diff options
| author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
|---|---|---|
| committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
| commit | fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch) | |
| tree | a57612d1888735a2ec7972891b68c1ac5ec8faea /security/keys | |
| parent | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff) | |
Diffstat (limited to 'security/keys')
| -rw-r--r-- | security/keys/ecryptfs_format.c | 81 | ||||
| -rw-r--r-- | security/keys/ecryptfs_format.h | 30 | ||||
| -rw-r--r-- | security/keys/encrypted.c | 1049 | ||||
| -rw-r--r-- | security/keys/encrypted.h | 54 |
4 files changed, 1214 insertions, 0 deletions
diff --git a/security/keys/ecryptfs_format.c b/security/keys/ecryptfs_format.c new file mode 100644 index 00000000000..6daa3b6ff9e --- /dev/null +++ b/security/keys/ecryptfs_format.c | |||
| @@ -0,0 +1,81 @@ | |||
| 1 | /* | ||
| 2 | * ecryptfs_format.c: helper functions for the encrypted key type | ||
| 3 | * | ||
| 4 | * Copyright (C) 2006 International Business Machines Corp. | ||
| 5 | * Copyright (C) 2010 Politecnico di Torino, Italy | ||
| 6 | * TORSEC group -- http://security.polito.it | ||
| 7 | * | ||
| 8 | * Authors: | ||
| 9 | * Michael A. Halcrow <mahalcro@us.ibm.com> | ||
| 10 | * Tyler Hicks <tyhicks@ou.edu> | ||
| 11 | * Roberto Sassu <roberto.sassu@polito.it> | ||
| 12 | * | ||
| 13 | * This program is free software; you can redistribute it and/or modify | ||
| 14 | * it under the terms of the GNU General Public License as published by | ||
| 15 | * the Free Software Foundation, version 2 of the License. | ||
| 16 | */ | ||
| 17 | |||
| 18 | #include <linux/module.h> | ||
| 19 | #include "ecryptfs_format.h" | ||
| 20 | |||
| 21 | u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok) | ||
| 22 | { | ||
| 23 | return auth_tok->token.password.session_key_encryption_key; | ||
| 24 | } | ||
| 25 | EXPORT_SYMBOL(ecryptfs_get_auth_tok_key); | ||
| 26 | |||
| 27 | /* | ||
| 28 | * ecryptfs_get_versions() | ||
| 29 | * | ||
| 30 | * Source code taken from the software 'ecryptfs-utils' version 83. | ||
| 31 | * | ||
| 32 | */ | ||
| 33 | void ecryptfs_get_versions(int *major, int *minor, int *file_version) | ||
| 34 | { | ||
| 35 | *major = ECRYPTFS_VERSION_MAJOR; | ||
| 36 | *minor = ECRYPTFS_VERSION_MINOR; | ||
| 37 | if (file_version) | ||
| 38 | *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION; | ||
| 39 | } | ||
| 40 | EXPORT_SYMBOL(ecryptfs_get_versions); | ||
| 41 | |||
| 42 | /* | ||
| 43 | * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure | ||
| 44 | * | ||
| 45 | * Fill the ecryptfs_auth_tok structure with required ecryptfs data. | ||
| 46 | * The source code is inspired to the original function generate_payload() | ||
| 47 | * shipped with the software 'ecryptfs-utils' version 83. | ||
| 48 | * | ||
| 49 | */ | ||
| 50 | int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, | ||
| 51 | const char *key_desc) | ||
| 52 | { | ||
| 53 | int major, minor; | ||
| 54 | |||
| 55 | ecryptfs_get_versions(&major, &minor, NULL); | ||
| 56 | auth_tok->version = (((uint16_t)(major << 8) & 0xFF00) | ||
| 57 | | ((uint16_t)minor & 0x00FF)); | ||
| 58 | auth_tok->token_type = ECRYPTFS_PASSWORD; | ||
| 59 | strncpy((char *)auth_tok->token.password.signature, key_desc, | ||
| 60 | ECRYPTFS_PASSWORD_SIG_SIZE); | ||
| 61 | auth_tok->token.password.session_key_encryption_key_bytes = | ||
| 62 | ECRYPTFS_MAX_KEY_BYTES; | ||
| 63 | /* | ||
| 64 | * Removed auth_tok->token.password.salt and | ||
| 65 | * auth_tok->token.password.session_key_encryption_key | ||
| 66 | * initialization from the original code | ||
| 67 | */ | ||
| 68 | /* TODO: Make the hash parameterizable via policy */ | ||
| 69 | auth_tok->token.password.flags |= | ||
| 70 | ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET; | ||
| 71 | /* The kernel code will encrypt the session key. */ | ||
| 72 | auth_tok->session_key.encrypted_key[0] = 0; | ||
| 73 | auth_tok->session_key.encrypted_key_size = 0; | ||
| 74 | /* Default; subject to change by kernel eCryptfs */ | ||
| 75 | auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512; | ||
| 76 | auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD); | ||
| 77 | return 0; | ||
| 78 | } | ||
| 79 | EXPORT_SYMBOL(ecryptfs_fill_auth_tok); | ||
| 80 | |||
| 81 | MODULE_LICENSE("GPL"); | ||
diff --git a/security/keys/ecryptfs_format.h b/security/keys/ecryptfs_format.h new file mode 100644 index 00000000000..40294de238b --- /dev/null +++ b/security/keys/ecryptfs_format.h | |||
| @@ -0,0 +1,30 @@ | |||
| 1 | /* | ||
| 2 | * ecryptfs_format.h: helper functions for the encrypted key type | ||
| 3 | * | ||
| 4 | * Copyright (C) 2006 International Business Machines Corp. | ||
| 5 | * Copyright (C) 2010 Politecnico di Torino, Italy | ||
| 6 | * TORSEC group -- http://security.polito.it | ||
| 7 | * | ||
| 8 | * Authors: | ||
| 9 | * Michael A. Halcrow <mahalcro@us.ibm.com> | ||
| 10 | * Tyler Hicks <tyhicks@ou.edu> | ||
| 11 | * Roberto Sassu <roberto.sassu@polito.it> | ||
| 12 | * | ||
| 13 | * This program is free software; you can redistribute it and/or modify | ||
| 14 | * it under the terms of the GNU General Public License as published by | ||
| 15 | * the Free Software Foundation, version 2 of the License. | ||
| 16 | */ | ||
| 17 | |||
| 18 | #ifndef __KEYS_ECRYPTFS_H | ||
| 19 | #define __KEYS_ECRYPTFS_H | ||
| 20 | |||
| 21 | #include <linux/ecryptfs.h> | ||
| 22 | |||
| 23 | #define PGP_DIGEST_ALGO_SHA512 10 | ||
| 24 | |||
| 25 | u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok); | ||
| 26 | void ecryptfs_get_versions(int *major, int *minor, int *file_version); | ||
| 27 | int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, | ||
| 28 | const char *key_desc); | ||
| 29 | |||
| 30 | #endif /* __KEYS_ECRYPTFS_H */ | ||
