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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - security/integrity/ima/ima_crypto.c
2 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
5 * Mimi Zohar <zohar@us.ibm.com>
6 * Kylene Hall <kjhall@us.ibm.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, version 2 of the License.
13 * Calculates md5/sha1 file hash, template hash, boot-aggreate hash
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/kernel.h>
19 #include <linux/file.h>
20 #include <linux/crypto.h>
21 #include <linux/scatterlist.h>
22 #include <linux/err.h>
23 #include <linux/slab.h>
24 #include <crypto/hash.h>
25 #include <crypto/hash_info.h>
28 static struct crypto_shash
*ima_shash_tfm
;
30 int ima_init_crypto(void)
34 ima_shash_tfm
= crypto_alloc_shash(hash_algo_name
[ima_hash_algo
], 0, 0);
35 if (IS_ERR(ima_shash_tfm
)) {
36 rc
= PTR_ERR(ima_shash_tfm
);
37 pr_err("Can not allocate %s (reason: %ld)\n",
38 hash_algo_name
[ima_hash_algo
], rc
);
44 static struct crypto_shash
*ima_alloc_tfm(enum hash_algo algo
)
46 struct crypto_shash
*tfm
= ima_shash_tfm
;
49 if (algo
!= ima_hash_algo
&& algo
< HASH_ALGO__LAST
) {
50 tfm
= crypto_alloc_shash(hash_algo_name
[algo
], 0, 0);
53 pr_err("Can not allocate %s (reason: %d)\n",
54 hash_algo_name
[algo
], rc
);
60 static void ima_free_tfm(struct crypto_shash
*tfm
)
62 if (tfm
!= ima_shash_tfm
)
63 crypto_free_shash(tfm
);
67 * Calculate the MD5/SHA1 file digest
69 static int ima_calc_file_hash_tfm(struct file
*file
,
70 struct ima_digest_data
*hash
,
71 struct crypto_shash
*tfm
)
73 loff_t i_size
, offset
= 0;
77 struct shash_desc shash
;
78 char ctx
[crypto_shash_descsize(tfm
)];
84 hash
->length
= crypto_shash_digestsize(tfm
);
86 rc
= crypto_shash_init(&desc
.shash
);
90 i_size
= i_size_read(file_inode(file
));
95 rbuf
= kzalloc(PAGE_SIZE
, GFP_KERNEL
);
99 if (!(file
->f_mode
& FMODE_READ
)) {
100 file
->f_mode
|= FMODE_READ
;
104 while (offset
< i_size
) {
107 rbuf_len
= kernel_read(file
, offset
, rbuf
, PAGE_SIZE
);
116 rc
= crypto_shash_update(&desc
.shash
, rbuf
, rbuf_len
);
121 file
->f_mode
&= ~FMODE_READ
;
125 rc
= crypto_shash_final(&desc
.shash
, hash
->digest
);
129 int ima_calc_file_hash(struct file
*file
, struct ima_digest_data
*hash
)
131 struct crypto_shash
*tfm
;
134 tfm
= ima_alloc_tfm(hash
->algo
);
138 rc
= ima_calc_file_hash_tfm(file
, hash
, tfm
);
146 * Calculate the hash of template data
148 static int ima_calc_field_array_hash_tfm(struct ima_field_data
*field_data
,
149 struct ima_template_desc
*td
,
151 struct ima_digest_data
*hash
,
152 struct crypto_shash
*tfm
)
155 struct shash_desc shash
;
156 char ctx
[crypto_shash_descsize(tfm
)];
160 desc
.shash
.tfm
= tfm
;
161 desc
.shash
.flags
= 0;
163 hash
->length
= crypto_shash_digestsize(tfm
);
165 rc
= crypto_shash_init(&desc
.shash
);
169 for (i
= 0; i
< num_fields
; i
++) {
170 u8 buffer
[IMA_EVENT_NAME_LEN_MAX
+ 1] = { 0 };
171 u8
*data_to_hash
= field_data
[i
].data
;
172 u32 datalen
= field_data
[i
].len
;
174 if (strcmp(td
->name
, IMA_TEMPLATE_IMA_NAME
) != 0) {
175 rc
= crypto_shash_update(&desc
.shash
,
176 (const u8
*) &field_data
[i
].len
,
177 sizeof(field_data
[i
].len
));
180 } else if (strcmp(td
->fields
[i
]->field_id
, "n") == 0) {
181 memcpy(buffer
, data_to_hash
, datalen
);
182 data_to_hash
= buffer
;
183 datalen
= IMA_EVENT_NAME_LEN_MAX
+ 1;
185 rc
= crypto_shash_update(&desc
.shash
, data_to_hash
, datalen
);
191 rc
= crypto_shash_final(&desc
.shash
, hash
->digest
);
196 int ima_calc_field_array_hash(struct ima_field_data
*field_data
,
197 struct ima_template_desc
*desc
, int num_fields
,
198 struct ima_digest_data
*hash
)
200 struct crypto_shash
*tfm
;
203 tfm
= ima_alloc_tfm(hash
->algo
);
207 rc
= ima_calc_field_array_hash_tfm(field_data
, desc
, num_fields
,
215 static void __init
ima_pcrread(int idx
, u8
*pcr
)
220 if (tpm_pcr_read(TPM_ANY_NUM
, idx
, pcr
) != 0)
221 pr_err("Error Communicating to TPM chip\n");
225 * Calculate the boot aggregate hash
227 static int __init
ima_calc_boot_aggregate_tfm(char *digest
,
228 struct crypto_shash
*tfm
)
230 u8 pcr_i
[TPM_DIGEST_SIZE
];
233 struct shash_desc shash
;
234 char ctx
[crypto_shash_descsize(tfm
)];
237 desc
.shash
.tfm
= tfm
;
238 desc
.shash
.flags
= 0;
240 rc
= crypto_shash_init(&desc
.shash
);
244 /* cumulative sha1 over tpm registers 0-7 */
245 for (i
= TPM_PCR0
; i
< TPM_PCR8
; i
++) {
246 ima_pcrread(i
, pcr_i
);
247 /* now accumulate with current aggregate */
248 rc
= crypto_shash_update(&desc
.shash
, pcr_i
, TPM_DIGEST_SIZE
);
251 crypto_shash_final(&desc
.shash
, digest
);
255 int __init
ima_calc_boot_aggregate(struct ima_digest_data
*hash
)
257 struct crypto_shash
*tfm
;
260 tfm
= ima_alloc_tfm(hash
->algo
);
264 hash
->length
= crypto_shash_digestsize(tfm
);
265 rc
= ima_calc_boot_aggregate_tfm(hash
->digest
, tfm
);