b24413180f560 (Greg Kroah-Hartman 2017-11-01 15:07:57 +0100 1) // SPDX-License-Identifier: GPL-2.0
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 2) /*
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 3) * Encryption policy functions for per-file encryption support.
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 4) *
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 5) * Copyright (C) 2015, Google, Inc.
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 6) * Copyright (C) 2015, Motorola Mobility.
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 7) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 8) * Originally written by Michael Halcrow, 2015.
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 9) * Modified by Jaegeuk Kim, 2015.
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 10) * Modified by Eric Biggers, 2019 for v2 policy support.
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 11) */
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 12)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 13) #include <linux/random.h>
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 14) #include <linux/seq_file.h>
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 15) #include <linux/string.h>
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 16) #include <linux/mount.h>
cc4e0df038ddb (Theodore Ts'o 2016-11-26 22:05:18 -0500 17) #include "fscrypt_private.h"
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 18)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 19) /**
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 20) * fscrypt_policies_equal() - check whether two encryption policies are the same
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 21) * @policy1: the first policy
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 22) * @policy2: the second policy
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 23) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 24) * Return: %true if equal, else %false
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 25) */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 26) bool fscrypt_policies_equal(const union fscrypt_policy *policy1,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 27) const union fscrypt_policy *policy2)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 28) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 29) if (policy1->version != policy2->version)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 30) return false;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 31)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 32) return !memcmp(policy1, policy2, fscrypt_policy_size(policy1));
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 33) }
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 34)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 35) static const union fscrypt_policy *
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 36) fscrypt_get_dummy_policy(struct super_block *sb)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 37) {
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 38) if (!sb->s_cop->get_dummy_policy)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 39) return NULL;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 40) return sb->s_cop->get_dummy_policy(sb);
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 41) }
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 42)
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 43) static bool fscrypt_valid_enc_modes(u32 contents_mode, u32 filenames_mode)
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 44) {
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 45) if (contents_mode == FSCRYPT_MODE_AES_256_XTS &&
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 46) filenames_mode == FSCRYPT_MODE_AES_256_CTS)
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 47) return true;
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 48)
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 49) if (contents_mode == FSCRYPT_MODE_AES_128_CBC &&
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 50) filenames_mode == FSCRYPT_MODE_AES_128_CTS)
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 51) return true;
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 52)
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 53) if (contents_mode == FSCRYPT_MODE_ADIANTUM &&
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 54) filenames_mode == FSCRYPT_MODE_ADIANTUM)
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 55) return true;
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 56)
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 57) return false;
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 58) }
ef5b18b00bada (Eric Biggers 2019-12-09 13:18:28 -0800 59)
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 60) static bool supported_direct_key_modes(const struct inode *inode,
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 61) u32 contents_mode, u32 filenames_mode)
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 62) {
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 63) const struct fscrypt_mode *mode;
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 64)
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 65) if (contents_mode != filenames_mode) {
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 66) fscrypt_warn(inode,
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 67) "Direct key flag not allowed with different contents and filenames modes");
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 68) return false;
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 69) }
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 70) mode = &fscrypt_modes[contents_mode];
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 71)
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 72) if (mode->ivsize < offsetofend(union fscrypt_iv, nonce)) {
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 73) fscrypt_warn(inode, "Direct key flag not allowed with %s",
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 74) mode->friendly_name);
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 75) return false;
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 76) }
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 77) return true;
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 78) }
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 79)
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 80) static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy,
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 81) const struct inode *inode,
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 82) const char *type,
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 83) int max_ino_bits, int max_lblk_bits)
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 84) {
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 85) struct super_block *sb = inode->i_sb;
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 86) int ino_bits = 64, lblk_bits = 64;
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 87)
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 88) /*
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 89) * IV_INO_LBLK_* exist only because of hardware limitations, and
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 90) * currently the only known use case for them involves AES-256-XTS.
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 91) * That's also all we test currently. For these reasons, for now only
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 92) * allow AES-256-XTS here. This can be relaxed later if a use case for
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 93) * IV_INO_LBLK_* with other encryption modes arises.
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 94) */
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 95) if (policy->contents_encryption_mode != FSCRYPT_MODE_AES_256_XTS) {
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 96) fscrypt_warn(inode,
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 97) "Can't use %s policy with contents mode other than AES-256-XTS",
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 98) type);
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 99) return false;
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 100) }
f000223c981a7 (Eric Biggers 2020-07-21 11:10:12 -0700 101)
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 102) /*
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 103) * It's unsafe to include inode numbers in the IVs if the filesystem can
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 104) * potentially renumber inodes, e.g. via filesystem shrinking.
