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-rw-r--r--security/keys/Makefile2
-rw-r--r--security/keys/ecryptfs_format.c81
-rw-r--r--security/keys/ecryptfs_format.h30
-rw-r--r--security/keys/encrypted.c75
4 files changed, 180 insertions, 8 deletions
diff --git a/security/keys/Makefile b/security/keys/Makefile
index 1bf090a885fe..b34cc6ee6900 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -14,7 +14,7 @@ obj-y := \
user_defined.o
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
-obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted.o
+obj-$(CONFIG_ENCRYPTED_KEYS) += ecryptfs_format.o encrypted.o
obj-$(CONFIG_KEYS_COMPAT) += compat.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_SYSCTL) += sysctl.o
diff --git a/security/keys/ecryptfs_format.c b/security/keys/ecryptfs_format.c
new file mode 100644
index 000000000000..6daa3b6ff9ed
--- /dev/null
+++ b/security/keys/ecryptfs_format.c
@@ -0,0 +1,81 @@
+/*
+ * ecryptfs_format.c: helper functions for the encrypted key type
+ *
+ * Copyright (C) 2006 International Business Machines Corp.
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ * TORSEC group -- http://security.polito.it
+ *
+ * Authors:
+ * Michael A. Halcrow <mahalcro@us.ibm.com>
+ * Tyler Hicks <tyhicks@ou.edu>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include "ecryptfs_format.h"
+
+u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok)
+{
+ return auth_tok->token.password.session_key_encryption_key;
+}
+EXPORT_SYMBOL(ecryptfs_get_auth_tok_key);
+
+/*
+ * ecryptfs_get_versions()
+ *
+ * Source code taken from the software 'ecryptfs-utils' version 83.
+ *
+ */
+void ecryptfs_get_versions(int *major, int *minor, int *file_version)
+{
+ *major = ECRYPTFS_VERSION_MAJOR;
+ *minor = ECRYPTFS_VERSION_MINOR;
+ if (file_version)
+ *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION;
+}
+EXPORT_SYMBOL(ecryptfs_get_versions);
+
+/*
+ * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure
+ *
+ * Fill the ecryptfs_auth_tok structure with required ecryptfs data.
+ * The source code is inspired to the original function generate_payload()
+ * shipped with the software 'ecryptfs-utils' version 83.
+ *
+ */
+int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok,
+ const char *key_desc)
+{
+ int major, minor;
+
+ ecryptfs_get_versions(&major, &minor, NULL);
+ auth_tok->version = (((uint16_t)(major << 8) & 0xFF00)
+ | ((uint16_t)minor & 0x00FF));
+ auth_tok->token_type = ECRYPTFS_PASSWORD;
+ strncpy((char *)auth_tok->token.password.signature, key_desc,
+ ECRYPTFS_PASSWORD_SIG_SIZE);
+ auth_tok->token.password.session_key_encryption_key_bytes =
+ ECRYPTFS_MAX_KEY_BYTES;
+ /*
+ * Removed auth_tok->token.password.salt and
+ * auth_tok->token.password.session_key_encryption_key
+ * initialization from the original code
+ */
+ /* TODO: Make the hash parameterizable via policy */
+ auth_tok->token.password.flags |=
+ ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET;
+ /* The kernel code will encrypt the session key. */
+ auth_tok->session_key.encrypted_key[0] = 0;
+ auth_tok->session_key.encrypted_key_size = 0;
+ /* Default; subject to change by kernel eCryptfs */
+ auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512;
+ auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD);
+ return 0;
+}
+EXPORT_SYMBOL(ecryptfs_fill_auth_tok);
+
+MODULE_LICENSE("GPL");
diff --git a/security/keys/ecryptfs_format.h b/security/keys/ecryptfs_format.h
new file mode 100644
index 000000000000..40294de238bb
--- /dev/null
+++ b/security/keys/ecryptfs_format.h
@@ -0,0 +1,30 @@
+/*
+ * ecryptfs_format.h: helper functions for the encrypted key type
+ *
+ * Copyright (C) 2006 International Business Machines Corp.
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ * TORSEC group -- http://security.polito.it
+ *
+ * Authors:
+ * Michael A. Halcrow <mahalcro@us.ibm.com>
+ * Tyler Hicks <tyhicks@ou.edu>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * 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.
