CN107613494B - Large-scale user sign-in method based on wireless equipment handshake protocol - Google Patents

Abstract

The invention provides a large-scale user sign-in method based on a wireless equipment handshake protocol, which comprises the following steps: (1) the server reads in user number information, creates an encrypted wireless local area network and waits for user connection; (2) a user joins a local area network through wireless equipment, inputs a user number as a network password, and the wireless equipment automatically sends a request message to a server through a handshake protocol; (3) the server filters out the authentication message, deciphers the number input by the user by a password collision method, and records the MAC address of the equipment in the user message; (4) the server marks the user as having checked in and rejects the user's connection. The invention has the advantages that the user does not need to install software, the server end only needs a common wireless router, and the number of users supported by the system is more than hundred.

Description

A large-scale user check-in method based on wireless device handshake protocol

technical field

The invention relates to the technical field of wireless networks, in particular to a large-scale user sign-in method based on a wireless device handshake protocol.

Background technique

User check-in is a method of confirming that a user actually appears in a designated scene, and the traditional approach is to require the user to sign on a piece of paper that lists the user's identification (eg, name). In daily life, teachers generally need to adopt some kind of sign-in method in order to obtain the attendance rate of students. However, when the number of users exceeds a certain number, the traditional check-in method will take too long to be of practical value. For example, when the number of students exceeds 100, this check-in method will take up a lot of class time.

The alternative is to utilize Bluetooth or WiFi. When using Bluetooth, the user should have a device with a Bluetooth module. When the device is close to the Bluetooth on the server side, the two can pair and exchange data, so that the server side can discover the user. The disadvantage of this method is caused by the limitations of the Bluetooth technology itself: the user is only perceived when the server is in the vicinity (generally within 10 meters), and the server can only connect to one user at a time. When the number of users increases, the whole process still takes a long time.

The traditional method of using WiFi to sign in is a connection-based method, that is, the user joins the local area network established by the server to establish a stable connection with the server, and sends any signal to the server through the local area network to achieve the purpose of sign-in. The disadvantage is that an ordinary wireless router (AP) can only support 30 clients to connect at the same time, and even an expensive enterprise-level wireless access terminal can only support about 60 clients to connect at the same time. Therefore, this method cannot be applied to scenarios with more than 100 people.

SUMMARY OF THE INVENTION

Purpose of the invention: In order to solve the above technical problems, the present invention proposes a large-scale user check-in method based on a wireless device handshake protocol, which is short-time-consuming and low-cost, and is suitable for large-scale user check-in.

Technical solution: In order to achieve the above technical effects, the present invention proposes a large-scale user check-in method based on a wireless device handshake protocol, which includes four stages:

(1) Server initialization phase:

The service provider assigns a unique sign-in number to each client in advance, and stores the sign-in number of each client in the server; the server creates an encrypted wireless local area network, and the encryption method of the encrypted wireless local area network is WEP;

(2) User access stage:

When the user accesses the encrypted wireless local area network through the client, a request message is sent to the server through the handshake protocol, and the request message includes the client's sign-in number;

(3) The server identifies the user stage:

(3-1) The server filters the interaction messages with the client, and looks for the request message containing the sign-in number;

(3-2) The server extracts the 51st to 53rd bytes of the message from the found request message as an initialization vector, denoted as 1;

(3-3) Enumerate all possible sign-in numbers and match with I one by one:

For any sign-in number U, after splicing it into I, the key K to be tested is formed. If the length of K does not reach 64 bits, 0 is added at the end of K so that K is 64 bits; use the key K to be tested according to The RC4 algorithm encrypts the content of 140 bytes starting from the 55th byte in the request message to obtain the encrypted message L; judge whether the last 4 bytes of L are the CRC32 checksum of the first 136 bytes of L If it is, the server determines that the sign-in number corresponding to the request message is U, and goes to step (3-4); otherwise, executes step (3-3) for the next sign-in number;

(3-4) The server extracts the MAC field of the request message, and records the MAC address and the sign-in number cracked in the step (3-3) to the local storage as the password of the corresponding client;

(3-5) The server marks the corresponding user as "arrived";

(4) Disconnection stage

When the "already arrived" user sends a request message to the server again, since the initial sign-in number in the request message is inconsistent with the password in the server's local storage, the server sends a connection rejection message to the user, and the user receives a connection rejection message. Abandon the connection after the message.

