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Hilko Bengen

2013-Nov-22 13:08 UTC

[Libguestfs] [PATCH 1/3] Document ntreg_nk_record.flags

---
 lib/hivex-internal.h | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/hivex-internal.h b/lib/hivex-internal.h
index f391b98..d7ce339 100644
--- a/lib/hivex-internal.h
+++ b/lib/hivex-internal.h
@@ -125,7 +125,19 @@ struct ntreg_hbin_block {
 struct ntreg_nk_record {
   int32_t seg_len;              /* length (always -ve because used) */
   char id[2];                   /* "nk" */
-  uint16_t flags;
+  uint16_t flags;               /* bit 1: HiveExit
+                                   bit 2: HiveEntry == root key
+                                   bit 3: NoDelete
+                                   bit 4: SymbolicLink
+                                   bit 5: CompressedName: Name is encoded
+                                          in ASCII (actually: Latin-1)
+                                          rather than UTF-16.
+                                   bit 6: PredefinedHandle
+                                   bit 7: VirtMirrored
+                                   bit 8: VirtTarget
+                                   bit 9: VirtualStore */
+  /* Information from: Peter Norris: The Internal Structure of the
+     Windows Registry, 2008, p.220 ff. */
   int64_t timestamp;
   uint32_t unknown1;
   uint32_t parent;              /* offset of owner/parent */
-- 
1.8.4.3

Hilko Bengen

2013-Nov-22 13:08 UTC

head link

[Libguestfs] [PATCH 2/3] Handle UTF-16-LE-encoded key/value names

---
 lib/node.c  | 23 +++++++++++------------
 lib/value.c | 18 +++++++++++-------
 2 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/lib/node.c b/lib/node.c
index 5090dbe..fda4592 100644
--- a/lib/node.c
+++ b/lib/node.c
@@ -79,11 +79,6 @@ hivex_node_name (hive_h *h, hive_node_h node)
   struct ntreg_nk_record *nk      (struct ntreg_nk_record *) ((char *)
h->addr + node);
 
-  /* AFAIK the node name is always plain ASCII, so no conversion
-   * to UTF-8 is necessary.  However we do need to nul-terminate
-   * the string.
-   */
-
   /* nk->name_len is unsigned, 16 bit, so this is safe ...  However
    * we have to make sure the length doesn't exceed the block length.
    */
@@ -93,13 +88,17 @@ hivex_node_name (hive_h *h, hive_node_h node)
     SET_ERRNO (EFAULT, "node name is too long (%zu, %zu)", len,
seg_len);
     return NULL;
   }
-
-  char *ret = malloc (len + 1);
-  if (ret == NULL)
-    return NULL;
-  memcpy (ret, nk->name, len);
-  ret[len] = '\0';
-  return ret;
+  size_t flags = le16toh (nk->flags);
+  if (flags & 0x20) {
+    char *ret = malloc (len + 1);
+    if (ret == NULL)
+      return NULL;
+    memcpy (ret, nk->name, len);
+    ret[len] = '\0';
+    return ret;
+  } else {
+    return _hivex_windows_utf16_to_utf8 (nk->name, len);
+  }
 }
 
 static int64_t
diff --git a/lib/value.c b/lib/value.c
index 6d0f266..66cde48 100644
--- a/lib/value.c
+++ b/lib/value.c
@@ -213,13 +213,17 @@ hivex_value_key (hive_h *h, hive_value_h value)
   size_t len = hivex_value_key_len (h, value);
   if (len == 0 && errno != 0)
     return NULL;
-
-  char *ret = malloc (len + 1);
-  if (ret == NULL)
-    return NULL;
-  memcpy (ret, vk->name, len);
-  ret[len] = '\0';
-  return ret;
+  size_t flags = le16toh (vk->flags);
+  if (flags & 0x01) {
+    char *ret = malloc (len + 1);
+    if (ret == NULL)
+      return NULL;
+    memcpy (ret, vk->name, len);
+    ret[len] = '\0';
+    return ret;
+  } else {
+    return _hivex_windows_utf16_to_utf8 (vk->name, len);
+  }
 }
 
 int
-- 
1.8.4.3

Hilko Bengen

2013-Nov-22 13:08 UTC

head link

[Libguestfs] [PATCH 3/3] Correctly handle latin1-encoded key/value names

---
 lib/hivex-internal.h | 6 +++++-
 lib/node.c           | 7 +------
 lib/utf16.c          | 5 ++---
 lib/value.c          | 7 +------
 4 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/lib/hivex-internal.h b/lib/hivex-internal.h
index d7ce339..4135f58 100644
--- a/lib/hivex-internal.h
+++ b/lib/hivex-internal.h
@@ -268,7 +268,11 @@ extern size_t * _hivex_return_offset_list (offset_list
*list);
 extern void _hivex_print_offset_list (offset_list *list, FILE *fp);
 
