b24413180f560 fs/crypto/fname.c (Greg Kroah-Hartman 2017-11-01 15:07:57 +0100 1) // SPDX-License-Identifier: GPL-2.0
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 2) /*
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 3) * This contains functions for filename crypto management
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 4) *
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 5) * Copyright (C) 2015, Google, Inc.
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 6) * Copyright (C) 2015, Motorola Mobility
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 7) *
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 8) * Written by Uday Savagaonkar, 2014.
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 9) * Modified by Jaegeuk Kim, 2015.
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 10) *
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 11) * This has not yet undergone a rigorous security audit.
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 12) */
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 13)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 14) #include <linux/namei.h>
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 15) #include <linux/scatterlist.h>
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 16) #include <crypto/hash.h>
a24d22b225ce1 fs/crypto/fname.c (Eric Biggers 2020-11-12 21:20:21 -0800 17) #include <crypto/sha2.h>
a575784c6c13b fs/crypto/fname.c (Eric Biggers 2018-01-05 10:45:00 -0800 18) #include <crypto/skcipher.h>
3325bea5b26ac fs/crypto/fname.c (Theodore Ts'o 2016-11-26 20:32:46 -0500 19) #include "fscrypt_private.h"
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 20)
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 21) /*
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 22) * struct fscrypt_nokey_name - identifier for directory entry when key is absent
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 23) *
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 24) * When userspace lists an encrypted directory without access to the key, the
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 25) * filesystem must present a unique "no-key name" for each filename that allows
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 26) * it to find the directory entry again if requested. Naively, that would just
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 27) * mean using the ciphertext filenames. However, since the ciphertext filenames
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 28) * can contain illegal characters ('\0' and '/'), they must be encoded in some
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 29) * way. We use base64. But that can cause names to exceed NAME_MAX (255
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 30) * bytes), so we also need to use a strong hash to abbreviate long names.
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 31) *
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 32) * The filesystem may also need another kind of hash, the "dirhash", to quickly
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 33) * find the directory entry. Since filesystems normally compute the dirhash
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 34) * over the on-disk filename (i.e. the ciphertext), it's not computable from
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 35) * no-key names that abbreviate the ciphertext using the strong hash to fit in
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 36) * NAME_MAX. It's also not computable if it's a keyed hash taken over the
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 37) * plaintext (but it may still be available in the on-disk directory entry);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 38) * casefolded directories use this type of dirhash. At least in these cases,
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 39) * each no-key name must include the name's dirhash too.
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 40) *
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 41) * To meet all these requirements, we base64-encode the following
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 42) * variable-length structure. It contains the dirhash, or 0's if the filesystem
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 43) * didn't provide one; up to 149 bytes of the ciphertext name; and for
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 44) * ciphertexts longer than 149 bytes, also the SHA-256 of the remaining bytes.
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 45) *
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 46) * This ensures that each no-key name contains everything needed to find the
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 47) * directory entry again, contains only legal characters, doesn't exceed
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 48) * NAME_MAX, is unambiguous unless there's a SHA-256 collision, and that we only
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 49) * take the performance hit of SHA-256 on very long filenames (which are rare).
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 50) */
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 51) struct fscrypt_nokey_name {
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 52) u32 dirhash[2];
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 53) u8 bytes[149];
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 54) u8 sha256[SHA256_DIGEST_SIZE];
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 55) }; /* 189 bytes => 252 bytes base64-encoded, which is <= NAME_MAX (255) */
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 56)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 57) /*
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 58) * Decoded size of max-size nokey name, i.e. a name that was abbreviated using
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 59) * the strong hash and thus includes the 'sha256' field. This isn't simply
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 60) * sizeof(struct fscrypt_nokey_name), as the padding at the end isn't included.
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 61) */
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 62) #define FSCRYPT_NOKEY_NAME_MAX offsetofend(struct fscrypt_nokey_name, sha256)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 63)
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 64) static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 65) {
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 66) if (str->len == 1 && str->name[0] == '.')
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 67) return true;
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 68)
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 69) if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 70) return true;
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 71)
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 72) return false;
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 73) }
dcf0db9e5df36 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:44:59 -0800 74)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 75) /**
1b3b827ee5230 fs/crypto/fname.c (Eric Biggers 2020-01-19 23:17:36 -0800 76) * fscrypt_fname_encrypt() - encrypt a filename
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 77) * @inode: inode of the parent directory (for regular filenames)
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 78) * or of the symlink (for symlink targets)
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 79) * @iname: the filename to encrypt
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 80) * @out: (output) the encrypted filename
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 81) * @olen: size of the encrypted filename. It must be at least @iname->len.
