Fixed MTP to work with TWRP

security/integrity/ima/ima_init.c

@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Reiner Sailer      <sailer@watson.ibm.com>
+ * Leendert van Doorn <leendert@watson.ibm.com>
+ * Mimi Zohar         <zohar@us.ibm.com>
+ *
+ * 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.
+ *
+ * File: ima_init.c
+ *             initialization and cleanup functions
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <crypto/hash_info.h>
+#include "ima.h"
+
+/* name for boot aggregate entry */
+static const char *boot_aggregate_name = "boot_aggregate";
+int ima_used_chip;
+
+/* Add the boot aggregate to the IMA measurement list and extend
+ * the PCR register.
+ *
+ * Calculate the boot aggregate, a SHA1 over tpm registers 0-7,
+ * assuming a TPM chip exists, and zeroes if the TPM chip does not
+ * exist.  Add the boot aggregate measurement to the measurement
+ * list and extend the PCR register.
+ *
+ * If a tpm chip does not exist, indicate the core root of trust is
+ * not hardware based by invalidating the aggregate PCR value.
+ * (The aggregate PCR value is invalidated by adding one value to
+ * the measurement list and extending the aggregate PCR value with
+ * a different value.) Violations add a zero entry to the measurement
+ * list and extend the aggregate PCR value with ff...ff's.
+ */
+static int __init ima_add_boot_aggregate(void)
+{
+	static const char op[] = "add_boot_aggregate";
+	const char *audit_cause = "ENOMEM";
+	struct ima_template_entry *entry;
+	struct integrity_iint_cache tmp_iint, *iint = &tmp_iint;
+	int result = -ENOMEM;
+	int violation = 0;
+	struct {
+		struct ima_digest_data hdr;
+		char digest[TPM_DIGEST_SIZE];
+	} hash;
+
+	memset(iint, 0, sizeof(*iint));
+	memset(&hash, 0, sizeof(hash));
+	iint->ima_hash = &hash.hdr;
+	iint->ima_hash->algo = HASH_ALGO_SHA1;
+	iint->ima_hash->length = SHA1_DIGEST_SIZE;
+
+	if (ima_used_chip) {
+		result = ima_calc_boot_aggregate(&hash.hdr);
+		if (result < 0) {
+			audit_cause = "hashing_error";
+			goto err_out;
+		}
+	}
+
+	result = ima_alloc_init_template(iint, NULL, boot_aggregate_name,
+					 NULL, 0, &entry);
+	if (result < 0) {
+		audit_cause = "alloc_entry";
+		goto err_out;
+	}
+
+	result = ima_store_template(entry, violation, NULL,
+				    boot_aggregate_name);
+	if (result < 0) {
+		ima_free_template_entry(entry);
+		audit_cause = "store_entry";
+		goto err_out;
+	}
+	return 0;
+err_out:
+	integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
+			    audit_cause, result, 0);
+	return result;
+}
+
+int __init ima_init(void)
+{
+	u8 pcr_i[TPM_DIGEST_SIZE];
+	int rc;
+
+	ima_used_chip = 0;
+	rc = tpm_pcr_read(TPM_ANY_NUM, 0, pcr_i);
+	if (rc == 0)
+		ima_used_chip = 1;
+
+	if (!ima_used_chip)
+		pr_info("No TPM chip found, activating TPM-bypass!\n");
+
+	rc = ima_init_keyring(INTEGRITY_KEYRING_IMA);
+	if (rc)
+		return rc;
+
+	rc = ima_init_crypto();
+	if (rc)
+		return rc;
+	rc = ima_init_template();
+	if (rc != 0)
+		return rc;
+
+	rc = ima_add_boot_aggregate();	/* boot aggregate must be first entry */
+	if (rc != 0)
+		return rc;
+
+	ima_init_policy();
+
+	return ima_fs_init();
+}