[SAML] Saml metadata signing (elastic/x-pack-elasticsearch#4184)

Adds option to sign generated Service Provider SAML metadata
- Using a (possibly password protected) PEM encoded keypair
- Using a keypair stored in a (possibly password protected) PKCSelastic/x-pack-elasticsearch#12 keystore

Resolves elastic/x-pack-elasticsearch#3982


Original commit: elastic/x-pack-elasticsearch@7b806d76f8

plugin/core/src/main/java/org/elasticsearch/xpack/core/ssl/CertUtils.java

@@ -396,7 +396,8 @@ public class CertUtils {
      * @param keyPassword A supplier for the password for each key. The key alias is supplied as an argument to the function, and it should
      *                    return the password for that key. If it returns {@code null}, then the key-pair for that alias is not read.
      */
-    static Map<Certificate, Key> readPkcs12KeyPairs(Path path, char[] password, Function<String, char[]> keyPassword, Environment env)
+    public static Map<Certificate, Key> readPkcs12KeyPairs(Path path, char[] password, Function<String, char[]> keyPassword, Environment
+            env)
             throws CertificateException, NoSuchAlgorithmException, KeyStoreException, IOException, UnrecoverableKeyException {
         final KeyStore store = readKeyStore(path, "PKCS12", password);
         final Enumeration<String> enumeration = store.aliases();

plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/saml/SamlMetadataCommand.java

@@ -6,9 +6,17 @@
 package org.elasticsearch.xpack.security.authc.saml;
 
 import java.io.InputStream;
+import java.io.Reader;
 import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.security.Key;
+import java.security.PrivateKey;
+import java.security.cert.Certificate;
+import java.security.cert.X509Certificate;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
@@ -16,6 +24,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 
 import joptsimple.OptionParser;
@@ -28,6 +37,7 @@ import org.elasticsearch.cli.ExitCodes;
 import org.elasticsearch.cli.SuppressForbidden;
 import org.elasticsearch.cli.Terminal;
 import org.elasticsearch.cli.UserException;
+import org.elasticsearch.common.CheckedFunction;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.PathUtils;
 import org.elasticsearch.common.logging.Loggers;
@@ -38,10 +48,18 @@ import org.elasticsearch.env.Environment;
 import org.elasticsearch.xpack.core.security.authc.RealmConfig;
 import org.elasticsearch.xpack.core.security.authc.RealmSettings;
 import org.elasticsearch.xpack.core.security.authc.saml.SamlRealmSettings;
+import org.elasticsearch.xpack.core.ssl.CertUtils;
 import org.elasticsearch.xpack.security.authc.saml.SamlSpMetadataBuilder.ContactInfo;
+import org.opensaml.core.xml.config.XMLObjectProviderRegistrySupport;
+import org.opensaml.core.xml.io.MarshallingException;
 import org.opensaml.saml.saml2.core.AuthnRequest;
 import org.opensaml.saml.saml2.metadata.EntityDescriptor;
 import org.opensaml.saml.saml2.metadata.impl.EntityDescriptorMarshaller;
+import org.opensaml.security.credential.Credential;
+import org.opensaml.security.x509.BasicX509Credential;
+import org.opensaml.xmlsec.signature.Signature;
+import org.opensaml.xmlsec.signature.support.SignatureConstants;
+import org.opensaml.xmlsec.signature.support.Signer;
 import org.w3c.dom.Element;
 import org.xml.sax.SAXException;
 
@@ -65,6 +83,10 @@ public class SamlMetadataCommand extends EnvironmentAwareCommand {
     private final OptionSpec<String> orgDisplayNameSpec;
     private final OptionSpec<String> orgUrlSpec;
     private final OptionSpec<Void> contactsSpec;
+    private final OptionSpec<String> signingPkcs12PathSpec;
+    private final OptionSpec<String> signingCertPathSpec;
+    private final OptionSpec<String> signingKeyPathSpec;
+    private final OptionSpec<String> keyPasswordSpec;
 
