cosmrs: add getrandom feature (#434)

Enables support for using CosmRS in environments unsupported by
`getrandom`, like non-JS WASM environments

.github/workflows/cosmrs.yml

@@ -35,7 +35,7 @@ jobs:
         with:
           toolchain: ${{ matrix.rust }}
           target: ${{ matrix.target }}
-      - run: cargo build --target ${{ matrix.target }} --release
+      - run: cargo build --target ${{ matrix.target }} --no-default-features --release
 
   test:
     runs-on: ubuntu-latest

cosmrs/Cargo.toml

@@ -13,31 +13,29 @@ rust-version = "1.72"
 
 [dependencies]
 cosmos-sdk-proto = { version = "=0.20.0-pre", default-features = false, path = "../cosmos-sdk-proto" }
-ecdsa = { version = "0.16", features = ["std"] }
+ecdsa = "0.16"
 eyre = "0.6"
-k256 = { version = "0.13", features = ["ecdsa", "sha256"] }
-rand_core = { version = "0.6", features = ["std"] }
+k256 = { version = "0.13", default-features = false, features = ["ecdsa", "sha256"] }
+rand_core = { version = "0.6", default-features = false }
 serde = { version = "1", features = ["serde_derive"] }
 serde_json = "1"
 subtle-encoding = { version = "0.5", features = ["bech32-preview"] }
 tendermint = { version = "0.34", features = ["secp256k1"] }
 thiserror = "1"
 
 # optional dependencies
-bip32 = { version = "0.5", optional = true }
+bip32 = { version = "0.5", optional = true, default-features = false, features = ["alloc", "secp256k1"] }
 tendermint-rpc = { version = "0.34", optional = true, features = ["http-client"] }
 tokio = { version = "1", optional = true }
 
-[target.'cfg(target_arch = "wasm32")'.dependencies]
-getrandom = { version = "0.2", features = ["js"] }
-
 [dev-dependencies]
 hex-literal = "0.4"
 
 [features]
-default   = ["bip32"]
+default   = ["bip32", "getrandom"]
 cosmwasm  = ["cosmos-sdk-proto/cosmwasm"]
 dev       = ["rpc", "tokio"]
+getrandom = ["rand_core/getrandom"]
 grpc      = ["cosmos-sdk-proto/grpc-transport", "grpc-core"]
 grpc-core = ["cosmos-sdk-proto/grpc"]
 rpc       = ["tendermint-rpc"]

cosmrs/src/crypto/secp256k1/signing_key.rs

@@ -5,7 +5,10 @@ use crate::{
     ErrorReport, Result,
 };
 use ecdsa::signature::{Keypair, Signer};
+use eyre::eyre;
 use k256::ecdsa::VerifyingKey;
+
+#[cfg(feature = "getrandom")]
 use rand_core::OsRng;
 
 /// ECDSA/secp256k1 signing key (i.e. private key)
@@ -35,11 +38,13 @@ impl SigningKey {
 
     /// Initialize from a raw scalar value (big endian).
     pub fn from_slice(bytes: &[u8]) -> Result<Self> {
-        let signing_key = k256::ecdsa::SigningKey::from_slice(bytes)?;
+        let signing_key =
+            k256::ecdsa::SigningKey::from_slice(bytes).map_err(|_| eyre!("invalid signing key"))?;
         Ok(Self::new(Box::new(signing_key)))
     }
 
     /// Generate a random signing key.
+    #[cfg(feature = "getrandom")]
     pub fn random() -> Self {
         Self::new(Box::new(k256::ecdsa::SigningKey::random(&mut OsRng)))
     }
@@ -58,7 +63,9 @@ impl SigningKey {
 
     /// Sign the given message, returning a signature.
     pub fn sign(&self, msg: &[u8]) -> Result<Signature> {
-        Ok(self.inner.try_sign(msg)?)
+        self.inner
+            .try_sign(msg)
+            .map_err(|_| eyre!("signing failure"))
     }
 
     /// Get the [`PublicKey`] for this [`SigningKey`].

cosmrs/src/tx.rs

@@ -21,7 +21,8 @@
 //! The following example illustrates how to build, sign, and parse
 //! a Cosmos SDK transaction:
 //!
-//! ```
+#![cfg_attr(feature = "getrandom", doc = " ```ignore")]
+#![cfg_attr(not(feature = "getrandom"), doc = " ```ignore")]
 //! # fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
 //! use cosmrs::{
 //!     bank::MsgSend,