Use /profiles/minecraft instead of /users/profiles/minecraft

The authlib-injector spect does not require /users/profiles/minecraft to
be implemented, so we should POST to /profiles/minecraft to get player
UUIDs.

libraries/launcher/legacy/org/prismlauncher/legacy/fix/online/OnlineModeFix.java

@@ -84,7 +84,7 @@ public static URLConnection openConnection(URL address, Proxy proxy) throws IOEx
         String accessToken = sessionId.split(":")[1];
 
         String uuid = null;
-        uuid = MojangApi.getUuid(user);
+        uuid = MojangApi.getUuid(user, proxy);
         if (uuid == null) {
             return new ByteArrayUrlConnection(("Couldn't find UUID of " + user).getBytes("utf-8"));
         }

libraries/launcher/legacy/org/prismlauncher/legacy/fix/online/SkinFix.java

@@ -80,7 +80,7 @@ static URLConnection openConnection(URL address, Proxy proxy) throws IOException
         if (capeOwner != null) {
             // since we do not need to process the image, open a direct connection bypassing
             // Handler
-            Texture texture = MojangApi.getTexture(MojangApi.getUuid(capeOwner), "CAPE");
+            Texture texture = MojangApi.getTexture(MojangApi.getUuid(capeOwner, proxy), "CAPE");
             if (texture == null)
                 return null;
 
@@ -91,7 +91,7 @@ static URLConnection openConnection(URL address, Proxy proxy) throws IOException
     }
 
     private static URLConnection getSkinConnection(String owner, Proxy proxy) throws IOException {
-        Texture texture = MojangApi.getTexture(MojangApi.getUuid(owner), "SKIN");
+        Texture texture = MojangApi.getTexture(MojangApi.getUuid(owner, proxy), "SKIN");
         if (texture == null)
             return null;
 

libraries/launcher/legacy/org/prismlauncher/legacy/utils/api/MojangApi.java

@@ -38,21 +38,36 @@
 import org.prismlauncher.legacy.utils.Base64;
 import org.prismlauncher.legacy.utils.api.ApiServers;
 import org.prismlauncher.legacy.utils.json.JsonParser;
+import org.prismlauncher.legacy.utils.url.UrlUtils;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.HttpURLConnection;
+import java.net.Proxy;
 import java.net.URL;
+import java.util.List;
 import java.util.Map;
 
 /**
  * Basic wrapper for Mojang's Minecraft API.
  */
 @SuppressWarnings("unchecked")
 public final class MojangApi {
-    public static String getUuid(String username) throws IOException {
-        try (InputStream in = new URL(ApiServers.getAccountURL() + "/users/profiles/minecraft/" + username).openStream()) {
-            Map<String, Object> map = (Map<String, Object>) JsonParser.parse(in);
-            return (String) map.get("id");
+    public static String getUuid(String username, Proxy proxy) throws IOException {
+        URL url = new URL(ApiServers.getAccountURL() + "/profiles/minecraft");
+        HttpURLConnection connection = (HttpURLConnection) UrlUtils.openConnection(url, proxy);
+        connection.setDoOutput(true);
+        connection.setRequestMethod("POST");
+        connection.setRequestProperty("Content-Type", "application/json");
+        connection.setRequestProperty("Accept", "application/json");
+        try (OutputStream os = connection.getOutputStream()) {
+            String payload = "[\"" + username + "\"]";
+            os.write(payload.getBytes("utf-8"));
+        }
+        try (InputStream in = connection.getInputStream()) {
+            List<Map<String, Object>> list = (List<Map<String, Object>>) JsonParser.parse(in);
+            return (String) list.get(0).get("id");
         }
     }