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Diffstat (limited to 'fs/crypto/keysetup.c')
-rw-r--r--fs/crypto/keysetup.c196
1 files changed, 115 insertions, 81 deletions
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index b4fe01ea4bd4..40fa05688d3a 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -9,6 +9,7 @@
*/
#include <crypto/skcipher.h>
+#include <linux/export.h>
#include <linux/random.h>
#include "fscrypt_private.h"
@@ -96,14 +97,15 @@ select_encryption_mode(const union fscrypt_policy *policy,
}
/* Create a symmetric cipher object for the given encryption mode and key */
-static struct crypto_skcipher *
+static struct crypto_sync_skcipher *
fscrypt_allocate_skcipher(struct fscrypt_mode *mode, const u8 *raw_key,
const struct inode *inode)
{
- struct crypto_skcipher *tfm;
+ struct crypto_sync_skcipher *tfm;
int err;
- tfm = crypto_alloc_skcipher(mode->cipher_str, 0, 0);
+ tfm = crypto_alloc_sync_skcipher(mode->cipher_str, 0,
+ FSCRYPT_CRYPTOAPI_MASK);
if (IS_ERR(tfm)) {
if (PTR_ERR(tfm) == -ENOENT) {
fscrypt_warn(inode,
@@ -123,21 +125,22 @@ fscrypt_allocate_skcipher(struct fscrypt_mode *mode, const u8 *raw_key,
* first time a mode is used.
*/
pr_info("fscrypt: %s using implementation \"%s\"\n",
- mode->friendly_name, crypto_skcipher_driver_name(tfm));
+ mode->friendly_name,
+ crypto_skcipher_driver_name(&tfm->base));
}
- if (WARN_ON_ONCE(crypto_skcipher_ivsize(tfm) != mode->ivsize)) {
+ if (WARN_ON_ONCE(crypto_sync_skcipher_ivsize(tfm) != mode->ivsize)) {
err = -EINVAL;
goto err_free_tfm;
}
- crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
- err = crypto_skcipher_setkey(tfm, raw_key, mode->keysize);
+ crypto_sync_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
+ err = crypto_sync_skcipher_setkey(tfm, raw_key, mode->keysize);
if (err)
goto err_free_tfm;
return tfm;
err_free_tfm:
- crypto_free_skcipher(tfm);
+ crypto_free_sync_skcipher(tfm);
return ERR_PTR(err);
}
@@ -150,10 +153,12 @@ err_free_tfm:
int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
const u8 *raw_key, const struct fscrypt_inode_info *ci)
{
- struct crypto_skcipher *tfm;
+ struct crypto_sync_skcipher *tfm;
if (fscrypt_using_inline_encryption(ci))
- return fscrypt_prepare_inline_crypt_key(prep_key, raw_key, ci);
+ return fscrypt_prepare_inline_crypt_key(prep_key, raw_key,
+ ci->ci_mode->keysize,
+ false, ci);
tfm = fscrypt_allocate_skcipher(ci->ci_mode, raw_key, ci->ci_inode);
if (IS_ERR(tfm))
@@ -172,7 +177,7 @@ int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
void fscrypt_destroy_prepared_key(struct super_block *sb,
struct fscrypt_prepared_key *prep_key)
{
- crypto_free_skcipher(prep_key->tfm);
+ crypto_free_sync_skcipher(prep_key->tfm);
fscrypt_destroy_inline_crypt_key(sb, prep_key);
memzero_explicit(prep_key, sizeof(*prep_key));
}
@@ -195,14 +200,29 @@ static int setup_per_mode_enc_key(struct fscrypt_inode_info *ci,
struct fscrypt_mode *mode = ci->ci_mode;
const u8 mode_num = mode - fscrypt_modes;
struct fscrypt_prepared_key *prep_key;
- u8 mode_key[FSCRYPT_MAX_KEY_SIZE];
+ u8 mode_key[FSCRYPT_MAX_RAW_KEY_SIZE];
u8 hkdf_info[sizeof(mode_num) + sizeof(sb->s_uuid)];
unsigned int hkdf_infolen = 0;
+ bool use_hw_wrapped_key = false;
int err;
if (WARN_ON_ONCE(mode_num > FSCRYPT_MODE_MAX))
return -EINVAL;
+ if (mk->mk_secret.is_hw_wrapped && S_ISREG(inode->i_mode)) {
+ /* Using a hardware-wrapped key for file contents encryption */
+ if (!fscrypt_using_inline_encryption(ci)) {
