[gnome-color-manager] Check the profile is a valid icc formatted file before we try to parse it

[Richard Hughes <rhughes src gnome org>]

commit caf6f010e4fdb194faf609c8bea786cba639b934
Author: Richard Hughes <richard hughsie com>
Date:   Sat Oct 31 12:22:56 2009 +0000

    Check the profile is a valid icc formatted file before we try to parse it

 src/gcm-profile.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)
---
diff --git a/src/gcm-profile.c b/src/gcm-profile.c
index 4c6c983..54030b5 100644
--- a/src/gcm-profile.c
+++ b/src/gcm-profile.c
@@ -41,6 +41,7 @@ static void     gcm_profile_finalize	(GObject     *object);
 #define GCM_PROFILE_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GCM_TYPE_PROFILE, GcmProfilePrivate))
 
 #define GCM_HEADER			0x00
+#define GCM_SIGNATURE			0x24
 #define GCM_NUMTAGS			0x80
 #define GCM_BODY			0x84
 
@@ -504,6 +505,26 @@ gcm_profile_load (GcmProfile *profile, const gchar *filename, GError **error)
 		goto out;
 	}
 
+	/* ensure we have the header */
+	if (length < 0x84) {
+		if (error != NULL)
+			*error = g_error_new (1, 0, "profile was not valid (file size too small)");
+		ret = FALSE;
+		goto out;
+	}
+
+	/* ensure this is a icc file */
+	if (data[GCM_SIGNATURE+0] != 'a' ||
+	    data[GCM_SIGNATURE+1] != 'c' ||
+	    data[GCM_SIGNATURE+2] != 's' ||
+	    data[GCM_SIGNATURE+3] != 'p') {
+		data[GCM_SIGNATURE+4] = '\0';
+		if (error != NULL)
+			*error = g_error_new (1, 0, "not an ICC profile, signature is '%s', expecting 'acsp'", &data[GCM_SIGNATURE]);
+		ret = FALSE;
+		goto out;
+	}
+
 	/* get the number of tags in the file */
 	num_tags = gcm_parser_unencode_32 (data, GCM_NUMTAGS);
 	egg_debug ("number of tags: %i", num_tags);