Revert "security/tpm/tss/tcg-2.0: Add multi digits support to tlcl_extend()"

This reverts commit fdb9805d6884090fd7bf62dbdf9c858692e55fb4.

CB:33252 wasn't reviewed by a TPM maintainer and breaks abstraction
layers (pulling TSS-details into TSPI, completely changing
interpretation of the arguments to tlcl_extend() based on TSS version).
It's also not clear why it was implemented the way it was (should have
been much easier and cleaner ways to achieve the same thing).

Since the author is not reacting, let's revert it for now. It can be
cleaned up and resubmitted later. (Not reverting the header changes
since those are not objectionable, and there are later patches dependent
on it.)

Change-Id: Ice44f55c75a0acc07794fe41c757a7bca75406eb
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35351
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>

2 files changed, 7 insertions, 74 deletions

diff --git a/src/security/tpm/tspi/tspi.c b/src/security/tpm/tspi/tspi.c
index e64e04fbbecb..4698a4dc8c99 100644
--- a/src/security/tpm/tspi/tspi.c
+++ b/src/security/tpm/tspi/tspi.c
@@ -4,7 +4,6 @@
  * Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
  * Copyright 2017 Facebook Inc.
  * Copyright 2018 Siemens AG
- * Copyright 2019 Eltan B.V.
  *
  * 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
@@ -21,7 +20,6 @@
 #include <security/tpm/tspi.h>
 #include <security/tpm/tss.h>
 #include <stdlib.h>
-#include <string.h>
 #if CONFIG(VBOOT)
 #include <vb2_api.h>
 #include <vb2_sha.h>
@@ -211,28 +209,7 @@ uint32_t tpm_extend_pcr(int pcr, enum vb2_hash_algorithm digest_algo,
 	if (!digest)
 		return TPM_E_IOERROR;
 
-#if CONFIG(TPM2)
-	TPML_DIGEST_VALUES tpml_digests;
-
-	tpml_digests.count = 1;
-	switch (digest_algo) {
-	case VB2_HASH_SHA1:
-		tpml_digests.digests[0].hashAlg = TPM_ALG_SHA1;
-		memcpy(tpml_digests.digests[0].digest.sha1,
-		       digest, SHA1_DIGEST_SIZE);
-		break;
-	case VB2_HASH_SHA256:
-		tpml_digests.digests[0].hashAlg = TPM_ALG_SHA256;
-		memcpy(tpml_digests.digests[0].digest.sha256,
-		       digest, SHA256_DIGEST_SIZE);
-		break;
-	default:
-		return TPM_E_IOERROR;
-	}
-	result = tlcl_extend(pcr, (uint8_t *)&tpml_digests, NULL);
-#else
 	result = tlcl_extend(pcr, digest, NULL);
-#endif
 	if (result != TPM_SUCCESS)
 		return result;
 
diff --git a/src/security/tpm/tss/tcg-2.0/tss.c b/src/security/tpm/tss/tcg-2.0/tss.c
index d9deba515dfb..16e40fe56974 100644
--- a/src/security/tpm/tss/tcg-2.0/tss.c
+++ b/src/security/tpm/tss/tcg-2.0/tss.c
@@ -127,68 +127,24 @@ uint32_t tlcl_assert_physical_presence(void)
 }
 
 /*
- * The caller will provide the digest in a 32 byte buffer
+ * The caller will provide the digest in a 32 byte buffer, let's consider it a
+ * sha256 digest.
  */
 uint32_t tlcl_extend(int pcr_num, const uint8_t *in_digest,
 		     uint8_t *out_digest)
 {
 	struct tpm2_pcr_extend_cmd pcr_ext_cmd;
 	struct tpm2_response *response;
-	int i;
-	TPML_DIGEST_VALUES *tpml_digests;
 
 	pcr_ext_cmd.pcrHandle = HR_PCR + pcr_num;
-	tpml_digests = (TPML_DIGEST_VALUES *)in_digest;
-	pcr_ext_cmd.digests.count = tpml_digests->count;
-
-	for (i = 0; i < tpml_digests->count ; i++) {
-		pcr_ext_cmd.digests.digests[i].hashAlg =
-			tpml_digests->digests[i].hashAlg;
-		switch (tpml_digests->digests[i].hashAlg) {
-		case TPM_ALG_SHA1:
-			memcpy(pcr_ext_cmd.digests.digests[i].digest.sha1,
-			       tpml_digests->digests[i].digest.sha1,
-			       SHA1_DIGEST_SIZE);
-			break;
-		case TPM_ALG_SHA256:
-			memcpy(pcr_ext_cmd.digests.digests[i].digest.sha256,
-			       tpml_digests->digests[i].digest.sha256,
-			       SHA256_DIGEST_SIZE);
-			break;
-		case TPM_ALG_SHA384:
-			memcpy(pcr_ext_cmd.digests.digests[i].digest.sha384,
-			       tpml_digests->digests[i].digest.sha384,
-			       SHA384_DIGEST_SIZE);
-			break;
-		case TPM_ALG_SHA512:
-			memcpy(pcr_ext_cmd.digests.digests[i].digest.sha512,
-			       tpml_digests->digests[i].digest.sha512,
-			       SHA512_DIGEST_SIZE);
-			break;
-		case TPM_ALG_SM3_256:
-			memcpy(pcr_ext_cmd.digests.digests[i].digest.sm3_256,
-			       tpml_digests->digests[i].digest.sm3_256,
-			       SM3_256_DIGEST_SIZE);
-			break;
-		}
-	}
+	pcr_ext_cmd.digests.count = 1;
+	pcr_ext_cmd.digests.digests[0].hashAlg = TPM_ALG_SHA256;
+	memcpy(pcr_ext_cmd.digests.digests[0].digest.sha256, in_digest,
+	       sizeof(pcr_ext_cmd.digests.digests[0].digest.sha256));
 
 	response = tpm_process_command(TPM2_PCR_Extend, &pcr_ext_cmd);
 
-	/*
-	 * Check if we are invalidating the pcrs, ignore the error if this is
-	 * the case
-	 */
-	if ((tpml_digests->count == 1) &&
-	    (tpml_digests->digests[0].hashAlg == TPM_ALG_ERROR) &&
-	    response && (response->hdr.tpm_code & ~TPM_RC_N_MASK) ==
-	      (TPM_RC_P | TPM_RC_HASH)) {
-		printk(BIOS_SPEW, "%s: TPM_RC_HASH returned this is"
-		       " expected\n", __func__);
-		return TPM_SUCCESS;
-	}
-
-	printk(BIOS_INFO, "%s: response is 0x%x\n",
+	printk(BIOS_INFO, "%s: response is %x\n",
 	       __func__, response ? response->hdr.tpm_code : -1);
 	if (!response || response->hdr.tpm_code)
 		return TPM_E_IOERROR;