diff --git a/security/keys/encrypted.c b/security/keys/encrypted.c new file mode 100644 index 00000000000..e7eca9ec4c6 --- /dev/null +++ b/security/keys/encrypted.c | |||
| @@ -0,0 +1,1049 @@ | |||
| 1 | /* | ||
| 2 | * Copyright (C) 2010 IBM Corporation | ||
| 3 | * Copyright (C) 2010 Politecnico di Torino, Italy | ||
| 4 | * TORSEC group -- http://security.polito.it | ||
| 5 | * | ||
| 6 | * Authors: | ||
| 7 | * Mimi Zohar <zohar@us.ibm.com> | ||
| 8 | * Roberto Sassu <roberto.sassu@polito.it> | ||
| 9 | * | ||
| 10 | * This program is free software; you can redistribute it and/or modify | ||
| 11 | * it under the terms of the GNU General Public License as published by | ||
| 12 | * the Free Software Foundation, version 2 of the License. | ||
| 13 | * | ||
| 14 | * See Documentation/security/keys-trusted-encrypted.txt | ||
| 15 | */ | ||
| 16 | |||
| 17 | #include <linux/uaccess.h> | ||
| 18 | #include <linux/module.h> | ||
| 19 | #include <linux/init.h> | ||
| 20 | #include <linux/slab.h> | ||
| 21 | #include <linux/parser.h> | ||
| 22 | #include <linux/string.h> | ||
| 23 | #include <linux/err.h> | ||
| 24 | #include <keys/user-type.h> | ||
| 25 | #include <keys/trusted-type.h> | ||
| 26 | #include <keys/encrypted-type.h> | ||
| 27 | #include <linux/key-type.h> | ||
| 28 | #include <linux/random.h> | ||
| 29 | #include <linux/rcupdate.h> | ||
| 30 | #include <linux/scatterlist.h> | ||
| 31 | #include <linux/crypto.h> | ||
| 32 | #include <linux/ctype.h> | ||
| 33 | #include <crypto/hash.h> | ||
| 34 | #include <crypto/sha.h> | ||
| 35 | #include <crypto/aes.h> | ||
| 36 | |||
| 37 | #include "encrypted.h" | ||
| 38 | #include "ecryptfs_format.h" | ||
| 39 | |||
| 40 | static const char KEY_TRUSTED_PREFIX[] = "trusted:"; | ||
| 41 | static const char KEY_USER_PREFIX[] = "user:"; | ||
| 42 | static const char hash_alg[] = "sha256"; | ||
| 43 | static const char hmac_alg[] = "hmac(sha256)"; | ||
| 44 | static const char blkcipher_alg[] = "cbc(aes)"; | ||
| 45 | static const char key_format_default[] = "default"; | ||
| 46 | static const char key_format_ecryptfs[] = "ecryptfs"; | ||
| 47 | static unsigned int ivsize; | ||
| 48 | static int blksize; | ||
| 49 | |||
| 50 | #define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1) | ||
| 51 | #define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1) | ||
| 52 | #define KEY_ECRYPTFS_DESC_LEN 16 | ||
| 53 | #define HASH_SIZE SHA256_DIGEST_SIZE | ||
| 54 | #define MAX_DATA_SIZE 4096 | ||
| 55 | #define MIN_DATA_SIZE 20 | ||
| 56 | |||
| 57 | struct sdesc { | ||
| 58 | struct shash_desc shash; | ||
| 59 | char ctx[]; | ||
| 60 | }; | ||
| 61 | |||
| 62 | static struct crypto_shash *hashalg; | ||
| 63 | static struct crypto_shash *hmacalg; | ||
| 64 | |||
| 65 | enum { | ||
| 66 | Opt_err = -1, Opt_new, Opt_load, Opt_update | ||
| 67 | }; | ||
| 68 | |||
| 69 | enum { | ||
| 70 | Opt_error = -1, Opt_default, Opt_ecryptfs | ||
| 71 | }; | ||
| 72 | |||
| 73 | static const match_table_t key_format_tokens = { | ||
| 74 | {Opt_default, "default"}, | ||
| 75 | {Opt_ecryptfs, "ecryptfs"}, | ||
| 76 | {Opt_error, NULL} | ||
| 77 | }; | ||
| 78 | |||
| 79 | static const match_table_t key_tokens = { | ||
| 80 | {Opt_new, "new"}, | ||
| 81 | {Opt_load, "load"}, | ||
| 82 | {Opt_update, "update"}, | ||
| 83 | {Opt_err, NULL} | ||
| 84 | }; | ||
| 85 | |||
| 86 | static int aes_get_sizes(void) | ||
| 87 | { | ||
| 88 | struct crypto_blkcipher *tfm; | ||
| 89 | |||
| 90 | tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); | ||
| 91 | if (IS_ERR(tfm)) { | ||
| 92 | pr_err("encrypted_key: failed to alloc_cipher (%ld)\n", | ||
| 93 | PTR_ERR(tfm)); | ||
| 94 | return PTR_ERR(tfm); | ||
| 95 | } | ||
| 96 | ivsize = crypto_blkcipher_ivsize(tfm); | ||
| 97 | blksize = crypto_blkcipher_blocksize(tfm); | ||
| 98 | crypto_free_blkcipher(tfm); | ||
| 99 | return 0; | ||
| 100 | } | ||
| 101 | |||
| 102 | /* | ||
| 103 | * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key | ||
| 104 | * | ||
| 105 | * The description of a encrypted key with format 'ecryptfs' must contain | ||
| 106 | * exactly 16 hexadecimal characters. | ||
| 107 | * | ||
| 108 | */ | ||
| 109 | static int valid_ecryptfs_desc(const char *ecryptfs_desc) | ||
| 110 | { | ||
| 111 | int i; | ||
| 112 | |||
| 113 | if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) { | ||
| 114 | pr_err("encrypted_key: key description must be %d hexadecimal " | ||
| 115 | "characters long\n", KEY_ECRYPTFS_DESC_LEN); | ||
| 116 | return -EINVAL; | ||
| 117 | } | ||
| 118 | |||
| 119 | for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) { | ||
| 120 | if (!isxdigit(ecryptfs_desc[i])) { | ||
| 121 | pr_err("encrypted_key: key description must contain " | ||
| 122 | "only hexadecimal characters\n"); | ||
| 123 | return -EINVAL; | ||
| 124 | } | ||
| 125 | } | ||
| 126 | |||
| 127 | return 0; | ||
| 128 | } | ||
| 129 | |||
| 130 | /* | ||
| 131 | * valid_master_desc - verify the 'key-type:desc' of a new/updated master-key | ||
| 132 | * | ||
| 133 | * key-type:= "trusted:" | "user:" | ||
| 134 | * desc:= master-key description | ||
| 135 | * | ||
| 136 | * Verify that 'key-type' is valid and that 'desc' exists. On key update, | ||
| 137 | * only the master key description is permitted to change, not the key-type. | ||
| 138 | * The key-type remains constant. | ||
| 139 | * | ||
| 140 | * On success returns 0, otherwise -EINVAL. | ||
| 141 | */ | ||
| 142 | static int valid_master_desc(const char *new_desc, const char *orig_desc) | ||
| 143 | { | ||
| 144 | if (!memcmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) { | ||
| 145 | if (strlen(new_desc) == KEY_TRUSTED_PREFIX_LEN) | ||
| 146 | goto out; | ||
| 147 | if (orig_desc) | ||
| 148 | if (memcmp(new_desc, orig_desc, KEY_TRUSTED_PREFIX_LEN)) | ||
| 149 | goto out; | ||
| 150 | } else if (!memcmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) { | ||
