https://github.com/ma1uta/ma1sd/issues/3 Allow extended character sets for backward compatibility.

Allow configuring unbind notifications to be sent or not.

README.md

@@ -10,11 +10,13 @@ ma1sd - Federated Matrix Identity Server
 - [Contribute](#contribute)
 - [Powered by ma1sd](#powered-by-ma1sd)
 - [FAQ](#faq)
+- [Migration from mxisd](#migration-from-mxisd)
 - [Contact](#contact)
 
 ---
 
-* This project is a fork of the https://github.com/kamax-matrix/mxisd which has been archived and no longer supported. *
+* This project is a fork (not successor) of the https://github.com/kamax-matrix/mxisd, which has been archived and no longer maintained as a standalone product.
+Also, ma1sd is supported by the volunteer not developers of the original project.
 
 ---
 
@@ -108,6 +110,10 @@ The following projects can use ma1sd under the hood for some or all their featur
 # FAQ
 See the [dedicated document](docs/faq.md)
 
+# Migration from mxisd
+
+See the [migration guide](docs/migration-from-mxisd.md)
+
 # Contact
 Get in touch via:
 - Matrix: [#ma1sd:ru-matrix.org](https://matrix.to/#/#ma1sd:ru-matrix.org)

docs/configure.md

@@ -45,6 +45,14 @@ Create a list under the label `myOtherServers` containing two Identity servers:
 - `server.port`: HTTP port to listen on (unencrypted)
 - `server.publicUrl`: Defaults to `https://{server.name}`
 
+## Unbind (MSC1915)
+- `session.policy.unbind.enabled`: Enable or disable unbind functionality (MSC1915). (Defaults to true).
+
+*Warning*: Unbind check incoming request by two ways:
+- session validation.
+- request signature via `X-Matrix` header and uses `server.publicUrl` property to construct the signing json;
+Commonly the `server.publicUrl` should be the same value as the `trusted_third_party_id_servers` property in the synapse config.
+
 ## Storage
 ### SQLite
 `storage.provider.sqlite.database`: Absolute location of the SQLite database

docs/getting-started.md

@@ -131,7 +131,7 @@ trusted_third_party_id_servers:
 It is **highly recommended** to remove `matrix.org` and `vector.im` (or any other default entry) from your configuration
 so only your own Identity server is authoritative for your HS.
 
-## Validate
+## Validate (Under reconstruction)
 **NOTE:** In case your homeserver has no working federation, step 5 will not happen. If step 4 took place, consider
 your installation validated.
 

docs/migration-from-mxisd.md

@@ -0,0 +1,16 @@
+# Migration from mxisd
+
+Version 2.0.0 of the ma1sd uses the same format of the database schema and main configuration file as mxisd.
+
+Migration from mxisd:
+- install ma1sd via deb package, docker image or zip/tar archive
+- stop mxisd
+- copy configuration file (by default /etc/mxisd/mxisd.yaml to /etc/ma1sd/ma1sd.yaml)
+- copy key store (by default /var/lib/mxisd/keys folder to /var/lib/ma1sd/keys)
+- copy storage (by default /var/lib/mxisd/store.db to /var/lib/ma1sd/store.db)
+- change paths in the new config file (ma1sd.yaml). There are options: `key.path` and `storage.provider.sqlite`
+- start ma1sd
+
+Due to ma1sd uses the same ports by default as mxisd it isn't necessary to change nginx/apache configuration.
+
+If you have any troubles with migration don't hesitate to ask questions in [#ma1sd:ru-matrix.org](https://matrix.to/#/#ma1sd:ru-matrix.org) room.

docs/threepids/notification/sendgrid-handler.md

@@ -31,8 +31,8 @@ notification:
               text: <Path to file containing the raw text part of the email. Do not set to not use one>
               html: <Path to file containing the HTML part of the email. Do not set to not use one>
           unbind:
-            fraudulent:
+            notification:
-              subject: <Subject of the email notification sent for potentially fraudulent 3PID unbinds>
+              subject: <Subject of the email notification sent for 3PID unbinds>
               body:
                 text: <Path to file containing the raw text part of the email. Do not set to not use one>
                 html: <Path to file containing the raw text part of the email. Do not set to not use one>

docs/threepids/notification/template-generator.md

@@ -9,7 +9,7 @@ provide your own custom templates.
 Templates for the following events/actions are available:
 - [3PID invite](../../features/identity.md)
 - [3PID session: validation](../session/session.md)
-- [3PID session: fraudulent unbind](https://github.com/kamax-matrix/ma1sd/wiki/ma1sd-and-your-privacy#improving-your-privacy-one-commit-at-the-time)
+- [3PID session: unbind](https://github.com/kamax-matrix/ma1sd/wiki/ma1sd-and-your-privacy#improving-your-privacy-one-commit-at-the-time)
 - [Matrix ID invite](../../features/experimental/application-service.md#email-notification-about-room-invites-by-matrix-ids)
 
 ## Placeholders
@@ -71,7 +71,7 @@ under the namespace `threepid.medium.<medium>.generators.template`.
 Under such namespace, the following keys are available:
 - `invite`: Path to the 3PID invite notification template
 - `session.validation`: Path to the 3PID session validation notification template
-- `session.unbind.fraudulent`: Path to the 3PID session fraudulent unbind notification template
+- `session.unbind`: Path to the 3PID session unbind notification template
 - `generic.matrixId`: Path to the Matrix ID invite notification template
 - `placeholder`: Map of key/values to set static values for some placeholders.
 
