WHY2/src/lib/decrypter.c

122 lines
2.7 KiB
C

#include <why2/decrypter.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/time.h>
#include <why2/flags.h>
#include <why2/misc.h>
outputFlags decryptText(char *text, char *keyNew, inputFlags flags)
{
//TIME VARIABLES
struct timeval startTime;
struct timeval finishTime;
gettimeofday(&startTime, NULL);
//CHECK FOR ACTIVE VERSION
checkVersion(flags);
//CHECK FOR INVALID text
checkText(text, flags);
//CHECK FOR INVALID key
checkKey(keyNew, flags);
//REDEFINE keyLength
setKeyLength(strlen(keyNew));
//VARIABLES
char *returningText;
int numberBuffer = 1;
char *textBuffer;
int textKeyChainLength;
int *textKeyChain;
char *key = malloc(strlen(keyNew));
//COPY keyNew TO key
strcpy(key, keyNew);
//GET LENGTH OF returningText AND textKeyChain
for (int i = 0; i < strlen(text); i++)
{
if (text[i] == ENCRYPTION_SEPARATOR) numberBuffer++;
}
//SET LENGTH (numberBuffer)
returningText = malloc(numberBuffer);
textKeyChain = malloc(sizeof(int) * numberBuffer);
int encryptedTextKeyChain[sizeof(int) * numberBuffer];
textKeyChainLength = numberBuffer;
//LOAD textKeyChain
generateTextKeyChain(key, textKeyChain, numberBuffer);
//LOAD encryptedTextKeyChain
for (int i = 0; i < textKeyChainLength; i++)
{
numberBuffer = 0;
//GET LENGTH OF EACH CHARACTER
for (int j = 0; j < strlen(text); j++)
{
if (text[j] == ENCRYPTION_SEPARATOR) break;
numberBuffer++;
}
textBuffer = malloc(numberBuffer);
//LOAD textBuffer
for (int j = 0; j < strlen(text); j++)
{
textBuffer[j] = text[j];
if (numberBuffer == j) break;
}
encryptedTextKeyChain[i] = atoi(textBuffer);
text += numberBuffer + 1;
free(textBuffer);
}
//DECRYPT TEXT
for (int i = 0; i < textKeyChainLength; i++)
{
textKeyChain[i] -= encryptedTextKeyChain[i];
}
//FIX returningText
strcpy(returningText, "");
for (int i = 0; i < textKeyChainLength; i++)
{
strcat(returningText, " ");
}
//LOAD returningText
for (int i = 0; i < textKeyChainLength; i++)
{
returningText[i] = textKeyChain[i];
}
//GET FINISH TIME
gettimeofday(&finishTime, NULL);
//LOAD output
outputFlags output =
{
returningText, //DECRYPTED TEXT
key, //USED KEY
countUnusedKeySize(returningText, key), // NUMBER OF UNUSED CHARS IN KEY
compareTimeMicro(startTime, finishTime), // ELAPSED TIME
SUCCESS //EXIT CODE
};
//DEALLOCATION
free(textKeyChain);
return output;
}