base 64 解码
base64 bb = new base64();
string orgStr= Encoding.Default.GetString(bb.GetDecoded("base64编译后的字符"));
UTF8
Subject = Encoding.GetEncoding("utf-8").GetString(Convert.FromBase64String("utf编译后的字符"));
base64加密
public class base64
{
char[] source;
int length, length2, length3;
int blockCount;
int paddingCount;
public static base64 Decoder = new base64();
public base64()
{ }
private void init(char[] input)
{
int temp = 0;
source = input;
length = input.Length; for (int x = 0; x < 2; x++)
{
if (input[length - x - 1] == '=')
temp++;
}
paddingCount = temp; blockCount = length / 4;
length2 = blockCount * 3;
}
/// <summary>
/// 加密后的字符串解密
/// </summary>
/// <param name="strInput"></param>
/// <returns></returns>
public byte[] GetDecoded(string strInput)
{
//初始化
init(strInput.ToCharArray()); byte[] buffer = new byte[length];
byte[] buffer2 = new byte[length2]; for (int x = 0; x < length; x++)
{
buffer[x] = char2sixbit(source[x]);
} byte b, b1, b2, b3;
byte temp1, temp2, temp3, temp4; for (int x = 0; x < blockCount; x++)
{
temp1 = buffer[x * 4];
temp2 = buffer[x * 4 + 1];
temp3 = buffer[x * 4 + 2];
temp4 = buffer[x * 4 + 3]; b = (byte)(temp1 << 2);
b1 = (byte)((temp2 & 48) >> 4);
b1 += b; b = (byte)((temp2 & 15) << 4);
b2 = (byte)((temp3 & 60) >> 2);
b2 += b; b = (byte)((temp3 & 3) << 6);
b3 = temp4;
b3 += b; buffer2[x * 3] = b1;
buffer2[x * 3 + 1] = b2;
buffer2[x * 3 + 2] = b3;
} length3 = length2 - paddingCount;
byte[] result = new byte[length3]; for (int x = 0; x < length3; x++)
{
result[x] = buffer2[x];
} return result;
} private byte char2sixbit(char c)
{
char[] lookupTable = new char[64]{
'A','B','C','D','E','F','G','H','I','J','K','L','M','N',
'O','P','Q','R','S','T','U','V','W','X','Y', 'Z',
'a','b','c','d','e','f','g','h','i','j','k','l','m','n',
'o','p','q','r','s','t','u','v','w','x','y','z',
'0','1','2','3','4','5','6','7','8','9','+','/'};
if (c == '=')
return 0;
else
{
for (int x = 0; x < 64; x++)
{
if (lookupTable[x] == c)
return (byte)x;
} return 0;
} } /// <summary>
/// Base64解密，采用utf8编码方式解密
/// </summary>
/// <param name="result">待解密的密文</param>
/// <returns>解密后的字符串</returns>
public static string DecodeBase64(string result)
{
return DecodeBase64(Encoding.UTF8, result);
}
/// <summary>
/// Base64解密
/// </summary>
/// <param name="codeName">解密采用的编码方式，注意和加密时采用的方式一致</param>
/// <param name="result">待解密的密文</param>
/// <returns>解密后的字符串</returns>
public static string DecodeBase64(Encoding encode, string result)
{
string decode = "";
byte[] bytes = Convert.FromBase64String(result);
try
{
decode = encode.GetString(bytes);
}
catch
{
decode = result;
}
return decode;
}
/// <summary>
/// Base64加密
/// </summary>
/// <param name="codeName">加密采用的编码方式</param>
/// <param name="source">待加密的明文</param>
/// <returns></returns>
public static string EncodeBase64(Encoding encode, string source)
{
string decode = "";
byte[] bytes = encode.GetBytes(source);
try
{
decode = Convert.ToBase64String(bytes);
}
catch
{
decode = source;
}
return decode;
} /// <summary>
/// Base64加密，采用utf8编码方式加密
/// </summary>
/// <param name="source">待加密的明文</param>
/// <returns>加密后的字符串</returns>
public static string EncodeBase64(string source)
{
return EncodeBase64(Encoding.UTF8, source);
}
}