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 105) */
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 106) if (!sb->s_cop->has_stable_inodes ||
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 107) !sb->s_cop->has_stable_inodes(sb)) {
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 108) fscrypt_warn(inode,
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 109) "Can't use %s policy on filesystem '%s' because it doesn't have stable inode numbers",
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 110) type, sb->s_id);
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 111) return false;
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 112) }
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 113) if (sb->s_cop->get_ino_and_lblk_bits)
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 114) sb->s_cop->get_ino_and_lblk_bits(sb, &ino_bits, &lblk_bits);
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 115) if (ino_bits > max_ino_bits) {
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 116) fscrypt_warn(inode,
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 117) "Can't use %s policy on filesystem '%s' because its inode numbers are too long",
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 118) type, sb->s_id);
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 119) return false;
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 120) }
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 121) if (lblk_bits > max_lblk_bits) {
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 122) fscrypt_warn(inode,
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 123) "Can't use %s policy on filesystem '%s' because its block numbers are too long",
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 124) type, sb->s_id);
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 125) return false;
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 126) }
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 127) return true;
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 128) }
b103fb7653fff (Eric Biggers 2019-10-24 14:54:36 -0700 129)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 130) static bool fscrypt_supported_v1_policy(const struct fscrypt_policy_v1 *policy,
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 131) const struct inode *inode)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 132) {
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 133) if (!fscrypt_valid_enc_modes(policy->contents_encryption_mode,
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 134) policy->filenames_encryption_mode)) {
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 135) fscrypt_warn(inode,
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 136) "Unsupported encryption modes (contents %d, filenames %d)",
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 137) policy->contents_encryption_mode,
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 138) policy->filenames_encryption_mode);
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 139) return false;
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 140) }
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 141)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 142) if (policy->flags & ~(FSCRYPT_POLICY_FLAGS_PAD_MASK |
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 143) FSCRYPT_POLICY_FLAG_DIRECT_KEY)) {
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 144) fscrypt_warn(inode, "Unsupported encryption flags (0x%02x)",
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 145) policy->flags);
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 146) return false;
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 147) }
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 148)
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 149) if ((policy->flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) &&
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 150) !supported_direct_key_modes(inode, policy->contents_encryption_mode,
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 151) policy->filenames_encryption_mode))
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 152) return false;
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 153)
6e1918cfb263a (Daniel Rosenberg 2020-01-20 14:31:56 -0800 154) if (IS_CASEFOLDED(inode)) {
6e1918cfb263a (Daniel Rosenberg 2020-01-20 14:31:56 -0800 155) /* With v1, there's no way to derive dirhash keys. */
6e1918cfb263a (Daniel Rosenberg 2020-01-20 14:31:56 -0800 156) fscrypt_warn(inode,
6e1918cfb263a (Daniel Rosenberg 2020-01-20 14:31:56 -0800 157) "v1 policies can't be used on casefolded directories");
6e1918cfb263a (Daniel Rosenberg 2020-01-20 14:31:56 -0800 158) return false;
6e1918cfb263a (Daniel Rosenberg 2020-01-20 14:31:56 -0800 159) }
6e1918cfb263a (Daniel Rosenberg 2020-01-20 14:31:56 -0800 160)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 161) return true;
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 162) }
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 163)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 164) static bool fscrypt_supported_v2_policy(const struct fscrypt_policy_v2 *policy,
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 165) const struct inode *inode)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 166) {
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 167) int count = 0;
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 168)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 169) if (!fscrypt_valid_enc_modes(policy->contents_encryption_mode,
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 170) policy->filenames_encryption_mode)) {
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 171) fscrypt_warn(inode,
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 172) "Unsupported encryption modes (contents %d, filenames %d)",
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 173) policy->contents_encryption_mode,
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 174) policy->filenames_encryption_mode);
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 175) return false;
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 176) }
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 177)
3ceb6543e9cf6 (Eric Biggers 2020-10-23 17:51:31 -0700 178) if (policy->flags & ~(FSCRYPT_POLICY_FLAGS_PAD_MASK |
3ceb6543e9cf6 (Eric Biggers 2020-10-23 17:51:31 -0700 179) FSCRYPT_POLICY_FLAG_DIRECT_KEY |
3ceb6543e9cf6 (Eric Biggers 2020-10-23 17:51:31 -0700 180) FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 |
3ceb6543e9cf6 (Eric Biggers 2020-10-23 17:51:31 -0700 181) FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) {
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 182) fscrypt_warn(inode, "Unsupported encryption flags (0x%02x)",
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 183) policy->flags);
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 184) return false;
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 185) }
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 186)
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 187) count += !!(policy->flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY);
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 188) count += !!(policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64);
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 189) count += !!(policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32);
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 190) if (count > 1) {
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 191) fscrypt_warn(inode, "Mutually exclusive encryption flags (0x%02x)",
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 192) policy->flags);
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 193) return false;
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 194) }
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 195)
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 196) if ((policy->flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) &&
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 197) !supported_direct_key_modes(inode, policy->contents_encryption_mode,
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 198) policy->filenames_encryption_mode))
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 199) return false;
85af90e57ce96 (Eric Biggers 2019-12-09 13:18:27 -0800 200)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 201) if ((policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) &&
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 202) !supported_iv_ino_lblk_policy(policy, inode, "IV_INO_LBLK_64",
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 203) 32, 32))
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 204) return false;
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 205)
5e895bd4d5233 (Eric Biggers 2020-08-24 13:38:41 -0700 206) /*
5e895bd4d5233 (Eric Biggers 2020-08-24 13:38:41 -0700 207) * IV_INO_LBLK_32 hashes the inode number, so in principle it can
5e895bd4d5233 (Eric Biggers 2020-08-24 13:38:41 -0700 208) * support any ino_bits. However, currently the inode number is gotten
5e895bd4d5233 (Eric Biggers 2020-08-24 13:38:41 -0700 209) * from inode::i_ino which is 'unsigned long'. So for now the
5e895bd4d5233 (Eric Biggers 2020-08-24 13:38:41 -0700 210) * implementation limit is 32 bits.
