AnyProxy
===================

AnyProxy is a fully configurable http/https proxy in NodeJS.

Ref: [中文文档](../cn)

Github:

* https://github.com/alibaba/anyproxy

Features:

* Offer you the ablity to handle http traffic by invoking a js module
* Intercept https
* GUI webinterface

Change Logs since 3.x:

* Support Promise and Generator in rule module
* Simplified interface in rule module
* A newly designed web interface

<img src="https://gw.alipayobjects.com/zos/rmsportal/JoxHUbVhXNedsPUUilnj.gif" width="1275px" />

# Getting Start
### install

To Debian and Ubuntu users, you may need to install `nodejs-legacy` at the same time

```bash
sudo apt-get install nodejs-legacy
```

Then install the AnyProxy

```bash
npm install -g anyproxy
```

### launch

* start AnyProxy in command line, with default port 8001

```bash
anyproxy
```

* now you can use http proxy server by 127.0.0.1:8001
* visit http://127.0.0.1:8002 to see the http requests

### options

* specify the port of http proxy

```bash
anyproxy --port 1080
```

### Use AnyProxy as an npm module

AnyProxy can be used as an npm module

> To enable https feature, please guide users to use `anyproxy-ca` in cli. Or use methods under `AnyProxy.utils.certMgr` to generate certificates.

* install

```bash
npm i anyproxy --save
```

* sample

```js
const AnyProxy = require('anyproxy');
const options = {
  port: 8001,
  rule: require('myRuleModule'),
  webInterface: {
    enable: true,
    webPort: 8002
  },
  throttle: 10000,
  forceProxyHttps: false,
  wsIntercept: false,
  silent: false
};
const proxyServer = new AnyProxy.ProxyServer(options);

proxyServer.on('ready', () => { /* */ });
proxyServer.on('error', (e) => { /* */ });
proxyServer.start();

//when finished
proxyServer.close();
```

* Class: AnyProxy.proxyServer
  * create a proxy server

    ```js
    const proxy = new AnyProxy.proxyServer(options)
    ```

  * `options`
    * `port` {number} required, port number of proxy server
    * `rule` {object} your rule module
    * `throttle` {number} throttle in kb/s, unlimited for default
    * `forceProxyHttps` {boolean} in force intercept all https request, default to `false`
    * `silent` {boolean} if keep silent in console, false for default `false`
    * `dangerouslyIgnoreUnauthorized` {boolean} if ignore certificate error in request, default to `false`
    * `wsIntercept` {boolean} whether to intercept websocket, default to `false`
    * `webInterface` {object} config for web interface
      * `enable` {boolean} if enable web interface, default to `false`
      * `webPort` {number} port number for web interface
  * Event: `ready`
    * emit when proxy server is ready
    * sample

    ```js
    proxy.on('ready', function() { })
    ```

  * Event: `error`
    * emit when error happened inside proxy server
    * sample

    ```js
    proxy.on('error', function() { })
    ```
  * Method: `start`
    * start proxy server
    * sample

    ```js
    proxy.start();
    ```
  * Method: `close`
    * close proxy server
    * sample

    ```js
    proxy.close();
    ```
* AnyProxy.utils.systemProxyMgr
  * manage the system proxy config. sudo password may be required
  * sample

  ```js
  // set 127.0.0.1:8001 as system http server
  AnyProxy.utils.systemProxyMgr.enableGlobalProxy('127.0.0.1', '8001');

  // disable global proxy server
  AnyProxy.utils.systemProxyMgr.disableGlobalProxy();
  ```

* AnyProxy.utils.certMgr
  * Manage certificates of AnyProxy
  * `AnyProxy.utils.certMgr.ifRootCAFileExists()`
    * detect if AnyProx rootCA exists
  * `AnyProxy.utils.certMgr.generateRootCA(callback)`
    * generate a rootCA
  * Sample

  ```js
    const AnyProxy = require('anyproxy');
    const exec = require('child_process').exec;

    if (!AnyProxy.utils.certMgr.ifRootCAFileExists()) {
      AnyProxy.utils.certMgr.generateRootCA((error, keyPath) => {
        // let users to trust this CA before using proxy
        if (!error) {
          const certDir = require('path').dirname(keyPath);
          console.log('The cert is generated at', certDir);
          const isWin = /^win/.test(process.platform);
          if (isWin) {
            exec('start .', { cwd: certDir });
          } else {
            exec('open .', { cwd: certDir });
          }
        } else {
          console.error('error when generating rootCA', error);
        }
      });
    }
  ```

# Proxy Https

* AnyProxy does NOT intercept https requests by default. To view decrypted info, you have to config the CA certificate.