     public static void main(String[] args) throws Exception {
         new SamlMetadataCommand().main(args, Terminal.DEFAULT);
@@ -84,6 +106,18 @@ public class SamlMetadataCommand extends EnvironmentAwareCommand {
         orgUrlSpec = parser.accepts("organisation-url", "the URL of the organisation operating this service")
                 .requiredIf(orgNameSpec).withRequiredArg();
         contactsSpec = parser.accepts("contacts", "Include contact information in metadata").availableUnless(batchSpec);
+        signingPkcs12PathSpec = parser.accepts("signing-bundle", "path to an existing key pair (in PKCS#12 format) to be used for " +
+                "signing ")
+                .withRequiredArg();
+        signingCertPathSpec = parser.accepts("signing-cert", "path to an existing signing certificate")
+                .availableUnless(signingPkcs12PathSpec)
+                .withRequiredArg();
+        signingKeyPathSpec = parser.accepts("signing-key", "path to an existing signing private key")
+                .availableIf(signingCertPathSpec)
+                .requiredIf(signingCertPathSpec)
+                .withRequiredArg();
+        keyPasswordSpec = parser.accepts("signing-key-password", "password for an existing signing private key or keypair")
+                .withOptionalArg();
     }
 
     @Override
@@ -95,7 +129,9 @@ public class SamlMetadataCommand extends EnvironmentAwareCommand {
         SamlUtils.initialize(logger);
 
         final EntityDescriptor descriptor = buildEntityDescriptor(terminal, options, env);
-        final Path xml = writeOutput(terminal, options, descriptor);
+        Element element = possiblySignDescriptor(terminal, options, descriptor, env);
+
+        final Path xml = writeOutput(terminal, options, element);
         validateXml(terminal, xml);
     }
 
@@ -181,9 +217,42 @@ public class SamlMetadataCommand extends EnvironmentAwareCommand {
         return builder.build();
     }
 
-    private Path writeOutput(Terminal terminal, OptionSet options, EntityDescriptor descriptor) throws Exception {
+    // package-protected for testing
+    Element possiblySignDescriptor(Terminal terminal, OptionSet options, EntityDescriptor descriptor, Environment env)
+            throws UserException {
+        try {
             final EntityDescriptorMarshaller marshaller = new EntityDescriptorMarshaller();
-        final Element element = marshaller.marshall(descriptor);
+            if (options.has(signingPkcs12PathSpec) || (options.has(signingCertPathSpec) && options.has(signingKeyPathSpec))) {
+                Signature signature = (Signature) XMLObjectProviderRegistrySupport.getBuilderFactory()
+                        .getBuilder(Signature.DEFAULT_ELEMENT_NAME)
+                        .buildObject(Signature.DEFAULT_ELEMENT_NAME);
+                signature.setSigningCredential(buildSigningCredential(terminal, options, env));
+                signature.setSignatureAlgorithm(SignatureConstants.ALGO_ID_SIGNATURE_RSA_SHA256);
+                signature.setCanonicalizationAlgorithm(SignatureConstants.ALGO_ID_C14N_EXCL_OMIT_COMMENTS);
+                descriptor.setSignature(signature);
+                Element element = marshaller.marshall(descriptor);
+                Signer.signObject(signature);
+                return element;
+            } else {
+                return marshaller.marshall(descriptor);
+            }
+        } catch (Exception e) {
+            String errorMessage;
+            if (e instanceof MarshallingException) {
+                errorMessage = "Error serializing Metadata to file";
+            } else if (e instanceof org.opensaml.xmlsec.signature.support.SignatureException) {
+                errorMessage = "Error attempting to sign Metadata";
+            } else {
+                errorMessage = "Error building signing credentials from provided keyPair";
+            }
+            terminal.println(Terminal.Verbosity.SILENT, errorMessage);
+            terminal.println("The following errors were found:");
+            printExceptions(terminal, e);
+            throw new UserException(ExitCodes.CANT_CREATE, "Unable to create metadata document");
+        }
+    }
+
+    private Path writeOutput(Terminal terminal, OptionSet options, Element element) throws Exception {
         final Path outputFile = resolvePath(option(outputPathSpec, options, "saml-elasticsearch-metadata.xml"));
         final Writer writer = Files.newBufferedWriter(outputFile);
         SamlUtils.print(element, writer, true);
@@ -191,7 +260,74 @@ public class SamlMetadataCommand extends EnvironmentAwareCommand {
         return outputFile;
     }
 