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 82) * Any extra space is filled with NUL padding before encryption.
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 83) *
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 84) * Return: 0 on success, -errno on failure
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 85) */
1b3b827ee5230 fs/crypto/fname.c (Eric Biggers 2020-01-19 23:17:36 -0800 86) int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname,
1b3b827ee5230 fs/crypto/fname.c (Eric Biggers 2020-01-19 23:17:36 -0800 87) u8 *out, unsigned int olen)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 88) {
2731a944f6512 fs/f2fs/crypto_fname.c (Herbert Xu 2016-01-24 21:17:49 +0800 89) struct skcipher_request *req = NULL;
d0082e1a7c8df fs/crypto/fname.c (Gilad Ben-Yossef 2017-10-18 08:00:44 +0100 90) DECLARE_CRYPTO_WAIT(wait);
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 91) const struct fscrypt_info *ci = inode->i_crypt_info;
5fee36095cda4 fs/crypto/fname.c (Satya Tangirala 2020-07-02 01:56:05 +0000 92) struct crypto_skcipher *tfm = ci->ci_enc_key.tfm;
8094c3ceb21ad fs/crypto/fname.c (Eric Biggers 2019-01-06 08:36:21 -0500 93) union fscrypt_iv iv;
08ae877f4e912 fs/crypto/fname.c (Eric Biggers 2016-11-13 20:35:52 -0500 94) struct scatterlist sg;
8094c3ceb21ad fs/crypto/fname.c (Eric Biggers 2019-01-06 08:36:21 -0500 95) int res;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 96)
08ae877f4e912 fs/crypto/fname.c (Eric Biggers 2016-11-13 20:35:52 -0500 97) /*
08ae877f4e912 fs/crypto/fname.c (Eric Biggers 2016-11-13 20:35:52 -0500 98) * Copy the filename to the output buffer for encrypting in-place and
08ae877f4e912 fs/crypto/fname.c (Eric Biggers 2016-11-13 20:35:52 -0500 99) * pad it with the needed number of NUL bytes.
08ae877f4e912 fs/crypto/fname.c (Eric Biggers 2016-11-13 20:35:52 -0500 100) */
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 101) if (WARN_ON(olen < iname->len))
76e81d6d50481 fs/crypto/fname.c (Eric Biggers 2018-01-05 10:45:01 -0800 102) return -ENOBUFS;
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 103) memcpy(out, iname->name, iname->len);
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 104) memset(out + iname->len, 0, olen - iname->len);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 105)
08ae877f4e912 fs/crypto/fname.c (Eric Biggers 2016-11-13 20:35:52 -0500 106) /* Initialize the IV */
8094c3ceb21ad fs/crypto/fname.c (Eric Biggers 2019-01-06 08:36:21 -0500 107) fscrypt_generate_iv(&iv, 0, ci);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 108)
08ae877f4e912 fs/crypto/fname.c (Eric Biggers 2016-11-13 20:35:52 -0500 109) /* Set up the encryption request */
2731a944f6512 fs/f2fs/crypto_fname.c (Herbert Xu 2016-01-24 21:17:49 +0800 110) req = skcipher_request_alloc(tfm, GFP_NOFS);
c90fd77562479 fs/crypto/fname.c (Eric Biggers 2018-04-30 15:51:38 -0700 111) if (!req)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 112) return -ENOMEM;
2731a944f6512 fs/f2fs/crypto_fname.c (Herbert Xu 2016-01-24 21:17:49 +0800 113) skcipher_request_set_callback(req,
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 114) CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
d0082e1a7c8df fs/crypto/fname.c (Gilad Ben-Yossef 2017-10-18 08:00:44 +0100 115) crypto_req_done, &wait);
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 116) sg_init_one(&sg, out, olen);
8094c3ceb21ad fs/crypto/fname.c (Eric Biggers 2019-01-06 08:36:21 -0500 117) skcipher_request_set_crypt(req, &sg, &sg, olen, &iv);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 118)
08ae877f4e912 fs/crypto/fname.c (Eric Biggers 2016-11-13 20:35:52 -0500 119) /* Do the encryption */
d0082e1a7c8df fs/crypto/fname.c (Gilad Ben-Yossef 2017-10-18 08:00:44 +0100 120) res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
2731a944f6512 fs/f2fs/crypto_fname.c (Herbert Xu 2016-01-24 21:17:49 +0800 121) skcipher_request_free(req);
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 122) if (res < 0) {
886da8b39cf27 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 123) fscrypt_err(inode, "Filename encryption failed: %d", res);
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 124) return res;
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 125) }
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 126)
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 127) return 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 128) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 129)
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 130) /**
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 131) * fname_decrypt() - decrypt a filename
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 132) * @inode: inode of the parent directory (for regular filenames)
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 133) * or of the symlink (for symlink targets)
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 134) * @iname: the encrypted filename to decrypt
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 135) * @oname: (output) the decrypted filename. The caller must have allocated
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 136) * enough space for this, e.g. using fscrypt_fname_alloc_buffer().
