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 <zohar@us.ibm.com>
   7  */
   8
   9 #ifdef pr_fmt
  10 #undef pr_fmt
  11 #endif
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/types.h>
  16 #include <linux/integrity.h>
  17 #include <crypto/sha1.h>
  18 #include <linux/key.h>
  19 #include <linux/audit.h>
  20
  21 /* iint action cache flags */
  22 #define IMA_MEASURE             0x00000001
  23 #define IMA_MEASURED            0x00000002
  24 #define IMA_APPRAISE            0x00000004
  25 #define IMA_APPRAISED           0x00000008
  26 /*#define IMA_COLLECT           0x00000010  do not use this flag */
  27 #define IMA_COLLECTED           0x00000020
  28 #define IMA_AUDIT               0x00000040
  29 #define IMA_AUDITED             0x00000080
  30 #define IMA_HASH                0x00000100
  31 #define IMA_HASHED              0x00000200
  32
  33 /* iint cache flags */
  34 #define IMA_ACTION_FLAGS        0xff000000
  35 #define IMA_DIGSIG_REQUIRED     0x01000000
  36 #define IMA_PERMIT_DIRECTIO     0x02000000
  37 #define IMA_NEW_FILE            0x04000000
  38 #define EVM_IMMUTABLE_DIGSIG    0x08000000
  39 #define IMA_FAIL_UNVERIFIABLE_SIGS      0x10000000
  40 #define IMA_MODSIG_ALLOWED      0x20000000
  41 #define IMA_CHECK_BLACKLIST     0x40000000
  42
  43 #define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
  44                                  IMA_HASH | IMA_APPRAISE_SUBMASK)
  45 #define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
  46                                  IMA_HASHED | IMA_COLLECTED | \
  47                                  IMA_APPRAISED_SUBMASK)
  48
  49 /* iint subaction appraise cache flags */
  50 #define IMA_FILE_APPRAISE       0x00001000
  51 #define IMA_FILE_APPRAISED      0x00002000
  52 #define IMA_MMAP_APPRAISE       0x00004000
  53 #define IMA_MMAP_APPRAISED      0x00008000
  54 #define IMA_BPRM_APPRAISE       0x00010000
  55 #define IMA_BPRM_APPRAISED      0x00020000
  56 #define IMA_READ_APPRAISE       0x00040000
  57 #define IMA_READ_APPRAISED      0x00080000
  58 #define IMA_CREDS_APPRAISE      0x00100000
  59 #define IMA_CREDS_APPRAISED     0x00200000
  60 #define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
  61                                  IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \
  62                                  IMA_CREDS_APPRAISE)
  63 #define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
  64                                  IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \
  65                                  IMA_CREDS_APPRAISED)
  66
  67 /* iint cache atomic_flags */
  68 #define IMA_CHANGE_XATTR        0
  69 #define IMA_UPDATE_XATTR        1
  70 #define IMA_CHANGE_ATTR         2
  71 #define IMA_DIGSIG              3
  72 #define IMA_MUST_MEASURE        4
  73
  74 enum evm_ima_xattr_type {
  75         IMA_XATTR_DIGEST = 0x01,
  76         EVM_XATTR_HMAC,
  77         EVM_IMA_XATTR_DIGSIG,
  78         IMA_XATTR_DIGEST_NG,
  79         EVM_XATTR_PORTABLE_DIGSIG,
  80         IMA_XATTR_LAST
  81 };
  82
  83 struct evm_ima_xattr_data {
  84         u8 type;
  85         u8 data[];
  86 } __packed;
  87
  88 /* Only used in the EVM HMAC code. */
  89 struct evm_xattr {
  90         struct evm_ima_xattr_data data;
  91         u8 digest[SHA1_DIGEST_SIZE];
  92 } __packed;
  93
  94 #define IMA_MAX_DIGEST_SIZE     64
  95
  96 struct ima_digest_data {
  97         u8 algo;
  98         u8 length;
  99         union {
 100                 struct {
 101                         u8 unused;
 102                         u8 type;
 103                 } sha1;
 104                 struct {
 105                         u8 type;
 106                         u8 algo;
 107                 } ng;
 108                 u8 data[2];
 109         } xattr;
 110         u8 digest[];
 111 } __packed;
 112
 113 /*
 114  * signature format v2 - for using with asymmetric keys
 115  */
 116 struct signature_v2_hdr {
 117         uint8_t type;           /* xattr type */
 118         uint8_t version;        /* signature format version */
 119         uint8_t hash_algo;      /* Digest algorithm [enum hash_algo] */
 120         __be32 keyid;           /* IMA key identifier - not X509/PGP specific */
 121         __be16 sig_size;        /* signature size */
 122         uint8_t sig[];          /* signature payload */
 123 } __packed;
 124
 125 /* integrity data associated with an inode */
 126 struct integrity_iint_cache {
 127         struct rb_node rb_node; /* rooted in integrity_iint_tree */
 128         struct mutex mutex;     /* protects: version, flags, digest */
 129         struct inode *inode;    /* back pointer to inode in question */
 130         u64 version;            /* track inode changes */
 131         unsigned long flags;
 132         unsigned long measured_pcrs;
 133         unsigned long atomic_flags;
 134         enum integrity_status ima_file_status:4;
 135         enum integrity_status ima_mmap_status:4;
 136         enum integrity_status ima_bprm_status:4;
 137         enum integrity_status ima_read_status:4;
 138         enum integrity_status ima_creds_status:4;
 139         enum integrity_status evm_status:4;
 140         struct ima_digest_data *ima_hash;
 141 };
 142
 143 /* rbtree tree calls to lookup, insert, delete
 144  * integrity data associated with an inode.
