Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 671 insertions, 0 deletions

diff --git a/security/manager/ssl/rsclientcerts/src/manager.rs b/security/manager/ssl/rsclientcerts/src/manager.rs
new file mode 100644
index 0000000000..507bed3a83
--- /dev/null
+++ b/security/manager/ssl/rsclientcerts/src/manager.rs
@@ -0,0 +1,671 @@
+/* -*- Mode: rust; rust-indent-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use pkcs11_bindings::*;
+use std::collections::{BTreeMap, BTreeSet};
+use std::sync::mpsc::{channel, Receiver, Sender};
+use std::thread;
+use std::thread::JoinHandle;
+use std::time::{Duration, Instant};
+
+use crate::error::{Error, ErrorType};
+use crate::error_here;
+use crate::util::*;
+
+/// Helper enum to differentiate between sessions on the modern slot and sessions on the legacy
+/// slot. The former is for EC keys and RSA keys that can be used with RSA-PSS whereas the latter is
+/// for RSA keys that cannot be used with RSA-PSS.
+#[derive(Clone, Copy, PartialEq)]
+pub enum SlotType {
+    Modern,
+    Legacy,
+}
+
+pub trait CryptokiObject {
+    fn matches(&self, slot_type: SlotType, attrs: &[(CK_ATTRIBUTE_TYPE, Vec<u8>)]) -> bool;
+    fn get_attribute(&self, attribute: CK_ATTRIBUTE_TYPE) -> Option<&[u8]>;
+}
+
+pub trait Sign {
+    fn get_signature_length(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<usize, Error>;
+    fn sign(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<Vec<u8>, Error>;
+}
+
+pub trait ClientCertsBackend {
+    type Cert: CryptokiObject;
+    type Key: CryptokiObject + Sign;
+
+    #[allow(clippy::type_complexity)]
+    fn find_objects(&self) -> Result<(Vec<Self::Cert>, Vec<Self::Key>), Error>;
+}
+
+/// Helper type for sending `ManagerArguments` to the real `Manager`.
+type ManagerArgumentsSender = Sender<ManagerArguments>;
+/// Helper type for receiving `ManagerReturnValue`s from the real `Manager`.
+type ManagerReturnValueReceiver = Receiver<ManagerReturnValue>;
+
+/// Helper enum that encapsulates arguments to send from the `ManagerProxy` to the real `Manager`.
+/// `ManagerArguments::Stop` is a special variant that stops the background thread and drops the
+/// `Manager`.
+enum ManagerArguments {
+    OpenSession(SlotType),
+    CloseSession(CK_SESSION_HANDLE),
+    CloseAllSessions(SlotType),
+    StartSearch(CK_SESSION_HANDLE, Vec<(CK_ATTRIBUTE_TYPE, Vec<u8>)>),
+    Search(CK_SESSION_HANDLE, usize),
+    ClearSearch(CK_SESSION_HANDLE),
+    GetAttributes(CK_OBJECT_HANDLE, Vec<CK_ATTRIBUTE_TYPE>),
+    StartSign(
+        CK_SESSION_HANDLE,
+        CK_OBJECT_HANDLE,
+        Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ),
+    GetSignatureLength(CK_SESSION_HANDLE, Vec<u8>),
+    Sign(CK_SESSION_HANDLE, Vec<u8>),
+    Stop,
+}
+
+/// Helper enum that encapsulates return values from the real `Manager` that are sent back to the
+/// `ManagerProxy`. `ManagerReturnValue::Stop` is a special variant that indicates that the
+/// `Manager` will stop.
+enum ManagerReturnValue {
+    OpenSession(Result<CK_SESSION_HANDLE, Error>),
+    CloseSession(Result<(), Error>),
+    CloseAllSessions(Result<(), Error>),
+    StartSearch(Result<(), Error>),
+    Search(Result<Vec<CK_OBJECT_HANDLE>, Error>),
+    ClearSearch(Result<(), Error>),
+    GetAttributes(Result<Vec<Option<Vec<u8>>>, Error>),
+    StartSign(Result<(), Error>),
+    GetSignatureLength(Result<usize, Error>),
+    Sign(Result<Vec<u8>, Error>),
+    Stop(Result<(), Error>),
+}
+
+/// Helper macro to implement the body of each public `ManagerProxy` function. Takes a
+/// `ManagerProxy` instance (should always be `self`), a `ManagerArguments` representing the
+/// `Manager` function to call and the arguments to use, and the qualified type of the expected
+/// `ManagerReturnValue` that will be received from the `Manager` when it is done.
