diff --git a/Podfile.lock b/Podfile.lock
index fd4bacac0e..1a7be042ef 100644
--- a/Podfile.lock
+++ b/Podfile.lock
@@ -174,4 +174,4 @@ SPEC CHECKSUMS:
 
 PODFILE CHECKSUM: 48dbf2fb380d626bb799a782dd41b6bf1e466506
 
-COCOAPODS: 1.2.0
+COCOAPODS: 1.1.1
diff --git a/Signal.xcodeproj/project.pbxproj b/Signal.xcodeproj/project.pbxproj
index 6f85706c06..f29eac74d5 100644
--- a/Signal.xcodeproj/project.pbxproj
+++ b/Signal.xcodeproj/project.pbxproj
@@ -11,6 +11,10 @@
 		341BB7491DB727EE001E2975 /* JSQMediaItem+OWS.m in Sources */ = {isa = PBXBuildFile; fileRef = 341BB7481DB727EE001E2975 /* JSQMediaItem+OWS.m */; };
 		344F2F671E57A932000D9322 /* UIViewController+OWS.m in Sources */ = {isa = PBXBuildFile; fileRef = 344F2F661E57A932000D9322 /* UIViewController+OWS.m */; };
 		34535D821E256BE9008A4747 /* UIView+OWS.m in Sources */ = {isa = PBXBuildFile; fileRef = 34535D811E256BE9008A4747 /* UIView+OWS.m */; };
+		348A08421E6A044E0057E290 /* MessagesViewController.xib in Resources */ = {isa = PBXBuildFile; fileRef = 348A08411E6A044E0057E290 /* MessagesViewController.xib */; };
+		348A08441E6A1D2C0057E290 /* OWSMessagesToolbarContentView.xib in Resources */ = {isa = PBXBuildFile; fileRef = 348A08431E6A1D2C0057E290 /* OWSMessagesToolbarContentView.xib */; };
+		348A08511E6C73490057E290 /* AttachmentApprovalViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 348A08501E6C73490057E290 /* AttachmentApprovalViewController.swift */; };
+		348A08531E6C75590057E290 /* SignalAttachment.swift in Sources */ = {isa = PBXBuildFile; fileRef = 348A08521E6C75590057E290 /* SignalAttachment.swift */; };
 		348F3A4F1E4A533900750D44 /* CallInterstitialViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 348F3A4E1E4A533900750D44 /* CallInterstitialViewController.swift */; };
 		34FD93701E3BD43A00109093 /* OWSAnyTouchGestureRecognizer.m in Sources */ = {isa = PBXBuildFile; fileRef = 34FD936F1E3BD43A00109093 /* OWSAnyTouchGestureRecognizer.m */; };
 		4505C2BF1E648EA300CEBF41 /* ExperienceUpgrade.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4505C2BE1E648EA300CEBF41 /* ExperienceUpgrade.swift */; };
@@ -624,6 +628,10 @@
 		344F2F661E57A932000D9322 /* UIViewController+OWS.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = "UIViewController+OWS.m"; path = "util/UIViewController+OWS.m"; sourceTree = "<group>"; };
 		34535D801E256BE9008A4747 /* UIView+OWS.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "UIView+OWS.h"; sourceTree = "<group>"; };
 		34535D811E256BE9008A4747 /* UIView+OWS.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "UIView+OWS.m"; sourceTree = "<group>"; };
+		348A08411E6A044E0057E290 /* MessagesViewController.xib */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = file.xib; path = MessagesViewController.xib; sourceTree = "<group>"; };
+		348A08431E6A1D2C0057E290 /* OWSMessagesToolbarContentView.xib */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = file.xib; path = OWSMessagesToolbarContentView.xib; sourceTree = "<group>"; };
+		348A08501E6C73490057E290 /* AttachmentApprovalViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AttachmentApprovalViewController.swift; sourceTree = "<group>"; };
+		348A08521E6C75590057E290 /* SignalAttachment.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SignalAttachment.swift; sourceTree = "<group>"; };
 		348F3A4E1E4A533900750D44 /* CallInterstitialViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CallInterstitialViewController.swift; sourceTree = "<group>"; };
 		34FD936E1E3BD43A00109093 /* OWSAnyTouchGestureRecognizer.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = OWSAnyTouchGestureRecognizer.h; path = views/OWSAnyTouchGestureRecognizer.h; sourceTree = "<group>"; };
 		34FD936F1E3BD43A00109093 /* OWSAnyTouchGestureRecognizer.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = OWSAnyTouchGestureRecognizer.m; path = views/OWSAnyTouchGestureRecognizer.m; sourceTree = "<group>"; };
@@ -2653,6 +2661,7 @@
 		FC3196321A08142D0094C78E /* Signals */ = {
 			isa = PBXGroup;
 			children = (
+				348A08501E6C73490057E290 /* AttachmentApprovalViewController.swift */,
 				348F3A4E1E4A533900750D44 /* CallInterstitialViewController.swift */,
 				4509E79B1DD6545B0025A59F /* CallViewController.swift */,
 				FC31962B1A06A2190094C78E /* FingerprintViewController.h */,
@@ -2663,12 +2672,15 @@
 				FC3196291A067D8F0094C78E /* MessageComposeTableViewController.m */,
 				FCAC964F19FF0A6E0046DFC5 /* MessagesViewController.h */,
 				FCAC965019FF0A6E0046DFC5 /* MessagesViewController.m */,
+				348A08411E6A044E0057E290 /* MessagesViewController.xib */,
 				FCFD256D1A151BCB00F4C644 /* NewGroupViewController.h */,
 				FCFD256E1A151BCB00F4C644 /* NewGroupViewController.m */,
 				452E3C8C1D935C77002A45B0 /* OWSConversationSettingsTableViewController.h */,
 				452E3C8D1D935C77002A45B0 /* OWSConversationSettingsTableViewController.m */,
+				348A08431E6A1D2C0057E290 /* OWSMessagesToolbarContentView.xib */,
 				A5D0699A1A50E9CB004CB540 /* ShowGroupMembersViewController.h */,
 				A5D069991A50E9CB004CB540 /* ShowGroupMembersViewController.m */,
+				348A08521E6C75590057E290 /* SignalAttachment.swift */,
 				FC4FA0241A1B9DC600DA100A /* SignalsNavigationController.h */,
 				FC4FA0251A1B9DC600DA100A /* SignalsNavigationController.m */,
 				FCAC963A19FEF9280046DFC5 /* SignalsViewController.h */,
@@ -2897,6 +2909,7 @@
 				E94066151DFC5B7B00B15392 /* ContactsPicker.xib in Resources */,
 				AD41D7B61A6F6F0600241130 /* play_button@2x.png in Resources */,
 				AD83FF3F1A73426500B5C81A /* audio_pause_button_blue.png in Resources */,
+				348A08421E6A044E0057E290 /* MessagesViewController.xib in Resources */,
 				45E1F3A31DEF1DF000852CF1 /* NoSignalContactsView.xib in Resources */,
 				A5509ECA1A69AB8B00ABA4BC /* Main.storyboard in Resources */,
 				A507A3B11A6C60E300BEED0D /* InboxTableViewCell.xib in Resources */,
@@ -2941,6 +2954,7 @@
 				E1370BE618A0686C00826894 /* sonarping.mp3 in Resources */,
 				B10C9B5F1A7049EC00ECA2BF /* pause_icon.png in Resources */,
 				AD83FF471A73428300B5C81A /* audio_play_button_blue.png in Resources */,
+				348A08441E6A1D2C0057E290 /* OWSMessagesToolbarContentView.xib in Resources */,
 				AD83FF451A73426500B5C81A /* audio_pause_button@2x.png in Resources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -3137,6 +3151,7 @@
 				45387B041E36D650005D00B3 /* OWS102MoveLoggingPreferenceToUserDefaults.m in Sources */,
 				E197B61818BBEC1A00F073E5 /* RemoteIOAudio.m in Sources */,
 				B67ADDC41989FF8700E1A773 /* RPServerRequestsManager.m in Sources */,
+				348A08511E6C73490057E290 /* AttachmentApprovalViewController.swift in Sources */,
 				348F3A4F1E4A533900750D44 /* CallInterstitialViewController.swift in Sources */,
 				EF764C351DB67CC5000D9A87 /* UIViewController+CameraPermissions.m in Sources */,
 				453201251E71100C00F20761 /* DisplayableTextFilter.swift in Sources */,
@@ -3147,6 +3162,7 @@
 				76EB05E018170B33006006FC /* NetworkStream.m in Sources */,
 				45794E861E00620000066731 /* CallUIAdapter.swift in Sources */,
 				FCFA64B71A24F6730007FB87 /* UIFont+OWS.m in Sources */,
+				348A08531E6C75590057E290 /* SignalAttachment.swift in Sources */,
 				B6B9ECFC198B31BA00C620D3 /* PushManager.m in Sources */,
 				45DF5DF21DDB843F00C936C7 /* CompareSafetyNumbersActivity.swift in Sources */,
 				76EB05D618170B33006006FC /* ZrtpResponder.m in Sources */,
diff --git a/Signal/Images.xcassets/file-icon-large.imageset/Contents.json b/Signal/Images.xcassets/file-icon-large.imageset/Contents.json
new file mode 100644
index 0000000000..e01e985e34
--- /dev/null
+++ b/Signal/Images.xcassets/file-icon-large.imageset/Contents.json
@@ -0,0 +1,21 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "file-icon-large@1x.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}
\ No newline at end of file
diff --git a/Signal/Images.xcassets/file-icon-large.imageset/file-icon-large@1x.png b/Signal/Images.xcassets/file-icon-large.imageset/file-icon-large@1x.png
new file mode 100644
index 0000000000..7adc6fe64a
Binary files /dev/null and b/Signal/Images.xcassets/file-icon-large.imageset/file-icon-large@1x.png differ
diff --git a/Signal/src/Signal-Bridging-Header.h b/Signal/src/Signal-Bridging-Header.h
index 3ba8ccb852..26f6950280 100644
--- a/Signal/src/Signal-Bridging-Header.h
+++ b/Signal/src/Signal-Bridging-Header.h
@@ -32,6 +32,7 @@
 #import <SignalServiceKit/Contact.h>
 #import <SignalServiceKit/ContactsUpdater.h>
 #import <SignalServiceKit/Cryptography.h>
+#import <SignalServiceKit/MIMETypeUtil.h>
 #import <SignalServiceKit/NSData+Base64.h>
 #import <SignalServiceKit/NSDate+millisecondTimeStamp.h>
 #import <SignalServiceKit/OWSAcknowledgeMessageDeliveryRequest.h>
diff --git a/Signal/src/Storyboard/Main.storyboard b/Signal/src/Storyboard/Main.storyboard
index 1ef96d8602..3308a70426 100644
--- a/Signal/src/Storyboard/Main.storyboard
+++ b/Signal/src/Storyboard/Main.storyboard
@@ -120,12 +120,33 @@
                         </barButtonItem>
                     </navigationItem>
                     <connections>
+                        <outlet property="inputToolbar" destination="BdJ-vY-dHA" id="EfK-zI-nSM"/>
                         <segue destination="4oU-Rv-yJi" kind="push" identifier="OWSMessagesViewControllerSeguePushConversationSettings" id="vOd-aS-6Wx"/>
                         <segue destination="urv-62-RsD" kind="modal" identifier="fingerprintSegue" id="tfr-ZV-qWs"/>
                         <segue destination="Tyf-mN-gzf" kind="modal" identifier="initiateCallSegue" modalTransitionStyle="crossDissolve" id="I6y-pT-nEd"/>
                     </connections>
                 </viewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="yXZ-iE-5va" userLabel="First Responder" sceneMemberID="firstResponder"/>
+                <toolbar opaque="NO" clearsContextBeforeDrawing="NO" contentMode="scaleToFill" id="BdJ-vY-dHA" customClass="OWSMessagesInputToolbar">
+                    <rect key="frame" x="0.0" y="0.0" width="375" height="44"/>
+                    <autoresizingMask key="autoresizingMask" widthSizable="YES" flexibleMinY="YES"/>
+                    <items>
+                        <barButtonItem title="Item" id="4F3-az-L9s"/>
+                    </items>
+                </toolbar>
+                <view contentMode="scaleToFill" id="X6H-b7-xZK" customClass="OWSMessagesToolbarContentView">
+                    <rect key="frame" x="0.0" y="0.0" width="240" height="128"/>
+                    <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
+                    <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
+                    <connections>
+                        <outlet property="textView" destination="XUl-oy-JS1" id="kzd-TM-IJT"/>
+                    </connections>
+                </view>
+                <view contentMode="scaleToFill" id="XUl-oy-JS1" customClass="JSQMessagesComposerTextView">
+                    <rect key="frame" x="0.0" y="0.0" width="240" height="128"/>
+                    <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
+                    <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
+                </view>
             </objects>
             <point key="canvasLocation" x="-2287" y="-1516"/>
         </scene>
@@ -352,7 +373,7 @@
         <!--Conversation Settings-->
         <scene sceneID="Flt-X5-Amc">
             <objects>
-                <tableViewController title="Contact Information" id="4oU-Rv-yJi" userLabel="Conversation Settings" customClass="OWSConversationSettingsTableViewController" sceneMemberID="viewController">
+                <tableViewController storyboardIdentifier="OWSConversationSettingsTableViewController" title="Contact Information" id="4oU-Rv-yJi" userLabel="Conversation Settings" customClass="OWSConversationSettingsTableViewController" sceneMemberID="viewController">
                     <tableView key="view" clipsSubviews="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" dataMode="static" style="grouped" separatorStyle="default" sectionIndexMinimumDisplayRowCount="1" rowHeight="44" sectionHeaderHeight="18" sectionFooterHeight="18" id="Dgp-fo-Lyr">
                         <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
@@ -625,7 +646,7 @@
                 </tableViewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="Ftx-dN-loa" userLabel="First Responder" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="-1393" y="-1482"/>
+            <point key="canvasLocation" x="-1448" y="-1570"/>
         </scene>
         <!--Show Group Members View Controller-->
         <scene sceneID="VBt-Ax-0G9">
@@ -1524,11 +1545,11 @@
                         <viewControllerLayoutGuide type="bottom" id="kH6-9L-pzh"/>
                     </layoutGuides>
                     <view key="view" contentMode="scaleToFill" id="P0X-AM-Yjw">
-                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <rect key="frame" x="0.0" y="64" width="375" height="603"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="Ukg-om-VX3" userLabel="Group Details">
-                                <rect key="frame" x="0.0" y="20" width="375" height="100"/>
+                                <rect key="frame" x="0.0" y="0.0" width="375" height="100"/>
                                 <subviews>
                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="Ul8-NY-i4c">
                                         <rect key="frame" x="8" y="20" width="60" height="60"/>
@@ -1563,7 +1584,7 @@
                                 </constraints>
                             </view>
                             <tableView clipsSubviews="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" dataMode="prototypes" style="plain" separatorStyle="default" allowsMultipleSelection="YES" rowHeight="44" sectionHeaderHeight="22" sectionFooterHeight="22" translatesAutoresizingMaskIntoConstraints="NO" id="cFo-AT-Srf">
-                                <rect key="frame" x="0.0" y="128" width="375" height="539"/>
+                                <rect key="frame" x="0.0" y="108" width="375" height="495"/>
                                 <color key="backgroundColor" red="0.94901960780000005" green="0.94901960780000005" blue="0.94901960780000005" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                                 <view key="tableHeaderView" contentMode="scaleToFill" id="ekO-kw-iHV" userLabel="Header View">
                                     <rect key="frame" x="0.0" y="0.0" width="375" height="40"/>
@@ -1700,8 +1721,8 @@
         <simulatedScreenMetrics key="destination" type="retina4_7.fullscreen"/>
     </simulatedMetricsContainer>
     <inferredMetricsTieBreakers>
-        <segue reference="E8S-Yc-X7E"/>
         <segue reference="wgA-Oo-kKq"/>
+        <segue reference="D0d-4f-lcI"/>
         <segue reference="G2B-Fr-Ezs"/>
     </inferredMetricsTieBreakers>
 </document>
diff --git a/Signal/src/UIColor+OWS.h b/Signal/src/UIColor+OWS.h
index f60e3672c0..7a9ab87f0b 100644
--- a/Signal/src/UIColor+OWS.h
+++ b/Signal/src/UIColor+OWS.h
@@ -18,5 +18,6 @@
 + (UIColor *)ows_errorMessageBorderColor;
 + (UIColor *)ows_infoMessageBorderColor;
 + (UIColor *)backgroundColorForContact:(NSString *)contactIdentifier;
++ (UIColor *)colorWithRGBHex:(unsigned long)value;
 