+ if (sb->s_flags & SB_INLINECRYPT)
+ fscrypt_warn(ci->ci_inode,
+ "Hardware-wrapped key required, but no suitable inline encryption capabilities are available");
+ else
+ fscrypt_warn(ci->ci_inode,
+ "Hardware-wrapped keys require inline encryption (-o inlinecrypt)");
+ return -EINVAL;
+ }
+ use_hw_wrapped_key = true;
+ }
+
prep_key = &keys[mode_num];
if (fscrypt_is_key_prepared(prep_key, ci)) {
ci->ci_enc_key = *prep_key;
@@ -214,6 +234,16 @@ static int setup_per_mode_enc_key(struct fscrypt_inode_info *ci,
if (fscrypt_is_key_prepared(prep_key, ci))
goto done_unlock;
+ if (use_hw_wrapped_key) {
+ err = fscrypt_prepare_inline_crypt_key(prep_key,
+ mk->mk_secret.bytes,
+ mk->mk_secret.size, true,
+ ci);
+ if (err)
+ goto out_unlock;
+ goto done_unlock;
+ }
+
BUILD_BUG_ON(sizeof(mode_num) != 1);
BUILD_BUG_ON(sizeof(sb->s_uuid) != 16);
BUILD_BUG_ON(sizeof(hkdf_info) != 17);
@@ -223,11 +253,8 @@ static int setup_per_mode_enc_key(struct fscrypt_inode_info *ci,
sizeof(sb->s_uuid));
hkdf_infolen += sizeof(sb->s_uuid);
}
- err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
- hkdf_context, hkdf_info, hkdf_infolen,
- mode_key, mode->keysize);
- if (err)
- goto out_unlock;
+ fscrypt_hkdf_expand(&mk->mk_secret.hkdf, hkdf_context, hkdf_info,
+ hkdf_infolen, mode_key, mode->keysize);
err = fscrypt_prepare_key(prep_key, mode_key, ci);
memzero_explicit(mode_key, mode->keysize);
if (err)
@@ -248,36 +275,25 @@ out_unlock:
* as a pair of 64-bit words. Therefore, on big endian CPUs we have to do an
* endianness swap in order to get the same results as on little endian CPUs.
*/
-static int fscrypt_derive_siphash_key(const struct fscrypt_master_key *mk,
- u8 context, const u8 *info,
- unsigned int infolen, siphash_key_t *key)
+static void fscrypt_derive_siphash_key(const struct fscrypt_master_key *mk,
+ u8 context, const u8 *info,
+ unsigned int infolen, siphash_key_t *key)
{
- int err;
-
- err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf, context, info, infolen,
- (u8 *)key, sizeof(*key));
- if (err)
- return err;
-
+ fscrypt_hkdf_expand(&mk->mk_secret.hkdf, context, info, infolen,
+ (u8 *)key, sizeof(*key));
BUILD_BUG_ON(sizeof(*key) != 16);
BUILD_BUG_ON(ARRAY_SIZE(key->key) != 2);
le64_to_cpus(&key->key[0]);
le64_to_cpus(&key->key[1]);
- return 0;
}
-int fscrypt_derive_dirhash_key(struct fscrypt_inode_info *ci,
- const struct fscrypt_master_key *mk)
+void fscrypt_derive_dirhash_key(struct fscrypt_inode_info *ci,
+ const struct fscrypt_master_key *mk)
{
- int err;
-
- err = fscrypt_derive_siphash_key(mk, HKDF_CONTEXT_DIRHASH_KEY,
- ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE,
- &ci->ci_dirhash_key);
- if (err)
- return err;
+ fscrypt_derive_siphash_key(mk, HKDF_CONTEXT_DIRHASH_KEY,
+ ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE,
+ &ci->ci_dirhash_key);
ci->ci_dirhash_key_initialized = true;
- return 0;
}
void fscrypt_hash_inode_number(struct fscrypt_inode_info *ci,
@@ -308,17 +324,12 @@ static int fscrypt_setup_iv_ino_lblk_32_key(struct fscrypt_inode_info *ci,
if (mk->mk_ino_hash_key_initialized)
goto unlock;
- err = fscrypt_derive_siphash_key(mk,
- HKDF_CONTEXT_INODE_HASH_KEY,
- NULL, 0, &mk->mk_ino_hash_key);
- if (err)
- goto unlock;
+ fscrypt_derive_siphash_key(mk, HKDF_CONTEXT_INODE_HASH_KEY,
+ NULL, 0, &mk->mk_ino_hash_key);
/* pairs with smp_load_acquire() above */
smp_store_release(&mk->mk_ino_hash_key_initialized, true);
unlock:
