1 files changed, 559 insertions, 0 deletions
diff --git a/src/security/tpm/tcg-2.0/tss_marshaling.c b/src/security/tpm/tcg-2.0/tss_marshaling.c
new file mode 100644
index 0000000000..b1d666362b
--- /dev/null
+++ b/src/security/tpm/tcg-2.0/tss_marshaling.c
@@ -0,0 +1,559 @@
+/*
+ * Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <arch/early_variables.h>
+#include <commonlib/iobuf.h>
+#include <console/console.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tss_marshaling.h"
+
+static uint16_t tpm_tag CAR_GLOBAL;  /* Depends on the command type. */
+
+#define unmarshal_TPM_CAP(a, b) ibuf_read_be32(a, b)
+#define unmarshal_TPM_CC(a, b) ibuf_read_be32(a, b)
+#define unmarshal_TPM_PT(a, b) ibuf_read_be32(a, b)
+#define unmarshal_TPM_HANDLE(a, b) ibuf_read_be32(a, b)
+
+#define marshal_TPM_HANDLE(a, b) obuf_write_be32(a, b)
+#define marshal_TPMI_ALG_HASH(a, b) obuf_write_be16(a, b)
+
+static int marshal_startup(struct obuf *ob, struct tpm2_startup *cmd_body)
+{
+	return obuf_write_be16(ob, cmd_body->startup_type);
+}
+
+static int marshal_get_capability(struct obuf *ob,
+				   struct tpm2_get_capability *cmd_body)
+{
+	int rc = 0;
+
+	rc |= obuf_write_be32(ob, cmd_body->capability);
+	rc |= obuf_write_be32(ob, cmd_body->property);
+	rc |= obuf_write_be32(ob, cmd_body->propertyCount);
+
+	return rc;
+}
+
+static int marshal_TPM2B(struct obuf *ob, TPM2B *data)
+{
+	int rc = 0;
+
+	rc |= obuf_write_be16(ob, data->size);
+	rc |= obuf_write(ob, data->buffer, data->size);
+
+	return rc;
+}
+
+static int marshal_TPMA_NV(struct obuf *ob, TPMA_NV *nv)
+{
+	uint32_t v;
+
+	memcpy(&v, nv, sizeof(v));
+	return obuf_write_be32(ob, v);
+}
+
+static int marshal_TPMS_NV_PUBLIC(struct obuf *ob, TPMS_NV_PUBLIC *nvpub)
+{
+	int rc = 0;
+
+	rc |= marshal_TPM_HANDLE(ob, nvpub->nvIndex);
+	rc |= marshal_TPMI_ALG_HASH(ob, nvpub->nameAlg);
+	rc |= marshal_TPMA_NV(ob, &nvpub->attributes);
+	rc |= marshal_TPM2B(ob, &nvpub->authPolicy.b);
+	rc |= obuf_write_be16(ob, nvpub->dataSize);
+
+	return rc;
+}
+
+static int marshal_TPMT_HA(struct obuf *ob, TPMT_HA *tpmtha)
+{
+	int rc = 0;
+
+	rc |= marshal_TPMI_ALG_HASH(ob, tpmtha->hashAlg);
+	rc |= obuf_write(ob, tpmtha->digest.sha256,
+			sizeof(tpmtha->digest.sha256));
+
+	return rc;
+}
+
+static int marshal_TPML_DIGEST_VALUES(struct obuf *ob,
+				       TPML_DIGEST_VALUES *dvalues)
+{
+	int i;
+	int rc = 0;
+
+	rc |= obuf_write_be32(ob, dvalues->count);
+	for (i = 0; i < dvalues->count; i++)
+		rc |= marshal_TPMT_HA(ob, &dvalues->digests[i]);
+
+	return rc;
+}
+
+static int marshal_session_header(struct obuf *ob,
+				   struct tpm2_session_header *session_header)
+{
+	int rc = 0;
+	struct obuf ob_sz;
+	size_t prev_written;
+
+	/* Snapshot current location to place size of header. */
+	if (obuf_splice_current(ob, &ob_sz, sizeof(uint32_t)) < 0)
+		return -1;
+
+	/* Write a size placeholder. */
+	rc |= obuf_write_be32(ob, 0);
+
+	/* Keep track of session header data size by tracking num written. */
+	prev_written = obuf_nr_written(ob);
+
+	rc |= obuf_write_be32(ob, session_header->session_handle);
+	rc |= obuf_write_be16(ob, session_header->nonce_size);
+	rc |= obuf_write(ob, session_header->nonce, session_header->nonce_size);
+	rc |= obuf_write_be8(ob, session_header->session_attrs);
+	rc |= obuf_write_be16(ob, session_header->auth_size);
+	rc |= obuf_write(ob, session_header->auth, session_header->auth_size);
+
+	/* Fill back in proper size of session header. */
+	rc |= obuf_write_be32(&ob_sz, obuf_nr_written(ob) - prev_written);
+
+	return rc;
+}
+
+/*
+ * Common session header can include one or two handles and an empty
+ * session_header structure.