+    private Credential buildSigningCredential(Terminal terminal, OptionSet options, Environment env) throws
+            Exception {
+        X509Certificate signingCertificate;
+        PrivateKey signingKey;
+        char[] password = getChars(keyPasswordSpec.value(options));
+        if (options.has(signingPkcs12PathSpec)) {
+            Path p12Path = resolvePath(signingPkcs12PathSpec.value(options));
+            Map<Certificate, Key> keys = withPassword("certificate bundle (" + p12Path + ")", password,
+                    terminal, keyPassword -> CertUtils.readPkcs12KeyPairs(p12Path, keyPassword, a -> keyPassword, env));
 
+            if (keys.size() != 1) {
+                throw new IllegalArgumentException("expected a single key in file [" + p12Path.toAbsolutePath() + "] but found [" +
+                        keys.size() + "]");
+            }
+            final Map.Entry<Certificate, Key> pair = keys.entrySet().iterator().next();
+            signingCertificate = (X509Certificate) pair.getKey();
+            signingKey = (PrivateKey) pair.getValue();
+        } else {
+            Path cert = resolvePath(signingCertPathSpec.value(options));
+            Path key = resolvePath(signingKeyPathSpec.value(options));
+            final String resolvedSigningCertPath = cert.toAbsolutePath().toString();
+            Certificate[] certificates = CertUtils.readCertificates(Collections.singletonList(resolvedSigningCertPath), env);
+            if (certificates.length != 1) {
+                throw new IllegalArgumentException("expected a single certificate in file [" + resolvedSigningCertPath + "] but found [" +
+                        certificates.length + "]");
+            }
+            signingCertificate = (X509Certificate) certificates[0];
+            signingKey = readSigningKey(key, password, terminal);
+        }
+        return new BasicX509Credential(signingCertificate, signingKey);
+    }
+
+    private static <T, E extends Exception> T withPassword(String description, char[] password, Terminal terminal,
+                                                           CheckedFunction<char[], T, E> body) throws E {
+        if (password == null) {
+            char[] promptedValue = terminal.readSecret("Enter password for " + description + " : ");
+            try {
+                return body.apply(promptedValue);
+            } finally {
+                Arrays.fill(promptedValue, (char) 0);
+            }
+        } else {
+            return body.apply(password);
+        }
+    }
+
+    private static char[] getChars(String password) {
+        return password == null ? null : password.toCharArray();
+    }
+
+    private static PrivateKey readSigningKey(Path path, char[] password, Terminal terminal)
+            throws Exception {
+        AtomicReference<char[]> passwordReference = new AtomicReference<>(password);
+        try (Reader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8)) {
+            return CertUtils.readPrivateKey(reader, () -> {
+                if (password != null) {
+                    return password;
+                }
+                char[] promptedValue = terminal.readSecret("Enter password for the signing key (" + path.getFileName() + ") : ");
+                passwordReference.set(promptedValue);
+                return promptedValue;
+            });
+        } finally {
+            if (passwordReference.get() != null) {
+                Arrays.fill(passwordReference.get(), (char) 0);
+            }
+        }
+    }
     private void validateXml(Terminal terminal, Path xml) throws Exception {
         try (InputStream xmlInput = Files.newInputStream(xml)) {
             SamlUtils.validate(xmlInput, METADATA_SCHEMA);

plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/saml/SamlMetadataCommandTests.java

