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/***************************************************************************
* Copyright (C) 2012 by Timothy Pearson *
* kb9vqf@pearsoncomputing.net *
* *
* 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, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#include <stdlib.h>
#include <unistd.h>
#include <tqapplication.h>
#include <sasl.h>
#include <saslplug.h>
#include <saslutil.h>
#include "tdekrbserversocket.h"
#define NET_SEC_BUF_SIZE (2048)
/* exception handling */
struct exit_exception {
int c;
exit_exception(int c):c(c) { }
};
class SASLDataPrivate
{
public:
sasl_callback_t m_callbacks[N_CALLBACKS];
sasl_conn_t *m_krbConnection;
};
static const char * safe_sasl_errdetail(sasl_conn_t *conn) {
const char * str = sasl_errdetail(conn);
if (str) {
return str;
}
else {
return "unknown error";
}
}
static int logSASLMessages(void *context __attribute__((unused)), int priority, const char *message) {
const char *label;
if (!message) {
return SASL_BADPARAM;
}
switch (priority) {
case SASL_LOG_ERR:
label = "Error";
break;
case SASL_LOG_NOTE:
label = "Info";
break;
default:
label = "Other";
break;
}
printf("[SASL %s] %s\n\r", label, message);
return SASL_OK;
}
TDEKerberosServerSocket::TDEKerberosServerSocket(TQObject *parent, const char *name) : TQSocket(parent, name), m_kerberosRequested(false), m_negotiatedMaxBufferSize(NET_SEC_BUF_SIZE), m_criticalSection(0) {
saslData = new SASLDataPrivate;
saslData->m_krbConnection = NULL;
}
TDEKerberosServerSocket::~TDEKerberosServerSocket() {
delete saslData;
}
bool TDEKerberosServerSocket::open(int mode) {
bool ret = TQSocket::open(mode);
if (m_kerberosRequested) {
initializeKerberosInterface();
}
return ret;
}
void TDEKerberosServerSocket::close() {
TQSocket::close();
if (m_criticalSection > 0) {
throw exit_exception(-1);
}
}
int TDEKerberosServerSocket::setUsingKerberos(bool krbactive) {
int ret = 0;
if (m_serviceName == "") {
printf("[ERROR] No service name set!\n\r"); fflush(stdout);
return -1;
}
if (krbactive) {
m_kerberosRequested = true;
if ((!saslData->m_krbConnection) && (state() == TQSocket::Connected)) {
ret = initializeKerberosInterface();
}
}
else {
m_kerberosRequested = false;
if (saslData->m_krbConnection) {
freeKerberosConnection();
}
}
return ret;
}
void TDEKerberosServerSocket::setServiceName(TQString name) {
m_serviceName = name;
}
void TDEKerberosServerSocket::setServerFQDN(TQString name) {
m_serverFQDN = name;
}
TQ_LONG TDEKerberosServerSocket::readBlock(char *data, TQ_ULONG maxlen) {
TQ_LONG ret;
if (m_kerberosRequested) {
ret = receiveEncryptedData(data, maxlen);
}
else {
ret = TQSocket::readBlock(data, maxlen);
}
return ret;
}
TQ_LONG TDEKerberosServerSocket::writeBlock(const char *data, TQ_ULONG len) {
TQ_LONG ret;
if (m_kerberosRequested) {
ret = transmitEncryptedData(socket(), data, len);
}
else {
ret = TQSocket::writeBlock(data, len);
}
return ret;
}
TQ_LONG TDEKerberosServerSocket::readLine(char *data, TQ_ULONG maxlen) {
TQ_LONG ret;
if (m_kerberosRequested) {
ret = receiveEncryptedData(data, maxlen);
}
else {
ret = TQSocket::readLine(data, maxlen);
}
return ret;
}
TQString TDEKerberosServerSocket::readLine() {
TQString ret;
char *buf;
if (m_kerberosRequested) {
buf = (char*)malloc(m_negotiatedMaxBufferSize);
receiveEncryptedData(buf, m_negotiatedMaxBufferSize);
ret = TQString(buf);
free(buf);
}
else {
ret = TQSocket::readLine();