| 151 | if (strlen(new_desc) == KEY_USER_PREFIX_LEN) | ||
| 152 | goto out; | ||
| 153 | if (orig_desc) | ||
| 154 | if (memcmp(new_desc, orig_desc, KEY_USER_PREFIX_LEN)) | ||
| 155 | goto out; | ||
| 156 | } else | ||
| 157 | goto out; | ||
| 158 | return 0; | ||
| 159 | out: | ||
| 160 | return -EINVAL; | ||
| 161 | } | ||
| 162 | |||
| 163 | /* | ||
| 164 | * datablob_parse - parse the keyctl data | ||
| 165 | * | ||
| 166 | * datablob format: | ||
| 167 | * new [<format>] <master-key name> <decrypted data length> | ||
| 168 | * load [<format>] <master-key name> <decrypted data length> | ||
| 169 | * <encrypted iv + data> | ||
| 170 | * update <new-master-key name> | ||
| 171 | * | ||
| 172 | * Tokenizes a copy of the keyctl data, returning a pointer to each token, | ||
| 173 | * which is null terminated. | ||
| 174 | * | ||
| 175 | * On success returns 0, otherwise -EINVAL. | ||
| 176 | */ | ||
| 177 | static int datablob_parse(char *datablob, const char **format, | ||
| 178 | char **master_desc, char **decrypted_datalen, | ||
| 179 | char **hex_encoded_iv) | ||
| 180 | { | ||
| 181 | substring_t args[MAX_OPT_ARGS]; | ||
| 182 | int ret = -EINVAL; | ||
| 183 | int key_cmd; | ||
| 184 | int key_format; | ||
| 185 | char *p, *keyword; | ||
| 186 | |||
| 187 | keyword = strsep(&datablob, " \t"); | ||
| 188 | if (!keyword) { | ||
| 189 | pr_info("encrypted_key: insufficient parameters specified\n"); | ||
| 190 | return ret; | ||
| 191 | } | ||
| 192 | key_cmd = match_token(keyword, key_tokens, args); | ||
| 193 | |||
| 194 | /* Get optional format: default | ecryptfs */ | ||
| 195 | p = strsep(&datablob, " \t"); | ||
| 196 | if (!p) { | ||
| 197 | pr_err("encrypted_key: insufficient parameters specified\n"); | ||
| 198 | return ret; | ||
| 199 | } | ||
| 200 | |||
| 201 | key_format = match_token(p, key_format_tokens, args); | ||
| 202 | switch (key_format) { | ||
| 203 | case Opt_ecryptfs: | ||
| 204 | case Opt_default: | ||
| 205 | *format = p; | ||
| 206 | *master_desc = strsep(&datablob, " \t"); | ||
| 207 | break; | ||
| 208 | case Opt_error: | ||
| 209 | *master_desc = p; | ||
| 210 | break; | ||
| 211 | } | ||
| 212 | |||
| 213 | if (!*master_desc) { | ||
| 214 | pr_info("encrypted_key: master key parameter is missing\n"); | ||
| 215 | goto out; | ||
| 216 | } | ||
| 217 | |||
| 218 | if (valid_master_desc(*master_desc, NULL) < 0) { | ||
| 219 | pr_info("encrypted_key: master key parameter \'%s\' " | ||
| 220 | "is invalid\n", *master_desc); | ||
| 221 | goto out; | ||
| 222 | } | ||
| 223 | |||
| 224 | if (decrypted_datalen) { | ||
| 225 | *decrypted_datalen = strsep(&datablob, " \t"); | ||
| 226 | if (!*decrypted_datalen) { | ||
| 227 | pr_info("encrypted_key: keylen parameter is missing\n"); | ||
| 228 | goto out; | ||
| 229 | } | ||
| 230 | } | ||
| 231 | |||
| 232 | switch (key_cmd) { | ||
| 233 | case Opt_new: | ||
| 234 | if (!decrypted_datalen) { | ||
| 235 | pr_info("encrypted_key: keyword \'%s\' not allowed " | ||
| 236 | "when called from .update method\n", keyword); | ||
| 237 | break; | ||
| 238 | } | ||
| 239 | ret = 0; | ||
| 240 | break; | ||
| 241 | case Opt_load: | ||
| 242 | if (!decrypted_datalen) { | ||
| 243 | pr_info("encrypted_key: keyword \'%s\' not allowed " | ||
| 244 | "when called from .update method\n", keyword); | ||
| 245 | break; | ||
| 246 | } | ||
| 247 | *hex_encoded_iv = strsep(&datablob, " \t"); | ||
| 248 | if (!*hex_encoded_iv) { | ||
| 249 | pr_info("encrypted_key: hex blob is missing\n"); | ||
| 250 | break; | ||
| 251 | } | ||
| 252 | ret = 0; | ||
| 253 | break; | ||
| 254 | case Opt_update: | ||
| 255 | if (decrypted_datalen) { | ||
| 256 | pr_info("encrypted_key: keyword \'%s\' not allowed " | ||
| 257 | "when called from .instantiate method\n", | ||
| 258 | keyword); | ||
| 259 | break; | ||
| 260 | } | ||
| 261 | ret = 0; | ||
| 262 | break; | ||
| 263 | case Opt_err: | ||
| 264 | pr_info("encrypted_key: keyword \'%s\' not recognized\n", | ||
| 265 | keyword); | ||
| 266 | break; | ||
| 267 | } | ||
| 268 | out: | ||
| 269 | return ret; | ||
| 270 | } | ||
| 271 | |||
| 272 | /* | ||
| 273 | * datablob_format - format as an ascii string, before copying to userspace | ||
| 274 | */ | ||
| 275 | static char *datablob_format(struct encrypted_key_payload *epayload, | ||
| 276 | size_t asciiblob_len) | ||
| 277 | { | ||
| 278 | char *ascii_buf, *bufp; | ||
| 279 | u8 *iv = epayload->iv; | ||
| 280 | int len; | ||
| 281 | int i; | ||
| 282 | |||
| 283 | ascii_buf = kmalloc(asciiblob_len + 1, GFP_KERNEL); | ||
| 284 | if (!ascii_buf) | ||
| 285 | goto out; | ||
| 286 | |||
| 287 | ascii_buf[asciiblob_len] = '\0'; | ||
| 288 | |||
| 289 | /* copy datablob master_desc and datalen strings */ | ||
| 290 | len = sprintf(ascii_buf, "%s %s %s ", epayload->format, | ||
| 291 | epayload->master_desc, epayload->datalen); | ||
| 292 | |||
| 293 | /* convert the hex encoded iv, encrypted-data and HMAC to ascii */ | ||
| 294 | bufp = &ascii_buf[len]; | ||
| 295 | for (i = 0; i < (asciiblob_len - len) / 2; i++) | ||
| 296 | bufp = pack_hex_byte(bufp, iv[i]); | ||
| 297 | out: | ||
| 298 | return ascii_buf; | ||
| 299 | } | ||
| 300 | |||
| 301 | /* | ||
| 302 | * request_trusted_key - request the trusted key | ||
| 303 | * | ||
| 304 | * Trusted keys are sealed to PCRs and other metadata. Although userspace | ||
| 305 | * manages both trusted/encrypted key-types, like the encrypted key type | ||
| 306 | * data, trusted key type data is not visible decrypted from userspace. | ||
| 307 | */ | ||
| 308 | static struct key *request_trusted_key(const char *trusted_desc, | ||
| 309 | u8 **master_key, size_t *master_keylen) | ||
| 310 | { | ||
| 311 | struct trusted_key_payload *tpayload; | ||
| 312 | struct key *tkey; | ||
| 313 | |||
| 314 | tkey = request_key(&key_type_trusted, trusted_desc, NULL); | ||
