V3 for detached headers and key files

V3 for detached headers and key files

[Denis 'GNUtoo' Carikli]

Hi,

Here's the v3 where I fixed the comments.

The additional changes which are not covered by the comments are
mentioned in the individual patches ChangeLogs.

PS: I'm really sorry for the delay. It is due to a combinaison
    of various things (personal issue, urgent things that needed
    to be done, etc).

Denis.

[Patchv3][ 1/6] cryptodisk: luks: unify grub_cryptodisk_dev function names

[Denis 'GNUtoo' Carikli]

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
 grub-core/disk/luks.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
index 410cd6f84..28585806a 100644
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -65,8 +65,7 @@ gcry_err_code_t AF_merge (const gcry_md_spec_t * hash, grub_uint8_t * src,
 			  grub_size_t blocknumbers);
 
 static grub_cryptodisk_t
-configure_ciphers (grub_disk_t disk, const char *check_uuid,
-		   int check_boot)
+luks_scan (grub_disk_t disk, const char *check_uuid, int check_boot)
 {
   grub_cryptodisk_t newdev;
   const char *iptr;
@@ -310,7 +309,7 @@ luks_recover_key (grub_disk_t source,
 }
 
 struct grub_cryptodisk_dev luks_crypto = {
-  .scan = configure_ciphers,
+  .scan = luks_scan,
   .recover_key = luks_recover_key
 };
 
-- 
2.26.2

[Patchv3][ 2/6] cryptodisk: geli: unify grub_cryptodisk_dev function names

[Denis 'GNUtoo' Carikli]

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
ChangeLog:
In addition to the requested changes (if any), the following was
changed:
- recover_keys was renamed to geli_recover_keys
---
 grub-core/disk/geli.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/grub-core/disk/geli.c b/grub-core/disk/geli.c
index e9d23299a..581631c1d 100644
--- a/grub-core/disk/geli.c
+++ b/grub-core/disk/geli.c
@@ -242,8 +242,7 @@ grub_util_get_geli_uuid (const char *dev)
 #endif
 
 static grub_cryptodisk_t
-configure_ciphers (grub_disk_t disk, const char *check_uuid,
-		   int boot_only)
+geli_scan (grub_disk_t disk, const char *check_uuid, int boot_only)
 {
   grub_cryptodisk_t newdev;
   struct grub_geli_phdr header;
@@ -398,7 +397,7 @@ configure_ciphers (grub_disk_t disk, const char *check_uuid,
 }
 
 static grub_err_t
-recover_key (grub_disk_t source, grub_cryptodisk_t dev)
+geli_recover_key (grub_disk_t source, grub_cryptodisk_t dev)
 {
   grub_size_t keysize;
   grub_uint8_t digest[GRUB_CRYPTO_MAX_MDLEN];
@@ -580,8 +579,8 @@ recover_key (grub_disk_t source, grub_cryptodisk_t dev)
 }
 
 struct grub_cryptodisk_dev geli_crypto = {
-  .scan = configure_ciphers,
-  .recover_key = recover_key
+  .scan = geli_scan,
+  .recover_key = geli_recover_key
 };
 
 GRUB_MOD_INIT (geli)
-- 
2.26.2

[Patchv3][ 3/6] cryptodisk: enable the backends to implement detached headers

[Denis 'GNUtoo' Carikli]

From: John Lane <john@lane.uk.net>

Signed-off-by: John Lane <john@lane.uk.net>
GNUtoo@cyberdimension.org: rebase, patch split, small fixes, commit message
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
ChangeLog:
In addition to the requested changes (if any), the following was
changed:
- __unused was removed as we now return an error when a header
  is given to an unsupported backend, in all backends (geli,
  luks, luks2)
- Added a "FIXME: support for detached headers." comment
  near similar FIXME comments in geli.c.
---
 grub-core/disk/cryptodisk.c | 24 ++++++++++++++++++++----
 grub-core/disk/geli.c       | 15 +++++++++++++--
 grub-core/disk/luks.c       | 14 +++++++++++---
 grub-core/disk/luks2.c      | 15 ++++++++++++---
 include/grub/cryptodisk.h   |  6 ++++--
 include/grub/file.h         |  2 ++
 6 files changed, 62 insertions(+), 14 deletions(-)

diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index 1897acc4b..6ad2e486e 100644
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -41,6 +41,7 @@ static const struct grub_arg_option options[] =
     /* TRANSLATORS: It's still restricted to cryptodisks only.  */
     {"all", 'a', 0, N_("Mount all."), 0, 0},
     {"boot", 'b', 0, N_("Mount all volumes with `boot' flag set."), 0, 0},
+    {"header", 'H', 0, N_("Read header from file"), 0, ARG_TYPE_STRING},
     {0, 0, 0, 0, 0, 0}
   };
 