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 137) *
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 138) * Return: 0 on success, -errno on failure
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 139) */
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 140) static int fname_decrypt(const struct inode *inode,
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 141) const struct fscrypt_str *iname,
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 142) struct fscrypt_str *oname)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 143) {
2731a944f6512 fs/f2fs/crypto_fname.c (Herbert Xu 2016-01-24 21:17:49 +0800 144) struct skcipher_request *req = NULL;
d0082e1a7c8df fs/crypto/fname.c (Gilad Ben-Yossef 2017-10-18 08:00:44 +0100 145) DECLARE_CRYPTO_WAIT(wait);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 146) struct scatterlist src_sg, dst_sg;
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 147) const struct fscrypt_info *ci = inode->i_crypt_info;
5fee36095cda4 fs/crypto/fname.c (Satya Tangirala 2020-07-02 01:56:05 +0000 148) struct crypto_skcipher *tfm = ci->ci_enc_key.tfm;
8094c3ceb21ad fs/crypto/fname.c (Eric Biggers 2019-01-06 08:36:21 -0500 149) union fscrypt_iv iv;
8094c3ceb21ad fs/crypto/fname.c (Eric Biggers 2019-01-06 08:36:21 -0500 150) int res;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 151)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 152) /* Allocate request */
2731a944f6512 fs/f2fs/crypto_fname.c (Herbert Xu 2016-01-24 21:17:49 +0800 153) req = skcipher_request_alloc(tfm, GFP_NOFS);
c90fd77562479 fs/crypto/fname.c (Eric Biggers 2018-04-30 15:51:38 -0700 154) if (!req)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 155) return -ENOMEM;
2731a944f6512 fs/f2fs/crypto_fname.c (Herbert Xu 2016-01-24 21:17:49 +0800 156) skcipher_request_set_callback(req,
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 157) CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
d0082e1a7c8df fs/crypto/fname.c (Gilad Ben-Yossef 2017-10-18 08:00:44 +0100 158) crypto_req_done, &wait);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 159)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 160) /* Initialize IV */
8094c3ceb21ad fs/crypto/fname.c (Eric Biggers 2019-01-06 08:36:21 -0500 161) fscrypt_generate_iv(&iv, 0, ci);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 162)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 163) /* Create decryption request */
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 164) sg_init_one(&src_sg, iname->name, iname->len);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 165) sg_init_one(&dst_sg, oname->name, oname->len);
8094c3ceb21ad fs/crypto/fname.c (Eric Biggers 2019-01-06 08:36:21 -0500 166) skcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, &iv);
d0082e1a7c8df fs/crypto/fname.c (Gilad Ben-Yossef 2017-10-18 08:00:44 +0100 167) res = crypto_wait_req(crypto_skcipher_decrypt(req), &wait);
2731a944f6512 fs/f2fs/crypto_fname.c (Herbert Xu 2016-01-24 21:17:49 +0800 168) skcipher_request_free(req);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 169) if (res < 0) {
886da8b39cf27 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 170) fscrypt_err(inode, "Filename decryption failed: %d", res);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 171) return res;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 172) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 173)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 174) oname->len = strnlen(oname->name, iname->len);
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 175) return 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 176) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 177)
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 178) static const char lookup_table[65] =
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 179) "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 180)
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 181) #define BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3)
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 182)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 183) /**
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 184) * base64_encode() - base64-encode some bytes
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 185) * @src: the bytes to encode
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 186) * @len: number of bytes to encode
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 187) * @dst: (output) the base64-encoded string. Not NUL-terminated.
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 188) *
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 189) * Encodes the input string using characters from the set [A-Za-z0-9+,].
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 190) * The encoded string is roughly 4/3 times the size of the input string.
