Mailbox system and method and device for accessing mailbox server

Abstract

The embodiment of the invention discloses a mailbox system and a method and device for accessing a mailbox server, and belongs to the technical field of Internet. The mailbox system comprises a mailbox server and a proxy server, the proxy server is used for establishing a first connection with the terminal and establishing a second connection with the mailbox server, the first connection and the second connection are connections based on a SOCKS5 protocol, and the first connection and the second connection are encrypted by adopting a TSL protocol; the proxy server is also used for receiving a mailbox access request sent by the terminal through the first connection, and forwarding the mailbox access request to the mailbox server through the second connection; the mailbox server is used for responding to the mailbox access request and sending a mailbox access response corresponding to the mailbox access request to the proxy server through the second connection; and the proxy server is also used for sending a mailbox access response to the terminal through the first connection. The method and the device have the advantages of convenience and safety at the same time.

Description

Technical Field

[0001] This application relates to the field of Internet technology, and in particular to an email system, a method and apparatus for accessing an email server. Background Technology

[0002] Since the advent of the internet age, email systems have played an indispensable role in people's work, study, and daily lives, providing essential information delivery services. Especially with the rapid development of mobile internet, people have become accustomed to receiving and browsing emails anytime, anywhere on their mobile devices.

[0003] However, for security reasons, external access to email servers is usually disabled, and access to email servers is restricted. This means that terminals can only access email servers when they are in an internal network environment. When terminals are in an external network environment, they will not be able to access email servers normally, thus eliminating the risk to email servers.

[0004] However, this restriction prevents terminals in external network environments from accessing the email server normally, resulting in insufficient convenience. Summary of the Invention

[0005] This application provides an email system, a method and apparatus for accessing an email server, which improves convenience and ensures transmission security, thus simultaneously achieving both convenience and security. The technical solution is as follows:

[0006] On the one hand, an email system is provided, which includes an email server and a proxy server. The email server and the proxy server are located in a first network environment. The email server disables external network access, while the proxy server enables external network access.

[0007] The proxy server is used to establish a first connection with the terminal and a second connection with the email server. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 protocol and are encrypted using the TSL protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email.

[0008] The proxy server is also configured to receive an email access request sent by the terminal through the first connection, and forward the email access request to the email server through the second connection;

[0009] The email server is configured to respond to the email access request by sending an email access response corresponding to the email access request to the proxy server via the second connection.

[0010] The proxy server is further configured to receive the email access response through the second connection and send the email access response to the terminal through the first connection. The terminal is configured to display the access result in the email client based on the email access response.

[0011] In one possible implementation, the proxy server is used for:

[0012] Perform a Transmission Control Protocol (TCP) handshake and a Transmission Control Protocol (TSL) handshake with the terminal;

[0013] Receive the SOCKS authentication request sent by the terminal, perform SOCKS authentication on the terminal, and send an authentication success response to the terminal after successful SOCKS authentication;

[0014] Receive a connection request sent by the terminal based on the authentication success response, the connection request carrying the address information of the email server;

[0015] Based on the address information, a TCP handshake and a TSL handshake are performed with the email server, and a connection completion response is sent to the terminal.

[0016] In one possible implementation, the proxy server is used for:

[0017] Receives a TCP connection request sent by the terminal, and in response to the TCP connection request, sends a TCP connection request confirmation to the terminal;

[0018] Receive the TCP acknowledgment sent by the terminal, the TCP acknowledgment being used to confirm the completion of the TCP handshake;

[0019] The terminal sends a first TSL greeting message, which carries a first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0020] In response to the first TSL greeting message, a second TSL greeting message is sent to the terminal. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key.

[0021] The terminal sends a key negotiation request, which carries a first session key determined by the terminal based on the first random number, the second random number, the first public key, and the terminal's second public key.

[0022] In response to the key negotiation request, a key negotiation response is sent to the terminal. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0023] On the other hand, a method for accessing a mail server is provided, the method being executed by a mail system including a mail server and a proxy server, the mail server and the proxy server being located in a first network environment, the mail server disabling external network access, and the proxy server enabling external network access; the method includes:

[0024] The proxy server establishes a first connection with the terminal and a second connection with the email server. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 socket security protocol and are encrypted using the TSL transport layer security protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is the operation of starting the email client, the operation of selecting any email, or the operation of sending an email.

[0025] The proxy server receives the email access request sent by the terminal through the first connection, and forwards the email access request to the email server through the second connection.

[0026] In response to the email access request, the email server sends the email access response corresponding to the email access request to the proxy server through the second connection;

[0027] The proxy server receives the email access response through the second connection and sends the email access response to the terminal through the first connection. The terminal is used to display the access result in the email client based on the email access response.

[0028] In one possible implementation, the proxy server establishes a first connection with the terminal and a second connection with the email server, including:

[0029] The proxy server performs a Transmission Control Protocol (TCP) handshake and a Transmission Control Protocol (TSL) handshake with the terminal.

[0030] The proxy server receives the SOCKS authentication request sent by the terminal, performs SOCKS authentication on the terminal, and sends an authentication success response to the terminal after successful SOCKS authentication.

[0031] The proxy server receives a connection request sent by the terminal based on the authentication success response, the connection request carrying the address information of the email server;

[0032] Based on the address information, the proxy server performs TCP and TLS handshakes with the email server and sends a connection completion response to the terminal.

[0033] In one possible implementation, the proxy server performs a Transmission Control Protocol (TCP) handshake and a Transmission Control Protocol (TLS) handshake with the terminal, including:

[0034] The proxy server receives the TCP connection request sent by the terminal and, in response to the TCP connection request, sends a TCP connection request confirmation to the terminal.

[0035] The proxy server receives a TCP acknowledgment sent by the terminal, which is used to confirm the completion of the TCP connection.

[0036] The proxy server receives a first TSL greeting message sent by the terminal. The first TSL greeting message carries a first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0037] In response to the first TSL greeting message, the proxy server sends a second TSL greeting message to the terminal. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key.

[0038] The proxy server receives a key negotiation request sent by the terminal, the key negotiation request carrying a first session key determined by the terminal based on the first random number, the second random number, the first public key, and the terminal's second public key;

[0039] In response to the key negotiation request, the proxy server sends a key negotiation response to the terminal. The key negotiation response carries a second session key determined based on the first session key and is used to confirm that the TSL handshake is complete.

[0040] On the other hand, a method for accessing a mail server is provided, wherein the method is executed by a proxy server, the mail server and the proxy server are in a first network environment, the mail server disables external network access, and the proxy server enables external network access; the method includes:

[0041] A first connection is established with the terminal, and a second connection is established with the email server. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 socket security protocol and are encrypted using the TSL transport layer security protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email.

[0042] The system receives an email access request from the terminal via the first connection and forwards the email access request to the email server via the second connection.

[0043] The system receives the email access response corresponding to the email access request through the second connection, and sends the email access response to the terminal through the first connection. The terminal is used to display the access result in the email client based on the email access response.

[0044] In one possible implementation, establishing the first connection with the terminal and the second connection with the email server includes:

[0045] Perform a Transmission Control Protocol (TCP) handshake and a Transmission Control Protocol (TSL) handshake with the terminal;

[0046] Receive the SOCKS authentication request sent by the terminal, perform SOCKS authentication on the terminal, and send an authentication success response to the terminal after successful SOCKS authentication;

[0047] Receive a connection request sent by the terminal based on the authentication success response, the connection request carrying the address information of the email server;

[0048] Based on the address information, a TCP handshake and a TSL handshake are performed with the email server, and a connection completion response is sent to the terminal.

[0049] In one possible implementation, the process of performing a Transmission Control Protocol (TCP) handshake and a Transmission Control Protocol (TSL) handshake with the terminal includes:

[0050] Receives a TCP connection request sent by the terminal, and in response to the TCP connection request, sends a TCP connection request confirmation to the terminal;

[0051] Receive a TCP acknowledgment sent by the terminal, the TCP acknowledgment being used to confirm the completion of the TCP connection;

[0052] The terminal sends a first TSL greeting message, which carries a first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0053] In response to the first TSL greeting message, a second TSL greeting message is sent to the terminal. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key.

[0054] The terminal sends a key negotiation request, which carries a first session key determined by the terminal based on the first random number, the second random number, the first public key, and the terminal's second public key.

