feat(openai): 新增 OpenAI v2 版接口客户端，并实现加解密及签名中间件

fudiwei · Jun 4, 2024 · 921b968 · 921b968
1 parent ad9b5a1
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diff --git a/docs/WechatOpenAI/README.md b/docs/WechatOpenAI/README.md
@@ -1,4 +1,4 @@
-# SKIT.FlurlHttpClient.Wechat.OpenAI
+# SKIT.FlurlHttpClient.Wechat.OpenAI
 
 基于 `Flurl.Http` 的[微信对话开放平台](https://chatbot.weixin.qq.com/) HTTP API SDK。
 
@@ -7,7 +7,8 @@
 ## 功能
 
 -   基于微信对话开放平台 API 封装。
--   提供了微信对话开放平台所需的 AES、SHA-1 等算法工具类。
+-   针对 v2 版接口，请求时自动生成签名，无需开发者手动干预。
+-   提供了微信对话开放平台所需的 AES、MD5、SHA-1 等算法工具类。
 -   提供了解析回调通知事件等扩展方法。
 
 ---

diff --git a/src/SKIT.FlurlHttpClient.Wechat.Api/Interceptors/WechatApiSecurityApiInterceptor.cs b/src/SKIT.FlurlHttpClient.Wechat.Api/Interceptors/WechatApiSecurityApiInterceptor.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Linq;
+using System.Net;
 using System.Net.Http;
 using System.Text;
 using System.Text.Json;
@@ -299,12 +300,12 @@ public override async Task AfterCallAsync(HttpInterceptorContext context, Cancel
 
             if (context.FlurlCall.HttpRequestMessage.Method != HttpMethod.Post)
                 return;
-            if (context.FlurlCall.HttpRequestMessage.RequestUri is null)
-                return;
-            if (!IsRequestUrlPathMatched(context.FlurlCall.HttpRequestMessage.RequestUri))
+            if (context.FlurlCall.HttpRequestMessage.RequestUri is null || !IsRequestUrlPathMatched(context.FlurlCall.HttpRequestMessage.RequestUri))
                 return;
             if (context.FlurlCall.HttpResponseMessage is null)
                 return;
+            if (context.FlurlCall.HttpResponseMessage.StatusCode != HttpStatusCode.OK)
+                return;
 
             string urlpath = GetRequestUrlPath(context.FlurlCall.HttpRequestMessage.RequestUri);
             byte[] respBytes = Array.Empty<byte>();

