[HITCTF](Cyptro)Symphony From Ne

题目链接：
题目链接
资源链接(音频)
资源链接(密文)

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分析：
1.利用搜索引擎找到Symphony From New World的作者是Antonín Dvořák
2.最后关头搜到Dvorak是一种键盘布局,如下图

Dvorak键盘布局 传统键盘布局

3.然后查看题目提供的密文

Paste_Image.png

4.想到有可能是两种键盘字符的对应关系,尝试了前几个字符,发现有实际意义,密文实际上是一串英文.
5.于是编写脚本破译密文:
C语言源码如下:

#include <stdio.h>
#include <stdlib.h>

//Dvorak->QWERTY
void Dvorak_To_QWERT();
//QWERTY->Dvorak
void QWERT_To_Dvorak();

//主函数
int main()
{
    int choose;//1,2表示不同功能
    do{
        fflush(stdin);
        printf("1. Dvorak->QWERT (Please make sure the input is ended with '$')\n");
        printf("2. QWERT->Dvorak (Please make sure the input is ended with '$')\n");
        printf("3. exit\n");
        scanf("%d", &choose);
        if(choose == 1){
            Dvorak_To_QWERT();
        }else if(choose == 2){
            QWERT_To_Dvorak();
        }else if(choose == 3){
            exit(0);
        }
        printf("\n");
    }while(choose != 1 && choose != 2 && choose != 3);
    return 0;
}

//Dvorak->QWERTY
void Dvorak_To_QWERT(){
    int i = 0;//times
    int count = 0;//the length of input string
    char ch[1000];//input string
    printf("Input : \n");
    fflush(stdin);
    while((ch[count] = getchar()) != '$'){
        count++;
    }
    printf("The length is : %d  \n", count);
    printf("Output : \n");
    printf("***********************************\n");
    for(i = 0; i < count; i++){
        if(ch[i] == '['){
            printf("-");
        }else if(ch[i] == '{'){
            printf("_");
        }else if(ch[i] == ']'){
            printf("=");
        }else if(ch[i] == '}'){
            printf("+");
        }else if(ch[i] == '\''){
            printf("q");
        }else if(ch[i] == '"'){
            printf("Q");
        }else if(ch[i] == ','){
            printf("w");
        }else if(ch[i] == '<'){
            printf("W");
        }else if(ch[i] == '.'){
            printf("e");
        }else if(ch[i] == '>'){
            printf("E");
        }else if(ch[i] == 'p'){
            printf("r");
        }else if(ch[i] == 'P'){
            printf("R");
        }else if(ch[i] == 'y'){
            printf("t");
        }else if(ch[i] == 'Y'){
            printf("T");
        }else if(ch[i] == 'f'){
            printf("y");
        }else if(ch[i] == 'F'){
            printf("Y");
        }else if(ch[i] == 'g'){
            printf("u");
        }else if(ch[i] == 'G'){
            printf("U");
        }else if(ch[i] == 'c'){
            printf("i");
        }else if(ch[i] == 'C'){
            printf("I");
        }else if(ch[i] == 'r'){
            printf("o");
        }else if(ch[i] == 'R'){
            printf("O");
        }else if(ch[i] == 'l'){
            printf("p");
        }else if(ch[i] == 'L'){
            printf("P");
        }else if(ch[i] == '/'){
            printf("[");
        }else if(ch[i] == '?'){
            printf("{");
        }else if(ch[i] == '='){
            printf("]");
        }else if(ch[i] == '+'){
            printf("}");
        }else if(ch[i] == 'o'){
            printf("s");
        }else if(ch[i] == 'O'){
            printf("S");
        }else if(ch[i] == 'e'){
            printf("d");
        }else if(ch[i] == 'E'){
            printf("D");
        }else if(ch[i] == 'u'){
            printf("f");
        }else if(ch[i] == 'U'){
            printf("F");
        }else if(ch[i] == 'i'){
            printf("g");
        }else if(ch[i] == 'I'){
            printf("G");
        }else if(ch[i] == 'd'){
            printf("h");
        }else if(ch[i] == 'D'){
            printf("H");
        }else if(ch[i] == 'h'){
            printf("j");
        }else if(ch[i] == 'H'){
            printf("J");
        }else if(ch[i] == 't'){
            printf("k");
        }else if(ch[i] == 'T'){
            printf("K");
        }else if(ch[i] == 'n'){
            printf("l");
        }else if(ch[i] == 'N'){
            printf("L");
        }else if(ch[i] == 's'){
            printf(";");
        }else if(ch[i] == 'S'){
            printf(":");
        }else if(ch[i] == '_'){
            printf("\'");
        }else if(ch[i] == '-'){
            printf("\"");
        }else if(ch[i] == ':'){
            printf("z");
        }else if(ch[i] == ';'){
            printf("Z");
        }else if(ch[i] == 'q'){
            printf("x");
        }else if(ch[i] == 'Q'){
            printf("X");
        }else if(ch[i] == 'j'){
            printf("c");
        }else if(ch[i] == 'J'){
            printf("C");
        }else if(ch[i] == 'k'){
            printf("v");
        }else if(ch[i] == 'K'){
            printf("V");
        }else if(ch[i] == 'x'){
            printf("b");
        }else if(ch[i] == 'X'){
            printf("B");
        }else if(ch[i] == 'b'){
            printf("n");
        }else if(ch[i] == 'B'){
            printf("N");
        }else if(ch[i] == 'w'){
            printf(",");
        }else if(ch[i] == 'W'){
            printf("<");
        }else if(ch[i] == 'v'){
            printf(".");
        }else if(ch[i] == 'V'){
            printf(">");
        }else if(ch[i] == 'z'){
            printf("/");
        }else if(ch[i] == 'Z'){
            printf("?");
        }else{
            printf("%c", ch[i]);
        }
    }
    printf("\n***********************************\n");
    printf("\nFinished!");
}

