disk/cryptodisk: Allows UUIDs to be compared in a dash-insensitive manner

A user can now specify UUID strings with dashes, instead of having to remove
dashes. This is backwards-compatibility preserving and also fixes a source
of user confusion over the inconsistency with how UUIDs are specified
between file system UUIDs and cryptomount UUIDs. Since cryptsetup, the
reference implementation for LUKS, displays and generates UUIDs with dashes
there has been additional confusion when using the UUID strings from
cryptsetup as exact input into GRUB does not find the expected cryptodisk.

A new function grub_uuidcasecmp() is added that is general enough to be used
other places where UUIDs are being compared.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index e894308129145df0e96687c7da8ca2782fd71230..a4cd8445f904b4a949d3a0d4acf74a5b14407032 100644 (file)
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -702,7 +702,7 @@ grub_cryptodisk_open (const char *name, grub_disk_t disk)
   if (grub_memcmp (name, "cryptouuid/", sizeof ("cryptouuid/") - 1) == 0)
     {
       for (dev = cryptodisk_list; dev != NULL; dev = dev->next)
-       if (grub_strcasecmp (name + sizeof ("cryptouuid/") - 1, dev->uuid) == 0)
+       if (grub_uuidcasecmp (name + sizeof ("cryptouuid/") - 1, dev->uuid, sizeof (dev->uuid)) == 0)
          break;
     }
   else
@@ -929,7 +929,7 @@ grub_cryptodisk_get_by_uuid (const char *uuid)
 {
   grub_cryptodisk_t dev;
   for (dev = cryptodisk_list; dev != NULL; dev = dev->next)
-    if (grub_strcasecmp (dev->uuid, uuid) == 0)
+    if (grub_uuidcasecmp (dev->uuid, uuid, sizeof (dev->uuid)) == 0)
       return dev;
   return NULL;
 }

diff --git a/grub-core/disk/geli.c b/grub-core/disk/geli.c
index e190066f97f0b739c5094471f1476cbf1279c9cf..722910d648ca855def95909168432d8f4fcc873e 100644 (file)
--- a/grub-core/disk/geli.c
+++ b/grub-core/disk/geli.c
@@ -305,7 +305,7 @@ geli_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
       return NULL;
     }
 
-  if (cargs->search_uuid != NULL && grub_strcasecmp (cargs->search_uuid, uuid) != 0)
+  if (cargs->search_uuid != NULL && grub_uuidcasecmp (cargs->search_uuid, uuid, sizeof (uuid)) != 0)
     {
       grub_dprintf ("geli", "%s != %s\n", uuid, cargs->search_uuid);
       return NULL;

diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
index 7f837d52c46f5ce3728721685040ea586b508e65..9e1e6a5d9006a8866d397e495c5d16a6841d5a9b 100644 (file)
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -66,10 +66,7 @@ static grub_cryptodisk_t
 luks_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
 {
   grub_cryptodisk_t newdev;
-  const char *iptr;
   struct grub_luks_phdr header;
-  char *optr;
-  char uuid[sizeof (header.uuid) + 1];
   char ciphername[sizeof (header.cipherName) + 1];
   char ciphermode[sizeof (header.cipherMode) + 1];
   char hashspec[sizeof (header.hashSpec) + 1];
@@ -92,19 +89,9 @@ luks_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
       || grub_be_to_cpu16 (header.version) != 1)
     return NULL;
 
-  grub_memset (uuid, 0, sizeof (uuid));
-  optr = uuid;
-  for (iptr = header.uuid; iptr < &header.uuid[ARRAY_SIZE (header.uuid)];
-       iptr++)
+  if (cargs->search_uuid != NULL && grub_uuidcasecmp (cargs->search_uuid, header.uuid, sizeof (header.uuid)) != 0)
     {
-      if (*iptr != '-')
-       *optr++ = *iptr;
-    }
-  *optr = 0;
-
-  if (cargs->search_uuid != NULL && grub_strcasecmp (cargs->search_uuid, uuid) != 0)
-    {
-      grub_dprintf ("luks", "%s != %s\n", uuid, cargs->search_uuid);
+      grub_dprintf ("luks", "%s != %s\n", header.uuid, cargs->search_uuid);
       return NULL;
     }
 
