/**
* ext4_derive_key_aes() - Derive a key using AES-128-ECB
- * @deriving_key: Encryption key used for derivatio.
+ * @deriving_key: Encryption key used for derivation.
* @source_key: Source key to which to apply derivation.
* @derived_key: Derived key.
*
EXT4_AES_256_XTS_KEY_SIZE, NULL);
res = crypto_ablkcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
- BUG_ON(req->base.data != &ecr);
wait_for_completion(&ecr.completion);
res = ecr.res;
}
return res;
}
-/**
- * ext4_generate_encryption_key() - generates an encryption key
- * @inode: The inode to generate the encryption key for.
- */
-int ext4_generate_encryption_key(struct inode *inode)
+void ext4_free_crypt_info(struct ext4_crypt_info *ci)
+{
+ if (!ci)
+ return;
+
+ if (ci->ci_keyring_key)
+ key_put(ci->ci_keyring_key);
+ crypto_free_ablkcipher(ci->ci_ctfm);
+ kmem_cache_free(ext4_crypt_info_cachep, ci);
+}
+
+void ext4_free_encryption_info(struct inode *inode,
+ struct ext4_crypt_info *ci)
{
struct ext4_inode_info *ei = EXT4_I(inode);
- struct ext4_encryption_key *crypt_key = &ei->i_encryption_key;
+ struct ext4_crypt_info *prev;
+
+ if (ci == NULL)
+ ci = ACCESS_ONCE(ei->i_crypt_info);
+ if (ci == NULL)
+ return;
+ prev = cmpxchg(&ei->i_crypt_info, ci, NULL);
+ if (prev != ci)
+ return;
+
+ ext4_free_crypt_info(ci);
+}
+
+int _ext4_get_encryption_info(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_crypt_info *crypt_info;
char full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
(EXT4_KEY_DESCRIPTOR_SIZE * 2) + 1];
struct key *keyring_key = NULL;
struct ext4_encryption_key *master_key;
struct ext4_encryption_context ctx;
- struct user_key_payload *ukp;
+ const struct user_key_payload *ukp;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
- &ctx, sizeof(ctx));
+ struct crypto_ablkcipher *ctfm;
+ const char *cipher_str;
+ char raw_key[EXT4_MAX_KEY_SIZE];
+ char mode;
+ int res;
- if (res != sizeof(ctx)) {
- if (res > 0)
- res = -EINVAL;
- goto out;
+ if (!ext4_read_workqueue) {
+ res = ext4_init_crypto();
+ if (res)
+ return res;
}
+
+retry:
+ crypt_info = ACCESS_ONCE(ei->i_crypt_info);
+ if (crypt_info) {
+ if (!crypt_info->ci_keyring_key ||
+ key_validate(crypt_info->ci_keyring_key) == 0)
+ return 0;
+ ext4_free_encryption_info(inode, crypt_info);
+ goto retry;
+ }
+
+ res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
+ EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
+ &ctx, sizeof(ctx));
+ if (res < 0) {
+ if (!DUMMY_ENCRYPTION_ENABLED(sbi))
+ return res;
+ ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
+ ctx.filenames_encryption_mode =
+ EXT4_ENCRYPTION_MODE_AES_256_CTS;
+ ctx.flags = 0;
+ } else if (res != sizeof(ctx))
+ return -EINVAL;
res = 0;
- ei->i_crypt_policy_flags = ctx.flags;
+ crypt_info = kmem_cache_alloc(ext4_crypt_info_cachep, GFP_KERNEL);
+ if (!crypt_info)
+ return -ENOMEM;
+
+ crypt_info->ci_flags = ctx.flags;
+ 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_key->mode = ctx.contents_encryption_mode;
+ mode = crypt_info->ci_data_mode;
else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
- crypt_key->mode = ctx.filenames_encryption_mode;
- else {
- printk(KERN_ERR "ext4 crypto: Unsupported inode type.\n");
+ mode = crypt_info->ci_filename_mode;
+ else
BUG();
+ switch (mode) {
+ case EXT4_ENCRYPTION_MODE_AES_256_XTS:
+ cipher_str = "xts(aes)";
+ break;
+ case EXT4_ENCRYPTION_MODE_AES_256_CTS:
+ cipher_str = "cts(cbc(aes))";
+ break;
+ default:
+ printk_once(KERN_WARNING
+ "ext4: unsupported key mode %d (ino %u)\n",
+ mode, (unsigned) inode->i_ino);
+ res = -ENOKEY;
+ goto out;
}
- crypt_key->size = ext4_encryption_key_size(crypt_key->mode);
- BUG_ON(!crypt_key->size);
if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
- memset(crypt_key->raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
- goto out;
+ memset(raw_key, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
+ goto got_key;
}
memcpy(full_key_descriptor, EXT4_KEY_DESC_PREFIX,
EXT4_KEY_DESC_PREFIX_SIZE);
keyring_key = NULL;
goto out;
}
- BUG_ON(keyring_key->type != &key_type_logon);
- ukp = ((struct user_key_payload *)keyring_key->payload.data);
+ crypt_info->ci_keyring_key = keyring_key;
+ if (keyring_key->type != &key_type_logon) {
+ printk_once(KERN_WARNING
+ "ext4: key type must be logon\n");
+ res = -ENOKEY;
+ goto out;
+ }
+ down_read(&keyring_key->sem);
+ ukp = user_key_payload(keyring_key);
if (ukp->datalen != sizeof(struct ext4_encryption_key)) {
res = -EINVAL;
+ up_read(&keyring_key->sem);
goto out;
}
master_key = (struct ext4_encryption_key *)ukp->data;
BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
EXT4_KEY_DERIVATION_NONCE_SIZE);
- BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE);
- res = ext4_derive_key_aes(ctx.nonce, master_key->raw, crypt_key->raw);
+ if (master_key->size != EXT4_AES_256_XTS_KEY_SIZE) {
+ printk_once(KERN_WARNING
+ "ext4: key size incorrect: %d\n",
+ master_key->size);
+ res = -ENOKEY;
+ up_read(&keyring_key->sem);
+ goto out;
+ }
+ res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
+ raw_key);
+ up_read(&keyring_key->sem);
+ if (res)
+ goto out;
+got_key:
+ 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;
+ }
+ 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,
+ ext4_encryption_key_size(mode));
+ if (res)
+ goto out;
+ memzero_explicit(raw_key, sizeof(raw_key));
+ if (cmpxchg(&ei->i_crypt_info, NULL, crypt_info) != NULL) {
+ ext4_free_crypt_info(crypt_info);
+ goto retry;
+ }
+ return 0;
+
out:
- if (keyring_key)
- key_put(keyring_key);
- if (res < 0)
- crypt_key->mode = EXT4_ENCRYPTION_MODE_INVALID;
+ if (res == -ENOKEY)
+ res = 0;
+ ext4_free_crypt_info(crypt_info);
+ memzero_explicit(raw_key, sizeof(raw_key));
return res;
}
int ext4_has_encryption_key(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
- struct ext4_encryption_key *crypt_key = &ei->i_encryption_key;
- return (crypt_key->mode != EXT4_ENCRYPTION_MODE_INVALID);
+ return (ei->i_crypt_info != NULL);
}
Code Review / kvmfornfv.git / blobdiff