public static string Decrypt(string Source, string Key)
{
if (String.IsNullOrEmpty(Source))
{
throw new Exception("没有输入密文！");
}
else if (Source.Length % 16 != 0)
{
throw new Exception("密文长度有误！（密文长度须为16的倍数）");
}
if (Encoding.Default.GetBytes(Key).Length != 8)
{
throw new Exception("密钥个数必须为8个字符或4个汉字！");
}
try
{
//用于检测，"密文内容有误！（密文内容应为16进制）"
int temp;
for (int i = 0; i < Source.Length; i++)
{
temp = Convert.ToInt32(Source[i].ToString(), 16);
}
}
catch
{
throw new Exception("密文内容有误！（密文内容应为16进制）");
}
IdeaKey key = new IdeaKey(Key, false);
IdeaCipher idea = new IdeaCipher(Source, false, key);
return(idea.GetOutStr());
}
public static string Encrypt(string Source, string Key)
{
if (String.IsNullOrEmpty(Source))
{
throw new Exception("没有输入明文！");
}
if (Encoding.UTF8.GetBytes(Key).Length != 8)
{
throw new Exception("密钥个数必须为8个字符或4个汉字！");
}
IdeaKey key = new IdeaKey(Key, true);
IdeaCipher idea = new IdeaCipher(Source, true, key);
return(idea.GetOutStr());
}
public IdeaCipher(string str, bool flag, IdeaKey key)
{
this.flag = flag;
if (flag == true)
{
int blank = 8 - (Encoding.Unicode.GetBytes(str).Length) % 8;
if (blank != 8)
{
for (int i = 0; i < blank; i++)
{
str += " ";
}
}
byte[] strByte = Encoding.Unicode.GetBytes(str);
StringBuilder strbdr = new StringBuilder();
for (int i = 0; i < strByte.Length; i++)
{
for (int j = 7; j >= 0; j--)
{
strbdr.Append(((strByte[i] >> j) & 1));
}
}
str = strbdr.ToString();
}
else
{
StringBuilder instrbd = new StringBuilder();
int inint = 0;
string instr = null;
for (int i = 0; i < str.Length; i++)
{
inint = Convert.ToInt32(str.Substring(i, 1), 16);
instr = Convert.ToString(inint, 2);
while (instr.Length < 4)
{
instr = 0 + instr;
}
instrbd.Append(instr);
}
str = instrbd.ToString();
}
string m1, m2, m3, m4;
string[] c = new string[15];
for (int n = 0; n < str.Length / 64; n++)
{
m1 = str.Substring(n * 64, 16);
m2 = str.Substring(n * 64 + 16, 16);
m3 = str.Substring(n * 64 + 32, 16);
m4 = str.Substring(n * 64 + 48, 16);
int pos = 1;
for (int i = 0; i < 8; i++)//8轮的加密变换
{
c[1] = Mul(m1, key.getKey(pos++));
c[2] = Add(m2, key.getKey(pos++));
c[3] = Add(m3, key.getKey(pos++));
c[4] = Mul(m4, key.getKey(pos++));
c[5] = Xor(c[1], c[3]);
c[6] = Xor(c[2], c[4]);
c[7] = Mul(c[5], key.getKey(pos++));
c[8] = Add(c[6], c[7]);
c[9] = Mul(c[8], key.getKey(pos++));
c[10] = Add(c[7], c[9]);
c[11] = Xor(c[1], c[9]);
c[12] = Xor(c[3], c[9]);
c[13] = Xor(c[2], c[10]);
c[14] = Xor(c[4], c[10]);
m1 = c[11];
m2 = c[13];
m3 = c[12];
m4 = c[14];
}
c[11] = Mul(m1, key.getKey(pos++));//开始第9轮的变换
c[12] = Add(m2, key.getKey(pos++));
c[13] = Add(m3, key.getKey(pos++));
c[14] = Mul(m4, key.getKey(pos++));
outStr = outStr + c[11] + c[12] + c[13] + c[14];
}
}
