generic: Update for subclassing API changes

1 files changed, 564 insertions, 0 deletions

diff --git a/generic/sodium/src/encrypter/imp.rs b/generic/sodium/src/encrypter/imp.rs
new file mode 100644
index 000000000..e17868ec7
--- /dev/null
+++ b/generic/sodium/src/encrypter/imp.rs
@@ -0,0 +1,564 @@
+// encrypter.rs
+//
+// Copyright 2019 Jordan Petridis <jordan@centricular.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+// SPDX-License-Identifier: MIT
+
+use glib::prelude::*;
+use glib::subclass;
+use glib::subclass::prelude::*;
+use gst::prelude::*;
+use gst::subclass::prelude::*;
+use smallvec::SmallVec;
+use sodiumoxide::crypto::box_;
+
+type BufferVec = SmallVec<[gst::Buffer; 16]>;
+
+use std::sync::Mutex;
+
+lazy_static! {
+    static ref CAT: gst::DebugCategory = {
+        gst::DebugCategory::new(
+            "sodiumencrypter",
+            gst::DebugColorFlags::empty(),
+            Some("Encrypter Element"),
+        )
+    };
+}
+
+static PROPERTIES: [subclass::Property; 3] = [
+    subclass::Property("receiver-key", |name| {
+        glib::ParamSpec::boxed(
+            name,
+            "Receiver Key",
+            "The public key of the Receiver",
+            glib::Bytes::static_type(),
+            glib::ParamFlags::READWRITE,
+        )
+    }),
+    subclass::Property("sender-key", |name| {
+        glib::ParamSpec::boxed(
+            name,
+            "Sender Key",
+            "The private key of the Sender",
+            glib::Bytes::static_type(),
+            glib::ParamFlags::WRITABLE,
+        )
+    }),
+    subclass::Property("block-size", |name| {
+        glib::ParamSpec::uint(
+            name,
+            "Block Size",
+            "The block-size of the chunks",
+            1024,
+            std::u32::MAX,
+            32768,
+            glib::ParamFlags::READWRITE,
+        )
+    }),
+];
+
+#[derive(Debug, Clone)]
+struct Props {
+    receiver_key: Option<glib::Bytes>,
+    sender_key: Option<glib::Bytes>,
+    block_size: u32,
+}
+
+impl Default for Props {
+    fn default() -> Self {
+        Props {
+            receiver_key: None,
+            sender_key: None,
+            block_size: 32768,
+        }
+    }
+}
+
+#[derive(Debug)]
+struct State {
+    adapter: gst_base::UniqueAdapter,
+    nonce: box_::Nonce,
+    precomputed_key: box_::PrecomputedKey,
+    block_size: u32,
+    write_headers: bool,
+}
+
+impl State {
+    fn from_props(props: &Props) -> Result<Self, gst::ErrorMessage> {
+        let sender_key = props
+            .sender_key
+            .as_ref()
+            .and_then(|k| box_::SecretKey::from_slice(&k))
+            .ok_or_else(|| {
+                gst_error_msg!(
+                    gst::ResourceError::NotFound,
+                    [format!(
+                        "Failed to set Sender's Key from property: {:?}",
+                        props.sender_key
+                    )
+                    .as_ref()]
+                )
+            })?;
+
+        let receiver_key = props
+            .receiver_key
+            .as_ref()
+            .and_then(|k| box_::PublicKey::from_slice(&k))
+            .ok_or_else(|| {
+                gst_error_msg!(
+                    gst::ResourceError::NotFound,
+                    [format!(
+                        "Failed to set Receiver's Key from property: {:?}",
+                        props.receiver_key
+                    )
+                    .as_ref()]
+                )
+            })?;
+
+        // This env variable is only meant to bypass nonce regeneration during
+        // tests to get determinisic results. It should never be used outside
+        // of testing environments.