 @end
diff --git a/Signal/src/UIColor+OWS.m b/Signal/src/UIColor+OWS.m
index ef4cebb073..d16d0e909d 100644
--- a/Signal/src/UIColor+OWS.m
+++ b/Signal/src/UIColor+OWS.m
@@ -107,4 +107,12 @@
     return [colors objectAtIndex:(choose % [colors count])];
 }
 
++ (UIColor *)colorWithRGBHex:(unsigned long)value
+{
+    CGFloat red = ((value >> 16) & 0xff) / 255.f;
+    CGFloat green = ((value >> 8) & 0xff) / 255.f;
+    CGFloat blue = ((value >> 0) & 0xff) / 255.f;
+    return [UIColor colorWithRed:red green:green blue:blue alpha:1.f];
+}
+
 @end
diff --git a/Signal/src/environment/PropertyListPreferences.h b/Signal/src/environment/PropertyListPreferences.h
index b6f5f7d994..b5590634db 100644
--- a/Signal/src/environment/PropertyListPreferences.h
+++ b/Signal/src/environment/PropertyListPreferences.h
@@ -13,13 +13,6 @@ typedef NS_ENUM(NSUInteger, NotificationType) {
     NotificationNamePreview,
 };
 
-typedef NS_ENUM(NSUInteger, TSImageQuality) {
-    TSImageQualityUncropped = 1,
-    TSImageQualityHigh = 2,
-    TSImageQualityMedium = 3,
-    TSImageQualityLow = 4
-};
-
 // Used when migrating logging to NSUserDefaults.
 extern NSString *const PropertyListPreferencesSignalDatabaseCollection;
 extern NSString *const PropertyListPreferencesKeyEnableDebugLog;
@@ -59,8 +52,6 @@ extern NSString *const PropertyListPreferencesKeyEnableDebugLog;
 - (BOOL)hasRegisteredVOIPPush;
 - (void)setHasRegisteredVOIPPush:(BOOL)enabled;
 
-- (TSImageQuality)imageUploadQuality;
-
 + (nullable NSString *)lastRanVersion;
 + (NSString *)setAndGetCurrentVersion;
 
diff --git a/Signal/src/environment/PropertyListPreferences.m b/Signal/src/environment/PropertyListPreferences.m
index 5caa7fc519..fe56892861 100644
--- a/Signal/src/environment/PropertyListPreferences.m
+++ b/Signal/src/environment/PropertyListPreferences.m
@@ -110,12 +110,6 @@ NSString *const PropertyListPreferencesKeyCallsHideIPAddress = @"CallsHideIPAddr
     }
 }
 
