Allow key deserialization from owned strings

Author: sgeisler

src/macros.rs

@@ -64,10 +64,11 @@ macro_rules! serde_impl(
             fn deserialize<D: ::serde::Deserializer<'de>>(d: D) -> Result<$t, D::Error> {
                 use ::serde::de::Error;
                 use core::str::FromStr;
+                use std::borrow::Cow;
 
                 if d.is_human_readable() {
-                    let sl: &str = ::serde::Deserialize::deserialize(d)?;
-                    SecretKey::from_str(sl).map_err(D::Error::custom)
+                    let sl: Cow<'de, str> = ::serde::Deserialize::deserialize(d)?;
+                    SecretKey::from_str(&sl).map_err(D::Error::custom)
                 } else {
                     let sl: &[u8] = ::serde::Deserialize::deserialize(d)?;
                     if sl.len() != $len {