feat(types): add event validation and tag marshal

go.mod

@@ -3,13 +3,17 @@ module github.com/dezh-tech/immortal
 go 1.22.5
 
 require (
+	github.com/btcsuite/btcd/btcec/v2 v2.3.4
 	github.com/mailru/easyjson v0.7.7
 	github.com/stretchr/testify v1.9.0
 	github.com/tidwall/gjson v1.17.3
 )
 
 require (
+	github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/decred/dcrd/crypto/blake256 v1.0.0 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/tidwall/match v1.1.1 // indirect

go.sum

@@ -1,5 +1,13 @@
+github.com/btcsuite/btcd/btcec/v2 v2.3.4 h1:3EJjcN70HCu/mwqlUsGK8GcNVyLVxFDlWurTXGPFfiQ=
+github.com/btcsuite/btcd/btcec/v2 v2.3.4/go.mod h1:zYzJ8etWJQIv1Ogk7OzpWjowwOdXY1W/17j2MW85J04=
+github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 h1:q0rUy8C/TYNBQS1+CGKw68tLOFYSNEs0TFnxxnS9+4U=
+github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1/go.mod h1:7SFka0XMvUgj3hfZtydOrQY2mwhPclbT2snogU7SQQc=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/decred/dcrd/crypto/blake256 v1.0.0 h1:/8DMNYp9SGi5f0w7uCm6d6M4OU2rGFK09Y2A4Xv7EE0=
+github.com/decred/dcrd/crypto/blake256 v1.0.0/go.mod h1:sQl2p6Y26YV+ZOcSTP6thNdn47hh8kt6rqSlvmrXFAc=
+github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 h1:YLtO71vCjJRCBcrPMtQ9nqBsqpA1m5sE92cU+pd5Mcc=
+github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1/go.mod h1:hyedUtir6IdtD/7lIxGeCxkaw7y45JueMRL4DIyJDKs=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=

makefile

@@ -0,0 +1,33 @@
+PACKAGES=$(shell go list ./... | grep -v 'tests' | grep -v 'grpc/gen')
+
+ifneq (,$(filter $(OS),Windows_NT MINGW64))
+EXE = .exe
+RM = del /q
+else
+RM = rm -rf
+endif
+
+### Tools needed for development
+devtools:
+	@echo "Installing devtools"
+	go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+	go install mvdan.cc/gofumpt@latest
+	go install github.com/ethereum/go-ethereum/cmd/abigen@latest
+
+### Testing
+unit_test:
+	go test $(PACKAGES)
+
+### Formatting the code
+fmt:
+	gofumpt -l -w .
+	go mod tidy
+
+check:
+	golangci-lint run --timeout=20m0s
+
+### pre commit
+pre-commit: fmt check unit_test
+	@echo ready to commit...
+
+.PHONY: build

types/event/event.go

@@ -1,9 +1,15 @@
 package event
 
 import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+
 	"github.com/dezh-tech/immortal/types"
 	"github.com/dezh-tech/immortal/types/filter"
 	"github.com/mailru/easyjson"
+
+	"github.com/btcsuite/btcd/btcec/v2/schnorr"
 )
 
 // Event represents an event structure defined on NIP-01.
@@ -89,7 +95,56 @@ func (e *Event) Encode() ([]byte, error) {
 	return b, nil
 }
 
+func (evt *Event) Serialize() []byte {
+	// the serialization process is just putting everything into a JSON array
+	// so the order is kept. See NIP-01
+	dst := make([]byte, 0)
+
+	// the header portion is easy to serialize
+	// [0,"pubkey",created_at,kind,[
+	dst = append(dst, []byte(
+		fmt.Sprintf(
+			"[0,\"%s\",%d,%d,",
+			evt.PublicKey,
+			evt.CreatedAt,
+			evt.Kind,
+		))...)
+
+	// tags
+	dst = types.MarshalTo(evt.Tags, dst)
+	dst = append(dst, ',')
+
+	// content needs to be escaped in general as it is user generated.
+	dst = types.EscapeString(dst, evt.Content)
+	dst = append(dst, ']')
+
+	return dst
+}
+
 // IsValid function validats an event Signature and ID.
-func (e *Event) IsValid() bool {
-	return false // TODO:::
+func (e *Event) IsValid() (bool, error) {
+	// read and check pubkey
+	pk, err := hex.DecodeString(e.PublicKey)
+	if err != nil {
+		return false, fmt.Errorf("event pubkey '%s' is invalid hex: %w", e.PublicKey, err)
+	}
+
+	pubkey, err := schnorr.ParsePubKey(pk)
+	if err != nil {
+		return false, fmt.Errorf("event has invalid pubkey '%s': %w", e.PublicKey, err)
+	}
+
+	// read signature
+	s, err := hex.DecodeString(e.Signature)
+	if err != nil {
+		return false, fmt.Errorf("signature '%s' is invalid hex: %w", e.Signature, err)
+	}
+	sig, err := schnorr.ParseSignature(s)
+	if err != nil {
+		return false, fmt.Errorf("failed to parse signature: %w", err)
+	}
+
+	// check signature
+	hash := sha256.Sum256(e.Serialize())
+	return sig.Verify(hash[:], pubkey), nil
 }

types/event/event_test.go

@@ -3,6 +3,7 @@ package event_test
 import (
 	"testing"
 
