Implement Keypair traits for SigningKeys

Signed-off-by: Dmitry Baryshkov <[email protected]>

Author: lumag

src/pkcs1v15.rs

@@ -9,7 +9,7 @@ use rand_core::{CryptoRng, RngCore};
 #[cfg(feature = "hazmat")]
 use signature::hazmat::{PrehashSigner, PrehashVerifier};
 use signature::{
-    DigestSigner, DigestVerifier, RandomizedDigestSigner, RandomizedSigner,
+    DigestSigner, DigestVerifier, Keypair, RandomizedDigestSigner, RandomizedSigner,
     Signature as SignSignature, Signer, Verifier,
 };
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq};
@@ -428,6 +428,13 @@ where
     }
 }
 
+impl<D> Keypair<Signature> for SigningKey<D>
+where
+    D: Digest,
+{
+    type VerifyingKey = VerifyingKey<D>;
+}
+
 impl<D> Signer<Signature> for SigningKey<D>
 where
     D: Digest,

src/pss.rs

@@ -10,7 +10,8 @@ use rand_core::{CryptoRng, RngCore};
 #[cfg(feature = "hazmat")]
 use signature::hazmat::{PrehashVerifier, RandomizedPrehashSigner};
 use signature::{
-    DigestVerifier, RandomizedDigestSigner, RandomizedSigner, Signature as SignSignature, Verifier,
+    DigestVerifier, Keypair, RandomizedDigestSigner, RandomizedSigner, Signature as SignSignature,
+    Verifier,
 };
 use subtle::ConstantTimeEq;
 
@@ -626,6 +627,13 @@ where
     }
 }
 
+impl<D> Keypair<Signature> for SigningKey<D>
+where
+    D: Digest,
+{
+    type VerifyingKey = VerifyingKey<D>;
+}
+
 impl<D> AsRef<VerifyingKey<D>> for SigningKey<D>
 where
     D: Digest,
@@ -799,6 +807,13 @@ where
     }
 }
 
+impl<D> Keypair<Signature> for BlindedSigningKey<D>
+where
+    D: Digest,
+{
+    type VerifyingKey = VerifyingKey<D>;
+}
+
 impl<D> RandomizedSigner<Signature> for BlindedSigningKey<D>
 where
     D: Digest + FixedOutputReset,