5e895bd4d5233 (Eric Biggers 2020-08-24 13:38:41 -0700 211) */
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 212) if ((policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) &&
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 213) !supported_iv_ino_lblk_policy(policy, inode, "IV_INO_LBLK_32",
5e895bd4d5233 (Eric Biggers 2020-08-24 13:38:41 -0700 214) 32, 32))
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 215) return false;
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 216)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 217) if (memchr_inv(policy->__reserved, 0, sizeof(policy->__reserved))) {
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 218) fscrypt_warn(inode, "Reserved bits set in encryption policy");
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 219) return false;
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 220) }
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 221)
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 222) return true;
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 223) }
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 224)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 225) /**
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 226) * fscrypt_supported_policy() - check whether an encryption policy is supported
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 227) * @policy_u: the encryption policy
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 228) * @inode: the inode on which the policy will be used
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 229) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 230) * Given an encryption policy, check whether all its encryption modes and other
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 231) * settings are supported by this kernel on the given inode. (But we don't
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 232) * currently don't check for crypto API support here, so attempting to use an
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 233) * algorithm not configured into the crypto API will still fail later.)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 234) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 235) * Return: %true if supported, else %false
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 236) */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 237) bool fscrypt_supported_policy(const union fscrypt_policy *policy_u,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 238) const struct inode *inode)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 239) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 240) switch (policy_u->version) {
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 241) case FSCRYPT_POLICY_V1:
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 242) return fscrypt_supported_v1_policy(&policy_u->v1, inode);
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 243) case FSCRYPT_POLICY_V2:
393a24a7956ce (Eric Biggers 2019-12-09 13:18:26 -0800 244) return fscrypt_supported_v2_policy(&policy_u->v2, inode);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 245) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 246) return false;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 247) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 248)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 249) /**
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 250) * fscrypt_new_context() - create a new fscrypt_context
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 251) * @ctx_u: output context
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 252) * @policy_u: input policy
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 253) * @nonce: nonce to use
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 254) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 255) * Create an fscrypt_context for an inode that is being assigned the given
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 256) * encryption policy. @nonce must be a new random nonce.
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 257) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 258) * Return: the size of the new context in bytes.
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 259) */
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 260) static int fscrypt_new_context(union fscrypt_context *ctx_u,
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 261) const union fscrypt_policy *policy_u,
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 262) const u8 nonce[FSCRYPT_FILE_NONCE_SIZE])
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 263) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 264) memset(ctx_u, 0, sizeof(*ctx_u));
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 265)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 266) switch (policy_u->version) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 267) case FSCRYPT_POLICY_V1: {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 268) const struct fscrypt_policy_v1 *policy = &policy_u->v1;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 269) struct fscrypt_context_v1 *ctx = &ctx_u->v1;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 270)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 271) ctx->version = FSCRYPT_CONTEXT_V1;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 272) ctx->contents_encryption_mode =
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 273) policy->contents_encryption_mode;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 274) ctx->filenames_encryption_mode =
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 275) policy->filenames_encryption_mode;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 276) ctx->flags = policy->flags;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 277) memcpy(ctx->master_key_descriptor,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 278) policy->master_key_descriptor,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 279) sizeof(ctx->master_key_descriptor));
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 280) memcpy(ctx->nonce, nonce, FSCRYPT_FILE_NONCE_SIZE);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 281) return sizeof(*ctx);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 282) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 283) case FSCRYPT_POLICY_V2: {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 284) const struct fscrypt_policy_v2 *policy = &policy_u->v2;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 285) struct fscrypt_context_v2 *ctx = &ctx_u->v2;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 286)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 287) ctx->version = FSCRYPT_CONTEXT_V2;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 288) ctx->contents_encryption_mode =
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 289) policy->contents_encryption_mode;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 290) ctx->filenames_encryption_mode =
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 291) policy->filenames_encryption_mode;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 292) ctx->flags = policy->flags;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 293) memcpy(ctx->master_key_identifier,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 294) policy->master_key_identifier,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 295) sizeof(ctx->master_key_identifier));
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 296) memcpy(ctx->nonce, nonce, FSCRYPT_FILE_NONCE_SIZE);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 297) return sizeof(*ctx);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 298) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 299) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 300) BUG();
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 301) }
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 302)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 303) /**
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 304) * fscrypt_policy_from_context() - convert an fscrypt_context to
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 305) * an fscrypt_policy
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 306) * @policy_u: output policy
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 307) * @ctx_u: input context
d2fe97545a1e2 (Eric Biggers 2020-05-11 12:13:56 -0700 308) * @ctx_size: size of input context in bytes
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 309) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 310) * Given an fscrypt_context, build the corresponding fscrypt_policy.