mutex_unlock(&fscrypt_mode_key_setup_mutex);
- if (err)
- return err;
}
/*
@@ -336,6 +347,14 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_inode_info *ci,
{
int err;
+ if (mk->mk_secret.is_hw_wrapped &&
+ !(ci->ci_policy.v2.flags & (FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 |
+ FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32))) {
+ fscrypt_warn(ci->ci_inode,
+ "Hardware-wrapped keys are only supported with IV_INO_LBLK policies");
+ return -EINVAL;
+ }
+
if (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) {
/*
* DIRECT_KEY: instead of deriving per-file encryption keys, the
@@ -362,15 +381,12 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_inode_info *ci,
FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) {
err = fscrypt_setup_iv_ino_lblk_32_key(ci, mk);
} else {
- u8 derived_key[FSCRYPT_MAX_KEY_SIZE];
-
- err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
- HKDF_CONTEXT_PER_FILE_ENC_KEY,
- ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE,
- derived_key, ci->ci_mode->keysize);
- if (err)
- return err;
+ u8 derived_key[FSCRYPT_MAX_RAW_KEY_SIZE];
+ fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
+ HKDF_CONTEXT_PER_FILE_ENC_KEY,
+ ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE,
+ derived_key, ci->ci_mode->keysize);
err = fscrypt_set_per_file_enc_key(ci, derived_key);
memzero_explicit(derived_key, ci->ci_mode->keysize);
}
@@ -378,11 +394,8 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_inode_info *ci,
return err;
/* Derive a secret dirhash key for directories that need it. */
- if (need_dirhash_key) {
- err = fscrypt_derive_dirhash_key(ci, mk);
- if (err)
- return err;
- }
+ if (need_dirhash_key)
+ fscrypt_derive_dirhash_key(ci, mk);
return 0;
}
@@ -445,10 +458,6 @@ static int setup_file_encryption_key(struct fscrypt_inode_info *ci,
struct fscrypt_master_key *mk;
int err;
- err = fscrypt_select_encryption_impl(ci);
- if (err)
- return err;
-
err = fscrypt_policy_to_key_spec(&ci->ci_policy, &mk_spec);
if (err)
return err;
@@ -476,6 +485,10 @@ static int setup_file_encryption_key(struct fscrypt_inode_info *ci,
if (ci->ci_policy.version != FSCRYPT_POLICY_V1)
return -ENOKEY;
+ err = fscrypt_select_encryption_impl(ci, false);
+ if (err)
+ return err;
+
/*
* As a legacy fallback for v1 policies, search for the key in
* the current task's subscribed keyrings too. Don't move this
@@ -497,9 +510,21 @@ static int setup_file_encryption_key(struct fscrypt_inode_info *ci,
goto out_release_key;
}
+ err = fscrypt_select_encryption_impl(ci, mk->mk_secret.is_hw_wrapped);
+ if (err)
+ goto out_release_key;
+
switch (ci->ci_policy.version) {
case FSCRYPT_POLICY_V1:
- err = fscrypt_setup_v1_file_key(ci, mk->mk_secret.raw);
+ if (WARN_ON_ONCE(mk->mk_secret.is_hw_wrapped)) {
+ /*
+ * This should never happen, as adding a v1 policy key
+ * that is hardware-wrapped isn't allowed.
+ */
+ err = -EINVAL;
+ goto out_release_key;
+ }
+ err = fscrypt_setup_v1_file_key(ci, mk->mk_secret.bytes);
break;
case FSCRYPT_POLICY_V2:
err = fscrypt_setup_v2_file_key(ci, mk, need_dirhash_key);
@@ -592,15 +617,16 @@ fscrypt_setup_encryption_info(struct inode *inode,
goto out;
/*
- * For existing inodes, multiple tasks may race to set ->i_crypt_info.
- * So use cmpxchg_release(). This pairs with the smp_load_acquire() in
- * fscrypt_get_inode_info(). I.e., here we publish ->i_crypt_info with
- * a RELEASE barrier so that other tasks can ACQUIRE it.
