linuxdebug/security/keys/encrypted-keys/ecryptfs_format.c

78 lines
2.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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 -- https://security.polito.it
*
* Authors:
* Michael A. Halcrow <mahalcro@us.ibm.com>
* Tyler Hicks <tyhicks@ou.edu>
* Roberto Sassu <roberto.sassu@polito.it>
*/
#include <linux/export.h>
#include <linux/string.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);