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 311) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 312) * Return: 0 on success, or -EINVAL if the fscrypt_context has an unrecognized
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 313) * version number or size.
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 314) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 315) * This does *not* validate the settings within the policy itself, e.g. the
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 316) * modes, flags, and reserved bits. Use fscrypt_supported_policy() for that.
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 317) */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 318) int fscrypt_policy_from_context(union fscrypt_policy *policy_u,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 319) const union fscrypt_context *ctx_u,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 320) int ctx_size)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 321) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 322) memset(policy_u, 0, sizeof(*policy_u));
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 323)
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 324) if (!fscrypt_context_is_valid(ctx_u, ctx_size))
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 325) return -EINVAL;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 326)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 327) switch (ctx_u->version) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 328) case FSCRYPT_CONTEXT_V1: {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 329) const struct fscrypt_context_v1 *ctx = &ctx_u->v1;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 330) struct fscrypt_policy_v1 *policy = &policy_u->v1;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 331)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 332) policy->version = FSCRYPT_POLICY_V1;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 333) policy->contents_encryption_mode =
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 334) ctx->contents_encryption_mode;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 335) policy->filenames_encryption_mode =
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 336) ctx->filenames_encryption_mode;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 337) policy->flags = ctx->flags;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 338) memcpy(policy->master_key_descriptor,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 339) ctx->master_key_descriptor,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 340) sizeof(policy->master_key_descriptor));
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 341) return 0;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 342) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 343) case FSCRYPT_CONTEXT_V2: {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 344) const struct fscrypt_context_v2 *ctx = &ctx_u->v2;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 345) struct fscrypt_policy_v2 *policy = &policy_u->v2;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 346)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 347) policy->version = FSCRYPT_POLICY_V2;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 348) policy->contents_encryption_mode =
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 349) ctx->contents_encryption_mode;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 350) policy->filenames_encryption_mode =
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 351) ctx->filenames_encryption_mode;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 352) policy->flags = ctx->flags;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 353) memcpy(policy->__reserved, ctx->__reserved,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 354) sizeof(policy->__reserved));
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 355) memcpy(policy->master_key_identifier,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 356) ctx->master_key_identifier,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 357) sizeof(policy->master_key_identifier));
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 358) return 0;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 359) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 360) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 361) /* unreachable */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 362) return -EINVAL;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 363) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 364)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 365) /* Retrieve an inode's encryption policy */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 366) static int fscrypt_get_policy(struct inode *inode, union fscrypt_policy *policy)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 367) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 368) const struct fscrypt_info *ci;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 369) union fscrypt_context ctx;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 370) int ret;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 371)
ab673b987488c (Eric Biggers 2020-07-21 15:59:19 -0700 372) ci = fscrypt_get_info(inode);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 373) if (ci) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 374) /* key available, use the cached policy */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 375) *policy = ci->ci_policy;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 376) return 0;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 377) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 378)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 379) if (!IS_ENCRYPTED(inode))
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 380) return -ENODATA;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 381)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 382) ret = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 383) if (ret < 0)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 384) return (ret == -ERANGE) ? -EINVAL : ret;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 385)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 386) return fscrypt_policy_from_context(policy, &ctx, ret);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 387) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 388)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 389) static int set_encryption_policy(struct inode *inode,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 390) const union fscrypt_policy *policy)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 391) {
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 392) u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 393) union fscrypt_context ctx;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 394) int ctxsize;
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 395) int err;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 396)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 397) if (!fscrypt_supported_policy(policy, inode))
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 398) return -EINVAL;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 399)
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 400) switch (policy->version) {
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 401) case FSCRYPT_POLICY_V1:
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 402) /*
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 403) * The original encryption policy version provided no way of
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 404) * verifying that the correct master key was supplied, which was
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 405) * insecure in scenarios where multiple users have access to the
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 406) * same encrypted files (even just read-only access). The new
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 407) * encryption policy version fixes this and also implies use of
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 408) * an improved key derivation function and allows non-root users
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 409) * to securely remove keys. So as long as compatibility with
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 410) * old kernels isn't required, it is recommended to use the new
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 411) * policy version for all new encrypted directories.
