c#　rsa加密需要xml公钥  如何将pem格式转换成xml (c# rsa只支持XML格式的)

RSA PEM格式(蓝色部分是 公钥=publicKey )：

-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUABgQD5MIb5ZQhNGhsUjfFbn7y6nY6tsqV9LcC2s/rLpu9sz8CplsTy2SuTG0o7y9ICXW6oRUC9bVxI8TfTK4bbSrNQ6UoExzQFdbc3pEGun3iCy+inBhIC6xf5Z7lN+WqTKCZ607iLwKh+wDdZc6U4x1rxF4vngk1sXIdnYEoGjpRNLQIDAQAB
-----END PUBLIC KEY-----

使用BouncyCastle组件，PM> Install-Package BouncyCastle

/// <summary>
/// RSA公钥格式转换，
/// </summary>
/// <param name="publicKey">pem公钥</param>
/// <returns></returns>
public static string RSAPublicKeyXML(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()));
}

最终写法：

/// <summary>
/// RSA公钥pem-->XML格式转换，
/// </summary>
/// <param name="publicKey">pem公钥</param>
/// <param name="content">要加密的内容：比如密码</param>
/// <returns></returns>
public string RSAPublicKey(string publicKey,string content)
{
RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey));
string XML = string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>",
Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()),
Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned()));

RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
byte[] cipherbytes;
rsa.FromXmlString(XML);
cipherbytes = rsa.Encrypt(Encoding.UTF8.GetBytes(content), false);
return Convert.ToBase64String(cipherbytes);
}

XML to PEM 和 PEM to XML相互转换：

https://superdry.apphb.com/tools/online-rsa-key-converter

在线RSA加密解密，RSA公钥私钥加密解密

http://www.metools.info/code/c81.html

JS加密公钥的方法：

var crypt = new JSEncrypt({
default_key_size: 1024
});
crypt.setPublicKey("MIGfMA0GCSqGSIb3DQEBAQgQDIDOFZiLonAYjlUg+fLIs6HbMFpnw+legVMfVsBB+lnsLYsaPYv/0RMMvjY06uPmdya6ymmYxRieGJiaf0N024oHNqtGnSNK/a8YP1nZLBtBwk2VzEb/rBbdCLhkznIOkNMwy20VG/M5LOXiLkYRry8AEQIDAQAB");
var PWD = crypt.encrypt('1');

console.log(PWD);------------->最终的公钥加密字符串，可以用于向后台接口请求数据。