Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1 | /** |
| 2 | * eCryptfs: Linux filesystem encryption layer |
| 3 | * |
| 4 | * Copyright (C) 1997-2004 Erez Zadok |
| 5 | * Copyright (C) 2001-2004 Stony Brook University |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 6 | * Copyright (C) 2004-2007 International Business Machines Corp. |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 7 | * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> |
| 8 | * Michael C. Thompson <mcthomps@us.ibm.com> |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License as |
| 12 | * published by the Free Software Foundation; either version 2 of the |
| 13 | * License, or (at your option) any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, but |
| 16 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 18 | * General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program; if not, write to the Free Software |
| 22 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
| 23 | * 02111-1307, USA. |
| 24 | */ |
| 25 | |
| 26 | #include <linux/fs.h> |
| 27 | #include <linux/mount.h> |
| 28 | #include <linux/pagemap.h> |
| 29 | #include <linux/random.h> |
| 30 | #include <linux/compiler.h> |
| 31 | #include <linux/key.h> |
| 32 | #include <linux/namei.h> |
| 33 | #include <linux/crypto.h> |
| 34 | #include <linux/file.h> |
| 35 | #include <linux/scatterlist.h> |
| 36 | #include "ecryptfs_kernel.h" |
| 37 | |
| 38 | static int |
| 39 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, |
| 40 | struct page *dst_page, int dst_offset, |
| 41 | struct page *src_page, int src_offset, int size, |
| 42 | unsigned char *iv); |
| 43 | static int |
| 44 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, |
| 45 | struct page *dst_page, int dst_offset, |
| 46 | struct page *src_page, int src_offset, int size, |
| 47 | unsigned char *iv); |
| 48 | |
| 49 | /** |
| 50 | * ecryptfs_to_hex |
| 51 | * @dst: Buffer to take hex character representation of contents of |
| 52 | * src; must be at least of size (src_size * 2) |
| 53 | * @src: Buffer to be converted to a hex string respresentation |
| 54 | * @src_size: number of bytes to convert |
| 55 | */ |
| 56 | void ecryptfs_to_hex(char *dst, char *src, size_t src_size) |
| 57 | { |
| 58 | int x; |
| 59 | |
| 60 | for (x = 0; x < src_size; x++) |
| 61 | sprintf(&dst[x * 2], "%.2x", (unsigned char)src[x]); |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * ecryptfs_from_hex |
| 66 | * @dst: Buffer to take the bytes from src hex; must be at least of |
| 67 | * size (src_size / 2) |
| 68 | * @src: Buffer to be converted from a hex string respresentation to raw value |
| 69 | * @dst_size: size of dst buffer, or number of hex characters pairs to convert |
| 70 | */ |
| 71 | void ecryptfs_from_hex(char *dst, char *src, int dst_size) |
| 72 | { |
| 73 | int x; |
| 74 | char tmp[3] = { 0, }; |
| 75 | |
| 76 | for (x = 0; x < dst_size; x++) { |
| 77 | tmp[0] = src[x * 2]; |
| 78 | tmp[1] = src[x * 2 + 1]; |
| 79 | dst[x] = (unsigned char)simple_strtol(tmp, NULL, 16); |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * ecryptfs_calculate_md5 - calculates the md5 of @src |
| 85 | * @dst: Pointer to 16 bytes of allocated memory |
| 86 | * @crypt_stat: Pointer to crypt_stat struct for the current inode |
| 87 | * @src: Data to be md5'd |
| 88 | * @len: Length of @src |
| 89 | * |
| 90 | * Uses the allocated crypto context that crypt_stat references to |
| 91 | * generate the MD5 sum of the contents of src. |
| 92 | */ |
| 93 | static int ecryptfs_calculate_md5(char *dst, |
| 94 | struct ecryptfs_crypt_stat *crypt_stat, |
| 95 | char *src, int len) |
| 96 | { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 97 | struct scatterlist sg; |
Michael Halcrow | 565d972 | 2006-10-30 22:07:17 -0800 | [diff] [blame] | 98 | struct hash_desc desc = { |
| 99 | .tfm = crypt_stat->hash_tfm, |
| 100 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP |
| 101 | }; |
| 102 | int rc = 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 103 | |
Michael Halcrow | 565d972 | 2006-10-30 22:07:17 -0800 | [diff] [blame] | 104 | mutex_lock(&crypt_stat->cs_hash_tfm_mutex); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 105 | sg_init_one(&sg, (u8 *)src, len); |
Michael Halcrow | 565d972 | 2006-10-30 22:07:17 -0800 | [diff] [blame] | 106 | if (!desc.tfm) { |
| 107 | desc.tfm = crypto_alloc_hash(ECRYPTFS_DEFAULT_HASH, 0, |
| 108 | CRYPTO_ALG_ASYNC); |
| 109 | if (IS_ERR(desc.tfm)) { |
| 110 | rc = PTR_ERR(desc.tfm); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 111 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
Michael Halcrow | 565d972 | 2006-10-30 22:07:17 -0800 | [diff] [blame] | 112 | "allocate crypto context; rc = [%d]\n", |
| 113 | rc); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 114 | goto out; |
| 115 | } |
Michael Halcrow | 565d972 | 2006-10-30 22:07:17 -0800 | [diff] [blame] | 116 | crypt_stat->hash_tfm = desc.tfm; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 117 | } |
Michael Halcrow | 8a29f2b | 2007-11-05 14:51:04 -0800 | [diff] [blame] | 118 | rc = crypto_hash_init(&desc); |
| 119 | if (rc) { |
| 120 | printk(KERN_ERR |
| 121 | "%s: Error initializing crypto hash; rc = [%d]\n", |
| 122 | __FUNCTION__, rc); |
| 123 | goto out; |
| 124 | } |
| 125 | rc = crypto_hash_update(&desc, &sg, len); |
| 126 | if (rc) { |
| 127 | printk(KERN_ERR |
| 128 | "%s: Error updating crypto hash; rc = [%d]\n", |
| 129 | __FUNCTION__, rc); |
| 130 | goto out; |
| 131 | } |
| 132 | rc = crypto_hash_final(&desc, dst); |
| 133 | if (rc) { |
| 134 | printk(KERN_ERR |
| 135 | "%s: Error finalizing crypto hash; rc = [%d]\n", |
| 136 | __FUNCTION__, rc); |
| 137 | goto out; |
| 138 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 139 | out: |
Michael Halcrow | 8a29f2b | 2007-11-05 14:51:04 -0800 | [diff] [blame] | 140 | mutex_unlock(&crypt_stat->cs_hash_tfm_mutex); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 141 | return rc; |
| 142 | } |
| 143 | |
Michael Halcrow | cd9d67d | 2007-10-16 01:28:04 -0700 | [diff] [blame] | 144 | static int ecryptfs_crypto_api_algify_cipher_name(char **algified_name, |
| 145 | char *cipher_name, |
| 146 | char *chaining_modifier) |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 147 | { |
| 148 | int cipher_name_len = strlen(cipher_name); |
| 149 | int chaining_modifier_len = strlen(chaining_modifier); |
| 150 | int algified_name_len; |
| 151 | int rc; |
| 152 | |
| 153 | algified_name_len = (chaining_modifier_len + cipher_name_len + 3); |
| 154 | (*algified_name) = kmalloc(algified_name_len, GFP_KERNEL); |
Michael Halcrow | 7bd473f | 2006-11-02 22:06:56 -0800 | [diff] [blame] | 155 | if (!(*algified_name)) { |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 156 | rc = -ENOMEM; |
| 157 | goto out; |
| 158 | } |
| 159 | snprintf((*algified_name), algified_name_len, "%s(%s)", |
| 160 | chaining_modifier, cipher_name); |
| 161 | rc = 0; |
| 162 | out: |
| 163 | return rc; |
| 164 | } |
| 165 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 166 | /** |
| 167 | * ecryptfs_derive_iv |
| 168 | * @iv: destination for the derived iv vale |
| 169 | * @crypt_stat: Pointer to crypt_stat struct for the current inode |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 170 | * @offset: Offset of the extent whose IV we are to derive |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 171 | * |
| 172 | * Generate the initialization vector from the given root IV and page |
| 173 | * offset. |
| 174 | * |
| 175 | * Returns zero on success; non-zero on error. |
| 176 | */ |
| 177 | static int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 178 | loff_t offset) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 179 | { |
| 180 | int rc = 0; |
| 181 | char dst[MD5_DIGEST_SIZE]; |
| 182 | char src[ECRYPTFS_MAX_IV_BYTES + 16]; |
| 183 | |
| 184 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 185 | ecryptfs_printk(KERN_DEBUG, "root iv:\n"); |
| 186 | ecryptfs_dump_hex(crypt_stat->root_iv, crypt_stat->iv_bytes); |
| 187 | } |
| 188 | /* TODO: It is probably secure to just cast the least |
| 189 | * significant bits of the root IV into an unsigned long and |
| 190 | * add the offset to that rather than go through all this |
| 191 | * hashing business. -Halcrow */ |
| 192 | memcpy(src, crypt_stat->root_iv, crypt_stat->iv_bytes); |
| 193 | memset((src + crypt_stat->iv_bytes), 0, 16); |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 194 | snprintf((src + crypt_stat->iv_bytes), 16, "%lld", offset); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 195 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 196 | ecryptfs_printk(KERN_DEBUG, "source:\n"); |
| 197 | ecryptfs_dump_hex(src, (crypt_stat->iv_bytes + 16)); |
| 198 | } |
| 199 | rc = ecryptfs_calculate_md5(dst, crypt_stat, src, |
| 200 | (crypt_stat->iv_bytes + 16)); |
| 201 | if (rc) { |
| 202 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " |
| 203 | "MD5 while generating IV for a page\n"); |
| 204 | goto out; |
| 205 | } |
| 206 | memcpy(iv, dst, crypt_stat->iv_bytes); |
| 207 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 208 | ecryptfs_printk(KERN_DEBUG, "derived iv:\n"); |
| 209 | ecryptfs_dump_hex(iv, crypt_stat->iv_bytes); |
| 210 | } |
| 211 | out: |
| 212 | return rc; |
| 213 | } |
| 214 | |
| 215 | /** |
| 216 | * ecryptfs_init_crypt_stat |
| 217 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. |
| 218 | * |
| 219 | * Initialize the crypt_stat structure. |
| 220 | */ |
| 221 | void |
| 222 | ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) |
| 223 | { |
| 224 | memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 225 | INIT_LIST_HEAD(&crypt_stat->keysig_list); |
| 226 | mutex_init(&crypt_stat->keysig_list_mutex); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 227 | mutex_init(&crypt_stat->cs_mutex); |
| 228 | mutex_init(&crypt_stat->cs_tfm_mutex); |
Michael Halcrow | 565d972 | 2006-10-30 22:07:17 -0800 | [diff] [blame] | 229 | mutex_init(&crypt_stat->cs_hash_tfm_mutex); |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 230 | crypt_stat->flags |= ECRYPTFS_STRUCT_INITIALIZED; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 231 | } |
| 232 | |
| 233 | /** |
Michael Halcrow | fcd1283 | 2007-10-16 01:28:01 -0700 | [diff] [blame] | 234 | * ecryptfs_destroy_crypt_stat |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 235 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. |
| 236 | * |
| 237 | * Releases all memory associated with a crypt_stat struct. |
| 238 | */ |
Michael Halcrow | fcd1283 | 2007-10-16 01:28:01 -0700 | [diff] [blame] | 239 | void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 240 | { |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 241 | struct ecryptfs_key_sig *key_sig, *key_sig_tmp; |
| 242 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 243 | if (crypt_stat->tfm) |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 244 | crypto_free_blkcipher(crypt_stat->tfm); |
Michael Halcrow | 565d972 | 2006-10-30 22:07:17 -0800 | [diff] [blame] | 245 | if (crypt_stat->hash_tfm) |
| 246 | crypto_free_hash(crypt_stat->hash_tfm); |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 247 | mutex_lock(&crypt_stat->keysig_list_mutex); |
| 248 | list_for_each_entry_safe(key_sig, key_sig_tmp, |
| 249 | &crypt_stat->keysig_list, crypt_stat_list) { |
| 250 | list_del(&key_sig->crypt_stat_list); |
| 251 | kmem_cache_free(ecryptfs_key_sig_cache, key_sig); |
| 252 | } |
| 253 | mutex_unlock(&crypt_stat->keysig_list_mutex); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 254 | memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); |
