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-rw-r--r--Documentation/filesystems/fscrypt.rst11
-rw-r--r--fs/crypto/fscrypt_private.h20
-rw-r--r--fs/crypto/keysetup.c16
-rw-r--r--fs/crypto/policy.c21
-rw-r--r--fs/ext4/ioctl.c6
-rw-r--r--fs/f2fs/file.c11
-rw-r--r--fs/ubifs/ioctl.c4
-rw-r--r--include/linux/fscrypt.h6
-rw-r--r--include/uapi/linux/fscrypt.h1
9 files changed, 81 insertions, 15 deletions
diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst
index bd9932344804..aa072112cfff 100644
--- a/Documentation/filesystems/fscrypt.rst
+++ b/Documentation/filesystems/fscrypt.rst
@@ -633,6 +633,17 @@ from a passphrase or other low-entropy user credential.
FS_IOC_GET_ENCRYPTION_PWSALT is deprecated. Instead, prefer to
generate and manage any needed salt(s) in userspace.
+Getting a file's encryption nonce
+---------------------------------
+
+Since Linux v5.7, the ioctl FS_IOC_GET_ENCRYPTION_NONCE is supported.
+On encrypted files and directories it gets the inode's 16-byte nonce.
+On unencrypted files and directories, it fails with ENODATA.
+
+This ioctl can be useful for automated tests which verify that the
+encryption is being done correctly. It is not needed for normal use
+of fscrypt.
+
Adding keys
-----------
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 9aae851409e5..dbced2937ec8 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -76,6 +76,26 @@ static inline int fscrypt_context_size(const union fscrypt_context *ctx)
return 0;
}
+/* Check whether an fscrypt_context has a recognized version number and size */
+static inline bool fscrypt_context_is_valid(const union fscrypt_context *ctx,
+ int ctx_size)
+{
+ return ctx_size >= 1 && ctx_size == fscrypt_context_size(ctx);
+}
+
+/* Retrieve the context's nonce, assuming the context was already validated */
+static inline const u8 *fscrypt_context_nonce(const union fscrypt_context *ctx)
+{
+ switch (ctx->version) {
+ case FSCRYPT_CONTEXT_V1:
+ return ctx->v1.nonce;
+ case FSCRYPT_CONTEXT_V2:
+ return ctx->v2.nonce;
+ }
+ WARN_ON(1);
+ return NULL;
+}
+
#undef fscrypt_policy
union fscrypt_policy {
u8 version;
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index 08c9f216a54d..302375e9f719 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -425,20 +425,8 @@ int fscrypt_get_encryption_info(struct inode *inode)
goto out;
}
- switch (ctx.version) {
- case FSCRYPT_CONTEXT_V1:
- memcpy(crypt_info->ci_nonce, ctx.v1.nonce,
- FS_KEY_DERIVATION_NONCE_SIZE);
- break;
- case FSCRYPT_CONTEXT_V2:
- memcpy(crypt_info->ci_nonce, ctx.v2.nonce,
- FS_KEY_DERIVATION_NONCE_SIZE);
- break;
- default:
- WARN_ON(1);
- res = -EINVAL;
- goto out;
- }
+ memcpy(crypt_info->ci_nonce, fscrypt_context_nonce(&ctx),
+ FS_KEY_DERIVATION_NONCE_SIZE);
if (!fscrypt_supported_policy(&crypt_info->ci_policy, inode)) {
res = -EINVAL;
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index cf2a9d26ef7d..10ccf945020c 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -258,7 +258,7 @@ int fscrypt_policy_from_context(union fscrypt_policy *policy_u,
{
memset(policy_u, 0, sizeof(*policy_u));
- if (ctx_size <= 0 || ctx_size != fscrypt_context_size(ctx_u))
+ if (!fscrypt_context_is_valid(ctx_u, ctx_size))
return -EINVAL;
switch (ctx_u->version) {
@@ -481,6 +481,25 @@ int fscrypt_ioctl_get_policy_ex(struct file *filp, void __user *uarg)
}
EXPORT_SYMBOL_GPL(fscrypt_ioctl_get_policy_ex);
+/* FS_IOC_GET_ENCRYPTION_NONCE: retrieve file's encryption nonce for testing */
+int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg)
+{
+ struct inode *inode = file_inode(filp);
+ union fscrypt_context ctx;
+ int ret;
+
+ ret = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
+ if (ret < 0)
+ return ret;
+ if (!fscrypt_context_is_valid(&ctx, ret))
+ return -EINVAL;
+ if (copy_to_user(arg, fscrypt_context_nonce(&ctx),
+ FS_KEY_DERIVATION_NONCE_SIZE))
+ return -EFAULT;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fscrypt_ioctl_get_nonce);
+
/**
* fscrypt_has_permitted_context() - is a file's encryption policy permitted
* within its directory?
