From cde4931f11c901849d126db54223f5397f512fb5 Mon Sep 17 00:00:00 2001
From: willclarktech <willclarktech@users.noreply.github.com>
Date: Tue, 6 Apr 2021 18:26:49 +0200
Subject: [PATCH] tendermint-rpc: Add address helpers

---
 packages/tendermint-rpc/src/addresses.ts | 33 ++++++++++++++++++++++++
 packages/tendermint-rpc/src/index.ts     |  6 +++++
 2 files changed, 39 insertions(+)
 create mode 100644 packages/tendermint-rpc/src/addresses.ts

diff --git a/packages/tendermint-rpc/src/addresses.ts b/packages/tendermint-rpc/src/addresses.ts
new file mode 100644
index 00000000..24c5d429
--- /dev/null
+++ b/packages/tendermint-rpc/src/addresses.ts
@@ -0,0 +1,33 @@
+import { ripemd160, sha256 } from "@cosmjs/crypto";
+import { toHex } from "@cosmjs/encoding";
+
+export function rawEd25519PubkeyToRawAddress(pubkeyData: Uint8Array): Uint8Array {
+  if (pubkeyData.length !== 32) {
+    throw new Error(`Invalid Ed25519 pubkey length: ${pubkeyData.length}`);
+  }
+  return sha256(pubkeyData).slice(0, 20);
+}
+
+export function rawSecp256k1PubkeyToRawAddress(pubkeyData: Uint8Array): Uint8Array {
+  if (pubkeyData.length !== 33) {
+    throw new Error(`Invalid Secp256k1 pubkey length (compressed): ${pubkeyData.length}`);
+  }
+  return ripemd160(sha256(pubkeyData));
+}
+
+// For secp256k1 this assumes we already have a compressed pubkey.
+export function pubkeyToRawAddress(type: "ed25519" | "secp256k1", data: Uint8Array): Uint8Array {
+  switch (type) {
+    case "ed25519":
+      return rawEd25519PubkeyToRawAddress(data);
+    case "secp256k1":
+      return rawSecp256k1PubkeyToRawAddress(data);
+    default:
+      // Keep this case here to guard against new types being added but not handled
+      throw new Error(`Pubkey type ${type} not supported`);
+  }
+}
+
+export function pubkeyToAddress(type: "ed25519" | "secp256k1", data: Uint8Array): string {
+  return toHex(pubkeyToRawAddress(type, data)).toUpperCase();
+}
diff --git a/packages/tendermint-rpc/src/index.ts b/packages/tendermint-rpc/src/index.ts
index 10c7e62e..1bcb3e6a 100644
--- a/packages/tendermint-rpc/src/index.ts
+++ b/packages/tendermint-rpc/src/index.ts
@@ -1,3 +1,9 @@
+export {
+  pubkeyToAddress,
+  pubkeyToRawAddress,
+  rawEd25519PubkeyToRawAddress,
+  rawSecp256k1PubkeyToRawAddress,
+} from "./addresses";
 export {
   adaptor33,
   adaptor34,