先梳理下你的问题背景和细节：

相关模块 #

botbuilder-viber

平台信息 #

• 操作系统：Ubuntu
• Node版本：9.3.0
• NPM版本：5.5.1

代码示例 #

var viber = require('botbuilder-viber'); 
var express = require('express'); 
var bodyParser = require('body-parser'); 

var viberOptions = { 
    Token: '***', 
    Name: '***', 
    AvatarUrl: '***' 
} 

var viberChannel = new viber.ViberEnabledConnector(viberOptions); 
var expressApp = express(); 

expressApp.listen(process.env.port || process.env.PORT || 3978, function() { 
    console.log("Express server is running."); 
}); 

expressApp.use(bodyParser.urlencoded({ extended: false })); 
expressApp.use(bodyParser.json()); 

bot.connector(viber.ViberChannelId, viberChannel); 
expressApp.use('/viber/webhook', viberChannel.listen()); 

预期行为 #

服务运行无错误，正常处理Viber机器人消息

实际行为 #

每次从Viber发送消息时，都会重复触发两次以下错误：

TypeError [ERR_INVALID_ARG_TYPE]: The "data"参数必须为string、TypedArray或DataView类型
at Hmac.update (internal/crypto/hash.js:53:11)
at MessageValidator._calculateHmacFromMessage (/app/node_modules/viber-bot/lib/message/message-validator.js:17:54)
at MessageValidator.validateMessage (/app/node_modules/viber-bot/lib/message/message-validator.js:11:30)
at _app.use (/app/node_modules/viber-bot/lib/middleware.js:61:32)
at Layer.handle [as handle_request] (/app/node_modules/express/lib/router/layer.js:95:5)
at trim_prefix (/app/node_modules/express/lib/router/index.js:317:13)
at /app/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/app/node_modules/express/lib/router/index.js:335:12)
at next (/app/node_modules/express/lib/router/index.js:275:10)
at textParser (/app/node_modules/body-parser/lib/types/text.js:60:7)
at Layer.handle [as handle_request] (/app/node_modules/express/lib/router/layer.js:95:5)
at trim_prefix (/app/node_modules/express/lib/router/index.js:317:13)
at /app/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/app/node_modules/express/lib/router/index.js:335:12)
at next (/app/node_modules/express/lib/router/index.js:275:10)
at expressInit (/app/node_modules/express/lib/middleware/init.js:40:5)
at Layer.handle [as handle_request] (/app/node_modules/express/lib/router/layer.js:95:5)
at trim_prefix (/app/node_modules/express/lib/router/index.js:317:13)
at /app/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/app/node_modules/express/lib/router/index.js:335:12)
at next (/app/node_modules/express/lib/router/index.js:275:10)
at query (/app/node_modules/express/lib/middleware/query.js:45:5)
at Layer.handle [as handle_request] (/app/node_modules/express/lib/router/layer.js:95:5)
at trim_prefix (/app/node_modules/express/lib/router/index.js:317:13)
at /app/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/app/node_modules/express/lib/router/index.js:335:12)
at next (/app/node_modules/express/lib/router/index.js:275:10)
at Function.handle (/app/node_modules/express/lib/router/index.js:174:3)

问题根源 #

这个错误的核心原因是：Viber的消息签名验证需要读取原始的HTTP请求体（字符串格式），但你的代码提前用body-parser把请求体解析成了JSON对象。当viber-bot库尝试用解析后的对象去计算HMAC签名时，就会触发Hmac.update()的类型错误——它只接受字符串、TypedArray或DataView类型的数据。

至于你看到重复两次错误，大概率是Viber服务器在第一次验证失败后会重试一次请求，导致错误被触发两次。

解决方案 #

你需要调整中间件的执行顺序，让/viber/webhook路由保留原始请求体，这里提供两种可行的方案：

方案1：为Viber webhook单独配置原始数据中间件

在body-parser之前，先为/viber/webhook添加express.raw()中间件，确保该路由保留原始请求体：

var viber = require('botbuilder-viber'); 
var express = require('express'); 
var bodyParser = require('body-parser'); 

var viberOptions = { 
    Token: '***', 
    Name: '***', 
    AvatarUrl: '***' 
} 

var viberChannel = new viber.ViberEnabledConnector(viberOptions); 
var expressApp = express(); 

expressApp.listen(process.env.port || process.env.PORT || 3978, function() { 
    console.log("Express server is running."); 
}); 

// 先为viber webhook配置原始数据解析
expressApp.use('/viber/webhook', express.raw({ type: 'application/json' }));
// 再为其他路由配置普通的body解析
expressApp.use(bodyParser.urlencoded({ extended: false })); 
expressApp.use(bodyParser.json()); 

bot.connector(viber.ViberChannelId, viberChannel); 
expressApp.use('/viber/webhook', viberChannel.listen()); 

方案2：排除Viber webhook路径不被body-parser解析

如果你不想用raw中间件，可以让body-parser跳过/viber/webhook路径：

var viber = require('botbuilder-viber'); 
var express = require('express'); 
var bodyParser = require('body-parser'); 

var viberOptions = { 
    Token: '***', 
    Name: '***', 
    AvatarUrl: '***' 
} 

var viberChannel = new viber.ViberEnabledConnector(viberOptions); 
var expressApp = express(); 

expressApp.listen(process.env.port || process.env.PORT || 3978, function() { 
    console.log("Express server is running."); 
}); 

// 只对非/viber/webhook的路径使用body-parser
expressApp.use((req, res, next) => {
    if (req.path !== '/viber/webhook') {
        bodyParser.urlencoded({ extended: false })(req, res, next);
        bodyParser.json()(req, res, next);
    } else {
        next();
    }
});

bot.connector(viber.ViberChannelId, viberChannel); 
expressApp.use('/viber/webhook', viberChannel.listen()); 

验证方法 #

修改代码后重启服务，再从Viber发送消息测试，应该就不会再出现这个类型错误了。

内容的提问来源于stack exchange，提问作者Alexey Mikhailov