- {
- /* This is how HMAC is supposed to be done:
- *
- * sha256( (pass xor 0x5c) + sha256((pass xor 0x36) + m) )
- *
- * 5c and 36 were chosen as part of the HMAC standard, because they
- * flip the bits in a way likely to strengthen the function.
- */
- std::string hmac1, hmac2;
-
- for (size_t n = 0; n < password.length(); n++)
- {
- hmac1.push_back(static_cast<char>(password[n] ^ 0x5C));
- hmac2.push_back(static_cast<char>(password[n] ^ 0x36));
- }
-
- if (proto_version >= 1202)
- {
- hmac2.append(challenge);
- std::string hmac = sha256->hexsum(hmac1 + sha256->sum(hmac2));