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 191) *
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 192) * Return: length of the encoded string
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 193) */
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 194) static int base64_encode(const u8 *src, int len, char *dst)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 195) {
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 196) int i, bits = 0, ac = 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 197) char *cp = dst;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 198)
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 199) for (i = 0; i < len; i++) {
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 200) ac += src[i] << bits;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 201) bits += 8;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 202) do {
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 203) *cp++ = lookup_table[ac & 0x3f];
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 204) ac >>= 6;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 205) bits -= 6;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 206) } while (bits >= 6);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 207) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 208) if (bits)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 209) *cp++ = lookup_table[ac & 0x3f];
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 210) return cp - dst;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 211) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 212)
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 213) static int base64_decode(const char *src, int len, u8 *dst)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 214) {
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 215) int i, bits = 0, ac = 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 216) const char *p;
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 217) u8 *cp = dst;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 218)
1c5100a2aab41 fs/crypto/fname.c (Eric Biggers 2019-07-24 11:07:58 -0700 219) for (i = 0; i < len; i++) {
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 220) p = strchr(lookup_table, src[i]);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 221) if (p == NULL || src[i] == 0)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 222) return -2;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 223) ac += (p - lookup_table) << bits;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 224) bits += 6;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 225) if (bits >= 8) {
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 226) *cp++ = ac & 0xff;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 227) ac >>= 8;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 228) bits -= 8;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 229) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 230) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 231) if (ac)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 232) return -1;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 233) return cp - dst;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 234) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 235)
ac4acb1f4b2b6 fs/crypto/fname.c (Eric Biggers 2020-09-16 21:11:35 -0700 236) bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy,
ac4acb1f4b2b6 fs/crypto/fname.c (Eric Biggers 2020-09-16 21:11:35 -0700 237) u32 orig_len, u32 max_len,
ac4acb1f4b2b6 fs/crypto/fname.c (Eric Biggers 2020-09-16 21:11:35 -0700 238) u32 *encrypted_len_ret)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 239) {
ac4acb1f4b2b6 fs/crypto/fname.c (Eric Biggers 2020-09-16 21:11:35 -0700 240) int padding = 4 << (fscrypt_policy_flags(policy) &
3b6df59bc4d24 fs/crypto/fname.c (Eric Biggers 2019-08-04 19:35:44 -0700 241) FSCRYPT_POLICY_FLAGS_PAD_MASK);
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 242) u32 encrypted_len;
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 243)
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 244) if (orig_len > max_len)
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 245) return false;
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 246) encrypted_len = max(orig_len, (u32)FS_CRYPTO_BLOCK_SIZE);
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 247) encrypted_len = round_up(encrypted_len, padding);
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 248) *encrypted_len_ret = min(encrypted_len, max_len);
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 249) return true;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 250) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 251)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 252) /**
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 253) * fscrypt_fname_alloc_buffer() - allocate a buffer for presented filenames
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 254) * @max_encrypted_len: maximum length of encrypted filenames the buffer will be
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 255) * used to present
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 256) * @crypto_str: (output) buffer to allocate
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 257) *
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 258) * Allocate a buffer that is large enough to hold any decrypted or encoded
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 259) * filename (null-terminated), for the given maximum encrypted filename length.
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 260) *
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 261) * Return: 0 on success, -errno on failure
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 262) */
8b10fe6898527 fs/crypto/fname.c (Jeff Layton 2020-08-10 10:21:39 -0400 263) int fscrypt_fname_alloc_buffer(u32 max_encrypted_len,
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 264) struct fscrypt_str *crypto_str)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 265) {
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 266) const u32 max_encoded_len = BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX);
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 267) u32 max_presented_len;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 268)
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 269) max_presented_len = max(max_encoded_len, max_encrypted_len);
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 270)
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 271) crypto_str->name = kmalloc(max_presented_len + 1, GFP_NOFS);
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 272) if (!crypto_str->name)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 273) return -ENOMEM;
2cbadadcfdf0d fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 274) crypto_str->len = max_presented_len;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 275) return 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 276) }
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 277) EXPORT_SYMBOL(fscrypt_fname_alloc_buffer);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 278)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 279) /**
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 280) * fscrypt_fname_free_buffer() - free a buffer for presented filenames
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 281) * @crypto_str: the buffer to free
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 282) *
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 283) * Free a buffer that was allocated by fscrypt_fname_alloc_buffer().
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 284) */
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 285) void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 286) {
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 287) if (!crypto_str)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 288) return;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 289) kfree(crypto_str->name);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 290) crypto_str->name = NULL;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 291) }
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 292) EXPORT_SYMBOL(fscrypt_fname_free_buffer);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 293)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 294) /**
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 295) * fscrypt_fname_disk_to_usr() - convert an encrypted filename to
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 296) * user-presentable form
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 297) * @inode: inode of the parent directory (for regular filenames)
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 298) * or of the symlink (for symlink targets)
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 299) * @hash: first part of the name's dirhash, if applicable. This only needs to
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 300) * be provided if the filename is located in an indexed directory whose
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 301) * encryption key may be unavailable. Not needed for symlink targets.
