Truncate all messages to valid length before sending.

briar-android/src/org/briarproject/android/blogs/WriteBlogPostActivity.java

@@ -128,12 +128,7 @@ public class WriteBlogPostActivity extends BriarActivity
 	}
 
 	private void enableOrDisablePublishButton() {
-		int bodyLength =
-				StringUtils.toUtf8(input.getText().toString()).length;
-		if (bodyLength > 0 && bodyLength <= MAX_BLOG_POST_BODY_LENGTH)
-			input.setSendButtonEnabled(true);
-		else
-			input.setSendButtonEnabled(false);
+		input.setSendButtonEnabled(input.getText().length() > 0);
 	}
 
 	@Override
@@ -142,6 +137,7 @@ public class WriteBlogPostActivity extends BriarActivity
 		input.setVisibility(GONE);
 		progressBar.setVisibility(VISIBLE);
 
+		body = StringUtils.truncateUtf8(body, MAX_BLOG_POST_BODY_LENGTH);
 		storePost(body);
 	}
 

briar-android/src/org/briarproject/android/contact/ConversationActivity.java

@@ -100,6 +100,7 @@ import static java.util.logging.Level.WARNING;
 import static org.briarproject.android.contact.ConversationItem.IncomingItem;
 import static org.briarproject.android.contact.ConversationItem.OutgoingItem;
 import static org.briarproject.android.fragment.SettingsFragment.SETTINGS_NAMESPACE;
+import static org.briarproject.api.messaging.MessagingConstants.MAX_PRIVATE_MESSAGE_BODY_LENGTH;
 
 public class ConversationActivity extends BriarActivity
 		implements EventListener, IntroductionHandler, TextInputListener {
@@ -656,6 +657,7 @@ public class ConversationActivity extends BriarActivity
 	public void onSendClick(String text) {
 		markMessagesRead();
 		if (text.equals("")) return;
+		text = StringUtils.truncateUtf8(text, MAX_PRIVATE_MESSAGE_BODY_LENGTH);
 		long timestamp = System.currentTimeMillis();
 		timestamp = Math.max(timestamp, getMinTimestampForNewMessage());
 		createMessage(StringUtils.toUtf8(text), timestamp);

briar-android/src/org/briarproject/android/introduction/IntroductionMessageFragment.java

@@ -20,6 +20,7 @@ import org.briarproject.api.contact.ContactId;
 import org.briarproject.api.contact.ContactManager;
 import org.briarproject.api.db.DbException;
 import org.briarproject.api.introduction.IntroductionManager;
+import org.briarproject.util.StringUtils;
 
 import java.util.logging.Logger;
 
@@ -33,6 +34,7 @@ import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.api.introduction.IntroductionConstants.MAX_INTRODUCTION_MESSAGE_LENGTH;
 
 public class IntroductionMessageFragment extends BaseFragment
 		implements TextInputView.TextInputListener {
@@ -176,6 +178,7 @@ public class IntroductionMessageFragment extends BaseFragment
 		ui.message.setSendButtonEnabled(false);
 
 		String msg = ui.message.getText().toString();
+		msg = StringUtils.truncateUtf8(msg, MAX_INTRODUCTION_MESSAGE_LENGTH);
 		makeIntroduction(contact1, contact2, msg);
 
 		// don't wait for the introduction to be made before finishing activity

briar-android/src/org/briarproject/android/sharing/ShareMessageFragment.java

@@ -15,6 +15,7 @@ import org.briarproject.api.blogs.BlogSharingManager;
 import org.briarproject.api.contact.ContactId;
 import org.briarproject.api.forum.ForumSharingManager;
 import org.briarproject.api.sync.GroupId;
+import org.briarproject.util.StringUtils;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -24,6 +25,7 @@ import javax.inject.Inject;
 import static org.briarproject.android.sharing.ShareActivity.CONTACTS;
 import static org.briarproject.android.sharing.ShareActivity.getContactsFromIds;
 import static org.briarproject.api.sharing.SharingConstants.GROUP_ID;
+import static org.briarproject.api.sharing.SharingConstants.MAX_INVITATION_MESSAGE_LENGTH;
 
 abstract class ShareMessageFragment extends BaseFragment
 		implements TextInputListener {
@@ -103,6 +105,7 @@ abstract class ShareMessageFragment extends BaseFragment
 		// disable button to prevent accidental double invitations
 		ui.message.setSendButtonEnabled(false);
 