> Under the hood, AnyProxy decryptes https requests by man-in-the-middle attack. Users have to trust the CA cert in advance. Otherwise, client side will issue errors about unsecure network.

* generate certifycates and intercept

```bash
anyproxy-ca #generate root CA. manually trust it after that.
anyproxy --intercept #launch anyproxy and intercept all https traffic
```

* [Appendix：how to trust CA](#config-certification)

# Proxy WebSocket

```bash
anyproxy --ws-intercept
```
> The `wss` requests will be handled automatically when the `HTTPS` intercept is turned on, but AnyProxy will not record the data by default. You need to specify the `--ws-intercept` to tell AnyProxy to record it.

# Rule Introduction

AnyProxy provides the ability to load your own rules written in javascript. With rule module, you could customize the logic to handle requests.

> Make sure your rule file is got from a trusted source. Otherwise, you may face some unknown security risk.

Rule module could do the following stuff:
* intercept and modify the request which is being sent
  * editable fields include request header, body, target address
* intercept and modify the response from server
  * editable fields include response status code, header, body
* intercept https requests, modify request and response

### sample

* Target
  * write a rule module to append some text to the response of GET http://httpbin.org/user-agent, and delay the response for 5 seconds

* Step 1，Write the rule file, save as sample.js

  ```js
  // file: sample.js
  module.exports = {
    summary: 'a rule to hack response',
    *beforeSendResponse(requestDetail, responseDetail) {
      if (requestDetail.url === 'http://httpbin.org/user-agent') {
        const newResponse = responseDetail.response;
        newResponse.body += '- AnyProxy Hacked!';

        return new Promise((resolve, reject) => {
          setTimeout(() => { // delay
            resolve({ response: newResponse });
          }, 5000);
        });
      }
    },
  };
  ```

* Step 2, start AnyProxy and load the rule file
  * run `anyproxy --rule sample.js`

* Step 3, test

  * use curl
    ```bash
    curl http://httpbin.org/user-agent --proxy http://127.0.0.1:8001
    ```

  * use browser. Point the http proxy of browser to 127.0.0.1:8001, then visit http://httpbin.org/user-agent

  * the expected response from proxy is

  ```
  {
    "user-agent": "curl/7.43.0"
  }
  - AnyProxy Hacked!
  ```

* Step 4, view the request log

  * visit http://127.0.0.1:8002, the request just sent should be listed here

### how does it work

* The flow chart is as follows

<img src="https://zos.alipayobjects.com/rmsportal/TWyNuSJtEZBdrdcOMRjE.png" width="550" />

* When got an http request, the entire process of proxy server is
  * AnyProxy collects all the quest info, include method, header, body
  * AnyProxy calls `beforeSendRequest` of the rule module. Rule module deal the request, return new request param or response content
  * If `beforeSendRequest` returns the response content, AnyProxy will send the response to client without sending to target server. The process ends here.
  * Send request to target server, collect response
  * Call `beforeSendResponse` of the rule module. Rule module deal the response data
  * Send response to client

* When AnyProxy get https request, it could replace the certificate and decrypt the request data
  * AnyProxy calls `beforeDealHttpsRequest` of the rule module
  * If the function returns `true`, AnyProxy will do the man-in-the-middle attack to it. Otherwise, the request will not be dealed.

