// Takes in a file, and pointer to a key and returns the line
// which is encrypted on that file, and saves the key used to
// encrypt that line to the pointer it was passed.
void findNeedle(FILE * haystack, int * needleLine, char * key){
char line[MAX_LINE];
memset(line, 0, MAX_LINE);
int lineNum = 1;
double lowestScore = INT_MAX;
char * encodedBuffer;
//Find the bestScoring phrase
while(fgets(line, MAX_LINE, haystack ) != NULL ){
line[strcspn(line, "\n")] = 0;
int len;
char * buffer = hexStrToBytes(line, &len);
char possibleKey = singleByteDecrypt(buffer, len);
if (possibleKey > -1){
double score = bufferScorer(buffer, len);
if (score < lowestScore){
lowestScore = score;
* needleLine = lineNum;
* key = possibleKey;
encodedBuffer = buffer;
printf("Found message on line: %d, key was: %x, scored: %f\n", lineNum, possibleKey, score);
printf("Message might be:");
printByteBuf(singleByteXOR(encodedBuffer, possibleKey, len), len);
}
} lineNum++;
free(buffer);
}
}
int main(int argc, char *argv[]) {
int bytesLen = 0;
char *bytes = hexStrToBytes(sInputStr, &bytesLen);
if (!bytes) {
printf("Failure! Couldn't convert hex to bytes.\n");
return 1;
}
char *base64Str = malloc(Base64encode_len(bytesLen));
if (!base64Str) {
printf("Failure! Couldn't alloc buffer for base64 string.\n");
return 1;
}
Base64encode(base64Str, bytes, bytesLen);
if (strcmp(base64Str, sOutputStr) == 0) {
printf("Success!\n");
} else {
printf("Failure!\n");
}
free(base64Str);
return 0;
}
int main(int argc, char *argv[]) {
int bytesLen1 = 0;
char *bytes1 = hexStrToBytes(sInputStr1, &bytesLen1);
if (!bytes1) {
printf("Failure! Couldn't convert hex to bytes for first input.\n");
return 1;
}
int bytesLen2 = 0;
char *bytes2 = hexStrToBytes(sInputStr2, &bytesLen2);
if (!bytes2) {
printf("Failure! Couldn't convert hex to bytes for second input.\n");
return 1;
}
char *xorResultStr = malloc(bytesLen1);
if (!xorResultStr) {
printf("Failure! Couldn't alloc buffer for xor result string.\n");
return 1;
}
if (bytesLen1 != bytesLen2) {
printf("Failure! The lengths of both inputs are different.\n");
return 1;
}
xorBytes(bytes1, bytes2, xorResultStr, bytesLen1);
char *aHexStr = malloc(bytesLen1 * 2);
if (!aHexStr) {
printf("Failure! Couldn't alloc buffer for hex string.\n");
return 1;
}
bytesToHexStr(xorResultStr, aHexStr, bytesLen1);
if (strcmp(aHexStr, sOutputStr) == 0) {
printf("Success!\n");
} else {
printf("Failure!\n");
}
free(xorResultStr);
free(aHexStr);
return 0;
}
int main(int argc, char *argv[]) {
int len;
char * aByteBuff = hexStrToBytes(aHexStr, &len);
char key = singleByteDecrypt(aByteBuff, len);
printf("The key was: %c \nThe message is: ", key);
char * result = singleByteXOR(aByteBuff, key, len);
printByteBuf(result, len);
free(result);
}
int main(int argc, char *argv[]) {
int blen;
double *freqMap = readFreqMap(freqFile);
if (!freqMap) {
printf("Couldn't read frequencies");
exit(1);
}
char* inputBytes = hexStrToBytes(inputString, &blen);
if (!inputBytes || !blen) {
printf("Error converting input to hex");
exit(1);
}
char key;
double score;
char *message = crackXOR(inputBytes, blen, freqMap, &key, &score);
printf("The message is: %s\n", message);
printf("The key is: %c\n", key);
free(inputBytes);
free(message);
free(freqMap);
return 0;
}
char * decode(char* hexStr, double* currentScore, char* bestKey){
int bytesLen1 = 0;
char *bytes1 = hexStrToBytes(hexStr, &bytesLen1);
if (!bytes1) {
printf("Failure! Couldn't convert hex to bytes.\n");
return NULL;
}
char *result = malloc(bytesLen1);
static double frequencyTable[NUM_LETTERS] =
{8.617, 1.492,2.782,4.253,12.702,2.228,2.015,6.094,6.966,
.153,.772,4.025,2.406,6.749, 7.507,1.929,.095,5.987,
6.327,9.056,2.758,.0978,2.36,.15,1.974,.074
};
double topScore = 0;
char* bestString = malloc(bytesLen1*2);
//char* bestKey = malloc(sizeof(char));// please please hold the key
for (int x = 0; x <= ASCII_MAX; x++) {
char* letterCount = malloc(sizeof(char)*ASCII_MAX);
for(int y = 0; y<bytesLen1; y++){
result[y] = bytes1[y] ^ (char) x;
result[y] = tolower(result[y]);
letterCount[result[y]] = letterCount[result[y]] + 1;
}
char key = (char)x; //hold this key here, for reference towards the bottom
double score = 100;
for(int x = 0; x < NUM_LETTERS; x++){//for 97-122 (a-z)
score = score - fabs(((double)letterCount[x+97]/(double)bytesLen1)*100.0 - frequencyTable[x]);
}
int spaceTotal = 0;
int punctTotal = 0;
for(int x = 0; x <= ASCII_MAX; x++){
if(ispunct(x)){
punctTotal = punctTotal + letterCount[x];
}
if(isspace(x)){
spaceTotal = spaceTotal + letterCount[x];
}
}
double punctScore = ((double)punctTotal)/((double)bytesLen1)*100.0;
double spaceScore = ((double)spaceTotal)/((double)bytesLen1)*100.0;
//will exclude strings that have too much punctuation
if(punctScore>25.0){
score = -1;
}
//will exclude strings that have too much white space
score = score - fabs(spaceScore - (1.0/6.0)*100.0);
//will keep track of the top scoring string
if(score>topScore){
topScore = score;
*bestKey = key;
for(int s = 0; s < bytesLen1; s++){
bestString[s] = result[s];
}
bestString[bytesLen1] = '\0';
}
}
*currentScore = topScore;
//printf("%c \n", *bestKey); //should print out the key that was used for the best string
//printf("%s \n", bestString);
return bestString;
}