@@ -123,7 +110,7 @@ luks_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
   newdev->source_disk = NULL;
   newdev->log_sector_size = GRUB_LUKS1_LOG_SECTOR_SIZE;
   newdev->total_sectors = grub_disk_native_sectors (disk) - newdev->offset_sectors;
-  grub_memcpy (newdev->uuid, uuid, sizeof (uuid));
+  grub_memcpy (newdev->uuid, header.uuid, sizeof (header.uuid));
   newdev->modname = "luks";
 
   /* Configure the hash used for the AF splitter and HMAC.  */
@@ -143,7 +130,7 @@ luks_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
       return NULL;
     }
 
-  COMPILE_TIME_ASSERT (sizeof (newdev->uuid) >= sizeof (uuid));
+  COMPILE_TIME_ASSERT (sizeof (newdev->uuid) >= sizeof (header.uuid));
   return newdev;
 }
 

diff --git a/grub-core/disk/luks2.c b/grub-core/disk/luks2.c
index e4bef3d0ea839e43a449fcaa639f512f0ac7cf8a..d5106402fb218ae0d91026fa188640e6201758e3 100644 (file)
--- a/grub-core/disk/luks2.c
+++ b/grub-core/disk/luks2.c
@@ -350,8 +350,6 @@ luks2_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
 {
   grub_cryptodisk_t cryptodisk;
   grub_luks2_header_t header;
-  char uuid[sizeof (header.uuid) + 1];
-  grub_size_t i, j;
 
   if (cargs->check_boot)
     return NULL;
@@ -362,14 +360,9 @@ luks2_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
       return NULL;
     }
 
-  for (i = 0, j = 0; i < sizeof (header.uuid); i++)
-    if (header.uuid[i] != '-')
-      uuid[j++] = header.uuid[i];
-  uuid[j] = '\0';
-
-  if (cargs->search_uuid != NULL && grub_strcasecmp (cargs->search_uuid, uuid) != 0)
+  if (cargs->search_uuid != NULL && grub_uuidcasecmp (cargs->search_uuid, header.uuid, sizeof (header.uuid)) != 0)
     {
-      grub_dprintf ("luks2", "%s != %s\n", uuid, cargs->search_uuid);
+      grub_dprintf ("luks2", "%s != %s\n", header.uuid, cargs->search_uuid);
       return NULL;
     }
 
@@ -377,8 +370,8 @@ luks2_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
   if (!cryptodisk)
     return NULL;
 
-  COMPILE_TIME_ASSERT (sizeof (cryptodisk->uuid) >= sizeof (uuid));
-  grub_memcpy (cryptodisk->uuid, uuid, sizeof (uuid));
+  COMPILE_TIME_ASSERT (sizeof (cryptodisk->uuid) >= sizeof (header.uuid));
+  grub_memcpy (cryptodisk->uuid, header.uuid, sizeof (header.uuid));
 
   cryptodisk->modname = "luks2";
   return cryptodisk;

diff --git a/include/grub/misc.h b/include/grub/misc.h
index 7489685d02f344523bea98e3ba21b677f3df43e0..892ac6a42dda107a027bc9b2b082a104f3212114 100644 (file)
--- a/include/grub/misc.h
+++ b/include/grub/misc.h
@@ -244,6 +244,36 @@ grub_strncasecmp (const char *s1, const char *s2, grub_size_t n)
     - (int) grub_tolower ((grub_uint8_t) *s2);
 }
 
+/*
+ * Do a case insensitive compare of two UUID strings by ignoring all dashes.
+ * Note that the parameter n, is the number of significant characters to
+ * compare, where significant characters are any except the dash.
+ */
+static inline int
+grub_uuidcasecmp (const char *uuid1, const char *uuid2, grub_size_t n)
+{
+  if (n == 0)
+    return 0;
+
+  while (*uuid1 && *uuid2 && --n)
+    {
+      /* Skip forward to non-dash on both UUIDs. */
+      while ('-' == *uuid1)
+        ++uuid1;
+
+      while ('-' == *uuid2)
+        ++uuid2;
+
+      if (grub_tolower ((grub_uint8_t) *uuid1) != grub_tolower ((grub_uint8_t) *uuid2))
+       break;
+
+      uuid1++;
+      uuid2++;
+    }
+
+  return (int) grub_tolower ((grub_uint8_t) *uuid1) - (int) grub_tolower ((grub_uint8_t) *uuid2);
+}
+
 /*
  * Note that these differ from the C standard's definitions of strtol,
  * strtoul(), and strtoull() by the addition of two const qualifiers on the end