| 315 | if (IS_ERR(tkey)) | ||
| 316 | goto error; | ||
| 317 | |||
| 318 | down_read(&tkey->sem); | ||
| 319 | tpayload = rcu_dereference(tkey->payload.data); | ||
| 320 | *master_key = tpayload->key; | ||
| 321 | *master_keylen = tpayload->key_len; | ||
| 322 | error: | ||
| 323 | return tkey; | ||
| 324 | } | ||
| 325 | |||
| 326 | /* | ||
| 327 | * request_user_key - request the user key | ||
| 328 | * | ||
| 329 | * Use a user provided key to encrypt/decrypt an encrypted-key. | ||
| 330 | */ | ||
| 331 | static struct key *request_user_key(const char *master_desc, u8 **master_key, | ||
| 332 | size_t *master_keylen) | ||
| 333 | { | ||
| 334 | struct user_key_payload *upayload; | ||
| 335 | struct key *ukey; | ||
| 336 | |||
| 337 | ukey = request_key(&key_type_user, master_desc, NULL); | ||
| 338 | if (IS_ERR(ukey)) | ||
| 339 | goto error; | ||
| 340 | |||
| 341 | down_read(&ukey->sem); | ||
| 342 | upayload = rcu_dereference(ukey->payload.data); | ||
| 343 | *master_key = upayload->data; | ||
| 344 | *master_keylen = upayload->datalen; | ||
| 345 | error: | ||
| 346 | return ukey; | ||
| 347 | } | ||
| 348 | |||
| 349 | static struct sdesc *alloc_sdesc(struct crypto_shash *alg) | ||
| 350 | { | ||
| 351 | struct sdesc *sdesc; | ||
| 352 | int size; | ||
| 353 | |||
| 354 | size = sizeof(struct shash_desc) + crypto_shash_descsize(alg); | ||
| 355 | sdesc = kmalloc(size, GFP_KERNEL); | ||
| 356 | if (!sdesc) | ||
| 357 | return ERR_PTR(-ENOMEM); | ||
| 358 | sdesc->shash.tfm = alg; | ||
| 359 | sdesc->shash.flags = 0x0; | ||
| 360 | return sdesc; | ||
| 361 | } | ||
| 362 | |||
| 363 | static int calc_hmac(u8 *digest, const u8 *key, unsigned int keylen, | ||
| 364 | const u8 *buf, unsigned int buflen) | ||
| 365 | { | ||
| 366 | struct sdesc *sdesc; | ||
| 367 | int ret; | ||
| 368 | |||
| 369 | sdesc = alloc_sdesc(hmacalg); | ||
| 370 | if (IS_ERR(sdesc)) { | ||
| 371 | pr_info("encrypted_key: can't alloc %s\n", hmac_alg); | ||
| 372 | return PTR_ERR(sdesc); | ||
| 373 | } | ||
| 374 | |||
| 375 | ret = crypto_shash_setkey(hmacalg, key, keylen); | ||
| 376 | if (!ret) | ||
| 377 | ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest); | ||
| 378 | kfree(sdesc); | ||
| 379 | return ret; | ||
| 380 | } | ||
| 381 | |||
| 382 | static int calc_hash(u8 *digest, const u8 *buf, unsigned int buflen) | ||
| 383 | { | ||
| 384 | struct sdesc *sdesc; | ||
| 385 | int ret; | ||
| 386 | |||
| 387 | sdesc = alloc_sdesc(hashalg); | ||
| 388 | if (IS_ERR(sdesc)) { | ||
| 389 | pr_info("encrypted_key: can't alloc %s\n", hash_alg); | ||
| 390 | return PTR_ERR(sdesc); | ||
| 391 | } | ||
| 392 | |||
| 393 | ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest); | ||
| 394 | kfree(sdesc); | ||
| 395 | return ret; | ||
| 396 | } | ||
| 397 | |||
| 398 | enum derived_key_type { ENC_KEY, AUTH_KEY }; | ||
| 399 | |||
| 400 | /* Derive authentication/encryption key from trusted key */ | ||
| 401 | static int get_derived_key(u8 *derived_key, enum derived_key_type key_type, | ||
| 402 | const u8 *master_key, size_t master_keylen) | ||
| 403 | { | ||
| 404 | u8 *derived_buf; | ||
| 405 | unsigned int derived_buf_len; | ||
| 406 | int ret; | ||
| 407 | |||
| 408 | derived_buf_len = strlen("AUTH_KEY") + 1 + master_keylen; | ||
| 409 | if (derived_buf_len < HASH_SIZE) | ||
| 410 | derived_buf_len = HASH_SIZE; | ||
| 411 | |||
| 412 | derived_buf = kzalloc(derived_buf_len, GFP_KERNEL); | ||
| 413 | if (!derived_buf) { | ||
| 414 | pr_err("encrypted_key: out of memory\n"); | ||
| 415 | return -ENOMEM; | ||
| 416 | } | ||
| 417 | if (key_type) | ||
| 418 | strcpy(derived_buf, "AUTH_KEY"); | ||
| 419 | else | ||
| 420 | strcpy(derived_buf, "ENC_KEY"); | ||
| 421 | |||
| 422 | memcpy(derived_buf + strlen(derived_buf) + 1, master_key, | ||
| 423 | master_keylen); | ||
| 424 | ret = calc_hash(derived_key, derived_buf, derived_buf_len); | ||
| 425 | kfree(derived_buf); | ||
| 426 | return ret; | ||
| 427 | } | ||
| 428 | |||
| 429 | static int init_blkcipher_desc(struct blkcipher_desc *desc, const u8 *key, | ||
| 430 | unsigned int key_len, const u8 *iv, | ||
| 431 | unsigned int ivsize) | ||
| 432 | { | ||
| 433 | int ret; | ||
| 434 | |||
| 435 | desc->tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); | ||
| 436 | if (IS_ERR(desc->tfm)) { | ||
| 437 | pr_err("encrypted_key: failed to load %s transform (%ld)\n", | ||
| 438 | blkcipher_alg, PTR_ERR(desc->tfm)); | ||
| 439 | return PTR_ERR(desc->tfm); | ||
| 440 | } | ||
| 441 | desc->flags = 0; | ||
| 442 | |||
| 443 | ret = crypto_blkcipher_setkey(desc->tfm, key, key_len); | ||
| 444 | if (ret < 0) { | ||
| 445 | pr_err("encrypted_key: failed to setkey (%d)\n", ret); | ||
| 446 | crypto_free_blkcipher(desc->tfm); | ||
| 447 | return ret; | ||
| 448 | } | ||
| 449 | crypto_blkcipher_set_iv(desc->tfm, iv, ivsize); | ||
| 450 | return 0; | ||
| 451 | } | ||
| 452 | |||
| 453 | static struct key *request_master_key(struct encrypted_key_payload *epayload, | ||
| 454 | u8 **master_key, size_t *master_keylen) | ||
| 455 | { | ||
| 456 | struct key *mkey = NULL; | ||
| 457 | |||
| 458 | if (!strncmp(epayload->master_desc, KEY_TRUSTED_PREFIX, | ||
| 459 | KEY_TRUSTED_PREFIX_LEN)) { | ||
| 460 | mkey = request_trusted_key(epayload->master_desc + | ||
| 461 | KEY_TRUSTED_PREFIX_LEN, | ||
| 462 | master_key, master_keylen); | ||
| 463 | } else if (!strncmp(epayload->master_desc, KEY_USER_PREFIX, | ||
| 464 | KEY_USER_PREFIX_LEN)) { | ||
| 465 | mkey = request_user_key(epayload->master_desc + | ||
| 466 | KEY_USER_PREFIX_LEN, | ||
| 467 | master_key, master_keylen); | ||
| 468 | } else | ||
| 469 | goto out; | ||
| 470 | |||
| 471 | if (IS_ERR(mkey)) { | ||
| 472 | pr_info("encrypted_key: key %s not found", | ||
| 473 | epayload->master_desc); | ||
| 474 | goto out; | ||
| 475 | } | ||
| 476 | |||
| 477 | dump_master_key(*master_key, *master_keylen); | ||
