commit 19a4eb88ab0108d75a42e7da535184ac8084e0dd
author Greg Kaiser <gkaiser@google.com> Mon Dec 03 12:30:42 2018 -0800
committer Greg Kaiser <gkaiser@google.com> Tue Dec 11 15:39:09 2018 -0800
tree 7a3932894a59eb208c70d424ee6eaaa780f7ec0a
parent 7a32cfa41172b5942f9adf82cf92e1f01cd1b575

fs_mgr_fstab: Add Adiantum support

Adiantum is a crypto method Android is supporting for devices
which don't have AES CPU instructions.  See the paper
"Adiantum: length-preserving encryption for entry-level processors"
(https://eprint.iacr.org/2018/720.pdf) for more details.

We add Adiantum to our list of supported encryption modes.

Bug: 112010205
Test: Tested on a device
Change-Id: I14a400164803a1e217d378ad9bd8b67a61b8b7d0

fs_mgr/fs_mgr_fstab.cpp

diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index 0fde22e..f00983a 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -120,9 +120,11 @@
 #define EM_ICE          2
 #define EM_AES_256_CTS  3
 #define EM_AES_256_HEH  4
+#define EM_ADIANTUM     5
 
 static const struct flag_list file_contents_encryption_modes[] = {
     {"aes-256-xts", EM_AES_256_XTS},
+    {"adiantum", EM_ADIANTUM},
     {"software", EM_AES_256_XTS}, /* alias for backwards compatibility */
     {"ice", EM_ICE}, /* hardware-specific inline cryptographic engine */
     {0, 0},
@@ -131,6 +133,7 @@
 static const struct flag_list file_names_encryption_modes[] = {
     {"aes-256-cts", EM_AES_256_CTS},
     {"aes-256-heh", EM_AES_256_HEH},
+    {"adiantum", EM_ADIANTUM},
     {0, 0},
 };
 
@@ -271,6 +274,8 @@
                         flag_vals->file_names_mode =
                             encryption_mode_to_flag(file_names_encryption_modes,
                                                     colon + 1, "file names");
+                    } else if (flag_vals->file_contents_mode == EM_ADIANTUM) {
+                        flag_vals->file_names_mode = EM_ADIANTUM;
                     } else {
                         flag_vals->file_names_mode = EM_AES_256_CTS;
                     }