diff --git a/lib/src/main/java/org/asamk/signal/manager/helper/AttachmentHelper.java b/lib/src/main/java/org/asamk/signal/manager/helper/AttachmentHelper.java
index b75f01eb..afafeb24 100644
--- a/lib/src/main/java/org/asamk/signal/manager/helper/AttachmentHelper.java
+++ b/lib/src/main/java/org/asamk/signal/manager/helper/AttachmentHelper.java
@@ -11,11 +11,14 @@ import org.signal.libsignal.protocol.InvalidMessageException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.whispersystems.signalservice.api.crypto.AttachmentCipherInputStream;
+import org.whispersystems.signalservice.api.crypto.AttachmentCipherStreamUtil;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachment;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentPointer;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentStream;
 import org.whispersystems.signalservice.api.push.exceptions.MissingConfigurationException;
 import org.whispersystems.signalservice.api.util.StreamDetails;
+import org.whispersystems.signalservice.internal.crypto.PaddingInputStream;
+import org.whispersystems.signalservice.internal.push.http.ResumableUploadSpec;
 
 import java.io.File;
 import java.io.IOException;
@@ -89,12 +92,12 @@ public class AttachmentHelper {
             final boolean voiceNote
     ) throws AttachmentInvalidException {
         try {
-            final var streamDetails = Utils.createStreamDetails(attachment);
-            final var uploadSpec = dependencies.getMessageSender()
-                    .getResumableUploadSpec(streamDetails.first().getLength());
+            final var streamDetailsAndFileName = Utils.createStreamDetails(attachment);
+            final var streamDetails = streamDetailsAndFileName.first();
+            final var uploadSpec = getResumableUploadSpec(streamDetails);
 
-            return AttachmentUtils.createAttachmentStream(streamDetails.first(),
-                    streamDetails.second(),
+            return AttachmentUtils.createAttachmentStream(streamDetails,
+                    streamDetailsAndFileName.second(),
                     voiceNote,
                     uploadSpec);
         } catch (IOException e) {
@@ -102,6 +105,13 @@ public class AttachmentHelper {
         }
     }
 
+    public ResumableUploadSpec getResumableUploadSpec(final StreamDetails streamDetails) throws IOException {
+        final var streamLength = streamDetails.getLength();
+        final var ciphertextLength = AttachmentCipherStreamUtil.getCiphertextLength(PaddingInputStream.getPaddedSize(
+                streamLength));
+        return dependencies.getMessageSender().getResumableUploadSpec(ciphertextLength);
+    }
+
     public SignalServiceAttachmentPointer uploadAttachment(String attachment) throws IOException, AttachmentInvalidException {
         final var attachmentStream = getAttachmentStream(attachment, false);
         return uploadAttachment(attachmentStream);
diff --git a/lib/src/main/java/org/asamk/signal/manager/helper/GroupHelper.java b/lib/src/main/java/org/asamk/signal/manager/helper/GroupHelper.java
index f7d67d79..024e84fc 100644
--- a/lib/src/main/java/org/asamk/signal/manager/helper/GroupHelper.java
+++ b/lib/src/main/java/org/asamk/signal/manager/helper/GroupHelper.java
@@ -123,7 +123,7 @@ public class GroupHelper {
             return Optional.empty();
         }
 
-        final var uploadSpec = dependencies.getMessageSender().getResumableUploadSpec(streamDetails.getLength());
+        final var uploadSpec = context.getAttachmentHelper().getResumableUploadSpec(streamDetails);
         return Optional.of(AttachmentUtils.createAttachmentStream(streamDetails, Optional.empty(), uploadSpec));
     }
 
diff --git a/lib/src/main/java/org/asamk/signal/manager/helper/SyncHelper.java b/lib/src/main/java/org/asamk/signal/manager/helper/SyncHelper.java
index ba2ca388..53ab3fa4 100644
--- a/lib/src/main/java/org/asamk/signal/manager/helper/SyncHelper.java
+++ b/lib/src/main/java/org/asamk/signal/manager/helper/SyncHelper.java
@@ -38,6 +38,7 @@ import org.whispersystems.signalservice.api.messages.multidevice.StickerPackOper
 import org.whispersystems.signalservice.api.messages.multidevice.VerifiedMessage;
 import org.whispersystems.signalservice.api.messages.multidevice.ViewedMessage;
 import org.whispersystems.signalservice.api.push.SignalServiceAddress;
+import org.whispersystems.signalservice.api.util.StreamDetails;
 import org.whispersystems.signalservice.internal.push.SyncMessage;
 
 import java.io.FileInputStream;
@@ -131,13 +132,14 @@ public class SyncHelper {
 
             if (groupsFile.exists() && groupsFile.length() > 0) {
                 try (var groupsFileStream = new FileInputStream(groupsFile)) {
-                    final var uploadSpec = context.getDependencies()
-                            .getMessageSender()
-                            .getResumableUploadSpec(groupsFile.length());
+                    final var streamDetails = new StreamDetails(groupsFileStream,
+                            MimeUtils.OCTET_STREAM,
+                            groupsFile.length());
+                    final var uploadSpec = context.getAttachmentHelper().getResumableUploadSpec(streamDetails);
                     var attachmentStream = SignalServiceAttachment.newStreamBuilder()
-                            .withStream(groupsFileStream)
-                            .withContentType(MimeUtils.OCTET_STREAM)
-                            .withLength(groupsFile.length())
+                            .withStream(streamDetails.getStream())
+                            .withContentType(streamDetails.getContentType())
+                            .withLength(streamDetails.getLength())
                             .withResumableUploadSpec(uploadSpec)
                             .build();
 
