security/integrity/integrity.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2009-2010 IBM Corporation
   4  *
   5  * Authors:
   6  * Mimi Zohar <[email protected]>
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/integrity.h>
  11 #include <crypto/sha.h>
  12 #include <linux/key.h>
  13 #include <linux/audit.h>
  14
  15 /* iint action cache flags */
  16 #define IMA_MEASURE             0x00000001
  17 #define IMA_MEASURED            0x00000002
  18 #define IMA_APPRAISE            0x00000004
  19 #define IMA_APPRAISED           0x00000008
  20 /*#define IMA_COLLECT           0x00000010  do not use this flag */
  21 #define IMA_COLLECTED           0x00000020
  22 #define IMA_AUDIT               0x00000040
  23 #define IMA_AUDITED             0x00000080
  24 #define IMA_HASH                0x00000100
  25 #define IMA_HASHED              0x00000200
  26
  27 /* iint cache flags */
  28 #define IMA_ACTION_FLAGS        0xff000000
  29 #define IMA_DIGSIG_REQUIRED     0x01000000
  30 #define IMA_PERMIT_DIRECTIO     0x02000000
  31 #define IMA_NEW_FILE            0x04000000
  32 #define EVM_IMMUTABLE_DIGSIG    0x08000000
  33 #define IMA_FAIL_UNVERIFIABLE_SIGS      0x10000000
  34 #define IMA_MODSIG_ALLOWED      0x20000000
  35
  36 #define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
  37                                  IMA_HASH | IMA_APPRAISE_SUBMASK)
  38 #define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
  39                                  IMA_HASHED | IMA_COLLECTED | \
  40                                  IMA_APPRAISED_SUBMASK)
  41
  42 /* iint subaction appraise cache flags */
  43 #define IMA_FILE_APPRAISE       0x00001000
  44 #define IMA_FILE_APPRAISED      0x00002000
  45 #define IMA_MMAP_APPRAISE       0x00004000
  46 #define IMA_MMAP_APPRAISED      0x00008000
  47 #define IMA_BPRM_APPRAISE       0x00010000
  48 #define IMA_BPRM_APPRAISED      0x00020000
  49 #define IMA_READ_APPRAISE       0x00040000
  50 #define IMA_READ_APPRAISED      0x00080000
  51 #define IMA_CREDS_APPRAISE      0x00100000
  52 #define IMA_CREDS_APPRAISED     0x00200000
  53 #define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
  54                                  IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \
  55                                  IMA_CREDS_APPRAISE)
  56 #define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
  57                                  IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \
  58                                  IMA_CREDS_APPRAISED)
  59
  60 /* iint cache atomic_flags */
  61 #define IMA_CHANGE_XATTR        0
  62 #define IMA_UPDATE_XATTR        1
  63 #define IMA_CHANGE_ATTR         2
  64 #define IMA_DIGSIG              3
  65 #define IMA_MUST_MEASURE        4
  66
  67 enum evm_ima_xattr_type {
  68         IMA_XATTR_DIGEST = 0x01,
  69         EVM_XATTR_HMAC,
  70         EVM_IMA_XATTR_DIGSIG,
  71         IMA_XATTR_DIGEST_NG,
  72         EVM_XATTR_PORTABLE_DIGSIG,
  73         IMA_XATTR_LAST
  74 };
  75
  76 struct evm_ima_xattr_data {
  77         u8 type;
  78         u8 data[];
  79 } __packed;
  80
  81 /* Only used in the EVM HMAC code. */
  82 struct evm_xattr {
  83         struct evm_ima_xattr_data data;
  84         u8 digest[SHA1_DIGEST_SIZE];
  85 } __packed;
  86
  87 #define IMA_MAX_DIGEST_SIZE     64
  88
  89 struct ima_digest_data {
  90         u8 algo;
  91         u8 length;
  92         union {
  93                 struct {
  94                         u8 unused;
  95                         u8 type;
  96                 } sha1;
  97                 struct {
  98                         u8 type;
  99                         u8 algo;
 100                 } ng;
 101                 u8 data[2];
 102         } xattr;
 103         u8 digest[0];
 104 } __packed;
 105
 106 /*
 107  * signature format v2 - for using with asymmetric keys
 108  */
 109 struct signature_v2_hdr {
 110         uint8_t type;           /* xattr type */
 111         uint8_t version;        /* signature format version */
 112         uint8_t hash_algo;      /* Digest algorithm [enum hash_algo] */
 113         __be32 keyid;           /* IMA key identifier - not X509/PGP specific */
 114         __be16 sig_size;        /* signature size */
 115         uint8_t sig[0];         /* signature payload */
 116 } __packed;
 117
 118 /* integrity data associated with an inode */
 119 struct integrity_iint_cache {
 120         struct rb_node rb_node; /* rooted in integrity_iint_tree */
 121         struct mutex mutex;     /* protects: version, flags, digest */
 122         struct inode *inode;    /* back pointer to inode in question */
 123         u64 version;            /* track inode changes */
 124         unsigned long flags;
 125         unsigned long measured_pcrs;
 126         unsigned long atomic_flags;
 127         enum integrity_status ima_file_status:4;
 128         enum integrity_status ima_mmap_status:4;
 129         enum integrity_status ima_bprm_status:4;
 130         enum integrity_status ima_read_status:4;
 131         enum integrity_status ima_creds_status:4;
 132         enum integrity_status evm_status:4;
 133         struct ima_digest_data *ima_hash;
 134 };
 135
 136 /* rbtree tree calls to lookup, insert, delete
 137  * integrity data associated with an inode.