@@ -970,6 +971,7 @@ grub_util_cryptodisk_get_uuid (grub_disk_t disk)
 
 static int check_boot, have_it;
 static char *search_uuid;
+static grub_file_t hdr;
 
 static void
 cryptodisk_close (grub_cryptodisk_t dev)
@@ -994,13 +996,13 @@ grub_cryptodisk_scan_device_real (const char *name, grub_disk_t source)
 
   FOR_CRYPTODISK_DEVS (cr)
   {
-    dev = cr->scan (source, search_uuid, check_boot);
+    dev = cr->scan (source, search_uuid, check_boot, hdr);
     if (grub_errno)
       return grub_errno;
     if (!dev)
       continue;
     
-    err = cr->recover_key (source, dev);
+    err = cr->recover_key (source, dev, hdr);
     if (err)
     {
       cryptodisk_close (dev);
@@ -1041,7 +1043,7 @@ grub_cryptodisk_cheat_mount (const char *sourcedev, const char *cheat)
 
   FOR_CRYPTODISK_DEVS (cr)
   {
-    dev = cr->scan (source, search_uuid, check_boot);
+    dev = cr->scan (source, search_uuid, check_boot, NULL);
     if (grub_errno)
       return grub_errno;
     if (!dev)
@@ -1095,6 +1097,20 @@ grub_cmd_cryptomount (grub_extcmd_context_t ctxt, int argc, char **args)
   if (argc < 1 && !state[1].set && !state[2].set)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, "device name required");
 
+  if (state[3].set) /* Detached header */
+    {
+      if (state[0].set)
+	return grub_error (GRUB_ERR_BAD_ARGUMENT,
+			   N_("Cannot use UUID lookup with detached header"));
+
+      hdr = grub_file_open (state[3].arg,
+			    GRUB_FILE_TYPE_CRYPTODISK_DETACHED_HEADER);
+      if (!hdr)
+	return grub_errno;
+    }
+  else
+    hdr = NULL;
+
   have_it = 0;
   if (state[0].set)
     {
@@ -1302,7 +1318,7 @@ GRUB_MOD_INIT (cryptodisk)
 {
   grub_disk_dev_register (&grub_cryptodisk_dev);
   cmd = grub_register_extcmd ("cryptomount", grub_cmd_cryptomount, 0,
-			      N_("SOURCE|-u UUID|-a|-b"),
+			      N_("SOURCE|-u UUID|-a|-b|-H file"),
 			      N_("Mount a crypto device."), options);
   grub_procfs_register ("luks_script", &luks_script);
 }
diff --git a/grub-core/disk/geli.c b/grub-core/disk/geli.c
index 581631c1d..acd09d874 100644
--- a/grub-core/disk/geli.c
+++ b/grub-core/disk/geli.c
@@ -52,6 +52,7 @@
 #include <grub/dl.h>
 #include <grub/err.h>
 #include <grub/disk.h>
+#include <grub/file.h>
 #include <grub/crypto.h>
 #include <grub/partition.h>
 #include <grub/i18n.h>
@@ -121,6 +122,7 @@ enum
 
 /* FIXME: support version 0.  */
 /* FIXME: support big-endian pre-version-4 volumes.  */
+/* FIXME: support for detached headers.  */
 /* FIXME: support for keyfiles.  */
 /* FIXME: support for HMAC.  */
 const char *algorithms[] = {
@@ -242,7 +244,8 @@ grub_util_get_geli_uuid (const char *dev)
 #endif
 
 static grub_cryptodisk_t
-geli_scan (grub_disk_t disk, const char *check_uuid, int boot_only)
+geli_scan (grub_disk_t disk, const char *check_uuid, int boot_only,
+	   grub_file_t hdr)
 {
   grub_cryptodisk_t newdev;
   struct grub_geli_phdr header;
@@ -254,6 +257,10 @@ geli_scan (grub_disk_t disk, const char *check_uuid, int boot_only)
   grub_disk_addr_t sector;
   grub_err_t err;
 
+  /* Detached headers are not implemented yet */
+  if (hdr)
+    return NULL;
+
   if (2 * GRUB_MD_SHA256->mdlen + 1 > GRUB_CRYPTODISK_MAX_UUID_LENGTH)
     return NULL;
 
@@ -397,7 +404,7 @@ geli_scan (grub_disk_t disk, const char *check_uuid, int boot_only)
 }
 
 static grub_err_t
-geli_recover_key (grub_disk_t source, grub_cryptodisk_t dev)
+geli_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr)
 {
   grub_size_t keysize;
   grub_uint8_t digest[GRUB_CRYPTO_MAX_MDLEN];
@@ -413,6 +420,10 @@ geli_recover_key (grub_disk_t source, grub_cryptodisk_t dev)
   grub_disk_addr_t sector;
   grub_err_t err;
 
