mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 05:34:00 +08:00
144 lines
2.9 KiB
C
144 lines
2.9 KiB
C
/*
|
|
* 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 <linux/slab.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("IMA: 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, offset = 0;
|
|
char *rbuf;
|
|
int rc;
|
|
|
|
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;
|
|
}
|
|
if (rbuf_len == 0)
|
|
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 __init ima_pcrread(int idx, u8 *pcr)
|
|
{
|
|
if (!ima_used_chip)
|
|
return;
|
|
|
|
if (tpm_pcr_read(TPM_ANY_NUM, idx, pcr) != 0)
|
|
pr_err("IMA: Error Communicating to TPM chip\n");
|
|
}
|
|
|
|
/*
|
|
* Calculate the boot aggregate hash
|
|
*/
|
|
int __init 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;
|
|
}
|