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 412) */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 413) pr_warn_once("%s (pid %d) is setting deprecated v1 encryption policy; recommend upgrading to v2.\n",
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 414) current->comm, current->pid);
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 415) break;
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 416) case FSCRYPT_POLICY_V2:
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 417) err = fscrypt_verify_key_added(inode->i_sb,
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 418) policy->v2.master_key_identifier);
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 419) if (err)
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 420) return err;
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 421) if (policy->v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 422) pr_warn_once("%s (pid %d) is setting an IV_INO_LBLK_32 encryption policy. This should only be used if there are certain hardware limitations.\n",
e3b1078bedd32 (Eric Biggers 2020-05-15 13:41:41 -0700 423) current->comm, current->pid);
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 424) break;
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 425) default:
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 426) WARN_ON(1);
5ab7189a31bad (Eric Biggers 2019-08-04 19:35:48 -0700 427) return -EINVAL;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 428) }
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 429)
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 430) get_random_bytes(nonce, FSCRYPT_FILE_NONCE_SIZE);
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 431) ctxsize = fscrypt_new_context(&ctx, policy, nonce);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 432)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 433) return inode->i_sb->s_cop->set_context(inode, &ctx, ctxsize, NULL);
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 434) }
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 435)
db717d8e26c2d (Eric Biggers 2016-11-26 19:07:49 -0500 436) int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 437) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 438) union fscrypt_policy policy;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 439) union fscrypt_policy existing_policy;
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 440) struct inode *inode = file_inode(filp);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 441) u8 version;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 442) int size;
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 443) int ret;
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 444)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 445) if (get_user(policy.version, (const u8 __user *)arg))
db717d8e26c2d (Eric Biggers 2016-11-26 19:07:49 -0500 446) return -EFAULT;
db717d8e26c2d (Eric Biggers 2016-11-26 19:07:49 -0500 447)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 448) size = fscrypt_policy_size(&policy);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 449) if (size <= 0)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 450) return -EINVAL;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 451)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 452) /*
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 453) * We should just copy the remaining 'size - 1' bytes here, but a
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 454) * bizarre bug in gcc 7 and earlier (fixed by gcc r255731) causes gcc to
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 455) * think that size can be 0 here (despite the check above!) *and* that
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 456) * it's a compile-time constant. Thus it would think copy_from_user()
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 457) * is passed compile-time constant ULONG_MAX, causing the compile-time
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 458) * buffer overflow check to fail, breaking the build. This only occurred
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 459) * when building an i386 kernel with -Os and branch profiling enabled.
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 460) *
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 461) * Work around it by just copying the first byte again...
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 462) */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 463) version = policy.version;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 464) if (copy_from_user(&policy, arg, size))
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 465) return -EFAULT;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 466) policy.version = version;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 467)
21cb47be6fb9e (Christian Brauner 2021-01-21 14:19:25 +0100 468) if (!inode_owner_or_capable(&init_user_ns, inode))
163ae1c6ad629 (Eric Biggers 2016-09-08 10:57:08 -0700 469) return -EACCES;
163ae1c6ad629 (Eric Biggers 2016-09-08 10:57:08 -0700 470)
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 471) ret = mnt_want_write_file(filp);
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 472) if (ret)
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 473) return ret;
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 474)
8906a8223ad49 (Eric Biggers 2016-10-15 09:48:50 -0400 475) inode_lock(inode);
8906a8223ad49 (Eric Biggers 2016-10-15 09:48:50 -0400 476)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 477) ret = fscrypt_get_policy(inode, &existing_policy);
efee590e4a3fa (Eric Biggers 2016-12-05 11:12:48 -0800 478) if (ret == -ENODATA) {
002ced4be6429 (Eric Biggers 2016-09-08 11:36:39 -0700 479) if (!S_ISDIR(inode->i_mode))
dffd0cfa06d4e (Eric Biggers 2016-12-05 11:12:45 -0800 480) ret = -ENOTDIR;
5858bdad4d0d0 (Hongjie Fang 2019-05-22 10:02:53 +0800 481) else if (IS_DEADDIR(inode))
5858bdad4d0d0 (Hongjie Fang 2019-05-22 10:02:53 +0800 482) ret = -ENOENT;
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 483) else if (!inode->i_sb->s_cop->empty_dir(inode))
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 484) ret = -ENOTEMPTY;
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 485) else
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 486) ret = set_encryption_policy(inode, &policy);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 487) } else if (ret == -EINVAL ||
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 488) (ret == 0 && !fscrypt_policies_equal(&policy,
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 489) &existing_policy))) {
efee590e4a3fa (Eric Biggers 2016-12-05 11:12:48 -0800 490) /* The file already uses a different encryption policy. */
8488cd96ff889 (Eric Biggers 2016-12-05 11:12:46 -0800 491) ret = -EEXIST;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 492) }
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 493)
8906a8223ad49 (Eric Biggers 2016-10-15 09:48:50 -0400 494) inode_unlock(inode);
8906a8223ad49 (Eric Biggers 2016-10-15 09:48:50 -0400 495)
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 496) mnt_drop_write_file(filp);
ba63f23d69a3a (Eric Biggers 2016-09-08 14:20:38 -0700 497) return ret;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 498) }
db717d8e26c2d (Eric Biggers 2016-11-26 19:07:49 -0500 499) EXPORT_SYMBOL(fscrypt_ioctl_set_policy);
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 500)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 501) /* Original ioctl version; can only get the original policy version */
db717d8e26c2d (Eric Biggers 2016-11-26 19:07:49 -0500 502) int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 503) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 504) union fscrypt_policy policy;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 505) int err;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 506)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 507) err = fscrypt_get_policy(file_inode(filp), &policy);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 508) if (err)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 509) return err;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 510)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 511) if (policy.version != FSCRYPT_POLICY_V1)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 512) return -EINVAL;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 513)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 514) if (copy_to_user(arg, &policy, sizeof(policy.v1)))
