C#笔记：RC6算法实现
public class RC6Cryptor
{
public byte[] Encrypt(byte[] data, string pwd)
{
SymmetricAlgorithm sa = Rc6.Create();
//
byte[] inputByteArray = data;//得到需要加密的字节数组
//设置密钥及密钥向量
sa.Key = Encoding.UTF8.GetBytes(pwd);
sa.IV = null;
byte[] cipherBytes = null;
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, sa.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
cipherBytes = ms.ToArray();//得到加密后的字节数组
}
}
return cipherBytes;
}
public byte[] Decrypt(byte[] data, string pwd)
{
SymmetricAlgorithm sa = Rc6.Create();
byte[] inputByteArray = data;//得到需要加密的字节数组
//设置密钥及密钥向量
sa.Key = Encoding.UTF8.GetBytes(pwd);
sa.IV = null;
byte[] textBytes = null;
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, sa.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
textBytes = ms.ToArray();//得到加密后的字节数组
}
}
return textBytes;
}
}
public class Rc6 : SymmetricAlgorithm
{
public override ICryptoTransform CreateDecryptor(byte[] rgbKey, byte[] rgbIV)
{
var tempCrytor = new RC6Transform(rgbKey);
tempCrytor.Type = "dec";
return tempCrytor;
}
public override ICryptoTransform CreateEncryptor(byte[] rgbKey, byte[] rgbIV)
{
var tempCrytor = new RC6Transform(rgbKey);
tempCrytor.Type = "enc";
return tempCrytor;
}
public override void GenerateIV()
{
//do nothing
}
public override byte[] Key
{
get
{
return this.KeyValue;
}
set
{
var key = padding(value, 32);
this.KeyValue = key;
}
}
public override byte[] IV
{
get
{
return new byte[1];
}
set
{
if (value != null && value.Length > 1)
throw new CryptographicException("RC6 doesn't use an Initialization Vector.");
}
}
private byte[] padding(byte[] inputBuffer, int BlockSize)
{
if (BlockSize > 255)
{
throw new CryptographicException("The blocksize can not be greater than 255");
}
int count = 0;
if (inputBuffer.Length == 0)
{
count = BlockSize;
}
else if (inputBuffer.Length % BlockSize == 0)
{
return inputBuffer;
}
else
{
count = BlockSize - inputBuffer.Length % BlockSize;
}
byte[] ret = new byte[inputBuffer.Length + count];
for (int i = 0; i < inputBuffer.Length; i++)
{
ret[i] = (byte)inputBuffer[i];
}
for (int i = inputBuffer.Length; i < ret.Length; i++)
{
ret[i] = (byte)count;
}
return ret;
}
public override void GenerateKey()
{
// doNothing
}
public static new Rc6 Create()
{
return new Rc6();
}
}
public class RC6Transform : ICryptoTransform
{
private const int w = 32;
private const int b = 16; //16,24,32
private const int r = 20;
private const uint P32 = 0xB7E15163;
private const uint Q32 = 0x9E3779B9;
private const int bytes = w / 8;
private const int c = (b + bytes - 1) / bytes;
private const int R24 = 2 * r + 4;
private const int lgw = 5;
private uint[] S;
private int keyLen;
public string Type;
public RC6Transform(byte[] key)
{
int Round = 32;
//Round = 16;
//Round = 24;
this.S = new uint[Round * 8]; //选择加密方式128位,192位,256位
this.keyLen = Round;
char[] _key = this.key(key);
this.setup(_key, this.keyLen); //setup(_key, 16);初始化,将私密与系统密钥混合
}
public bool CanReuseTransform
{
get { return true; }
}
public bool CanTransformMultipleBlocks
{
get { return true; }
}
public int InputBlockSize
{
get { return 16; }
}
public int OutputBlockSize
{
get { return 16; }
}
public int TransformBlock(byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
{
if (this.Type == "enc")
{
int length = inputCount;
byte[] orgCopy = new byte[length];
Array.Copy(inputBuffer, inputOffset, orgCopy, 0, length);
orgCopy = this.EncryptBuffer(orgCopy);
Array.Copy(orgCopy, 0, outputBuffer, 0, length);
return length;
}
else
{
int length = inputOffset + inputCount;
byte[] orgCopy = new byte[inputCount];
Array.Copy(inputBuffer, inputOffset, orgCopy, 0, inputCount);
orgCopy = this.DecryptBuffer(orgCopy);
length = length - IsPadding(orgCopy);
Array.Copy(orgCopy, 0, outputBuffer, outputOffset, length);
return length;
}
}
private int IsPadding(byte[] orgCopy)
{
