[JENKINS-73806] Do not allows users to authenticate with short passwords in FIPS mode

src/main/java/hudson/security/LDAPSecurityRealm.java

@@ -39,6 +39,7 @@
 import hudson.util.Secret;
 import jenkins.model.IdStrategy;
 import jenkins.model.Jenkins;
+import jenkins.security.FIPS140;
 import jenkins.security.SecurityListener;
 import jenkins.security.plugins.ldap.FromGroupSearchLDAPGroupMembershipStrategy;
 import jenkins.security.plugins.ldap.LDAPConfiguration;
@@ -986,6 +987,12 @@
         @Override
         public Authentication authenticate(Authentication authentication) throws AuthenticationException {
         try (SetContextClassLoader sccl = new SetContextClassLoader()) {
+            String password = authentication.getCredentials() instanceof String ? (String) authentication.getCredentials() : null;
+            if(FIPS140.useCompliantAlgorithms() && (StringUtils.isBlank(password) || password.length() < 14)) {
+                final String message =  "When running in FIPS compliance mode, the password must be at least 14 characters long";
+                LOGGER.warning(message);
+                throw new org.springframework.ldap.AuthenticationException(new javax.naming.AuthenticationException(message));
+            }
             AuthenticationException lastException = null;
             for (ManagerEntry delegate : delegates) {
                 try {

src/test/java/hudson/security/LDAPSecurityRealmWithFIPSTest.java

@@ -0,0 +1,75 @@
+package hudson.security;
+
+import java.util.logging.Level;
+
+import hudson.util.Secret;
+import jenkins.model.IdStrategy;
+import jenkins.security.FIPS140;
+import jenkins.security.plugins.ldap.FromUserRecordLDAPGroupMembershipStrategy;
+
+import org.htmlunit.FailingHttpStatusCodeException;
+import org.junit.ClassRule;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.FlagRule;
+import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.LoggerRule;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThrows;
+
+public class LDAPSecurityRealmWithFIPSTest {
+
+    @Rule
+    public JenkinsRule r = new JenkinsRule();
+    @Rule
+    public LoggerRule log = new LoggerRule();
+
+    @ClassRule
+    public static FlagRule<String> fipsFlag = FlagRule.systemProperty(FIPS140.class.getName() + ".COMPLIANCE", "true");
+
+    @Test
+    public void ldapAuthenticationWithFIPSTest() throws Exception {
+        final String server = "localhost";
+        final String rootDN = "ou=umich,dc=ou.edu";
+        final String userSearchBase = "cn=users,ou=umich,ou.edu";
+        final String managerDN = "cn=admin,ou=umich,ou.edu";
+        final String managerSecret = "secret";
+        final LDAPSecurityRealm realm = new LDAPSecurityRealm(
+                server,
+                rootDN,
+                userSearchBase,
+                null,
+                null,
+                null,
+                new FromUserRecordLDAPGroupMembershipStrategy("previousValue"),
+                managerDN,
+                Secret.fromString(managerSecret),
+                false,
+                false,
+                null,
+                null,
+                null,
+                null,
+                IdStrategy.CASE_INSENSITIVE,
+                IdStrategy.CASE_INSENSITIVE);
+        r.jenkins.setSecurityRealm(realm);
+
+        JenkinsRule.WebClient wc = r.createWebClient();
+
+        log.record(LDAPSecurityRealm.class, Level.WARNING).capture(10); // reset
+        FailingHttpStatusCodeException cannotLogin = assertThrows("Valid password, but expected to fail as there is no such user. Just 401",
+                                                                  FailingHttpStatusCodeException.class,
+                                                                  () -> wc.login("alice", "passwordLongEnoughToBeFIPScompliant"));
+        assertThat("Invalid user", cannotLogin.getStatusCode(), is(401));
+
+        log.record(LDAPSecurityRealm.class, Level.WARNING).capture(10); // reset
+        cannotLogin = assertThrows("Short password, so the error is different now",
+                                   FailingHttpStatusCodeException.class,
+                                   () -> wc.login("bob", "shortPassword"));
+        assertThat("Password invalid in FIPS, not even authenticated", cannotLogin.getStatusCode(), is(500));
+        assertThat("FIPS message is logged", log, LoggerRule.recorded(Level.WARNING, containsString("the password must be at least 14 characters long")));
+    }
+}