.Net Core微信服务商二次进件的开发

 #region 服务商签名 private string SrvPayBuildAuthAsync(string uri, string body, string method = "POST") { var timestamp = DateTimeOffset.Now.ToUnixTimeSeconds(); string nonce = Guid.NewGuid().ToString(); string message = $"{method}\n{uri}\n{timestamp}\n{nonce}\n{body}\n"; string signature = SrvSign(message); return $"mchid=\"{_wxCfg.SrvPayMerchantId}\",nonce_str=\"{nonce}\",timestamp=\"{timestamp}\",serial_no=\"{_wxCfg.SrvPayCertNo}\",signature=\"{signature}\""; } private string SrvSign(string message) { var bytes = Utils.ReadBytesIfExist(_wxCfg.SrvPayCertFile); if (bytes is null) { return ""; } X509Certificate2 cert = new(bytes, _wxCfg.SrvPayMerchantId); RSA rsa = cert.GetRSAPrivateKey(); var signData = rsa.SignData(Encoding.UTF8.GetBytes(message), HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1); return Convert.ToBase64String(signData); }

 #region 获取平台证书 public async Task GetSrvCert() { string uri = "/v3/certificates"; var auth = SrvPayBuildAuthAsync(uri, "", "GET"); var header = new Dictionary { { "Authorization",$"WECHATPAY2-SHA256-RSA2048 {auth}"}, { "Accept","*/*" }, { "Accept-Encoding","gzip,deflate,brn" }, { "User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.85 Safari/537.36 Edg/90.0.818.46" }, }; return await GetUrlAsync(uri, header); } #endregion

 public sealed class CertificatesOutModel : IWXResponse { [JsonPropertyName("data")] public IEnumerable Data { get; set; } public string Code { get; set; } public string Message { get; set; } } public class Certificates { [JsonPropertyName("serial_no")] public string SerialNo { get; set; } [JsonPropertyName("effective_time")] public string EffectiveTime { get; set; } [JsonPropertyName("expire_time")] public string ExpireTime { get; set; } [JsonPropertyName("encrypt_certificate")] public EncryptCertificate EncryptCertificate { get; set; } }

 protected async Task GetUrlAsync(string url, Dictionary headers = null) { HttpResponseMessage res = null; try { if (headers != null && headers.Count > 0) { foreach (var header in headers) { _client.DefaultRequestHeaders.TryAddWithoutValidation(header.Key, header.Value); } } res = await _client.GetAsync(url); res.EnsureSuccessStatusCode(); var result = await res.Content.ReadAsStringAsync(); if (result == null) { return default; } return result.ToJson(); } catch { var result = await res.Content.ReadAsStringAsync(); if (result == null) { return default; } return result.ToJson(); } }

 //获取证书 var cert = await _wxClient.GetSrvCert(); var certificateModel = cert.Data.FirstOrDefault(); if (!cert.Data.Any()) { return new MKResult(code: 400, msg: "未获取到平台证书"); } if (!string.IsNullOrEmpty(applyment.Body.SerialNo)) { certificateModel = cert.Data.SingleOrDefault(s => s.SerialNo == applyment.Body.SerialNo); } certificateModel.EncryptCertificate.Ciphertext = AESUtility.AesGcmDecrypt( _wxCfg.SrvApiV3Key, certificateModel.EncryptCertificate.AssociatedData, certificateModel.EncryptCertificate.Nonce, certificateModel.EncryptCertificate.Ciphertext );

 protected async Task GetUrlBytesAsync(string url, Dictionary headers = null) { try { if (headers != null && headers.Count > 0) { foreach (var header in headers) { _client.DefaultRequestHeaders.TryAddWithoutValidation(header.Key, header.Value); } } var res = await _client.GetAsync(url); res.EnsureSuccessStatusCode(); return await res.Content.ReadAsByteArrayAsync(); } catch { return default; } }