| 255 | } |
| 256 | |
Michael Halcrow | fcd1283 | 2007-10-16 01:28:01 -0700 | [diff] [blame] | 257 | void ecryptfs_destroy_mount_crypt_stat( |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 258 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
| 259 | { |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 260 | struct ecryptfs_global_auth_tok *auth_tok, *auth_tok_tmp; |
| 261 | |
| 262 | if (!(mount_crypt_stat->flags & ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED)) |
| 263 | return; |
| 264 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| 265 | list_for_each_entry_safe(auth_tok, auth_tok_tmp, |
| 266 | &mount_crypt_stat->global_auth_tok_list, |
| 267 | mount_crypt_stat_list) { |
| 268 | list_del(&auth_tok->mount_crypt_stat_list); |
| 269 | mount_crypt_stat->num_global_auth_toks--; |
| 270 | if (auth_tok->global_auth_tok_key |
| 271 | && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID)) |
| 272 | key_put(auth_tok->global_auth_tok_key); |
| 273 | kmem_cache_free(ecryptfs_global_auth_tok_cache, auth_tok); |
| 274 | } |
| 275 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 276 | memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat)); |
| 277 | } |
| 278 | |
| 279 | /** |
| 280 | * virt_to_scatterlist |
| 281 | * @addr: Virtual address |
| 282 | * @size: Size of data; should be an even multiple of the block size |
| 283 | * @sg: Pointer to scatterlist array; set to NULL to obtain only |
| 284 | * the number of scatterlist structs required in array |
| 285 | * @sg_size: Max array size |
| 286 | * |
| 287 | * Fills in a scatterlist array with page references for a passed |
| 288 | * virtual address. |
| 289 | * |
| 290 | * Returns the number of scatterlist structs in array used |
| 291 | */ |
| 292 | int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, |
| 293 | int sg_size) |
| 294 | { |
| 295 | int i = 0; |
| 296 | struct page *pg; |
| 297 | int offset; |
| 298 | int remainder_of_page; |
| 299 | |
Herbert Xu | 68e3f5d | 2007-10-27 00:52:07 -0700 | [diff] [blame] | 300 | sg_init_table(sg, sg_size); |
| 301 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 302 | while (size > 0 && i < sg_size) { |
| 303 | pg = virt_to_page(addr); |
| 304 | offset = offset_in_page(addr); |
Jens Axboe | 642f149 | 2007-10-24 11:20:47 +0200 | [diff] [blame] | 305 | if (sg) |
| 306 | sg_set_page(&sg[i], pg, 0, offset); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 307 | remainder_of_page = PAGE_CACHE_SIZE - offset; |
| 308 | if (size >= remainder_of_page) { |
| 309 | if (sg) |
| 310 | sg[i].length = remainder_of_page; |
| 311 | addr += remainder_of_page; |
| 312 | size -= remainder_of_page; |
| 313 | } else { |
| 314 | if (sg) |
| 315 | sg[i].length = size; |
| 316 | addr += size; |
| 317 | size = 0; |
| 318 | } |
| 319 | i++; |
| 320 | } |
| 321 | if (size > 0) |
| 322 | return -ENOMEM; |
| 323 | return i; |
| 324 | } |
| 325 | |
| 326 | /** |
| 327 | * encrypt_scatterlist |
| 328 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. |
| 329 | * @dest_sg: Destination of encrypted data |
| 330 | * @src_sg: Data to be encrypted |
| 331 | * @size: Length of data to be encrypted |
| 332 | * @iv: iv to use during encryption |
| 333 | * |
| 334 | * Returns the number of bytes encrypted; negative value on error |
| 335 | */ |
| 336 | static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, |
| 337 | struct scatterlist *dest_sg, |
| 338 | struct scatterlist *src_sg, int size, |
| 339 | unsigned char *iv) |
| 340 | { |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 341 | struct blkcipher_desc desc = { |
| 342 | .tfm = crypt_stat->tfm, |
| 343 | .info = iv, |
| 344 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP |
| 345 | }; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 346 | int rc = 0; |
| 347 | |
| 348 | BUG_ON(!crypt_stat || !crypt_stat->tfm |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 349 | || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 350 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 351 | ecryptfs_printk(KERN_DEBUG, "Key size [%d]; key:\n", |
| 352 | crypt_stat->key_size); |
| 353 | ecryptfs_dump_hex(crypt_stat->key, |
| 354 | crypt_stat->key_size); |
| 355 | } |
| 356 | /* Consider doing this once, when the file is opened */ |
| 357 | mutex_lock(&crypt_stat->cs_tfm_mutex); |
Trevor Highland | 8e3a6f1 | 2008-02-06 01:38:33 -0800 | [diff] [blame] | 358 | if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) { |
| 359 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, |
| 360 | crypt_stat->key_size); |
| 361 | crypt_stat->flags |= ECRYPTFS_KEY_SET; |
| 362 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 363 | if (rc) { |
| 364 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", |
| 365 | rc); |
| 366 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
| 367 | rc = -EINVAL; |
| 368 | goto out; |
| 369 | } |
| 370 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes.\n", size); |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 371 | crypto_blkcipher_encrypt_iv(&desc, dest_sg, src_sg, size); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 372 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
| 373 | out: |
| 374 | return rc; |
| 375 | } |
| 376 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 377 | /** |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 378 | * ecryptfs_lower_offset_for_extent |
| 379 | * |
| 380 | * Convert an eCryptfs page index into a lower byte offset |
| 381 | */ |
Adrian Bunk | 7896b63 | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 382 | static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num, |
| 383 | struct ecryptfs_crypt_stat *crypt_stat) |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 384 | { |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 385 | (*offset) = (crypt_stat->num_header_bytes_at_front |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 386 | + (crypt_stat->extent_size * extent_num)); |
| 387 | } |
| 388 | |
| 389 | /** |
| 390 | * ecryptfs_encrypt_extent |
| 391 | * @enc_extent_page: Allocated page into which to encrypt the data in |
| 392 | * @page |
| 393 | * @crypt_stat: crypt_stat containing cryptographic context for the |
| 394 | * encryption operation |
| 395 | * @page: Page containing plaintext data extent to encrypt |
| 396 | * @extent_offset: Page extent offset for use in generating IV |
| 397 | * |
| 398 | * Encrypts one extent of data. |
| 399 | * |
| 400 | * Return zero on success; non-zero otherwise |
| 401 | */ |
| 402 | static int ecryptfs_encrypt_extent(struct page *enc_extent_page, |
| 403 | struct ecryptfs_crypt_stat *crypt_stat, |
| 404 | struct page *page, |
| 405 | unsigned long extent_offset) |
| 406 | { |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 407 | loff_t extent_base; |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 408 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
| 409 | int rc; |
| 410 | |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 411 | extent_base = (((loff_t)page->index) |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 412 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
| 413 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, |
| 414 | (extent_base + extent_offset)); |
| 415 | if (rc) { |
| 416 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
| 417 | "derive IV for extent [0x%.16x]; " |
| 418 | "rc = [%d]\n", (extent_base + extent_offset), |
| 419 | rc); |
| 420 | goto out; |
| 421 | } |
| 422 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 423 | ecryptfs_printk(KERN_DEBUG, "Encrypting extent " |
| 424 | "with iv:\n"); |
| 425 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); |
| 426 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " |
| 427 | "encryption:\n"); |
| 428 | ecryptfs_dump_hex((char *) |
| 429 | (page_address(page) |
| 430 | + (extent_offset * crypt_stat->extent_size)), |
| 431 | 8); |
| 432 | } |
| 433 | rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0, |
| 434 | page, (extent_offset |
| 435 | * crypt_stat->extent_size), |
| 436 | crypt_stat->extent_size, extent_iv); |
| 437 | if (rc < 0) { |
| 438 | printk(KERN_ERR "%s: Error attempting to encrypt page with " |
| 439 | "page->index = [%ld], extent_offset = [%ld]; " |
| 440 | "rc = [%d]\n", __FUNCTION__, page->index, extent_offset, |
| 441 | rc); |
| 442 | goto out; |
| 443 | } |
| 444 | rc = 0; |
| 445 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 446 | ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; " |
| 447 | "rc = [%d]\n", (extent_base + extent_offset), |
| 448 | rc); |
| 449 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " |
| 450 | "encryption:\n"); |
| 451 | ecryptfs_dump_hex((char *)(page_address(enc_extent_page)), 8); |
| 452 | } |
| 453 | out: |
| 454 | return rc; |
| 455 | } |
| 456 | |
| 457 | /** |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 458 | * ecryptfs_encrypt_page |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 459 | * @page: Page mapped from the eCryptfs inode for the file; contains |
| 460 | * decrypted content that needs to be encrypted (to a temporary |
| 461 | * page; not in place) and written out to the lower file |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 462 | * |
| 463 | * Encrypt an eCryptfs page. This is done on a per-extent basis. Note |
| 464 | * that eCryptfs pages may straddle the lower pages -- for instance, |
| 465 | * if the file was created on a machine with an 8K page size |
| 466 | * (resulting in an 8K header), and then the file is copied onto a |
| 467 | * host with a 32K page size, then when reading page 0 of the eCryptfs |
| 468 | * file, 24K of page 0 of the lower file will be read and decrypted, |
| 469 | * and then 8K of page 1 of the lower file will be read and decrypted. |
| 470 | * |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 471 | * Returns zero on success; negative on error |
| 472 | */ |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 473 | int ecryptfs_encrypt_page(struct page *page) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 474 | { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 475 | struct inode *ecryptfs_inode; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 476 | struct ecryptfs_crypt_stat *crypt_stat; |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 477 | char *enc_extent_virt = NULL; |
| 478 | struct page *enc_extent_page; |
| 479 | loff_t extent_offset; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 480 | int rc = 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 481 | |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 482 | ecryptfs_inode = page->mapping->host; |
| 483 | crypt_stat = |
| 484 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 485 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 486 | rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, |
| 487 | 0, PAGE_CACHE_SIZE); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 488 | if (rc) |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 489 | printk(KERN_ERR "%s: Error attempting to copy " |
| 490 | "page at index [%ld]\n", __FUNCTION__, |
| 491 | page->index); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 492 | goto out; |
| 493 | } |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 494 | enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER); |
| 495 | if (!enc_extent_virt) { |
| 496 | rc = -ENOMEM; |
| 497 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " |
| 498 | "encrypted extent\n"); |
| 499 | goto out; |
| 500 | } |
| 501 | enc_extent_page = virt_to_page(enc_extent_virt); |
| 502 | for (extent_offset = 0; |