-- (TSImageQuality)imageUploadQuality
-{
-    // always return average image quality
-    return TSImageQualityMedium;
-}
-
 - (void)setScreenSecurity:(BOOL)flag
 {
     [self setValueForKey:PropertyListPreferencesKeyScreenSecurity toValue:@(flag)];
diff --git a/Signal/src/view controllers/AttachmentApprovalViewController.swift b/Signal/src/view controllers/AttachmentApprovalViewController.swift
new file mode 100644
index 0000000000..c8b80002a4
--- /dev/null
+++ b/Signal/src/view controllers/AttachmentApprovalViewController.swift	
@@ -0,0 +1,215 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+import Foundation
+
+class AttachmentApprovalViewController: UIViewController {
+
+    let TAG = "[AttachmentApprovalViewController]"
+
+    // MARK: Properties
+
+    let attachment: SignalAttachment
+
+    var successCompletion : (() -> Void)?
+
+    // MARK: Initializers
+
+    @available(*, unavailable, message:"use attachment: constructor instead.")
+    required init?(coder aDecoder: NSCoder) {
+        self.attachment = SignalAttachment.genericAttachment(data: nil,
+                                                             dataUTI: kUTTypeContent as String)
+        super.init(coder: aDecoder)
+        assert(false)
+    }
+
+    required init(attachment: SignalAttachment, successCompletion : @escaping () -> Void) {
+        assert(!attachment.hasError)
+        self.attachment = attachment
+        self.successCompletion = successCompletion
+        super.init(nibName: nil, bundle: nil)
+    }
+
+    // MARK: View Lifecycle
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        view.backgroundColor = UIColor.black
+
+        self.navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem:.done,
+            target:self,
+            action:#selector(donePressed))
+        self.navigationItem.title = NSLocalizedString("ATTACHMENT_APPROVAL_DIALOG_TITLE",
+                                                      comment: "Title for the 'attachment approval' dialog.")
+
+        createViews()
+    }
+
+    // MARK: - Create Views
+
+    private func createViews() {
+        let previewTopMargin: CGFloat = 30
+        let previewHMargin: CGFloat = 20
+
+        let attachmentPreviewView = UIView()
+        self.view.addSubview(attachmentPreviewView)
+        attachmentPreviewView.autoPinWidthToSuperview(withMargin:previewHMargin)
+        attachmentPreviewView.autoPin(toTopLayoutGuideOf: self, withInset:previewTopMargin)
+
+        createButtonRow(attachmentPreviewView:attachmentPreviewView)
+
+        if attachment.isImage {
+            createImagePreview(attachmentPreviewView:attachmentPreviewView)
+        } else {
+            createGenericPreview(attachmentPreviewView:attachmentPreviewView)
+        }
+    }
+
+    private func createImagePreview(attachmentPreviewView: UIView) {
+        var image = attachment.image
+        if image == nil {
+            image = UIImage(data:attachment.data)
+        }
+        if image != nil {
+            let imageView = UIImageView(image:image)
+            imageView.layer.minificationFilter = kCAFilterTrilinear
+            imageView.layer.magnificationFilter = kCAFilterTrilinear
+            imageView.contentMode = .scaleAspectFit
+            attachmentPreviewView.addSubview(imageView)
+            imageView.autoPinWidthToSuperview()
+            imageView.autoPinHeightToSuperview()
+        } else {
+            createGenericPreview(attachmentPreviewView:attachmentPreviewView)
+        }
+    }
+
+    private func createGenericPreview(attachmentPreviewView: UIView) {
+        let stackView = UIView()
+        attachmentPreviewView.addSubview(stackView)
+        stackView.autoCenterInSuperview()
+
+        let imageSize = ScaleFromIPhone5To7Plus(175, 225)
+        let image = UIImage(named:"file-icon-large")
+        assert(image != nil)
+        let imageView = UIImageView(image:image)
+        imageView.layer.minificationFilter = kCAFilterTrilinear
+        imageView.layer.magnificationFilter = kCAFilterTrilinear
+        stackView.addSubview(imageView)
+        imageView.autoHCenterInSuperview()
+        imageView.autoPinEdge(toSuperviewEdge:.top)
+        imageView.autoSetDimension(.width, toSize:imageSize)
+        imageView.autoSetDimension(.height, toSize:imageSize)
+
+        var lastView: UIView = imageView
+
+        let labelFont = UIFont.ows_regularFont(withSize:ScaleFromIPhone5To7Plus(18, 24))
+
+        if let fileExtension = attachment.fileExtension {
+            let fileExtensionLabel = UILabel()
+            fileExtensionLabel.text = String(format:NSLocalizedString("ATTACHMENT_APPROVAL_FILE_EXTENSION_FORMAT",
+                                                                 comment: "Format string for file extension label in call interstitial view"),
+                                             fileExtension.capitalized)
+
+            fileExtensionLabel.textColor = UIColor.white
+            fileExtensionLabel.font = labelFont
+            fileExtensionLabel.textAlignment = .center
+            stackView.addSubview(fileExtensionLabel)
+            fileExtensionLabel.autoHCenterInSuperview()
+            fileExtensionLabel.autoPinEdge(.top, to:.bottom, of:lastView, withOffset:10)
+
+            lastView = fileExtensionLabel
+        }
+
+        let numberFormatter = NumberFormatter()
+        numberFormatter.numberStyle = NumberFormatter.Style.decimal
+        let fileSizeLabel = UILabel()
+        fileSizeLabel.text = String(format:NSLocalizedString("ATTACHMENT_APPROVAL_FILE_SIZE_FORMAT",
+                                                             comment: "Format string for file size label in call interstitial view"),
+                                    numberFormatter.string(from: NSNumber(value: attachment.data.count))!)
+
+        fileSizeLabel.textColor = UIColor.white
+        fileSizeLabel.font = labelFont
+        fileSizeLabel.textAlignment = .center
+        stackView.addSubview(fileSizeLabel)
+        fileSizeLabel.autoHCenterInSuperview()
+        fileSizeLabel.autoPinEdge(.top, to:.bottom, of:lastView, withOffset:10)
+        fileSizeLabel.autoPinEdge(toSuperviewEdge:.bottom)
+    }
+
+    private func createButtonRow(attachmentPreviewView: UIView) {
+        let buttonTopMargin = ScaleFromIPhone5To7Plus(30, 40)
+        let buttonBottomMargin = ScaleFromIPhone5To7Plus(25, 40)
+        let buttonHSpacing = ScaleFromIPhone5To7Plus(20, 30)
+
+        let buttonRow = UIView()
+        self.view.addSubview(buttonRow)
+        buttonRow.autoPinWidthToSuperview()
+        buttonRow.autoPinEdge(toSuperviewEdge:.bottom, withInset:buttonBottomMargin)
+        buttonRow.autoPinEdge(.top, to:.bottom, of:attachmentPreviewView, withOffset:buttonTopMargin)
+
+        // We use this invisible subview to ensure that the buttons are centered
+        // horizontally.
+        let buttonSpacer = UIView()
+        buttonRow.addSubview(buttonSpacer)
+        // Vertical positioning of this view doesn't matter.
+        buttonSpacer.autoPinEdge(toSuperviewEdge:.top)
+        buttonSpacer.autoSetDimension(.width, toSize:buttonHSpacing)
+        buttonSpacer.autoHCenterInSuperview()
+
+        let cancelButton = createButton(title: NSLocalizedString("TXT_CANCEL_TITLE",
+                                                                 comment: ""),
+                                        color : UIColor(rgbHex:0xff3B30),
+                                        action: #selector(cancelPressed))
+        buttonRow.addSubview(cancelButton)
+        cancelButton.autoPinEdge(toSuperviewEdge:.top)
+        cancelButton.autoPinEdge(toSuperviewEdge:.bottom)
+        cancelButton.autoPinEdge(.right, to:.left, of:buttonSpacer)
+
+        let sendButton = createButton(title: NSLocalizedString("ATTACHMENT_APPROVAL_SEND_BUTTON",
+                                                               comment: "Label for 'send' button in the 'attachment approval' dialog."),
+                                      color : UIColor(rgbHex:0x4CD964),
+                                      action: #selector(sendPressed))
+        buttonRow.addSubview(sendButton)
+        sendButton.autoPinEdge(toSuperviewEdge:.top)
+        sendButton.autoPinEdge(toSuperviewEdge:.bottom)
+        sendButton.autoPinEdge(.left, to:.right, of:buttonSpacer)
+    }
+
+    private func createButton(title: String, color: UIColor, action: Selector) -> UIButton {
+        let buttonFont = UIFont.ows_mediumFont(withSize:ScaleFromIPhone5To7Plus(18, 22))
+        let buttonCornerRadius = ScaleFromIPhone5To7Plus(4, 5)
+        let buttonWidth = ScaleFromIPhone5To7Plus(110, 140)
+        let buttonHeight = ScaleFromIPhone5To7Plus(35, 45)
+
+        let button = UIButton()
+        button.setTitle(title, for:.normal)
+        button.setTitleColor(UIColor.white, for:.normal)
+        button.titleLabel!.font = buttonFont
+        button.backgroundColor = color
+        button.layer.cornerRadius = buttonCornerRadius
+        button.clipsToBounds = true
+        button.addTarget(self, action:action, for:.touchUpInside)
+        button.autoSetDimension(.width, toSize:buttonWidth)
+        button.autoSetDimension(.height, toSize:buttonHeight)
+        return button
+    }
+
+    // MARK: - Event Handlers
+
+    func donePressed(sender: UIButton) {
+        dismiss(animated: true, completion:nil)
+    }
+
+    func cancelPressed(sender: UIButton) {
+        dismiss(animated: true, completion:nil)
+    }
+
+    func sendPressed(sender: UIButton) {
+        let successCompletion = self.successCompletion
+        dismiss(animated: true, completion: {
+            successCompletion?()
+        })
+    }
+}
diff --git a/Signal/src/view controllers/MessageComposeTableViewController.h b/Signal/src/view controllers/MessageComposeTableViewController.h
index 788f39ad6e..aacf226279 100644
--- a/Signal/src/view controllers/MessageComposeTableViewController.h	
+++ b/Signal/src/view controllers/MessageComposeTableViewController.h	
@@ -1,16 +1,8 @@
 //
-//  MessageComposeTableViewController.h
-//
-//
-//  Created by Dylan Bourgeois on 02/11/14.
-//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
 //
 
 #import <UIKit/UIKit.h>
-#import <JSQMessagesViewController/JSQMessagesComposerTextView.h>
-#import <JSQMessagesViewController/JSQMessagesInputToolbar.h>
-#import <JSQMessagesViewController/JSQMessagesToolbarContentView.h>
-#import <JSQMessagesViewController/JSQMessagesKeyboardController.h>
 #import "Contact.h"
 #import "LocalizableText.h"
 
diff --git a/Signal/src/view controllers/MessagesViewController.h b/Signal/src/view controllers/MessagesViewController.h
index de5f60a36f..877c6117e7 100644
--- a/Signal/src/view controllers/MessagesViewController.h	
+++ b/Signal/src/view controllers/MessagesViewController.h	
@@ -1,9 +1,5 @@
 //
-//  MessagesViewController.h
-//  Signal
-//
-//  Created by Dylan Bourgeois on 28/10/14.
-//  Copyright (c) 2014 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
 //
 
 #import <AVFoundation/AVFoundation.h>
@@ -14,6 +10,24 @@
 
 extern NSString *const OWSMessagesViewControllerDidAppearNotification;
 