@@ -104,7 +104,7 @@ threepid:
           session:
             validation: '/path/to/validate-template.eml'
             unbind:
-              fraudulent: '/path/to/unbind-fraudulent-template.eml'
+              notification: '/path/to/unbind-notification-template.eml'
           generic:
             matrixId: '/path/to/mxid-invite-template.eml'
           placeholder:

docs/threepids/session/session.md

@@ -103,8 +103,8 @@ session:
     validation:
       enabled: true
     unbind:
-      fraudulent:
+      notifications: true
-        sendWarning: true
+      enabled: true
 
 # DO NOT COPY/PASTE AS-IS IN YOUR CONFIGURATION
 # CONFIGURATION EXAMPLE
@@ -115,11 +115,7 @@ are allowed to do in terms of 3PID sessions. The policy has a global on/off swit
 
 ---
 
-`unbind.fraudulent` controls warning notifications if an illegal/fraudulent 3PID removal is attempted on the Identity server.  
+`unbind` controls warning notifications for 3PID removal. Setting `notifications` for `unbind` to false will prevent unbind emails from sending.
-This is directly related to synapse disregard for privacy and new GDPR laws in Europe in an attempt to inform users about
-potential privacy leaks.
-
-For more information, see the corresponding [synapse issue](https://github.com/matrix-org/synapse/issues/4540).
 
 ### Web views
 Once a user click on a validation link, it is taken to the Identity Server validation page where the token is submitted.  

src/main/java/io/kamax/mxisd/Mxisd.java

@@ -118,7 +118,7 @@ public class Mxisd {
         idStrategy = new RecursivePriorityLookupStrategy(cfg.getLookup(), ThreePidProviders.get(), bridgeFetcher);
         pMgr = new ProfileManager(ProfileProviders.get(), clientDns, httpClient);
         notifMgr = new NotificationManager(cfg.getNotification(), NotificationHandlers.get());
-        sessMgr = new SessionManager(cfg.getSession(), cfg.getMatrix(), store, notifMgr);
+        sessMgr = new SessionManager(cfg, store, notifMgr, resolver, httpClient, signMgr);
         invMgr = new InvitationManager(cfg, store, idStrategy, keyMgr, signMgr, resolver, notifMgr, pMgr);
         authMgr = new AuthManager(cfg, AuthProviders.get(), idStrategy, invMgr, clientDns, httpClient);
         dirMgr = new DirectoryManager(cfg.getDirectory(), clientDns, httpClient, DirectoryProviders.get());

src/main/java/io/kamax/mxisd/auth/AuthManager.java

@@ -140,7 +140,7 @@ public class AuthManager {
                 }
 
                 try {
-                    MatrixID.asValid(mxId);
+                    MatrixID.asAcceptable(mxId);
                 } catch (IllegalArgumentException e) {
                     log.warn("The returned User ID {} is not a valid Matrix ID. Login might fail at the Homeserver level", mxId);
                 }

src/main/java/io/kamax/mxisd/config/SessionConfig.java

@@ -46,34 +46,31 @@ public class SessionConfig {
 
         public static class PolicyUnbind {
 
-            public static class PolicyUnbindFraudulent {
+            private boolean enabled = true;
             
-                private boolean sendWarning = true;
+            private boolean notifications = true;
 
-                public boolean getSendWarning() {
+            public boolean getEnabled() {
-                    return sendWarning;
+                return enabled;
-                }
-
-                public void setSendWarning(boolean sendWarning) {
-                    this.sendWarning = sendWarning;
-                }
             }
 
-
+            public void setEnabled(boolean enabled) {
-            private PolicyUnbindFraudulent fraudulent = new PolicyUnbindFraudulent();
+                this.enabled = enabled;
-
-            public PolicyUnbindFraudulent getFraudulent() {
-                return fraudulent;
             }
             
-            public void setFraudulent(PolicyUnbindFraudulent fraudulent) {
+            public boolean shouldNotify() {
-                this.fraudulent = fraudulent;
+                return notifications;
             }
             
+            public void setNotifications(boolean notifications) {
+                this.notifications = notifications;
+            }
         }
 
         public Policy() {
             validation.enabled = true;
+            unbind.enabled = true;
+            unbind.notifications = true;
         }
 
         private PolicyTemplate validation = new PolicyTemplate();

src/main/java/io/kamax/mxisd/config/threepid/connector/EmailSendGridConfig.java

@@ -115,24 +115,10 @@ public class EmailSendGridConfig {
 
     public static class Templates {
 
-        public static class TemplateSessionUnbind {
-
-            private EmailTemplate fraudulent = new EmailTemplate();
-
-            public EmailTemplate getFraudulent() {
-                return fraudulent;
-            }
-
-            public void setFraudulent(EmailTemplate fraudulent) {
-                this.fraudulent = fraudulent;
-            }
-
-        }
-
         public static class TemplateSession {
 
             private EmailTemplate validation = new EmailTemplate();
-            private TemplateSessionUnbind unbind = new TemplateSessionUnbind();
+            private EmailTemplate unbind = new EmailTemplate();
 
             public EmailTemplate getValidation() {
                 return validation;
@@ -142,11 +128,11 @@ public class EmailSendGridConfig {
                 this.validation = validation;
             }
 
-            public TemplateSessionUnbind getUnbind() {
+            public EmailTemplate getUnbind() {
                 return unbind;
             }
 
