Core/Auth: Implement time-based token for user login as described in RFC 6238.

New column in account table is a base32 of token key bytes,
coincidentally it is the same format Google's Authenticator Android app uses.
If you want that to work, set system time on server correctly and use ntpd.

Closes #10527

Signed-off-by: Nay <dnpd.dd@gmail.com>

4 files changed, 150 insertions, 0 deletions

diff --git a/src/server/authserver/Authentication/TOTP.cpp b/src/server/authserver/Authentication/TOTP.cpp
new file mode 100644
index 00000000000..43c97c296d9
--- /dev/null
+++ b/src/server/authserver/Authentication/TOTP.cpp
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2008-2013 TrinityCore <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "TOTP.h"
+
+int base32_decode(const char* encoded, char* result, int bufSize)
+{
+    // Base32 implementation
+    // Copyright 2010 Google Inc.
+    // Author: Markus Gutschke
+    // Licensed under the Apache License, Version 2.0
+    int buffer = 0;
+    int bitsLeft = 0;
+    int count = 0;
+    for (const char *ptr = encoded; count < bufSize && *ptr; ++ptr)
+    {
+        char ch = *ptr;
+        if (ch == ' ' || ch == '    ' || ch == '\r' || ch == '\n' || ch == '-')
+            continue;
+        buffer <<= 5;
+
+        // Deal with commonly mistyped characters
+        if (ch == '0')
+            ch = 'O';
+        else if (ch == '1')
+            ch = 'L';
+        else if (ch == '8')
+            ch = 'B';
+
+        // Look up one base32 digit
+        if ((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'))
+            ch = (ch & 0x1F) - 1;
+        else if (ch >= '2' && ch <= '7')
+            ch -= '2' - 26;
+        else
+            return -1;
+
+        buffer |= ch;
+        bitsLeft += 5;
+        if (bitsLeft >= 8)
+        {
+            result[count++] = buffer >> (bitsLeft - 8);
+            bitsLeft -= 8;
+        }
+    }
+
+    if (count < bufSize)
+        result[count] = '\000';
+    return count;
+}
+
+#define HMAC_RES_SIZE 20
+
+namespace TOTP
+{
+    unsigned int GenerateToken(const char* b32key)
+    {
+        size_t keySize = strlen(b32key);
+        int bufsize = (keySize + 7)/8*5;
+        char* encoded = new char[bufsize];
+        memset(encoded, 0, bufsize);
+        unsigned int hmacResSize = HMAC_RES_SIZE;
+        unsigned char hmacRes[HMAC_RES_SIZE];
+        unsigned long timestamp = time(NULL)/30;
+        unsigned char challenge[8];
+
+        for (int i = 8; i--;timestamp >>= 8)
+            challenge[i] = timestamp;
+
+        base32_decode(b32key, encoded, bufsize);
+        HMAC(EVP_sha1(), encoded, bufsize, challenge, 8, hmacRes, &hmacResSize);
+        unsigned int offset = hmacRes[19] & 0xF;
+        unsigned int truncHash = (hmacRes[offset] << 24) | (hmacRes[offset+1] << 16 )| (hmacRes[offset+2] << 8) | (hmacRes[offset+3]);
+        truncHash &= 0x7FFFFFFF;
+
+        delete[] encoded;
+
+        return truncHash % 1000000;
+    }
+}
diff --git a/src/server/authserver/Authentication/TOTP.h b/src/server/authserver/Authentication/TOTP.h
new file mode 100644
index 00000000000..3080e7c7787
--- /dev/null
+++ b/src/server/authserver/Authentication/TOTP.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2008-2013 TrinityCore <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TOTP_H
+#define _TOPT_H
+
+#include "openssl/hmac.h"
+#include "openssl/evp.h"
+
+namespace TOTP
+{
+    unsigned int GenerateToken(const char* b32key);
+}
+
+#endif
diff --git a/src/server/authserver/Server/AuthSocket.cpp b/src/server/authserver/Server/AuthSocket.cpp
index c2131f5dbf7..93c03e26c88 100644
--- a/src/server/authserver/Server/AuthSocket.cpp
+++ b/src/server/authserver/Server/AuthSocket.cpp
@@ -27,6 +27,7 @@
 #include "RealmList.h"
 #include "AuthSocket.h"
 #include "AuthCodes.h"
+#include "TOTP.h"
 #include "SHA1.h"
 #include "openssl/crypto.h"
 
@@ -492,6 +493,12 @@ bool AuthSocket::_HandleLogonChallenge()
                     pkt.append(s.AsByteArray().get(), s.GetNumBytes());   // 32 bytes
                     pkt.append(unk3.AsByteArray(16).get(), 16);
                     uint8 securityFlags = 0;
+
+                    // Check if token is used
+                    _tokenKey = fields[8].GetString();
+                    if (!_tokenKey.empty())
+                        securityFlags = 4;
+
                     pkt << uint8(securityFlags);            // security flags (0x0...0x04)
 
                     if (securityFlags & 0x01)               // PIN input
@@ -652,6 +659,25 @@ bool AuthSocket::_HandleLogonProof()
         sha.UpdateBigNumbers(&A, &M, &K, NULL);
         sha.Finalize();
 
+        // Check auth token
+        if ((lp.securityFlags & 0x04) || !_tokenKey.empty())
+        {
+            uint8 size;
+            socket().recv((char*)&size, 1);
+            char* token = new char[size + 1];
+            token[size] = '\0';
+            socket().recv(token, size);
+            unsigned int validToken = TOTP::GenerateToken(_tokenKey.c_str());
+            unsigned int incomingToken = atoi(token);
+            delete[] token;
+            if (validToken != incomingToken)
+            {
+                char data[] = { AUTH_LOGON_PROOF, WOW_FAIL_UNKNOWN_ACCOUNT, 3, 0 };
+                socket().send(data, sizeof(data));
+                return false;
+            }
+        }
+
         if (_expversion & POST_BC_EXP_FLAG)                 // 2.x and 3.x clients
         {
             sAuthLogonProof_S proof;
diff --git a/src/server/authserver/Server/AuthSocket.h b/src/server/authserver/Server/AuthSocket.h
index 6c13f85a022..c6513eaa5bf 100644
--- a/src/server/authserver/Server/AuthSocket.h
+++ b/src/server/authserver/Server/AuthSocket.h
@@ -69,6 +69,7 @@ private:
     bool _authed;
 
     std::string _login;
+    std::string _tokenKey;
 
     // Since GetLocaleByName() is _NOT_ bijective, we have to store the locale as a string. Otherwise we can't differ
     // between enUS and enGB, which is important for the patch system