RSA 登錄加密與解密

  最近公司項目驗收後，客戶請來的信息安全技術人員對咱們的網站進行了各類安全測試與排查問題，其中就有一個登錄時的加密問題。原本若是隻是單純的加密，能夠直接在前臺用MD5加密，將加密的值添加到數據庫便可。可是如今的項目裏有不少的用戶，密碼也是後臺MD5加密了的。這樣就不能單純在前臺用MD5加密，多是本人能力有限，使用的前臺MD5加密與後臺的MD5加密的值不一致，用戶登錄在密碼比對的時候就會失敗登錄不了。只能使用非對稱加密，前臺加密後臺解密後使用MD5加密再做對比，這種作法才能使用改動最少。網上查資料後就使用了RSA非對稱加密。

http://www.javashuo.com/article/p-kdgwcjig-ma.html

前端代碼

 <script src="http://code.jquery.com/jquery-1.8.3.min.js"></script>

 <script src="http://passport.cnblogs.com/scripts/jsencrypt.min.js"></script>

<script>

   var encrypt = new JSEncrypt();

    encrypt.setPublicKey("公鑰能夠用工具生成");
    var userPwd = encrypt.encrypt(輸入的密碼);     //加密後的密碼

</script>

後端代碼

var publicKey = "公鑰能夠用工具生成"

var privateKey = "私鑰能夠用工具生成「

RSACrypto rsaCrypto = new RSACrypto(privateKey, publicKey);
userPwd = rsaCrypto.Decrypt(userPwd);    //解密後的密碼，就是輸入密碼的值

 

/// <summary>
/// RSA非對稱加密
/// </summary>
public class RSACrypto
{
private RSACryptoServiceProvider _privateKeyRsaProvider;
private RSACryptoServiceProvider _publicKeyRsaProvider;

public RSACrypto(string privateKey, string publicKey = null)
{
if (!string.IsNullOrEmpty(privateKey))
{
_privateKeyRsaProvider = CreateRsaProviderFromPrivateKey(privateKey);
}

if (!string.IsNullOrEmpty(publicKey))
{
_publicKeyRsaProvider = CreateRsaProviderFromPublicKey(publicKey);
}
}

public string Decrypt(string cipherText)
{
if (_privateKeyRsaProvider == null)
{
throw new Exception("_privateKeyRsaProvider is null");
}
return Encoding.UTF8.GetString(_privateKeyRsaProvider.Decrypt(System.Convert.FromBase64String(cipherText), false));
}

public string Encrypt(string text)
{
if (_publicKeyRsaProvider == null)
{
throw new Exception("_publicKeyRsaProvider is null");
}
return Convert.ToBase64String(_publicKeyRsaProvider.Encrypt(Encoding.UTF8.GetBytes(text), false));
}

private RSACryptoServiceProvider CreateRsaProviderFromPrivateKey(string privateKey)
{
var privateKeyBits = System.Convert.FromBase64String(privateKey);

var RSA = new RSACryptoServiceProvider();
var RSAparams = new RSAParameters();

using (BinaryReader binr = new BinaryReader(new MemoryStream(privateKeyBits)))
{
byte bt = 0;
ushort twobytes = 0;
twobytes = binr.ReadUInt16();
if (twobytes == 0x8130)
binr.ReadByte();
else if (twobytes == 0x8230)
binr.ReadInt16();
else
throw new Exception("Unexpected value read binr.ReadUInt16()");

twobytes = binr.ReadUInt16();
if (twobytes != 0x0102)
throw new Exception("Unexpected version");

bt = binr.ReadByte();
if (bt != 0x00)
throw new Exception("Unexpected value read binr.ReadByte()");

RSAparams.Modulus = binr.ReadBytes(GetIntegerSize(binr));
RSAparams.Exponent = binr.ReadBytes(GetIntegerSize(binr));
RSAparams.D = binr.ReadBytes(GetIntegerSize(binr));
RSAparams.P = binr.ReadBytes(GetIntegerSize(binr));
RSAparams.Q = binr.ReadBytes(GetIntegerSize(binr));
RSAparams.DP = binr.ReadBytes(GetIntegerSize(binr));
RSAparams.DQ = binr.ReadBytes(GetIntegerSize(binr));
RSAparams.InverseQ = binr.ReadBytes(GetIntegerSize(binr));
}

