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 #include <linux/audit.h>
  19
  20 /* iint action cache flags */
  21 #define IMA_MEASURE             0x00000001
  22 #define IMA_MEASURED            0x00000002
  23 #define IMA_APPRAISE            0x00000004
  24 #define IMA_APPRAISED           0x00000008
  25 /*#define IMA_COLLECT           0x00000010  do not use this flag */
  26 #define IMA_COLLECTED           0x00000020
  27 #define IMA_AUDIT               0x00000040
  28 #define IMA_AUDITED             0x00000080
  29 #define IMA_HASH                0x00000100
  30 #define IMA_HASHED              0x00000200
  31
  32 /* iint cache flags */
  33 #define IMA_ACTION_FLAGS        0xff000000
  34 #define IMA_DIGSIG_REQUIRED     0x01000000
  35 #define IMA_PERMIT_DIRECTIO     0x02000000
  36 #define IMA_NEW_FILE            0x04000000
  37 #define EVM_IMMUTABLE_DIGSIG    0x08000000
  38 #define IMA_FAIL_UNVERIFIABLE_SIGS      0x10000000
  39
  40 #define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
  41                                  IMA_HASH | IMA_APPRAISE_SUBMASK)
  42 #define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
  43                                  IMA_HASHED | IMA_COLLECTED | \
  44                                  IMA_APPRAISED_SUBMASK)
  45
  46 /* iint subaction appraise cache flags */
  47 #define IMA_FILE_APPRAISE       0x00001000
  48 #define IMA_FILE_APPRAISED      0x00002000
  49 #define IMA_MMAP_APPRAISE       0x00004000
  50 #define IMA_MMAP_APPRAISED      0x00008000
  51 #define IMA_BPRM_APPRAISE       0x00010000
  52 #define IMA_BPRM_APPRAISED      0x00020000
  53 #define IMA_READ_APPRAISE       0x00040000
  54 #define IMA_READ_APPRAISED      0x00080000
  55 #define IMA_CREDS_APPRAISE      0x00100000
  56 #define IMA_CREDS_APPRAISED     0x00200000
  57 #define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
  58                                  IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \
  59                                  IMA_CREDS_APPRAISE)
  60 #define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
  61                                  IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \
  62                                  IMA_CREDS_APPRAISED)
  63
  64 /* iint cache atomic_flags */
  65 #define IMA_CHANGE_XATTR        0
  66 #define IMA_UPDATE_XATTR        1
  67 #define IMA_CHANGE_ATTR         2
  68 #define IMA_DIGSIG              3
  69 #define IMA_MUST_MEASURE        4
  70
  71 enum evm_ima_xattr_type {
  72         IMA_XATTR_DIGEST = 0x01,
  73         EVM_XATTR_HMAC,
  74         EVM_IMA_XATTR_DIGSIG,
  75         IMA_XATTR_DIGEST_NG,
  76         EVM_XATTR_PORTABLE_DIGSIG,
  77         IMA_XATTR_LAST
  78 };
  79
  80 struct evm_ima_xattr_data {
  81         u8 type;
  82         u8 digest[SHA1_DIGEST_SIZE];
  83 } __packed;
  84
  85 #define IMA_MAX_DIGEST_SIZE     64
  86
  87 struct ima_digest_data {
  88         u8 algo;
  89         u8 length;
  90         union {
  91                 struct {
  92                         u8 unused;
  93                         u8 type;
  94                 } sha1;
  95                 struct {
  96                         u8 type;
  97                         u8 algo;
  98                 } ng;
  99                 u8 data[2];
 100         } xattr;
 101         u8 digest[0];
 102 } __packed;
 103
 104 /*
 105  * signature format v2 - for using with asymmetric keys
 106  */
 107 struct signature_v2_hdr {
 108         uint8_t type;           /* xattr type */
 109         uint8_t version;        /* signature format version */
 110         uint8_t hash_algo;      /* Digest algorithm [enum hash_algo] */
 111         __be32 keyid;           /* IMA key identifier - not X509/PGP specific */
 112         __be16 sig_size;        /* signature size */
 113         uint8_t sig[0];         /* signature payload */
 114 } __packed;
 115
 116 /* integrity data associated with an inode */
 117 struct integrity_iint_cache {
 118         struct rb_node rb_node; /* rooted in integrity_iint_tree */
 119         struct mutex mutex;     /* protects: version, flags, digest */
 120         struct inode *inode;    /* back pointer to inode in question */
 121         u64 version;            /* track inode changes */
 122         unsigned long flags;
 123         unsigned long measured_pcrs;
 124         unsigned long atomic_flags;
 125         enum integrity_status ima_file_status:4;
 126         enum integrity_status ima_mmap_status:4;
 127         enum integrity_status ima_bprm_status:4;
 128         enum integrity_status ima_read_status:4;
 129         enum integrity_status ima_creds_status:4;
 130         enum integrity_status evm_status:4;
 131         struct ima_digest_data *ima_hash;
 132 };
 133
 134 /* rbtree tree calls to lookup, insert, delete
 135  * integrity data associated with an inode.