db717d8e26c2d (Eric Biggers 2016-11-26 19:07:49 -0500 515) return -EFAULT;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 516) return 0;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 517) }
db717d8e26c2d (Eric Biggers 2016-11-26 19:07:49 -0500 518) EXPORT_SYMBOL(fscrypt_ioctl_get_policy);
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 519)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 520) /* Extended ioctl version; can get policies of any version */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 521) int fscrypt_ioctl_get_policy_ex(struct file *filp, void __user *uarg)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 522) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 523) struct fscrypt_get_policy_ex_arg arg;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 524) union fscrypt_policy *policy = (union fscrypt_policy *)&arg.policy;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 525) size_t policy_size;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 526) int err;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 527)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 528) /* arg is policy_size, then policy */
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 529) BUILD_BUG_ON(offsetof(typeof(arg), policy_size) != 0);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 530) BUILD_BUG_ON(offsetofend(typeof(arg), policy_size) !=
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 531) offsetof(typeof(arg), policy));
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 532) BUILD_BUG_ON(sizeof(arg.policy) != sizeof(*policy));
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 533)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 534) err = fscrypt_get_policy(file_inode(filp), policy);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 535) if (err)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 536) return err;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 537) policy_size = fscrypt_policy_size(policy);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 538)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 539) if (copy_from_user(&arg, uarg, sizeof(arg.policy_size)))
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 540) return -EFAULT;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 541)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 542) if (policy_size > arg.policy_size)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 543) return -EOVERFLOW;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 544) arg.policy_size = policy_size;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 545)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 546) if (copy_to_user(uarg, &arg, sizeof(arg.policy_size) + policy_size))
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 547) return -EFAULT;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 548) return 0;
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 549) }
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 550) EXPORT_SYMBOL_GPL(fscrypt_ioctl_get_policy_ex);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 551)
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 552) /* FS_IOC_GET_ENCRYPTION_NONCE: retrieve file's encryption nonce for testing */
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 553) int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg)
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 554) {
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 555) struct inode *inode = file_inode(filp);
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 556) union fscrypt_context ctx;
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 557) int ret;
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 558)
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 559) ret = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 560) if (ret < 0)
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 561) return ret;
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 562) if (!fscrypt_context_is_valid(&ctx, ret))
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 563) return -EINVAL;
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 564) if (copy_to_user(arg, fscrypt_context_nonce(&ctx),
1d6217a4f9905 (Eric Biggers 2020-07-08 14:57:22 -0700 565) FSCRYPT_FILE_NONCE_SIZE))
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 566) return -EFAULT;
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 567) return 0;
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 568) }
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 569) EXPORT_SYMBOL_GPL(fscrypt_ioctl_get_nonce);
e98ad464750c0 (Eric Biggers 2020-03-14 13:50:49 -0700 570)
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 571) /**
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 572) * fscrypt_has_permitted_context() - is a file's encryption policy permitted
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 573) * within its directory?
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 574) *
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 575) * @parent: inode for parent directory
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 576) * @child: inode for file being looked up, opened, or linked into @parent
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 577) *
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 578) * Filesystems must call this before permitting access to an inode in a
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 579) * situation where the parent directory is encrypted (either before allowing
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 580) * ->lookup() to succeed, or for a regular file before allowing it to be opened)
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 581) * and before any operation that involves linking an inode into an encrypted
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 582) * directory, including link, rename, and cross rename. It enforces the
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 583) * constraint that within a given encrypted directory tree, all files use the
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 584) * same encryption policy. The pre-access check is needed to detect potentially
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 585) * malicious offline violations of this constraint, while the link and rename
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 586) * checks are needed to prevent online violations of this constraint.
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 587) *
f5e55e777cc93 (Eric Biggers 2019-01-22 16:20:21 -0800 588) * Return: 1 if permitted, 0 if forbidden.
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 589) */
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 590) int fscrypt_has_permitted_context(struct inode *parent, struct inode *child)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 591) {
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 592) union fscrypt_policy parent_policy, child_policy;
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 593) int err, err1, err2;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 594)
42d97eb0ade31 (Eric Biggers 2016-12-19 14:20:13 -0800 595) /* No restrictions on file types which are never encrypted */
42d97eb0ade31 (Eric Biggers 2016-12-19 14:20:13 -0800 596) if (!S_ISREG(child->i_mode) && !S_ISDIR(child->i_mode) &&
42d97eb0ade31 (Eric Biggers 2016-12-19 14:20:13 -0800 597) !S_ISLNK(child->i_mode))
42d97eb0ade31 (Eric Biggers 2016-12-19 14:20:13 -0800 598) return 1;
42d97eb0ade31 (Eric Biggers 2016-12-19 14:20:13 -0800 599)
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 600) /* No restrictions if the parent directory is unencrypted */
e0428a266d5a2 (Eric Biggers 2017-10-09 12:15:36 -0700 601) if (!IS_ENCRYPTED(parent))
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 602) return 1;
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 603)
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 604) /* Encrypted directories must not contain unencrypted files */
e0428a266d5a2 (Eric Biggers 2017-10-09 12:15:36 -0700 605) if (!IS_ENCRYPTED(child))
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 606) return 0;
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 607)
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 608) /*
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 609) * Both parent and child are encrypted, so verify they use the same
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 610) * encryption policy. Compare the fscrypt_info structs if the keys are
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 611) * available, otherwise retrieve and compare the fscrypt_contexts.
