1.解析密钥
/// <summary>
/// 把二进制密钥解析成RSACryptoServiceProvider
/// </summary>
/// <param name="privkey"></param>
/// <returns></returns>
private static RSACryptoServiceProvider DecodeRSAPrivateKey(byte[] privkey)
{
byte[] MODULUS, E, D, P, Q, DP, DQ, IQ;
// --------- Set up stream to decode the asn.1 encoded RSA private key ------
MemoryStream mem = new MemoryStream(privkey);
BinaryReader binr = new BinaryReader(mem); //wrap Memory Stream with BinaryReader for easy reading
byte bt = ;
ushort twobytes = ;
int elems = ;
try
{
twobytes = binr.ReadUInt16();
if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81)
binr.ReadByte(); //advance 1 byte
else if (twobytes == 0x8230)
binr.ReadInt16(); //advance 2 bytes
else
return null; twobytes = binr.ReadUInt16();
if (twobytes != 0x0102) //version number
return null;
bt = binr.ReadByte();
if (bt != 0x00)
return null; //------ all private key components are Integer sequences ----
elems = GetIntegerSize(binr);
MODULUS = binr.ReadBytes(elems); elems = GetIntegerSize(binr);
E = binr.ReadBytes(elems); elems = GetIntegerSize(binr);
D = binr.ReadBytes(elems); elems = GetIntegerSize(binr);
P = binr.ReadBytes(elems); elems = GetIntegerSize(binr);
Q = binr.ReadBytes(elems); elems = GetIntegerSize(binr);
DP = binr.ReadBytes(elems); elems = GetIntegerSize(binr);
DQ = binr.ReadBytes(elems); elems = GetIntegerSize(binr);
IQ = binr.ReadBytes(elems); // ------- create RSACryptoServiceProvider instance and initialize with public key -----
CspParameters CspParameters = new CspParameters();
CspParameters.Flags = CspProviderFlags.UseMachineKeyStore;
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(, CspParameters);
RSAParameters RSAparams = new RSAParameters();
RSAparams.Modulus = MODULUS;
RSAparams.Exponent = E;
RSAparams.D = D;
RSAparams.P = P;
RSAparams.Q = Q;
RSAparams.DP = DP;
RSAparams.DQ = DQ;
RSAparams.InverseQ = IQ;
RSA.ImportParameters(RSAparams);
return RSA;
}
catch (Exception ex)
{
return null;
}
finally
{
binr.Close();
}
}
/// <summary>
/// 二进制解析辅助函数
/// </summary>
/// <param name="binr"></param>
/// <returns></returns>
private static int GetIntegerSize(BinaryReader binr)
{
byte bt = ;
byte lowbyte = 0x00;
byte highbyte = 0x00;
int count = ;
bt = binr.ReadByte();
if (bt != 0x02) //expect integer
return ;
bt = binr.ReadByte(); if (bt == 0x81)
count = binr.ReadByte(); // data size in next byte
else
if (bt == 0x82)
{
highbyte = binr.ReadByte(); // data size in next 2 bytes
lowbyte = binr.ReadByte();
byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };
count = BitConverter.ToInt32(modint, );
}
else
{
count = bt; // we already have the data size
} while (binr.ReadByte() == 0x00)
{ //remove high order zeros in data
count -= ;
}
binr.BaseStream.Seek(-, SeekOrigin.Current); //last ReadByte wasn't a removed zero, so back up a byte
return count;
}
2.导出私钥字符串格式
/// <summary>
/// 导出RSACryptoServiceProvider对象私钥成XML格式
/// </summary>
/// <param name="privatekey"></param>
/// <returns></returns>
public static string GetRSAKeyValueXml(string privatekey)
{
byte[] data = Convert.FromBase64String(privatekey);
RSACryptoServiceProvider rsa = DecodeRSAPrivateKey(data);
return rsa.ToXmlString(true);
}
3.不可解密的方式加密
/// <summary>
/// 加密
/// </summary>
/// <param name="txt">待加密字符串</param>
/// <param name="privatekey">私钥</param>
/// <returns>Base64加案后结果</returns>
public static string SHA1(string txt, string rsaXML)
{
RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
rsa.FromXmlString(rsaXML);
byte[] data = System.Text.Encoding.UTF8.GetBytes(txt);
//
return Convert.ToBase64String(rsa.SignData(data, "SHA1"));
}
4.普通的加密方式
/// <summary>
/// 加密
/// </summary>
/// <param name="txt">待加密字符串</param>
/// <param name="privatekey">私钥</param>
/// <returns>Base64加案后结果</returns>
public static string Encrypt(string txt, string rsaXML)
{
RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
rsa.FromXmlString(rsaXML);
byte[] data = System.Text.Encoding.UTF8.GetBytes(txt);
int MaxBlockSize = rsa.KeySize / - ; //加密块最大长度限制 if (data.Length <= MaxBlockSize)
return Convert.ToBase64String(rsa.Encrypt(data, false));
using (MemoryStream PlaiStream = new MemoryStream(data))
{
using (MemoryStream CrypStream = new MemoryStream())
{
Byte[] Buffer = new Byte[MaxBlockSize];
int BlockSize = PlaiStream.Read(Buffer, , MaxBlockSize); while (BlockSize > )
{
Byte[] ToEncrypt = new Byte[BlockSize];
Array.Copy(Buffer, , ToEncrypt, , BlockSize);
Byte[] Cryptograph = rsa.Encrypt(ToEncrypt, false);
CrypStream.Write(Cryptograph, , Cryptograph.Length);
BlockSize = PlaiStream.Read(Buffer, , MaxBlockSize);
} return Convert.ToBase64String(CrypStream.ToArray(), Base64FormattingOptions.None);
}
}
}
5.普通的解密方式
/// <summary>
/// 解密
/// </summary>
public static string Decrypt(string txt, string rsaXML)
{
RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
rsa.FromXmlString(rsaXML);
byte[] data = Convert.FromBase64String(txt);
int MaxBlockSize = rsa.KeySize / ; //加密块最大长度限制
if (data.Length <= MaxBlockSize)
return System.Text.Encoding.UTF8.GetString(rsa.Decrypt(data, false));
using (MemoryStream PlaiStream = new MemoryStream(data))
{
using (MemoryStream CrypStream = new MemoryStream())
{
Byte[] Buffer = new Byte[MaxBlockSize];
int BlockSize = PlaiStream.Read(Buffer, , MaxBlockSize);
while (BlockSize > )
{
Byte[] ToEncrypt = new Byte[BlockSize];
Array.Copy(Buffer, , ToEncrypt, , BlockSize);
Byte[] Cryptograph = rsa.Decrypt(ToEncrypt, false);
CrypStream.Write(Cryptograph, , Cryptograph.Length);
BlockSize = PlaiStream.Read(Buffer, , MaxBlockSize);
}
return System.Text.Encoding.UTF8.GetString(CrypStream.ToArray());
}
}
}