+		msg = StringUtils.truncateUtf8(msg, MAX_INVITATION_MESSAGE_LENGTH);
 		share(msg);
 
 		// don't wait for the invitation to be made before finishing activity

briar-api/src/org/briarproject/api/blogs/BlogConstants.java

@@ -13,6 +13,9 @@ public interface BlogConstants {
 	/** The maximum length of a blog post's body in bytes. */
 	int MAX_BLOG_POST_BODY_LENGTH = MAX_MESSAGE_BODY_LENGTH - 1024;
 
+	/** The maximum length of a blog comment in bytes. */
+	int MAX_BLOG_COMMENT_LENGTH = MAX_BLOG_POST_BODY_LENGTH;
+
 	/** The internal name of personal blogs that are created automatically */
 	String PERSONAL_BLOG_NAME = "briar.PERSONAL_BLOG_NAME";
 

briar-api/src/org/briarproject/api/blogs/BlogSharingManager.java

 package org.briarproject.api.blogs;
 
-import org.briarproject.api.contact.Contact;
-import org.briarproject.api.contact.ContactId;
-import org.briarproject.api.db.DbException;
-import org.briarproject.api.sharing.InvitationItem;
-import org.briarproject.api.sharing.InvitationMessage;
 import org.briarproject.api.sharing.SharingManager;
-import org.briarproject.api.sync.ClientId;
-import org.briarproject.api.sync.GroupId;
-
-import java.util.Collection;
 
 public interface BlogSharingManager extends SharingManager<Blog> {
 
-	/**
-	 * Returns the unique ID of the blog sharing client.
-	 */
-	ClientId getClientId();
-
-	/**
-	 * Sends an invitation to share the given blog with the given contact
-	 * and sends an optional message along with it.
-	 */
-	void sendInvitation(GroupId groupId, ContactId contactId,
-			String message) throws DbException;
-
-	/**
-	 * Responds to a pending blog invitation
-	 */
-	void respondToInvitation(Blog b, Contact c, boolean accept)
-			throws DbException;
-
-	/**
-	 * Returns all blogs sharing messages sent by the Contact
-	 * identified by contactId.
-	 */
-	Collection<InvitationMessage> getInvitationMessages(
-			ContactId contactId) throws DbException;
-
-	/**
-	 * Returns all blogs to which the user has been invited.
-	 */
-	Collection<InvitationItem> getInvitations() throws DbException;
-
-	/**
-	 * Returns all contacts who are sharing the given blog with us.
-	 */
-	Collection<Contact> getSharedBy(GroupId g) throws DbException;
-
-	/**
-	 * Returns the IDs of all contacts with whom the given blog is shared.
-	 */
-	Collection<Contact> getSharedWith(GroupId g) throws DbException;
-
-	/**
-	 * Returns true if the blog not already shared and no invitation is open
-	 */
-	boolean canBeShared(GroupId g, Contact c) throws DbException;
-
 }

briar-api/src/org/briarproject/api/forum/ForumSharingManager.java

 package org.briarproject.api.forum;
 
-import org.briarproject.api.contact.Contact;
-import org.briarproject.api.contact.ContactId;
-import org.briarproject.api.db.DbException;
-import org.briarproject.api.sharing.InvitationItem;
-import org.briarproject.api.sharing.InvitationMessage;
 import org.briarproject.api.sharing.SharingManager;
-import org.briarproject.api.sync.ClientId;
-import org.briarproject.api.sync.GroupId;
-
-import java.util.Collection;
 