-            public void setUnbind(TemplateSessionUnbind unbind) {
+            public void setUnbind(EmailTemplate unbind) {
                 this.unbind = unbind;
             }
 

src/main/java/io/kamax/mxisd/config/threepid/medium/EmailTemplateConfig.java

@@ -31,7 +31,7 @@ public class EmailTemplateConfig extends GenericTemplateConfig {
         setInvite("classpath:/threepids/email/invite-template.eml");
         getGeneric().put("matrixId", "classpath:/threepids/email/mxid-template.eml");
         getSession().setValidation("classpath:/threepids/email/validate-template.eml");
-        getSession().getUnbind().setFraudulent("classpath:/threepids/email/unbind-fraudulent.eml");
+        getSession().getUnbind().setNotification("classpath:/threepids/email/unbind-notification.eml");
     }
 
     public EmailTemplateConfig build() {
@@ -40,7 +40,7 @@ public class EmailTemplateConfig extends GenericTemplateConfig {
         log.info("Session:");
         log.info("  Validation: {}", getSession().getValidation());
         log.info("  Unbind:");
-        log.info("    Fraudulent: {}", getSession().getUnbind().getFraudulent());
+        log.info("    Notification: {}", getSession().getUnbind().getNotification());
 
         return this;
     }

src/main/java/io/kamax/mxisd/config/threepid/medium/GenericTemplateConfig.java

@@ -41,16 +41,25 @@ public class GenericTemplateConfig {
 
         public static class SessionUnbind {
 
-            private String fraudulent;
+            private String validation;
 
-            public String getFraudulent() {
+            private String notification;
-                return fraudulent;
+
+            public String getValidation() {
+                return validation;
             }
 
-            public void setFraudulent(String fraudulent) {
+            public void setValidation(String validation) {
-                this.fraudulent = fraudulent;
+                this.validation = validation;
             }
 
+            public String getNotification() {
+                return notification;
+            }
+
+            public void setNotification(String notification) {
+                this.notification = notification;
+            }
         }
 
         private String validation;

src/main/java/io/kamax/mxisd/config/threepid/medium/PhoneSmsTemplateConfig.java

@@ -30,7 +30,8 @@ public class PhoneSmsTemplateConfig extends GenericTemplateConfig {
     public PhoneSmsTemplateConfig() {
         setInvite("classpath:/threepids/sms/invite-template.txt");
         getSession().setValidation("classpath:/threepids/sms/validate-template.txt");
-        getSession().getUnbind().setFraudulent("classpath:/threepids/sms/unbind-fraudulent.txt");
+        getSession().getUnbind().setValidation("classpath:/threepids/sms/unbind-validation.txt");
+        getSession().getUnbind().setNotification("classpath:/threepids/sms/unbind-notification.txt");
     }
 
     public PhoneSmsTemplateConfig build() {
@@ -39,7 +40,8 @@ public class PhoneSmsTemplateConfig extends GenericTemplateConfig {
         log.info("Session:");
         log.info("  Validation: {}", getSession().getValidation());
         log.info("  Unbind:");
-        log.info("    Fraudulent: {}", getSession().getUnbind().getFraudulent());
+        log.info("    Validation: {}", getSession().getUnbind().getValidation());
+        log.info("    Notification: {}", getSession().getUnbind().getNotification());
 
         return this;
     }

src/main/java/io/kamax/mxisd/crypto/CryptoFactory.java

@@ -58,5 +58,4 @@ public class CryptoFactory {
     public static SignatureManager getSignatureManager(MxisdConfig cfg, Ed25519KeyManager keyMgr) {
         return new Ed25519SignatureManager(cfg, keyMgr);
     }
-
 }

src/main/java/io/kamax/mxisd/crypto/SignatureManager.java

@@ -26,6 +26,7 @@ import io.kamax.matrix.event.EventKey;
 import io.kamax.matrix.json.MatrixJson;
 
 import java.nio.charset.StandardCharsets;
+import java.security.PublicKey;
 import java.util.Objects;
 
 public interface SignatureManager {
@@ -106,4 +107,13 @@ public interface SignatureManager {
      */
     Signature sign(byte[] data);
 
+    /**
+     * Verify the data.
+     *
+     * @param publicKey public key to verify
+     * @param signature signature to verify
+     * @param data      the data to verify
+     * @return {@code true} if signature is valid, else {@code false}
+     */
+    boolean verify(PublicKey publicKey, String signature, byte[] data);
 }

src/main/java/io/kamax/mxisd/crypto/ed25519/Ed25519SignatureManager.java

@@ -33,7 +33,9 @@ import net.i2p.crypto.eddsa.EdDSAEngine;
 import java.security.InvalidKeyException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.security.PublicKey;
 import java.security.SignatureException;
+import java.util.Base64;
 
 public class Ed25519SignatureManager implements SignatureManager {
 
@@ -92,4 +94,15 @@ public class Ed25519SignatureManager implements SignatureManager {
         }
     }
 
+    @Override
+    public boolean verify(PublicKey publicKey, String signature, byte[] data) {
+        try {
+            EdDSAEngine signEngine = new EdDSAEngine(MessageDigest.getInstance(keyMgr.getKeySpecs().getHashAlgorithm()));
+            signEngine.initVerify(publicKey);
+            signEngine.update(data);
+            return signEngine.verify(Base64.getDecoder().decode(signature));
+        } catch (NoSuchAlgorithmException | InvalidKeyException | SignatureException e) {
+            throw new RuntimeException(e);
+        }
+    }
 }

src/main/java/io/kamax/mxisd/http/undertow/handler/identity/v1/SessionTpidUnbindHandler.java

