中文版请点击这里

An unofficial .NET 10 wrapper for the WeChat Work (WeCom) Finance SDK (企业微信会话内容存档 SDK). This library encapsulates the C SDK provided by Tencent, offering a convenient, strong-typed C# interface for fetching, decrypting, and parsing chat history.

• Cross-Platform Support: Works on Windows (x64) and Linux (x64).
• Managed Wrapper: WeWorkChatClient class handles P/Invoke complexity and resource management (IDisposable), directly integrates RSA and AES decryption for convenience, and supports encrypted PEM private keys with a password.
• Strong-Typed Models: Automatically deserializes JSON messages into C# objects (WeWorkChatMessage and specific types like TextMessage, ImageMessage, etc.).
• Simplified Data Retrieval: The GetChatMessages method combines fetching, RSA key decryption, and message AES decryption into a single, easy-to-use call.
• Media Handling: Helper methods to download and save media files (images, videos, files).

• .NET 10 SDK
• Windows: Visual C++ Redistributable (usually installed, but required for native DLLs).
• Linux: Standard C libraries.

1. Clone or download this repository.
2. Reference the WeWorkFinanceSdk.csproj in your solution.
3. Ensure the native libraries in the libs/ folder are correctly copied to the output directory. The .csproj file is configured to handle this automatically for libs/win-x64 and libs/linux-x64.

Initialize the client with your Corporate ID (CorpId) and Secret.

using WeWorkFinanceSdk;
using WeWorkFinanceSdk.Models;

// Replace with your actual CorpId and Secret
string corpId = "wwd08c8exxxx5ab44d";
string secret = "your_secret_key";

using var client = new WeWorkChatClient(corpId, secret);

Fetch a batch of encrypted chat messages using the sequence number (seq).

ulong seq = 0; // Start from 0, then update with the latest 'seq' from the response
uint limit = 100; // Max 1000
string proxy = ""; // Optional proxy
string passwd = ""; // Optional proxy password
int timeout = 10; // Timeout in seconds

// Returns a JSON string containing the encrypted list
string chatDataJson = client.GetChatData(seq, limit, proxy, passwd, timeout);
Console.WriteLine(chatDataJson);

The GetChatMessages method combines fetching, RSA key decryption, and message AES decryption into a single call. This requires providing your RSA private key in PEM format when initializing WeWorkChatClient.

// 1. Initialize client with your RSA Private Key (PEM format)
string rsaPrivateKey = @"-----BEGIN RSA PRIVATE KEY-----
... your actual private key content ...
-----END RSA PRIVATE KEY-----";

// If your private key is encrypted (e.g., has ENCRYPTED in the header), provide a password:
string? privateKeyPassword = "your_key_password"; // Or null if not encrypted

using var client = new WeWorkChatClient(corpId, secret, rsaPrivateKey, privateKeyPassword); // Use the new constructor

// 2. Fetch and automatically decrypt messages
var response = client.GetChatMessages(seq: 0, limit: 100); // Use the new method

if (response.ErrCode == 0)
{
    Console.WriteLine($"Successfully fetched and decrypted {response.Messages.Count} messages. Last Seq: {response.LastSeq}");
    foreach (var message in response.Messages)
    {
        Console.WriteLine($"MsgId: {message.MsgId}, Type: {message.MsgType}");
        if (message.MsgType == "text" && message.Text != null)
        {
            Console.WriteLine($"Content: {message.Text.Content}");
        }
        // ... handle other message types
    }
}
else
{
    Console.WriteLine($"Failed to fetch and decrypt messages: {response.ErrMsg} (ErrCode: {response.ErrCode})");
}

If you need to perform RSA decryption manually (e.g., in a separate service) or only want the raw decrypted JSON string:

You can still use the DecryptChatMessage method:

string encryptRandomKey = "..."; // From GetChatData response
string encryptChatMsg = "...";   // From GetChatData response

// Manually decrypt 'encryptRandomKey' to get the AES Key
string decryptedAesKey = MyRSADecryptionMethod(encryptRandomKey, myPrivateKey, myPassword); // Your RSA decryption logic (pass password if key is encrypted)

