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_ACTION_RULE_FLAGS   0x06000000
  32 #define IMA_DIGSIG_REQUIRED     0x01000000
  33 #define IMA_PERMIT_DIRECTIO     0x02000000
  34 #define IMA_NEW_FILE            0x04000000
  35 #define EVM_IMMUTABLE_DIGSIG    0x08000000
  36
  37 #define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
  38                                  IMA_APPRAISE_SUBMASK)
  39 #define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
  40                                  IMA_COLLECTED | IMA_APPRAISED_SUBMASK)
  41
  42 /* iint subaction appraise cache flags */
  43 #define IMA_FILE_APPRAISE       0x00000100
  44 #define IMA_FILE_APPRAISED      0x00000200
  45 #define IMA_MMAP_APPRAISE       0x00000400
  46 #define IMA_MMAP_APPRAISED      0x00000800
  47 #define IMA_BPRM_APPRAISE       0x00001000
  48 #define IMA_BPRM_APPRAISED      0x00002000
  49 #define IMA_READ_APPRAISE       0x00004000
  50 #define IMA_READ_APPRAISED      0x00008000
  51 #define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
  52                                  IMA_BPRM_APPRAISE | IMA_READ_APPRAISE)
  53 #define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
  54                                  IMA_BPRM_APPRAISED | IMA_READ_APPRAISED)
  55
  56 /* iint cache atomic_flags */
  57 #define IMA_CHANGE_XATTR        0
  58 #define IMA_UPDATE_XATTR        1
  59 #define IMA_CHANGE_ATTR         2
  60 #define IMA_DIGSIG              3
  61 #define IMA_MUST_MEASURE        4
  62
  63 enum evm_ima_xattr_type {
  64         IMA_XATTR_DIGEST = 0x01,
  65         EVM_XATTR_HMAC,
  66         EVM_IMA_XATTR_DIGSIG,
  67         IMA_XATTR_DIGEST_NG,
  68         EVM_XATTR_PORTABLE_DIGSIG,
  69         IMA_XATTR_LAST
  70 };
  71
  72 struct evm_ima_xattr_data {
  73         u8 type;
  74         u8 digest[SHA1_DIGEST_SIZE];
  75 } __packed;
  76
  77 #define IMA_MAX_DIGEST_SIZE     64
  78
  79 struct ima_digest_data {
  80         u8 algo;
  81         u8 length;
  82         union {
  83                 struct {
  84                         u8 unused;
  85                         u8 type;
  86                 } sha1;
  87                 struct {
  88                         u8 type;
  89                         u8 algo;
  90                 } ng;
  91                 u8 data[2];
  92         } xattr;
  93         u8 digest[0];
  94 } __packed;
  95
  96 /*
  97  * signature format v2 - for using with asymmetric keys
  98  */
  99 struct signature_v2_hdr {
 100         uint8_t type;           /* xattr type */
 101         uint8_t version;        /* signature format version */
 102         uint8_t hash_algo;      /* Digest algorithm [enum hash_algo] */
 103         uint32_t keyid;         /* IMA key identifier - not X509/PGP specific */
 104         uint16_t sig_size;      /* signature size */
 105         uint8_t sig[0];         /* signature payload */
 106 } __packed;
 107
 108 /* integrity data associated with an inode */
 109 struct integrity_iint_cache {
 110         struct rb_node rb_node; /* rooted in integrity_iint_tree */
 111         struct mutex mutex;     /* protects: version, flags, digest */
 112         struct inode *inode;    /* back pointer to inode in question */
 113         u64 version;            /* track inode changes */
 114         unsigned long flags;
 115         unsigned long measured_pcrs;
 116         unsigned long atomic_flags;
 117         enum integrity_status ima_file_status:4;
 118         enum integrity_status ima_mmap_status:4;
 119         enum integrity_status ima_bprm_status:4;
 120         enum integrity_status ima_read_status:4;
 121         enum integrity_status evm_status:4;
 122         struct ima_digest_data *ima_hash;
 123 };
 124
 125 /* rbtree tree calls to lookup, insert, delete
 126  * integrity data associated with an inode.
 127  */
 128 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 129
 130 int integrity_kernel_read(struct file *file, loff_t offset,
 131                           char *addr, unsigned long count);
 132 int __init integrity_read_file(const char *path, char **data);
 133
 134 #define INTEGRITY_KEYRING_EVM           0
 135 #define INTEGRITY_KEYRING_IMA           1
 136 #define INTEGRITY_KEYRING_MODULE        2
 137 #define INTEGRITY_KEYRING_MAX           3
 138
 139 #ifdef CONFIG_INTEGRITY_SIGNATURE
 140
 141 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 142                             const char *digest, int digestlen);
 143
 144 int __init integrity_init_keyring(const unsigned int id);
 145 int __init integrity_load_x509(const unsigned int id, const char *path);
 146 #else
 147
 148 static inline int integrity_digsig_verify(const unsigned int id,
 149                                           const char *sig, int siglen,
 150                                           const char *digest, int digestlen)
 151 {
 152         return -EOPNOTSUPP;
 153 }
 154
 155 static inline int integrity_init_keyring(const unsigned int id)
 156 {
 157         return 0;
 158 }
 159 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 160
 161 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
 162 int asymmetric_verify(struct key *keyring, const char *sig,
 163                       int siglen, const char *data, int datalen);
 164 #else
 165 static inline int asymmetric_verify(struct key *keyring, const char *sig,
 166                                     int siglen, const char *data, int datalen)
 167 {
 168         return -EOPNOTSUPP;
 169 }
 170 #endif
 171
 172 #ifdef CONFIG_IMA_LOAD_X509
 173 void __init ima_load_x509(void);
 174 #else
 175 static inline void ima_load_x509(void)
 176 {
 177 }
 178 #endif
 179
 180 #ifdef CONFIG_EVM_LOAD_X509
 181 void __init evm_load_x509(void);
 182 #else
 183 static inline void evm_load_x509(void)
 184 {
 185 }
 186 #endif
 187
 188 #ifdef CONFIG_INTEGRITY_AUDIT
 189 /* declarations */
 190 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 191                          const unsigned char *fname, const char *op,
 192                          const char *cause, int result, int info);
 193 #else
 194 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 195                                        const unsigned char *fname,
 196                                        const char *op, const char *cause,
 197                                        int result, int info)
 198 {
 199 }
 200 #endif