chore!: update minimum golang version (#58)

* update readme about MSGV

* update to 1.20

* fix deprecated method

* remove deprecated rand.Read method

* run: `gofumpt -w .`

* update CI to run against minimum, current and latest

* update readme

.github/workflows/test.yml

@@ -18,9 +18,9 @@ jobs:
           - macos-latest
           - windows-latest
         go-version:
-          - 1.18.x
-          - 1.19.x
-          - 1.20.x
+          - 1.18.x # Minimmum version
+          - 1.20.x # Current version
+          - 1.21.x # Latest version
 
     steps:
     - uses: actions/checkout@v3

bench_test.go

@@ -1,28 +1,35 @@
 package gokzg4844_test
 
 import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
 	"fmt"
-	// We do not require crypto/rand in tests
-	"math/rand"
+	"log"
 	"testing"
 
 	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
 	gokzg4844 "github.com/crate-crypto/go-kzg-4844"
 	"github.com/stretchr/testify/require"
 )
 
-// / Returns a serialized random field element in big-endian
-func GetRandFieldElement(seed int64) [32]byte {
-	rand.Seed(seed)
-
-	bytes := make([]byte, 32)
-	_, err := rand.Read(bytes)
+func deterministicRandomness(seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
 	if err != nil {
-		panic("failed to get random field element")
+		log.Fatalf("Failed to write int64 to bytes buffer: %v", err)
 	}
+	bytes := buf.Bytes()
 
+	return sha256.Sum256(bytes)
+}
+
+// Returns a serialized random field element in big-endian
+func GetRandFieldElement(seed int64) [32]byte {
+	bytes := deterministicRandomness(seed)
 	var r fr.Element
-	r.SetBytes(bytes)
+	r.SetBytes(bytes[:])
 
 	return gokzg4844.SerializeScalar(r)
 }

go.mod

@@ -1,6 +1,6 @@
 module github.com/crate-crypto/go-kzg-4844
 
-go 1.18
+go 1.20
 
 require (
 	github.com/consensys/gnark-crypto v0.10.0

readme.md

@@ -53,9 +53,9 @@ to only panic on startup; only methods which are called when we create the
 
 ## Minimum Supported Golang Version
 
-Because we use generics, the minimum golang version is 1.18, which seems to be
-fairly conservative. However, if a lower version is needed, replacing the
-generics is fairly straightforward.
+Because we use generics, the minimum golang version needs to be 1.18 or above. Since Golang only back ports security fixes to the latest version and one version behind latest, this library will at most be one version behind latest.
+
+Tests are ran against the 1.18, the current version and the latest version. If support for 1.18 is broken, we will update the CI to reflect this with a given reason.
 
 ## License