 length,
>>>> - struct tpml_digest_values *digest_list)
>>>> -{
>>>> - sha1_context ctx;
>>>> - sha256_context ctx_256;
>>>> - sha512_context ctx_512;
>>>> - u8 final[TPM2_SHA512_DIGEST_SIZE];
>>>> - efi_status_t ret;
>>>> - u32 active;
>>>> - size_t i;
>>>> -
>>>> - ret = __get_active_pcr_banks(&active);
>>>> - if (ret != EFI_SUCCESS)
>>>> - return ret;
>>>> -
>>>> - 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_starts(&ctx);
>>>> - sha1_update(&ctx, input, length);
>>>> - sha1_finish(&ctx, final);
>>>> - break;
>>>> - case TPM2_ALG_SHA256:
>>>> - sha256_starts(&ctx_256);
>>>> - sha256_update(&ctx_256, input, length);
>>>> - sha256_finish(&ctx_256, final);
>>>> - break;
>>>> - case TPM2_ALG_SHA384:
>>>> - sha384_starts(&ctx_512);
>>>> - sha384_update(&ctx_512, input, length);
>>>> - sha384_finish(&ctx_512, final);
>>>> - break;
>>>> - case TPM2_ALG_SHA512:
>>>> - sha512_starts(&ctx_512);
>>>> - sha512_update(&ctx_512, input, length);
>>>> - sha512_finish(&ctx_512, final);
>>>> - break;
>>>> - default:
>>>> - EFI_PRINT("Unsupported algorithm %x\n", hash_alg);
>>>> - return EFI_INVALID_PARAMETER;
>>>> - }
>>>> - digest_list->digests[digest_list->count].hash_alg = hash_alg;
>>>> - memcpy(&digest_list->digests[digest_list->count].digest, final,
>>>> - (u32)alg_to_len(hash_alg));
>>>> - digest_list->count++;
>>>> - }
>>>> -
>>>> - return EFI_SUCCESS;
>>>> -}
>>>> -
>>>> /**
>>>> * efi_tcg2_get_capability() - protocol capability information and state information
>>>> *
>>>> @@ -759,7 +258,7 @@ efi_tcg2_get_capability(struct efi_tcg2_protocol *this,
>>>> capability->protocol_version.major = 1;
>>>> capability->protocol_version.minor = 1;
>>>>
>>>> - efi_ret = platform_get_tpm2_device(&dev);
>>>> + efi_ret = tcg2_platform_get_tpm2(&dev);
>>>> if (efi_ret != EFI_SUCCESS) {
>>>> capability->supported_event_logs = 0;
>>>> capability->hash_algorithm_bitmap = 0;
>>>> @@ -855,7 +354,7 @@ efi_tcg2_get_eventlog(struct efi_tcg2_protocol *this,
>>>> goto out;
>>>> }
>>>>
>>>> - ret = platform_get_tpm2_device(&dev);
>>>> + ret = tcg2_platform_get_tpm2(&dev);
>>>> if (ret != EFI_SUCCESS) {
>>>> event_log_location = NULL;
>>>> event_log_last_entry = NULL;
>>>> @@ -890,6 +389,7 @@ static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size,
>>>> struct efi_image_regions *regs = NULL;
>>>> void *new_efi = NULL;
>>>> u8 hash[TPM2_SHA512_DIGEST_SIZE];
>>>> + struct udevice *dev;
>>>> efi_status_t ret;
>>>> u32 active;
>>>> int i;
>>>> @@ -905,16 +405,20 @@ static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size,
>>>> goto out;
>>>> }
>>>>
>>>> - ret = __get_active_pcr_banks(&active);
>>>> + ret = tcg2_platform_get_tpm2(&dev);
>>>> + if (ret != EFI_SUCCESS)
>>>> + goto out;
>>>> +
>>>> + ret = tcg2_get_active_pcr_banks(dev, &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;
>>>> + for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); i++) {
>>>> + u16 hash_alg = tpm2_supported_algorithms[i];
>>>>