@@ -21,13 +21,10 @@
 package io.kamax.mxisd.http.undertow.handler.identity.v1;
 
 import com.google.gson.JsonObject;
-import io.kamax.mxisd.exception.BadRequestException;
-import io.kamax.mxisd.exception.NotAllowedException;
 import io.kamax.mxisd.http.IsAPIv1;
 import io.kamax.mxisd.http.undertow.handler.BasicHttpHandler;
 import io.kamax.mxisd.session.SessionManager;
 import io.undertow.server.HttpServerExchange;
-import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -46,20 +43,9 @@ public class SessionTpidUnbindHandler extends BasicHttpHandler {
     @Override
     public void handleRequest(HttpServerExchange exchange) {
         String auth = exchange.getRequestHeaders().getFirst("Authorization");
-        if (StringUtils.isNotEmpty(auth)) {
-            // We have a auth header to process
-            if (StringUtils.startsWith(auth, "X-Matrix ")) {
-                log.warn("A remote host attempted to unbind without proper authorization. Request was denied");
-                log.warn("See https://github.com/kamax-matrix/mxisd/wiki/mxisd-and-your-privacy for more info");
-                throw new NotAllowedException("3PID can only be removed via 3PID sessions, not via Homeserver signature");
-            } else {
-                throw new BadRequestException("Illegal authorization type");
-            }
-        }
 
         JsonObject body = parseJsonObject(exchange);
-        sessionMgr.unbind(body);
+        sessionMgr.unbind(auth, body);
         writeBodyAsUtf8(exchange, "{}");
     }
-
 }

src/main/java/io/kamax/mxisd/notification/NotificationHandler.java

@@ -37,6 +37,6 @@ public interface NotificationHandler {
 
     void sendForValidation(IThreePidSession session);
 
-    void sendForFraudulentUnbind(ThreePid tpid);
+    void sendForUnbind(ThreePid tpid);
 
 }

src/main/java/io/kamax/mxisd/notification/NotificationManager.java

@@ -78,8 +78,8 @@ public class NotificationManager {
         ensureMedium(session.getThreePid().getMedium()).sendForValidation(session);
     }
 
-    public void sendForFraudulentUnbind(ThreePid tpid) throws NotImplementedException {
+    public void sendForUnbind(ThreePid tpid) throws NotImplementedException {
-        ensureMedium(tpid.getMedium()).sendForFraudulentUnbind(tpid);
+        ensureMedium(tpid.getMedium()).sendForUnbind(tpid);
     }
 
 }

src/main/java/io/kamax/mxisd/session/SessionManager.java

@@ -20,52 +20,74 @@
 
 package io.kamax.mxisd.session;
 
+import static io.kamax.mxisd.config.SessionConfig.Policy.PolicyTemplate;
+
 import com.google.gson.JsonObject;
 import io.kamax.matrix.MatrixID;
 import io.kamax.matrix.ThreePid;
 import io.kamax.matrix._MatrixID;
 import io.kamax.matrix.json.GsonUtil;
-import io.kamax.mxisd.config.MatrixConfig;
+import io.kamax.matrix.json.MatrixJson;
-import io.kamax.mxisd.config.SessionConfig;
+import io.kamax.mxisd.config.MxisdConfig;
+import io.kamax.mxisd.crypto.SignatureManager;
 import io.kamax.mxisd.exception.BadRequestException;
 import io.kamax.mxisd.exception.NotAllowedException;
+import io.kamax.mxisd.exception.RemoteHomeServerException;
 import io.kamax.mxisd.exception.SessionNotValidatedException;
 import io.kamax.mxisd.exception.SessionUnknownException;
 import io.kamax.mxisd.lookup.SingleLookupReply;
 import io.kamax.mxisd.lookup.SingleLookupRequest;
 import io.kamax.mxisd.lookup.ThreePidValidation;
+import io.kamax.mxisd.matrix.HomeserverFederationResolver;
 import io.kamax.mxisd.notification.NotificationManager;
 import io.kamax.mxisd.storage.IStorage;
 import io.kamax.mxisd.storage.dao.IThreePidSessionDao;
 import io.kamax.mxisd.threepid.session.ThreePidSession;
+import net.i2p.crypto.eddsa.EdDSAPublicKey;
+import net.i2p.crypto.eddsa.spec.EdDSANamedCurveSpec;
+import net.i2p.crypto.eddsa.spec.EdDSANamedCurveTable;
+import net.i2p.crypto.eddsa.spec.EdDSAPublicKeySpec;
+import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.RandomStringUtils;
 import org.apache.commons.lang3.StringUtils;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.IOException;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
+import java.util.Calendar;
 import java.util.Optional;
 
-import static io.kamax.mxisd.config.SessionConfig.Policy.PolicyTemplate;
-
 public class SessionManager {
 
     private static final Logger log = LoggerFactory.getLogger(SessionManager.class);
 
-    private SessionConfig cfg;
+    private MxisdConfig cfg;
-    private MatrixConfig mxCfg;
     private IStorage storage;
     private NotificationManager notifMgr;
+    private HomeserverFederationResolver resolver;
+    private CloseableHttpClient client;
+    private SignatureManager signatureManager;
 
     public SessionManager(
-            SessionConfig cfg,
+        MxisdConfig cfg,
-            MatrixConfig mxCfg,
+        IStorage storage,
-            IStorage storage,
+        NotificationManager notifMgr,
-            NotificationManager notifMgr
+        HomeserverFederationResolver resolver,
+        CloseableHttpClient client,
+        SignatureManager signatureManager
     ) {
         this.cfg = cfg;
-        this.mxCfg = mxCfg;
         this.storage = storage;
         this.notifMgr = notifMgr;
+        this.resolver = resolver;
+        this.client = client;
+        this.signatureManager = signatureManager;
     }
 
     private ThreePidSession getSession(String sid, String secret) {
@@ -86,7 +108,7 @@ public class SessionManager {
     }
 
     public String create(String server, ThreePid tpid, String secret, int attempt, String nextLink) {
-        PolicyTemplate policy = cfg.getPolicy().getValidation();
+        PolicyTemplate policy = cfg.getSession().getPolicy().getValidation();
         if (!policy.isEnabled()) {
             throw new NotAllowedException("Validating 3PID is disabled");
         }
@@ -98,7 +120,8 @@ public class SessionManager {
                 ThreePidSession session = new ThreePidSession(dao.get());
                 log.info("We already have a session for {}: {}", tpid, session.getId());
                 if (session.getAttempt() < attempt) {
-                    log.info("Received attempt {} is greater than stored attempt {}, sending validation communication", attempt, session.getAttempt());
+                    log.info("Received attempt {} is greater than stored attempt {}, sending validation communication", attempt,
+                        session.getAttempt());
                     notifMgr.sendForValidation(session);
                     log.info("Sent validation notification to {}", tpid);
                     session.increaseAttempt();
@@ -161,12 +184,13 @@ public class SessionManager {
         _MatrixID mxid = MatrixID.asAcceptable(mxidRaw);
 
