标签：decode 加密 convert name break static ret bre ++
private static string base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
private static int[] base64DecodeChars ={
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1 };
///
/// Base64加密
///
///
///
public static string Base64Encode(string str)
{
string res = "";
int i = 0, len;
int c1, c2, c3;
len = str.Length;
i = 0;
res = "";
while (i len)
{
c1 = Convert.ToByte(str[i++]) & 0xff;
if (i == len)
{
res += base64EncodeChars.CharAt(c1 >> 2);
res += base64EncodeChars.CharAt((c1 & 0x3) 4);
res += "==";
break;
}
c2 = Convert.ToByte(str[i++]);
if (i == len)
{
res += base64EncodeChars.CharAt(c1 >> 2);
res += base64EncodeChars.CharAt(((c1 & 0x3) 4) | ((c2 & 0xF0) >> 4));
res += base64EncodeChars.CharAt((c2 & 0xF) 2);
res += "=";
break;
}
c3 = Convert.ToByte(str[i++]);
res += base64EncodeChars.CharAt(c1 >> 2);
res += base64EncodeChars.CharAt(((c1 & 0x3) 4) | ((c2 & 0xF0) >> 4));
res += base64EncodeChars.CharAt(((c2 & 0xF) 2) | ((c3 & 0xC0) >> 6));
res += base64EncodeChars.CharAt(c3 & 0x3F);
}
return res;
}
///
/// Base64加解密
///
///
///
public static string Base64Decode(string str)
{
string res = "";
int i = 0, len;
int c1, c2, c3, c4;
len = str.Length;
len = str.Length;
i = 0;
res = "";
while (i len)
{
/* c1 */
do
{
c1 = base64DecodeChars[Convert.ToByte(str[i++]) & 0xff];
} while (i 1);
if (c1 == -1)
break;
/* c2 */
do
{
c2 = base64DecodeChars[Convert.ToByte(str[i++]) & 0xff];
} while (i 1);
if (c2 == -1)
break;
res += Convert.ToChar((c1 2) | ((c2 & 0x30) >> 4));
/* c3 */
do
{
c3 = Convert.ToByte(str[i++]) & 0xff;
if (c3 == 61)
return res;
c3 = base64DecodeChars[c3];
} while (i 1);
if (c3 == -1)
break;
res += Convert.ToChar(((c2 & 0XF) 4) | ((c3 & 0x3C) >> 2));
/* c4 */
do
{
c4 = Convert.ToByte(str[i++]) & 0xff;
if (c4 == 61)
return res;
c4 = base64DecodeChars[c4];
} while (i 1);
if (c4 == -1)
break;
res += Convert.ToChar(((c3 & 0x03) 6) | c4);
}
return res;
}
c# Base64解密加密
标签：decode 加密 convert name break static ret bre ++
原文地址：https://www.cnblogs.com/yuanzijian-ruiec/p/9734263.html