>>>> - if (!(active & alg_to_mask(hash_alg)))
>>>> + if (!(active & tpm2_algorithm_to_mask(hash_alg)))
>>>> continue;
>>>> switch (hash_alg) {
>>>> case TPM2_ALG_SHA1:
>>>> @@ -935,7 +439,7 @@ static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size,
>>>> }
>>>> digest_list->digests[digest_list->count].hash_alg = hash_alg;
>>>> memcpy(&digest_list->digests[digest_list->count].digest, hash,
>>>> - (u32)alg_to_len(hash_alg));
>>>> + (u32)tpm2_algorithm_to_len(hash_alg));
>>>> digest_list->count++;
>>>> }
>>>>
>>>> @@ -975,7 +479,7 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
>>>> if (!is_tcg2_protocol_installed())
>>>> return EFI_SUCCESS;
>>>>
>>>> - ret = platform_get_tpm2_device(&dev);
>>>> + ret = tcg2_platform_get_tpm2(&dev);
>>>> if (ret != EFI_SUCCESS)
>>>> return EFI_SECURITY_VIOLATION;
>>>>
>>>> @@ -1084,7 +588,7 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags,
>>>> goto out;
>>>> }
>>>>
>>>> - ret = platform_get_tpm2_device(&dev);
>>>> + ret = tcg2_platform_get_tpm2(&dev);
>>>> if (ret != EFI_SUCCESS)
>>>> goto out;
>>>>
>>>> @@ -1119,7 +623,7 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags,
>>>> 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,
>>>> + ret = tcg2_create_digest(dev, (u8 *)(uintptr_t)data_to_hash,
>>>> data_to_hash_len, &digest_list);
>>>> }
>>>>
>>>> @@ -1182,7 +686,7 @@ efi_tcg2_submit_command(struct efi_tcg2_protocol *this,
>>>> goto out;
>>>> }
>>>>
>>>> - ret = platform_get_tpm2_device(&dev);
>>>> + ret = tcg2_platform_get_tpm2(&dev);
>>>> if (ret != EFI_SUCCESS)
>>>> goto out;
>>>>
>>>> @@ -1211,6 +715,7 @@ static efi_status_t EFIAPI
>>>> efi_tcg2_get_active_pcr_banks(struct efi_tcg2_protocol *this,
>>>> u32 *active_pcr_banks)
>>>> {
>>>> + struct udevice *dev;
>>>> efi_status_t ret;
>>>>
>>>> if (!this || !active_pcr_banks) {
>>>> @@ -1218,8 +723,12 @@ efi_tcg2_get_active_pcr_banks(struct efi_tcg2_protocol *this,
>>>> goto out;
>>>> }
>>>>
>>>> + ret = tcg2_platform_get_tpm2(&dev);
>>>> + if (ret != EFI_SUCCESS)
>>>> + goto out;
>>>> +
>>>> EFI_ENTRY("%p, %p", this, active_pcr_banks);
>>>> - ret = __get_active_pcr_banks(active_pcr_banks);
>>>> + ret = tcg2_get_active_pcr_banks(dev, active_pcr_banks);
>>>>
>>>> out:
>>>> return EFI_EXIT(ret);
>>>> @@ -1270,397 +779,6 @@ static const struct efi_tcg2_protocol efi_tcg2_protocol = {
>>>> .get_result_of_set_active_pcr_banks = efi_tcg2_get_result_of_set_active_pcr_banks,
>>>> };
>>>>
>>>> -/**
>>>> - * parse_event_log_header() - Parse and verify the event log header fields
>>>> - *
>>>> - * @buffer: Pointer to the start of the eventlog
>>>> - * @size: Size of the eventlog
>>>> - * @pos: Return offset of the next event in buffer right
>>>> - * after the event header i.e specID
>>>> - *
>>>> - * Return: status code
>>>> - */
>>>> -static efi_status_t parse_event_log_header(void *buffer, u32 size, u32 *pos)
>>>> -{
>>>> - struct tcg_pcr_event *event_header = (struct tcg_pcr_event *)buffer;
>>>> - int i = 0;
>>>> -