         // Only accept binds if the domain matches our own
-        if (!StringUtils.equalsIgnoreCase(mxCfg.getDomain(), mxid.getDomain())) {
+        final String domain = cfg.getMatrix().getDomain();
-            throw new NotAllowedException("Only Matrix IDs from domain " + mxCfg.getDomain() + " can be bound");
+        if (!StringUtils.equalsIgnoreCase(domain, mxid.getDomain())) {
+            throw new NotAllowedException("Only Matrix IDs from domain " + domain + " can be bound");
         }
 
         log.info("Session {}: Binding of {}:{} to Matrix ID {} is accepted",
-                session.getId(), session.getThreePid().getMedium(), session.getThreePid().getAddress(), mxid.getId());
+            session.getId(), session.getThreePid().getMedium(), session.getThreePid().getAddress(), mxid.getId());
 
         SingleLookupRequest request = new SingleLookupRequest();
         request.setType(session.getThreePid().getMedium());
@@ -174,7 +198,12 @@ public class SessionManager {
         return new SingleLookupReply(request, mxid);
     }
 
-    public void unbind(JsonObject reqData) {
+    public void unbind(String auth, JsonObject reqData) {
+        if (!cfg.getSession().getPolicy().getUnbind().getEnabled()) {
+            log.error("Unbind disabled.");
+            throw new NotAllowedException("Unbinding 3PID is disabled");
+        }
+
         _MatrixID mxid;
         try {
             mxid = MatrixID.asAcceptable(GsonUtil.getStringOrThrow(reqData, "mxid"));
@@ -186,6 +215,146 @@ public class SessionManager {
         String secret = GsonUtil.getStringOrNull(reqData, "client_secret");
         ThreePid tpid = GsonUtil.get().fromJson(GsonUtil.getObj(reqData, "threepid"), ThreePid.class);
 