| 478 | out: | ||
| 479 | return mkey; | ||
| 480 | } | ||
| 481 | |||
| 482 | /* Before returning data to userspace, encrypt decrypted data. */ | ||
| 483 | static int derived_key_encrypt(struct encrypted_key_payload *epayload, | ||
| 484 | const u8 *derived_key, | ||
| 485 | unsigned int derived_keylen) | ||
| 486 | { | ||
| 487 | struct scatterlist sg_in[2]; | ||
| 488 | struct scatterlist sg_out[1]; | ||
| 489 | struct blkcipher_desc desc; | ||
| 490 | unsigned int encrypted_datalen; | ||
| 491 | unsigned int padlen; | ||
| 492 | char pad[16]; | ||
| 493 | int ret; | ||
| 494 | |||
| 495 | encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); | ||
| 496 | padlen = encrypted_datalen - epayload->decrypted_datalen; | ||
| 497 | |||
| 498 | ret = init_blkcipher_desc(&desc, derived_key, derived_keylen, | ||
| 499 | epayload->iv, ivsize); | ||
| 500 | if (ret < 0) | ||
| 501 | goto out; | ||
| 502 | dump_decrypted_data(epayload); | ||
| 503 | |||
| 504 | memset(pad, 0, sizeof pad); | ||
| 505 | sg_init_table(sg_in, 2); | ||
| 506 | sg_set_buf(&sg_in[0], epayload->decrypted_data, | ||
| 507 | epayload->decrypted_datalen); | ||
| 508 | sg_set_buf(&sg_in[1], pad, padlen); | ||
| 509 | |||
| 510 | sg_init_table(sg_out, 1); | ||
| 511 | sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen); | ||
| 512 | |||
| 513 | ret = crypto_blkcipher_encrypt(&desc, sg_out, sg_in, encrypted_datalen); | ||
| 514 | crypto_free_blkcipher(desc.tfm); | ||
| 515 | if (ret < 0) | ||
| 516 | pr_err("encrypted_key: failed to encrypt (%d)\n", ret); | ||
| 517 | else | ||
| 518 | dump_encrypted_data(epayload, encrypted_datalen); | ||
| 519 | out: | ||
| 520 | return ret; | ||
| 521 | } | ||
| 522 | |||
| 523 | static int datablob_hmac_append(struct encrypted_key_payload *epayload, | ||
| 524 | const u8 *master_key, size_t master_keylen) | ||
| 525 | { | ||
| 526 | u8 derived_key[HASH_SIZE]; | ||
| 527 | u8 *digest; | ||
| 528 | int ret; | ||
| 529 | |||
| 530 | ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); | ||
| 531 | if (ret < 0) | ||
| 532 | goto out; | ||
| 533 | |||
| 534 | digest = epayload->format + epayload->datablob_len; | ||
| 535 | ret = calc_hmac(digest, derived_key, sizeof derived_key, | ||
| 536 | epayload->format, epayload->datablob_len); | ||
| 537 | if (!ret) | ||
| 538 | dump_hmac(NULL, digest, HASH_SIZE); | ||
| 539 | out: | ||
| 540 | return ret; | ||
| 541 | } | ||
| 542 | |||
| 543 | /* verify HMAC before decrypting encrypted key */ | ||
| 544 | static int datablob_hmac_verify(struct encrypted_key_payload *epayload, | ||
| 545 | const u8 *format, const u8 *master_key, | ||
| 546 | size_t master_keylen) | ||
| 547 | { | ||
| 548 | u8 derived_key[HASH_SIZE]; | ||
| 549 | u8 digest[HASH_SIZE]; | ||
| 550 | int ret; | ||
| 551 | char *p; | ||
| 552 | unsigned short len; | ||
| 553 | |||
| 554 | ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); | ||
| 555 | if (ret < 0) | ||
| 556 | goto out; | ||
| 557 | |||
| 558 | len = epayload->datablob_len; | ||
| 559 | if (!format) { | ||
| 560 | p = epayload->master_desc; | ||
| 561 | len -= strlen(epayload->format) + 1; | ||
| 562 | } else | ||
| 563 | p = epayload->format; | ||
| 564 | |||
| 565 | ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len); | ||
| 566 | if (ret < 0) | ||
| 567 | goto out; | ||
| 568 | ret = memcmp(digest, epayload->format + epayload->datablob_len, | ||
| 569 | sizeof digest); | ||
| 570 | if (ret) { | ||
| 571 | ret = -EINVAL; | ||
| 572 | dump_hmac("datablob", | ||
| 573 | epayload->format + epayload->datablob_len, | ||
| 574 | HASH_SIZE); | ||
| 575 | dump_hmac("calc", digest, HASH_SIZE); | ||
| 576 | } | ||
| 577 | out: | ||
| 578 | return ret; | ||
| 579 | } | ||
| 580 | |||
| 581 | static int derived_key_decrypt(struct encrypted_key_payload *epayload, | ||
| 582 | const u8 *derived_key, | ||
| 583 | unsigned int derived_keylen) | ||
| 584 | { | ||
| 585 | struct scatterlist sg_in[1]; | ||
| 586 | struct scatterlist sg_out[2]; | ||
| 587 | struct blkcipher_desc desc; | ||
| 588 | unsigned int encrypted_datalen; | ||
| 589 | char pad[16]; | ||
| 590 | int ret; | ||
| 591 | |||
| 592 | encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); | ||
| 593 | ret = init_blkcipher_desc(&desc, derived_key, derived_keylen, | ||
| 594 | epayload->iv, ivsize); | ||
| 595 | if (ret < 0) | ||
| 596 | goto out; | ||
| 597 | dump_encrypted_data(epayload, encrypted_datalen); | ||
| 598 | |||
| 599 | memset(pad, 0, sizeof pad); | ||
| 600 | sg_init_table(sg_in, 1); | ||
| 601 | sg_init_table(sg_out, 2); | ||
| 602 | sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen); | ||
| 603 | sg_set_buf(&sg_out[0], epayload->decrypted_data, | ||
| 604 | epayload->decrypted_datalen); | ||
| 605 | sg_set_buf(&sg_out[1], pad, sizeof pad); | ||
| 606 | |||
| 607 | ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in, encrypted_datalen); | ||
| 608 | crypto_free_blkcipher(desc.tfm); | ||
| 609 | if (ret < 0) | ||
| 610 | goto out; | ||
| 611 | dump_decrypted_data(epayload); | ||
| 612 | out: | ||
| 613 | return ret; | ||
| 614 | } | ||
| 615 | |||
| 616 | /* Allocate memory for decrypted key and datablob. */ | ||
| 617 | static struct encrypted_key_payload *encrypted_key_alloc(struct key *key, | ||
| 618 | const char *format, | ||
| 619 | const char *master_desc, | ||
| 620 | const char *datalen) | ||
| 621 | { | ||
| 622 | struct encrypted_key_payload *epayload = NULL; | ||
| 623 | unsigned short datablob_len; | ||
| 624 | unsigned short decrypted_datalen; | ||
| 625 | unsigned short payload_datalen; | ||
| 626 | unsigned int encrypted_datalen; | ||
| 627 | unsigned int format_len; | ||
| 628 | long dlen; | ||
| 629 | int ret; | ||
| 630 | |||
| 631 | ret = strict_strtol(datalen, 10, &dlen); | ||
| 632 | if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE) | ||
| 633 | return ERR_PTR(-EINVAL); | ||
