/*16 round feistel network with 64 bit block length and 56 bit keylength*/
int des(int key, int message){
//split message into left and right halves
//for-loop calling sboxes and keyschedule
int left = //LEFT OF THE MESSAGE;
int right = //RIGHT OF THE MESSAGE;
int round;
for(round = 0; round < 16; round++){
int oldleft = left;
left = right;
right = XOR(oldleft, mangler(keyschedule(key,round),right)); //fix this
}
return left CONCAT right; //fix this; perform concatenation
}
/*
* DES decryption of input from FILE pointer `fp' using key `sKey' and
* tables specified in file `tablefile'.
*/
void decrypt(const char* sKey, const char* tablefile, FILE* fp)
{
uint8_t buf[8]; /* block size is 64 bits */
memset(buf, 0, 8 * sizeof(uint8_t));
int keys[16][48]; /* represent each key bit as an integer */
for (int i = 0; i < 16; ++i) {
memset(keys[i], 0, 48 * sizeof(int));
}
int** table = tablecheck(tablefile);
int* V = table[11];
int* PC1 = table[12];
int* PC2 = table[13];
keyschedule(sKey, V, PC1, PC2, keys);
reverse(keys, 16);
int m[64];
int res[64];
memset(m, 0, 64 * sizeof(int));
memset(res, 0, 64 * sizeof(int));
while (!feof(fp)) {
memset(buf, 0, 8 * sizeof(uint8_t));
int nObj = 0;
for (int i =0; i < 8; ++i) {
nObj = fread(&buf[i], 1, 1, fp);
if (nObj == 0) {
if (i == 0) {
return;
}
else {
break;
}
}
}
unpack(buf, m);
des(m, table, keys, res);
pack(res, buf);
fwrite(buf, 1, 8, stdout);
}
}
void ubiimplement(void)//function to implement the ubi chaining mode
{
int originalsize,i1,mini,w,j,tempe[100000],tempe1[128],i,tempe2[127],maxaddvalue,tempe3[128],tweakbyte1[16];
originalsize=sizeofplaintext;
while((sizeofplaintext%32)!=0)//making the size of plaintext a multiple of 32 bytes
{
plaintext[sizeofplaintext]=0;
sizeofplaintext=sizeofplaintext+1;
}
bytestowords(plaintext,0,sizeofplaintext);//converting from bytes to 64 bit words for use in threefish
for(i1=1;i1<=(sizeofplaintext/32);i1++)//the rounds in ubi chaining mode
{
mini=originalsize;//implementing the generation of tweak value for each round
if(mini<(i*32))
mini=(i*32);
w=0;
for(j=mini;j!=0;j=(j/2))//converting to bits
{
tempe[w]=(j%2);
w=w+1;
}
for(i=0,j=127;i<128;i++,j--)//inverting input tweak
{
tempe1[i]=tweak[j];
}
addbyte(tempe1,tempe,128,w);//performing bit addition
if(w>128)
maxaddvalue=w;
else
maxaddvalue=128;
if((i1-1)==0)
{
for(i=0;i<126;i++)//finding 2^126
{
tempe2[i]=0;
}
tempe2[i]=1;
addbyte(addvalue,tempe2,maxaddvalue,127);//adding bits
if(maxaddvalue<127)//updating max array size
maxaddvalue=127;
}
if(i1==(sizeofplaintext-1))
{
for(i=0;i<127;i++)//finding 2^127
{
tempe3[i]=0;
}
tempe3[i]=1;
addbyte(addvalue,tempe3,maxaddvalue,128);//adding bits
if(maxaddvalue<128)//updating max array size
maxaddvalue=128;
}
changebyte(addvalue,maxaddvalue);//changing to byte format from bits
for(i=0,j=15;i<16;i++,j--)//changing to lsb first mode
{
tweakbyte1[i]=tweakbyte[j];
}
bytestowords(blockcipherkey,1,32);//changing from bytes to 64-bit words for threefish
bytestowords(tweakbyte1,2,16);
keyschedule();//generating key schedule
rounds();//performing rounds in threefish
for(i=0;i<32;i++)//generating block cipher key for next ubi round
{
blockcipherkey[i]=ciphertext[i];
if(move1<originalsize)
{
entireciphertext[move1]=ciphertext[i];
move1=move1+1;
}
}
}
}