+        if (tpid == null || StringUtils.isBlank(tpid.getAddress()) || StringUtils.isBlank(tpid.getMedium())) {
+            throw new BadRequestException("Missing required 3PID");
+        }
+
+        // We only allow unbind for the domain we manage, mirroring bind
+        final CharSequence domain = cfg.getMatrix().getDomain();
+        if (!StringUtils.equalsIgnoreCase(domain, mxid.getDomain())) {
+            throw new NotAllowedException("Only Matrix IDs from domain " + domain + " can be unbound");
+        }
+
+        log.info("Request was authorized.");
+        if (StringUtils.isNotBlank(sid) && StringUtils.isNotBlank(secret)) {
+            checkSession(sid, secret, tpid);
+        } else if (StringUtils.isNotBlank(auth)) {
+            checkAuthorization(auth, reqData);
+        } else {
+            throw new NotAllowedException("Unable to validate request");
+        }
+
+        log.info("Unbinding of {} {} to {} is accepted", tpid.getMedium(), tpid.getAddress(), mxid.getId());
+        if (cfg.getSession().getPolicy().getUnbind().shouldNotify()) {
+            notifMgr.sendForUnbind(tpid);
+        }
+    }
+
+    private void checkAuthorization(String auth, JsonObject reqData) {
+        if (!auth.startsWith("X-Matrix ")) {
+            throw new NotAllowedException("Wrong authorization header");
+        }
+
+        if (StringUtils.isBlank(cfg.getServer().getPublicUrl())) {
+            throw new NotAllowedException("Unable to verify request, missing `server.publicUrl` property");
+        }
+
+        String[] params = auth.substring("X-Matrix ".length()).split(",");
+
+        String origin = null;
+        String key = null;
+        String sig = null;
+        for (String param : params) {
+            String[] paramItems = param.split("=");
+            String paramKey = paramItems[0];
+            String paramValue = paramItems[1];
+            switch (paramKey) {
+                case "origin":
+                    origin = removeQuotes(paramValue);
+                    break;
+                case "key":
+                    key = removeQuotes(paramValue);
+                    break;
+                case "sig":
+                    sig = removeQuotes(paramValue);
+                    break;
+                default:
+                    log.error("Unknown parameter: {}", param);
+                    throw new BadRequestException("Authorization with unknown parameter");
+            }
+        }
+
+        if (StringUtils.isBlank(origin) || StringUtils.isBlank(key) || StringUtils.isBlank(sig)) {
+            log.error("Missing required parameters");
+            throw new BadRequestException("Missing required header parameters");
+        }
+
+        if (!cfg.getMatrix().getDomain().equalsIgnoreCase(origin)) {
+            throw new NotAllowedException("Only Matrix IDs from domain " + origin + " can be unbound");
+        }
+
+        JsonObject jsonObject = new JsonObject();
+        jsonObject.addProperty("method", "POST");
+        jsonObject.addProperty("uri", "/_matrix/identity/api/v1/3pid/unbind");
+        jsonObject.addProperty("origin", origin);
+        jsonObject.addProperty("destination_is", URI.create(cfg.getServer().getPublicUrl()).getHost());
+        jsonObject.add("content", reqData);
+
+        String canonical = MatrixJson.encodeCanonical(jsonObject);
+
+        String originUrl = resolver.resolve(origin).toString();
+
+        validateServerKey(key, sig, canonical, originUrl);
+    }
+
+    private String removeQuotes(String origin) {
+        return origin.startsWith("\"") && origin.endsWith("\"") ? origin.substring(1, origin.length() - 1) : origin;
+    }
+
+    private void validateServerKey(String key, String signature, String canonical, String originUrl) {
+        HttpGet request = new HttpGet(originUrl + "/_matrix/key/v2/server");
+        log.info("Get keys from the server {}", request.getURI());
+        try (CloseableHttpResponse response = client.execute(request)) {
+            int statusCode = response.getStatusLine().getStatusCode();
+            log.info("Answer code: {}", statusCode);
+            if (statusCode == 200) {
+                verifyKey(key, signature, canonical, response);
+            } else {
+                throw new RemoteHomeServerException("Unable to fetch server keys.");
+            }
+        } catch (IOException e) {
+            String message = "Unable to get server keys: " + originUrl;
+            log.error(message, e);
+            throw new IllegalArgumentException(message);
+        }
+    }
+
+    private void verifyKey(String key, String signature, String canonical, CloseableHttpResponse response) throws IOException {
+        final String content = IOUtils.toString(response.getEntity().getContent(), StandardCharsets.UTF_8);
+        log.info("Answer body: {}", content);
+        final JsonObject responseObject = GsonUtil.parseObj(content);
+        final long validUntilTs = GsonUtil.getLong(responseObject, "valid_until_ts");
+
+        final Calendar calendar = Calendar.getInstance();
+        calendar.setTimeInMillis(validUntilTs);
+        if (calendar.before(Calendar.getInstance())) {
+            final String msg = "Key is expired";
+            log.error(msg);
+            throw new RemoteHomeServerException(msg);
+        }
+
+        final JsonObject verifyKeys = GsonUtil.getObj(responseObject, "verify_keys");
+        final JsonObject keyObject = GsonUtil.getObj(verifyKeys, key);
+        final String publicKey = GsonUtil.getStringOrNull(keyObject, "key");
+
+        if (StringUtils.isBlank(publicKey)) {
+            throw new RemoteHomeServerException("Missing server key.");
+        }
+
+        EdDSANamedCurveSpec ed25519CurveSpec = EdDSANamedCurveTable.ED_25519_CURVE_SPEC;
+        EdDSAPublicKeySpec publicKeySpec = new EdDSAPublicKeySpec(Base64.getDecoder().decode(publicKey), ed25519CurveSpec);
+        EdDSAPublicKey dsaPublicKey = new EdDSAPublicKey(publicKeySpec);
+
+        final boolean verificationResult = signatureManager.verify(dsaPublicKey, signature, canonical.getBytes(StandardCharsets.UTF_8));
+        log.info("Verification result: {}", verificationResult);
+        if (!verificationResult) {
+            throw new RemoteHomeServerException("Unable to verify request.");
+        }
+
+        log.info("Request was authorized.");
+    }
+
+    private void checkSession(String sid, String secret, ThreePid tpid) {
         // We ensure the session was validated
         ThreePidSession session = getSessionIfValidated(sid, secret);
 
@@ -193,14 +362,5 @@ public class SessionManager {
         if (!session.getThreePid().equals(tpid)) {
             throw new BadRequestException("3PID to unbind does not match the one from the validated session");
         }
-
-        // We only allow unbind for the domain we manage, mirroring bind
-        if (!StringUtils.equalsIgnoreCase(mxCfg.getDomain(), mxid.getDomain())) {
-            throw new NotAllowedException("Only Matrix IDs from domain " + mxCfg.getDomain() + " can be unbound");
-        }
-
-        log.info("Session {}: Unbinding of {}:{} to Matrix ID {} is accepted",
-                session.getId(), session.getThreePid().getMedium(), session.getThreePid().getAddress(), mxid.getId());
     }
-
 }

src/main/java/io/kamax/mxisd/threepid/connector/email/EmailSmtpConnector.java

@@ -115,7 +115,7 @@ public class EmailSmtpConnector implements EmailConnector {
             msg.setRecipients(Message.RecipientType.TO, recipient);
             msg.saveChanges();
 
-            log.info("Sending invite to {} via SMTP using {}:{}", recipient, cfg.getHost(), cfg.getPort());
+            log.info("Sending email to {} via SMTP using {}:{}", recipient, cfg.getHost(), cfg.getPort());
             SMTPTransport transport = (SMTPTransport) session.getTransport("smtp");
 
             if (cfg.getTls() < 3) {
@@ -134,12 +134,12 @@ public class EmailSmtpConnector implements EmailConnector {
 
             try {
                 transport.sendMessage(msg, InternetAddress.parse(recipient));
-                log.info("Invite to {} was sent", recipient);
+                log.info("Email to {} was sent", recipient);
             } finally {
                 transport.close();
             }
         } catch (UnsupportedEncodingException | MessagingException e) {
-            throw new RuntimeException("Unable to send e-mail invite to " + recipient, e);
+            throw new RuntimeException("Unable to send e-mail to " + recipient, e);
         }
     }
 

src/main/java/io/kamax/mxisd/threepid/generator/GenericTemplateNotificationGenerator.java

@@ -79,9 +79,9 @@ public abstract class GenericTemplateNotificationGenerator extends PlaceholderNo
     }
 
     @Override
-    public String getForFraudulentUnbind(ThreePid tpid) {
+    public String getForNotificationUnbind(ThreePid tpid) {
-        log.info("Generating notification content for fraudulent unbind");
+        log.info("Generating notification content for unbind");
-        return populateForFraudulentUndind(tpid, getTemplateContent(cfg.getSession().getUnbind().getFraudulent()));
+        return populateForNotificationUndind(tpid, getTemplateContent(cfg.getSession().getUnbind().getNotification()));
     }
 
