From 0b81d0779072696371822e5ed9e7c6292e547024 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Fri, 15 May 2015 16:26:10 -0700 Subject: fs crypto: move per-file encryption from f2fs tree to fs/crypto This patch adds the renamed functions moved from the f2fs crypto files. 1. definitions for per-file encryption used by ext4 and f2fs. 2. crypto.c for encrypt/decrypt functions a. IO preparation: - fscrypt_get_ctx / fscrypt_release_ctx b. before IOs: - fscrypt_encrypt_page - fscrypt_decrypt_page - fscrypt_zeroout_range c. after IOs: - fscrypt_decrypt_bio_pages - fscrypt_pullback_bio_page - fscrypt_restore_control_page 3. policy.c supporting context management. a. For ioctls: - fscrypt_process_policy - fscrypt_get_policy b. For context permission - fscrypt_has_permitted_context - fscrypt_inherit_context 4. keyinfo.c to handle permissions - fscrypt_get_encryption_info - fscrypt_free_encryption_info 5. fname.c to support filename encryption a. general wrapper functions - fscrypt_fname_disk_to_usr - fscrypt_fname_usr_to_disk - fscrypt_setup_filename - fscrypt_free_filename b. specific filename handling functions - fscrypt_fname_alloc_buffer - fscrypt_fname_free_buffer 6. Makefile and Kconfig Cc: Al Viro Signed-off-by: Michael Halcrow Signed-off-by: Ildar Muslukhov Signed-off-by: Uday Savagaonkar Signed-off-by: Theodore Ts'o Signed-off-by: Arnd Bergmann Signed-off-by: Jaegeuk Kim diff --git a/fs/Kconfig b/fs/Kconfig index 9adee0d..9d75767 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -84,6 +84,8 @@ config MANDATORY_FILE_LOCKING To the best of my knowledge this is dead code that no one cares about. +source "fs/crypto/Kconfig" + source "fs/notify/Kconfig" source "fs/quota/Kconfig" diff --git a/fs/Makefile b/fs/Makefile index 79f5225..252c968 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_EVENTFD) += eventfd.o obj-$(CONFIG_USERFAULTFD) += userfaultfd.o obj-$(CONFIG_AIO) += aio.o obj-$(CONFIG_FS_DAX) += dax.o +obj-$(CONFIG_FS_ENCRYPTION) += crypto/ obj-$(CONFIG_FILE_LOCKING) += locks.o obj-$(CONFIG_COMPAT) += compat.o compat_ioctl.o obj-$(CONFIG_BINFMT_AOUT) += binfmt_aout.o diff --git a/fs/crypto/Kconfig b/fs/crypto/Kconfig new file mode 100644 index 0000000..92348fa --- /dev/null +++ b/fs/crypto/Kconfig @@ -0,0 +1,18 @@ +config FS_ENCRYPTION + tristate "FS Encryption (Per-file encryption)" + depends on BLOCK + select CRYPTO + select CRYPTO_AES + select CRYPTO_CBC + select CRYPTO_ECB + select CRYPTO_XTS + select CRYPTO_CTS + select CRYPTO_CTR + select CRYPTO_SHA256 + select KEYS + select ENCRYPTED_KEYS + help + Enable encryption of files and directories. This + feature is similar to ecryptfs, but it is more memory + efficient since it avoids caching the encrypted and + decrypted pages in the page cache. diff --git a/fs/crypto/Makefile b/fs/crypto/Makefile new file mode 100644 index 0000000..f17684c --- /dev/null +++ b/fs/crypto/Makefile @@ -0,0 +1,3 @@ +obj-$(CONFIG_FS_ENCRYPTION) += fscrypto.o + +fscrypto-y := crypto.o fname.o policy.o keyinfo.o diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c new file mode 100644 index 0000000..d45c331 --- /dev/null +++ b/fs/crypto/crypto.c @@ -0,0 +1,556 @@ +/* + * This contains encryption functions for per-file encryption. + * + * Copyright (C) 2015, Google, Inc. + * Copyright (C) 2015, Motorola Mobility + * + * Written by Michael Halcrow, 2014. + * + * Filename encryption additions + * Uday Savagaonkar, 2014 + * Encryption policy handling additions + * Ildar Muslukhov, 2014 + * Add fscrypt_pullback_bio_page() + * Jaegeuk Kim, 2015. + * + * This has not yet undergone a rigorous security audit. + * + * The usage of AES-XTS should conform to recommendations in NIST + * Special Publication 800-38E and IEEE P1619/D16. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static unsigned int num_prealloc_crypto_pages = 32; +static unsigned int num_prealloc_crypto_ctxs = 128; + +module_param(num_prealloc_crypto_pages, uint, 0444); +MODULE_PARM_DESC(num_prealloc_crypto_pages, + "Number of crypto pages to preallocate"); +module_param(num_prealloc_crypto_ctxs, uint, 0444); +MODULE_PARM_DESC(num_prealloc_crypto_ctxs, + "Number of crypto contexts to preallocate"); + +static mempool_t *fscrypt_bounce_page_pool = NULL; + +static LIST_HEAD(fscrypt_free_ctxs); +static DEFINE_SPINLOCK(fscrypt_ctx_lock); + +static struct workqueue_struct *fscrypt_read_workqueue; +static DEFINE_MUTEX(fscrypt_init_mutex); + +static struct kmem_cache *fscrypt_ctx_cachep; +struct kmem_cache *fscrypt_info_cachep; + +/** + * fscrypt_release_ctx() - Releases an encryption context + * @ctx: The encryption context to release. + * + * If the encryption context was allocated from the pre-allocated pool, returns + * it to that pool. Else, frees it. + * + * If there's a bounce page in the context, this frees that. + */ +void fscrypt_release_ctx(struct fscrypt_ctx *ctx) +{ + unsigned long flags; + + if (ctx->flags & FS_WRITE_PATH_FL && ctx->w.bounce_page) { + mempool_free(ctx->w.bounce_page, fscrypt_bounce_page_pool); + ctx->w.bounce_page = NULL; + } + ctx->w.control_page = NULL; + if (ctx->flags & FS_CTX_REQUIRES_FREE_ENCRYPT_FL) { + kmem_cache_free(fscrypt_ctx_cachep, ctx); + } else { + spin_lock_irqsave(&fscrypt_ctx_lock, flags); + list_add(&ctx->free_list, &fscrypt_free_ctxs); + spin_unlock_irqrestore(&fscrypt_ctx_lock, flags); + } +} +EXPORT_SYMBOL(fscrypt_release_ctx); + +/** + * fscrypt_get_ctx() - Gets an encryption context + * @inode: The inode for which we are doing the crypto + * + * Allocates and initializes an encryption context. + * + * Return: An allocated and initialized encryption context on success; error + * value or NULL otherwise. + */ +struct fscrypt_ctx *fscrypt_get_ctx(struct inode *inode) +{ + struct fscrypt_ctx *ctx = NULL; + struct fscrypt_info *ci = inode->i_crypt_info; + unsigned long flags; + + if (ci == NULL) + return ERR_PTR(-ENOKEY); + + /* + * We first try getting the ctx from a free list because in + * the common case the ctx will have an allocated and + * initialized crypto tfm, so it's probably a worthwhile + * optimization. For the bounce page, we first try getting it + * from the kernel allocator because that's just about as fast + * as getting it from a list and because a cache of free pages + * should generally be a "last resort" option for a filesystem + * to be able to do its job. + */ + spin_lock_irqsave(&fscrypt_ctx_lock, flags); + ctx = list_first_entry_or_null(&fscrypt_free_ctxs, + struct fscrypt_ctx, free_list); + if (ctx) + list_del(&ctx->free_list); + spin_unlock_irqrestore(&fscrypt_ctx_lock, flags); + if (!ctx) { + ctx = kmem_cache_zalloc(fscrypt_ctx_cachep, GFP_NOFS); + if (!ctx) + return ERR_PTR(-ENOMEM); + ctx->flags |= FS_CTX_REQUIRES_FREE_ENCRYPT_FL; + } else { + ctx->flags &= ~FS_CTX_REQUIRES_FREE_ENCRYPT_FL; + } + ctx->flags &= ~FS_WRITE_PATH_FL; + return ctx; +} +EXPORT_SYMBOL(fscrypt_get_ctx); + +/** + * fscrypt_complete() - The completion callback for page encryption + * @req: The asynchronous encryption request context + * @res: The result of the encryption operation + */ +static void fscrypt_complete(struct crypto_async_request *req, int res) +{ + struct fscrypt_completion_result *ecr = req->data; + + if (res == -EINPROGRESS) + return; + ecr->res = res; + complete(&ecr->completion); +} + +typedef enum { + FS_DECRYPT = 0, + FS_ENCRYPT, +} fscrypt_direction_t; + +static int do_page_crypto(struct inode *inode, + fscrypt_direction_t rw, pgoff_t index, + struct page *src_page, struct page *dest_page) +{ + u8 xts_tweak[FS_XTS_TWEAK_SIZE]; + struct ablkcipher_request *req = NULL; + DECLARE_FS_COMPLETION_RESULT(ecr); + struct scatterlist dst, src; + struct fscrypt_info *ci = inode->i_crypt_info; + struct crypto_ablkcipher *tfm = ci->ci_ctfm; + int res = 0; + + req = ablkcipher_request_alloc(tfm, GFP_NOFS); + if (!req) { + printk_ratelimited(KERN_ERR + "%s: crypto_request_alloc() failed\n", + __func__); + return -ENOMEM; + } + + ablkcipher_request_set_callback( + req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, + fscrypt_complete, &ecr); + + BUILD_BUG_ON(FS_XTS_TWEAK_SIZE < sizeof(index)); + memcpy(xts_tweak, &inode->i_ino, sizeof(index)); + memset(&xts_tweak[sizeof(index)], 0, + FS_XTS_TWEAK_SIZE - sizeof(index)); + + sg_init_table(&dst, 1); + sg_set_page(&dst, dest_page, PAGE_CACHE_SIZE, 0); + sg_init_table(&src, 1); + sg_set_page(&src, src_page, PAGE_CACHE_SIZE, 0); + ablkcipher_request_set_crypt(req, &src, &dst, PAGE_CACHE_SIZE, + xts_tweak); + if (rw == FS_DECRYPT) + res = crypto_ablkcipher_decrypt(req); + else + res = crypto_ablkcipher_encrypt(req); + if (res == -EINPROGRESS || res == -EBUSY) { + BUG_ON(req->base.data != &ecr); + wait_for_completion(&ecr.completion); + res = ecr.res; + } + ablkcipher_request_free(req); + if (res) { + printk_ratelimited(KERN_ERR + "%s: crypto_ablkcipher_encrypt() returned %d\n", + __func__, res); + return res; + } + return 0; +} + +static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx) +{ + ctx->w.bounce_page = mempool_alloc(fscrypt_bounce_page_pool, + GFP_NOWAIT); + if (ctx->w.bounce_page == NULL) + return ERR_PTR(-ENOMEM); + ctx->flags |= FS_WRITE_PATH_FL; + return ctx->w.bounce_page; +} + +/** + * fscypt_encrypt_page() - Encrypts a page + * @inode: The inode for which the encryption should take place + * @plaintext_page: The page to encrypt. Must be locked. + * + * Allocates a ciphertext page and encrypts plaintext_page into it using the ctx + * encryption context. + * + * Called on the page write path. The caller must call + * fscrypt_restore_control_page() on the returned ciphertext page to + * release the bounce buffer and the encryption context. + * + * Return: An allocated page with the encrypted content on success. Else, an + * error value or NULL. + */ +struct page *fscrypt_encrypt_page(struct inode *inode, + struct page *plaintext_page) +{ + struct fscrypt_ctx *ctx; + struct page *ciphertext_page = NULL; + int err; + + BUG_ON(!PageLocked(plaintext_page)); + + ctx = fscrypt_get_ctx(inode); + if (IS_ERR(ctx)) + return (struct page *)ctx; + + /* The encryption operation will require a bounce page. */ + ciphertext_page = alloc_bounce_page(ctx); + if (IS_ERR(ciphertext_page)) + goto errout; + + ctx->w.control_page = plaintext_page; + err = do_page_crypto(inode, FS_ENCRYPT, plaintext_page->index, + plaintext_page, ciphertext_page); + if (err) { + ciphertext_page = ERR_PTR(err); + goto errout; + } + SetPagePrivate(ciphertext_page); + set_page_private(ciphertext_page, (unsigned long)ctx); + lock_page(ciphertext_page); + return ciphertext_page; + +errout: + fscrypt_release_ctx(ctx); + return ciphertext_page; +} +EXPORT_SYMBOL(fscrypt_encrypt_page); + +/** + * f2crypt_decrypt_page() - Decrypts a page in-place + * @page: The page to decrypt. Must be locked. + * + * Decrypts page in-place using the ctx encryption context. + * + * Called from the read completion callback. + * + * Return: Zero on success, non-zero otherwise. + */ +int fscrypt_decrypt_page(struct page *page) +{ + BUG_ON(!PageLocked(page)); + + return do_page_crypto(page->mapping->host, + FS_DECRYPT, page->index, page, page); +} +EXPORT_SYMBOL(fscrypt_decrypt_page); + +int fscrypt_zeroout_range(struct inode *inode, pgoff_t lblk, + sector_t pblk, unsigned int len) +{ + struct fscrypt_ctx *ctx; + struct page *ciphertext_page = NULL; + struct bio *bio; + int ret, err = 0; + + BUG_ON(inode->i_sb->s_blocksize != PAGE_CACHE_SIZE); + + ctx = fscrypt_get_ctx(inode); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); + + ciphertext_page = alloc_bounce_page(ctx); + if (IS_ERR(ciphertext_page)) { + err = PTR_ERR(ciphertext_page); + goto errout; + } + + while (len--) { + err = do_page_crypto(inode, FS_ENCRYPT, lblk, + ZERO_PAGE(0), ciphertext_page); + if (err) + goto errout; + + bio = bio_alloc(GFP_KERNEL, 1); + if (!bio) { + err = -ENOMEM; + goto errout; + } + bio->bi_bdev = inode->i_sb->s_bdev; + bio->bi_iter.bi_sector = + pblk << (inode->i_sb->s_blocksize_bits - 9); + ret = bio_add_page(bio, ciphertext_page, + inode->i_sb->s_blocksize, 0); + if (ret != inode->i_sb->s_blocksize) { + /* should never happen! */ + WARN_ON(1); + bio_put(bio); + err = -EIO; + goto errout; + } + err = submit_bio_wait(WRITE, bio); + if ((err == 0) && bio->bi_error) + err = -EIO; + bio_put(bio); + if (err) + goto errout; + lblk++; + pblk++; + } + err = 0; +errout: + fscrypt_release_ctx(ctx); + return err; +} +EXPORT_SYMBOL(fscrypt_zeroout_range); + +/* + * Validate dentries for encrypted directories to make sure we aren't + * potentially caching stale data after a key has been added or + * removed. + */ +static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags) +{ + struct inode *dir = d_inode(dentry->d_parent); + struct fscrypt_info *ci = dir->i_crypt_info; + int dir_has_key, cached_with_key; + + if (!dir->i_sb->s_cop->is_encrypted(dir)) + return 0; + + if (ci && ci->ci_keyring_key && + (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED) | + (1 << KEY_FLAG_DEAD)))) + ci = NULL; + + /* this should eventually be an flag in d_flags */ + spin_lock(&dentry->d_lock); + cached_with_key = dentry->d_flags & DCACHE_ENCRYPTED_WITH_KEY; + spin_unlock(&dentry->d_lock); + dir_has_key = (ci != NULL); + + /* + * If the dentry was cached without the key, and it is a + * negative dentry, it might be a valid name. We can't check + * if the key has since been made available due to locking + * reasons, so we fail the validation so ext4_lookup() can do + * this check. + * + * We also fail the validation if the dentry was created with + * the key present, but we no longer have the key, or vice versa. + */ + if ((!cached_with_key && d_is_negative(dentry)) || + (!cached_with_key && dir_has_key) || + (cached_with_key && !dir_has_key)) + return 0; + return 1; +} + +const struct dentry_operations fscrypt_d_ops = { + .d_revalidate = fscrypt_d_revalidate, +}; +EXPORT_SYMBOL(fscrypt_d_ops); + +/* + * Call fscrypt_decrypt_page on every single page, reusing the encryption + * context. + */ +static void completion_pages(struct work_struct *work) +{ + struct fscrypt_ctx *ctx = + container_of(work, struct fscrypt_ctx, r.work); + struct bio *bio = ctx->r.bio; + struct bio_vec *bv; + int i; + + bio_for_each_segment_all(bv, bio, i) { + struct page *page = bv->bv_page; + int ret = fscrypt_decrypt_page(page); + + if (ret) { + WARN_ON_ONCE(1); + SetPageError(page); + } else { + SetPageUptodate(page); + } + unlock_page(page); + } + fscrypt_release_ctx(ctx); + bio_put(bio); +} + +void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *ctx, struct bio *bio) +{ + INIT_WORK(&ctx->r.work, completion_pages); + ctx->r.bio = bio; + queue_work(fscrypt_read_workqueue, &ctx->r.work); +} +EXPORT_SYMBOL(fscrypt_decrypt_bio_pages); + +void fscrypt_pullback_bio_page(struct page **page, bool restore) +{ + struct fscrypt_ctx *ctx; + struct page *bounce_page; + + /* The bounce data pages are unmapped. */ + if ((*page)->mapping) + return; + + /* The bounce data page is unmapped. */ + bounce_page = *page; + ctx = (struct fscrypt_ctx *)page_private(bounce_page); + + /* restore control page */ + *page = ctx->w.control_page; + + if (restore) + fscrypt_restore_control_page(bounce_page); +} +EXPORT_SYMBOL(fscrypt_pullback_bio_page); + +void