@@ -18,12 +18,22 @@ import org.opensaml.saml.common.xml.SAMLConstants;
 import org.opensaml.saml.saml2.metadata.EntityDescriptor;
 import org.opensaml.saml.saml2.metadata.RequestedAttribute;
 import org.opensaml.saml.saml2.metadata.SPSSODescriptor;
+import org.opensaml.saml.security.impl.SAMLSignatureProfileValidator;
+import org.opensaml.security.credential.Credential;
 import org.opensaml.security.credential.UsageType;
+import org.opensaml.security.x509.BasicX509Credential;
 import org.opensaml.xmlsec.keyinfo.KeyInfoSupport;
+import org.opensaml.xmlsec.signature.Signature;
 import org.opensaml.xmlsec.signature.X509Certificate;
 import org.opensaml.xmlsec.signature.X509Data;
+import org.opensaml.xmlsec.signature.support.SignatureValidator;
+import org.w3c.dom.Element;
 
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.security.PrivateKey;
+import java.security.cert.Certificate;
 import java.util.Collections;
 import java.util.List;
 
@@ -267,4 +277,270 @@ public class SamlMetadataCommandTests extends SamlTestCase {
         assertThat(attributes.get(1).getFriendlyName(), equalTo("principal"));
         assertThat(attributes.get(1).getName(), equalTo("urn:oid:0.9.2342.19200300.100.1.1"));
     }
+
+    public void testSigningMetadataWithPfx() throws Exception {
+        final Path certPath = getDataPath("saml.crt");
+        final Path keyPath = getDataPath("saml.key");
+        final Path p12Path = getDataPath("saml.p12");
+        final SamlMetadataCommand command = new SamlMetadataCommand();
+        final OptionSet options = command.getParser().parse(new String[]{
+                "-signing-bundle", p12Path.toString()
+        });
+
+        final boolean useSigningCredentials = randomBoolean();
+        final Settings.Builder settingsBuilder = Settings.builder()
+                .put("path.home", createTempDir())
+                .put(RealmSettings.PREFIX + "my_saml.type", "saml")
+                .put(RealmSettings.PREFIX + "my_saml.order", 1)
+                .put(RealmSettings.PREFIX + "my_saml.idp.entity_id", "https://okta.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.entity_id", "https://kibana.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.acs", "https://kibana.my.corp/saml/login")
+                .put(RealmSettings.PREFIX + "my_saml.sp.logout", "https://kibana.my.corp/saml/logout")
+                .put(RealmSettings.PREFIX + "my_saml.attributes.principal", "urn:oid:0.9.2342.19200300.100.1.1");
+        if (useSigningCredentials) {
+            settingsBuilder.put(RealmSettings.PREFIX + "my_saml.signing.certificate", certPath.toString())
+                    .put(RealmSettings.PREFIX + "my_saml.signing.key", keyPath.toString());
+        }
+        final Settings settings = settingsBuilder.build();
+        final Environment env = TestEnvironment.newEnvironment(settings);
+
+        final MockTerminal terminal = new MockTerminal();
+
+        // What is the friendly name for "principal" attribute "urn:oid:0.9.2342.19200300.100.1.1" [default: principal]
+        terminal.addTextInput("");
+        terminal.addSecretInput("");
+
+        final EntityDescriptor descriptor = command.buildEntityDescriptor(terminal, options, env);
+        command.possiblySignDescriptor(terminal, options, descriptor, env);
+        assertThat(descriptor, notNullValue());
+        // Verify generated signature
+        assertThat(descriptor.getSignature(), notNullValue());
+        assertThat(validateSignature(descriptor.getSignature()), equalTo(true));
+        // Make sure that Signing didn't mangle the XML at all and we can still read metadata
+        assertThat(descriptor.getEntityID(), equalTo("https://kibana.my.corp/"));
+
+        assertThat(descriptor.getRoleDescriptors(), iterableWithSize(1));
+        assertThat(descriptor.getRoleDescriptors().get(0), instanceOf(SPSSODescriptor.class));
+        final SPSSODescriptor spDescriptor = (SPSSODescriptor) descriptor.getRoleDescriptors().get(0);
+
+        assertThat(spDescriptor.getAssertionConsumerServices(), iterableWithSize(1));
+        assertThat(spDescriptor.getAssertionConsumerServices().get(0).getLocation(), equalTo("https://kibana.my.corp/saml/login"));
