diff options
| -rw-r--r-- | fs/crypto/fname.c | 53 |
1 files changed, 21 insertions, 32 deletions
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index 9a28133ac3b8..9b774f4b50c8 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -39,65 +39,54 @@ static void fname_crypt_complete(struct crypto_async_request *req, int res) static int fname_encrypt(struct inode *inode, const struct qstr *iname, struct fscrypt_str *oname) { - u32 ciphertext_len; struct skcipher_request *req = NULL; DECLARE_FS_COMPLETION_RESULT(ecr); struct fscrypt_info *ci = inode->i_crypt_info; struct crypto_skcipher *tfm = ci->ci_ctfm; int res = 0; char iv[FS_CRYPTO_BLOCK_SIZE]; - struct scatterlist src_sg, dst_sg; + struct scatterlist sg; int padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK); - char *workbuf, buf[32], *alloc_buf = NULL; - unsigned lim; + unsigned int lim; + unsigned int cryptlen; lim = inode->i_sb->s_cop->max_namelen(inode); if (iname->len <= 0 || iname->len > lim) return -EIO; - ciphertext_len = max(iname->len, (u32)FS_CRYPTO_BLOCK_SIZE); - ciphertext_len = round_up(ciphertext_len, padding); - ciphertext_len = min(ciphertext_len, lim); + /* + * Copy the filename to the output buffer for encrypting in-place and + * pad it with the needed number of NUL bytes. + */ + cryptlen = max_t(unsigned int, iname->len, FS_CRYPTO_BLOCK_SIZE); + cryptlen = round_up(cryptlen, padding); + cryptlen = min(cryptlen, lim); + memcpy(oname->name, iname->name, iname->len); + memset(oname->name + iname->len, 0, cryptlen - iname->len); - if (ciphertext_len <= sizeof(buf)) { - workbuf = buf; - } else { - alloc_buf = kmalloc(ciphertext_len, GFP_NOFS); - if (!alloc_buf) - return -ENOMEM; - workbuf = alloc_buf; - } + /* Initialize the IV */ + memset(iv, 0, FS_CRYPTO_BLOCK_SIZE); - /* Allocate request */ + /* Set up the encryption request */ req = skcipher_request_alloc(tfm, GFP_NOFS); if (!req) { printk_ratelimited(KERN_ERR - "%s: crypto_request_alloc() failed\n", __func__); - kfree(alloc_buf); + "%s: skcipher_request_alloc() failed\n", __func__); return -ENOMEM; } skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, fname_crypt_complete, &ecr); + sg_init_one(&sg, oname->name, cryptlen); + skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv); - /* 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); - skcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv); + /* Do the encryption */ res = crypto_skcipher_encrypt(req); if (res == -EINPROGRESS || res == -EBUSY) { + /* Request is being completed asynchronously; wait for it */ wait_for_completion(&ecr.completion); res = ecr.res; } - kfree(alloc_buf); skcipher_request_free(req); if (res < 0) { printk_ratelimited(KERN_ERR @@ -105,7 +94,7 @@ static int fname_encrypt(struct inode *inode, return res; } - oname->len = ciphertext_len; + oname->len = cryptlen; return 0; } |