From ea45550d61f04af6144e02cad95fc04d070d4580 Mon Sep 17 00:00:00 2001
From: folex <0xdxdy@gmail.com>
Date: Thu, 25 Jun 2020 13:15:33 +0300
Subject: [PATCH] Add Deserialize for ed25519::PublicKey (#21)

---
 core/Cargo.toml              |  1 +
 core/src/identity/ed25519.rs | 47 ++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/core/Cargo.toml b/core/Cargo.toml
index 98db09f0..3b11a7fc 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -34,6 +34,7 @@ thiserror = "1.0"
 unsigned-varint = "0.3"
 void = "1"
 zeroize = "1"
+serde = { version = "1.0.114", default-features = false }
 
 [target.'cfg(not(any(target_os = "emscripten", target_os = "unknown")))'.dependencies]
 ring = { version = "0.16.9", features = ["alloc", "std"], default-features = false }
diff --git a/core/src/identity/ed25519.rs b/core/src/identity/ed25519.rs
index f68e5d03..9d0b4751 100644
--- a/core/src/identity/ed25519.rs
+++ b/core/src/identity/ed25519.rs
@@ -84,6 +84,13 @@ impl Clone for Keypair {
     }
 }
 
+/// Build keypair from existing ed25519 keypair
+impl From<ed25519::Keypair> for Keypair {
+    fn from(kp: ed25519::Keypair) -> Self {
+        Keypair(kp)
+    }
+}
+
 /// Demote an Ed25519 keypair to a secret key.
 impl From<Keypair> for SecretKey {
     fn from(kp: Keypair) -> SecretKey {
@@ -124,6 +131,46 @@ impl PublicKey {
     }
 }
 
+impl<'de> serde::Deserialize<'de> for PublicKey {
+    fn deserialize<D>(deserializer: D) -> Result<PublicKey, D::Error>
+        where
+            D: serde::Deserializer<'de>,
+    {
+        use serde::de::{Error, Visitor};
+
+        struct PKVisitor;
+
+        impl<'de> Visitor<'de> for PKVisitor {
+            type Value = PublicKey;
+
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("byte array or base58 string")
+            }
+
+            fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
+                where
+                    E: Error,
+            {
+                bs58::decode(s)
+                    .into_vec()
+                    .map_err(|err| Error::custom(format!("Invalid string '{}': {}", s, err)))
+                    .and_then(|v| self.visit_bytes(v.as_slice()))
+                    .map_err(|err: E| Error::custom(format!("Parsed string '{}' as base58, but {}", s, err)))
+            }
+
+            fn visit_bytes<E>(self, b: &[u8]) -> Result<Self::Value, E>
+                where
+                    E: Error,
+            {
+                PublicKey::decode(b)
+                    .map_err(|err| Error::custom(format!("Invalid bytes {:?}: {}", b, err)))
+            }
+        }
+
+        deserializer.deserialize_str(PKVisitor)
+    }
+}
+
 /// An Ed25519 secret key.
 pub struct SecretKey(ed25519::SecretKey);