| 634 | |||
| 635 | format_len = (!format) ? strlen(key_format_default) : strlen(format); | ||
| 636 | decrypted_datalen = dlen; | ||
| 637 | payload_datalen = decrypted_datalen; | ||
| 638 | if (format && !strcmp(format, key_format_ecryptfs)) { | ||
| 639 | if (dlen != ECRYPTFS_MAX_KEY_BYTES) { | ||
| 640 | pr_err("encrypted_key: keylen for the ecryptfs format " | ||
| 641 | "must be equal to %d bytes\n", | ||
| 642 | ECRYPTFS_MAX_KEY_BYTES); | ||
| 643 | return ERR_PTR(-EINVAL); | ||
| 644 | } | ||
| 645 | decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES; | ||
| 646 | payload_datalen = sizeof(struct ecryptfs_auth_tok); | ||
| 647 | } | ||
| 648 | |||
| 649 | encrypted_datalen = roundup(decrypted_datalen, blksize); | ||
| 650 | |||
| 651 | datablob_len = format_len + 1 + strlen(master_desc) + 1 | ||
| 652 | + strlen(datalen) + 1 + ivsize + 1 + encrypted_datalen; | ||
| 653 | |||
| 654 | ret = key_payload_reserve(key, payload_datalen + datablob_len | ||
| 655 | + HASH_SIZE + 1); | ||
| 656 | if (ret < 0) | ||
| 657 | return ERR_PTR(ret); | ||
| 658 | |||
| 659 | epayload = kzalloc(sizeof(*epayload) + payload_datalen + | ||
| 660 | datablob_len + HASH_SIZE + 1, GFP_KERNEL); | ||
| 661 | if (!epayload) | ||
| 662 | return ERR_PTR(-ENOMEM); | ||
| 663 | |||
| 664 | epayload->payload_datalen = payload_datalen; | ||
| 665 | epayload->decrypted_datalen = decrypted_datalen; | ||
| 666 | epayload->datablob_len = datablob_len; | ||
| 667 | return epayload; | ||
| 668 | } | ||
| 669 | |||
| 670 | static int encrypted_key_decrypt(struct encrypted_key_payload *epayload, | ||
| 671 | const char *format, const char *hex_encoded_iv) | ||
| 672 | { | ||
| 673 | struct key *mkey; | ||
| 674 | u8 derived_key[HASH_SIZE]; | ||
| 675 | u8 *master_key; | ||
| 676 | u8 *hmac; | ||
| 677 | const char *hex_encoded_data; | ||
| 678 | unsigned int encrypted_datalen; | ||
| 679 | size_t master_keylen; | ||
| 680 | size_t asciilen; | ||
| 681 | int ret; | ||
| 682 | |||
| 683 | encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); | ||
| 684 | asciilen = (ivsize + 1 + encrypted_datalen + HASH_SIZE) * 2; | ||
| 685 | if (strlen(hex_encoded_iv) != asciilen) | ||
| 686 | return -EINVAL; | ||
| 687 | |||
| 688 | hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2; | ||
| 689 | hex2bin(epayload->iv, hex_encoded_iv, ivsize); | ||
| 690 | hex2bin(epayload->encrypted_data, hex_encoded_data, encrypted_datalen); | ||
| 691 | |||
| 692 | hmac = epayload->format + epayload->datablob_len; | ||
| 693 | hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), HASH_SIZE); | ||
| 694 | |||
| 695 | mkey = request_master_key(epayload, &master_key, &master_keylen); | ||
| 696 | if (IS_ERR(mkey)) | ||
| 697 | return PTR_ERR(mkey); | ||
| 698 | |||
| 699 | ret = datablob_hmac_verify(epayload, format, master_key, master_keylen); | ||
| 700 | if (ret < 0) { | ||
| 701 | pr_err("encrypted_key: bad hmac (%d)\n", ret); | ||
| 702 | goto out; | ||
| 703 | } | ||
| 704 | |||
| 705 | ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); | ||
| 706 | if (ret < 0) | ||
| 707 | goto out; | ||
| 708 | |||
| 709 | ret = derived_key_decrypt(epayload, derived_key, sizeof derived_key); | ||
| 710 | if (ret < 0) | ||
| 711 | pr_err("encrypted_key: failed to decrypt key (%d)\n", ret); | ||
| 712 | out: | ||
| 713 | up_read(&mkey->sem); | ||
| 714 | key_put(mkey); | ||
| 715 | return ret; | ||
| 716 | } | ||
| 717 | |||
| 718 | static void __ekey_init(struct encrypted_key_payload *epayload, | ||
| 719 | const char *format, const char *master_desc, | ||
| 720 | const char *datalen) | ||
| 721 | { | ||
| 722 | unsigned int format_len; | ||
| 723 | |||
| 724 | format_len = (!format) ? strlen(key_format_default) : strlen(format); | ||
| 725 | epayload->format = epayload->payload_data + epayload->payload_datalen; | ||
| 726 | epayload->master_desc = epayload->format + format_len + 1; | ||
| 727 | epayload->datalen = epayload->master_desc + strlen(master_desc) + 1; | ||
| 728 | epayload->iv = epayload->datalen + strlen(datalen) + 1; | ||
| 729 | epayload->encrypted_data = epayload->iv + ivsize + 1; | ||
| 730 | epayload->decrypted_data = epayload->payload_data; | ||
| 731 | |||
| 732 | if (!format) | ||
| 733 | memcpy(epayload->format, key_format_default, format_len); | ||
| 734 | else { | ||
| 735 | if (!strcmp(format, key_format_ecryptfs)) | ||
| 736 | epayload->decrypted_data = | ||
| 737 | ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data); | ||
| 738 | |||
| 739 | memcpy(epayload->format, format, format_len); | ||
| 740 | } | ||
| 741 | |||
| 742 | memcpy(epayload->master_desc, master_desc, strlen(master_desc)); | ||
| 743 | memcpy(epayload->datalen, datalen, strlen(datalen)); | ||
| 744 | } | ||
| 745 | |||
| 746 | /* | ||
| 747 | * encrypted_init - initialize an encrypted key | ||
| 748 | * | ||
| 749 | * For a new key, use a random number for both the iv and data | ||
| 750 | * itself. For an old key, decrypt the hex encoded data. | ||
| 751 | */ | ||
| 752 | static int encrypted_init(struct encrypted_key_payload *epayload, | ||
| 753 | const char *key_desc, const char *format, | ||
| 754 | const char *master_desc, const char *datalen, | ||
| 755 | const char *hex_encoded_iv) | ||
| 756 | { | ||
| 757 | int ret = 0; | ||
| 758 | |||
| 759 | if (format && !strcmp(format, key_format_ecryptfs)) { | ||
| 760 | ret = valid_ecryptfs_desc(key_desc); | ||
| 761 | if (ret < 0) | ||
| 762 | return ret; | ||
| 763 | |||
| 764 | ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data, | ||
| 765 | key_desc); | ||
| 766 | } | ||
| 767 | |||
| 768 | __ekey_init(epayload, format, master_desc, datalen); | ||
| 769 | if (!hex_encoded_iv) { | ||
| 770 | get_random_bytes(epayload->iv, ivsize); | ||
| 771 | |||
| 772 | get_random_bytes(epayload->decrypted_data, | ||
| 773 | epayload->decrypted_datalen); | ||