fscrypt_restore_control_page(struct page *page) +{ + struct fscrypt_ctx *ctx; + + ctx = (struct fscrypt_ctx *)page_private(page); + set_page_private(page, (unsigned long)NULL); + ClearPagePrivate(page); + unlock_page(page); + fscrypt_release_ctx(ctx); +} +EXPORT_SYMBOL(fscrypt_restore_control_page); + +static void fscrypt_destroy(void) +{ + struct fscrypt_ctx *pos, *n; + + list_for_each_entry_safe(pos, n, &fscrypt_free_ctxs, free_list) + kmem_cache_free(fscrypt_ctx_cachep, pos); + INIT_LIST_HEAD(&fscrypt_free_ctxs); + mempool_destroy(fscrypt_bounce_page_pool); + fscrypt_bounce_page_pool = NULL; +} + +/** + * fscrypt_initialize() - allocate major buffers for fs encryption. + * + * We only call this when we start accessing encrypted files, since it + * results in memory getting allocated that wouldn't otherwise be used. + * + * Return: Zero on success, non-zero otherwise. + */ +int fscrypt_initialize(void) +{ + int i, res = -ENOMEM; + + if (fscrypt_bounce_page_pool) + return 0; + + mutex_lock(&fscrypt_init_mutex); + if (fscrypt_bounce_page_pool) + goto already_initialized; + + for (i = 0; i < num_prealloc_crypto_ctxs; i++) { + struct fscrypt_ctx *ctx; + + ctx = kmem_cache_zalloc(fscrypt_ctx_cachep, GFP_NOFS); + if (!ctx) + goto fail; + list_add(&ctx->free_list, &fscrypt_free_ctxs); + } + + fscrypt_bounce_page_pool = + mempool_create_page_pool(num_prealloc_crypto_pages, 0); + if (!fscrypt_bounce_page_pool) + goto fail; + +already_initialized: + mutex_unlock(&fscrypt_init_mutex); + return 0; +fail: + fscrypt_destroy(); + mutex_unlock(&fscrypt_init_mutex); + return res; +} +EXPORT_SYMBOL(fscrypt_initialize); + +/** + * fscrypt_init() - Set up for fs encryption. + */ +static int __init fscrypt_init(void) +{ + fscrypt_read_workqueue = alloc_workqueue("fscrypt_read_queue", + WQ_HIGHPRI, 0); + if (!fscrypt_read_workqueue) + goto fail; + + fscrypt_ctx_cachep = KMEM_CACHE(fscrypt_ctx, SLAB_RECLAIM_ACCOUNT); + if (!fscrypt_ctx_cachep) + goto fail_free_queue; + + fscrypt_info_cachep = KMEM_CACHE(fscrypt_info, SLAB_RECLAIM_ACCOUNT); + if (!fscrypt_info_cachep) + goto fail_free_ctx; + + return 0; + +fail_free_ctx: + kmem_cache_destroy(fscrypt_ctx_cachep); +fail_free_queue: + destroy_workqueue(fscrypt_read_workqueue); +fail: + return -ENOMEM; +} +module_init(fscrypt_init) + +/** + * fscrypt_exit() - Shutdown the fs encryption system + */ +static void __exit fscrypt_exit(void) +{ + fscrypt_destroy(); + + if (fscrypt_read_workqueue) + destroy_workqueue(fscrypt_read_workqueue); + kmem_cache_destroy(fscrypt_ctx_cachep); + kmem_cache_destroy(fscrypt_info_cachep); +} +module_exit(fscrypt_exit); + +MODULE_LICENSE("GPL"); diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c new file mode 100644 index 0000000..5e4ddee --- /dev/null +++ b/fs/crypto/fname.c @@ -0,0 +1,427 @@ +/* + * This contains functions for filename crypto management + * + * Copyright (C) 2015, Google, Inc. + * Copyright (C) 2015, Motorola Mobility + * + * Written by Uday Savagaonkar, 2014. + * Modified by Jaegeuk Kim, 2015. + * + * This has not yet undergone a rigorous security audit. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +static u32 size_round_up(size_t size, size_t blksize) +{ + return ((size + blksize - 1) / blksize) * blksize; +} + +/** + * dir_crypt_complete() - + */ +static void dir_crypt_complete(struct crypto_async_request *req, int res) +{ + struct fscrypt_completion_result *ecr = req->data; + + if (res == -EINPROGRESS) + return; + ecr->res = res; + complete(&ecr->completion); +} + +/** + * fname_encrypt() - + * + * This function encrypts the input filename, and returns the length of the + * ciphertext. Errors are returned as negative numbers. We trust the caller to + * allocate sufficient memory to oname string. + */ +static int fname_encrypt(struct inode *inode, + const struct qstr *iname, struct fscrypt_str *oname) +{ + u32 ciphertext_len; + struct ablkcipher_request *req = NULL; + DECLARE_FS_COMPLETION_RESULT(ecr); + struct fscrypt_info *ci = inode->i_crypt_info; + struct crypto_ablkcipher *tfm = ci->ci_ctfm; + int res = 0; + char iv[FS_CRYPTO_BLOCK_SIZE]; + struct scatterlist src_sg, dst_sg; + int padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK); + char *workbuf, buf[32], *alloc_buf = NULL; + unsigned lim; + + lim = inode->i_sb->s_cop->max_namelen(inode); + if (iname->len <= 0 || iname->len > lim) + return -EIO; + + ciphertext_len = (iname->len < FS_CRYPTO_BLOCK_SIZE) ? + FS_CRYPTO_BLOCK_SIZE : iname->len; + ciphertext_len = size_round_up(ciphertext_len, padding); + ciphertext_len = (ciphertext_len > lim) ? lim : ciphertext_len; + + if (ciphertext_len <= sizeof(buf)) { + workbuf = buf; + } else { + alloc_buf = kmalloc(ciphertext_len, GFP_NOFS); + if (!alloc_buf) + return -ENOMEM; + workbuf = alloc_buf; + } + + /* Allocate request */ + req = ablkcipher_request_alloc(tfm, GFP_NOFS); + if (!req) { + printk_ratelimited(KERN_ERR + "%s: crypto_request_alloc() failed\n", __func__); + kfree(alloc_buf); + return -ENOMEM; + } + ablkcipher_request_set_callback(req, + CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, + dir_crypt_complete, &ecr); + + /* Copy the input */ + memcpy(workbuf, iname->name, iname->len); + if (iname->len < ciphertext_len) + memset(workbuf + iname->len, 0, ciphertext_len - iname->len); + + /* Initialize IV */ + memset(iv, 0, FS_CRYPTO_BLOCK_SIZE); + + /* Create encryption request */ + sg_init_one(&src_sg, workbuf, ciphertext_len); + sg_init_one(&dst_sg, oname->name, ciphertext_len); + ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv); + res = crypto_ablkcipher_encrypt(req); + if (res == -EINPROGRESS || res == -EBUSY) { + wait_for_completion(&ecr.completion); + res = ecr.res; + } + kfree(alloc_buf); + ablkcipher_request_free(req); + if (res < 0) + printk_ratelimited(KERN_ERR + "%s: Error (error code %d)\n", __func__, res); + + oname->len = ciphertext_len; + return res; +} + +/* + * fname_decrypt() + * This function decrypts the input filename, and returns + * the length of the plaintext. + * Errors are returned as negative numbers. + * We trust the caller to allocate sufficient memory to oname string. + */ +static int fname_decrypt(struct inode *inode, + const struct fscrypt_str *iname, + struct fscrypt_str *oname) +{ + struct ablkcipher_request *req = NULL; + DECLARE_FS_COMPLETION_RESULT(ecr); + struct scatterlist src_sg, dst_sg; + struct fscrypt_info *ci = inode->i_crypt_info; + struct crypto_ablkcipher *tfm = ci->ci_ctfm; + int res = 0; + char iv[FS_CRYPTO_BLOCK_SIZE]; + unsigned lim; + + lim = inode->i_sb->s_cop->max_namelen(inode); + if (iname->len <= 0 || iname->len > lim) + return -EIO; + + /* Allocate request */ + req = ablkcipher_request_alloc(tfm, GFP_NOFS); + if (!req) { + printk_ratelimited(KERN_ERR + "%s: crypto_request_alloc() failed\n", __func__); + return -ENOMEM; + } + ablkcipher_request_set_callback(req, + CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, + dir_crypt_complete, &ecr); + + /* Initialize IV */ + memset(iv, 0, FS_CRYPTO_BLOCK_SIZE); + + /* Create decryption request */ + sg_init_one(&src_sg, iname->name, iname->len); + sg_init_one(&dst_sg, oname->name, oname->len); + ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv); + res = crypto_ablkcipher_decrypt(req); + if (res == -EINPROGRESS || res == -EBUSY) { + wait_for_completion(&ecr.completion); + res = ecr.res; + } + ablkcipher_request_free(req); + if (res < 0) { + printk_ratelimited(KERN_ERR + "%s: Error (error code %d)\n", __func__, res); + return res; + } + + oname->len = strnlen(oname->name, iname->len); + return oname->len; +} + +static const char *lookup_table = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,"; + +/** + * digest_encode() - + * + * Encodes the input digest using characters from the set [a-zA-Z0-9_+]. + * The encoded string is roughly 4/3 times the size of the input string. + */ +static int digest_encode(const char *src, int len, char *dst) +{ + int i = 0, bits = 0, ac = 0; + char *cp = dst; + + while (i < len) { + ac += (((unsigned char) src[i]) << bits); + bits += 8; + do { + *cp++ = lookup_table[ac & 0x3f]; + ac >>= 6; + bits -= 6; + } while (bits >= 6); + i++; + } + if (bits) + *cp++ = lookup_table[ac & 0x3f]; + return cp - dst; +} + +static int digest_decode(const char *src, int len, char *dst) +{ + int i = 0, bits = 0, ac = 0; + const char *p; + char *cp = dst; + + while (i < len) { + p = strchr(lookup_table, src[i]); + if (p == NULL || src[i] == 0) + return -2; + ac += (p - lookup_table) << bits; + bits += 6; + if (bits >= 8) { + *cp++ = ac & 0xff; + ac >>= 8; + bits -= 8; + } + i++; + } + if (ac) + return -1; + return cp - dst; +} + +u32 fscrypt_fname_encrypted_size(struct inode *inode, u32 ilen) +{ + int padding = 32; + struct fscrypt_info *ci = inode->i_crypt_info; + + if (ci) + padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK); + if (ilen < FS_CRYPTO_BLOCK_SIZE) + ilen = FS_CRYPTO_BLOCK_SIZE; + return size_round_up(ilen, padding); +} +EXPORT_SYMBOL(fscrypt_fname_encrypted_size); + +/** + * fscrypt_fname_crypto_alloc_obuff() - + * + * Allocates an output buffer that is sufficient for the crypto operation + * specified by the context and the direction. + */ +int fscrypt_fname_alloc_buffer(struct inode *inode, + u32 ilen, struct fscrypt_str *crypto_str) +{ + unsigned int olen = fscrypt_fname_encrypted_size(inode, ilen); + + crypto_str->len = olen; + if (olen < FS_FNAME_CRYPTO_DIGEST_SIZE * 2) + olen = FS_FNAME_CRYPTO_DIGEST_SIZE * 2; + /* + * Allocated buffer can hold one more character to null-terminate the + * string + */ + crypto_str->name = kmalloc(olen + 1, GFP_NOFS); + if (!(crypto_str->name)) + return -ENOMEM; + return 0; +} +EXPORT_SYMBOL(fscrypt_fname_alloc_buffer); + +/** + * fscrypt_fname_crypto_free_buffer() - + * + * Frees the buffer allocated for crypto operation. + */ +void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str) +{ + if (!crypto_str) + return; + kfree(crypto_str->name); + crypto_str->name = NULL; +} +EXPORT_SYMBOL(fscrypt_fname_free_buffer); + +/** + * fscrypt_fname_disk_to_usr() - converts a filename from disk space to user + * space + */ +int fscrypt_fname_disk_to_usr(struct inode *inode, + u32 hash, u32 minor_hash, + const struct fscrypt_str *iname, + struct fscrypt_str *oname) +{ + const struct qstr qname = FSTR_TO_QSTR(iname); + char buf[24]; + int ret; + + if (fscrypt_is_dot_dotdot(&qname)) { + oname->name[0] = '.'; + oname->name[iname->len - 1] = '.'; + oname->len = iname->len; + return oname->len; + } + + if (iname->len < FS_CRYPTO_BLOCK_SIZE) + return -EUCLEAN; + + if (inode->i_crypt_info) + return fname_decrypt(inode, iname, oname); + + if (iname->len <= FS_FNAME_CRYPTO_DIGEST_SIZE) { + ret = digest_encode(iname->name, iname->len, oname->name); + oname->len = ret; + return ret; + } + if (hash) { + memcpy(buf, &hash, 4); + memcpy(buf + 4, &minor_hash, 4); + } else { + memset(buf, 0, 8); + } + memcpy(buf + 8, iname->name + iname->len - 16, 16); + oname->name[0] = '_'; + ret = digest_encode(buf, 24, oname->name + 1); + oname->len = ret + 1; + return ret + 1; +} +EXPORT_SYMBOL(fscrypt_fname_disk_to_usr); + +/** + * fscrypt_fname_usr_to_disk() - converts a filename from user space to disk + * space + */ +int fscrypt_fname_usr_to_disk(struct inode *inode, + const struct qstr *iname, + struct fscrypt_str *oname) +{ + if (fscrypt_is_dot_dotdot(iname)) { + oname->name[0] = '.'; + oname->name[iname->len - 1] = '.'; + oname->len = iname->len; + return oname->len; + } + if (inode->i_crypt_info) + return fname_encrypt(inode, iname, oname); + /* + * Without a proper key, a user is not allowed to modify the filenames + * in a directory. Consequently, a user space name cannot be mapped to + * a disk-space name + */ + return -EACCES; +} +EXPORT_SYMBOL(fscrypt_fname_usr_to_disk); + +int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, + int lookup, struct fscrypt_name *fname) +{ + int ret = 0, bigname = 0; + + memset(fname, 0, sizeof(struct fscrypt_name)); + fname->usr_fname = iname; + + if (!dir->i_sb->s_cop->is_encrypted(dir) || + fscrypt_is_dot_dotdot(iname)) { + fname->disk_name.name = (unsigned char *)iname->name; + fname->disk_name.len = iname->len; + return 0; + } + ret = get_crypt_info(dir); + if (ret && ret != -EOPNOTSUPP) + return ret; + + if (dir->i_crypt_info) { + ret = fscrypt_fname_alloc_buffer(dir, iname->len, + &fname->crypto_buf); + if (ret < 0) + return ret; + ret = fname_encrypt(dir, iname, &fname->crypto_buf); + if (ret < 0) + goto errout; + fname->disk_name.name = fname->crypto_buf.name; + fname->disk_name.len = fname->crypto_buf.len; + return 0; + } + if (!lookup) + return -EACCES; + + /* + * We don't have the key and we are doing a lookup; decode the + * user-supplied name + */ + if (iname->name[0] == '_') + bigname = 1; + if ((bigname && (iname->len != 33)) || (!bigname && (iname->len > 43))) + return -ENOENT; + + fname->crypto_buf.name = kmalloc(32, GFP_KERNEL); + if (fname->crypto_buf.name == NULL) + return -ENOMEM; + + ret = digest_decode(iname->name + bigname, iname->len - bigname, + fname->crypto_buf.name); + if (ret < 0) { + ret = -ENOENT; + goto errout; + } + fname->crypto_buf.len = ret; + if (bigname) { + memcpy(&fname->hash, fname->crypto_buf.name, 4); + memcpy(&fname->minor_hash, fname->crypto_buf.name + 4, 4); + } else { + fname->disk_name.name = fname->crypto_buf.name; + fname->disk_name.len = fname->crypto_buf.len; + } + return 0; + +errout: + fscrypt_fname_free_buffer(&fname->crypto_buf); + return ret; +} +EXPORT_SYMBOL(fscrypt_setup_filename); + +void fscrypt_free_filename(struct fscrypt_name *fname) +{ + kfree(fname->crypto_buf.name); + fname->crypto_buf.name = NULL; + fname->usr_fname = NULL; + fname->disk_name.name = NULL; +} +EXPORT_SYMBOL(fscrypt_free_filename); diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c new file mode 100644 index 0000000..cb61842 --- /dev/null +++ b/fs/crypto/keyinfo.c @@ -0,0 +1,278 @@ +/* + * key management facility for FS encryption support. + * + * Copyright (C) 2015, Google, Inc. + * + * This contains encryption key functions. + * + * Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015. + */ + +#include +#include +#include +#include +#include +#include +#include + +static void derive_crypt_complete(struct crypto_async_request *req, int rc) +{ + struct fscrypt_completion_result *ecr = req->data; + + if (rc == -EINPROGRESS) + return; + + ecr->res = rc; + complete(&ecr->completion); +} + +/** + * 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 derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE], + u8 source_key[FS_AES_256_XTS_KEY_SIZE], + u8 derived_key[FS_AES_256_XTS_KEY_SIZE]) +{ + int res = 0; + struct ablkcipher_request *req = NULL; + DECLARE_FS_COMPLETION_RESULT(ecr); + struct scatterlist src_sg, dst_sg; + struct crypto_ablkcipher *tfm = crypto_alloc_ablkcipher("ecb(aes)", 0, + 0); + + if (IS_ERR(tfm)) { + res = PTR_ERR(tfm); + tfm = NULL; + goto out; + } + crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_REQ_WEAK_KEY); + req = ablkcipher_request_alloc(tfm, GFP_NOFS); + if (!req) { + res = -ENOMEM; + goto