feat: EIP191 sign mode (#11533)

## Description

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

Ref: #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)

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.
 * (x/genutil) [\#11500](https://github.com/cosmos/cosmos-sdk/pull/11500) Fix GenTx validation and adjust error messages
 * [\#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/upgrade) [\#11116](https://github.com/cosmos/cosmos-sdk/pull/11116) `MsgSoftwareUpgrade` and  has been added to support v1beta2 msgs-based gov proposals.

client/cmd.go

@@ -274,7 +274,7 @@ func readTxCommandFlags(clientCtx Context, flagSet *pflag.FlagSet) (Context, err
 				clientCtx = clientCtx.WithOutputFormat("json")
 			}
 
-			// If the user didn't explicity set a --sign-mode flag, use
+			// If the user didn't explicitly set a --sign-mode flag, use
 			// DIRECT_AUX by default.
 			if clientCtx.SignModeStr == "" || !flagSet.Changed(flags.FlagSignMode) {
 				clientCtx = clientCtx.WithSignModeStr(flags.SignModeDirectAux)

client/flags/flags.go

@@ -37,6 +37,8 @@ const (
 	SignModeLegacyAminoJSON = "amino-json"
 	// SignModeDirectAux is the value of the --sign-mode flag for SIGN_MODE_DIRECT_AUX
 	SignModeDirectAux = "direct-aux"
+	// 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

@@ -51,6 +51,8 @@ func NewFactoryCLI(clientCtx client.Context, flagSet *pflag.FlagSet) Factory {
 		signMode = signing.SignMode_SIGN_MODE_LEGACY_AMINO_JSON
 	case flags.SignModeDirectAux:
 		signMode = signing.SignMode_SIGN_MODE_DIRECT_AUX
+	case flags.SignModeEIP191:
+		signMode = signing.SignMode_SIGN_MODE_EIP_191
 	}
 
 	accNum, _ := flagSet.GetUint64(flags.FlagAccountNumber)