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 612) *
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 613) * Note that the fscrypt_context retrieval will be required frequently
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 614) * when accessing an encrypted directory tree without the key.
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 615) * Performance-wise this is not a big deal because we already don't
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 616) * really optimize for file access without the key (to the extent that
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 617) * such access is even possible), given that any attempted access
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 618) * already causes a fscrypt_context retrieval and keyring search.
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 619) *
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 620) * In any case, if an unexpected error occurs, fall back to "forbidden".
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 621) */
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 622)
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 623) err = fscrypt_get_encryption_info(parent, true);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 624) if (err)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 625) return 0;
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 626) err = fscrypt_get_encryption_info(child, true);
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 627) if (err)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 628) return 0;
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 629)
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 630) err1 = fscrypt_get_policy(parent, &parent_policy);
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 631) err2 = fscrypt_get_policy(child, &child_policy);
272f98f684627 (Eric Biggers 2017-04-07 10:58:37 -0700 632)
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 633) /*
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 634) * Allow the case where the parent and child both have an unrecognized
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 635) * encryption policy, so that files with an unrecognized encryption
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 636) * policy can be deleted.
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 637) */
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 638) if (err1 == -EINVAL && err2 == -EINVAL)
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 639) return 1;
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 640)
a14d0b6764917 (Eric Biggers 2020-12-02 18:20:41 -0800 641) if (err1 || err2)
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 642) return 0;
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 643)
5dae460c2292d (Eric Biggers 2019-08-04 19:35:47 -0700 644) return fscrypt_policies_equal(&parent_policy, &child_policy);
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 645) }
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 646) EXPORT_SYMBOL(fscrypt_has_permitted_context);
0b81d07790726 (Jaegeuk Kim 2015-05-15 16:26:10 -0700 647)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 648) /*
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 649) * Return the encryption policy that new files in the directory will inherit, or
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 650) * NULL if none, or an ERR_PTR() on error. If the directory is encrypted, also
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 651) * ensure that its key is set up, so that the new filename can be encrypted.
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 652) */
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 653) const union fscrypt_policy *fscrypt_policy_to_inherit(struct inode *dir)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 654) {
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 655) int err;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 656)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 657) if (IS_ENCRYPTED(dir)) {
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 658) err = fscrypt_require_key(dir);
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 659) if (err)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 660) return ERR_PTR(err);
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 661) return &dir->i_crypt_info->ci_policy;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 662) }
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 663)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 664) return fscrypt_get_dummy_policy(dir->i_sb);
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 665) }
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 666)
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 667) /**
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 668) * fscrypt_set_context() - Set the fscrypt context of a new inode
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 669) * @inode: a new inode
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 670) * @fs_data: private data given by FS and passed to ->set_context()
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 671) *
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 672) * This should be called after fscrypt_prepare_new_inode(), generally during a
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 673) * filesystem transaction. Everything here must be %GFP_NOFS-safe.
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 674) *
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 675) * Return: 0 on success, -errno on failure
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 676) */
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 677) int fscrypt_set_context(struct inode *inode, void *fs_data)
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 678) {
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 679) struct fscrypt_info *ci = inode->i_crypt_info;
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 680) union fscrypt_context ctx;
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 681) int ctxsize;
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 682)
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 683) /* fscrypt_prepare_new_inode() should have set up the key already. */
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 684) if (WARN_ON_ONCE(!ci))
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 685) return -ENOKEY;
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 686)
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 687) BUILD_BUG_ON(sizeof(ctx) != FSCRYPT_SET_CONTEXT_MAX_SIZE);
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 688) ctxsize = fscrypt_new_context(&ctx, &ci->ci_policy, ci->ci_nonce);
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 689)
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 690) /*
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 691) * This may be the first time the inode number is available, so do any
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 692) * delayed key setup that requires the inode number.
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 693) */
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 694) if (ci->ci_policy.version == FSCRYPT_POLICY_V2 &&
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 695) (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) {
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 696) const struct fscrypt_master_key *mk =
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 697) ci->ci_master_key->payload.data[0];
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 698)
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 699) fscrypt_hash_inode_number(ci, mk);
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 700) }
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 701)
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 702) return inode->i_sb->s_cop->set_context(inode, &ctx, ctxsize, fs_data);
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 703) }
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 704) EXPORT_SYMBOL_GPL(fscrypt_set_context);
a992b20cd4ee3 (Eric Biggers 2020-09-16 21:11:24 -0700 705)
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 706) /**
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 707) * fscrypt_set_test_dummy_encryption() - handle '-o test_dummy_encryption'
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 708) * @sb: the filesystem on which test_dummy_encryption is being specified
c8c868abc91ff (Eric Biggers 2020-09-16 21:11:36 -0700 709) * @arg: the argument to the test_dummy_encryption option. May be NULL.