+  /* Detached headers are not implemented yet */
+  if (hdr)
+    return GRUB_ERR_NOT_IMPLEMENTED_YET;
+
   if (dev->cipher->cipher->blocksize > GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE)
     return grub_error (GRUB_ERR_BUG, "cipher block is too long");
 
diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
index 28585806a..ffeb679d1 100644
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -65,7 +65,8 @@ gcry_err_code_t AF_merge (const gcry_md_spec_t * hash, grub_uint8_t * src,
 			  grub_size_t blocknumbers);
 
 static grub_cryptodisk_t
-luks_scan (grub_disk_t disk, const char *check_uuid, int check_boot)
+luks_scan (grub_disk_t disk, const char *check_uuid, int check_boot,
+	   grub_file_t hdr)
 {
   grub_cryptodisk_t newdev;
   const char *iptr;
@@ -77,6 +78,10 @@ luks_scan (grub_disk_t disk, const char *check_uuid, int check_boot)
   char hashspec[sizeof (header.hashSpec) + 1];
   grub_err_t err;
 
+  /* Detached headers are not implemented yet */
+  if (hdr)
+    return NULL;
+
   if (check_boot)
     return NULL;
 
@@ -149,8 +154,7 @@ luks_scan (grub_disk_t disk, const char *check_uuid, int check_boot)
 }
 
 static grub_err_t
-luks_recover_key (grub_disk_t source,
-		  grub_cryptodisk_t dev)
+luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr)
 {
   struct grub_luks_phdr header;
   grub_size_t keysize;
@@ -163,6 +167,10 @@ luks_recover_key (grub_disk_t source,
   grub_size_t max_stripes = 1;
   char *tmp;
 
+  /* Detached headers are not implemented yet */
+  if (hdr)
+    return GRUB_ERR_NOT_IMPLEMENTED_YET;
+
   err = grub_disk_read (source, 0, 0, sizeof (header), &header);
   if (err)
     return err;
diff --git a/grub-core/disk/luks2.c b/grub-core/disk/luks2.c
index e3ff7c83d..bc00e8bbc 100644
--- a/grub-core/disk/luks2.c
+++ b/grub-core/disk/luks2.c
@@ -342,11 +342,16 @@ luks2_read_header (grub_disk_t disk, grub_luks2_header_t *outhdr)
 }
 
 static grub_cryptodisk_t
-luks2_scan (grub_disk_t disk, const char *check_uuid, int check_boot)
+luks2_scan (grub_disk_t disk, const char *check_uuid, int check_boot,
+	    grub_file_t hdr_file)
 {
   grub_cryptodisk_t cryptodisk;
   grub_luks2_header_t header;
 
+  /* Detached headers are not implemented yet */
+  if (hdr_file)
+    return NULL;
+
   if (check_boot)
     return NULL;
 
@@ -523,8 +528,8 @@ luks2_decrypt_key (grub_uint8_t *out_key,
 }
 
 static grub_err_t
-luks2_recover_key (grub_disk_t disk,
-		   grub_cryptodisk_t crypt)
+luks2_recover_key (grub_disk_t disk, grub_cryptodisk_t crypt,
+		   grub_file_t hdr_file)
 {
   grub_uint8_t candidate_key[GRUB_CRYPTODISK_MAX_KEYLEN];
   char passphrase[MAX_PASSPHRASE], cipher[32];
@@ -538,6 +543,10 @@ luks2_recover_key (grub_disk_t disk,
   grub_json_t *json = NULL, keyslots;
   grub_err_t ret;
 
+  /* Detached headers are not implemented yet */
+  if (hdr_file)
+    return GRUB_ERR_NOT_IMPLEMENTED_YET;
+
   ret = luks2_read_header (disk, &header);
   if (ret)
     return ret;
diff --git a/include/grub/cryptodisk.h b/include/grub/cryptodisk.h
index e1b21e785..e24b1b8cb 100644
--- a/include/grub/cryptodisk.h
+++ b/include/grub/cryptodisk.h
@@ -20,6 +20,7 @@
 #define GRUB_CRYPTODISK_HEADER	1
 
 #include <grub/disk.h>
+#include <grub/file.h>
 #include <grub/crypto.h>
 #include <grub/list.h>
 #ifdef GRUB_UTIL
@@ -107,8 +108,9 @@ struct grub_cryptodisk_dev
   struct grub_cryptodisk_dev **prev;
 
   grub_cryptodisk_t (*scan) (grub_disk_t disk, const char *check_uuid,
-			     int boot_only);
-  grub_err_t (*recover_key) (grub_disk_t disk, grub_cryptodisk_t dev);
+			     int boot_only, grub_file_t hdr);
+  grub_err_t (*recover_key) (grub_disk_t disk, grub_cryptodisk_t dev,
+			     grub_file_t hdr);
 };
 typedef struct grub_cryptodisk_dev *grub_cryptodisk_dev_t;
 
diff --git a/include/grub/file.h b/include/grub/file.h
index 31567483c..a7d7be853 100644
--- a/include/grub/file.h
+++ b/include/grub/file.h
@@ -90,6 +90,8 @@ enum grub_file_type
     GRUB_FILE_TYPE_FONT,
     /* File holding encryption key for encrypted ZFS.  */
     GRUB_FILE_TYPE_ZFS_ENCRYPTION_KEY,
+    /* File holiding the encryption metadata header */
+    GRUB_FILE_TYPE_CRYPTODISK_DETACHED_HEADER,
     /* File we open n grub-fstest.  */
     GRUB_FILE_TYPE_FSTEST,
     /* File we open n grub-mount.  */
-- 
2.26.2

