diff options
Diffstat (limited to 'fs/crypto')
-rw-r--r-- | fs/crypto/bio.c | 35 | ||||
-rw-r--r-- | fs/crypto/crypto.c | 55 | ||||
-rw-r--r-- | fs/crypto/fname.c | 32 | ||||
-rw-r--r-- | fs/crypto/fscrypt_private.h | 24 | ||||
-rw-r--r-- | fs/crypto/hooks.c | 5 | ||||
-rw-r--r-- | fs/crypto/keyinfo.c | 286 |
6 files changed, 259 insertions, 178 deletions
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c index 0d5e6a569d58..0959044c5cee 100644 --- a/fs/crypto/bio.c +++ b/fs/crypto/bio.c @@ -26,15 +26,8 @@ #include <linux/namei.h> #include "fscrypt_private.h" -/* - * Call fscrypt_decrypt_page on every single page, reusing the encryption - * context. - */ -static void completion_pages(struct work_struct *work) +static void __fscrypt_decrypt_bio(struct bio *bio, bool done) { - struct fscrypt_ctx *ctx = - container_of(work, struct fscrypt_ctx, r.work); - struct bio *bio = ctx->r.bio; struct bio_vec *bv; int i; @@ -46,22 +39,38 @@ static void completion_pages(struct work_struct *work) if (ret) { WARN_ON_ONCE(1); SetPageError(page); - } else { + } else if (done) { SetPageUptodate(page); } - unlock_page(page); + if (done) + unlock_page(page); } +} + +void fscrypt_decrypt_bio(struct bio *bio) +{ + __fscrypt_decrypt_bio(bio, false); +} +EXPORT_SYMBOL(fscrypt_decrypt_bio); + +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; + + __fscrypt_decrypt_bio(bio, true); fscrypt_release_ctx(ctx); bio_put(bio); } -void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *ctx, struct bio *bio) +void fscrypt_enqueue_decrypt_bio(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); + fscrypt_enqueue_decrypt_work(&ctx->r.work); } -EXPORT_SYMBOL(fscrypt_decrypt_bio_pages); +EXPORT_SYMBOL(fscrypt_enqueue_decrypt_bio); void fscrypt_pullback_bio_page(struct page **page, bool restore) { diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index ce654526c0fb..0f46cf550907 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -45,12 +45,18 @@ static mempool_t *fscrypt_bounce_page_pool = NULL; static LIST_HEAD(fscrypt_free_ctxs); static DEFINE_SPINLOCK(fscrypt_ctx_lock); -struct workqueue_struct *fscrypt_read_workqueue; +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; +void fscrypt_enqueue_decrypt_work(struct work_struct *work) +{ + queue_work(fscrypt_read_workqueue, work); +} +EXPORT_SYMBOL(fscrypt_enqueue_decrypt_work); + /** * fscrypt_release_ctx() - Releases an encryption context * @ctx: The encryption context to release. @@ -156,12 +162,8 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw, } req = skcipher_request_alloc(tfm, gfp_flags); - if (!req) { - printk_ratelimited(KERN_ERR - "%s: crypto_request_alloc() failed\n", - __func__); + if (!req) return -ENOMEM; - } skcipher_request_set_callback( req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, @@ -178,9 +180,10 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw, res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); skcipher_request_free(req); if (res) { - printk_ratelimited(KERN_ERR - "%s: crypto_skcipher_encrypt() returned %d\n", - __func__, res); + fscrypt_err(inode->i_sb, + "%scryption failed for inode %lu, block %llu: %d", + (rw == FS_DECRYPT ? "de" : "en"), + inode->i_ino, lblk_num, res); return res; } return 0; @@ -326,7 +329,6 @@ static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags) return 0; } - /* 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); @@ -353,7 +355,6 @@ static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags) const struct dentry_operations fscrypt_d_ops = { .d_revalidate = fscrypt_d_revalidate, }; -EXPORT_SYMBOL(fscrypt_d_ops); void fscrypt_restore_control_page(struct page *page) { @@ -422,13 +423,43 @@ fail: return res; } +void fscrypt_msg(struct super_block *sb, const char *level, + const char *fmt, ...) +{ + static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + struct va_format vaf; + va_list args; + + if (!