 /* utf16.c */
-extern char *_hivex_windows_utf16_to_utf8 (/* const */ char *input, size_t
len);
+extern char* _hivex_to_utf8 (/* const */ char *input, size_t len, char*
input_encoding);
+#define _hivex_windows_utf16_to_utf8(_input, _len) \
+  _hivex_to_utf8 (_input, _len, "UTF-16LE")
+#define _hivex_windows_latin1_to_utf8(_input, _len) \
+  _hivex_to_utf8 (_input, _len, "LATIN1")
 extern size_t _hivex_utf16_string_len_in_bytes_max (const char *str, size_t
len);
 
 /* util.c */
diff --git a/lib/node.c b/lib/node.c
index fda4592..fcd7442 100644
--- a/lib/node.c
+++ b/lib/node.c
@@ -90,12 +90,7 @@ hivex_node_name (hive_h *h, hive_node_h node)
   }
   size_t flags = le16toh (nk->flags);
   if (flags & 0x20) {
-    char *ret = malloc (len + 1);
-    if (ret == NULL)
-      return NULL;
-    memcpy (ret, nk->name, len);
-    ret[len] = '\0';
-    return ret;
+    return _hivex_windows_latin1_to_utf8 (nk->name, len);
   } else {
     return _hivex_windows_utf16_to_utf8 (nk->name, len);
   }
diff --git a/lib/utf16.c b/lib/utf16.c
index 844715c..eca2343 100644
--- a/lib/utf16.c
+++ b/lib/utf16.c
@@ -29,15 +29,14 @@
 #include "hivex-internal.h"
 
 char *
-_hivex_windows_utf16_to_utf8 (/* const */ char *input, size_t len)
+_hivex_to_utf8 (/* const */ char *input, size_t len, char* input_encoding)
 {
-  iconv_t ic = iconv_open ("UTF-8", "UTF-16LE");
+  iconv_t ic = iconv_open ("UTF-8", input_encoding);
   if (ic == (iconv_t) -1)
     return NULL;
 
   /* iconv(3) has an insane interface ... */
 
-  /* Mostly UTF-8 will be smaller, so this is a good initial guess. */
   size_t outalloc = len;
 
  again:;
diff --git a/lib/value.c b/lib/value.c
index 66cde48..3460a8c 100644
--- a/lib/value.c
+++ b/lib/value.c
@@ -215,12 +215,7 @@ hivex_value_key (hive_h *h, hive_value_h value)
     return NULL;
   size_t flags = le16toh (vk->flags);
   if (flags & 0x01) {
-    char *ret = malloc (len + 1);
-    if (ret == NULL)
-      return NULL;
-    memcpy (ret, vk->name, len);
-    ret[len] = '\0';
-    return ret;
+    return _hivex_windows_latin1_to_utf8 (vk->name, len);
   } else {
     return _hivex_windows_utf16_to_utf8 (vk->name, len);
   }
-- 
1.8.4.3

Richard W.M. Jones

2013-Nov-22 15:59 UTC

head link

Re: [Libguestfs] [PATCH 1/3] Document ntreg_nk_record.flags

On Fri, Nov 22, 2013 at 02:08:33PM +0100, Hilko Bengen
wrote:> ---
>  lib/hivex-internal.h | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/hivex-internal.h b/lib/hivex-internal.h
> index f391b98..d7ce339 100644
> --- a/lib/hivex-internal.h
> +++ b/lib/hivex-internal.h
> @@ -125,7 +125,19 @@ struct ntreg_hbin_block {
>  struct ntreg_nk_record {
>    int32_t seg_len;              /* length (always -ve because used) */
>    char id[2];                   /* "nk" */
> -  uint16_t flags;
> +  uint16_t flags;               /* bit 1: HiveExit
> +                                   bit 2: HiveEntry == root key
> +                                   bit 3: NoDelete
> +                                   bit 4: SymbolicLink
> +                                   bit 5: CompressedName: Name is encoded
> +                                          in ASCII (actually: Latin-1)
> +                                          rather than UTF-16.
> +                                   bit 6: PredefinedHandle
> +                                   bit 7: VirtMirrored
> +                                   bit 8: VirtTarget
> +                                   bit 9: VirtualStore */
> +  /* Information from: Peter Norris: The Internal Structure of the
> +     Windows Registry, 2008, p.220 ff. */
>    int64_t timestamp;
>    uint32_t unknown1;
>    uint32_t parent;              /* offset of owner/parent */
> -- 
> 1.8.4.3
Simple and obvious documentation fix, so ACK.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top

Richard W.M. Jones

2013-Nov-22 16:10 UTC

head link

Re: [Libguestfs] [PATCH 3/3] Correctly handle latin1-encoded key/value names

I tested 2 & 3 against the hivex-test-data repository and indeed your
patches found (and fixed) some registry encoding issues:

http://git.annexia.org/?p=hivex-test-data.git;a=commitdiff_plain;h=d1b6c9d294287642d035f3a7fb20081865962086

Thanks, I have pushed all three patches to hivex.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v

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