}
return ret;
}
void TDEKerberosServerSocket::writeLine(TQString str) {
if (m_kerberosRequested) {
transmitEncryptedData(socket(), str.ascii(), str.length());
}
else {
TQSocket::writeBlock(str.ascii(), str.length());
}
}
void TDEKerberosServerSocket::freeKerberosConnection(void) {
if (saslData->m_krbConnection) {
sasl_dispose(&saslData->m_krbConnection);
}
saslData->m_krbConnection = 0;
}
void TDEKerberosServerSocket::sendSASLDataToNetwork(const char *buffer, unsigned length, int netfd) {
char *buf;
unsigned len, alloclen;
int result;
alloclen = ((length / 3) + 1) * 4 + 1;
buf = (char*)malloc(alloclen);
if (!buf) {
printf("[ERROR] Unable to malloc()!\n\r");
return;
}
result = sasl_encode64(buffer, length, buf, alloclen, &len);
if (result != SASL_OK) {
printf("[ERROR] Encoding data in base64 returned %s (%d)\n\r", sasl_errstring(result, NULL, NULL), result);
return;
}
len = strlen(buf);
buf[len] = '\n';
buf[len+1] = 0;
write(netfd, buf, len+1);
free(buf);
}
int TDEKerberosServerSocket::getSASLDataFromNetwork(char *buf, int trunclen) {
m_criticalSection++;
try {
unsigned int len;
int result;
TQByteArray ba(2048);
len = 0;
while (1) {
tqApp->processEvents();
if (state() != TQSocket::Connected) {
m_criticalSection--;
return -1;
}
if (TQSocket::readBlock(ba.data()+len, 1) > 0) {
if (ba.data()[len] == '\n') {
ba.data()[len] = 0;
break;
}
if (ba.data()[len] != '\r') {
len++;
}
}
else {
usleep(1000);
}
if (len >= (ba.size()-1)) {
ba.resize(ba.size()+2048);
}
}
len = strlen(ba.data());
result = sasl_decode64(ba.data(), strlen(ba.data()), buf, trunclen, &len);
if (result != SASL_OK) {
printf("[ERROR] Decoding data from base64 returned %s (%d)\n\r", sasl_errstring(result, NULL, NULL), result);
m_criticalSection--;
return -1;
}
buf[len] = '\0';
m_criticalSection--;
return len;
}
catch(exit_exception& e) {
m_criticalSection--;
return -1;
}
}
int TDEKerberosServerSocket::transmitEncryptedData(int fd, const char* readbuf, int cc) {
int result = 0;
unsigned int len;
const char *data;
result=sasl_encode(saslData->m_krbConnection, readbuf, cc, &data, &len);
if (result != SASL_OK) {
printf("[ERROR] Encrypting data returned %s (%d)\n\r", safe_sasl_errdetail(saslData->m_krbConnection), result);
return -1;
}
sendSASLDataToNetwork(data, len, fd);
return 0;
}
int TDEKerberosServerSocket::receiveEncryptedData(char *buf, int trunclen) {
unsigned int recv_len;
const char *recv_data;
int result;
int len;
char *encbuf = (char*)malloc(m_negotiatedMaxBufferSize);
len = getSASLDataFromNetwork(encbuf, m_negotiatedMaxBufferSize);
if (len < 0) {
return -1;
}
if (len >= 0) {
result=sasl_decode(saslData->m_krbConnection, encbuf, len, &recv_data, &recv_len);
if (result != SASL_OK) {
free(encbuf);
printf("[ERROR] Decrypting data returned %s (%d)\n\r", safe_sasl_errdetail(saslData->m_krbConnection), result);
return -1;
}
if (recv_len > trunclen) {
recv_len = trunclen;
}
memcpy(buf, recv_data, recv_len);
}
free(encbuf);
return recv_len;
}
int TDEKerberosServerSocket::initializeKerberosInterface() {
if (state() != TQSocket::Connected) {
saslData->m_krbConnection = false;
return -1;
}
sasl_callback_t *callback;
char buf[NET_SEC_BUF_SIZE];
int result = 0;
int serverlast = 0;
sasl_security_properties_t secprops;
const char *ext_authid = NULL;
unsigned int len;
int slen;
int count;
const char *data;
char user_authorized = 0;
sasl_ssf_t *ssf;
// FIXME
// Populate these fields!