| 503 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); |
| 504 | extent_offset++) { |
| 505 | loff_t offset; |
| 506 | |
| 507 | rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page, |
| 508 | extent_offset); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 509 | if (rc) { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 510 | printk(KERN_ERR "%s: Error encrypting extent; " |
| 511 | "rc = [%d]\n", __FUNCTION__, rc); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 512 | goto out; |
| 513 | } |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 514 | ecryptfs_lower_offset_for_extent( |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 515 | &offset, ((((loff_t)page->index) |
| 516 | * (PAGE_CACHE_SIZE |
| 517 | / crypt_stat->extent_size)) |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 518 | + extent_offset), crypt_stat); |
| 519 | rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, |
| 520 | offset, crypt_stat->extent_size); |
| 521 | if (rc) { |
| 522 | ecryptfs_printk(KERN_ERR, "Error attempting " |
| 523 | "to write lower page; rc = [%d]" |
| 524 | "\n", rc); |
| 525 | goto out; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 526 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 527 | } |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 528 | out: |
| 529 | kfree(enc_extent_virt); |
| 530 | return rc; |
| 531 | } |
| 532 | |
| 533 | static int ecryptfs_decrypt_extent(struct page *page, |
| 534 | struct ecryptfs_crypt_stat *crypt_stat, |
| 535 | struct page *enc_extent_page, |
| 536 | unsigned long extent_offset) |
| 537 | { |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 538 | loff_t extent_base; |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 539 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
| 540 | int rc; |
| 541 | |
Michael Halcrow | d6a13c1 | 2007-10-16 01:28:12 -0700 | [diff] [blame] | 542 | extent_base = (((loff_t)page->index) |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 543 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
| 544 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, |
| 545 | (extent_base + extent_offset)); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 546 | if (rc) { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 547 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
| 548 | "derive IV for extent [0x%.16x]; " |
| 549 | "rc = [%d]\n", (extent_base + extent_offset), |
| 550 | rc); |
| 551 | goto out; |
| 552 | } |
| 553 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 554 | ecryptfs_printk(KERN_DEBUG, "Decrypting extent " |
| 555 | "with iv:\n"); |
| 556 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); |
| 557 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " |
| 558 | "decryption:\n"); |
| 559 | ecryptfs_dump_hex((char *) |
| 560 | (page_address(enc_extent_page) |
| 561 | + (extent_offset * crypt_stat->extent_size)), |
| 562 | 8); |
| 563 | } |
| 564 | rc = ecryptfs_decrypt_page_offset(crypt_stat, page, |
| 565 | (extent_offset |
| 566 | * crypt_stat->extent_size), |
| 567 | enc_extent_page, 0, |
| 568 | crypt_stat->extent_size, extent_iv); |
| 569 | if (rc < 0) { |
| 570 | printk(KERN_ERR "%s: Error attempting to decrypt to page with " |
| 571 | "page->index = [%ld], extent_offset = [%ld]; " |
| 572 | "rc = [%d]\n", __FUNCTION__, page->index, extent_offset, |
| 573 | rc); |
| 574 | goto out; |
| 575 | } |
| 576 | rc = 0; |
| 577 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 578 | ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16x]; " |
| 579 | "rc = [%d]\n", (extent_base + extent_offset), |
| 580 | rc); |
| 581 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " |
| 582 | "decryption:\n"); |
| 583 | ecryptfs_dump_hex((char *)(page_address(page) |
| 584 | + (extent_offset |
| 585 | * crypt_stat->extent_size)), 8); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 586 | } |
| 587 | out: |
| 588 | return rc; |
| 589 | } |
| 590 | |
| 591 | /** |
| 592 | * ecryptfs_decrypt_page |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 593 | * @page: Page mapped from the eCryptfs inode for the file; data read |
| 594 | * and decrypted from the lower file will be written into this |
| 595 | * page |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 596 | * |
| 597 | * Decrypt an eCryptfs page. This is done on a per-extent basis. Note |
| 598 | * that eCryptfs pages may straddle the lower pages -- for instance, |
| 599 | * if the file was created on a machine with an 8K page size |
| 600 | * (resulting in an 8K header), and then the file is copied onto a |
| 601 | * host with a 32K page size, then when reading page 0 of the eCryptfs |
| 602 | * file, 24K of page 0 of the lower file will be read and decrypted, |
| 603 | * and then 8K of page 1 of the lower file will be read and decrypted. |
| 604 | * |
| 605 | * Returns zero on success; negative on error |
| 606 | */ |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 607 | int ecryptfs_decrypt_page(struct page *page) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 608 | { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 609 | struct inode *ecryptfs_inode; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 610 | struct ecryptfs_crypt_stat *crypt_stat; |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 611 | char *enc_extent_virt = NULL; |
| 612 | struct page *enc_extent_page; |
| 613 | unsigned long extent_offset; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 614 | int rc = 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 615 | |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 616 | ecryptfs_inode = page->mapping->host; |
| 617 | crypt_stat = |
| 618 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 619 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 620 | rc = ecryptfs_read_lower_page_segment(page, page->index, 0, |
| 621 | PAGE_CACHE_SIZE, |
| 622 | ecryptfs_inode); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 623 | if (rc) |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 624 | printk(KERN_ERR "%s: Error attempting to copy " |
| 625 | "page at index [%ld]\n", __FUNCTION__, |
| 626 | page->index); |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 627 | goto out; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 628 | } |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 629 | enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER); |
| 630 | if (!enc_extent_virt) { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 631 | rc = -ENOMEM; |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 632 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " |
| 633 | "encrypted extent\n"); |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 634 | goto out; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 635 | } |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 636 | enc_extent_page = virt_to_page(enc_extent_virt); |
| 637 | for (extent_offset = 0; |
| 638 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); |
| 639 | extent_offset++) { |
| 640 | loff_t offset; |
| 641 | |
| 642 | ecryptfs_lower_offset_for_extent( |
| 643 | &offset, ((page->index * (PAGE_CACHE_SIZE |
| 644 | / crypt_stat->extent_size)) |
| 645 | + extent_offset), crypt_stat); |
| 646 | rc = ecryptfs_read_lower(enc_extent_virt, offset, |
| 647 | crypt_stat->extent_size, |
| 648 | ecryptfs_inode); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 649 | if (rc) { |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 650 | ecryptfs_printk(KERN_ERR, "Error attempting " |
| 651 | "to read lower page; rc = [%d]" |
| 652 | "\n", rc); |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 653 | goto out; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 654 | } |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 655 | rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page, |
| 656 | extent_offset); |
| 657 | if (rc) { |
| 658 | printk(KERN_ERR "%s: Error encrypting extent; " |
| 659 | "rc = [%d]\n", __FUNCTION__, rc); |
Michael Halcrow | 16a72c4 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 660 | goto out; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 661 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 662 | } |
| 663 | out: |
Michael Halcrow | 0216f7f | 2007-10-16 01:28:08 -0700 | [diff] [blame] | 664 | kfree(enc_extent_virt); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 665 | return rc; |
| 666 | } |
| 667 | |
| 668 | /** |
| 669 | * decrypt_scatterlist |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 670 | * @crypt_stat: Cryptographic context |
| 671 | * @dest_sg: The destination scatterlist to decrypt into |
| 672 | * @src_sg: The source scatterlist to decrypt from |
| 673 | * @size: The number of bytes to decrypt |
| 674 | * @iv: The initialization vector to use for the decryption |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 675 | * |
| 676 | * Returns the number of bytes decrypted; negative value on error |
| 677 | */ |
| 678 | static int decrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, |
| 679 | struct scatterlist *dest_sg, |
| 680 | struct scatterlist *src_sg, int size, |
| 681 | unsigned char *iv) |
| 682 | { |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 683 | struct blkcipher_desc desc = { |
| 684 | .tfm = crypt_stat->tfm, |
| 685 | .info = iv, |
| 686 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP |
| 687 | }; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 688 | int rc = 0; |
| 689 | |
| 690 | /* Consider doing this once, when the file is opened */ |
| 691 | mutex_lock(&crypt_stat->cs_tfm_mutex); |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 692 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, |
| 693 | crypt_stat->key_size); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 694 | if (rc) { |
| 695 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", |
| 696 | rc); |
| 697 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
| 698 | rc = -EINVAL; |
| 699 | goto out; |
| 700 | } |
| 701 | ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size); |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 702 | rc = crypto_blkcipher_decrypt_iv(&desc, dest_sg, src_sg, size); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 703 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
| 704 | if (rc) { |
| 705 | ecryptfs_printk(KERN_ERR, "Error decrypting; rc = [%d]\n", |
| 706 | rc); |
| 707 | goto out; |
| 708 | } |
| 709 | rc = size; |
| 710 | out: |
| 711 | return rc; |
| 712 | } |
| 713 | |
| 714 | /** |
| 715 | * ecryptfs_encrypt_page_offset |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 716 | * @crypt_stat: The cryptographic context |
| 717 | * @dst_page: The page to encrypt into |
| 718 | * @dst_offset: The offset in the page to encrypt into |
| 719 | * @src_page: The page to encrypt from |
| 720 | * @src_offset: The offset in the page to encrypt from |
| 721 | * @size: The number of bytes to encrypt |
| 722 | * @iv: The initialization vector to use for the encryption |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 723 | * |
| 724 | * Returns the number of bytes encrypted |
| 725 | */ |
| 726 | static int |
| 727 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, |
| 728 | struct page *dst_page, int dst_offset, |
| 729 | struct page *src_page, int src_offset, int size, |
| 730 | unsigned char *iv) |
| 731 | { |
| 732 | struct scatterlist src_sg, dst_sg; |
| 733 | |
Jens Axboe | 60c74f8 | 2007-10-22 19:43:30 +0200 | [diff] [blame] | 734 | sg_init_table(&src_sg, 1); |
| 735 | sg_init_table(&dst_sg, 1); |
| 736 | |
