//Decrypts cipher with AES cipher
void AES::decrypt(int keySize, uint64_t numBytes, uint8_t*& data, uint8_t* key) {
int size=numBytes-16; //don't worry about iv
uint8_t* decrypted=new uint8_t[size];
for(int i=0;i<size;i++) //copy over data
decrypted[i]=data[i+16];
uint8_t* expandedKey=expandKey(keySize,key); //generate expanded key
for(int i=0;i<(int) numBytes/16;i++) { //decrypt each block
decryptBlock(keySize,decrypted+i*16,expandedKey);
}
/*
int padding=decrypted[size-1]; //len of padding
uint8_t* unpadded=new uint8_t[numBytes-padding];
for(int i=0;i<(int)numBytes-padding;i++)
unpadded[i]=decrypted[i];
delete decrypted;
data=unpadded;*/
data=decrypted;
}
//Encrypts stream with AES cipher
void AES::encryptStream (int keySize, uint8_t* iv, std::istream* in, std::ostream* out, uint8_t* key) {
uint8_t* expandedKey=expandKey(keySize,key); //generate expanded key
uint8_t newiv[16]; //temp iv to encrypt
for(int i=0;i<16;i++)
newiv[i]=iv[i];
encryptBlock(keySize,newiv,expandedKey);
out->write((char*)newiv,16);
uint8_t block[16];
uint8_t pnum=1; //padding counter
char c;
while(!in->eof()) {
for(int i=0;i<16;i++) { //read block
c=in->get(); //check if next char is eof
if(!in->eof())
block[i]=(uint8_t) c;
else //pad with chars
block[i]=pnum++;
}
encryptBlock(keySize,block,expandedKey);
out->write((char*)block,16);
}
if(pnum==1) {
for(int i=0;i<16;i++)
block[i]=(uint8_t)i;
encryptBlock(keySize,block,expandedKey);
out->write((char*)block,16);
}
}
//Encrypts plaintext with AES cipher
void AES::encrypt(int keySize, uint64_t numBytes, uint8_t* iv, uint8_t*& data, uint8_t* key) {
int size=numBytes+16; //input array length + iv length
if(numBytes%16!=0)
size+=16-numBytes%16; //pads up to block size
else
size+=16; //else pads another block
uint8_t* encrypted=new uint8_t[size]; //output array
for(int i=0;i<16;i++) //copy over iv
encrypted[i]=iv[i];
uint8_t pnum=1;
for(int i=16;i<size;i++) { //copy over array, pad if necessary
if(i<(int) numBytes)
encrypted[i]=data[i];
else
encrypted[i]=pnum++;
}
data=encrypted;
uint8_t* expandedKey=expandKey(keySize,key); //generate expanded key
for(int i=0;i<size/16;i++) { //encrypt each block
encryptBlock(keySize,data+i*16,expandedKey);
}
}
//Decrypts stream with AES cipher
void AES::decryptStream (int keySize, std::istream* in, std::ostream* out, uint8_t* key) {
uint8_t* expandedKey=expandKey(keySize,key); //generate expanded key
uint8_t block[16];
in->read((char*)block,16); //skips first 16 bytes of iv
while(!in->eof()) {
in->read((char*)block,16);
decryptBlock(keySize,block,expandedKey);
in->get(); //check if next is eof
if(!in->eof()) {
out->write((char*)block,16);
}
else {
out->write((char*)block,16-block[15]);
}
in->unget(); //go back
}
}
int main(int argc, char *argv[])
{
//skip argv[0]
argc--;
argv++;
if(argc <= 0) //No arguments provided
{
fprintf(stderr, "Please enter command line arguments.\n");
printUsage();
return EXIT_FAILURE;
}
//tablecheck
if(strcmp(*argv, "tablecheck") == 0)
{
if(argc-1 < 1 || argc-1 > 1)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
char* tablefile = malloc(100*sizeof(char));
for(argc--; argc>0; argc--)
{
argv++;
if(strlen(*argv) < 4)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
//tablefile
if(argv[0][0]=='-' && argv[0][1]=='t' && argv[0][2]=='=')
{
//Get tablefile from argv
int i=0;
for(i=3; i<strlen(*argv); i++)
{
tablefile[i-3] = argv[0][i];
}
tablefile[i-3] = '\0';
}
else
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
}
checkTable(tablefile);
}
//modprod
else if(strcmp(*argv, "modprod") == 0)
{
//Get hold of arguments
char* poly1 = malloc(100*sizeof(char));
char* poly2 = malloc(100*sizeof(char));
//No, less or extra parameters for modprod
if(argc-1 < 2 || argc-1 > 2)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
for(argc--; argc>0; argc--)
{
argv++;
if(strlen(*argv) < 5)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
//poly1
if(argv[0][0]=='-' && argv[0][1]=='p' && argv[0][2]=='1' && argv[0][3]=='=')
{
//Get poly1 from argv
int i=0;
for(i=4; i<strlen(*argv); i++)
{
poly1[i-4] = argv[0][i];
}
poly1[i-4] = '\0';
}
//poly2
else if(argv[0][0]=='-' && argv[0][1]=='p' && argv[0][2]=='2' && argv[0][3]=='=')