+@interface OWSMessagesComposerTextView : JSQMessagesComposerTextView
+
+@end
+
+#pragma mark -
+
+@interface OWSMessagesToolbarContentView : JSQMessagesToolbarContentView
+
+@end
+
+#pragma mark -
+
+@interface OWSMessagesInputToolbar : JSQMessagesInputToolbar
+
+@end
+
+#pragma mark -
+
 @interface MessagesViewController : JSQMessagesViewController <UIImagePickerControllerDelegate,
                                                                UINavigationControllerDelegate,
                                                                UITextViewDelegate,
diff --git a/Signal/src/view controllers/MessagesViewController.m b/Signal/src/view controllers/MessagesViewController.m
index 07fb46b026..063e2029d7 100644
--- a/Signal/src/view controllers/MessagesViewController.m	
+++ b/Signal/src/view controllers/MessagesViewController.m	
@@ -74,8 +74,7 @@
 static NSTimeInterval const kTSMessageSentDateShowTimeInterval = 5 * 60;
 
 static NSString *const OWSMessagesViewControllerSegueShowFingerprint = @"fingerprintSegue";
-static NSString *const OWSMessagesViewControllerSeguePushConversationSettings =
-    @"OWSMessagesViewControllerSeguePushConversationSettings";
+static NSString *const OWSMessagesViewControllerSeguePushConversationSettings = @"OWSMessagesViewControllerSeguePushConversationSettings";
 
 NSString *const OWSMessagesViewControllerDidAppearNotification = @"OWSMessagesViewControllerDidAppear";
 
@@ -84,10 +83,96 @@ typedef enum : NSUInteger {
     kMediaTypeVideo,
 } kMediaTypes;
 
-@interface MessagesViewController () {
+@protocol OWSTextViewPasteDelegate <NSObject>
+
+- (void)didPasteAttachment:(SignalAttachment * _Nullable)attachment;
+
+@end
+
+#pragma mark -
+
+@interface OWSMessagesComposerTextView ()
+
+@property (weak, nonatomic) id<OWSTextViewPasteDelegate> textViewPasteDelegate;
+
+@end
+
+#pragma mark -
+
+@implementation OWSMessagesComposerTextView
+
+- (BOOL)canBecomeFirstResponder {
+    return YES;
+}
+
+- (BOOL)pasteBoardHasPossibleAttachment {
+    NSSet *pasteboardUTISet = [NSSet setWithArray:[UIPasteboard generalPasteboard].pasteboardTypes];
+    if ([UIPasteboard generalPasteboard].numberOfItems == 1 &&
+        [[SignalAttachment validInputUTISet] intersectsSet:pasteboardUTISet]) {
+        // We don't want to load/convert images more than once so we
+        // only do a cursory validation pass at this time.
+        return YES;
+    }
+    return NO;
+}
+
+- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
+    if (action == @selector(paste:)) {
+        if ([self pasteBoardHasPossibleAttachment]) {
+            return YES;
+        }
+    }
+    return [super canPerformAction:action withSender:sender];
+}
+
+- (void)paste:(id)sender {
+    if ([self pasteBoardHasPossibleAttachment]) {
+        SignalAttachment *attachment = [SignalAttachment attachmentFromPasteboard];
+        // Note: attachment might be nil or have an error at this point; that's fine.
+        [self.textViewPasteDelegate didPasteAttachment:attachment];
+        return;
+    }
+    
+    [super paste:sender];
+}
+
+@end
+
+#pragma mark -
+
+@implementation OWSMessagesToolbarContentView
+
+#pragma mark - Class methods
+
++ (UINib *)nib
+{
+    return [UINib nibWithNibName:NSStringFromClass([OWSMessagesToolbarContentView class])
+                          bundle:[NSBundle bundleForClass:[OWSMessagesToolbarContentView class]]];
+}
+
+@end
+
+#pragma mark -
+
+@implementation OWSMessagesInputToolbar
+
+- (JSQMessagesToolbarContentView *)loadToolbarContentView {
+    NSArray *views = [[OWSMessagesToolbarContentView nib] instantiateWithOwner:nil
+                                                                       options:nil];
+    OWSAssert(views.count == 1);
+    OWSMessagesToolbarContentView *view = views[0];
+    OWSAssert([view isKindOfClass:[OWSMessagesToolbarContentView class]]);
+    return view;
+}
+
+@end
+
+#pragma mark -
+
+@interface MessagesViewController () <JSQMessagesComposerTextViewPasteDelegate, OWSTextViewPasteDelegate> {
     UIImage *tappedImage;
     BOOL isGroupConversation;
-
+    
     UIView *_unreadContainer;
     UIImageView *_unreadBackground;
     UILabel *_unreadLabel;
@@ -160,7 +245,18 @@ typedef enum : NSUInteger {
     }
 
     [self commonInit];
+    
+    return self;
+}
 
+- (instancetype)initWithNibName:(nullable NSString *)nibNameOrNil bundle:(nullable NSBundle *)nibBundleOrNil {
+    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
+    if (!self) {
+        return self;
+    }
+    
+    [self commonInit];
+    
     return self;
 }
 
@@ -665,6 +761,11 @@ typedef enum : NSUInteger {
     // prevent draft from obscuring message history in case user wants to scroll back to refer to something
     // while composing a long message.
     self.inputToolbar.maximumHeight = 300;
+    
+    OWSAssert(self.inputToolbar.contentView);
+    OWSAssert(self.inputToolbar.contentView.textView);
+    self.inputToolbar.contentView.textView.pasteDelegate = self;
+    ((OWSMessagesComposerTextView *) self.inputToolbar.contentView.textView).textViewPasteDelegate = self;
 }
 
 - (nullable UILabel *)findNavbarTitleLabel
@@ -1211,7 +1312,11 @@ typedef enum : NSUInteger {
         DDLogDebug(@"%@ Ignoring request to show conversation settings, since user left group", self.tag);
         return;
     }
-    [self performSegueWithIdentifier:OWSMessagesViewControllerSeguePushConversationSettings sender:self];
+    
+    OWSConversationSettingsTableViewController *settingsVC = [[UIStoryboard storyboardWithName:AppDelegateStoryboardMain bundle:NULL]
+                                                              instantiateViewControllerWithIdentifier:@"OWSConversationSettingsTableViewController"];
+    [settingsVC configureWithThread:self.thread];
+    [self.navigationController pushViewController:settingsVC animated:YES];
 }
 
 - (void)didTapTitle
@@ -1726,10 +1831,6 @@ typedef enum : NSUInteger {
 
         NSString *contactName = [self.contactsManager displayNameForPhoneIdentifier:fingerprint.theirStableId];
         [vc configureWithThread:self.thread fingerprint:fingerprint contactName:contactName];
-    } else if ([segue.destinationViewController isKindOfClass:[OWSConversationSettingsTableViewController class]]) {
-        OWSConversationSettingsTableViewController *controller
-            = (OWSConversationSettingsTableViewController *)segue.destinationViewController;
-        [controller configureWithThread:self.thread];
     } else {
         DDLogDebug(@"%@ Received segue: %@", self.tag, segue.identifier);
     }
@@ -1809,7 +1910,18 @@ typedef enum : NSUInteger {
 
         UIImage *imageFromCamera = [info[UIImagePickerControllerOriginalImage] normalizedImage];
         if (imageFromCamera) {
-            [self sendMessageAttachment:[self qualityAdjustedAttachmentForImage:imageFromCamera] ofType:@"image/jpeg"];
+            SignalAttachment *attachment = [SignalAttachment imageAttachmentWithImage:imageFromCamera
+                                                                              dataUTI:(NSString *) kUTTypeJPEG];
+            if (!attachment ||
+                [attachment hasError]) {
+                DDLogWarn(@"%@ %s Invalid attachment: %@.",
+                          self.tag,
+                          __PRETTY_FUNCTION__,
+                          attachment ? [attachment errorMessage] : @"Missing data");
+                failedToPickAttachment(nil);
+            } else {
+                [self sendMessageAttachment:attachment];
+            }
         } else {
             failedToPickAttachment(nil);
         }
@@ -1827,46 +1939,47 @@ typedef enum : NSUInteger {
         options.networkAccessAllowed = YES; // iCloud OK
         options.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat; // Don't need quick/dirty version
         [[PHImageManager defaultManager]
-            requestImageDataForAsset:asset
-                             options:options
-                       resultHandler:^(NSData *_Nullable imageData,
-                           NSString *_Nullable dataUTI,
-                           UIImageOrientation orientation,
-                           NSDictionary *_Nullable assetInfo) {
-
-                           NSError *assetFetchingError = assetInfo[PHImageErrorKey];
-                           if (assetFetchingError || !imageData) {
-                               return failedToPickAttachment(assetFetchingError);
-                           }
-                           DDLogVerbose(
-                               @"Size in bytes: %lu; detected filetype: %@", (unsigned long)imageData.length, dataUTI);
-
-                           if ([dataUTI isEqualToString:(__bridge NSString *)kUTTypeGIF]
-                               && imageData.length <= 5 * 1024 * 1024) {
-                               DDLogVerbose(@"Sending raw image/gif to retain any animation");
-                               /**
-                                * Media Size constraints lifted from Signal-Android
-                                * (org/thoughtcrime/securesms/mms/PushMediaConstraints.java)
-                                *
-                                * GifMaxSize return 5 * MB;
-                                * For reference, other media size limits we're not explicitly enforcing:
-                                * ImageMaxSize return 420 * KB;
-                                * VideoMaxSize return 100 * MB;
-                                * getAudioMaxSize 100 * MB;
-                                */
-                               [self sendMessageAttachment:imageData ofType:@"image/gif"];
-                           } else {
-                               DDLogVerbose(@"Compressing attachment as image/jpeg");
-                               UIImage *pickedImage = [[UIImage alloc] initWithData:imageData];
-                               [self sendMessageAttachment:[self qualityAdjustedAttachmentForImage:pickedImage]
-                                                    ofType:@"image/jpeg"];
-                           }
-                       }];
+         requestImageDataForAsset:asset
+         options:options
+         resultHandler:^(NSData *_Nullable imageData,
+                         NSString *_Nullable dataUTI,
+                         UIImageOrientation orientation,
+                         NSDictionary *_Nullable assetInfo) {
+             
+             NSError *assetFetchingError = assetInfo[PHImageErrorKey];
+             if (assetFetchingError || !imageData) {
+                 return failedToPickAttachment(assetFetchingError);
+             }
+             OWSAssert([NSThread isMainThread]);
+             
+             SignalAttachment *attachment = [SignalAttachment imageAttachmentWithData:imageData
+                                                                              dataUTI:dataUTI];
+             if (!attachment ||
+                 [attachment hasError]) {
+                 DDLogWarn(@"%@ %s Invalid attachment: %@.",
+                           self.tag,
+                           __PRETTY_FUNCTION__,
+                           attachment ? [attachment errorMessage] : @"Missing data");
+                 failedToPickAttachment(nil);
+             } else {
+                 [self dismissViewControllerAnimated:YES
+                                          completion:^{
+                                              OWSAssert([NSThread isMainThread]);
+                                              [self sendMessageAttachment:attachment];
+                                          }];
+             }
+         }];
     }
 }
 