+ */
+static int marshal_common_session_header(struct obuf *ob,
+					  const uint32_t *handles,
+					  size_t handle_count)
+{
+	size_t i;
+	struct tpm2_session_header session_header;
+	int rc = 0;
+
+	car_set_var(tpm_tag, TPM_ST_SESSIONS);
+
+	for (i = 0; i < handle_count; i++)
+		rc |= marshal_TPM_HANDLE(ob, handles[i]);
+
+	memset(&session_header, 0, sizeof(session_header));
+	session_header.session_handle = TPM_RS_PW;
+	rc |= marshal_session_header(ob, &session_header);
+
+	return rc;
+}
+
+static int marshal_nv_define_space(struct obuf *ob,
+				    struct tpm2_nv_define_space_cmd *nvd_in)
+{
+	const uint32_t handle[] = { TPM_RH_PLATFORM };
+	struct obuf ob_sz;
+	size_t prev_written;
+	int rc = 0;
+
+	rc |= marshal_common_session_header(ob, handle, ARRAY_SIZE(handle));
+	rc |= marshal_TPM2B(ob, &nvd_in->auth.b);
+
+	/* Snapshot current location to place size field. */
+	if (obuf_splice_current(ob, &ob_sz, sizeof(uint16_t)) < 0)
+		return -1;
+
+	/* Put placeholder for size */
+	rc |= obuf_write_be16(ob, 0);
+
+	/* Keep track of nv define space data size by tracking num written. */
+	prev_written = obuf_nr_written(ob);
+
+	rc |= marshal_TPMS_NV_PUBLIC(ob, &nvd_in->publicInfo);
+	rc |= obuf_write_be16(&ob_sz, obuf_nr_written(ob) - prev_written);
+
+	return rc;
+}
+
+static int marshal_nv_write(struct obuf *ob,
+			     struct tpm2_nv_write_cmd *command_body)
+{
+	int rc = 0;
+	uint32_t handles[] = { TPM_RH_PLATFORM, command_body->nvIndex };
+
+	rc |= marshal_common_session_header(ob, handles, ARRAY_SIZE(handles));
+	rc |= marshal_TPM2B(ob, &command_body->data.b);
+	rc |= obuf_write_be16(ob, command_body->offset);
+
+	return rc;
+}
+
+static int marshal_nv_write_lock(struct obuf *ob,
+				  struct tpm2_nv_write_lock_cmd *command_body)
+{
+	uint32_t handles[] = { TPM_RH_PLATFORM, command_body->nvIndex };
+
+	return marshal_common_session_header(ob, handles, ARRAY_SIZE(handles));
+}
+
+static int marshal_pcr_extend(struct obuf *ob,
+			       struct tpm2_pcr_extend_cmd *command_body)
+{
+	int rc = 0;
+	uint32_t handles[] = { command_body->pcrHandle };
+
+	rc |= marshal_common_session_header(ob, handles, ARRAY_SIZE(handles));
+	rc |= marshal_TPML_DIGEST_VALUES(ob, &command_body->digests);
+
+	return rc;
+}
+
+static int marshal_nv_read(struct obuf *ob,
+			    struct tpm2_nv_read_cmd *command_body)
+{
+	int rc = 0;
+	uint32_t handles[] = { TPM_RH_PLATFORM, command_body->nvIndex };
+
+	rc |= marshal_common_session_header(ob, handles, ARRAY_SIZE(handles));
+	rc |= obuf_write_be16(ob, command_body->size);
+	rc |= obuf_write_be16(ob, command_body->offset);
+
+	return rc;
+}
+
+/* TPM2_Clear command does not require paramaters. */
+static int marshal_clear(struct obuf *ob)
+{
+	const uint32_t handle[] = { TPM_RH_PLATFORM };
