security/tpm: Add TCPA logging functionality

* TCG spec only applies to BIOS or UEFI.
* Therefore implement coreboot TCPA compliant log
in CBMEM.
* Write CBMEM log into the coreboot table for CBMEM tool access

Change-Id: I0a52494f647d21e2587231af26ed13d62b3a72f5
Signed-off-by: Philipp Deppenwiese <zaolin@das-labor.org>
Reviewed-on: https://review.coreboot.org/22867
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

3 files changed, 95 insertions, 8 deletions

diff --git a/src/security/tpm/Makefile.inc b/src/security/tpm/Makefile.inc
index 9157fec386..34ead8f07d 100644
--- a/src/security/tpm/Makefile.inc
+++ b/src/security/tpm/Makefile.inc
@@ -12,11 +12,11 @@ postcar-$(CONFIG_VBOOT) += tss/tcg-1.2/tss.c
 
 ## TSPI
 
-ramstage-y += tspi/tspi.c
-romstage-y += tspi/tspi.c
+ramstage-y += tspi/tspi.c tspi/log.c
+romstage-y += tspi/tspi.c tspi/log.c
 
-verstage-$(CONFIG_VBOOT) += tspi/tspi.c
-postcar-$(CONFIG_VBOOT) += tspi/tspi.c
+verstage-$(CONFIG_VBOOT) += tspi/tspi.c tspi/log.c
+postcar-$(CONFIG_VBOOT) += tspi/tspi.c tspi/log.c
 
 endif # CONFIG_TPM1
 
@@ -36,10 +36,10 @@ postcar-$(CONFIG_VBOOT) += tss/tcg-2.0/tss.c
 
 ## TSPI
 
-ramstage-y += tspi/tspi.c
-romstage-y += tspi/tspi.c
+ramstage-y += tspi/tspi.c tspi/log.c
+romstage-y += tspi/tspi.c tspi/log.c
 
-verstage-$(CONFIG_VBOOT) += tspi/tspi.c
-postcar-$(CONFIG_VBOOT) += tspi/tspi.c
+verstage-$(CONFIG_VBOOT) += tspi/tspi.c tspi/log.c
+postcar-$(CONFIG_VBOOT) += tspi/tspi.c tspi/log.c
 
 endif # CONFIG_TPM2
diff --git a/src/security/tpm/tspi.h b/src/security/tpm/tspi.h
index fdc9e1c187..01b2984599 100644
--- a/src/security/tpm/tspi.h
+++ b/src/security/tpm/tspi.h
@@ -18,6 +18,18 @@
 #define TSPI_H_
 
 #include <security/tpm/tss.h>
+#include <commonlib/tcpa_log_serialized.h>
+
+/**
+ * Setup TCPA cbmem log.
+ */
+void tcpa_log_init(void);
+
+/**
+ * Add table entry for cbmem TCPA log.
+ */
+int tcpa_log_add_table_entry(const char *name, const uint32_t pcr,
+			     const uint8_t *digest, const size_t digest_length);
 
 /**
  * Ask vboot for a digest and extend a TPM PCR with it.
diff --git a/src/security/tpm/tspi/log.c b/src/security/tpm/tspi/log.c
new file mode 100644
index 0000000000..6091dfe5b9
--- /dev/null
+++ b/src/security/tpm/tspi/log.c
@@ -0,0 +1,75 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 Facebook Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <string.h>
+#include <cbmem.h>
+#include <console/console.h>
+#include <security/tpm/tspi.h>
+
+void tcpa_log_init(void)
+{
+	const struct cbmem_entry *ce;
+	struct tcpa_table *tclt;
+
+	if (!cbmem_possibly_online())
+		return;
+
+	ce = cbmem_entry_find(CBMEM_ID_TCPA_LOG);
+	if (ce)
+		return;
+
+	tclt = cbmem_add(CBMEM_ID_TCPA_LOG,
+			 sizeof(struct tcpa_table) +
+				 MAX_TCPA_LOG_ENTRIES *
+					 sizeof(struct tcpa_entry));
+
+	if (!tclt)
+		return;
+
+	tclt->max_entries = MAX_TCPA_LOG_ENTRIES;
+	tclt->num_entries = 0;
+
+	printk(BIOS_DEBUG, "TCPA log created at %p\n", tclt);
+}
+
+int tcpa_log_add_table_entry(const char *name, const uint32_t pcr,
+			     const uint8_t *digest, const size_t digest_length)
+{
+	MAYBE_STATIC struct tcpa_table *tclt = NULL;
+	struct tcpa_entry *tce;
+
+	if (!cbmem_possibly_online())
+		return -1;
+
+	tclt = cbmem_find(CBMEM_ID_TCPA_LOG);
+	if (!tclt) {
+		printk(BIOS_ERR, "ERROR: No TCPA log table found\n");
+		return -1;
+	}
+
+	if (tclt->num_entries == tclt->max_entries) {
+		printk(BIOS_WARNING, "ERROR: TCPA log table is full\n");
+		return -1;
+	}
+
+	tce = &tclt->entries[tclt->num_entries++];
+
+	memcpy(tce->name, name, TCPA_PCR_HASH_NAME);
+	tce->pcr = pcr;
+	memcpy(tce->digest, digest, digest_length);
+	tce->digest_length = digest_length;
+
+	return 0;
+}