此為工具類，這個和java版本的加密對比過了，結果是一樣的，代碼賦值黏貼直接用，不多比比，直接上代碼（需要在nuget上尋找"Portable.BouncyCastle"包安裝）：
using Org.BouncyCastle.Asn1.Pkcs; using Org.BouncyCastle.Asn1.X509; using Org.BouncyCastle.Crypto; using Org.BouncyCastle.Crypto.Parameters; using Org.BouncyCastle.Math; using Org.BouncyCastle.Pkcs; using Org.BouncyCastle.Security; using Org.BouncyCastle.X509; using System; using System.IO; using System.Security.Cryptography; using System.Text; using System.Xml; public class RSAUtil { /// <summary> /// 生成公鑰與私鑰方法 /// </summary> /// <returns></returns> public static string[] CreateKey(KeyType keyType, KeySize keySize) { try { string[] sKeys = new string[2]; RSACryptoServiceProvider rsa = new RSACryptoServiceProvider((int)keySize); switch (keyType) { case KeyType.XML: { //私鑰 sKeys[0] = rsa.ToXmlString(true); //公鑰 sKeys[1] = rsa.ToXmlString(false); } break; case KeyType.PKS8: { sKeys[0] = rsa.ToXmlString(true); //公鑰 sKeys[1] = rsa.ToXmlString(false); //JAVA私鑰 sKeys[0] = RSAPrivateKeyDotNet2Java(sKeys[0]); //JAVA公鑰 sKeys[1] = RSAPublicKeyDotNet2Java(sKeys[1]); } break; default: break; } return sKeys; } catch (Exception ex) { return null; } } /// <summary> /// 密鑰類型 /// </summary> public enum KeyType { /// <summary> /// xml類型 /// </summary> XML, /// <summary> /// pks8類型 /// </summary> PKS8 } /// <summary> /// 密鑰尺寸(一般都是1024位的) /// </summary> public enum KeySize { SMALL = 1024, BIG = 2048 } /// <summary> /// RSA私鑰格式轉換，.net->java /// </summary> /// <param name="privateKey">.net生成的私鑰</param> /// <returns></returns> public static string RSAPrivateKeyDotNet2Java(string privateKey) { XmlDocument doc = new XmlDocument(); doc.LoadXml(privateKey); BigInteger m = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Modulus")[0].InnerText)); BigInteger exp = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Exponent")[0].InnerText)); BigInteger d = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("D")[0].InnerText)); BigInteger p = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("P")[0].InnerText)); BigInteger q = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Q")[0].InnerText)); BigInteger dp = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("DP")[0].InnerText)); BigInteger dq = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("DQ")[0].InnerText)); BigInteger qinv = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("InverseQ")[0].InnerText)); RsaPrivateCrtKeyParameters privateKeyParam = new RsaPrivateCrtKeyParameters(m, exp, d, p, q, dp, dq, qinv); PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(privateKeyParam); byte[] serializedPrivateBytes = privateKeyInfo.ToAsn1Object().GetEncoded(); return Convert.ToBase64String(serializedPrivateBytes); } /// <summary> /// RSA公鑰格式轉換，.net->java /// </summary> /// <param name="publicKey">.net生成的公鑰</param> /// <returns></returns> public static string RSAPublicKeyDotNet2Java(string publicKey) { XmlDocument doc = new XmlDocument(); doc.LoadXml(publicKey); BigInteger m = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Modulus")[0].InnerText)); BigInteger p = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Exponent")[0].InnerText)); RsaKeyParameters pub = new RsaKeyParameters(false, m, p); SubjectPublicKeyInfo publicKeyInfo = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(pub); byte[] serializedPublicBytes = publicKeyInfo.ToAsn1Object().GetDerEncoded(); return Convert.ToBase64String(serializedPublicBytes); } /// <summary> /// RSA私鑰格式轉換，java->.net /// </summary> /// <param name="privateKey">java生成的RSA私鑰</param> /// <returns></returns> public static string RSAPrivateKeyJavaToDotNet(string privateKey) { RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKey)); return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent><P>{2}</P><Q>{3}</Q><DP>{4}</DP><DQ>{5}</DQ><InverseQ>{6}</InverseQ><D>{7}</D></RSAKeyValue>", Convert.ToBase64String(privateKeyParam.Modulus.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.PublicExponent.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.P.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.Q.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.DP.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.DQ.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.QInv.