[PATCH v6 3/6] tpm: Support boot measurements
Ilias Apalodimas
ilias.apalodimas at linaro.org
Thu Feb 23 10:30:29 CET 2023
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
Cheers
/Ilias
>
> Thanks!
> /Ilias
> >
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