Add function to export certificate's public key

Author: shahn

src/signed_data.rs

@@ -145,6 +145,12 @@ pub fn verify_signature(signature_alg: &SignatureAlgorithm,
         .map_err(|_| Error::InvalidSignatureForPublicKey)
 }
 
+pub fn public_key_bytes(spki_value: untrusted::Input) ->
+        Result<untrusted::Input, Error> {
+    let spki = parse_spki_value(spki_value)?;
+    Ok(spki.key_value)
+}
+
 
 struct SubjectPublicKeyInfo<'a> {
     algorithm_id_value: untrusted::Input<'a>,

src/webpki.rs

@@ -246,6 +246,11 @@ impl <'a> EndEntityCert<'a> {
         signed_data::verify_signature(signature_alg, self.inner.spki, msg,
                                       signature)
     }
+
+    /// Returns the certificate's public key.
+    pub fn public_key_bytes(&self) -> Result<untrusted::Input, Error> {
+        signed_data::public_key_bytes(self.inner.spki)
+    }
 }
 
 

tests/integration.rs

@@ -104,6 +104,12 @@ pub fn ed25519()
     let _ = cert.verify_is_valid_tls_server_cert(ALL_SIGALGS, &anchors,
                                                  &inter_vec, time)
         .unwrap();
+    assert_eq!(cert.public_key_bytes(),
+               Ok(untrusted::Input::from(
+                &[0xfe, 0x5a, 0x1e, 0x36, 0x6c, 0x17, 0x27, 0x5b, 0xf1,
+                0x58, 0x1e, 0x3a, 0x0e, 0xe6, 0x56, 0x29, 0x8d, 0x9e,
+                0x1b, 0x3f, 0xd3, 0x3f, 0x96, 0x46, 0xef, 0xbf, 0x04,
+                0x6b, 0xc7, 0x3d, 0x47, 0x5c])));
 }
 
 #[cfg(feature = "trust_anchor_util")]