out; + } + ablkcipher_request_set_callback(req, + CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, + derive_crypt_complete, &ecr); + res = crypto_ablkcipher_setkey(tfm, deriving_key, + FS_AES_128_ECB_KEY_SIZE); + if (res < 0) + goto out; + + sg_init_one(&src_sg, source_key, FS_AES_256_XTS_KEY_SIZE); + sg_init_one(&dst_sg, derived_key, FS_AES_256_XTS_KEY_SIZE); + ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, + FS_AES_256_XTS_KEY_SIZE, NULL); + res = crypto_ablkcipher_encrypt(req); + if (res == -EINPROGRESS || res == -EBUSY) { + wait_for_completion(&ecr.completion); + res = ecr.res; + } +out: + if (req) + ablkcipher_request_free(req); + if (tfm) + crypto_free_ablkcipher(tfm); + return res; +} + +static void put_crypt_info(struct fscrypt_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(fscrypt_info_cachep, ci); +} + +int get_crypt_info(struct inode *inode) +{ + struct fscrypt_info *crypt_info; + u8 full_key_descriptor[FS_KEY_DESC_PREFIX_SIZE + + (FS_KEY_DESCRIPTOR_SIZE * 2) + 1]; + struct key *keyring_key = NULL; + struct fscrypt_key *master_key; + struct fscrypt_context ctx; + const struct user_key_payload *ukp; + struct crypto_ablkcipher *ctfm; + const char *cipher_str; + u8 raw_key[FS_MAX_KEY_SIZE]; + u8 mode; + int res; + + res = fscrypt_initialize(); + if (res) + return res; + + if (!inode->i_sb->s_cop->get_context) + return -EOPNOTSUPP; +retry: + crypt_info = ACCESS_ONCE(inode->i_crypt_info); + if (crypt_info) { + if (!crypt_info->ci_keyring_key || + key_validate(crypt_info->ci_keyring_key) == 0) + return 0; + fscrypt_put_encryption_info(inode, crypt_info); + goto retry; + } + + res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx)); + if (res < 0) { + if (!fscrypt_dummy_context_enabled(inode)) + return res; + ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS; + ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS; + ctx.flags = 0; + } else if (res != sizeof(ctx)) { + return -EINVAL; + } + res = 0; + + crypt_info = kmem_cache_alloc(fscrypt_info_cachep, GFP_NOFS); + 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 FS_ENCRYPTION_MODE_AES_256_XTS: + cipher_str = "xts(aes)"; + break; + case FS_ENCRYPTION_MODE_AES_256_CTS: + cipher_str = "cts(cbc(aes))"; + break; + default: + printk_once(KERN_WARNING + "%s: unsupported key mode %d (ino %u)\n", + __func__, mode, (unsigned) inode->i_ino); + res = -ENOKEY; + goto out; + } + if (fscrypt_dummy_context_enabled(inode)) { + memset(raw_key, 0x42, FS_AES_256_XTS_KEY_SIZE); + goto got_key; + } + memcpy(full_key_descriptor, FS_KEY_DESC_PREFIX, + FS_KEY_DESC_PREFIX_SIZE); + sprintf(full_key_descriptor + FS_KEY_DESC_PREFIX_SIZE, + "%*phN", FS_KEY_DESCRIPTOR_SIZE, + ctx.master_key_descriptor); + full_key_descriptor[FS_KEY_DESC_PREFIX_SIZE + + (2 * FS_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 + "%s: key type must be logon\n", __func__); + res = -ENOKEY; + goto out; + } + down_read(&keyring_key->sem); + ukp = user_key_payload(keyring_key); + if (ukp->datalen != sizeof(struct fscrypt_key)) { + res = -EINVAL; + up_read(&keyring_key->sem); + goto out; + } + master_key = (struct fscrypt_key *)ukp->data; + BUILD_BUG_ON(FS_AES_128_ECB_KEY_SIZE != FS_KEY_DERIVATION_NONCE_SIZE); + + if (master_key->size != FS_AES_256_XTS_KEY_SIZE) { + printk_once(KERN_WARNING + "%s: key size incorrect: %d\n", + __func__, master_key->size); + res = -ENOKEY; + up_read(&keyring_key->sem); + goto out; + } + res = 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, fscrypt_key_size(mode)); + if (res) + goto out; + + memzero_explicit(raw_key, sizeof(raw_key)); + if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) != NULL) { + put_crypt_info(crypt_info); + goto retry; + } + return 0; + +out: + if (res == -ENOKEY) + res = 0; + put_crypt_info(crypt_info); + memzero_explicit(raw_key, sizeof(raw_key)); + return res; +} + +void fscrypt_put_encryption_info(struct inode *inode, struct fscrypt_info *ci) +{ + struct fscrypt_info *prev; + + if (ci == NULL) + ci = ACCESS_ONCE(inode->i_crypt_info); + if (ci == NULL) + return; + + prev = cmpxchg(&inode->i_crypt_info, ci, NULL); + if (prev != ci) + return; + + put_crypt_info(ci); +} +EXPORT_SYMBOL(fscrypt_put_encryption_info); + +int fscrypt_get_encryption_info(struct inode *inode) +{ + struct fscrypt_info *ci = inode->i_crypt_info; + + if (!ci || + (ci->ci_keyring_key && + (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED) | + (1 << KEY_FLAG_DEAD))))) + return get_crypt_info(inode); + return 0; +} +EXPORT_SYMBOL(fscrypt_get_encryption_info); diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c new file mode 100644 index 0000000..0f9961e --- /dev/null +++ b/fs/crypto/policy.c @@ -0,0 +1,229 @@ +/* + * Encryption policy functions for per-file encryption support. + * + * Copyright (C) 2015, Google, Inc. + * Copyright (C) 2015, Motorola Mobility. + * + * Written by Michael Halcrow, 2015. + * Modified by Jaegeuk Kim, 2015. + */ + +#include +#include +#include + +static int inode_has_encryption_context(struct inode *inode) +{ + if (!inode->i_sb->s_cop->get_context) + return 0; + return (inode->i_sb->s_cop->get_context(inode, NULL, 0L) > 0); +} + +/* + * check whether the policy is consistent with the encryption context + * for the inode + */ +static int is_encryption_context_consistent_with_policy(struct inode *inode, + const struct fscrypt_policy *policy) +{ + struct fscrypt_context ctx; + int res; + + if (!inode->i_sb->s_cop->get_context) + return 0; + + res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx)); + if (res != sizeof(ctx)) + return 0; + + return (memcmp(ctx.master_key_descriptor, policy->master_key_descriptor, + FS_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 create_encryption_context_from_policy(struct inode *inode, + const struct fscrypt_policy *policy) +{ + struct fscrypt_context ctx; + int res; + + if (!inode->i_sb->s_cop->set_context) + return -EOPNOTSUPP; + + if (inode->i_sb->s_cop->prepare_context) { + res = inode->i_sb->s_cop->prepare_context(inode); + if (res) + return res; + } + + ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1; + memcpy(ctx.master_key_descriptor, policy->master_key_descriptor, + FS_KEY_DESCRIPTOR_SIZE); + + if (!fscrypt_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 (!fscrypt_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 & ~FS_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) != FS_KEY_DERIVATION_NONCE_SIZE); + get_random_bytes(ctx.nonce, FS_KEY_DERIVATION_NONCE_SIZE); + + return inode->i_sb->s_cop->set_context(inode, &ctx, sizeof(ctx), NULL); +} + +int fscrypt_process_policy(struct inode *inode, + const struct fscrypt_policy *policy) +{ + if (policy->version != 0) + return -EINVAL; + + if (!inode_has_encryption_context(inode)) { + if (!inode->i_sb->s_cop->empty_dir) + return -EOPNOTSUPP; + if (!inode->i_sb->s_cop->empty_dir(inode)) + return -ENOTEMPTY; + return create_encryption_context_from_policy(inode, policy); + } + + if (is_encryption_context_consistent_with_policy(inode, policy)) + return 0; + + printk(KERN_WARNING "%s: Policy inconsistent with encryption context\n", + __func__); + return -EINVAL; +} +EXPORT_SYMBOL(fscrypt_process_policy); + +int fscrypt_get_policy(struct inode *inode, struct fscrypt_policy *policy) +{ + struct fscrypt_context ctx; + int res; + + if (!inode->i_sb->s_cop->get_context || + !inode->i_sb->s_cop->is_encrypted(inode)) + return -ENODATA; + + res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx)); + if (res != sizeof(ctx)) + return -ENODATA; + if (ctx.format != FS_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, + FS_KEY_DESCRIPTOR_SIZE); + return 0; +} +EXPORT_SYMBOL(fscrypt_get_policy); + +int fscrypt_has_permitted_context(struct inode *parent, struct inode *child) +{ + struct fscrypt_info *parent_ci, *child_ci; + int res; + + if ((parent == NULL) || (child == NULL)) { + printk(KERN_ERR "parent %p child %p\n", parent, child); + BUG_ON(1); + } + + /* no restrictions if the parent directory is not encrypted */ + if (!parent->i_sb->s_cop->is_encrypted(parent)) + return 1; + /* if the child directory is not encrypted, this is always a problem */ + if (!parent->i_sb->s_cop->is_encrypted(child)) + return 0; + res = fscrypt_get_encryption_info(parent); + if (res) + return 0; + res = fscrypt_get_encryption_info(child); + if (res) + return 0; + parent_ci = parent->i_crypt_info; + child_ci = 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, + FS_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)); +} +EXPORT_SYMBOL(fscrypt_has_permitted_context); + +/** + * fscrypt_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. + * @fs_data: private data given by FS. + * @preload: preload child i_crypt_info + * + * Return: Zero on success, non-zero otherwise + */ +int fscrypt_inherit_context(struct inode *parent, struct inode *child, + void *fs_data, bool preload) +{ + struct fscrypt_context ctx; + struct fscrypt_info *ci; + int res; + + if (!parent->i_sb->s_cop->set_context) + return -EOPNOTSUPP; + + res = fscrypt_get_encryption_info(parent); + if (res < 0) + return res; + + ci = parent->i_crypt_info; + if (ci == NULL) + return -ENOKEY; + + ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1; + if (fscrypt_dummy_context_enabled(parent)) { + ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS; + ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS; + ctx.flags = 0; + memset(ctx.master_key_descriptor, 0x42, FS_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, + FS_KEY_DESCRIPTOR_SIZE); + } + get_random_bytes(ctx.nonce, FS_KEY_DERIVATION_NONCE_SIZE); + res = parent->i_sb->s_cop->set_context(child, &ctx, + sizeof(ctx), fs_data); + if (res) + return res; + return preload ? fscrypt_get_encryption_info(child): 0; +} +EXPORT_SYMBOL(fscrypt_inherit_context); diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig index b0a9dc9..402792b 100644 --- a/fs/f2fs/Kconfig +++ b/fs/f2fs/Kconfig @@ -76,15 +76,7 @@ config F2FS_FS_ENCRYPTION bool "F2FS Encryption" depends on F2FS_FS depends on F2FS_FS_XATTR - select CRYPTO_AES - select CRYPTO_CBC - select CRYPTO_ECB - select CRYPTO_XTS - select CRYPTO_CTS - select CRYPTO_CTR - select CRYPTO_SHA256 - select KEYS - select ENCRYPTED_KEYS + select FS_ENCRYPTION help Enable encryption of f2fs files and directories. This feature is similar to ecryptfs, but it is more memory diff --git a/fs/f2fs/Makefile b/fs/f2fs/Makefile index 08e101e..ca949ea 100644 --- a/fs/f2fs/Makefile +++ b/fs/f2fs/Makefile @@ -7,5 +7,3 @@ f2fs-$(CONFIG_F2FS_STAT_FS) += debug.o f2fs-$(CONFIG_F2FS_FS_XATTR) += xattr.o f2fs-$(CONFIG_F2FS_FS_POSIX_ACL) += acl.o f2fs-$(CONFIG_F2FS_IO_TRACE) += trace.o -f2fs-$(CONFIG_F2FS_FS_ENCRYPTION) += crypto_policy.o crypto.o \ - crypto_key.o crypto_fname.o diff --git a/fs/f2fs/crypto.c b/fs/f2fs/crypto.c deleted file mode 100644 index 3ef3786..0000000 --- a/fs/f2fs/crypto.c +++ /dev/null @@ -1,473 +0,0 @@ -/* - * linux/fs/f2fs/crypto.c - * - * Copied from linux/fs/ext4/crypto.c - * - * Copyright (C) 2015, Google, Inc. - * Copyright (C) 2015, Motorola Mobility - * - * This contains encryption functions for f2fs - * - * Written by Michael Halcrow, 2014. - * - * Filename encryption additions - * Uday Savagaonkar, 2014 - * Encryption policy handling additions - * Ildar Muslukhov, 2014 - * Remove ext4_encrypted_zeroout(), - * add f2fs_restore_and_release_control_page() - * Jaegeuk Kim, 2015. - * - * This has not yet undergone a rigorous security audit. - * - * The usage of AES-XTS should conform to recommendations in NIST - * Special Publication 800-38E and IEEE P1619/D16. - */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "f2fs.h" -#include "xattr.h" - -/* Encryption added and removed here! (L: */ - -static unsigned int num_prealloc_crypto_pages = 32; -static unsigned int num_prealloc_crypto_ctxs = 128; - -module_param(num_prealloc_crypto_pages, uint, 0444); -MODULE_PARM_DESC(num_prealloc_crypto_pages, - "Number of crypto pages to preallocate"); -module_param(num_prealloc_crypto_ctxs, uint, 0444); -MODULE_PARM_DESC(num_prealloc_crypto_ctxs, - "Number of crypto contexts to preallocate"); - -static mempool_t *f2fs_bounce_page_pool; - -static LIST_HEAD(f2fs_free_crypto_ctxs); -static DEFINE_SPINLOCK(f2fs_crypto_ctx_lock); - -static struct workqueue_struct *f2fs_read_workqueue; -static DEFINE_MUTEX(crypto_init); - -static struct kmem_cache *f2fs_crypto_ctx_cachep; -struct kmem_cache *f2fs_crypt_info_cachep; - -/** - * f2fs_release_crypto_ctx() - Releases an encryption context - * @ctx: The encryption context to release. - * - * If the encryption context was allocated from the pre-allocated pool, returns - * it to that pool. Else, frees it. - * - * If there's a bounce page in the context, this frees that. - */ -void f2fs_release_crypto_ctx(struct f2fs_crypto_ctx *ctx) -{ - unsigned long flags; - - if (ctx->flags & F2FS_WRITE_PATH_FL && ctx->w.bounce_page) { - mempool_free(ctx->w.bounce_page, f2fs_bounce_page_pool); - ctx->w.bounce_page = NULL; - } - ctx->w.control_page = NULL; - if (ctx->flags & F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL) { - kmem_cache_free(f2fs_crypto_ctx_cachep, ctx); - } else { - spin_lock_irqsave(&f2fs_crypto_ctx_lock, flags); - list_add(&ctx->free_list, &f2fs_free_crypto_ctxs); - spin_unlock_irqrestore(&f2fs_crypto_ctx_lock, flags); - } -} - -/** - * f2fs_get_crypto_ctx() - Gets an encryption context - * @inode: The inode for which we are doing the crypto - * - * Allocates and initializes an encryption context. - * - * Return: An allocated and initialized encryption context on success; error - * value or NULL otherwise. - */ -struct f2fs_crypto_ctx *f2fs_get_crypto_ctx(struct inode *inode) -{ - struct f2fs_crypto_ctx *ctx = NULL; - unsigned long flags; - struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info; - - if (ci == NULL) - return ERR_PTR(-ENOKEY); - - /* - * We first try getting the ctx from a free list because in - * the common case the ctx will have an allocated and - * initialized crypto tfm, so it's probably a worthwhile - * optimization. For the bounce page, we first try getting it - * from the kernel allocator because that's just about as fast - * as getting it from a list and because a cache of free pages - * should generally be a "last resort" option for a filesystem - * to be able to do its job. - */ - spin_lock_irqsave(&f2fs_crypto_ctx_lock, flags); - ctx = list_first_entry_or_null(&f2fs_free_crypto_ctxs, - struct f2fs_crypto_ctx, free_list); - if (ctx) - list_del(&ctx->free_list); - spin_unlock_irqrestore(&f2fs_crypto_ctx_lock, flags); - if (!ctx) { - ctx = kmem_cache_zalloc(f2fs_crypto_ctx_cachep, GFP_NOFS); - if (!ctx) - return ERR_PTR(-ENOMEM); - ctx->flags |= F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL; - } else { - ctx->flags &= ~F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL; - } - ctx->flags &= ~F2FS_WRITE_PATH_FL; - return ctx; -} - -/* - * Call f2fs_decrypt on every single page, reusing the encryption - * context. - */ -static void completion_pages(struct work_struct *work) -{ - struct f2fs_crypto_ctx *ctx = - container_of(work, struct f2fs_crypto_ctx, r.work); - struct bio *bio = ctx->r.bio; - struct bio_vec *bv; - int i; - - bio_for_each_segment_all(bv, bio, i) { - struct page *page = bv->bv_page; - int ret = f2fs_decrypt(page); - - if (ret) { - WARN_ON_ONCE(1); - SetPageError(page); - } else - SetPageUptodate(page); - unlock_page(page); - } - f2fs_release_crypto_ctx(ctx); - bio_put(bio); -} - -void f2fs_end_io_crypto_work(struct f2fs_crypto_ctx *ctx, struct bio *bio) -{ - INIT_WORK(&ctx->r.work, completion_pages); - ctx->r.bio = bio; - queue_work(f2fs_read_workqueue, &ctx->r.work); -} - -static void f2fs_crypto_destroy(void) -{ - struct f2fs_crypto_ctx *pos, *n; - - list_for_each_entry_safe(pos, n, &f2fs_free_crypto_ctxs, free_list) - kmem_cache_free(f2fs_crypto_ctx_cachep, pos); - INIT_LIST_HEAD(&f2fs_free_crypto_ctxs); - if (f2fs_bounce_page_pool) - mempool_destroy(f2fs_bounce_page_pool); - f2fs_bounce_page_pool = NULL; -} - -/** - * f2fs_crypto_initialize() - Set up for f2fs encryption. - * - * We only call this when we start accessing encrypted files, since it - * results in memory getting allocated that wouldn't otherwise be used. - * - * Return: Zero on success, non-zero otherwise. - */ -int f2fs_crypto_initialize(void) -{ - int i, res = -ENOMEM; - - if (f2fs_bounce_page_pool) - return 0; - - mutex_lock(&crypto_init); - if (f2fs_bounce_page_pool) - goto already_initialized; - - for (i = 0; i < num_prealloc_crypto_ctxs; i++) { - struct f2fs_crypto_ctx *ctx; - - ctx = kmem_cache_zalloc(f2fs_crypto_ctx_cachep, GFP_KERNEL); - if (!ctx) - goto fail; - list_add(&ctx->free_list, &f2fs_free_crypto_ctxs); - } - - /* must be allocated at the last step to avoid race condition above */ - f2fs_bounce_page_pool = - mempool_create_page_pool(num_prealloc_crypto_pages, 0); - if (!f2fs_bounce_page_pool) - goto fail; - -already_initialized: - mutex_unlock(&crypto_init); - return 0; -fail: - f2fs_crypto_destroy(); - mutex_unlock(&crypto_init); - return res; -} - -/** - * f2fs_exit_crypto() - Shutdown the f2fs encryption system - */ -void f2fs_exit_crypto(void) -{ - f2fs_crypto_destroy(); - - if (f2fs_read_workqueue) - destroy_workqueue(f2fs_read_workqueue); - if (f2fs_crypto_ctx_cachep) - kmem_cache_destroy(f2fs_crypto_ctx_cachep); - if (f2fs_crypt_info_cachep) - kmem_cache_destroy(f2fs_crypt_info_cachep); -} - -int __init f2fs_init_crypto(void) -{ - int res = -ENOMEM; - - f2fs_read_workqueue = alloc_workqueue("f2fs_crypto", WQ_HIGHPRI, 0); - if (!f2fs_read_workqueue) - goto fail; - - f2fs_crypto_ctx_cachep = KMEM_CACHE(f2fs_crypto_ctx, - SLAB_RECLAIM_ACCOUNT); - if (!f2fs_crypto_ctx_cachep) - goto fail; - - f2fs_crypt_info_cachep = KMEM_CACHE(f2fs_crypt_info, - SLAB_RECLAIM_ACCOUNT); - if (!f2fs_crypt_info_cachep) - goto fail; - - return 0; -fail: - f2fs_exit_crypto(); - return res; -} - -void f2fs_restore_and_release_control_page(struct page **page) -{ - struct f2fs_crypto_ctx *ctx; - struct page *bounce_page; - - /* The bounce data pages are unmapped. */ - if ((*page)->mapping) - return; - - /* The bounce data page is unmapped. */ - bounce_page = *page; - ctx = (struct f2fs_crypto_ctx *)page_private(bounce_page); - - /* restore control page */ - *page = ctx->w.control_page; - - f2fs_restore_control_page(bounce_page); -} - -void f2fs_restore_control_page(struct page *data_page) -{ - struct f2fs_crypto_ctx *ctx = - (struct f2fs_crypto_ctx *)page_private(data_page); - - set_page_private(data_page, (unsigned long)NULL); - ClearPagePrivate(data_page); - unlock_page(data_page); - f2fs_release_crypto_ctx(ctx); -} - -/** - * f2fs_crypt_complete() - The completion callback for page encryption - * @req: The asynchronous encryption request context - * @res: The result of the encryption operation - */ -static void f2fs_crypt_complete(struct crypto_async_request *req, int res) -{ - struct f2fs_completion_result *ecr = req->data; - - if (res == -EINPROGRESS) - return; - ecr->res = res; - complete(&ecr->completion); -} - -typedef enum { - F2FS_DECRYPT = 0, - F2FS_ENCRYPT, -} f2fs_direction_t; - -static int f2fs_page_crypto(struct inode *inode, - f2fs_direction_t rw, - pgoff_t index, - struct page *src_page, - struct page *dest_page) -{ - u8 xts_tweak[F2FS_XTS_TWEAK_SIZE]; - struct ablkcipher_request *req = NULL; - DECLARE_F2FS_COMPLETION_RESULT(ecr); - struct scatterlist dst, src; - struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info; - struct crypto_ablkcipher *tfm = ci->ci_ctfm; - int res = 0; - - req = ablkcipher_request_alloc(tfm, GFP_NOFS); - if (!req) { - printk_ratelimited(KERN_ERR - "%s: crypto_request_alloc() failed\n", - __func__); - return -ENOMEM; - } - ablkcipher_request_set_callback( - req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, - f2fs_crypt_complete, &ecr); - - BUILD_BUG_ON(F2FS_XTS_TWEAK_SIZE < sizeof(index)); - memcpy(xts_tweak, &index, sizeof(index)); - memset(&xts_tweak[sizeof(index)], 0, - F2FS_XTS_TWEAK_SIZE - sizeof(index)); - - sg_init_table(&dst, 1); - sg_set_page(&dst, dest_page, PAGE_CACHE_SIZE, 0); - sg_init_table(&src, 1); - sg_set_page(&src, src_page, PAGE_CACHE_SIZE, 0); - ablkcipher_request_set_crypt(req, &src, &dst, PAGE_CACHE_SIZE, - xts_tweak); - if (rw == F2FS_DECRYPT) - res = crypto_ablkcipher_decrypt(req); - else - res = crypto_ablkcipher_encrypt(req); - if (res == -EINPROGRESS || res == -EBUSY) { - wait_for_completion(&ecr.completion); - res = ecr.res; - } - ablkcipher_request_free(req); - if (res) { - printk_ratelimited(KERN_ERR - "%s: crypto_ablkcipher_encrypt() returned %d\n", - __func__, res); - return res; - } - return 0; -} - -static struct page *alloc_bounce_page(struct f2fs_crypto_ctx *ctx) -{ - ctx->w.bounce_page = mempool_alloc(f2fs_bounce_page_pool, GFP_NOWAIT); - if (ctx->w.bounce_page == NULL) - return ERR_PTR(-ENOMEM); - ctx->flags |= F2FS_WRITE_PATH_FL; - return ctx->w.bounce_page; -} - -/** - * f2fs_encrypt() - Encrypts a page - * @inode: The inode for which the encryption should take place - * @plaintext_page: The page to encrypt. Must be locked. - * - * Allocates a ciphertext page and encrypts plaintext_page into it using the ctx - * encryption context. - * - * Called on the page write path. The caller must call - * f2fs_restore_control_page() on the returned ciphertext page to - * release the bounce buffer and the encryption context. - * - * Return: An allocated page with the encrypted content on success. Else, an - * error value or NULL. - */ -struct page *f2fs_encrypt(struct inode *inode, - struct page *plaintext_page) -{ - struct f2fs_crypto_ctx *ctx; - struct page *ciphertext_page = NULL; - int err; - - BUG_ON(!PageLocked(plaintext_page)); - - ctx = f2fs_get_crypto_ctx(inode); - if (IS_ERR(ctx)) - return (struct page *)ctx; - - /* The encryption operation will require a bounce page. */ - ciphertext_page = alloc_bounce_page(ctx); - if (IS_ERR(ciphertext_page)) - goto err_out; - - ctx->w.control_page = plaintext_page; - err = f2fs_page_crypto(inode, F2FS_ENCRYPT, plaintext_page->index, - plaintext_page, ciphertext_page); - if (err) { - ciphertext_page = ERR_PTR(err); - goto err_out; - } - - SetPagePrivate(ciphertext_page); - set_page_private(ciphertext_page, (unsigned long)ctx); - lock_page(ciphertext_page); - return ciphertext_page; - -err_out: - f2fs_release_crypto_ctx(ctx); - return ciphertext_page; -} - -/** - * f2fs_decrypt() - Decrypts a page in-place - * @ctx: The encryption context. - * @page: The page to decrypt. Must be locked. - * - * Decrypts page in-place using the ctx encryption context. - * - * Called from the read completion callback. - * - * Return: Zero on success, non-zero otherwise. - */ -int f2fs_decrypt(struct page *page) -{ - BUG_ON(!PageLocked(page)); - - return f2fs_page_crypto(page->mapping->host, - F2FS_DECRYPT, page->index, page, page); -} - -bool f2fs_valid_contents_enc_mode(uint32_t mode) -{ - return (mode == F2FS_ENCRYPTION_MODE_AES_256_XTS); -} - -/** - * f2fs_validate_encryption_key_size() - Validate the encryption key size - * @mode: The key mode. - * @size: The key size to validate. - * - * Return: The validated key size for @mode. Zero if invalid. - */ -uint32_t f2fs_validate_encryption_key_size(uint32_t mode, uint32_t size) -{ - if (size == f2fs_encryption_key_size(mode)) - return size; - return 0; -} diff --git a/fs/f2fs/crypto_fname.c b/fs/f2fs/crypto_fname.c deleted file mode 100644 index 6dfdc97..0000000 --- a/fs/f2fs/crypto_fname.c +++ /dev/null @@ -1,446 +0,0 @@ -/* - * linux/fs/f2fs/crypto_fname.c - * - * Copied from linux/fs/ext4/crypto.c - * - * Copyright (C) 2015, Google, Inc. - * Copyright (C) 2015, Motorola Mobility - * - * This contains functions for filename crypto management in f2fs - * - * Written by Uday Savagaonkar, 2014. - * - * Adjust f2fs dentry structure - * Jaegeuk Kim, 2015. - * - * This has not yet undergone a rigorous security audit. - */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "f2fs.h" -#include "f2fs_crypto.h" -#include "xattr.h" - -/** - * f2fs_dir_crypt_complete() - - */ -static void f2fs_dir_crypt_complete(struct crypto_async_request *req, int res) -{ - struct f2fs_completion_result *ecr = req->data; - - if (res == -EINPROGRESS) - return; - ecr->res = res; - complete(&ecr->completion); -} - -bool f2fs_valid_filenames_enc_mode(uint32_t mode) -{ - return (mode == F2FS_ENCRYPTION_MODE_AES_256_CTS); -} - -static unsigned max_name_len(struct inode *inode) -{ - return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize : - F2FS_NAME_LEN; -} - -/** - * f2fs_fname_encrypt() - - * - * This function encrypts the input filename, and returns the length of the - * ciphertext. Errors are returned as negative numbers. We trust the caller to - * allocate sufficient memory to oname string. - */ -static int f2fs_fname_encrypt(struct inode *inode, - const struct qstr *iname, struct f2fs_str *oname) -{ - u32 ciphertext_len; - struct ablkcipher_request *req = NULL; - DECLARE_F2FS_COMPLETION_RESULT(ecr); - struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info; - struct crypto_ablkcipher *tfm = ci->ci_ctfm; - int res = 0; - char iv[F2FS_CRYPTO_BLOCK_SIZE]; - struct scatterlist src_sg, dst_sg; - int padding = 4 << (ci->ci_flags & F2FS_POLICY_FLAGS_PAD_MASK); - char *workbuf, buf[32], *alloc_buf = NULL; - unsigned lim = max_name_len(inode); - - if (iname->len <= 0 || iname->len > lim) - return -EIO; - - ciphertext_len = (iname->len < F2FS_CRYPTO_BLOCK_SIZE) ? - F2FS_CRYPTO_BLOCK_SIZE : iname->len; - ciphertext_len = f2fs_fname_crypto_round_up(ciphertext_len, padding); - ciphertext_len = (ciphertext_len > lim) ? lim : ciphertext_len; - - if (ciphertext_len <= sizeof(buf)) { - workbuf = buf; - } else { - alloc_buf = kmalloc(ciphertext_len, GFP_NOFS); - if (!alloc_buf) - return -ENOMEM; - workbuf = alloc_buf; - } - - /* Allocate request */ - req = ablkcipher_request_alloc(tfm, GFP_NOFS); - if (!req) { - printk_ratelimited(KERN_ERR - "%s: crypto_request_alloc() failed\n", __func__); - kfree(alloc_buf); - return -ENOMEM; - } - ablkcipher_request_set_callback(req, - CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, - f2fs_dir_crypt_complete, &ecr); - - /* Copy the input */ - memcpy(workbuf, iname->name, iname->len); - if (iname->len < ciphertext_len) - memset(workbuf + iname->len, 0, ciphertext_len - iname->len); - - /* Initialize IV */ - memset(iv, 0, F2FS_CRYPTO_BLOCK_SIZE); - - /* Create encryption request */ - sg_init_one(&src_sg, workbuf, ciphertext_len); - sg_init_one(&dst_sg, oname->name, ciphertext_len); - ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv); - res = crypto_ablkcipher_encrypt(req); - if (res == -EINPROGRESS || res == -EBUSY) { - wait_for_completion(&ecr.completion); - res = ecr.res; - } - kfree(alloc_buf); - ablkcipher_request_free(req); - if (res < 0) { - printk_ratelimited(KERN_ERR - "%s: Error (error code %d)\n", __func__, res); - } - oname->len = ciphertext_len; - return res; -} - -/* - * f2fs_fname_decrypt() - * This function decrypts the input filename, and returns - * the length of the plaintext. - * Errors are returned as negative numbers. - * We trust the caller to allocate sufficient memory to oname string. - */ -static int f2fs_fname_decrypt(struct inode *inode, - const struct f2fs_str *iname, struct f2fs_str *oname) -{ - struct ablkcipher_request *req = NULL; - DECLARE_F2FS_COMPLETION_RESULT(ecr); - struct scatterlist src_sg, dst_sg; - struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info; - struct crypto_ablkcipher *tfm = ci->ci_ctfm; - int res = 0; - char iv[F2FS_CRYPTO_BLOCK_SIZE]; - unsigned lim = max_name_len(inode); - - if (iname->len <= 0 || iname->len > lim) - return -EIO; - - /* Allocate request */ - req = ablkcipher_request_alloc(tfm, GFP_NOFS); - if (!req) { - printk_ratelimited(KERN_ERR - "%s: crypto_request_alloc() failed\n", __func__); - return -ENOMEM; - } - ablkcipher_request_set_callback(req, - CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, - f2fs_dir_crypt_complete, &ecr); - - /* Initialize IV */ - memset(iv, 0, F2FS_CRYPTO_BLOCK_SIZE); - - /* Create decryption request */ - sg_init_one(&src_sg, iname->name, iname->len); - sg_init_one(&dst_sg, oname->name, oname->len); - ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv); - res = crypto_ablkcipher_decrypt(req); - if (res == -EINPROGRESS || res == -EBUSY) { - wait_for_completion(&ecr.completion); - res = ecr.res; - } - ablkcipher_request_free(req); - if (res < 0) { - printk_ratelimited(KERN_ERR - "%s: Error in f2fs_fname_decrypt (error code %d)\n", - __func__, res); - return res; - } - - oname->len = strnlen(oname->name, iname->len); - return oname->len; -} - -static const char *lookup_table = - "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,"; - -/** - * f2fs_fname_encode_digest() - - * - * Encodes the input digest using characters from the set [a-zA-Z0-9_+]. - * The encoded string is roughly 4/3 times the size of the input string. - */ -static int digest_encode(const char *src, int len, char *dst) -{ - int i = 0, bits = 0, ac = 0; - char *cp = dst; - - while (i < len) { - ac += (((unsigned char) src[i]) << bits); - bits += 8; - do { - *cp++ = lookup_table[ac & 0x3f]; - ac >>= 6; - bits -= 6; - } while (bits >= 6); - i++; - } - if (bits) - *cp++ = lookup_table[ac & 0x3f]; - return cp - dst; -} - -static int digest_decode(const char *src, int len, char *dst) -{ - int i = 0, bits = 0, ac = 0; - const char *p; - char *cp = dst; - - while (i < len) { - p = strchr(lookup_table, src[i]); - if (p == NULL || src[i] == 0) - return -2; - ac += (p - lookup_table) << bits; - bits += 6; - if (bits >= 8) { - *cp++ = ac & 0xff; - ac >>= 8; - bits -= 8; - } - i++; - } - if (ac) - return -1; - return cp - dst; -} - -/** - * f2fs_fname_crypto_round_up() - - * - * Return: The next multiple of block size - */ -u32 f2fs_fname_crypto_round_up(u32 size, u32 blksize) -{ - return ((size + blksize - 1) / blksize) * blksize; -} - -unsigned f2fs_fname_encrypted_size(struct inode *inode, u32 ilen) -{ - struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info; - int padding = 32; - - if (ci) - padding = 4 << (ci->ci_flags & F2FS_POLICY_FLAGS_PAD_MASK); - if (ilen < F2FS_CRYPTO_BLOCK_SIZE) - ilen = F2FS_CRYPTO_BLOCK_SIZE; - return f2fs_fname_crypto_round_up(ilen, padding); -} - -/** - * f2fs_fname_crypto_alloc_obuff() - - * - * Allocates an output buffer that is sufficient for the crypto operation - * specified by the context and the direction. - */ -int f2fs_fname_crypto_alloc_buffer(struct inode *inode, - u32 ilen, struct f2fs_str *crypto_str) -{ - unsigned int olen = f2fs_fname_encrypted_size(inode, ilen); - - crypto_str->len = olen; - if (olen < F2FS_FNAME_CRYPTO_DIGEST_SIZE * 2) - olen = F2FS_FNAME_CRYPTO_DIGEST_SIZE * 2; - /* Allocated buffer can hold one more character to null-terminate the - * string */ - crypto_str->name = kmalloc(olen + 1, GFP_NOFS); - if (!