 145  */
 146 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 147
 148 int integrity_kernel_read(struct file *file, loff_t offset,
 149                           void *addr, unsigned long count);
 150
 151 #define INTEGRITY_KEYRING_EVM           0
 152 #define INTEGRITY_KEYRING_IMA           1
 153 #define INTEGRITY_KEYRING_PLATFORM      2
 154 #define INTEGRITY_KEYRING_MAX           3
 155
 156 extern struct dentry *integrity_dir;
 157
 158 struct modsig;
 159
 160 #ifdef CONFIG_INTEGRITY_SIGNATURE
 161
 162 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 163                             const char *digest, int digestlen);
 164 int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
 165
 166 int __init integrity_init_keyring(const unsigned int id);
 167 int __init integrity_load_x509(const unsigned int id, const char *path);
 168 int __init integrity_load_cert(const unsigned int id, const char *source,
 169                                const void *data, size_t len, key_perm_t perm);
 170 #else
 171
 172 static inline int integrity_digsig_verify(const unsigned int id,
 173                                           const char *sig, int siglen,
 174                                           const char *digest, int digestlen)
 175 {
 176         return -EOPNOTSUPP;
 177 }
 178
 179 static inline int integrity_modsig_verify(unsigned int id,
 180                                           const struct modsig *modsig)
 181 {
 182         return -EOPNOTSUPP;
 183 }
 184
 185 static inline int integrity_init_keyring(const unsigned int id)
 186 {
 187         return 0;
 188 }
 189
 190 static inline int __init integrity_load_cert(const unsigned int id,
 191                                              const char *source,
 192                                              const void *data, size_t len,
 193                                              key_perm_t perm)
 194 {
 195         return 0;
 196 }
 197 #endif /* CONFIG_INTEGRITY_SIGNATURE */
 198
 199 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
 200 int asymmetric_verify(struct key *keyring, const char *sig,
 201                       int siglen, const char *data, int datalen);
 202 #else
 203 static inline int asymmetric_verify(struct key *keyring, const char *sig,
 204                                     int siglen, const char *data, int datalen)
 205 {
 206         return -EOPNOTSUPP;
 207 }
 208 #endif
 209
 210 #ifdef CONFIG_IMA_APPRAISE_MODSIG
 211 int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
 212 #else
 213 static inline int ima_modsig_verify(struct key *keyring,
 214                                     const struct modsig *modsig)
 215 {
 216         return -EOPNOTSUPP;
 217 }
 218 #endif
 219
 220 #ifdef CONFIG_IMA_LOAD_X509
 221 void __init ima_load_x509(void);
 222 #else
 223 static inline void ima_load_x509(void)
 224 {
 225 }
 226 #endif
 227
 228 #ifdef CONFIG_EVM_LOAD_X509
 229 void __init evm_load_x509(void);
 230 #else
 231 static inline void evm_load_x509(void)
 232 {
 233 }
 234 #endif
 235
 236 #ifdef CONFIG_INTEGRITY_AUDIT
 237 /* declarations */
 238 void integrity_audit_msg(int audit_msgno, struct inode *inode,
 239                          const unsigned char *fname, const char *op,
 240                          const char *cause, int result, int info);
 241
 242 void integrity_audit_message(int audit_msgno, struct inode *inode,
 243                              const unsigned char *fname, const char *op,
 244                              const char *cause, int result, int info,
 245                              int errno);
 246
 247 static inline struct audit_buffer *
 248 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
 249 {
 250         return audit_log_start(ctx, gfp_mask, type);
 251 }
 252
 253 #else
 254 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 255                                        const unsigned char *fname,
 256                                        const char *op, const char *cause,
 257                                        int result, int info)
 258 {
 259 }
 260
 261 static inline void integrity_audit_message(int audit_msgno,
 262                                            struct inode *inode,
 263                                            const unsigned char *fname,
 264                                            const char *op, const char *cause,
 265                                            int result, int info, int errno)
 266 {
 267 }
 268
 269 static inline struct audit_buffer *
 270 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
 271 {
 272         return NULL;
 273 }
 274
 275 #endif
 276
 277 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
 278 void __init add_to_platform_keyring(const char *source, const void *data,
 279                                     size_t len);
 280 #else
 281 static inline void __init add_to_platform_keyring(const char *source,
 282                                                   const void *data, size_t len)
 283 {
 284 }
 285 #endif