C# RSA-OAEP Encrypt

csharp_rsa_oaep_encrypt.cs

using System;
using System.Text;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;

namespace Qiniu.Util
{
	public static class Base64URLSafe
	{
		public static string Encode (string text)
		{
			if (String.IsNullOrEmpty (text))
				return "";
			byte[] bs = Encoding.UTF8.GetBytes (text);
			string encodedStr = Convert.ToBase64String (bs);
			encodedStr = encodedStr.Replace ('+', '-').Replace ('/', '_');
			return encodedStr;
		}

		/// <summary>
		/// string扩展方法，生成base64UrlSafe
		/// </summary>
		/// <param name="str"></param>
		/// <returns></returns>
		public static string ToBase64URLSafe (string str)
		{
			return Encode (str);
		}

		public static string Encode (byte[] bs)
		{
			if (bs == null || bs.Length == 0)
				return "";
			string encodedStr = Convert.ToBase64String (bs,Base64FormattingOptions.None);
			encodedStr = encodedStr.Replace ('+', '-').Replace ('/', '_');
			return encodedStr;
		}

        static readonly string publickey = @"<RSAKeyValue><Modulus>MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAygGoUiTD+LjwZIgwFZyjiibWNQ2LM9xZ2pjKQGP8iUBtAuAW629/Ofw8qxToMyixPrG4A7j8+KOPwYrWPGV6Og//4zm3cG+1hQvnNUWtMjHHBY8OByUPQ6/T8XHER1DxFBfnWfFLZ1yFX6oNNuvtLgOreI6ehehJd5IB/4mOjMvFEBgOEejado2n55VNdcFpdQ3RcvGV+f/rl/lsIM08QvL3lc5gqawj53sW9YZi1DL/uN48R+ghvAYhtx2jpHDBvlH1NCF1rU6CynYsgV9QIksv0ihwl4T+k5F9ir0uv0WIS6kKKS1SRpAprRKunos4PlE8l2+jC6LaJUPhDZlj/wID</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";

        /// <summary> 
        /// RSA加密
        /// </summary>
        /// <param name="content"></param>
        /// <returns></returns>
        public static string RSAEncrypt(string content)
        {
            using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())
            {
                byte[] cipherbytes;
                rsa.FromXmlString(publickey);
                byte[] contentBytes = UTF8Encoding.UTF8.GetBytes(content);
                cipherbytes = rsa.Encrypt(contentBytes, true);       //以RSA的OAEP加密方式
                string encodedStr = Encode(cipherbytes);
                return encodedStr;
            }
        }
	}
}