### how to load rule module

* use local file
```bash
anyproxy --rule ./rule.js
```

* use an online rule file
```bash
anyproxy --rule https://sample.com/rule.js
```

* use an npm module
  * AnyProxy uses `require()` to load rule module. You could either load a local npm module or a global-installed one.

  ```bash
anyproxy --rule ./myRulePkg/ #local module
npm i -g myRulePkg && anyproxy --rule myRulePkg #global-installed module
  ```

# Rule module interface

A typical rule module is as follows. All the functions are optional, just write the part you are interested in.

```js
module.exports = {
  // introduction
  summary: 'my customized rule for AnyProxy',
  // intercept before send request to server
  *beforeSendRequest(requestDetail) { /* ... */ },
  // deal response before send to client
  *beforeSendResponse(requestDetail, responseDetail) { /* ... */ },
  // if deal https request
  *beforeDealHttpsRequest(requestDetail) { /* ... */ },
  // error happened when dealing requests
  *onError(requestDetail, error) { /* ... */ },
  // error happened when connect to https server
  *onConnectError(requestDetail, error) { /* ... */ }
};
```

> All functions in your rule file, except summary, are all driven by [co](https://www.npmjs.com/package/co) . They should be yieldable, i.e. return a promise or be a generator function.

### summary

#### summary

* Introduction of this rule file. AnyProxy will read this field and give some tip to user.

### beforeSendRequest
#### beforeSendRequest(requestDetail)

* Before sending request to server, AnyProxy will call `beforeSendRequest` with param `requestDetail`
* `requestDetail`
  * `protocol` {string} the protocol to use, http or https
  * `requestOptions` {object} the options of the request-to-go, a param of require('http').request . ref: https://nodejs.org/api/http.html#http_http_request_options_callback
  * `requestData` {object} request body
  * `url` {string} request url
  * `_req` {object} the native node.js request object
* e.g. When requesting  *anyproxy.io*, `requestDetail` is something like the following

  ```js
  {
    protocol: 'http',
    url: 'http://anyproxy.io/',
    requestOptions: {
      hostname: 'anyproxy.io',
      port: 80,
      path: '/',
      method: 'GET',
      headers: {
        Host: 'anyproxy.io',
        'Proxy-Connection': 'keep-alive',
        'User-Agent': '...'
      }
    },
    requestData: '...',
    _req: { /* ... */}
  }
  ```

* Any of these return values are valid
  * do nothing, and return null

  ```js
  return null;
  ```

  * modify the request protocol，i.e. force use https

  ```js
  return {
    protocol: 'https'
  };
  ```

  * modify request param

  ```js
  var newOption = Object.assign({}, requestDetail.requestOptions);
  newOption.path = '/redirect/to/another/path';
  return {
    requestOptions: newOption
  };
  ```
  * modify request body

  ```js
  return {
    requestData: 'my new request data'
    // requestOptions can also be used here
  };
  ```
  * give response to the client, not sending request any longer. `statusCode` `headers`are required is this situation.

  ```js
  return {
    response: {
      statusCode: 200,
      header: { 'content-type': 'text/html' },
      body: 'this could be a <string> or <buffer>'
    }
  };
  ```

### beforeSendResponse

#### beforeSendResponse(requestDetail, responseDetail)

* Before sending response to client, AnyProxy will call `beforeSendResponse` with param `requestDetail` `responseDetail`
* `requestDetail` is the same param as in `beforeSendRequest`
* `responseDetail`
  * `response` {object} the response from server, includes `statusCode` `header` `body`
  * `_res` {object} the native node.js response object
* e.g. When requesting *anyproxy.io*, `responseDetail` is something like the following

  ```js
  {
    response: {
      statusCode: 200,
      header: {
        'Content-Type': 'image/gif',
        Connection: 'close',
        'Cache-Control': '...'
      },
      body: '...'
    },
    _res: { /* ... */ }
  }
  ```
* Any of these return values are valid
  * do nothing, and return null

  ```js
  return null;
  ```

  * modify the response status code

  ```js
  var newResponse = Object.assign({}, responseDetail.response);
  newResponse.statusCode = 404;
  return {
    response: newResponse
  };
  ```

  * modify the response content

  ```js
  var newResponse = Object.assign({}, responseDetail.response);
  newResponse.body += '--from anyproxy--';
  return {
    response: newResponse
  };
  ```

### beforeDealHttpsRequest

#### beforeDealHttpsRequest(requestDetail)

* When receiving https request, AnyProxy will call `beforeDealHttpsRequest` with param `requestDetail`
* If configed with `forceProxyHttps` in launching, AnyProxy will skip calling this method
* Only by returning true, AnyProxy will try to replace the certificate and intercept the https request.
* `requestDetail`
  * `host` {string} the target host to request. Due to the request protocol, full url couldn't be got here
  * `_req` {object} the native node.js request object. The `_req` here refers to the CONNECT request.
* return value
  * `true` or `false`, whether AnyProxy should intercept the https request

