check that the w30 app is actually an zip-archive with an index.html

Cargo.lock

@@ -1131,6 +1131,7 @@ dependencies = [
  "toml",
  "url",
  "uuid",
+ "zip",
 ]
 
 [[package]]
@@ -4254,3 +4255,15 @@ dependencies = [
  "syn",
  "synstructure",
 ]
+
+[[package]]
+name = "zip"
+version = "0.5.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93ab48844d61251bb3835145c521d88aa4031d7139e8485990f60ca911fa0815"
+dependencies = [
+ "byteorder",
+ "crc32fast",
+ "flate2",
+ "thiserror",
+]

Cargo.toml

@@ -76,6 +76,7 @@ humansize = "1"
 qrcodegen = "1.7.0"
 tagger = "4.0.1"
 textwrap = "0.14.2"
+zip = { version = "0.5.13", default-features = false, features = ["deflate"] }
 
 [dev-dependencies]
 ansi_term = "0.12.0"

deltachat-ffi/deltachat.h

@@ -3675,6 +3675,20 @@ char*           dc_msg_get_filename           (const dc_msg_t* msg);
 char*           dc_msg_get_filemime           (const dc_msg_t* msg);
 
 
+/**
+ * Return file from inside an archive.
+ * Currently, this works for W30 messages only.
+ *
+ * @param msg The W30 instance.
+ * @param filename The name inside the archive,
+ *     must be given as a relative path (no leading `/`).
+ * @param ret_bytes Pointer to a size_t. The size of the blob will be written here.
+ * @return The blob must be released using dc_str_unref() after usage.
+ *     NULL if there is no such file in the archive or on errors.
+ */
+char*             dc_msg_get_blob_from_archive  (const dc_msg_t* msg, const char* filename, size_t* ret_bytes);
+
+
 /**
  * Get the size of the file.  Returns the size of the file associated with a
  * message, if applicable.

deltachat-ffi/src/lib.rs

@@ -3070,6 +3070,39 @@ pub unsafe extern "C" fn dc_msg_get_filename(msg: *mut dc_msg_t) -> *mut libc::c
     ffi_msg.message.get_filename().unwrap_or_default().strdup()
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn dc_msg_get_blob_from_archive(
+    msg: *mut dc_msg_t,
+    filename: *const libc::c_char,
+    ret_bytes: *mut libc::size_t,
+) -> *mut libc::c_char {
+    if msg.is_null() || filename.is_null() || ret_bytes.is_null() {
+        eprintln!("ignoring careless call to dc_msg_get_blob_from_archive()");
+        return ptr::null_mut();
+    }
+    let ffi_msg = &*msg;
+    let ctx = &*ffi_msg.context;
+    let blob = block_on(async move {
+        ffi_msg
+            .message
+            .get_blob_from_archive(ctx, &to_string_lossy(filename))
+            .await
+    });
+    match blob {
+        Ok(blob) => {
+            // TODO: introduce dc_blob_t to avoid malloc and returning size by pointer and to save copying data
+            *ret_bytes = blob.len();
+            let ptr = libc::malloc(*ret_bytes);
+            libc::memcpy(ptr, blob.as_ptr() as *mut libc::c_void, *ret_bytes);
+            ptr as *mut libc::c_char
+        }
+        Err(err) => {
+            eprintln!("failed read blob from archive: {}", err);
+            ptr::null_mut()
+        }
+    }
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn dc_msg_get_filemime(msg: *mut dc_msg_t) -> *mut libc::c_char {
     if msg.is_null() {

src/message.rs

@@ -1168,7 +1168,7 @@ pub fn guess_msgtype_from_suffix(path: &Path) -> Option<(Viewtype, &str)> {
         "ttf" => (Viewtype::File, "font/ttf"),
         "vcard" => (Viewtype::File, "text/vcard"),
         "vcf" => (Viewtype::File, "text/vcard"),
-        "w30" => (Viewtype::W30, "application/html+w30"),
+        "w30" => (Viewtype::W30, "application/w30+zip"),
         "wav" => (Viewtype::File, "audio/wav"),
         "weba" => (Viewtype::File, "audio/webm"),
         "webm" => (Viewtype::Video, "video/webm"),
@@ -1705,7 +1705,7 @@ mod tests {
         );
         assert_eq!(
             guess_msgtype_from_suffix(Path::new("foo/file.w30")),
-            Some((Viewtype::W30, "application/html+w30"))
+            Some((Viewtype::W30, "application/w30+zip"))
         );
     }
 

src/w30.rs

@@ -2,16 +2,18 @@
 
 use crate::constants::Viewtype;
 use crate::context::Context;
+use crate::dc_tools::dc_open_file_std;
 use crate::message::{Message, MessageState, MsgId};
 use crate::mimeparser::SystemMessage;
 use crate::param::Param;
 use crate::{chat, EventType};
-use anyhow::{bail, Result};
+use anyhow::{bail, ensure, format_err, Result};
 use lettre_email::mime::{self};
 use lettre_email::PartBuilder;
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 use std::convert::TryFrom;
+use std::io::Read;
 
 pub const W30_SUFFIX: &str = "w30";
 
