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|
/* +------------------------------------+
* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
* InspIRCd: (C) 2002-2010 InspIRCd Development Team
* See: http://wiki.inspircd.org/Credits
*
* This program is free but copyrighted software; see
* the file COPYING for details.
*
* ---------------------------------------------------
*/
#include "inspircd.h"
#include "socket.h"
#include "xline.h"
#include "../m_hash.h"
#include "../ssl.h"
#include "socketengine.h"
#include "main.h"
#include "utils.h"
#include "treeserver.h"
#include "link.h"
#include "treesocket.h"
#include "resolvers.h"
const std::string& TreeSocket::GetOurChallenge()
{
return capab->ourchallenge;
}
void TreeSocket::SetOurChallenge(const std::string &c)
{
capab->ourchallenge = c;
}
const std::string& TreeSocket::GetTheirChallenge()
{
return capab->theirchallenge;
}
void TreeSocket::SetTheirChallenge(const std::string &c)
{
capab->theirchallenge = c;
}
std::string TreeSocket::MakePass(const std::string &password, const std::string &challenge)
{
/* This is a simple (maybe a bit hacky?) HMAC algorithm, thanks to jilles for
* suggesting the use of HMAC to secure the password against various attacks.
*
* Note: If m_sha256.so is not loaded, we MUST fall back to plaintext with no
* HMAC challenge/response.
*/
HashProvider* sha256 = ServerInstance->Modules->FindDataService<HashProvider>("hash/sha256");
if (Utils->ChallengeResponse && sha256 && !challenge.empty())
{
/* 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));
return "AUTH:" + hmac;
}
else
{
// version 1.2 used a weaker HMAC, using hex output in the intermediate step
hmac2.append(challenge);
hmac2 = sha256->hexsum(hmac2);
std::string hmac = hmac1 + hmac2;
hmac = sha256->hexsum(hmac);
return "HMAC-SHA256:"+ hmac;
}
}
else if (!challenge.empty() && !sha256)
ServerInstance->Logs->Log("m_spanningtree",DEFAULT,"Not authenticating to server using SHA256/HMAC because we don't have m_sha256 loaded!");
return password;
}
std::string TreeSocket::RandString(unsigned int ilength)
{
char* randombuf = new char[ilength+1];
std::string out;
#ifndef WINDOWS
int f = open("/dev/urandom", O_RDONLY, 0);
if (f >= 0)
{
if (read(f, randombuf, ilength) < (int)ilength)
ServerInstance->Logs->Log("m_spanningtree", DEFAULT, "Entropy source has gone predictable (did not return enough data)");
close(f);
}
else
#endif
{
for (unsigned int i = 0; i < ilength; i++)
randombuf[i] = rand();
}
for (unsigned int i = 0; i < ilength; i++)
{
char randchar = static_cast<char>(0x3F + (randombuf[i] & 0x3F));
out += randchar;
}
delete[] randombuf;
return out;
}
bool TreeSocket::ComparePass(const Link& link, const std::string &theirs)
{
capab->auth_fingerprint = !link.Fingerprint.empty();
capab->auth_challenge = !capab->ourchallenge.empty() && !capab->theirchallenge.empty();
std::string fp;
if (GetIOHook())
{
SocketCertificateRequest req(this, Utils->Creator, GetIOHook());
if (req.cert)
{
fp = req.cert->GetFingerprint();
}
}
if (capab->auth_challenge)
{
std::string our_hmac = MakePass(link.RecvPass, capab->ourchallenge);
/* Straight string compare of hashes */
if (our_hmac != theirs)
return false;
}
else
{
/* Straight string compare of plaintext */
if (link.RecvPass != theirs)
return false;
}
if (capab->auth_fingerprint)
{
/* Require fingerprint to exist and match */
if (link.Fingerprint != fp)
{
ServerInstance->SNO->WriteToSnoMask('l',"Invalid SSL fingerprint on link %s: need \"%s\" got \"%s\"",
link.Name.c_str(), link.Fingerprint.c_str(), fp.c_str());
SendError("Provided invalid SSL fingerprint " + fp + " - expected " + link.Fingerprint);
return false;
}
}
else if (!fp.empty())
{
ServerInstance->SNO->WriteToSnoMask('l', "SSL fingerprint for link %s is \"%s\". "
"You can improve security by specifying this in <link:fingerprint>.", link.Name.c_str(), fp.c_str());
}
return true;
}
|