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 302) * @minor_hash: second part of the name's dirhash, if applicable
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 303) * @iname: encrypted filename to convert. May also be "." or "..", which
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 304) * aren't actually encrypted.
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 305) * @oname: output buffer for the user-presentable filename. The caller must
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 306) * have allocated enough space for this, e.g. using
d2fe97545a1e2 fs/crypto/fname.c (Eric Biggers 2020-05-11 12:13:56 -0700 307) * fscrypt_fname_alloc_buffer().
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 308) *
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 309) * If the key is available, we'll decrypt the disk name. Otherwise, we'll
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 310) * encode it for presentation in fscrypt_nokey_name format.
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 311) * See struct fscrypt_nokey_name for details.
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 312) *
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 313) * Return: 0 on success, -errno on failure
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 314) */
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 315) int fscrypt_fname_disk_to_usr(const struct inode *inode,
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 316) u32 hash, u32 minor_hash,
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 317) const struct fscrypt_str *iname,
8a4ab0b866d8a fs/crypto/fname.c (Eric Biggers 2019-12-15 13:39:47 -0800 318) struct fscrypt_str *oname)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 319) {
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 320) const struct qstr qname = FSTR_TO_QSTR(iname);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 321) struct fscrypt_nokey_name nokey_name;
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 322) u32 size; /* size of the unencoded no-key name */
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 323)
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 324) if (fscrypt_is_dot_dotdot(&qname)) {
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 325) oname->name[0] = '.';
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 326) oname->name[iname->len - 1] = '.';
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 327) oname->len = iname->len;
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 328) return 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 329) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 330)
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 331) if (iname->len < FS_CRYPTO_BLOCK_SIZE)
1dafa51d45c63 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2016-02-05 19:37:27 -0800 332) return -EUCLEAN;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 333)
e37a784d8b6a1 fs/crypto/fname.c (Eric Biggers 2019-04-11 14:32:15 -0700 334) if (fscrypt_has_encryption_key(inode))
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 335) return fname_decrypt(inode, iname, oname);
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 336)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 337) /*
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 338) * Sanity check that struct fscrypt_nokey_name doesn't have padding
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 339) * between fields and that its encoded size never exceeds NAME_MAX.
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 340) */
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 341) BUILD_BUG_ON(offsetofend(struct fscrypt_nokey_name, dirhash) !=
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 342) offsetof(struct fscrypt_nokey_name, bytes));
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 343) BUILD_BUG_ON(offsetofend(struct fscrypt_nokey_name, bytes) !=
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 344) offsetof(struct fscrypt_nokey_name, sha256));
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 345) BUILD_BUG_ON(BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX) > NAME_MAX);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 346)
119782bf159e4 fs/crypto/fname.c (Eric Biggers 2021-05-27 16:52:36 -0700 347) nokey_name.dirhash[0] = hash;
119782bf159e4 fs/crypto/fname.c (Eric Biggers 2021-05-27 16:52:36 -0700 348) nokey_name.dirhash[1] = minor_hash;
119782bf159e4 fs/crypto/fname.c (Eric Biggers 2021-05-27 16:52:36 -0700 349)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 350) if (iname->len <= sizeof(nokey_name.bytes)) {
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 351) memcpy(nokey_name.bytes, iname->name, iname->len);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 352) size = offsetof(struct fscrypt_nokey_name, bytes[iname->len]);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 353) } else {
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 354) memcpy(nokey_name.bytes, iname->name, sizeof(nokey_name.bytes));
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 355) /* Compute strong hash of remaining part of name. */
0c6a113b2446e fs/crypto/fname.c (Eric Biggers 2020-09-16 21:53:41 -0700 356) sha256(&iname->name[sizeof(nokey_name.bytes)],
0c6a113b2446e fs/crypto/fname.c (Eric Biggers 2020-09-16 21:53:41 -0700 357) iname->len - sizeof(nokey_name.bytes),
0c6a113b2446e fs/crypto/fname.c (Eric Biggers 2020-09-16 21:53:41 -0700 358) nokey_name.sha256);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 359) size = FSCRYPT_NOKEY_NAME_MAX;
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 360) }
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 361) oname->len = base64_encode((const u8 *)&nokey_name, size, oname->name);
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 362) return 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 363) }
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 364) EXPORT_SYMBOL(fscrypt_fname_disk_to_usr);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 365)
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 366) /**
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 367) * fscrypt_setup_filename() - prepare to search a possibly encrypted directory
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 368) * @dir: the directory that will be searched
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 369) * @iname: the user-provided filename being searched for
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 370) * @lookup: 1 if we're allowed to proceed without the key because it's
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 371) * ->lookup() or we're finding the dir_entry for deletion; 0 if we cannot
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 372) * proceed without the key because we're going to create the dir_entry.
