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
  35 #define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
  36                                  IMA_APPRAISE_SUBMASK)
  37 #define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
  38                                  IMA_COLLECTED | IMA_APPRAISED_SUBMASK)
  39
  40 /* iint subaction appraise cache flags */
  41 #define IMA_FILE_APPRAISE       0x00000100
  42 #define IMA_FILE_APPRAISED      0x00000200
  43 #define IMA_MMAP_APPRAISE       0x00000400
  44 #define IMA_MMAP_APPRAISED      0x00000800
  45 #define IMA_BPRM_APPRAISE       0x00001000
  46 #define IMA_BPRM_APPRAISED      0x00002000
  47 #define IMA_MODULE_APPRAISE     0x00004000
  48 #define IMA_MODULE_APPRAISED    0x00008000
  49 #define IMA_FIRMWARE_APPRAISE   0x00010000
  50 #define IMA_FIRMWARE_APPRAISED  0x00020000
  51 #define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
  52                                  IMA_BPRM_APPRAISE | IMA_MODULE_APPRAISE | \
  53                                  IMA_FIRMWARE_APPRAISE)
  54 #define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
  55                                  IMA_BPRM_APPRAISED | IMA_MODULE_APPRAISED | \
  56                                  IMA_FIRMWARE_APPRAISED)
  57
  58 enum evm_ima_xattr_type {
  59         IMA_XATTR_DIGEST = 0x01,
  60         EVM_XATTR_HMAC,
  61         EVM_IMA_XATTR_DIGSIG,
  62         IMA_XATTR_DIGEST_NG,
  63 };
  64
  65 struct evm_ima_xattr_data {
  66         u8 type;
  67         u8 digest[SHA1_DIGEST_SIZE];
  68 } __packed;
  69
  70 #define IMA_MAX_DIGEST_SIZE     64
  71
  72 struct ima_digest_data {
  73         u8 algo;
  74         u8 length;
  75         union {
  76                 struct {
  77                         u8 unused;
  78                         u8 type;
  79                 } sha1;
  80                 struct {
  81                         u8 type;
  82                         u8 algo;
  83                 } ng;
  84                 u8 data[2];
  85         } xattr;
  86         u8 digest[0];
  87 } __packed;
  88
  89 /*
  90  * signature format v2 - for using with asymmetric keys
  91  */
  92 struct signature_v2_hdr {
  93         uint8_t type;           /* xattr type */
  94         uint8_t version;        /* signature format version */
  95         uint8_t hash_algo;      /* Digest algorithm [enum pkey_hash_algo] */
  96         uint32_t keyid;         /* IMA key identifier - not X509/PGP specific */
  97         uint16_t sig_size;      /* signature size */
  98         uint8_t sig[0];         /* signature payload */
  99 } __packed;
 100
 101 /* integrity data associated with an inode */
 102 struct integrity_iint_cache {
 103         struct rb_node rb_node; /* rooted in integrity_iint_tree */
 104         struct inode *inode;    /* back pointer to inode in question */
 105         u64 version;            /* track inode changes */
 106         unsigned long flags;
 107         enum integrity_status ima_file_status:4;
 108         enum integrity_status ima_mmap_status:4;
 109         enum integrity_status ima_bprm_status:4;
 110         enum integrity_status ima_module_status:4;
 111         enum integrity_status ima_firmware_status:4;
 112         enum integrity_status evm_status:4;
 113         struct ima_digest_data *ima_hash;
 114 };
 115
 116 /* rbtree tree calls to lookup, insert, delete
 117  * integrity data associated with an inode.
 118  */
 119 struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
 120 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 121
 122 #define INTEGRITY_KEYRING_EVM           0
 123 #define INTEGRITY_KEYRING_MODULE        1
 124 #define INTEGRITY_KEYRING_IMA           2
 125 #define INTEGRITY_KEYRING_MAX           3
 126
 127 #ifdef CONFIG_INTEGRITY_SIGNATURE
 128
 129 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 130                             const char *digest, int digestlen);
 131
 132 int integrity_init_keyring(const unsigned int id);
 133 #else
 134
 135 static inline int integrity_digsig_verify(const unsigned int id,
 136                                           const char *sig, int siglen,
 137                                           const char *digest, int digestlen)
 138 {
 139         return -EOPNOTSUPP;
 140 }
 141
 142 static inline int integrity_init_keyring(const unsigned int id)
 143 {
 144         return 0;
 145 }
 146 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 147
 148 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
 149 int asymmetric_verify(struct key *keyring, const char *sig,
 150                       int siglen, const char *data, int datalen);
 151 #else
 152 static inline int asymmetric_verify(struct key *keyring, const char *sig,
 153                                     int siglen, const char *data, int datalen)
 154 {
 155         return -EOPNOTSUPP;
 156 }
 157 #endif
 158
 159 #ifdef CONFIG_INTEGRITY_AUDIT
 160 /* declarations */
 161 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 162                          const unsigned char *fname, const char *op,
 163                          const char *cause, int result, int info);
 164 #else
 165 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 166                                        const unsigned char *fname,
 167                                        const char *op, const char *cause,
 168                                        int result, int info)
 169 {
 170 }
 171 #endif
 172
 173 /* set during initialization */
 174 extern int iint_initialized;