完成皮肤数据的RSA签名和皮肤安全检查

src/models/player.js

@@ -1,6 +1,7 @@
 import mongoose from 'mongoose'
 const { Schema } = mongoose
 import { uuidToNoSymboUUID } from '../generator.js'
+import { ImageSecurity } from '../secure.js'
 
 export const PlayerSchema = new Schema({
     username: String, // 有符号 UUID
@@ -89,13 +90,16 @@ export function getPlayerSerialization(player) {
         }
     }
 
+    const val = Buffer.from(JSON.stringify(textures)).toString('base64')
+
     return {
         uuid: uuidToNoSymboUUID(player.uuid),
         name: player.username,
         properties: [
             { 
                 name: "texturs",
-                value: Buffer.from(JSON.stringify(textures)).toString('base64')
+                value: val,
+                signature: ImageSecurity.sign(val),
             }
         ]
     }

src/secure.js

@@ -1,3 +1,89 @@
-export {
-    
+import { PNG } from 'pngjs'
+import fs from 'fs'
+import { createHash, createPrivateKey, createSign } from 'crypto'
+import { config } from './config.js'
+
+export const ImageSecurity =  {
+    createImageHash: async (path, isCape) => {
+        const png = await new Promise((resolve, reject) => {
+            fs.createReadStream(path).pipe(new PNG()).on('metadata', function(metadata) {
+                if(metadata.width * metadata.height > 40960) {
+                    reject('Image size exceeds 40960 pixels')
+                }
+            }).on('parsed', function(buff) {
+                resolve(this)
+            })
+        })
+
+        if (isCape) {
+            if(png.width % 64 === 0 && png.height % 32 === 0) {
+                return createHashInternal(png)
+            } else if (png.width % 22 === 0 && png.height % 17 === 0) {
+                const newPNG = new PNG({
+                    width: Math.ceil(png.width / 22),
+                    height: Math.ceil(png.height / 17),
+                })
+
+                for (let y = 0; y < png.height; y++) {
+                    for (let x = 0; x < png.width; x++) {
+                        const idx = (png.width * y + x) << 2
+                        newPNG.data[idx] = png.data[idx]
+                        newPNG.data[idx + 1] = png.data[idx + 1]
+                        newPNG.data[idx + 2] = png.data[idx + 2]
+                        newPNG.data[idx + 3] = png.data[idx + 3]
+                    }
+                }
+
+                for (let y = png.height; y < newPNG.height; y++) {
+                    for (let x = png.width; x < newPNG.width; x++) {
+                        const idx = (png.width * y + x) << 2
+                        newPNG.data[idx] = 0
+                        newPNG.data[idx + 1] = 0
+                        newPNG.data[idx + 2] = 0
+                        newPNG.data[idx + 3] = 0
+                    }
+                }
+
+                return createHashInternal(newPNG)
+            }
+        } else {
+            if(png.width % 64 === 0 && png.height % 32 === 0) {
+                const newPNG = new PNG({
+                    width: png.width,
+                    height: png.height
+                })
+
+                for (let y = 0; y < png.height; y++) {
+                    for (let x = 0; x < png.width; x++) {
+                        const idx = (png.width * y + x) << 2
+                        newPNG.data[idx] = png.data[idx]
+                        newPNG.data[idx + 1] = png.data[idx + 1]
+                        newPNG.data[idx + 2] = png.data[idx + 2]
+                        newPNG.data[idx + 3] = png.data[idx + 3]
+                    }
+                }
+
+                return createHashInternal(png)
+            } 
+        }
+
+        throw new Error('Invalid image size')
+    },
+    sign: async (data) => {
+        return createSign('RSA-SHA1').update(data).sign(createPrivateKey(config.privateKey), 'hex')
+    }
+}
+
+const createHashInternal = (png) => {
+    const hash = createHash('sha256')
+    for (let y = 0; y < png.height; y++) {
+        for (let x = 0; x < png.width; x++) {
+            const idx = (png.width * y + x) << 2
+            hash.update(png.data[idx].toString(16))
+            hash.update(png.data[idx + 1].toString(16))
+            hash.update(png.data[idx + 2].toString(16))
+            hash.update(png.data[idx + 3].toString(16))
+        }
+    }
+    return hash.digest('hex')
 }