(crypto_str->name)) - return -ENOMEM; - return 0; -} - -/** - * f2fs_fname_crypto_free_buffer() - - * - * Frees the buffer allocated for crypto operation. - */ -void f2fs_fname_crypto_free_buffer(struct f2fs_str *crypto_str) -{ - if (!crypto_str) - return; - kfree(crypto_str->name); - crypto_str->name = NULL; -} - -/** - * f2fs_fname_disk_to_usr() - converts a filename from disk space to user space - */ -int f2fs_fname_disk_to_usr(struct inode *inode, - f2fs_hash_t *hash, - const struct f2fs_str *iname, - struct f2fs_str *oname) -{ - const struct qstr qname = FSTR_TO_QSTR(iname); - char buf[24]; - int ret; - - if (is_dot_dotdot(&qname)) { - oname->name[0] = '.'; - oname->name[iname->len - 1] = '.'; - oname->len = iname->len; - return oname->len; - } - if (iname->len < F2FS_CRYPTO_BLOCK_SIZE) { - printk("encrypted inode too small"); - return -EUCLEAN; - } - if (F2FS_I(inode)->i_crypt_info) - return f2fs_fname_decrypt(inode, iname, oname); - - if (iname->len <= F2FS_FNAME_CRYPTO_DIGEST_SIZE) { - ret = digest_encode(iname->name, iname->len, oname->name); - oname->len = ret; - return ret; - } - if (hash) { - memcpy(buf, hash, 4); - memset(buf + 4, 0, 4); - } else - memset(buf, 0, 8); - memcpy(buf + 8, iname->name + iname->len - 16, 16); - oname->name[0] = '_'; - ret = digest_encode(buf, 24, oname->name + 1); - oname->len = ret + 1; - return ret + 1; -} - -/** - * f2fs_fname_usr_to_disk() - converts a filename from user space to disk space - */ -int f2fs_fname_usr_to_disk(struct inode *inode, - const struct qstr *iname, - struct f2fs_str *oname) -{ - int res; - struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info; - - if (is_dot_dotdot(iname)) { - oname->name[0] = '.'; - oname->name[iname->len - 1] = '.'; - oname->len = iname->len; - return oname->len; - } - - if (ci) { - res = f2fs_fname_encrypt(inode, iname, oname); - return res; - } - /* Without a proper key, a user is not allowed to modify the filenames - * in a directory. Consequently, a user space name cannot be mapped to - * a disk-space name */ - return -EACCES; -} - -int f2fs_fname_setup_filename(struct inode *dir, const struct qstr *iname, - int lookup, struct f2fs_filename *fname) -{ - struct f2fs_crypt_info *ci; - int ret = 0, bigname = 0; - - memset(fname, 0, sizeof(struct f2fs_filename)); - fname->usr_fname = iname; - - if (!f2fs_encrypted_inode(dir) || is_dot_dotdot(iname)) { - fname->disk_name.name = (unsigned char *)iname->name; - fname->disk_name.len = iname->len; - return 0; - } - ret = f2fs_get_encryption_info(dir); - if (ret) - return ret; - ci = F2FS_I(dir)->i_crypt_info; - if (ci) { - ret = f2fs_fname_crypto_alloc_buffer(dir, iname->len, - &fname->crypto_buf); - if (ret < 0) - return ret; - ret = f2fs_fname_encrypt(dir, iname, &fname->crypto_buf); - if (ret < 0) - goto errout; - fname->disk_name.name = fname->crypto_buf.name; - fname->disk_name.len = fname->crypto_buf.len; - return 0; - } - if (!lookup) - return -EACCES; - - /* We don't have the key and we are doing a lookup; decode the - * user-supplied name - */ - if (iname->name[0] == '_') - bigname = 1; - if ((bigname && (iname->len != 33)) || - (!bigname && (iname->len > 43))) - return -ENOENT; - - fname->crypto_buf.name = kmalloc(32, GFP_KERNEL); - if (fname->crypto_buf.name == NULL) - return -ENOMEM; - ret = digest_decode(iname->name + bigname, iname->len - bigname, - fname->crypto_buf.name); - if (ret < 0) { - ret = -ENOENT; - goto errout; - } - fname->crypto_buf.len = ret; - if (bigname) { - memcpy(&fname->hash, fname->crypto_buf.name, 4); - } else { - fname->disk_name.name = fname->crypto_buf.name; - fname->disk_name.len = fname->crypto_buf.len; - } - return 0; -errout: - f2fs_fname_crypto_free_buffer(&fname->crypto_buf); - return ret; -} - -void f2fs_fname_free_filename(struct f2fs_filename *fname) -{ - kfree(fname->crypto_buf.name); - fname->crypto_buf.name = NULL; - fname->usr_fname = NULL; - fname->disk_name.name = NULL; -} diff --git a/fs/f2fs/crypto_key.c b/fs/f2fs/crypto_key.c deleted file mode 100644 index 9094fca..0000000 --- a/fs/f2fs/crypto_key.c +++ /dev/null @@ -1,267 +0,0 @@ -/* - * linux/fs/f2fs/crypto_key.c - * - * Copied from linux/fs/f2fs/crypto_key.c - * - * Copyright (C) 2015, Google, Inc. - * - * This contains encryption key functions for f2fs - * - * Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015. - */ -#include -#include -#include -#include -#include -#include -#include - -#include "f2fs.h" -#include "xattr.h" - -static void derive_crypt_complete(struct crypto_async_request *req, int rc) -{ - struct f2fs_completion_result *ecr = req->data; - - if (rc == -EINPROGRESS) - return; - - ecr->res = rc; - complete(&ecr->completion); -} - -/** - * f2fs_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 f2fs_derive_key_aes(char deriving_key[F2FS_AES_128_ECB_KEY_SIZE], - char source_key[F2FS_AES_256_XTS_KEY_SIZE], - char derived_key[F2FS_AES_256_XTS_KEY_SIZE]) -{ - int res = 0; - struct ablkcipher_request *req = NULL; - DECLARE_F2FS_COMPLETION_RESULT(ecr); - struct scatterlist src_sg, dst_sg; - struct crypto_ablkcipher *tfm = crypto_alloc_ablkcipher("ecb(aes)", 0, - 0); - - if (IS_ERR(tfm)) { - res = PTR_ERR(tfm); - tfm = NULL; - goto out; - } - crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_REQ_WEAK_KEY); - req = ablkcipher_request_alloc(tfm, GFP_NOFS); - if (!req) { - res = -ENOMEM; - goto out; - } - ablkcipher_request_set_callback(req, - CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, - derive_crypt_complete, &ecr); - res = crypto_ablkcipher_setkey(tfm, deriving_key, - F2FS_AES_128_ECB_KEY_SIZE); - if (res < 0) - goto out; - - sg_init_one(&src_sg, source_key, F2FS_AES_256_XTS_KEY_SIZE); - sg_init_one(&dst_sg, derived_key, F2FS_AES_256_XTS_KEY_SIZE); - ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, - F2FS_AES_256_XTS_KEY_SIZE, NULL); - res = crypto_ablkcipher_encrypt(req); - if (res == -EINPROGRESS || res == -EBUSY) { - wait_for_completion(&ecr.completion); - res = ecr.res; - } -out: - if (req) - ablkcipher_request_free(req); - if (tfm) - crypto_free_ablkcipher(tfm); - return res; -} - -static void f2fs_free_crypt_info(struct f2fs_crypt_info *ci) -{ - if (!ci) - return; - - key_put(ci->ci_keyring_key); - crypto_free_ablkcipher(ci->ci_ctfm); - kmem_cache_free(f2fs_crypt_info_cachep, ci); -} - -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) -{ - struct f2fs_inode_info *fi = F2FS_I(inode); - struct f2fs_crypt_info *crypt_info; - char full_key_descriptor[F2FS_KEY_DESC_PREFIX_SIZE + - (F2FS_KEY_DESCRIPTOR_SIZE * 2) + 1]; - struct key *keyring_key = NULL; - struct f2fs_encryption_key *master_key; - struct f2fs_encryption_context ctx; - const 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; -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, crypt_info); - goto retry; - } - - res = f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION, - F2FS_XATTR_NAME_ENCRYPTION_CONTEXT, - &ctx, sizeof(ctx), NULL); - if (res < 0) - return res; - else if (res != sizeof(ctx)) - return -EINVAL; - res = 0; - - crypt_info = kmem_cache_alloc(f2fs_crypt_info_cachep, GFP_NOFS); - 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 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); - sprintf(full_key_descriptor + F2FS_KEY_DESC_PREFIX_SIZE, - "%*phN", F2FS_KEY_DESCRIPTOR_SIZE, - ctx.master_key_descriptor); - full_key_descriptor[F2FS_KEY_DESC_PREFIX_SIZE + - (2 * F2FS_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 "f2fs: 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 f2fs_encryption_key)) { - res = -EINVAL; - up_read(&keyring_key->sem); - goto out; - } - master_key = (struct f2fs_encryption_key *)ukp->data; - BUILD_BUG_ON(F2FS_AES_128_ECB_KEY_SIZE != - F2FS_KEY_DERIVATION_NONCE_SIZE); - if (master_key->size != F2FS_AES_256_XTS_KEY_SIZE) { - printk_once(KERN_WARNING - "f2fs: key size incorrect: %d\n", - master_key->size); - res = -ENOKEY; - up_read(&keyring_key->sem); - goto out; - } - res = f2fs_derive_key_aes(ctx.nonce, master_key->raw, - raw_key); - up_read(&keyring_key->sem); - 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; - } - 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; -} - -int f2fs_has_encryption_key(struct inode *inode) -{ - struct f2fs_inode_info *fi = F2FS_I(inode); - - return (fi->i_crypt_info != NULL); -} diff --git a/fs/f2fs/crypto_policy.c b/fs/f2fs/crypto_policy.c deleted file mode 100644 index 596f024..0000000 --- a/fs/f2fs/crypto_policy.c +++ /dev/null @@ -1,210 +0,0 @@ -/* - * copied from linux/fs/ext4/crypto_policy.c - * - * Copyright (C) 2015, Google, Inc. - * Copyright (C) 2015, Motorola Mobility. - * - * This contains encryption policy functions for f2fs with some modifications - * to support f2fs-specific xattr APIs. - * - * Written by Michael Halcrow, 2015. - * Modified by Jaegeuk Kim, 2015. - */ -#include -#include -#include -#include - -#include "f2fs.h" -#include "xattr.h" - -static int f2fs_inode_has_encryption_context(struct inode *inode) -{ - int res = f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION, - F2FS_XATTR_NAME_ENCRYPTION_CONTEXT, NULL, 0, NULL); - return (res > 0); -} - -/* - * check whether the policy is consistent with the encryption context - * for the inode - */ -static int f2fs_is_encryption_context_consistent_with_policy( - struct inode *inode, const struct f2fs_encryption_policy *policy) -{ - struct f2fs_encryption_context ctx; - int res = f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION, - F2FS_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx, - sizeof(ctx), NULL); - - if (res != sizeof(ctx)) - return 0; - - return (memcmp(ctx.master_key_descriptor, policy->master_key_descriptor, - F2FS_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 f2fs_create_encryption_context_from_policy( - struct inode *inode, const struct f2fs_encryption_policy *policy) -{ - struct f2fs_encryption_context ctx; - - ctx.format = F2FS_ENCRYPTION_CONTEXT_FORMAT_V1; - memcpy(ctx.master_key_descriptor, policy->master_key_descriptor, - F2FS_KEY_DESCRIPTOR_SIZE); - - if (!f2fs_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 (!f2fs_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 & ~F2FS_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) != F2FS_KEY_DERIVATION_NONCE_SIZE); - get_random_bytes(ctx.nonce, F2FS_KEY_DERIVATION_NONCE_SIZE); - - return f2fs_setxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION, - F2FS_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx, - sizeof(ctx), NULL, XATTR_CREATE); -} - -int f2fs_process_policy(const struct f2fs_encryption_policy *policy, - struct inode *inode) -{ - if (policy->version != 0) - return -EINVAL; - - if (!S_ISDIR(inode->i_mode)) - return -EINVAL; - - if (!f2fs_inode_has_encryption_context(inode)) { - if (!f2fs_empty_dir(inode)) - return -ENOTEMPTY; - return f2fs_create_encryption_context_from_policy(inode, - policy); - } - - if (f2fs_is_encryption_context_consistent_with_policy(inode, policy)) - return 0; - - printk(KERN_WARNING "%s: Policy inconsistent with encryption context\n", - __func__); - return -EINVAL; -} - -int f2fs_get_policy(struct inode *inode, struct f2fs_encryption_policy *policy) -{ - struct f2fs_encryption_context ctx; - int res; - - if (!f2fs_encrypted_inode(inode)) - return -ENODATA; - - res = f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION, - F2FS_XATTR_NAME_ENCRYPTION_CONTEXT, - &ctx, sizeof(ctx), NULL); - if (res != sizeof(ctx)) - return -ENODATA; - if (ctx.format != F2FS_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, - F2FS_KEY_DESCRIPTOR_SIZE); - return 0; -} - -int f2fs_is_child_context_consistent_with_parent(struct inode *parent, - struct inode *child) -{ - struct f2fs_crypt_info *parent_ci, *child_ci; - int res; - - if ((parent == NULL) || (child == NULL)) { - pr_err("parent %p child %p\n", parent, child); - BUG_ON(1); - } - - /* no restrictions if the parent directory is not encrypted */ - if (!f2fs_encrypted_inode(parent)) - return 1; - /* if the child directory is not encrypted, this is always a problem */ - if (!f2fs_encrypted_inode(child)) - return 0; - res = f2fs_get_encryption_info(parent); - if (res) - return 0; - res = f2fs_get_encryption_info(child); - if (res) - return 0; - parent_ci = F2FS_I(parent)->i_crypt_info; - child_ci = F2FS_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, - F2FS_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)); -} - -/** - * f2fs_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 f2fs_inherit_context(struct inode *parent, struct inode *child, - struct page *ipage) -{ - struct f2fs_encryption_context ctx; - struct f2fs_crypt_info *ci; - int res; - - res = f2fs_get_encryption_info(parent); - if (res < 0) - return res; - - ci = F2FS_I(parent)->i_crypt_info; - if (ci == NULL) - return -ENOKEY; - - ctx.format = F2FS_ENCRYPTION_CONTEXT_FORMAT_V1; - - 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, - F2FS_KEY_DESCRIPTOR_SIZE); - - get_random_bytes(ctx.nonce, F2FS_KEY_DERIVATION_NONCE_SIZE); - return f2fs_setxattr(child, F2FS_XATTR_INDEX_ENCRYPTION, - F2FS_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx, - sizeof(ctx), ipage, XATTR_CREATE); -} diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 9643d88..e5c762b 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -34,9 +34,9 @@ static void f2fs_read_end_io(struct bio *bio) if (f2fs_bio_encrypted(bio)) { if (bio->bi_error) { - f2fs_release_crypto_ctx(bio->bi_private); + fscrypt_release_ctx(bio->bi_private); } else { - f2fs_end_io_crypto_work(bio->bi_private, bio); + fscrypt_decrypt_bio_pages(bio->bi_private, bio); return; } } @@ -64,7 +64,7 @@ static void f2fs_write_end_io(struct bio *bio) bio_for_each_segment_all(bvec, bio, i) { struct page *page = bvec->bv_page; - f2fs_restore_and_release_control_page(&page); + fscrypt_pullback_bio_page(&page, true); if (unlikely(bio->bi_error)) { set_bit(AS_EIO, &page->mapping->flags); @@ -129,16 +129,10 @@ static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode, bio_for_each_segment_all(bvec, io->bio, i) { - if (bvec->bv_page->mapping) { + if (bvec->bv_page->mapping) target = bvec->bv_page; - } else { - struct f2fs_crypto_ctx *ctx; - - /* encrypted page */ - ctx = (struct f2fs_crypto_ctx *)page_private( - bvec->bv_page); - target = ctx->w.control_page; - } + else + target = fscrypt_control_page(bvec->bv_page); if (inode && inode == target->mapping->host) return true; @@ -220,7 +214,8 @@ void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi) int f2fs_submit_page_bio(struct f2fs_io_info *fio) { struct bio *bio; - struct page *page = fio->encrypted_page ? fio->encrypted_page : fio->page; + struct page *page = fio->encrypted_page ? + fio->encrypted_page : fio->page; trace_f2fs_submit_page_bio(page, fio); f2fs_trace_ios(fio, 