| 774 | } else | ||
| 775 | ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv); | ||
| 776 | return ret; | ||
| 777 | } | ||
| 778 | |||
| 779 | /* | ||
| 780 | * encrypted_instantiate - instantiate an encrypted key | ||
| 781 | * | ||
| 782 | * Decrypt an existing encrypted datablob or create a new encrypted key | ||
| 783 | * based on a kernel random number. | ||
| 784 | * | ||
| 785 | * On success, return 0. Otherwise return errno. | ||
| 786 | */ | ||
| 787 | static int encrypted_instantiate(struct key *key, const void *data, | ||
| 788 | size_t datalen) | ||
| 789 | { | ||
| 790 | struct encrypted_key_payload *epayload = NULL; | ||
| 791 | char *datablob = NULL; | ||
| 792 | const char *format = NULL; | ||
| 793 | char *master_desc = NULL; | ||
| 794 | char *decrypted_datalen = NULL; | ||
| 795 | char *hex_encoded_iv = NULL; | ||
| 796 | int ret; | ||
| 797 | |||
| 798 | if (datalen <= 0 || datalen > 32767 || !data) | ||
| 799 | return -EINVAL; | ||
| 800 | |||
| 801 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | ||
| 802 | if (!datablob) | ||
| 803 | return -ENOMEM; | ||
| 804 | datablob[datalen] = 0; | ||
| 805 | memcpy(datablob, data, datalen); | ||
| 806 | ret = datablob_parse(datablob, &format, &master_desc, | ||
| 807 | &decrypted_datalen, &hex_encoded_iv); | ||
| 808 | if (ret < 0) | ||
| 809 | goto out; | ||
| 810 | |||
| 811 | epayload = encrypted_key_alloc(key, format, master_desc, | ||
| 812 | decrypted_datalen); | ||
| 813 | if (IS_ERR(epayload)) { | ||
| 814 | ret = PTR_ERR(epayload); | ||
| 815 | goto out; | ||
| 816 | } | ||
| 817 | ret = encrypted_init(epayload, key->description, format, master_desc, | ||
| 818 | decrypted_datalen, hex_encoded_iv); | ||
| 819 | if (ret < 0) { | ||
| 820 | kfree(epayload); | ||
| 821 | goto out; | ||
| 822 | } | ||
| 823 | |||
| 824 | rcu_assign_pointer(key->payload.data, epayload); | ||
| 825 | out: | ||
| 826 | kfree(datablob); | ||
| 827 | return ret; | ||
| 828 | } | ||
| 829 | |||
| 830 | static void encrypted_rcu_free(struct rcu_head *rcu) | ||
| 831 | { | ||
| 832 | struct encrypted_key_payload *epayload; | ||
| 833 | |||
| 834 | epayload = container_of(rcu, struct encrypted_key_payload, rcu); | ||
| 835 | memset(epayload->decrypted_data, 0, epayload->decrypted_datalen); | ||
| 836 | kfree(epayload); | ||
| 837 | } | ||
| 838 | |||
| 839 | /* | ||
| 840 | * encrypted_update - update the master key description | ||
| 841 | * | ||
| 842 | * Change the master key description for an existing encrypted key. | ||
| 843 | * The next read will return an encrypted datablob using the new | ||
| 844 | * master key description. | ||
| 845 | * | ||
| 846 | * On success, return 0. Otherwise return errno. | ||
| 847 | */ | ||
| 848 | static int encrypted_update(struct key *key, const void *data, size_t datalen) | ||
| 849 | { | ||
| 850 | struct encrypted_key_payload *epayload = key->payload.data; | ||
| 851 | struct encrypted_key_payload *new_epayload; | ||
| 852 | char *buf; | ||
| 853 | char *new_master_desc = NULL; | ||
| 854 | const char *format = NULL; | ||
| 855 | int ret = 0; | ||
| 856 | |||
| 857 | if (datalen <= 0 || datalen > 32767 || !data) | ||
| 858 | return -EINVAL; | ||
| 859 | |||
| 860 | buf = kmalloc(datalen + 1, GFP_KERNEL); | ||
| 861 | if (!buf) | ||
| 862 | return -ENOMEM; | ||
| 863 | |||
| 864 | buf[datalen] = 0; | ||
| 865 | memcpy(buf, data, datalen); | ||
| 866 | ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL); | ||
| 867 | if (ret < 0) | ||
| 868 | goto out; | ||
| 869 | |||
| 870 | ret = valid_master_desc(new_master_desc, epayload->master_desc); | ||
| 871 | if (ret < 0) | ||
| 872 | goto out; | ||
| 873 | |||
| 874 | new_epayload = encrypted_key_alloc(key, epayload->format, | ||
| 875 | new_master_desc, epayload->datalen); | ||
| 876 | if (IS_ERR(new_epayload)) { | ||
| 877 | ret = PTR_ERR(new_epayload); | ||
| 878 | goto out; | ||
| 879 | } | ||
| 880 | |||
| 881 | __ekey_init(new_epayload, epayload->format, new_master_desc, | ||
| 882 | epayload->datalen); | ||
| 883 | |||
| 884 | memcpy(new_epayload->iv, epayload->iv, ivsize); | ||
| 885 | memcpy(new_epayload->payload_data, epayload->payload_data, | ||
| 886 | epayload->payload_datalen); | ||
| 887 | |||
| 888 | rcu_assign_pointer(key->payload.data, new_epayload); | ||
| 889 | call_rcu(&epayload->rcu, encrypted_rcu_free); | ||
| 890 | out: | ||
| 891 | kfree(buf); | ||
| 892 | return ret; | ||
| 893 | } | ||
| 894 | |||
| 895 | /* | ||
| 896 | * encrypted_read - format and copy the encrypted data to userspace | ||
| 897 | * | ||
| 898 | * The resulting datablob format is: | ||
| 899 | * <master-key name> <decrypted data length> <encrypted iv> <encrypted data> | ||
| 900 | * | ||
| 901 | * On success, return to userspace the encrypted key datablob size. | ||
| 902 | */ | ||
| 903 | static long encrypted_read(const struct key *key, char __user *buffer, | ||
| 904 | size_t buflen) | ||
| 905 | { | ||
| 906 | struct encrypted_key_payload *epayload; | ||
| 907 | struct key *mkey; | ||
| 908 | u8 *master_key; | ||
| 909 | size_t master_keylen; | ||
| 910 | char derived_key[HASH_SIZE]; | ||
| 911 | char *ascii_buf; | ||
| 912 | size_t asciiblob_len; | ||
| 913 | int ret; | ||
| 914 | |||
| 915 | epayload = rcu_dereference_key(key); | ||
| 916 | |||
| 917 | /* returns the hex encoded iv, encrypted-data, and hmac as ascii */ | ||
| 918 | asciiblob_len = epayload->datablob_len + ivsize + 1 | ||
| 919 | + roundup(epayload->decrypted_datalen, blksize) | ||
| 920 | + (HASH_SIZE * 2); | ||
| 921 | |||
| 922 | if (!buffer || buflen < asciiblob_len) | ||
| 923 | return asciiblob_len; | ||
| 924 | |||
| 925 | mkey = request_master_key(epayload, &master_key, &master_keylen); | ||
| 926 | if (IS_ERR(mkey)) | ||
| 927 | return PTR_ERR(mkey); | ||
| 928 | |||
| 929 | ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); | ||
