Adding upstream version 2.06.upstream/2.06upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 329 insertions, 0 deletions

diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
new file mode 100644
index 0000000..13103ea
--- /dev/null
+++ b/grub-core/disk/luks.c
@@ -0,0 +1,329 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2003,2007,2010,2011,2019  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/cryptodisk.h>
+#include <grub/types.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/dl.h>
+#include <grub/err.h>
+#include <grub/disk.h>
+#include <grub/crypto.h>
+#include <grub/partition.h>
+#include <grub/i18n.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+#define MAX_PASSPHRASE 256
+
+#define LUKS_KEY_ENABLED  0x00AC71F3
+
+/* On disk LUKS header */
+struct grub_luks_phdr
+{
+  grub_uint8_t magic[6];
+#define LUKS_MAGIC        "LUKS\xBA\xBE"
+  grub_uint16_t version;
+  char cipherName[32];
+  char cipherMode[32];
+  char hashSpec[32];
+  grub_uint32_t payloadOffset;
+  grub_uint32_t keyBytes;
+  grub_uint8_t mkDigest[20];
+  grub_uint8_t mkDigestSalt[32];
+  grub_uint32_t mkDigestIterations;
+  char uuid[40];
+  struct
+  {
+    grub_uint32_t active;
+    grub_uint32_t passwordIterations;
+    grub_uint8_t passwordSalt[32];
+    grub_uint32_t keyMaterialOffset;
+    grub_uint32_t stripes;
+  } keyblock[8];
+} GRUB_PACKED;
+
+typedef struct grub_luks_phdr *grub_luks_phdr_t;
+
+gcry_err_code_t AF_merge (const gcry_md_spec_t * hash, grub_uint8_t * src,
+			  grub_uint8_t * dst, grub_size_t blocksize,
+			  grub_size_t blocknumbers);
+
+static grub_cryptodisk_t
+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];
+  grub_err_t err;
+
+  if (check_boot)
+    return NULL;
+
+  /* Read the LUKS header.  */
+  err = grub_disk_read (disk, 0, 0, sizeof (header), &header);
+  if (err)
+    {
+      if (err == GRUB_ERR_OUT_OF_RANGE)
+	grub_errno = GRUB_ERR_NONE;
+      return NULL;
+    }
+
+  /* Look for LUKS magic sequence.  */
+  if (grub_memcmp (header.magic, LUKS_MAGIC, sizeof (header.magic))
+      || 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 (*iptr != '-')
+	*optr++ = *iptr;
+    }
+  *optr = 0;
+
+  if (check_uuid && grub_strcasecmp (check_uuid, uuid) != 0)
+    {
+      grub_dprintf ("luks", "%s != %s\n", uuid, check_uuid);
+      return NULL;
+    }
+
+  /* Make sure that strings are null terminated.  */
+  grub_memcpy (ciphername, header.cipherName, sizeof (header.cipherName));
+  ciphername[sizeof (header.cipherName)] = 0;
+  grub_memcpy (ciphermode, header.cipherMode, sizeof (header.cipherMode));
+  ciphermode[sizeof (header.cipherMode)] = 0;
+  grub_memcpy (hashspec, header.hashSpec, sizeof (header.hashSpec));
+  hashspec[sizeof (header.hashSpec)] = 0;
+
+  newdev = grub_zalloc (sizeof (struct grub_cryptodisk));
+  if (!newdev)
+      return NULL;
+  newdev->offset_sectors = grub_be_to_cpu32 (header.payloadOffset);
+  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));
+  newdev->modname = "luks";
+
+  /* Configure the hash used for the AF splitter and HMAC.  */
+  newdev->hash = grub_crypto_lookup_md_by_name (hashspec);
+  if (!newdev->hash)
+    {
+      grub_free (newdev);
+      grub_error (GRUB_ERR_FILE_NOT_FOUND, "Couldn't load %s hash",
+		  hashspec);
+      return NULL;
+    }
+
+  err = grub_cryptodisk_setcipher (newdev, ciphername, ciphermode);
+  if (err)
+    {
+      grub_free (newdev);
+      return NULL;
+    }
+
+  COMPILE_TIME_ASSERT (sizeof (newdev->uuid) >= sizeof (uuid));
+  return newdev;
+}
+
+static grub_err_t
+luks_recover_key (grub_disk_t source,
+		  grub_cryptodisk_t dev)
+{
+  struct grub_luks_phdr header;
+  grub_size_t keysize;
+  grub_uint8_t *split_key = NULL;
+  char passphrase[MAX_PASSPHRASE] = "";
+  grub_uint8_t candidate_digest[sizeof (header.mkDigest)];
+  unsigned i;
+  grub_size_t length;
+  grub_err_t err;
+  grub_size_t max_stripes = 1;
+  char *tmp;
+
+  err = grub_disk_read (source, 0, 0, sizeof (header), &header);
+  if (err)
+    return err;
+
+  grub_puts_ (N_("Attempting to decrypt master key..."));
+  keysize = grub_be_to_cpu32 (header.keyBytes);
+  if (keysize > GRUB_CRYPTODISK_MAX_KEYLEN)
+    return grub_error (GRUB_ERR_BAD_FS, "key is too long");
+
+  for (i = 0; i < ARRAY_SIZE (header.keyblock); i++)
+    if (grub_be_to_cpu32 (header.keyblock[i].active) == LUKS_KEY_ENABLED
+	&& grub_be_to_cpu32 (header.keyblock[i].stripes) > max_stripes)
