OsslRandom::OsslRandom() :
initOk(false)
{
FILE *fp = 0;
unsigned char buff[128];
// TODO: make Windows Random Generator here
#ifdef WIN32
HCRYPTPROV hCryptProv;
if(!CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, 0))
{
return;
}
if(!CryptGenRandom(hCryptProv, sizeof(buff), buff))
{
return;
}
CryptReleaseContext(hCryptProv, 0);
#else
fp = fopen("/dev/urandom", "r");
if (fp)
{
size_t count = fread(buff, sizeof(unsigned char), sizeof(buff), fp);
if (count != sizeof(buff)) throw DsrpException("Could not initialize random number generator - small seed");
fclose(fp);
}
else throw DsrpException("Could not initialize random number generator");
#endif
RAND_seed(buff, sizeof(buff));
initOk = true;
}
bytes SrpClientAuthenticator::getSessionKey(bytes M2_from_server)
{
if (M2_from_server.size() == 0) throw DsrpException("SrpClientAuthenticator::getSessionKey: M2_from_server.size() == 0");
if (M2_calculated.size() == 0) throw DsrpException("SrpClientAuthenticator::getSessionKey: M2_calculated.size() == 0");
if (M2_from_server != M2_calculated) throw DsrpException("Authentification failed, bad password");
return K;
}
DatagramEncryptor::DatagramEncryptor(const bytes &encryptionKey, const bytes &IV, const bytes &macKey) :
aesCtr(&IV[0], IV.size(), &encryptionKey[0], encryptionKey.size()),
hmac(sha1, macKey)
{
if (macKey.size() < sha1.outputLen()) throw DsrpException("DatagramEncryptor::DatagramEncryptor: macKey not long enough");
}
bytes OsslRandom::getRandom(unsigned int lenBytes)
{
if (!initOk) throw DsrpException("Could not get random number - PRNG not initialized");
if (lenBytes <= 0) throw DsrpException("Could not get random number - size is zero or negative");
unsigned char *r = (unsigned char *) malloc(lenBytes);
if (r == NULL) throw DsrpException("Could not get random number - malloc() failed");
int rval = RAND_bytes(r, lenBytes);
if (rval != 1)
{
free(r);
throw DsrpException("Could not get random number");
}
bytes out = Conversion::array2bytes(r, lenBytes);
free(r);
return out;
}