>>>> - if (size < sizeof(*event_header))
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - if (get_unaligned_le32(&event_header->pcr_index) != 0 ||
>>>> - get_unaligned_le32(&event_header->event_type) != EV_NO_ACTION)
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - for (i = 0; i < sizeof(event_header->digest); i++) {
>>>> - if (event_header->digest[i])
>>>> - return EFI_COMPROMISED_DATA;
>>>> - }
>>>> -
>>>> - *pos += sizeof(*event_header);
>>>> -
>>>> - return EFI_SUCCESS;
>>>> -}
>>>> -
>>>> -/**
>>>> - * parse_specid_event() - Parse and verify the specID Event in the eventlog
>>>> - *
>>>> - * @dev: udevice
>>>> - * @buffer: Pointer to the start of the eventlog
>>>> - * @log_size: Size of the eventlog
>>>> - * @pos: [in] Offset of specID event in the eventlog buffer
>>>> - * [out] Return offset of the next event in the buffer
>>>> - * after the specID
>>>> - * @digest_list: list of digests in the event
>>>> - *
>>>> - * Return: status code
>>>> - * @pos Offset in the eventlog where the specID event ends
>>>> - * @digest_list: list of digests in the event
>>>> - */
>>>> -static efi_status_t parse_specid_event(struct udevice *dev, void *buffer,
>>>> - u32 log_size, u32 *pos,
>>>> - struct tpml_digest_values *digest_list)
>>>> -{
>>>> - struct tcg_efi_spec_id_event *spec_event;
>>>> - struct tcg_pcr_event *event_header = (struct tcg_pcr_event *)buffer;
>>>> - size_t spec_event_size;
>>>> - u32 active = 0, supported = 0, pcr_count = 0, alg_count = 0;
>>>> - u32 spec_active = 0;
>>>> - u16 hash_alg;
>>>> - u8 vendor_sz;
>>>> - int err, i;
>>>> -
>>>> - if (*pos >= log_size || (*pos + sizeof(*spec_event)) > log_size)
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - /* Check specID event data */
>>>> - spec_event = (struct tcg_efi_spec_id_event *)((uintptr_t)buffer + *pos);
>>>> - /* Check for signature */
>>>> - if (memcmp(spec_event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03,
>>>> - sizeof(TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03))) {
>>>> - log_err("specID Event: Signature mismatch\n");
>>>> - return EFI_COMPROMISED_DATA;
>>>> - }
>>>> -
>>>> - if (spec_event->spec_version_minor !=
>>>> - TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 ||
>>>> - spec_event->spec_version_major !=
>>>> - TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2)
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - if (spec_event->number_of_algorithms > MAX_HASH_COUNT ||
>>>> - spec_event->number_of_algorithms < 1) {
>>>> - log_err("specID Event: Number of algorithms incorrect\n");
>>>> - return EFI_COMPROMISED_DATA;
>>>> - }
>>>> -
>>>> - alg_count = spec_event->number_of_algorithms;
>>>> -
>>>> - err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_count);
>>>> - if (err)
>>>> - return EFI_DEVICE_ERROR;
>>>> -
>>>> - digest_list->count = 0;
>>>> - /*
>>>> - * We have to take care that the sequence of algorithms that we record
>>>> - * in digest_list matches the sequence in eventlog.