WeWorkChatMessage? message = client.DecryptChatMessage(decryptedAesKey, encryptChatMsg);
// ... process message

Download images, videos, or files using the sdkfileid.

string sdkFileId = "..."; // From Image/Video/File message
string indexBuf = ""; // Start with empty string
string savePath = "downloaded_file.jpg";

using var fs = new FileStream(savePath, FileMode.Create, FileAccess.Write);

while (true)
{
    // Fetch a chunk of data
    var chunk = client.GetMediaData(indexBuf, sdkFileId);
    
    if (chunk.Data.Length > 0)
    {
        fs.Write(chunk.Data, 0, chunk.Data.Length);
    }

    if (chunk.IsFinish)
    {
        break;
    }

    // Update indexBuf for the next chunk
    indexBuf = chunk.OutIndexBuf;
}

WeWorkChatClient is the main entry point for interacting with the SDK. It implements IDisposable.

public WeWorkChatClient(string corpId, string secret, string? privateKey = null, string? privateKeyPassword = null)

• corpId: Your WeCom Corporate ID.
• secret: Your Chat History Archiving Secret.
• privateKey: (Optional) Your enterprise's RSA private key in PEM format. Required for GetChatMessages to automatically decrypt encrypt_random_key.
• privateKeyPassword: (Optional) Password for the privateKey if it is encrypted.

public WeWorkChatBatchResponse GetChatMessages(ulong seq, uint limit = 1000, string proxy = "", string passwd = "", int timeout = 10)

Fetches encrypted chat data, decrypts the RSA keys, and decrypts the messages into strongly-typed objects. Requires privateKey to be provided in the constructor.

• seq: The cursor sequence number. Start with 0.
• limit: Number of messages to fetch (Max 1000).
• proxy & passwd: Optional proxy settings.
• timeout: Request timeout in seconds.
• Returns: A WeWorkChatBatchResponse object containing a list of WeWorkChatMessage and the last processed sequence number.

public string GetChatData(ulong seq, uint limit, string proxy = "", string passwd = "", int timeout = 10)

Fetches encrypted chat data.

• seq: The cursor sequence number. Start with 0.
• limit: Number of messages to fetch (Max 1000).
• proxy & passwd: Optional proxy settings.
• timeout: Request timeout in seconds.
• Returns: A JSON string containing the message list and next cursor.

public WeWorkChatMessage? DecryptChatMessage(string encryptKey, string encryptMsg)

Decrypts an encrypted message payload and deserializes it into a WeWorkChatMessage object.

• encryptKey: The AES key (decrypted from encrypt_random_key using your RSA private key).
• encryptMsg: The encrypt_chat_msg payload from the chat data.
• Returns: A WeWorkChatMessage object or null if decryption fails.

public string DecryptData(string encryptKey, string encryptMsg)

Low-level decryption method.

• Returns: The raw JSON string of the decrypted message.

public MediaDataChunk GetMediaData(string indexBuf, string sdkFileId, string proxy = "", string passwd = "", int timeout = 10)

Downloads a chunk of a media file.

• indexBuf: The cursor for the current download chunk. Pass empty string "" for the first chunk.
• sdkFileId: The ID of the file to download.
• Returns: A MediaDataChunk containing the data bytes, next index buffer, and finish status.

Releases the native SDK resources.

• WeWorkFinanceSdk/: The main C# project.
  • FinanceSdk.cs: Native P/Invoke definitions.
  • WeWorkChatClient.cs: High-level wrapper class.
  • Models/: Strong-typed message classes (WeWorkChatMessage.cs etc.).
• libs/: Native libraries (required at runtime).
  • win-x64/: WeWorkFinanceSdk.dll, libcrypto-3-x64.dll, etc.
  • linux-x64/: libWeWorkFinanceSdk.so.
  • include/: C header files (for reference).

• Official Tencent WeCom Documentation
• Message Types & JSON Structure