Further, the 27th byte of the request message is 0xB0, and the 28th byte is 0x40.

Further, the server has WiFi function, and the client is a wireless terminal with WiFi function.

Further, the server is composed of a computer and a router, and the client is a mobile phone, a notebook or a tablet computer with a WiFi transceiver function.

Beneficial effect: Compared with the prior art, the present invention has the following advantages:

(1) The number of supported users is large, and applications with more than 100 people can be supported.

(2) Convenient and easy to use. Users do not need to approach the server when checking in, and they can check in in the area covered by wireless signals. At the same time, users do not need to install any special software on the device.

(3) The deployment cost is low. Providers of check-in services do not need to purchase enterprise-level wireless routers, but can use ordinary wireless routers, which reduces deployment costs.

(4) Time-consuming is short. The method proposed by the present invention captures the message of the wireless device in the handshake process, and extracts information from it to sign in. The handshake phase is the first phase in which wireless devices interact and therefore takes less time.

Description of drawings

Figure 1 is a flowchart of the server cracking the user ID according to the handshake message.

Figure 2 is a graph showing the variation of the average check-in delay of a single user with the number of check-in users observed experimentally.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

When the present invention is implemented, the sign-in service provider needs a server with WiFi function, and the sign-in user needs a WiFi wireless terminal. The aforementioned server with WiFi function can be constituted by a wireless router and a computer. The aforementioned WiFi wireless terminal may be a device with a WiFi transceiver function, such as a mobile phone, a notebook computer, or a tablet computer.

The whole process is divided into four stages:

1. Server initialization phase

1.1 The service provider enters the check-in information into the server. The sign-in information at least includes the sign-in number used to distinguish the sign-in users, such as the student number.

1.2 The server creates an encrypted wireless LAN and waits for the user to connect. Select WEP as the encryption method. The specific encrypted password can be any combination of numbers or letters, which can be the same as the sign-in number of a certain user, or different from the sign-in number of any user.

2. User access stage

The user joins the encrypted wireless LAN through the client, and when prompted to enter the password, enter the user's sign-in number. At this time, the client will automatically send request packets to the server through the handshake protocol, and these request packets contain information related to the user's sign-in number.

3. The server identifies the user stage

The server filters the user's request message, extracts the message containing the user's sign-in number information, and uses the method of password collision to decipher the sign-in number entered by the user. Finally, the user sign-in number and the MAC address of the wireless device are recorded locally for use next time. The process of identifying users by the server is shown in Figure 1, and the details are as follows:

3.1 The server tracks the packets interacting with the client, and looks for the request packet containing the encryption information of the client. The 27th byte of this message is 0xB0, and the 28th byte is 0x40.

3.2 The server extracts the initialization vector from the previously found request message, denoted as I. The vector I is 24 bits and is located in the 51st to 53rd bytes of the message.

3.3 Enumerate all possible user sign-in numbers and match with I one by one: for sign-in number U, splicing it to I to form a 64-bit long key to be tested K (if the length of U does not meet the requirements, in 0 is added at the end to make the key under test 64 bits). Extract the content of 140 bytes starting from the 55th byte in the message, denoted as J, and encrypt the content of J with the key K to be tested according to the RC4 algorithm to obtain the encrypted message L. If the last 4 bytes A of the encrypted message L happen to be the CRC32 check code of the first 136 bytes B of the encrypted message L, it means that the user sign-in number corresponding to the request message is U, the exhaustion is over, and go to the step 3.4; otherwise, try the next check-in number, that is, perform step 3.3 for the next check-in number.

3.4 The server extracts the MAC field of the request message, and records the MAC address and the sign-in number cracked in 3.3 locally as the new password of the corresponding user.