[0055] In response to the key negotiation request, a key negotiation response is sent to the terminal. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0056] On the other hand, a method for accessing a mailbox server is provided, the method being executed by a terminal, the method comprising:

[0057] In response to an access operation in the email client, a first connection is established with a proxy server. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email. The proxy server is used to establish a second connection with the email server. The email server and the proxy server are in a first network environment. The email server disables external network access, and the proxy server enables external network access. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are connections based on the SOCKS5 socket security protocol, and the first connection and the second connection are encrypted using the TSL transport layer security protocol.

[0058] The proxy server sends an email access request to the proxy server through the first connection, and the proxy server receives an email access response corresponding to the email access request through the second connection.

[0059] Through the first connection, receive the email access response sent by the proxy server;

[0060] Based on the email access response, the access result is displayed in the email client.

[0061] In one possible implementation, displaying the access result in the email client based on the email access response includes:

[0062] If the access operation is to launch the email client, the email data carried in the email access response is displayed on the homepage of the email client; or,

[0063] If the access operation involves selecting any email, the email details data from the email in the email client's email details page will be displayed; or,

[0064] If the access operation is a mail sending operation, the mail client displays the sending notification carried in the mail access response.

[0065] In one possible implementation, establishing the first connection with the proxy server includes:

[0066] Perform TCP handshake and TLS handshake with the proxy server;

[0067] A SOCKS authentication request is sent to the proxy server, which receives the SOCKS authentication request sent by the terminal and performs SOCKS authentication on the terminal.

[0068] Receive the authentication success response sent by the proxy server after successful SOCKS authentication;

[0069] Based on the authentication pass response, a connection request is sent to the proxy server. The connection request carries the address information of the email server. The proxy server is used to perform TCP handshake and TLS handshake with the email server based on the address information.

[0070] Receive the connection completion response sent by the proxy server.

[0071] In one possible implementation, the TCP handshake and TLS handshake with the proxy server include:

[0072] Send a TCP connection request to the proxy server and receive a connection request confirmation from the proxy server;

[0073] Send a TCP acknowledgment to the proxy server; the TCP acknowledgment is used to confirm that the TCP handshake is complete.

[0074] Send a first TSL greeting message to the proxy server. The first TSL greeting message carries a first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0075] The proxy server receives a second TSL greeting message in response to the first TSL greeting message. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key.

[0076] Send a key negotiation request to the proxy server, the key negotiation request carrying a first session key determined by the terminal based on the first random number, the second random number, the first public key and the second public key of the terminal;

[0077] The proxy server receives a key negotiation response in response to the key negotiation request. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0078] On the other hand, an apparatus for accessing an email server is provided. The apparatus is configured on a proxy server, the email server and the proxy server are in a first network environment, the email server has external network access disabled, and the proxy server has external network access enabled; the apparatus includes:

[0079] A connection establishment module is used to establish a first connection with the terminal and a second connection with the email server. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 socket security protocol and are encrypted using the TSL transport layer security protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email.

[0080] The request sending and receiving module is used to receive the email access request sent by the terminal through the first connection, and to forward the email access request to the email server through the second connection;

[0081] The response sending and receiving module is used to receive the email access response corresponding to the email access request through the second connection, and to send the email access response to the terminal through the first connection. The terminal is used to display the access result in the email client based on the email access response.

[0082] In one possible implementation, the connection establishment module is configured to:

[0083] Perform a Transmission Control Protocol (TCP) handshake and a Transmission Control Protocol (TSL) handshake with the terminal;

[0084] Receive the SOCKS authentication request sent by the terminal, perform SOCKS authentication on the terminal, and send an authentication success response to the terminal after successful SOCKS authentication;

[0085] Receive a connection request sent by the terminal based on the authentication success response, the connection request carrying the address information of the email server;

[0086] Based on the address information, a TCP handshake and a TSL handshake are performed with the email server, and a connection completion response is sent to the terminal.

[0087] In one possible implementation, the connection establishment module is configured to:

[0088] Receives a TCP connection request sent by the terminal, and in response to the TCP connection request, sends a TCP connection request confirmation to the terminal;

[0089] Receive a TCP acknowledgment sent by the terminal, the TCP acknowledgment being used to confirm the completion of the TCP connection;

[0090] The terminal sends a first TSL greeting message, which carries a first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0091] In response to the first TSL greeting message, a second TSL greeting message is sent to the terminal. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key.

[0092] The terminal sends a key negotiation request, which carries a first session key determined by the terminal based on the first random number, the second random number, the first public key, and the terminal's second public key.

[0093] In response to the key negotiation request, a key negotiation response is sent to the terminal. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0094] On the other hand, an apparatus for accessing a mailbox server is provided, the apparatus being configured on a terminal, the apparatus comprising:

[0095] A connection establishment module is used to respond to an access operation in the email client and establish a first connection with a proxy server. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email. The proxy server is used to establish a second connection with the email server. The email server and the proxy server are in a first network environment. The email server disables external network access, and the proxy server enables external network access. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are connections based on the SOCKS5 socket security protocol, and the first connection and the second connection are encrypted using the TSL transport layer security protocol.

[0096] The request sending module is used to send an email access request to the proxy server through the first connection, and the proxy server is used to receive an email access response corresponding to the email access request through the second connection.

[0097] A response receiving module is configured to receive the email access response sent by the proxy server through the first connection;

[0098] The display module is used to display the access result in the email client based on the email access response.

[0099] In one possible implementation, the display module is used for:

[0100] If the access operation is to launch the email client, the email data carried in the email access response is displayed on the homepage of the email client; or,

[0101] If the access operation involves selecting any email, the email details data from the email in the email client's email details page will be displayed; or,

[0102] If the access operation is a mail sending operation, the mail client displays the sending notification carried in the mail access response.

[0103] In one possible implementation, the connection establishment module is configured to:

[0104] Perform TCP handshake and TLS handshake with the proxy server;

[0105] A SOCKS authentication request is sent to the proxy server, which receives the SOCKS authentication request sent by the terminal and performs SOCKS authentication on the terminal.

[0106] Receive the authentication success response sent by the proxy server after successful SOCKS authentication;

[0107] Based on the authentication pass response, a connection request is sent to the proxy server. The connection request carries the address information of the email server. The proxy server is used to perform TCP handshake and TLS handshake with the email server based on the address information.

[0108] Receive the connection completion response sent by the proxy server.

[0109] In one possible implementation, the connection establishment module is configured to:

[0110] Send a TCP connection request to the proxy server and receive a connection request confirmation from the proxy server;

[0111] Send a TCP acknowledgment to the proxy server; the TCP acknowledgment is used to confirm that the TCP handshake is complete.

[0112] Send a first TSL greeting message to the proxy server. The first TSL greeting message carries a first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0113] The proxy server receives a second TSL greeting message in response to the first TSL greeting message. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key.

[0114] Send a key negotiation request to the proxy server, the key negotiation request carrying a first session key determined by the terminal based on the first random number, the second random number, the first public key and the second public key of the terminal;

[0115] The proxy server receives a key negotiation response in response to the key negotiation request. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0116] On the other hand, a computer device is provided, the computer device including a processor and a memory, the memory storing at least one computer program, the at least one computer program being loaded and executed by the processor to perform the operations performed by the method of accessing a mailbox server as described above.

[0117] On the other hand, a computer-readable storage medium is provided that stores at least one computer program, which is loaded and executed by a processor to perform the operations performed by the method of accessing a mailbox server as described above.

[0118] On the other hand, a computer program product is provided, including a computer program loaded and executed by a processor to perform the operations performed by the method of accessing a mailbox server as described above.

[0119] This application provides a scheme for accessing an email server across networks. A proxy server connects the email server and the terminal across networks. Even when the email server has external network access disabled, it ensures that terminals in external network environments can still access the email server normally through the proxy server, improving convenience. Furthermore, the TLS protocol is used to encrypt the first connection between the proxy server and the terminal, as well as the second connection between the proxy server and the email server, ensuring transmission security. Therefore, this application simultaneously offers both convenience and security. Attached Figure Description

[0120] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0121] Figure 1 This is a schematic diagram of an email system provided in an embodiment of this application;

[0122] Figure 2 This is a flowchart illustrating a method for accessing a mail server according to an embodiment of this application;

[0123] Figure 3 This is a flowchart of another method for accessing a mailbox server provided in an embodiment of this application;

[0124] Figure 4 This is a flowchart illustrating the establishment of a first connection and a second connection, provided in an embodiment of this application.