### onError

#### onError(requestDetail, error)

* AnyProxy will call this method when an error happened in request handling.
* Errors usually are issued during requesting, e.g. DNS failure, request timeout
* `requestDetail` is the same one as in `beforeSendRequest`
* Any of these return values are valid
  * do nothing, and AnyProxy will response a default error page

  ```js
  return null;
  ```

  * return a customized error page

  ```js
  return {
    response: {
      statusCode: 200,
      header: { 'content-type': 'text/html' },
      body: 'this could be a <string> or <buffer>'
    }
  };
  ```

### onConnectError

#### onConnectError(requestDetail, error)

* AnyProxy will call this method when failed to connect target server in https request
* `requestDetail` is the same one as in `beforeDealHttpsRequest`
* no return value is required

# Rule Samples

* here are some samples about frequently used rule file
* try these samples by `anyproxy --rule http://....js`
* how to test with curl:
  * request the server directly `curl http://httpbin.org/`
  * request the server via proxy `curl http://httpbin.org/ --proxy http://127.0.0.1:8001`

### use local response
  * intercept the request towards http://httpbin.org , return the local-defined response

```bash
anyproxy --rule rule_sample/sample_use_local_response.js
```
```js
/* 
  sample: 
    intercept all requests toward httpbin.org, use a local response
  test:
    curl http://httpbin.org/user-agent --proxy http://127.0.0.1:8001
*/
module.exports = {
  *beforeSendRequest(requestDetail) {
    const localResponse = {
      statusCode: 200,
      header: { 'Content-Type': 'application/json' },
      body: '{"hello": "this is local response"}'
    };
    if (requestDetail.url.indexOf('http://httpbin.org') === 0) {
      return {
        response: localResponse
      };
    }
  },
};

```

### modify request header
  * modify the user-agent sent to httpbin.org

```bash
anyproxy --rule rule_sample/sample_modify_request_header.js
```
```js
/* 
  sample: 
    modify the user-agent in requests toward httpbin.org
  test:
    curl http://httpbin.org/user-agent --proxy http://127.0.0.1:8001
*/
module.exports = {
  *beforeSendRequest(requestDetail) {
    if (requestDetail.url.indexOf('http://httpbin.org') === 0) {
      const newRequestOptions = requestDetail.requestOptions;
      newRequestOptions.headers['User-Agent'] = 'AnyProxy/0.0.0';
      return {
        requestOptions: newRequestOptions
      };
    }
  },
};

```

### modify request body
  * modify the post body of http://httpbin.org/post

```bash
anyproxy --rule rule_sample/sample_modify_request_data.js
```
```js
/*
  sample:
    modify the post data towards http://httpbin.org/post
  test:
    curl -H "Content-Type: text/plain" -X POST -d 'original post data' http://httpbin.org/post --proxy http://127.0.0.1:8001
  expected response:
    { "data": "i-am-anyproxy-modified-post-data" }
*/
module.exports = {
  summary: 'Rule to modify request data',
  *beforeSendRequest(requestDetail) {
    if (requestDetail.url.indexOf('http://httpbin.org/post') === 0) {
      return {
        requestData: 'i-am-anyproxy-modified-post-data'
      };
    }
  },
};

```

### modify the request target
  * send all the request towards http://httpbin.org/ to http://httpbin.org/user-agent

```bash
anyproxy --rule rule_sample/sample_modify_request_path.js
```
```js
/*
  sample:
    redirect all https://httpbin.org/user-agent requests to http://localhost:8008/index.html
  test:
    curl https://httpbin.org/user-agent --proxy http://127.0.0.1:8001
  expected response:
    'hello world' from 127.0.0.1:8001/index.html
*/
module.exports = {
  *beforeSendRequest(requestDetail) {
    if (requestDetail.url.indexOf('https://httpbin.org/user-agent') === 0) {
      const newRequestOptions = requestDetail.requestOptions;
      requestDetail.protocol = 'http';
      newRequestOptions.hostname = '127.0.0.1'
      newRequestOptions.port = '8008';
      newRequestOptions.path = '/index.html';
      newRequestOptions.method = 'GET';
      return requestDetail;
    }
  },
  *beforeDealHttpsRequest(requestDetail) {
    return true;
  }
};