+        assertThat(spDescriptor.getAssertionConsumerServices().get(0).isDefault(), equalTo(true));
+        assertThat(spDescriptor.getAssertionConsumerServices().get(0).getIndex(), equalTo(1));
+        assertThat(spDescriptor.getAssertionConsumerServices().get(0).getBinding(), equalTo(SAMLConstants.SAML2_POST_BINDING_URI));
+
+        final RequestedAttribute uidAttribute = spDescriptor.getAttributeConsumingServices().get(0).getRequestAttributes().get(0);
+        assertThat(uidAttribute.getName(), equalTo("urn:oid:0.9.2342.19200300.100.1.1"));
+        assertThat(uidAttribute.getFriendlyName(), equalTo("principal"));
+
+        assertThat(spDescriptor.isAuthnRequestsSigned(), equalTo(useSigningCredentials));
+        assertThat(spDescriptor.getWantAssertionsSigned(), equalTo(true));
+    }
+
+    public void testSigningMetadataWithPasswordProtectedPfx() throws Exception {
+        final Path certPath = getDataPath("saml.crt");
+        final Path keyPath = getDataPath("saml.key");
+        final Path p12Path = getDataPath("saml_with_password.p12");
+        final SamlMetadataCommand command = new SamlMetadataCommand();
+        final OptionSet options = command.getParser().parse(new String[]{
+                "-signing-bundle", p12Path.toString(),
+                "-signing-key-password", "saml"
+        });
+
+        final boolean useSigningCredentials = randomBoolean();
+        final Settings.Builder settingsBuilder = Settings.builder()
+                .put("path.home", createTempDir())
+                .put(RealmSettings.PREFIX + "my_saml.type", "saml")
+                .put(RealmSettings.PREFIX + "my_saml.order", 1)
+                .put(RealmSettings.PREFIX + "my_saml.idp.entity_id", "https://okta.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.entity_id", "https://kibana.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.acs", "https://kibana.my.corp/saml/login")
+                .put(RealmSettings.PREFIX + "my_saml.sp.logout", "https://kibana.my.corp/saml/logout");
+        if (useSigningCredentials) {
+            settingsBuilder.put(RealmSettings.PREFIX + "my_saml.signing.certificate", certPath.toString())
+                    .put(RealmSettings.PREFIX + "my_saml.signing.key", keyPath.toString());
+        }
+        final Settings settings = settingsBuilder.build();
+        final Environment env = TestEnvironment.newEnvironment(settings);
+
+        final MockTerminal terminal = new MockTerminal();
+
+        final EntityDescriptor descriptor = command.buildEntityDescriptor(terminal, options, env);
+        Element e = command.possiblySignDescriptor(terminal, options, descriptor, env);
+        String a = SamlUtils.toString(e);
+        assertThat(descriptor, notNullValue());
+        // Verify generated signature
+        assertThat(descriptor.getSignature(), notNullValue());
+        assertThat(validateSignature(descriptor.getSignature()), equalTo(true));
+    }
+
+    public void testErrorSigningMetadataWithWrongPassword() throws Exception {
+        final Path certPath = getDataPath("saml.crt");
+        final Path keyPath = getDataPath("saml.key");
+        final Path p12Path = getDataPath("saml_with_password.p12");
+        final SamlMetadataCommand command = new SamlMetadataCommand();
+        final OptionSet options = command.getParser().parse(new String[]{
+                "-signing-bundle", p12Path.toString(),
+                "-signing-key-password", "wrong_password"
+        });
+
+        final boolean useSigningCredentials = randomBoolean();
+        final Settings.Builder settingsBuilder = Settings.builder()
+                .put("path.home", createTempDir())
+                .put(RealmSettings.PREFIX + "my_saml.type", "saml")
+                .put(RealmSettings.PREFIX + "my_saml.order", 1)
+                .put(RealmSettings.PREFIX + "my_saml.idp.entity_id", "https://okta.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.entity_id", "https://kibana.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.acs", "https://kibana.my.corp/saml/login")
+                .put(RealmSettings.PREFIX + "my_saml.sp.logout", "https://kibana.my.corp/saml/logout");
+        if (useSigningCredentials) {
+            settingsBuilder.put(RealmSettings.PREFIX + "my_saml.signing.certificate", certPath.toString())
