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Diffstat (limited to 'fs/ext4/crypto_policy.c')
-rw-r--r--fs/ext4/crypto_policy.c232
1 files changed, 0 insertions, 232 deletions
diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c
deleted file mode 100644
index 8a9feb341..000000000
--- a/fs/ext4/crypto_policy.c
+++ /dev/null
@@ -1,232 +0,0 @@
-/*
- * linux/fs/ext4/crypto_policy.c
- *
- * Copyright (C) 2015, Google, Inc.
- *
- * This contains encryption policy functions for ext4
- *
- * Written by Michael Halcrow, 2015.
- */
-
-#include <linux/random.h>
-#include <linux/string.h>
-#include <linux/types.h>
-
-#include "ext4_jbd2.h"
-#include "ext4.h"
-#include "xattr.h"
-
-static int ext4_inode_has_encryption_context(struct inode *inode)
-{
- int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, NULL, 0);
- return (res > 0);
-}
-
-/*
- * check whether the policy is consistent with the encryption context
- * for the inode
- */
-static int ext4_is_encryption_context_consistent_with_policy(
- struct inode *inode, const struct ext4_encryption_policy *policy)
-{
- struct ext4_encryption_context ctx;
- int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
- sizeof(ctx));
- if (res != sizeof(ctx))
- return 0;
- return (memcmp(ctx.master_key_descriptor, policy->master_key_descriptor,
- EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
- (ctx.flags ==
- policy->flags) &&
- (ctx.contents_encryption_mode ==
- policy->contents_encryption_mode) &&
- (ctx.filenames_encryption_mode ==
- policy->filenames_encryption_mode));
-}
-
-static int ext4_create_encryption_context_from_policy(
- struct inode *inode, const struct ext4_encryption_policy *policy)
-{
- struct ext4_encryption_context ctx;
- handle_t *handle;
- int res, res2;
-
- res = ext4_convert_inline_data(inode);
- if (res)
- return res;
-
- ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
- memcpy(ctx.master_key_descriptor, policy->master_key_descriptor,
- EXT4_KEY_DESCRIPTOR_SIZE);
- if (!ext4_valid_contents_enc_mode(policy->contents_encryption_mode)) {
- printk(KERN_WARNING
- "%s: Invalid contents encryption mode %d\n", __func__,
- policy->contents_encryption_mode);
- return -EINVAL;
- }
- if (!ext4_valid_filenames_enc_mode(policy->filenames_encryption_mode)) {
- printk(KERN_WARNING
- "%s: Invalid filenames encryption mode %d\n", __func__,
- policy->filenames_encryption_mode);
- return -EINVAL;
- }
- if (policy->flags & ~EXT4_POLICY_FLAGS_VALID)
- return -EINVAL;
- ctx.contents_encryption_mode = policy->contents_encryption_mode;
- ctx.filenames_encryption_mode = policy->filenames_encryption_mode;
- ctx.flags = policy->flags;
- BUILD_BUG_ON(sizeof(ctx.nonce) != EXT4_KEY_DERIVATION_NONCE_SIZE);
- get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
-
- handle = ext4_journal_start(inode, EXT4_HT_MISC,
- ext4_jbd2_credits_xattr(inode));
- if (IS_ERR(handle))
- return PTR_ERR(handle);
- res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
- sizeof(ctx), 0);
- if (!res) {
- ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
- res = ext4_mark_inode_dirty(handle, inode);
- if (res)
- EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
- }
- res2 = ext4_journal_stop(handle);
- if (!res)
- res = res2;
- return res;
-}
-
-int ext4_process_policy(const struct ext4_encryption_policy *policy,
- struct inode *inode)
-{
- if (!inode_owner_or_capable(inode))
- return -EACCES;
-
- if (policy->version != 0)
- return -EINVAL;
-
- if (!ext4_inode_has_encryption_context(inode)) {
- if (!S_ISDIR(inode->i_mode))
- return -EINVAL;
- if (!ext4_empty_dir(inode))
