1Fs-verity keys
2==============
3All AOSP compatible devices ship with the Google-managed fs-verity certificate
4(located at build/make/target/product/security/fsverity-release.x509.der). The
5public key can verify the signature prebuilt of .dm.fsv\_sig in res/.
6
7Modifying a .dm file requires to regenerate the signature with some debug key.
8To use the debug key, you can run the following commands once per boot.
9
10```
11KEY_DIR=$ANDROID_BUILD_TOP/cts/hostsidetests/appsecurity/test-apps/ApkVerityTestApp/testdata
12
13adb root
14adb shell 'mini-keyctl padd asymmetric fsv-play .fs-verity' < $KEY_DIR/fsverity-debug.x509.der
15```
16
17Alternatively, copy the .der file to /{system, product}/etc/security/fsverity.
18The key will be located upon reboot.
19
20How to modify the signed .dm
21============================
22The easiet way is to re-sign and replace the signature in place. For example,
23
24```
25m fsverity
26
27fsverity sign CtsDexMetadataSplitApp.dm CtsDexMetadataSplitApp.dm.fsv_sig \
28  --key="$KEY_DIR/fsverity-debug-key.pem" \
29  --cert="$KEY_DIR/fsverity-debug.x509.pem"
30```
31