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 710) * @dummy_policy: the filesystem's current dummy policy (input/output, see
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 711) * below)
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 712) *
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 713) * Handle the test_dummy_encryption mount option by creating a dummy encryption
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 714) * policy, saving it in @dummy_policy, and adding the corresponding dummy
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 715) * encryption key to the filesystem. If the @dummy_policy is already set, then
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 716) * instead validate that it matches @arg. Don't support changing it via
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 717) * remount, as that is difficult to do safely.
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 718) *
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 719) * Return: 0 on success (dummy policy set, or the same policy is already set);
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 720) * -EEXIST if a different dummy policy is already set;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 721) * or another -errno value.
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 722) */
c8c868abc91ff (Eric Biggers 2020-09-16 21:11:36 -0700 723) int fscrypt_set_test_dummy_encryption(struct super_block *sb, const char *arg,
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 724) struct fscrypt_dummy_policy *dummy_policy)
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 725) {
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 726) struct fscrypt_key_specifier key_spec = { 0 };
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 727) int version;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 728) union fscrypt_policy *policy = NULL;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 729) int err;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 730)
c8c868abc91ff (Eric Biggers 2020-09-16 21:11:36 -0700 731) if (!arg)
c8c868abc91ff (Eric Biggers 2020-09-16 21:11:36 -0700 732) arg = "v2";
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 733)
c8c868abc91ff (Eric Biggers 2020-09-16 21:11:36 -0700 734) if (!strcmp(arg, "v1")) {
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 735) version = FSCRYPT_POLICY_V1;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 736) key_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 737) memset(key_spec.u.descriptor, 0x42,
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 738) FSCRYPT_KEY_DESCRIPTOR_SIZE);
c8c868abc91ff (Eric Biggers 2020-09-16 21:11:36 -0700 739) } else if (!strcmp(arg, "v2")) {
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 740) version = FSCRYPT_POLICY_V2;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 741) key_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 742) /* key_spec.u.identifier gets filled in when adding the key */
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 743) } else {
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 744) err = -EINVAL;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 745) goto out;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 746) }
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 747)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 748) policy = kzalloc(sizeof(*policy), GFP_KERNEL);
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 749) if (!policy) {
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 750) err = -ENOMEM;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 751) goto out;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 752) }
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 753)
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 754) err = fscrypt_add_test_dummy_key(sb, &key_spec);
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 755) if (err)
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 756) goto out;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 757)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 758) policy->version = version;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 759) switch (policy->version) {
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 760) case FSCRYPT_POLICY_V1:
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 761) policy->v1.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 762) policy->v1.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 763) memcpy(policy->v1.master_key_descriptor, key_spec.u.descriptor,
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 764) FSCRYPT_KEY_DESCRIPTOR_SIZE);
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 765) break;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 766) case FSCRYPT_POLICY_V2:
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 767) policy->v2.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 768) policy->v2.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 769) memcpy(policy->v2.master_key_identifier, key_spec.u.identifier,
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 770) FSCRYPT_KEY_IDENTIFIER_SIZE);
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 771) break;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 772) default:
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 773) WARN_ON(1);
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 774) err = -EINVAL;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 775) goto out;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 776) }
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 777)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 778) if (dummy_policy->policy) {
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 779) if (fscrypt_policies_equal(policy, dummy_policy->policy))
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 780) err = 0;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 781) else
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 782) err = -EEXIST;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 783) goto out;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 784) }
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 785) dummy_policy->policy = policy;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 786) policy = NULL;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 787) err = 0;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 788) out:
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 789) kfree(policy);
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 790) return err;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 791) }
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 792) EXPORT_SYMBOL_GPL(fscrypt_set_test_dummy_encryption);
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 793)
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 794) /**
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 795) * fscrypt_show_test_dummy_encryption() - show '-o test_dummy_encryption'
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 796) * @seq: the seq_file to print the option to
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 797) * @sep: the separator character to use
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 798) * @sb: the filesystem whose options are being shown
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 799) *
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 800) * Show the test_dummy_encryption mount option, if it was specified.
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 801) * This is mainly used for /proc/mounts.
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 802) */
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 803) void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep,
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 804) struct super_block *sb)
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 805) {
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 806) const union fscrypt_policy *policy = fscrypt_get_dummy_policy(sb);
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 807) int vers;
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 808)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 809) if (!policy)
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 810) return;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 811)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 812) vers = policy->version;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 813) if (vers == FSCRYPT_POLICY_V1) /* Handle numbering quirk */
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 814) vers = 1;
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 815)
ac4acb1f4b2b6 (Eric Biggers 2020-09-16 21:11:35 -0700 816) seq_printf(seq, "%ctest_dummy_encryption=v%d", sep, vers);
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 817) }
ed318a6cc0b62 (Eric Biggers 2020-05-12 16:32:50 -0700 818) EXPORT_SYMBOL_GPL(fscrypt_show_test_dummy_encryption);
VisionFive2 Linux kernel
StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)
More than 9999 Commits
32 Branches
54 Tags