+macro_rules! manager_proxy_fn_impl {
+    ($manager:ident, $argument_enum:expr, $return_type:path) => {
+        match $manager.proxy_call($argument_enum) {
+            Ok($return_type(result)) => result,
+            Ok(_) => Err(error_here!(ErrorType::LibraryFailure)),
+            Err(e) => Err(e),
+        }
+    };
+}
+
+/// `ManagerProxy` synchronously proxies calls from any thread to the `Manager` that runs on a
+/// single thread. This is necessary because the underlying OS APIs in use are not guaranteed to be
+/// thread-safe (e.g. they may use thread-local storage). Using it should be identical to using the
+/// real `Manager`.
+pub struct ManagerProxy {
+    sender: ManagerArgumentsSender,
+    receiver: ManagerReturnValueReceiver,
+    thread_handle: Option<JoinHandle<()>>,
+}
+
+impl ManagerProxy {
+    pub fn new<B: ClientCertsBackend + Send + 'static>(backend: B) -> Result<ManagerProxy, Error> {
+        let (proxy_sender, manager_receiver) = channel();
+        let (manager_sender, proxy_receiver) = channel();
+        let thread_handle = thread::Builder::new()
+            .name("osclientcert".into())
+            .spawn(move || {
+                let mut real_manager = Manager::new(backend);
+                while let Ok(arguments) = manager_receiver.recv() {
+                    let results = match arguments {
+                        ManagerArguments::OpenSession(slot_type) => {
+                            ManagerReturnValue::OpenSession(real_manager.open_session(slot_type))
+                        }
+                        ManagerArguments::CloseSession(session_handle) => {
+                            ManagerReturnValue::CloseSession(
+                                real_manager.close_session(session_handle),
+                            )
+                        }
+                        ManagerArguments::CloseAllSessions(slot_type) => {
+                            ManagerReturnValue::CloseAllSessions(
+                                real_manager.close_all_sessions(slot_type),
+                            )
+                        }
+                        ManagerArguments::StartSearch(session, attrs) => {
+                            ManagerReturnValue::StartSearch(
+                                real_manager.start_search(session, attrs),
+                            )
+                        }
+                        ManagerArguments::Search(session, max_objects) => {
+                            ManagerReturnValue::Search(real_manager.search(session, max_objects))
+                        }
+                        ManagerArguments::ClearSearch(session) => {
+                            ManagerReturnValue::ClearSearch(real_manager.clear_search(session))
+                        }
+                        ManagerArguments::GetAttributes(object_handle, attr_types) => {
+                            ManagerReturnValue::GetAttributes(
+                                real_manager.get_attributes(object_handle, attr_types),
+                            )
+                        }
+                        ManagerArguments::StartSign(session, key_handle, params) => {
+                            ManagerReturnValue::StartSign(
+                                real_manager.start_sign(session, key_handle, params),
+                            )
+                        }
+                        ManagerArguments::GetSignatureLength(session, data) => {
+                            ManagerReturnValue::GetSignatureLength(
+                                real_manager.get_signature_length(session, data),
+                            )
+                        }
+                        ManagerArguments::Sign(session, data) => {
+                            ManagerReturnValue::Sign(real_manager.sign(session, data))
+                        }
+                        ManagerArguments::Stop => ManagerReturnValue::Stop(Ok(())),
+                    };
+                    let stop_after_send = matches!(&results, &ManagerReturnValue::Stop(_));
+                    match manager_sender.send(results) {
+                        Ok(()) => {}
+                        Err(_) => {
+                            break;
+                        }
+                    }
+                    if stop_after_send {