diff --git a/...SKIT.FlurlHttpClient.Wechat.OpenAI/Extensions/WechatOpenAIClientExecuteTokenExtensions.cs b/...SKIT.FlurlHttpClient.Wechat.OpenAI/Extensions/WechatOpenAIClientExecuteTokenExtensions.cs
@@ -0,0 +1,33 @@
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using Flurl.Http;
+
+namespace SKIT.FlurlHttpClient.Wechat.OpenAI
+{
+    public static class WechatOpenAIClientExecuteTokenExtensions
+    {
+        /// <summary>
+        /// <para>异步调用 [POST] /v2/token 接口。</para>
+        /// <para>
+        /// REF: <br/>
+        /// <![CDATA[ https://developers.weixin.qq.com/doc/aispeech/confapi/dialog/token.html ]]>
+        /// </para>
+        /// </summary>
+        /// <param name="client"></param>
+        /// <param name="request"></param>
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        public static async Task<Models.TokenV2Response> ExecuteTokenV2Async(this WechatOpenAIClient client, Models.TokenV2Request request, CancellationToken cancellationToken = default)
+        {
+            if (client is null) throw new ArgumentNullException(nameof(client));
+            if (request is null) throw new ArgumentNullException(nameof(request));
+
+            IFlurlRequest flurlReq = client
+                .CreateFlurlRequest(request, HttpMethod.Post, "v2", "token");
+
+            return await client.SendFlurlRequestAsJsonAsync<Models.TokenV2Response>(flurlReq, data: request, cancellationToken: cancellationToken).ConfigureAwait(false);
+        }
+    }
+}
diff --git a/...IT.FlurlHttpClient.Wechat.OpenAI/Interceptors/WechatOpenAIRequestEncryptionInterceptor.cs b/...IT.FlurlHttpClient.Wechat.OpenAI/Interceptors/WechatOpenAIRequestEncryptionInterceptor.cs
@@ -0,0 +1,158 @@
+using System;
+using System.Collections.Generic;
+using System.Net;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using Flurl.Http;
+
+namespace SKIT.FlurlHttpClient.Wechat.OpenAI.Interceptors
+{
+    using SKIT.FlurlHttpClient.Internal;
+
+    internal class WechatOpenAIRequestEncryptionInterceptor : HttpInterceptor
+    {
+        /**
+         * REF:
+         *   https://developers.weixin.qq.com/doc/aispeech/confapi/dialog/token.html
+         */
+        private static readonly ISet<string> ENCRYPT_REQUIRED_URLS = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
+        {
+            "/v2/bot/query"
+        };
+
+        private readonly string _baseUrl;
+        private readonly string _encodingAESKey;
+        private readonly Func<string, bool>? _customEncryptedRequestPathMatcher;
+
+        public WechatOpenAIRequestEncryptionInterceptor(string baseUrl, string encodingAESKey, Func<string, bool>? customEncryptedRequestPathMatcher)
+        {
+            _baseUrl = baseUrl;
+            _encodingAESKey = encodingAESKey;
+            _customEncryptedRequestPathMatcher = customEncryptedRequestPathMatcher;
+
+            // AES 密钥的长度不是 4 的倍数需要补齐，确保其始终为有效的 Base64 字符串
+            const int MULTI = 4;
+            int tLen = _encodingAESKey.Length;
+            int tRem = tLen % MULTI;
+            if (tRem > 0)
+            {
+                _encodingAESKey = _encodingAESKey.PadRight(tLen - tRem + MULTI, '=');
+            }
+        }
+
+        public override async Task BeforeCallAsync(HttpInterceptorContext context, CancellationToken cancellationToken = default)
+        {
+            if (context is null) throw new ArgumentNullException(nameof(context));
+            if (context.FlurlCall.Completed) throw new WechatOpenAIException("Failed to encrypt request. This interceptor must be called before request completed.");
+
+            if (context.FlurlCall.HttpRequestMessage.RequestUri is null || !IsRequestUrlPathMatched(context.FlurlCall.HttpRequestMessage.RequestUri))
+                return;
+
+            byte[] reqBytes = Array.Empty<byte>();
+            if (context.FlurlCall.HttpRequestMessage?.Content is not null)
+            {
+                if (context.FlurlCall.HttpRequestMessage.Content is not MultipartFormDataContent)
+                {
+                    reqBytes = await
+#if NET5_0_OR_GREATER
+                        context.FlurlCall.HttpRequestMessage.Content.ReadAsByteArrayAsync(cancellationToken).ConfigureAwait(false);
+#else
+                        _AsyncEx.RunTaskWithCancellationTokenAsync(context.FlurlCall.HttpRequestMessage.Content.ReadAsByteArrayAsync(), cancellationToken).ConfigureAwait(false);
+#endif
+                }
+            }
+
+            byte[] reqBytesEncrypted = Array.Empty<byte>();
+            try
+            {
+                const int AES_BLOCK_SIZE = 16;
+                byte[] keyBytes = Convert.FromBase64String(_encodingAESKey);
+                byte[] ivBytes = new byte[AES_BLOCK_SIZE]; // iv 是 key 的前 16 个字节
+                Buffer.BlockCopy(keyBytes, 0, ivBytes, 0, ivBytes.Length);
+
+                reqBytesEncrypted = Utilities.AESUtility.EncryptWithCBC(
+                    keyBytes: keyBytes,
+                    ivBytes: ivBytes,
+                    plainBytes: reqBytes
+                )!;
+            }
+            catch (Exception ex)
+            {
+                throw new WechatOpenAIException("Failed to encrypt request. Please see the inner exception for more details.", ex);
+            }
+
+            context.FlurlCall.HttpRequestMessage!.Content?.Dispose();
+            context.FlurlCall.HttpRequestMessage!.Content = new ByteArrayContent(reqBytesEncrypted);
+            context.FlurlCall.Request.WithHeader(HttpHeaders.ContentType, MimeTypes.Text);
+        }
+
+        public override async Task AfterCallAsync(HttpInterceptorContext context, CancellationToken cancellationToken = default)
+        {
+            if (context is null) throw new ArgumentNullException(nameof(context));
+            if (!context.FlurlCall.Completed) throw new WechatOpenAIException("Failed to decrypt response. This interceptor must be called after request completed.");
+
+            if (context.FlurlCall.HttpRequestMessage.RequestUri is null || !IsRequestUrlPathMatched(context.FlurlCall.HttpRequestMessage.RequestUri))
+                return;
+            if (context.FlurlCall.HttpResponseMessage is null)
+                return;
+            if (context.FlurlCall.HttpResponseMessage.StatusCode != HttpStatusCode.OK)
+                return;
+
+            byte[] respBytes = Array.Empty<byte>();