0); @@ -992,12 +987,12 @@ submit_and_realloc: bio = NULL; } if (bio == NULL) { - struct f2fs_crypto_ctx *ctx = NULL; + struct fscrypt_ctx *ctx = NULL; if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) { - ctx = f2fs_get_crypto_ctx(inode); + ctx = fscrypt_get_ctx(inode); if (IS_ERR(ctx)) goto set_error_page; @@ -1010,7 +1005,7 @@ submit_and_realloc: min_t(int, nr_pages, BIO_MAX_PAGES)); if (!bio) { if (ctx) - f2fs_release_crypto_ctx(ctx); + fscrypt_release_ctx(ctx); goto set_error_page; } bio->bi_bdev = bdev; @@ -1102,7 +1097,7 @@ int do_write_data_page(struct f2fs_io_info *fio) f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode), fio->old_blkaddr); - fio->encrypted_page = f2fs_encrypt(inode, fio->page); + fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page); if (IS_ERR(fio->encrypted_page)) { err = PTR_ERR(fio->encrypted_page); goto out_writepage; @@ -1608,7 +1603,7 @@ repeat: /* avoid symlink page */ if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) { - err = f2fs_decrypt(page); + err = fscrypt_decrypt_page(page); if (err) goto fail; } diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 8f09da0..f82e28b 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -77,7 +77,7 @@ static unsigned long dir_block_index(unsigned int level, } static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, - struct f2fs_filename *fname, + struct fscrypt_name *fname, f2fs_hash_t namehash, int *max_slots, struct page **res_page) @@ -103,15 +103,15 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, return de; } -struct f2fs_dir_entry *find_target_dentry(struct f2fs_filename *fname, +struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname, f2fs_hash_t namehash, int *max_slots, struct f2fs_dentry_ptr *d) { struct f2fs_dir_entry *de; unsigned long bit_pos = 0; int max_len = 0; - struct f2fs_str de_name = FSTR_INIT(NULL, 0); - struct f2fs_str *name = &fname->disk_name; + struct fscrypt_str de_name = FSTR_INIT(NULL, 0); + struct fscrypt_str *name = &fname->disk_name; if (max_slots) *max_slots = 0; @@ -157,7 +157,7 @@ found: static struct f2fs_dir_entry *find_in_level(struct inode *dir, unsigned int level, - struct f2fs_filename *fname, + struct fscrypt_name *fname, struct page **res_page) { struct qstr name = FSTR_TO_QSTR(&fname->disk_name); @@ -218,12 +218,12 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir, struct f2fs_dir_entry *de = NULL; unsigned int max_depth; unsigned int level; - struct f2fs_filename fname; + struct fscrypt_name fname; int err; *res_page = NULL; - err = f2fs_fname_setup_filename(dir, child, 1, &fname); + err = fscrypt_setup_filename(dir, child, 1, &fname); if (err) return NULL; @@ -251,7 +251,7 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir, break; } out: - f2fs_fname_free_filename(&fname); + fscrypt_free_filename(&fname); return de; } @@ -413,7 +413,7 @@ struct page *init_inode_metadata(struct inode *inode, struct inode *dir, goto put_error; if (f2fs_encrypted_inode(dir) && f2fs_may_encrypt(inode)) { - err = f2fs_inherit_context(dir, inode, page); + err = fscrypt_inherit_context(dir, inode, page, false); if (err) goto put_error; } @@ -536,11 +536,11 @@ int __f2fs_add_link(struct inode *dir, const struct qstr *name, struct f2fs_dentry_block *dentry_blk = NULL; struct f2fs_dentry_ptr d; struct page *page = NULL; - struct f2fs_filename fname; + struct fscrypt_name fname; struct qstr new_name; int slots, err; - err = f2fs_fname_setup_filename(dir, name, 0, &fname); + err = fscrypt_setup_filename(dir, name, 0, &fname); if (err) return err; @@ -639,7 +639,7 @@ fail: kunmap(dentry_page); f2fs_put_page(dentry_page, 1); out: - f2fs_fname_free_filename(&fname); + fscrypt_free_filename(&fname); f2fs_update_time(F2FS_I_SB(dir), REQ_TIME); return err; } @@ -781,12 +781,12 @@ bool f2fs_empty_dir(struct inode *dir) } bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, - unsigned int start_pos, struct f2fs_str *fstr) + unsigned int start_pos, struct fscrypt_str *fstr) { unsigned char d_type = DT_UNKNOWN; unsigned int bit_pos; struct f2fs_dir_entry *de = NULL; - struct f2fs_str de_name = FSTR_INIT(NULL, 0); + struct fscrypt_str de_name = FSTR_INIT(NULL, 0); bit_pos = ((unsigned long)ctx->pos % d->max); @@ -820,8 +820,9 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, memcpy(de_name.name, d->filename[bit_pos], de_name.len); - ret = f2fs_fname_disk_to_usr(d->inode, &de->hash_code, - &de_name, fstr); + ret = fscrypt_fname_disk_to_usr(d->inode, + (u32)de->hash_code, 0, + &de_name, fstr); kfree(de_name.name); if (ret < 0) return true; @@ -849,16 +850,15 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx) struct file_ra_state *ra = &file->f_ra; unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK); struct f2fs_dentry_ptr d; - struct f2fs_str fstr = FSTR_INIT(NULL, 0); + struct fscrypt_str fstr = FSTR_INIT(NULL, 0); int err = 0; if (f2fs_encrypted_inode(inode)) { - err = f2fs_get_encryption_info(inode); + err = fscrypt_get_encryption_info(inode); if (err) return err; - err = f2fs_fname_crypto_alloc_buffer(inode, F2FS_NAME_LEN, - &fstr); + err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr); if (err < 0) return err; } @@ -898,14 +898,14 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx) f2fs_put_page(dentry_page, 1); } out: - f2fs_fname_crypto_free_buffer(&fstr); + fscrypt_fname_free_buffer(&fstr); return err; } static int f2fs_dir_open(struct inode *inode, struct file *filp) { if (f2fs_encrypted_inode(inode)) - return f2fs_get_encryption_info(inode) ? -EACCES : 0; + return fscrypt_get_encryption_info(inode) ? -EACCES : 0; return 0; } diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index ffd0336..6447e90 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -22,6 +22,7 @@ #include #include #include +#include #ifdef CONFIG_F2FS_CHECK_FS #define f2fs_bug_on(sbi, condition) BUG_ON(condition) @@ -231,12 +232,9 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal, #define F2FS_IOC_WRITE_CHECKPOINT _IO(F2FS_IOCTL_MAGIC, 7) #define F2FS_IOC_DEFRAGMENT _IO(F2FS_IOCTL_MAGIC, 8) -#define F2FS_IOC_SET_ENCRYPTION_POLICY \ - _IOR('f', 19, struct f2fs_encryption_policy) -#define F2FS_IOC_GET_ENCRYPTION_PWSALT \ - _IOW('f', 20, __u8[16]) -#define F2FS_IOC_GET_ENCRYPTION_POLICY \ - _IOW('f', 21, struct f2fs_encryption_policy) +#define F2FS_IOC_SET_ENCRYPTION_POLICY FS_IOC_SET_ENCRYPTION_POLICY +#define F2FS_IOC_GET_ENCRYPTION_POLICY FS_IOC_GET_ENCRYPTION_POLICY +#define F2FS_IOC_GET_ENCRYPTION_PWSALT FS_IOC_GET_ENCRYPTION_PWSALT /* * should be same as XFS_IOC_GOINGDOWN. @@ -266,25 +264,6 @@ struct f2fs_defragment { * For INODE and NODE manager */ /* for directory operations */ -struct f2fs_str { - unsigned char *name; - u32 len; -}; - -struct f2fs_filename { - const struct qstr *usr_fname; - struct f2fs_str disk_name; - f2fs_hash_t hash; -#ifdef CONFIG_F2FS_FS_ENCRYPTION - struct f2fs_str crypto_buf; -#endif -}; - -#define FSTR_INIT(n, l) { .name = n, .len = l } -#define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len) -#define fname_name(p) ((p)->disk_name.name) -#define fname_len(p) ((p)->disk_name.len) - struct f2fs_dentry_ptr { struct inode *inode; const void *bitmap; @@ -412,15 +391,6 @@ struct f2fs_map_blocks { #define file_enc_name(inode) is_file(inode, FADVISE_ENC_NAME_BIT) #define file_set_enc_name(inode) set_file(inode, FADVISE_ENC_NAME_BIT) -/* Encryption algorithms */ -#define F2FS_ENCRYPTION_MODE_INVALID 0 -#define F2FS_ENCRYPTION_MODE_AES_256_XTS 1 -#define F2FS_ENCRYPTION_MODE_AES_256_GCM 2 -#define F2FS_ENCRYPTION_MODE_AES_256_CBC 3 -#define F2FS_ENCRYPTION_MODE_AES_256_CTS 4 - -#include "f2fs_crypto.h" - #define DEF_DIR_LEVEL 0 struct f2fs_inode_info { @@ -444,13 +414,7 @@ struct f2fs_inode_info { struct list_head dirty_list; /* linked in global dirty list */ struct list_head inmem_pages; /* inmemory pages managed by f2fs */ struct mutex inmem_lock; /* lock for inmemory pages */ - struct extent_tree *extent_tree; /* cached extent_tree entry */ - -#ifdef CONFIG_F2FS_FS_ENCRYPTION - /* Encryption params */ - struct f2fs_crypt_info *i_crypt_info; -#endif }; static inline void get_extent_info(struct extent_info *ext, @@ -1741,10 +1705,10 @@ struct dentry *f2fs_get_parent(struct dentry *child); extern unsigned char f2fs_filetype_table[F2FS_FT_MAX]; void set_de_type(struct f2fs_dir_entry *, umode_t); -struct f2fs_dir_entry *find_target_dentry(struct f2fs_filename *, +struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *, f2fs_hash_t, int *, struct f2fs_dentry_ptr *); bool f2fs_fill_dentries(struct dir_context *, struct f2fs_dentry_ptr *, - unsigned int, struct f2fs_str *); + unsigned int, struct fscrypt_str *); void do_make_empty_dir(struct inode *, struct inode *, struct f2fs_dentry_ptr *); struct page *init_inode_metadata(struct inode *, struct inode *, @@ -2120,7 +2084,7 @@ int f2fs_convert_inline_inode(struct inode *); int f2fs_write_inline_data(struct inode *, struct page *); bool recover_inline_data(struct inode *, struct page *); struct f2fs_dir_entry *find_in_inline_dir(struct inode *, - struct f2fs_filename *, struct page **); + struct fscrypt_name *, struct page **); struct f2fs_dir_entry *f2fs_parent_inline_dir(struct inode *, struct page **); int make_empty_inline_dir(struct inode *inode, struct inode *, struct page *); int f2fs_add_inline_entry(struct inode *, const struct qstr *, struct inode *, @@ -2129,7 +2093,7 @@ void f2fs_delete_inline_entry(struct f2fs_dir_entry *, struct page *, struct inode *, struct inode *); bool f2fs_empty_inline_dir(struct inode *); int f2fs_read_inline_dir(struct file *, struct dir_context *, - struct f2fs_str *); + struct fscrypt_str *); int f2fs_inline_data_fiemap(struct inode *, struct fiemap_extent_info *, __u64, __u64); @@ -2159,13 +2123,9 @@ void destroy_extent_cache(void); /* * crypto support */ -static inline int f2fs_encrypted_inode(struct inode *inode) +static inline bool f2fs_encrypted_inode(struct inode *inode) { -#ifdef CONFIG_F2FS_FS_ENCRYPTION return file_is_encrypt(inode); -#else - return 0; -#endif } static inline void f2fs_set_encrypted_inode(struct inode *inode) @@ -2177,20 +2137,12 @@ static inline void f2fs_set_encrypted_inode(struct inode *inode) static inline bool f2fs_bio_encrypted(struct bio *bio) { -#ifdef CONFIG_F2FS_FS_ENCRYPTION - return unlikely(bio->bi_private != NULL); -#else - return false; -#endif + return bio->bi_private != NULL; } static inline int f2fs_sb_has_crypto(struct super_block *sb) { -#ifdef CONFIG_F2FS_FS_ENCRYPTION return F2FS_HAS_FEATURE(sb, F2FS_FEATURE_ENCRYPT); -#else - return 0; -#endif } static inline bool f2fs_may_encrypt(struct inode *inode) @@ -2204,86 +2156,28 @@ static inline bool f2fs_may_encrypt(struct inode *inode) #endif } -/* crypto_policy.c */ -int f2fs_is_child_context_consistent_with_parent(struct inode *, - struct inode *); -int f2fs_inherit_context(struct inode *, struct inode *, struct page *); -int f2fs_process_policy(const struct f2fs_encryption_policy *, struct inode *); -int f2fs_get_policy(struct inode *, struct f2fs_encryption_policy *); - -/* crypt.c */ -extern struct kmem_cache *f2fs_crypt_info_cachep; -bool f2fs_valid_contents_enc_mode(uint32_t); -uint32_t f2fs_validate_encryption_key_size(uint32_t, uint32_t); -struct f2fs_crypto_ctx *f2fs_get_crypto_ctx(struct inode *); -void f2fs_release_crypto_ctx(struct f2fs_crypto_ctx *); -struct page *f2fs_encrypt(struct inode *, struct page *); -int f2fs_decrypt(struct page *); -void f2fs_end_io_crypto_work(struct f2fs_crypto_ctx *, struct bio *); - -/* crypto_key.c */ -void f2fs_free_encryption_info(struct inode *, struct f2fs_crypt_info *); -int _f2fs_get_encryption_info(struct inode *inode); - -/* crypto_fname.c */ -bool f2fs_valid_filenames_enc_mode(uint32_t); -u32 f2fs_fname_crypto_round_up(u32, u32); -unsigned f2fs_fname_encrypted_size(struct inode *, u32); -int f2fs_fname_crypto_alloc_buffer(struct inode *, u32, struct f2fs_str *); -int f2fs_fname_disk_to_usr(struct inode *, f2fs_hash_t *, - const struct f2fs_str *, struct f2fs_str *); -int f2fs_fname_usr_to_disk(struct inode *, const struct qstr *, - struct f2fs_str *); - -#ifdef CONFIG_F2FS_FS_ENCRYPTION -void f2fs_restore_and_release_control_page(struct page **); -void f2fs_restore_control_page(struct page *); - -int __init f2fs_init_crypto(void); -int f2fs_crypto_initialize(void); -void f2fs_exit_crypto(void); - -int f2fs_has_encryption_key(struct inode *); - -static inline int f2fs_get_encryption_info(struct inode *inode) -{ - struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info; - - if (!ci || - (ci->ci_keyring_key && - (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) | - (1 << KEY_FLAG_REVOKED) | - (1 << KEY_FLAG_DEAD))))) - return _f2fs_get_encryption_info(inode); - return 0; -} - -void f2fs_fname_crypto_free_buffer(struct f2fs_str *); -int f2fs_fname_setup_filename(struct inode *, const struct qstr *, - int lookup, struct f2fs_filename *); -void f2fs_fname_free_filename(struct f2fs_filename *); -#else -static inline void f2fs_restore_and_release_control_page(struct page **p) { } -static inline void f2fs_restore_control_page(struct page *p) { } - -static inline int __init f2fs_init_crypto(void) { return 0; } -static inline void f2fs_exit_crypto(void) { } - -static inline int f2fs_has_encryption_key(struct inode *i) { return 0; } -static inline int f2fs_get_encryption_info(struct inode *i) { return 0; } -static inline void f2fs_fname_crypto_free_buffer(struct f2fs_str *p) { } - -static inline int f2fs_fname_setup_filename(struct inode *dir, - const struct qstr *iname, - int lookup, struct f2fs_filename *fname) -{ - memset(fname, 0, sizeof(struct f2fs_filename)); - fname->usr_fname = iname; - fname->disk_name.name = (unsigned char *)iname->name; - fname->disk_name.len = iname->len; - return 0; -} - -static inline void f2fs_fname_free_filename(struct f2fs_filename *fname) { } +#ifndef CONFIG_F2FS_FS_ENCRYPTION +#define fscrypt_set_d_op(i) +#define fscrypt_get_ctx fscrypt_notsupp_get_ctx +#define fscrypt_release_ctx fscrypt_notsupp_release_ctx +#define fscrypt_encrypt_page fscrypt_notsupp_encrypt_page +#define fscrypt_decrypt_page fscrypt_notsupp_decrypt_page +#define fscrypt_decrypt_bio_pages fscrypt_notsupp_decrypt_bio_pages +#define fscrypt_pullback_bio_page fscrypt_notsupp_pullback_bio_page +#define fscrypt_restore_control_page fscrypt_notsupp_restore_control_page +#define fscrypt_zeroout_range fscrypt_notsupp_zeroout_range +#define fscrypt_process_policy fscrypt_notsupp_process_policy +#define fscrypt_get_policy fscrypt_notsupp_get_policy +#define fscrypt_has_permitted_context fscrypt_notsupp_has_permitted_context +#define fscrypt_inherit_context fscrypt_notsupp_inherit_context +#define fscrypt_get_encryption_info fscrypt_notsupp_get_encryption_info +#define fscrypt_put_encryption_info fscrypt_notsupp_put_encryption_info +#define fscrypt_setup_filename fscrypt_notsupp_setup_filename +#define fscrypt_free_filename fscrypt_notsupp_free_filename +#define fscrypt_fname_encrypted_size fscrypt_notsupp_fname_encrypted_size +#define fscrypt_fname_alloc_buffer fscrypt_notsupp_fname_alloc_buffer +#define fscrypt_fname_free_buffer fscrypt_notsupp_fname_free_buffer +#define