From 7243d7151d204637ed226242b42348ad44b43f9b Mon Sep 17 00:00:00 2001
From: Isis Lovecruft <isis@patternsinthevoid.net>
Date: Thu, 16 Jul 2020 22:19:40 +0000
Subject: [PATCH] Fix handling of external error types.

---
 src/errors.rs    |  5 ++++-
 src/keypair.rs   | 27 ++++++++++++++++++++-------
 src/secret.rs    |  2 +-
 tests/ed25519.rs |  6 +++---
 4 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/src/errors.rs b/src/errors.rs
index 8a35093..3194737 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -45,6 +45,9 @@ pub(crate) enum InternalError {
     PrehashedContextLengthError,
 }
 
+unsafe impl Send for InternalError {}
+unsafe impl Sync for InternalError {}
+
 impl Display for InternalError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
@@ -61,7 +64,7 @@ impl Display for InternalError {
                                              name_c: nc, length_c: lc, }
                 => write!(f, "Arrays must be the same length: {} has length {},
                               {} has length {}, {} has length {}.", na, la, nb, lb, nc, lc),
-            InternalError::PrehashedContextError
+            InternalError::PrehashedContextLengthError
                 => write!(f, "An ed25519ph signature can only take up to 255 octets of context"),
         }
     }
diff --git a/src/keypair.rs b/src/keypair.rs
index ae242d1..e4f2a4f 100644
--- a/src/keypair.rs
+++ b/src/keypair.rs
@@ -207,11 +207,11 @@ impl Keypair {
     /// # use ed25519_dalek::Digest;
     /// # use ed25519_dalek::Keypair;
     /// # use ed25519_dalek::Signature;
+    /// # use ed25519_dalek::SignatureError;
     /// # use ed25519_dalek::Sha512;
     /// # use rand::rngs::OsRng;
     /// #
-    /// # #[cfg(feature = "std")]
-    /// # fn main() {
+    /// # fn do_test() -> Result<Signature, SignatureError> {
     /// # let mut csprng = OsRng{};
     /// # let keypair: Keypair = Keypair::generate(&mut csprng);
     /// # let message: &[u8] = b"All I want is to pet all of the dogs.";
@@ -220,7 +220,13 @@ impl Keypair {
     /// #
     /// let context: &[u8] = b"Ed25519DalekSignPrehashedDoctest";
     ///
-    /// let sig: Signature = keypair.sign_prehashed(prehashed, Some(context));
+    /// let sig: Signature = keypair.sign_prehashed(prehashed, Some(context))?;
+    /// #
+    /// # Ok(sig)
+    /// # }
+    /// # #[cfg(feature = "std")]
+    /// # fn main() {
+    /// #     do_test();
     /// # }
     /// #
     /// # #[cfg(not(feature = "std"))]
@@ -233,7 +239,7 @@ impl Keypair {
         &self,
         prehashed_message: D,
         context: Option<&[u8]>,
-    ) -> ed25519::Signature
+    ) -> Result<ed25519::Signature, SignatureError>
     where
         D: Digest<OutputSize = U64>,
     {
@@ -278,11 +284,11 @@ impl Keypair {
     /// use ed25519_dalek::Digest;
     /// use ed25519_dalek::Keypair;
     /// use ed25519_dalek::Signature;
+    /// use ed25519_dalek::SignatureError;
     /// use ed25519_dalek::Sha512;
     /// use rand::rngs::OsRng;
     ///
-    /// # #[cfg(feature = "std")]
-    /// # fn main() {
+    /// # fn do_test() -> Result<(), SignatureError> {
     /// let mut csprng = OsRng{};
     /// let keypair: Keypair = Keypair::generate(&mut csprng);
     /// let message: &[u8] = b"All I want is to pet all of the dogs.";
@@ -292,7 +298,7 @@ impl Keypair {
     ///
     /// let context: &[u8] = b"Ed25519DalekSignPrehashedDoctest";
     ///
-    /// let sig: Signature = keypair.sign_prehashed(prehashed, Some(context));
+    /// let sig: Signature = keypair.sign_prehashed(prehashed, Some(context))?;
     ///
     /// // The sha2::Sha512 struct doesn't implement Copy, so we'll have to create a new one:
     /// let mut prehashed_again: Sha512 = Sha512::default();
@@ -301,6 +307,13 @@ impl Keypair {
     /// let verified = keypair.public.verify_prehashed(prehashed_again, Some(context), &sig);
     ///
     /// assert!(verified.is_ok());
+    ///
+    /// # verified
+    /// # }
+    /// #
+    /// # #[cfg(feature = "std")]
+    /// # fn main() {
+    /// #     do_test();
     /// # }
     /// #
     /// # #[cfg(not(feature = "std"))]
diff --git a/src/secret.rs b/src/secret.rs
index 03af823..ca57062 100644
--- a/src/secret.rs
+++ b/src/secret.rs
@@ -466,7 +466,7 @@ impl ExpandedSecretKey {
         let ctx: &[u8] = context.unwrap_or(b""); // By default, the context is an empty string.
 
         if ctx.len() > 255 {
-            return Err(SignatureError(InternalError::PrehashedContextLengthError));
+            return Err(SignatureError::from_source(InternalError::PrehashedContextLengthError));
         }
 
         let ctx_len: u8 = ctx.len() as u8;
diff --git a/tests/ed25519.rs b/tests/ed25519.rs
index 732b29d..b0e206f 100644
--- a/tests/ed25519.rs
+++ b/tests/ed25519.rs
@@ -104,7 +104,7 @@ mod vectors {
         prehash_for_signing.input(&msg_bytes[..]);
         prehash_for_verifying.input(&msg_bytes[..]);
 
-        let sig2: Signature = keypair.sign_prehashed(prehash_for_signing, None);
+        let sig2: Signature = keypair.sign_prehashed(prehash_for_signing, None).unwrap();
 
         assert!(sig1 == sig2,
                 "Original signature from test vectors doesn't equal signature produced:\
@@ -169,8 +169,8 @@ mod integrations {
         let context: &[u8] = b"testing testing 1 2 3";
 
         keypair  = Keypair::generate(&mut csprng);
-        good_sig = keypair.sign_prehashed(prehashed_good1, Some(context));
-        bad_sig  = keypair.sign_prehashed(prehashed_bad1,  Some(context));
+        good_sig = keypair.sign_prehashed(prehashed_good1, Some(context)).unwrap();
+        bad_sig  = keypair.sign_prehashed(prehashed_bad1,  Some(context)).unwrap();
 
         assert!(keypair.verify_prehashed(prehashed_good2, Some(context), &good_sig).is_ok(),
                 "Verification of a valid signature failed!");