k256: impl pkcs8 traits for k256::ecdsa::{SigningKey, VerifyingKey} (…

…#251)

k256/src/ecdsa/sign.rs

@@ -19,6 +19,12 @@ use elliptic_curve::{
 #[cfg(any(feature = "keccak256", feature = "sha256"))]
 use ecdsa_core::signature::{self, digest::Digest, PrehashSignature, RandomizedSigner};
 
+#[cfg(feature = "pkcs8")]
+use crate::pkcs8::{self, FromPrivateKey};
+
+#[cfg(feature = "pem")]
+use core::str::FromStr;
+
 /// ECDSA/secp256k1 signing key
 #[cfg_attr(docsrs, doc(cfg(feature = "ecdsa")))]
 pub struct SigningKey {
@@ -35,7 +41,6 @@ impl SigningKey {
     }
 
     /// Initialize [`SigningKey`] from a raw scalar value (big endian).
-    // TODO(tarcieri): PKCS#8 support
     pub fn from_bytes(bytes: &[u8]) -> Result<Self, Error> {
         SecretKey::from_bytes(bytes)
             .map(|sk| Self { inner: sk })
@@ -232,6 +237,26 @@ impl RecoverableSignPrimitive<Secp256k1> for Scalar {
     }
 }
 
+#[cfg(feature = "pkcs8")]
+#[cfg_attr(docsrs, doc(cfg(feature = "pkcs8")))]
+impl FromPrivateKey for SigningKey {
+    fn from_pkcs8_private_key_info(
+        private_key_info: pkcs8::PrivateKeyInfo<'_>,
+    ) -> pkcs8::Result<Self> {
+        SecretKey::from_pkcs8_private_key_info(private_key_info).map(|inner| Self { inner })
+    }
+}
+
+#[cfg(feature = "pem")]
+#[cfg_attr(docsrs, doc(cfg(feature = "pem")))]
+impl FromStr for SigningKey {
+    type Err = Error;
+
+    fn from_str(s: &str) -> Result<Self, Error> {
+        Self::from_pkcs8_pem(s).map_err(|_| Error::new())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::{test_vectors::ecdsa::ECDSA_TEST_VECTORS, Secp256k1};

k256/src/ecdsa/verify.rs

@@ -10,6 +10,15 @@ use signature::{digest::Digest, DigestVerifier};
 #[cfg(feature = "sha256")]
 use signature::PrehashSignature;
 
+#[cfg(feature = "pkcs8")]
+use crate::{
+    elliptic_curve::PublicKey,
+    pkcs8::{self, FromPublicKey},
+};
+
+#[cfg(feature = "pem")]
+use core::str::FromStr;
+
 /// ECDSA/secp256k1 verification key (i.e. public key)
 #[cfg_attr(docsrs, doc(cfg(feature = "ecdsa")))]
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -122,6 +131,24 @@ impl VerifyPrimitive<Secp256k1> for AffinePoint {
     }
 }
 
+#[cfg(feature = "pkcs8")]
+#[cfg_attr(docsrs, doc(cfg(feature = "pkcs8")))]
+impl FromPublicKey for VerifyingKey {
+    fn from_spki(spki: pkcs8::SubjectPublicKeyInfo<'_>) -> pkcs8::Result<Self> {
+        PublicKey::from_spki(spki).map(|pk| Self { inner: pk.into() })
+    }
+}
+
+#[cfg(feature = "pem")]
+#[cfg_attr(docsrs, doc(cfg(feature = "pem")))]
+impl FromStr for VerifyingKey {
+    type Err = Error;
+
+    fn from_str(s: &str) -> Result<Self, Error> {
+        Self::from_public_key_pem(s).map_err(|_| Error::new())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::{test_vectors::ecdsa::ECDSA_TEST_VECTORS, Secp256k1};