+            if (context.FlurlCall.HttpResponseMessage.Content is not null)
+            {
+                HttpContent httpContent = context.FlurlCall.HttpResponseMessage.Content;
+                respBytes = await
+#if NET5_0_OR_GREATER
+                    httpContent.ReadAsByteArrayAsync(cancellationToken).ConfigureAwait(false);
+#else
+                    _AsyncEx.RunTaskWithCancellationTokenAsync(httpContent.ReadAsByteArrayAsync(), cancellationToken).ConfigureAwait(false);
+#endif
+            }
+
+            byte[] respBytesDecrypted;
+            try
+            {
+                const int AES_BLOCK_SIZE = 16;
+                byte[] keyBytes = Convert.FromBase64String(_encodingAESKey);
+                byte[] ivBytes = new byte[AES_BLOCK_SIZE]; // iv 是 key 的前 16 个字节
+                Buffer.BlockCopy(keyBytes, 0, ivBytes, 0, ivBytes.Length);
+
+                respBytesDecrypted = Utilities.AESUtility.DecryptWithCBC(
+                    keyBytes: keyBytes,
+                    ivBytes: ivBytes,
+                    cipherBytes: respBytes
+                )!;
+            }
+            catch (Exception ex)
+            {
+                throw new WechatOpenAIException("Failed to decrypt response. Please see the inner exception for more details.", ex);
+            }
+
+            context.FlurlCall.HttpResponseMessage!.Content?.Dispose();
+            context.FlurlCall.HttpResponseMessage!.Content = new ByteArrayContent(respBytesDecrypted);
+        }
+
+        private string GetRequestUrlPath(Uri uri)
+        {
+            return uri.AbsoluteUri.Substring(0, uri.AbsoluteUri.Length - uri.Query.Length);
+        }
+
+        private bool IsRequestUrlPathMatched(Uri uri)
+        {
+            string absoluteUrl = GetRequestUrlPath(uri);
+            if (!absoluteUrl.StartsWith(_baseUrl))
+                return false;
+
+            string relativeUrl = absoluteUrl.Substring(_baseUrl.TrimEnd('/').Length);
+            if (!ENCRYPT_REQUIRED_URLS.Contains(relativeUrl))
+            { 
+                if (_customEncryptedRequestPathMatcher is not null)
+                    return _customEncryptedRequestPathMatcher(relativeUrl);
+            }
+
+            return true;
+        }
+    }
+}
diff --git a/src/SKIT.FlurlHttpClient.Wechat.OpenAI/Interceptors/WechatOpenAIRequestSigningInterceptor.cs b/src/SKIT.FlurlHttpClient.Wechat.OpenAI/Interceptors/WechatOpenAIRequestSigningInterceptor.cs
@@ -0,0 +1,56 @@
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using Flurl.Http;
+
+namespace SKIT.FlurlHttpClient.Wechat.OpenAI.Interceptors
+{
+    using SKIT.FlurlHttpClient.Internal;
+
+    internal class WechatOpenAIRequestSigningInterceptor : HttpInterceptor
+    {
+        private readonly string _token;
+
+        public WechatOpenAIRequestSigningInterceptor(string token)
+        {
+            _token = token;
+        }
+
+        public override async Task BeforeCallAsync(HttpInterceptorContext context, CancellationToken cancellationToken = default)
+        {
+            if (context is null) throw new ArgumentNullException(nameof(context));
+            if (context.FlurlCall.Completed) throw new WechatOpenAIException("Failed to sign request. This interceptor must be called before request completed.");
+
+            if (context.FlurlCall.HttpRequestMessage.RequestUri is null)
+                return;
+
+            string timestamp = DateTimeOffset.Now.ToLocalTime().ToUnixTimeSeconds().ToString();
+            string nonce = Guid.NewGuid().ToString("N");
+            string body = string.Empty;
+            if (context.FlurlCall.HttpRequestMessage?.Content is not null)
+            {
+                if (context.FlurlCall.HttpRequestMessage.Content is MultipartFormDataContent)
+                {
+                    body = string.Empty;
+                }
+                else
+                {
+                    body = await
+#if NET5_0_OR_GREATER
+                    context.FlurlCall.HttpRequestMessage.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
+#else
+                    _AsyncEx.RunTaskWithCancellationTokenAsync(context.FlurlCall.HttpRequestMessage.Content.ReadAsStringAsync(), cancellationToken).ConfigureAwait(false);
+#endif
+                }
+            }
+
+            string signData = $"{_token}{timestamp}{nonce}{Utilities.MD5Utility.Hash(body).Value!.ToLower()}";
+            string sign = Utilities.MD5Utility.Hash(signData).Value!.ToLower();
+
+            context.FlurlCall.Request.WithHeader("timestamp", timestamp);
+            context.FlurlCall.Request.WithHeader("nonce", nonce);
+            context.FlurlCall.Request.WithHeader("sign", sign);
+        }
+    }
+}
diff --git a/src/SKIT.FlurlHttpClient.Wechat.OpenAI/Models/OpenAI/Token/TokenV2Request.cs b/src/SKIT.FlurlHttpClient.Wechat.OpenAI/Models/OpenAI/Token/TokenV2Request.cs
@@ -0,0 +1,15 @@
+namespace SKIT.FlurlHttpClient.Wechat.OpenAI.Models
+{
+    /// <summary>
+    /// <para>表示 [POST] /v2/token 接口的请求。</para>
+    /// </summary>
+    public class TokenV2Request : WechatOpenAIRequest
+    {
+        /// <summary>
+        /// 获取或设置操作数据的管理员 ID。
+        /// </summary>
+        [Newtonsoft.Json.JsonProperty("account")]
+        [System.Text.Json.Serialization.JsonPropertyName("account")]
+        public string Account { get; set; } = string.Empty;
+    }
+}
diff --git a/src/SKIT.FlurlHttpClient.Wechat.OpenAI/Models/OpenAI/Token/TokenV2Response.cs b/src/SKIT.FlurlHttpClient.Wechat.OpenAI/Models/OpenAI/Token/TokenV2Response.cs
@@ -0,0 +1,21 @@
+namespace SKIT.FlurlHttpClient.Wechat.OpenAI.Models
+{
+    /// <summary>
+    /// <para>表示 [POST] /v2/token 接口的响应。</para>
+    /// </summary>
+    public class TokenV2Response : WechatOpenAIResponse<TokenV2Response.Types.Data>
+    {
+        public static class Types
+        {
+            public class Data
+            {
+                /// <summary>
+                /// 获取或设置接口访问令牌。
+                /// </summary>
+                [Newtonsoft.Json.JsonProperty("access_token")]
+                [System.Text.Json.Serialization.JsonPropertyName("access_token")]
+                public string AccessToken { get; set; } = default!;
+            }
+        }
+    }
+}
diff --git a/src/SKIT.FlurlHttpClient.Wechat.OpenAI/README.md b/src/SKIT.FlurlHttpClient.Wechat.OpenAI/README.md
@@ -9,7 +9,8 @@
 ### 【功能特性】
 