 public interface ForumSharingManager extends SharingManager<Forum> {
 
-	/** Returns the unique ID of the forum sharing client. */
-	ClientId getClientId();
-
-	/**
-	 * Sends an invitation to share the given forum with the given contact
-	 * and sends an optional message along with it.
-	 */
-	void sendInvitation(GroupId groupId, ContactId contactId,
-			String message)	throws DbException;
-
-	/**
-	 * Responds to a pending forum invitation
-	 */
-	void respondToInvitation(Forum f, Contact c, boolean accept)
-			throws DbException;
-
-	/**
-	 * Returns all forum sharing messages sent by the Contact
-	 * identified by contactId.
-	 */
-	Collection<InvitationMessage> getInvitationMessages(
-			ContactId contactId) throws DbException;
-
-	/** Returns all forums to which the user has been invited. */
-	Collection<InvitationItem> getInvitations() throws DbException;
-
-	/** Returns all contacts who are sharing the given forum with us. */
-	Collection<Contact> getSharedBy(GroupId g) throws DbException;
-
-	/** Returns the IDs of all contacts with whom the given forum is shared. */
-	Collection<Contact> getSharedWith(GroupId g) throws DbException;
-
-	/** Returns true if the forum not already shared and no invitation is open */
-	boolean canBeShared(GroupId g, Contact c) throws DbException;
-
 }

briar-api/src/org/briarproject/api/introduction/IntroductionConstants.java

 package org.briarproject.api.introduction;
 
+import static org.briarproject.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
+
 public interface IntroductionConstants {
 
 	/* Protocol roles */
@@ -30,8 +32,18 @@ public interface IntroductionConstants {
 	String SIGNATURE = "signature";
 
 	/* Validation Constants */
+
+	/**
+	 * The length of the message authentication code in bytes.
+	 */
 	int MAC_LENGTH = 32;
 
+	/**
+	 * The maximum length of the introducer's optional message to the
+	 * introducees in UTF-8 bytes.
+	 */
+	int MAX_INTRODUCTION_MESSAGE_LENGTH = MAX_MESSAGE_BODY_LENGTH - 1024;
+
 	/* Introducer Local State Metadata */
 	String STATE = "state";
 	String ROLE = "role";

briar-api/src/org/briarproject/api/sharing/SharingConstants.java

 package org.briarproject.api.sharing;
 
+import static org.briarproject.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
+
 public interface SharingConstants {
 
-	/** The length of a sharing session's random salt in bytes. */
+	/**
+	 * The length of a sharing session's random salt in bytes.
+	 */
 	int SHARING_SALT_LENGTH = 32;
 
+	/**
+	 * The maximum length of the optional message from the inviter to the
+	 * invitee in UTF-8 bytes.
+	 */
+	int MAX_INVITATION_MESSAGE_LENGTH = MAX_MESSAGE_BODY_LENGTH - 1204;
+
 	String CONTACT_ID = "contactId";
 	String GROUP_ID = "groupId";
 	String TO_BE_SHARED_BY_US = "toBeSharedByUs";

briar-api/src/org/briarproject/api/sharing/SharingManager.java

@@ -11,15 +11,17 @@ import java.util.Collection;
 
 public interface SharingManager<S extends Shareable> extends MessageTracker {
 
-	/** Returns the unique ID of the group sharing client. */
+	/**
+	 * Returns the unique ID of the group sharing client.
+	 */
 	ClientId getClientId();
 
 	/**
-	 * Sends an invitation to share the given shareable with the given contact
+	 * Sends an invitation to share the given group with the given contact
 	 * and sends an optional message along with it.
 	 */
 	void sendInvitation(GroupId groupId, ContactId contactId,
-			String message)	throws DbException;
+			String message) throws DbException;
 
 	/**
 	 * Responds to a pending group invitation
@@ -28,22 +30,29 @@ public interface SharingManager<S extends Shareable> extends MessageTracker {
 			throws DbException;
 
 	/**
-	 * Returns all group sharing messages sent by the Contact
-	 * identified by contactId.
+	 * Returns all group sharing messages sent by the given contact.
 	 */
 	Collection<InvitationMessage> getInvitationMessages(
 			ContactId contactId) throws DbException;
 
-	/** Returns all invitations to shareables. */
+	/**
+	 * Returns all invitations to groups.
+	 */
 	Collection<InvitationItem> getInvitations() throws DbException;
 