[0125] Figure 5 This is a flowchart of another method for accessing a mailbox server provided in an embodiment of this application;

[0126] Figure 6 This is a flowchart of another method for accessing a mailbox server provided in an embodiment of this application;

[0127] Figure 7This is a schematic diagram of the structure of a device for accessing a mailbox server provided in an embodiment of this application;

[0128] Figure 8 This is a schematic diagram of another device for accessing a mailbox server provided in an embodiment of this application;

[0129] Figure 9 This is a schematic diagram of the structure of a terminal provided in an embodiment of this application;

[0130] Figure 10 This is a schematic diagram of the structure of a server provided in an embodiment of this application. Detailed Implementation

[0131] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0132] It is understood that the terms "first," "second," etc., used in this application may be used to describe various concepts herein, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of this application, first information may be referred to as second information, and similarly, second information may be referred to as first information.

[0133] Here, "at least two" means two or more pieces of information. For example, "at least two pieces of information" can be any integer number of pieces of information greater than or equal to two, such as two pieces of information, three pieces of information, etc. "Each" refers to each of the "at least two" pieces of information. For example, "each piece of information" refers to each of the "at least two" pieces of information. If the "at least two" pieces of information are three pieces of information, then "each piece of information" refers to each of the three pieces of information.

[0134] It should be noted that the information (including but not limited to user equipment information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals (including but not limited to signals transmitted between user terminals and other devices) involved in this application have all been fully authorized by the user or relevant parties, and the collection, use and processing of the relevant data shall comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0135] First, the concepts involved in this application are explained as follows:

[0136] 1. SOCKS5 (Socket Secure version 5) protocol: It is a network proxy protocol that establishes an encrypted communication channel between the client and the server to achieve a secure network connection. The SOCKS5 protocol supports TCP (Transmission Control Protocol) and UDP (User Data Protocol) protocols and provides an authentication mechanism.

[0137] 2. TLS (Transport Layer Security) protocol: This is an encryption protocol designed to ensure the security and privacy of internet communications. TLS is a successor to the SSL (Secure Sockets Layer) protocol and is defined and maintained by the IETF (Internet Engineering Task Force).

[0138] 3. Socket: A socket is a communication endpoint used to transmit data over a network, allowing data exchange between different computers or different processes on the same computer. Sockets are typically used to implement client-server architecture applications, where the client and server communicate through sockets.

[0139] Figure 1 This is a schematic diagram of an email system provided in an embodiment of this application, such as... Figure 1 As shown, the email system includes an email server 101 and a proxy server 102. Email server 101 and proxy server 102 are located in a first network environment. Email server 101 has external network access disabled, while proxy server 102 has external network access enabled. That is, devices in other network environments different from the first network environment cannot access email server 101, but are allowed to access proxy server 102.

[0140] Optionally, the email server 101 or the proxy server 102 is a server cluster or distributed system consisting of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0141] Proxy server 102 establishes a first connection with terminal 103 and a second connection with email server 101. Terminal 103 is in a second network environment different from the first network environment, so it cannot directly access email server 101 and needs to access email server 101 indirectly through proxy server 102.

[0142] The first and second connections are based on the SOCKS5 protocol and are encrypted using the TLS protocol. Terminal 103 sends an email access request to proxy server 102 via the first connection. Proxy server 102 receives the email access request via the first connection and forwards it to email server 101 via the second connection. Email server 101 responds to the email access request by sending an email access response to proxy server 102 via the second connection. Proxy server 102 then sends an email access response to terminal 103 via the first connection, ensuring that terminal 103 can access email server 101 even in an external network environment.

[0143] Optionally, the terminal 103 can be a smartphone, tablet, laptop, desktop computer, etc., but is not limited to these. The terminal 103 has an email client 111 installed and running. The email server 101 provides backend services for the email client 111, including email sending and receiving, email display, and other functions. This embodiment does not limit the functions of the email server 101. The terminal 103 can access the proxy server 102 through the email client 111, and thus indirectly access the email server 101.

[0144] For example, in addition to email processing functions, the email client 111 may also have social functions, such as chat functions, video resource sharing functions, etc., and may also have online shopping functions or live streaming functions, etc. This application embodiment does not limit these.

[0145] Those skilled in the art will understand that the number of terminals described above can be more or less. For example, there may be only one terminal, or there may be six, eight, or more terminals. This application does not limit the number of terminals or the type of device.

[0146] Optionally, a proxy server is used for:

[0147] Perform TCP and TLS handshakes with the terminal;

[0148] Receive the SOCKS authentication request sent by the terminal, perform SOCKS authentication on the terminal, and send an authentication success response to the terminal after successful SOCKS authentication.

[0149] The receiving terminal sends a connection request based on successful authentication, and the connection request carries the address information of the email server;

[0150] Based on the address information, a TCP handshake and a TLS handshake are performed with the email server, and a connection completion response is sent to the terminal.

[0151] Optionally, a proxy server is used for:

[0152] Receives a TCP connection request sent by the terminal, and responds to the TCP connection request by sending a TCP connection request confirmation to the terminal;

[0153] The receiving terminal sends a TCP acknowledgment, which is used to confirm the completion of the TCP handshake.

[0154] The receiving terminal sends a first TSL greeting message, which carries the first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0155] In response to the first TSL greeting message, a second TSL greeting message is sent to the terminal. The second TSL greeting message carries the second TSL version supported by the proxy server, the cipher suite, the second random number, and the first public key.

[0156] The receiving terminal sends a key negotiation request, which carries a first session key determined by the terminal based on a first random number, a second random number, a first public key, and the terminal's second public key;

[0157] In response to the key negotiation request, a key negotiation response is sent to the terminal. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0158] The processing procedures of the aforementioned email server 101, proxy server 102, and terminal 103 are detailed in the following method embodiments, and will not be described in detail here.

[0159] Figure 2 This is a flowchart illustrating a method for accessing a mail server according to an embodiment of this application. This embodiment is executed by a mail system, which includes a mail server and a proxy server. See also... Figure 2 The method includes:

[0160] 201. The proxy server establishes a first connection with the terminal and a second connection with the email server.

[0161] In this setup, the email server and proxy server reside in a first network environment, while the terminals are located in a second network environment, distinct from the first. Furthermore, the email server has external network access disabled, while the proxy server has it enabled. The first network environment can be considered the email server's dedicated internal network, while the second network environment can be any network environment different from the first, i.e., the external network environment. The first and external network environments are isolated from each other, but the proxy server, by enabling external network access, creates a transmission channel between the first and external network environments, allowing communication between the email server and terminals in the external network environment. Therefore, terminals in the external network environment cannot directly access the email server, but they can access the proxy server.

[0162] The first and second connections are based on the SOCKS5 protocol and are encrypted using the TLS protocol. The TLS-encrypted proxy server provides terminal connection capabilities, supporting TLS handshakes with the terminal to ensure transmission security at the transport layer. The proxy server also provides server connection capabilities, supporting TLS handshakes with the email server to ensure transmission security at the transport layer.

[0163] The first and second connections are established when an access operation is triggered in the email client on the terminal. This access operation could be launching the email client, selecting any email, or sending an email. In other words, the process of establishing the first and second connections is initiated when an access operation is triggered in the email client on the terminal.

[0164] 202. The proxy server receives the email access request sent by the terminal through the first connection, and forwards the email access request to the email server through the second connection.

[0165] In this embodiment of the disclosure, the terminal installs and runs an email client, and the proxy server establishes a first connection with the email client. The email client can access the proxy server, thereby accessing the email server through the proxy server.

[0166] Furthermore, the email access request corresponds to the access operation. In one possible implementation, the access operation is launching an email client. Launching the email client requires retrieving email data from the email server. Therefore, the email access request is used to request email data from the email account logged into the email client, including emails in the inbox, outbox, or favorites. Emails in the inbox can include emails previously received by the email account, as well as emails not yet received. Alternatively, the access operation is selecting any email. Selecting any email requires retrieving email details from the email server. Therefore, the email access request is used to request the email details of the clicked email. Or, the access operation is sending an email. The user composes email details in the email client and triggers the send operation, requiring the email to be sent through the email server. Therefore, the email access request is used to request sending the email. This email access request can carry the email details composed by the user in the email client, including the sender (i.e., the email account), recipient, email subject, and email content.