-- (void)sendMessageAttachment:(NSData *)attachmentData ofType:(NSString *)attachmentType
+- (void)sendMessageAttachment:(SignalAttachment *)attachment
 {
+    OWSAssert([NSThread isMainThread]);
+    // TODO: Should we assume non-nil or should we check for non-nil?
+    OWSAssert(attachment != nil);
+    OWSAssert(![attachment hasError]);
+    OWSAssert([attachment mimeType].length > 0);
+    
     TSOutgoingMessage *message;
     OWSDisappearingMessagesConfiguration *configuration =
         [OWSDisappearingMessagesConfiguration fetchObjectWithUniqueID:self.thread.uniqueId];
@@ -1882,25 +1995,20 @@ typedef enum : NSUInteger {
                                                    messageBody:nil
                                                  attachmentIds:[NSMutableArray new]];
     }
-
-    dispatch_async(dispatch_get_main_queue(), ^{
-        [self dismissViewControllerAnimated:YES
-                                 completion:^{
-                                     DDLogVerbose(@"Sending attachment. Size in bytes: %lu, contentType: %@",
-                                                  (unsigned long)attachmentData.length,
-                                                  attachmentType);
-                                     [self.messageSender sendAttachmentData:attachmentData
-                                                                contentType:attachmentType
-                                                                  inMessage:message
-                                                                    success:^{
-                                                                        DDLogDebug(@"%@ Successfully sent message attachment.", self.tag);
-                                                                    }
-                                                                    failure:^(NSError *error) {
-                                                                        DDLogError(
-                                                                                   @"%@ Failed to send message attachment with error: %@", self.tag, error);
-                                                                    }];
-                                 }];
-    });
+    
+    DDLogVerbose(@"Sending attachment. Size in bytes: %lu, contentType: %@",
+                 (unsigned long)attachment.data.length,
+                 [attachment mimeType]);
+    [self.messageSender sendAttachmentData:attachment.data
+                               contentType:[attachment mimeType]
+                                 inMessage:message
+                                   success:^{
+                                       DDLogDebug(@"%@ Successfully sent message attachment.", self.tag);
+                                   }
+                                   failure:^(NSError *error) {
+                                       DDLogError(
+                                                  @"%@ Failed to send message attachment with error: %@", self.tag, error);
+                                   }];
 }
 
 - (NSURL *)videoTempFolder {
@@ -1930,75 +2038,28 @@ typedef enum : NSUInteger {
 
     exportSession.outputURL = compressedVideoUrl;
     [exportSession exportAsynchronouslyWithCompletionHandler:^{
-      NSError *error;
-      [self sendMessageAttachment:[NSData dataWithContentsOfURL:compressedVideoUrl] ofType:@"video/mp4"];
-      [[NSFileManager defaultManager] removeItemAtURL:compressedVideoUrl error:&error];
-      if (error) {
-          DDLogWarn(@"Failed to remove cached video file: %@", error.debugDescription);
-      }
+        NSData *videoData = [NSData dataWithContentsOfURL:compressedVideoUrl];
+        SignalAttachment *attachment = [SignalAttachment videoAttachmentWithData:videoData
+                                                                         dataUTI:(NSString *) kUTTypeMPEG4];
+        if (!attachment ||
+            [attachment hasError]) {
+            DDLogWarn(@"%@ %s Invalid attachment: %@.",
+                      self.tag,
+                      __PRETTY_FUNCTION__,
+                      attachment ? [attachment errorMessage] : @"Missing data");
+            // TODO: How should we handle errors here?
+        } else {
+            [self sendMessageAttachment:attachment];
+        }
+        
+        NSError *error;
+        [[NSFileManager defaultManager] removeItemAtURL:compressedVideoUrl error:&error];
+        if (error) {
+            DDLogWarn(@"Failed to remove cached video file: %@", error.debugDescription);
+        }
     }];
 }
 
-- (NSData *)qualityAdjustedAttachmentForImage:(UIImage *)image {
-    return UIImageJPEGRepresentation([self adjustedImageSizedForSending:image], [self compressionRate]);
-}
-
-- (UIImage *)adjustedImageSizedForSending:(UIImage *)image {
-    CGFloat correctedWidth;
-    switch ([Environment.preferences imageUploadQuality]) {
-        case TSImageQualityUncropped:
-            return image;
-
-        case TSImageQualityHigh:
-            correctedWidth = 2048;
-            break;
-        case TSImageQualityMedium:
-            correctedWidth = 1024;
-            break;
-        case TSImageQualityLow:
-            correctedWidth = 512;
-            break;
-        default:
-            break;
-    }
-
-    return [self imageScaled:image toMaxSize:correctedWidth];
-}
-
-- (UIImage *)imageScaled:(UIImage *)image toMaxSize:(CGFloat)size {
-    CGFloat scaleFactor;
-    CGFloat aspectRatio = image.size.height / image.size.width;
-
-    if (aspectRatio > 1) {
-        scaleFactor = size / image.size.width;
-    } else {
-        scaleFactor = size / image.size.height;
-    }
-
-    CGSize newSize = CGSizeMake(image.size.width * scaleFactor, image.size.height * scaleFactor);
-
-    UIGraphicsBeginImageContext(newSize);
-    [image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
-    UIImage *updatedImage = UIGraphicsGetImageFromCurrentImageContext();
-    UIGraphicsEndImageContext();
-
-    return updatedImage;
-}
-
-- (CGFloat)compressionRate {
-    switch ([Environment.preferences imageUploadQuality]) {
-        case TSImageQualityUncropped:
-            return 1;
-        case TSImageQualityHigh:
-            return 0.9f;
-        case TSImageQualityMedium:
-            return 0.5f;
-        case TSImageQualityLow:
-            return 0.3f;
-        default:
-            break;
-    }
-}
 
 #pragma mark Storage access
 
@@ -2192,7 +2253,19 @@ typedef enum : NSUInteger {
 
 - (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag {
     if (flag) {
-        [self sendMessageAttachment:[NSData dataWithContentsOfURL:recorder.url] ofType:@"audio/m4a"];
+        NSData *audioData = [NSData dataWithContentsOfURL:recorder.url];
+        SignalAttachment *attachment = [SignalAttachment audioAttachmentWithData:audioData
+                                                                         dataUTI:(NSString *) kUTTypeMPEG4Audio];
+        if (!attachment ||
+            [attachment hasError]) {
+            DDLogWarn(@"%@ %s Invalid attachment: %@.",
+                      self.tag,
+                      __PRETTY_FUNCTION__,
+                      attachment ? [attachment errorMessage] : @"Missing data");
+            // TODO: How should we handle errors here?
+        } else {
+            [self sendMessageAttachment:attachment];
+        }
     }
 }
 
@@ -2408,7 +2481,55 @@ typedef enum : NSUInteger {
         [self showConversationSettings];
     }
 }
-         
+
+#pragma mark - JSQMessagesComposerTextViewPasteDelegate
+
+- (BOOL)composerTextView:(JSQMessagesComposerTextView *)textView
+   shouldPasteWithSender:(id)sender {
+    return YES;
+}
+
+#pragma mark - OWSTextViewPasteDelegate
+
+- (void)didPasteAttachment:(SignalAttachment * _Nullable)attachment {
+    DDLogError(@"%@ %s",
+               self.tag,
+               __PRETTY_FUNCTION__);
+    
+    if (attachment == nil ||
+        [attachment hasError]) {
+        DDLogWarn(@"%@ %s Invalid attachment: %@.",
+                  self.tag,
+                  __PRETTY_FUNCTION__,
+                  attachment ? [attachment errorMessage] : @"Missing data");
+        // TODO: Add UI.
+    } else {
+        __weak MessagesViewController *weakSelf = self;
+        UIViewController *viewController = [[AttachmentApprovalViewController alloc] initWithAttachment:attachment
+                                            successCompletion:^{
+                                                [weakSelf sendMessageAttachment:attachment];
+                                            }];
+        UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
+        [self.navigationController presentViewController:navigationController
+                                                animated:YES
+                                              completion:nil];
+    }
+}
+
+#pragma mark - Class methods
+
++ (UINib *)nib
+{
+    return [UINib nibWithNibName:NSStringFromClass([MessagesViewController class])
+                          bundle:[NSBundle bundleForClass:[MessagesViewController class]]];
+}
+
++ (instancetype)messagesViewController
+{
+    return [[[self class] alloc] initWithNibName:NSStringFromClass([MessagesViewController class])
+                                          bundle:[NSBundle bundleForClass:[MessagesViewController class]]];
+}
+
 #pragma mark - Logging
 
