Rating:
# Rotate away
The first challenge is worth 100 points and it is called **Rotate away**. The description of the challenge says:
```
Rotate every damn day of the year
rxms{xqfedafmfqftueftuzs}
Flag format: flag{string}
```
## Solution
Both the name of the challenge and the first row of the description give us an hint about what we have to do; these references to the word *rotate* makes me think about **Caesar's cipher**. The third row of the description tells us that the flag starts with the word *flag*; it's easy to see that the first part of the string in the second row of the description (i.e. *rxms*) is the word *flag* where every character has been shifted by 12 position. It is reasonable to think that the second string is the flag, with every character shifted by 12 positions; to check this hypothesis I created a C program to shift the string and check the resulting string:
```
#include <stdio.h>
#include <string.h>
int main(){
char* msg = "rxms{xqfedafmfqftueftuzs}";
printf("len = %ld\n", strlen(msg));
char plain[strlen(msg) + 1];
int i;
int j;
//iterate through the string
for(i = strlen(msg) - 1; i >= 0; i--){
char new;
if(msg[i] < 123) //do not rotate the parenthesis
//manage the out-of-bound rotation
if(msg[i] - 12 >= 97)
new = msg[i] - 12;
else
new = msg[i] - 12 + 26;
else
new = msg[i];
plain[i] = new;
}
plain[strlen(msg)] = 0; //string terminator
printf("plain = %s\n",plain);
return 0;
}
```
The output of the program is **plain = flag{letsrotatethisthing}**, which is the flag.