[Patchv3][ 4/6] cryptodisk: add support for LUKS1 detached headers

[Denis 'GNUtoo' Carikli]

From: John Lane <john@lane.uk.net>

cryptsetup supports having a detached header through the
--header command line argument for both LUKS1 and LUKS2.

This adds support for LUKS1 detached headers.

Signed-off-by: John Lane <john@lane.uk.net>
GNUtoo@cyberdimension.org: rebase, small fixes, commit message
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
 grub-core/disk/luks.c | 48 ++++++++++++++++++++++++++++++-------------
 1 file changed, 34 insertions(+), 14 deletions(-)

diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
index ffeb679d1..0b20908ac 100644
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -23,6 +23,7 @@
 #include <grub/dl.h>
 #include <grub/err.h>
 #include <grub/disk.h>
+#include <grub/file.h>
 #include <grub/crypto.h>
 #include <grub/partition.h>
 #include <grub/i18n.h>
@@ -76,17 +77,23 @@ luks_scan (grub_disk_t disk, const char *check_uuid, int check_boot,
   char ciphername[sizeof (header.cipherName) + 1];
   char ciphermode[sizeof (header.cipherMode) + 1];
   char hashspec[sizeof (header.hashSpec) + 1];
-  grub_err_t err;
-
-  /* Detached headers are not implemented yet */
-  if (hdr)
-    return NULL;
+  grub_err_t err = GRUB_ERR_NONE;
 
   if (check_boot)
     return NULL;
 
   /* Read the LUKS header.  */
-  err = grub_disk_read (disk, 0, 0, sizeof (header), &header);
+  if (hdr)
+    {
+      if (grub_file_seek (hdr, 0) == (grub_off_t) -1)
+	return NULL;
+
+      if (grub_file_read (hdr, &header, sizeof (header)) != sizeof (header))
+	return NULL;
+    }
+  else
+    err = grub_disk_read (disk, 0, 0, sizeof (header), &header);
+
   if (err)
     {
       if (err == GRUB_ERR_OUT_OF_RANGE)
@@ -163,15 +170,22 @@ luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr)
   grub_uint8_t candidate_digest[sizeof (header.mkDigest)];
   unsigned i;
   grub_size_t length;
-  grub_err_t err;
+  grub_err_t err = GRUB_ERR_NONE;
   grub_size_t max_stripes = 1;
   char *tmp;
+  grub_uint32_t sector;
 
-  /* Detached headers are not implemented yet */
   if (hdr)
-    return GRUB_ERR_NOT_IMPLEMENTED_YET;
+    {
+      if (grub_file_seek (hdr, 0) == (grub_off_t) -1)
+	return grub_errno;
+
+      if (grub_file_read (hdr, &header, sizeof (header)) != sizeof (header))
+	return grub_errno;
+    }
+  else
+    err = grub_disk_read (source, 0, 0, sizeof (header), &header);
 
-  err = grub_disk_read (source, 0, 0, sizeof (header), &header);
   if (err)
     return err;
 
@@ -240,13 +254,19 @@ luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr)
 	  return grub_crypto_gcry_error (gcry_err);
 	}
 
+      sector = grub_be_to_cpu32 (header.keyblock[i].keyMaterialOffset);
       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 (hdr)
+      {
+        if (grub_file_seek (hdr, sector * 512))
+          return grub_errno;
+        if (grub_file_read (hdr, split_key, length) != (grub_ssize_t)length)
+          return grub_errno;
+      }
+      else
+        err = grub_disk_read (source, sector, 0, length, split_key);
       if (err)
 	{
 	  grub_free (split_key);
-- 
2.26.2

[Patchv3][ 5/6] cryptodisk: enable the backends to implement key files

[Denis 'GNUtoo' Carikli]