[0167] In this embodiment, since the email server does not have external network access enabled, the terminal is in a different network environment than the email server and therefore cannot directly establish a connection with it. Thus, the terminal first sends an email access request to the proxy server via a first connection, and the proxy server forwards the request to the email server via a second connection. Because the first and second connections are encrypted using the TLS protocol, communication security at the transport layer is guaranteed.

[0168] Optionally, to ensure the security of other devices in the first network environment, the proxy server can restrict terminals to accessing only the email server and not other devices in the first network environment. Therefore, when the email server receives an access request from the terminal via the first connection, if it determines that the target server for the access request is the email server, it sends the access request to the target server via the second connection. However, if it determines that the target server for the access request is not the email server, it does not send the access request to the target server but instead sends a denial response to the terminal, thus denying the terminal's access.

[0169] For example, the proxy server can set a whitelist to add email servers to the whitelist. Only email servers on the whitelist can be accessed by terminals in the external network environment, while servers not on the whitelist cannot be accessed by terminals in the external network environment.

[0170] 203. In response to the email access request, the email server sends the corresponding email access response to the proxy server through the second connection.

[0171] 204. The proxy server receives the email access response through the second connection and sends the email access response to the terminal through the first connection.

[0172] After receiving an email access request, the email server retrieves the corresponding email access response and returns it to the proxy server via a second connection. The proxy server receives the email access response via the second connection and then sends it to the terminal via the first connection. The terminal uses this email access response to display the access result in its email client.

[0173] In one possible implementation, the process of displaying the access results on the terminal may include any of the following:

[0174] 1. When the access operation is to launch the email client, display the email data carried in the email access response on the email client's homepage.

[0175] When the access operation is to launch an email client, the email access request is used to retrieve email data from the email account logged into that email client. The email server's response will then carry the email data, including emails from the account's inbox, outbox, or favorites. Emails in the inbox can include both previously received and unreceived emails. The terminal can then display this email data on the email client's homepage.

[0176] For example, if the email data includes emails in the inbox, the terminal displays an email list consisting of emails in the inbox on the homepage of the email client. It also displays the outbox and favorites on the homepage. When the user selects the outbox, the terminal can also display emails in the outbox, or when the user clicks on the favorites, the terminal can also display emails in the favorites.

[0177] 2. When the access operation is to select any email, display the email details data from the email access response on the email details page of the email client.

[0178] When the access operation involves selecting any email, the email access request is used to request the email details data from the clicked email. The email server will then return an email access response containing the email details data, which can then be displayed on the email details page on the terminal.

[0179] 3. When the access operation is to send an email, display the sending notification carried by the email access response in the email client.

[0180] When the access operation is to send an email, the mailbox access request is used to request the email to be sent. This request can carry email data composed by the user in the email client, including the sender (i.e., the email account), recipient, email subject, and email content. The mailbox server will execute the email sending operation and return a mailbox access response containing a sending notification. This notification indicates whether the email sending operation was successful. For example, the sending notification might be a successful sending notification, indicating that the email was sent successfully, or a sending failure notification, indicating that the email failed to send. The sending failure notification can also include the reason for the failure, so that the user understands why the email failed to send and can resend it.

[0181] This application provides a scheme for accessing an email server across networks. A proxy server connects the email server and the terminal across networks. Even when the email server has external network access disabled, it ensures that terminals in external network environments can still access the email server normally through the proxy server, improving convenience. Furthermore, the TLS protocol is used to encrypt the first connection between the proxy server and the terminal, as well as the second connection between the proxy server and the email server, ensuring transmission security. Therefore, this application simultaneously offers both convenience and security.

[0182] The above embodiments are a brief description of the method for accessing an email server. Based on the above embodiments, this application also provides another method for accessing an email server. Figure 3 This is a flowchart illustrating another method for accessing a mail server provided in this application embodiment. This application embodiment is executed by a mail system, which includes a mail server and a proxy server. See also... Figure 3 The method includes:

[0183] 301. The proxy server performs TCP handshake and TLS handshake with the terminal.

[0184] In this embodiment, the first connection between the proxy server and the terminal, and the second connection between the proxy server and the email server, are based on the SOCKS5 protocol. The SOCKS5 protocol allows communication between the proxy server and the target server, thereby enabling data exchange and sharing of network resources. The SOCKS5 protocol is based on the application layer of the TCP / IP protocol and can handle various types of requests, including HTTP (Hypertext Transfer Protocol), HTTPS (Hypertext Transfer Protocol Secure), and POP3 (Post Office Protocol-Version 3).

[0185] The first and second connections are established when an access operation is triggered in the email client on the terminal. This access operation could be launching the email client, selecting any email, or sending an email. In other words, the process of establishing the first and second connections is initiated when an access operation is triggered in the email client on the terminal.

[0186] When establishing the first connection based on the SOCKS5 protocol, the first step is for the proxy server and the terminal to perform a TCP handshake to establish a TCP connection. Furthermore, in this embodiment, to improve transmission security, the TSL protocol is also used for encryption. The TSL protocol is an application layer protocol that uses a transport layer TCP connection for communication. Therefore, a TSL handshake process is introduced after the TCP handshake process, improving the SOCKS5 protocol to ensure secure communication at the transport layer.

[0187] Optionally, see Figure 4 The process of a proxy server performing TCP handshakes and TLS handshakes with a terminal includes the following steps (3011-3016):

[0188] 3011. The proxy server receives a TCP connection request sent by the terminal and responds to the TCP connection request by sending a TCP connection request confirmation to the terminal.

[0189] The TCP connection request is used to request the establishment of a TCP connection with the proxy server, and the TCP connection request acknowledgment is used to indicate that the proxy server has received the TCP connection request. For example, the TCP connection request is a data packet carrying the SYN (Synchronize Sequence Numbers) flag, and the TCP connection request acknowledgment is a data packet carrying the SYN / ACK (Acknowledge character) flag.

[0190] 3012. The proxy server receives TCP acknowledgments sent by the terminal. TCP acknowledgments are used to confirm the completion of the TCP connection.

[0191] For example, the TCP acknowledgment indicates that the packet carries the ACK flag.

[0192] By executing steps 3011-3012 above, the TCP handshake process is completed.

[0193] 3013. The proxy server receives the first TSL greeting message sent by the terminal. The first TSL greeting message carries the first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0194] The first TSL greeting message is used to request the establishment of a connection with the proxy server based on the TSL protocol. The first TSL version refers to the version of the TSL protocol supported by the terminal. The first cipher suite list includes one or more cipher suites supported by the terminal. A cipher suite refers to a combination of algorithms used in the TSL protocol to encrypt data. The first random number refers to a random number generated by the terminal.

[0195] For example, the first TSL greeting message is the Client Hello message.

[0196] 3014. In response to the first TSL greeting message, the proxy server sends a second TSL greeting message, a first public key, and a greeting completion message to the terminal. The second TSL greeting message carries the second TSL version supported by the proxy server, the encryption suite, and the second random number of the first public key.

[0197] Here, the second TSL version refers to the version of the TSL protocol supported by the proxy server, the cipher suite refers to the cipher suite that the proxy server selects from the first cipher suite list and that the proxy server supports, the second random number refers to the random number generated by the proxy server, and the first public key refers to the public key used by the proxy server.

[0198] For example, the second TSL greeting message is a Server Hello message, which carries the second TSL version. The proxy server also sends a Certificate message to the terminal, which carries the first public key and may also include certificate holder information. The greeting completion message confirms that the greeting process in the TSL protocol has been completed; this message can be a Server Hello Done message.

[0199] 3015. The proxy server receives a key negotiation request sent by the terminal. The key negotiation request carries a first session key determined by the terminal based on a first random number, a second random number, a first public key, and a second public key of the terminal.

[0200] Optionally, after receiving the Certificate message from the proxy server, the terminal verifies the validity of the proxy server's certificate. If the certificate is valid, the terminal uses the certificate's public key to design the first public key to verify the certificate's data integrity and security. Then, the terminal determines a first session key based on a first random number, a second random number, the first public key, and the terminal's second public key. This first session key is the key used by the terminal in subsequent communications with the proxy server. The terminal sends a key negotiation request to the proxy server, carrying the first session key, indicating that the first session key has taken effect.

[0201] 3016. In response to the key negotiation request, the proxy server sends a key negotiation response to the terminal. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0202] The second session key is the key used by the proxy server in subsequent communications with the terminal. Optionally, the proxy server can determine the second session key based on the first session key, the first random number, and the second random number.

[0203] By executing steps 3013-3016 above, the TSL handshake process is completed.