Jens Axboe | 642f149 | 2007-10-24 11:20:47 +0200 | [diff] [blame] | 737 | sg_set_page(&src_sg, src_page, size, src_offset); |
| 738 | sg_set_page(&dst_sg, dst_page, size, dst_offset); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 739 | return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
| 740 | } |
| 741 | |
| 742 | /** |
| 743 | * ecryptfs_decrypt_page_offset |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 744 | * @crypt_stat: The cryptographic context |
| 745 | * @dst_page: The page to decrypt into |
| 746 | * @dst_offset: The offset in the page to decrypt into |
| 747 | * @src_page: The page to decrypt from |
| 748 | * @src_offset: The offset in the page to decrypt from |
| 749 | * @size: The number of bytes to decrypt |
| 750 | * @iv: The initialization vector to use for the decryption |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 751 | * |
| 752 | * Returns the number of bytes decrypted |
| 753 | */ |
| 754 | static int |
| 755 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, |
| 756 | struct page *dst_page, int dst_offset, |
| 757 | struct page *src_page, int src_offset, int size, |
| 758 | unsigned char *iv) |
| 759 | { |
| 760 | struct scatterlist src_sg, dst_sg; |
| 761 | |
Jens Axboe | 60c74f8 | 2007-10-22 19:43:30 +0200 | [diff] [blame] | 762 | sg_init_table(&src_sg, 1); |
Jens Axboe | 642f149 | 2007-10-24 11:20:47 +0200 | [diff] [blame] | 763 | sg_set_page(&src_sg, src_page, size, src_offset); |
Jens Axboe | 60c74f8 | 2007-10-22 19:43:30 +0200 | [diff] [blame] | 764 | |
Jens Axboe | 642f149 | 2007-10-24 11:20:47 +0200 | [diff] [blame] | 765 | sg_init_table(&dst_sg, 1); |
| 766 | sg_set_page(&dst_sg, dst_page, size, dst_offset); |
| 767 | |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 768 | return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
| 769 | } |
| 770 | |
| 771 | #define ECRYPTFS_MAX_SCATTERLIST_LEN 4 |
| 772 | |
| 773 | /** |
| 774 | * ecryptfs_init_crypt_ctx |
| 775 | * @crypt_stat: Uninitilized crypt stats structure |
| 776 | * |
| 777 | * Initialize the crypto context. |
| 778 | * |
| 779 | * TODO: Performance: Keep a cache of initialized cipher contexts; |
| 780 | * only init if needed |
| 781 | */ |
| 782 | int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat) |
| 783 | { |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 784 | char *full_alg_name; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 785 | int rc = -EINVAL; |
| 786 | |
| 787 | if (!crypt_stat->cipher) { |
| 788 | ecryptfs_printk(KERN_ERR, "No cipher specified\n"); |
| 789 | goto out; |
| 790 | } |
| 791 | ecryptfs_printk(KERN_DEBUG, |
| 792 | "Initializing cipher [%s]; strlen = [%d]; " |
| 793 | "key_size_bits = [%d]\n", |
| 794 | crypt_stat->cipher, (int)strlen(crypt_stat->cipher), |
| 795 | crypt_stat->key_size << 3); |
| 796 | if (crypt_stat->tfm) { |
| 797 | rc = 0; |
| 798 | goto out; |
| 799 | } |
| 800 | mutex_lock(&crypt_stat->cs_tfm_mutex); |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 801 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, |
| 802 | crypt_stat->cipher, "cbc"); |
| 803 | if (rc) |
Eric Sandeen | c8161f6 | 2007-12-22 14:03:26 -0800 | [diff] [blame] | 804 | goto out_unlock; |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 805 | crypt_stat->tfm = crypto_alloc_blkcipher(full_alg_name, 0, |
| 806 | CRYPTO_ALG_ASYNC); |
| 807 | kfree(full_alg_name); |
Akinobu Mita | de88777 | 2006-11-28 12:29:49 -0800 | [diff] [blame] | 808 | if (IS_ERR(crypt_stat->tfm)) { |
| 809 | rc = PTR_ERR(crypt_stat->tfm); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 810 | ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): " |
| 811 | "Error initializing cipher [%s]\n", |
| 812 | crypt_stat->cipher); |
Eric Sandeen | c8161f6 | 2007-12-22 14:03:26 -0800 | [diff] [blame] | 813 | goto out_unlock; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 814 | } |
Herbert Xu | f1ddcaf | 2007-01-27 10:05:15 +1100 | [diff] [blame] | 815 | crypto_blkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 816 | rc = 0; |
Eric Sandeen | c8161f6 | 2007-12-22 14:03:26 -0800 | [diff] [blame] | 817 | out_unlock: |
| 818 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 819 | out: |
| 820 | return rc; |
| 821 | } |
| 822 | |
| 823 | static void set_extent_mask_and_shift(struct ecryptfs_crypt_stat *crypt_stat) |
| 824 | { |
| 825 | int extent_size_tmp; |
| 826 | |
| 827 | crypt_stat->extent_mask = 0xFFFFFFFF; |
| 828 | crypt_stat->extent_shift = 0; |
| 829 | if (crypt_stat->extent_size == 0) |
| 830 | return; |
| 831 | extent_size_tmp = crypt_stat->extent_size; |
| 832 | while ((extent_size_tmp & 0x01) == 0) { |
| 833 | extent_size_tmp >>= 1; |
| 834 | crypt_stat->extent_mask <<= 1; |
| 835 | crypt_stat->extent_shift++; |
| 836 | } |
| 837 | } |
| 838 | |
| 839 | void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat) |
| 840 | { |
| 841 | /* Default values; may be overwritten as we are parsing the |
| 842 | * packets. */ |
| 843 | crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE; |
| 844 | set_extent_mask_and_shift(crypt_stat); |
| 845 | crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES; |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 846 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 847 | crypt_stat->num_header_bytes_at_front = 0; |
Michael Halcrow | 45eaab7 | 2007-10-16 01:28:05 -0700 | [diff] [blame] | 848 | else { |
| 849 | if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 850 | crypt_stat->num_header_bytes_at_front = |
| 851 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; |
Michael Halcrow | 45eaab7 | 2007-10-16 01:28:05 -0700 | [diff] [blame] | 852 | else |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 853 | crypt_stat->num_header_bytes_at_front = PAGE_CACHE_SIZE; |
Michael Halcrow | 45eaab7 | 2007-10-16 01:28:05 -0700 | [diff] [blame] | 854 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 855 | } |
| 856 | |
| 857 | /** |
| 858 | * ecryptfs_compute_root_iv |
| 859 | * @crypt_stats |
| 860 | * |
| 861 | * On error, sets the root IV to all 0's. |
| 862 | */ |
| 863 | int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat) |
| 864 | { |
| 865 | int rc = 0; |
| 866 | char dst[MD5_DIGEST_SIZE]; |
| 867 | |
| 868 | BUG_ON(crypt_stat->iv_bytes > MD5_DIGEST_SIZE); |
| 869 | BUG_ON(crypt_stat->iv_bytes <= 0); |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 870 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 871 | rc = -EINVAL; |
| 872 | ecryptfs_printk(KERN_WARNING, "Session key not valid; " |
| 873 | "cannot generate root IV\n"); |
| 874 | goto out; |
| 875 | } |
| 876 | rc = ecryptfs_calculate_md5(dst, crypt_stat, crypt_stat->key, |
| 877 | crypt_stat->key_size); |
| 878 | if (rc) { |
| 879 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " |
| 880 | "MD5 while generating root IV\n"); |
| 881 | goto out; |
| 882 | } |
| 883 | memcpy(crypt_stat->root_iv, dst, crypt_stat->iv_bytes); |
| 884 | out: |
| 885 | if (rc) { |
| 886 | memset(crypt_stat->root_iv, 0, crypt_stat->iv_bytes); |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 887 | crypt_stat->flags |= ECRYPTFS_SECURITY_WARNING; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 888 | } |
| 889 | return rc; |
| 890 | } |
| 891 | |
| 892 | static void ecryptfs_generate_new_key(struct ecryptfs_crypt_stat *crypt_stat) |
| 893 | { |
| 894 | get_random_bytes(crypt_stat->key, crypt_stat->key_size); |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 895 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 896 | ecryptfs_compute_root_iv(crypt_stat); |
| 897 | if (unlikely(ecryptfs_verbosity > 0)) { |
| 898 | ecryptfs_printk(KERN_DEBUG, "Generated new session key:\n"); |
| 899 | ecryptfs_dump_hex(crypt_stat->key, |
| 900 | crypt_stat->key_size); |
| 901 | } |
| 902 | } |
| 903 | |
| 904 | /** |
Michael Halcrow | 1739895 | 2007-02-12 00:53:45 -0800 | [diff] [blame] | 905 | * ecryptfs_copy_mount_wide_flags_to_inode_flags |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 906 | * @crypt_stat: The inode's cryptographic context |
| 907 | * @mount_crypt_stat: The mount point's cryptographic context |
Michael Halcrow | 1739895 | 2007-02-12 00:53:45 -0800 | [diff] [blame] | 908 | * |
| 909 | * This function propagates the mount-wide flags to individual inode |
| 910 | * flags. |
| 911 | */ |
| 912 | static void ecryptfs_copy_mount_wide_flags_to_inode_flags( |
| 913 | struct ecryptfs_crypt_stat *crypt_stat, |
| 914 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
| 915 | { |
| 916 | if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) |
| 917 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; |
| 918 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) |
| 919 | crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; |
| 920 | } |
| 921 | |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 922 | static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( |
| 923 | struct ecryptfs_crypt_stat *crypt_stat, |
| 924 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
| 925 | { |
| 926 | struct ecryptfs_global_auth_tok *global_auth_tok; |
| 927 | int rc = 0; |
| 928 | |
| 929 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| 930 | list_for_each_entry(global_auth_tok, |
| 931 | &mount_crypt_stat->global_auth_tok_list, |
| 932 | mount_crypt_stat_list) { |
| 933 | rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); |
| 934 | if (rc) { |
| 935 | printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); |
| 936 | mutex_unlock( |
| 937 | &mount_crypt_stat->global_auth_tok_list_mutex); |
| 938 | goto out; |
| 939 | } |
| 940 | } |
| 941 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| 942 | out: |
| 943 | return rc; |
| 944 | } |
| 945 | |
Michael Halcrow | 1739895 | 2007-02-12 00:53:45 -0800 | [diff] [blame] | 946 | /** |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 947 | * ecryptfs_set_default_crypt_stat_vals |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 948 | * @crypt_stat: The inode's cryptographic context |
| 949 | * @mount_crypt_stat: The mount point's cryptographic context |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 950 | * |
| 951 | * Default values in the event that policy does not override them. |
| 952 | */ |
| 953 | static void ecryptfs_set_default_crypt_stat_vals( |
| 954 | struct ecryptfs_crypt_stat *crypt_stat, |
| 955 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
| 956 | { |
Michael Halcrow | 1739895 | 2007-02-12 00:53:45 -0800 | [diff] [blame] | 957 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
| 958 | mount_crypt_stat); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 959 | ecryptfs_set_default_sizes(crypt_stat); |
| 960 | strcpy(crypt_stat->cipher, ECRYPTFS_DEFAULT_CIPHER); |
| 961 | crypt_stat->key_size = ECRYPTFS_DEFAULT_KEY_BYTES; |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 962 | crypt_stat->flags &= ~(ECRYPTFS_KEY_VALID); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 963 | crypt_stat->file_version = ECRYPTFS_FILE_VERSION; |
| 964 | crypt_stat->mount_crypt_stat = mount_crypt_stat; |
| 965 | } |
| 966 | |
| 967 | /** |
| 968 | * ecryptfs_new_file_context |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 969 | * @ecryptfs_dentry: The eCryptfs dentry |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 970 | * |
| 971 | * If the crypto context for the file has not yet been established, |
| 972 | * this is where we do that. Establishing a new crypto context |
| 973 | * involves the following decisions: |
| 974 | * - What cipher to use? |
| 975 | * - What set of authentication tokens to use? |
| 976 | * Here we just worry about getting enough information into the |