+
+	return marshal_common_session_header(ob, handle, ARRAY_SIZE(handle));
+}
+
+static int marshal_selftest(struct obuf *ob,
+			     struct tpm2_self_test *command_body)
+{
+	return obuf_write_be8(ob, command_body->yes_no);
+}
+
+static int marshal_hierarchy_control(struct obuf *ob,
+			struct tpm2_hierarchy_control_cmd *command_body)
+{
+	int rc = 0;
+	struct tpm2_session_header session_header;
+
+	car_set_var(tpm_tag, TPM_ST_SESSIONS);
+
+	rc |= marshal_TPM_HANDLE(ob, TPM_RH_PLATFORM);
+	memset(&session_header, 0, sizeof(session_header));
+	session_header.session_handle = TPM_RS_PW;
+	rc |= marshal_session_header(ob, &session_header);
+
+	rc |= marshal_TPM_HANDLE(ob, command_body->enable);
+	rc |= obuf_write_be8(ob, command_body->state);
+
+	return rc;
+}
+
+static int marshal_cr50_vendor_command(struct obuf *ob, void *command_body)
+{
+	int rc = 0;
+	uint16_t *sub_command = command_body;
+
+	switch (*sub_command) {
+	case TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS:
+		rc |= obuf_write_be16(ob, *sub_command);
+		break;
+	case TPM2_CR50_SUB_CMD_TURN_UPDATE_ON:
+		rc |= obuf_write_be16(ob, sub_command[0]);
+		rc |= obuf_write_be16(ob, sub_command[1]);
+		break;
+	default:
+		/* Unsupported subcommand. */
+		printk(BIOS_WARNING, "Unsupported cr50 subcommand: 0x%04x\n",
+			*sub_command);
+		rc = -1;
+		break;
+	}
+	return rc;
+}
+
+int tpm_marshal_command(TPM_CC command, void *tpm_command_body, struct obuf *ob)
+{
+	struct obuf ob_hdr;
+	const size_t hdr_sz = sizeof(uint16_t) + 2 * sizeof(uint32_t);
+	int rc = 0;
+
+	car_set_var(tpm_tag, TPM_ST_NO_SESSIONS);
+
+	if (obuf_splice_current(ob, &ob_hdr, hdr_sz) < 0)
+		return -1;
+
+	/* Write TPM command header with placeholder field values. */
+	rc |= obuf_write_be16(ob, 0);
+	rc |= obuf_write_be32(ob, 0);
+	rc |= obuf_write_be32(ob, command);
+
+	if (rc != 0)
+		return rc;
+
+	switch (command) {
+	case TPM2_Startup:
+		rc |= marshal_startup(ob, tpm_command_body);
+		break;
+
+	case TPM2_GetCapability:
+		rc |= marshal_get_capability(ob, tpm_command_body);
+		break;
+
+	case TPM2_NV_Read:
+		rc |= marshal_nv_read(ob, tpm_command_body);
+		break;
+
+	case TPM2_NV_DefineSpace:
+		rc |= marshal_nv_define_space(ob, tpm_command_body);
+		break;
+
+	case TPM2_NV_Write:
+		rc |= marshal_nv_write(ob, tpm_command_body);
+		break;
+
+	case TPM2_NV_WriteLock:
+		rc |= marshal_nv_write_lock(ob, tpm_command_body);
+		break;
+
+	case TPM2_SelfTest:
+		rc |= marshal_selftest(ob, tpm_command_body);
+		break;
+
+	case TPM2_Hierarchy_Control:
+		rc |= marshal_hierarchy_control(ob, tpm_command_body);
+		break;
+
+	case TPM2_Clear:
+		rc |= marshal_clear(ob);
+		break;
+
+	case TPM2_PCR_Extend:
+		rc |= marshal_pcr_extend(ob, tpm_command_body);
