Added "Content-ID" header when sending an email with attachments. | #107.

Author: DenBond7

FlowCrypt/src/main/java/com/flowcrypt/email/api/email/EmailUtil.java

@@ -0,0 +1,22 @@
+/*
+ * Business Source License 1.0 © 2017 FlowCrypt Limited ([email protected]).
+ * Use limitations apply. See https://github.com/FlowCrypt/flowcrypt-android/blob/master/LICENSE
+ * Contributors: DenBond7
+ */
+
+package com.flowcrypt.email.api.email;
+
+import java.util.UUID;
+
+/**
+ * @author Denis Bondarenko
+ *         Date: 29.09.2017
+ *         Time: 15:31
+ *         E-mail: [email protected]
+ */
+
+public class EmailUtil {
+    public static String generateContentId() {
+        return "<" + UUID.randomUUID().toString() + "@flowcrypt" + ">";
+    }
+}

FlowCrypt/src/main/java/com/flowcrypt/email/api/email/sync/tasks/SendMessageSyncTask.java

@@ -13,6 +13,7 @@
 import android.text.TextUtils;
 import android.util.Log;
 
+import com.flowcrypt.email.api.email.EmailUtil;
 import com.flowcrypt.email.api.email.FoldersManager;
 import com.flowcrypt.email.api.email.model.AttachmentInfo;
 import com.flowcrypt.email.api.email.model.OutgoingMessageInfo;
@@ -174,8 +175,10 @@ private MimeMessage createMimeMessage(Session session, Context context, File pgp
             MimeMultipart mimeMultipart = (MimeMultipart) mimeMessage.getContent();
 
             for (AttachmentInfo attachmentInfo : outgoingMessageInfo.getAttachmentInfoArrayList()) {
-                mimeMultipart.addBodyPart(generateBodyPartWithAttachment(context, pgpCacheDirectory,
-                        js, pubKeys, attachmentInfo));
+                MimeBodyPart bodyPart = generateBodyPartWithAttachment(context, pgpCacheDirectory,
+                        js, pubKeys, attachmentInfo);
+                bodyPart.setContentID(EmailUtil.generateContentId());
+                mimeMultipart.addBodyPart(bodyPart);
             }
 
             mimeMessage.setContent(mimeMultipart);
@@ -193,15 +196,15 @@ private MimeMessage createMimeMessage(Session session, Context context, File pgp
      * @param js                The {@link Js} tools.
      * @param pubKeys           The public keys which will be used for generate an encrypted attachments.
      * @param attachmentInfo    The {@link AttachmentInfo} object, which contains general information about attachment.
-     * @return Generated {@link BodyPart} with an attachment.
+     * @return Generated {@link MimeBodyPart} with an attachment.
      * @throws IOException
      * @throws MessagingException
      */
     @NonNull
-    private BodyPart generateBodyPartWithAttachment(Context context, File pgpCacheDirectory, Js js,
-                                                    String[] pubKeys, AttachmentInfo attachmentInfo)
+    private MimeBodyPart generateBodyPartWithAttachment(Context context, File pgpCacheDirectory, Js js,
+                                                        String[] pubKeys, AttachmentInfo attachmentInfo)
             throws IOException, MessagingException {
-        BodyPart attachmentsBodyPart = new MimeBodyPart();
+        MimeBodyPart attachmentsBodyPart = new MimeBodyPart();
         switch (outgoingMessageInfo.getMessageEncryptionType()) {
             case ENCRYPTED:
                 InputStream inputStream =

FlowCrypt/src/main/java/com/flowcrypt/email/api/email/sync/tasks/SendMessageWithBackupToKeyOwnerSynsTask.java

@@ -12,6 +12,7 @@
 import android.text.TextUtils;
 
 import com.flowcrypt.email.R;
+import com.flowcrypt.email.api.email.EmailUtil;
 import com.flowcrypt.email.api.email.JavaEmailConstants;
 import com.flowcrypt.email.api.email.sync.SyncListener;
 import com.flowcrypt.email.database.dao.source.AccountDao;
@@ -115,8 +116,9 @@ private Message generateMessage(Context context, Session session) throws Excepti
         List<PrivateKeyInfo> privateKeyInfoList = SecurityUtils.getPrivateKeysInfo(context);
 
         for (int i = 0; i < privateKeyInfoList.size(); i++) {
-            BodyPart attachmentsBodyPart = generateAttachmentBodyPartWithPrivateKey
+            MimeBodyPart attachmentsBodyPart = generateAttachmentBodyPartWithPrivateKey
                     (context, privateKeyInfoList, i);
+            attachmentsBodyPart.setContentID(EmailUtil.generateContentId());
             multipart.addBodyPart(attachmentsBodyPart);
         }
 
@@ -134,13 +136,13 @@ private Message generateMessage(Context context, Session session) throws Excepti
      * @throws Exception will occur when generate this {@link BodyPart}.
      */
     @NonNull
-    private BodyPart generateAttachmentBodyPartWithPrivateKey(
+    private MimeBodyPart generateAttachmentBodyPartWithPrivateKey(
             Context context, List<PrivateKeyInfo> privateKeyInfoList, int i)
             throws Exception {
         Js js = new Js(context, new SecurityStorageConnector(context));
 
         PrivateKeyInfo privateKeyInfo = privateKeyInfoList.get(i);
-        BodyPart attachmentsBodyPart = new MimeBodyPart();
+        MimeBodyPart attachmentsBodyPart = new MimeBodyPart();
         String attachmentName = SecurityUtils.generateNameForPrivateKey(accountName +
                 "_" + i);