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Diffstat (limited to 'fs/ext4/crypto_key.c')
-rw-r--r--fs/ext4/crypto_key.c274
1 files changed, 0 insertions, 274 deletions
diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
deleted file mode 100644
index 0129d688d1f7..000000000000
--- a/fs/ext4/crypto_key.c
+++ /dev/null
@@ -1,274 +0,0 @@
-/*
- * linux/fs/ext4/crypto_key.c
- *
- * Copyright (C) 2015, Google, Inc.
- *
- * This contains encryption key functions for ext4
- *
- * Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
- */
-
-#include <crypto/skcipher.h>
-#include <keys/encrypted-type.h>
-#include <keys/user-type.h>
-#include <linux/random.h>
-#include <linux/scatterlist.h>
-#include <uapi/linux/keyctl.h>
-
-#include "ext4.h"
-#include "xattr.h"
-
-static void derive_crypt_complete(struct crypto_async_request *req, int rc)
-{
-	struct ext4_completion_result *ecr = req->data;
-
-	if (rc == -EINPROGRESS)
-		return;
-
-	ecr->res = rc;
-	complete(&ecr->completion);
-}
-
-/**
- * ext4_derive_key_aes() - Derive a key using AES-128-ECB
- * @deriving_key: Encryption key used for derivation.
- * @source_key:   Source key to which to apply derivation.
- * @derived_key:  Derived key.
- *
- * Return: Zero on success; non-zero otherwise.
- */
-static int ext4_derive_key_aes(char deriving_key[EXT4_AES_128_ECB_KEY_SIZE],
-			       char source_key[EXT4_AES_256_XTS_KEY_SIZE],
-			       char derived_key[EXT4_AES_256_XTS_KEY_SIZE])
-{
-	int res = 0;
-	struct skcipher_request *req = NULL;
-	DECLARE_EXT4_COMPLETION_RESULT(ecr);
-	struct scatterlist src_sg, dst_sg;
-	struct crypto_skcipher *tfm = crypto_alloc_skcipher("ecb(aes)", 0, 0);
-
-	if (IS_ERR(tfm)) {
-		res = PTR_ERR(tfm);
-		tfm = NULL;
-		goto out;
-	}
-	crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_WEAK_KEY);
-	req = skcipher_request_alloc(tfm, GFP_NOFS);
-	if (!req) {
-		res = -ENOMEM;
-		goto out;
-	}
-	skcipher_request_set_callback(req,
-			CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-			derive_crypt_complete, &ecr);
-	res = crypto_skcipher_setkey(tfm, deriving_key,
-				     EXT4_AES_128_ECB_KEY_SIZE);
-	if (res < 0)
-		goto out;
-	sg_init_one(&src_sg, source_key, EXT4_AES_256_XTS_KEY_SIZE);
-	sg_init_one(&dst_sg, derived_key, EXT4_AES_256_XTS_KEY_SIZE);
-	skcipher_request_set_crypt(req, &src_sg, &dst_sg,
-				   EXT4_AES_256_XTS_KEY_SIZE, NULL);
-	res = crypto_skcipher_encrypt(req);
-	if (res == -EINPROGRESS || res == -EBUSY) {
-		wait_for_completion(&ecr.completion);
-		res = ecr.res;
-	}
-
-out:
-	skcipher_request_free(req);
-	crypto_free_skcipher(tfm);
-	return res;
-}
-
-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_skcipher(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_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;
-	const struct user_key_payload *ukp;
-	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-	struct crypto_skcipher *ctfm;
-	const char *cipher_str;
-	char raw_key[EXT4_MAX_KEY_SIZE];
-	char mode;
-	int res;
-
-	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;
-
-	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))
-		mode = crypt_info->ci_data_mode;
-	else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-		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;
-	}
-	if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
-		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);
-	sprintf(full_key_descriptor + EXT4_KEY_DESC_PREFIX_SIZE,
-		"%*phN", EXT4_KEY_DESCRIPTOR_SIZE,
-		ctx.master_key_descriptor);
-	full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
-			    (2 * EXT4_KEY_DESCRIPTOR_SIZE)] = '\0';
-	keyring_key = request_key(&key_type_logon, full_key_descriptor, NULL);
-	if (IS_ERR(keyring_key)) {
-		res = PTR_ERR(keyring_key);
-		keyring_key = NULL;
-		goto out;
-	}
-	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);
-	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_skcipher(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_skcipher_clear_flags(ctfm, ~0);
-	crypto_tfm_set_flags(crypto_skcipher_tfm(ctfm),
-			     CRYPTO_TFM_REQ_WEAK_KEY);
-	res = crypto_skcipher_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 (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);
-
-	return (ei->i_crypt_info != NULL);
-}