Graffiti hex support (#8894)

* more or less feature complete, needs unit tests

* Test support and concomitant refactors

* Resolving requested changes on PR

* minor fix before trying to figure out bazel

* bazel change

* minor changes requested in pr

* fixing build errors

* fixing build errors

* fixing PR feedback

* fixing PR feedback

* resolving nitpicks

* resolving nitpicks

* build failures REEEEE

* tests fail if its not this way, so this way it is

* getting the tests to pass

Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>
Co-authored-by: Preston Van Loon <preston@prysmaticlabs.com>

validator/graffiti/BUILD.bazel

@@ -3,12 +3,16 @@ load("@prysm//tools/go:def.bzl", "go_library")
 
 go_library(
     name = "go_default_library",
-    srcs = ["parse_graffiti.go"],
+    srcs = [
+        "log.go",
+        "parse_graffiti.go",
+    ],
     importpath = "github.com/prysmaticlabs/prysm/validator/graffiti",
     visibility = ["//validator:__subpackages__"],
     deps = [
         "//shared/hashutil:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
         "@in_gopkg_yaml_v2//:go_default_library",
     ],
 )
@@ -19,6 +23,7 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//shared/hashutil:go_default_library",
+        "//shared/testutil/assert:go_default_library",
         "//shared/testutil/require:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
     ],

validator/graffiti/log.go

@@ -0,0 +1,5 @@
+package graffiti
+
+import "github.com/sirupsen/logrus"
+
+var log = logrus.WithField("prefix", "graffiti")

validator/graffiti/parse_graffiti.go

@@ -1,13 +1,20 @@
 package graffiti
 
 import (
+	"encoding/hex"
 	"io/ioutil"
+	"strings"
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/shared/hashutil"
 	"gopkg.in/yaml.v2"
 )
 
+const (
+	hexGraffitiPrefix = "hex"
+	hex0xPrefix       = "0x"
+)
+
 // Graffiti is a graffiti container.
 type Graffiti struct {
 	Hash     [32]byte
@@ -27,6 +34,47 @@ func ParseGraffitiFile(f string) (*Graffiti, error) {
 	if err := yaml.Unmarshal(yamlFile, g); err != nil {
 		return nil, err
 	}
+
+	for i, o := range g.Specific {
+		g.Specific[types.ValidatorIndex(i)] = ParseHexGraffiti(o)
+	}
+
+	for i, v := range g.Ordered {
+		g.Ordered[i] = ParseHexGraffiti(v)
+	}
+
+	for i, v := range g.Random {
+		g.Random[i] = ParseHexGraffiti(v)
+	}
+
+	g.Default = ParseHexGraffiti(g.Default)
 	g.Hash = hashutil.Hash(yamlFile)
+
 	return g, nil
 }
+
+// ParseHexGraffiti checks if a graffiti input is being represented in hex and converts it to ASCII if so
+func ParseHexGraffiti(rawGraffiti string) string {
+	splitGraffiti := strings.SplitN(rawGraffiti, ":", 2)
+	if strings.ToLower(splitGraffiti[0]) == hexGraffitiPrefix {
+		target := splitGraffiti[1]
+		if target == "" {
+			log.WithField("graffiti", rawGraffiti).Debug("Blank hex tag to be interpreted as itself")
+			return rawGraffiti
+		}
+		if len(target) > 3 && target[:2] == hex0xPrefix {
+			target = target[2:]
+		}
+		if target == "" {
+			log.WithField("graffiti", rawGraffiti).Debug("Nothing after 0x prefix, hex tag to be interpreted as itself")
+			return rawGraffiti
+		}
+		graffiti, err := hex.DecodeString(target)
+		if err != nil {
+			log.WithError(err).Debug("Error while decoding hex string")
+			return rawGraffiti
+		}
+		return string(graffiti)
+	}
+	return rawGraffiti
+}

validator/graffiti/parse_graffiti_test.go

@@ -8,6 +8,7 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/shared/hashutil"
+	"github.com/prysmaticlabs/prysm/shared/testutil/assert"
 	"github.com/prysmaticlabs/prysm/shared/testutil/require"
 )
 
@@ -157,3 +158,64 @@ specific:
 	}
 	require.DeepEqual(t, wanted, got)
 }
+
+func TestParseHexGraffiti(t *testing.T) {
+	tests := []struct {
+		name  string
+		want  string
+		input string
+	}{
+		{
+			name:  "standard",
+			want:  "hola mundo!",
+			input: "hola mundo!",
+		},
+		{
+			name:  "standard with hex tag",
+			want:  "hola mundo!",
+			input: "hex:686f6c61206d756e646f21",
+		},
+		{
+			name:  "irregularly cased hex tag",
+			want:  "hola mundo!",
+			input: "HEX:686f6c61206d756e646f21",
+		},
+		{
+			name:  "hex tag without accompanying data",
+			want:  "hex:",
+			input: "hex:",
+		},
+		{
+			name:  "Passing non-hex data with hex tag",
+			want:  "hex:hola mundo!",
+			input: "hex:hola mundo!",
+		},
+		{
+			name:  "unmarked hex input",
+			want:  "0x686f6c61206d756e646f21",
+			input: "0x686f6c61206d756e646f21",
+		},
+		{
+			name:  "Properly tagged hex data with 0x prefix",
+			want:  "hola mundo!",
+			input: "hex:0x686f6c61206d756e646f21",
+		},
+		{
+			name:  "hex tag with 0x prefix and no other data",
+			want:  "hex:0x",
+			input: "hex:0x",
+		},
+		{
+			name:  "hex tag with 0x prefix and invalid hex data",
+			want:  "hex:0xhola mundo",
+			input: "hex:0xhola mundo",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			out := ParseHexGraffiti(tt.input)
+			assert.Equal(t, out, tt.want)
+		})
+	}
+}

validator/node/node.go

@@ -409,7 +409,7 @@ func (c *ValidatorClient) registerValidatorService(
 		LogValidatorBalances:       logValidatorBalances,
 		EmitAccountMetrics:         emitAccountMetrics,
 		CertFlag:                   cert,
-		GraffitiFlag:               graffiti,
+		GraffitiFlag:               g.ParseHexGraffiti(graffiti),
 		GrpcMaxCallRecvMsgSizeFlag: maxCallRecvMsgSize,
 		GrpcRetriesFlag:            grpcRetries,
 		GrpcRetryDelay:             grpcRetryDelay,
@@ -421,10 +421,10 @@ func (c *ValidatorClient) registerValidatorService(
 		GraffitiStruct:             gStruct,
 		LogDutyCountDown:           c.cliCtx.Bool(flags.EnableDutyCountDown.Name),
 	})
-
 	if err != nil {
 		return errors.Wrap(err, "could not initialize validator service")
 	}
+
 	return c.services.RegisterService(v)
 }
 func (c *ValidatorClient) registerSlasherService() error {