Merge pull request #16 from ricardoboss/feature/pow-upgrade

feat: allow gradual increase of POW

src/config/constants.js

@@ -9,9 +9,12 @@ const TOPIC = crypto.createHash("sha256").update(TOPIC_NAME).digest();
  * 
  * I ran it that way and I was fairly isolated, with hundreds of failed POW, shame.
  * adding an extra 0 makes it very expensive on attacker to make it worth the fun for them, so maybe consider it.
- * 
+ * ----
+ * ricardoboss: added a way to get the best of both worlds: newer nodes will use a harder POW, making them compatible
+ * with others who use a harder POW while still being able to accept "old" POWs from clients
  */
-const POW_PREFIX = "0000";
+const MY_POW_PREFIX = "00000";
+const VERIFICATION_POW_PREFIX = "0000";
 
 const MAX_PEERS = parseInt(process.env.MAX_PEERS) || 1000000;
 const MAX_MESSAGE_SIZE = 2048;
@@ -28,7 +31,8 @@ const PORT = process.env.PORT || 3000;
 module.exports = {
     TOPIC_NAME,
     TOPIC,
-    POW_PREFIX,
+    MY_POW_PREFIX,
+    VERIFICATION_POW_PREFIX,
     MAX_PEERS,
     MAX_MESSAGE_SIZE,
     MAX_RELAY_HOPS,

src/core/identity.js

@@ -1,5 +1,5 @@
 const crypto = require("crypto");
-const { POW_PREFIX } = require("../config/constants");
+const { MY_POW_PREFIX } = require("../config/constants");
 
 const generateIdentity = () => {
     const { publicKey, privateKey } = crypto.generateKeyPairSync("ed25519");
@@ -11,7 +11,7 @@ const generateIdentity = () => {
             .createHash("sha256")
             .update(id + nonce)
             .digest("hex");
-        if (hash.startsWith(POW_PREFIX)) break;
+        if (hash.startsWith(MY_POW_PREFIX)) break;
         nonce++;
     }
 

src/core/security.js

@@ -1,5 +1,5 @@
 const crypto = require("crypto");
-const { POW_PREFIX } = require("../config/constants");
+const { VERIFICATION_POW_PREFIX } = require("../config/constants");
 
 const verifyPoW = (id, nonce) => {
     if (!nonce) return false;
@@ -7,7 +7,7 @@ const verifyPoW = (id, nonce) => {
         .createHash("sha256")
         .update(id + nonce)
         .digest("hex");
-    return powHash.startsWith(POW_PREFIX);
+    return powHash.startsWith(VERIFICATION_POW_PREFIX);
 }
 
 const signMessage = (message, privateKey) => {