From d635711daa98be86d4c7fd01499c34f566b54ccb Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Fri, 10 Jun 2016 05:30:17 -0300 Subject: Linux-libre 4.6.2-gnu --- fs/f2fs/crypto_fname.c | 440 ------------------------------------------------- 1 file changed, 440 deletions(-) delete mode 100644 fs/f2fs/crypto_fname.c (limited to 'fs/f2fs/crypto_fname.c') diff --git a/fs/f2fs/crypto_fname.c b/fs/f2fs/crypto_fname.c deleted file mode 100644 index ab377d496..000000000 --- a/fs/f2fs/crypto_fname.c +++ /dev/null @@ -1,440 +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) { - BUG_ON(req->base.data != &ecr); - 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) { - BUG_ON(req->base.data != &ecr); - 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; -} - -/** - * 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; - int padding = 16; - struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info; - - if (ci) - padding = 4 << (ci->ci_flags & F2FS_POLICY_FLAGS_PAD_MASK); - if (padding < F2FS_CRYPTO_BLOCK_SIZE) - padding = F2FS_CRYPTO_BLOCK_SIZE; - olen = f2fs_fname_crypto_round_up(ilen, padding); - 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 (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; -} -- cgit v1.2.3-54-g00ecf