[0204] 302. The proxy server receives the SOCKS authentication request sent by the terminal, performs SOCKS authentication on the terminal, and sends an authentication success response to the terminal after successful SOCKS authentication.

[0205] Optionally, before sending a SOCKS authentication request, the terminal first sends the authentication methods it supports to the proxy server. The proxy server can then select one authentication method it supports from the terminal's supported methods and send it to the terminal. Afterward, the terminal sends a SOCKS authentication request to the proxy server based on the authentication method negotiated by both parties.

[0206] The SOCKS authentication request can include the terminal's username and password, among other authentication information. The proxy server verifies the correctness of this information to confirm whether the terminal authentication is successful.

[0207] In another embodiment, if the terminal's SOCKS authentication fails, the proxy server disconnects from the terminal.

[0208] 303. The proxy server receives a connection request sent by the terminal based on successful authentication. The connection request carries the address information of the email server.

[0209] After receiving the authentication success response, the terminal sends a connection request to the proxy server. This connection request is used to request the proxy server to establish a connection with the email server. The connection request carries the address information of the email server, which may include the email server's address and port, etc.

[0210] 304. The proxy server performs TCP and TLS handshakes with the email server based on the address information and sends a connection completion response to the terminal.

[0211] The proxy server establishes a second connection by performing TCP and TLS handshakes with the email server based on the address information. Then, it sends a connection completion response to the terminal, thus establishing the first connection. At this point, both the first and second connections are complete. Because both the first and second connection handshakes utilize TLS, a secure and encrypted channel is established between the proxy server and the terminal, as well as between the proxy server and the email server. Data transmitted through this secure and encrypted channel will not be easily leaked.

[0212] The process of TCP handshake and TSL handshake between the proxy server and the email server is the same as that between the proxy server and the terminal, and will not be described in detail here.

[0213] It should be noted that the following conditions must be met during deployment:

[0214] First, deploy an email server and a proxy server in the first network environment. The email server has its external network access disabled, so it no longer has the ability to connect to the external network. The proxy server has its external network access enabled.

[0215] Second, provide a client-side security connection certificate to ensure that the connection between the email client and the proxy server is a TLS secure connection.

[0216] Third, provide a server-side security connection certificate to ensure that the connection between the proxy server and the email server is a TLS secure connection.

[0217] 305. The proxy server receives the email access request sent by the terminal through the first connection, and forwards the email access request to the email server through the second connection.

[0218] 306. In response to the email access request, the email server sends the corresponding email access response to the proxy server through a second connection.

[0219] 307. The proxy server receives the email access response through the second connection and sends the email access response to the terminal through the first connection. The terminal uses the email access response to display the access result in the email client.

[0220] Steps 305-307 above are the same as steps 202-204 above, and will not be repeated here.

[0221] In this embodiment of the application, both the first connection and the second connection are encrypted using the TSL protocol, which ensures the security of data transmission at the transport layer. Therefore, even if the transport protocol uses a non-SSL (Secure Socket Layer) encryption protocol, data leakage can still be prevented.

[0222] This application provides a scheme for accessing an email server across networks. A proxy server connects the email server and the terminal across networks. Even when the email server has external network access disabled, it ensures that terminals in external network environments can still access the email server normally through the proxy server, improving convenience. Furthermore, the TLS protocol is used to encrypt the first connection between the proxy server and the terminal, as well as the second connection between the proxy server and the email server, ensuring transmission security. Therefore, this application simultaneously offers both convenience and security.

[0223] Considering the potential vulnerabilities in email servers, which pose a significant challenge to data security, network control and restriction strategies can be employed to limit access to the email server and restrict email data access to the internal network environment (i.e., the first network environment mentioned above) in order to minimize security risks. However, convenience and security are contradictory. With the increasing convenience of mobile work, receiving or sending emails in external network environments has become a common need for users. How to enable terminals in external network environments to access the email server while disabling external network access is a problem that urgently needs to be solved. The embodiments of this application aim to resolve the aforementioned contradiction between convenience and security. Without changing the original network control and restriction strategy of the email server, i.e., without enabling external access to the email server, terminals can access the email server normally in external network environments, thereby realizing cross-network email sending and receiving functions.

[0224] This application embodiment uses a proxy server as an access intermediary, enabling the terminal to access the email server through the proxy server's forwarding function. In related technologies, proxy services based on the SOCKS5 protocol use a non-TLS handshake during TCP connection establishment, thus exposing the transmitted data in the transmission channel, resulting in poor security and security risks. In this application embodiment, a TLS handshake is implemented at the transport layer above the SOCKS5 protocol, and SOCKS5 protocol transmission is implemented at the data layer, thus improving the SOCKS5 protocol and enhancing security.

[0225] In summary, the embodiments of this application can simultaneously satisfy convenience and security, enabling terminals in an external network environment to access the email server normally under the premise of security and controllability, thereby providing an email user experience that combines convenience and security.

[0226] Based on the above embodiments, this application also provides another method for accessing a mailbox server. Figure 5 This is a flowchart illustrating another method for accessing a mail server provided in an embodiment of this application. This method is executed by a proxy server. The mail server and the proxy server are in a first network environment. The mail server disables external network access, while the proxy server enables external network access. (See also...) Figure 5 The method includes:

[0227] 501. The proxy server establishes a first connection with the terminal and a second connection with the email server. The terminal is in a second network environment that is different from the first network environment. The first connection and the second connection are based on the SOCKS5 protocol and are encrypted using the TSL protocol.

[0228] The first and second connections are established when an access operation is triggered in the email client on the terminal. This access operation could be launching the email client, selecting any email, or sending an email. In other words, the process of establishing the first and second connections is initiated when an access operation is triggered in the email client on the terminal.

[0229] 502. The proxy server receives the email access request sent by the terminal through the first connection, and forwards the email access request to the email server through the second connection.

[0230] 503. The proxy server receives the email access response corresponding to the email access request through the second connection, and sends the email access response to the terminal through the first connection. The terminal uses the email access response to display the access result in the email client.

[0231] The embodiments of this application are the same as those described above. Figure 3The steps performed by the proxy server in the illustrated embodiment are the same and will not be repeated here.

[0232] In one possible implementation, establishing a first connection with the terminal and a second connection with the email server includes:

[0233] Perform TCP and TSL handshakes with the terminal;

[0234] Receive the SOCKS authentication request sent by the terminal, perform SOCKS authentication on the terminal, and send an authentication success response to the terminal after successful SOCKS authentication.

[0235] The receiving terminal sends a connection request based on successful authentication, and the connection request carries the address information of the email server;

[0236] Based on the address information, a TCP handshake and a TLS handshake are performed with the email server, and a connection completion response is sent to the terminal.

[0237] In one possible implementation, the Transmission Control Protocol (TCP) handshake and Transmission Control Protocol (TSL) handshake are performed with the terminal, including:

[0238] Receives a TCP connection request sent by the terminal, and responds to the TCP connection request by sending a TCP connection request confirmation to the terminal;

[0239] The receiving terminal sends a TCP acknowledgment, which is used to confirm the completion of the TCP connection.

[0240] The receiving terminal sends a first TSL greeting message, which carries the first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0241] In response to the first TSL greeting message, a second TSL greeting message is sent to the terminal. The second TSL greeting message carries the second TSL version supported by the proxy server, the cipher suite, the second random number, and the first public key.

[0242] The receiving terminal sends a key negotiation request, which carries a first session key determined by the terminal based on a first random number, a second random number, a first public key, and the terminal's second public key;

[0243] In response to the key negotiation request, a key negotiation response is sent to the terminal. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0244] This application provides a scheme for accessing an email server across networks. A proxy server connects the email server and the terminal across networks. Even when the email server has external network access disabled, it ensures that terminals in external network environments can still access the email server normally through the proxy server, improving convenience. Furthermore, the TLS protocol is used to encrypt the first connection between the proxy server and the terminal, as well as the second connection between the proxy server and the email server, ensuring transmission security. Therefore, this application simultaneously offers both convenience and security.

[0245] Based on the above embodiments, this application also provides a method for accessing a mailbox server. Figure 6 This is a flowchart of another method for accessing a mailbox server provided in an embodiment of this application. This method is executed by a terminal. See [link to flowchart]. Figure 6 The method includes:

[0246] 601. The terminal responds to an access operation in the email client by establishing a first connection with the proxy server. The access operation is to launch the email client, select any email, or send an email. The proxy server is used to establish a second connection with the email server. The email server and the proxy server are in a first network environment. The email server disables external network access, while the proxy server enables external network access. The terminal is in a second network environment different from the first network environment. The first and second connections are based on the SOCKS5 secure socket protocol and are encrypted using the Transport Layer Security (TSL) protocol.

