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); 117 118 #define INTEGRITY_KEYRING_EVM 0 119 #define INTEGRITY_KEYRING_IMA 1 120 #define INTEGRITY_KEYRING_PLATFORM 2 121 #define INTEGRITY_KEYRING_MACHINE 3 122 #define INTEGRITY_KEYRING_MAX 4 123 124 extern struct dentry *integrity_dir; 125 126 struct modsig; 127 128 #ifdef CONFIG_INTEGRITY_SIGNATURE 129 130 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, 131 const char *digest, int digestlen); 132 int integrity_modsig_verify(unsigned int id, const struct modsig *modsig); 133 134 int __init integrity_init_keyring(const unsigned int id); 135 int __init integrity_load_x509(const unsigned int id, const char *path); 136 int __init integrity_load_cert(const unsigned int id, const char *source, 137 const void *data, size_t len, key_perm_t perm); 138 #else 139 140 static inline int integrity_digsig_verify(const unsigned int id, 141 const char *sig, int siglen, 142 const char *digest, int digestlen) 143 { 144 return -EOPNOTSUPP; 145 } 146 147 static inline int integrity_modsig_verify(unsigned int id, 148 const struct modsig *modsig) 149 { 150 return -EOPNOTSUPP; 151 } 152 153 static inline int integrity_init_keyring(const unsigned int id) 154 { 155 return 0; 156 } 157 158 static inline int __init integrity_load_cert(const unsigned int id, 159 const char *source, 160 const void *data, size_t len, 161 key_perm_t perm) 162 { 163 return 0; 164 } 165 #endif /* CONFIG_INTEGRITY_SIGNATURE */ 166 167 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS 168 int asymmetric_verify(struct key *keyring, const char *sig, 169 int siglen, const char *data, int datalen); 170 #else 171 static inline int asymmetric_verify(struct key *keyring, const char *sig, 172 int siglen, const char *data, int datalen) 173 { 174 return -EOPNOTSUPP; 175 } 176 #endif 177 178 #ifdef CONFIG_IMA_APPRAISE_MODSIG 179 int ima_modsig_verify(struct key *keyring, const struct modsig *modsig); 180 #else 181 static inline int ima_modsig_verify(struct key *keyring, 182 const struct modsig *modsig) 183 { 184 return -EOPNOTSUPP; 185 } 186 #endif 187 188 #ifdef CONFIG_IMA_LOAD_X509 189 void __init ima_load_x509(void); 190 #else 191 static inline void ima_load_x509(void) 192 { 193 } 194 #endif 195 196 #ifdef CONFIG_EVM_LOAD_X509 197 void __init evm_load_x509(void); 198 #else 199 static inline void evm_load_x509(void) 200 { 201 } 202 #endif 203 204 #ifdef CONFIG_INTEGRITY_AUDIT 205 /* declarations */ 206 void integrity_audit_msg(int audit_msgno, struct inode *inode, 207 const unsigned char *fname, const char *op, 208 const char *cause, int result, int info); 209 210 void integrity_audit_message(int audit_msgno, struct inode *inode, 211 const unsigned char *fname, const char *op, 212 const char *cause, int result, int info, 213 int errno); 214 215 static inline struct audit_buffer * 216 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type) 217 { 218 return audit_log_start(ctx, gfp_mask, type); 219 } 220 221 #else 222 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode, 223 const unsigned char *fname, 224 const char *op, const char *cause, 225 int result, int info) 226 { 227 } 228 229 static inline void integrity_audit_message(int audit_msgno, 230 struct inode *inode, 231 const unsigned char *fname, 232 const char *op, const char *cause, 233 int result, int info, int errno) 234 { 235 } 236 237 static inline struct audit_buffer * 238 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type) 239 { 240 return NULL; 241 } 242 243 #endif 244 245 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING 246 void __init add_to_platform_keyring(const char *source, const void *data, 247 size_t len); 248 #else 249 static inline void __init add_to_platform_keyring(const char *source, 250 const void *data, size_t len) 251 { 252 } 253 #endif 254 255 #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING 256 void __init add_to_machine_keyring(const char *source, const void *data, size_t len); 257 bool __init imputed_trust_enabled(void); 258 #else 259 static inline void __init add_to_machine_keyring(const char *source, 260 const void *data, size_t len) 261 { 262 } 263 264 static inline bool __init imputed_trust_enabled(void) 265 { 266 return false; 267 } 268 #endif 269