Don't tie Session's lifetime to the Pkcs11 object.

This commit effective reverts
1994987, which made Session take a
reference to Pkcs11 and removed the inner Arc.

As discussed in
#333 , tying a
Session object to a Pkcs11 object reference can complicate object
management.

Signed-off-by: Neal H. Walfield <neal@sequoia-pgp.org>

Author: nwalfield

cryptoki/src/context/mod.rs

@@ -33,6 +33,7 @@ use crate::error::{Error, Result, Rv};
 use std::fmt;
 use std::path::Path;
 use std::ptr;
+use std::sync::Arc;
 
 /// Enum for various function lists
 /// Each following is super-set of the previous one with overlapping start so we store them
@@ -75,9 +76,9 @@ impl Pkcs11Impl {
 }
 
 /// Main PKCS11 context. Should usually be unique per application.
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct Pkcs11 {
-    pub(crate) impl_: Pkcs11Impl,
+    pub(crate) impl_: Arc<Pkcs11Impl>,
 }
 
 impl Pkcs11 {
@@ -128,19 +129,19 @@ impl Pkcs11 {
                         let list32_ptr: *mut cryptoki_sys::CK_FUNCTION_LIST_3_2 =
                             ifce.pFunctionList as *mut cryptoki_sys::CK_FUNCTION_LIST_3_2;
                         return Ok(Pkcs11 {
-                            impl_: Pkcs11Impl {
+                            impl_: Arc::new(Pkcs11Impl {
                                 _pkcs11_lib: pkcs11_lib,
                                 function_list: FunctionList::V3_2(*list32_ptr),
-                            },
+                            }),
                         });
                     }
                     let list30_ptr: *mut cryptoki_sys::CK_FUNCTION_LIST_3_0 =
                         ifce.pFunctionList as *mut cryptoki_sys::CK_FUNCTION_LIST_3_0;
                     return Ok(Pkcs11 {
-                        impl_: Pkcs11Impl {
+                        impl_: Arc::new(Pkcs11Impl {
                             _pkcs11_lib: pkcs11_lib,
                             function_list: FunctionList::V3_0(v30tov32(*list30_ptr)),
-                        },
+                        }),
                     });
                 }
                 /* fall back to the 2.* API */
@@ -152,10 +153,10 @@ impl Pkcs11 {
             .into_result(Function::GetFunctionList)?;
 
         Ok(Pkcs11 {
-            impl_: Pkcs11Impl {
+            impl_: Arc::new(Pkcs11Impl {
                 _pkcs11_lib: pkcs11_lib,
                 function_list: FunctionList::V2(v2tov3(*list_ptr)),
-            },
+            }),
         })
     }
 

cryptoki/src/context/session_management.rs

@@ -13,7 +13,7 @@ use super::Function;
 
 impl Pkcs11 {
     #[inline(always)]
-    fn open_session(&self, slot_id: Slot, read_write: bool) -> Result<Session<'_>> {
+    fn open_session(&self, slot_id: Slot, read_write: bool) -> Result<Session> {
         let mut session_handle = 0;
 
         let flags = if read_write {
@@ -33,7 +33,7 @@ impl Pkcs11 {
             .into_result(Function::OpenSession)?;
         }
 
-        Ok(Session::new(session_handle, self))
+        Ok(Session::new(session_handle, self.clone()))
     }
 
     /// Open a new Read-Only session
@@ -62,14 +62,14 @@ impl Pkcs11 {
     /// let session = client.open_ro_session(slot)?;
     /// # let _ = session; Ok(()) }
     /// ```
-    pub fn open_ro_session(&self, slot_id: Slot) -> Result<Session<'_>> {
+    pub fn open_ro_session(&self, slot_id: Slot) -> Result<Session> {
         self.open_session(slot_id, false)
     }
 
     /// Open a new Read/Write session
     ///
     /// Note: No callback is set when opening the session.
-    pub fn open_rw_session(&self, slot_id: Slot) -> Result<Session<'_>> {
+    pub fn open_rw_session(&self, slot_id: Slot) -> Result<Session> {
         self.open_session(slot_id, true)
     }
 }

cryptoki/src/session/decryption.rs

@@ -10,7 +10,7 @@ use crate::session::Session;
 use cryptoki_sys::*;
 use std::convert::TryInto;
 