[0247] 602. The terminal sends an email access request to the proxy server through the first connection, and the proxy server receives the email access response corresponding to the email access request through the second connection.

[0248] Email access requests correspond to access operations. In one possible implementation, the access operation is launching an email client. Launching the email client requires retrieving email data from the email server. Therefore, this email access request is used to request email data from the email account logged into the email client, including emails in the inbox, outbox, or favorites. Emails in the inbox can include both previously received and unreceived emails. Alternatively, the access operation is selecting any email. Selecting any email requires retrieving email details from the email server. In this case, the email access request is used to request the email details of the clicked email. Or, the access operation is sending an email. The user composes email details in the email client and triggers the send operation, requiring the email to be sent through the email server. This email access request can carry the email details composed by the user in the email client, including the sender (i.e., the email account), recipient, subject, and content.

[0249] 603. The terminal receives the email access response sent by the proxy server through the first connection.

[0250] 604. The terminal responds to the email access request and displays the access result in the email client.

[0251] In one possible implementation, the process of displaying the access results on the terminal may include any of the following:

[0252] 1. When the access operation is to launch the email client, display the email data carried in the email access response on the email client's homepage.

[0253] When the access operation is to launch an email client, the email access request is used to retrieve email data from the email account logged into that email client. The email server's response will then carry the email data, including emails from the account's inbox, outbox, or favorites. Emails in the inbox can include both previously received and unreceived emails. The terminal can then display this email data on the email client's homepage.

[0254] For example, if the email data includes emails in the inbox, the terminal displays an email list consisting of emails in the inbox on the homepage of the email client. It also displays the outbox and favorites on the homepage. When the user selects the outbox, the terminal can also display emails in the outbox, or when the user clicks on the favorites, the terminal can also display emails in the favorites.

[0255] 2. When the access operation is to select any email, display the email details data from the email access response on the email details page of the email client.

[0256] When the access operation involves selecting any email, the email access request is used to request the email details data from the clicked email. The email server will then return an email access response containing the email details data, which can then be displayed on the email details page on the terminal.

[0257] 3. When the access operation is to send an email, display the sending notification carried by the email access response in the email client.

[0258] When the access operation is to send an email, the mailbox access request is used to request the email to be sent. This request can carry email data composed by the user in the email client, including the sender (i.e., the email account), recipient, email subject, and email content. The mailbox server will execute the email sending operation and return a mailbox access response containing a sending notification. This notification indicates whether the email sending operation was successful. For example, the sending notification might be a successful sending notification, indicating that the email was sent successfully, or a sending failure notification, indicating that the email failed to send. The sending failure notification can also include the reason for the failure, so that the user understands why the email failed to send and can resend it.

[0259] The embodiments of this application are the same as those described above. Figure 3 The steps executed by the terminal in the illustrated embodiment are similar and will not be repeated here.

[0260] In one possible implementation, establishing a first connection with the proxy server includes:

[0261] Perform TCP and TLS handshakes with the proxy server;

[0262] The terminal sends a SOCKS authentication request to the proxy server, which receives the SOCKS authentication request and performs SOCKS authentication on the terminal.

[0263] Receive the authentication success response sent by the proxy server after successful SOCKS authentication;

[0264] Based on the successful authentication response, a connection request is sent to the proxy server. The connection request carries the address information of the email server. The proxy server uses the address information to perform TCP handshake and TLS handshake with the email server.

[0265] Received a connection completion response from the proxy server.

[0266] In one possible implementation, the TCP handshake and TLS handshake with the proxy server include:

[0267] Send a TCP connection request to the proxy server and receive a connection request confirmation from the proxy server;

[0268] Send a TCP acknowledgment to the proxy server. The TCP acknowledgment is used to confirm that the TCP handshake is complete.

[0269] Send a first TSL greeting message to the proxy server. The first TSL greeting message carries the first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0270] The proxy server receives a second TSL greeting message in response to the first TSL greeting message. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key.

[0271] Send a key negotiation request to the proxy server. The key negotiation request carries a first session key determined by the terminal based on a first random number, a second random number, a first public key, and the terminal's second public key.

[0272] The receiving proxy server responds to the key negotiation request by sending a key negotiation response. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0273] This application provides a scheme for accessing an email server across networks. A proxy server connects the email server and the terminal across networks. Even when the email server has external network access disabled, it ensures that terminals in external network environments can still access the email server normally through the proxy server, improving convenience. Furthermore, the TLS protocol is used to encrypt the first connection between the proxy server and the terminal, as well as the second connection between the proxy server and the email server, ensuring transmission security. Therefore, this application simultaneously offers both convenience and security.

[0274] Figure 7 This is a schematic diagram of a device for accessing an email server provided in an embodiment of this application. The device is configured on a proxy server, and the email server and proxy server are in a first network environment. The email server has external network access disabled, while the proxy server has external network access enabled; see also... Figure 7 The device includes:

[0275] The connection establishment module 701 is used to establish a first connection with the terminal and a second connection with the email server. The terminal is in a second network environment that is different from the first network environment. The first connection and the second connection are based on the SOCKS5 socket security protocol and are encrypted using the TSL transport layer security protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is the operation of starting the email client, the operation of selecting any email, or the operation of sending an email.

[0276] The request sending and receiving module 702 is used to receive email access requests sent by the terminal through the first connection, and to forward email access requests to the email server through the second connection.

[0277] The response sending and receiving module 703 is used to receive the email access response corresponding to the email access request through the second connection, and send the email access response to the terminal through the first connection. The terminal is used to display the access result in the email client based on the email access response.

[0278] In one possible implementation, the connection establishment module 701 is used for:

[0279] Perform TCP and TSL handshakes with the terminal;

[0280] Receive the SOCKS authentication request sent by the terminal, perform SOCKS authentication on the terminal, and send an authentication success response to the terminal after successful SOCKS authentication.

[0281] The receiving terminal sends a connection request based on successful authentication, and the connection request carries the address information of the email server;

[0282] Based on the address information, a TCP handshake and a TLS handshake are performed with the email server, and a connection completion response is sent to the terminal.

[0283] In one possible implementation, the connection establishment module 701 is used for:

[0284] Receives a TCP connection request sent by the terminal, and responds to the TCP connection request by sending a TCP connection request confirmation to the terminal;

[0285] The receiving terminal sends a TCP acknowledgment, which is used to confirm the completion of the TCP connection.

[0286] The receiving terminal sends a first TSL greeting message, which carries the first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0287] In response to the first TSL greeting message, a second TSL greeting message is sent to the terminal. The second TSL greeting message carries the second TSL version supported by the proxy server, the cipher suite, the second random number, and the first public key.

[0288] The receiving terminal sends a key negotiation request, which carries a first session key determined by the terminal based on a first random number, a second random number, a first public key, and the terminal's second public key;

[0289] In response to the key negotiation request, a key negotiation response is sent to the terminal. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0290] This application provides a scheme for accessing an email server across networks. A proxy server connects the email server and the terminal across networks. Even when the email server has external network access disabled, it ensures that terminals in external network environments can still access the email server normally through the proxy server, improving convenience. Furthermore, the TLS protocol is used to encrypt the first connection between the proxy server and the terminal, as well as the second connection between the proxy server and the email server, ensuring transmission security. Therefore, this application simultaneously offers both convenience and security.

[0291] It should be noted that the apparatus for accessing an email server provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the proxy server can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus for accessing an email server provided in the above embodiments and the method embodiments for accessing an email server belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0292] Figure 8 This is a schematic diagram of another device for accessing a mailbox server provided in an embodiment of this application. The device is configured on a terminal; see [link to diagram]. Figure 8 The device includes:

[0293] The connection establishment module 801 is used to respond to access operations in the email client and establish a first connection with the proxy server. The access operation is to start the email client, select any email, or send an email. The proxy server is used to establish a second connection with the email server. The email server and the proxy server are in a first network environment. The email server has closed external network access, and the proxy server has opened external network access. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 secure socket protocol and are encrypted using the Transport Layer Security (TLS) protocol.

[0294] The request sending module 802 is used to send an email access request to the proxy server through a first connection, and the proxy server is used to receive the email access response corresponding to the email access request through a second connection.

