1 files changed, 140 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
new file mode 100644
index 00000000000..50d572b74ca
--- /dev/null
+++ b/security/integrity/ima/ima_crypto.c
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ * Kylene Hall <kjhall@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_crypto.c
+ * 	Calculates md5/sha1 file hash, template hash, boot-aggreate hash
+ */
+
+#include <linux/kernel.h>
+#include <linux/file.h>
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+#include <linux/err.h>
+#include "ima.h"
+
+static int init_desc(struct hash_desc *desc)
+{
+	int rc;
+
+	desc->tfm = crypto_alloc_hash(ima_hash, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(desc->tfm)) {
+		pr_info("failed to load %s transform: %ld\n",
+			ima_hash, PTR_ERR(desc->tfm));
+		rc = PTR_ERR(desc->tfm);
+		return rc;
+	}
+	desc->flags = 0;
+	rc = crypto_hash_init(desc);
+	if (rc)
+		crypto_free_hash(desc->tfm);
+	return rc;
+}
+
+/*
+ * Calculate the MD5/SHA1 file digest
+ */
+int ima_calc_hash(struct file *file, char *digest)
+{
+	struct hash_desc desc;
+	struct scatterlist sg[1];
+	loff_t i_size;
+	char *rbuf;
+	int rc, offset = 0;
+
+	rc = init_desc(&desc);
+	if (rc != 0)
+		return rc;
+
+	rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!rbuf) {
+		rc = -ENOMEM;
+		goto out;
+	}
+	i_size = i_size_read(file->f_dentry->d_inode);
+	while (offset < i_size) {
+		int rbuf_len;
+
+		rbuf_len = kernel_read(file, offset, rbuf, PAGE_SIZE);
+		if (rbuf_len < 0) {
+			rc = rbuf_len;
+			break;
+		}
+		offset += rbuf_len;
+		sg_init_one(sg, rbuf, rbuf_len);
+
+		rc = crypto_hash_update(&desc, sg, rbuf_len);
+		if (rc)
+			break;
+	}
+	kfree(rbuf);
+	if (!rc)
+		rc = crypto_hash_final(&desc, digest);
+out:
+	crypto_free_hash(desc.tfm);
+	return rc;
+}
+
+/*
+ * Calculate the hash of a given template
+ */
+int ima_calc_template_hash(int template_len, void *template, char *digest)
+{
+	struct hash_desc desc;
+	struct scatterlist sg[1];
+	int rc;
+
+	rc = init_desc(&desc);
+	if (rc != 0)
+		return rc;
+
+	sg_init_one(sg, template, template_len);
+	rc = crypto_hash_update(&desc, sg, template_len);
+	if (!rc)
+		rc = crypto_hash_final(&desc, digest);
+	crypto_free_hash(desc.tfm);
+	return rc;
+}
+
+static void ima_pcrread(int idx, u8 *pcr)
+{
+	if (!ima_used_chip)
+		return;
+
+	if (tpm_pcr_read(TPM_ANY_NUM, idx, pcr) != 0)
+		pr_err("Error Communicating to TPM chip\n");
+}
+
+/*
+ * Calculate the boot aggregate hash
+ */
+int ima_calc_boot_aggregate(char *digest)
+{
+	struct hash_desc desc;
+	struct scatterlist sg;
+	u8 pcr_i[IMA_DIGEST_SIZE];
+	int rc, i;
+
+	rc = init_desc(&desc);
+	if (rc != 0)
+		return rc;
+
+	/* cumulative sha1 over tpm registers 0-7 */
+	for (i = TPM_PCR0; i < TPM_PCR8; i++) {
+		ima_pcrread(i, pcr_i);
+		/* now accumulate with current aggregate */
+		sg_init_one(&sg, pcr_i, IMA_DIGEST_SIZE);
+		rc = crypto_hash_update(&desc, &sg, IMA_DIGEST_SIZE);
+	}
+	if (!rc)
+		crypto_hash_final(&desc, digest);
+	crypto_free_hash(desc.tfm);
+	return rc;
+}