On 9/19/19 7:18 PM, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> Add a 'rm_enckey' command to xfs_io, to provide a command-line interface
> to the FS_IOC_REMOVE_ENCRYPTION_KEY and
> FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS ioctls.
>
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> ---
> io/encrypt.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++
> man/man8/xfs_io.8 | 15 ++++++++++
> 2 files changed, 90 insertions(+)
>
> diff --git a/io/encrypt.c b/io/encrypt.c
> index d38ac595..7531c4ad 100644
> --- a/io/encrypt.c
> +++ b/io/encrypt.c
> @@ -139,6 +139,7 @@ struct fscrypt_get_key_status_arg {
> static cmdinfo_t get_encpolicy_cmd;
> static cmdinfo_t set_encpolicy_cmd;
> static cmdinfo_t add_enckey_cmd;
> +static cmdinfo_t rm_enckey_cmd;
>
> static void
> get_encpolicy_help(void)
> @@ -200,6 +201,21 @@ add_enckey_help(void)
> "\n"));
> }
>
> +static void
> +rm_enckey_help(void)
> +{
> + printf(_(
> +"\n"
> +" remove an encryption key from the filesystem\n"
> +"\n"
> +" Examples:\n"
> +" 'rm_enckey 0000111122223333' - remove key for v1 policies w/ given descriptor\n"
> +" 'rm_enckey 00001111222233334444555566667777' - remove key for v2 policies w/ given identifier\n"
> +"\n"
> +" -a -- remove key for all users who have added it (privileged operation)\n"
> +"\n"));
> +}
> +
> static const struct {
> __u8 mode;
> const char *name;
> @@ -693,6 +709,54 @@ out:
> return 0;
> }
>
> +static int
> +rm_enckey_f(int argc, char **argv)
> +{
> + int c;
> + struct fscrypt_remove_key_arg arg;
> + int ioc = FS_IOC_REMOVE_ENCRYPTION_KEY;
> +
> + memset(&arg, 0, sizeof(arg));
> +
> + while ((c = getopt(argc, argv, "a")) != EOF) {
> + switch (c) {
> + case 'a':
> + ioc = FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS;
> + break;
> + default:
> + return command_usage(&rm_enckey_cmd);
> + }
> + }
> + argc -= optind;
> + argv += optind;
> +
> + if (argc != 1)
> + return command_usage(&rm_enckey_cmd);
> +
> + if (str2keyspec(argv[0], -1, &arg.key_spec) < 0)
> + return 0;
> +
> + if (ioctl(file->fd, ioc, &arg) != 0) {
> + fprintf(stderr, "Error removing encryption key: %s\n",
> + strerror(errno));
> + exitcode = 1;
> + return 0;
> + }
> + if (arg.removal_status_flags &
> + FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS) {
> + printf("Removed user's claim to encryption key with %s %s\n",
> + keyspectype(&arg.key_spec), keyspec2str(&arg.key_spec));
> + } else if (arg.removal_status_flags &
> + FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY) {
> + printf("Removed encryption key with %s %s, but files still busy\n",
> + keyspectype(&arg.key_spec), keyspec2str(&arg.key_spec));
> + } else {
> + printf("Removed encryption key with %s %s\n",
> + keyspectype(&arg.key_spec), keyspec2str(&arg.key_spec));
> + }
> + return 0;
> +}
> +
> void
> encrypt_init(void)
> {
> @@ -726,7 +790,18 @@ encrypt_init(void)
> add_enckey_cmd.oneline = _("add an encryption key to the filesystem");
> add_enckey_cmd.help = add_enckey_help;
>
> + rm_enckey_cmd.name = "rm_enckey";
> + rm_enckey_cmd.cfunc = rm_enckey_f;
> + rm_enckey_cmd.args = _("keyspec");
can you add "-a" to the args for the shorthelp/args here please?
I don't know anything about this stuff. :( Is it to be used as:
rm_enckey -a <keyspec> ?
> + rm_enckey_cmd.argmin = 0;
> + rm_enckey_cmd.argmax = -1;
I wonder if min/max should be 1/2 but eh, I think you catch wrong counts
in the function itself, just without the explicit message the built-in
checkers would give.
> + rm_enckey_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
> + rm_enckey_cmd.oneline =
> + _("remove an encryption key from the filesystem");
> + rm_enckey_cmd.help = rm_enckey_help;
> +
> add_command(&get_encpolicy_cmd);
> add_command(&set_encpolicy_cmd);
> add_command(&add_enckey_cmd);
> + add_command(&rm_enckey_cmd);
> }
> diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
> index 7d6a23fe..a6894778 100644
> --- a/man/man8/xfs_io.8
> +++ b/man/man8/xfs_io.8
> @@ -764,6 +764,21 @@ Otherwise, the key is added as a v2 policy key, and on success the resulting
> .RE
> .PD
> .TP
> +.BI "rm_enckey " keyspec
show [-a] here as well?
> +On filesystems that support encryption, remove an encryption key from the
> +filesystem containing the currently open file.
> +.I keyspec
> +is a hex string specifying the key to remove, as a 16-character "key descriptor"
> +or a 32-character "key identifier".
> +.RS 1.0i
> +.PD 0
> +.TP 0.4i
> +.BI \-a
> +Remove the key for all users who have added it, not just the current user. This
> +is a privileged operation.
> +.RE
> +.PD
> +.TP
> .BR lsattr " [ " \-R " | " \-D " | " \-a " | " \-v " ]"
> List extended inode flags on the currently open file. If the
> .B \-R
>