char *iplocal = NULL;
char *ipremote = NULL;
char *localdomain = NULL;
char *userdomain = NULL;
callback = saslData->m_callbacks;
// log
callback->id = SASL_CB_LOG;
callback->proc = (sasl_callback_ft)&logSASLMessages;
callback->context = NULL;
++callback;
// end of callback list
callback->id = SASL_CB_LIST_END;
callback->proc = NULL;
callback->context = NULL;
++callback;
// Initialize default data structures
memset(&secprops, 0L, sizeof(secprops));
secprops.maxbufsize = NET_SEC_BUF_SIZE;
secprops.max_ssf = UINT_MAX;
result = sasl_server_init(saslData->m_callbacks, m_serviceName.ascii());
if (result != SASL_OK) {
printf("[ERROR] Initializing libsasl returned %s (%d)\n\r", safe_sasl_errdetail(saslData->m_krbConnection), result);
return -1;
}
result = sasl_server_new(m_serviceName.ascii(), localdomain, userdomain, iplocal, ipremote, NULL, serverlast, &saslData->m_krbConnection);
if (result != SASL_OK) {
printf("[ERROR] Allocating sasl connection state returned %s (%d)\n\r", safe_sasl_errdetail(saslData->m_krbConnection), result);
return -1;
}
result = sasl_setprop(saslData->m_krbConnection, SASL_SEC_PROPS, &secprops);
if (result != SASL_OK) {
printf("[ERROR] Setting security properties returned %s (%d)\n\r", safe_sasl_errdetail(saslData->m_krbConnection), result);
freeKerberosConnection();
return -1;
}
puts("[DEBUG] Generating client mechanism list...");
result = sasl_listmech(saslData->m_krbConnection, ext_authid, NULL, " ", NULL, &data, &len, &count);
if (result != SASL_OK) {
printf("[ERROR] Generating client mechanism list returned %s (%d)\n\r", safe_sasl_errdetail(saslData->m_krbConnection), result);
freeKerberosConnection();
return -1;
}
printf("[DEBUG] Sending list of %d mechanism(s)\n\r", count);
sendSASLDataToNetwork(data, len, socket());
printf("[DEBUG] Waiting for client mechanism...\n\r");
slen = getSASLDataFromNetwork(buf, NET_SEC_BUF_SIZE);
if (slen < 0) {
return -2;
}
len = slen;
if (strlen(buf) < len) {
printf("[DEBUG] Initial response received\n\r");
// An initial response is present
data = buf + strlen(buf) + 1;
len = len - (unsigned) strlen(buf) - 1;
}
else {
data = NULL;
len = 0;
}
result = sasl_server_start(saslData->m_krbConnection, buf, data, len, &data, &len);
if (result != SASL_OK && result != SASL_CONTINUE) {
printf("[ERROR] Starting SASL negotiation returned %s (%d)\n\r", safe_sasl_errdetail(saslData->m_krbConnection), result);
freeKerberosConnection();
return -1;
}
while (result == SASL_CONTINUE) {
if (data) {
printf("[DEBUG] Sending response...\n\r");
sendSASLDataToNetwork(data, len, socket());
}
else {
printf("[ERROR] No data to send!\n\r");
freeKerberosConnection();
return -1;
}
printf("[DEBUG] Waiting for client reply...\n\r");
slen = getSASLDataFromNetwork(buf, NET_SEC_BUF_SIZE);
if (slen < 0) {
return -2;
}
len = slen;
data = NULL;
result = sasl_server_step(saslData->m_krbConnection, buf, len, &data, &len);
if (result != SASL_OK && result != SASL_CONTINUE) {
printf("[ERROR] Performing SASL negotiation returned %s (%d)\n\r", safe_sasl_errdetail(saslData->m_krbConnection), result);
freeKerberosConnection();
return -1;
}
}
printf("[DEBUG] Negotiation complete\n\r");
if(serverlast && data) {
printf("[DEBUG] Additional information needed to be sent\n\r");
sendSASLDataToNetwork(data, len, socket());
}
result = sasl_getprop(saslData->m_krbConnection, SASL_USERNAME, (const void **)&data);
if (result != SASL_OK) {
printf("[WARNING] Unable to determine authenticated username!\n\r");
}
else {
printf("[DEBUG] Authenticated username: %s\n\r", data ? data : "(NULL)");
}
result = sasl_getprop(saslData->m_krbConnection, SASL_DEFUSERREALM, (const void **)&data);
if (result != SASL_OK) {
printf("[WARNING] Unable to determine authenticated realm!\n\r");
}
else {
printf("[DEBUG] Authenticated realm: %s\n\r", data ? data : "(NULL)");
}
result = sasl_getprop(saslData->m_krbConnection, SASL_SSF, (const void **)&ssf);
if (result != SASL_OK) {
printf("[WARNING] Unable to determine SSF!\n\r");
}
else {
printf("[DEBUG] Authenticated SSF: %d\n", *ssf);
}
return 0;
}