__ratelimit(&rs)) + return; + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + if (sb) + printk("%sfscrypt (%s): %pV\n", level, sb->s_id, &vaf); + else + printk("%sfscrypt: %pV\n", level, &vaf); + va_end(args); +} + /** * fscrypt_init() - Set up for fs encryption. */ static int __init fscrypt_init(void) { + /* + * Use an unbound workqueue to allow bios to be decrypted in parallel + * even when they happen to complete on the same CPU. This sacrifices + * locality, but it's worthwhile since decryption is CPU-intensive. + * + * Also use a high-priority workqueue to prioritize decryption work, + * which blocks reads from completing, over regular application tasks. + */ fscrypt_read_workqueue = alloc_workqueue("fscrypt_read_queue", - WQ_HIGHPRI, 0); + WQ_UNBOUND | WQ_HIGHPRI, + num_online_cpus()); if (!fscrypt_read_workqueue) goto fail; diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index e33f3d3c5ade..d7a0f682ca12 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -59,11 +59,8 @@ int fname_encrypt(struct inode *inode, const struct qstr *iname, /* Set up the encryption request */ req = skcipher_request_alloc(tfm, GFP_NOFS); - if (!req) { - printk_ratelimited(KERN_ERR - "%s: skcipher_request_alloc() failed\n", __func__); + if (!req) return -ENOMEM; - } skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, crypto_req_done, &wait); @@ -74,8 +71,9 @@ int fname_encrypt(struct inode *inode, const struct qstr *iname, res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); skcipher_request_free(req); if (res < 0) { - printk_ratelimited(KERN_ERR - "%s: Error (error code %d)\n", __func__, res); + fscrypt_err(inode->i_sb, + "Filename encryption failed for inode %lu: %d", + inode->i_ino, res); return res; } @@ -96,23 +94,14 @@ static int fname_decrypt(struct inode *inode, struct skcipher_request *req = NULL; DECLARE_CRYPTO_WAIT(wait); struct scatterlist src_sg, dst_sg; - struct fscrypt_info *ci = inode->i_crypt_info; - struct crypto_skcipher *tfm = ci->ci_ctfm; + struct crypto_skcipher *tfm = inode->i_crypt_info->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 = skcipher_request_alloc(tfm, GFP_NOFS); - if (!req) { - printk_ratelimited(KERN_ERR - "%s: crypto_request_alloc() failed\n", __func__); + if (!req) return -ENOMEM; - } skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, crypto_req_done, &wait); @@ -127,8 +116,9 @@ static int fname_decrypt(struct inode *inode, res = crypto_wait_req(crypto_skcipher_decrypt(req), &wait); skcipher_request_free(req); if (res < 0) { - printk_ratelimited(KERN_ERR - "%s: Error (error code %d)\n", __func__, res); + fscrypt_err(inode->i_sb, + "Filename decryption failed for inode %lu: %d", + inode->i_ino, res); return res; } @@ -341,12 +331,12 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, return 0; } ret = fscrypt_get_encryption_info(dir); - if (ret && ret != -EOPNOTSUPP) + if (ret) return ret; if (dir->i_crypt_info) { if (!fscrypt_fname_encrypted_size(dir, iname->len, - dir->i_sb->s_cop->max_namelen(dir), + dir->i_sb->s_cop->max_namelen, &fname->crypto_buf.len)) return -ENAMETOOLONG; fname->crypto_buf.name = kmalloc(fname->crypto_buf.len, diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index ad6722bae8b7..39c20ef26db4 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -18,15 +18,7 @@ /* Encryption parameters */ #define FS_IV_SIZE 16 -#define FS_AES_128_ECB_KEY_SIZE 16 -#define FS_AES_128_CBC_KEY_SIZE 16 -#define FS_AES_128_CTS_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_KEY_DERIVATION_NONCE_SIZE 16 +#define FS_KEY_DERIVATION_NONCE_SIZE 16 /** * Encryption context for inode @@ -91,13 +83,16 @@ static inline bool fscrypt_valid_enc_modes(u32 contents_mode, filenames_mode == FS_ENCRYPTION_MODE_AES_256_CTS) return true; + if (contents_mode == FS_ENCRYPTION_MODE_SPECK128_256_XTS && + filenames_mode == FS_ENCRYPTION_MODE_SPECK128_256_CTS) + return true; + return false; } /* crypto.c */ extern struct kmem_cache *fscrypt_info_cachep; extern int fscrypt_initialize(unsigned int cop_flags); -extern struct workqueue_struct *fscrypt_read_workqueue; extern int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw, u64 lblk_num, struct page *src_page, @@ -106,6 +101,15 @@ extern int fscrypt_do_page_crypto(const struct inode *inode, gfp_t gfp_flags); extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags); +extern const struct dentry_operations fscrypt_d_ops; + +extern void __printf(3, 4) __cold +fscrypt_msg(struct super_block *sb, const char *level, const char *fmt, ...); + +#define fscrypt_warn(sb, fmt, ...) \ + fscrypt_msg(sb, KERN_WARNING, fmt, ##__VA_ARGS__) +#define fscrypt_err(sb, fmt, ...) \ + fscrypt_msg(sb, KERN_ERR, fmt, ##__VA_ARGS__) /* fname.c */ extern int fname_encrypt(struct inode *inode, const struct qstr *iname, diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index bec06490fb13..926e5df20ec3 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -39,8 +39,9 @@ int fscrypt_file_open(struct inode *inode, struct file *filp) dir = dget_parent(file_dentry(filp)); if (IS_ENCRYPTED(d_inode(dir)) && !fscrypt_has_permitted_context(d_inode(dir), inode)) { - pr_warn_ratelimited("fscrypt: inconsistent encryption contexts: %lu/%lu", - d_inode(dir)->i_ino, inode->i_ino); + fscrypt_warn(inode->i_sb, + "inconsistent encryption contexts: %lu/%lu", + d_inode(dir)->i_ino, inode->i_ino); err = -EPERM; } dput(dir); diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c index 05f5ee1f0705..e997ca51192f 100644 --- a/fs/crypto/keyinfo.c +++ b/fs/crypto/keyinfo.c @@ -19,17 +19,16 @@ static struct crypto_shash *essiv_hash_tfm; -/** - * 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_raw_key: Derived raw key. +/* + * Key derivation function. This generates the derived key by encrypting the + * master key with AES-128-ECB using the inode's nonce as the AES key. * - * Return: Zero on success; non-zero otherwise. + * The master key must be at least as long as the derived key. If the master + * key is longer, then only the first 'derived_keysize' bytes are used. */ -static int derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE], - const struct fscrypt_key *source_key, - u8 derived_raw_key[FS_MAX_KEY_SIZE]) +static int derive_key_aes(const u8 *master_key, + const struct fscrypt_context *ctx, + u8 *derived_key, unsigned int derived_keysize) { int res = 0; struct skcipher_request *req = NULL; @@ -51,14 +50,13 @@ static int derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE], skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, crypto_req_done, &wait); - res = crypto_skcipher_setkey(tfm, deriving_key, - FS_AES_128_ECB_KEY_SIZE); + res = crypto_skcipher_setkey(tfm, ctx->nonce, sizeof(ctx->nonce)); if (res < 0) goto out; - sg_init_one(&src_sg, source_key->raw, source_key->size); - sg_init_one(&dst_sg, derived_raw_key, source_key->size); - skcipher_request_set_crypt(req, &src_sg, &dst_sg, source_key->size, + sg_init_one(&src_sg, master_key, derived_keysize); + sg_init_one(&dst_sg, derived_key, derived_keysize); + skcipher_request_set_crypt(req, &src_sg, &dst_sg, derived_keysize, NULL); res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); out: @@ -67,101 +65,147 @@ out: return res; } -static int validate_user_key(struct fscrypt_info *crypt_info, - struct fscrypt_context *ctx, u8 *raw_key, - const char *prefix, int min_keysize) +/* + * Search the current task's subscribed keyrings for a "logon" key with + * description prefix:descriptor, and if found acquire a read lock on it and + * return a pointer to its validated payload in *payload_ret. + */ +static struct key * +find_and_lock_process_key(const char *prefix, + const u8 descriptor[FS_KEY_DESCRIPTOR_SIZE], + unsigned int min_keysize, + const struct fscrypt_key **payload_ret) { char *description; - struct key *keyring_key; - struct fscrypt_key *master_key; + struct key *key; const struct user_key_payload *ukp; - int res; + const struct fscrypt_key *payload; description = kasprintf(GFP_NOFS, "%s%*phN", prefix, - FS_KEY_DESCRIPTOR_SIZE, - ctx->master_key_descriptor); + FS_KEY_DESCRIPTOR_SIZE, descriptor); if (!description) - return -ENOMEM; + return ERR_PTR(-ENOMEM); - keyring_key = request_key(&key_type_logon, description, NULL); + key = request_key(&key_type_logon, description, NULL); kfree(description); - if (IS_ERR(keyring_key)) - return PTR_ERR(keyring_key); - down_read(&keyring_key->sem); - - if (keyring_key->type != &key_type_logon) { - printk_once(KERN_WARNING - "%s: key type must be logon\n", __func__); - res = -ENOKEY; - goto out; - } - ukp = user_key_payload_locked(keyring_key); - if (!ukp) { - /* key was revoked before we acquired its semaphore */ - res = -EKEYREVOKED; - goto out; + if (IS_ERR(key)) + return key; + + down_read(&key->sem); + ukp = user_key_payload_locked(key); + + if (!ukp) /* was the key revoked before we acquired its semaphore? */ + goto invalid; + + payload = (const struct fscrypt_key *)ukp->data; + + if (ukp->datalen != sizeof(struct fscrypt_key) || + payload->size < 1 || payload->size > FS_MAX_KEY_SIZE) { + fscrypt_warn(NULL, + "key with description '%s' has invalid payload", + key->description); + goto invalid; } - if (ukp->datalen != sizeof(struct fscrypt_key)) { - res = -EINVAL; - goto out; + + if (payload->size < min_keysize) { + fscrypt_warn(NULL, + "key with description '%s' is too short (got %u bytes, need %u+ bytes)", + key->description, payload->size, min_keysize); + goto invalid; } - 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 < min_keysize || master_key->size > FS_MAX_KEY_SIZE - || master_key->size % AES_BLOCK_SIZE != 0) { - printk_once(KERN_WARNING - "%s: key size incorrect: %d\n", - __func__, master_key->size); - res = -ENOKEY; - goto out; + + *payload_ret = payload; + return key; + +invalid: + up_read(&key->sem); + key_put(key); + return ERR_PTR(-ENOKEY); +} + +/* Find the master key, then derive the inode's actual encryption key */ +static int find_and_derive_key(const struct inode *inode, + const struct fscrypt_context *ctx, + u8 *derived_key, unsigned int derived_keysize) +{ + struct key *key; + const struct fscrypt_key *payload; + int err; + + key = find_and_lock_process_key(FS_KEY_DESC_PREFIX, + ctx->master_key_descriptor, + derived_keysize, &payload); + if (key == ERR_PTR(-ENOKEY) && inode->i_sb->s_cop->key_prefix) { + key = find_and_lock_process_key(inode->i_sb->s_cop->key_prefix, + ctx->master_key_descriptor, + derived_keysize, &payload); } - res = derive_key_aes(ctx->nonce, master_key, raw_key); -out: - up_read(&keyring_key->sem); - key_put(keyring_key); - return res; + if (IS_ERR(key)) + return PTR_ERR(key); + err = derive_key_aes(payload->raw, ctx, derived_key, derived_keysize); + up_read(&key->sem); + key_put(key); + return err; } -static const struct { +static struct fscrypt_mode { + const char *friendly_name; const char *cipher_str; int keysize; + bool logged_impl_name; } available_modes[] = { - [FS_ENCRYPTION_MODE_AES_256_XTS] = { "xts(aes)", - FS_AES_256_XTS_KEY_SIZE }, - [FS_ENCRYPTION_MODE_AES_256_CTS] = { "cts(cbc(aes))", - FS_AES_256_CTS_KEY_SIZE }, - [FS_ENCRYPTION_MODE_AES_128_CBC] = { "cbc(aes)", - FS_AES_128_CBC_KEY_SIZE }, - [FS_ENCRYPTION_MODE_AES_128_CTS] = { "cts(cbc(aes))", - FS_AES_128_CTS_KEY_SIZE }, + [FS_ENCRYPTION_MODE_AES_256_XTS] = { + .friendly_name = "AES-256-XTS", + .cipher_str = "xts(aes)", + .keysize = 64, + }, + [FS_ENCRYPTION_MODE_AES_256_CTS] = { + .friendly_name = "AES-256-CTS-CBC", + .cipher_str = "cts(cbc(aes))", + .keysize = 32, + }, + [FS_ENCRYPTION_MODE_AES_128_CBC] = { + .friendly_name = "AES-128-CBC", + .cipher_str = "cbc(aes)", + .keysize = 16, + }, + [FS_ENCRYPTION_MODE_AES_128_CTS] = { + .friendly_name = "AES-128-CTS-CBC", + .cipher_str = "cts(cbc(aes))", + .keysize = 16, + }, + [FS_ENCRYPTION_MODE_SPECK128_256_XTS] = { + .friendly_name = "Speck128/256-XTS", + .cipher_str = "xts(speck128)", + .keysize = 64, + }, + [FS_ENCRYPTION_MODE_SPECK128_256_CTS] = { + .friendly_name = "Speck128/256-CTS-CBC", + .cipher_str = "cts(cbc(speck128))", + .keysize = 32, + }, }; -static int determine_cipher_type(struct fscrypt_info *ci, struct inode *inode, - const char **cipher_str_ret, int *keysize_ret) +static struct fscrypt_mode * +select_encryption_mode(const struct fscrypt_info *ci, const struct inode *inode) { - u32 mode; - if (!fscrypt_valid_enc_modes(ci->ci_data_mode, ci->ci_filename_mode)) { - pr_warn_ratelimited("fscrypt: inode %lu uses unsupported encryption modes (contents mode %d, filenames mode %d)\n", - inode->i_ino, - ci->ci_data_mode, ci->ci_filename_mode); - return -EINVAL; + fscrypt_warn(inode->i_sb, + "inode %lu uses unsupported encryption modes (contents mode %d, filenames mode %d)", + inode->i_ino, ci->ci_data_mode, + ci->ci_filename_mode); + return ERR_PTR(-EINVAL); } - if (S_ISREG(inode->i_mode)) { - mode = ci->ci_data_mode; - } else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) { - mode = ci->ci_filename_mode; - } else { - WARN_ONCE(1, "fscrypt: filesystem tried to load encryption info for inode %lu, which is not encryptable (file type %d)\n", - inode->i_ino, (inode->i_mode & S_IFMT)); - return -EINVAL; - } + if (S_ISREG(inode->i_mode)) + return &available_modes[ci->ci_data_mode]; + + if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) + return &available_modes[ci->ci_filename_mode]; - *cipher_str_ret = available_modes[mode].cipher_str; - *keysize_ret = available_modes[mode].keysize; - return 0; + WARN_ONCE(1, "fscrypt: filesystem tried to load encryption info for inode %lu, which is not encryptable (file type %d)\n", + inode->i_ino, (inode->i_mode & S_IFMT)); + return ERR_PTR(-EINVAL); } static void put_crypt_info(struct fscrypt_info *ci) @@ -184,8 +228,9 @@ static int derive_essiv_salt(const u8 *key, int keysize, u8 *salt) tfm = crypto_alloc_shash("sha256", 0, 0); if (IS_ERR(tfm)) { - pr_warn_ratelimited("fscrypt: error allocating SHA-256 transform: %ld\n", - PTR_ERR(tfm)); + fscrypt_warn(NULL, + "error allocating SHA-256 transform: %ld", + PTR_ERR(tfm)); return PTR_ERR(tfm); } prev_tfm = cmpxchg(&essiv_hash_tfm, NULL, tfm); @@ -245,8 +290,7 @@ int fscrypt_get_encryption_info(struct inode *inode) struct fscrypt_info *crypt_info; struct fscrypt_context ctx; struct crypto_skcipher *ctfm; - const char *cipher_str; - int keysize; + struct fscrypt_mode *mode; u8 *raw_key = NULL; int res; @@ -290,57 +334,59 @@ int fscrypt_get_encryption_info(struct inode *inode) memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor, sizeof(crypt_info->ci_master_key)); - res = determine_cipher_type(crypt_info, inode, &cipher_str, &keysize); - if (res) + mode = select_encryption_mode(crypt_info, inode); + if (IS_ERR(mode)) { + res = PTR_ERR(mode); goto out; + } /* * This cannot be a stack buffer because it is passed to the scatterlist * crypto API as part of key derivation. */ res = -ENOMEM; - raw_key = kmalloc(FS_MAX_KEY_SIZE, GFP_NOFS); + raw_key = kmalloc(mode->keysize, GFP_NOFS); if (!raw_key) goto out; - res = validate_user_key(crypt_info, &ctx, raw_key, FS_KEY_DESC_PREFIX, - keysize); - if (res && inode->i_sb->s_cop->key_prefix) { - int res2 = validate_user_key(crypt_info, &ctx, raw_key, - inode->i_sb->s_cop->key_prefix, - keysize); - if (res2) { - if (res2 == -ENOKEY) - res = -ENOKEY; - goto out; - } - } else if (res) { + res = find_and_derive_key(inode, &ctx, raw_key, mode->keysize); + if (res) goto out; - } - ctfm = crypto_alloc_skcipher(cipher_str, 0, 0); - if (!ctfm || IS_ERR(ctfm)) { - res = ctfm ? PTR_ERR(ctfm) : -ENOMEM; - pr_debug("%s: error %d (inode %lu) allocating crypto tfm\n", - __func__, res, inode->i_ino); + + ctfm = crypto_alloc_skcipher(mode->cipher_str, 0, 0); + if (IS_ERR(ctfm)) { + res = PTR_ERR(ctfm); + fscrypt_warn(inode->i_sb, + "error allocating '%s' transform for inode %lu: %d", + mode->cipher_str, inode->i_ino, res); goto out; } + if (unlikely(!mode->logged_impl_name)) { + /* + * fscrypt performance can vary greatly depending on which + * crypto algorithm implementation is used. Help people debug + * performance problems by logging the ->cra_driver_name the + * first time a mode is used. Note that multiple threads can + * race here, but it doesn't really matter. + */ + mode->logged_impl_name = true; + pr_info("fscrypt: %s using implementation \"%s\"\n", + mode->friendly_name, + crypto_skcipher_alg(ctfm)->base.cra_driver_name); + } crypt_info->ci_ctfm = ctfm; - crypto_skcipher_clear_flags(ctfm, ~0); crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_REQ_WEAK_KEY); - /* - * if the provided key is longer than keysize, we use the first - * keysize bytes of the derived key only - */ - res = crypto_skcipher_setkey(ctfm, raw_key, keysize); + res = crypto_skcipher_setkey(ctfm, raw_key, mode->keysize); if (res) goto out; if (S_ISREG(inode->i_mode) && crypt_info->ci_data_mode == FS_ENCRYPTION_MODE_AES_128_CBC) { - res = init_essiv_generator(crypt_info, raw_key, keysize); + res = init_essiv_generator(crypt_info, raw_key, mode->keysize); if (res) { - pr_debug("%s: error %d (inode %lu) allocating essiv tfm\n", - __func__, res, inode->i_ino); + fscrypt_warn(inode->i_sb, + "error initializing ESSIV generator for inode %lu: %d", + inode->i_ino, res); goto out; } } |