//QWERTY->Dvorak
void QWERT_To_Dvorak(){
    int i = 0;//times
    int count = 0;//the length of input string
    char ch[1000];//input string
    printf("Input : \n");
    fflush(stdin);
    while((ch[count] = getchar()) != '$'){
        count++;
    }
    printf("The length is : %d  \n", count);
    printf("Output : \n");
    printf("***********************************\n");
    for(i = 0; i < count; i++){
        if(ch[i] == '-'){
            printf("[");
        }else if(ch[i] == '_'){
            printf("{");
        }else if(ch[i] == '='){
            printf("]");
        }else if(ch[i] == '+'){
            printf("}");
        }else if(ch[i] == 'q'){
            printf("\'");
        }else if(ch[i] == 'Q'){
            printf("\"");
        }else if(ch[i] == 'w'){
            printf(",");
        }else if(ch[i] == 'W'){
            printf("<");
        }else if(ch[i] == 'e'){
            printf(".");
        }else if(ch[i] == 'E'){
            printf(">");
        }else if(ch[i] == 'r'){
            printf("p");
        }else if(ch[i] == 'R'){
            printf("P");
        }else if(ch[i] == 't'){
            printf("y");
        }else if(ch[i] == 'T'){
            printf("Y");
        }else if(ch[i] == 'y'){
            printf("f");
        }else if(ch[i] == 'Y'){
            printf("F");
        }else if(ch[i] == 'u'){
            printf("g");
        }else if(ch[i] == 'U'){
            printf("G");
        }else if(ch[i] == 'i'){
            printf("c");
        }else if(ch[i] == 'I'){
            printf("C");
        }else if(ch[i] == 'o'){
            printf("r");
        }else if(ch[i] == 'O'){
            printf("R");
        }else if(ch[i] == 'p'){
            printf("l");
        }else if(ch[i] == 'P'){
            printf("L");
        }else if(ch[i] == '['){
            printf("/");
        }else if(ch[i] == '{'){
            printf("?");
        }else if(ch[i] == ']'){
            printf("=");
        }else if(ch[i] == '}'){
            printf("+");
        }else if(ch[i] == 's'){
            printf("o");
        }else if(ch[i] == 'S'){
            printf("O");
        }else if(ch[i] == 'd'){
            printf("e");
        }else if(ch[i] == 'D'){
            printf("E");
        }else if(ch[i] == 'f'){
            printf("u");
        }else if(ch[i] == 'F'){
            printf("U");
        }else if(ch[i] == 'g'){
            printf("i");
        }else if(ch[i] == 'G'){
            printf("I");
        }else if(ch[i] == 'h'){
            printf("d");
        }else if(ch[i] == 'H'){
            printf("D");
        }else if(ch[i] == 'j'){
            printf("h");
        }else if(ch[i] == 'J'){
            printf("H");
        }else if(ch[i] == 'k'){
            printf("t");
        }else if(ch[i] == 'K'){
            printf("T");
        }else if(ch[i] == 'l'){
            printf("n");
        }else if(ch[i] == 'L'){
            printf("N");
        }else if(ch[i] == ';'){
            printf("s");
        }else if(ch[i] == ':'){
            printf("S");
        }else if(ch[i] == '\''){
            printf("_");
        }else if(ch[i] == '"'){
            printf("-");
        }else if(ch[i] == 'z'){
            printf(":");
        }else if(ch[i] == 'Z'){
            printf(";");
        }else if(ch[i] == 'x'){
            printf("q");
        }else if(ch[i] == 'X'){
            printf("Q");
        }else if(ch[i] == 'c'){
            printf("j");
        }else if(ch[i] == 'C'){
            printf("J");
        }else if(ch[i] == 'v'){
            printf("k");
        }else if(ch[i] == 'V'){
            printf("K");
        }else if(ch[i] == 'b'){
            printf("x");
        }else if(ch[i] == 'B'){
            printf("X");
        }else if(ch[i] == 'n'){
            printf("b");
        }else if(ch[i] == 'N'){
            printf("B");
        }else if(ch[i] == ','){
            printf("w");
        }else if(ch[i] == '<'){
            printf("W");
        }else if(ch[i] == '.'){
            printf("v");
        }else if(ch[i] == '>'){
            printf("V");
        }else if(ch[i] == '/'){
            printf("z");
        }else if(ch[i] == '?'){
            printf("Z");
        }else{
            printf("%c", ch[i]);
        }
    }
    printf("\n***********************************\n");
    printf("\nFinished!");
}

运行的结果如下:

Paste_Image.png

成功拿到flag

后记:

Bug

发现出题人的一个小Bug
在成功翻译出明文后,利用搜索引擎找到了原文
然后利用NodePad的插件Compare进行原文和明文进行比较
发现有两处不同,这也是出题人有一点不严密的地方吧
在写算法的时候可能没有考虑到键盘上某一些符号的转换

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答案：
hitctf{Dv0raks{3ymph0nies{are{gr8}

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知识点：
1.Dvorak键盘布局
2.计算机基本编程