+		break;
+
+	case TPM2_CR50_VENDOR_COMMAND:
+		rc |= marshal_cr50_vendor_command(ob, tpm_command_body);
+		break;
+
+	default:
+		printk(BIOS_INFO, "%s:%d:Request to marshal unsupported command %#x\n",
+		       __FILE__, __LINE__, command);
+		rc = -1;
+	}
+
+	if (rc != 0)
+		return rc;
+
+	/* Fix up the command header with known values. */
+	rc |= obuf_write_be16(&ob_hdr, car_get_var(tpm_tag));
+	rc |= obuf_write_be32(&ob_hdr, obuf_nr_written(ob));
+
+	return rc;
+}
+
+static int unmarshal_get_capability(struct ibuf *ib,
+				     struct get_cap_response *gcr)
+{
+	int i;
+	int rc = 0;
+
+	rc |= ibuf_read_be8(ib, &gcr->more_data);
+	rc |= unmarshal_TPM_CAP(ib, &gcr->cd.capability);
+
+	if (rc != 0)
+		return rc;
+
+	switch (gcr->cd.capability) {
+	case TPM_CAP_TPM_PROPERTIES:
+		if (ibuf_read_be32(ib, &gcr->cd.data.tpmProperties.count))
+			return -1;
+		if (gcr->cd.data.tpmProperties.count > ARRAY_SIZE
+		    (gcr->cd.data.tpmProperties.tpmProperty)) {
+			printk(BIOS_INFO, "%s:%s:%d - %d - too many properties\n",
+			       __FILE__, __func__, __LINE__,
+			       gcr->cd.data.tpmProperties.count);
+			return -1;
+		}
+		for (i = 0; i < gcr->cd.data.tpmProperties.count; i++) {
+			TPMS_TAGGED_PROPERTY *pp;
+
+			pp = gcr->cd.data.tpmProperties.tpmProperty + i;
+			rc |= unmarshal_TPM_PT(ib, &pp->property);
+			rc |= ibuf_read_be32(ib, &pp->value);
+		}
+		break;
+	default:
+		printk(BIOS_ERR,
+		       "%s:%d - unable to unmarshal capability response",
+		       __func__, __LINE__);
+		printk(BIOS_ERR, " for %d\n", gcr->cd.capability);
+		rc = -1;
+		break;
+	}
+
+	return rc;
+}
+
+static int unmarshal_TPM2B_MAX_NV_BUFFER(struct ibuf *ib,
+					  TPM2B_MAX_NV_BUFFER *nv_buffer)
+{
+	if (ibuf_read_be16(ib, &nv_buffer->t.size))
+		return -1;
+
+	nv_buffer->t.buffer = ibuf_oob_drain(ib, nv_buffer->t.size);
+
+	if (nv_buffer->t.buffer == NULL) {
+		printk(BIOS_ERR, "%s:%d - "
+		       "size mismatch: expected %d, remaining %zd\n",
+		       __func__, __LINE__, nv_buffer->t.size,
+			ibuf_remaining(ib));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int unmarshal_nv_read(struct ibuf *ib, struct nv_read_response *nvr)
+{
+	/* Total size of the parameter field. */
+	if (ibuf_read_be32(ib, &nvr->params_size))
+		return -1;
+
+	if (unmarshal_TPM2B_MAX_NV_BUFFER(ib, &nvr->buffer))
+		return -1;
+
+	if (nvr->params_size !=
+	    (nvr->buffer.t.size + sizeof(nvr->buffer.t.size))) {
+		printk(BIOS_ERR,
+		       "%s:%d - parameter/buffer %d/%d size mismatch",
+		       __func__, __LINE__, nvr->params_size,
+		       nvr->buffer.t.size);
+		return -1;
+	}
+
+	/*
+	 * Let's ignore the authorisation section. It should be 5 bytes total,
+	 * just confirm that this is the case and report any discrepancy.
