diff options
Diffstat (limited to 'fs/f2fs/crypto_key.c')
| -rw-r--r-- | fs/f2fs/crypto_key.c | 107 |
1 files changed, 79 insertions, 28 deletions
diff --git a/fs/f2fs/crypto_key.c b/fs/f2fs/crypto_key.c index 8a10569..95b8f93 100644 --- a/fs/f2fs/crypto_key.c +++ b/fs/f2fs/crypto_key.c @@ -87,20 +87,31 @@ out: return res; } -void f2fs_free_encryption_info(struct inode *inode) +static void f2fs_free_crypt_info(struct f2fs_crypt_info *ci) { - struct f2fs_inode_info *fi = F2FS_I(inode); - struct f2fs_crypt_info *ci = fi->i_crypt_info; - if (!ci) return; if (ci->ci_keyring_key) key_put(ci->ci_keyring_key); crypto_free_ablkcipher(ci->ci_ctfm); - memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw)); kmem_cache_free(f2fs_crypt_info_cachep, ci); - fi->i_crypt_info = NULL; +} + +void f2fs_free_encryption_info(struct inode *inode, struct f2fs_crypt_info *ci) +{ + struct f2fs_inode_info *fi = F2FS_I(inode); + struct f2fs_crypt_info *prev; + + if (ci == NULL) + ci = ACCESS_ONCE(fi->i_crypt_info); + if (ci == NULL) + return; + prev = cmpxchg(&fi->i_crypt_info, ci, NULL); + if (prev != ci) + return; + + f2fs_free_crypt_info(ci); } int _f2fs_get_encryption_info(struct inode *inode) @@ -113,17 +124,23 @@ int _f2fs_get_encryption_info(struct inode *inode) struct f2fs_encryption_key *master_key; struct f2fs_encryption_context ctx; struct user_key_payload *ukp; + struct crypto_ablkcipher *ctfm; + const char *cipher_str; + char raw_key[F2FS_MAX_KEY_SIZE]; + char mode; int res; res = f2fs_crypto_initialize(); if (res) return res; - - if (fi->i_crypt_info) { - if (!fi->i_crypt_info->ci_keyring_key || - key_validate(fi->i_crypt_info->ci_keyring_key) == 0) +retry: + crypt_info = ACCESS_ONCE(fi->i_crypt_info); + if (crypt_info) { + if (!crypt_info->ci_keyring_key || + key_validate(crypt_info->ci_keyring_key) == 0) return 0; - f2fs_free_encryption_info(inode); + f2fs_free_encryption_info(inode, crypt_info); + goto retry; } res = f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION, @@ -143,18 +160,30 @@ int _f2fs_get_encryption_info(struct inode *inode) crypt_info->ci_data_mode = ctx.contents_encryption_mode; crypt_info->ci_filename_mode = ctx.filenames_encryption_mode; crypt_info->ci_ctfm = NULL; + crypt_info->ci_keyring_key = NULL; memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor, sizeof(crypt_info->ci_master_key)); if (S_ISREG(inode->i_mode)) - crypt_info->ci_size = - f2fs_encryption_key_size(crypt_info->ci_data_mode); + mode = crypt_info->ci_data_mode; else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) - crypt_info->ci_size = - f2fs_encryption_key_size(crypt_info->ci_filename_mode); + mode = crypt_info->ci_filename_mode; else BUG(); - BUG_ON(!crypt_info->ci_size); + switch (mode) { + case F2FS_ENCRYPTION_MODE_AES_256_XTS: + cipher_str = "xts(aes)"; + break; + case F2FS_ENCRYPTION_MODE_AES_256_CTS: + cipher_str = "cts(cbc(aes))"; + break; + default: + printk_once(KERN_WARNING + "f2fs: unsupported key mode %d (ino %u)\n", + mode, (unsigned) inode->i_ino); + res = -ENOKEY; + goto out; + } memcpy(full_key_descriptor, F2FS_KEY_DESC_PREFIX, F2FS_KEY_DESC_PREFIX_SIZE); @@ -169,6 +198,7 @@ int _f2fs_get_encryption_info(struct inode *inode) keyring_key = NULL; goto out; } + crypt_info->ci_keyring_key = keyring_key; BUG_ON(keyring_key->type != &key_type_logon); ukp = ((struct user_key_payload *)keyring_key->payload.data); if (ukp->datalen != sizeof(struct f2fs_encryption_key)) { @@ -180,19 +210,40 @@ int _f2fs_get_encryption_info(struct inode *inode) F2FS_KEY_DERIVATION_NONCE_SIZE); BUG_ON(master_key->size != F2FS_AES_256_XTS_KEY_SIZE); res = f2fs_derive_key_aes(ctx.nonce, master_key->raw, - crypt_info->ci_raw); -out: - if (res < 0) { - if (res == -ENOKEY) - res = 0; - kmem_cache_free(f2fs_crypt_info_cachep, crypt_info); - } else { - fi->i_crypt_info = crypt_info; - crypt_info->ci_keyring_key = keyring_key; - keyring_key = NULL; + raw_key); + if (res) + goto out; + + ctfm = crypto_alloc_ablkcipher(cipher_str, 0, 0); + if (!ctfm || IS_ERR(ctfm)) { + res = ctfm ? PTR_ERR(ctfm) : -ENOMEM; + printk(KERN_DEBUG + "%s: error %d (inode %u) allocating crypto tfm\n", + __func__, res, (unsigned) inode->i_ino); + goto out; } - if (keyring_key) - key_put(keyring_key); + crypt_info->ci_ctfm = ctfm; + crypto_ablkcipher_clear_flags(ctfm, ~0); + crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm), + CRYPTO_TFM_REQ_WEAK_KEY); + res = crypto_ablkcipher_setkey(ctfm, raw_key, + f2fs_encryption_key_size(mode)); + if (res) + goto out; + + memzero_explicit(raw_key, sizeof(raw_key)); + if (cmpxchg(&fi->i_crypt_info, NULL, crypt_info) != NULL) { + f2fs_free_crypt_info(crypt_info); + goto retry; + } + return 0; + +out: + if (res == -ENOKEY && !S_ISREG(inode->i_mode)) + res = 0; + + f2fs_free_crypt_info(crypt_info); + memzero_explicit(raw_key, sizeof(raw_key)); return res; } |