[0295] The response receiving module 803 is used to receive an email access response sent by the proxy server through the first connection;

[0296] Display module 804 is used to display the access results in the email client based on the email access response.

[0297] In one possible implementation, the display module 804 is used for:

[0298] If the access action is to launch an email client, the email data carried in the email access response will be displayed on the email client's homepage; or,

[0299] If the access operation involves selecting any email, the email details data from the email access response will be displayed on the email details page of the email client; or,

[0300] When the access operation is to send an email, the email client displays the sending notification carried in the email access response.

[0301] In one possible implementation, the connection establishment module 801 is used for:

[0302] Perform TCP and TLS handshakes with the proxy server;

[0303] The terminal sends a SOCKS authentication request to the proxy server, which receives the SOCKS authentication request and performs SOCKS authentication on the terminal.

[0304] Receive the authentication success response sent by the proxy server after successful SOCKS authentication;

[0305] Based on the successful authentication response, a connection request is sent to the proxy server. The connection request carries the address information of the email server. The proxy server uses the address information to perform TCP handshake and TLS handshake with the email server.

[0306] Received a connection completion response from the proxy server.

[0307] In one possible implementation, the connection establishment module 801 is used for:

[0308] Send a TCP connection request to the proxy server and receive a connection request confirmation from the proxy server;

[0309] Send a TCP acknowledgment to the proxy server. The TCP acknowledgment is used to confirm that the TCP handshake is complete.

[0310] Send a first TSL greeting message to the proxy server. The first TSL greeting message carries the first TSL version supported by the terminal, a list of encryption suites, and a first random number.

[0311] The proxy server receives a second TSL greeting message in response to the first TSL greeting message. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key.

[0312] Send a key negotiation request to the proxy server. The key negotiation request carries a first session key determined by the terminal based on a first random number, a second random number, a first public key, and the terminal's second public key.

[0313] The receiving proxy server responds to the key negotiation request by sending a key negotiation response. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

[0314] This application provides a scheme for accessing an email server across networks. A proxy server connects the email server and the terminal across networks. Even when the email server has external network access disabled, it ensures that terminals in external network environments can still access the email server normally through the proxy server, improving convenience. Furthermore, the TLS protocol is used to encrypt the first connection between the proxy server and the terminal, as well as the second connection between the proxy server and the email server, ensuring transmission security. Therefore, this application simultaneously offers both convenience and security.

[0315] It should be noted that the apparatus for accessing an email server provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the terminal can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus for accessing an email server provided in the above embodiments and the method embodiments for accessing an email server belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0316] This application also provides a computer device, which includes a processor and a memory. The memory stores at least one computer program, which is loaded and executed by the processor to perform the operations of the method for accessing the email server described in the above embodiments.

[0317] Optionally, the computer device is provided as a terminal. Figure 9 A schematic diagram of the structure of a terminal 900 provided in an exemplary embodiment of this application is shown.

[0318] The terminal 900 includes a processor 901 and a memory 902.

[0319] Processor 901 may include one or more processing cores, such as a quad-core processor, an octa-core processor, etc. Processor 901 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field Programmable Gate Array), and PLA (Programmable Logic Array). Processor 901 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 901 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, processor 901 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0320] The memory 902 may include one or more computer-readable storage media, which may be non-transitory. The memory 902 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory 902 are used to store at least one computer program, which is used by the processor 901 to implement the method for accessing a mailbox server provided in the method embodiments of this application.

[0321] In some embodiments, the terminal 900 may also optionally include a peripheral device interface 903 and at least one peripheral device. The processor 901, memory 902, and peripheral device interface 903 can be connected via a bus or signal line. Each peripheral device can be connected to the peripheral device interface 903 via a bus, signal line, or circuit board. Optionally, the peripheral device includes at least one of a radio frequency circuit 904, a display screen 905, a camera assembly 906, and a power supply 907.

[0322] Peripheral device interface 903 can be used to connect at least one I / O (Input / Output) related peripheral device to processor 901 and memory 902. In some embodiments, processor 901, memory 902 and peripheral device interface 903 are integrated on the same chip or circuit board; in some other embodiments, any one or two of processor 901, memory 902 and peripheral device interface 903 can be implemented on separate chips or circuit boards, which is not limited in this embodiment.

[0323] The radio frequency (RF) circuit 904 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The RF circuit 904 communicates with communication networks and other communication devices via electromagnetic signals. The RF circuit 904 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals back into electrical signals. Optionally, the RF circuit 904 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a user identity module card, etc. The RF circuit 904 can communicate with other devices through at least one wireless communication protocol. This wireless communication protocol includes, but is not limited to: metropolitan area networks (MANs), various generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks (WLANs), and / or WiFi (Wireless Fidelity) networks. In some embodiments, the RF circuit 904 may also include circuitry related to NFC (Near Field Communication), which is not limited in this application.

[0324] Display screen 905 is used to display a UI (User Interface). This UI may include graphics, text, icons, videos, and any combination thereof. When display screen 905 is a touch display screen, it also has the ability to collect touch signals on or above its surface. These touch signals can be input as control signals to processor 901 for processing. In this case, display screen 905 can also be used to provide virtual buttons and / or a virtual keyboard, also known as soft buttons and / or a soft keyboard. In some embodiments, there may be one display screen 905, disposed on the front panel of terminal 900; in other embodiments, there may be at least two display screens 905, disposed on different surfaces of terminal 900 or in a folded design; in other embodiments, display screen 905 may be a flexible display screen, disposed on a curved or folded surface of terminal 900. Furthermore, display screen 905 may be configured as a non-rectangular irregular shape, i.e., a non-rectangular screen. Display screen 905 may be made of materials such as LCD (Liquid Crystal Display) or OLED (Organic Light-Emitting Diode).

[0325] The camera assembly 906 is used to acquire images or videos. Optionally, the camera assembly 906 includes a front-facing camera and a rear-facing camera. The front-facing camera is disposed on the front panel of the terminal 900, and the rear-facing camera is disposed on the back of the terminal 900. In some embodiments, there are at least two rear-facing cameras, which are any one of a main camera, a depth-sensing camera, a wide-angle camera, and a telephoto camera, to achieve background blurring by fusion of the main camera and the depth-sensing camera, panoramic shooting by fusion of the main camera and the wide-angle camera, VR (Virtual Reality) shooting, or other fusion shooting functions. In some embodiments, the camera assembly 906 may also include a flash. The flash may be a single-color temperature flash or a dual-color temperature flash. A dual-color temperature flash refers to a combination of a warm light flash and a cool light flash, which can be used for light compensation at different color temperatures.

[0326] Power supply 907 is used to power the various components in terminal 900. Power supply 907 can be AC ​​power, DC power, a disposable battery, or a rechargeable battery. When power supply 907 includes a rechargeable battery, the rechargeable battery can support wired or wireless charging. The rechargeable battery can also be used to support fast charging technology.

[0327] Those skilled in the art will understand that Figure 9 The structure shown does not constitute a limitation on terminal 900, and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0328] Optionally, the computer device is provided as a server. Figure 10 This is a schematic diagram of a server structure provided in an embodiment of this application. The server 1000 can vary significantly depending on its configuration or accuracy. It may include one or more Central Processing Units (CPUs) 1001 and one or more memories 1002. The memories 1002 store at least one computer program, which is loaded and executed by the processor 1001 to implement the methods provided in the various method embodiments described above. Of course, the server may also have wired or wireless network interfaces, a keyboard, and input / output interfaces for input and output. The server may also include other components for implementing device functions, which will not be elaborated upon here.

[0329] This application also provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to perform the operations of the method for accessing a mailbox server described above.

[0330] This application also provides a computer program product, including a computer program loaded and executed by a processor to perform the operations performed by the method of accessing a mailbox server as described in the above embodiments.

[0331] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0332] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present application should be included within the protection scope of the present application.

Claims

1. An email system, characterized in that, The email system includes an email server and a proxy server. The email server and the proxy server are located in a first network environment. The email server disables external network access, while the proxy server enables external network access. The proxy server is used to establish a first connection with the terminal and a second connection with the email server. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 protocol and are encrypted using the TSL protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email. The proxy server is also configured to receive an email access request sent by the terminal through the first connection, and forward the email access request to the email server through the second connection; The email server is configured to respond to the email access request by sending an email access response corresponding to the email access request to the proxy server via the second connection. The proxy server is further configured to receive the email access response through the second connection and send the email access response to the terminal through the first connection. The terminal is configured to display the access result in the email client based on the email access response.

