对接致远OA单点登录的例子

对接致远OA单点登录，需要实现以下步骤：

1. 在致远OA系统中，配置单点登录参数，包括应用系统的名称、登录地址、退出地址等信息，并生成密钥和向量。

2. 在应用系统中，使用C#语言实现单点登录的逻辑，包括接收和解析来自致远OA系统的加密字符串、校验签名、验证时间戳等操作。

以下是一个简单的示例代码，用于演示如何实现对接致远OA单点登录：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Cryptography;
using System.Text;

public partial class SsoLogin : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // 从请求参数中获取加密字符串
        string encryptData = Request.QueryString["data"];

        // 解密字符串
        string decryptedData = Decrypt(encryptData);

        // 解析字符串
        Dictionary<string, string> dataDict = ParseData(decryptedData);

        // 校验签名
        if (!VerifySignature(dataDict))
        {
            Response.Write("Invalid signature");
            return;
        }

        // 验证时间戳
        if (!VerifyTimestamp(dataDict))
        {
            Response.Write("Invalid timestamp");
            return;
        }

        // 获取用户名和用户ID
        string username = dataDict["username"];
        string userId = dataDict["userid"];

        // 在应用系统中进行单点登录
        // ...

        // 跳转到应用系统的首页
        Response.Redirect("home.aspx");
    }

    // 解密方法
    private string Decrypt(string encryptData)
    {
        // 根据实际情况，使用致远OA系统中生成的密钥和向量进行解密
        byte[] key = Encoding.ASCII.GetBytes("1234567890123456");
        byte[] iv = Encoding.ASCII.GetBytes("abcdefghijklmnop");
        byte[] encryptedBytes = Convert.FromBase64String(encryptData);
        string decryptedData = "";
        using (AesCryptoServiceProvider aes = new AesCryptoServiceProvider())
        {
            aes.Key = key;
            aes.IV = iv;
            ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);
            using (MemoryStream ms = new MemoryStream(encryptedBytes))
            {
                using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader sr = new StreamReader(cs))
                    {
                        decryptedData = sr.ReadToEnd();
                    }
                }
            }
        }
        return decryptedData;
    }

    // 解析数据方法
    private Dictionary<string, string> ParseData(string decryptedData)
    {
        Dictionary<string, string> dataDict = new Dictionary<string, string>();
        string[] dataArray = decryptedData.Split('&');
        foreach (string data in dataArray)
        {
            string[] keyValue = data.Split('=');
            dataDict[keyValue[0]] = keyValue[1];
        }
        return dataDict;
    }

    // 校验签名方法
    private bool VerifySignature(Dictionary<string, string> dataDict)
    {
        // 根据实际情况，使用致远OA系统中生成的密钥和向量进行签名校验
        string key = "1234567890123456";
        string iv = "abcdefghijklmnop";
        string data = dataDict["data"];
        string signature = dataDict["signature"];
        byte[] keyBytes = Encoding.ASCII.GetBytes(key);
        byte[] ivBytes = Encoding.ASCII.GetBytes(iv);
        byte[] dataBytes = Encoding.ASCII.GetBytes(data);
        using (AesCryptoServiceProvider aes = new AesCryptoServiceProvider())
        {
            aes.Key = keyBytes;
            aes.IV = ivBytes;
            ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);
            using (MemoryStream ms = new MemoryStream(dataBytes))
            {
                using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader sr = new StreamReader(cs))
                    {
                        string decryptedData = sr.ReadToEnd();
                        string computedSignature = ComputeSignature(decryptedData, key);
                        return signature.Equals(computedSignature);
                    }
                }
            }
        }
    }

    // 计算签名方法
    private string ComputeSignature(string decryptedData, string key)
    {
        byte[] keyBytes = Encoding.ASCII.GetBytes(key);
        byte[] dataBytes = Encoding.ASCII.GetBytes(decryptedData);
        HMACSHA1 hmac = new HMACSHA1(keyBytes);
        byte[] signatureBytes = hmac.ComputeHash(dataBytes);
        return Convert.ToBase64String(signatureBytes);
    }

    // 验证时间戳方法
    private bool VerifyTimestamp(Dictionary<string, string> dataDict)
    {
        // 根据实际情况，可以设置一个有效时间段，超过该时间段的请求将被视为无效
        string timestamp = dataDict["timestamp"];
        DateTime dateTime = DateTime.ParseExact(timestamp, "yyyyMMddHHmmss", null);
        TimeSpan timeSpan = DateTime.Now - dateTime;
        return timeSpan.TotalMinutes <= 5;
    }
}

以上代码仅作为参考，实际对接过程中需要根据具体情况进行修改和调整。