```

### modify request protocol
  * modify the http request towards http://httpbin.org to https

```bash
anyproxy --rule rule_sample/sample_modify_request_protocol.js
```
```js
/* 
  sample: 
    redirect all http requests of httpbin.org to https
  test:
    curl 'http://httpbin.org/get?show_env=1' --proxy http://127.0.0.1:8001
  expected response:
    { "X-Forwarded-Protocol": "https" }
*/
module.exports = {
  *beforeSendRequest(requestDetail) {
    if (requestDetail.url.indexOf('http://httpbin.org') === 0) {
      const newOption = requestDetail.requestOptions;
      newOption.port = 443;
      return {
        protocol: 'https',
        requestOptions: newOption
      };
    }
  }
};

```

### modify response status code
  * modify all status code from http://httpbin.org to 404

```bash
anyproxy --rule rule_sample/sample_modify_response_statuscode.js
```
```js
/* 
  sample: 
    modify all status code of http://httpbin.org/ to 404
  test:
    curl -I 'http://httpbin.org/user-agent' --proxy http://127.0.0.1:8001
  expected response:
    HTTP/1.1 404 Not Found
*/
module.exports = {
  *beforeSendResponse(requestDetail, responseDetail) {
    if (requestDetail.url.indexOf('http://httpbin.org') === 0) {
      const newResponse = responseDetail.response;
      newResponse.statusCode = 404;
      return {
        response: newResponse
      };
    }
  }
};

```

### modify the response header
  * add X-Proxy-By:AnyProxy to the response header from http://httpbin.org/user-agent

```bash
anyproxy --rule rule_sample/sample_modify_response_header.js
```
```js
/* 
  sample: 
    modify response header of http://httpbin.org/user-agent
  test:
    curl -I 'http://httpbin.org/user-agent' --proxy http://127.0.0.1:8001
  expected response:
    X-Proxy-By: AnyProxy
*/
module.exports = {
  *beforeSendResponse(requestDetail, responseDetail) {
    if (requestDetail.url.indexOf('http://httpbin.org/user-agent') === 0) {
      const newResponse = responseDetail.response;
      newResponse.header['X-Proxy-By'] = 'AnyProxy';
      return {
        response: newResponse
      };
    }
  }
};

```

### modify response data and delay
  * append some info to the response of http://httpbin.org/user-agent, then delay the response for 5 seconds.

```bash
anyproxy --rule rule_sample/sample_modify_response_data.js
```
```js
/* 
  sample: 
    modify response data of http://httpbin.org/user-agent
  test:
    curl 'http://httpbin.org/user-agent' --proxy http://127.0.0.1:8001
  expected response:
    { "user-agent": "curl/7.43.0" } -- AnyProxy Hacked! --
*/

module.exports = {
  *beforeSendResponse(requestDetail, responseDetail) {
    if (requestDetail.url === 'http://httpbin.org/user-agent') {
      const newResponse = responseDetail.response;
      newResponse.body += '-- AnyProxy Hacked! --';
      return new Promise((resolve, reject) => {
        setTimeout(() => { // delay the response for 5s
          resolve({ response: newResponse });
        }, 5000);
      });
    }
  },
};

```

# Config Certification

### Config root CA in OSX

* this kind of errors is usually caused by untrusted root CA

<img src="https://zos.alipayobjects.com/rmsportal/CBkLGYgvoHAYwNVAYkpk.png" width="450" />

> Warning: please keep your root CA safe since it may influence your system security.

install ：

* double click *rootCA.crt*

* add cert into login or system

<img src="https://zos.alipayobjects.com/rmsportal/bCwNUFFpvsmVuljQKrIk.png" width="350" />

* find the newly imported AnyProxy certificates, configured as **Always Trust**

<img src="https://zos.alipayobjects.com/rmsportal/HOmEElNGdoZEWFMLsTNT.png" width="700" />

### Config root CA in windows

<img src="https://t.alipayobjects.com/tfscom/T1D3hfXeFtXXXXXXXX.jpg" width="700" />


