Oh My Keymint
Custom keystore implementation for Android Keystore Spoofer
What is this?
This is a complete implementation of the keystore, which fully implements the AOSP AIDL interface, referencing the official AOSP implementation.
In theory, this would make it harder for detectors to identify behavior inconsistent with AOSP, thus achieving greater stealth than the FOSS branch of TrickyStore or other TrickyStore-based module like TEESimulator.
Android 12 or above required.
Install this module.
Configure OMK if needed.
Change the active keybox.xml from the WebUI (if you need)
The keybox file must contain at least one complete RSA or EC entry, and every
private key present must match its certificate chain. A keybox may contain both
algorithms or only one; RKP-extracted keyboxes are legitimately EC-only. Keep
the XML free of extra content such as watermarks or invisible characters. The
embedded WebUI opens Android's system document picker when installing a
replacement, so the default file manager or another installed storage app such
as MT Manager can provide the file. The picker requests all MIME types; the
WebUI still requires an .xml file and the native helper performs the complete
validation. If the system picker cannot be opened, the WebUI falls back to its
shared-storage browser.
The active files are /data/misc/keystore/omk/config.toml and
/data/misc/keystore/omk/injector.toml. Read the
Configuration Guide for complete annotated examples,
field-by-field explanations, safety notes, and restart requirements.
The [main] settings ta_operation_delay_ms, ta_generation_delay_ms, and
ta_control_delay_ms in config.toml add a fresh random wait before each
covered software TA call. Their default ranges are [9, 21], [6, 16], and
[1, 4] milliseconds, including when a field is absent. Set a range to
[0, 0] to disable that category. Valid changes apply to new calls without a
restart. These are extra waits, which add to any enabled injector delays;
they do not provide hardware security or guarantee a detector result. See
TA delay ranges for coverage and limits.
Optional injector.toml settings under [main] can mitigate timing-based client
heuristics: attestation_generation_delay_ms delays successful challenged key
generation replies, and operation_start_delay_ms delays two-way OMK
createOperation calls before the RPC, including calls that return business
errors. Both default to 0 (disabled), accept 0..250 milliseconds, and occupy
a Binder worker while waiting. They do not provide hardware security or
guarantee a detector result. See the Configuration Guide before enabling them.
In injector.toml, keep the scoop = [ and closing ] lines, then add each
exact package name on its own line. Bare entries omit both quotes and commas;
blank lines and lines beginning with # are ignored. The traditional quoted,
comma-separated TOML form remains accepted.
Embedded WebUI
The module includes a WebUI for choosing the exact packages in scoop,
installing a local keybox, managing the Android security patch level, and
applying a Pixel PIF fingerprint through OMK's own Zygisk payload. It also
provides an ADB Disabler with independent controls for developer options, USB
debugging, and OEM unlocking:
- In KernelSU, open Oh My Keymint from the module list and select its WebUI.
- In Magisk, open an installed KSUWebUIStandalone or WebUI X host and select
Oh My Keymint. The module does not install a WebUI host.
The WebUI uses bundled assets for normal operation. Sync security patch
uses the module's native HTTPS client to download the Android Security Bulletin
overview from Google's official source.android.com host (with its official
Chinese mirror as a fallback), and parses the newest published patch level.
The synchronized value always uses that level's year and month. If the saved
default ro.build.version.security_patch ends in day 01, it uses day 01;
otherwise it keeps Google's published date. A saved day 05 therefore follows
Google's published date. If the saved system and vendor patch dates disagree,
the system date determines this choice. It does not require curl or
wget on the device. TLS uses the client's embedded WebPKI roots, and HTTPS
redirects are accepted only when they end at the official bulletin page.
Before the first sync, the
helper records the current ro.build.version.security_patch and
ro.vendor.build.security_patch values in
/data/misc/keystore/omk/data/security_patch_defaults.toml. Later syncs keep
that original snapshot. Each sync writes the selected date to all four
[trust] patch-level fields and applies it to both runtime properties with
resetprop. While that valid snapshot remains, the module's early boot hook
reapplies the paired properties before Android framework values are cached;
keymint also reapplies them at startup. A manually configured exact date
without the snapshot continues to use the normal configuration behavior. After a
successful sync or restore, the WebUI reports completion and asks you to reboot;
it does not reboot the device automatically.
Restore default security patch does not use the network. It restores both
runtime properties from the saved snapshot, sets security_patch,
os_patchlevel, vendor_patchlevel, and boot_patchlevel to auto, and then
deletes the snapshot. These runtime properties are global for the current boot,
so other processes can observe the synchronized or restored values. A failed
operation is reported, property writes are rolled back when a later step fails,
and a snapshot needed for another restore attempt is retained.