 }

src/main/java/io/kamax/mxisd/threepid/generator/NotificationGenerator.java

@@ -37,6 +37,6 @@ public interface NotificationGenerator {
 
     String getForValidation(IThreePidSession session);
 
-    String getForFraudulentUnbind(ThreePid tpid);
+    String getForNotificationUnbind(ThreePid tpid);
 
 }

src/main/java/io/kamax/mxisd/threepid/generator/PlaceholderNotificationGenerator.java

@@ -127,7 +127,7 @@ public abstract class PlaceholderNotificationGenerator {
                 .replace("%NEXT_URL%", validationLink);
     }
 
-    protected String populateForFraudulentUndind(ThreePid tpid, String input) {
+    protected String populateForNotificationUndind(ThreePid tpid, String input) {
         return populateForCommon(tpid, input);
     }
 

src/main/java/io/kamax/mxisd/threepid/notification/GenericNotificationHandler.java

@@ -73,8 +73,8 @@ public abstract class GenericNotificationHandler<A extends ThreePidConnector, B
     }
 
     @Override
-    public void sendForFraudulentUnbind(ThreePid tpid) {
+    public void sendForUnbind(ThreePid tpid) {
-        send(connector, tpid.getAddress(), generator.getForFraudulentUnbind(tpid));
+        send(connector, tpid.getAddress(), generator.getForNotificationUnbind(tpid));
     }
 
 }

src/main/java/io/kamax/mxisd/threepid/notification/email/EmailSendGridNotificationHandler.java

@@ -129,10 +129,10 @@ public class EmailSendGridNotificationHandler extends PlaceholderNotificationGen
     }
 
     @Override
-    public void sendForFraudulentUnbind(ThreePid tpid) {
+    public void sendForUnbind(ThreePid tpid) {
-        EmailTemplate template = cfg.getTemplates().getSession().getUnbind().getFraudulent();
+        EmailTemplate template = cfg.getTemplates().getSession().getUnbind();
         if (StringUtils.isAllBlank(template.getBody().getText(), template.getBody().getHtml())) {
-            throw new FeatureNotAvailable("No template has been configured for fraudulent unbind notifications");
+            throw new FeatureNotAvailable("No template has been configured for unbind notifications");
         }
 
         Email email = getEmail();

src/main/resources/threepids/email/unbind-fraudulent.eml

@@ -1,135 +0,0 @@
-Subject: IMPORTANT - %DOMAIN% Matrix Identity Server - Unauthorized 3PID unbind blocked
-MIME-Version: 1.0
-Content-Type: multipart/alternative;
-	boundary="7REaIwWQCioQ6NaBlAQlg8ztbUQj6PKJ"
-
---7REaIwWQCioQ6NaBlAQlg8ztbUQj6PKJ
-Content-Type: text/plain; charset=UTF-8
-Content-Disposition: inline
-
-Hi,
-
-**THIS IS IMPORTANT, PLEASE READ CAREFULLY**.
-If you are the system administrator of the Matrix installation, read the second section.
-
-This is a notification email that a possibly unauthorized entity has attempted to alter your
-3PIDs (email, phone numbers, etc.) settings. The request was denied and no change has been made.
-
-This is so you are aware of a possible failure in case you just tried to remove a 3PID from your account.
-
-If you do not understand this email, please forward it to your System administrator.
-
------------
-
-As the system administrator:
-
-If you are using synapse as a Homeserver, this is a known issue related to MSC1194 [1] and abuse of separation of concerns.
-As a privacy-centric product and to protect your privacy, the request was actively blocked. We have written a more detailed
-explanation on our Privacy wiki page [2] (Direct link [3]) so you can fully grasp the impact for you and your users.
-
-We have open an issue [4] on the synapse repos to reflect the related privacy concerns and GDPR violation(s) and would
-appreciate if you could comment on it or simply adds a thumbs up so the concerns are finally dealt with by the synapse dev team.
-
-If you are using another Homeserver or this came following no action from your own users, then you have been the target
-of an unbind attack from a rogue entity which was blocked. You may want to check your logs to see the exact source of
-the attack and take relevant actions following your policy.
-
-If you would like to disable these notifications, please see the 3PID sessions configuration documentation [5].
-
-Thanks,
-
-%DOMAIN_PRETTY% Admins
-
----
-
-[1] https://github.com/matrix-org/matrix-doc/issues/1194
-[2] https://github.com/kamax-matrix/mxisd/wiki/mxisd-and-your-privacy
-[3] https://github.com/kamax-matrix/mxisd/wiki/mxisd-and-your-privacy#msc1194-synapse-and-impacts-on-your-privacy
-[4] https://github.com/matrix-org/synapse/issues/4540
-[5] https://github.com/kamax-matrix/mxisd/blob/master/docs/threepids/session/session.md#configuration
-
---7REaIwWQCioQ6NaBlAQlg8ztbUQj6PKJ
-Content-Type: multipart/related;
-	boundary="M3yzHl5YZehm9v4bAM8sKEdcOoVnRnKR";
-	type="text/html"
-
---M3yzHl5YZehm9v4bAM8sKEdcOoVnRnKR
-Content-Type: text/html; charset=UTF-8
-Content-Disposition: inline
-
-<!doctype html>
-<html lang="en">
-    <head>
-        <style type="text/css">
-            body {
-                margin: 0px;
-            }
-
-            pre, code {
-                word-break: break-word;
-                white-space: pre-wrap;
-            }
-
-            #page {
-                font-family: 'Open Sans', Helvetica, Arial, Sans-Serif;
-                font-color: #454545;
-                font-size: 12pt;
-                width: 100%%;
-                padding: 20px;
-            }
-
-            #inner {
-                width: 640px;
-            }
-        </style>
-    </head>
-    <body>
-        <table id="page">
-            <tr>
-                <td> </td>
-                <td id="inner">
-                    <p>Hi,</p>
-
-                    <p><b>THIS IS IMPORTANT, PLEASE READ CAREFULLY</b>.<br/>
-                    If you are the system administrator of the Matrix installation, read the second section.</p>
-
-                    <p>This is a notification email that a possibly unauthorized entity has attempted to alter your
-                       3PIDs (email, phone numbers, etc.) settings. The request was denied and no change has been made.</p>
-
-                    <p>This is so you are aware of a possible failure in case you just tried to remove a 3PID from your account.</p>
-
-                    <p>If you do not understand this email, please forward it to your System administrator.</p>
-
-                    <hr>
-
-                    <p>As the system administrator:</p>
-
-                    <p>If you are using synapse as a Homeserver, this is a known issue related to <a href="https://github.com/matrix-org/matrix-doc/issues/1194">MSC1194</a>
-                       and abuse of separation of concerns. As a privacy-centric product and to protect your privacy, the request was actively
-                       blocked. We have written a more detailed explanation on our <a href="https://github.com/kamax-matrix/mxisd/wiki/mxisd-and-your-privacy">Privacy wiki page</a>
-                       (<a href="https://github.com/kamax-matrix/mxisd/wiki/mxisd-and-your-privacy#msc1194-synapse-and-impacts-on-your-privacy">Direct link to section</a>)
-                       so you can fully grasp the impact for you and your users.</p>
-
-                    <p>We have open an issue on the synapse repos to reflect the related privacy concerns and GDPR violation(s) and would
-                       appreciate if you could comment on it or simply adds a thumbs up so the concerns are finally dealt with by the synapse dev team.<br/>
-                       Issue: <a href="https://github.com/matrix-org/synapse/issues/4540">https://github.com/matrix-org/synapse/issues/4540</a></p>
-
-                    <p>If you are using another Homeserver or this came following no action from your own users, then you have been the target
-                       of an unbind attack from a rogue entity which was blocked. You may want to check your logs to see the exact source of
-                       the attack and take relevant actions following your policy.</p>
-
-                    <p>If you would like to disable these notifications, please see the
-                    <a href="https://github.com/kamax-matrix/mxisd/blob/master/docs/threepids/session/session.md#configuration">3PID sessions configuration documentation.</a></p>
-
-                    <p>Thanks,</p>
-
-                    <p>%DOMAIN_PRETTY% Admins</p>
-                </td>
-                <td> </td>
-            </tr>
-        </table>
-    </body>
-</html>
---M3yzHl5YZehm9v4bAM8sKEdcOoVnRnKR--
-
---7REaIwWQCioQ6NaBlAQlg8ztbUQj6PKJ--