-	/** Returns all contacts who are sharing the given group with us. */
+	/**
+	 * Returns all contacts who are sharing the given group with us.
+	 */
 	Collection<Contact> getSharedBy(GroupId g) throws DbException;
 
-	/** Returns the IDs of all contacts with whom the given group is shared. */
+	/**
+	 * Returns all contacts with whom the given group is shared.
+	 */
 	Collection<Contact> getSharedWith(GroupId g) throws DbException;
 
-	/** Returns true if the group not already shared and no invitation is open */
+	/**
+	 * Returns true if the group not already shared and no invitation is open
+	 */
 	boolean canBeShared(GroupId g, Contact c) throws DbException;
 
 }

briar-core/src/org/briarproject/blogs/BlogPostFactoryImpl.java

@@ -11,6 +11,7 @@ import org.briarproject.api.sync.GroupId;
 import org.briarproject.api.sync.Message;
 import org.briarproject.api.sync.MessageId;
 import org.briarproject.api.system.Clock;
+import org.briarproject.util.StringUtils;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -18,6 +19,7 @@ import java.security.GeneralSecurityException;
 
 import javax.inject.Inject;
 
+import static org.briarproject.api.blogs.BlogConstants.MAX_BLOG_COMMENT_LENGTH;
 import static org.briarproject.api.blogs.BlogConstants.MAX_BLOG_POST_BODY_LENGTH;
 import static org.briarproject.api.blogs.MessageType.COMMENT;
 import static org.briarproject.api.blogs.MessageType.POST;
@@ -42,7 +44,8 @@ class BlogPostFactoryImpl implements BlogPostFactory {
 			throws FormatException, GeneralSecurityException {
 
 		// Validate the arguments
-		if (body.length() > MAX_BLOG_POST_BODY_LENGTH)
+		int bodyLength = StringUtils.toUtf8(body).length;
+		if (bodyLength > MAX_BLOG_POST_BODY_LENGTH)
 			throw new IllegalArgumentException();
 
 		// Serialise the data to be signed
@@ -62,6 +65,13 @@ class BlogPostFactoryImpl implements BlogPostFactory {
 			@Nullable String comment, MessageId pOriginalId, MessageId parentId)
 			throws FormatException, GeneralSecurityException {
 
+		if (comment != null) {
+			int commentLength = StringUtils.toUtf8(comment).length;
+			if (commentLength == 0) throw new IllegalArgumentException();
+			if (commentLength > MAX_BLOG_COMMENT_LENGTH)
+				throw new IllegalArgumentException();
+		}
+
 		long timestamp = clock.currentTimeMillis();
 
 		// Generate the signature

briar-core/src/org/briarproject/blogs/BlogPostValidator.java

@@ -40,6 +40,7 @@ import static org.briarproject.api.blogs.BlogConstants.KEY_READ;
 import static org.briarproject.api.blogs.BlogConstants.KEY_TIMESTAMP;
 import static org.briarproject.api.blogs.BlogConstants.KEY_TIME_RECEIVED;
 import static org.briarproject.api.blogs.BlogConstants.KEY_TYPE;
+import static org.briarproject.api.blogs.BlogConstants.MAX_BLOG_COMMENT_LENGTH;
 import static org.briarproject.api.blogs.BlogConstants.MAX_BLOG_POST_BODY_LENGTH;
 import static org.briarproject.api.blogs.MessageType.COMMENT;
 import static org.briarproject.api.blogs.MessageType.POST;
@@ -125,7 +126,7 @@ class BlogPostValidator extends BdfMessageValidator {
 
 		// Comment
 		String comment = body.getOptionalString(0);
-		checkLength(comment, 1, MAX_BLOG_POST_BODY_LENGTH);
+		checkLength(comment, 1, MAX_BLOG_COMMENT_LENGTH);
 
 		// parent_original_id
 		// The ID of a post or comment in this group or another group
@@ -216,7 +217,7 @@ class BlogPostValidator extends BdfMessageValidator {
 