fscrypt_fname_disk_to_usr fscrypt_notsupp_fname_disk_to_usr +#define fscrypt_fname_usr_to_disk fscrypt_notsupp_fname_usr_to_disk #endif #endif diff --git a/fs/f2fs/f2fs_crypto.h b/fs/f2fs/f2fs_crypto.h deleted file mode 100644 index c2c1c2b..0000000 --- a/fs/f2fs/f2fs_crypto.h +++ /dev/null @@ -1,151 +0,0 @@ -/* - * linux/fs/f2fs/f2fs_crypto.h - * - * Copied from linux/fs/ext4/ext4_crypto.h - * - * Copyright (C) 2015, Google, Inc. - * - * This contains encryption header content for f2fs - * - * Written by Michael Halcrow, 2015. - * Modified by Jaegeuk Kim, 2015. - */ -#ifndef _F2FS_CRYPTO_H -#define _F2FS_CRYPTO_H - -#include - -#define F2FS_KEY_DESCRIPTOR_SIZE 8 - -/* Policy provided via an ioctl on the topmost directory */ -struct f2fs_encryption_policy { - char version; - char contents_encryption_mode; - char filenames_encryption_mode; - char flags; - char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE]; -} __attribute__((__packed__)); - -#define F2FS_ENCRYPTION_CONTEXT_FORMAT_V1 1 -#define F2FS_KEY_DERIVATION_NONCE_SIZE 16 - -#define F2FS_POLICY_FLAGS_PAD_4 0x00 -#define F2FS_POLICY_FLAGS_PAD_8 0x01 -#define F2FS_POLICY_FLAGS_PAD_16 0x02 -#define F2FS_POLICY_FLAGS_PAD_32 0x03 -#define F2FS_POLICY_FLAGS_PAD_MASK 0x03 -#define F2FS_POLICY_FLAGS_VALID 0x03 - -/** - * Encryption context for inode - * - * Protector format: - * 1 byte: Protector format (1 = this version) - * 1 byte: File contents encryption mode - * 1 byte: File names encryption mode - * 1 byte: Flags - * 8 bytes: Master Key descriptor - * 16 bytes: Encryption Key derivation nonce - */ -struct f2fs_encryption_context { - char format; - char contents_encryption_mode; - char filenames_encryption_mode; - char flags; - char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE]; - char nonce[F2FS_KEY_DERIVATION_NONCE_SIZE]; -} __attribute__((__packed__)); - -/* Encryption parameters */ -#define F2FS_XTS_TWEAK_SIZE 16 -#define F2FS_AES_128_ECB_KEY_SIZE 16 -#define F2FS_AES_256_GCM_KEY_SIZE 32 -#define F2FS_AES_256_CBC_KEY_SIZE 32 -#define F2FS_AES_256_CTS_KEY_SIZE 32 -#define F2FS_AES_256_XTS_KEY_SIZE 64 -#define F2FS_MAX_KEY_SIZE 64 - -#define F2FS_KEY_DESC_PREFIX "f2fs:" -#define F2FS_KEY_DESC_PREFIX_SIZE 5 - -struct f2fs_encryption_key { - __u32 mode; - char raw[F2FS_MAX_KEY_SIZE]; - __u32 size; -} __attribute__((__packed__)); - -struct f2fs_crypt_info { - char ci_data_mode; - char ci_filename_mode; - char ci_flags; - struct crypto_ablkcipher *ci_ctfm; - struct key *ci_keyring_key; - char ci_master_key[F2FS_KEY_DESCRIPTOR_SIZE]; -}; - -#define F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 -#define F2FS_WRITE_PATH_FL 0x00000002 - -struct f2fs_crypto_ctx { - union { - struct { - struct page *bounce_page; /* Ciphertext page */ - struct page *control_page; /* Original page */ - } w; - struct { - struct bio *bio; - struct work_struct work; - } r; - struct list_head free_list; /* Free list */ - }; - char flags; /* Flags */ -}; - -struct f2fs_completion_result { - struct completion completion; - int res; -}; - -#define DECLARE_F2FS_COMPLETION_RESULT(ecr) \ - struct f2fs_completion_result ecr = { \ - COMPLETION_INITIALIZER((ecr).completion), 0 } - -static inline int f2fs_encryption_key_size(int mode) -{ - switch (mode) { - case F2FS_ENCRYPTION_MODE_AES_256_XTS: - return F2FS_AES_256_XTS_KEY_SIZE; - case F2FS_ENCRYPTION_MODE_AES_256_GCM: - return F2FS_AES_256_GCM_KEY_SIZE; - case F2FS_ENCRYPTION_MODE_AES_256_CBC: - return F2FS_AES_256_CBC_KEY_SIZE; - case F2FS_ENCRYPTION_MODE_AES_256_CTS: - return F2FS_AES_256_CTS_KEY_SIZE; - default: - BUG(); - } - return 0; -} - -#define F2FS_FNAME_NUM_SCATTER_ENTRIES 4 -#define F2FS_CRYPTO_BLOCK_SIZE 16 -#define F2FS_FNAME_CRYPTO_DIGEST_SIZE 32 - -/** - * For encrypted symlinks, the ciphertext length is stored at the beginning - * of the string in little-endian format. - */ -struct f2fs_encrypted_symlink_data { - __le16 len; - char encrypted_path[1]; -} __attribute__((__packed__)); - -/** - * This function is used to calculate the disk space required to - * store a filename of length l in encrypted symlink format. - */ -static inline u32 encrypted_symlink_data_len(u32 l) -{ - return (l + sizeof(struct f2fs_encrypted_symlink_data) - 1); -} -#endif /* _F2FS_CRYPTO_H */ diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index ffa1ec2..04ab1e4 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -421,7 +421,7 @@ static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma) int err; if (f2fs_encrypted_inode(inode)) { - err = f2fs_get_encryption_info(inode); + err = fscrypt_get_encryption_info(inode); if (err) return 0; if (!f2fs_encrypted_inode(inode)) @@ -443,10 +443,10 @@ static int f2fs_file_open(struct inode *inode, struct file *filp) int ret = generic_file_open(inode, filp); if (!ret && f2fs_encrypted_inode(inode)) { - ret = f2fs_get_encryption_info(inode); + ret = fscrypt_get_encryption_info(inode); if (ret) return -EACCES; - if (!f2fs_encrypted_inode(inode)) + if (!fscrypt_has_encryption_key(inode)) return -ENOKEY; } return ret; @@ -526,7 +526,8 @@ static int truncate_partial_data_page(struct inode *inode, u64 from, truncate_out: f2fs_wait_on_page_writeback(page, DATA, true); zero_user(page, offset, PAGE_CACHE_SIZE - offset); - if (!cache_only || !f2fs_encrypted_inode(inode) || !S_ISREG(inode->i_mode)) + if (!cache_only || !f2fs_encrypted_inode(inode) || + !S_ISREG(inode->i_mode)) set_page_dirty(page); f2fs_put_page(page, 1); return 0; @@ -674,7 +675,7 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr) if (attr->ia_valid & ATTR_SIZE) { if (f2fs_encrypted_inode(inode) && - f2fs_get_encryption_info(inode)) + fscrypt_get_encryption_info(inode)) return -EACCES; if (attr->ia_size <= i_size_read(inode)) { @@ -1529,39 +1530,30 @@ static bool uuid_is_nonzero(__u8 u[16]) static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg) { -#ifdef CONFIG_F2FS_FS_ENCRYPTION - struct f2fs_encryption_policy policy; + struct fscrypt_policy policy; struct inode *inode = file_inode(filp); - if (copy_from_user(&policy, (struct f2fs_encryption_policy __user *)arg, - sizeof(policy))) + if (copy_from_user(&policy, (struct fscrypt_policy __user *)arg, + sizeof(policy))) return -EFAULT; f2fs_update_time(F2FS_I_SB(inode), REQ_TIME); - return f2fs_process_policy(&policy, inode); -#else - return -EOPNOTSUPP; -#endif + return fscrypt_process_policy(inode, &policy); } static int f2fs_ioc_get_encryption_policy(struct file *filp, unsigned long arg) { -#ifdef CONFIG_F2FS_FS_ENCRYPTION - struct f2fs_encryption_policy policy; + struct fscrypt_policy policy; struct inode *inode = file_inode(filp); int err; - err = f2fs_get_policy(inode, &policy); + err = fscrypt_get_policy(inode, &policy); if (err) return err; - if (copy_to_user((struct f2fs_encryption_policy __user *)arg, &policy, - sizeof(policy))) + if (copy_to_user((struct fscrypt_policy __user *)arg, &policy, sizeof(policy))) return -EFAULT; return 0; -#else - return -EOPNOTSUPP; -#endif } static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg) @@ -1873,8 +1865,8 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) ssize_t ret; if (f2fs_encrypted_inode(inode) && - !f2fs_has_encryption_key(inode) && - f2fs_get_encryption_info(inode)) + !fscrypt_has_encryption_key(inode) && + fscrypt_get_encryption_info(inode)) return -EACCES; inode_lock(inode); diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c index 1c00f2c..358214e 100644 --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -277,7 +277,7 @@ process_inline: } struct f2fs_dir_entry *find_in_inline_dir(struct inode *dir, - struct f2fs_filename *fname, struct page **res_page) + struct fscrypt_name *fname, struct page **res_page) { struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb); struct f2fs_inline_dentry *inline_dentry; @@ -535,7 +535,7 @@ bool f2fs_empty_inline_dir(struct inode *dir) } int f2fs_read_inline_dir(struct file *file, struct dir_context *ctx, - struct f2fs_str *fstr) + struct fscrypt_str *fstr) { struct inode *inode = file_inode(file); struct f2fs_inline_dentry *inline_dentry = NULL; diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index d447707..cb269c4 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -389,10 +389,7 @@ no_delete: } } out_clear: -#ifdef CONFIG_F2FS_FS_ENCRYPTION - if (fi->i_crypt_info) - f2fs_free_encryption_info(inode, fi->i_crypt_info); -#endif + fscrypt_put_encryption_info(inode, NULL); clear_inode(inode); } diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index b3c423a..3bddd9f 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -169,7 +169,7 @@ static int f2fs_link(struct dentry *old_dentry, struct inode *dir, int err; if (f2fs_encrypted_inode(dir) && - !f2fs_is_child_context_consistent_with_parent(dir, inode)) + !fscrypt_has_permitted_context(dir, inode)) return -EPERM; f2fs_balance_fs(sbi, true); @@ -352,20 +352,20 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry, struct f2fs_sb_info *sbi = F2FS_I_SB(dir); struct inode *inode; size_t len = strlen(symname); - struct f2fs_str disk_link = FSTR_INIT((char *)symname, len + 1); - struct f2fs_encrypted_symlink_data *sd = NULL; + struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1); + struct fscrypt_symlink_data *sd = NULL; int err; if (f2fs_encrypted_inode(dir)) { - err = f2fs_get_encryption_info(dir); + err = fscrypt_get_encryption_info(dir); if (err) return err; - if (!f2fs_encrypted_inode(dir)) + if (!fscrypt_has_encryption_key(dir)) return -EPERM; - disk_link.len = (f2fs_fname_encrypted_size(dir, len) + - sizeof(struct f2fs_encrypted_symlink_data)); + disk_link.len = (fscrypt_fname_encrypted_size(dir, len) + + sizeof(struct fscrypt_symlink_data)); } if (disk_link.len > dir->i_sb->s_blocksize) @@ -393,7 +393,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry, if (f2fs_encrypted_inode(inode)) { struct qstr istr = QSTR_INIT(symname, len); - struct f2fs_str ostr; + struct fscrypt_str ostr; sd = kzalloc(disk_link.len, GFP_NOFS); if (!sd) { @@ -401,18 +401,18 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry, goto err_out; } - err = f2fs_get_encryption_info(inode); + err = fscrypt_get_encryption_info(inode); if (err) goto err_out; - if (!f2fs_encrypted_inode(inode)) { + if (!fscrypt_has_encryption_key(inode)) { err = -EPERM; goto err_out; } ostr.name = sd->encrypted_path; ostr.len = disk_link.len; - err = f2fs_fname_usr_to_disk(inode, &istr, &ostr); + err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr); if (err < 0) goto err_out; @@ -593,7 +593,7 @@ out: static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) { if (f2fs_encrypted_inode(dir)) { - int err = f2fs_get_encryption_info(dir); + int err = fscrypt_get_encryption_info(dir); if (err) return err; } @@ -623,8 +623,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry, int err = -ENOENT; if ((old_dir != new_dir) && f2fs_encrypted_inode(new_dir) && - !f2fs_is_child_context_consistent_with_parent(new_dir, - old_inode)) { + !fscrypt_has_permitted_context(new_dir, old_inode)) { err = -EPERM; goto out; } @@ -804,11 +803,9 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry, int err = -ENOENT; if ((f2fs_encrypted_inode(old_dir) || f2fs_encrypted_inode(new_dir)) && - (old_dir != new_dir) && - (!f2fs_is_child_context_consistent_with_parent(new_dir, - old_inode) || - !f2fs_is_child_context_consistent_with_parent(old_dir, - new_inode))) + (old_dir != new_dir) && + (!fscrypt_has_permitted_context(new_dir, old_inode) || + !fscrypt_has_permitted_context(old_dir, new_inode))) return -EPERM; old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page); @@ -970,16 +967,15 @@ static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry, return f2fs_rename(old_dir, old_dentry, new_dir, new_dentry, flags); } -#ifdef CONFIG_F2FS_FS_ENCRYPTION static const char *f2fs_encrypted_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) { struct page *cpage = NULL; char *caddr, *paddr = NULL; - struct f2fs_str cstr = FSTR_INIT(NULL, 0); - struct f2fs_str pstr = FSTR_INIT(NULL, 0); - struct f2fs_encrypted_symlink_data *sd; + struct fscrypt_str cstr = FSTR_INIT(NULL, 0); + struct fscrypt_str pstr = FSTR_INIT(NULL, 0); + struct fscrypt_symlink_data *sd; loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1); u32 max_size = inode->i_sb->s_blocksize; int res; @@ -987,7 +983,7 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry, if (!dentry) return ERR_PTR(-ECHILD); - res = f2fs_get_encryption_info(inode); + res = fscrypt_get_encryption_info(inode); if (res) return ERR_PTR(res); @@ -998,7 +994,7 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry, caddr[size] = 0; /* Symlink is encrypted */ - sd = (struct f2fs_encrypted_symlink_data *)caddr; + sd = (struct fscrypt_symlink_data *)caddr; cstr.name = sd->encrypted_path; cstr.len = le16_to_cpu(sd->len); @@ -1014,17 +1010,16 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry, goto errout; } - if ((cstr.len + sizeof(struct f2fs_encrypted_symlink_data) - 1) > - max_size) { + if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) { /* Symlink data on the disk is corrupted */ res = -EIO; goto errout; } - res = f2fs_fname_crypto_alloc_buffer(inode, cstr.len, &pstr); + res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr); if (res) goto errout; - res = f2fs_fname_disk_to_usr(inode, NULL, &cstr, &pstr); + res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr); if (res < 0) goto errout; @@ -1037,7 +1032,7 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry, set_delayed_call(done, kfree_link, paddr); return paddr; errout: - f2fs_fname_crypto_free_buffer(&pstr); + fscrypt_fname_free_buffer(&pstr); page_cache_release(cpage); return ERR_PTR(res); } @@ -1054,7 +1049,6 @@ const struct inode_operations f2fs_encrypted_symlink_inode_operations = { .removexattr = generic_removexattr, #endif }; -#endif const struct inode_operations f2fs_dir_inode_operations = { .create = f2fs_create, diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 579372d9..7b62016 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -470,10 +470,6 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb) /* Will be used by directory only */ fi->i_dir_level = F2FS_SB(sb)->dir_level; - -#ifdef CONFIG_F2FS_FS_ENCRYPTION - fi->i_crypt_info = NULL; -#endif return &fi->vfs_inode; } @@ -507,11 +503,7 @@ static int f2fs_drop_inode(struct inode *inode) sb_end_intwrite(inode->i_sb); -#ifdef CONFIG_F2FS_FS_ENCRYPTION - if (F2FS_I(inode)->i_crypt_info) - f2fs_free_encryption_info(inode, - F2FS_I(inode)->i_crypt_info); -#endif + fscrypt_put_encryption_info(inode, NULL); spin_lock(&inode->i_lock); atomic_dec(&inode->i_count); } @@ -891,6 +883,41 @@ static struct super_operations f2fs_sops = { .remount_fs = f2fs_remount, }; +#ifdef CONFIG_F2FS_FS_ENCRYPTION +static int f2fs_get_context(struct inode *inode, void *ctx, size_t len) +{ + return f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION, + F2FS_XATTR_NAME_ENCRYPTION_CONTEXT, + ctx, len, NULL); +} + +static int f2fs_set_context(struct inode *inode, const void *ctx, size_t len, + void *fs_data) +{ + return f2fs_setxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION, + F2FS_XATTR_NAME_ENCRYPTION_CONTEXT, + ctx, len, fs_data, XATTR_CREATE); +} + +static