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 373) * @fname: the filename information to be filled in
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 374) *
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 375) * Given a user-provided filename @iname, this function sets @fname->disk_name
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 376) * to the name that would be stored in the on-disk directory entry, if possible.
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 377) * If the directory is unencrypted this is simply @iname. Else, if we have the
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 378) * directory's encryption key, then @iname is the plaintext, so we encrypt it to
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 379) * get the disk_name.
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 380) *
70fb2612aab62 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:23 -0700 381) * Else, for keyless @lookup operations, @iname should be a no-key name, so we
70fb2612aab62 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:23 -0700 382) * decode it to get the struct fscrypt_nokey_name. Non-@lookup operations will
70fb2612aab62 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:23 -0700 383) * be impossible in this case, so we fail them with ENOKEY.
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 384) *
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 385) * If successful, fscrypt_free_filename() must be called later to clean up.
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 386) *
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 387) * Return: 0 on success, -errno on failure
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 388) */
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 389) int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 390) int lookup, struct fscrypt_name *fname)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 391) {
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 392) struct fscrypt_nokey_name *nokey_name;
17159420a6c18 fs/crypto/fname.c (Eric Biggers 2017-04-24 10:00:10 -0700 393) int ret;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 394)
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 395) memset(fname, 0, sizeof(struct fscrypt_name));
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 396) fname->usr_fname = iname;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 397)
e0428a266d5a2 fs/crypto/fname.c (Eric Biggers 2017-10-09 12:15:36 -0700 398) if (!IS_ENCRYPTED(dir) || fscrypt_is_dot_dotdot(iname)) {
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 399) fname->disk_name.name = (unsigned char *)iname->name;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 400) fname->disk_name.len = iname->len;
7bf4b5576af81 fs/f2fs/crypto_fname.c (Chao Yu 2015-05-13 18:20:54 +0800 401) return 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 402) }
a14d0b6764917 fs/crypto/fname.c (Eric Biggers 2020-12-02 18:20:41 -0800 403) ret = fscrypt_get_encryption_info(dir, lookup);
17bfde6097bd5 fs/crypto/fname.c (Eric Biggers 2018-04-30 15:51:41 -0700 404) if (ret)
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 405) return ret;
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 406)
e37a784d8b6a1 fs/crypto/fname.c (Eric Biggers 2019-04-11 14:32:15 -0700 407) if (fscrypt_has_encryption_key(dir)) {
ac4acb1f4b2b6 fs/crypto/fname.c (Eric Biggers 2020-09-16 21:11:35 -0700 408) if (!fscrypt_fname_encrypted_size(&dir->i_crypt_info->ci_policy,
ac4acb1f4b2b6 fs/crypto/fname.c (Eric Biggers 2020-09-16 21:11:35 -0700 409) iname->len,
e12ee6836a3fd fs/crypto/fname.c (Eric Biggers 2018-04-30 15:51:44 -0700 410) dir->i_sb->s_cop->max_namelen,
b9db0b4a68d37 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 411) &fname->crypto_buf.len))
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 412) return -ENAMETOOLONG;
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 413) fname->crypto_buf.name = kmalloc(fname->crypto_buf.len,
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 414) GFP_NOFS);
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 415) if (!fname->crypto_buf.name)
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 416) return -ENOMEM;
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 417)
1b3b827ee5230 fs/crypto/fname.c (Eric Biggers 2020-01-19 23:17:36 -0800 418) ret = fscrypt_fname_encrypt(dir, iname, fname->crypto_buf.name,
1b3b827ee5230 fs/crypto/fname.c (Eric Biggers 2020-01-19 23:17:36 -0800 419) fname->crypto_buf.len);
ef1eb3aa50930 fs/crypto/fname.c (Eric Biggers 2016-09-15 17:25:55 -0400 420) if (ret)
e5e0906b6b4c5 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-05-28 17:06:40 -0700 421) goto errout;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 422) fname->disk_name.name = fname->crypto_buf.name;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 423) fname->disk_name.len = fname->crypto_buf.len;
7bf4b5576af81 fs/f2fs/crypto_fname.c (Chao Yu 2015-05-13 18:20:54 +0800 424) return 0;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 425) }
e5e0906b6b4c5 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-05-28 17:06:40 -0700 426) if (!lookup)
54475f531bb8d fs/crypto/fname.c (Eric Biggers 2016-12-05 11:12:44 -0800 427) return -ENOKEY;
70fb2612aab62 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:23 -0700 428) fname->is_nokey_name = true;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 429)
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 430) /*
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 431) * We don't have the key and we are doing a lookup; decode the
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 432) * user-supplied name
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 433) */
e5e0906b6b4c5 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-05-28 17:06:40 -0700 434)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 435) if (iname->len > BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX))
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 436) return -ENOENT;
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 437)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 438) fname->crypto_buf.name = kmalloc(FSCRYPT_NOKEY_NAME_MAX, GFP_KERNEL);
e5e0906b6b4c5 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-05-28 17:06:40 -0700 439) if (fname->crypto_buf.name == NULL)
e5e0906b6b4c5 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-05-28 17:06:40 -0700 440) return -ENOMEM;
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 441)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 442) ret = base64_decode(iname->name, iname->len, fname->crypto_buf.name);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 443) if (ret < (int)offsetof(struct fscrypt_nokey_name, bytes[1]) ||