+        let nonce = if let Ok(val) = std::env::var("GST_SODIUM_ENCRYPT_NONCE") {
+            let bytes = hex::decode(val).expect("Failed to decode hex variable");
+            assert_eq!(bytes.len(), box_::NONCEBYTES);
+            box_::Nonce::from_slice(&bytes).unwrap()
+        } else {
+            box_::gen_nonce()
+        };
+
+        let precomputed_key = box_::precompute(&receiver_key, &sender_key);
+
+        Ok(Self {
+            adapter: gst_base::UniqueAdapter::new(),
+            precomputed_key,
+            nonce,
+            block_size: props.block_size,
+            write_headers: true,
+        })
+    }
+
+    fn seal(&mut self, message: &[u8]) -> Vec<u8> {
+        let ciphertext = box_::seal_precomputed(message, &self.nonce, &self.precomputed_key);
+        self.nonce.increment_le_inplace();
+        ciphertext
+    }
+
+    fn encrypt_message(&mut self, buffer: &gst::BufferRef) -> gst::Buffer {
+        let map = buffer
+            .map_readable()
+            .expect("Failed to map buffer readable");
+
+        let sealed = self.seal(&map);
+        gst::Buffer::from_mut_slice(sealed)
+    }
+
+    fn encrypt_blocks(&mut self, block_size: usize) -> Result<BufferVec, gst::FlowError> {
+        assert_ne!(block_size, 0);
+
+        let mut buffers = BufferVec::new();
+
+        // As long we have enough bytes to encrypt a block, or more, we do so
+        // else the leftover bytes on the adapter will be pushed when EOS
+        // is sent.
+        while self.adapter.available() >= block_size {
+            let buffer = self.adapter.take_buffer(block_size).unwrap();
+            let out_buf = self.encrypt_message(&buffer);
+
+            buffers.push(out_buf);
+        }
+
+        Ok(buffers)
+    }
+}
+
+pub struct Encrypter {
+    srcpad: gst::Pad,
+    sinkpad: gst::Pad,
+    props: Mutex<Props>,
+    state: Mutex<Option<State>>,
+}
+
+impl Encrypter {
+    fn sink_chain(
+        &self,
+        pad: &gst::Pad,
+        element: &super::Encrypter,
+        buffer: gst::Buffer,
+    ) -> Result<gst::FlowSuccess, gst::FlowError> {
+        gst_log!(CAT, obj: pad, "Handling buffer {:?}", buffer);
+
+        let mut buffers = BufferVec::new();
+        let mut state_guard = self.state.lock().unwrap();
+        let state = state_guard.as_mut().unwrap();
+
+        if state.write_headers {
+            let mut headers = Vec::with_capacity(40);
+            headers.extend_from_slice(crate::TYPEFIND_HEADER);
+            // Write the Nonce used into the stream.
+            headers.extend_from_slice(state.nonce.as_ref());
+            // Write the block_size into the stream
+            headers.extend_from_slice(&state.block_size.to_le_bytes());
+
+            buffers.push(gst::Buffer::from_mut_slice(headers));
+            state.write_headers = false;
+        }
+
+        state.adapter.push(buffer);
+
+        // Encrypt the whole blocks, if any, and push them.
+        buffers.extend(
+            state
+                .encrypt_blocks(state.block_size as usize)
+                .map_err(|err| {
+                    // log the error to the bus
+                    gst_element_error!(
+                        element,
+                        gst::ResourceError::Write,
+                        ["Failed to decrypt buffer"]
+                    );
+                    err
+                })?,
+        );
+
+        drop(state_guard);
+
+        for buffer in buffers {
+            self.srcpad.push(buffer).map_err(|err| {
+                gst_error!(CAT, obj: element, "Failed to push buffer {:?}", err);
+                err
+            })?;
+        }
+
+        Ok(gst::FlowSuccess::Ok)
+    }
+
+    fn sink_event(&self, pad: &gst::Pad, element: &super::Encrypter, event: gst::Event) -> bool {
+        use gst::EventView;
+
+        gst_log!(CAT, obj: pad, "Handling event {:?}", event);
+
+        match event.view() {
+            EventView::Caps(_) => {
+                // We send our own caps downstream
+                let caps = gst::Caps::builder("application/x-sodium-encrypted").build();
+                self.srcpad.push_event(gst::event::Caps::new(&caps))
+            }
+            EventView::Eos(_) => {
+                let mut state_mutex = self.state.lock().unwrap();
+                let mut buffers = BufferVec::new();
+                // This will only be run after READY state,
+                // and will be guaranted to be initialized
+                let state = state_mutex.as_mut().unwrap();
+
+                // Now that all the full size blocks are pushed, drain the
+                // rest of the adapter and push whatever is left.
+                let avail = state.adapter.available();
+                // logic error, all the complete blocks that can be pushed
+                // should have been done in the sink_chain call.
