systemd/0245-cryptsetup-Support-key-slot-option.patch
Zbigniew Jędrzejewski-Szmek ca73a27582 A new batch of fixes
2014-02-17 01:16:32 -05:00

92 lines
4.2 KiB
Diff

From 47ac3edbade8ab5f4a205f2c1bad11ec9643b8b6 Mon Sep 17 00:00:00 2001
From: Christian Seiler <christian@iwakd.de>
Date: Sun, 26 Jan 2014 12:02:49 +0100
Subject: [PATCH] cryptsetup: Support key-slot option
Debian recently introduced the option key-slot to /etc/crypttab to
specify the LUKS key slot to be used for decrypting the device. On
systems where a keyfile is used and the key is not in the first slot,
this can speed up the boot process quite a bit, since cryptsetup does
not need to try all of the slots sequentially. (Unsuccessfully testing
a key slot typically takes up to about 1 second.)
This patch makes systemd aware of this option.
Debian bug that introduced the feature:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=704470
---
man/crypttab.xml | 14 ++++++++++++++
src/cryptsetup/cryptsetup.c | 13 +++++++++++--
2 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/man/crypttab.xml b/man/crypttab.xml
index 90d8ce9..5f386e5 100644
--- a/man/crypttab.xml
+++ b/man/crypttab.xml
@@ -164,6 +164,20 @@
</varlistentry>
<varlistentry>
+ <term><varname>key-slot=</varname></term>
+
+ <listitem><para>Specifies the key slot to
+ compare the passphrase or key against.
+ If the key slot does not match the given
+ passphrase or key, but another would, the
+ setup of the device will fail regardless.
+ This implies <varname>luks</varname>. See
+ <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for possible values. The default is to try
+ all key slots in sequential order.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
<term><varname>luks</varname></term>
<listitem><para>Force LUKS mode. When this mode
diff --git a/src/cryptsetup/cryptsetup.c b/src/cryptsetup/cryptsetup.c
index 39f7db7..6a76d21 100644
--- a/src/cryptsetup/cryptsetup.c
+++ b/src/cryptsetup/cryptsetup.c
@@ -39,6 +39,7 @@
static const char *opt_type = NULL; /* CRYPT_LUKS1, CRYPT_TCRYPT or CRYPT_PLAIN */
static char *opt_cipher = NULL;
static unsigned opt_key_size = 0;
+static int opt_key_slot = CRYPT_ANY_SLOT;
static unsigned opt_keyfile_size = 0;
static unsigned opt_keyfile_offset = 0;
static char *opt_hash = NULL;
@@ -87,6 +88,14 @@ static int parse_one_option(const char *option) {
return 0;
}
+ } else if (startswith(option, "key-slot=")) {
+
+ opt_type = CRYPT_LUKS1;
+ if (safe_atoi(option+9, &opt_key_slot) < 0) {
+ log_error("key-slot= parse failure, ignoring.");
+ return 0;
+ }
+
} else if (startswith(option, "tcrypt-keyfile=")) {
opt_type = CRYPT_TCRYPT;
@@ -432,7 +441,7 @@ static int attach_luks_or_plain(struct crypt_device *cd,
crypt_get_device_name(cd));
if (key_file) {
- r = crypt_activate_by_keyfile_offset(cd, name, CRYPT_ANY_SLOT,
+ r = crypt_activate_by_keyfile_offset(cd, name, opt_key_slot,
key_file, opt_keyfile_size,
opt_keyfile_offset, flags);
if (r < 0) {
@@ -446,7 +455,7 @@ static int attach_luks_or_plain(struct crypt_device *cd,
if (pass_volume_key)
r = crypt_activate_by_volume_key(cd, name, *p, opt_key_size, flags);
else
- r = crypt_activate_by_passphrase(cd, name, CRYPT_ANY_SLOT, *p, strlen(*p), flags);
+ r = crypt_activate_by_passphrase(cd, name, opt_key_slot, *p, strlen(*p), flags);
if (r >= 0)
break;