bindings/python: Add token example

This includes a HACK to fix `from_hex` for publickey
that I discovered while writting this example.

Will include a real fix for this in seperate commit

bindings/cashu-ffi/bindings-python/examples/test.py

@@ -1,5 +0,0 @@
-from cashu_protocol import Amount
-
-amount = Amount().from_sat(10)
-
-print(amount.to_sat())

bindings/cashu-ffi/bindings-python/examples/token.py

@@ -0,0 +1,29 @@
+from cashu_protocol import Token, Proof, PublicKey, Amount
+
+token_str = "cashuAeyJ0b2tlbiI6W3sibWludCI6Imh0dHBzOi8vODMzMy5zcGFjZTozMzM4IiwicHJvb2ZzIjpbeyJpZCI6IkRTQWw5bnZ2eWZ2YSIsImFtb3VudCI6Miwic2VjcmV0IjoiRWhwZW5uQzlxQjNpRmxXOEZaX3BadyIsIkMiOiIwMmMwMjAwNjdkYjcyN2Q1ODZiYzMxODNhZWNmOTdmY2I4MDBjM2Y0Y2M0NzU5ZjY5YzYyNmM5ZGI1ZDhmNWI1ZDQifSx7ImlkIjoiRFNBbDludnZ5ZnZhIiwiYW1vdW50Ijo4LCJzZWNyZXQiOiJUbVM2Q3YwWVQ1UFVfNUFUVktudWt3IiwiQyI6IjAyYWM5MTBiZWYyOGNiZTVkNzMyNTQxNWQ1YzI2MzAyNmYxNWY5Yjk2N2EwNzljYTk3NzlhYjZlNWMyZGIxMzNhNyJ9XX1dLCJtZW1vIjoiVGhhbmsgeW91LiJ9"
+
+token = Token.from_string(token_str)
+
+
+print(token.memo())
+for p in token.token():
+    print(p.url())
+    for proof in p.proofs():
+        print(proof.id())
+        print(proof.amount().to_sat())
+        print(proof.secret())
+        print(proof.c().to_hex())
+
+
+proof_one = Proof(Amount.from_sat(2), "EhpennC9qB3iFlW8FZ_pZw", PublicKey.from_hex("02c020067db727d586bc3183aecf97fcb800c3f4cc4759f69c626c9db5d8f5b5d4"), "DSAl9nvvyfva")
+
+proof_two = Proof(Amount.from_sat(8), "TmS6Cv0YT5PU_5ATVKnukw", PublicKey.from_hex("02ac910bef28cbe5d7325415d5c263026f15f9b967a079ca9779ab6e5c2db133a7"), "DSAl9nvvyfva")
+
+new_token = Token("https://8333.space:3338", [proof_one, proof_two], "Thank you.")
+
+print(new_token.as_string())
+
+# This is failing because of the url serialization.
+# https://github.com/thesimplekid/cashu-crab/issues/13
+# It is still a valid token, just does not match the referance
+print(new_token.as_string == token_str)

crates/cashu/src/nuts/nut01.rs

@@ -32,8 +32,12 @@ impl From<k256::PublicKey> for PublicKey {
 }
 
 impl PublicKey {
+    // HACK: Fix the from_hex and to_hex
+    // just leaving this hack for now as this pr is big enough
     pub fn from_hex(hex: String) -> Result<Self, Error> {
-        Ok(serde_json::from_str(&hex)?)
+        let hex = hex::decode(hex)?;
+
+        Ok(PublicKey(k256::PublicKey::from_sec1_bytes(&hex).unwrap()))
     }
 
     pub fn to_hex(&self) -> Result<String, Error> {
@@ -57,6 +61,7 @@ impl From<k256::SecretKey> for SecretKey {
     }
 }
 
+// REVIEW: Guessing this is broken as well since its the same as pubkey
 impl SecretKey {
     pub fn from_hex(hex: String) -> Result<Self, Error> {
         Ok(serde_json::from_str(&hex)?)
@@ -135,3 +140,17 @@ pub mod mint {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+
+    use super::PublicKey;
+
+    #[test]
+    fn pubkey() {
+        let pubkey = PublicKey::from_hex(
+            "02c020067db727d586bc3183aecf97fcb800c3f4cc4759f69c626c9db5d8f5b5d4".to_string(),
+        )
+        .unwrap();
+    }
+}