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 444) (ret > offsetof(struct fscrypt_nokey_name, sha256) &&
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 445) ret != FSCRYPT_NOKEY_NAME_MAX)) {
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 446) ret = -ENOENT;
e5e0906b6b4c5 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-05-28 17:06:40 -0700 447) goto errout;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 448) }
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 449) fname->crypto_buf.len = ret;
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 450)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 451) nokey_name = (void *)fname->crypto_buf.name;
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 452) fname->hash = nokey_name->dirhash[0];
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 453) fname->minor_hash = nokey_name->dirhash[1];
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 454) if (ret != FSCRYPT_NOKEY_NAME_MAX) {
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 455) /* The full ciphertext filename is available. */
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 456) fname->disk_name.name = nokey_name->bytes;
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 457) fname->disk_name.len =
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 458) ret - offsetof(struct fscrypt_nokey_name, bytes);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 459) }
7bf4b5576af81 fs/f2fs/crypto_fname.c (Chao Yu 2015-05-13 18:20:54 +0800 460) return 0;
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 461)
e5e0906b6b4c5 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-05-28 17:06:40 -0700 462) errout:
50c961de59ec8 fs/crypto/fname.c (Eric Biggers 2018-01-11 23:30:08 -0500 463) kfree(fname->crypto_buf.name);
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 464) return ret;
6b3bd08f93a84 fs/f2fs/crypto_fname.c (Jaegeuk Kim 2015-04-26 00:12:50 -0700 465) }
0b81d07790726 fs/crypto/fname.c (Jaegeuk Kim 2015-05-15 16:26:10 -0700 466) EXPORT_SYMBOL(fscrypt_setup_filename);
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 467)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 468) /**
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 469) * fscrypt_match_name() - test whether the given name matches a directory entry
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 470) * @fname: the name being searched for
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 471) * @de_name: the name from the directory entry
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 472) * @de_name_len: the length of @de_name in bytes
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 473) *
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 474) * Normally @fname->disk_name will be set, and in that case we simply compare
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 475) * that to the name stored in the directory entry. The only exception is that
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 476) * if we don't have the key for an encrypted directory and the name we're
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 477) * looking for is very long, then we won't have the full disk_name and instead
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 478) * we'll need to match against a fscrypt_nokey_name that includes a strong hash.
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 479) *
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 480) * Return: %true if the name matches, otherwise %false.
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 481) */
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 482) bool fscrypt_match_name(const struct fscrypt_name *fname,
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 483) const u8 *de_name, u32 de_name_len)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 484) {
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 485) const struct fscrypt_nokey_name *nokey_name =
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 486) (const void *)fname->crypto_buf.name;
0c6a113b2446e fs/crypto/fname.c (Eric Biggers 2020-09-16 21:53:41 -0700 487) u8 digest[SHA256_DIGEST_SIZE];
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 488)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 489) if (likely(fname->disk_name.name)) {
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 490) if (de_name_len != fname->disk_name.len)
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 491) return false;
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 492) return !memcmp(de_name, fname->disk_name.name, de_name_len);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 493) }
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 494) if (de_name_len <= sizeof(nokey_name->bytes))
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 495) return false;
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 496) if (memcmp(de_name, nokey_name->bytes, sizeof(nokey_name->bytes)))
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 497) return false;
0c6a113b2446e fs/crypto/fname.c (Eric Biggers 2020-09-16 21:53:41 -0700 498) sha256(&de_name[sizeof(nokey_name->bytes)],
0c6a113b2446e fs/crypto/fname.c (Eric Biggers 2020-09-16 21:53:41 -0700 499) de_name_len - sizeof(nokey_name->bytes), digest);
0c6a113b2446e fs/crypto/fname.c (Eric Biggers 2020-09-16 21:53:41 -0700 500) return !memcmp(digest, nokey_name->sha256, sizeof(digest));
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 501) }
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 502) EXPORT_SYMBOL_GPL(fscrypt_match_name);
edc440e3d27fb fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:32:01 -0800 503)
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 504) /**
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 505) * fscrypt_fname_siphash() - calculate the SipHash of a filename
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 506) * @dir: the parent directory
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 507) * @name: the filename to calculate the SipHash of
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 508) *
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 509) * Given a plaintext filename @name and a directory @dir which uses SipHash as
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 510) * its dirhash method and has had its fscrypt key set up, this function
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 511) * calculates the SipHash of that name using the directory's secret dirhash key.