{
//Get poly2 from argv
int i=0;
for(i=4; i<strlen(*argv); i++)
{
poly2[i-4] = argv[0][i];
}
poly2[i-4] = '\0';
}
else
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
}
if(strlen(poly1) == 0 || strlen(poly2) == 0)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
computeModprod(poly1, poly2);
free(poly1);
free(poly2);
}
//keyexpand
else if(strcmp(*argv, "keyexpand") == 0)
{
//Get hold of arguments
char* key = malloc(100*sizeof(char));
char* tablefileName = malloc(100*sizeof(char));
//No, less or extra parameters for keyexpand
if(argc-1 < 2 || argc-1 > 2)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
for(argc--; argc>0; argc--)
{
argv++;
if(strlen(*argv) < 4)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
//key
if(argv[0][0]=='-' && argv[0][1]=='k' && argv[0][2]=='=')
{
//Get key from argv
int i=0;
for(i=3; i<strlen(*argv); i++)
{
key[i-3] = argv[0][i];
}
key[i-3] = '\0';
}
//tablefile
else if(argv[0][0]=='-' && argv[0][1]=='t' && argv[0][2]=='=')
{
//Get tablefile from argv
int i=0;
for(i=3; i<strlen(*argv); i++)
{
tablefileName[i-3] = argv[0][i];
}
tablefileName[i-3] = '\0';
}
else
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
}
if(strlen(key) == 0 || strlen(tablefileName) == 0)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
expandKey(key, tablefileName);
free(key);
free(tablefileName);
}
//Encrypt - Decrypt
else if(strcmp(*argv, "encrypt") == 0 || strcmp(*argv, "decrypt") == 0)
{
char command[10]="";
if(strcmp(*argv, "encrypt") == 0)strcpy(command, "encrypt");
if(strcmp(*argv, "decrypt") == 0)strcpy(command, "decrypt");
//Get hold of arguments
char* key = malloc(100*sizeof(char));
char* tableFileName = malloc(100*sizeof(char));
char* file = malloc(100*sizeof(char));
*file='\0';
//No, less or extra parameters
if(argc-1 < 2 || argc-1 > 3)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
for(argc--; argc>0; argc--)
{
argv++;
//Commanldine option encountered
if(argv[0][0] == '-')
{
if(strlen(*argv) < 4)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
//key
if(argv[0][0]=='-' && argv[0][1]=='k' && argv[0][2]=='=')
{
//Get key from argv
int i=0;
for(i=3; i<strlen(*argv); i++)
{
key[i-3] = argv[0][i];
}
key[i-3] = '\0';
}
else if(argv[0][0]=='-' && argv[0][1]=='t' && argv[0][2]=='=')
{
//Get tableFileName from argv
int i=0;
for(i=3; i<strlen(*argv); i++)
{
tableFileName[i-3] = argv[0][i];
}
tableFileName[i-3] = '\0';
}
else
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
}
//file
else if(strlen(*argv) > 0)
{
//Get file from argv
int i=0;
for(i=0; i<strlen(*argv); i++)
{
file[i] = argv[0][i];
}
file[i] = '\0';
}
}
//Check for errors
if(strlen(key)==0 || strlen(tableFileName)==0)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
else
{
if(strcmp(command, "encrypt")==0 || strcmp(command, "decrypt")==0)
{
//CHECK FORMAT OF KEY
/*if(strlen(key)!=16)
{
fprintf(stderr, "Key should be 8-bytes long, in hexstring format.\n");
printUsage();
return EXIT_FAILURE;
}
else if(strlen(key)==16)
{
int k=0;
for(k=0; k<16; k++)
{
if(key[k] < 48 || (key[k] > 57 && key[k] < 97) || key[k] > 102)
{
fprintf(stderr, "Key is not in hexstring format.\n");
printUsage();
return EXIT_FAILURE;
}
}
}*/
}
}
if(strlen(key) == 0 || strlen(tableFileName) == 0)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
if(strcmp(command, "encrypt") == 0) performEncrypt(key, tableFileName, file);
if(strcmp(command, "decrypt") == 0) performDecrypt(key, tableFileName, file);
free(key);
free(tableFileName);
free(file);
}
//inverse
else if(strcmp(*argv, "inverse") == 0)
{
if(argc-1 < 1 || argc-1 > 1)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
char* poly = malloc(100*sizeof(char));
for(argc--; argc>0; argc--)
{
argv++;
if(strlen(*argv) < 4)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
//poly
if(argv[0][0]=='-' && argv[0][1]=='p' && argv[0][2]=='=')
{
//Get tablefile from argv
int i=0;
for(i=3; i<strlen(*argv); i++)
{
poly[i-3] = argv[0][i];
}
poly[i-3] = '\0';
}
}
if(strlen(poly) == 0)
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
computeInverse(poly);
}
else
{
fprintf(stderr, "Malformed command.\n");
printUsage();
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
