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..c2a46e40999
--- /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_set_buf(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_set_buf(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;
+}