config: Install FRP wipe script into recovery /system/bin

Change-Id: I24e217e6af87f2002193ac7b6defb158cce0a776

config/common.mk

@@ -178,6 +178,10 @@ PRODUCT_ARTIFACT_PATH_REQUIREMENT_ALLOWED_LIST += \
     system/%/libfuse-lite.so \
     system/%/libntfs-3g.so
 
+# FRP
+PRODUCT_COPY_FILES += \
+    vendor/lineage/prebuilt/common/bin/wipe-frp.sh:$(TARGET_COPY_OUT_RECOVERY)/root/system/bin/wipe-frp
+
 # Openssh
 PRODUCT_PACKAGES += \
     scp \

prebuilt/common/bin/wipe-frp.sh

@@ -0,0 +1,68 @@
+#!/system/bin/sh
+#
+# SPDX-FileCopyrightText: 2025 The LineageOS Project
+# SPDX-License-Identifier: Apache-2.0
+#
+
+FRP_BLOCK=$(getprop ro.frp.pst)
+
+if [[ -z "${FRP_BLOCK}" ]]; then
+    echo "FRP prop not set"
+    exit -1
+fi
+
+FRP_BLOCK_SIZE=$(blockdev --getsize64 "${FRP_BLOCK}")
+
+if [[ "${FRP_BLOCK_SIZE}" -le 0 ]]; then
+    echo "FRP block size <= 0"
+    exit -1
+fi
+
+# Calculate offsets
+DIGEST_SIZE=32
+DIGEST_OFFSET=0
+
+FRP_OEM_UNLOCK_SIZE=1
+FRP_OEM_UNLOCK_OFFSET=$((${FRP_BLOCK_SIZE} - 1))
+
+FRP_CREDENTIAL_RESERVED_SIZE=1000
+FRP_CREDENTIAL_RESERVED_OFFSET=$((${FRP_OEM_UNLOCK_OFFSET} - ${FRP_CREDENTIAL_RESERVED_SIZE}))
+
+TEST_MODE_RESERVED_SIZE=10000
+TEST_MODE_RESERVED_OFFSET=$((${FRP_CREDENTIAL_RESERVED_OFFSET} - ${TEST_MODE_RESERVED_SIZE}))
+
+FRP_SECRET_SIZE=32
+FRP_SECRET_OFFSET=$((${TEST_MODE_RESERVED_OFFSET} - ${FRP_SECRET_SIZE}))
+
+FRP_SECRET_MAGIC_SIZE=8
+FRP_SECRET_MAGIC_OFFSET=$((${FRP_SECRET_OFFSET} - ${FRP_SECRET_MAGIC_SIZE}))
+
+# Clear digest
+dd if=/dev/zero of="${FRP_BLOCK}" \
+   seek="${DIGEST_OFFSET}" \
+   count="${DIGEST_SIZE}" \
+   bs=1
+
+# Clear credential storage
+dd if=/dev/zero of="${FRP_BLOCK}" \
+   seek="${FRP_CREDENTIAL_RESERVED_OFFSET}" \
+   count="${FRP_CREDENTIAL_RESERVED_SIZE}" \
+   bs=1
+
+# Clear FRP secret
+dd if=/dev/zero of="${FRP_BLOCK}" \
+   seek="${FRP_SECRET_OFFSET}" \
+   count="${FRP_SECRET_SIZE}" \
+   bs=1
+
+# Write default FRP secret magic
+printf "\xDA\xC2\xFC\xCD\xB9\x1B\x09\x88" | dd of="${FRP_BLOCK}" \
+    seek="${FRP_SECRET_MAGIC_OFFSET}" \
+    count="${FRP_SECRET_MAGIC_SIZE}" \
+    bs=1
+
+# Write digest
+sha256sum -b "${FRP_BLOCK}" | xxd -r -p | dd of="${FRP_BLOCK}" \
+    seek="${DIGEST_OFFSET}" \
+    count="${DIGEST_SIZE}" \
+    bs=1