 138  */
 139 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 140
 141 int integrity_kernel_read(struct file *file, loff_t offset,
 142                           void *addr, unsigned long count);
 143
 144 #define INTEGRITY_KEYRING_EVM           0
 145 #define INTEGRITY_KEYRING_IMA           1
 146 #define INTEGRITY_KEYRING_PLATFORM      2
 147 #define INTEGRITY_KEYRING_MAX           3
 148
 149 extern struct dentry *integrity_dir;
 150
 151 struct modsig;
 152
 153 #ifdef CONFIG_INTEGRITY_SIGNATURE
 154
 155 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 156                             const char *digest, int digestlen);
 157 int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
 158
 159 int __init integrity_init_keyring(const unsigned int id);
 160 int __init integrity_load_x509(const unsigned int id, const char *path);
 161 int __init integrity_load_cert(const unsigned int id, const char *source,
 162                                const void *data, size_t len, key_perm_t perm);
 163 #else
 164
 165 static inline int integrity_digsig_verify(const unsigned int id,
 166                                           const char *sig, int siglen,
 167                                           const char *digest, int digestlen)
 168 {
 169         return -EOPNOTSUPP;
 170 }
 171
 172 static inline int integrity_modsig_verify(unsigned int id,
 173                                           const struct modsig *modsig)
 174 {
 175         return -EOPNOTSUPP;
 176 }
 177
 178 static inline int integrity_init_keyring(const unsigned int id)
 179 {
 180         return 0;
 181 }
 182
 183 static inline int __init integrity_load_cert(const unsigned int id,
 184                                              const char *source,
 185                                              const void *data, size_t len,
 186                                              key_perm_t perm)
 187 {
 188         return 0;
 189 }
 190 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 191
 192 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
 193 int asymmetric_verify(struct key *keyring, const char *sig,
 194                       int siglen, const char *data, int datalen);
 195 #else
 196 static inline int asymmetric_verify(struct key *keyring, const char *sig,
 197                                     int siglen, const char *data, int datalen)
 198 {
 199         return -EOPNOTSUPP;
 200 }
 201 #endif
 202
 203 #ifdef CONFIG_IMA_APPRAISE_MODSIG
 204 int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
 205 #else
 206 static inline int ima_modsig_verify(struct key *keyring,
 207                                     const struct modsig *modsig)
 208 {
 209         return -EOPNOTSUPP;
 210 }
 211 #endif
 212
 213 #ifdef CONFIG_IMA_LOAD_X509
 214 void __init ima_load_x509(void);
 215 #else
 216 static inline void ima_load_x509(void)
 217 {
 218 }
 219 #endif
 220
 221 #ifdef CONFIG_EVM_LOAD_X509
 222 void __init evm_load_x509(void);
 223 #else
 224 static inline void evm_load_x509(void)
 225 {
 226 }
 227 #endif
 228
 229 #ifdef CONFIG_INTEGRITY_AUDIT
 230 /* declarations */
 231 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 232                          const unsigned char *fname, const char *op,
 233                          const char *cause, int result, int info);
 234
 235 static inline struct audit_buffer *
 236 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
 237 {
 238         return audit_log_start(ctx, gfp_mask, type);
 239 }
 240
 241 #else
 242 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 243                                        const unsigned char *fname,
 244                                        const char *op, const char *cause,
 245                                        int result, int info)
 246 {
 247 }
 248
 249 static inline struct audit_buffer *
 250 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
 251 {
 252         return NULL;
 253 }
 254
 255 #endif
 256
 257 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
 258 void __init add_to_platform_keyring(const char *source, const void *data,
 259                                     size_t len);
 260 #else
 261 static inline void __init add_to_platform_keyring(const char *source,
 262                                                   const void *data, size_t len)
 263 {
 264 }
 265 #endif