openpgp: Make conversions into Key<SecretParts, _> fallible.

  - Fixes #380.

3 files changed, 30 insertions, 2 deletions

diff --git a/openpgp-ffi/src/common.rs b/openpgp-ffi/src/common.rs
index 078c035e..7c615bab 100644
--- a/openpgp-ffi/src/common.rs
+++ b/openpgp-ffi/src/common.rs
@@ -164,6 +164,30 @@ macro_rules! ffi_make_fry_from_errp {
 
         /// Like try! for ffi glue.
         ///
+        /// Evaluates the given expression.  `Ok(v)` evaluates to `v`.
+        /// On failure, stashes the error in the context and returns
+        /// the appropriate Status code.
+        #[allow(unused_macros)]
+        macro_rules! ffi_try_or_status {
+            ($expr:expr) => {
+                match $expr {
+                    Ok(v) => v,
+                    Err(e) => {
+                        use crate::MoveIntoRaw;
+                        use failure::Error;
+                        let status = crate::error::Status::from(&e);
+                        if let Some(errp) = $errp {
+                            let e : Error = e.into();
+                            *errp = e.move_into_raw();
+                        }
+                        return status;
+                    },
+                }
+            };
+        }
+
+        /// Like try! for ffi glue.
+        ///
         /// Unwraps the given expression.  On failure, stashes the
         /// error in the context and returns $or.
         #[allow(unused_macros)]
diff --git a/openpgp-ffi/src/packet/key.rs b/openpgp-ffi/src/packet/key.rs
index e0eead22..7f08d040 100644
--- a/openpgp-ffi/src/packet/key.rs
+++ b/openpgp-ffi/src/packet/key.rs
@@ -4,6 +4,8 @@
 //!
 //!   [Section 5.5 of RFC 4880]: https://tools.ietf.org/html/rfc4880#section-5.5
 
+use std::convert::TryInto;
+
 use libc::{c_int, time_t};
 
 extern crate sequoia_openpgp as openpgp;
@@ -79,6 +81,6 @@ fn pgp_key_into_key_pair(errp: Option<&mut *mut crate::error::Error>,
 {
     ffi_make_fry_from_errp!(errp);
     let key : self::openpgp::packet::key::UnspecifiedSecret
-        = key.move_from_raw().into();
+        = ffi_try!(key.move_from_raw().try_into());
     ffi_try_box!(key.into_keypair())
 }
diff --git a/openpgp-ffi/src/packet/pkesk.rs b/openpgp-ffi/src/packet/pkesk.rs
index 8f844d6c..82227065 100644
--- a/openpgp-ffi/src/packet/pkesk.rs
+++ b/openpgp-ffi/src/packet/pkesk.rs
@@ -44,7 +44,9 @@ pub extern "C" fn pgp_pkesk_decrypt(errp: Option<&mut *mut crate::error::Error>,
     let algo = ffi_param_ref_mut!(algo);
     let key_len = ffi_param_ref_mut!(key_len);
 
-    match secret_key.clone().mark_parts_secret().into_keypair() {
+    match ffi_try_or_status!(secret_key.clone().mark_parts_secret())
+        .into_keypair()
+    {
         Ok(mut keypair) => {
             match pkesk.decrypt(&mut keypair) {
                 Ok((a, k)) => {