@@ -49,13 +51,17 @@ pub(crate) struct StatusUpdateItem {
 }
 
 impl Context {
-    pub(crate) async fn is_w30_file(&self, filename: &str, _decoded_data: &[u8]) -> Result<bool> {
+    pub(crate) async fn is_w30_file(&self, filename: &str, buf: &[u8]) -> Result<bool> {
         if filename.ends_with(W30_SUFFIX) {
-            Ok(true)
+            let reader = std::io::Cursor::new(buf);
-        } else {
+            if let Ok(mut archive) = zip::ZipArchive::new(reader) {
-            Ok(false)
+                if let Ok(_index_html) = archive.by_name("index.html") {
+                    return Ok(true);
                 }
             }
+        }
+        Ok(false)
+    }
 
     async fn create_status_update_record(
         &self,
@@ -221,6 +227,26 @@ impl Context {
     }
 }
 
+impl Message {
+    /// Return file form inside an archive.
+    /// Currently, this works only if the message is an w30 instance.
+    pub async fn get_blob_from_archive(&self, context: &Context, name: &str) -> Result<Vec<u8>> {
+        ensure!(self.viewtype == Viewtype::W30, "No w30 instance.");
+
+        let archive = self
+            .get_file(context)
+            .ok_or_else(|| format_err!("No w30 instance file."))?;
+        let archive = dc_open_file_std(context, archive)?;
+        let mut archive = zip::ZipArchive::new(archive)?;
+
+        let mut file = archive.by_name(name)?;
+
+        let mut buf = Vec::new();
+        file.read_to_end(&mut buf)?;
+        Ok(buf)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -239,14 +265,35 @@ mod tests {
         let t = TestContext::new().await;
         assert!(
             !t.is_w30_file(
-                "issue_523.txt",
+                "bad-ext-no-zip.txt",
                 include_bytes!("../test-data/message/issue_523.txt")
             )
             .await?
         );
+        assert!(
+            !t.is_w30_file(
+                "bad-ext-good-zip.txt",
+                include_bytes!("../test-data/w30/minimal.w30")
+            )
+            .await?
+        );
+        assert!(
+            !t.is_w30_file(
+                "good-ext-no-zip.w30",
+                include_bytes!("../test-data/message/issue_523.txt")
+            )
+            .await?
+        );
+        assert!(
+            !t.is_w30_file(
+                "good-ext-no-index-html.w30",
+                include_bytes!("../test-data/w30/no-index-html.w30")
+            )
+            .await?
+        );
         assert!(
             t.is_w30_file(
-                "minimal.w30",
+                "good-ext-good-zip.w30",
                 include_bytes!("../test-data/w30/minimal.w30")
             )
             .await?
@@ -255,10 +302,10 @@ mod tests {
     }
 
     async fn create_w30_instance(t: &TestContext) -> Result<Message> {
-        let file = t.get_blobdir().join("index.w30");
+        let file = t.get_blobdir().join("minimal.w30");
         File::create(&file)
             .await?
-            .write_all("<html>ola!</html>".as_ref())
+            .write_all(include_bytes!("../test-data/w30/minimal.w30"))
             .await?;
         let mut instance = Message::new(Viewtype::File);
         instance.set_file(file.to_str().unwrap(), None);
@@ -279,7 +326,7 @@ mod tests {
         // send as .w30 file
         let instance = send_w30_instance(&t, chat_id).await?;
         assert_eq!(instance.viewtype, Viewtype::W30);
-        assert_eq!(instance.get_filename(), Some("index.w30".to_string()));
+        assert_eq!(instance.get_filename(), Some("minimal.w30".to_string()));
         assert_eq!(instance.chat_id, chat_id);
 
         // sending using bad extension is not working, even when setting Viewtype to W30
@@ -308,7 +355,7 @@ mod tests {
         .await?;
         let instance = t.get_last_msg().await;
         assert_eq!(instance.viewtype, Viewtype::W30);
-        assert_eq!(instance.get_filename(), Some("index.w30".to_string()));
+        assert_eq!(instance.get_filename(), Some("minimal.w30".to_string()));
 
         dc_receive_imf(
             &t,
@@ -596,14 +643,17 @@ mod tests {
         let sent1 = alice.pop_sent_msg().await;
         let alice_instance = Message::load_from_db(&alice, alice_instance_id).await?;
         assert_eq!(alice_instance.viewtype, Viewtype::W30);
-        assert_eq!(alice_instance.get_filename(), Some("index.w30".to_string()));
+        assert_eq!(
+            alice_instance.get_filename(),
+            Some("minimal.w30".to_string())
+        );
         assert_eq!(alice_instance.chat_id, alice_chat_id);
 
