1 /* 2 * ecryptfs_format.c: helper functions for the encrypted key type 3 * 4 * Copyright (C) 2006 International Business Machines Corp. 5 * Copyright (C) 2010 Politecnico di Torino, Italy 6 * TORSEC group -- http://security.polito.it 7 * 8 * Authors: 9 * Michael A. Halcrow <mahalcro@us.ibm.com> 10 * Tyler Hicks <tyhicks@ou.edu> 11 * Roberto Sassu <roberto.sassu@polito.it> 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation, version 2 of the License. 16 */ 17 18 #include <linux/module.h> 19 #include "ecryptfs_format.h" 20 21 u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok) 22 { 23 return auth_tok->token.password.session_key_encryption_key; 24 } 25 EXPORT_SYMBOL(ecryptfs_get_auth_tok_key); 26 27 /* 28 * ecryptfs_get_versions() 29 * 30 * Source code taken from the software 'ecryptfs-utils' version 83. 31 * 32 */ 33 void ecryptfs_get_versions(int *major, int *minor, int *file_version) 34 { 35 *major = ECRYPTFS_VERSION_MAJOR; 36 *minor = ECRYPTFS_VERSION_MINOR; 37 if (file_version) 38 *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION; 39 } 40 EXPORT_SYMBOL(ecryptfs_get_versions); 41 42 /* 43 * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure 44 * 45 * Fill the ecryptfs_auth_tok structure with required ecryptfs data. 46 * The source code is inspired to the original function generate_payload() 47 * shipped with the software 'ecryptfs-utils' version 83. 48 * 49 */ 50 int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, 51 const char *key_desc) 52 { 53 int major, minor; 54 55 ecryptfs_get_versions(&major, &minor, NULL); 56 auth_tok->version = (((uint16_t)(major << 8) & 0xFF00) 57 | ((uint16_t)minor & 0x00FF)); 58 auth_tok->token_type = ECRYPTFS_PASSWORD; 59 strncpy((char *)auth_tok->token.password.signature, key_desc, 60 ECRYPTFS_PASSWORD_SIG_SIZE); 61 auth_tok->token.password.session_key_encryption_key_bytes = 62 ECRYPTFS_MAX_KEY_BYTES; 63 /* 64 * Removed auth_tok->token.password.salt and 65 * auth_tok->token.password.session_key_encryption_key 66 * initialization from the original code 67 */ 68 /* TODO: Make the hash parameterizable via policy */ 69 auth_tok->token.password.flags |= 70 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET; 71 /* The kernel code will encrypt the session key. */ 72 auth_tok->session_key.encrypted_key[0] = 0; 73 auth_tok->session_key.encrypted_key_size = 0; 74 /* Default; subject to change by kernel eCryptfs */ 75 auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512; 76 auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD); 77 return 0; 78 } 79 EXPORT_SYMBOL(ecryptfs_fill_auth_tok); 80 81 MODULE_LICENSE("GPL"); 82