 + (NSString *)tag
diff --git a/Signal/src/view controllers/MessagesViewController.xib b/Signal/src/view controllers/MessagesViewController.xib
new file mode 100644
index 0000000000..d4b3087a1f
--- /dev/null
+++ b/Signal/src/view controllers/MessagesViewController.xib	
@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="11762" systemVersion="15G1217" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" colorMatched="YES">
+    <device id="retina4_7" orientation="portrait">
+        <adaptation id="fullscreen"/>
+    </device>
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="11757"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <objects>
+        <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner" customClass="MessagesViewController">
+            <connections>
+                <outlet property="collectionView" destination="l9u-2b-4LK" id="bLP-6g-CkO"/>
+                <outlet property="inputToolbar" destination="BoD-Az-3DM" id="w74-g9-1qA"/>
+                <outlet property="toolbarBottomLayoutGuide" destination="rHs-6q-NX4" id="d6h-iu-VMX"/>
+                <outlet property="toolbarHeightConstraint" destination="HIk-02-qcW" id="jE8-xC-1eD"/>
+                <outlet property="view" destination="mUa-cS-ru4" id="nki-T1-RTI"/>
+            </connections>
+        </placeholder>
+        <placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
+        <view contentMode="scaleToFill" id="mUa-cS-ru4">
+            <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+            <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
+            <subviews>
+                <collectionView opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="scaleToFill" minimumZoomScale="0.0" maximumZoomScale="0.0" dataMode="prototypes" translatesAutoresizingMaskIntoConstraints="NO" id="l9u-2b-4LK" customClass="JSQMessagesCollectionView">
+                    <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                    <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                    <collectionViewLayout key="collectionViewLayout" id="dZl-7C-LHR" customClass="JSQMessagesCollectionViewFlowLayout"/>
+                    <cells/>
+                </collectionView>
+                <toolbar opaque="NO" clearsContextBeforeDrawing="NO" contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="BoD-Az-3DM" customClass="OWSMessagesInputToolbar">
+                    <rect key="frame" x="0.0" y="623" width="375" height="44"/>
+                    <constraints>
+                        <constraint firstAttribute="height" constant="44" id="HIk-02-qcW"/>
+                    </constraints>
+                    <items/>
+                </toolbar>
+            </subviews>
+            <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+            <constraints>
+                <constraint firstAttribute="trailing" secondItem="BoD-Az-3DM" secondAttribute="trailing" id="7xc-Ha-asg"/>
+                <constraint firstItem="l9u-2b-4LK" firstAttribute="leading" secondItem="mUa-cS-ru4" secondAttribute="leading" id="MmF-oh-Y75"/>
+                <constraint firstAttribute="trailing" secondItem="l9u-2b-4LK" secondAttribute="trailing" id="O9u-TA-A0e"/>
+                <constraint firstAttribute="bottom" secondItem="l9u-2b-4LK" secondAttribute="bottom" id="Re7-WW-UmS"/>
+                <constraint firstItem="l9u-2b-4LK" firstAttribute="top" secondItem="mUa-cS-ru4" secondAttribute="top" id="dCQ-DM-Wdj"/>
+                <constraint firstAttribute="bottom" secondItem="BoD-Az-3DM" secondAttribute="bottom" id="rHs-6q-NX4"/>
+                <constraint firstItem="BoD-Az-3DM" firstAttribute="leading" secondItem="mUa-cS-ru4" secondAttribute="leading" id="ts7-8f-0lH"/>
+            </constraints>
+            <nil key="simulatedStatusBarMetrics"/>
+        </view>
+    </objects>
+    <simulatedMetricsContainer key="defaultSimulatedMetrics">
+        <simulatedStatusBarMetrics key="statusBar"/>
+        <simulatedOrientationMetrics key="orientation"/>
+        <simulatedScreenMetrics key="destination" type="retina4_7.fullscreen"/>
+    </simulatedMetricsContainer>
+</document>
diff --git a/Signal/src/view controllers/OWSConversationSettingsTableViewController.m b/Signal/src/view controllers/OWSConversationSettingsTableViewController.m
index b5abbe19c0..9b24646eae 100644
--- a/Signal/src/view controllers/OWSConversationSettingsTableViewController.m	
+++ b/Signal/src/view controllers/OWSConversationSettingsTableViewController.m	
@@ -93,12 +93,7 @@ static NSString *const OWSConversationSettingsTableViewControllerSegueShowGroupM
         return self;
     }
 
-    _storageManager = [TSStorageManager sharedManager];
-    _contactsManager = [Environment getCurrent].contactsManager;
-    _messageSender = [[OWSMessageSender alloc] initWithNetworkManager:[Environment getCurrent].networkManager
-                                                       storageManager:_storageManager
-                                                      contactsManager:_contactsManager
-                                                      contactsUpdater:[Environment getCurrent].contactsUpdater];
+    [self commonInit];
 
     return self;
 }
@@ -110,14 +105,30 @@ static NSString *const OWSConversationSettingsTableViewControllerSegueShowGroupM
         return self;
     }
 
+    [self commonInit];
+
+    return self;
+}
+
+- (instancetype)initWithNibName:(nullable NSString *)nibNameOrNil bundle:(nullable NSBundle *)nibBundleOrNil {
+    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
+    if (!self) {
+        return self;
+    }
+    
+    [self commonInit];
+    
+    return self;
+}
+
+- (void)commonInit
+{
     _storageManager = [TSStorageManager sharedManager];
     _contactsManager = [Environment getCurrent].contactsManager;
     _messageSender = [[OWSMessageSender alloc] initWithNetworkManager:[Environment getCurrent].networkManager
                                                        storageManager:_storageManager
                                                       contactsManager:_contactsManager
                                                       contactsUpdater:[Environment getCurrent].contactsUpdater];
-
-    return self;
 }
 