 		// Body of Wrapped Comment
 		String comment = body.getOptionalString(2);
-		checkLength(comment, 1, MAX_BLOG_POST_BODY_LENGTH);
+		checkLength(comment, 1, MAX_BLOG_COMMENT_LENGTH);
 
 		// c_parent_original_id
 		// Taken from the original comment

briar-core/src/org/briarproject/feed/FeedManagerImpl.java

@@ -484,10 +484,7 @@ class FeedManagerImpl implements FeedManager, Client, EventListener {
 
 	private String getPostBody(String text) {
 		text = clean(text, article);
-		byte[] textBytes = StringUtils.toUtf8(text);
-		if (textBytes.length <= MAX_BLOG_POST_BODY_LENGTH)
-			return text;
-		return StringUtils.fromUtf8(textBytes, 0, MAX_BLOG_POST_BODY_LENGTH);
+		return StringUtils.truncateUtf8(text, MAX_BLOG_POST_BODY_LENGTH);
 	}
 
 	/**

briar-core/src/org/briarproject/introduction/IntroducerManager.java

@@ -31,6 +31,7 @@ import static org.briarproject.api.introduction.IntroductionConstants.CONTACT_ID
 import static org.briarproject.api.introduction.IntroductionConstants.CONTACT_ID_2;
 import static org.briarproject.api.introduction.IntroductionConstants.GROUP_ID_1;
 import static org.briarproject.api.introduction.IntroductionConstants.GROUP_ID_2;
+import static org.briarproject.api.introduction.IntroductionConstants.MAX_INTRODUCTION_MESSAGE_LENGTH;
 import static org.briarproject.api.introduction.IntroductionConstants.MESSAGE_TIME;
 import static org.briarproject.api.introduction.IntroductionConstants.MSG;
 import static org.briarproject.api.introduction.IntroductionConstants.PUBLIC_KEY1;
@@ -103,7 +104,7 @@ class IntroducerManager {
 		return d;
 	}
 
-	public void makeIntroduction(Transaction txn, Contact c1, Contact c2,
+	void makeIntroduction(Transaction txn, Contact c1, Contact c2,
 			String msg, long timestamp) throws DbException, FormatException {
 
 		// TODO check for existing session with those contacts?
@@ -116,6 +117,9 @@ class IntroducerManager {
 		BdfDictionary localAction = new BdfDictionary();
 		localAction.put(TYPE, TYPE_REQUEST);
 		if (!StringUtils.isNullOrEmpty(msg)) {
+			int msgLength = StringUtils.toUtf8(msg).length;
+			if (msgLength > MAX_INTRODUCTION_MESSAGE_LENGTH)
+				throw new IllegalArgumentException();
 			localAction.put(MSG, msg);
 		}
 		localAction.put(PUBLIC_KEY1, c1.getAuthor().getPublicKey());

briar-core/src/org/briarproject/introduction/IntroductionValidator.java

@@ -21,6 +21,7 @@ import static org.briarproject.api.introduction.IntroductionConstants.E_PUBLIC_K
 import static org.briarproject.api.introduction.IntroductionConstants.GROUP_ID;
 import static org.briarproject.api.introduction.IntroductionConstants.MAC;
 import static org.briarproject.api.introduction.IntroductionConstants.MAC_LENGTH;
+import static org.briarproject.api.introduction.IntroductionConstants.MAX_INTRODUCTION_MESSAGE_LENGTH;
 import static org.briarproject.api.introduction.IntroductionConstants.MESSAGE_ID;
 import static org.briarproject.api.introduction.IntroductionConstants.MESSAGE_TIME;
 import static org.briarproject.api.introduction.IntroductionConstants.MSG;
@@ -37,7 +38,6 @@ import static org.briarproject.api.introduction.IntroductionConstants.TYPE_REQUE
 import static org.briarproject.api.introduction.IntroductionConstants.TYPE_RESPONSE;
 import static org.briarproject.api.properties.TransportPropertyConstants.MAX_PROPERTIES_PER_TRANSPORT;
 import static org.briarproject.api.properties.TransportPropertyConstants.MAX_PROPERTY_LENGTH;
-import static org.briarproject.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
 
 class IntroductionValidator extends BdfMessageValidator {
 
@@ -92,7 +92,7 @@ class IntroductionValidator extends BdfMessageValidator {
 		String msg = null;
 		if (message.size() == 5) {
 			msg = message.getString(4);
-			checkLength(msg, 0, MAX_MESSAGE_BODY_LENGTH);
+			checkLength(msg, 0, MAX_INTRODUCTION_MESSAGE_LENGTH);
 		}
 