+                        break;
+                    }
+                }
+            });
+        match thread_handle {
+            Ok(thread_handle) => Ok(ManagerProxy {
+                sender: proxy_sender,
+                receiver: proxy_receiver,
+                thread_handle: Some(thread_handle),
+            }),
+            Err(_) => Err(error_here!(ErrorType::LibraryFailure)),
+        }
+    }
+
+    fn proxy_call(&self, args: ManagerArguments) -> Result<ManagerReturnValue, Error> {
+        match self.sender.send(args) {
+            Ok(()) => {}
+            Err(_) => {
+                return Err(error_here!(ErrorType::LibraryFailure));
+            }
+        };
+        let result = match self.receiver.recv() {
+            Ok(result) => result,
+            Err(_) => {
+                return Err(error_here!(ErrorType::LibraryFailure));
+            }
+        };
+        Ok(result)
+    }
+
+    pub fn open_session(&mut self, slot_type: SlotType) -> Result<CK_SESSION_HANDLE, Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::OpenSession(slot_type),
+            ManagerReturnValue::OpenSession
+        )
+    }
+
+    pub fn close_session(&mut self, session: CK_SESSION_HANDLE) -> Result<(), Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::CloseSession(session),
+            ManagerReturnValue::CloseSession
+        )
+    }
+
+    pub fn close_all_sessions(&mut self, slot_type: SlotType) -> Result<(), Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::CloseAllSessions(slot_type),
+            ManagerReturnValue::CloseAllSessions
+        )
+    }
+
+    pub fn start_search(
+        &mut self,
+        session: CK_SESSION_HANDLE,
+        attrs: Vec<(CK_ATTRIBUTE_TYPE, Vec<u8>)>,
+    ) -> Result<(), Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::StartSearch(session, attrs),
+            ManagerReturnValue::StartSearch
+        )
+    }
+
+    pub fn search(
+        &mut self,
+        session: CK_SESSION_HANDLE,
+        max_objects: usize,
+    ) -> Result<Vec<CK_OBJECT_HANDLE>, Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::Search(session, max_objects),
+            ManagerReturnValue::Search
+        )
+    }
+
+    pub fn clear_search(&mut self, session: CK_SESSION_HANDLE) -> Result<(), Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::ClearSearch(session),
+            ManagerReturnValue::ClearSearch
+        )
+    }
+
+    pub fn get_attributes(
+        &self,
+        object_handle: CK_OBJECT_HANDLE,
+        attr_types: Vec<CK_ATTRIBUTE_TYPE>,
+    ) -> Result<Vec<Option<Vec<u8>>>, Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::GetAttributes(object_handle, attr_types,),
+            ManagerReturnValue::GetAttributes
+        )
+    }
+
+    pub fn start_sign(
+        &mut self,
+        session: CK_SESSION_HANDLE,
+        key_handle: CK_OBJECT_HANDLE,
+        params: Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<(), Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::StartSign(session, key_handle, params),
+            ManagerReturnValue::StartSign
+        )
+    }
+
+    pub fn get_signature_length(
+        &self,
+        session: CK_SESSION_HANDLE,
+        data: Vec<u8>,
+    ) -> Result<usize, Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::GetSignatureLength(session, data),
+            ManagerReturnValue::GetSignatureLength
+        )
+    }
+
+    pub fn sign(&mut self, session: CK_SESSION_HANDLE, data: Vec<u8>) -> Result<Vec<u8>, Error> {
+        manager_proxy_fn_impl!(
+            self,
+            ManagerArguments::Sign(session, data),
+            ManagerReturnValue::Sign
+        )
+    }
+
+    pub fn stop(&mut self) -> Result<(), Error> {
+        manager_proxy_fn_impl!(self, ManagerArguments::Stop, ManagerReturnValue::Stop)?;
+        let thread_handle = match self.thread_handle.take() {
+            Some(thread_handle) => thread_handle,
+            None => return Err(error_here!(ErrorType::LibraryFailure)),
+        };
+        thread_handle
+            .join()
+            .map_err(|_| error_here!(ErrorType::LibraryFailure))
+    }
+}
+
+// Determines if the attributes of a given search correspond to NSS looking for all certificates or
+// private keys. Returns true if so, and false otherwise.
