Embedded LDAP server LdapAuth3: support hashed passwords (sha1, sha-256)

Note that none of the currently supported hash are safe against
brute force attacks.

If ldapFilter property does not contain any occurrence of "${password}",
the user DN found via the filter expression will be authenticated
via a regular LDAP bind operation, using the entered password. In this
case, with embedded LDAP server, but probably also with others, hashed
passwords are supported and make sense.

Change-Id: I725832a2faa484623edcebeeeb727b23b6186de2
diff --git a/full/src/main/java/de/ids_mannheim/korap/authentication/LdapAuth3.java b/full/src/main/java/de/ids_mannheim/korap/authentication/LdapAuth3.java
index bdfb2ad..9975fcc 100644
--- a/full/src/main/java/de/ids_mannheim/korap/authentication/LdapAuth3.java
+++ b/full/src/main/java/de/ids_mannheim/korap/authentication/LdapAuth3.java
@@ -83,16 +83,16 @@
             }
         }
 
-        SearchResult srchRes = search(login, password, ldapConfig);
+        SearchResult srchRes = search(login, password, ldapConfig, !ldapConfig.searchFilter.contains("${password}"));
 
         if (srchRes == null || srchRes.getEntryCount() == 0) {
             if (DEBUGLOG) System.out.printf("Finding '%s': no entry found!\n", login);
             return LDAP_AUTH_RNAUTH;
         }
+
         return LDAP_AUTH_ROK;
     }
-
-    public static SearchResult search(String login, String password, LDAPConfig ldapConfig) throws LDAPException {
+    public static SearchResult search(String login, String password, LDAPConfig ldapConfig, boolean bindWithFoundDN) throws LDAPException {
         Map<String, String> valuesMap = new HashMap<>();
         valuesMap.put("login", login);
         valuesMap.put("password", password);
@@ -174,16 +174,32 @@
 
             if (DEBUGLOG) System.out.printf("Finding '%s': %d entries.\n", login, srchRes.getEntryCount());
         } catch (LDAPSearchException e) {
-            System.err.printf("Error: login: Search for User failed: '%s'!\n", e);
+            System.err.printf("Error: Search for User failed: '%s'!\n", e);
             ldapTerminate(lc);
             return null;
         }
 
-        if (srchRes.getEntryCount() == 0) {
+        if (srchRes == null || srchRes.getEntryCount() == 0) {
             if (DEBUGLOG) System.out.printf("Finding '%s': no entry found!\n", login);
+            ldapTerminate(lc);
             return null;
         }
 
+        if (bindWithFoundDN) {
+            String matchedDN = srchRes.getSearchEntries().get(0).getDN();
+            if (DEBUGLOG) System.out.printf("Requested bind for found user %s' failed.\n", matchedDN);
+            try {
+                // bind to server:
+                if (DEBUGLOG) System.out.printf("Binding with '%s' ...\n", matchedDN);
+                lc.bind(matchedDN, password);
+                if (DEBUGLOG) System.out.print("Binding: OK.\n");
+            } catch (LDAPException e) {
+                System.err.printf("Error: login: Binding failed: '%s'!\n", e);
+                ldapTerminate(lc);
+                return null;
+            }
+        }
+
         ldapTerminate(lc);
         return srchRes;
     }
@@ -193,7 +209,7 @@
         LDAPConfig ldapConfig = new LDAPConfig(ldapConfigFilename);
         final String emailAttribute = ldapConfig.emailAttribute;
 
-        SearchResult searchResult = search(sUserDN, sUserPwd, ldapConfig);
+        SearchResult searchResult = search(sUserDN, sUserPwd, ldapConfig, false);
 
         if (searchResult == null) {
             return null;
diff --git a/full/src/main/java/de/ids_mannheim/korap/server/EmbeddedLdapServer.java b/full/src/main/java/de/ids_mannheim/korap/server/EmbeddedLdapServer.java
index 76f6494..88dfe2e 100644
--- a/full/src/main/java/de/ids_mannheim/korap/server/EmbeddedLdapServer.java
+++ b/full/src/main/java/de/ids_mannheim/korap/server/EmbeddedLdapServer.java
@@ -1,9 +1,8 @@
 package de.ids_mannheim.korap.server;
 
