feat: EIP191 sign mode (backport cosmos#11533) (cosmos#11545)

* feat: EIP191 sign mode (cosmos#11533)

## Description

Adds [EIP-191](https://eips.ethereum.org/EIPS/eip-191) as a supported sign mode.

Ref: cosmos#10553 (comment)

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

(cherry picked from commit dc66ddd)

# Conflicts:
#	CHANGELOG.md
#	api/cosmos/distribution/v1beta1/tx.pulsar.go
#	api/cosmos/tx/signing/v1beta1/signing.pulsar.go
#	client/cmd.go
#	client/flags/flags.go
#	client/tx/factory.go
#	go.sum
#	types/tx/signing/signing.pb.go
#	x/distribution/types/tx.pb.go

* fix conflicts

* fix conflicts++

Co-authored-by: Federico Kunze Küllmer <31522760+fedekunze@users.noreply.github.com>
Co-authored-by: marbar3778 <marbar3778@yahoo.com>

CHANGELOG.md

@@ -39,6 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Features
 
+* (tx) [#\11533](https://github.com/cosmos/cosmos-sdk/pull/11533) Register [`EIP191`](https://eips.ethereum.org/EIPS/eip-191) as an available `SignMode` for chains to use.
 * [\#11430](https://github.com/cosmos/cosmos-sdk/pull/11430) Introduce a new `grpc-only` flag, such that when enabled, will start the node in a query-only mode. Note, gRPC MUST be enabled with this flag.
 * (x/bank) [\#11417](https://github.com/cosmos/cosmos-sdk/pull/11417) Introduce a new `SpendableBalances` gRPC query that retrieves an account's total (paginated) spendable balances.
 * (x/bank) [\#10771](https://github.com/cosmos/cosmos-sdk/pull/10771) Add safety check on bank module perms to allow module-specific mint restrictions (e.g. only minting a certain denom).

client/cmd.go

@@ -250,7 +250,6 @@ func readTxCommandFlags(clientCtx Context, flagSet *pflag.FlagSet) (Context, err
 			clientCtx = clientCtx.WithSignModeStr(flags.SignModeLegacyAminoJSON)
 		}
 	}
-
 	return clientCtx, nil
 }
 

client/flags/flags.go

@@ -35,6 +35,8 @@ const (
 	SignModeDirect = "direct"
 	// SignModeLegacyAminoJSON is the value of the --sign-mode flag for SIGN_MODE_LEGACY_AMINO_JSON
 	SignModeLegacyAminoJSON = "amino-json"
+	// SignModeEIP191 is the value of the --sign-mode flag for SIGN_MODE_EIP_191
+	SignModeEIP191 = "eip-191"
 )
 
 // List of CLI flags

client/tx/factory.go

@@ -45,6 +45,8 @@ func NewFactoryCLI(clientCtx client.Context, flagSet *pflag.FlagSet) Factory {
 		signMode = signing.SignMode_SIGN_MODE_DIRECT
 	case flags.SignModeLegacyAminoJSON:
 		signMode = signing.SignMode_SIGN_MODE_LEGACY_AMINO_JSON
+	case flags.SignModeEIP191:
+		signMode = signing.SignMode_SIGN_MODE_EIP_191
 	}
 
 	accNum, _ := flagSet.GetUint64(flags.FlagAccountNumber)

proto/cosmos/tx/signing/v1beta1/signing.proto

@@ -24,6 +24,18 @@ enum SignMode {
   // SIGN_MODE_LEGACY_AMINO_JSON is a backwards compatibility mode which uses
   // Amino JSON and will be removed in the future
   SIGN_MODE_LEGACY_AMINO_JSON = 127;
+
+  // SIGN_MODE_EIP_191 specifies the sign mode for EIP 191 signing on the Cosmos
+  // SDK. Ref: https://eips.ethereum.org/EIPS/eip-191
+  // 
+  // Currently, SIGN_MODE_EIP_191 is registered as a SignMode enum variant,
+  // but is not implemented on the SDK by default. To enable EIP-191, you need
+  // to pass a custom `TxConfig` that has an implementation of
+  // `SignModeHandler` for EIP-191. The SDK may decide to fully support
+  // EIP-191 in the future.
+  //
+  // Since: cosmos-sdk 0.45.2
+  SIGN_MODE_EIP_191 = 191;
 }
 
 // SignatureDescriptors wraps multiple SignatureDescriptor's.

x/auth/tx/config.go

@@ -23,9 +23,16 @@ type config struct {
 
 // NewTxConfig returns a new protobuf TxConfig using the provided ProtoCodec and sign modes. The
 // first enabled sign mode will become the default sign mode.
+// NOTE: Use NewTxConfigWithHandler to provide a custom signing handler in case the sign mode
+// is not supported by default (eg: SignMode_SIGN_MODE_EIP_191).
 func NewTxConfig(protoCodec codec.ProtoCodecMarshaler, enabledSignModes []signingtypes.SignMode) client.TxConfig {
+	return NewTxConfigWithHandler(protoCodec, makeSignModeHandler(enabledSignModes))
+}
+
+// NewTxConfig returns a new protobuf TxConfig using the provided ProtoCodec and signing handler.
+func NewTxConfigWithHandler(protoCodec codec.ProtoCodecMarshaler, handler signing.SignModeHandler) client.TxConfig {
 	return &config{
-		handler:     makeSignModeHandler(enabledSignModes),
+		handler:     handler,
 		decoder:     DefaultTxDecoder(protoCodec),
 		encoder:     DefaultTxEncoder(),
 		jsonDecoder: DefaultJSONTxDecoder(protoCodec),