-impl Session<'_> {
+impl Session {
     /// Single-part decryption operation
     pub fn decrypt(
         &self,

cryptoki/src/session/digesting.rs

@@ -10,7 +10,7 @@ use crate::session::Session;
 use cryptoki_sys::*;
 use std::convert::TryInto;
 
-impl Session<'_> {
+impl Session {
     /// Single-part digesting operation
     pub fn digest(&self, m: &Mechanism, data: &[u8]) -> Result<Vec<u8>> {
         let mut mechanism: CK_MECHANISM = m.into();

cryptoki/src/session/encapsulation.rs

@@ -10,7 +10,7 @@ use crate::session::Session;
 use cryptoki_sys::*;
 use std::convert::TryInto;
 
-impl Session<'_> {
+impl Session {
     /// Encapsulate key
     pub fn encapsulate_key(
         &self,

cryptoki/src/session/encryption.rs

@@ -10,7 +10,7 @@ use crate::session::Session;
 use cryptoki_sys::*;
 use std::convert::TryInto;
 
-impl Session<'_> {
+impl Session {
     /// Single-part encryption operation
     pub fn encrypt(
         &self,

cryptoki/src/session/key_management.rs

@@ -10,7 +10,7 @@ use crate::session::Session;
 use cryptoki_sys::{CK_ATTRIBUTE, CK_MECHANISM, CK_MECHANISM_PTR};
 use std::convert::TryInto;
 
-impl Session<'_> {
+impl Session {
     /// Generate a secret key
     pub fn generate_key(
         &self,

cryptoki/src/session/message_decryption.rs

@@ -10,7 +10,7 @@ use crate::session::Session;
 use cryptoki_sys::*;
 use std::convert::TryInto;
 
-impl Session<'_> {
+impl Session {
     /// Prepare a session for one or more Message-based decryption using the same mechanism and key
     pub fn message_decrypt_init(&self, mechanism: &Mechanism, key: ObjectHandle) -> Result<()> {
         let mut mechanism: CK_MECHANISM = mechanism.into();

cryptoki/src/session/message_encryption.rs

@@ -10,7 +10,7 @@ use crate::session::Session;
 use cryptoki_sys::*;
 use std::convert::TryInto;
 
-impl Session<'_> {
+impl Session {
     /// Prepare a session for one or more Message-based encryption using the same mechanism and key
     pub fn message_encrypt_init(&self, mechanism: &Mechanism, key: ObjectHandle) -> Result<()> {
         let mut mechanism: CK_MECHANISM = mechanism.into();

cryptoki/src/session/mod.rs

@@ -35,33 +35,33 @@ pub use validation::ValidationFlagsType;
 /// threads. A Session needs to be created in its own thread or to be passed by ownership to
 /// another thread.
 #[derive(Debug)]
-pub struct Session<'a> {
+pub struct Session {
     handle: CK_SESSION_HANDLE,
-    client: &'a Pkcs11,
+    client: Pkcs11,
     // This is not used but to prevent Session to automatically implement Send and Sync
     _guard: PhantomData<*mut u32>,
 }
 
-impl<'a> std::fmt::Display for Session<'a> {
+impl std::fmt::Display for Session {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}", self.handle)
     }
 }
 
-impl<'a> std::fmt::LowerHex for Session<'a> {
+impl std::fmt::LowerHex for Session {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         write!(f, "{:08x}", self.handle)
     }
 }
 
-impl<'a> std::fmt::UpperHex for Session<'a> {
+impl std::fmt::UpperHex for Session {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         write!(f, "{:08X}", self.handle)
     }
 }
 
-impl<'a> Session<'a> {
-    pub(crate) fn new(handle: CK_SESSION_HANDLE, client: &'a Pkcs11) -> Self {
+impl Session {
+    pub(crate) fn new(handle: CK_SESSION_HANDLE, client: Pkcs11) -> Self {
         Session {
             handle,
             client,
@@ -70,7 +70,7 @@ impl<'a> Session<'a> {
     }
 }
 
-impl<'a> Session<'a> {
+impl Session {
     /// Close a session
     /// This will be called on drop as well.
     pub fn close(self) -> Result<()> {
@@ -83,7 +83,7 @@ impl<'a> Session<'a> {
     }
 
     pub(crate) fn client(&self) -> &Pkcs11 {
-        self.client
+        &self.client
     }
 }