+                assert!(avail < state.block_size as usize);
+
+                if avail > 0 {
+                    match state.encrypt_blocks(avail) {
+                        Err(_) => {
+                            gst_element_error!(
+                                element,
+                                gst::ResourceError::Write,
+                                ["Failed to encrypt buffers at EOS"]
+                            );
+                            return false;
+                        }
+                        Ok(b) => buffers.extend(b),
+                    }
+                }
+
+                // drop the lock before pushing into the pad
+                drop(state_mutex);
+
+                for buffer in buffers {
+                    if let Err(err) = self.srcpad.push(buffer) {
+                        gst_error!(CAT, obj: element, "Failed to push buffer at EOS {:?}", err);
+                        return false;
+                    }
+                }
+
+                pad.event_default(Some(element), event)
+            }
+            _ => pad.event_default(Some(element), event),
+        }
+    }
+
+    fn src_event(&self, pad: &gst::Pad, element: &super::Encrypter, event: gst::Event) -> bool {
+        use gst::EventView;
+
+        gst_log!(CAT, obj: pad, "Handling event {:?}", event);
+
+        match event.view() {
+            EventView::Seek(_) => false,
+            _ => pad.event_default(Some(element), event),
+        }
+    }
+
+    fn src_query(
+        &self,
+        pad: &gst::Pad,
+        element: &super::Encrypter,
+        query: &mut gst::QueryRef,
+    ) -> bool {
+        use gst::QueryView;
+
+        gst_log!(CAT, obj: pad, "Handling query {:?}", query);
+
+        match query.view_mut() {
+            QueryView::Seeking(mut q) => {
+                let format = q.get_format();
+                q.set(
+                    false,
+                    gst::GenericFormattedValue::Other(format, -1),
+                    gst::GenericFormattedValue::Other(format, -1),
+                );
+                gst_log!(CAT, obj: pad, "Returning {:?}", q.get_mut_query());
+                true
+            }
+            QueryView::Duration(ref mut q) => {
+                use std::convert::TryInto;
+
+                if q.get_format() != gst::Format::Bytes {
+                    return pad.query_default(Some(element), query);
+                }
+
+                /* First let's query the bytes duration upstream */
+                let mut peer_query = gst::query::Duration::new(gst::Format::Bytes);
+
+                if !self.sinkpad.peer_query(&mut peer_query) {
+                    gst_error!(CAT, "Failed to query upstream duration");
+                    return false;
+                }
+
+                let size = match peer_query.get_result().try_into().unwrap() {
+                    gst::format::Bytes(Some(size)) => size,
+                    gst::format::Bytes(None) => {
+                        gst_error!(CAT, "Failed to query upstream duration");
+
+                        return false;
+                    }
+                };
+
+                let state = self.state.lock().unwrap();
+                let state = match state.as_ref() {
+                    // If state isn't set, it means that the
+                    // element hasn't been activated yet.
+                    None => return false,
+                    Some(s) => s,
+                };
+
+                // calculate the number of chunks that exist in the stream
+                let total_chunks = (size + state.block_size as u64 - 1) / state.block_size as u64;
+                // add the MAC of each block
+                let size = size + total_chunks * box_::MACBYTES as u64;
+
+                // add static offsets
+                let size = size + crate::HEADERS_SIZE as u64;
+
+                gst_debug!(CAT, obj: pad, "Setting duration bytes: {}", size);
+                q.set(gst::format::Bytes::from(size));
+
+                true
+            }
+            _ => pad.query_default(Some(element), query),
+        }
+    }
+}
+
+impl ObjectSubclass for Encrypter {
+    const NAME: &'static str = "RsSodiumEncrypter";
+    type Type = super::Encrypter;
+    type ParentType = gst::Element;
+    type Instance = gst::subclass::ElementInstanceStruct<Self>;
+    type Class = subclass::simple::ClassStruct<Self>;
+
+    glib_object_subclass!();
+
+    fn with_class(klass: &Self::Class) -> Self {
+        let templ = klass.get_pad_template("sink").unwrap();
+        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+            .chain_function(|pad, parent, buffer| {
+                Encrypter::catch_panic_pad_function(
+                    parent,
+                    || Err(gst::FlowError::Error),
+                    |encrypter, element| encrypter.sink_chain(pad, element, buffer),
+                )
+            })
