org.postgresql.sspi.SSPIClient Maven / Gradle / Ivy
package org.postgresql.sspi;
import java.io.IOException;
import java.sql.SQLException;
import org.postgresql.core.Logger;
import org.postgresql.core.PGStream;
import org.postgresql.util.HostSpec;
import org.postgresql.util.PSQLException;
import org.postgresql.util.PSQLState;
import com.sun.jna.LastErrorException;
import com.sun.jna.Platform;
import com.sun.jna.platform.win32.Sspi;
import com.sun.jna.platform.win32.Sspi.SecBufferDesc;
import com.sun.jna.platform.win32.Win32Exception;
import waffle.windows.auth.IWindowsAuthProvider;
import waffle.windows.auth.IWindowsCredentialsHandle;
import waffle.windows.auth.IWindowsSecurityContext;
import waffle.windows.auth.impl.WindowsAccountImpl;
import waffle.windows.auth.impl.WindowsAuthProviderImpl;
import waffle.windows.auth.impl.WindowsCredentialsHandleImpl;
import waffle.windows.auth.impl.WindowsSecurityContextImpl;
/**
* Use Waffle-JNI to support SSPI authentication when PgJDBC is running on a Windows
* client and talking to a Windows server.
*
* SSPI is not supported on a non-Windows client.
*
*
* @author craig
*
*/
public class SSPIClient {
public static String SSPI_DEFAULT_SPN_SERVICE_CLASS = "POSTGRES";
private final Logger logger;
private final PGStream pgStream;
private final String spnServiceClass;
private final boolean enableNegotiate;
private IWindowsCredentialsHandle clientCredentials;
private WindowsSecurityContextImpl sspiContext;
private String targetName;
/**
* Instantiate an SSPIClient for authentication of a connection.
*
* SSPIClient is not re-usable across connections.
*
* It is safe to instantiate SSPIClient even if Waffle and JNA are missing
* or on non-Windows platforms, however you may not call any methods other than
* isSSPISupported().
*
* @param pgStream PostgreSQL connection stream
* @param spnServiceClass SSPI SPN service class, defaults to POSTGRES if null
* @param logger
*/
public SSPIClient(PGStream pgStream,
String spnServiceClass,
boolean enableNegotiate,
Logger logger) {
this.logger = logger;
this.pgStream = pgStream;
/* If blank or unspecified, SPN service class should be POSTGRES */
String realServiceClass = spnServiceClass;
if (spnServiceClass != null && spnServiceClass.isEmpty())
spnServiceClass = null;
if (spnServiceClass == null)
spnServiceClass = SSPI_DEFAULT_SPN_SERVICE_CLASS;
this.spnServiceClass = spnServiceClass;
/* If we're forcing Kerberos (no spnego), disable SSPI negotiation */
this.enableNegotiate = enableNegotiate;
}
/**
* Test whether we can attempt SSPI authentication. If false,
* do not attempt to call any other SSPIClient methods.
*
* @return true if it's safe to attempt SSPI authentication
*/
public boolean isSSPISupported() {
try {
/*
* SSPI is windows-only. Attempt to use JNA to identify the platform.
* If Waffle is missing we won't have JNA and this will throw a
* NoClassDefFoundError.
*/
if (!Platform.isWindows())
{
logger.debug("SSPI not supported: non-Windows host");
return false;
}
/* Waffle must be on the CLASSPATH */
Class.forName("waffle.windows.auth.impl.WindowsSecurityContextImpl");
return true;
} catch (NoClassDefFoundError ex) {
if (logger.logDebug())
logger.debug("SSPI unavailable (no Waffle/JNA libraries?)", ex);
return false;
} catch (ClassNotFoundException ex) {
if (logger.logDebug())
logger.debug("SSPI unavailable (no Waffle/JNA libraries?)", ex);
return false;
}
}
private String makeSPN() throws PSQLException
{
final HostSpec hs = pgStream.getHostSpec();
try {
return NTDSAPIWrapper.instance.DsMakeSpn(
spnServiceClass, hs.getHost(),
null, (short)hs.getPort(), null);
} catch (LastErrorException ex) {
throw new PSQLException("SSPI setup failed to determine SPN",
PSQLState.CONNECTION_UNABLE_TO_CONNECT, ex);
}
}
/**
* Respond to an authentication request from the back-end
* for SSPI authentication (AUTH_REQ_SSPI).