 -   基于微信对话开放平台 API 封装。
--   提供了微信对话开放平台所需的 AES、SHA-1 等算法工具类。
+-   针对 v2 版接口，请求时自动生成签名，无需开发者手动干预。
+-   提供了微信对话开放平台所需的 AES、MD5、SHA-1 等算法工具类。
 -   提供了解析回调通知事件等扩展方法。
 
 ---

diff --git a/src/SKIT.FlurlHttpClient.Wechat.OpenAI/Settings/Credentials.cs b/src/SKIT.FlurlHttpClient.Wechat.OpenAI/Settings/Credentials.cs
@@ -5,20 +5,29 @@ namespace SKIT.FlurlHttpClient.Wechat.OpenAI.Settings
     public sealed class Credentials
     {
         /// <summary>
-        /// 初始化客户端时 <see cref="WechatChatbotClientOptions.AppId"/> 的副本。
+        /// 初始化客户端时 <see cref="WechatOpenAIClientOptions.AppId"/> / <see cref="WechatChatbotClientOptions.AppId"/> 的副本。
         /// </summary>
         public string AppId { get; }
 
         /// <summary>
-        /// 初始化客户端时 <see cref="WechatChatbotClientOptions.Token"/> 的副本。
+        /// 初始化客户端时 <see cref="WechatOpenAIClientOptions.Token"/> / <see cref="WechatChatbotClientOptions.Token"/> 的副本。
         /// </summary>
         public string Token { get; }
 
         /// <summary>
-        /// 初始化客户端时 <see cref="WechatChatbotClientOptions.EncodingAESKey"/> 的副本。
+        /// 初始化客户端时 <see cref="WechatOpenAIClientOptions.EncodingAESKey"/> / <see cref="WechatChatbotClientOptions.EncodingAESKey"/> 的副本。
         /// </summary>
         public string EncodingAESKey { get; }
 
+        internal Credentials(WechatOpenAIClientOptions options)
+        {
+            if (options is null) throw new ArgumentNullException(nameof(options));
+
+            AppId = options.AppId;
+            Token = options.Token;
+            EncodingAESKey = options.EncodingAESKey;
+        }
+
         internal Credentials(WechatChatbotClientOptions options)
         {
             if (options is null) throw new ArgumentNullException(nameof(options));