#!/bin/sh
# Copyright (c) Advanced Micro Devices, Inc. All rights reserved.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

# Provisions the HMAC key used by libamdcuid to generate stable CUIDs.
# Template processed by CMake to substitute @AMDCUID_SHARED_CONFIG_DIR@.
# Do not edit the generated script directly; edit this .in template instead.
#
# Idempotent — safe to run on reinstalls and upgrades. An existing key is
# never overwritten so existing CUID files remain valid.

CONFIG_DIR="@AMDCUID_SHARED_CONFIG_DIR@"
HMAC_KEY_FILE="$CONFIG_DIR/hmac_key.bin"

mkdir -p "$CONFIG_DIR"
chmod 755 "$CONFIG_DIR"

if [ ! -f "$HMAC_KEY_FILE" ]; then
    echo "Generating HMAC key at $HMAC_KEY_FILE..."
    # openssl is already a hard dependency (libssl); use it to produce 32 bytes
    # of cryptographically-random key material and immediately restrict access.
    if ! openssl rand -out "$HMAC_KEY_FILE" 32; then
        echo "ERROR: Failed to generate HMAC key with openssl." >&2
        rm -f "$HMAC_KEY_FILE"
        exit 1
    fi
    chmod 600 "$HMAC_KEY_FILE"
    chown root:root "$HMAC_KEY_FILE"
else
    echo "HMAC key already exists at $HMAC_KEY_FILE; leaving it unchanged."
fi