get secret files working

assets/js/definitions/index.d.ts

@@ -2,3 +2,8 @@ type IntendedUser = {
   name: string;
   emails: string[];
 };
+
+type IntendedLink = {
+  filename: string | null,
+  filetype: string | null
+};

assets/js/pages/AuthPage.tsx

@@ -27,15 +27,18 @@ interface Keys {
   iv: string;
 }
 
-interface Link {
+interface LinkFiles {
   text: Blob | null;
   file: Blob | null;
+  filename: string | null;
+  filetype: string | null;
 }
 
 const AuthPage = (props: AuthPageProps) => {
   const { service, recipient, user } = props;
 
-  const [secretFileUrl, _setsecretFileUrl] = useState<string>("#");
+  const [secretFileUrl, setSecretFileUrl] = useState<string>("#");
+  const [secretFileName, setSecretFileName] = useState<string>("");
   const [secretMessage, setSecretMessage] = useState<string>("Decrypting...");
 
   useEffect(() => {
@@ -45,14 +48,14 @@ const AuthPage = (props: AuthPageProps) => {
   }, []);
 
   const init = async (): Promise<void> => {
+    const link: LinkFiles | null = await retrieveLink();
     const keys: Keys | null = await retrieveKeys();
-    const link: Link | null = await retrieveLink();
     if (link && keys) {
       await decrypt(link, keys);
     }
   };
 
-  const retrieveLink = async (): Promise<Link | null> => {
+  const retrieveLink = async (): Promise<LinkFiles | null> => {
     const urlSegments = new URL(document.URL).pathname.split("/");
     const linkId = urlSegments.pop() || urlSegments.pop();
     if (!linkId) {
@@ -60,14 +63,26 @@ const AuthPage = (props: AuthPageProps) => {
       return null;
     }
 
-    const textResponse = await fetch(`/uploads/links/${linkId}/text`);
+    const linkResponse = await fetch(`/links/${linkId}`);
+    const linkData: IntendedLink = await linkResponse.json();
+    const textResponse = await fetch(
+      `/uploads/links/${linkId}/secret_message.txt`
+    );
     const textData = await textResponse.blob();
-    const fileResponse = await fetch(`/uploads/links/${linkId}/file`);
+    const fileResponse = await fetch(
+      `/uploads/links/${linkId}/${linkData.filename}`
+    );
     const fileData = await fileResponse.blob();
 
+    if (linkData.filename) {
+      await setSecretFileName(linkData.filename);
+    }
+
     return {
       text: textData.size > 0 ? textData : null,
       file: fileData.size > 0 ? fileData : null,
+      filename: linkData.filename,
+      filetype: linkData.filetype,
     };
   };
 
@@ -96,7 +111,7 @@ const AuthPage = (props: AuthPageProps) => {
     }
   };
 
-  const decrypt = async (link: Link, keys: Keys) => {
+  const decrypt = async (link: LinkFiles, keys: Keys) => {
     const convertedKey = HexMix.hexToUint8(keys.key);
     const convertedIv = HexMix.hexToUint8(keys.iv);
     const importedKey = await window.crypto.subtle.importKey(
@@ -123,6 +138,21 @@ const AuthPage = (props: AuthPageProps) => {
       });
     }
     if (link?.file) {
+      const uploadedFile = await link.file.arrayBuffer();
+      const encodedFile = await window.crypto.subtle.decrypt(
+        {
+          name: "AES-GCM",
+          length: 256,
+          iv: convertedIv,
+        },
+        importedKey,
+        uploadedFile
+      );
+
+      const blob = new Blob([encodedFile], {
+        type: link.filetype ? link.filetype : "text/plain",
+      });
+      setSecretFileUrl(window.URL.createObjectURL(blob));
     }
   };
 