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.Exponent.ToByteArrayUnsigned())); } /// <summary> /// RSA公鑰格式轉換，java->.net /// </summary> /// <param name="publicKey">java生成的公鑰</param> /// <returns></returns> public static string RSAPublicKeyJavaToDotNet(string publicKey) { RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey)); return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>", Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()), Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned())); } /// <summary> /// 最大加密長度 /// </summary> private const int MAX_ENCRYPT_BLOCK = 245; /// <summary> /// 最大解密長度 /// </summary> private const int MAX_DECRYPT_BLOCK = 256; /// <summary> /// 用私鑰給數據進行RSA加密 /// </summary> /// <param name="xmlPrivateKey"></param> /// <param name="strEncryptString"></param> /// <returns></returns> public static string PrivateKeyEncrypt(string xmlPrivateKey, string strEncryptString) { //加載私鑰 RSACryptoServiceProvider privateRsa = new RSACryptoServiceProvider(); privateRsa.FromXmlString(xmlPrivateKey); //轉換密鑰 AsymmetricCipherKeyPair keyPair = DotNetUtilities.GetKeyPair(privateRsa); IBufferedCipher c = CipherUtilities.GetCipher("RSA/ECB/PKCS1Padding"); //使用RSA/ECB/PKCS1Padding格式 c.Init(true, keyPair.Private);//第一個參數為true表示加密，為false表示解密；第二個參數表示密鑰 byte[] dataToEncrypt = Encoding.UTF8.GetBytes(strEncryptString);//獲取字節 byte[] cache; int time = 0;//次數 int inputLen = dataToEncrypt.Length; int offSet = 0; MemoryStream outStream = new MemoryStream(); while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_ENCRYPT_BLOCK) { cache = c.DoFinal(dataToEncrypt, offSet, MAX_ENCRYPT_BLOCK); } else { cache = c.DoFinal(dataToEncrypt, offSet, inputLen - offSet); } //寫入 outStream.Write(cache, 0, cache.Length); time++; offSet = time * MAX_ENCRYPT_BLOCK; } byte[] resData = outStream.ToArray(); string strBase64 = Convert.ToBase64String(resData); outStream.Close(); return strBase64; } /// <summary> /// 用公鑰給數據進行RSA解密 /// </summary> /// <param name="xmlPublicKey"> 公鑰(XML格式字符串) </param> /// <param name="strDecryptString"> 要解密數據 </param> /// <returns> 解密后的數據 </returns> public static string PublicKeyDecrypt(string xmlPublicKey, string strDecryptString) { //加載公鑰 RSACryptoServiceProvider publicRsa = new RSACryptoServiceProvider(); publicRsa.FromXmlString(xmlPublicKey); RSAParameters rp = publicRsa.ExportParameters(false); //轉換密鑰 AsymmetricKeyParameter pbk = DotNetUtilities.GetRsaPublicKey(rp); IBufferedCipher c = CipherUtilities.GetCipher("RSA/ECB/PKCS1Padding"); //第一個參數為true表示加密，為false表示解密；第二個參數表示密鑰 c.Init(false, pbk); byte[] DataToDecrypt = Convert.FromBase64String(strDecryptString); byte[] cache; int time = 0;//次數 int inputLen = DataToDecrypt.Length; int offSet = 0; MemoryStream outStream = new MemoryStream(); while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_DECRYPT_BLOCK) { cache = c.DoFinal(DataToDecrypt, offSet, MAX_DECRYPT_BLOCK); } else { cache = c.DoFinal(DataToDecrypt, offSet, inputLen - offSet); } //寫入 outStream.Write(cache, 0, cache.Length); time++; offSet = time * MAX_DECRYPT_BLOCK; } byte[] resData = outStream.ToArray(); string strDec = Encoding.UTF8.GetString(resData); return strDec; } /// <summary> /// 簽名 /// </summary> /// <param name="str">需簽名的數據</param> /// <returns>簽名后的值</returns> public static string Sign(string str, string privateKey, SignAlgType signAlgType) { //根據需要加簽時的哈希算法轉化成對應的hash字符節 byte[] bt = Encoding.GetEncoding("utf-8").GetBytes(str); byte[] rgbHash = null; switch (signAlgType) { case SignAlgType.SHA256: { SHA256CryptoServiceProvider csp = new SHA256CryptoServiceProvider(); rgbHash = csp.ComputeHash(bt); } break; case SignAlgType.MD5: { MD5CryptoServiceProvider csp = new MD5CryptoServiceProvider(); rgbHash = csp.ComputeHash(bt); } break; case SignAlgType.SHA1: { SHA1 csp = new SHA1CryptoServiceProvider(); rgbHash = csp.ComputeHash(bt); } break; default: break; } RSACryptoServiceProvider key = new RSACryptoServiceProvider(); key.FromXmlString(privateKey); RSAPKCS1SignatureFormatter formatter = new RSAPKCS1SignatureFormatter(key); formatter.SetHashAlgorithm(signAlgType.ToString());//此處是你需要加簽的hash算法，需要和上邊你計算的hash值的算法一致，不然會報錯。 byte[] inArray = formatter.CreateSignature(rgbHash); return Convert.ToBase64String(inArray); } /// <summary> /// 簽名驗證 /// </summary> /// <param name="str">待驗證的字符串</param> /// <param name="sign">加簽之后的字符串</param> /// <returns>簽名是否符合</returns> public static bool Verify(string str, string sign, string publicKey, SignAlgType signAlgType) { byte[] bt = Encoding.GetEncoding("utf-8").GetBytes(str); byte[] rgbHash = null; switch (signAlgType) { case SignAlgType.SHA256: { SHA256CryptoServiceProvider csp = new SHA256CryptoServiceProvider(); rgbHash = csp.ComputeHash(bt); } break; case SignAlgType.MD5: { MD5CryptoServiceProvider csp = new MD5CryptoServiceProvider(); rgbHash = csp.ComputeHash(bt); } break; case SignAlgType.SHA1: { SHA1 csp = new SHA1CryptoServiceProvider(); rgbHash = csp.ComputeHash(bt); } break; default: break; } RSACryptoServiceProvider key = new RSACryptoServiceProvider(); key.FromXmlString(publicKey); RSAPKCS1SignatureDeformatter deformatter = new RSAPKCS1SignatureDeformatter(key); deformatter.SetHashAlgorithm(signAlgType.ToString()); byte[] rgbSignature = Convert.FromBase64String(sign); if (deformatter.VerifySignature(rgbHash, rgbSignature)) return true; return false; } /// <summary> /// 簽名算法類型 /// </summary> public enum SignAlgType { /// <summary> /// sha256 /// </summary> SHA256, /// <summary> /// md5 /// </summary> MD5, /// <summary> /// sha1 /// </summary> SHA1 } }