av_cold int av_cast5_init(AVCAST5* cs, const uint8_t *key, int key_bits)
{
uint8_t newKey[16];
int i;
uint32_t p[4],q[4];
if (key_bits%8||key_bits<40||key_bits>128)
return -1;
memset(newKey,0,sizeof(newKey));
memcpy(newKey,key,key_bits>>3);
cs->rounds = key_bits<=80 ? 12:16;
for (i=0;i<4;i++)
q[i]=AV_RB32(newKey+(4*i));
generate_round_keys(cs->rounds,cs->Km,q,p);
generate_round_keys(cs->rounds,cs->Kr,q,p);
for (i=0;i<cs->rounds;i++)
cs->Kr[i]=cs->Kr[i]&0x1f;
return 0;
}
// given plain text and key, return cipher text
std::bitset<BLOCK_SIZE> encrypt(const std::bitset<BLOCK_SIZE>& input_text, const std::bitset<INPUT_KEY_SIZE>& input_key, bool encrypt) {
std::bitset<BLOCK_SIZE> cipher_block;
// generate initial key
std::bitset<KEY_SIZE> initial_key = generate_initial_key(input_key);
// generate round keys
std::vector<std::bitset<ROUND_KEY_SIZE> > round_keys = generate_round_keys(initial_key);
// split input text into two blocks of 32b
std::bitset<BLOCK_SIZE/2> lower; // use lower to represent bits [0,BLOCK_SIZE/2), and
std::bitset<BLOCK_SIZE/2> upper; // user upper to represent bits [BLOCK_SIZE/2,BLOCK_SIZE)
int mid = input_text.size() / 2;
for (int i = 0; i < input_text.size(); i++)
if (i < mid) lower.set(i, input_text.test(i));
else upper.set(i % mid, input_text.test(i));
std::bitset<BLOCK_SIZE/2> temp; // temporarily hold lower, so that upper can be used in XOR
// if encryption
if (encrypt) {
for (int i = 0; i < ROUND_NUM; ++i) {
//std::cout << "ROUND " << i << "----------------------------------------" << std::endl;
//std::cout << "Using key " << i << ":\t\t" << round_keys[i] << std::endl;
temp = copy_bit_pattern(lower); // hold r_i-1 in temp
lower = perform_round(lower, round_keys[i]);
lower ^= upper; // r_i = f(r_i-1,key) xor l_i-1
upper = copy_bit_pattern(temp); // l_i = r_i-1
std::cout << "ROUND " << i << " ENDED" << "----------------------------------" << std::endl;
}
} else {
// if decryption
for (int i = ROUND_NUM -1; i >= 0; --i) {
//std::cout << "ROUND " << i << "----------------------------------------" << std::endl;
//std::cout << "Using key " << i << ":\t\t" << round_keys[i] << std::endl;
temp = copy_bit_pattern(lower); // hold r_i-1 in temp
lower = perform_round(lower, round_keys[i]);
lower ^= upper; // r_i = f(r_i-1,key) xor l_i-1
upper = copy_bit_pattern(temp); // l_i = r_i-1
//std::cout << "ROUND " << i << " ENDED" << "----------------------------------" << std::endl;
}
}
// perform final swap
for (int i = 0; i < cipher_block.size(); ++i) {
if (i < mid) cipher_block.set(i, upper.test(i));
else cipher_block.set(i, lower.test(i % mid));
}
return cipher_block;
}
void generate_round_keys_time() {
//100000 runs of round_keys to generate mean for this function
uint32_t key[80] = {0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff,0xffffffff};
clock_t start, end, result = 0;
mach_timebase_info_data_t info;
mach_timebase_info(&info);
for(int run = 0; run < 100000; run++) {
uint32_t round_keys[32][64] = {{ 0 }};
start = mach_absolute_time();
generate_round_keys(key, round_keys);
end = mach_absolute_time();
result += (end - start);
for(int bit = 0; bit < 80; bit++) {
key[bit] = 0xffffffff;
}
}
printf("generate_round_keys time: %lu\n", (result / 100000) * info.numer / info.denom);
}
int main(int argc, char *argv[]) {
int nonce_flag = 0;
int nonce;
int i;
int length = atoi(argv[1]);
char* key_string = argv[3];
if (argc > 4) {
nonce = atoi(argv[4]);
nonce_flag = 1;
}
int num_blocks = ceil( (double)length / 8.0);
int pad = length - (length/8)*8;
byte key1 = convert_char_to_hex(key_string[0]);
byte key2 = convert_char_to_hex(key_string[1]);
byte key = (key1 << 4) + key2;
byte* keys = generate_round_keys(key);
printf("Pad:\t\t%d\n", pad);
printf("#Blocks:\t%d\n", num_blocks);
printf("Key:\t\t0x%02X\n", key);
byte IV;
if(nonce_flag) {
IV = generate_IV_from_nonce(nonce, keys);
printf("Nonce:\t\t%d\n", nonce);
} else
IV = 0xA5;
printf("IV:\t\t0x%02X\n", IV);
byte* CTR = (byte*)malloc(num_blocks*sizeof(byte));
for(i = 0; i < num_blocks; i++) {
CTR[i] = generate_IV_from_nonce( IV++, keys);
//printf("CTR%d:\t\t0x%02X\n", i,CTR[i]);
}
char** bitstream = (char**)malloc(num_blocks*sizeof(char*));
for(i = 0; i < num_blocks; i++) {
byte out = encrypt_block(CTR[i], keys);
bitstream[i] = byte_to_bit_string(out);
}
if(pad > 0)
bitstream[num_blocks-1][8-pad] = '\0';
char * outfile = argv[2];
FILE * ofp = fopen(outfile, "w");
if(ofp == NULL) {
printf("Cannot open output file. Exiting...\n");
exit(1);
} else {
for(i = 0; i < num_blocks; i++)
fprintf(ofp, "%s\n", bitstream[i]);
}
fprintf(ofp,"\n");
fclose(ofp);
}
