pkg/utils: add RawReportContext and HashReport to support non-evm rel…

…ays (#60)

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.12.0
 	github.com/riferrei/srclient v0.4.1-0.20211229125508-8edc580da179
+	github.com/satori/go.uuid v1.2.0
 	github.com/smartcontractkit/libocr v0.0.0-20211210213233-5443fb9db7f7
 	github.com/stretchr/testify v1.7.0
 	go.uber.org/atomic v1.7.0

go.sum

@@ -1068,6 +1068,7 @@ github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb
 github.com/samuel/go-zookeeper v0.0.0-20190923202752-2cc03de413da/go.mod h1:gi+0XIa01GRL2eRQVjQkKGqKF3SF9vZR/HnPullcV2E=
 github.com/santhosh-tekuri/jsonschema/v5 v5.0.0 h1:TToq11gyfNlrMFZiYujSekIsPd9AmsA2Bj/iv+s4JHE=
 github.com/santhosh-tekuri/jsonschema/v5 v5.0.0/go.mod h1:FKdcjfQW6rpZSnxxUvEA5H/cDPdvJ/SZJQLWWXWGrZ0=
+github.com/satori/go.uuid v1.2.0 h1:0uYX9dsZ2yD7q2RtLRtPSdGDWzjeM3TbMJP9utgA0ww=
 github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdhQKdks0=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/segmentio/kafka-go v0.1.0/go.mod h1:X6itGqS9L4jDletMsxZ7Dz+JFWxM6JHfPOCvTvk+EJo=

pkg/utils/report.go

@@ -0,0 +1,32 @@
+package utils
+
+import (
+	"crypto/sha256"
+	"encoding/binary"
+
+	"github.com/smartcontractkit/libocr/offchainreporting2/types"
+)
+
+// RawReportContext is a copy of evmutil.RawReportContext to avoid importing go-ethereum.
+// github.com/smartcontractkit/libocr/offchainreporting2/chains/evmutil#RawReportContext
+func RawReportContext(repctx types.ReportContext) [3][32]byte {
+	rawRepctx := [3][32]byte{}
+	copy(rawRepctx[0][:], repctx.ConfigDigest[:])
+	binary.BigEndian.PutUint32(rawRepctx[1][32-5:32-1], repctx.Epoch)
+	rawRepctx[1][31] = repctx.Round
+	rawRepctx[2] = repctx.ExtraHash
+	return rawRepctx
+}
+
+// HashReport returns a report digest using SHA256 hash.
+func HashReport(ctx types.ReportContext, r types.Report) ([]byte, error) {
+	rawCtx := RawReportContext(ctx)
+	buf := sha256.New()
+	for _, v := range [][]byte{r[:], rawCtx[0][:], rawCtx[1][:], rawCtx[2][:]} {
+		if _, err := buf.Write(v); err != nil {
+			return []byte{}, err
+		}
+	}
+
+	return buf.Sum(nil), nil
+}