fence code
The so-called fence cipher is to divide the plaintext to be encrypted into groups of N, and then connect the first words of each group to form an irregular sentence. However, there is an unspoken rule in the fence password itself, that is, there should generally not be too many letters forming a fence. (Generally no more than 30, that is, one or two sentences)
Caesar cipher
In cryptography, Caesar cipher (English: Caesar cipher), also known as Caesar cipher, Caesar transformation, transformation cipher, is the simplest and most well-known encryption technology. It is a substitution encryption technique in which all letters in the plaintext are replaced with ciphertext after being shifted backwards (or forwards) by a fixed number in the alphabet. For example, when the offset is 3, all letters A will be replaced with D, B with E, and so on.
MD5
The principle of the MD5 algorithm can be briefly described as follows: MD5 code uses 512-bit groups to process input information, and each group is divided into 16 32-bit sub-groups. After a series of processing, the output of the algorithm consists of four Composed of 32-bit groups, concatenating these four 32-bit groups will generate a 128-bit hash value.
#include<iostream>
#include<string>
using namespace std;
#define shift(x, n) (((x) << (n)) | ((x) >> (32-(n))))//右移的时候，高位一定要补零，而不是补充符号位
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))
#define A 0x67452301
#define B 0xefcdab89
#define C 0x98badcfe
#define D 0x10325476
//strBaye的长度
unsigned int strlength;
//A,B,C,D的临时变量
unsigned int atemp;
unsigned int btemp;
unsigned int ctemp;
unsigned int dtemp;
//常量ti unsigned int(abs(sin(i+1))*(2pow32))
const unsigned int k[]={
0xd76aa478,0xe8c7b756,0x242070db,0xc1bdceee,
0xf57c0faf,0x4787c62a,0xa8304613,0xfd469501,0x698098d8,
0x8b44f7af,0xffff5bb1,0x895cd7be,0x6b901122,0xfd987193,
0xa679438e,0x49b40821,0xf61e2562,0xc040b340,0x265e5a51,
0xe9b6c7aa,0xd62f105d,0x02441453,0xd8a1e681,0xe7d3fbc8,
0x21e1cde6,0xc33707d6,0xf4d50d87,0x455a14ed,0xa9e3e905,
0xfcefa3f8,0x676f02d9,0x8d2a4c8a,0xfffa3942,0x8771f681,
0x6d9d6122,0xfde5380c,0xa4beea44,0x4bdecfa9,0xf6bb4b60,
0xbebfbc70,0x289b7ec6,0xeaa127fa,0xd4ef3085,0x04881d05,
0xd9d4d039,0xe6db99e5,0x1fa27cf8,0xc4ac5665,0xf4292244,
0x432aff97,0xab9423a7,0xfc93a039,0x655b59c3,0x8f0ccc92,
0xffeff47d,0x85845dd1,0x6fa87e4f,0xfe2ce6e0,0xa3014314,
0x4e0811a1,0xf7537e82,0xbd3af235,0x2ad7d2bb,0xeb86d391};
//向左位移数
const unsigned int s[]={7,12,17,22,7,12,17,22,7,12,17,22,7,
12,17,22,5,9,14,20,5,9,14,20,5,9,14,20,5,9,14,20,
4,11,16,23,4,11,16,23,4,11,16,23,4,11,16,23,6,10,
15,21,6,10,15,21,6,10,15,21,6,10,15,21};
const char str16[]="0123456789abcdef";
void mainLoop(unsigned int M[])
{
unsigned int f,g;
unsigned int a=atemp;
unsigned int b=btemp;
unsigned int c=ctemp;
unsigned int d=dtemp;
for (unsigned int i = 0; i < 64; i++)
{
if(i<16){
f=F(b,c,d);
g=i;
}else if (i<32)
{
f=G(b,c,d);
g=(5*i+1)%16;
}else if(i<48){
f=H(b,c,d);
g=(3*i+5)%16;
}else{
f=I(b,c,d);
g=(7*i)%16;
}
unsigned int tmp=d;
d=c;
c=b;
b=b+shift((a+f+k[i]+M[g]),s[i]);
a=tmp;
}
atemp=a+atemp;
btemp=b+btemp;
ctemp=c+ctemp;
dtemp=d+dtemp;
}
/*
*填充函数
*处理后应满足bits≡448(mod512),字节就是bytes≡56（mode64)
*填充方式为先加一个1,其它位补零
*最后加上64位的原来长度
*/
unsigned int* add(string str)
{
unsigned int num=((str.length()+8)/64)+1;//以512位,64个字节为一组
unsigned int *strByte=new unsigned int[num*16]; //64/4=16,所以有16个整数
strlength=num*16;
for (unsigned int i = 0; i < num*16; i++)
strByte[i]=0;
for (unsigned int i=0; i <str.length(); i++)
{
strByte[i>>2]|=(str[i])<<((i%4)*8);//一个整数存储四个字节，i>>2表示i/4 一个unsigned int对应4个字节，保存4个字符信息
}
strByte[str.length()>>2]|=0x80<<(((str.length()%4))*8);//尾部添加1 一个unsigned int保存4个字符信息,所以用128左移
/*