| 977 | * authentication tokens so that we know that they are available. |
| 978 | * We associate the available authentication tokens with the new file |
| 979 | * via the set of signatures in the crypt_stat struct. Later, when |
| 980 | * the headers are actually written out, we may again defer to |
| 981 | * userspace to perform the encryption of the session key; for the |
| 982 | * foreseeable future, this will be the case with public key packets. |
| 983 | * |
| 984 | * Returns zero on success; non-zero otherwise |
| 985 | */ |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 986 | int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry) |
| 987 | { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 988 | struct ecryptfs_crypt_stat *crypt_stat = |
| 989 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; |
| 990 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
| 991 | &ecryptfs_superblock_to_private( |
| 992 | ecryptfs_dentry->d_sb)->mount_crypt_stat; |
| 993 | int cipher_name_len; |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 994 | int rc = 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 995 | |
| 996 | ecryptfs_set_default_crypt_stat_vals(crypt_stat, mount_crypt_stat); |
Michael Halcrow | af655dc | 2007-10-16 01:28:00 -0700 | [diff] [blame] | 997 | crypt_stat->flags |= (ECRYPTFS_ENCRYPTED | ECRYPTFS_KEY_VALID); |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 998 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
| 999 | mount_crypt_stat); |
| 1000 | rc = ecryptfs_copy_mount_wide_sigs_to_inode_sigs(crypt_stat, |
| 1001 | mount_crypt_stat); |
| 1002 | if (rc) { |
| 1003 | printk(KERN_ERR "Error attempting to copy mount-wide key sigs " |
| 1004 | "to the inode key sigs; rc = [%d]\n", rc); |
| 1005 | goto out; |
| 1006 | } |
| 1007 | cipher_name_len = |
| 1008 | strlen(mount_crypt_stat->global_default_cipher_name); |
| 1009 | memcpy(crypt_stat->cipher, |
| 1010 | mount_crypt_stat->global_default_cipher_name, |
| 1011 | cipher_name_len); |
| 1012 | crypt_stat->cipher[cipher_name_len] = '\0'; |
| 1013 | crypt_stat->key_size = |
| 1014 | mount_crypt_stat->global_default_cipher_key_size; |
| 1015 | ecryptfs_generate_new_key(crypt_stat); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1016 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
| 1017 | if (rc) |
| 1018 | ecryptfs_printk(KERN_ERR, "Error initializing cryptographic " |
| 1019 | "context for cipher [%s]: rc = [%d]\n", |
| 1020 | crypt_stat->cipher, rc); |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1021 | out: |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1022 | return rc; |
| 1023 | } |
| 1024 | |
| 1025 | /** |
| 1026 | * contains_ecryptfs_marker - check for the ecryptfs marker |
| 1027 | * @data: The data block in which to check |
| 1028 | * |
| 1029 | * Returns one if marker found; zero if not found |
| 1030 | */ |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1031 | static int contains_ecryptfs_marker(char *data) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1032 | { |
| 1033 | u32 m_1, m_2; |
| 1034 | |
| 1035 | memcpy(&m_1, data, 4); |
| 1036 | m_1 = be32_to_cpu(m_1); |
| 1037 | memcpy(&m_2, (data + 4), 4); |
| 1038 | m_2 = be32_to_cpu(m_2); |
| 1039 | if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2) |
| 1040 | return 1; |
| 1041 | ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; " |
| 1042 | "MAGIC_ECRYPTFS_MARKER = [0x%.8x]\n", m_1, m_2, |
| 1043 | MAGIC_ECRYPTFS_MARKER); |
| 1044 | ecryptfs_printk(KERN_DEBUG, "(m_1 ^ MAGIC_ECRYPTFS_MARKER) = " |
| 1045 | "[0x%.8x]\n", (m_1 ^ MAGIC_ECRYPTFS_MARKER)); |
| 1046 | return 0; |
| 1047 | } |
| 1048 | |
| 1049 | struct ecryptfs_flag_map_elem { |
| 1050 | u32 file_flag; |
| 1051 | u32 local_flag; |
| 1052 | }; |
| 1053 | |
| 1054 | /* Add support for additional flags by adding elements here. */ |
| 1055 | static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = { |
| 1056 | {0x00000001, ECRYPTFS_ENABLE_HMAC}, |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1057 | {0x00000002, ECRYPTFS_ENCRYPTED}, |
| 1058 | {0x00000004, ECRYPTFS_METADATA_IN_XATTR} |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1059 | }; |
| 1060 | |
| 1061 | /** |
| 1062 | * ecryptfs_process_flags |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1063 | * @crypt_stat: The cryptographic context |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1064 | * @page_virt: Source data to be parsed |
| 1065 | * @bytes_read: Updated with the number of bytes read |
| 1066 | * |
| 1067 | * Returns zero on success; non-zero if the flag set is invalid |
| 1068 | */ |
| 1069 | static int ecryptfs_process_flags(struct ecryptfs_crypt_stat *crypt_stat, |
| 1070 | char *page_virt, int *bytes_read) |
| 1071 | { |
| 1072 | int rc = 0; |
| 1073 | int i; |
| 1074 | u32 flags; |
| 1075 | |
| 1076 | memcpy(&flags, page_virt, 4); |
| 1077 | flags = be32_to_cpu(flags); |
| 1078 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) |
| 1079 | / sizeof(struct ecryptfs_flag_map_elem))); i++) |
| 1080 | if (flags & ecryptfs_flag_map[i].file_flag) { |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 1081 | crypt_stat->flags |= ecryptfs_flag_map[i].local_flag; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1082 | } else |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 1083 | crypt_stat->flags &= ~(ecryptfs_flag_map[i].local_flag); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1084 | /* Version is in top 8 bits of the 32-bit flag vector */ |
| 1085 | crypt_stat->file_version = ((flags >> 24) & 0xFF); |
| 1086 | (*bytes_read) = 4; |
| 1087 | return rc; |
| 1088 | } |
| 1089 | |
| 1090 | /** |
| 1091 | * write_ecryptfs_marker |
| 1092 | * @page_virt: The pointer to in a page to begin writing the marker |
| 1093 | * @written: Number of bytes written |
| 1094 | * |
| 1095 | * Marker = 0x3c81b7f5 |
| 1096 | */ |
| 1097 | static void write_ecryptfs_marker(char *page_virt, size_t *written) |
| 1098 | { |
| 1099 | u32 m_1, m_2; |
| 1100 | |
| 1101 | get_random_bytes(&m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); |
| 1102 | m_2 = (m_1 ^ MAGIC_ECRYPTFS_MARKER); |
| 1103 | m_1 = cpu_to_be32(m_1); |
| 1104 | memcpy(page_virt, &m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); |
| 1105 | m_2 = cpu_to_be32(m_2); |
| 1106 | memcpy(page_virt + (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2), &m_2, |
| 1107 | (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); |
| 1108 | (*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; |
| 1109 | } |
| 1110 | |
| 1111 | static void |
| 1112 | write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat, |
| 1113 | size_t *written) |
| 1114 | { |
| 1115 | u32 flags = 0; |
| 1116 | int i; |
| 1117 | |
| 1118 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) |
| 1119 | / sizeof(struct ecryptfs_flag_map_elem))); i++) |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 1120 | if (crypt_stat->flags & ecryptfs_flag_map[i].local_flag) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1121 | flags |= ecryptfs_flag_map[i].file_flag; |
| 1122 | /* Version is in top 8 bits of the 32-bit flag vector */ |
| 1123 | flags |= ((((u8)crypt_stat->file_version) << 24) & 0xFF000000); |
| 1124 | flags = cpu_to_be32(flags); |
| 1125 | memcpy(page_virt, &flags, 4); |
| 1126 | (*written) = 4; |
| 1127 | } |
| 1128 | |
| 1129 | struct ecryptfs_cipher_code_str_map_elem { |
| 1130 | char cipher_str[16]; |
Trevor Highland | 19e66a6 | 2008-02-06 01:38:36 -0800 | [diff] [blame] | 1131 | u8 cipher_code; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1132 | }; |
| 1133 | |
| 1134 | /* Add support for additional ciphers by adding elements here. The |
| 1135 | * cipher_code is whatever OpenPGP applicatoins use to identify the |
| 1136 | * ciphers. List in order of probability. */ |
| 1137 | static struct ecryptfs_cipher_code_str_map_elem |
| 1138 | ecryptfs_cipher_code_str_map[] = { |
| 1139 | {"aes",RFC2440_CIPHER_AES_128 }, |
| 1140 | {"blowfish", RFC2440_CIPHER_BLOWFISH}, |
| 1141 | {"des3_ede", RFC2440_CIPHER_DES3_EDE}, |
| 1142 | {"cast5", RFC2440_CIPHER_CAST_5}, |
| 1143 | {"twofish", RFC2440_CIPHER_TWOFISH}, |
| 1144 | {"cast6", RFC2440_CIPHER_CAST_6}, |
| 1145 | {"aes", RFC2440_CIPHER_AES_192}, |
| 1146 | {"aes", RFC2440_CIPHER_AES_256} |
| 1147 | }; |
| 1148 | |
| 1149 | /** |
| 1150 | * ecryptfs_code_for_cipher_string |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1151 | * @crypt_stat: The cryptographic context |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1152 | * |
| 1153 | * Returns zero on no match, or the cipher code on match |
| 1154 | */ |
Trevor Highland | 19e66a6 | 2008-02-06 01:38:36 -0800 | [diff] [blame] | 1155 | u8 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1156 | { |
| 1157 | int i; |
Trevor Highland | 19e66a6 | 2008-02-06 01:38:36 -0800 | [diff] [blame] | 1158 | u8 code = 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1159 | struct ecryptfs_cipher_code_str_map_elem *map = |
| 1160 | ecryptfs_cipher_code_str_map; |
| 1161 | |
| 1162 | if (strcmp(crypt_stat->cipher, "aes") == 0) { |
| 1163 | switch (crypt_stat->key_size) { |
| 1164 | case 16: |
| 1165 | code = RFC2440_CIPHER_AES_128; |
| 1166 | break; |
| 1167 | case 24: |
| 1168 | code = RFC2440_CIPHER_AES_192; |
| 1169 | break; |
| 1170 | case 32: |
| 1171 | code = RFC2440_CIPHER_AES_256; |
| 1172 | } |
| 1173 | } else { |
| 1174 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) |
| 1175 | if (strcmp(crypt_stat->cipher, map[i].cipher_str) == 0){ |
| 1176 | code = map[i].cipher_code; |
| 1177 | break; |
| 1178 | } |
| 1179 | } |
| 1180 | return code; |
| 1181 | } |
| 1182 | |
| 1183 | /** |
| 1184 | * ecryptfs_cipher_code_to_string |
| 1185 | * @str: Destination to write out the cipher name |
| 1186 | * @cipher_code: The code to convert to cipher name string |
| 1187 | * |
| 1188 | * Returns zero on success |
| 1189 | */ |
Trevor Highland | 19e66a6 | 2008-02-06 01:38:36 -0800 | [diff] [blame] | 1190 | int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1191 | { |
| 1192 | int rc = 0; |
| 1193 | int i; |
| 1194 | |
| 1195 | str[0] = '\0'; |
| 1196 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) |
| 1197 | if (cipher_code == ecryptfs_cipher_code_str_map[i].cipher_code) |
| 1198 | strcpy(str, ecryptfs_cipher_code_str_map[i].cipher_str); |
| 1199 | if (str[0] == '\0') { |
| 1200 | ecryptfs_printk(KERN_WARNING, "Cipher code not recognized: " |
| 1201 | "[%d]\n", cipher_code); |
| 1202 | rc = -EINVAL; |
| 1203 | } |
| 1204 | return rc; |
| 1205 | } |
| 1206 | |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1207 | int ecryptfs_read_and_validate_header_region(char *data, |
| 1208 | struct inode *ecryptfs_inode) |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1209 | { |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1210 | struct ecryptfs_crypt_stat *crypt_stat = |
| 1211 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1212 | int rc; |
| 1213 | |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1214 | rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size, |
| 1215 | ecryptfs_inode); |
| 1216 | if (rc) { |
| 1217 | printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n", |
| 1218 | __FUNCTION__, rc); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1219 | goto out; |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1220 | } |
| 1221 | if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) { |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1222 | rc = -EINVAL; |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1223 | ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n"); |