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 512) *
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 513) * Return: the SipHash of @name using the hash key of @dir
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 514) */
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 515) u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name)
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 516) {
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 517) const struct fscrypt_info *ci = dir->i_crypt_info;
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 518)
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 519) WARN_ON(!ci->ci_dirhash_key_initialized);
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 520)
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 521) return siphash(name->name, name->len, &ci->ci_dirhash_key);
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 522) }
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 523) EXPORT_SYMBOL_GPL(fscrypt_fname_siphash);
aa408f835d025 fs/crypto/fname.c (Daniel Rosenberg 2020-01-20 14:31:57 -0800 524)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 525) /*
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 526) * Validate dentries in encrypted directories to make sure we aren't potentially
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 527) * caching stale dentries after a key has been added.
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 528) */
5b2a828b98ec1 fs/crypto/fname.c (Eric Biggers 2020-09-23 22:47:21 -0700 529) int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 530) {
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 531) struct dentry *dir;
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 532) int err;
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 533) int valid;
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 534)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 535) /*
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 536) * Plaintext names are always valid, since fscrypt doesn't support
70fb2612aab62 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:23 -0700 537) * reverting to no-key names without evicting the directory's inode
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 538) * -- which implies eviction of the dentries in the directory.
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 539) */
501e43fbea468 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:24 -0700 540) if (!(dentry->d_flags & DCACHE_NOKEY_NAME))
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 541) return 1;
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 542)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 543) /*
70fb2612aab62 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:23 -0700 544) * No-key name; valid if the directory's key is still unavailable.
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 545) *
70fb2612aab62 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:23 -0700 546) * Although fscrypt forbids rename() on no-key names, we still must use
70fb2612aab62 fs/crypto/fname.c (Eric Biggers 2020-09-23 21:26:23 -0700 547) * dget_parent() here rather than use ->d_parent directly. That's
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 548) * because a corrupted fs image may contain directory hard links, which
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 549) * the VFS handles by moving the directory's dentry tree in the dcache
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 550) * each time ->lookup() finds the directory and it already has a dentry
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 551) * elsewhere. Thus ->d_parent can be changing, and we must safely grab
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 552) * a reference to some ->d_parent to prevent it from being freed.
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 553) */
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 554)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 555) if (flags & LOOKUP_RCU)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 556) return -ECHILD;
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 557)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 558) dir = dget_parent(dentry);
a14d0b6764917 fs/crypto/fname.c (Eric Biggers 2020-12-02 18:20:41 -0800 559) /*
a14d0b6764917 fs/crypto/fname.c (Eric Biggers 2020-12-02 18:20:41 -0800 560) * Pass allow_unsupported=true, so that files with an unsupported
a14d0b6764917 fs/crypto/fname.c (Eric Biggers 2020-12-02 18:20:41 -0800 561) * encryption policy can be deleted.
a14d0b6764917 fs/crypto/fname.c (Eric Biggers 2020-12-02 18:20:41 -0800 562) */
a14d0b6764917 fs/crypto/fname.c (Eric Biggers 2020-12-02 18:20:41 -0800 563) err = fscrypt_get_encryption_info(d_inode(dir), true);
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 564) valid = !fscrypt_has_encryption_key(d_inode(dir));
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 565) dput(dir);
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 566)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 567) if (err < 0)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 568) return err;
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 569)
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 570) return valid;
2ebdef6d8c766 fs/crypto/fname.c (Eric Biggers 2019-12-09 12:43:59 -0800 571) }
5b2a828b98ec1 fs/crypto/fname.c (Eric Biggers 2020-09-23 22:47:21 -0700 572) EXPORT_SYMBOL_GPL(fscrypt_d_revalidate);
VisionFive2 Linux kernel
StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)
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