+// These searches are of the form:
+//   { { type: CKA_TOKEN, value: [1] },
+//     { type: CKA_CLASS, value: [CKO_CERTIFICATE or CKO_PRIVATE_KEY, as serialized bytes] } }
+// (although not necessarily in that order - see nssToken_TraverseCertificates and
+// nssToken_FindPrivateKeys)
+fn search_is_for_all_certificates_or_keys(
+    attrs: &[(CK_ATTRIBUTE_TYPE, Vec<u8>)],
+) -> Result<bool, Error> {
+    if attrs.len() != 2 {
+        return Ok(false);
+    }
+    let token_bytes = vec![1_u8];
+    let mut found_token = false;
+    let cko_certificate_bytes = serialize_uint(CKO_CERTIFICATE)?;
+    let cko_private_key_bytes = serialize_uint(CKO_PRIVATE_KEY)?;
+    let mut found_certificate_or_private_key = false;
+    for (attr_type, attr_value) in attrs.iter() {
+        if attr_type == &CKA_TOKEN && attr_value == &token_bytes {
+            found_token = true;
+        }
+        if attr_type == &CKA_CLASS
+            && (attr_value == &cko_certificate_bytes || attr_value == &cko_private_key_bytes)
+        {
+            found_certificate_or_private_key = true;
+        }
+    }
+    Ok(found_token && found_certificate_or_private_key)
+}
+
+const SUPPORTED_ATTRIBUTES: &[CK_ATTRIBUTE_TYPE] = &[
+    CKA_CLASS,
+    CKA_TOKEN,
+    CKA_LABEL,
+    CKA_ID,
+    CKA_VALUE,
+    CKA_ISSUER,
+    CKA_SERIAL_NUMBER,
+    CKA_SUBJECT,
+    CKA_PRIVATE,
+    CKA_KEY_TYPE,
+    CKA_MODULUS,
+    CKA_EC_PARAMS,
+];
+
+enum Object<B: ClientCertsBackend> {
+    Cert(B::Cert),
+    Key(B::Key),
+}
+
+impl<B: ClientCertsBackend> Object<B> {
+    fn matches(&self, slot_type: SlotType, attrs: &[(CK_ATTRIBUTE_TYPE, Vec<u8>)]) -> bool {
+        match self {
+            Object::Cert(cert) => cert.matches(slot_type, attrs),
+            Object::Key(key) => key.matches(slot_type, attrs),
+        }
+    }
+
+    fn get_attribute(&self, attribute: CK_ATTRIBUTE_TYPE) -> Option<&[u8]> {
+        match self {
+            Object::Cert(cert) => cert.get_attribute(attribute),
+            Object::Key(key) => key.get_attribute(attribute),
+        }
+    }
+
+    fn id(&self) -> Result<&[u8], Error> {
+        self.get_attribute(CKA_ID)
+            .ok_or_else(|| error_here!(ErrorType::LibraryFailure))
+    }
+
+    fn get_signature_length(
+        &mut self,
+        data: Vec<u8>,
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<usize, Error> {
+        match self {
+            Object::Cert(_) => Err(error_here!(ErrorType::InvalidArgument)),
+            Object::Key(key) => key.get_signature_length(&data, params),
+        }
+    }
+
+    fn sign(
+        &mut self,
+        data: Vec<u8>,
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<Vec<u8>, Error> {
+        match self {
+            Object::Cert(_) => Err(error_here!(ErrorType::InvalidArgument)),
+            Object::Key(key) => key.sign(&data, params),
+        }
+    }
+}
+
+/// The `Manager` keeps track of the state of this module with respect to the PKCS #11
+/// specification. This includes what sessions are open, which search and sign operations are
+/// ongoing, and what objects are known and by what handle.
+pub struct Manager<B: ClientCertsBackend> {
+    /// A map of session to session type (modern or legacy). Sessions can be created (opened) and
+    /// later closed.
+    sessions: BTreeMap<CK_SESSION_HANDLE, SlotType>,
+    /// A map of searches to PKCS #11 object handles that match those searches.
+    searches: BTreeMap<CK_SESSION_HANDLE, Vec<CK_OBJECT_HANDLE>>,
+    /// A map of sign operations to a pair of the object handle and optionally some params being
+    /// used by each one.
+    signs: BTreeMap<CK_SESSION_HANDLE, (CK_OBJECT_HANDLE, Option<CK_RSA_PKCS_PSS_PARAMS>)>,
+    /// A map of object handles to the underlying objects.
+    objects: BTreeMap<CK_OBJECT_HANDLE, Object<B>>,
+    /// A set of certificate identifiers (not the same as handles).
+    cert_ids: BTreeSet<Vec<u8>>,
+    /// A set of key identifiers (not the same as handles). For each id in this set, there should be
+    /// a corresponding identical id in the `cert_ids` set.
+    key_ids: BTreeSet<Vec<u8>>,
+    /// The next session handle to hand out.
+    next_session: CK_SESSION_HANDLE,
+    /// The next object handle to hand out.
+    next_handle: CK_OBJECT_HANDLE,
+    /// The last time the implementation looked for new objects in the backend.
+    /// The implementation does this search no more than once every 3 seconds.