>>>> - */
>>>> - for (i = 0; i < alg_count; i++) {
>>>> - hash_alg =
>>>> - get_unaligned_le16(&spec_event->digest_sizes[i].algorithm_id);
>>>> -
>>>> - if (!(supported & alg_to_mask(hash_alg))) {
>>>> - log_err("specID Event: Unsupported algorithm\n");
>>>> - return EFI_COMPROMISED_DATA;
>>>> - }
>>>> - digest_list->digests[digest_list->count++].hash_alg = hash_alg;
>>>> -
>>>> - spec_active |= alg_to_mask(hash_alg);
>>>> - }
>>>> -
>>>> - /*
>>>> - * TCG specification expects the event log to have hashes for all
>>>> - * active PCR's
>>>> - */
>>>> - if (spec_active != active) {
>>>> - /*
>>>> - * Previous stage bootloader should know all the active PCR's
>>>> - * and use them in the Eventlog.
>>>> - */
>>>> - log_err("specID Event: All active hash alg not present\n");
>>>> - return EFI_COMPROMISED_DATA;
>>>> - }
>>>> -
>>>> - /*
>>>> - * the size of the spec event and placement of vendor_info_size
>>>> - * depends on supported algoriths
>>>> - */
>>>> - spec_event_size =
>>>> - offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
>>>> - alg_count * sizeof(spec_event->digest_sizes[0]);
>>>> -
>>>> - if (*pos + spec_event_size >= log_size)
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - vendor_sz = *(uint8_t *)((uintptr_t)buffer + *pos + spec_event_size);
>>>> -
>>>> - spec_event_size += sizeof(vendor_sz) + vendor_sz;
>>>> - *pos += spec_event_size;
>>>> -
>>>> - if (get_unaligned_le32(&event_header->event_size) != spec_event_size) {
>>>> - log_err("specID event: header event size mismatch\n");
>>>> - /* Right way to handle this can be to call SetActive PCR's */
>>>> - return EFI_COMPROMISED_DATA;
>>>> - }
>>>> -
>>>> - return EFI_SUCCESS;
>>>> -}
>>>> -
>>>> -/**
>>>> - * tcg2_parse_event() - Parse the event in the eventlog
>>>> - *
>>>> - * @dev: udevice
>>>> - * @buffer: Pointer to the start of the eventlog
>>>> - * @log_size: Size of the eventlog
>>>> - * @offset: [in] Offset of the event in the eventlog buffer
>>>> - * [out] Return offset of the next event in the buffer
>>>> - * @digest_list: list of digests in the event
>>>> - * @pcr Index of the PCR in the event
>>>> - *
>>>> - * Return: status code
>>>> - */
>>>> -static efi_status_t tcg2_parse_event(struct udevice *dev, void *buffer,
>>>> - u32 log_size, u32 *offset,
>>>> - struct tpml_digest_values *digest_list,
>>>> - u32 *pcr)
>>>> -{
>>>> - struct tcg_pcr_event2 *event = NULL;
>>>> - u32 count, size, event_size;
>>>> - size_t pos;
>>>> -
>>>> - event_size = tcg_event_final_size(digest_list);
>>>> - if (*offset >= log_size || *offset + event_size > log_size) {
>>>> - log_err("Event exceeds log size\n");
>>>> - return EFI_COMPROMISED_DATA;
>>>> - }
>>>> -
>>>> - event = (struct tcg_pcr_event2 *)((uintptr_t)buffer + *offset);
>>>> - *pcr = get_unaligned_le32(&event->pcr_index);
>>>> -
>>>> - /* get the count */
>>>> - count = get_unaligned_le32(&event->digests.count);
>>>> - if (count != digest_list->count)
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - pos = offsetof(struct tcg_pcr_event2, digests);
>>>> - pos += offsetof(struct tpml_digest_values, digests);
>>>> -
>>>> - for (int i = 0; i < digest_list->count; i++) {
>>>> - u16 alg;
>>>> - u16 hash_alg = digest_list->digests[i].hash_alg;
>>>> - u8 *digest = (u8 *)&digest_list->digests[i].digest;
>>>> -
>>>> - alg = get_unaligned_le16((void *)((uintptr_t)event + pos));
>>>> -
>>>> - if (alg != hash_alg)
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - pos += offsetof(struct tpmt_ha, digest);
>>>> - memcpy(digest, (void *)((uintptr_t)event + pos), alg_to_len(hash_alg));
>>>> - pos += alg_to_len(hash_alg);
>>>> - }
>>>> -
>>>> - size = get_unaligned_le32((void *)((uintptr_t)event + pos));
>>>> - event_size += size;
>>>> - pos += sizeof(u32); /* tcg_pcr_event2 event_size*/
>>>> - pos += size;
>>>> -
>>>> - /* make sure the calculated buffer is what we checked against */
>>>> - if (pos != event_size)
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - if (pos > log_size)
>>>> - return EFI_COMPROMISED_DATA;
>>>> -
>>>> - *offset += pos;
>>>> -
>>>> - return EFI_SUCCESS;
>>>> -}
>>>> -
>>>> -/**
>>>> - * tcg2_get_fw_eventlog() - Get the eventlog address and size
>>>> - *
>>>> - * If the previous firmware has passed some eventlog, this function get it's
>>>> - * location and check for it's validity.
