From 063a7a0071a0e6b01426088c8003e24e160937d1 Mon Sep 17 00:00:00 2001

From: Dimitri John Ledkov <xnox@ubuntu.com>

Date: Wed, 29 Aug 2018 15:38:09 +0100

Subject: [PATCH] cryptsetup: add support for sector-size= option (#9936)

Bug-Ubuntu: https://launchpad.net/bugs/1776626

Closes #8881.

(cherry picked from commit a9fc640671ef60ac949f1ace6fa687ff242fc233)

Resolves: #1571801

---

 configure.ac                |  6 ++++++

 man/crypttab.xml            |  9 +++++++++

 src/cryptsetup/cryptsetup.c | 35 ++++++++++++++++++++++++++++++++++-

 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac

index ee147e28eb..19d42602c9 100644

--- a/configure.ac

+++ b/configure.ac

@@ -832,6 +832,12 @@ if test "x$enable_libcryptsetup" != "xno"; then

         if test "x$have_libcryptsetup" = xno -a "x$enable_libcryptsetup" = xyes; then

                 AC_MSG_ERROR([*** libcryptsetup support requested but libraries not found])

         fi

+        AC_CHECK_MEMBER(

+                [struct crypt_params_plain.sector_size],

+                [AC_DEFINE([HAVE_LIBCRYPTSETUP_SECTOR_SIZE], [1], [Define if libcryptsetup supports sector_size param])],

+                [],

+                [#include <libcryptsetup.h>]

+        )

 fi

 AM_CONDITIONAL(HAVE_LIBCRYPTSETUP, [test "$have_libcryptsetup" = "yes"])

diff --git a/man/crypttab.xml b/man/crypttab.xml

index e4ecab3dcb..df75007072 100644

--- a/man/crypttab.xml

+++ b/man/crypttab.xml

@@ -248,6 +248,15 @@

         option.</para></listitem>

       </varlistentry>

+      <varlistentry>

+        <term><option>sector-size=</option></term>

+

+        <listitem><para>Specifies the sector size in bytes. See

+        <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>

+        for possible values and the default value of this

+        option.</para></listitem>

+      </varlistentry>

+

       <varlistentry>

         <term><option>swap</option></term>

diff --git a/src/cryptsetup/cryptsetup.c b/src/cryptsetup/cryptsetup.c

index 528c36c48b..fd8b9ba9ec 100644

--- a/src/cryptsetup/cryptsetup.c

+++ b/src/cryptsetup/cryptsetup.c

@@ -43,10 +43,14 @@

 /* internal helper */

 #define ANY_LUKS "LUKS"

+/* as in src/cryptsetup.h */

+#define CRYPT_SECTOR_SIZE 512

+#define CRYPT_MAX_SECTOR_SIZE 4096

 static const char *arg_type = NULL; /* ANY_LUKS, CRYPT_LUKS1, CRYPT_LUKS2, CRYPT_TCRYPT or CRYPT_PLAIN */

 static char *arg_cipher = NULL;

 static unsigned arg_key_size = 0;

+static unsigned arg_sector_size = CRYPT_SECTOR_SIZE;

 static int arg_key_slot = CRYPT_ANY_SLOT;

 static unsigned arg_keyfile_size = 0;

 static unsigned arg_keyfile_offset = 0;

@@ -104,6 +108,31 @@ static int parse_one_option(const char *option) {

                 arg_key_size /= 8;

+        } else if (startswith(option, "sector-size=")) {

+

+#if HAVE_LIBCRYPTSETUP_SECTOR_SIZE

+                int r;

+

+                r = safe_atou(option+12, &arg_sector_size);

+                if (r < 0) {

+                        log_error_errno(r, "Failed to parse %s, ignoring: %m", option);

+                        return 0;

+                }

+

+                if (arg_sector_size % 2) {

+                        log_error("sector-size= not a multiple of 2, ignoring.");

+                        return 0;

+                }

+

+                if (arg_sector_size < CRYPT_SECTOR_SIZE || arg_sector_size > CRYPT_MAX_SECTOR_SIZE) {

+                        log_error("sector-size= is outside of %u and %u, ignoring.", CRYPT_SECTOR_SIZE, CRYPT_MAX_SECTOR_SIZE);

+                        return 0;

+                }

+#else

+                log_error("sector-size= is not supported, compiled with old libcryptsetup.");

+                return 0;

+#endif

+

         } else if (startswith(option, "key-slot=")) {

                 arg_type = ANY_LUKS;

@@ -450,7 +479,11 @@ static int attach_luks_or_plain(struct crypt_device *cd,

         }

         if ((!arg_type && r < 0) || streq_ptr(arg_type, CRYPT_PLAIN)) {

-                struct crypt_params_plain params = {};

+                struct crypt_params_plain params = {

+#if HAVE_LIBCRYPTSETUP_SECTOR_SIZE

+                        .sector_size = arg_sector_size,

+#endif

+                };

                 const char *cipher, *cipher_mode;

                 _cleanup_free_ char *truncated_cipher = NULL;