+            .event_function(|pad, parent, event| {
+                Encrypter::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |encrypter, element| encrypter.sink_event(pad, element, event),
+                )
+            })
+            .build();
+
+        let templ = klass.get_pad_template("src").unwrap();
+        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+            .query_function(|pad, parent, query| {
+                Encrypter::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |encrypter, element| encrypter.src_query(pad, element, query),
+                )
+            })
+            .event_function(|pad, parent, event| {
+                Encrypter::catch_panic_pad_function(
+                    parent,
+                    || false,
+                    |encrypter, element| encrypter.src_event(pad, element, event),
+                )
+            })
+            .build();
+
+        let props = Mutex::new(Props::default());
+        let state = Mutex::new(None);
+
+        Self {
+            srcpad,
+            sinkpad,
+            props,
+            state,
+        }
+    }
+
+    fn class_init(klass: &mut Self::Class) {
+        klass.set_metadata(
+            "Encrypter",
+            "Generic",
+            "libsodium-based file encrypter",
+            "Jordan Petridis <jordan@centricular.com>",
+        );
+
+        let src_caps = gst::Caps::builder("application/x-sodium-encrypted").build();
+        let src_pad_template = gst::PadTemplate::new(
+            "src",
+            gst::PadDirection::Src,
+            gst::PadPresence::Always,
+            &src_caps,
+        )
+        .unwrap();
+        klass.add_pad_template(src_pad_template);
+
+        let sink_pad_template = gst::PadTemplate::new(
+            "sink",
+            gst::PadDirection::Sink,
+            gst::PadPresence::Always,
+            &gst::Caps::new_any(),
+        )
+        .unwrap();
+        klass.add_pad_template(sink_pad_template);
+        klass.install_properties(&PROPERTIES);
+    }
+}
+
+impl ObjectImpl for Encrypter {
+    fn constructed(&self, obj: &Self::Type) {
+        self.parent_constructed(obj);
+
+        obj.add_pad(&self.sinkpad).unwrap();
+        obj.add_pad(&self.srcpad).unwrap();
+    }
+
+    fn set_property(&self, _obj: &Self::Type, id: usize, value: &glib::Value) {
+        let prop = &PROPERTIES[id];
+
+        match *prop {
+            subclass::Property("sender-key", ..) => {
+                let mut props = self.props.lock().unwrap();
+                props.sender_key = value.get().expect("type checked upstream");
+            }
+
+            subclass::Property("receiver-key", ..) => {
+                let mut props = self.props.lock().unwrap();
+                props.receiver_key = value.get().expect("type checked upstream");
+            }
+
+            subclass::Property("block-size", ..) => {
+                let mut props = self.props.lock().unwrap();
+                props.block_size = value.get_some().expect("type checked upstream");
+            }
+
+            _ => unimplemented!(),
+        }
+    }
+
+    fn get_property(&self, _obj: &Self::Type, id: usize) -> Result<glib::Value, ()> {
+        let prop = &PROPERTIES[id];
+
+        match *prop {
+            subclass::Property("receiver-key", ..) => {
+                let props = self.props.lock().unwrap();
+                Ok(props.receiver_key.to_value())
+            }
+
+            subclass::Property("block-size", ..) => {
+                let props = self.props.lock().unwrap();
+                Ok(props.block_size.to_value())
+            }
+
+            _ => unimplemented!(),
+        }
+    }
+}
+
+impl ElementImpl for Encrypter {
+    fn change_state(
+        &self,
+        element: &Self::Type,
+        transition: gst::StateChange,
+    ) -> Result<gst::StateChangeSuccess, gst::StateChangeError> {
+        gst_debug!(CAT, obj: element, "Changing state {:?}", transition);
+
+        match transition {
+            gst::StateChange::NullToReady => {
+                let props = self.props.lock().unwrap().clone();
+
+                // Create an internal state struct from the provided properties or
+                // refuse to change state
+                let state_ = State::from_props(&props).map_err(|err| {
+                    element.post_error_message(err);
+                    gst::StateChangeError
+                })?;
+
+                let mut state = self.state.lock().unwrap();
+                *state = Some(state_);
+            }
+            gst::StateChange::ReadyToNull => {
+                let _ = self.state.lock().unwrap().take();
+            }
+            _ => (),
+        }
+
+        let success = self.parent_change_state(element, transition)?;
+
+        if transition == gst::StateChange::ReadyToNull {
+            let _ = self.state.lock().unwrap().take();
+        }
+
+        Ok(success)
+    }
+}