tpm2: implement and use pcr_extend command
TPM PCRs are used in Chrome OS for two purposes: to communicate crucial information from RO firmware and to protect FW and kernel rollback counters from being deleted. As implemented in a TPM1 compatible way, the PCR extension command requires a prebuilt digest to calculate a new PCR value. TPM2 specification introduces a PCR_Event command, where the TPM itself calculates the digest of an arbitrary length string, and then uses the calculated digest for PCR extension. PCR_Event could be a better option for Chrome OS, this needs to be investigated separately. BRANCH=none BUG=chrome-os-partner:50645 TEST=verified that the two PCRs are successfully extended before the RW firmware is called. Change-Id: I38fc88172de8ec8bef56fec026f83058480c8010 Signed-off-by: Martin Roth <martinroth@chromium.org> Original-Commit-Id: 73388139db3ffaf61a3d9027522c5ebecb3ad051 Original-Change-Id: I1a9bab7396fdb652e2e3bc8529b828ea3423d851 Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/358098 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Original-Reviewed-by: Darren Krahn <dkrahn@chromium.org> Reviewed-on: https://review.coreboot.org/15639 Tested-by: build bot (Jenkins) Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@googlemail.com>
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@ -201,6 +201,27 @@ static void marshal_TPMS_NV_PUBLIC(void **buffer,
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marshal_u16(buffer, nvpub->dataSize, buffer_space);
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marshal_u16(buffer, nvpub->dataSize, buffer_space);
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}
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}
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static void marshal_TPMT_HA(void **buffer,
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TPMT_HA *tpmtha,
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size_t *buffer_space)
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{
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marshal_TPMI_ALG_HASH(buffer, tpmtha->hashAlg, buffer_space);
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marshal_blob(buffer, tpmtha->digest.sha256,
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sizeof(tpmtha->digest.sha256),
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buffer_space);
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}
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static void marshal_TPML_DIGEST_VALUES(void **buffer,
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TPML_DIGEST_VALUES *dvalues,
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size_t *buffer_space)
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{
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int i;
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marshal_u32(buffer, dvalues->count, buffer_space);
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for (i = 0; i < dvalues->count; i++)
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marshal_TPMT_HA(buffer, &dvalues->digests[i], buffer_space);
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}
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static void marshal_session_header(void **buffer,
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static void marshal_session_header(void **buffer,
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struct tpm2_session_header *session_header,
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struct tpm2_session_header *session_header,
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size_t *buffer_space)
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size_t *buffer_space)
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@ -312,6 +333,17 @@ static void marshal_nv_write_lock(void **buffer,
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ARRAY_SIZE(handles), buffer_space);
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ARRAY_SIZE(handles), buffer_space);
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}
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}
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static void marshal_pcr_extend(void **buffer,
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struct tpm2_pcr_extend_cmd *command_body,
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size_t *buffer_space)
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{
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uint32_t handle = command_body->pcrHandle;
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marshal_common_session_header(buffer, &handle, 1, buffer_space);
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marshal_TPML_DIGEST_VALUES(buffer,
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&command_body->digests, buffer_space);
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}
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static void marshal_nv_read(void **buffer,
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static void marshal_nv_read(void **buffer,
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struct tpm2_nv_read_cmd *command_body,
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struct tpm2_nv_read_cmd *command_body,
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size_t *buffer_space)
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size_t *buffer_space)
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@ -385,6 +417,10 @@ int tpm_marshal_command(TPM_CC command, void *tpm_command_body,
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marshal_clear(&cmd_body, &body_size);
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marshal_clear(&cmd_body, &body_size);
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break;
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break;
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case TPM2_PCR_Extend:
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marshal_pcr_extend(&cmd_body, tpm_command_body, &body_size);
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break;
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default:
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default:
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body_size = 0;
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body_size = 0;
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printk(BIOS_INFO, "%s:%d:Request to marshal unsupported command %#x\n",
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printk(BIOS_INFO, "%s:%d:Request to marshal unsupported command %#x\n",
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@ -547,6 +583,7 @@ struct tpm2_response *tpm_unmarshal_response(TPM_CC command,
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case TPM2_NV_DefineSpace:
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case TPM2_NV_DefineSpace:
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case TPM2_NV_Write:
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case TPM2_NV_Write:
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case TPM2_NV_WriteLock:
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case TPM2_NV_WriteLock:
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case TPM2_PCR_Extend:
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/* Session data included in response can be safely ignored. */
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/* Session data included in response can be safely ignored. */
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cr_size = 0;
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cr_size = 0;
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break;
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break;
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@ -65,10 +65,29 @@ uint32_t tlcl_assert_physical_presence(void)
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return TPM_SUCCESS;
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return TPM_SUCCESS;
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}
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}
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/*
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* The caller will provide the digest in a 32 byte buffer, let's consider it a
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* sha256 digest.