| 1224 | } |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1225 | out: |
| 1226 | return rc; |
| 1227 | } |
| 1228 | |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 1229 | void |
| 1230 | ecryptfs_write_header_metadata(char *virt, |
| 1231 | struct ecryptfs_crypt_stat *crypt_stat, |
| 1232 | size_t *written) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1233 | { |
| 1234 | u32 header_extent_size; |
| 1235 | u16 num_header_extents_at_front; |
| 1236 | |
Michael Halcrow | 45eaab7 | 2007-10-16 01:28:05 -0700 | [diff] [blame] | 1237 | header_extent_size = (u32)crypt_stat->extent_size; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1238 | num_header_extents_at_front = |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1239 | (u16)(crypt_stat->num_header_bytes_at_front |
| 1240 | / crypt_stat->extent_size); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1241 | header_extent_size = cpu_to_be32(header_extent_size); |
| 1242 | memcpy(virt, &header_extent_size, 4); |
| 1243 | virt += 4; |
| 1244 | num_header_extents_at_front = cpu_to_be16(num_header_extents_at_front); |
| 1245 | memcpy(virt, &num_header_extents_at_front, 2); |
| 1246 | (*written) = 6; |
| 1247 | } |
| 1248 | |
| 1249 | struct kmem_cache *ecryptfs_header_cache_0; |
| 1250 | struct kmem_cache *ecryptfs_header_cache_1; |
| 1251 | struct kmem_cache *ecryptfs_header_cache_2; |
| 1252 | |
| 1253 | /** |
| 1254 | * ecryptfs_write_headers_virt |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1255 | * @page_virt: The virtual address to write the headers to |
| 1256 | * @size: Set to the number of bytes written by this function |
| 1257 | * @crypt_stat: The cryptographic context |
| 1258 | * @ecryptfs_dentry: The eCryptfs dentry |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1259 | * |
| 1260 | * Format version: 1 |
| 1261 | * |
| 1262 | * Header Extent: |
| 1263 | * Octets 0-7: Unencrypted file size (big-endian) |
| 1264 | * Octets 8-15: eCryptfs special marker |
| 1265 | * Octets 16-19: Flags |
| 1266 | * Octet 16: File format version number (between 0 and 255) |
| 1267 | * Octets 17-18: Reserved |
| 1268 | * Octet 19: Bit 1 (lsb): Reserved |
| 1269 | * Bit 2: Encrypted? |
| 1270 | * Bits 3-8: Reserved |
| 1271 | * Octets 20-23: Header extent size (big-endian) |
| 1272 | * Octets 24-25: Number of header extents at front of file |
| 1273 | * (big-endian) |
| 1274 | * Octet 26: Begin RFC 2440 authentication token packet set |
| 1275 | * Data Extent 0: |
| 1276 | * Lower data (CBC encrypted) |
| 1277 | * Data Extent 1: |
| 1278 | * Lower data (CBC encrypted) |
| 1279 | * ... |
| 1280 | * |
| 1281 | * Returns zero on success |
| 1282 | */ |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1283 | static int ecryptfs_write_headers_virt(char *page_virt, size_t *size, |
| 1284 | struct ecryptfs_crypt_stat *crypt_stat, |
| 1285 | struct dentry *ecryptfs_dentry) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1286 | { |
| 1287 | int rc; |
| 1288 | size_t written; |
| 1289 | size_t offset; |
| 1290 | |
| 1291 | offset = ECRYPTFS_FILE_SIZE_BYTES; |
| 1292 | write_ecryptfs_marker((page_virt + offset), &written); |
| 1293 | offset += written; |
| 1294 | write_ecryptfs_flags((page_virt + offset), crypt_stat, &written); |
| 1295 | offset += written; |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 1296 | ecryptfs_write_header_metadata((page_virt + offset), crypt_stat, |
| 1297 | &written); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1298 | offset += written; |
| 1299 | rc = ecryptfs_generate_key_packet_set((page_virt + offset), crypt_stat, |
| 1300 | ecryptfs_dentry, &written, |
| 1301 | PAGE_CACHE_SIZE - offset); |
| 1302 | if (rc) |
| 1303 | ecryptfs_printk(KERN_WARNING, "Error generating key packet " |
| 1304 | "set; rc = [%d]\n", rc); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1305 | if (size) { |
| 1306 | offset += written; |
| 1307 | *size = offset; |
| 1308 | } |
| 1309 | return rc; |
| 1310 | } |
| 1311 | |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1312 | static int |
| 1313 | ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1314 | struct dentry *ecryptfs_dentry, |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1315 | char *virt) |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1316 | { |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1317 | int rc; |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1318 | |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1319 | rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, virt, |
| 1320 | 0, crypt_stat->num_header_bytes_at_front); |
| 1321 | if (rc) |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1322 | printk(KERN_ERR "%s: Error attempting to write header " |
| 1323 | "information to lower file; rc = [%d]\n", __FUNCTION__, |
| 1324 | rc); |
Michael Halcrow | 7045660 | 2007-02-12 00:53:48 -0800 | [diff] [blame] | 1325 | return rc; |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1326 | } |
| 1327 | |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1328 | static int |
| 1329 | ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, |
| 1330 | struct ecryptfs_crypt_stat *crypt_stat, |
| 1331 | char *page_virt, size_t size) |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1332 | { |
| 1333 | int rc; |
| 1334 | |
| 1335 | rc = ecryptfs_setxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, page_virt, |
| 1336 | size, 0); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1337 | return rc; |
| 1338 | } |
| 1339 | |
| 1340 | /** |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1341 | * ecryptfs_write_metadata |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1342 | * @ecryptfs_dentry: The eCryptfs dentry |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1343 | * |
| 1344 | * Write the file headers out. This will likely involve a userspace |
| 1345 | * callout, in which the session key is encrypted with one or more |
| 1346 | * public keys and/or the passphrase necessary to do the encryption is |
| 1347 | * retrieved via a prompt. Exactly what happens at this point should |
| 1348 | * be policy-dependent. |
| 1349 | * |
| 1350 | * Returns zero on success; non-zero on error |
| 1351 | */ |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1352 | int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1353 | { |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1354 | struct ecryptfs_crypt_stat *crypt_stat = |
| 1355 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1356 | char *virt; |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1357 | size_t size = 0; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1358 | int rc = 0; |
| 1359 | |
Michael Halcrow | e2bd99e | 2007-02-12 00:53:49 -0800 | [diff] [blame] | 1360 | if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
| 1361 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1362 | printk(KERN_ERR "Key is invalid; bailing out\n"); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1363 | rc = -EINVAL; |
| 1364 | goto out; |
| 1365 | } |
| 1366 | } else { |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1367 | printk(KERN_WARNING "%s: Encrypted flag not set\n", |
| 1368 | __FUNCTION__); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1369 | rc = -EINVAL; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1370 | goto out; |
| 1371 | } |
| 1372 | /* Released in this function */ |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1373 | virt = kzalloc(crypt_stat->num_header_bytes_at_front, GFP_KERNEL); |
| 1374 | if (!virt) { |
| 1375 | printk(KERN_ERR "%s: Out of memory\n", __FUNCTION__); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1376 | rc = -ENOMEM; |
| 1377 | goto out; |
| 1378 | } |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1379 | rc = ecryptfs_write_headers_virt(virt, &size, crypt_stat, |
| 1380 | ecryptfs_dentry); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1381 | if (unlikely(rc)) { |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1382 | printk(KERN_ERR "%s: Error whilst writing headers; rc = [%d]\n", |
| 1383 | __FUNCTION__, rc); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1384 | goto out_free; |
| 1385 | } |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1386 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
| 1387 | rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1388 | crypt_stat, virt, size); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1389 | else |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1390 | rc = ecryptfs_write_metadata_to_contents(crypt_stat, |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1391 | ecryptfs_dentry, virt); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1392 | if (rc) { |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1393 | printk(KERN_ERR "%s: Error writing metadata out to lower file; " |
| 1394 | "rc = [%d]\n", __FUNCTION__, rc); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1395 | goto out_free; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1396 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1397 | out_free: |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1398 | memset(virt, 0, crypt_stat->num_header_bytes_at_front); |
| 1399 | kfree(virt); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1400 | out: |
| 1401 | return rc; |
| 1402 | } |
| 1403 | |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1404 | #define ECRYPTFS_DONT_VALIDATE_HEADER_SIZE 0 |
| 1405 | #define ECRYPTFS_VALIDATE_HEADER_SIZE 1 |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1406 | static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat, |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1407 | char *virt, int *bytes_read, |
| 1408 | int validate_header_size) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1409 | { |
| 1410 | int rc = 0; |
| 1411 | u32 header_extent_size; |
| 1412 | u16 num_header_extents_at_front; |
| 1413 | |
Michael Halcrow | ecbdc93 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 1414 | memcpy(&header_extent_size, virt, sizeof(u32)); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1415 | header_extent_size = be32_to_cpu(header_extent_size); |
Michael Halcrow | ecbdc93 | 2007-10-16 01:28:14 -0700 | [diff] [blame] | 1416 | virt += sizeof(u32); |
| 1417 | memcpy(&num_header_extents_at_front, virt, sizeof(u16)); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1418 | num_header_extents_at_front = be16_to_cpu(num_header_extents_at_front); |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1419 | crypt_stat->num_header_bytes_at_front = |
| 1420 | (((size_t)num_header_extents_at_front |
| 1421 | * (size_t)header_extent_size)); |
Michael Halcrow | 45eaab7 | 2007-10-16 01:28:05 -0700 | [diff] [blame] | 1422 | (*bytes_read) = (sizeof(u32) + sizeof(u16)); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1423 | if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE) |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1424 | && (crypt_stat->num_header_bytes_at_front |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1425 | < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1426 | rc = -EINVAL; |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1427 | printk(KERN_WARNING "Invalid header size: [%zd]\n", |
| 1428 | crypt_stat->num_header_bytes_at_front); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1429 | } |
| 1430 | return rc; |
| 1431 | } |
| 1432 | |
| 1433 | /** |
| 1434 | * set_default_header_data |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1435 | * @crypt_stat: The cryptographic context |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1436 | * |
