Revert "Securely encrypt the master key"

This reverts commit 4bf1887c787a025aad2fbafe382e556e85ac73b0.

Change-Id: Ie6d1f39de530b99b50a27ddc45bcc900a24e04b5

3 files changed, 44 insertions, 21 deletions

diff --git a/fs_mgr/fs_mgr.c b/fs_mgr/fs_mgr.c
index 1dd071c42..273a2ec0f 100644
--- a/fs_mgr/fs_mgr.c
+++ b/fs_mgr/fs_mgr.c
@@ -31,7 +31,7 @@
 #include <dirent.h>
 #include <ext4.h>
 #include <ext4_sb.h>
-#include <ext4_crypt_init_extensions.h>
+#include <ext4_crypt.h>
 
 #include <linux/loop.h>
 #include <private/android_filesystem_config.h>
@@ -480,6 +480,16 @@ static int handle_encryptable(struct fstab *fstab, const struct fstab_rec* rec)
             return FS_MGR_MNTALL_FAIL;
         }
 
+        // Link it to the normal place so ext4_crypt functions work normally
+        strlcat(tmp_mnt, "/unencrypted", sizeof(tmp_mnt));
+        char link_path[PATH_MAX];
+        strlcpy(link_path, rec->mount_point, sizeof(link_path));
+        strlcat(link_path, "/unencrypted", sizeof(link_path));
+        if (symlink(tmp_mnt, link_path)) {
+            ERROR("Error creating symlink to unencrypted directory\n");
+            return FS_MGR_MNTALL_FAIL;
+        }
+
         return FS_MGR_MNTALL_DEV_NON_DEFAULT_FILE_ENCRYPTED;
     }
 
diff --git a/init/builtins.cpp b/init/builtins.cpp
index d0e56ec0c..3bbaf8336 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -29,7 +29,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 #include <linux/loop.h>
-#include <ext4_crypt_init_extensions.h>
+#include <ext4_crypt.h>
 
 #include <selinux/selinux.h>
 #include <selinux/label.h>
@@ -386,6 +386,18 @@ static int wipe_data_via_recovery()
 }
 
 /*
+ * Callback to make a directory from the ext4 code
+ */
+static int do_mount_alls_make_dir(const char* dir)
+{
+    if (make_dir(dir, 0700) && errno != EEXIST) {
+        return -1;
+    }
+
+    return 0;
+}
+
+/*
  * This function might request a reboot, in which case it will
  * not return.
  */
@@ -453,6 +465,22 @@ int do_mount_all(int nargs, char **args)
         ret = wipe_data_via_recovery();
         /* If reboot worked, there is no return. */
     } else if (ret == FS_MGR_MNTALL_DEV_DEFAULT_FILE_ENCRYPTED) {
+        // We have to create the key files here. Only init can call make_dir,
+        // and we can't do it from fs_mgr as then fs_mgr would depend on
+        // make_dir creating a circular dependency.
+        fstab = fs_mgr_read_fstab(args[1]);
+        for (int i = 0; i < fstab->num_entries; ++i) {
+            if (fs_mgr_is_file_encrypted(&fstab->recs[i])) {
+              if (e4crypt_create_device_key(fstab->recs[i].mount_point,
+                                            do_mount_alls_make_dir)) {
+                    ERROR("Could not create device key on %s"
+                          " - continue unencrypted\n",
+                          fstab->recs[i].mount_point);
+                }
+            }
+        }
+        fs_mgr_free_fstab(fstab);
+
         if (e4crypt_install_keyring()) {
             return -1;
         }
@@ -821,23 +849,10 @@ int do_wait(int nargs, char **args)
         return -1;
 }
 
-/*
- * Callback to make a directory from the ext4 code
- */
-static int do_installkeys_ensure_dir_exists(const char* dir)
-{
-    if (make_dir(dir, 0700) && errno != EEXIST) {
-        return -1;
-    }
-
-    return 0;
-}
-
 int do_installkey(int nargs, char **args)
 {
     if (nargs == 2) {
-      return e4crypt_create_device_key(args[1],
-                                       do_installkeys_ensure_dir_exists);
+        return e4crypt_install_key(args[1]);
     }
 
     return -1;
diff --git a/rootdir/init.rc b/rootdir/init.rc
index b353d9d4c..a5ea60aaa 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -226,17 +226,14 @@ on post-fs
     mkdir /cache/lost+found 0770 root root
 
 on post-fs-data
+    installkey /data
+
     # We chown/chmod /data again so because mount is run as root + defaults
     chown system system /data
     chmod 0771 /data
     # We restorecon /data in case the userdata partition has been reset.
     restorecon /data
 
-    # Make sure we have the device encryption key
-    start logd
-    start vold
-    installkey /data
-
     # Start bootcharting as soon as possible after the data partition is
     # mounted to collect more data.
     mkdir /data/bootchart 0755 shell shell
@@ -457,6 +454,7 @@ on property:vold.decrypt=trigger_restart_min_framework
     class_start main
 
 on property:vold.decrypt=trigger_restart_framework
+    installkey /data
     class_start main
     class_start late_start