+    last_scan_time: Option<Instant>,
+    backend: B,
+}
+
+impl<B: ClientCertsBackend> Manager<B> {
+    pub fn new(backend: B) -> Manager<B> {
+        Manager {
+            sessions: BTreeMap::new(),
+            searches: BTreeMap::new(),
+            signs: BTreeMap::new(),
+            objects: BTreeMap::new(),
+            cert_ids: BTreeSet::new(),
+            key_ids: BTreeSet::new(),
+            next_session: 1,
+            next_handle: 1,
+            last_scan_time: None,
+            backend,
+        }
+    }
+
+    /// When a new search session is opened (provided at least 3 seconds have elapsed since the
+    /// last session was opened), this searches for certificates and keys to expose. We
+    /// de-duplicate previously-found certificates and keys by keeping track of their IDs.
+    fn maybe_find_new_objects(&mut self) -> Result<(), Error> {
+        let now = Instant::now();
+        match self.last_scan_time {
+            Some(last_scan_time) => {
+                if now.duration_since(last_scan_time) < Duration::new(3, 0) {
+                    return Ok(());
+                }
+            }
+            None => {}
+        }
+        self.last_scan_time = Some(now);
+        let (certs, keys) = self.backend.find_objects()?;
+        for cert in certs {
+            let object = Object::Cert(cert);
+            if self.cert_ids.contains(object.id()?) {
+                continue;
+            }
+            self.cert_ids.insert(object.id()?.to_vec());
+            let handle = self.get_next_handle();
+            self.objects.insert(handle, object);
+        }
+        for key in keys {
+            let object = Object::Key(key);
+            if self.key_ids.contains(object.id()?) {
+                continue;
+            }
+            self.key_ids.insert(object.id()?.to_vec());
+            let handle = self.get_next_handle();
+            self.objects.insert(handle, object);
+        }
+        Ok(())
+    }
+
+    pub fn open_session(&mut self, slot_type: SlotType) -> Result<CK_SESSION_HANDLE, Error> {
+        let next_session = self.next_session;
+        self.next_session += 1;
+        self.sessions.insert(next_session, slot_type);
+        Ok(next_session)
+    }
+
+    pub fn close_session(&mut self, session: CK_SESSION_HANDLE) -> Result<(), Error> {
+        self.sessions
+            .remove(&session)
+            .ok_or_else(|| error_here!(ErrorType::InvalidInput))
+            .map(|_| ())
+    }
+
+    pub fn close_all_sessions(&mut self, slot_type: SlotType) -> Result<(), Error> {
+        let mut to_remove = Vec::new();
+        for (session, open_slot_type) in self.sessions.iter() {
+            if slot_type == *open_slot_type {
+                to_remove.push(*session);
+            }
+        }
+        for session in to_remove {
+            if self.sessions.remove(&session).is_none() {
+                return Err(error_here!(ErrorType::LibraryFailure));
+            }
+        }
+        Ok(())
+    }
+
+    fn get_next_handle(&mut self) -> CK_OBJECT_HANDLE {
+        let next_handle = self.next_handle;
+        self.next_handle += 1;
+        next_handle
+    }
+
+    /// PKCS #11 specifies that search operations happen in three phases: setup, get any matches
+    /// (this part may be repeated if the caller uses a small buffer), and end. This implementation
+    /// does all of the work up front and gathers all matching objects during setup and retains them
+    /// until they are retrieved and consumed via `search`.
+    pub fn start_search(
+        &mut self,
+        session: CK_SESSION_HANDLE,
+        attrs: Vec<(CK_ATTRIBUTE_TYPE, Vec<u8>)>,
+    ) -> Result<(), Error> {
+        let slot_type = match self.sessions.get(&session) {
+            Some(slot_type) => *slot_type,
+            None => return Err(error_here!(ErrorType::InvalidArgument)),
+        };
+        // If the search is for an attribute we don't support, no objects will match. This check
+        // saves us having to look through all of our objects.
+        for (attr, _) in &attrs {
+            if !SUPPORTED_ATTRIBUTES.contains(attr) {
+                self.searches.insert(session, Vec::new());
+                return Ok(());
+            }
+        }
+        // When NSS wants to find all certificates or all private keys, it will perform a search
+        // with a particular set of attributes. This implementation uses these searches as an
+        // indication for the backend to re-scan for new objects from tokens that may have been
+        // inserted or certificates that may have been imported into the OS. Since these searches
+        // are relatively rare, this minimizes the impact of doing these re-scans.