+                    .put(RealmSettings.PREFIX + "my_saml.signing.key", keyPath.toString());
+        }
+        final Settings settings = settingsBuilder.build();
+        final Environment env = TestEnvironment.newEnvironment(settings);
+
+        final MockTerminal terminal = new MockTerminal();
+
+        final EntityDescriptor descriptor = command.buildEntityDescriptor(terminal, options, env);
+        final UserException userException = expectThrows(UserException.class, () -> command.possiblySignDescriptor(terminal, options,
+                descriptor, env));
+        assertThat(userException.getMessage(), containsString("Unable to create metadata document"));
+        assertThat(terminal.getOutput(), containsString("keystore password was incorrect"));
+    }
+
+    public void testSigningMetadataWithPem() throws Exception {
+        //Use this keypair for signing the metadata also
+        final Path certPath = getDataPath("saml.crt");
+        final Path keyPath = getDataPath("saml.key");
+
+        final SamlMetadataCommand command = new SamlMetadataCommand();
+        final OptionSet options = command.getParser().parse(new String[]{
+                "-signing-cert", certPath.toString(),
+                "-signing-key", keyPath.toString()
+        });
+
+        final boolean useSigningCredentials = randomBoolean();
+        final Settings.Builder settingsBuilder = Settings.builder()
+                .put("path.home", createTempDir())
+                .put(RealmSettings.PREFIX + "my_saml.type", "saml")
+                .put(RealmSettings.PREFIX + "my_saml.order", 1)
+                .put(RealmSettings.PREFIX + "my_saml.idp.entity_id", "https://okta.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.entity_id", "https://kibana.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.acs", "https://kibana.my.corp/saml/login")
+                .put(RealmSettings.PREFIX + "my_saml.sp.logout", "https://kibana.my.corp/saml/logout");
+        if (useSigningCredentials) {
+            settingsBuilder.put(RealmSettings.PREFIX + "my_saml.signing.certificate", certPath.toString())
+                    .put(RealmSettings.PREFIX + "my_saml.signing.key", keyPath.toString());
+        }
+        final Settings settings = settingsBuilder.build();
+        final Environment env = TestEnvironment.newEnvironment(settings);
+
+        final MockTerminal terminal = new MockTerminal();
+
+        final EntityDescriptor descriptor = command.buildEntityDescriptor(terminal, options, env);
+        command.possiblySignDescriptor(terminal, options, descriptor, env);
+        assertThat(descriptor, notNullValue());
+        // Verify generated signature
+        assertThat(descriptor.getSignature(), notNullValue());
+        assertThat(validateSignature(descriptor.getSignature()), equalTo(true));
+    }
+
+    public void testSigningMetadataWithPasswordProtectedPem() throws Exception {
+        //Use same keypair for signing the metadata
+        final Path signingKeyPath = getDataPath("saml_with_password.key");
+
+        final Path certPath = getDataPath("saml.crt");
+        final Path keyPath = getDataPath("saml.key");
+
+        final SamlMetadataCommand command = new SamlMetadataCommand();
+        final OptionSet options = command.getParser().parse(new String[]{
+                "-signing-cert", certPath.toString(),
+                "-signing-key", signingKeyPath.toString(),
+                "-signing-key-password", "saml"
+
+        });
+
+        final boolean useSigningCredentials = randomBoolean();
+        final Settings.Builder settingsBuilder = Settings.builder()
+                .put("path.home", createTempDir())
+                .put(RealmSettings.PREFIX + "my_saml.type", "saml")
+                .put(RealmSettings.PREFIX + "my_saml.order", 1)
+                .put(RealmSettings.PREFIX + "my_saml.idp.entity_id", "https://okta.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.entity_id", "https://kibana.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.acs", "https://kibana.my.corp/saml/login")
+                .put(RealmSettings.PREFIX + "my_saml.sp.logout", "https://kibana.my.corp/saml/logout");
+        if (useSigningCredentials) {