 136  */
 137 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 138
 139 int integrity_kernel_read(struct file *file, loff_t offset,
 140                           void *addr, unsigned long count);
 141
 142 #define INTEGRITY_KEYRING_EVM           0
 143 #define INTEGRITY_KEYRING_IMA           1
 144 #define INTEGRITY_KEYRING_PLATFORM      2
 145 #define INTEGRITY_KEYRING_MAX           3
 146
 147 extern struct dentry *integrity_dir;
 148
 149 #ifdef CONFIG_INTEGRITY_SIGNATURE
 150
 151 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 152                             const char *digest, int digestlen);
 153
 154 int __init integrity_init_keyring(const unsigned int id);
 155 int __init integrity_load_x509(const unsigned int id, const char *path);
 156 int __init integrity_load_cert(const unsigned int id, const char *source,
 157                                const void *data, size_t len, key_perm_t perm);
 158 #else
 159
 160 static inline int integrity_digsig_verify(const unsigned int id,
 161                                           const char *sig, int siglen,
 162                                           const char *digest, int digestlen)
 163 {
 164         return -EOPNOTSUPP;
 165 }
 166
 167 static inline int integrity_init_keyring(const unsigned int id)
 168 {
 169         return 0;
 170 }
 171
 172 static inline int __init integrity_load_cert(const unsigned int id,
 173                                              const char *source,
 174                                              const void *data, size_t len,
 175                                              key_perm_t perm)
 176 {
 177         return 0;
 178 }
 179 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 180
 181 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
 182 int asymmetric_verify(struct key *keyring, const char *sig,
 183                       int siglen, const char *data, int datalen);
 184 #else
 185 static inline int asymmetric_verify(struct key *keyring, const char *sig,
 186                                     int siglen, const char *data, int datalen)
 187 {
 188         return -EOPNOTSUPP;
 189 }
 190 #endif
 191
 192 #ifdef CONFIG_IMA_LOAD_X509
 193 void __init ima_load_x509(void);
 194 #else
 195 static inline void ima_load_x509(void)
 196 {
 197 }
 198 #endif
 199
 200 #ifdef CONFIG_EVM_LOAD_X509
 201 void __init evm_load_x509(void);
 202 #else
 203 static inline void evm_load_x509(void)
 204 {
 205 }
 206 #endif
 207
 208 #ifdef CONFIG_INTEGRITY_AUDIT
 209 /* declarations */
 210 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 211                          const unsigned char *fname, const char *op,
 212                          const char *cause, int result, int info);
 213
 214 static inline struct audit_buffer *
 215 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
 216 {
 217         return audit_log_start(ctx, gfp_mask, type);
 218 }
 219
 220 #else
 221 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 222                                        const unsigned char *fname,
 223                                        const char *op, const char *cause,
 224                                        int result, int info)
 225 {
 226 }
 227
 228 static inline struct audit_buffer *
 229 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
 230 {
 231         return NULL;
 232 }
 233
 234 #endif
 235
 236 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
 237 void __init add_to_platform_keyring(const char *source, const void *data,
 238                                     size_t len);
 239 #else
 240 static inline void __init add_to_platform_keyring(const char *source,
 241                                                   const void *data, size_t len)
 242 {
 243 }
 244 #endif