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*/
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uint32_t tlcl_extend(int pcr_num, const uint8_t *in_digest,
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uint32_t tlcl_extend(int pcr_num, const uint8_t *in_digest,
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uint8_t *out_digest)
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uint8_t *out_digest)
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{
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{
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printk(BIOS_INFO, "%s:%s:%d\n", __FILE__, __func__, __LINE__);
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struct tpm2_pcr_extend_cmd pcr_ext_cmd;
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struct tpm2_response *response;
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pcr_ext_cmd.pcrHandle = HR_PCR + pcr_num;
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pcr_ext_cmd.digests.count = 1;
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pcr_ext_cmd.digests.digests[0].hashAlg = TPM_ALG_SHA256;
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memcpy(pcr_ext_cmd.digests.digests[0].digest.sha256, in_digest,
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sizeof(pcr_ext_cmd.digests.digests[0].digest.sha256));
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response = tpm_process_command(TPM2_PCR_Extend, &pcr_ext_cmd);
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printk(BIOS_INFO, "%s: response is %x\n",
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__func__, response ? response->hdr.tpm_code : -1);
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if (!response || response->hdr.tpm_code)
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return TPM_E_IOERROR;
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return TPM_SUCCESS;
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return TPM_SUCCESS;
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}
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}
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@ -25,11 +25,12 @@ typedef uint32_t TPM_CC;
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typedef uint32_t TPM_HANDLE;
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typedef uint32_t TPM_HANDLE;
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typedef uint32_t TPM_RC;
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typedef uint32_t TPM_RC;
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typedef uint8_t TPMI_YES_NO;
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typedef uint8_t TPMI_YES_NO;
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typedef TPM_ALG_ID TPMI_ALG_HASH;
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typedef TPM_HANDLE TPMI_DH_PCR;
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typedef TPM_HANDLE TPMI_RH_NV_INDEX;
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typedef TPM_HANDLE TPMI_RH_NV_INDEX;
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typedef TPM_HANDLE TPMI_RH_PROVISION;
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typedef TPM_HANDLE TPMI_RH_PROVISION;
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typedef TPM_HANDLE TPMI_SH_AUTH_SESSION;
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typedef TPM_HANDLE TPMI_SH_AUTH_SESSION;
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typedef TPM_HANDLE TPM_RH;
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typedef TPM_HANDLE TPM_RH;
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typedef TPM_ALG_ID TPMI_ALG_HASH;
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/* Some hardcoded algorithm values. */
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/* Some hardcoded algorithm values. */
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#define TPM_ALG_HMAC ((TPM_ALG_ID)0x0005)
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#define TPM_ALG_HMAC ((TPM_ALG_ID)0x0005)
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@ -37,6 +38,8 @@ typedef TPM_ALG_ID TPMI_ALG_HASH;
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#define TPM_ALG_SHA1 ((TPM_ALG_ID)0x0004)
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#define TPM_ALG_SHA1 ((TPM_ALG_ID)0x0004)
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#define TPM_ALG_SHA256 ((TPM_ALG_ID)0x000b)
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#define TPM_ALG_SHA256 ((TPM_ALG_ID)0x000b)
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#define SHA256_DIGEST_SIZE 32
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/* Some hardcoded hierarchies. */
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/* Some hardcoded hierarchies. */
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#define TPM_RH_NULL 0x40000007
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#define TPM_RH_NULL 0x40000007
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#define TPM_RS_PW 0x40000009
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#define TPM_RS_PW 0x40000009
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@ -64,11 +67,13 @@ struct tpm_header {
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#define TPM2_Startup ((TPM_CC)0x00000144)
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#define TPM2_Startup ((TPM_CC)0x00000144)
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#define TPM2_NV_Read ((TPM_CC)0x0000014E)
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#define TPM2_NV_Read ((TPM_CC)0x0000014E)
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#define TPM2_GetCapability ((TPM_CC)0x0000017A)
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#define TPM2_GetCapability ((TPM_CC)0x0000017A)
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#define TPM2_PCR_Extend ((TPM_CC)0x00000182)
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/* Startup values. */
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/* Startup values. */
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#define TPM_SU_CLEAR 0
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#define TPM_SU_CLEAR 0
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#define TPM_SU_STATE 1
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#define TPM_SU_STATE 1
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#define TPM_HT_PCR 0x00
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#define TPM_HT_NV_INDEX 0x01
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#define TPM_HT_NV_INDEX 0x01
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#define TPM_HT_HMAC_SESSION 0x02
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#define TPM_HT_HMAC_SESSION 0x02
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#define TPM_HT_POLICY_SESSION 0x03
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#define TPM_HT_POLICY_SESSION 0x03
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@ -241,6 +246,24 @@ typedef union {
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TPM2B b;
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TPM2B b;
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} TPM2B_MAX_NV_BUFFER;
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} TPM2B_MAX_NV_BUFFER;
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/*
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* This is a union, but as of now we support just one digest - sha256, so
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* there is just one element.
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*/
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typedef union {
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uint8_t sha256[SHA256_DIGEST_SIZE];
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} TPMU_HA;
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typedef struct {
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TPMI_ALG_HASH hashAlg;
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TPMU_HA digest;
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} TPMT_HA;
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typedef struct {
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uint32_t count;
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TPMT_HA digests[1]; /* Limit max number of hashes to 1. */
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} TPML_DIGEST_VALUES;
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struct nv_read_response {
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struct nv_read_response {
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uint32_t params_size;
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uint32_t params_size;
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TPM2B_MAX_NV_BUFFER buffer;
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TPM2B_MAX_NV_BUFFER buffer;
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@ -306,4 +329,9 @@ struct tpm2_nv_write_lock_cmd {
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TPMI_RH_NV_INDEX nvIndex;
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TPMI_RH_NV_INDEX nvIndex;
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};
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};
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struct tpm2_pcr_extend_cmd {
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TPMI_DH_PCR pcrHandle;
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TPML_DIGEST_VALUES digests;
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};
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#endif // __SRC_LIB_TPM2_TLCL_STRUCTURES_H
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#endif // __SRC_LIB_TPM2_TLCL_STRUCTURES_H
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