[PATCH v9 3/7] cryptodisk: Add --header option to cryptomount and fail to implement it in the backends

[Glenn Washburn]

Add a --header (short -H) option to cryptomount which takes a file argument.
Pass the file to the backends via cargs struct and cause the backends to
fail when passed a header. Detached header file support will be added later
for individual backends.

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>
development@efficientek.com: rebase, rework for cryptomount parameter passing,
  improve commit message
Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/disk/cryptodisk.c | 15 ++++++++++++++-
 grub-core/disk/geli.c       | 10 ++++++++++
 grub-core/disk/luks.c       |  8 ++++++++
 grub-core/disk/luks2.c      |  8 ++++++++
 include/grub/cryptodisk.h   |  2 ++
 include/grub/file.h         |  2 ++
 6 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index 9f5dc7acbc..063997d2f0 100644
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -42,6 +42,7 @@ 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},
     {"password", 'p', 0, N_("Password to open volumes."), 0, ARG_TYPE_STRING},
+    {"header", 'H', 0, N_("Read header from file"), 0, ARG_TYPE_STRING},
     {0, 0, 0, 0, 0, 0}
   };
 
@@ -1172,6 +1173,18 @@ grub_cmd_cryptomount (grub_extcmd_context_t ctxt, int 
argc, char **args)
       cargs.key_len = grub_strlen (state[3].arg);
     }
 
+  if (state[4].set) /* header */
+    {
+      if (state[0].set)
+       return grub_error (GRUB_ERR_BAD_ARGUMENT,
+                          N_("cannot use UUID lookup with detached header"));
+
+      cargs.hdr_file = grub_file_open (state[4].arg,
+                           GRUB_FILE_TYPE_CRYPTODISK_DETACHED_HEADER);
+      if (cargs.hdr_file == NULL)
+       return grub_errno;
+    }
+
   if (state[0].set) /* uuid */
     {
       int found_uuid;
@@ -1384,7 +1397,7 @@ GRUB_MOD_INIT (cryptodisk)
 {
   grub_disk_dev_register (&grub_cryptodisk_dev);
   cmd = grub_register_extcmd ("cryptomount", grub_cmd_cryptomount, 0,
-                             N_("[-p password] <SOURCE|-u UUID|-a|-b>"),
+                             N_("[-p password] [-H file] <SOURCE|-u 
UUID|-a|-b>"),
                              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 91eb101224..39b32a2add 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[] = {
@@ -252,6 +254,10 @@ geli_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
   grub_disk_addr_t sector;
   grub_err_t err;
 
+  /* Detached headers are not implemented yet */
+  if (cargs->hdr_file)
+    return NULL;
+
   if (2 * GRUB_MD_SHA256->mdlen + 1 > GRUB_CRYPTODISK_MAX_UUID_LENGTH)
     return NULL;
 
@@ -412,6 +418,10 @@ geli_recover_key (grub_disk_t source, grub_cryptodisk_t 
dev, grub_cryptomount_ar
   if (cargs->key_data == NULL || cargs->key_len == 0)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, "no key data");
 
+  /* Detached headers are not implemented yet */
+  if (cargs->hdr_file)
+     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 7f837d52c4..fe1655c3c2 100644
--- a/grub-core/disk/luks.c
+++ b/grub-core/disk/luks.c
@@ -75,6 +75,10 @@ luks_scan (grub_disk_t disk, grub_cryptomount_args_t cargs)
   char hashspec[sizeof (header.hashSpec) + 1];
   grub_err_t err;
 
+  /* Detached headers are not implemented yet */
+  if (cargs->hdr_file)
+    return NULL;
+
   if (cargs->check_boot)
     return NULL;
 
@@ -164,6 +168,10 @@ luks_recover_key (grub_disk_t source,
   if (cargs->key_data == NULL || cargs->key_len == 0)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, "no key data");
 
+  /* Detached headers are not implemented yet */
+  if (cargs->hdr_file)
+     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 bf741d70f3..349462c61a 100644
--- a/grub-core/disk/luks2.c
+++ b/grub-core/disk/luks2.c
@@ -353,6 +353,10 @@ luks2_scan (grub_disk_t disk, grub_cryptomount_args_t 
cargs)
   char uuid[sizeof (header.uuid) + 1];
   grub_size_t i, j;
 
+  /* Detached headers are not implemented yet */
+  if (cargs->hdr_file)
+    return NULL;
+
   if (cargs->check_boot)
     return NULL;
 
@@ -560,6 +564,10 @@ luks2_recover_key (grub_disk_t source,
   if (cargs->key_data == NULL || cargs->key_len == 0)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, "no key data");
 
+  /* Detached headers are not implemented yet */
+  if (cargs->hdr_file)
+     return GRUB_ERR_NOT_IMPLEMENTED_YET;
+
   ret = luks2_read_header (source, &header);
   if (ret)
     return ret;
diff --git a/include/grub/cryptodisk.h b/include/grub/cryptodisk.h
index c6524c9ea9..9fe451de92 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
@@ -77,6 +78,7 @@ struct grub_cryptomount_args
   grub_uint8_t *key_data;
   /* recover_key: Length of key_data */
   grub_size_t key_len;
+  grub_file_t hdr_file;
 };
 typedef struct grub_cryptomount_args *grub_cryptomount_args_t;
 
diff --git a/include/grub/file.h b/include/grub/file.h
index 31567483cc..3a3c49a04c 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 holding 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.  */
-- 
2.25.1