cosmos-stdtx: add Amino types for encoding StdTx

The schema-based encoder is only for `Msg`. This adds a `StdTx` type
using `prost-amino-derive` to programatically declare it.

cosmos-stdtx/Cargo.toml

@@ -16,6 +16,7 @@ circle-ci = { repository = "tendermint/kms" }
 [dependencies]
 anomaly = "0.1"
 prost-amino = "0.5"
+prost-amino-derive = "0.5"
 rust_decimal = "1.1"
 serde = { version = "1", features = ["serde_derive"] }
 sha2 = "0.8"

cosmos-stdtx/src/lib.rs

@@ -16,6 +16,7 @@ pub mod address;
 pub mod error;
 pub mod msg;
 pub mod schema;
+pub mod stdtx;
 pub mod type_name;
 
 pub use self::{address::Address, error::Error, msg::Msg, schema::Schema, type_name::TypeName};

cosmos-stdtx/src/stdtx.rs

@@ -0,0 +1,75 @@
+//! StdTx Amino types
+
+use crate::type_name::TypeName;
+use prost_amino::{encode_length_delimiter, Message};
+use prost_amino_derive::Message;
+
+/// StdTx Amino type
+#[derive(Clone, Message)]
+pub struct StdTx {
+    /// Messages in transction
+    #[prost_amino(bytes, repeated, tag = "1")]
+    pub msg: Vec<Vec<u8>>,
+
+    /// Feeds to be paid
+    #[prost_amino(message)]
+    pub fee: Option<StdFee>,
+
+    /// Signatures
+    #[prost_amino(message, repeated)]
+    pub signatures: Vec<StdSignature>,
+
+    /// Memo field
+    #[prost_amino(string)]
+    pub memo: String,
+}
+
+impl StdTx {
+    /// Encode this [`StdTx`] in Amino encoding identifying it with the given
+    /// type name (e.g. `cosmos-sdk/StdTx`)
+    pub fn to_amino_bytes(&self, type_name: &TypeName) -> Vec<u8> {
+        let mut amino_tx = type_name.amino_prefix();
+        self.encode(&mut amino_tx).expect("LEB128 encoding error");
+
+        let mut amino_encoded = vec![];
+        encode_length_delimiter(amino_tx.len(), &mut amino_encoded).expect("LEB128 encoding error");
+        amino_encoded.append(&mut amino_tx);
+        amino_encoded
+    }
+}
+
+/// StdFee amino type
+#[derive(Clone, Message)]
+pub struct StdFee {
+    /// Fee to be paid
+    #[prost_amino(message, repeated, tag = "1")]
+    pub amount: Vec<Coin>,
+
+    /// Gas requested for transaction
+    #[prost_amino(uint64)]
+    pub gas: u64,
+}
+
+/// Coin amino type
+#[derive(Clone, Message)]
+pub struct Coin {
+    /// Denomination of coin
+    #[prost_amino(string, tag = "1")]
+    pub denom: String,
+
+    /// Amount of the given denomination
+    #[prost_amino(string)]
+    pub amount: String,
+}
+
+/// StdSignature amino type
+#[derive(Clone, Message)]
+pub struct StdSignature {
+    /// Public key which can verify this signature
+    #[prost_amino(bytes, tag = "1", amino_name = "tendermint/PubKeySecp256k1")]
+    pub pub_key: Vec<u8>,
+
+    /// Serialized signature
+    #[prost_amino(bytes)]
+    pub signature: Vec<u8>,
+}