Public Key plain byte encoding (#540)

* public key is encoded in bytes

* ECDSA pubkey in uncompressed format

libraries/crypto/src/ec/point.rs

@@ -16,9 +16,8 @@ use super::exponent256::ExponentP256;
 use super::gfp256::GFP256;
 use super::int256::Int256;
 use super::montgomery::Montgomery;
-#[cfg(test)]
-use arrayref::array_mut_ref;
 #[cfg(feature = "std")]
+use arrayref::array_mut_ref;
 use arrayref::array_ref;
 use core::ops::Add;
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq};
@@ -45,7 +44,6 @@ impl PointP256 {
     /** Serialization **/
     // This uses uncompressed point format from "SEC 1: Elliptic Curve Cryptography" ("Standards for
     // Efficient Cryptography").
-    #[cfg(feature = "std")]
     pub fn from_bytes_uncompressed_vartime(bytes: &[u8]) -> Option<PointP256> {
         if bytes.len() != 65 || bytes[0] != 0x04 {
             None
@@ -57,7 +55,7 @@ impl PointP256 {
         }
     }
 
-    #[cfg(test)]
+    #[cfg(feature = "std")]
     pub fn to_bytes_uncompressed(&self, bytes: &mut [u8; 65]) {
         bytes[0] = 0x04;
         self.x.to_int().to_bin(array_mut_ref![bytes, 1, 32]);

libraries/crypto/src/ecdsa.rs

@@ -231,13 +231,12 @@ impl PubKey {
             .map(|p| PubKey { p })
     }
 
-    #[cfg(feature = "std")]
     pub fn from_bytes_uncompressed(bytes: &[u8]) -> Option<PubKey> {
         PointP256::from_bytes_uncompressed_vartime(bytes).map(|p| PubKey { p })
     }
 
-    #[cfg(test)]
-    fn to_bytes_uncompressed(&self, bytes: &mut [u8; 65]) {
+    #[cfg(feature = "std")]
+    pub fn to_bytes_uncompressed(&self, bytes: &mut [u8; 65]) {
         self.p.to_bytes_uncompressed(bytes);
     }