| 1437 | * For version 0 file format; this function is only for backwards |
| 1438 | * compatibility for files created with the prior versions of |
| 1439 | * eCryptfs. |
| 1440 | */ |
| 1441 | static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat) |
| 1442 | { |
Michael Halcrow | cc11bef | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1443 | crypt_stat->num_header_bytes_at_front = |
| 1444 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1445 | } |
| 1446 | |
| 1447 | /** |
| 1448 | * ecryptfs_read_headers_virt |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1449 | * @page_virt: The virtual address into which to read the headers |
| 1450 | * @crypt_stat: The cryptographic context |
| 1451 | * @ecryptfs_dentry: The eCryptfs dentry |
| 1452 | * @validate_header_size: Whether to validate the header size while reading |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1453 | * |
| 1454 | * Read/parse the header data. The header format is detailed in the |
| 1455 | * comment block for the ecryptfs_write_headers_virt() function. |
| 1456 | * |
| 1457 | * Returns zero on success |
| 1458 | */ |
| 1459 | static int ecryptfs_read_headers_virt(char *page_virt, |
| 1460 | struct ecryptfs_crypt_stat *crypt_stat, |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1461 | struct dentry *ecryptfs_dentry, |
| 1462 | int validate_header_size) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1463 | { |
| 1464 | int rc = 0; |
| 1465 | int offset; |
| 1466 | int bytes_read; |
| 1467 | |
| 1468 | ecryptfs_set_default_sizes(crypt_stat); |
| 1469 | crypt_stat->mount_crypt_stat = &ecryptfs_superblock_to_private( |
| 1470 | ecryptfs_dentry->d_sb)->mount_crypt_stat; |
| 1471 | offset = ECRYPTFS_FILE_SIZE_BYTES; |
| 1472 | rc = contains_ecryptfs_marker(page_virt + offset); |
| 1473 | if (rc == 0) { |
| 1474 | rc = -EINVAL; |
| 1475 | goto out; |
| 1476 | } |
| 1477 | offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; |
| 1478 | rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset), |
| 1479 | &bytes_read); |
| 1480 | if (rc) { |
| 1481 | ecryptfs_printk(KERN_WARNING, "Error processing flags\n"); |
| 1482 | goto out; |
| 1483 | } |
| 1484 | if (crypt_stat->file_version > ECRYPTFS_SUPPORTED_FILE_VERSION) { |
| 1485 | ecryptfs_printk(KERN_WARNING, "File version is [%d]; only " |
| 1486 | "file version [%d] is supported by this " |
| 1487 | "version of eCryptfs\n", |
| 1488 | crypt_stat->file_version, |
| 1489 | ECRYPTFS_SUPPORTED_FILE_VERSION); |
| 1490 | rc = -EINVAL; |
| 1491 | goto out; |
| 1492 | } |
| 1493 | offset += bytes_read; |
| 1494 | if (crypt_stat->file_version >= 1) { |
| 1495 | rc = parse_header_metadata(crypt_stat, (page_virt + offset), |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1496 | &bytes_read, validate_header_size); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1497 | if (rc) { |
| 1498 | ecryptfs_printk(KERN_WARNING, "Error reading header " |
| 1499 | "metadata; rc = [%d]\n", rc); |
| 1500 | } |
| 1501 | offset += bytes_read; |
| 1502 | } else |
| 1503 | set_default_header_data(crypt_stat); |
| 1504 | rc = ecryptfs_parse_packet_set(crypt_stat, (page_virt + offset), |
| 1505 | ecryptfs_dentry); |
| 1506 | out: |
| 1507 | return rc; |
| 1508 | } |
| 1509 | |
| 1510 | /** |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1511 | * ecryptfs_read_xattr_region |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1512 | * @page_virt: The vitual address into which to read the xattr data |
Michael Halcrow | 2ed9255 | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1513 | * @ecryptfs_inode: The eCryptfs inode |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1514 | * |
| 1515 | * Attempts to read the crypto metadata from the extended attribute |
| 1516 | * region of the lower file. |
Michael Halcrow | 22e78fa | 2007-10-16 01:28:02 -0700 | [diff] [blame] | 1517 | * |
| 1518 | * Returns zero on success; non-zero on error |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1519 | */ |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1520 | int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode) |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1521 | { |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1522 | struct dentry *lower_dentry = |
| 1523 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1524 | ssize_t size; |
| 1525 | int rc = 0; |
| 1526 | |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1527 | size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME, |
| 1528 | page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1529 | if (size < 0) { |
Michael Halcrow | 25bd817 | 2008-02-06 01:38:35 -0800 | [diff] [blame] | 1530 | if (unlikely(ecryptfs_verbosity > 0)) |
| 1531 | printk(KERN_INFO "Error attempting to read the [%s] " |
| 1532 | "xattr from the lower file; return value = " |
| 1533 | "[%zd]\n", ECRYPTFS_XATTR_NAME, size); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1534 | rc = -EINVAL; |
| 1535 | goto out; |
| 1536 | } |
| 1537 | out: |
| 1538 | return rc; |
| 1539 | } |
| 1540 | |
| 1541 | int ecryptfs_read_and_validate_xattr_region(char *page_virt, |
| 1542 | struct dentry *ecryptfs_dentry) |
| 1543 | { |
| 1544 | int rc; |
| 1545 | |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1546 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1547 | if (rc) |
| 1548 | goto out; |
| 1549 | if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) { |
| 1550 | printk(KERN_WARNING "Valid data found in [%s] xattr, but " |
| 1551 | "the marker is invalid\n", ECRYPTFS_XATTR_NAME); |
| 1552 | rc = -EINVAL; |
| 1553 | } |
| 1554 | out: |
| 1555 | return rc; |
| 1556 | } |
| 1557 | |
| 1558 | /** |
| 1559 | * ecryptfs_read_metadata |
| 1560 | * |
| 1561 | * Common entry point for reading file metadata. From here, we could |
| 1562 | * retrieve the header information from the header region of the file, |
| 1563 | * the xattr region of the file, or some other repostory that is |
| 1564 | * stored separately from the file itself. The current implementation |
| 1565 | * supports retrieving the metadata information from the file contents |
| 1566 | * and from the xattr region. |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1567 | * |
| 1568 | * Returns zero if valid headers found and parsed; non-zero otherwise |
| 1569 | */ |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1570 | int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1571 | { |
| 1572 | int rc = 0; |
| 1573 | char *page_virt = NULL; |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1574 | struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1575 | struct ecryptfs_crypt_stat *crypt_stat = |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1576 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 1577 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
| 1578 | &ecryptfs_superblock_to_private( |
| 1579 | ecryptfs_dentry->d_sb)->mount_crypt_stat; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1580 | |
Michael Halcrow | e77a56d | 2007-02-12 00:53:47 -0800 | [diff] [blame] | 1581 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
| 1582 | mount_crypt_stat); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1583 | /* Read the first page from the underlying file */ |
Christoph Lameter | f7267c0 | 2006-12-06 20:33:15 -0800 | [diff] [blame] | 1584 | page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1585 | if (!page_virt) { |
| 1586 | rc = -ENOMEM; |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1587 | printk(KERN_ERR "%s: Unable to allocate page_virt\n", |
| 1588 | __FUNCTION__); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1589 | goto out; |
| 1590 | } |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1591 | rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size, |
| 1592 | ecryptfs_inode); |
| 1593 | if (!rc) |
| 1594 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, |
| 1595 | ecryptfs_dentry, |
| 1596 | ECRYPTFS_VALIDATE_HEADER_SIZE); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1597 | if (rc) { |
Michael Halcrow | d7cdc5f | 2007-10-16 01:28:10 -0700 | [diff] [blame] | 1598 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode); |
Michael Halcrow | dd2a3b7 | 2007-02-12 00:53:46 -0800 | [diff] [blame] | 1599 | if (rc) { |
| 1600 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " |
| 1601 | "file header region or xattr region\n"); |
| 1602 | rc = -EINVAL; |
| 1603 | goto out; |
| 1604 | } |
| 1605 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, |
| 1606 | ecryptfs_dentry, |
| 1607 | ECRYPTFS_DONT_VALIDATE_HEADER_SIZE); |
| 1608 | if (rc) { |
| 1609 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " |
| 1610 | "file xattr region either\n"); |
| 1611 | rc = -EINVAL; |
| 1612 | } |
| 1613 | if (crypt_stat->mount_crypt_stat->flags |
| 1614 | & ECRYPTFS_XATTR_METADATA_ENABLED) { |
| 1615 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; |
| 1616 | } else { |
| 1617 | printk(KERN_WARNING "Attempt to access file with " |
| 1618 | "crypto metadata only in the extended attribute " |
| 1619 | "region, but eCryptfs was mounted without " |
| 1620 | "xattr support enabled. eCryptfs will not treat " |
| 1621 | "this like an encrypted file.\n"); |
| 1622 | rc = -EINVAL; |
| 1623 | } |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1624 | } |
| 1625 | out: |
| 1626 | if (page_virt) { |
| 1627 | memset(page_virt, 0, PAGE_CACHE_SIZE); |
| 1628 | kmem_cache_free(ecryptfs_header_cache_1, page_virt); |
| 1629 | } |
| 1630 | return rc; |
| 1631 | } |
| 1632 | |
| 1633 | /** |
| 1634 | * ecryptfs_encode_filename - converts a plaintext file name to cipher text |
| 1635 | * @crypt_stat: The crypt_stat struct associated with the file anem to encode |
| 1636 | * @name: The plaintext name |
| 1637 | * @length: The length of the plaintext |
| 1638 | * @encoded_name: The encypted name |
| 1639 | * |
| 1640 | * Encrypts and encodes a filename into something that constitutes a |
| 1641 | * valid filename for a filesystem, with printable characters. |
| 1642 | * |
| 1643 | * We assume that we have a properly initialized crypto context, |
| 1644 | * pointed to by crypt_stat->tfm. |
| 1645 | * |
| 1646 | * TODO: Implement filename decoding and decryption here, in place of |
| 1647 | * memcpy. We are keeping the framework around for now to (1) |
| 1648 | * facilitate testing of the components needed to implement filename |
| 1649 | * encryption and (2) to provide a code base from which other |
| 1650 | * developers in the community can easily implement this feature. |
| 1651 | * |
| 1652 | * Returns the length of encoded filename; negative if error |
| 1653 | */ |
| 1654 | int |
| 1655 | ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat, |
| 1656 | const char *name, int length, char **encoded_name) |
| 1657 | { |
| 1658 | int error = 0; |
| 1659 | |
| 1660 | (*encoded_name) = kmalloc(length + 2, GFP_KERNEL); |
| 1661 | if (!(*encoded_name)) { |
| 1662 | error = -ENOMEM; |
| 1663 | goto out; |
| 1664 | } |
| 1665 | /* TODO: Filename encryption is a scheduled feature for a |
| 1666 | * future version of eCryptfs. This function is here only for |
| 1667 | * the purpose of providing a framework for other developers |
| 1668 | * to easily implement filename encryption. Hint: Replace this |
| 1669 | * memcpy() with a call to encrypt and encode the |
| 1670 | * filename, the set the length accordingly. */ |
| 1671 | memcpy((void *)(*encoded_name), (void *)name, length); |
| 1672 | (*encoded_name)[length] = '\0'; |
| 1673 | error = length + 1; |
| 1674 | out: |
| 1675 | return error; |
| 1676 | } |
| 1677 | |
| 1678 | /** |