src/main/resources/threepids/email/unbind-notification.eml

@@ -0,0 +1,77 @@
+Subject: Unbind 3PID
+MIME-Version: 1.0
+Content-Type: multipart/alternative;
+	boundary="7REaIwWQCioQ6NaBlAQlg8ztbUQj6PKJ"
+
+--7REaIwWQCioQ6NaBlAQlg8ztbUQj6PKJ
+Content-Type: text/plain; charset=UTF-8
+Content-Disposition: inline
+
+Hello there!
+
+You or a server on your behalf unbinded your email.
+
+If you didn't make this request, please contact the system administrator.
+
+%DOMAIN_PRETTY% Admins
+
+--7REaIwWQCioQ6NaBlAQlg8ztbUQj6PKJ
+Content-Type: multipart/related;
+	boundary="M3yzHl5YZehm9v4bAM8sKEdcOoVnRnKR";
+	type="text/html"
+
+--M3yzHl5YZehm9v4bAM8sKEdcOoVnRnKR
+Content-Type: text/html; charset=UTF-8
+Content-Disposition: inline
+
+<!doctype html>
+<html lang="en">
+    <head>
+        <style type="text/css">
+            body {
+                margin: 0px;
+            }
+
+            pre, code {
+                word-break: break-word;
+                white-space: pre-wrap;
+            }
+
+            #page {
+                font-family: 'Open Sans', Helvetica, Arial, Sans-Serif;
+                font-color: #454545;
+                font-size: 12pt;
+                width: 100%%;
+                padding: 20px;
+            }
+
+            #inner {
+                width: 640px;
+            }
+
+            .notif_link a, .footer a {
+                color: #76CFA6 ! important;
+            }
+        </style>
+    </head>
+    <body>
+        <table id="page">
+            <tr>
+                <td></td>
+                <td id="inner">
+                    <p>Hello there!</p>
+
+                    <p>You or a server on your behalf unbinded your email.</p>
+
+                    <p>If you didn't make this request, please contact the system administrator.</p>
+
+                    <p>%DOMAIN_PRETTY% Admins</p>
+                </td>
+                <td></td>
+            </tr>
+        </table>
+    </body>
+</html>
+--M3yzHl5YZehm9v4bAM8sKEdcOoVnRnKR--
+
+--7REaIwWQCioQ6NaBlAQlg8ztbUQj6PKJ--

src/main/resources/threepids/sms/unbind-fraudulent.txt

@@ -1 +0,0 @@
-INFORMATIONAL ONLY - Someone attempted to change your Matrix 3PIDs, with a potential data leak. Please contact your system administrator.

src/main/resources/threepids/sms/unbind-notification.txt

@@ -0,0 +1 @@
+Your Matrix 3PID was unbinded.