From 246d921646c071b878480997c294db6c83215b06 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 23 Nov 2021 13:37:52 -0500 Subject: fs-verity: define a function to return the integrity protected file digest Define a function named fsverity_get_digest() to return the verity file digest and the associated hash algorithm (enum hash_algo). This assumes that before calling fsverity_get_digest() the file must have been opened, which is even true for the IMA measure/appraise on file open policy rule use case (func=FILE_CHECK). do_open() calls vfs_open() immediately prior to ima_file_check(). Acked-by: Eric Biggers Signed-off-by: Mimi Zohar --- include/linux/fsverity.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include') diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h index a7afc800bd8d..7af030fa3c36 100644 --- a/include/linux/fsverity.h +++ b/include/linux/fsverity.h @@ -12,8 +12,16 @@ #define _LINUX_FSVERITY_H #include +#include +#include #include +/* + * Largest digest size among all hash algorithms supported by fs-verity. + * Currently assumed to be <= size of fsverity_descriptor::root_hash. + */ +#define FS_VERITY_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE + /* Verity operations for filesystems */ struct fsverity_operations { @@ -131,6 +139,9 @@ int fsverity_ioctl_enable(struct file *filp, const void __user *arg); /* measure.c */ int fsverity_ioctl_measure(struct file *filp, void __user *arg); +int fsverity_get_digest(struct inode *inode, + u8 digest[FS_VERITY_MAX_DIGEST_SIZE], + enum hash_algo *alg); /* open.c */ @@ -170,6 +181,13 @@ static inline int fsverity_ioctl_measure(struct file *filp, void __user *arg) return -EOPNOTSUPP; } +static inline int fsverity_get_digest(struct inode *inode, + u8 digest[FS_VERITY_MAX_DIGEST_SIZE], + enum hash_algo *alg) +{ + return -EOPNOTSUPP; +} + /* open.c */ static inline int fsverity_file_open(struct inode *inode, struct file *filp) -- cgit v1.2.3