// Returns true if string is not correctly formatted
bool not_formatted(unsigned char *str) {
if (b64len(str) < E_KEY_SIZE) {
err(ERR_FMT, "Number of Base64 encoded characters less than keysize");
return true;
}
return false;
}
// Convert encoded string to dheluks data package
// has_msg = false: package contains bare minimum (header + pubkey)
// has_msg = true: package contains a message (header + pubkey + nonce + cphtxt)
int str_to_pkg(unsigned char *str, dheluks_pkg_t *pkg, bool has_msg) {
if (not_dheluks(str)) //if the string is not a dheluks string,
return -1; //return error
if (str[VSN_POSITION] == '0') {
int codelen; //length of encoded data (not including header)
size_t datalen; //length of decoded data (not including header)
uint8_t *data; //holds decoded data
codelen = b64len(str+HEADER_LEN); //codlen = length of b64 chars after header
data = malloc(codelen); //it will be less than size of code
datalen = str_to_uint8(str+HEADER_LEN, data, codelen); //convert string to data
memcpy(pkg->pubkey, data, KEY_SIZE); //place key into package
if (has_msg == true) { //if there supposed to be a message
if (datalen - KEY_SIZE - NONCE_SIZE - DIGEST_SIZE < BLOCK_SIZE) { //but there actually isn't one,
err(ERR_SZE, "Ciphertext not found");
return -1; //raise an error
}
pkg->csize = extrap_csize(datalen); //set cphtxt size
pkg->cphtxt = malloc(pkg->csize); //allocate mem for cphtxt
memcpy(pkg->nonce, data + KEY_SIZE, NONCE_SIZE); //place nonce
memcpy(pkg->digest, data + KEY_SIZE + NONCE_SIZE, DIGEST_SIZE);
memcpy(pkg->cphtxt, data + KEY_SIZE + NONCE_SIZE + DIGEST_SIZE, pkg->csize); //place cphtxt
if (not_block(pkg->csize)) //if cphtxt not correct block size,
return -1; //return error
}
return 0; //there were no errors
}
else //we were expecting version 0
return -1;
}
static uint32_t enclen(uint32_t outlen, uint32_t saltlen, uint32_t t_cost,
uint32_t m_cost, uint32_t lanes) {
return strlen("$argon2x$m=,t=,p=$$") + numlen(t_cost) + numlen(m_cost)
+ numlen(lanes) + b64len(saltlen) + b64len(outlen);
}