*
* @throws SQLException on SSPI authentication handshake failure
* @throws IOException on network I/O issues
*/
public void startSSPI() throws SQLException, IOException {
/*
* We usually use SSPI negotiation (spnego), but it's disabled if the client
* asked for GSSPI and usespngo isn't explicitly turned on.
*/
final String securityPackage = enableNegotiate ? "negotiate" : "kerberos";
logger.debug("Beginning SSPI/Kerberos negotiation with SSPI package: " + securityPackage);
try {
/*
* Acquire a handle for the local Windows login credentials for the current user
*
* See AcquireCredentialsHandle (http://msdn.microsoft.com/en-us/library/windows/desktop/aa374712%28v=vs.85%29.aspx)
*
* This corresponds to pg_SSPI_startup in libpq/fe-auth.c .
*/
try {
clientCredentials = WindowsCredentialsHandleImpl.getCurrent(securityPackage);
clientCredentials.initialize();
} catch (Win32Exception ex) {
throw new PSQLException(
"Could not obtain local Windows credentials for SSPI",
PSQLState.CONNECTION_UNABLE_TO_CONNECT /* TODO: Should be authentication error */,
ex);
}
try {
targetName = makeSPN();
if (logger.logDebug())
{
logger.debug("SSPI target name: " + targetName);
}
sspiContext = new WindowsSecurityContextImpl();
sspiContext.setPrincipalName(targetName);
sspiContext.setCredentialsHandle(clientCredentials.getHandle());
sspiContext.setSecurityPackage(securityPackage);
sspiContext.initialize(null, null, targetName);
} catch (Win32Exception ex) {
throw new PSQLException(
"Could not initialize SSPI security context",
PSQLState.CONNECTION_UNABLE_TO_CONNECT /* TODO: Should be auth error */,
ex);
}
sendSSPIResponse(sspiContext.getToken());
logger.debug("Sent first SSPI negotiation message");
} catch (NoClassDefFoundError ex) {
throw new PSQLException(
"SSPI cannot be used, Waffle or its dependencies are missing from the classpath",
PSQLState.NOT_IMPLEMENTED, ex);
}
}
/**
* Continue an existing authentication conversation with
* the back-end in resonse to an authentication request
* of type AUTH_REQ_GSS_CONT.
*
* @param msgLength Length of message to read, excluding length word and message type word
* @throws SQLException
* @throws IOException
*/
public void continueSSPI(int msgLength) throws SQLException, IOException {
if (sspiContext == null)
throw new IllegalStateException(
"Cannot continue SSPI authentication that we didn't begin");
logger.debug("Continuing SSPI negotiation");
/* Read the response token from the server */
byte[] receivedToken = pgStream.Receive(msgLength);
SecBufferDesc continueToken = new SecBufferDesc(Sspi.SECBUFFER_TOKEN, receivedToken);
sspiContext.initialize(sspiContext.getHandle(), continueToken, targetName);
/*
* Now send the response token. If negotiation is complete
* there may be zero bytes to send, in which case we shouldn't
* send a reply as the server is not expecting one; see fe-auth.c
* in libpq for details.
*/
byte[] responseToken = sspiContext.getToken();
if (responseToken.length > 0)
{
sendSSPIResponse(responseToken);
logger.debug("Sent SSPI negotiation continuation message");
} else {
logger.debug("SSPI authentication complete, no reply required");
}
}
private void sendSSPIResponse(byte[] outToken) throws IOException {
/*
* The sspiContext now contains a token we can send to the server to
* start the handshake. Send a 'password' message containing the
* required data; the server knows we're doing SSPI negotiation
* and will deal with it appropriately.
*/
pgStream.SendChar('p');
pgStream.SendInteger4(4 + outToken.length);
pgStream.Send(outToken);
pgStream.flush();
}
/**
* Clean up native win32 resources after completion or failure of
* SSPI authentication. This SSPIClient instance becomes unusable
* after disposal.
*/
public void dispose() {
if (sspiContext != null) {
sspiContext.dispose();
sspiContext = null;
}
if (clientCredentials != null) {
clientCredentials.dispose();
clientCredentials = null;
}
}
}
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