*添加原长度，长度指位的长度，所以要乘8，然后是小端序，所以放在倒数第二个,这里长度只用了32位
*/
strByte[num*16-2]=str.length()*8;
return strByte;
}
string changeHex(int a)
{
int b;
string str1;
string str="";
for(int i=0;i<4;i++)
{
str1="";
b=((a>>i*8)%(1<<8))&0xff; //逆序处理每个字节
for (int j = 0; j < 2; j++)
{
str1.insert(0,1,str16[b%16]);
b=b/16;
}
str+=str1;
}
return str;
}
string getMD5(string source)
{
atemp=A; //初始化
btemp=B;
ctemp=C;
dtemp=D;
unsigned int *strByte=add(source);
for(unsigned int i=0;i<strlength/16;i++)
{
unsigned int num[16];
for(unsigned int j=0;j<16;j++)
num[j]=strByte[i*16+j];
mainLoop(num);
}
return changeHex(atemp).append(changeHex(btemp)).append(changeHex(ctemp)).append(changeHex(dtemp));
}
unsigned int main()
{
string ss;
// cin>>ss;
string s=getMD5("abc");
cout<<s;
return 0;
}
Base64
The most common encryption method, there are corresponding plug-ins in python and burp suite
hexadecimal
#include <stdio.h>
#include <string.h>
int strToHex(char *ch, char *hex);
int hexToStr(char *hex, char *ch);
int hexCharToValue(const char ch);
char valueToHexCh(const int value);
int main(int argc, char *argv[])
{
char ch[1024];
char hex[1024];
char result[1024];
char *p_ch = ch;
char *p_hex = hex;
char *p_result = result;
printf("please input the string:");
scanf("%s",p_ch);
strToHex(p_ch,p_hex);
printf("the hex is:%s\n",p_hex);
hexToStr(p_hex, p_result);
printf("the string is:%s\n", p_result);
return 0;
}
int strToHex(char *ch, char *hex)
{
int high,low;
int tmp = 0;
if(ch == NULL || hex == NULL){
return -1;
}
if(strlen(ch) == 0){
return -2;
}
while(*ch){
tmp = (int)*ch;
high = tmp >> 4;
low = tmp & 15;
*hex++ = valueToHexCh(high); //先写高字节
*hex++ = valueToHexCh(low); //其次写低字节
ch++;
}
*hex = '\0';
return 0;
}
int hexToStr(char *hex, char *ch)
{
int high,low;
int tmp = 0;
if(hex == NULL || ch == NULL){
return -1;
}
if(strlen(hex) %2 == 1){
return -2;
}
while(*hex){
high = hexCharToValue(*hex);
if(high < 0){
*ch = '\0';
return -3;
}
hex++; //指针移动到下一个字符上
low = hexCharToValue(*hex);
if(low < 0){
*ch = '\0';
return -3;
}
tmp = (high << 4) + low;
*ch++ = (char)tmp;
hex++;
}
*ch = '\0';
return 0;
}
int hexCharToValue(const char ch){
int result = 0;
//获取16进制的高字节位数据
if(ch >= '0' && ch <= '9'){
result = (int)(ch - '0');
}
else if(ch >= 'a' && ch <= 'z'){
result = (int)(ch - 'a') + 10;
}
else if(ch >= 'A' && ch <= 'Z'){
result = (int)(ch - 'A') + 10;
}
else{
result = -1;
}
return result;
}
char valueToHexCh(const int value)
{
char result = '\0';
if(value >= 0 && value <= 9){
result = (char)(value + 48); //48为ascii编码的‘0’字符编码值
}
else if(value >= 10 && value <= 15){
result = (char)(value - 10 + 65); //减去10则找出其在16进制的偏移量，65为ascii的'A'的字符编码值
}
else{
;
}
return result;
}
Unicode encoding
There are three specific implementations of Unicode encoding, namely utf-8, utf-16, and utf-32. Among them, utf-8 occupies one to four bytes, utf-16 occupies two or four bytes, and utf-32 occupies four bytes. bytes.
URL encoding
Escape encoding
The escape() function encodes a string so that it can be read on all computers. Some of these characters are replaced with hexadecimal escape sequences.
This encoding does not encode ASCII letters and numbers, nor does it encode the following ASCII punctuation characters: * @ - _ + . /. All other characters will be replaced by escape sequences.
Morse code
bacon code
The Bacon cipher is actually a substitution cipher, which can be encrypted and decrypted according to the one-to-one conversion according to the given table. What's special about it is that password information can be hidden through non-obvious features, such as uppercase and lowercase, italics, etc. As long as there are two different attributes, the password can be hidden.
Pigsty password
ASCII encoding
