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 <crypto/hash.h> 19 #include <linux/key.h> 20 #include <linux/audit.h> 21 #include <linux/lsm_hooks.h> 22 23 enum evm_ima_xattr_type { 24 IMA_XATTR_DIGEST = 0x01, 25 EVM_XATTR_HMAC, 26 EVM_IMA_XATTR_DIGSIG, 27 IMA_XATTR_DIGEST_NG, 28 EVM_XATTR_PORTABLE_DIGSIG, 29 IMA_VERITY_DIGSIG, 30 IMA_XATTR_LAST 31 }; 32 33 struct evm_ima_xattr_data { 34 /* New members must be added within the __struct_group() macro below. */ 35 __struct_group(evm_ima_xattr_data_hdr, hdr, __packed, 36 u8 type; 37 ); 38 u8 data[]; 39 } __packed; 40 static_assert(offsetof(struct evm_ima_xattr_data, data) == sizeof(struct evm_ima_xattr_data_hdr), 41 "struct member likely outside of __struct_group()"); 42 43 /* Only used in the EVM HMAC code. */ 44 struct evm_xattr { 45 struct evm_ima_xattr_data_hdr data; 46 u8 digest[SHA1_DIGEST_SIZE]; 47 } __packed; 48 49 #define IMA_MAX_DIGEST_SIZE HASH_MAX_DIGESTSIZE 50 51 struct ima_digest_data { 52 /* New members must be added within the __struct_group() macro below. */ 53 __struct_group(ima_digest_data_hdr, hdr, __packed, 54 u8 algo; 55 u8 length; 56 union { 57 struct { 58 u8 unused; 59 u8 type; 60 } sha1; 61 struct { 62 u8 type; 63 u8 algo; 64 } ng; 65 u8 data[2]; 66 } xattr; 67 ); 68 u8 digest[]; 69 } __packed; 70 static_assert(offsetof(struct ima_digest_data, digest) == sizeof(struct ima_digest_data_hdr), 71 "struct member likely outside of __struct_group()"); 72 73 /* 74 * Instead of wrapping the ima_digest_data struct inside a local structure 75 * with the maximum hash size, define ima_max_digest_data struct. 76 */ 77 struct ima_max_digest_data { 78 struct ima_digest_data_hdr hdr; 79 u8 digest[HASH_MAX_DIGESTSIZE]; 80 } __packed; 81 82 /* 83 * signature header format v2 - for using with asymmetric keys 84 * 85 * The signature_v2_hdr struct includes a signature format version 86 * to simplify defining new signature formats. 87 * 88 * signature format: 89 * version 2: regular file data hash based signature 90 * version 3: struct ima_file_id data based signature 91 */ 92 struct signature_v2_hdr { 93 uint8_t type; /* xattr type */ 94 uint8_t version; /* signature format version */ 95 uint8_t hash_algo; /* Digest algorithm [enum hash_algo] */ 96 __be32 keyid; /* IMA key identifier - not X509/PGP specific */ 97 __be16 sig_size; /* signature size */ 98 uint8_t sig[]; /* signature payload */ 99 } __packed; 100 101 /* 102 * IMA signature version 3 disambiguates the data that is signed, by 103 * indirectly signing the hash of the ima_file_id structure data, 104 * containing either the fsverity_descriptor struct digest or, in the 105 * future, the regular IMA file hash. 106 * 107 * (The hash of the ima_file_id structure is only of the portion used.) 108 */ 109 struct ima_file_id { 110 __u8 hash_type; /* xattr type [enum evm_ima_xattr_type] */ 111 __u8 hash_algorithm; /* Digest algorithm [enum hash_algo] */ 112 __u8 hash[HASH_MAX_DIGESTSIZE]; 113 } __packed; 114 115 int integrity_kernel_read(struct file *file, loff_t offset, 116 void *addr, unsigned long count); 117 int __init integrity_fs_init(void); 118 void __init integrity_fs_fini(void); 119 120 #define INTEGRITY_KEYRING_EVM 0 121 #define INTEGRITY_KEYRING_IMA 1 122 #define INTEGRITY_KEYRING_PLATFORM 2 123 #define INTEGRITY_KEYRING_MACHINE 3 124 #define INTEGRITY_KEYRING_MAX 4 125 126 extern struct dentry *integrity_dir; 127 128 struct modsig; 129 130 #ifdef CONFIG_INTEGRITY_SIGNATURE 131 132 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, 133 const char *digest, int digestlen); 134 int integrity_modsig_verify(unsigned int id, const struct modsig *modsig); 135 136 int __init integrity_init_keyring(const