int count = orgCopy[orgCopy.Length - 1];
if (count <= 255)
{
for (int i = orgCopy.Length - 1, j = 0; j < count; i--, j++)
{
if (orgCopy[i] != count)
{
return 0;
}
}
}
else
{
return 0;
}
return count;
}
public byte[] TransformFinalBlock(byte[] inputBuffer, int inputOffset, int inputCount)
{
int length = inputCount;
if (inputCount == 0) return new byte[0];
byte[] ret = padding(inputBuffer, InputBlockSize, inputCount);
ret = this.EncryptBuffer(ret);
return ret;
}
private byte[] padding(byte[] inputBuffer, int BlockSize, int inputCount)
{
int count = BlockSize - inputCount;
byte[] ret = new byte[inputCount + count];
for (int i = 0; i < inputCount; i++)
{
ret[i] = (byte)inputBuffer[i];
}
for (int i = inputCount; i < ret.Length; i++)
{
ret[i] = (byte)count;
}
return ret;
}
public void Dispose()
{
try
{
GC.SuppressFinalize(this);
}
catch { }
}
private uint ROTL(uint x, uint y) { return ((x << (int)(y & (w - 1))) | (x >> (int)(w - (y & (w - 1))))); }
private uint ROTR(uint x, uint y) { return ((x >> (int)(y & (w - 1))) | (x << (int)(w - (y & (w - 1))))); }
public char[] key(byte[] key)
{
// pwd = (pwd.Length % 16 != 0 ? pwd.PadRight(pwd.Length + (16 - (pwd.Length % 16)), ' ') : pwd);
//这里必须保证加密私密的密码长为为16,不足加空隔满足长度需要
byte[] asciiBytes = Encoding.Convert(Encoding.UTF8, Encoding.ASCII, key);
char[] asciiChars = new char[Encoding.ASCII.GetCharCount(asciiBytes, 0, asciiBytes.Length)];
Encoding.ASCII.GetChars(asciiBytes, 0, asciiBytes.Length, asciiChars, 0);
return asciiChars;
}
/// <summary>
/// 初始化并混合用户密钥
/// </summary>
/// <param name="K"></param>
/// <param name="b"></param>
public void setup(char[] K, int b)
{
int i, j, s, v;
uint[] L = new uint[b]; /* Big enough for max b */
uint A, B;
L[b - 1] = 0;
for (i = 15 - 1; i >= 0; i--)
L[i / bytes] = (L[i / bytes] << 8) + K[i];
S[0] = P32;
unchecked
{
for (i = 1; i <= 2 * r + 3; i++)
S[i] = S[i - 1] + Q32;
}
A = B = 0;
i = j = 0;
v = R24;
if (c > v) v = c;
v *= 3;
unchecked
{
for (s = 1; s <= v; s++)
{
A = S[i] = ROTL(S[i] + A + B, 3);
B = L[j] = ROTL(L[j] + A + B, A + B);
i = (i + 1) % R24;
j = (j + 1) % c;
}
}
}
public byte[] EncryptBuffer(byte[] buffer)
{
int UpperBound = buffer.Length - 15;
for (int i = 0; i < UpperBound; i += 16)
{
uint A = BitConverter.ToUInt32(buffer, i);
uint B = BitConverter.ToUInt32(buffer, i + 4);
uint C = BitConverter.ToUInt32(buffer, i + 8);
uint D = BitConverter.ToUInt32(buffer, i + 12);
unchecked
{
B += S[0];
D += S[1];
for (int j = 2; j <= 2 * r; j += 2)
{
uint t = ROTL(B * (2 * B + 1), lgw);
uint u = ROTL(D * (2 * D + 1), lgw);
A = ROTL(A ^ t, u) + S[j];
C = ROTL(C ^ u, t) + S[j + 1];
uint x = A;
A = B;
B = C;
C = D;
D = x;
}
A += S[2 * r + 2];
C += S[2 * r + 3];
}
BitConverter.GetBytes(A).CopyTo(buffer, i);
BitConverter.GetBytes(B).CopyTo(buffer, i + 4);
BitConverter.GetBytes(C).CopyTo(buffer, i + 8);
BitConverter.GetBytes(D).CopyTo(buffer, i + 12);
}
return buffer;
}
public byte[] DecryptBuffer(byte[] buffer)
{
int UpperBound = buffer.Length - 15;
for (int i = 0; i < UpperBound; i += 16)
{
uint A = BitConverter.ToUInt32(buffer, i);
uint B = BitConverter.ToUInt32(buffer, i + 4);
uint C = BitConverter.ToUInt32(buffer, i + 8);
uint D = BitConverter.ToUInt32(buffer, i + 12);
unchecked
{
C -= S[2 * r + 3];
A -= S[2 * r + 2];
for (int j = 2 * r; j >= 2; j -= 2)
{
uint x = D;
D = C;
C = B;
B = A;
A = x;
uint u = ROTL(D * (2 * D + 1), lgw);
uint t = ROTL(B * (2 * B + 1), lgw);
C = ROTR(C - S[j + 1], t) ^ u;
A = ROTR(A - S[j], u) ^ t;
}
D -= S[1];
B -= S[0];
}
BitConverter.GetBytes(A).CopyTo(buffer, i);
BitConverter.GetBytes(B).CopyTo(buffer, i + 4);
BitConverter.GetBytes(C).CopyTo(buffer, i + 8);
BitConverter.GetBytes(D).CopyTo(buffer, i + 12);
}
return buffer;
}
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原始发表：2015-02-15 ，如有侵权请联系 cloudcommunity@tencent.com 删除
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