3.5 The server marks the corresponding user as "arrived".

4. Disconnect Phase

When the "already arrived" user sends a request message to the server again, since the sign-in number in the request message is inconsistent with the new password in the server's local memory, the server sends a connection rejection message to the user, and the user receives a connection rejection message. Abandon the connection after the message. In this way, users who have signed in can be made to give up the wireless channel as soon as possible, saving wireless network resources and facilitating the sign-in of the next user.

Implementation case

Core^TM i5-4210M。服务器通过USB接口连接到型号为Netgearwg111 v2 RTL8187的无线网卡。服务器通过无线网卡创建了WEP加密无线局域网。用户的WiFi无线终端采用智能手机。实验测试了用户签到时延随用户数的变化情况。这里的用户签到时延为服务器接收到用户的第一个无线报文开始至服务器破解出用户的编号为止的时间。图2为实验结果，可以看到，用户签到时延随着用户数的增加而增加，但当用户数为300人时，单用户的平均签到时延依然低于1.2毫秒。A specific implementation case of the present invention is as follows. The server is a laptop running Ubuntu 16.04 operating system with a processor of

Core ^™ i5-4210M. The server is connected to a wireless network card model Netgearwg111 v2 RTL8187 through the USB interface. The server creates a WEP encrypted wireless LAN through the wireless network card. The user's WiFi wireless terminal adopts a smart phone. The experiment tests the change of user sign-in delay with the number of users. The user sign-in delay here is the time from when the server receives the first wireless message of the user until the server deciphers the user's number. Figure 2 shows the experimental results. It can be seen that the user check-in delay increases as the number of users increases, but when the number of users is 300, the average check-in delay for a single user is still lower than 1.2 milliseconds.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (4)

1. A large-scale user check-in method based on a wireless device handshake protocol is characterized by comprising four stages:

(1) a server initialization stage:

the service provider allocates a unique sign-in number for each client in advance, and stores the sign-in number of each client in the server; the server creates an encryption wireless local area network, and the encryption mode of the encryption wireless local area network is WEP;

(2) and a user access stage:

when a user accesses the encrypted wireless local area network through a client, a request message is sent to a server through a handshake protocol, and the request message contains the number of a sign-in person of the client;

(3) the server identifies the user stage:

(3-1) filtering interactive messages with the client by the server, and searching for a request message containing the number of the attendance register;

(3-2) the server extracts 51 st to 53 th bytes of the message from the found request message as an initialization vector, and the initialization vector is marked as I;

(3-3) exhausting all possible sign-in person numbers, and matching with I one by one:

splicing any one of the attendance number U to I to form a key K to be tested, and if the length of the K does not reach 64 bits, supplementing 0 at the tail of the K to enable the K to be 64 bits; encrypting the contents of 140 bytes from the 55 th byte in the request message by using a key K to be tested according to an RC4 algorithm to obtain an encrypted message L; judging whether the last 4 bytes of the L are CRC32 check codes of the first 136 bytes of the L; if yes, the server judges that the number of the signatory corresponding to the request message is U, and the step (3-4) is carried out; otherwise, executing step (3-3) for the next signer number;

(3-4) the server extracts the MAC field of the request message, and records the MAC address and the number of the check-in person cracked in the step (3-3) into a local memory as a password of the corresponding client;

(3-5) the server marks that the corresponding user is 'arrived';

(4) disconnection phase

When the user who has arrived sends the request message to the server again, the server sends a connection rejection message to the user because the initial sign-in number in the request message is inconsistent with the password in the local memory of the server, and the user abandons the connection after receiving the connection rejection message.

2. The large scale user check-in method based on wireless device handshake protocol as claimed in claim 1, wherein the 27 th byte of the request message is 0xB0, and the 28 th byte is 0x 40.

3. The large-scale user check-in method based on wireless device handshake protocol as claimed in claim 1, wherein the server has WiFi function, and the client is a wireless terminal with WiFi function.

4. The large-scale user check-in method based on the wireless device handshake protocol as claimed in claim 3, wherein the server is composed of a computer and a router, and the client is a mobile phone, a notebook or a tablet computer with WiFi transceiving function.

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