-import com.unboundid.ldap.listener.InMemoryDirectoryServer;
-import com.unboundid.ldap.listener.InMemoryDirectoryServerConfig;
-import com.unboundid.ldap.listener.InMemoryListenerConfig;
+import com.unboundid.ldap.listener.*;
 import com.unboundid.ldap.sdk.LDAPException;
+import com.unboundid.util.CryptoHelper;
 import com.unboundid.util.ssl.SSLUtil;
 import com.unboundid.util.ssl.TrustAllTrustManager;
 import de.ids_mannheim.korap.authentication.LDAPConfig;
@@ -11,6 +10,7 @@
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.security.GeneralSecurityException;
+import java.security.MessageDigest;
 
 public class EmbeddedLdapServer {
     static InMemoryDirectoryServer server;
@@ -21,6 +21,9 @@
         }
 
         InMemoryDirectoryServerConfig config = new InMemoryDirectoryServerConfig(ldapConfig.searchBase);
+        final MessageDigest sha1Digest = CryptoHelper.getMessageDigest("SHA1");
+        final MessageDigest sha256Digest = CryptoHelper.getMessageDigest("SHA-256");
+        config.setPasswordEncoders(new ClearInMemoryPasswordEncoder("{CLEAR}", null), new ClearInMemoryPasswordEncoder("{HEX}", HexPasswordEncoderOutputFormatter.getLowercaseInstance()), new ClearInMemoryPasswordEncoder("{BASE64}", Base64PasswordEncoderOutputFormatter.getInstance()), new UnsaltedMessageDigestInMemoryPasswordEncoder("{SHA}", Base64PasswordEncoderOutputFormatter.getInstance(), sha1Digest), new UnsaltedMessageDigestInMemoryPasswordEncoder("{SHA256}", Base64PasswordEncoderOutputFormatter.getInstance(), sha256Digest));
         config.addAdditionalBindCredentials(ldapConfig.sLoginDN, ldapConfig.sPwd);
         config.setSchema(null);
 
diff --git a/full/src/main/resources/embedded-ldap-default.conf b/full/src/main/resources/embedded-ldap-default.conf
index becf6e0..00cd2a2 100644
--- a/full/src/main/resources/embedded-ldap-default.conf
+++ b/full/src/main/resources/embedded-ldap-default.conf
@@ -5,6 +5,6 @@
 searchBase=dc=example,dc=com
 sLoginDN=cn=admin,dc=example,dc=com
 pwd=admin
-searchFilter=(&(uid=${login})(userPassword=${password}))
+searchFilter=(uid=${login})
 useEmbeddedServer=true
 ldifFile=src/main/resources/korap-users.ldif
diff --git a/full/src/main/resources/korap-users.ldif b/full/src/main/resources/korap-users.ldif
index 4a3e69c..8760df9 100644
--- a/full/src/main/resources/korap-users.ldif
+++ b/full/src/main/resources/korap-users.ldif
@@ -12,16 +12,35 @@
 cn: user
 uid: user
 mail: user@example.com
-userPassword: cGFzc3dvcmQ=
+userPassword: {BASE64}cGFzc3dvcmQ=
 
 dn: uid=user1,ou=people,dc=example,dc=com
 cn: user1
 uid: user1
 mail: user1@example.com
-userPassword: password1
+userPassword: {CLEAR}password1
 
 dn: uid=user2,ou=people,dc=example,dc=com
 cn: user2
 uid: user2
 mail: user2@example.com
 userPassword: password2
+
+dn: uid=user3,ou=people,dc=example,dc=com
+cn: user3
+uid: user3
+mail: user3@example.com
+userPassword: {SHA}ERnP037iRzV+A0oI2ETuol9v0g8=
+
+dn: uid=user4,ou=people,dc=example,dc=com
+cn: user4
+uid: user4
+mail: user4@example.com
+userPassword: {SHA256}uXhzpA9zq+3Y1oWnzV5fheSpz7g+rCaIZkCggThQEis=
+
+dn: uid=user5,ou=people,dc=example,dc=com
+cn: user5
+uid: user5
+mail: user5@example.com
+userPassword: {PBKDF2-SHA256}26PFrg++/nI8YOiHum5MyAMp0HdqKMNOcLpY5RuO2bY=
+