[billing] Add billing server

src/main/java/icu/samnyan/aqua/sega/billing/BillingController.java

@@ -0,0 +1,117 @@
+package icu.samnyan.aqua.sega.billing;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import icu.samnyan.aqua.sega.billing.model.response.BillingResponse;
+import icu.samnyan.aqua.sega.billing.util.Decoder;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.core.io.Resource;
+import org.springframework.core.io.ResourceLoader;
+import org.springframework.util.FileCopyUtils;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.security.KeyFactory;
+import java.security.Signature;
+import java.security.interfaces.RSAPrivateKey;
+import java.security.spec.KeySpec;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.util.Map;
+import javax.servlet.http.HttpServletRequest;
+
+@RestController
+public class BillingController {
+
+    private static final Logger logger = LoggerFactory.getLogger(BillingController.class);
+
+    private final ObjectMapper mapper = new ObjectMapper();
+
+    private final ResourceLoader resourceLoader;
+
+    public BillingController(ResourceLoader resourceLoader) {
+        this.resourceLoader = resourceLoader;
+    }
+
+    @PostMapping(value = "/request", produces = "text/plain")
+    public String powerOn(InputStream dataStream, HttpServletRequest req) throws IOException {
+
+        RSAPrivateKey key = loadBillingKey();
+
+        byte[] bytes = dataStream.readAllBytes();
+        Map<String, String> reqMap = Decoder.decode(bytes);
+
+        logger.info("Request: Billing, " + mapper.writeValueAsString(reqMap));
+
+        String keychipId = reqMap.getOrDefault("keychipid", "");
+
+        BillingResponse resp = new BillingResponse(
+                0,
+                100,
+                1,
+                "",
+                1024,
+                signWithKey(key, keychipId, 1024),
+                "1.000",
+                66048, // 0x00010200
+                signWithKey(key, keychipId, 66048),
+                0,
+                5,
+                "000000/0:000000/0:000000/0");
+        logger.info("Response: " + mapper.writeValueAsString(resp));
+        return resp.toString().concat("\n");
+    }
+
+    private String signWithKey(RSAPrivateKey key, String keychipId, int val) {
+        String result = "";
+
+        ByteBuffer sigbytes = ByteBuffer.allocate(15);
+        sigbytes.order(ByteOrder.LITTLE_ENDIAN);
+        sigbytes.putInt(0, val);
+        sigbytes.put(4, keychipId.getBytes());
+
+        Signature sig;
+        try {
+            sig = Signature.getInstance("SHA1withRSA");
+            sig.initSign(key);
+            sig.update(sigbytes);
+            byte[] signedData = sig.sign();
+            result = bytesToHex(signedData);
+        } catch (Exception e) {
+            logger.error("Failed to sign with billing key, " + e.getMessage());
+        }
+
+        return result;
+    }
+
+    private RSAPrivateKey loadBillingKey() {
+        RSAPrivateKey billingKey = null;
+        
+        Resource keyRes = resourceLoader.getResource("classpath:billing.der");
+        byte[] key;
+        try {
+            key = FileCopyUtils.copyToByteArray(keyRes.getInputStream());
+            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
+            KeySpec keySpec = new PKCS8EncodedKeySpec(key);
+            billingKey = (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
+        } catch (Exception e) {
+            logger.error("Failed to load billing key file, " + e.getMessage());
+        }
+
+        return billingKey;
+    }
+
+    private String bytesToHex(byte[] in) {
+        final StringBuilder builder = new StringBuilder();
+        for(byte b : in) {
+            builder.append(String.format("%02x", b));
+        }
+        return builder.toString();
+    }
+
+}