+        if search_is_for_all_certificates_or_keys(&attrs)? {
+            self.maybe_find_new_objects()?;
+        }
+        let mut handles = Vec::new();
+        for (handle, object) in &self.objects {
+            if object.matches(slot_type, &attrs) {
+                handles.push(*handle);
+            }
+        }
+        self.searches.insert(session, handles);
+        Ok(())
+    }
+
+    /// Given a session and a maximum number of object handles to return, attempts to retrieve up to
+    /// that many objects from the corresponding search. Updates the search so those objects are not
+    /// returned repeatedly. `max_objects` must be non-zero.
+    pub fn search(
+        &mut self,
+        session: CK_SESSION_HANDLE,
+        max_objects: usize,
+    ) -> Result<Vec<CK_OBJECT_HANDLE>, Error> {
+        if max_objects == 0 {
+            return Err(error_here!(ErrorType::InvalidArgument));
+        }
+        match self.searches.get_mut(&session) {
+            Some(search) => {
+                let split_at = if max_objects >= search.len() {
+                    0
+                } else {
+                    search.len() - max_objects
+                };
+                let to_return = search.split_off(split_at);
+                if to_return.len() > max_objects {
+                    return Err(error_here!(ErrorType::LibraryFailure));
+                }
+                Ok(to_return)
+            }
+            None => Err(error_here!(ErrorType::InvalidArgument)),
+        }
+    }
+
+    pub fn clear_search(&mut self, session: CK_SESSION_HANDLE) -> Result<(), Error> {
+        self.searches.remove(&session);
+        Ok(())
+    }
+
+    pub fn get_attributes(
+        &self,
+        object_handle: CK_OBJECT_HANDLE,
+        attr_types: Vec<CK_ATTRIBUTE_TYPE>,
+    ) -> Result<Vec<Option<Vec<u8>>>, Error> {
+        let object = match self.objects.get(&object_handle) {
+            Some(object) => object,
+            None => return Err(error_here!(ErrorType::InvalidArgument)),
+        };
+        let mut results = Vec::with_capacity(attr_types.len());
+        for attr_type in attr_types {
+            let result = object
+                .get_attribute(attr_type)
+                .map(|value| value.to_owned());
+            results.push(result);
+        }
+        Ok(results)
+    }
+
+    /// The way NSS uses PKCS #11 to sign data happens in two phases: setup and sign. This
+    /// implementation makes a note of which key is to be used (if it exists) during setup. When the
+    /// caller finishes with the sign operation, this implementation retrieves the key handle and
+    /// performs the signature.
+    pub fn start_sign(
+        &mut self,
+        session: CK_SESSION_HANDLE,
+        key_handle: CK_OBJECT_HANDLE,
+        params: Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<(), Error> {
+        if self.signs.contains_key(&session) {
+            return Err(error_here!(ErrorType::InvalidArgument));
+        }
+        self.signs.insert(session, (key_handle, params));
+        Ok(())
+    }
+
+    pub fn get_signature_length(
+        &mut self,
+        session: CK_SESSION_HANDLE,
+        data: Vec<u8>,
+    ) -> Result<usize, Error> {
+        let (key_handle, params) = match self.signs.get(&session) {
+            Some((key_handle, params)) => (key_handle, params),
+            None => return Err(error_here!(ErrorType::InvalidArgument)),
+        };
+        let key = match self.objects.get_mut(key_handle) {
+            Some(key) => key,
+            None => return Err(error_here!(ErrorType::InvalidArgument)),
+        };
+        key.get_signature_length(data, params)
+    }
+
+    pub fn sign(&mut self, session: CK_SESSION_HANDLE, data: Vec<u8>) -> Result<Vec<u8>, Error> {
+        // Performing the signature (via C_Sign, which is the only way we support) finishes the sign
+        // operation, so it needs to be removed here.
+        let (key_handle, params) = match self.signs.remove(&session) {
+            Some((key_handle, params)) => (key_handle, params),
+            None => return Err(error_here!(ErrorType::InvalidArgument)),
+        };
+        let key = match self.objects.get_mut(&key_handle) {
+            Some(key) => key,
+            None => return Err(error_here!(ErrorType::InvalidArgument)),
+        };
+        key.sign(data, &params)
+    }
+}