RSA.ImportParameters(RSAparams);
return RSA;
}

private int GetIntegerSize(BinaryReader binr)
{
byte bt = 0;
byte lowbyte = 0x00;
byte highbyte = 0x00;
int count = 0;
bt = binr.ReadByte();
if (bt != 0x02)
return 0;
bt = binr.ReadByte();

if (bt == 0x81)
count = binr.ReadByte();
else
if (bt == 0x82)
{
highbyte = binr.ReadByte();
lowbyte = binr.ReadByte();
byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };
count = BitConverter.ToInt32(modint, 0);
}
else
{
count = bt;
}

while (binr.ReadByte() == 0x00)
{
count -= 1;
}
binr.BaseStream.Seek(-1, SeekOrigin.Current);
return count;
}

private RSACryptoServiceProvider CreateRsaProviderFromPublicKey(string publicKeyString)
{
// encoded OID sequence for PKCS #1 rsaEncryption szOID_RSA_RSA = "1.2.840.113549.1.1.1"
byte[] SeqOID = { 0x30, 0x0D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01, 0x05, 0x00 };
byte[] x509key;
byte[] seq = new byte[15];
int x509size;

x509key = Convert.FromBase64String(publicKeyString);
x509size = x509key.Length;

// --------- Set up stream to read the asn.1 encoded SubjectPublicKeyInfo blob ------
using (MemoryStream mem = new MemoryStream(x509key))
{
using (BinaryReader binr = new BinaryReader(mem)) //wrap Memory Stream with BinaryReader for easy reading
{
byte bt = 0;
ushort twobytes = 0;

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;

seq = binr.ReadBytes(15); //read the Sequence OID
if (!CompareBytearrays(seq, SeqOID)) //make sure Sequence for OID is correct
return null;

twobytes = binr.ReadUInt16();
if (twobytes == 0x8103) //data read as little endian order (actual data order for Bit String is 03 81)
binr.ReadByte(); //advance 1 byte
else if (twobytes == 0x8203)
binr.ReadInt16(); //advance 2 bytes
else
return null;

bt = binr.ReadByte();
if (bt != 0x00) //expect null byte next
return null;

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();
byte lowbyte = 0x00;
byte highbyte = 0x00;

if (twobytes == 0x8102) //data read as little endian order (actual data order for Integer is 02 81)
lowbyte = binr.ReadByte(); // read next bytes which is bytes in modulus
else if (twobytes == 0x8202)
{
highbyte = binr.ReadByte(); //advance 2 bytes
lowbyte = binr.ReadByte();
}
else
return null;
byte[] modint = { lowbyte, highbyte, 0x00, 0x00 }; //reverse byte order since asn.1 key uses big endian order
int modsize = BitConverter.ToInt32(modint, 0);

int firstbyte = binr.PeekChar();
if (firstbyte == 0x00)
{ //if first byte (highest order) of modulus is zero, don't include it
binr.ReadByte(); //skip this null byte
modsize -= 1; //reduce modulus buffer size by 1
}

byte[] modulus = binr.ReadBytes(modsize); //read the modulus bytes

if (binr.ReadByte() != 0x02) //expect an Integer for the exponent data
return null;
int expbytes = (int)binr.ReadByte(); // should only need one byte for actual exponent data (for all useful values)
byte[] exponent = binr.ReadBytes(expbytes);

// ------- create RSACryptoServiceProvider instance and initialize with public key -----
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
RSAParameters RSAKeyInfo = new RSAParameters();
RSAKeyInfo.Modulus = modulus;
RSAKeyInfo.Exponent = exponent;
RSA.ImportParameters(RSAKeyInfo);

return RSA;
}

}
}

private bool CompareBytearrays(byte[] a, byte[] b)
{
if (a.Length != b.Length)
return false;
int i = 0;
foreach (byte c in a)
{
if (c != b[i])
return false;
i++;
}
return true;
}
}

RSA密鑰對生成工具---------http://web.chacuo.net/netrsakeypair

請選用PKCS#1來生成公鑰與私鑰