From: John Lane <john@lane.uk.net>

Signed-off-by: John Lane <john@lane.uk.net>
GNUtoo@cyberdimension.org: rebase, patch split, small fixes, commit message
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
ChangeLog:
In addition to the requested changes (if any), the following was
changed:
- Changed a bit the error message "Keyfile is too small"
  from the one suggested in the review.
---
 grub-core/disk/cryptodisk.c | 87 ++++++++++++++++++++++++++++++++++++-
 grub-core/disk/geli.c       |  7 +--
 grub-core/disk/luks.c       |  7 ++-
 grub-core/disk/luks2.c      |  7 +--
 include/grub/cryptodisk.h   |  5 ++-
 include/grub/file.h         |  2 +
 6 files changed, 106 insertions(+), 9 deletions(-)

diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index 6ad2e486e..ab4a62b7f 100644
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -42,6 +42,9 @@ static const struct grub_arg_option options[] =
     {"all", 'a', 0, N_("Mount all."), 0, 0},
     {"boot", 'b', 0, N_("Mount all volumes with `boot' flag set."), 0, 0},
     {"header", 'H', 0, N_("Read header from file"), 0, ARG_TYPE_STRING},
+    {"keyfile", 'k', 0, N_("Key file"), 0, ARG_TYPE_STRING},
+    {"keyfile-offset", 'O', 0, N_("Key file offset (bytes)"), 0, ARG_TYPE_INT},
+    {"keyfile-size", 'S', 0, N_("Key file data size (bytes)"), 0, ARG_TYPE_INT},
     {0, 0, 0, 0, 0, 0}
   };
 
@@ -972,6 +975,8 @@ grub_util_cryptodisk_get_uuid (grub_disk_t disk)
 static int check_boot, have_it;
 static char *search_uuid;
 static grub_file_t hdr;
+static grub_uint8_t *key, keyfile_buffer[GRUB_CRYPTODISK_MAX_KEYFILE_SIZE];
+static grub_ssize_t key_size;
 
 static void
 cryptodisk_close (grub_cryptodisk_t dev)
@@ -1002,7 +1007,7 @@ grub_cryptodisk_scan_device_real (const char *name, grub_disk_t source)
     if (!dev)
       continue;
     
-    err = cr->recover_key (source, dev, hdr);
+    err = cr->recover_key (source, dev, hdr, key, key_size);
     if (err)
     {
       cryptodisk_close (dev);
@@ -1112,6 +1117,86 @@ grub_cmd_cryptomount (grub_extcmd_context_t ctxt, int argc, char **args)
     hdr = NULL;
 
   have_it = 0;
+  key = NULL;
+
+  if (state[4].set) /* keyfile */
+    {
+      const char *p = NULL;
+      grub_file_t keyfile;
+      int keyfile_offset;
+      grub_size_t requested_keyfile_size = 0;
+
+
+      if (state[5].set) /* keyfile-offset */
+	{
+	  keyfile_offset = grub_strtoul (state[5].arg, &p, 0);
+
+	  if (grub_errno != GRUB_ERR_NONE)
+	    return grub_errno;
+
+	  if (*p != '\0')
+	    return grub_error (GRUB_ERR_BAD_ARGUMENT,
+			       N_("unrecognized number"));
+	}
+      else
+	{
+	  keyfile_offset = 0;
+	}
+
+      if (state[6].set) /* keyfile-size */
+	{
+	  requested_keyfile_size = grub_strtoul(state[6].arg, &p, 0);
+
+	  if (*p != '\0')
+	    return grub_error (GRUB_ERR_BAD_ARGUMENT,
+			       N_("unrecognized number"));
+
+	  if (grub_errno != GRUB_ERR_NONE)
+	    return grub_errno;
+
+	  if (requested_keyfile_size > GRUB_CRYPTODISK_MAX_KEYFILE_SIZE)
+	    return grub_error(GRUB_ERR_OUT_OF_RANGE,
+			      N_("Key file size exceeds maximum (%llu)\n"), \
+			      (unsigned long long) GRUB_CRYPTODISK_MAX_KEYFILE_SIZE);
+
+	  if (requested_keyfile_size == 0)
+	    return grub_error(GRUB_ERR_OUT_OF_RANGE,
+			      N_("Key file size is 0\n"));
+	}
+
+
+      keyfile = grub_file_open (state[4].arg,
+				GRUB_FILE_TYPE_CRYPTODISK_ENCRYPTION_KEY);
+      if (!keyfile)
+	return grub_errno;
+
+      if (grub_file_seek (keyfile, keyfile_offset) == (grub_off_t)-1)
+	return grub_errno;
+
+
+      if (requested_keyfile_size)
+	{
+	  if (requested_keyfile_size > (keyfile->size - keyfile_offset))
+	    return grub_error (GRUB_ERR_FILE_READ_ERROR,
+			       N_("Keyfile is too small: "
+				  "requested %llu bytes, "
+				  "but the file only has %llu bytes.\n"),
+			       (unsigned long long) requested_keyfile_size,
+			       (unsigned long long) keyfile->size);
+
+	  key_size = requested_keyfile_size;
+	}
+      else
+	{
+	  key_size = keyfile->size - keyfile_offset;
+	}
+
+      if (grub_file_read (keyfile, keyfile_buffer, key_size) != key_size)
+	return grub_error (GRUB_ERR_FILE_READ_ERROR,
+			   (N_("Error reading key file\n")));
+      key = keyfile_buffer;
+    }
+
   if (state[0].set)
     {
       grub_cryptodisk_t dev;
diff --git a/grub-core/disk/geli.c b/grub-core/disk/geli.c
index acd09d874..159ac0f96 100644
--- a/grub-core/disk/geli.c
+++ b/grub-core/disk/geli.c
@@ -404,7 +404,8 @@ geli_scan (grub_disk_t disk, const char *check_uuid, int boot_only,
 }
 