+	 */
+	if (ibuf_remaining(ib) != 5)
+		printk(BIOS_ERR,
+		       "%s:%d - unexpected authorisation seciton size %zd\n",
+		       __func__, __LINE__, ibuf_remaining(ib));
+
+	ibuf_oob_drain(ib, ibuf_remaining(ib));
+
+	return 0;
+}
+
+static int unmarshal_vendor_command(struct ibuf *ib,
+				     struct vendor_command_response *vcr)
+{
+	if (ibuf_read_be16(ib, &vcr->vc_subcommand))
+		return -1;
+
+	switch (vcr->vc_subcommand) {
+	case TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS:
+		break;
+	case TPM2_CR50_SUB_CMD_TURN_UPDATE_ON:
+		return ibuf_read_be8(ib, &vcr->num_restored_headers);
+		break;
+	default:
+		printk(BIOS_ERR,
+		       "%s:%d - unsupported vendor command %#04x!\n",
+		       __func__, __LINE__, vcr->vc_subcommand);
+		return -1;
+	}
+
+	return 0;
+}
+
+struct tpm2_response *tpm_unmarshal_response(TPM_CC command, struct ibuf *ib)
+{
+	static struct tpm2_response tpm2_static_resp CAR_GLOBAL;
+	struct tpm2_response *tpm2_resp = car_get_var_ptr(&tpm2_static_resp);
+	int rc = 0;
+
+	rc |= ibuf_read_be16(ib, &tpm2_resp->hdr.tpm_tag);
+	rc |= ibuf_read_be32(ib, &tpm2_resp->hdr.tpm_size);
+	rc |= unmarshal_TPM_CC(ib, &tpm2_resp->hdr.tpm_code);
+
+	if (rc != 0)
+		return NULL;
+
+	if (ibuf_remaining(ib) == 0) {
+		if (tpm2_resp->hdr.tpm_size != ibuf_nr_read(ib))
+			printk(BIOS_ERR,
+			       "%s: size mismatch in response to command %#x\n",
+			       __func__, command);
+		return tpm2_resp;
+	}
+
+	switch (command) {
+	case TPM2_Startup:
+		break;
+
+	case TPM2_GetCapability:
+		rc |= unmarshal_get_capability(ib, &tpm2_resp->gc);
+		break;
+
+	case TPM2_NV_Read:
+		rc |= unmarshal_nv_read(ib, &tpm2_resp->nvr);
+		break;
+
+	case TPM2_Hierarchy_Control:
+	case TPM2_Clear:
+	case TPM2_NV_DefineSpace:
+	case TPM2_NV_Write:
+	case TPM2_NV_WriteLock:
+	case TPM2_PCR_Extend:
+		/* Session data included in response can be safely ignored. */
+		ibuf_oob_drain(ib, ibuf_remaining(ib));
+		break;
+
+	case TPM2_CR50_VENDOR_COMMAND:
+		rc |= unmarshal_vendor_command(ib, &tpm2_resp->vcr);
+		break;
+
+	default:
+		{
+			size_t i;
+			size_t sz_left;
+			const uint8_t *data;
+
+			printk(BIOS_INFO, "%s:%d:"
+			       "Request to unmarshal unexpected command %#x,"
+			       " code %#x",
+			       __func__, __LINE__, command,
+			       tpm2_resp->hdr.tpm_code);
+
+			sz_left = ibuf_remaining(ib);
+			data = ibuf_oob_drain(ib, sz_left);
+
+			for (i = 0; i < sz_left; i++) {
+				if (!(i % 16))
+					printk(BIOS_INFO, "\n");
+				printk(BIOS_INFO, "%2.2x ", data[i]);
+			}
+		}
+		printk(BIOS_INFO, "\n");
+		return NULL;
+	}
+
+	if (ibuf_remaining(ib)) {
+		printk(BIOS_INFO,
+		       "%s:%d got %d bytes back in response to %#x,"
+		       " failed to parse (%zd)\n",
+		       __func__, __LINE__, tpm2_resp->hdr.tpm_size,
+		       command, ibuf_remaining(ib));
+		return NULL;
+	}
+
+	/* The entire message have been parsed. */
+	return tpm2_resp;
+}