+ */
+
+#ifndef __KEYS_ECRYPTFS_H
+#define __KEYS_ECRYPTFS_H
+
+#include <linux/ecryptfs.h>
+
+#define PGP_DIGEST_ALGO_SHA512 10
+
+u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok);
+void ecryptfs_get_versions(int *major, int *minor, int *file_version);
+int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok,
+ const char *key_desc);
+
+#endif /* __KEYS_ECRYPTFS_H */
diff --git a/security/keys/encrypted.c b/security/keys/encrypted.c
index 89981c987ba7..e7eca9ec4c65 100644
--- a/security/keys/encrypted.c
+++ b/security/keys/encrypted.c
@@ -29,11 +29,13 @@
#include <linux/rcupdate.h>
#include <linux/scatterlist.h>
#include <linux/crypto.h>
+#include <linux/ctype.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
#include <crypto/aes.h>
#include "encrypted.h"
+#include "ecryptfs_format.h"
static const char KEY_TRUSTED_PREFIX[] = "trusted:";
static const char KEY_USER_PREFIX[] = "user:";
@@ -41,11 +43,13 @@ static const char hash_alg[] = "sha256";
static const char hmac_alg[] = "hmac(sha256)";
static const char blkcipher_alg[] = "cbc(aes)";
static const char key_format_default[] = "default";
+static const char key_format_ecryptfs[] = "ecryptfs";
static unsigned int ivsize;
static int blksize;
#define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1)
#define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1)
+#define KEY_ECRYPTFS_DESC_LEN 16
#define HASH_SIZE SHA256_DIGEST_SIZE
#define MAX_DATA_SIZE 4096
#define MIN_DATA_SIZE 20
@@ -63,11 +67,12 @@ enum {
};
enum {
- Opt_error = -1, Opt_default
+ Opt_error = -1, Opt_default, Opt_ecryptfs
};
static const match_table_t key_format_tokens = {
{Opt_default, "default"},
+ {Opt_ecryptfs, "ecryptfs"},
{Opt_error, NULL}
};
@@ -95,6 +100,34 @@ static int aes_get_sizes(void)
}
/*
+ * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key
+ *
+ * The description of a encrypted key with format 'ecryptfs' must contain
+ * exactly 16 hexadecimal characters.
+ *
+ */
+static int valid_ecryptfs_desc(const char *ecryptfs_desc)
+{
+ int i;
+
+ if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) {
+ pr_err("encrypted_key: key description must be %d hexadecimal "
+ "characters long\n", KEY_ECRYPTFS_DESC_LEN);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) {
+ if (!isxdigit(ecryptfs_desc[i])) {
+ pr_err("encrypted_key: key description must contain "
+ "only hexadecimal characters\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/*
* valid_master_desc - verify the 'key-type:desc' of a new/updated master-key
*
* key-type:= "trusted:" | "user:"
@@ -158,7 +191,7 @@ static int datablob_parse(char *datablob, const char **format,
}
key_cmd = match_token(keyword, key_tokens, args);
- /* Get optional format: default */
+ /* Get optional format: default | ecryptfs */
p = strsep(&datablob, " \t");
if (!p) {
pr_err("encrypted_key: insufficient parameters specified\n");
@@ -167,6 +200,7 @@ static int datablob_parse(char *datablob, const char **format,
key_format = match_token(p, key_format_tokens, args);
switch (key_format) {
+ case Opt_ecryptfs:
case Opt_default:
*format = p;
*master_desc = strsep(&datablob, " \t");
@@ -601,6 +635,17 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
format_len = (!format) ? strlen(key_format_default) : strlen(format);
decrypted_datalen = dlen;
payload_datalen = decrypted_datalen;
+ if (format && !strcmp(format, key_format_ecryptfs)) {
+ if (dlen != ECRYPTFS_MAX_KEY_BYTES) {
+ pr_err("encrypted_key: keylen for the ecryptfs format "
+ "must be equal to %d bytes\n",
+ ECRYPTFS_MAX_KEY_BYTES);
+ return ERR_PTR(-EINVAL);
+ }
+ decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES;
+ payload_datalen = sizeof(struct ecryptfs_auth_tok);
+ }
+
encrypted_datalen = roundup(decrypted_datalen, blksize);
datablob_len = format_len + 1 + strlen(master_desc) + 1
@@ -686,8 +731,14 @@ static void __ekey_init(struct encrypted_key_payload *epayload,
if (!format)
memcpy(epayload->format, key_format_default, format_len);
- else
+ else {
+ if (!strcmp(format, key_format_ecryptfs))
+ epayload->decrypted_data =
+ ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data);
+
memcpy(epayload->format, format, format_len);
+ }
+
memcpy(epayload->master_desc, master_desc, strlen(master_desc));
memcpy(epayload->datalen, datalen, strlen(datalen));
}
@@ -699,11 +750,21 @@ static void __ekey_init(struct encrypted_key_payload *epayload,
* itself. For an old key, decrypt the hex encoded data.
*/
static int encrypted_init(struct encrypted_key_payload *epayload,
- const char *format, const char *master_desc,
- const char *datalen, const char *hex_encoded_iv)
+ const char *key_desc, const char *format,
+ const char *master_desc, const char *datalen,
+ const char *hex_encoded_iv)
{
int ret = 0;
+ if (format && !strcmp(format, key_format_ecryptfs)) {
+ ret = valid_ecryptfs_desc(key_desc);
+ if (ret < 0)
+ return ret;
+
+ ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data,
+ key_desc);
+ }
+
__ekey_init(epayload, format, master_desc, datalen);
if (!hex_encoded_iv) {
get_random_bytes(epayload->iv, ivsize);
@@ -753,8 +814,8 @@ static int encrypted_instantiate(struct key *key, const void *data,
ret = PTR_ERR(epayload);
goto out;
}
- ret = encrypted_init(epayload, format, master_desc, decrypted_datalen,
- hex_encoded_iv);
+ ret = encrypted_init(epayload, key->description, format, master_desc,
+ decrypted_datalen, hex_encoded_iv);
if (ret < 0) {
kfree(epayload);
goto out;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 19:53:40 +0000