| 1679 | * ecryptfs_decode_filename - converts the cipher text name to plaintext |
| 1680 | * @crypt_stat: The crypt_stat struct associated with the file |
| 1681 | * @name: The filename in cipher text |
| 1682 | * @length: The length of the cipher text name |
| 1683 | * @decrypted_name: The plaintext name |
| 1684 | * |
| 1685 | * Decodes and decrypts the filename. |
| 1686 | * |
| 1687 | * We assume that we have a properly initialized crypto context, |
| 1688 | * pointed to by crypt_stat->tfm. |
| 1689 | * |
| 1690 | * TODO: Implement filename decoding and decryption here, in place of |
| 1691 | * memcpy. We are keeping the framework around for now to (1) |
| 1692 | * facilitate testing of the components needed to implement filename |
| 1693 | * encryption and (2) to provide a code base from which other |
| 1694 | * developers in the community can easily implement this feature. |
| 1695 | * |
| 1696 | * Returns the length of decoded filename; negative if error |
| 1697 | */ |
| 1698 | int |
| 1699 | ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, |
| 1700 | const char *name, int length, char **decrypted_name) |
| 1701 | { |
| 1702 | int error = 0; |
| 1703 | |
| 1704 | (*decrypted_name) = kmalloc(length + 2, GFP_KERNEL); |
| 1705 | if (!(*decrypted_name)) { |
| 1706 | error = -ENOMEM; |
| 1707 | goto out; |
| 1708 | } |
| 1709 | /* TODO: Filename encryption is a scheduled feature for a |
| 1710 | * future version of eCryptfs. This function is here only for |
| 1711 | * the purpose of providing a framework for other developers |
| 1712 | * to easily implement filename encryption. Hint: Replace this |
| 1713 | * memcpy() with a call to decode and decrypt the |
| 1714 | * filename, the set the length accordingly. */ |
| 1715 | memcpy((void *)(*decrypted_name), (void *)name, length); |
| 1716 | (*decrypted_name)[length + 1] = '\0'; /* Only for convenience |
| 1717 | * in printing out the |
| 1718 | * string in debug |
| 1719 | * messages */ |
| 1720 | error = length; |
| 1721 | out: |
| 1722 | return error; |
| 1723 | } |
| 1724 | |
| 1725 | /** |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1726 | * ecryptfs_process_key_cipher - Perform key cipher initialization. |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1727 | * @key_tfm: Crypto context for key material, set by this function |
Michael Halcrow | e5d9cbd | 2006-10-30 22:07:16 -0800 | [diff] [blame] | 1728 | * @cipher_name: Name of the cipher |
| 1729 | * @key_size: Size of the key in bytes |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1730 | * |
| 1731 | * Returns zero on success. Any crypto_tfm structs allocated here |
| 1732 | * should be released by other functions, such as on a superblock put |
| 1733 | * event, regardless of whether this function succeeds for fails. |
| 1734 | */ |
Michael Halcrow | cd9d67d | 2007-10-16 01:28:04 -0700 | [diff] [blame] | 1735 | static int |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1736 | ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, |
| 1737 | char *cipher_name, size_t *key_size) |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1738 | { |
| 1739 | char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 1740 | char *full_alg_name; |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1741 | int rc; |
| 1742 | |
Michael Halcrow | e5d9cbd | 2006-10-30 22:07:16 -0800 | [diff] [blame] | 1743 | *key_tfm = NULL; |
| 1744 | if (*key_size > ECRYPTFS_MAX_KEY_BYTES) { |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1745 | rc = -EINVAL; |
| 1746 | printk(KERN_ERR "Requested key size is [%Zd] bytes; maximum " |
Michael Halcrow | e5d9cbd | 2006-10-30 22:07:16 -0800 | [diff] [blame] | 1747 | "allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1748 | goto out; |
| 1749 | } |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 1750 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, cipher_name, |
| 1751 | "ecb"); |
| 1752 | if (rc) |
| 1753 | goto out; |
| 1754 | *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC); |
| 1755 | kfree(full_alg_name); |
| 1756 | if (IS_ERR(*key_tfm)) { |
| 1757 | rc = PTR_ERR(*key_tfm); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1758 | printk(KERN_ERR "Unable to allocate crypto cipher with name " |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 1759 | "[%s]; rc = [%d]\n", cipher_name, rc); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1760 | goto out; |
| 1761 | } |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 1762 | crypto_blkcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
| 1763 | if (*key_size == 0) { |
| 1764 | struct blkcipher_alg *alg = crypto_blkcipher_alg(*key_tfm); |
| 1765 | |
| 1766 | *key_size = alg->max_keysize; |
| 1767 | } |
Michael Halcrow | e5d9cbd | 2006-10-30 22:07:16 -0800 | [diff] [blame] | 1768 | get_random_bytes(dummy_key, *key_size); |
Michael Halcrow | 8bba066 | 2006-10-30 22:07:18 -0800 | [diff] [blame] | 1769 | rc = crypto_blkcipher_setkey(*key_tfm, dummy_key, *key_size); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1770 | if (rc) { |
| 1771 | printk(KERN_ERR "Error attempting to set key of size [%Zd] for " |
Michael Halcrow | e5d9cbd | 2006-10-30 22:07:16 -0800 | [diff] [blame] | 1772 | "cipher [%s]; rc = [%d]\n", *key_size, cipher_name, rc); |
Michael Halcrow | 237fead | 2006-10-04 02:16:22 -0700 | [diff] [blame] | 1773 | rc = -EINVAL; |
| 1774 | goto out; |
| 1775 | } |
| 1776 | out: |
| 1777 | return rc; |
| 1778 | } |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1779 | |
| 1780 | struct kmem_cache *ecryptfs_key_tfm_cache; |
Adrian Bunk | 7896b63 | 2008-02-06 01:38:32 -0800 | [diff] [blame] | 1781 | static struct list_head key_tfm_list; |
Eric Sandeen | af440f5 | 2008-02-06 01:38:37 -0800 | [diff] [blame] | 1782 | struct mutex key_tfm_list_mutex; |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1783 | |
| 1784 | int ecryptfs_init_crypto(void) |
| 1785 | { |
| 1786 | mutex_init(&key_tfm_list_mutex); |
| 1787 | INIT_LIST_HEAD(&key_tfm_list); |
| 1788 | return 0; |
| 1789 | } |
| 1790 | |
Eric Sandeen | af440f5 | 2008-02-06 01:38:37 -0800 | [diff] [blame] | 1791 | /** |
| 1792 | * ecryptfs_destroy_crypto - free all cached key_tfms on key_tfm_list |
| 1793 | * |
| 1794 | * Called only at module unload time |
| 1795 | */ |
Michael Halcrow | fcd1283 | 2007-10-16 01:28:01 -0700 | [diff] [blame] | 1796 | int ecryptfs_destroy_crypto(void) |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1797 | { |
| 1798 | struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp; |
| 1799 | |
| 1800 | mutex_lock(&key_tfm_list_mutex); |
| 1801 | list_for_each_entry_safe(key_tfm, key_tfm_tmp, &key_tfm_list, |
| 1802 | key_tfm_list) { |
| 1803 | list_del(&key_tfm->key_tfm_list); |
| 1804 | if (key_tfm->key_tfm) |
| 1805 | crypto_free_blkcipher(key_tfm->key_tfm); |
| 1806 | kmem_cache_free(ecryptfs_key_tfm_cache, key_tfm); |
| 1807 | } |
| 1808 | mutex_unlock(&key_tfm_list_mutex); |
| 1809 | return 0; |
| 1810 | } |
| 1811 | |
| 1812 | int |
| 1813 | ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name, |
| 1814 | size_t key_size) |
| 1815 | { |
| 1816 | struct ecryptfs_key_tfm *tmp_tfm; |
| 1817 | int rc = 0; |
| 1818 | |
Eric Sandeen | af440f5 | 2008-02-06 01:38:37 -0800 | [diff] [blame] | 1819 | BUG_ON(!mutex_is_locked(&key_tfm_list_mutex)); |
| 1820 | |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1821 | tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL); |
| 1822 | if (key_tfm != NULL) |
| 1823 | (*key_tfm) = tmp_tfm; |
| 1824 | if (!tmp_tfm) { |
| 1825 | rc = -ENOMEM; |
| 1826 | printk(KERN_ERR "Error attempting to allocate from " |
| 1827 | "ecryptfs_key_tfm_cache\n"); |
| 1828 | goto out; |
| 1829 | } |
| 1830 | mutex_init(&tmp_tfm->key_tfm_mutex); |
| 1831 | strncpy(tmp_tfm->cipher_name, cipher_name, |
| 1832 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); |
Eric Sandeen | b886290 | 2007-12-22 14:03:24 -0800 | [diff] [blame] | 1833 | tmp_tfm->cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1834 | tmp_tfm->key_size = key_size; |
Michael Halcrow | 5dda699 | 2007-10-16 01:28:06 -0700 | [diff] [blame] | 1835 | rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm, |
| 1836 | tmp_tfm->cipher_name, |
| 1837 | &tmp_tfm->key_size); |
| 1838 | if (rc) { |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1839 | printk(KERN_ERR "Error attempting to initialize key TFM " |
| 1840 | "cipher with name = [%s]; rc = [%d]\n", |
| 1841 | tmp_tfm->cipher_name, rc); |
| 1842 | kmem_cache_free(ecryptfs_key_tfm_cache, tmp_tfm); |
| 1843 | if (key_tfm != NULL) |
| 1844 | (*key_tfm) = NULL; |
| 1845 | goto out; |
| 1846 | } |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1847 | list_add(&tmp_tfm->key_tfm_list, &key_tfm_list); |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1848 | out: |
| 1849 | return rc; |
| 1850 | } |
| 1851 | |
Eric Sandeen | af440f5 | 2008-02-06 01:38:37 -0800 | [diff] [blame] | 1852 | /** |
| 1853 | * ecryptfs_tfm_exists - Search for existing tfm for cipher_name. |
| 1854 | * @cipher_name: the name of the cipher to search for |
| 1855 | * @key_tfm: set to corresponding tfm if found |
| 1856 | * |
| 1857 | * Searches for cached key_tfm matching @cipher_name |
| 1858 | * Must be called with &key_tfm_list_mutex held |
| 1859 | * Returns 1 if found, with @key_tfm set |
| 1860 | * Returns 0 if not found, with @key_tfm set to NULL |
| 1861 | */ |
| 1862 | int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm) |
| 1863 | { |
| 1864 | struct ecryptfs_key_tfm *tmp_key_tfm; |
| 1865 | |
| 1866 | BUG_ON(!mutex_is_locked(&key_tfm_list_mutex)); |
| 1867 | |
| 1868 | list_for_each_entry(tmp_key_tfm, &key_tfm_list, key_tfm_list) { |
| 1869 | if (strcmp(tmp_key_tfm->cipher_name, cipher_name) == 0) { |
| 1870 | if (key_tfm) |
| 1871 | (*key_tfm) = tmp_key_tfm; |
| 1872 | return 1; |
| 1873 | } |
| 1874 | } |
| 1875 | if (key_tfm) |
| 1876 | (*key_tfm) = NULL; |
| 1877 | return 0; |
| 1878 | } |
| 1879 | |
| 1880 | /** |
| 1881 | * ecryptfs_get_tfm_and_mutex_for_cipher_name |
| 1882 | * |
| 1883 | * @tfm: set to cached tfm found, or new tfm created |
| 1884 | * @tfm_mutex: set to mutex for cached tfm found, or new tfm created |
| 1885 | * @cipher_name: the name of the cipher to search for and/or add |
| 1886 | * |
| 1887 | * Sets pointers to @tfm & @tfm_mutex matching @cipher_name. |
| 1888 | * Searches for cached item first, and creates new if not found. |
| 1889 | * Returns 0 on success, non-zero if adding new cipher failed |
| 1890 | */ |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1891 | int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, |
| 1892 | struct mutex **tfm_mutex, |
| 1893 | char *cipher_name) |
| 1894 | { |
| 1895 | struct ecryptfs_key_tfm *key_tfm; |
| 1896 | int rc = 0; |
| 1897 | |
| 1898 | (*tfm) = NULL; |
| 1899 | (*tfm_mutex) = NULL; |
Eric Sandeen | af440f5 | 2008-02-06 01:38:37 -0800 | [diff] [blame] | 1900 | |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1901 | mutex_lock(&key_tfm_list_mutex); |
Eric Sandeen | af440f5 | 2008-02-06 01:38:37 -0800 | [diff] [blame] | 1902 | if (!ecryptfs_tfm_exists(cipher_name, &key_tfm)) { |
| 1903 | rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0); |
| 1904 | if (rc) { |
| 1905 | printk(KERN_ERR "Error adding new key_tfm to list; " |
| 1906 | "rc = [%d]\n", rc); |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1907 | goto out; |
| 1908 | } |
| 1909 | } |
| 1910 | mutex_unlock(&key_tfm_list_mutex); |
Michael Halcrow | f4aad16 | 2007-10-16 01:27:53 -0700 | [diff] [blame] | 1911 | (*tfm) = key_tfm->key_tfm; |
| 1912 | (*tfm_mutex) = &key_tfm->key_tfm_mutex; |
| 1913 | out: |
| 1914 | return rc; |
| 1915 | } |