[PATCH v6 3/6] tpm: Support boot measurements
Ilias Apalodimas
ilias.apalodimas at linaro.org
Thu Feb 23 10:47:35 CET 2023
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.
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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