+      max_stripes = grub_be_to_cpu32 (header.keyblock[i].stripes);
+
+  split_key = grub_calloc (keysize, max_stripes);
+  if (!split_key)
+    return grub_errno;
+
+  /* Get the passphrase from the user.  */
+  tmp = NULL;
+  if (source->partition)
+    tmp = grub_partition_get_name (source->partition);
+  grub_printf_ (N_("Enter passphrase for %s%s%s (%s): "), source->name,
+	       source->partition ? "," : "", tmp ? : "",
+	       dev->uuid);
+  grub_free (tmp);
+  if (!grub_password_get (passphrase, MAX_PASSPHRASE))
+    {
+      grub_free (split_key);
+      return grub_error (GRUB_ERR_BAD_ARGUMENT, "Passphrase not supplied");
+    }
+
+  /* Try to recover master key from each active keyslot.  */
+  for (i = 0; i < ARRAY_SIZE (header.keyblock); i++)
+    {
+      gcry_err_code_t gcry_err;
+      grub_uint8_t candidate_key[GRUB_CRYPTODISK_MAX_KEYLEN];
+      grub_uint8_t digest[GRUB_CRYPTODISK_MAX_KEYLEN];
+
+      /* Check if keyslot is enabled.  */
+      if (grub_be_to_cpu32 (header.keyblock[i].active) != LUKS_KEY_ENABLED)
+	continue;
+
+      grub_dprintf ("luks", "Trying keyslot %d\n", i);
+
+      /* Calculate the PBKDF2 of the user supplied passphrase.  */
+      gcry_err = grub_crypto_pbkdf2 (dev->hash, (grub_uint8_t *) passphrase,
+				     grub_strlen (passphrase),
+				     header.keyblock[i].passwordSalt,
+				     sizeof (header.keyblock[i].passwordSalt),
+				     grub_be_to_cpu32 (header.keyblock[i].
+						       passwordIterations),
+				     digest, keysize);
+
+      if (gcry_err)
+	{
+	  grub_free (split_key);
+	  return grub_crypto_gcry_error (gcry_err);
+	}
+
+      grub_dprintf ("luks", "PBKDF2 done\n");
+
+      gcry_err = grub_cryptodisk_setkey (dev, digest, keysize); 
+      if (gcry_err)
+	{
+	  grub_free (split_key);
+	  return grub_crypto_gcry_error (gcry_err);
+	}
+
+      length = (keysize * grub_be_to_cpu32 (header.keyblock[i].stripes));
+
+      /* Read and decrypt the key material from the disk.  */
+      err = grub_disk_read (source,
+			    grub_be_to_cpu32 (header.keyblock
+					      [i].keyMaterialOffset), 0,
+			    length, split_key);
+      if (err)
+	{
+	  grub_free (split_key);
+	  return err;
+	}
+
+      gcry_err = grub_cryptodisk_decrypt (dev, split_key, length, 0,
+					  GRUB_LUKS1_LOG_SECTOR_SIZE);
+      if (gcry_err)
+	{
+	  grub_free (split_key);
+	  return grub_crypto_gcry_error (gcry_err);
+	}
+
+      /* Merge the decrypted key material to get the candidate master key.  */
+      gcry_err = AF_merge (dev->hash, split_key, candidate_key, keysize,
+			   grub_be_to_cpu32 (header.keyblock[i].stripes));
+      if (gcry_err)
+	{
+	  grub_free (split_key);
+	  return grub_crypto_gcry_error (gcry_err);
+	}
+
+      grub_dprintf ("luks", "candidate key recovered\n");
+
+      /* Calculate the PBKDF2 of the candidate master key.  */
+      gcry_err = grub_crypto_pbkdf2 (dev->hash, candidate_key,
+				     grub_be_to_cpu32 (header.keyBytes),
+				     header.mkDigestSalt,
+				     sizeof (header.mkDigestSalt),
+				     grub_be_to_cpu32
+				     (header.mkDigestIterations),
+				     candidate_digest,
+				     sizeof (candidate_digest));
+      if (gcry_err)
+	{
+	  grub_free (split_key);
+	  return grub_crypto_gcry_error (gcry_err);
+	}
+
+      /* Compare the calculated PBKDF2 to the digest stored
+         in the header to see if it's correct.  */
+      if (grub_memcmp (candidate_digest, header.mkDigest,
+		       sizeof (header.mkDigest)) != 0)
+	{
+	  grub_dprintf ("luks", "bad digest\n");
+	  continue;
+	}
+
+      /* TRANSLATORS: It's a cryptographic key slot: one element of an array
+	 where each element is either empty or holds a key.  */
+      grub_printf_ (N_("Slot %d opened\n"), i);
+
+      /* Set the master key.  */
+      gcry_err = grub_cryptodisk_setkey (dev, candidate_key, keysize); 
+      if (gcry_err)
+	{
+	  grub_free (split_key);
+	  return grub_crypto_gcry_error (gcry_err);
+	}
+
+      grub_free (split_key);
+
+      return GRUB_ERR_NONE;
+    }
+
+  grub_free (split_key);
+  return GRUB_ACCESS_DENIED;
+}
+
+struct grub_cryptodisk_dev luks_crypto = {
+  .scan = configure_ciphers,
+  .recover_key = luks_recover_key
+};
+
+GRUB_MOD_INIT (luks)
+{
+  COMPILE_TIME_ASSERT (sizeof (((struct grub_luks_phdr *) 0)->uuid)
+		       < GRUB_CRYPTODISK_MAX_UUID_LENGTH);
+  grub_cryptodisk_dev_register (&luks_crypto);
+}
+
+GRUB_MOD_FINI (luks)
+{
+  grub_cryptodisk_dev_unregister (&luks_crypto);
+}