@@ -193,12 +223,14 @@ const AuthPage = (props: AuthPageProps) => {
           <TextAlignWrapper align="left">
             <Label htmlFor="service">Secret File</Label>
           </TextAlignWrapper>
-          <InputButtonWithIcon
-            variant="download"
-            id="downloadfile"
-            value={secretFileUrl}
-            onClick={() => {}}
-          />
+          <a href={secretFileUrl} download style={{ width: "100%" }}>
+            <InputButtonWithIcon
+              variant="download"
+              id="downloadfile"
+              value={secretFileName}
+              onClick={() => {}}
+            />
+          </a>
           <Spacer space="3rem" />
           <a href={`https://intended.link/auth/${service}`}>
             <Button variant="primary" wide onClick={() => {}}>

assets/js/pages/JustPage.tsx

@@ -1,80 +1,157 @@
 import React, { useEffect, useState } from "react";
 
-import { ProgressIndicator, Header2, Button, IconArrow, Label, FileInput, TextArea, CenteredContainer, Spacer, TextAlignWrapper, GlobalStyle } from '@intended/intended-ui';
+import {
+  ProgressIndicator,
+  Header2,
+  Button,
+  IconArrow,
+  Label,
+  FileInput,
+  TextArea,
+  CenteredContainer,
+  Spacer,
+  TextAlignWrapper,
+  GlobalStyle,
+} from "@intended/intended-ui";
 import HexMix from "../utils/hexmix";
 
 type JustPageProps = {
-  csrf: string
+  csrf: string;
+};
+
+interface AESKey {
+  key: CryptoKey;
+  iv: Uint8Array;
+  exported: ArrayBuffer;
+  keyHex: string;
+  ivHex: string;
 }
 
 const JustPage = (props: JustPageProps) => {
   const [secretInput, setSecretInput] = useState("");
-  const [fileInput, setFileInput] = useState<File | null>(null);
+  const [fileInput, setFileInput] = useState<string | null>(null);
   const [fileName, setFileName] = useState("");
+  const [fileType, setFileType] = useState("");
 
   useEffect(() => {
     sessionStorage.clear();
-  }, [])
+  }, []);
 
   const handleChange = (e: React.ChangeEvent<HTMLTextAreaElement>) => {
     setSecretInput(e.target.value);
   };
 
   const handleFile = (file: File) => {
-    setFileInput(file);
-
     setFileName(file.name);
+    setFileType(file.type);
+
+    if (file instanceof File) {
+      if (file.size > 2097152) {
+        // TODO: may not need this check
+        alert("Error: Max file size is 2mb.");
+        return;
+      }
+
+      const reader = new FileReader();
+      reader.onloadend = loadFile;
+      reader.readAsArrayBuffer(file);
+    }
+  };
+
+  const loadFile = (fileEvent: ProgressEvent<FileReader>) => {
+    // Make sure we actually got a binary file
+    if (
+      fileEvent &&
+      fileEvent.target &&
+      fileEvent.target.result instanceof ArrayBuffer
+    ) {
+      const data = fileEvent.target.result as ArrayBuffer;
+      HexMix.arrayBufferToString(data, (result: string) => {
+        setFileInput(result);
+      });
+    } else {
+      alert("File is either missing or corrupt.");
+    }
+  };
+
+  const fileFormData = async (form: FormData, aesKey: AESKey) => {
+    const encoded = HexMix.stringToArrayBuffer(fileInput as string);
+    const encrypted = await window.crypto.subtle.encrypt(
+      {
+        name: "AES-GCM",
+        iv: aesKey.iv,
+      },
+      aesKey.key,
+      encoded
+    );
+    const blobData = new Blob([encrypted]);
+    form.append("file_content", blobData, fileName);
+    form.append("filename", fileName);
+    form.append("filetype", fileType);
+  };
+
+  const textFormData = async (form: FormData, aesKey: AESKey) => {
+    const encoded = HexMix.stringToArrayBuffer(secretInput);
+    const encrypted = await window.crypto.subtle.encrypt(
+      {
+        name: "AES-GCM",
+        iv: aesKey.iv,
+      },
+      aesKey.key,
+      encoded
+    );
+    const blobData = new Blob([encrypted]);
+    form.append("text_content", blobData, "secret_message.txt");
+  };
+
+  const createKey = async (): Promise<AESKey> => {
+    const key = await window.crypto.subtle.generateKey(
+      {
+        name: "AES-GCM",
+        length: 256,
+      },
+      true,
+      ["encrypt", "decrypt"]
+    );
+
+    const iv = window.crypto.getRandomValues(new Uint8Array(16));
+    const exported = await window.crypto.subtle.exportKey("raw", key);
+    const keyHex = HexMix.uint8ToHex(new Uint8Array(exported));
+    const ivHex = HexMix.uint8ToHex(iv);
+
+    return {
+      key,
+      iv,
+      exported,
+      keyHex,
+      ivHex,
+    };
   };
 