@@ -192,13 +194,14 @@ public class SyncHelper {
 
             if (contactsFile.exists() && contactsFile.length() > 0) {
                 try (var contactsFileStream = new FileInputStream(contactsFile)) {
-                    final var uploadSpec = context.getDependencies()
-                            .getMessageSender()
-                            .getResumableUploadSpec(contactsFile.length());
+                    final var streamDetails = new StreamDetails(contactsFileStream,
+                            MimeUtils.OCTET_STREAM,
+                            contactsFile.length());
+                    final var uploadSpec = context.getAttachmentHelper().getResumableUploadSpec(streamDetails);
                     var attachmentStream = SignalServiceAttachment.newStreamBuilder()
-                            .withStream(contactsFileStream)
-                            .withContentType(MimeUtils.OCTET_STREAM)
-                            .withLength(contactsFile.length())
+                            .withStream(streamDetails.getStream())
+                            .withContentType(streamDetails.getContentType())
+                            .withLength(streamDetails.getLength())
                             .withResumableUploadSpec(uploadSpec)
                             .build();
 
diff --git a/lib/src/main/java/org/asamk/signal/manager/internal/ManagerImpl.java b/lib/src/main/java/org/asamk/signal/manager/internal/ManagerImpl.java
index 45d2fc8e..08214d01 100644
--- a/lib/src/main/java/org/asamk/signal/manager/internal/ManagerImpl.java
+++ b/lib/src/main/java/org/asamk/signal/manager/internal/ManagerImpl.java
@@ -839,8 +839,7 @@ public class ManagerImpl implements Manager {
                 final var streamDetails = new StreamDetails(new ByteArrayInputStream(messageBytes),
                         MimeUtils.LONG_TEXT,
                         messageBytes.length);
-                final var uploadSpec = dependencies.getMessageSender()
-                        .getResumableUploadSpec(streamDetails.getLength());
+                final var uploadSpec = context.getAttachmentHelper().getResumableUploadSpec(streamDetails);
                 final var textAttachment = AttachmentUtils.createAttachmentStream(streamDetails,
                         Optional.empty(),
                         uploadSpec);
@@ -908,7 +907,7 @@ public class ManagerImpl implements Manager {
             if (streamDetails == null) {
                 throw new InvalidStickerException("Missing local sticker file");
             }
-            final var uploadSpec = dependencies.getMessageSender().getResumableUploadSpec(streamDetails.getLength());
+            final var uploadSpec = context.getAttachmentHelper().getResumableUploadSpec(streamDetails);
             final var stickerAttachment = AttachmentUtils.createAttachmentStream(streamDetails,
                     Optional.empty(),
                     uploadSpec);
diff --git a/src/main/resources/META-INF/native-image/org.asamk/signal-cli/reachability-metadata.json b/src/main/resources/META-INF/native-image/org.asamk/signal-cli/reachability-metadata.json
index db19a986..f70e705d 100644
--- a/src/main/resources/META-INF/native-image/org.asamk/signal-cli/reachability-metadata.json
+++ b/src/main/resources/META-INF/native-image/org.asamk/signal-cli/reachability-metadata.json
@@ -1486,6 +1486,13 @@
       "type": "kotlin.Pair",
       "jniAccessible": true,
       "methods": [
+        {
+          "name": "<init>",
+          "parameterTypes": [
+            "java.lang.Object",
+            "java.lang.Object"
+          ]
+        },
         {
           "name": "getFirst",
           "parameterTypes": []
@@ -1496,6 +1503,9 @@
         }
       ]
     },
+    {
+      "type": "kotlin.Pair[]"
+    },
     {
       "type": "kotlin.SafePublicationLazyImpl",
       "fields": [
@@ -5821,6 +5831,21 @@
         }
       ]
     },
+    {
+      "type": "org.signal.libsignal.net.UploadForm",
+      "jniAccessible": true,
+      "methods": [
+        {
+          "name": "fromNative",
+          "parameterTypes": [
+            "int",
+            "java.lang.String",
+            "java.lang.Object[]",
+            "java.lang.String"
+          ]
+        }
+      ]
+    },
     {
       "type": "org.signal.libsignal.net.internal.BridgeChatListener",
       "jniAccessible": true