From dd4d2074ea9015564eafb019a9b113d87d66638d Mon Sep 17 00:00:00 2001
From: Carsten Otto <git@c-otto.de>
Date: Sat, 2 Apr 2022 17:58:20 +0200
Subject: [PATCH] remove expensive regular expression matching for pubkeys

---
 .../java/de/cotto/lndmanagej/model/Pubkey.java | 10 +++++-----
 .../de/cotto/lndmanagej/model/PubkeyTest.java  | 18 ++++++++++++++++--
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/model/src/main/java/de/cotto/lndmanagej/model/Pubkey.java b/model/src/main/java/de/cotto/lndmanagej/model/Pubkey.java
index 5a8cce5b..cd615c56 100644
--- a/model/src/main/java/de/cotto/lndmanagej/model/Pubkey.java
+++ b/model/src/main/java/de/cotto/lndmanagej/model/Pubkey.java
@@ -3,10 +3,10 @@ package de.cotto.lndmanagej.model;
 import java.util.Arrays;
 import java.util.HexFormat;
 import java.util.Locale;
-import java.util.regex.Pattern;
 
 public final class Pubkey implements Comparable<Pubkey> {
-    private static final Pattern PATTERN = Pattern.compile("[0-9a-fA-F]{66}");
+    private static final int EXPECTED_NUMBER_OF_BYTES = 33;
+
     private final String string;
     private final byte[] byteArray;
     private final int hash;
@@ -15,12 +15,12 @@ public final class Pubkey implements Comparable<Pubkey> {
         this.string = string;
         byteArray = HexFormat.of().parseHex(string);
         hash = Arrays.hashCode(byteArray);
+        if (byteArray.length != EXPECTED_NUMBER_OF_BYTES) {
+            throw new IllegalArgumentException();
+        }
     }
 
     public static Pubkey create(String string) {
-        if (!PATTERN.matcher(string).matches()) {
-            throw new IllegalArgumentException("Pubkey must have 66 hex characters");
-        }
         return new Pubkey(string.toLowerCase(Locale.US));
     }
 
diff --git a/model/src/test/java/de/cotto/lndmanagej/model/PubkeyTest.java b/model/src/test/java/de/cotto/lndmanagej/model/PubkeyTest.java
index 076bd1cd..4bc15342 100644
--- a/model/src/test/java/de/cotto/lndmanagej/model/PubkeyTest.java
+++ b/model/src/test/java/de/cotto/lndmanagej/model/PubkeyTest.java
@@ -20,14 +20,28 @@ class PubkeyTest {
     @Test
     void too_short() {
         assertThatIllegalArgumentException().isThrownBy(
-                () -> Pubkey.create("027abc123abc123abc123abc123123abc123abc123abc123abc123abc123abc12")
+                () -> Pubkey.create("027abc123abc123abc123abc123123abc123abc123abc123abc123abc123abc1")
+        );
+    }
+
+    @Test
+    void odd_number_of_characters() {
+        assertThatIllegalArgumentException().isThrownBy(
+                () -> Pubkey.create("0")
+        );
+    }
+
+    @Test
+    void not_hex() {
+        assertThatIllegalArgumentException().isThrownBy(
+                () -> Pubkey.create("fg")
         );
     }
 
     @Test
     void too_long() {
         assertThatIllegalArgumentException().isThrownBy(
-                () -> Pubkey.create("027abc123abc123abc123abc123123abc123abc123abc123abc123abc123abc123a")
+                () -> Pubkey.create("027abc123abc123abc123abc123123abc123abc123abc123abc123abc123abc123aa")
         );
     }