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 #define IMA_HASH                0x00000100
  29 #define IMA_HASHED              0x00000200
  30
  31 /* iint cache flags */
  32 #define IMA_ACTION_FLAGS        0xff000000
  33 #define IMA_DIGSIG_REQUIRED     0x01000000
  34 #define IMA_PERMIT_DIRECTIO     0x02000000
  35 #define IMA_NEW_FILE            0x04000000
  36 #define EVM_IMMUTABLE_DIGSIG    0x08000000
  37 #define IMA_FAIL_UNVERIFIABLE_SIGS      0x10000000
  38
  39 #define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
  40                                  IMA_HASH | IMA_APPRAISE_SUBMASK)
  41 #define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
  42                                  IMA_HASHED | IMA_COLLECTED | \
  43                                  IMA_APPRAISED_SUBMASK)
  44
  45 /* iint subaction appraise cache flags */
  46 #define IMA_FILE_APPRAISE       0x00001000
  47 #define IMA_FILE_APPRAISED      0x00002000
  48 #define IMA_MMAP_APPRAISE       0x00004000
  49 #define IMA_MMAP_APPRAISED      0x00008000
  50 #define IMA_BPRM_APPRAISE       0x00010000
  51 #define IMA_BPRM_APPRAISED      0x00020000
  52 #define IMA_READ_APPRAISE       0x00040000
  53 #define IMA_READ_APPRAISED      0x00080000
  54 #define IMA_CREDS_APPRAISE      0x00100000
  55 #define IMA_CREDS_APPRAISED     0x00200000
  56 #define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
  57                                  IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \
  58                                  IMA_CREDS_APPRAISE)
  59 #define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
  60                                  IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \
  61                                  IMA_CREDS_APPRAISED)
  62
  63 /* iint cache atomic_flags */
  64 #define IMA_CHANGE_XATTR        0
  65 #define IMA_UPDATE_XATTR        1
  66 #define IMA_CHANGE_ATTR         2
  67 #define IMA_DIGSIG              3
  68 #define IMA_MUST_MEASURE        4
  69
  70 enum evm_ima_xattr_type {
  71         IMA_XATTR_DIGEST = 0x01,
  72         EVM_XATTR_HMAC,
  73         EVM_IMA_XATTR_DIGSIG,
  74         IMA_XATTR_DIGEST_NG,
  75         EVM_XATTR_PORTABLE_DIGSIG,
  76         IMA_XATTR_LAST
  77 };
  78
  79 struct evm_ima_xattr_data {
  80         u8 type;
  81         u8 digest[SHA1_DIGEST_SIZE];
  82 } __packed;
  83
  84 #define IMA_MAX_DIGEST_SIZE     64
  85
  86 struct ima_digest_data {
  87         u8 algo;
  88         u8 length;
  89         union {
  90                 struct {
  91                         u8 unused;
  92                         u8 type;
  93                 } sha1;
  94                 struct {
  95                         u8 type;
  96                         u8 algo;
  97                 } ng;
  98                 u8 data[2];
  99         } xattr;
 100         u8 digest[0];
 101 } __packed;
 102
 103 /*
 104  * signature format v2 - for using with asymmetric keys
 105  */
 106 struct signature_v2_hdr {
 107         uint8_t type;           /* xattr type */
 108         uint8_t version;        /* signature format version */
 109         uint8_t hash_algo;      /* Digest algorithm [enum hash_algo] */
 110         __be32 keyid;           /* IMA key identifier - not X509/PGP specific */
 111         __be16 sig_size;        /* signature size */
 112         uint8_t sig[0];         /* signature payload */
 113 } __packed;
 114
 115 /* integrity data associated with an inode */
 116 struct integrity_iint_cache {
 117         struct rb_node rb_node; /* rooted in integrity_iint_tree */
 118         struct mutex mutex;     /* protects: version, flags, digest */
 119         struct inode *inode;    /* back pointer to inode in question */
 120         u64 version;            /* track inode changes */
 121         unsigned long flags;
 122         unsigned long measured_pcrs;
 123         unsigned long atomic_flags;
 124         enum integrity_status ima_file_status:4;
 125         enum integrity_status ima_mmap_status:4;
 126         enum integrity_status ima_bprm_status:4;
 127         enum integrity_status ima_read_status:4;
 128         enum integrity_status ima_creds_status:4;
 129         enum integrity_status evm_status:4;
 130         struct ima_digest_data *ima_hash;
 131 };
 132
 133 /* rbtree tree calls to lookup, insert, delete
 134  * integrity data associated with an inode.
 135  */
 136 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 137
 138 int integrity_kernel_read(struct file *file, loff_t offset,
 139                           void *addr, unsigned long count);
 140
 141 #define INTEGRITY_KEYRING_EVM           0
 142 #define INTEGRITY_KEYRING_IMA           1
 143 #define INTEGRITY_KEYRING_MODULE        2
 144 #define INTEGRITY_KEYRING_MAX           3
 145
 146 extern struct dentry *integrity_dir;
 147
 148 #ifdef CONFIG_INTEGRITY_SIGNATURE
 149
 150 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 151                             const char *digest, int digestlen);
 152
 153 int __init integrity_init_keyring(const unsigned int id);
 154 int __init integrity_load_x509(const unsigned int id, const char *path);
 155 #else
 156
 157 static inline int integrity_digsig_verify(const unsigned int id,
 158                                           const char *sig, int siglen,
 159                                           const char *digest, int digestlen)
 160 {
 161         return -EOPNOTSUPP;
 162 }
 163
 164 static inline int integrity_init_keyring(const unsigned int id)
 165 {
 166         return 0;
 167 }
 168 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 169
 170 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
 171 int asymmetric_verify(struct key *keyring, const char *sig,
 172                       int siglen, const char *data, int datalen);
 173 #else
 174 static inline int asymmetric_verify(struct key *keyring, const char *sig,
 175                                     int siglen, const char *data, int datalen)
 176 {
 177         return -EOPNOTSUPP;
 178 }
 179 #endif
 180
 181 #ifdef CONFIG_IMA_LOAD_X509
 182 void __init ima_load_x509(void);
 183 #else
 184 static inline void ima_load_x509(void)
 185 {
 186 }
 187 #endif
 188
 189 #ifdef CONFIG_EVM_LOAD_X509
 190 void __init evm_load_x509(void);
 191 #else
 192 static inline void evm_load_x509(void)
 193 {
 194 }
 195 #endif
 196
 197 #ifdef CONFIG_INTEGRITY_AUDIT
 198 /* declarations */
 199 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 200                          const unsigned char *fname, const char *op,
 201                          const char *cause, int result, int info);
 202 #else
 203 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 204                                        const unsigned char *fname,
 205                                        const char *op, const char *cause,
 206                                        int result, int info)
 207 {
 208 }
 209 #endif