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index a0ec750018dd..0c1d1720cf1a 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -1210,6 +1210,11 @@ resizefs_out:
return -EOPNOTSUPP;
return fscrypt_ioctl_get_key_status(filp, (void __user *)arg);
+ case FS_IOC_GET_ENCRYPTION_NONCE:
+ if (!ext4_has_feature_encrypt(sb))
+ return -EOPNOTSUPP;
+ return fscrypt_ioctl_get_nonce(filp, (void __user *)arg);
+
case EXT4_IOC_CLEAR_ES_CACHE:
{
if (!inode_owner_or_capable(inode))
@@ -1370,6 +1375,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case FS_IOC_REMOVE_ENCRYPTION_KEY:
case FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS:
case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
+ case FS_IOC_GET_ENCRYPTION_NONCE:
case EXT4_IOC_SHUTDOWN:
case FS_IOC_GETFSMAP:
case FS_IOC_ENABLE_VERITY:
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 0d4da644df3b..351762f77840 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2423,6 +2423,14 @@ static int f2fs_ioc_get_encryption_key_status(struct file *filp,
return fscrypt_ioctl_get_key_status(filp, (void __user *)arg);
}
+static int f2fs_ioc_get_encryption_nonce(struct file *filp, unsigned long arg)
+{
+ if (!f2fs_sb_has_encrypt(F2FS_I_SB(file_inode(filp))))
+ return -EOPNOTSUPP;
+
+ return fscrypt_ioctl_get_nonce(filp, (void __user *)arg);
+}
+
static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@@ -3437,6 +3445,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return f2fs_ioc_remove_encryption_key_all_users(filp, arg);
case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
return f2fs_ioc_get_encryption_key_status(filp, arg);
+ case FS_IOC_GET_ENCRYPTION_NONCE:
+ return f2fs_ioc_get_encryption_nonce(filp, arg);
case F2FS_IOC_GARBAGE_COLLECT:
return f2fs_ioc_gc(filp, arg);
case F2FS_IOC_GARBAGE_COLLECT_RANGE:
@@ -3611,6 +3621,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case FS_IOC_REMOVE_ENCRYPTION_KEY:
case FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS:
case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
+ case FS_IOC_GET_ENCRYPTION_NONCE:
case F2FS_IOC_GARBAGE_COLLECT:
case F2FS_IOC_GARBAGE_COLLECT_RANGE:
case F2FS_IOC_WRITE_CHECKPOINT:
diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c
index d49fc04f2d7d..3df9be2c684c 100644
--- a/fs/ubifs/ioctl.c
+++ b/fs/ubifs/ioctl.c
@@ -208,6 +208,9 @@ long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
return fscrypt_ioctl_get_key_status(file, (void __user *)arg);
+ case FS_IOC_GET_ENCRYPTION_NONCE:
+ return fscrypt_ioctl_get_nonce(file, (void __user *)arg);
+
default:
return -ENOTTY;
}
@@ -230,6 +233,7 @@ long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case FS_IOC_REMOVE_ENCRYPTION_KEY:
case FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS:
case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
+ case FS_IOC_GET_ENCRYPTION_NONCE:
break;
default:
return -ENOIOCTLCMD;
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 556f4adf5dc5..e3c2d2a15525 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -139,6 +139,7 @@ extern void fscrypt_free_bounce_page(struct page *bounce_page);
extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
extern int fscrypt_ioctl_get_policy_ex(struct file *, void __user *);
+extern int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg);
extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
extern int fscrypt_inherit_context(struct inode *, struct inode *,
void *, bool);
@@ -300,6 +301,11 @@ static inline int fscrypt_ioctl_get_policy_ex(struct file *filp,
return -EOPNOTSUPP;
}
+static inline int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg)
+{
+ return -EOPNOTSUPP;
+}
+
static inline int fscrypt_has_permitted_context(struct inode *parent,
struct inode *child)
{
diff --git a/include/uapi/linux/fscrypt.h b/include/uapi/linux/fscrypt.h
index 0d8a6f47711c..a10e3cdc2839 100644
--- a/include/uapi/linux/fscrypt.h
+++ b/include/uapi/linux/fscrypt.h
@@ -163,6 +163,7 @@ struct fscrypt_get_key_status_arg {
#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
#define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg)
#define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg)
+#define FS_IOC_GET_ENCRYPTION_NONCE _IOR('f', 27, __u8[16])
/**********************************************************************/
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-10 09:42:15 +0000