[PATCH 07/17] cryptodisk, luks: Allow special processing for comparing UUIDs.

[development]

From: Glenn Washburn <development@efficientek.com>

Create grub_uuidcasecmp to compare UUIDs in a case-insensitive manner and
that ignores '-' characters. This is backwards compatible with the old LUKS1
code that stored and compared against UUIDs without dashes. However, the new
LUKS2 code stores and compares UUIDs that contain dashes. Really, the UUID
comparison shouldn't care about the dashes, as this change implements. Now
your old scripts will continue to work with UUIDs without dashes, but you
may choose to use UUIDs with dashes now too for both LUKS1 and LUKS2.

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/disk/cryptodisk.c |  4 ++--
 grub-core/disk/luks.c       | 20 ++++----------------
 grub-core/disk/luks2.c      |  2 +-
 include/grub/misc.h         | 21 +++++++++++++++++++++
 4 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index f6b6302e1..f460ab838 100644
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -660,7 +660,7 @@ 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) == 
0)
          break;
     }
   else
@@ -897,7 +897,7 @@ 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) == 0)
       return dev;
   return NULL;
 }
diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
index 6ae162601..ea54a9d10 100644
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -69,10 +69,7 @@ configure_ciphers (grub_disk_t disk, const char *check_uuid,
                   int check_boot)
 {
   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];
@@ -95,18 +92,9 @@ configure_ciphers (grub_disk_t disk, const char *check_uuid,
       || grub_be_to_cpu16 (header.version) != 1)
     return NULL;
 
-  optr = uuid;
-  for (iptr = header.uuid; iptr < &header.uuid[ARRAY_SIZE (header.uuid)];
-       iptr++)
+  if (check_uuid && grub_uuidcasecmp (check_uuid, header.uuid) != 0)
     {
-      if (*iptr != '-')
-       *optr++ = *iptr;
-    }
-  *optr = 0;
-
-  if (check_uuid && grub_strcasecmp (check_uuid, uuid) != 0)
-    {
-      grub_dprintf ("luks", "%s != %s\n", uuid, check_uuid);
+      grub_dprintf ("luks", "%s != %s\n", header.uuid, check_uuid);
       return NULL;
     }
 
@@ -125,7 +113,7 @@ configure_ciphers (grub_disk_t disk, const char *check_uuid,
   newdev->source_disk = NULL;
   newdev->log_sector_size = 9;
   newdev->total_length = grub_disk_get_size (disk) - newdev->offset;
-  grub_memcpy (newdev->uuid, uuid, sizeof (newdev->uuid));
+  grub_memcpy (newdev->uuid, header.uuid, sizeof (newdev->uuid));
   newdev->modname = "luks";
 
   /* Configure the hash used for the AF splitter and HMAC.  */
@@ -145,7 +133,7 @@ configure_ciphers (grub_disk_t disk, const char *check_uuid,
       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 632309e3c..3c571b7fd 100644
--- a/grub-core/disk/luks2.c
+++ b/grub-core/disk/luks2.c
@@ -356,7 +356,7 @@ luks2_scan (grub_disk_t disk, const char *check_uuid, int 
check_boot)
       return NULL;
     }
 
-  if (check_uuid && grub_strcasecmp (check_uuid, header.uuid) != 0)
+  if (check_uuid && grub_uuidcasecmp (check_uuid, header.uuid) != 0)
     return NULL;
 
   cryptodisk = grub_zalloc (sizeof (*cryptodisk));
diff --git a/include/grub/misc.h b/include/grub/misc.h
index b7ca6dd58..3f0f42c22 100644
--- a/include/grub/misc.h
+++ b/include/grub/misc.h
@@ -243,6 +243,27 @@ grub_strncasecmp (const char *s1, const char *s2, 
grub_size_t n)
     - (int) grub_tolower ((grub_uint8_t) *s2);
 }
 
+static inline int
+grub_uuidcasecmp (const char *uuid1, const char *uuid2)
+{
+  while (*uuid1 && *uuid2)
+    {
+      while (*uuid1 == '-')
+        uuid1++;
+      while (*uuid2 == '-')
+        uuid2++;
+
+      if (grub_tolower (*uuid1) != grub_tolower (*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
-- 
2.25.1