+	"github.com/dezh-tech/immortal/types"
 	"github.com/dezh-tech/immortal/types/event"
 	"github.com/dezh-tech/immortal/types/filter"
 	"github.com/stretchr/testify/assert"
@@ -29,6 +30,20 @@ var (
 
 	DecodedEvent *event.Event
 	EncodedEvent []byte
+
+	events = []event.Event{
+		{
+			ID:        "dc90c95f09947507c1044e8f48bcf6350aa6bff1507dd4acfc755b9239b5c962",
+			PublicKey: "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d",
+			CreatedAt: 1644271588,
+			Kind:      types.KindTextNote,
+			Tags:      []types.Tag{},
+			Content:   "now that https://blueskyweb.org/blog/2-7-2022-overview was announced we can stop working on nostr?",
+			Signature: "230e9d8f0ddaf7eb70b5f7741ccfa37e87a455c9a469282e3464e2052d3192cd63a167e196e381ef9d7e69e9ea43af2443b839974dc85d8aaab9efe1d9296524",
+		},
+	}
+
+	EventValidation bool
 )
 
 func TestDecode(t *testing.T) {
@@ -91,3 +106,22 @@ func TestMatch(t *testing.T) {
 
 	assert.True(t, e.Match(*f))
 }
+
+func TestValidate(t *testing.T) {
+	for _, e := range events {
+		valid, err := e.IsValid()
+
+		assert.NoError(t, err)
+		assert.True(t, valid)
+	}
+}
+
+func BenchmarkValidate(b *testing.B) {
+	var eventValidation bool
+	for i := 0; i < b.N; i++ {
+		for _, e := range events {
+			eventValidation, _ = e.IsValid()
+		}
+	}
+	EventValidation = eventValidation
+}

types/tag.go

@@ -1,3 +1,30 @@
 package types
 
 type Tag []string
+
+// Marshal Tag. Used for Serialization so string escaping should be as in RFC8259.
+func (tag Tag) MarshalTo(dst []byte) []byte {
+	dst = append(dst, '[')
+	for i, s := range tag {
+		if i > 0 {
+			dst = append(dst, ',')
+		}
+		dst = EscapeString(dst, s)
+	}
+	dst = append(dst, ']')
+	return dst
+}
+
+// MarshalTo appends the JSON encoded byte of Tags as [][]string to dst.
+// String escaping is as described in RFC8259.
+func MarshalTo(tags []Tag, dst []byte) []byte {
+	dst = append(dst, '[')
+	for i, tag := range tags {
+		if i > 0 {
+			dst = append(dst, ',')
+		}
+		dst = tag.MarshalTo(dst)
+	}
+	dst = append(dst, ']')
+	return dst
+}

types/utils.go

@@ -23,3 +23,43 @@ func ContainsKind(target Kind, arr []Kind) bool {
 
 	return false
 }
+
+// Escaping strings for JSON encoding according to RFC8259.
+// Also encloses result in quotation marks "".
+func EscapeString(dst []byte, s string) []byte {
+	dst = append(dst, '"')
+	for i := 0; i < len(s); i++ {
+		c := s[i]
+		switch {
+		case c == '"':
+			// quotation mark
+			dst = append(dst, []byte{'\\', '"'}...)
+		case c == '\\':
+			// reverse solidus
+			dst = append(dst, []byte{'\\', '\\'}...)
+		case c >= 0x20:
+			// default, rest below are control chars
+			dst = append(dst, c)
+		case c == 0x08:
+			dst = append(dst, []byte{'\\', 'b'}...)
+		case c < 0x09:
+			dst = append(dst, []byte{'\\', 'u', '0', '0', '0', '0' + c}...)
+		case c == 0x09:
+			dst = append(dst, []byte{'\\', 't'}...)
+		case c == 0x0a:
+			dst = append(dst, []byte{'\\', 'n'}...)
+		case c == 0x0c:
+			dst = append(dst, []byte{'\\', 'f'}...)
+		case c == 0x0d:
+			dst = append(dst, []byte{'\\', 'r'}...)
+		case c < 0x10:
+			dst = append(dst, []byte{'\\', 'u', '0', '0', '0', 0x57 + c}...)
+		case c < 0x1a:
+			dst = append(dst, []byte{'\\', 'u', '0', '0', '1', 0x20 + c}...)
+		case c < 0x20:
+			dst = append(dst, []byte{'\\', 'u', '0', '0', '1', 0x47 + c}...)
+		}
+	}
+	dst = append(dst, '"')
+	return dst
+}