unsigned int id); 137 int __init integrity_load_x509(const unsigned int id, const char *path); 138 int __init integrity_load_cert(const unsigned int id, const char *source, 139 const void *data, size_t len, key_perm_t perm); 140 #else 141 142 static inline int integrity_digsig_verify(const unsigned int id, 143 const char *sig, int siglen, 144 const char *digest, int digestlen) 145 { 146 return -EOPNOTSUPP; 147 } 148 149 static inline int integrity_modsig_verify(unsigned int id, 150 const struct modsig *modsig) 151 { 152 return -EOPNOTSUPP; 153 } 154 155 static inline int integrity_init_keyring(const unsigned int id) 156 { 157 return 0; 158 } 159 160 static inline int __init integrity_load_cert(const unsigned int id, 161 const char *source, 162 const void *data, size_t len, 163 key_perm_t perm) 164 { 165 return 0; 166 } 167 #endif /* CONFIG_INTEGRITY_SIGNATURE */ 168 169 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS 170 int asymmetric_verify(struct key *keyring, const char *sig, 171 int siglen, const char *data, int datalen); 172 #else 173 static inline int asymmetric_verify(struct key *keyring, const char *sig, 174 int siglen, const char *data, int datalen) 175 { 176 return -EOPNOTSUPP; 177 } 178 #endif 179 180 #ifdef CONFIG_IMA_APPRAISE_MODSIG 181 int ima_modsig_verify(struct key *keyring, const struct modsig *modsig); 182 #else 183 static inline int ima_modsig_verify(struct key *keyring, 184 const struct modsig *modsig) 185 { 186 return -EOPNOTSUPP; 187 } 188 #endif 189 190 #ifdef CONFIG_IMA_LOAD_X509 191 void __init ima_load_x509(void); 192 #else 193 static inline void ima_load_x509(void) 194 { 195 } 196 #endif 197 198 #ifdef CONFIG_EVM_LOAD_X509 199 void __init evm_load_x509(void); 200 #else 201 static inline void evm_load_x509(void) 202 { 203 } 204 #endif 205 206 #ifdef CONFIG_INTEGRITY_AUDIT 207 /* declarations */ 208 void integrity_audit_msg(int audit_msgno, struct inode *inode, 209 const unsigned char *fname, const char *op, 210 const char *cause, int result, int info); 211 212 void integrity_audit_message(int audit_msgno, struct inode *inode, 213 const unsigned char *fname, const char *op, 214 const char *cause, int result, int info, 215 int errno); 216 217 static inline struct audit_buffer * 218 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type) 219 { 220 return audit_log_start(ctx, gfp_mask, type); 221 } 222 223 #else 224 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode, 225 const unsigned char *fname, 226 const char *op, const char *cause, 227 int result, int info) 228 { 229 } 230 231 static inline void integrity_audit_message(int audit_msgno, 232 struct inode *inode, 233 const unsigned char *fname, 234 const char *op, const char *cause, 235 int result, int info, int errno) 236 { 237 } 238 239 static inline struct audit_buffer * 240 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type) 241 { 242 return NULL; 243 } 244 245 #endif 246 247 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING 248 void __init add_to_platform_keyring(const char *source, const void *data, 249 size_t len); 250 #else 251 static inline void __init add_to_platform_keyring(const char *source, 252 const void *data, size_t len) 253 { 254 } 255 #endif 256 257 #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING 258 void __init add_to_machine_keyring(const char *source, const void *data, size_t len); 259 bool __init imputed_trust_enabled(void); 260 #else 261 static inline void __init add_to_machine_keyring(const char *source, 262 const void *data, size_t len) 263 { 264 } 265 266 static inline bool __init imputed_trust_enabled(void) 267 { 268 return false; 269 } 270 #endif 271