 /// 
 /// 上传图片 /// 
 ///  ///  public async Task> UploadFile(string url) { string fileContentType; string filetype; if (url!.Contains(".bmp", StringComparison.OrdinalIgnoreCase)) { fileContentType = "image/bmp"; filetype = ".bmp"; } else if (url!.Contains(".jpg-600", StringComparison.OrdinalIgnoreCase)) { fileContentType = "image/jpeg"; filetype = ".jpg-600"; } else if (url!.Contains(".jpeg", StringComparison.OrdinalIgnoreCase)) { fileContentType = "image/jpeg"; filetype = ".jpeg"; } else { fileContentType = "image/png"; filetype = ".png-600"; } UploadMerchantMediaImageRequest meta = new(); var fileBytes = await GetUrlBytesAsync(url);//获取网络图片Bytes if ((fileBytes?.Length ?? 0) == 0) { return new MKResult(code: 400, msg: "转换图片失败"); } meta.FileHash = GetHash(fileBytes); meta.FileName = Guid.NewGuid().ToString("N").ToLower() + filetype; string boundary = "--BOUNDARY--" + DateTimeOffset.Now.Ticks.ToString("x"); using var fileContent = new ByteArrayContent(fileBytes); using var metaContent = new StringContent(meta.ToJson(), Encoding.UTF8, "application/json"); using var httpContent = new MultipartFormDataContent(boundary); httpContent.Add(metaContent, "\"meta\"");//meta 必须要加双引号 httpContent.Add(fileContent, "\"file\"", "\"" + meta.FileName + "\"");//必须要加双引号 httpContent.Headers.ContentType = MediaTypeHeaderValue.Parse("multipart/form-data; boundary=" + boundary);// boundary不能加引号 metaContent.Headers.ContentType = MediaTypeHeaderValue.Parse("application/json"); fileContent.Headers.ContentType = MediaTypeHeaderValue.Parse(fileContentType); var uri = $"/v3/merchant/media/upload"; var res = await V3UpLoadFile(uri, meta.ToJson(), httpContent); return new MKResult(res, 1); }

 private async Task V3UpLoadFile(string uri, string meta, MultipartFormDataContent content) { var auth = SrvPayBuildAuthAsync(uri, meta); var header = new Dictionary { { "Authorization",$"WECHATPAY2-SHA256-RSA2048 {auth}"}, { "Accept","*/*" }, { "Accept-Encoding","gzip,deflate,brn" }, { "User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.85 Safari/537.36 Edg/90.0.818.46" }, }; return await V3PostFileAsync(uri, header, content); }

 protected async Task V3PostFileAsync(string url, Dictionary headers, MultipartFormDataContent content) { HttpResponseMessage res = null; try { if (headers != null && headers.Count > 0) { foreach (var header in headers) { _client.DefaultRequestHeaders.TryAddWithoutValidation(header.Key, header.Value); } } res = await _client.PostAsync(url, content); res.EnsureSuccessStatusCode(); var result = await res.Content.ReadAsStringAsync(); if (result == null) { return default; } return result.ToJson(); } catch { var result = await res.Content.ReadAsStringAsync(); if (result == null) { return default; } return result.ToJson(); } finally { if (content != null) { content.Dispose(); } } }

 #region 二进制内容进行sha256 private static string GetHash(byte[] bytes) { if (bytes == null) throw new ArgumentNullException(nameof(bytes)); using SHA256 sha = SHA256.Create(); byte[] hashBytes = sha.ComputeHash(bytes); return BitConverter.ToString(hashBytes).Replace("-", "").ToLower(); }

 public static class RSAUtility { public static string RSAEncrypt(string text, Certificates certificateModel) { var bytes = Encoding.UTF8.GetBytes(certificateModel.EncryptCertificate.Ciphertext); using var x509 = new X509Certificate2(bytes); var rsaParam = x509.GetRSAPublicKey().ExportParameters(false); var rsa = new RSACryptoServiceProvider(); rsa.ImportParameters(rsaParam); var buff = rsa.Encrypt(Encoding.UTF8.GetBytes(text), true); return Convert.ToBase64String(buff); } }