 - (void)configureWithThread:(TSThread *)thread
diff --git a/Signal/src/view controllers/OWSMessagesToolbarContentView.xib b/Signal/src/view controllers/OWSMessagesToolbarContentView.xib
new file mode 100644
index 0000000000..45937cf82c
--- /dev/null
+++ b/Signal/src/view controllers/OWSMessagesToolbarContentView.xib	
@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="11762" systemVersion="15G1217" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" colorMatched="YES">
+    <device id="retina4_7" orientation="portrait">
+        <adaptation id="fullscreen"/>
+    </device>
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="11757"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <objects>
+        <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner"/>
+        <placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
+        <view contentMode="scaleToFill" id="1" customClass="OWSMessagesToolbarContentView">
+            <rect key="frame" x="0.0" y="0.0" width="320" height="44"/>
+            <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+            <subviews>
+                <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="LEq-G7-jGt" userLabel="Left button container">
+                    <rect key="frame" x="8" y="6" width="34" height="32"/>
+                    <color key="backgroundColor" red="0.66666666666666663" green="0.66666666666666663" blue="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                    <constraints>
+                        <constraint firstAttribute="height" constant="32" id="0sE-GV-joM"/>
+                        <constraint firstAttribute="width" constant="34" id="eMy-Af-wwH"/>
+                    </constraints>
+                </view>
+                <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="Myo-1S-Vg1" userLabel="Right button container">
+                    <rect key="frame" x="262" y="6" width="50" height="32"/>
+                    <color key="backgroundColor" red="0.66666666666666663" green="0.66666666666666663" blue="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                    <constraints>
+                        <constraint firstAttribute="height" constant="32" id="NaR-re-dJ4"/>
+                        <constraint firstAttribute="width" constant="50" id="yde-S9-dHe"/>
+                    </constraints>
+                </view>
+                <textView clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="dm4-NT-mvr" customClass="OWSMessagesComposerTextView">
+                    <rect key="frame" x="50" y="7" width="204" height="30"/>
+                    <color key="backgroundColor" red="0.66666666666666663" green="0.66666666666666663" blue="0.66666666666666663" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                    <fontDescription key="fontDescription" type="system" pointSize="14"/>
+                    <textInputTraits key="textInputTraits" autocapitalizationType="sentences"/>
+                </textView>
+            </subviews>
+            <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+            <constraints>
+                <constraint firstItem="Myo-1S-Vg1" firstAttribute="leading" secondItem="dm4-NT-mvr" secondAttribute="trailing" constant="8" id="7Ld-5r-Hp3"/>
+                <constraint firstItem="dm4-NT-mvr" firstAttribute="top" secondItem="1" secondAttribute="top" constant="7" id="9Tz-Wq-xIf"/>
+                <constraint firstAttribute="bottom" secondItem="dm4-NT-mvr" secondAttribute="bottom" constant="7" id="CCb-V7-yek"/>
+                <constraint firstAttribute="bottom" secondItem="Myo-1S-Vg1" secondAttribute="bottom" constant="6" id="EaS-Oq-Qp5"/>
+                <constraint firstItem="LEq-G7-jGt" firstAttribute="leading" secondItem="1" secondAttribute="leading" constant="8" id="LAU-fo-GJJ"/>
+                <constraint firstAttribute="trailing" secondItem="Myo-1S-Vg1" secondAttribute="trailing" constant="8" id="ds6-61-GNv"/>
+                <constraint firstAttribute="bottom" secondItem="LEq-G7-jGt" secondAttribute="bottom" constant="6" id="oG2-YD-ZZI"/>
+                <constraint firstItem="dm4-NT-mvr" firstAttribute="leading" secondItem="LEq-G7-jGt" secondAttribute="trailing" constant="8" id="owo-gB-gyR"/>
+            </constraints>
+            <nil key="simulatedStatusBarMetrics"/>
+            <freeformSimulatedSizeMetrics key="simulatedDestinationMetrics"/>
+            <connections>
+                <outlet property="leftBarButtonContainerView" destination="LEq-G7-jGt" id="F0V-4N-1Mo"/>
+                <outlet property="leftBarButtonContainerViewWidthConstraint" destination="eMy-Af-wwH" id="FI9-F2-2bN"/>
+                <outlet property="leftHorizontalSpacingConstraint" destination="LAU-fo-GJJ" id="X2c-BI-0Q4"/>
+                <outlet property="rightBarButtonContainerView" destination="Myo-1S-Vg1" id="0SR-cw-EkD"/>
+                <outlet property="rightBarButtonContainerViewWidthConstraint" destination="yde-S9-dHe" id="WGu-df-M3L"/>
+                <outlet property="rightHorizontalSpacingConstraint" destination="ds6-61-GNv" id="ZQh-8M-QFs"/>
+                <outlet property="textView" destination="dm4-NT-mvr" id="PFw-HO-oT8"/>
+            </connections>
+            <point key="canvasLocation" x="268" y="548"/>
+        </view>
+    </objects>
+    <simulatedMetricsContainer key="defaultSimulatedMetrics">
+        <simulatedStatusBarMetrics key="statusBar"/>
+        <simulatedOrientationMetrics key="orientation"/>
+        <simulatedScreenMetrics key="destination" type="retina4_7.fullscreen"/>
+    </simulatedMetricsContainer>
+</document>
diff --git a/Signal/src/view controllers/SignalAttachment.swift b/Signal/src/view controllers/SignalAttachment.swift
new file mode 100644
index 0000000000..897bebb9cb
--- /dev/null
+++ b/Signal/src/view controllers/SignalAttachment.swift	
@@ -0,0 +1,530 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+import Foundation
+import MobileCoreServices
+
+enum SignalAttachmentError: String {
+    case missingData
+    case fileSizeTooLarge
+    case invalidData
+    case couldNotParseImage
+    case couldNotConvertToJpeg
+    case invalidFileFormat
+}
+
+enum TSImageQuality: Int {
+    case uncropped
+    case high
+    case medium
+    case low
+}
+
+// Represents a possible attachment to upload.
+// The attachment may be invalid.
+//
+// Signal attachments are subject to validation and 
+// in some cases, file format conversion.
+//
+// This class gathers that logic.  It offers factory methods
+// for attachments that do the necessary work. 
+//
+// The return value for the factory methods will be nil if the input is nil.
+//
+// [SignalAttachment hasError] will be true for non-valid attachments.
+//
+// TODO: Perhaps do conversion off the main thread?
+// TODO: Show error on error.
+// TODO: Show progress on upload.
+class SignalAttachment: NSObject {
+
+    static let TAG = "[SignalAttachment]"
+
+    // MARK: Properties
+
+    let data: Data
+
+    // Attachment types are identified using UTIs.
+    //
+    // See: https://developer.apple.com/library/content/documentation/Miscellaneous/Reference/UTIRef/Articles/System-DeclaredUniformTypeIdentifiers.html
+    let dataUTI: String
+
+    var error: SignalAttachmentError? {
+        didSet {
+            AssertIsOnMainThread()
+
+            assert(oldValue == nil)
+            Logger.verbose("\(SignalAttachment.TAG) Attachment has error: \(error)")
+        }
+    }
+
+    // To avoid redundant work of repeatedly compressing/uncompressing
+    // images, we cache the UIImage associated with this attachment if
+    // possible.
+    public var image: UIImage?
+
+    // MARK: Constants
+
+    /**
+     * Media Size constraints from Signal-Android
+     *
+     * https://github.com/WhisperSystems/Signal-Android/blob/master/src/org/thoughtcrime/securesms/mms/PushMediaConstraints.java
+     */
+    static let kMaxFileSizeAnimatedImage = 6 * 1024 * 1024
+    static let kMaxFileSizeImage = 6 * 1024 * 1024
+    static let kMaxFileSizeVideo = 100 * 1024 * 1024
+    static let kMaxFileSizeAudio = 100 * 1024 * 1024
+    static let kMaxFileSizeGeneric = 100 * 1024 * 1024
+
+    // MARK: Constructor
+
+    // This method should not be called directly; use the factory
+    // methods instead.
+    internal required init(data: Data, dataUTI: String) {
+        self.data = data
+        self.dataUTI = dataUTI
+        super.init()
+    }
+
+    var hasError: Bool {
+        return error != nil
+    }
+
+    var errorMessage: String? {
+        guard let error = error else {
+            // This method should only be called if there is an error.
+            assert(false)
+            return nil
+        }
+        return "\(error)"
+    }
+
+    // Returns the MIME type for this attachment or nil if no MIME type
+    // can be identified.
+    var mimeType: String? {
+        let mimeType = UTTypeCopyPreferredTagWithClass(dataUTI as CFString, kUTTagClassMIMEType)
+        guard mimeType != nil else {
+            return nil
+        }
+        return mimeType?.takeRetainedValue() as? String
+    }
+
+    // Returns the file extension for this attachment or nil if no file extension
+    // can be identified.
+    var fileExtension: String? {
+        guard let fileExtension = UTTypeCopyPreferredTagWithClass(dataUTI as CFString,
+                                                                  kUTTagClassFilenameExtension) else {
+            return nil
+        }
+        return fileExtension.takeRetainedValue() as String
+    }
+
+    private static let allowArbitraryAttachments = false
+
+    // Returns the set of UTIs that correspond to valid _input_ image formats
+    // for Signal attachments.
+    //
+    // Image attachments may be converted to another image format before 
+    // being uploaded.
+    private class var inputImageUTISet: Set<String> {
+        return MIMETypeUtil.supportedImageUTITypes()
+    }
+
+    // Returns the set of UTIs that correspond to valid _output_ image formats
+    // for Signal attachments.
+    private class var outputImageUTISet: Set<String> {
+        if allowArbitraryAttachments {
+            return MIMETypeUtil.supportedImageUTITypes()
+        } else {
+            // Until Android client can handle arbitrary attachments,
+            // restrict output.
+            return [
+                kUTTypeJPEG as String,
+                kUTTypeGIF as String,
+                kUTTypePNG as String
+            ]
+        }
+    }
+
+    // Returns the set of UTIs that correspond to valid animated image formats
+    // for Signal attachments.
+    private class var animatedImageUTISet: Set<String> {
+        return MIMETypeUtil.supportedAnimatedImageUTITypes()
+    }
+
+    // Returns the set of UTIs that correspond to valid video formats
+    // for Signal attachments.
+    private class var videoUTISet: Set<String> {
+        if allowArbitraryAttachments {
+            return MIMETypeUtil.supportedVideoUTITypes()
+        } else {
+            return [
+                kUTTypeMPEG4 as String
+            ]
+        }
+    }
+
+    // Returns the set of UTIs that correspond to valid audio formats
+    // for Signal attachments.
+    private class var audioUTISet: Set<String> {
+        if allowArbitraryAttachments {
+            return MIMETypeUtil.supportedAudioUTITypes()
+        } else {
+            return [
+                kUTTypeMP3 as String,
+                kUTTypeMPEG4Audio as String
+            ]
+        }
+    }
+
+    // Returns the set of UTIs that correspond to valid input formats
+    // for Signal attachments.
+    public class var validInputUTISet: Set<String> {
+        return inputImageUTISet.union(videoUTISet.union(audioUTISet))
+    }
+
+    public var isImage: Bool {
+        return SignalAttachment.outputImageUTISet.contains(dataUTI)
+    }
+
+    public var isVideo: Bool {
+        return SignalAttachment.videoUTISet.contains(dataUTI)
+    }
+
+    public var isAudio: Bool {
+        return SignalAttachment.audioUTISet.contains(dataUTI)
+    }
+
+    // Returns an attachment from the pasteboard, or nil if no attachment
+    // can be found.
+    //
+    // NOTE: The attachment returned by this method may not be valid.
+    //       Check the attachment's error property.
+    public class func attachmentFromPasteboard() -> SignalAttachment? {
+        guard UIPasteboard.general.numberOfItems >= 1 else {
+            return nil
+        }
+        // If pasteboard contains multiple items, use only the first.
+        let itemSet = IndexSet(integer:0)
+        guard let pasteboardUTITypes = UIPasteboard.general.types(forItemSet:itemSet) else {
+            return nil
+        }
+        let pasteboardUTISet = Set<String>(pasteboardUTITypes[0])
+        for dataUTI in inputImageUTISet {
+            if pasteboardUTISet.contains(dataUTI) {
+                guard let data = dataForFirstPasteboardItem(dataUTI:dataUTI) else {
+                    Logger.verbose("\(TAG) Missing expected pasteboard data for UTI: \(dataUTI)")
+                    return nil
+                }
+                return imageAttachment(data : data, dataUTI : dataUTI)
+            }
+        }
+        for dataUTI in videoUTISet {
+            if pasteboardUTISet.contains(dataUTI) {
+                guard let data = dataForFirstPasteboardItem(dataUTI:dataUTI) else {
+                    Logger.verbose("\(TAG) Missing expected pasteboard data for UTI: \(dataUTI)")
+                    return nil
+                }
+                return videoAttachment(data : data, dataUTI : dataUTI)
+            }
+        }
+        for dataUTI in audioUTISet {
+            if pasteboardUTISet.contains(dataUTI) {
+                guard let data = dataForFirstPasteboardItem(dataUTI:dataUTI) else {
+                    Logger.verbose("\(TAG) Missing expected pasteboard data for UTI: \(dataUTI)")
+                    return nil
+                }
+                return audioAttachment(data : data, dataUTI : dataUTI)
+            }
+        }
+        // TODO: We could handle generic attachments at this point.
+
+        return nil
+    }
+
+    // This method should only be called for dataUTIs that
+    // are appropriate for the first pasteboard item.
+    private class func dataForFirstPasteboardItem(dataUTI: String) -> Data? {
+        let itemSet = IndexSet(integer:0)
+        guard let datas = UIPasteboard.general.data(forPasteboardType:dataUTI, inItemSet:itemSet) else {
+            Logger.verbose("\(TAG) Missing expected pasteboard data for UTI: \(dataUTI)")
+            return nil
+        }
+        guard datas.count > 0 else {
+            Logger.verbose("\(TAG) Missing expected pasteboard data for UTI: \(dataUTI)")
+            return nil
+        }
+        guard let data = datas[0] as? Data else {
+            Logger.verbose("\(TAG) Missing expected pasteboard data for UTI: \(dataUTI)")
+            return nil
+        }
+        return data
+    }
+
+    // MARK: Image Attachments
+
+    // Factory method for an image attachment.
+    //
+    // NOTE: The attachment returned by this method may not be valid.
+    //       Check the attachment's error property.
+    public class func imageAttachment(data imageData: Data?, dataUTI: String) -> SignalAttachment {
+        assert(dataUTI.characters.count > 0)
+
+        assert(imageData != nil)
+        guard let imageData = imageData else {
+            let attachment = SignalAttachment(data : Data(), dataUTI: dataUTI)
+            attachment.error = .missingData
+            return attachment
+        }
+
+        let attachment = SignalAttachment(data : imageData, dataUTI: dataUTI)
+
+        guard inputImageUTISet.contains(dataUTI) else {
+            attachment.error = .invalidFileFormat
+            return attachment
+        }
+
+        guard imageData.count > 0 else {
+            assert(imageData.count > 0)
+            attachment.error = .invalidData
+            return attachment
+        }
+
+        if animatedImageUTISet.contains(dataUTI) {
+            guard imageData.count <= kMaxFileSizeAnimatedImage else {
+                attachment.error = .fileSizeTooLarge
+                return attachment
+            }
+            // Never re-encode animated images (i.e. GIFs) as JPEGs.
+            Logger.verbose("\(TAG) Sending raw \(attachment.mimeType) to retain any animation")
+            return attachment
+        } else {
+            guard let image = UIImage(data:imageData) else {
+                attachment.error = .couldNotParseImage
+                return attachment
+            }
+            attachment.image = image
+
+            if isInputImageValidOutputImage(image: image, imageData: imageData, dataUTI: dataUTI) {
+                Logger.verbose("\(TAG) Sending raw \(attachment.mimeType)")
+                return attachment
+            }
+
+            Logger.verbose("\(TAG) Compressing attachment as image/jpeg")
+            return compressImageAsJPEG(image : image, attachment : attachment)
+        }
+    }
+
+    private class func defaultImageUploadQuality() -> TSImageQuality {
+        // Currently default to a middling image quality and size.
+        // 
+        // TODO: We're likely to change this behavior soon.
+        return .medium
+    }
+
+    // If the proposed attachment already conforms to the
+    // file size and content size limits, don't recompress it.
+    private class func isInputImageValidOutputImage(image: UIImage?, imageData: Data?, dataUTI: String) -> Bool {
+        guard let image = image else {
+            return false
+        }
+        guard let imageData = imageData else {
+            return false
+        }
+        guard SignalAttachment.outputImageUTISet.contains(dataUTI) else {
+            return false
+        }
+
+        let maxSize = maxSizeForImage(image: image,
+                                      imageUploadQuality:defaultImageUploadQuality())
+        if image.size.width <= maxSize &&
+            image.size.height <= maxSize &&
+            imageData.count <= kMaxFileSizeImage {
+            return true
+        }
+        return false
+    }
+
+    // Factory method for an image attachment.
+    //
+    // NOTE: The attachment returned by this method may nil or not be valid.
+    //       Check the attachment's error property.
+    public class func imageAttachment(image: UIImage?, dataUTI: String) -> SignalAttachment {
+        assert(dataUTI.characters.count > 0)
+
+        guard let image = image else {
+            let attachment = SignalAttachment(data : Data(), dataUTI: dataUTI)
+            attachment.error = .missingData
+            return attachment
+        }
+
+        // Make a placeholder attachment on which to hang errors if necessary.
+        let attachment = SignalAttachment(data : Data(), dataUTI: dataUTI)
+        attachment.image = image
+
+        Logger.verbose("\(TAG) Writing \(attachment.mimeType) as image/jpeg")
+        return compressImageAsJPEG(image : image, attachment : attachment)
+    }
+
+    private class func compressImageAsJPEG(image: UIImage, attachment: SignalAttachment) -> SignalAttachment {
+        assert(attachment.error == nil)
+
+        var imageUploadQuality = defaultImageUploadQuality()
+
+        while true {
+            let maxSize = maxSizeForImage(image: image, imageUploadQuality:imageUploadQuality)
+            var dstImage: UIImage! = image
+            if image.size.width > maxSize ||
+                image.size.height > maxSize {
+                dstImage = imageScaled(image, toMaxSize: maxSize)
+            }
+            guard let jpgImageData = UIImageJPEGRepresentation(dstImage,
+                                                               jpegCompressionQuality(imageUploadQuality:imageUploadQuality)) else {
+                                                                attachment.error = .couldNotConvertToJpeg
+                                                                return attachment
+            }
+
+            if jpgImageData.count <= kMaxFileSizeImage {
+                let recompressedAttachment = SignalAttachment(data : jpgImageData, dataUTI: kUTTypeJPEG as String)
+                recompressedAttachment.image = dstImage
+                return recompressedAttachment
+            }
+
+            // If the JPEG output is larger than the file size limit,
+            // continue to try again by progressively reducing the
+            // image upload quality.
+            switch imageUploadQuality {
+            case .uncropped:
+                imageUploadQuality = .high
+            case .high:
+                imageUploadQuality = .medium
+            case .medium:
+                imageUploadQuality = .low
+            case .low:
+                attachment.error = .fileSizeTooLarge
+                return attachment
+            }
+        }
+    }
+
+    private class func imageScaled(_ image: UIImage, toMaxSize size: CGFloat) -> UIImage {
+        var scaleFactor: CGFloat
+        let aspectRatio: CGFloat = image.size.height / image.size.width
+        if aspectRatio > 1 {
+            scaleFactor = size / image.size.width
+        } else {
+            scaleFactor = size / image.size.height
+        }
+        let newSize = CGSize(width: CGFloat(image.size.width * scaleFactor), height: CGFloat(image.size.height * scaleFactor))
+        UIGraphicsBeginImageContext(newSize)
+        image.draw(in: CGRect(x: CGFloat(0), y: CGFloat(0), width: CGFloat(newSize.width), height: CGFloat(newSize.height)))
+        let updatedImage: UIImage? = UIGraphicsGetImageFromCurrentImageContext()
+        UIGraphicsEndImageContext()
+        return updatedImage!
+    }
+
+    private class func maxSizeForImage(image: UIImage, imageUploadQuality: TSImageQuality) -> CGFloat {
+        switch imageUploadQuality {
+        case .uncropped:
+            return max(image.size.width, image.size.height)
+        case .high:
+            return 2048
+        case .medium:
+            return 1024
+        case .low:
+            return 512
+        }
+    }
+
+    private class func jpegCompressionQuality(imageUploadQuality: TSImageQuality) -> CGFloat {
+        switch imageUploadQuality {
+        case .uncropped:
+            return 1
+        case .high:
+            return 0.9
+        case .medium:
+            return 0.5
+        case .low:
+            return 0.3
+        }
+    }
+
+    // MARK: Video Attachments
+
+    // Factory method for video attachments.
+    //
+    // NOTE: The attachment returned by this method may not be valid.
+    //       Check the attachment's error property.
+    public class func videoAttachment(data: Data?, dataUTI: String) -> SignalAttachment {
+        return newAttachment(data : data,
+                             dataUTI : dataUTI,
+                             validUTISet : videoUTISet,
+                             maxFileSize : kMaxFileSizeVideo)
+    }
+
+    // MARK: Audio Attachments
+
+    // Factory method for audio attachments.
+    //
+    // NOTE: The attachment returned by this method may not be valid.
+    //       Check the attachment's error property.
+    public class func audioAttachment(data: Data?, dataUTI: String) -> SignalAttachment {
+        return newAttachment(data : data,
+                             dataUTI : dataUTI,
+                             validUTISet : audioUTISet,
+                             maxFileSize : kMaxFileSizeAudio)
+    }
+
+    // MARK: Generic Attachments
+
+    // Factory method for generic attachments.
+    //
+    // NOTE: The attachment returned by this method may not be valid.
+    //       Check the attachment's error property.
+    public class func genericAttachment(data: Data?, dataUTI: String) -> SignalAttachment {
+        return newAttachment(data : data,
+                             dataUTI : dataUTI,
+                             validUTISet : nil,
+                             maxFileSize : kMaxFileSizeGeneric)
+    }
+
+    // MARK: Helper Methods
+
+    private class func newAttachment(data: Data?,
+                                     dataUTI: String,
+                                     validUTISet: Set<String>?,
+                                     maxFileSize: Int) -> SignalAttachment {
+        assert(dataUTI.characters.count > 0)
+
+        assert(data != nil)
+        guard let data = data else {
+            let attachment = SignalAttachment(data : Data(), dataUTI: dataUTI)
+            attachment.error = .missingData
+            return attachment
+        }
+
+        let attachment = SignalAttachment(data : data, dataUTI: dataUTI)
+
+        if let validUTISet = validUTISet {
+            guard validUTISet.contains(dataUTI) else {
+                attachment.error = .invalidFileFormat
+                return attachment
+            }
+        }
+
+        guard data.count > 0 else {
+            assert(data.count > 0)
+            attachment.error = .invalidData
+            return attachment
+        }
+
+        guard data.count <= maxFileSize else {
+            attachment.error = .fileSizeTooLarge
+            return attachment
+        }
+
+        // Attachment is valid
+        return attachment
+    }
+}
diff --git a/Signal/src/view controllers/SignalsViewController.m b/Signal/src/view controllers/SignalsViewController.m
index 7c442d6bdf..4fbacad5c8 100644
--- a/Signal/src/view controllers/SignalsViewController.m	
+++ b/Signal/src/view controllers/SignalsViewController.m	
@@ -564,8 +564,8 @@ NSString *const SignalsViewControllerSegueShowIncomingCall = @"ShowIncomingCallS
 
