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>

1 files changed, 75 insertions, 0 deletions

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;
+}