- return -ENOTEMPTY;
- return ext4_create_encryption_context_from_policy(inode,
- policy);
- }
-
- if (ext4_is_encryption_context_consistent_with_policy(inode, policy))
- return 0;
-
- printk(KERN_WARNING "%s: Policy inconsistent with encryption context\n",
- __func__);
- return -EINVAL;
-}
-
-int ext4_get_policy(struct inode *inode, struct ext4_encryption_policy *policy)
-{
- struct ext4_encryption_context ctx;
-
- int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
- &ctx, sizeof(ctx));
- if (res != sizeof(ctx))
- return -ENOENT;
- if (ctx.format != EXT4_ENCRYPTION_CONTEXT_FORMAT_V1)
- return -EINVAL;
- policy->version = 0;
- policy->contents_encryption_mode = ctx.contents_encryption_mode;
- policy->filenames_encryption_mode = ctx.filenames_encryption_mode;
- policy->flags = ctx.flags;
- memcpy(&policy->master_key_descriptor, ctx.master_key_descriptor,
- EXT4_KEY_DESCRIPTOR_SIZE);
- return 0;
-}
-
-int ext4_is_child_context_consistent_with_parent(struct inode *parent,
- struct inode *child)
-{
- struct ext4_crypt_info *parent_ci, *child_ci;
- int res;
-
- if ((parent == NULL) || (child == NULL)) {
- pr_err("parent %p child %p\n", parent, child);
- WARN_ON(1); /* Should never happen */
- return 0;
- }
- /* no restrictions if the parent directory is not encrypted */
- if (!ext4_encrypted_inode(parent))
- return 1;
- /* if the child directory is not encrypted, this is always a problem */
- if (!ext4_encrypted_inode(child))
- return 0;
- res = ext4_get_encryption_info(parent);
- if (res)
- return 0;
- res = ext4_get_encryption_info(child);
- if (res)
- return 0;
- parent_ci = EXT4_I(parent)->i_crypt_info;
- child_ci = EXT4_I(child)->i_crypt_info;
- if (!parent_ci && !child_ci)
- return 1;
- if (!parent_ci || !child_ci)
- return 0;
-
- return (memcmp(parent_ci->ci_master_key,
- child_ci->ci_master_key,
- EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
- (parent_ci->ci_data_mode == child_ci->ci_data_mode) &&
- (parent_ci->ci_filename_mode == child_ci->ci_filename_mode) &&
- (parent_ci->ci_flags == child_ci->ci_flags));
-}
-
-/**
- * ext4_inherit_context() - Sets a child context from its parent
- * @parent: Parent inode from which the context is inherited.
- * @child: Child inode that inherits the context from @parent.
- *
- * Return: Zero on success, non-zero otherwise
- */
-int ext4_inherit_context(struct inode *parent, struct inode *child)
-{
- struct ext4_encryption_context ctx;
- struct ext4_crypt_info *ci;
- int res;
-
- res = ext4_get_encryption_info(parent);
- if (res < 0)
- return res;
- ci = EXT4_I(parent)->i_crypt_info;
- if (ci == NULL)
- return -ENOKEY;
-
- ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
- if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) {
- ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
- ctx.filenames_encryption_mode =
- EXT4_ENCRYPTION_MODE_AES_256_CTS;
- ctx.flags = 0;
- memset(ctx.master_key_descriptor, 0x42,
- EXT4_KEY_DESCRIPTOR_SIZE);
- res = 0;
- } else {
- ctx.contents_encryption_mode = ci->ci_data_mode;
- ctx.filenames_encryption_mode = ci->ci_filename_mode;
- ctx.flags = ci->ci_flags;
- memcpy(ctx.master_key_descriptor, ci->ci_master_key,
- EXT4_KEY_DESCRIPTOR_SIZE);
- }
- get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
- res = ext4_xattr_set(child, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
- sizeof(ctx), 0);
- if (!res) {
- ext4_set_inode_flag(child, EXT4_INODE_ENCRYPT);
- ext4_clear_inode_state(child, EXT4_STATE_MAY_INLINE_DATA);
- res = ext4_get_encryption_info(child);
- }
- return res;
-}
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