 - (void)presentThread:(TSThread *)thread keyboardOnViewAppearing:(BOOL)keyboardOnViewAppearing {
     dispatch_async(dispatch_get_main_queue(), ^{
-        MessagesViewController *mvc = [[UIStoryboard storyboardWithName:AppDelegateStoryboardMain bundle:NULL]
-            instantiateViewControllerWithIdentifier:@"MessagesViewController"];
+        MessagesViewController *mvc = [[MessagesViewController alloc] initWithNibName:@"MessagesViewController"
+                                                                               bundle:nil];
 
         if (self.presentedViewController) {
             [self.presentedViewController dismissViewControllerAnimated:YES completion:nil];
diff --git a/Signal/translations/en.lproj/Localizable.strings b/Signal/translations/en.lproj/Localizable.strings
index 3e98c54b5f..5ce57cb56a 100644
--- a/Signal/translations/en.lproj/Localizable.strings
+++ b/Signal/translations/en.lproj/Localizable.strings
@@ -52,6 +52,21 @@
 /* No comment provided by engineer. */
 "ATTACHMENT" = "Attachment";
 
+/* Label for 'cancel' button in the 'attachment approval' dialog. */
+"ATTACHMENT_APPROVAL_CANCEL_BUTTON" = "Cancel";
+
+/* Title for the 'attachment approval' dialog. */
+"ATTACHMENT_APPROVAL_DIALOG_TITLE" = "Attachment";
+
+/* Format string for file extension label in call interstitial view */
+"ATTACHMENT_APPROVAL_FILE_EXTENSION_FORMAT" = "File type: %@";
+
+/* Format string for file size label in call interstitial view */
+"ATTACHMENT_APPROVAL_FILE_SIZE_FORMAT" = "File size: %@";
+
+/* Label for 'send' button in the 'attachment approval' dialog. */
+"ATTACHMENT_APPROVAL_SEND_BUTTON" = "Send";
+
 /* No comment provided by engineer. */
 "ATTACHMENT_DOWNLOAD_FAILED" = "Attachment download failed, tap to retry.";