openpgp: Do not return stringy errors.

  - See #1068.

3 files changed, 18 insertions, 11 deletions

diff --git a/openpgp/src/crypto/backend/rust/symmetric.rs b/openpgp/src/crypto/backend/rust/symmetric.rs
index f96def91..fd010824 100644
--- a/openpgp/src/crypto/backend/rust/symmetric.rs
+++ b/openpgp/src/crypto/backend/rust/symmetric.rs
@@ -222,8 +222,9 @@ macro_rules! impl_enc_mode {
                 _dst: &mut [u8],
                 _src: &[u8],
             ) -> Result<()> {
-                Err(anyhow::anyhow!(
-                    "decryption not supported in encryption mode"))
+                Err(Error::InvalidOperation(
+                    "decryption not supported in encryption mode".into())
+                    .into())
             }
         }
     }
@@ -240,8 +241,9 @@ macro_rules! impl_dec_mode {
                 _dst: &mut [u8],
                 _src: &[u8],
             ) -> Result<()> {
-                Err(anyhow::anyhow!(
-                    "encryption not supported in decryption mode"))
+                Err(Error::InvalidOperation(
+                    "encryption not supported in decryption mode".into())
+                    .into())
             }
 
             fn decrypt(
diff --git a/openpgp/src/packet/userid.rs b/openpgp/src/packet/userid.rs
index 1ad272f0..4a1a6016 100644
--- a/openpgp/src/packet/userid.rs
+++ b/openpgp/src/packet/userid.rs
@@ -971,8 +971,8 @@ impl UserID {
 
                 // Normalize Unicode in domains.
                 let domain = idna::domain_to_ascii(domain)
-                    .map_err(|e| anyhow::anyhow!(
-                        "punycode conversion failed: {:?}", e))?;
+                    .map_err(|e| anyhow::Error::from(e)
+                             .context("punycode conversion failed"))?;
 
                 // Join.
                 let address = format!("{}@{}", localpart, domain);
diff --git a/openpgp/src/policy.rs b/openpgp/src/policy.rs
index 744f8387..9ea4fcb2 100644
--- a/openpgp/src/policy.rs
+++ b/openpgp/src/policy.rs
@@ -80,7 +80,8 @@ pub trait Policy : fmt::Debug + Send + Sync {
     /// revocations: if you reject a revocation certificate, it may
     /// inadvertently make something else valid!
     fn signature(&self, _sig: &Signature, _sec: HashAlgoSecurity) -> Result<()> {
-        Err(anyhow::anyhow!("By default all signatures are rejected."))
+        Err(Error::PolicyViolation(
+            "By default all signatures are rejected.".into(), None).into())
     }
 
     /// Returns an error if the key violates the policy.
@@ -107,7 +108,8 @@ pub trait Policy : fmt::Debug + Send + Sync {
     fn key(&self, _ka: &ValidErasedKeyAmalgamation<key::PublicParts>)
         -> Result<()>
     {
-        Err(anyhow::anyhow!("By default all keys are rejected."))
+        Err(Error::PolicyViolation(
+            "By default all keys are rejected.".into(), None).into())
     }
 
     /// Returns an error if the symmetric encryption algorithm
@@ -119,7 +121,8 @@ pub trait Policy : fmt::Debug + Send + Sync {
     /// With this function, you can prevent the use of insecure
     /// symmetric encryption algorithms.
     fn symmetric_algorithm(&self, _algo: SymmetricAlgorithm) -> Result<()> {
-        Err(anyhow::anyhow!("By default all symmetric algorithms are rejected."))
+        Err(Error::PolicyViolation(
+            "By default all symmetric algorithms are rejected.".into(), None).into())
     }
 
     /// Returns an error if the AEAD mode violates the policy.
@@ -132,7 +135,8 @@ pub trait Policy : fmt::Debug + Send + Sync {
     ///
     /// This feature is [experimental](super#experimental-features).
     fn aead_algorithm(&self, _algo: AEADAlgorithm) -> Result<()> {
-        Err(anyhow::anyhow!("By default all AEAD algorithms are rejected."))
+        Err(Error::PolicyViolation(
+            "By default all AEAD algorithms are rejected.".into(), None).into())
     }
 
     /// Returns an error if the packet violates the policy.
@@ -144,7 +148,8 @@ pub trait Policy : fmt::Debug + Send + Sync {
     /// encryption containers, notably the *Symmetrically Encrypted
     /// Data Packet*.
     fn packet(&self, _packet: &Packet) -> Result<()> {
-        Err(anyhow::anyhow!("By default all packets are rejected."))
+        Err(Error::PolicyViolation(
+            "By default all packets are rejected.".into(), None).into())
     }
 }