 static grub_err_t
-geli_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr)
+geli_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr,
+		  grub_uint8_t *key, grub_size_t keyfile_size)
 {
   grub_size_t keysize;
   grub_uint8_t digest[GRUB_CRYPTO_MAX_MDLEN];
@@ -420,8 +421,8 @@ geli_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr)
   grub_disk_addr_t sector;
   grub_err_t err;
 
-  /* Detached headers are not implemented yet */
-  if (hdr)
+  /* Detached headers and keyfiles are not implemented yet */
+  if (hdr || key || keyfile_size)
     return GRUB_ERR_NOT_IMPLEMENTED_YET;
 
   if (dev->cipher->cipher->blocksize > GRUB_CRYPTO_MAX_CIPHER_BLOCKSIZE)
diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
index 0b20908ac..8dde70d8d 100644
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -161,7 +161,8 @@ luks_scan (grub_disk_t disk, const char *check_uuid, int check_boot,
 }
 
 static grub_err_t
-luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr)
+luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr,
+		  grub_uint8_t *keyfile_bytes, grub_size_t keyfile_bytes_size)
 {
   struct grub_luks_phdr header;
   grub_size_t keysize;
@@ -175,6 +176,10 @@ luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr)
   char *tmp;
   grub_uint32_t sector;
 
+  /* Keyfiles are not implemented yet */
+  if (keyfile_bytes || keyfile_bytes_size)
+     return GRUB_ERR_NOT_IMPLEMENTED_YET;
+
   if (hdr)
     {
       if (grub_file_seek (hdr, 0) == (grub_off_t) -1)
diff --git a/grub-core/disk/luks2.c b/grub-core/disk/luks2.c
index bc00e8bbc..6a38a1f4d 100644
--- a/grub-core/disk/luks2.c
+++ b/grub-core/disk/luks2.c
@@ -529,7 +529,8 @@ luks2_decrypt_key (grub_uint8_t *out_key,
 
 static grub_err_t
 luks2_recover_key (grub_disk_t disk, grub_cryptodisk_t crypt,
-		   grub_file_t hdr_file)
+		   grub_file_t hdr_file, grub_uint8_t *key,
+		   grub_size_t keyfile_size)
 {
   grub_uint8_t candidate_key[GRUB_CRYPTODISK_MAX_KEYLEN];
   char passphrase[MAX_PASSPHRASE], cipher[32];
@@ -543,8 +544,8 @@ luks2_recover_key (grub_disk_t disk, grub_cryptodisk_t crypt,
   grub_json_t *json = NULL, keyslots;
   grub_err_t ret;
 
-  /* Detached headers are not implemented yet */
-  if (hdr_file)
+  /* Detached headers and keyfiles are not implemented yet */
+  if (hdr_file || key || keyfile_size)
     return GRUB_ERR_NOT_IMPLEMENTED_YET;
 
   ret = luks2_read_header (disk, &header);
diff --git a/include/grub/cryptodisk.h b/include/grub/cryptodisk.h
index e24b1b8cb..6d2610f93 100644
--- a/include/grub/cryptodisk.h
+++ b/include/grub/cryptodisk.h
@@ -55,6 +55,8 @@ typedef enum
 #define GRUB_CRYPTODISK_GF_BYTES (1U << GRUB_CRYPTODISK_GF_LOG_BYTES)
 #define GRUB_CRYPTODISK_MAX_KEYLEN 128
 
+#define GRUB_CRYPTODISK_MAX_KEYFILE_SIZE 8192
+
 struct grub_cryptodisk;
 
 typedef gcry_err_code_t
@@ -110,7 +112,8 @@ struct grub_cryptodisk_dev
   grub_cryptodisk_t (*scan) (grub_disk_t disk, const char *check_uuid,
 			     int boot_only, grub_file_t hdr);
   grub_err_t (*recover_key) (grub_disk_t disk, grub_cryptodisk_t dev,
-			     grub_file_t hdr);
+			     grub_file_t hdr, grub_uint8_t *key,
+			     grub_size_t keyfile_size);
 };
 typedef struct grub_cryptodisk_dev *grub_cryptodisk_dev_t;
 
diff --git a/include/grub/file.h b/include/grub/file.h
index a7d7be853..97678aa45 100644
--- a/include/grub/file.h
+++ b/include/grub/file.h
@@ -92,6 +92,8 @@ enum grub_file_type
     GRUB_FILE_TYPE_ZFS_ENCRYPTION_KEY,
     /* File holiding the encryption metadata header */
     GRUB_FILE_TYPE_CRYPTODISK_DETACHED_HEADER,
+    /* File holiding the encryption key */
+    GRUB_FILE_TYPE_CRYPTODISK_ENCRYPTION_KEY,
     /* File we open n grub-fstest.  */
     GRUB_FILE_TYPE_FSTEST,
     /* File we open n grub-mount.  */
-- 
2.26.2

