efi_loader: Add an S-CRTM even for firmware version

Message ID 20210324145046.1220041-1-ilias.apalodimas@linaro.org
State Accepted
Commit f69a2016b6330b70915c371491af33f5fd58c849
Headers show
Series
  • efi_loader: Add an S-CRTM even for firmware version
Related show

Commit Message

Ilias Apalodimas March 24, 2021, 2:50 p.m.
TCG PC Client Platform Firmware Profile Spec mandates that an S-CRTM
event for the version identifier using the event type EV_S_CRTM_VERSION
must be measured.

So since we are trying to add more conformance into U-Boot, let's add
the event using U_BOOT_VERSION_STRING, extend PCR[0] accordingly and log
it in the EventLog

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

---
Heinrich this won't apply without my previous patch fixing EFI TCG memory 
when the protocol installation fails

 lib/efi_loader/efi_tcg2.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

-- 
2.31.0

Patch

diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 02de63808f9a..c0efd867a486 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -13,6 +13,7 @@ 
 #include <efi_loader.h>
 #include <efi_tcg2.h>
 #include <log.h>
+#include <version.h>
 #include <tpm-v2.h>
 #include <u-boot/sha1.h>
 #include <u-boot/sha256.h>
@@ -1051,6 +1052,36 @@  out:
 	return ret;
 }
 
+/**
+ * efi_append_scrtm_version - Append an S-CRTM EV_S_CRTM_VERSION event on the
+ *			      eventlog and extend the PCRs
+ *
+ * @dev:	TPM device
+ *
+ * @Return:	status code
+ */
+static efi_status_t efi_append_scrtm_version(struct udevice *dev)
+{
+	struct tpml_digest_values digest_list;
+	u8 ver[] = U_BOOT_VERSION_STRING;
+	const int pcr_index = 0;
+	efi_status_t ret;
+
+	ret = tcg2_create_digest(ver, sizeof(ver), &digest_list);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_pcr_extend(dev, pcr_index, &digest_list);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_agile_log_append(pcr_index, EV_S_CRTM_VERSION, &digest_list,
+				    sizeof(ver), ver);
+
+out:
+	return ret;
+}
+
 /**
  * efi_tcg2_register() - register EFI_TCG2_PROTOCOL
  *
@@ -1074,6 +1105,10 @@  efi_status_t efi_tcg2_register(void)
 	if (ret != EFI_SUCCESS)
 		goto fail;
 
+	ret = efi_append_scrtm_version(dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
 	ret = efi_add_protocol(efi_root, &efi_guid_tcg2_protocol,
 			       (void *)&efi_tcg2_protocol);
 	if (ret != EFI_SUCCESS) {