   const postContents = async () => {
     if (!window.crypto.subtle) {
-      alert('Browser does not support SubtleCrypto');
+      alert("Browser does not support SubtleCrypto");
       return;
     }
 
-    const key = await window.crypto.subtle.generateKey(
-      {
-        name: 'AES-GCM',
-        length: 256
-      },
-      true,
-      ['encrypt', 'decrypt']
-    );
-    const encoded = HexMix.stringToArrayBuffer(secretInput);
-    const iv = window.crypto.getRandomValues(new Uint8Array(16));
-    const exported = await window.crypto.subtle.exportKey('raw', key);
-    const encrypted = await window.crypto.subtle.encrypt(
-      {
-        name: 'AES-GCM',
-        iv
-      },
-      key,
-      encoded
-    );
-
-    const keyHex = HexMix.uint8ToHex(new Uint8Array(exported));
-    const ivHex = HexMix.uint8ToHex(iv);
-
+    const key = await createKey();
     const formData = new FormData();
-    const blobData = new Blob([encrypted]);
-
-    formData.append('text_content', blobData);
-    // formData.append('filetype', 'text/plain');
-    // formData.append('filename', 'secret.txt');
+    await fileFormData(formData, key);
+    await textFormData(formData, key);
 
     try {
       const link: Response = await fetch(`${window.location.origin}/just`, {
         headers: {
-          "X-CSRF-Token": props.csrf
+          "X-CSRF-Token": props.csrf,
         },
         body: formData,
-        method: "POST"
+        method: "POST",
       });
-      const { id: link_id } = await link.json()
+      const { id: link_id } = await link.json();
 
       sessionStorage.setItem("link_id", link_id);
-      sessionStorage.setItem("key_hex", keyHex);
-      sessionStorage.setItem("iv_hex", ivHex);
+      sessionStorage.setItem("key_hex", key.keyHex);
+      sessionStorage.setItem("iv_hex", key.ivHex);
       window.location.href = `${window.location.origin}/just/for`;
     } catch (err: any) {
       alert(err.message);
@@ -103,10 +180,13 @@ const JustPage = (props: JustPageProps) => {
           </TextAlignWrapper>
           <Spacer space="1.6rem" />
           <FileInput id="fileInput" value={fileName} handleFile={handleFile} />
-          { fileInput ? "" : ""}
           <Spacer space="4rem" />
           <div
-            style={{ display: "flex", justifyContent: "flex-end", width: "100%" }}
+            style={{
+              display: "flex",
+              justifyContent: "flex-end",
+              width: "100%",
+            }}
           >
             <Button variant="secondary" onClick={postContents}>
               <IconArrow arrowDirection="right" />

lib/entendu_web/controllers/link_controller.ex

@@ -47,26 +47,15 @@ defmodule EntenduWeb.LinkController do
   def auth_page(conn, %{"id" => link_id}) do
     with %Link{service: service, recipient: recipient} = link <- Links.get_link(link_id) do
       conn
-      |> put_session(:intended_link, link)
+      |> put_session(:intended_link, %{service: service, recipient: recipient})
       |> render("auth.html", %{intended_link: %{service: service, recipient: recipient}})
     end
   end
 