>>>> - *
>>>> - * @dev: udevice
>>>> - * @log_buffer: eventlog address
>>>> - * @log_sz: eventlog size
>>>> - *
>>>> - * Return: status code
>>>> - */
>>>> -static efi_status_t tcg2_get_fw_eventlog(struct udevice *dev, void *log_buffer,
>>>> - size_t *log_sz)
>>>> -{
>>>> - struct tpml_digest_values digest_list;
>>>> - void *buffer;
>>>> - efi_status_t ret;
>>>> - u32 pcr, pos;
>>>> - u64 base;
>>>> - u32 sz;
>>>> - bool extend_pcr = false;
>>>> - int i;
>>>> -
>>>> - ret = platform_get_eventlog(dev, &base, &sz);
>>>> - if (ret != EFI_SUCCESS)
>>>> - return ret;
>>>> -
>>>> - if (sz > TPM2_EVENT_LOG_SIZE)
>>>> - return EFI_VOLUME_FULL;
>>>> -
>>>> - buffer = (void *)(uintptr_t)base;
>>>> - pos = 0;
>>>> - /* Parse the eventlog to check for its validity */
>>>> - ret = parse_event_log_header(buffer, sz, &pos);
>>>> - if (ret)
>>>> - return ret;
>>>> -
>>>> - ret = parse_specid_event(dev, buffer, sz, &pos, &digest_list);
>>>> - if (ret) {
>>>> - log_err("Error parsing SPEC ID Event\n");
>>>> - return ret;
>>>> - }
>>>> -
>>>> - ret = tcg2_pcr_read(dev, 0, &digest_list);
>>>> - if (ret) {
>>>> - log_err("Error reading PCR 0\n");
>>>> - return ret;
>>>> - }
>>>> -
>>>> - /*
>>>> - * If PCR0 is 0, previous firmware didn't have the capability
>>>> - * to extend the PCR. In this scenario, extend the PCR as
>>>> - * the eventlog is parsed.
