Update StakePoolVerificationKeyParser.java (#656)

Author: matiwinnetou

examples/StakePoolVerificationKeyParser.java

@@ -1,38 +1,69 @@
 //DEPS com.bloxbean.cardano:cardano-client-lib:0.6.3
-//JAVA 24
+//JAVA 21
 
 import static com.bloxbean.cardano.client.util.HexUtil.decodeHexString;
 import static com.bloxbean.cardano.client.util.HexUtil.encodeHexString;
 import static com.bloxbean.cardano.client.crypto.Bech32.encode;
 import static com.bloxbean.cardano.client.crypto.Bech32.decode;
 import static com.bloxbean.cardano.client.crypto.Blake2bUtil.blake2bHash224;
 
+/**
+ * Utility to convert a hex-encoded Stake Pool Verification Key (potentially CBOR-prefixed)
+ * into a Cardano Pool Hash (Blake2b-224 hash) and its Bech32 representation ("pool" HRP).
+ * * Usage: jbang StakePoolVerificationKeyParser.java <HEX_POOL_VERIFICATION_KEY>
+ */
 public class StakePoolVerificationKeyParser {
 
+    private static final int CBOR_PREFIX_LENGTH = 4;
+    private static final int STANDARD_KEY_LENGTH = 64; // Expected length for a standard hex key
+
     public static void main(String[] args) {
         if (args.length != 1) {
-            System.err.println("Bech32Pool usage, jbang Bech32Pool.java 582060afbe982faaee34b02ad0e75cd50d5d7a734f5daaf7b67bc8c492eb5299af2b");
+            // Throwing an exception is cleaner than printing to System.err and returning
+            throw new IllegalArgumentException(
+                "Usage: jbang StakePoolVerificationKeyParser.java <HEX_POOL_VERIFICATION_KEY>\n" +
+                "Example: jbang StakePoolVerificationKeyParser.java 582060afbe982faaee34b02ad0e75cd50d5d7a734f5daaf7b67bc8c492eb5299af2b"
+            );
         }
-        var poolVerificationKey = args[0];
-        var poolVerifcationKeyStripped = poolVerificationKey.substring(4);
 
-        System.out.println("pool_verification_key: " + poolVerificationKey);
-        System.out.println("pool_verification_key_stripped: " + poolVerifcationKeyStripped);
+        final var poolVerificationKey = args[0];
+        
+        if (poolVerificationKey.length() < STANDARD_KEY_LENGTH) {
+             throw new IllegalArgumentException(
+                "Invalid key length: Expected at least 64 hex characters (32 bytes), but got " + poolVerificationKey.length()
+            );
+        }
 
-        System.out.println("pool_verification_key_length: " + poolVerificationKey.length());
-        System.out.println("pool_verification_key_stripped_length: " + poolVerifcationKeyStripped.length());
+        // The key is assumed to be an extended format (e.g., CBOR-prefixed `5820...`), 
+        // requiring the first 4 hex characters (2 bytes) to be stripped before hashing.
+        final var poolVerifcationKeyStripped = poolVerificationKey.substring(CBOR_PREFIX_LENGTH);
 
-        var poolVerificationKeyBlake224Hash = blake2bHash224(decodeHexString(poolVerificationKey));
-        var poolVerificationKeyBlake224HashStripped = blake2bHash224(decodeHexString(poolVerifcationKeyStripped));
+        System.out.println("Input_Pool_Verification_Key: " + poolVerificationKey);
+        System.out.println("Input_Key_Length: " + poolVerificationKey.length());
 
-        var poolVerificationKeyBech32 = encode(poolVerificationKeyBlake224HashStripped, "pool");
+        // Log the stripped key only if it was actually stripped
+        if (poolVerificationKey.length() != poolVerifcationKeyStripped.length()) {
+            System.out.println("Stripped_Key: " + poolVerifcationKeyStripped);
+            System.out.println("Stripped_Key_Length: " + poolVerifcationKeyStripped.length());
+        }
 
-        System.out.println("pool_hash: " + encodeHexString(poolVerificationKeyBlake224HashStripped));
-        System.out.println("pool_hash_as_bech32: " + poolVerificationKeyBech32);
+        // Decode the stripped hex string to bytes and compute the Blake2b-224 hash.
+        // This 28-byte hash is the canonical Pool Hash.
+        final var keyBytesStripped = decodeHexString(poolVerifcationKeyStripped);
+        final var poolHashBytes = blake2bHash224(keyBytesStripped);
+        
+        final var poolHashHex = encodeHexString(poolHashBytes);
+        
+        // Encode the pool hash bytes using the "pool" Human-Readable Part (HRP)
+        final var poolHashBech32 = encode(poolHashBytes, "pool");
 
-        var decodedBech32 = decode(poolVerificationKeyBech32);
-        System.out.println("decoded_bech32_hrp: " + decodedBech32.hrp);
-        System.out.println("decoded_bech32_data: " + encodeHexString(decodedBech32.data));
-    }
+        System.out.println("--- Results ---");
+        System.out.println("Pool_Hash (Hex): " + poolHashHex);
+        System.out.println("Pool_Hash (Bech32): " + poolHashBech32);
 
+        // Optional: Decode the Bech32 string to verify
+        final var decodedBech32 = decode(poolHashBech32);
+        System.out.println("Decoded_Bech32_HRP: " + decodedBech32.hrp);
+        System.out.println("Decoded_Bech32_Data (Hex): " + encodeHexString(decodedBech32.data));
+    }
 }