| 930 | if (ret < 0) | ||
| 931 | goto out; | ||
| 932 | |||
| 933 | ret = derived_key_encrypt(epayload, derived_key, sizeof derived_key); | ||
| 934 | if (ret < 0) | ||
| 935 | goto out; | ||
| 936 | |||
| 937 | ret = datablob_hmac_append(epayload, master_key, master_keylen); | ||
| 938 | if (ret < 0) | ||
| 939 | goto out; | ||
| 940 | |||
| 941 | ascii_buf = datablob_format(epayload, asciiblob_len); | ||
| 942 | if (!ascii_buf) { | ||
| 943 | ret = -ENOMEM; | ||
| 944 | goto out; | ||
| 945 | } | ||
| 946 | |||
| 947 | up_read(&mkey->sem); | ||
| 948 | key_put(mkey); | ||
| 949 | |||
| 950 | if (copy_to_user(buffer, ascii_buf, asciiblob_len) != 0) | ||
| 951 | ret = -EFAULT; | ||
| 952 | kfree(ascii_buf); | ||
| 953 | |||
| 954 | return asciiblob_len; | ||
| 955 | out: | ||
| 956 | up_read(&mkey->sem); | ||
| 957 | key_put(mkey); | ||
| 958 | return ret; | ||
| 959 | } | ||
| 960 | |||
| 961 | /* | ||
| 962 | * encrypted_destroy - before freeing the key, clear the decrypted data | ||
| 963 | * | ||
| 964 | * Before freeing the key, clear the memory containing the decrypted | ||
| 965 | * key data. | ||
| 966 | */ | ||
| 967 | static void encrypted_destroy(struct key *key) | ||
| 968 | { | ||
| 969 | struct encrypted_key_payload *epayload = key->payload.data; | ||
| 970 | |||
| 971 | if (!epayload) | ||
| 972 | return; | ||
| 973 | |||
| 974 | memset(epayload->decrypted_data, 0, epayload->decrypted_datalen); | ||
| 975 | kfree(key->payload.data); | ||
| 976 | } | ||
| 977 | |||
| 978 | struct key_type key_type_encrypted = { | ||
| 979 | .name = "encrypted", | ||
| 980 | .instantiate = encrypted_instantiate, | ||
| 981 | .update = encrypted_update, | ||
| 982 | .match = user_match, | ||
| 983 | .destroy = encrypted_destroy, | ||
| 984 | .describe = user_describe, | ||
| 985 | .read = encrypted_read, | ||
| 986 | }; | ||
| 987 | EXPORT_SYMBOL_GPL(key_type_encrypted); | ||
| 988 | |||
| 989 | static void encrypted_shash_release(void) | ||
| 990 | { | ||
| 991 | if (hashalg) | ||
| 992 | crypto_free_shash(hashalg); | ||
| 993 | if (hmacalg) | ||
| 994 | crypto_free_shash(hmacalg); | ||
| 995 | } | ||
| 996 | |||
| 997 | static int __init encrypted_shash_alloc(void) | ||
| 998 | { | ||
| 999 | int ret; | ||
| 1000 | |||
| 1001 | hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); | ||
| 1002 | if (IS_ERR(hmacalg)) { | ||
| 1003 | pr_info("encrypted_key: could not allocate crypto %s\n", | ||
| 1004 | hmac_alg); | ||
| 1005 | return PTR_ERR(hmacalg); | ||
| 1006 | } | ||
| 1007 | |||
| 1008 | hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); | ||
| 1009 | if (IS_ERR(hashalg)) { | ||
| 1010 | pr_info("encrypted_key: could not allocate crypto %s\n", | ||
| 1011 | hash_alg); | ||
| 1012 | ret = PTR_ERR(hashalg); | ||
| 1013 | goto hashalg_fail; | ||
| 1014 | } | ||
| 1015 | |||
| 1016 | return 0; | ||
| 1017 | |||
| 1018 | hashalg_fail: | ||
| 1019 | crypto_free_shash(hmacalg); | ||
| 1020 | return ret; | ||
| 1021 | } | ||
| 1022 | |||
| 1023 | static int __init init_encrypted(void) | ||
| 1024 | { | ||
| 1025 | int ret; | ||
| 1026 | |||
| 1027 | ret = encrypted_shash_alloc(); | ||
| 1028 | if (ret < 0) | ||
| 1029 | return ret; | ||
| 1030 | ret = register_key_type(&key_type_encrypted); | ||
| 1031 | if (ret < 0) | ||
| 1032 | goto out; | ||
| 1033 | return aes_get_sizes(); | ||
| 1034 | out: | ||
| 1035 | encrypted_shash_release(); | ||
| 1036 | return ret; | ||
| 1037 | |||
| 1038 | } | ||
| 1039 | |||
| 1040 | static void __exit cleanup_encrypted(void) | ||
| 1041 | { | ||
| 1042 | encrypted_shash_release(); | ||
| 1043 | unregister_key_type(&key_type_encrypted); | ||
| 1044 | } | ||
| 1045 | |||
| 1046 | late_initcall(init_encrypted); | ||
| 1047 | module_exit(cleanup_encrypted); | ||
| 1048 | |||
| 1049 | MODULE_LICENSE("GPL"); | ||
diff --git a/security/keys/encrypted.h b/security/keys/encrypted.h new file mode 100644 index 00000000000..cef5e2f2b7d --- /dev/null +++ b/security/keys/encrypted.h | |||
| @@ -0,0 +1,54 @@ | |||
| 1 | #ifndef __ENCRYPTED_KEY_H | ||
| 2 | #define __ENCRYPTED_KEY_H | ||
| 3 | |||
| 4 | #define ENCRYPTED_DEBUG 0 | ||
| 5 | |||
| 6 | #if ENCRYPTED_DEBUG | ||
| 7 | static inline void dump_master_key(const u8 *master_key, size_t master_keylen) | ||
| 8 | { | ||
| 9 | print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1, | ||
| 10 | master_key, master_keylen, 0); | ||
| 11 | } | ||
| 12 | |||
| 13 | static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) | ||
| 14 | { | ||
| 15 | print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1, | ||
| 16 | epayload->decrypted_data, | ||
| 17 | epayload->decrypted_datalen, 0); | ||
| 18 | } | ||
| 19 | |||
| 20 | static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, | ||
| 21 | unsigned int encrypted_datalen) | ||
| 22 | { | ||
| 23 | print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1, | ||
| 24 | epayload->encrypted_data, encrypted_datalen, 0); | ||
| 25 | } | ||
| 26 | |||
| 27 | static inline void dump_hmac(const char *str, const u8 *digest, | ||
| 28 | unsigned int hmac_size) | ||
| 29 | { | ||
| 30 | if (str) | ||
| 31 | pr_info("encrypted_key: %s", str); | ||
| 32 | print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest, | ||
| 33 | hmac_size, 0); | ||
| 34 | } | ||
| 35 | #else | ||
| 36 | static inline void dump_master_key(const u8 *master_key, size_t master_keylen) | ||
| 37 | { | ||
| 38 | } | ||
| 39 | |||
| 40 | static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) | ||
| 41 | { | ||
| 42 | } | ||
| 43 | |||
| 44 | static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, | ||
| 45 | unsigned int encrypted_datalen) | ||
| 46 | { | ||
| 47 | } | ||
| 48 | |||
| 49 | static inline void dump_hmac(const char *str, const u8 *digest, | ||
| 50 | unsigned int hmac_size) | ||
| 51 | { | ||
| 52 | } | ||
| 53 | #endif | ||
| 54 | #endif | ||
