Java RSA公钥、私钥与C#RSA公钥、私钥转换

最近公司项目需要对接第四方支付接口，但是对方的demo是Java的,给的算法是Java版本的公钥和私钥，如果要做RSA加密就需要将Java的公钥和私钥转换成dotnet版本的公钥和私钥，具体的算法如下：

 1         /// <summary>  
 2         /// RSA私钥格式转换，java->.net  
 3         /// </summary>  
 4         /// <param name="privateKey">java生成的RSA私钥</param>  
 5         /// <returns></returns>  
 6         public static string RSAPrivateKeyJava2DotNet(string privateKey)
 7         {
 8             RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKey));
 9             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>",
10                 Convert.ToBase64String(privateKeyParam.Modulus.ToByteArrayUnsigned()),
11                 Convert.ToBase64String(privateKeyParam.PublicExponent.ToByteArrayUnsigned()),
12                 Convert.ToBase64String(privateKeyParam.P.ToByteArrayUnsigned()),
13                 Convert.ToBase64String(privateKeyParam.Q.ToByteArrayUnsigned()),
14                 Convert.ToBase64String(privateKeyParam.DP.ToByteArrayUnsigned()),
15                 Convert.ToBase64String(privateKeyParam.DQ.ToByteArrayUnsigned()),
16                 Convert.ToBase64String(privateKeyParam.QInv.ToByteArrayUnsigned()),
17                 Convert.ToBase64String(privateKeyParam.Exponent.ToByteArrayUnsigned()));
18         }
19 
20         /// <summary>  
21         /// RSA私钥格式转换，.net->java  
22         /// </summary>  
23         /// <param name="privateKey">.net生成的私钥</param>  
24         /// <returns></returns>  
25         public static string RSAPrivateKeyDotNet2Java(string privateKey)
26         {
27             XmlDocument doc = new XmlDocument();
28             doc.LoadXml(privateKey);
29             BigInteger m = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Modulus")[0].InnerText));
30             BigInteger exp = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Exponent")[0].InnerText));
31             BigInteger d = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("D")[0].InnerText));
32             BigInteger p = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("P")[0].InnerText));
33             BigInteger q = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Q")[0].InnerText));
34             BigInteger dp = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("DP")[0].InnerText));
35             BigInteger dq = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("DQ")[0].InnerText));
36             BigInteger qinv = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("InverseQ")[0].InnerText));
37 
38             RsaPrivateCrtKeyParameters privateKeyParam = new RsaPrivateCrtKeyParameters(m, exp, d, p, q, dp, dq, qinv);
39 
40             PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(privateKeyParam);
41             byte[] serializedPrivateBytes = privateKeyInfo.ToAsn1Object().GetEncoded();
42             return Convert.ToBase64String(serializedPrivateBytes);
43         }
44 
45         /// <summary>  
46         /// RSA公钥格式转换，java->.net  
47         /// </summary>  
48         /// <param name="publicKey">java生成的公钥</param>  
49         /// <returns></returns>  
50         public static string RSAPublicKeyJava2DotNet(string publicKey)
51         {
52             RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey));
53             return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>",
54                 Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()),
55                 Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned()));
56         }
57 
58         /// <summary>  
59         /// RSA公钥格式转换，.net->java  
60         /// </summary>  
61         /// <param name="publicKey">.net生成的公钥</param>  
62         /// <returns></returns>  
63         public static string RSAPublicKeyDotNet2Java(string publicKey)
64         {
65             XmlDocument doc = new XmlDocument();
66             doc.LoadXml(publicKey);
67             BigInteger m = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Modulus")[0].InnerText));
68             BigInteger p = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Exponent")[0].InnerText));
69             RsaKeyParameters pub = new RsaKeyParameters(false, m, p);
70 
71             SubjectPublicKeyInfo publicKeyInfo = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(pub);
72             byte[] serializedPublicBytes = publicKeyInfo.ToAsn1Object().GetDerEncoded();
73             return Convert.ToBase64String(serializedPublicBytes);
74         }