[Patchv3][ 6/6] cryptodisk: Add support for LUKS1 key files

[Denis 'GNUtoo' Carikli]

cryptsetup supports key files thourh the --key-file
--header command line argument for both LUKS1 and LUKS2.

This adds support for LUKS1 key files.

Signed-off-by: John Lane <john@lane.uk.net>
GNUtoo@cyberdimension.org: rebase, fixes, commit message
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
---
 grub-core/disk/luks.c | 43 ++++++++++++++++++++++++++-----------------
 1 file changed, 26 insertions(+), 17 deletions(-)

diff --git a/grub-core/disk/luks.c b/grub-core/disk/luks.c
index 8dde70d8d..376895259 100644
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -167,7 +167,9 @@ luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr,
   struct grub_luks_phdr header;
   grub_size_t keysize;
   grub_uint8_t *split_key = NULL;
-  char passphrase[MAX_PASSPHRASE] = "";
+  char interactive_passphrase[MAX_PASSPHRASE] = "";
+  grub_uint8_t *passphrase;
+  grub_size_t passphrase_length;
   grub_uint8_t candidate_digest[sizeof (header.mkDigest)];
   unsigned i;
   grub_size_t length;
@@ -176,10 +178,6 @@ luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr,
   char *tmp;
   grub_uint32_t sector;
 
-  /* Keyfiles are not implemented yet */
-  if (keyfile_bytes || keyfile_bytes_size)
-     return GRUB_ERR_NOT_IMPLEMENTED_YET;
-
   if (hdr)
     {
       if (grub_file_seek (hdr, 0) == (grub_off_t) -1)
@@ -208,18 +206,29 @@ luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr,
   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))
+  if (keyfile_bytes)
     {
-      grub_free (split_key);
-      return grub_error (GRUB_ERR_BAD_ARGUMENT, "Passphrase not supplied");
+      /* Use bytestring from key file as passphrase */
+      passphrase = keyfile_bytes;
+      passphrase_length = keyfile_bytes_size;
+    }
+  else
+    {
+      /* 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 (interactive_passphrase, MAX_PASSPHRASE))
+        {
+          grub_free (split_key);
+          return grub_error (GRUB_ERR_BAD_ARGUMENT, "Passphrase not supplied");
+        }
+
+      passphrase = (grub_uint8_t *)interactive_passphrase;
+      passphrase_length = grub_strlen (interactive_passphrase);
     }
 
   /* Try to recover master key from each active keyslot.  */
@@ -237,7 +246,7 @@ luks_recover_key (grub_disk_t source, grub_cryptodisk_t dev, grub_file_t hdr,
 
       /* Calculate the PBKDF2 of the user supplied passphrase.  */
       gcry_err = grub_crypto_pbkdf2 (dev->hash, (grub_uint8_t *) passphrase,
-				     grub_strlen (passphrase),
+				     passphrase_length,
 				     header.keyblock[i].passwordSalt,
 				     sizeof (header.keyblock[i].passwordSalt),
 				     grub_be_to_cpu32 (header.keyblock[i].
-- 
2.26.2

Re: [Patchv3][ 5/6] cryptodisk: enable the backends to implement key files

[Patrick Steinhardt]

[-- Attachment #1: Type: text/plain, Size: 4632 bytes --]