Spoof PIF fingerprint downloads the current Pixel device catalog and the
selected profile from the bot branch of KOWX712/PlayIntegrityFix. That feed
is generated daily from Google's Android preview pages, Android Flash Tool
metadata, and Pixel security bulletin. The native helper validates the
catalog, the four profile fields, and the complete fingerprint structure. It
then derives the matching Build fields and atomically stores the active profile
at /data/misc/keystore/omk/data/pif_fingerprint.json. OMK's own Zygisk
payload applies these values inside newly started
com.google.android.gms.unstable and com.android.vending processes (including
their named :... child processes) through the Zygisk Next loader. During
pre-app specialization it installs available PLT hooks and, on AArch64, tries a
process-wide bionic callback hook only after validating the wrapper semantics,
memory mappings, and BTI/MTE permissions. A rejected callback hook leaves libc
unchanged, records the reason, and continues with the available PLT and Java
paths. Java Build fields and a property probe are updated after
specialization.
Zygisk Next must already be
installed and enabled by the user; OMK does not bundle, install, or implement
that loader. The selected values are process-local, are not global Android
properties, and do not change OMK's [device] identity. Disabling the action
removes the OMK profile and restarts the affected processes so their next
instances use the original values.
The ADB Disabler action stores four strict 0/1 values in
/data/misc/keystore/omk/data/adb_disabler.conf. When enabled, the selected
settings are applied immediately and replayed by the module service at every
boot. Disabling the master switch stops future replay; it intentionally does
not restore properties already changed during the current boot.
The security-patch and PIF network actions use the bundled native HTTPS client
and require neither curl nor wget. Other WebUI operations remain local.
The WebUI can also read and replace scoop and select a local XML file from
shared storage or through another installed file app to replace the active OMK
keybox. The security-patch actions do not change secrets, identity fields, or
other settings.
When the module is uninstalled from KernelSU, its bundled uninstaller removes
exactly /data/adb/omk and /data/misc/keystore/omk, including OMK-created key
data. This is irreversible and can require affected apps to register or sign in
again; disabling the module does not remove the directories. Reboot after an
uninstall.
Saving scoop is delegated to the native inject helper, which validates the
current configuration and package names before atomically replacing
injector.toml. Installing a keybox is delegated to the native keymint
helper. That helper checks the size, decodes UTF-8, and performs the complete
in-memory KeyBox validation before atomically replacing the canonical
lowercase /data/misc/keystore/omk/keybox.xml. A failed read, size, UTF-8,
validation, or write leaves the corresponding active file unchanged. The
appropriate watcher loads a successful change automatically, so a restart is
normally unnecessary.
Third-party source and licensing details for the adapted WebUI are listed in
Third-Party Software.
Restarting keymint and injector
The module ships two background daemons: one for keymint, one for injector.
You can restart them by following commands.
touch /data/adb/omk/restart.keymint
touch /data/adb/omk/restart.injector
touch /data/adb/omk/restart.all
See the Configuration Guide for
which changes need a component restart or a full device reboot.
License
YOU MUST AGREE TO BOTH OF THE LICENSE BEFORE USING THIS SOFTWARE.
AGPL-3.0-or-later
OhMyKeymint - Custom keymint implementation for Android Keystore Spoofer
Copyright (C) 2025 James Clef <[email protected]>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
Oh My Keymint License
1. 您不得将本软件、本软件的任意部分或将本软件作为依赖的软件用于任何商业用途。该
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赖的软件与其他资源、物品或服务捆绑销售。
2. 您不得暗示或明示本软件与其他软件有任何从属关系。
3. 未经本软件作者书面允许，您不得超出合理使用范围或协议许可范围使用本软件的名称。
4. 除非您所在的司法管辖区的适用法律另行规定，您同意将纠纷或争议提交至中国大陆境
内有管辖权的人民法院管辖。
5. 本协议与GNU Affero General Public License（以下简称AGPL）共同发挥效力，
当本协议内容与AGPL冲突时，应当优先应用本协议内容，本协议仅覆盖本软件作者拥有
完全著作权的部分，对于使用其他协议的软件代码不发挥效力。
Credit
Some code from AOSP
License: Apache-2.0
Copyright 2022, The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Oh My Keymint (OMK) is a custom Android Keystore implementation that fully mirrors the AOSP AIDL interface, designed to spoof key attestation and make app behavior harder for detectors to distinguish from a genuine AOSP device.