-  def text(conn, %{"id" => link_id}) do
-    with user = get_session(conn, :current_user),
-         %Link{recipient: recipient} = link <- Links.get_link(link_id),
-         true <- UserFromAuth.can_access?(recipient, user) do
-      path = EncryptedLink.url({link.text_content, link})
-      send_file(conn, 200, path)
-    end
-  end
-
-  def file(conn, %{"id" => link_id}) do
-    with user = get_session(conn, :current_user),
-         %Link{recipient: recipient} = link <- Links.get_link(link_id),
-         true <- UserFromAuth.can_access?(recipient, user) do
-      path = EncryptedLink.url({link.file_content, link})
-      send_file(conn, 200, path)
+  def authorized_link(conn, %{"id" => link_id}) do
+    with %Link{} = link <- Links.get_link(link_id) do
+      conn
+      |> render("show_authorized.json", %{link: link})
     end
   end
 end

lib/entendu_web/plugs/authorize_link.ex

@@ -12,8 +12,12 @@ defmodule EntenduWeb.Plugs.AuthorizeLink do
   def init(_params) do
   end
 
-  def call(conn, params) do
-    %{params: %{"path" => [_, link_id, _]}} = conn
+  defp get_link_id(%{params: %{"id" => link_id}}), do: link_id
+
+  defp get_link_id(%{params: %{"path" => [_, link_id, _]}}), do: link_id
+
+  def call(conn, _params) do
+    link_id = get_link_id(conn)
     user = get_session(conn, :current_user)
 
     if !user do
@@ -23,8 +27,7 @@ defmodule EntenduWeb.Plugs.AuthorizeLink do
       |> render("error_code.json", message: "Unauthorized", code: 403)
       |> halt
     else
-      with {:ok, user} <- get_user_from_path(conn),
-           %Link{recipient: recipient} = link <- Links.get_link(link_id),
+      with %Link{recipient: recipient} = link <- Links.get_link(link_id),
            true <- UserFromAuth.can_access?(recipient, user) do
         conn
         |> assign(:link, link)
@@ -52,19 +55,4 @@ defmodule EntenduWeb.Plugs.AuthorizeLink do
       end
     end
   end
-
-  defp get_user_from_path(%{params: %{"path" => [_, link_id, _]}} = conn) do
-    get_session(conn, :current_user)
-    |> get_user_from_path()
-  end
-
-  defp get_user_from_path(nil) do
-    {:error, "User not authenticated"}
-  end
-
-  defp get_user_from_path(%{id: _, name: _, emails: _} = user) do
-    {:ok, user}
-  end
-
-  defp get_user_from_path(_), do: {:error, "Link does not exist"}
 end

lib/entendu_web/router.ex

@@ -16,11 +16,15 @@ defmodule EntenduWeb.Router do
     plug :accepts, ["json"]
   end
 
-  pipeline :authorized_links do
+  pipeline :authorized_files do
     plug AuthorizeLink
     plug Plug.Static, at: "/uploads", from: Path.expand('./uploads'), gzip: false
   end
 
+  pipeline :authorized_link do
+    plug AuthorizeLink
+  end
+
   scope "/", EntenduWeb do
     pipe_through :browser
 
@@ -31,8 +35,6 @@ defmodule EntenduWeb.Router do
     post "/just/for", LinkController, :for
     get "/just/for/you", LinkController, :you_page
     get "/just/for/you/:id", LinkController, :auth_page
-    get "/links/:id/text", LinkController, :text
-    get "/links/:id/file", LinkController, :file
   end
 
   scope "/auth", EntenduWeb do
@@ -44,10 +46,15 @@ defmodule EntenduWeb.Router do
   end
 
   scope "/uploads", EntenduWeb do
-    pipe_through [:browser, :authorized_links]
+    pipe_through [:browser, :authorized_files]
     get "/*path", FileNotFoundController, :index
   end
 
+  scope "/links", EntenduWeb do
+    pipe_through [:browser, :authorized_link]
+    get "/:id", LinkController, :authorized_link
+  end
+
   # Other scopes may use custom stacks.
   # scope "/api", EntenduWeb do
   #   pipe_through :api

lib/entendu_web/uploaders/encrypted_link.ex

@@ -31,9 +31,9 @@ defmodule Entendu.EncryptedLink do
   # end
 
   # Override the persisted filenames:
-  def filename(_version, {_file, %{filename: filename}}) do
-    if filename, do: filename, else: "text"
-  end
+  # def filename(_version, {_file, %{filename: filename}}) do
+  #   if filename, do: filename, else: "text"
+  # end
 
   # Override the storage directory:
   def storage_dir(version, {_file, scope}) do