         // bob receives the instance together with the initial updates in a single message
         bob.recv_msg(&sent1).await;
         let bob_instance = bob.get_last_msg().await;
         assert_eq!(bob_instance.viewtype, Viewtype::W30);
-        assert_eq!(bob_instance.get_filename(), Some("index.w30".to_string()));
+        assert_eq!(bob_instance.get_filename(), Some("minimal.w30".to_string()));
         assert!(sent1.payload().contains("Content-Type: application/json"));
         assert!(sent1.payload().contains("status-update.json"));
         assert!(sent1.payload().contains(r#""payload":{"foo":"bar"}"#));
@@ -627,4 +677,63 @@ mod tests {
             .is_err());
         Ok(())
     }
+
+    #[async_std::test]
+    async fn test_get_blob_from_archive() -> Result<()> {
+        let t = TestContext::new_alice().await;
+        let chat_id = create_group_chat(&t, ProtectionStatus::Unprotected, "foo").await?;
+        let instance = send_w30_instance(&t, chat_id).await?;
+
+        let buf = instance.get_blob_from_archive(&t, "index.html").await?;
+        assert_eq!(buf.len(), 188);
+        assert!(String::from_utf8_lossy(&buf).contains("document.write"));
+
+        assert!(instance
+            .get_blob_from_archive(&t, "not-existent.html")
+            .await
+            .is_err());
+        Ok(())
+    }
+
+    #[async_std::test]
+    async fn test_get_blob_from_archive_subdirs() -> Result<()> {
+        let t = TestContext::new_alice().await;
+        let chat_id = create_group_chat(&t, ProtectionStatus::Unprotected, "foo").await?;
+        let file = t.get_blobdir().join("some-files.w30");
+        File::create(&file)
+            .await?
+            .write_all(include_bytes!("../test-data/w30/some-files.w30"))
+            .await?;
+        let mut instance = Message::new(Viewtype::W30);
+        instance.set_file(file.to_str().unwrap(), None);
+        chat_id.set_draft(&t, Some(&mut instance)).await?;
+
+        let buf = instance.get_blob_from_archive(&t, "index.html").await?;
+        assert_eq!(buf.len(), 65);
+        assert!(String::from_utf8_lossy(&buf).contains("many files"));
+
+        let buf = instance.get_blob_from_archive(&t, "subdir/bla.txt").await?;
+        assert_eq!(buf.len(), 4);
+        assert!(String::from_utf8_lossy(&buf).starts_with("bla"));
+
+        let buf = instance
+            .get_blob_from_archive(&t, "subdir/subsubdir/text.md")
+            .await?;
+        assert_eq!(buf.len(), 24);
+        assert!(String::from_utf8_lossy(&buf).starts_with("this is a markdown file"));
+
+        let buf = instance
+            .get_blob_from_archive(&t, "subdir/subsubdir/text2.md")
+            .await?;
+        assert_eq!(buf.len(), 22);
+        assert!(String::from_utf8_lossy(&buf).starts_with("another markdown"));
+
+        let buf = instance
+            .get_blob_from_archive(&t, "anotherdir/anothersubsubdir/foo.txt")
+            .await?;
+        assert_eq!(buf.len(), 4);
+        assert!(String::from_utf8_lossy(&buf).starts_with("foo"));
+
+        Ok(())
+    }
 }

test-data/message/w30_good_extension.eml

@@ -11,12 +11,19 @@ Content-Type: multipart/mixed; boundary="==BREAK=="
 Content-Type: text/plain; charset=utf-8
 
 w30 with good extension;
-the mimetype is ignored then.
+the mimetype is ignored then,
+content is checked.
 
 --==BREAK==
 Content-Type: text/html
-Content-Disposition: attachment; filename=index.w30
+Content-Disposition: attachment; filename=minimal.w30
+Content-Transfer-Encoding: base64
 
-<html>hey!<html>
+UEsDBBQAAgAIAFJqnVOItjSofAAAALwAAAAKABwAaW5kZXguaHRtbFVUCQADG1LMYV1SzGF1eAsAAQ
+T1AQAABBQAAACzUXTxdw6JDHBVyCjJzbHjsoFQCgo2SfkplSCGgkJJanGJIphlU5xclFlQAhFWUEjJ
+Ty7NTc0r0SsvyixJ1VAqyU8EqlTStIYo1kdWbZOXj6o5uiQjsxhodkWJQnFGfmlOikJefolCUiqIV5
+4XCzUCWZeNPsRNNvoQRwIAUEsBAh4DFAACAAgAUmqdU4i2NKh8AAAAvAAAAAoAGAAAAAAAAQAAAKSB
+AAAAAGluZGV4Lmh0bWxVVAUAAxtSzGF1eAsAAQT1AQAABBQAAABQSwUGAAAAAAEAAQBQAAAAwAAAAA
+AA
 
 --==BREAK==--