### Config OSX system proxy

* the config is in wifi - advanced

<img src="https://zos.alipayobjects.com/rmsportal/vduwhobSTypTfgniBvoa.png" width="500" />

### config http proxy server

* take Chrome extent [SwitchyOmega] as an example(https://chrome.google.com/webstore/detail/padekgcemlokbadohgkifijomclgjgif)为例

<img src="https://zos.alipayobjects.com/rmsportal/jIPZrKmqXRaSledQeJUJ.png" width="500" />

### trust root CA in iOS

* Click *Root CA* in web ui, and follow the instruction to install

<img src="https://zos.alipayobjects.com/rmsportal/BrugmMelGVysLDOIBblj.png" width="260" />

### trust root CA in iOS after 10.3

* Besides installing root CA, you have to "turn on" the certificate for web manually in *settings - general - about - Certificate Trust Settings*. Otherwire, safari will not trust the root CA generated by AnyProxy.

<img src="https://zos.alipayobjects.com/rmsportal/hVWkXHrzHmOKOtCKGUWx.png" width="500" />

### trust root CA in Android
First of all, you need to download the root CA by clicking *Root CA* in web ui, and then scan the QR code.
Installing CA in Android could be different based on the system, we list some common steps as below, but you can find the right way in you system with similar menu path.

* The downloaded CA file can be directly installed by clicking, this is the easist way
* You need to install the CA file from other menu, such as:
  * Settings -> Security & Location > Encryption & credentials -> Install from storage, and find your CA file to install
  * Settings -> Security -> Install from SD card, and find you CA file to install

There are several file extensions of CA file which may not be compatible with all kinds of Android phones. `.crt` file is the most popular, while a few systems could only use .cer file such as OPPO R15. In AnyProxy, you can choose the type of certificate you need before installing.

### config iOS/Android proxy server

* proxy settings are placed in wifi setting

* iOS

<img src="https://zos.alipayobjects.com/rmsportal/tLGqIozhffTccUgPakuw.png" width="260" />

* Android

<img src="https://zos.alipayobjects.com/rmsportal/YQtbQYVNuOszZGdAOauU.png" width="260" />


# FAQ


### Q: can not deal https request in rule module.
 * A: Any of these options could be used to change the way AnyProxy deall https requests
     1. config `--intercept` when luanching AnyProxy via cli, or use `forceProxyHttps` when using as an npm module
     2. place a `beforeDealHttpsRequest` function in your rule file and determine which request to intercept by your own.

### Q: get an error says *function is not yieldable*
 * A: Rule module is driven by [co](https://www.npmjs.com/package/co). The functions inside should  be yieldable, i.e. return a promise or be a generator function.

### Q: The connection is not private
AnyProxy will propmt this message when the certification of the site you're visiting is not issued by a common known CA. This happens when the certification is self-signed. If you know and trust it, you can ignore the error as below.

- If you run AnyProxy by command line
  Pass in the option `--ignore-unauthorized-ssl` to ignore the certification errors, please mind that the option will be active for all connections.

  ```bash
  anyproxy -i --ignore-unauthorized-ssl
  ```
- If you run AnyProxy by Nodejs
  Pass in the option `dangerouslyIgnoreUnauthorized:true`, like this:

  ```js
  const options = {
   ...,
   dangerouslyIgnoreUnauthorized: true
  };

  const anyproxyIns = new AnyProxy.ProxyCore(options);
  anyproxyIns.start();
  ```

  *This is also a global option, all certification errors will be ignored*

- With the help of AnyProxy Rule
  You can change the request with rule of course. For this scenario, all you need is to pass in an option to Nodejs `Http.rquest`, as we do in AnyProxy. A simple demo below:

  ```js
  module.exports = {
    *beforeSendRequest(requestDetail) {
      if (requestDetail.url.indexOf('https://the-site-you-know.com') === 0) {
        const newRequestOptions = requestDetail.requestOptions;
        // set rejectUnauthorized as false
        newRequestOptions.rejectUnauthorized = false;
        return {
          requestOptions: newRequestOptions
        };
      }
    },
  };
  ```

  And we get a bonous here, AnyProxy will only ignore the errors for the site(s) we want it to!