2. The email system according to claim 1, characterized in that, The proxy server is used for: Perform a Transmission Control Protocol (TCP) handshake and a Transmission Control Protocol (TSL) handshake with the terminal; Receive the SOCKS authentication request sent by the terminal, perform SOCKS authentication on the terminal, and send an authentication success response to the terminal after successful SOCKS authentication; Receive a connection request sent by the terminal based on the authentication success response, the connection request carrying the address information of the email server; Based on the address information, a TCP handshake and a TSL handshake are performed with the email server, and a connection completion response is sent to the terminal.

3. The email system according to claim 2, characterized in that, The proxy server is used for: Receives a TCP connection request sent by the terminal, and in response to the TCP connection request, sends a TCP connection request confirmation to the terminal; Receive the TCP acknowledgment sent by the terminal, the TCP acknowledgment being used to confirm the completion of the TCP handshake; The terminal sends a first TSL greeting message, which carries a first TSL version supported by the terminal, a list of encryption suites, and a first random number. In response to the first TSL greeting message, a second TSL greeting message, a first public key, and a greeting completion message are sent to the terminal. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, and a second random number. The terminal sends a key negotiation request, which carries a first session key determined by the terminal based on the first random number, the second random number, the first public key, and the terminal's second public key. In response to the key negotiation request, a key negotiation response is sent to the terminal. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

4. A method for accessing an email server, characterized in that, The method is executed by an email system, which includes an email server and a proxy server. The email server and the proxy server are located in a first network environment. The email server disables external network access, while the proxy server enables external network access. The method includes: The proxy server establishes a first connection with the terminal and a second connection with the email server. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 socket security protocol and are encrypted using the TSL transport layer security protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is the operation of starting the email client, the operation of selecting any email, or the operation of sending an email. The proxy server receives the email access request sent by the terminal through the first connection, and forwards the email access request to the email server through the second connection. In response to the email access request, the email server sends the email access response corresponding to the email access request to the proxy server through the second connection; The proxy server receives the email access response through the second connection and sends the email access response to the terminal through the first connection. The terminal is used to display the access result in the email client based on the email access response.

5. A method for accessing a mail server, characterized in that, The method is executed by a proxy server. The email server and the proxy server are in a first network environment. The email server disables external network access, while the proxy server enables external network access. The method includes: A first connection is established with the terminal, and a second connection is established with the email server. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 socket security protocol and are encrypted using the TSL transport layer security protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email. The system receives an email access request from the terminal via the first connection and forwards the email access request to the email server via the second connection. The system receives the email access response corresponding to the email access request through the second connection, and sends the email access response to the terminal through the first connection. The terminal is used to display the access result in the email client based on the email access response.

6. The method according to claim 5, characterized in that, Establishing a first connection with the terminal and a second connection with the email server includes: Perform a Transmission Control Protocol (TCP) handshake and a Transmission Control Protocol (TSL) handshake with the terminal; Receive the SOCKS authentication request sent by the terminal, perform SOCKS authentication on the terminal, and send an authentication success response to the terminal after successful SOCKS authentication; Receive a connection request sent by the terminal based on the authentication success response, the connection request carrying the address information of the email server; Based on the address information, a TCP handshake and a TSL handshake are performed with the email server, and a connection completion response is sent to the terminal.

7. A method for accessing a mail server, characterized in that, The method is executed by a terminal, and the method includes: In response to an access operation in the email client, a first connection is established with a proxy server. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email. The proxy server is used to establish a second connection with the email server. The email server and the proxy server are in a first network environment. The email server disables external network access, and the proxy server enables external network access. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are connections based on the SOCKS5 socket security protocol, and the first connection and the second connection are encrypted using the TSL transport layer security protocol. The proxy server sends an email access request to the proxy server through the first connection, and the proxy server receives an email access response corresponding to the email access request through the second connection. Through the first connection, receive the email access response sent by the proxy server; Based on the email access response, the access result is displayed in the email client.

8. The method according to claim 7, characterized in that, The step of displaying the access result in the email client based on the email access response includes: If the access operation is to launch the email client, the email data carried in the email access response is displayed on the homepage of the email client; or, If the access operation involves selecting any email, the email details data from the email in the email client's email details page will be displayed; or, If the access operation is a mail sending operation, the mail client displays the sending notification carried in the mail access response.

9. The method according to claim 7, characterized in that, Establishing the first connection with the proxy server includes: Perform TCP handshake and TLS handshake with the proxy server; A SOCKS authentication request is sent to the proxy server, which receives the SOCKS authentication request sent by the terminal and performs SOCKS authentication on the terminal. Receive the authentication success response sent by the proxy server after successful SOCKS authentication; Based on the authentication pass response, a connection request is sent to the proxy server. The connection request carries the address information of the email server. The proxy server is used to perform TCP handshake and TLS handshake with the email server based on the address information. Receive the connection completion response sent by the proxy server.

10. The method according to claim 9, characterized in that, The process of performing TCP handshakes and TLS handshakes with the proxy server includes: Send a TCP connection request to the proxy server and receive a connection request confirmation from the proxy server; Send a TCP acknowledgment to the proxy server; the TCP acknowledgment is used to confirm that the TCP handshake is complete. Send a first TSL greeting message to the proxy server. The first TSL greeting message carries a first TSL version supported by the terminal, a list of encryption suites, and a first random number. The proxy server receives a second TSL greeting message in response to the first TSL greeting message. The second TSL greeting message carries a second TSL version supported by the proxy server, a cipher suite, a second random number, and a first public key. Send a key negotiation request to the proxy server, the key negotiation request carrying a first session key determined by the terminal based on the first random number, the second random number, the first public key and the second public key of the terminal; The proxy server receives a key negotiation response in response to the key negotiation request. The key negotiation response carries a second session key determined based on the first session key. The key negotiation response is used to confirm that the TSL handshake is complete.

11. An apparatus for accessing an email server, characterized in that, The device is configured on a proxy server, and the email server and the proxy server are in a first network environment. The email server has external network access disabled, while the proxy server has external network access enabled. The device includes: A connection establishment module is used to establish a first connection with the terminal and a second connection with the email server. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are based on the SOCKS5 socket security protocol and are encrypted using the TSL transport layer security protocol. The first connection and the second connection are established when an access operation is triggered in the email client of the terminal. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email. The request sending and receiving module is used to receive the email access request sent by the terminal through the first connection, and to forward the email access request to the email server through the second connection; The response sending and receiving module is used to receive the email access response corresponding to the email access request through the second connection, and to send the email access response to the terminal through the first connection. The terminal is used to display the access result in the email client based on the email access response.

12. An apparatus for accessing a mail server, characterized in that, The device is configured in a terminal, and the device includes: A connection establishment module is used to respond to an access operation in the email client and establish a first connection with a proxy server. The access operation is an operation to start the email client, an operation to select any email, or an operation to send an email. The proxy server is used to establish a second connection with the email server. The email server and the proxy server are in a first network environment. The email server disables external network access, and the proxy server enables external network access. The terminal is in a second network environment different from the first network environment. The first connection and the second connection are connections based on the SOCKS5 socket security protocol, and the first connection and the second connection are encrypted using the TSL transport layer security protocol. The request sending module is used to send an email access request to the proxy server through the first connection, and the proxy server is used to receive an email access response corresponding to the email access request through the second connection. A response receiving module is configured to receive the email access response sent by the proxy server through the first connection; The display module is used to display the access result in the email client based on the email access response.

13. A computer device, characterized in that, The computer device includes a processor and a memory, the memory storing at least one computer program, the at least one computer program being loaded and executed by the processor to perform the operations performed by the method of accessing a mailbox server as described in any one of claims 5 to 6, or to perform the operations performed by the method of accessing a mailbox server as described in any one of claims 7 to 10.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one computer program, which is loaded and executed by a processor to perform the operations performed by the method of accessing the email server as described in any one of claims 5 to 6, or to perform the operations performed by the method of accessing the email server as described in any one of claims 7 to 10.

15. A computer program product, comprising a computer program, characterized in that, The computer program is loaded and executed by a processor to perform the operations performed by the method of accessing a mailbox server as described in any one of claims 5 to 6, or to perform the operations performed by the method of accessing a mailbox server as described in any one of claims 7 to 10.

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