From f6970a51b2b1974b90e43d3786e55dcef04d6a8e Mon Sep 17 00:00:00 2001
From: Haowei Wen <yushijinhun@gmail.com>
Date: Wed, 1 Nov 2023 18:47:45 +0800
Subject: [PATCH] Fix skin not displayed in Minecraft 1.20.2

---
 .../support/YggdrasilKeyTransformUnit.java    | 38 ++++++++++++++-----
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/src/main/java/moe/yushi/authlibinjector/transform/support/YggdrasilKeyTransformUnit.java b/src/main/java/moe/yushi/authlibinjector/transform/support/YggdrasilKeyTransformUnit.java
index 8145491..8212797 100644
--- a/src/main/java/moe/yushi/authlibinjector/transform/support/YggdrasilKeyTransformUnit.java
+++ b/src/main/java/moe/yushi/authlibinjector/transform/support/YggdrasilKeyTransformUnit.java
@@ -16,16 +16,17 @@
  */
 package moe.yushi.authlibinjector.transform.support;
 
+import static java.lang.invoke.MethodHandles.publicLookup;
+import static java.lang.invoke.MethodType.methodType;
 import static moe.yushi.authlibinjector.util.IOUtils.asBytes;
 import static moe.yushi.authlibinjector.util.Logging.Level.DEBUG;
 import static org.objectweb.asm.Opcodes.ALOAD;
 import static org.objectweb.asm.Opcodes.ARETURN;
 import static org.objectweb.asm.Opcodes.ASM9;
-import static org.objectweb.asm.Opcodes.GETFIELD;
-import static org.objectweb.asm.Opcodes.INVOKEVIRTUAL;
 import static org.objectweb.asm.Opcodes.IRETURN;
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.invoke.MethodHandle;
 import java.security.GeneralSecurityException;
 import java.security.InvalidKeyException;
 import java.security.PrivateKey;
@@ -61,7 +62,32 @@ public class YggdrasilKeyTransformUnit implements TransformUnit {
 	}
 
 	@CallbackMethod
-	public static boolean verifyPropertySignature(String propertyValue, String base64Signature) {
+	public static boolean verifyPropertySignature(Object propertyObj) {
+		String base64Signature;
+		String propertyValue;
+
+		try {
+			MethodHandle valueHandle;
+			try {
+				valueHandle = publicLookup().findVirtual(propertyObj.getClass(), "getValue", methodType(String.class));
+			} catch (NoSuchMethodException ignored) {
+				valueHandle = publicLookup().findVirtual(propertyObj.getClass(), "value", methodType(String.class));
+			}
+
+			MethodHandle signatureHandle;
+			try {
+				signatureHandle = publicLookup().findVirtual(propertyObj.getClass(), "getSignature", methodType(String.class));
+			} catch(NoSuchMethodException ignored) {
+				signatureHandle = publicLookup().findVirtual(propertyObj.getClass(), "signature", methodType(String.class));
+			}
+
+			base64Signature = (String) signatureHandle.invokeWithArguments(propertyObj);
+			propertyValue = (String) valueHandle.invokeWithArguments(propertyObj);
+		} catch (Throwable e) {
+			Logging.log(Level.ERROR, "Failed to get property attributes", e);
+			return false;
+		}
+
 		byte[] sig = Base64.getDecoder().decode(base64Signature);
 		byte[] data = propertyValue.getBytes();
 
@@ -145,9 +171,6 @@ public class YggdrasilKeyTransformUnit implements TransformUnit {
 						MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
 						mv.visitCode();
 						mv.visitVarInsn(ALOAD, 0);
-						mv.visitFieldInsn(GETFIELD, "com/mojang/authlib/properties/Property", "value", "Ljava/lang/String;");
-						mv.visitVarInsn(ALOAD, 0);
-						mv.visitFieldInsn(GETFIELD, "com/mojang/authlib/properties/Property", "signature", "Ljava/lang/String;");
 						ctx.invokeCallback(mv, YggdrasilKeyTransformUnit.class, "verifyPropertySignature");
 						mv.visitInsn(IRETURN);
 						mv.visitMaxs(-1, -1);
@@ -170,9 +193,6 @@ public class YggdrasilKeyTransformUnit implements TransformUnit {
 						MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
 						mv.visitCode();
 						mv.visitVarInsn(ALOAD, 1);
-						mv.visitMethodInsn(INVOKEVIRTUAL, "com/mojang/authlib/properties/Property", "getValue", "()Ljava/lang/String;", false);
-						mv.visitVarInsn(ALOAD, 1);
-						mv.visitMethodInsn(INVOKEVIRTUAL, "com/mojang/authlib/properties/Property", "getSignature", "()Ljava/lang/String;", false);
 						ctx.invokeCallback(mv, YggdrasilKeyTransformUnit.class, "verifyPropertySignature");
 						mv.visitInsn(IRETURN);
 						mv.visitMaxs(-1, -1);