tpm: Auto-detection of legacy TPM 2.0 devices

src/libimcv/pts/pts.c

@@ -318,8 +318,8 @@ METHOD(pts_t, get_tpm, tpm_tss_t*,
 METHOD(pts_t, get_tpm_version_info, bool,
 	private_pts_t *this, chunk_t *info)
 {
-	*info = this->tpm ? this->tpm->get_version_info(this->tpm) :
-						this->tpm_version_info;
+	*info = this->tpm_version_info;
+
 	return info->len > 0;
 }
 
@@ -369,7 +369,8 @@ METHOD(pts_t, set_tpm_version_info, void,
 
 		this->tpm_version = TPM_VERSION_2_0;
 
-		if (reader->read_uint16(reader, &reserved)  &&
+		if (reader->read_uint8 (reader, &reserved)  &&
+			reader->read_uint8 (reader, &locality)  &&
 			reader->read_uint32(reader, &revision)  &&
 			reader->read_uint32(reader, &year)      &&
 			reader->read_data  (reader, 4, &vendor))
@@ -838,12 +839,29 @@ METHOD(pts_t, verify_quote_signature, bool,
 	return TRUE;
 }
 
+/**
+ * Extracts the locality from a TPM 2.0 Version Info struct
+ */
+static uint8_t get_tpm_locality(chunk_t tpm_version_info)
+{
+	if (tpm_version_info.len < 4 ||
+	    tpm_version_info.ptr[0] != 0x02 || tpm_version_info.ptr[1] != 0x00)
+	{
+		return 0;
+	}
+	else
+	{
+		return tpm_version_info.ptr[3];
+	}
+}
+
 METHOD(pts_t, get_pcrs, pts_pcr_t*,
 	private_pts_t *this)
 {
 	if (!this->pcrs)
 	{
-		this->pcrs = pts_pcr_create(this->tpm_version, this->algorithm);
+		this->pcrs = pts_pcr_create(this->tpm_version, this->algorithm,
+							get_tpm_locality(this->tpm_version_info));
 	}
 	return this->pcrs;
 }
@@ -912,6 +930,7 @@ pts_t *pts_create(bool is_imc)
 		{
 			this->proto_caps |= PTS_PROTO_CAPS_T | PTS_PROTO_CAPS_D;
 			this->tpm_version = this->tpm->get_version(this->tpm);
+			this->tpm_version_info = this->tpm->get_version_info(this->tpm);
 			load_aik(this);
 		}
 	}

src/libimcv/pts/pts_pcr.c

@@ -259,7 +259,8 @@ METHOD(pts_pcr_t, destroy, void,
 /**
  * See header
  */
-pts_pcr_t *pts_pcr_create(tpm_version_t tpm_version, pts_meas_algorithms_t algo)
+pts_pcr_t *pts_pcr_create(tpm_version_t tpm_version, pts_meas_algorithms_t algo,
+						  uint8_t locality)
 {
 	private_pts_pcr_t *this;
 	hash_algorithm_t hash_alg;
@@ -302,8 +303,6 @@ pts_pcr_t *pts_pcr_create(tpm_version_t tpm_version, pts_meas_algorithms_t algo)
 	/* Set locality indicator in PCR[0] */
 	if (tpm_version == TPM_VERSION_2_0)
 	{
-		const uint8_t locality = 3;
-
 		DBG2(DBG_PTS, "TPM 2.0 - locality indicator set to %u",
 					  (uint32_t)locality);
 		this->pcrs[0].ptr[this->pcr_len - 1] = locality;

src/libimcv/pts/pts_pcr.h

@@ -122,7 +122,9 @@ struct pts_pcr_t {
  *
  * @param tpm_version		TPM version
  * @param algo				Hash algorithm used by PCR bank
+ * @param locality			TPM locality in which the PCR bank was initialized
  */
-pts_pcr_t* pts_pcr_create(tpm_version_t tpm_version, pts_meas_algorithms_t algo);
+pts_pcr_t* pts_pcr_create(tpm_version_t tpm_version, pts_meas_algorithms_t algo,
+						  uint8_t locality);
 
 #endif /** PTS_PCR_H_ @}*/