On Fri, May 08, 2020 at 01:19:42AM +0200, Denis 'GNUtoo' Carikli wrote:
> From: John Lane <john@lane.uk.net>
> 
> Signed-off-by: John Lane <john@lane.uk.net>
> GNUtoo@cyberdimension.org: rebase, patch split, small fixes, commit message
> Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
> ---
> ChangeLog:
> In addition to the requested changes (if any), the following was
> changed:
> - Changed a bit the error message "Keyfile is too small"
>   from the one suggested in the review.
> ---
>  grub-core/disk/cryptodisk.c | 87 ++++++++++++++++++++++++++++++++++++-
>  grub-core/disk/geli.c       |  7 +--
>  grub-core/disk/luks.c       |  7 ++-
>  grub-core/disk/luks2.c      |  7 +--
>  include/grub/cryptodisk.h   |  5 ++-
>  include/grub/file.h         |  2 +
>  6 files changed, 106 insertions(+), 9 deletions(-)
> 
> diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
> index 6ad2e486e..ab4a62b7f 100644
> --- a/grub-core/disk/cryptodisk.c
> +++ b/grub-core/disk/cryptodisk.c
> @@ -42,6 +42,9 @@ static const struct grub_arg_option options[] =
>      {"all", 'a', 0, N_("Mount all."), 0, 0},
>      {"boot", 'b', 0, N_("Mount all volumes with `boot' flag set."), 0, 0},
>      {"header", 'H', 0, N_("Read header from file"), 0, ARG_TYPE_STRING},
> +    {"keyfile", 'k', 0, N_("Key file"), 0, ARG_TYPE_STRING},
> +    {"keyfile-offset", 'O', 0, N_("Key file offset (bytes)"), 0, ARG_TYPE_INT},
> +    {"keyfile-size", 'S', 0, N_("Key file data size (bytes)"), 0, ARG_TYPE_INT},
>      {0, 0, 0, 0, 0, 0}
>    };
>  
> @@ -972,6 +975,8 @@ grub_util_cryptodisk_get_uuid (grub_disk_t disk)
>  static int check_boot, have_it;
>  static char *search_uuid;
>  static grub_file_t hdr;
> +static grub_uint8_t *key, keyfile_buffer[GRUB_CRYPTODISK_MAX_KEYFILE_SIZE];
> +static grub_ssize_t key_size;
>  
>  static void
>  cryptodisk_close (grub_cryptodisk_t dev)
> @@ -1002,7 +1007,7 @@ grub_cryptodisk_scan_device_real (const char *name, grub_disk_t source)
>      if (!dev)
>        continue;
>      
> -    err = cr->recover_key (source, dev, hdr);
> +    err = cr->recover_key (source, dev, hdr, key, key_size);
>      if (err)
>      {
>        cryptodisk_close (dev);
> @@ -1112,6 +1117,86 @@ grub_cmd_cryptomount (grub_extcmd_context_t ctxt, int argc, char **args)
>      hdr = NULL;
>  
>    have_it = 0;
> +  key = NULL;
> +
> +  if (state[4].set) /* keyfile */
> +    {
> +      const char *p = NULL;
> +      grub_file_t keyfile;
> +      int keyfile_offset;
> +      grub_size_t requested_keyfile_size = 0;
> +
> +
> +      if (state[5].set) /* keyfile-offset */
> +	{
> +	  keyfile_offset = grub_strtoul (state[5].arg, &p, 0);
> +
> +	  if (grub_errno != GRUB_ERR_NONE)
> +	    return grub_errno;
> +
> +	  if (*p != '\0')
> +	    return grub_error (GRUB_ERR_BAD_ARGUMENT,
> +			       N_("unrecognized number"));
> +	}
> +      else
> +	{
> +	  keyfile_offset = 0;
> +	}
> +
> +      if (state[6].set) /* keyfile-size */
> +	{
> +	  requested_keyfile_size = grub_strtoul(state[6].arg, &p, 0);
> +
> +	  if (*p != '\0')
> +	    return grub_error (GRUB_ERR_BAD_ARGUMENT,
> +			       N_("unrecognized number"));
> +
> +	  if (grub_errno != GRUB_ERR_NONE)
> +	    return grub_errno;
> +
> +	  if (requested_keyfile_size > GRUB_CRYPTODISK_MAX_KEYFILE_SIZE)
> +	    return grub_error(GRUB_ERR_OUT_OF_RANGE,
> +			      N_("Key file size exceeds maximum (%llu)\n"), \
> +			      (unsigned long long) GRUB_CRYPTODISK_MAX_KEYFILE_SIZE);
> +
> +	  if (requested_keyfile_size == 0)
> +	    return grub_error(GRUB_ERR_OUT_OF_RANGE,
> +			      N_("Key file size is 0\n"));
> +	}
> +
> +
> +      keyfile = grub_file_open (state[4].arg,
> +				GRUB_FILE_TYPE_CRYPTODISK_ENCRYPTION_KEY);
> +      if (!keyfile)
> +	return grub_errno;
> +
> +      if (grub_file_seek (keyfile, keyfile_offset) == (grub_off_t)-1)
> +	return grub_errno;
> +
> +
> +      if (requested_keyfile_size)
> +	{
> +	  if (requested_keyfile_size > (keyfile->size - keyfile_offset))
> +	    return grub_error (GRUB_ERR_FILE_READ_ERROR,
> +			       N_("Keyfile is too small: "
> +				  "requested %llu bytes, "
> +				  "but the file only has %llu bytes.\n"),
> +			       (unsigned long long) requested_keyfile_size,
> +			       (unsigned long long) keyfile->size);

Instead of casting these, you may also just use `PRIuGRUB_SIZE` as
formatter.

Execept for this minor nit the patches all look good to me. Not sure if
it's worth much, but you may add my Reviewed-by tag if you want to.

Patrick

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