>>>> - */
>>>> - for (i = 0; i < digest_list.count; i++) {
>>>> - u8 hash_buf[TPM2_SHA512_DIGEST_SIZE] = { 0 };
>>>> - u16 hash_alg = digest_list.digests[i].hash_alg;
>>>> -
>>>> - if (!memcmp((u8 *)&digest_list.digests[i].digest, hash_buf,
>>>> - alg_to_len(hash_alg)))
>>>> - extend_pcr = true;
>>>> - }
>>>> -
>>>> - while (pos < sz) {
>>>> - ret = tcg2_parse_event(dev, buffer, sz, &pos, &digest_list,
>>>> - &pcr);
>>>> - if (ret) {
>>>> - log_err("Error parsing event\n");
>>>> - return ret;
>>>> - }
>>>> - if (extend_pcr) {
>>>> - ret = tcg2_pcr_extend(dev, pcr, &digest_list);
>>>> - if (ret != EFI_SUCCESS) {
>>>> - log_err("Error in extending PCR\n");
>>>> - return ret;
>>>> - }
>>>> -
>>>> - /* Clear the digest for next event */
>>>> - for (i = 0; i < digest_list.count; i++) {
>>>> - u16 hash_alg = digest_list.digests[i].hash_alg;
>>>> - u8 *digest =
>>>> - (u8 *)&digest_list.digests[i].digest;
>>>> -
>>>> - memset(digest, 0, alg_to_len(hash_alg));
>>>> - }
>>>> - }
>>>> - }
>>>> -
>>>> - memcpy(log_buffer, buffer, sz);
>>>> - *log_sz = sz;
>>>> -
>>>> - return ret;
>>>> -}
>>>> -
>>>> -/**
>>>> - * create_specid_event() - Create the first event in the eventlog
>>>> - *
>>>> - * @dev: tpm device
>>>> - * @event_header: Pointer to the final event header
>>>> - * @event_size: final spec event size
>>>> - *
>>>> - * Return: status code
>>>> - */
>>>> -static efi_status_t create_specid_event(struct udevice *dev, void *buffer,
>>>> - size_t *event_size)
>>>> -{
>>>> - struct tcg_efi_spec_id_event *spec_event;
>>>> - size_t spec_event_size;
>>>> - efi_status_t ret = EFI_DEVICE_ERROR;
>>>> - u32 active = 0, supported = 0, pcr_count = 0, alg_count = 0;
>>>> - int err;
>>>> - size_t i;
>>>> -
>>>> - /*
>>>> - * Create Spec event. This needs to be the first event in the log
>>>> - * according to the TCG EFI protocol spec
>>>> - */
>>>> -
>>>> - /* Setup specID event data */
>>>> - spec_event = (struct tcg_efi_spec_id_event *)buffer;
>>>> - memcpy(spec_event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03,
>>>> - sizeof(spec_event->signature));
>>>> - put_unaligned_le32(0, &spec_event->platform_class); /* type client */
>>>> - spec_event->spec_version_minor =
>>>> - TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2;
>>>> - spec_event->spec_version_major =
>>>> - TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2;
>>>> - spec_event->spec_errata =
>>>> - TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2;
>>>> - spec_event->uintn_size = sizeof(efi_uintn_t) / sizeof(u32);
>>>> -
>>>> - err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_count);
>>>> -
>>>> - if (err)
>>>> - goto out;
>>>> -
>>>> - for (i = 0; i < pcr_count; i++) {
>>>> - u16 hash_alg = hash_algo_list[i].hash_alg;
>>>> - u16 hash_len = hash_algo_list[i].hash_len;
>>>> -
>>>> - if (active & alg_to_mask(hash_alg)) {
>>>> - put_unaligned_le16(hash_alg,
>>>> - &spec_event->digest_sizes[alg_count].algorithm_id);
>>>> - put_unaligned_le16(hash_len,
>>>> - &spec_event->digest_sizes[alg_count].digest_size);
>>>> - alg_count++;
>>>> - }
>>>> - }
>>>> -
>>>> - spec_event->number_of_algorithms = alg_count;
>>>> - if (spec_event->number_of_algorithms > MAX_HASH_COUNT ||
>>>> - spec_event->number_of_algorithms < 1)
>>>> - goto out;
>>>> -
>>>> - /*
>>>> - * the size of the spec event and placement of vendor_info_size
>>>> - * depends on supported algoriths
>>>> - */