 		// Return the metadata

briar-core/src/org/briarproject/sharing/BlogSharingManagerImpl.java

@@ -204,6 +204,7 @@ class BlogSharingManagerImpl extends
 					.createBlog(msg.getBlogTitle(), msg.getBlogDesc(), author);
 		}
 
+		@Override
 		public Blog parse(BlogInviteeSessionState state) {
 			Author author = authorFactory
 					.createAuthor(state.getBlogAuthorName(),

briar-core/src/org/briarproject/sharing/BlogSharingValidator.java

@@ -16,14 +16,15 @@ import javax.inject.Inject;
 
 import static org.briarproject.api.blogs.BlogConstants.BLOG_AUTHOR_NAME;
 import static org.briarproject.api.blogs.BlogConstants.BLOG_DESC;
-import static org.briarproject.api.blogs.BlogConstants.BLOG_TITLE;
 import static org.briarproject.api.blogs.BlogConstants.BLOG_PUBLIC_KEY;
+import static org.briarproject.api.blogs.BlogConstants.BLOG_TITLE;
 import static org.briarproject.api.blogs.BlogConstants.MAX_BLOG_DESC_LENGTH;
 import static org.briarproject.api.blogs.BlogConstants.MAX_BLOG_TITLE_LENGTH;
 import static org.briarproject.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
 import static org.briarproject.api.sharing.SharingConstants.INVITATION_MSG;
 import static org.briarproject.api.sharing.SharingConstants.LOCAL;
+import static org.briarproject.api.sharing.SharingConstants.MAX_INVITATION_MESSAGE_LENGTH;
 import static org.briarproject.api.sharing.SharingConstants.SESSION_ID;
 import static org.briarproject.api.sharing.SharingConstants.SHARE_MSG_TYPE_ABORT;
 import static org.briarproject.api.sharing.SharingConstants.SHARE_MSG_TYPE_ACCEPT;
@@ -32,7 +33,6 @@ import static org.briarproject.api.sharing.SharingConstants.SHARE_MSG_TYPE_INVIT
 import static org.briarproject.api.sharing.SharingConstants.SHARE_MSG_TYPE_LEAVE;
 import static org.briarproject.api.sharing.SharingConstants.TIME;
 import static org.briarproject.api.sharing.SharingConstants.TYPE;
-import static org.briarproject.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
 
 class BlogSharingValidator extends BdfMessageValidator {
 
@@ -76,7 +76,7 @@ class BlogSharingValidator extends BdfMessageValidator {
 
 			if (body.size() > 5) {
 				String msg = body.getString(5);
-				checkLength(msg, 0, MAX_MESSAGE_BODY_LENGTH);
+				checkLength(msg, 0, MAX_INVITATION_MESSAGE_LENGTH);
 				d.put(INVITATION_MSG, msg);
 			}
 		} else {

briar-core/src/org/briarproject/sharing/ForumSharingManagerImpl.java

@@ -167,6 +167,7 @@ class ForumSharingManagerImpl extends
 					.createForum(msg.getForumName(), msg.getForumSalt());
 		}
 