+ * For existing inodes, multiple tasks may race to set the inode's
+ * fscrypt info pointer. So use cmpxchg_release(). This pairs with the
+ * smp_load_acquire() in fscrypt_get_inode_info(). I.e., publish the
+ * pointer with a RELEASE barrier so that other tasks can ACQUIRE it.
*/
- if (cmpxchg_release(&inode->i_crypt_info, NULL, crypt_info) == NULL) {
+ if (cmpxchg_release(fscrypt_inode_info_addr(inode), NULL, crypt_info) ==
+ NULL) {
/*
- * We won the race and set ->i_crypt_info to our crypt_info.
- * Now link it into the master key's inode list.
+ * We won the race and set the inode's fscrypt info to our
+ * crypt_info. Now link it into the master key's inode list.
*/
if (mk) {
crypt_info->ci_master_key = mk;
@@ -631,13 +657,13 @@ out:
* %false unless the operation being performed is needed in
* order for files (or directories) to be deleted.
*
- * Set up ->i_crypt_info, if it hasn't already been done.
+ * Set up the inode's encryption key, if it hasn't already been done.
*
- * Note: unless ->i_crypt_info is already set, this isn't %GFP_NOFS-safe. So
+ * Note: unless the key setup was already done, this isn't %GFP_NOFS-safe. So
* generally this shouldn't be called from within a filesystem transaction.
*
- * Return: 0 if ->i_crypt_info was set or was already set, *or* if the
- * encryption key is unavailable. (Use fscrypt_has_encryption_key() to
+ * Return: 0 if the key is now set up, *or* if it couldn't be set up because the
+ * needed master key is absent. (Use fscrypt_has_encryption_key() to
* distinguish these cases.) Also can return another -errno code.
*/
int fscrypt_get_encryption_info(struct inode *inode, bool allow_unsupported)
@@ -691,9 +717,9 @@ int fscrypt_get_encryption_info(struct inode *inode, bool allow_unsupported)
* ->i_ino doesn't need to be set yet.
* @encrypt_ret: (output) set to %true if the new inode will be encrypted
*
- * If the directory is encrypted, set up its ->i_crypt_info in preparation for
+ * If the directory is encrypted, set up its encryption key in preparation for
* encrypting the name of the new file. Also, if the new inode will be
- * encrypted, set up its ->i_crypt_info and set *encrypt_ret=true.
+ * encrypted, set up its encryption key too and set *encrypt_ret=true.
*
* This isn't %GFP_NOFS-safe, and therefore it should be called before starting
* any filesystem transaction to create the inode. For this reason, ->i_ino
@@ -702,8 +728,8 @@ int fscrypt_get_encryption_info(struct inode *inode, bool allow_unsupported)
* This doesn't persist the new inode's encryption context. That still needs to
* be done later by calling fscrypt_set_context().
*
- * Return: 0 on success, -ENOKEY if the encryption key is missing, or another
- * -errno code
+ * Return: 0 on success, -ENOKEY if a key needs to be set up for @dir or @inode
+ * but the needed master key is absent, or another -errno code
*/
int fscrypt_prepare_new_inode(struct inode *dir, struct inode *inode,
bool *encrypt_ret)
@@ -750,8 +776,16 @@ EXPORT_SYMBOL_GPL(fscrypt_prepare_new_inode);
*/
void fscrypt_put_encryption_info(struct inode *inode)
{
- put_crypt_info(inode->i_crypt_info);
- inode->i_crypt_info = NULL;
+ /*
+ * Ideally we'd start with a lightweight IS_ENCRYPTED() check here
+ * before proceeding to retrieve and check the pointer. However, during
+ * inode creation, the fscrypt_inode_info is set before S_ENCRYPTED. If
+ * an error occurs, it needs to be cleaned up regardless.
+ */
+ struct fscrypt_inode_info **ci_addr = fscrypt_inode_info_addr(inode);
+
+ put_crypt_info(*ci_addr);
+ *ci_addr = NULL;
}
EXPORT_SYMBOL(fscrypt_put_encryption_info);
@@ -800,7 +834,7 @@ int fscrypt_drop_inode(struct inode *inode)
* userspace is still using the files, inodes can be dirtied between
* then and now. We mustn't lose any writes, so skip dirty inodes here.
*/
- if (inode->i_state & I_DIRTY_ALL)
+ if (inode_state_read(inode) & I_DIRTY_ALL)
return 0;
/*
generated by cgit (git 2.34.1) at 2025-12-24 23:23:24 +0000