1 files changed, 158 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
new file mode 100644
index 000000000..63979aefc
--- /dev/null
+++ b/security/integrity/ima/ima_init.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ *
+ * File: ima_init.c
+ *             initialization and cleanup functions
+ */
+
+#include <linux/init.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/ima.h>
+#include <generated/utsrelease.h>
+
+#include "ima.h"
+
+/* name for boot aggregate entry */
+const char boot_aggregate_name[] = "boot_aggregate";
+struct tpm_chip *ima_tpm_chip;
+
+/* Add the boot aggregate to the IMA measurement list and extend
+ * the PCR register.
+ *
+ * Calculate the boot aggregate, a hash 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;
+	struct ima_event_data event_data = { .iint = iint,
+					     .filename = boot_aggregate_name };
+	struct ima_max_digest_data hash;
+	int result = -ENOMEM;
+	int violation = 0;
+
+	memset(iint, 0, sizeof(*iint));
+	memset(&hash, 0, sizeof(hash));
+	iint->ima_hash = &hash.hdr;
+	iint->ima_hash->algo = ima_hash_algo;
+	iint->ima_hash->length = hash_digest_size[ima_hash_algo];
+
+	/*
+	 * With TPM 2.0 hash agility, TPM chips could support multiple TPM
+	 * PCR banks, allowing firmware to configure and enable different
+	 * banks.  The SHA1 bank is not necessarily enabled.
+	 *
+	 * Use the same hash algorithm for reading the TPM PCRs as for
+	 * calculating the boot aggregate digest.  Preference is given to
+	 * the configured IMA default hash algorithm.  Otherwise, use the
+	 * TCG required banks - SHA256 for TPM 2.0, SHA1 for TPM 1.2.
+	 * Ultimately select SHA1 also for TPM 2.0 if the SHA256 PCR bank
+	 * is not found.
+	 */
+	if (ima_tpm_chip) {
+		result = ima_calc_boot_aggregate(&hash.hdr);
+		if (result < 0) {
+			audit_cause = "hashing_error";
+			goto err_out;
+		}
+	}
+
+	result = ima_alloc_init_template(&event_data, &entry, NULL);
+	if (result < 0) {
+		audit_cause = "alloc_entry";
+		goto err_out;
+	}
+
+	result = ima_store_template(entry, violation, NULL,
+				    boot_aggregate_name,
+				    CONFIG_IMA_MEASURE_PCR_IDX);
+	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;
+}
+
+#ifdef CONFIG_IMA_LOAD_X509
+void __init ima_load_x509(void)
+{
+	int unset_flags = ima_policy_flag & IMA_APPRAISE;
+
+	ima_policy_flag &= ~unset_flags;
+	integrity_load_x509(INTEGRITY_KEYRING_IMA, CONFIG_IMA_X509_PATH);
+
+	/* load also EVM key to avoid appraisal */
+	evm_load_x509();
+
+	ima_policy_flag |= unset_flags;
+}
+#endif
+
+int __init ima_init(void)
+{
+	int rc;
+
+	ima_tpm_chip = tpm_default_chip();
+	if (!ima_tpm_chip)
+		pr_info("No TPM chip found, activating TPM-bypass!\n");
+
+	rc = integrity_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;
+
+	/* It can be called before ima_init_digests(), it does not use TPM. */
+	ima_load_kexec_buffer();
+
+	rc = ima_init_digests();
+	if (rc != 0)
+		return rc;
+	rc = ima_add_boot_aggregate();	/* boot aggregate must be first entry */
+	if (rc != 0)
+		return rc;
+
+	ima_init_policy();
+
+	rc = ima_fs_init();
+	if (rc != 0)
+		return rc;
+
+	ima_init_key_queue();
+
+	ima_measure_critical_data("kernel_info", "kernel_version",
+				  UTS_RELEASE, strlen(UTS_RELEASE), false,
+				  NULL, 0);
+
+	return rc;
+}