+		@Override
 		public Forum parse(ForumInviteeSessionState state) {
 			return forumFactory
 					.createForum(state.getForumName(), state.getForumSalt());

briar-core/src/org/briarproject/sharing/ForumSharingValidator.java

 package org.briarproject.sharing;
 
 import org.briarproject.api.FormatException;
+import org.briarproject.api.clients.BdfMessageContext;
 import org.briarproject.api.clients.ClientHelper;
 import org.briarproject.api.clients.SessionId;
-import org.briarproject.api.clients.BdfMessageContext;
 import org.briarproject.api.data.BdfDictionary;
 import org.briarproject.api.data.BdfList;
 import org.briarproject.api.data.MetadataEncoder;
@@ -20,6 +20,7 @@ import static org.briarproject.api.forum.ForumConstants.FORUM_SALT_LENGTH;
 import static org.briarproject.api.forum.ForumConstants.MAX_FORUM_NAME_LENGTH;
 import static org.briarproject.api.sharing.SharingConstants.INVITATION_MSG;
 import static org.briarproject.api.sharing.SharingConstants.LOCAL;
+import static org.briarproject.api.sharing.SharingConstants.MAX_INVITATION_MESSAGE_LENGTH;
 import static org.briarproject.api.sharing.SharingConstants.SESSION_ID;
 import static org.briarproject.api.sharing.SharingConstants.SHARE_MSG_TYPE_ABORT;
 import static org.briarproject.api.sharing.SharingConstants.SHARE_MSG_TYPE_ACCEPT;
@@ -28,7 +29,6 @@ import static org.briarproject.api.sharing.SharingConstants.SHARE_MSG_TYPE_INVIT
 import static org.briarproject.api.sharing.SharingConstants.SHARE_MSG_TYPE_LEAVE;
 import static org.briarproject.api.sharing.SharingConstants.TIME;
 import static org.briarproject.api.sharing.SharingConstants.TYPE;
-import static org.briarproject.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
 
 class ForumSharingValidator extends BdfMessageValidator {
 
@@ -61,7 +61,7 @@ class ForumSharingValidator extends BdfMessageValidator {
 
 			if (body.size() > 4) {
 				String msg = body.getString(4);
-				checkLength(msg, 0, MAX_MESSAGE_BODY_LENGTH);
+				checkLength(msg, 0, MAX_INVITATION_MESSAGE_LENGTH);
 				d.put(INVITATION_MSG, msg);
 			}
 		} else {

briar-core/src/org/briarproject/sharing/SharingManagerImpl.java

@@ -29,7 +29,6 @@ import org.briarproject.api.sharing.InvitationItem;
 import org.briarproject.api.sharing.InvitationMessage;
 import org.briarproject.api.sharing.Shareable;
 import org.briarproject.api.sharing.SharingManager;
-import org.briarproject.api.sync.ClientId;
 import org.briarproject.api.sync.Group;
 import org.briarproject.api.sync.GroupId;
 import org.briarproject.api.sync.Message;
@@ -58,6 +57,7 @@ import static org.briarproject.api.clients.ProtocolEngine.StateUpdate;
 import static org.briarproject.api.sharing.SharingConstants.CONTACT_ID;
 import static org.briarproject.api.sharing.SharingConstants.IS_SHARER;
 import static org.briarproject.api.sharing.SharingConstants.LOCAL;
+import static org.briarproject.api.sharing.SharingConstants.MAX_INVITATION_MESSAGE_LENGTH;
 import static org.briarproject.api.sharing.SharingConstants.SESSION_ID;
 import static org.briarproject.api.sharing.SharingConstants.SHAREABLE_ID;
 import static org.briarproject.api.sharing.SharingConstants.SHARED_BY_US;
@@ -115,8 +115,6 @@ abstract class SharingManagerImpl<S extends Shareable, I extends Invitation, IS
 		localGroup = contactGroupFactory.createLocalGroup(getClientId());
 	}
 
-	public abstract ClientId getClientId();
-
 	protected abstract InvitationMessage createInvitationRequest(MessageId id,
 			I msg, ContactId contactId, boolean available, long time,
 			boolean local, boolean sent, boolean seen, boolean read);
@@ -282,6 +280,9 @@ abstract class SharingManagerImpl<S extends Shareable, I extends Invitation, IS
 
 			// add invitation message to local state to be available for engine
 			if (!StringUtils.isNullOrEmpty(msg)) {
+				int msgLength = StringUtils.toUtf8(msg).length;
+				if (msgLength > MAX_INVITATION_MESSAGE_LENGTH)
+					throw new IllegalArgumentException();
 				localState.setMessage(msg);
 			}