>>>> - spec_event_size =
>>>> - offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
>>>> - spec_event->number_of_algorithms * sizeof(spec_event->digest_sizes[0]);
>>>> - /* no vendor info for us */
>>>> - memset(buffer + spec_event_size, 0, 1);
>>>> - /* add a byte for vendor_info_size in the spec event */
>>>> - spec_event_size += 1;
>>>> - *event_size = spec_event_size;
>>>> -
>>>> - return EFI_SUCCESS;
>>>> -
>>>> -out:
>>>> - return ret;
>>>> -}
>>>> -
>>>> /**
>>>> * tcg2_uninit - remove the final event table and free efi memory on failures
>>>> */
>>>> @@ -1722,7 +840,7 @@ out:
>>>> }
>>>>
>>>> /**
>>>> - * tcg2_measure_event() - common function to add event log and extend PCR
>>>> + * measure_event() - common function to add event log and extend PCR
>>>> *
>>>> * @dev: TPM device
>>>> * @pcr_index: PCR index
>>>> @@ -1732,14 +850,13 @@ out:
>>>> *
>>>> * Return: status code
>>>> */
>>>> -static efi_status_t
>>>> -tcg2_measure_event(struct udevice *dev, u32 pcr_index, u32 event_type,
>>>> - u32 size, u8 event[])
>>>> +static efi_status_t measure_event(struct udevice *dev, u32 pcr_index,
>>>> + u32 event_type, u32 size, u8 event[])
>>>> {
>>>> struct tpml_digest_values digest_list;
>>>> efi_status_t ret;
>>>>
>>>> - ret = tcg2_create_digest(event, size, &digest_list);
>>>> + ret = tcg2_create_digest(dev, event, size, &digest_list);
>>>> if (ret != EFI_SUCCESS)
>>>> goto out;
>>>>
>>>> @@ -1766,9 +883,8 @@ static efi_status_t efi_append_scrtm_version(struct udevice *dev)
>>>> {
>>>> efi_status_t ret;
>>>>
>>>> - ret = tcg2_measure_event(dev, 0, EV_S_CRTM_VERSION,
>>>> - strlen(version_string) + 1,
>>>> - (u8 *)version_string);
>>>> + ret = measure_event(dev, 0, EV_S_CRTM_VERSION,
>>>> + strlen(version_string) + 1, (u8 *)version_string);
>>>>
>>>> return ret;
>>>> }
>>>> @@ -1784,12 +900,11 @@ static efi_status_t efi_init_event_log(void)
>>>> * vendor_info_size is currently set to 0, we need to change the length
>>>> * and allocate the flexible array member if this changes
>>>> */
>>>> - struct tcg_pcr_event *event_header = NULL;
>>>> + struct tcg2_event_log elog;
>>>> struct udevice *dev;
>>>> - size_t spec_event_size;
>>>> efi_status_t ret;
>>>>
>>>> - ret = platform_get_tpm2_device(&dev);
>>>> + ret = tcg2_platform_get_tpm2(&dev);
>>>> if (ret != EFI_SUCCESS)
>>>> return ret;
>>>>
>>>> @@ -1808,7 +923,6 @@ static efi_status_t efi_init_event_log(void)
>>>> * The log header is defined to be in SHA1 event log entry format.
>>>> * Setup event header
>>>> */
>>>> - event_header = (struct tcg_pcr_event *)event_log.buffer;
>>>> event_log.pos = 0;
>>>> event_log.last_event_size = 0;
>>>> event_log.get_event_called = false;
>>>> @@ -1819,34 +933,19 @@ static efi_status_t efi_init_event_log(void)
>>>> * Check if earlier firmware have passed any eventlog. Different
>>>> * platforms can use different ways to do so.
>>>> */
>>>> - ret = tcg2_get_fw_eventlog(dev, event_log.buffer, &event_log.pos);
>>>> + ret = tcg2_init_log(dev, &elog);
>>>> + if (ret != EFI_SUCCESS)
>>>> + goto free_pool;
>>> So I think this is the last bit we need to change in order to support EFI
>>> properly. I read the email regarding the newly added reserved memory memory
>>> to the TPM node and it's fine, but that won't work for the existing U-Boot
>>> dtbs. Since this was working out of the box, I'd still prefer to keep that
>>> working even if that entry is missing.
