Fix BIP44 coin type (#480)

* fix docsearch * update BIP44 coin type * changelog * set HD path
cosmos · Aug 28, 2020 · 8a3692e · 8a3692e
1 parent 6307ba9
commit 8a3692e
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -41,6 +41,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 * (app) [\#471](https://github.com/ChainSafe/ethermint/pull/471) Add `x/upgrade` module for managing software updates.
 
+### Bug Fixes
+
+* (types) [\#480](https://github.com/ChainSafe/ethermint/pull/480) Update [BIP44](https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki) coin type to `60` to satisfy [EIP84](https://github.com/ethereum/EIPs/issues/84).
+
 ## [v0.1.0] - 2020-08-23
 
 ### Improvements

diff --git a/app/ethermint.go b/app/ethermint.go
@@ -42,6 +42,7 @@ func init() {
 	// set the address prefixes
 	config := sdk.GetConfig()
 	ethermint.SetBech32Prefixes(config)
+	ethermint.SetBip44CoinType(config)
 }
 
 const appName = "Ethermint"

diff --git a/cmd/ethermintcli/main.go b/cmd/ethermintcli/main.go
@@ -46,6 +46,7 @@ func main() {
 	// Read in the configuration file for the sdk
 	config := sdk.GetConfig()
 	ethermint.SetBech32Prefixes(config)
+	ethermint.SetBip44CoinType(config)
 	config.Seal()
 
 	rootCmd := &cobra.Command{

diff --git a/cmd/ethermintd/main.go b/cmd/ethermintd/main.go
@@ -53,6 +53,7 @@ func main() {
 
 	config := sdk.GetConfig()
 	ethermint.SetBech32Prefixes(config)
+	ethermint.SetBip44CoinType(config)
 	config.Seal()
 
 	ctx := server.NewDefaultContext()

diff --git a/docs/basics/accounts.md b/docs/basics/accounts.md
@@ -6,16 +6,45 @@ order: 1
 
 This document describes the in-built accounts system of Ethermint. {synopsis}
 
-## Cosmos SDK Accounts
+## Pre-requisite Readings
 
-<!-- TODO: -->
+- [Cosmos SDK Accounts](https://docs.cosmos.network/master/basics/accounts.html) {prereq}
+- [Ethereum Accounts](https://ethereum.org/en/whitepaper/#ethereum-accounts) {prereq}
 
 ## Ethermint Accounts
 
-<!-- TODO: -->
+Ethermint defines its own custom `Account` type that uses Ethereum's ECDSA secp256k1 curve for keys. This
+satisfies the [EIP84](https://github.com/ethereum/EIPs/issues/84) for full [BIP44](https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki) paths.
+The root HD path for Ethermint-based accounts is `m/44'/60'/0'/0`.
+
++++ https://github.com/ChainSafe/ethermint/blob/v0.1.0/types/account.go#L31-L36
+
+## Addresses and Public Keys
+
+There are 3 main types of `Addresses`/`PubKeys` available by default on Ethermint:
+
+- Addresses and Keys for **accounts**, which identify users (e.g. the sender of a `message`). They are derived using the **`eth_secp256k1`** curve.
+- Addresses and Keys for **validator operators**, which identify the operators of validators. They are derived using the **`eth_secp256k1`** curve.
+- Addresses and Keys for **consensus nodes**, which identify the validator nodes participating in consensus. They are derived using the **`ed25519`** curve.
+
+|                    | Address bech32 Prefix | Pubkey bech32 Prefix | Curve           | Address byte length | Pubkey byte length |
+|--------------------|-----------------------|----------------------|-----------------|---------------------|--------------------|
+| Accounts           | `eth`                 | `ethpub`             | `eth_secp256k1` | `20`                | `33` (compressed)  |
+| Validator Operator | `ethvaloper`          | `ethvaloperpub`      | `eth_secp256k1` | `20`                | `33` (compressed)  |
+| Consensus Nodes    | `ethvalcons`          | `ethvalconspub`      | `ed25519`       | `20`                | `32`               |
 
 ## Address formats for clients
 
+`EthAccount`s have can be represented in both [Bech32](https://en.bitcoin.it/wiki/Bech32) and hex format for Ethereum's Web3 tooling compatibility.
+
+The Bech32 format is the default format for Cosmos-SDK queries and transactions through CLI and REST
+clients. The hex format on the other hand, is the Ethereum `common.Address` representation of a
+Cosmos `sdk.AccAddress`.
+
+- Address (Bech32): `eth1crwhac03z2pcgu88jfnqnwu66xlthlz2rhljah`
+- Address (Hex): `0xc0dd7ee1f112838470e7926609bb9ad1bebbfc4a`
+- Public Key (Bech32): `ethpub1pfqnmk6pqnwwuw0h9hj58t2hyzwvqc3truhhp5tl5hfucezcfy2rs8470nkyzju2vmk645fzmw2wveaqcqek767kwa0es9rmxe9nmmjq84cpny3fvj6tpg`
+
 ## Next {hide}
 
 Learn about Ethermint [transactions](./transactions.md) {hide}
diff --git a/types/config.go b/types/config.go
@@ -20,6 +20,12 @@ const (
 	Bech32PrefixConsAddr = EthBech32Prefix + sdk.PrefixValidator + sdk.PrefixConsensus
 	// Bech32PrefixConsPub defines the Bech32 prefix of a consensus node public key
 	Bech32PrefixConsPub = EthBech32Prefix + sdk.PrefixValidator + sdk.PrefixConsensus + sdk.PrefixPublic
+
+	// Bip44CoinType satisfies EIP84. See https://github.com/ethereum/EIPs/issues/84 for more info.
+	Bip44CoinType = 60
+
+	// BIP44HDPath is the BIP44 HD path used on Ethereum.
+	BIP44HDPath = "44'/60'/0'/0/0"
 )
 
 // SetBech32Prefixes sets the global prefixes to be used when serializing addresses and public keys to Bech32 strings.
@@ -28,3 +34,9 @@ func SetBech32Prefixes(config *sdk.Config) {
 	config.SetBech32PrefixForValidator(Bech32PrefixValAddr, Bech32PrefixValPub)
 	config.SetBech32PrefixForConsensusNode(Bech32PrefixConsAddr, Bech32PrefixConsPub)
 }
+
+// SetBip44CoinType sets the global coin type to be used in hierarchical deterministic wallets.
+func SetBip44CoinType(config *sdk.Config) {
+	config.SetCoinType(Bip44CoinType)
+	config.SetFullFundraiserPath(BIP44HDPath)
+}
diff --git a/types/config_test.go b/types/config_test.go
@@ -32,3 +32,12 @@ func TestSetBech32Prefixes(t *testing.T) {
 	require.Equal(t, sdk.GetConfig().GetBech32ConsensusAddrPrefix(), config.GetBech32ConsensusAddrPrefix())
 	require.Equal(t, sdk.GetConfig().GetBech32ConsensusPubPrefix(), config.GetBech32ConsensusPubPrefix())
 }
+
+func TestSetCoinType(t *testing.T) {
+	config := sdk.GetConfig()
+	require.Equal(t, sdk.CoinType, int(config.GetCoinType()))
+
+	SetBip44CoinType(config)
+	require.Equal(t, Bip44CoinType, int(config.GetCoinType()))
+	require.Equal(t, sdk.GetConfig().GetCoinType(), config.GetCoinType())
+}