unsigned f2fs_max_namelen(struct inode *inode) +{ + return S_ISLNK(inode->i_mode) ? + inode->i_sb->s_blocksize : F2FS_NAME_LEN; +} + +static struct fscrypt_operations f2fs_cryptops = { + .get_context = f2fs_get_context, + .set_context = f2fs_set_context, + .is_encrypted = f2fs_encrypted_inode, + .empty_dir = f2fs_empty_dir, + .max_namelen = f2fs_max_namelen, +}; +#else +static struct fscrypt_operations f2fs_cryptops = { + .is_encrypted = f2fs_encrypted_inode, +}; +#endif + static struct inode *f2fs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation) { @@ -1314,6 +1341,7 @@ try_onemore: get_random_bytes(&sbi->s_next_generation, sizeof(u32)); sb->s_op = &f2fs_sops; + sb->s_cop = &f2fs_cryptops; sb->s_xattr = f2fs_xattr_handlers; sb->s_export_op = &f2fs_export_ops; sb->s_magic = F2FS_SUPER_MAGIC; @@ -1619,13 +1647,9 @@ static int __init init_f2fs_fs(void) err = -ENOMEM; goto free_extent_cache; } - err = f2fs_init_crypto(); - if (err) - goto free_kset; - err = register_shrinker(&f2fs_shrinker_info); if (err) - goto free_crypto; + goto free_kset; err = register_filesystem(&f2fs_fs_type); if (err) @@ -1640,8 +1664,6 @@ free_filesystem: unregister_filesystem(&f2fs_fs_type); free_shrinker: unregister_shrinker(&f2fs_shrinker_info); -free_crypto: - f2fs_exit_crypto(); free_kset: kset_unregister(f2fs_kset); free_extent_cache: @@ -1664,7 +1686,6 @@ static void __exit exit_f2fs_fs(void) f2fs_destroy_root_stats(); unregister_shrinker(&f2fs_shrinker_info); unregister_filesystem(&f2fs_fs_type); - f2fs_exit_crypto(); destroy_extent_cache(); destroy_checkpoint_caches(); destroy_segment_manager_caches(); diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 7781ce11..c7bdfc5 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -228,6 +228,8 @@ struct dentry_operations { #define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */ #define DCACHE_OP_SELECT_INODE 0x02000000 /* Unioned entry: dcache op selects inode */ +#define DCACHE_ENCRYPTED_WITH_KEY 0x04000000 /* dir is encrypted with a valid key */ + extern seqlock_t rename_lock; /* diff --git a/include/linux/fs.h b/include/linux/fs.h index ae68100..28fc121 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -53,6 +53,8 @@ struct swap_info_struct; struct seq_file; struct workqueue_struct; struct iov_iter; +struct fscrypt_info; +struct fscrypt_operations; extern void __init inode_init(void); extern void __init inode_init_early(void); @@ -678,6 +680,10 @@ struct inode { struct hlist_head i_fsnotify_marks; #endif +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) + struct fscrypt_info *i_crypt_info; +#endif + void *i_private; /* fs or device private pointer */ }; @@ -1323,6 +1329,8 @@ struct super_block { #endif const struct xattr_handler **s_xattr; + const struct fscrypt_operations *s_cop; + struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */ struct list_head s_mounts; /* list of mounts; _not_ for fs use */ struct block_device *s_bdev; diff --git a/include/linux/fscrypto.h b/include/linux/fscrypto.h new file mode 100644 index 0000000..895cdac --- /dev/null +++ b/include/linux/fscrypto.h @@ -0,0 +1,433 @@ +/* + * General per-file encryption definition + * + * Copyright (C) 2015, Google, Inc. + * + * Written by Michael Halcrow, 2015. + * Modified by Jaegeuk Kim, 2015. + */ + +#ifndef _LINUX_FSCRYPTO_H +#define _LINUX_FSCRYPTO_H + +#include +#include +#include +#include +#include +#include + +#define FS_KEY_DERIVATION_NONCE_SIZE 16 +#define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1 + +#define FS_POLICY_FLAGS_PAD_4 0x00 +#define FS_POLICY_FLAGS_PAD_8 0x01 +#define FS_POLICY_FLAGS_PAD_16 0x02 +#define FS_POLICY_FLAGS_PAD_32 0x03 +#define FS_POLICY_FLAGS_PAD_MASK 0x03 +#define FS_POLICY_FLAGS_VALID 0x03 + +/* Encryption algorithms */ +#define FS_ENCRYPTION_MODE_INVALID 0 +#define FS_ENCRYPTION_MODE_AES_256_XTS 1 +#define FS_ENCRYPTION_MODE_AES_256_GCM 2 +#define FS_ENCRYPTION_MODE_AES_256_CBC 3 +#define FS_ENCRYPTION_MODE_AES_256_CTS 4 + +/** + * Encryption context for inode + * + * Protector format: + * 1 byte: Protector format (1 = this version) + * 1 byte: File contents encryption mode + * 1 byte: File names encryption mode + * 1 byte: Flags + * 8 bytes: Master Key descriptor + * 16 bytes: Encryption Key derivation nonce + */ +struct fscrypt_context { + u8 format; + u8 contents_encryption_mode; + u8 filenames_encryption_mode; + u8 flags; + u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE]; + u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; +} __packed; + +/* Encryption parameters */ +#define FS_XTS_TWEAK_SIZE 16 +#define FS_AES_128_ECB_KEY_SIZE 16 +#define FS_AES_256_GCM_KEY_SIZE 32 +#define FS_AES_256_CBC_KEY_SIZE 32 +#define FS_AES_256_CTS_KEY_SIZE 32 +#define FS_AES_256_XTS_KEY_SIZE 64 +#define FS_MAX_KEY_SIZE 64 + +#define FS_KEY_DESC_PREFIX "fscrypt:" +#define FS_KEY_DESC_PREFIX_SIZE 8 + +/* This is passed in from userspace into the kernel keyring */ +struct fscrypt_key { + u32 mode; + u8 raw[FS_MAX_KEY_SIZE]; + u32 size; +} __packed; + +struct fscrypt_info { + u8 ci_data_mode; + u8 ci_filename_mode; + u8 ci_flags; + struct crypto_ablkcipher *ci_ctfm; + struct key *ci_keyring_key; + u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE]; +}; + +#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 +#define FS_WRITE_PATH_FL 0x00000002 + +struct fscrypt_ctx { + union { + struct { + struct page *bounce_page; /* Ciphertext page */ + struct page *control_page; /* Original page */ + } w; + struct { + struct bio *bio; + struct work_struct work; + } r; + struct list_head free_list; /* Free list */ + }; + u8 flags; /* Flags */ + u8 mode; /* Encryption mode for tfm */ +}; + +struct fscrypt_completion_result { + struct completion completion; + int res; +}; + +#define DECLARE_FS_COMPLETION_RESULT(ecr) \ + struct fscrypt_completion_result ecr = { \ + COMPLETION_INITIALIZER((ecr).completion), 0 } + +static inline int fscrypt_key_size(int mode) +{ + switch (mode) { + case FS_ENCRYPTION_MODE_AES_256_XTS: + return FS_AES_256_XTS_KEY_SIZE; + case FS_ENCRYPTION_MODE_AES_256_GCM: + return FS_AES_256_GCM_KEY_SIZE; + case FS_ENCRYPTION_MODE_AES_256_CBC: + return FS_AES_256_CBC_KEY_SIZE; + case FS_ENCRYPTION_MODE_AES_256_CTS: + return FS_AES_256_CTS_KEY_SIZE; + default: + BUG(); + } + return 0; +} + +#define FS_FNAME_NUM_SCATTER_ENTRIES 4 +#define FS_CRYPTO_BLOCK_SIZE 16 +#define FS_FNAME_CRYPTO_DIGEST_SIZE 32 + +/** + * For encrypted symlinks, the ciphertext length is stored at the beginning + * of the string in little-endian format. + */ +struct fscrypt_symlink_data { + __le16 len; + char encrypted_path[1]; +} __packed; + +/** + * This function is used to calculate the disk space required to + * store a filename of length l in encrypted symlink format. + */ +static inline u32 fscrypt_symlink_data_len(u32 l) +{ + if (l < FS_CRYPTO_BLOCK_SIZE) + l = FS_CRYPTO_BLOCK_SIZE; + return (l + sizeof(struct fscrypt_symlink_data) - 1); +} + +struct fscrypt_str { + unsigned char *name; + u32 len; +}; + +struct fscrypt_name { + const struct qstr *usr_fname; + struct fscrypt_str disk_name; + u32 hash; + u32 minor_hash; + struct fscrypt_str crypto_buf; +}; + +#define FSTR_INIT(n, l) { .name = n, .len = l } +#define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len) +#define fname_name(p) ((p)->disk_name.name) +#define fname_len(p) ((p)->disk_name.len) + +/* + * crypto opertions for filesystems + */ +struct fscrypt_operations { + int (*get_context)(struct inode *, void *, size_t); + int (*prepare_context)(struct inode *); + int (*set_context)(struct inode *, const void *, size_t, void *); + int (*dummy_context)(struct inode *); + bool (*is_encrypted)(struct inode *); + bool (*empty_dir)(struct inode *); + unsigned (*max_namelen)(struct inode *); +}; + +static inline bool fscrypt_dummy_context_enabled(struct inode *inode) +{ + if (inode->i_sb->s_cop->dummy_context && + inode->i_sb->s_cop->dummy_context(inode)) + return true; + return false; +} + +static inline bool fscrypt_valid_contents_enc_mode(u32 mode) +{ + return (mode == FS_ENCRYPTION_MODE_AES_256_XTS); +} + +static inline bool fscrypt_valid_filenames_enc_mode(u32 mode) +{ + return (mode == FS_ENCRYPTION_MODE_AES_256_CTS); +} + +static inline u32 fscrypt_validate_encryption_key_size(u32 mode, u32 size) +{ + if (size == fscrypt_key_size(mode)) + return size; + return 0; +} + +static inline bool fscrypt_is_dot_dotdot(const struct qstr *str) +{ + if (str->len == 1 && str->name[0] == '.') + return true; + + if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.') + return true; + + return false; +} + +static inline struct page *fscrypt_control_page(struct page *page) +{ +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) + return ((struct fscrypt_ctx *)page_private(page))->w.control_page; +#else + WARN_ON_ONCE(1); + return ERR_PTR(-EINVAL); +#endif +} + +static inline int fscrypt_has_encryption_key(struct inode *inode) +{ +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) + return (inode->i_crypt_info != NULL); +#else + return 0; +#endif +} + +static inline void fscrypt_set_encrypted_dentry(struct dentry *dentry) +{ +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_ENCRYPTED_WITH_KEY; + spin_unlock(&dentry->d_lock); +#endif +} + +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) +extern const struct dentry_operations fscrypt_d_ops; +#endif + +static inline void fscrypt_set_d_op(struct dentry *dentry) +{ +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) + d_set_d_op(dentry, &fscrypt_d_ops); +#endif +} + +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) +/* crypto.c */ +extern struct kmem_cache *fscrypt_info_cachep; +int fscrypt_initialize(void); + +extern struct fscrypt_ctx *fscrypt_get_ctx(struct inode *); +extern void fscrypt_release_ctx(struct fscrypt_ctx *); +extern struct page *fscrypt_encrypt_page(struct inode *, struct page *); +extern int fscrypt_decrypt_page(struct page *); +extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *); +extern void fscrypt_pullback_bio_page(struct page **, bool); +extern void fscrypt_restore_control_page(struct page *); +extern int fscrypt_zeroout_range(struct inode *, pgoff_t, sector_t, + unsigned int); +/* policy.c */ +extern int fscrypt_process_policy(struct inode *, + const struct fscrypt_policy *); +extern int fscrypt_get_policy(struct inode *, struct fscrypt_policy *); +extern int fscrypt_has_permitted_context(struct inode *, struct inode *); +extern int fscrypt_inherit_context(struct inode *, struct inode *, + void *, bool); +/* keyinfo.c */ +extern int get_crypt_info(struct inode *); +extern int fscrypt_get_encryption_info(struct inode *); +extern void fscrypt_put_encryption_info(struct inode *, struct fscrypt_info *); + +/* fname.c */ +extern int fscrypt_setup_filename(struct inode *, const struct qstr *, + int lookup, struct fscrypt_name *); +extern void fscrypt_free_filename(struct fscrypt_name *); +extern u32 fscrypt_fname_encrypted_size(struct inode *, u32); +extern int fscrypt_fname_alloc_buffer(struct inode *, u32, + struct fscrypt_str *); +extern void fscrypt_fname_free_buffer(struct fscrypt_str *); +extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32, + const struct fscrypt_str *, struct fscrypt_str *); +extern int fscrypt_fname_usr_to_disk(struct inode *, const struct qstr *, + struct fscrypt_str *); +#endif + +/* crypto.c */ +static inline struct fscrypt_ctx *fscrypt_notsupp_get_ctx(struct inode *i) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +static inline void fscrypt_notsupp_release_ctx(struct fscrypt_ctx *c) +{ + return; +} + +static inline struct page *fscrypt_notsupp_encrypt_page(struct inode *i, + struct page *p) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +static inline int fscrypt_notsupp_decrypt_page(struct page *p) +{ + return -EOPNOTSUPP; +} + +static inline void fscrypt_notsupp_decrypt_bio_pages(struct fscrypt_ctx *c, + struct bio *b) +{ + return; +} + +static inline void fscrypt_notsupp_pullback_bio_page(struct page **p, bool b) +{ + return; +} + +static inline void fscrypt_notsupp_restore_control_page(struct page *p) +{ + return; +} + +static inline int fscrypt_notsupp_zeroout_range(struct inode *i, pgoff_t p, + sector_t s, unsigned int f) +{ + return -EOPNOTSUPP; +} + +/* policy.c */ +static inline int fscrypt_notsupp_process_policy(struct inode *i, + const struct fscrypt_policy *p) +{ + return -EOPNOTSUPP; +} + +static inline int fscrypt_notsupp_get_policy(struct inode *i, + struct fscrypt_policy *p) +{ + return -EOPNOTSUPP; +} + +static inline int fscrypt_notsupp_has_permitted_context(struct inode *p, + struct inode *i) +{ + return 0; +} + +static inline int fscrypt_notsupp_inherit_context(struct inode *p, + struct inode *i, void *v, bool b) +{ + return -EOPNOTSUPP; +} + +/* keyinfo.c */ +static inline int fscrypt_notsupp_get_encryption_info(struct inode *i) +{ + return -EOPNOTSUPP; +} + +static inline void fscrypt_notsupp_put_encryption_info(struct inode *i, + struct fscrypt_info *f) +{ + return; +} + + /* fname.c */ +static inline int fscrypt_notsupp_setup_filename(struct inode *dir, + const struct qstr *iname, + int lookup, struct fscrypt_name *fname) +{ + if (dir->i_sb->s_cop->is_encrypted(dir)) + return -EOPNOTSUPP; + + memset(fname, 0, sizeof(struct fscrypt_name)); + fname->usr_fname = iname; + fname->disk_name.name = (unsigned char *)iname->name; + fname->disk_name.len = iname->len; + return 0; +} + +static inline void fscrypt_notsupp_free_filename(struct fscrypt_name *fname) +{ + return; +} + +static inline u32 fscrypt_notsupp_fname_encrypted_size(struct inode *i, u32 s) +{ + /* never happens */ + WARN_ON(1); + return 0; +} + +static inline int fscrypt_notsupp_fname_alloc_buffer(struct inode *inode, + u32 ilen, struct fscrypt_str *crypto_str) +{ + return -EOPNOTSUPP; +} + +static inline void fscrypt_notsupp_fname_free_buffer(struct fscrypt_str *c) +{ + return; +} + +static inline int fscrypt_notsupp_fname_disk_to_usr(struct inode *inode, + u32 hash, u32 minor_hash, + const struct fscrypt_str *iname, + struct fscrypt_str *oname) +{ + return -EOPNOTSUPP; +} + +static inline int fscrypt_notsupp_fname_usr_to_disk(struct inode *inode, + const struct qstr *iname, + struct fscrypt_str *oname) +{ + return -EOPNOTSUPP; +} +#endif /* _LINUX_FSCRYPTO_H */ diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 149bec8..cec100b 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -247,6 +247,24 @@ struct fsxattr { #define FS_IOC_FSSETXATTR _IOW ('X', 32, struct fsxattr) /* + * File system encryption support + */ +/* Policy provided via an ioctl on the topmost directory */ +#define FS_KEY_DESCRIPTOR_SIZE 8 + +struct fscrypt_policy { + __u8 version; + __u8 contents_encryption_mode; + __u8 filenames_encryption_mode; + __u8 flags; + __u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE]; +} __packed; + +#define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy) +#define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16]) +#define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy) + +/* * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS) * * Note: for historical reasons, these flags were originally used and -- cgit v0.10.2