>>>
>>> If you look at this function, there is an efi_allocate_pool() call a few
>>> lines above. What this does is allocate the EventLog memory for EFI.
>>> Note here that this *has* to be EFI memory since the kernel's efi-stub
>>> can still call into the firmware (and in fact it does, that's who we measure
>>> the initrd in > 5.18 kernels). After the allocation it looks for those DT
>>> entries, and if tpm_event_log_addr is found it parses the EventLog and
>>> 1. Extends the PCRs
>>> 2. Adds the events into the Eventlog
>>>
>>> The reason for that is that TF-A (the Arm first stage boot loader),
>>> doesn't have any TPM drivers. So U-Boot is trying to be 'smart' here.
>>> We are grabbing the EventLog from the previous bootloader and if PCR0!=0 we
>>> replay that into the hardware and re-create the EventLog.
>>>
>>> [...]
>>
>> This will fix the protocol installation, however there's still still
>> something missing on the EFI side, since reading the eventlog fails
>> with
>>
>> tpm2_eventlog /sys/kernel/security/tpm0/binary_bios_measurements
>> version: 1
>> events:
>> ERROR: failed to parse tpm2 eventlog
>> ERROR: Unable to run tpm2_eventlog
>> But at least the kernel can find the EFI config tables properly.
>> Also, note that the ret is efi_status_t and the new function you added
>> returns an int. Just switch the ret here accordingly.
>>
>>
>> * platforms can use different ways to do so.
>> */
>> ret = tcg2_init_log(dev, &elog);
>> - if (ret != EFI_SUCCESS)
>> - goto free_pool;
>> -
>> - memcpy(event_log.buffer, elog.log, elog.log_position);
>> - event_log.pos = elog.log_position;
>> + if (ret == EFI_SUCCESS) {
>> + memcpy(event_log.buffer, elog.log, elog.log_position);
>> + event_log.pos = elog.log_position;
>> + }
>>
>>
>> I'll try digging into the EFI issues more once I get some time
> Ok Ignore the previous mail. I just noticed that the specid event is
> generated by tcg2_log_init() and that's where the errors come from.
OK, I think I understand the problem. One problem with your solution
below is that it's only useful for EFI; writing the event log to a
temporary buffer in the non-EFI case is a waste of time, since it can't
go anywhere. I have a solution where the user can pass in their buffer
in the tcg2_event_log structure in the event that no memory region is
discovered. EFI can use that path.
Thanks for the debugging effort!
Eddie
>
> So something like the *really ugly hack* fixes EFI. Can you please
> turn it into human-readable code
>
> #include <linux/unaligned/be_byteshift.h>
> #include <linux/unaligned/generic.h>
> #include <linux/unaligned/le_byteshift.h>
> +#include <malloc.h>
>
> #include "tpm-utils.h"
>
> @@ -634,7 +635,7 @@ __weak int tcg2_platform_get_log(struct udevice
> *dev, void **addr, u32 *size)
>
> if (dev_read_phandle_with_args(dev, "memory-region", NULL, 0,
> 0, &args))
> - return -ENODEV;
> + goto alloc;
>
> a = ofnode_get_addr_size(args.node, "reg", &s);
> if (a == FDT_ADDR_T_NONE)
> @@ -643,6 +644,9 @@ __weak int tcg2_platform_get_log(struct udevice
> *dev, void **addr, u32 *size)
> *addr = map_physmem(a, s, MAP_NOCACHE);
> *size = (u32)s;
> }
> +alloc:
> + *addr = calloc(1, 4096);
> + *size = 4096;
>
> return 0;
> }
>
> Cheers
> /Ilias
>
>> Cheers
>> /Ilias
>>> Thanks!
>>> /Ilias
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