+            settingsBuilder.put(RealmSettings.PREFIX + "my_saml.signing.certificate", certPath.toString())
+                    .put(RealmSettings.PREFIX + "my_saml.signing.key", keyPath.toString());
+        }
+        final Settings settings = settingsBuilder.build();
+        final Environment env = TestEnvironment.newEnvironment(settings);
+
+        final MockTerminal terminal = new MockTerminal();
+
+        final EntityDescriptor descriptor = command.buildEntityDescriptor(terminal, options, env);
+        command.possiblySignDescriptor(terminal, options, descriptor, env);
+        assertThat(descriptor, notNullValue());
+        // Verify generated signature
+        assertThat(descriptor.getSignature(), notNullValue());
+        assertThat(validateSignature(descriptor.getSignature()), equalTo(true));
+    }
+
+    public void testSigningMetadataWithPasswordProtectedPemInTerminal() throws Exception {
+        //Use same keypair for signing the metadata
+        final Path signingKeyPath = getDataPath("saml_with_password.key");
+
+        final Path certPath = getDataPath("saml.crt");
+        final Path keyPath = getDataPath("saml.key");
+
+        final SamlMetadataCommand command = new SamlMetadataCommand();
+        final OptionSet options = command.getParser().parse(new String[]{
+                "-signing-cert", certPath.toString(),
+                "-signing-key", signingKeyPath.toString()
+
+        });
+
+        final boolean useSigningCredentials = randomBoolean();
+        final Settings.Builder settingsBuilder = Settings.builder()
+                .put("path.home", createTempDir())
+                .put(RealmSettings.PREFIX + "my_saml.type", "saml")
+                .put(RealmSettings.PREFIX + "my_saml.order", 1)
+                .put(RealmSettings.PREFIX + "my_saml.idp.entity_id", "https://okta.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.entity_id", "https://kibana.my.corp/")
+                .put(RealmSettings.PREFIX + "my_saml.sp.acs", "https://kibana.my.corp/saml/login")
+                .put(RealmSettings.PREFIX + "my_saml.sp.logout", "https://kibana.my.corp/saml/logout");
+        if (useSigningCredentials) {
+            settingsBuilder.put(RealmSettings.PREFIX + "my_saml.signing.certificate", certPath.toString())
+                    .put(RealmSettings.PREFIX + "my_saml.signing.key", keyPath.toString());
+        }
+        final Settings settings = settingsBuilder.build();
+        final Environment env = TestEnvironment.newEnvironment(settings);
+
+        final MockTerminal terminal = new MockTerminal();
+
+        terminal.addSecretInput("saml");
+
+        final EntityDescriptor descriptor = command.buildEntityDescriptor(terminal, options, env);
+        command.possiblySignDescriptor(terminal, options, descriptor, env);
+        assertThat(descriptor, notNullValue());
+        // Verify generated signature
+        assertThat(descriptor.getSignature(), notNullValue());
+        assertThat(validateSignature(descriptor.getSignature()), equalTo(true));
+    }
+
+    private boolean validateSignature(Signature signature) {
+        try {
+            Certificate[] certificates = CertUtils.readCertificates(Collections.singletonList(getDataPath("saml.crt").toString()), null);
+            PrivateKey key = CertUtils.readPrivateKey(Files.newBufferedReader(getDataPath("saml.key"), StandardCharsets.UTF_8),
+                    ""::toCharArray);
+            Credential verificationCredential = new BasicX509Credential((java.security.cert.X509Certificate) certificates[0], key);
+            SAMLSignatureProfileValidator profileValidator = new SAMLSignatureProfileValidator();
+            profileValidator.validate(signature);
+            SignatureValidator.validate(signature, verificationCredential);
+            return true;
+        } catch (Exception e) {
+            return false;
+        }
+    }
 }

plugin/security/src/test/resources/org/elasticsearch/xpack/security/authc/saml/saml_with_password.key

@@ -0,0 +1,30 @@
+-----BEGIN RSA PRIVATE KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: DES-EDE3-CBC,E5CF40A599E7BBB7
+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-----END RSA PRIVATE KEY-----