go.sum

@@ -63,7 +63,6 @@ cloud.google.com/go/storage v1.14.0/go.mod h1:GrKmX003DSIwi9o29oFT7YDnHYwZoctc3f
 collectd.org v0.3.0/go.mod h1:A/8DzQBkF6abtvrT2j/AU/4tiBgJWYyh0y/oB/4MlWE=
 contrib.go.opencensus.io/exporter/stackdriver v0.13.4/go.mod h1:aXENhDJ1Y4lIg4EUaVTwzvYETVNZk10Pu26tevFKLUc=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
-filippo.io/edwards25519 v1.0.0-beta.2/go.mod h1:X+pm78QAUPtFLi1z9PYIlS/bdDnvbCOGKtZ+ACWEf7o=
 filippo.io/edwards25519 v1.0.0-rc.1 h1:m0VOOB23frXZvAOK44usCgLWvtsxIoMCTBGJZlpmGfU=
 filippo.io/edwards25519 v1.0.0-rc.1/go.mod h1:N1IkdkCkiLB6tki+MYJoSx2JTY9NUlxZE7eHn5EwJns=
 git.sr.ht/~sircmpwn/getopt v0.0.0-20191230200459-23622cc906b3/go.mod h1:wMEGFFFNuPos7vHmWXfszqImLppbc0wEhh6JBfJIUgw=
@@ -286,7 +285,6 @@ github.com/cosmos/cosmos-sdk/errors v1.0.0-beta.3 h1:Ep7FHNViVwwGnwLFEPewZYsyN2C
 github.com/cosmos/cosmos-sdk/errors v1.0.0-beta.3/go.mod h1:HFea93YKmoMJ/mNKtkSeJZDtyJ4inxBsUK928KONcqo=
 github.com/cosmos/go-bip39 v1.0.0 h1:pcomnQdrdH22njcAatO0yWojsUnCO3y2tNoV1cb6hHY=
 github.com/cosmos/go-bip39 v1.0.0/go.mod h1:RNJv0H/pOIVgxw6KS7QeX2a0Uo0aKUlfhZ4xuwvCdJw=
-github.com/cosmos/gorocksdb v1.2.0/go.mod h1:aaKvKItm514hKfNJpUJXnnOWeBnk2GL4+Qw9NHizILw=
 github.com/cosmos/iavl v0.18.0 h1:02ur4vnalMR2GuWCFNkuseUcl/BCVmg9tOeHOGiZOkE=
 github.com/cosmos/iavl v0.18.0/go.mod h1:L0VZHfq0tqMNJvXlslGExaaiZM7eSm+90Vh9QUbp6j4=
 github.com/cosmos/keyring v1.1.7-0.20210622111912-ef00f8ac3d76 h1:DdzS1m6o/pCqeZ8VOAit/gyATedRgjvkVI+UCrLpyuU=
@@ -322,7 +320,6 @@ github.com/desertbit/timer v0.0.0-20180107155436-c41aec40b27f/go.mod h1:xH/i4TFM
 github.com/dgraph-io/badger/v2 v2.2007.2/go.mod h1:26P/7fbL4kUZVEVKLAKXkBXKOydDmM2p1e+NhhnBCAE=
 github.com/dgraph-io/badger/v2 v2.2007.4 h1:TRWBQg8UrlUhaFdco01nO2uXwzKS7zd+HVdwV/GHc4o=
 github.com/dgraph-io/badger/v2 v2.2007.4/go.mod h1:vSw/ax2qojzbN6eXHIx6KPKtCSHJN/Uz0X0VPruTIhk=
-github.com/dgraph-io/badger/v3 v3.2103.2/go.mod h1:RHo4/GmYcKKh5Lxu63wLEMHJ70Pac2JqZRYGhlyAo2M=
 github.com/dgraph-io/ristretto v0.0.3-0.20200630154024-f66de99634de/go.mod h1:KPxhHT9ZxKefz+PCeOGsrHpl1qZ7i70dGTu2u+Ahh6E=
 github.com/dgraph-io/ristretto v0.0.3/go.mod h1:KPxhHT9ZxKefz+PCeOGsrHpl1qZ7i70dGTu2u+Ahh6E=
 github.com/dgraph-io/ristretto v0.1.0 h1:Jv3CGQHp9OjuMBSne1485aDpUkTKEcUqF+jm/LuerPI=
@@ -535,8 +532,6 @@ github.com/google/btree v1.0.1/go.mod h1:xXMiIv4Fb/0kKde4SpL7qlzvu5cMJDRkFDxJfI9
 github.com/google/certificate-transparency-go v1.0.21/go.mod h1:QeJfpSbVSfYc7RgB3gJFj9cbuQMMchQxrWXz8Ruopmg=
 github.com/google/certificate-transparency-go v1.1.1/go.mod h1:FDKqPvSXawb2ecErVRrD+nfy23RCzyl7eqVCEmlT1Zs=
 github.com/google/flatbuffers v1.11.0/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
-github.com/google/flatbuffers v1.12.1/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
-github.com/google/flatbuffers v2.0.0+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
@@ -700,8 +695,6 @@ github.com/hashicorp/memberlist v0.3.0/go.mod h1:MS2lj3INKhZjWNqd3N0m3J+Jxf3DAOn
 github.com/hashicorp/serf v0.8.2/go.mod h1:6hOLApaqBFA1NXqRQAsxw9QxuDEvNxSQRwA/JwenrHc=
 github.com/hashicorp/serf v0.9.5/go.mod h1:UWDWwZeL5cuWDJdl0C6wrvrUwEqtQ4ZKBKKENpqIUyk=
 github.com/hashicorp/serf v0.9.6/go.mod h1:TXZNMjZQijwlDvp+r0b63xZ45H7JmCmgg4gpTwn9UV4=
-github.com/hdevalence/ed25519consensus v0.0.0-20210204194344-59a8610d2b87 h1:uUjLpLt6bVvZ72SQc/B4dXcPBw4Vgd7soowdRl52qEM=
-github.com/hdevalence/ed25519consensus v0.0.0-20210204194344-59a8610d2b87/go.mod h1:XGsKKeXxeRr95aEOgipvluMPlgjr7dGlk9ZTWOjcUcg=
 github.com/hdevalence/ed25519consensus v0.0.0-20220222234857-c00d1f31bab3 h1:aSVUgRRRtOrZOC1fYmY9gV0e9z/Iu+xNVSASWjsuyGU=
 github.com/hdevalence/ed25519consensus v0.0.0-20220222234857-c00d1f31bab3/go.mod h1:5PC6ZNPde8bBqU/ewGZig35+UIZtw9Ytxez8/q5ZyFE=
 github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
@@ -1644,7 +1637,6 @@ golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211105183446-c75c47738b0c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20211113001501-0c823b97ae02/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211124211545-fe61309f8881/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211205182925-97ca703d548d/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211210111614-af8b64212486/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -1913,7 +1905,6 @@ google.golang.org/genproto v0.0.0-20211129164237-f09f9a12af12/go.mod h1:5CzLGKJ6
 google.golang.org/genproto v0.0.0-20211203200212-54befc351ae9/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211206160659-862468c7d6e0/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211208223120-3a66f561d7aa/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
-google.golang.org/genproto v0.0.0-20211223182754-3ac035c7e7cb/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20220222213610-43724f9ea8cf h1:SVYXkUz2yZS9FWb2Gm8ivSlbNQzL2Z/NpPKE3RG2jWk=
 google.golang.org/genproto v0.0.0-20220222213610-43724f9ea8cf/go.mod h1:kGP+zUP2Ddo0ayMi4YuN7C3WZyJvGLZRh8Z5wnAqvEI=
 google.golang.org/grpc v1.8.0/go.mod h1:yo6s7OP7yaDglbqo1J04qKzAhqBH6lvTonzMVmEdcZw=

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

@@ -39,6 +39,18 @@ 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.