security/integrity/integrity.h

   1 /*
   2  * Copyright (C) 2009-2010 IBM Corporation
   3  *
   4  * Authors:
   5  * Mimi Zohar <zohar@us.ibm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation, version 2 of the
  10  * License.
  11  *
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/integrity.h>
  16 #include <crypto/sha.h>
  17 #include <linux/key.h>
  18
  19 /* iint action cache flags */
  20 #define IMA_MEASURE             0x00000001
  21 #define IMA_MEASURED            0x00000002
  22 #define IMA_APPRAISE            0x00000004
  23 #define IMA_APPRAISED           0x00000008
  24 /*#define IMA_COLLECT           0x00000010  do not use this flag */
  25 #define IMA_COLLECTED           0x00000020
  26 #define IMA_AUDIT               0x00000040
  27 #define IMA_AUDITED             0x00000080
  28
  29 /* iint cache flags */
  30 #define IMA_ACTION_FLAGS        0xff000000
  31 #define IMA_DIGSIG              0x01000000
  32 #define IMA_DIGSIG_REQUIRED     0x02000000
  33 #define IMA_PERMIT_DIRECTIO     0x04000000
  34 #define IMA_NEW_FILE            0x08000000
  35
  36 #define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
  37                                  IMA_APPRAISE_SUBMASK)
  38 #define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
  39                                  IMA_COLLECTED | IMA_APPRAISED_SUBMASK)
  40
  41 /* iint subaction appraise cache flags */
  42 #define IMA_FILE_APPRAISE       0x00000100
  43 #define IMA_FILE_APPRAISED      0x00000200
  44 #define IMA_MMAP_APPRAISE       0x00000400
  45 #define IMA_MMAP_APPRAISED      0x00000800
  46 #define IMA_BPRM_APPRAISE       0x00001000
  47 #define IMA_BPRM_APPRAISED      0x00002000
  48 #define IMA_MODULE_APPRAISE     0x00004000
  49 #define IMA_MODULE_APPRAISED    0x00008000
  50 #define IMA_FIRMWARE_APPRAISE   0x00010000
  51 #define IMA_FIRMWARE_APPRAISED  0x00020000
  52 #define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
  53                                  IMA_BPRM_APPRAISE | IMA_MODULE_APPRAISE | \
  54                                  IMA_FIRMWARE_APPRAISE)
  55 #define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
  56                                  IMA_BPRM_APPRAISED | IMA_MODULE_APPRAISED | \
  57                                  IMA_FIRMWARE_APPRAISED)
  58
  59 enum evm_ima_xattr_type {
  60         IMA_XATTR_DIGEST = 0x01,
  61         EVM_XATTR_HMAC,
  62         EVM_IMA_XATTR_DIGSIG,
  63         IMA_XATTR_DIGEST_NG,
  64         IMA_XATTR_LAST
  65 };
  66
  67 struct evm_ima_xattr_data {
  68         u8 type;
  69         u8 digest[SHA1_DIGEST_SIZE];
  70 } __packed;
  71
  72 #define IMA_MAX_DIGEST_SIZE     64
  73
  74 struct ima_digest_data {
  75         u8 algo;
  76         u8 length;
  77         union {
  78                 struct {
  79                         u8 unused;
  80                         u8 type;
  81                 } sha1;
  82                 struct {
  83                         u8 type;
  84                         u8 algo;
  85                 } ng;
  86                 u8 data[2];
  87         } xattr;
  88         u8 digest[0];
  89 } __packed;
  90
  91 /*
  92  * signature format v2 - for using with asymmetric keys
  93  */
  94 struct signature_v2_hdr {
  95         uint8_t type;           /* xattr type */
  96         uint8_t version;        /* signature format version */
  97         uint8_t hash_algo;      /* Digest algorithm [enum pkey_hash_algo] */
  98         uint32_t keyid;         /* IMA key identifier - not X509/PGP specific */
  99         uint16_t sig_size;      /* signature size */
 100         uint8_t sig[0];         /* signature payload */
 101 } __packed;
 102
 103 /* integrity data associated with an inode */
 104 struct integrity_iint_cache {
 105         struct rb_node rb_node; /* rooted in integrity_iint_tree */
 106         struct inode *inode;    /* back pointer to inode in question */
 107         u64 version;            /* track inode changes */
 108         unsigned long flags;
 109         enum integrity_status ima_file_status:4;
 110         enum integrity_status ima_mmap_status:4;
 111         enum integrity_status ima_bprm_status:4;
 112         enum integrity_status ima_module_status:4;
 113         enum integrity_status ima_firmware_status:4;
 114         enum integrity_status evm_status:4;
 115         struct ima_digest_data *ima_hash;
 116 };
 117
 118 /* rbtree tree calls to lookup, insert, delete
 119  * integrity data associated with an inode.
 120  */
 121 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 122
 123 #define INTEGRITY_KEYRING_EVM           0
 124 #define INTEGRITY_KEYRING_MODULE        1
 125 #define INTEGRITY_KEYRING_IMA           2
 126 #define INTEGRITY_KEYRING_MAX           3
 127
 128 #ifdef CONFIG_INTEGRITY_SIGNATURE
 129
 130 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 131                             const char *digest, int digestlen);
 132
 133 int integrity_init_keyring(const unsigned int id);
 134 #else
 135
 136 static inline int integrity_digsig_verify(const unsigned int id,
 137                                           const char *sig, int siglen,
 138                                           const char *digest, int digestlen)
 139 {
 140         return -EOPNOTSUPP;
 141 }
 142
 143 static inline int integrity_init_keyring(const unsigned int id)
 144 {
 145         return 0;
 146 }
 147 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 148
 149 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
 150 int asymmetric_verify(struct key *keyring, const char *sig,
 151                       int siglen, const char *data, int datalen);
 152 #else
 153 static inline int asymmetric_verify(struct key *keyring, const char *sig,
 154                                     int siglen, const char *data, int datalen)
 155 {
 156         return -EOPNOTSUPP;
 157 }
 158 #endif
 159
 160 #ifdef CONFIG_INTEGRITY_AUDIT
 161 /* declarations */
 162 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 163                          const unsigned char *fname, const char *op,
 164                          const char *cause, int result, int info);
 165 #else
 166 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 167                                        const unsigned char *fname,
 168                                        const char *op, const char *cause,
 169                                        int result, int info)
 170 {
 171 }
 172 #endif
 173
 174 /* set during initialization */
 175 extern int iint_initialized;