fix(deps): Internalize pion/randutil

Signed-off-by: Steffen Vogel <post@steffenvogel.de>

go.mod

@@ -27,7 +27,6 @@ require (
 	github.com/mitchellh/mapstructure v1.5.0
 	github.com/pion/ice/v4 v4.0.3
 	github.com/pion/logging v0.2.2
-	github.com/pion/randutil v0.1.0
 	github.com/pion/stun/v3 v3.0.0
 	github.com/spf13/cobra v1.8.1
 	github.com/spf13/pflag v1.0.5
@@ -77,6 +76,7 @@ require (
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
 	github.com/pion/dtls/v3 v3.0.4 // indirect
 	github.com/pion/mdns/v2 v2.0.7 // indirect
+	github.com/pion/randutil v0.1.0 // indirect
 	github.com/pion/transport/v3 v3.0.7 // indirect
 	github.com/pion/turn/v4 v4.0.0 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect

pkg/crypto/crypto.go

@@ -4,7 +4,10 @@
 // Package crypto implements basic crypto primitives used in the project
 package crypto
 
-import "crypto/rand"
+import (
+	"crypto/rand"
+	"math/big"
+)
 
 func GetNonce(length int) (Nonce, error) {
 	nonce := make(Nonce, length)
@@ -16,3 +19,17 @@ func GetNonce(length int) (Nonce, error) {
 
 	return nonce, nil
 }
+
+// GetRandomString generates a random string for cryptographic usage.
+func GetRandomString(n int, runes string) (string, error) {
+	letters := []rune(runes)
+	b := make([]rune, n)
+	for i := range b {
+		v, err := rand.Int(rand.Reader, big.NewInt(int64(len(letters))))
+		if err != nil {
+			return "", err
+		}
+		b[i] = letters[v.Int64()]
+	}
+	return string(b), nil
+}

pkg/crypto/crypto_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"cunicu.li/cunicu/pkg/crypto"
+	"cunicu.li/cunicu/pkg/tty"
 	"cunicu.li/cunicu/test"
 
 	. "github.com/onsi/ginkgo/v2"
@@ -19,11 +20,20 @@ func TestSuite(t *testing.T) {
 	RunSpecs(t, "Crypto Suite")
 }
 
-var _ = Describe("nonce", func() {
+var _ = Describe("generate", func() {
-	It("can generate a valid nonce", func() {
+	It("nonce", func() {
 		nonce, err := crypto.GetNonce(100)
 		Expect(err).To(Succeed())
 		Expect(nonce).To(HaveLen(100))
 		Expect([]byte(nonce)).To(test.BeRandom())
 	})
+
+	It("random string", func() {
+		for i := 0; i < 10000; i++ {
+			s, err := crypto.GetRandomString(10, tty.RunesAlpha)
+			Expect(err).To(Succeed())
+			Expect(s).To(HaveLen(10))
+			Expect(s).To(MatchRegexp(`^[a-zA-Z]+$`), "Generator returned unexpected character")
+		}
+	})
 })

pkg/proto/feature/epdisc/epdisc.go

@@ -10,8 +10,8 @@ import (
 	"strings"
 
 	"github.com/pion/ice/v4"
-	"github.com/pion/randutil"
 
+	"cunicu.li/cunicu/pkg/crypto"
 	"cunicu.li/cunicu/pkg/log"
 	"cunicu.li/cunicu/pkg/tty"
 )
@@ -43,12 +43,12 @@ func NewConnectionState(cs ice.ConnectionState) ConnectionState {
 }
 
 func NewCredentials() *Credentials {
-	ufrag, err := randutil.GenerateCryptoRandomString(lenUFrag, tty.RunesAlpha)
+	ufrag, err := crypto.GetRandomString(lenUFrag, tty.RunesAlpha)
 	if err != nil {
 		panic(err)
 	}
 
-	pwd, err := randutil.GenerateCryptoRandomString(lenPwd, tty.RunesAlpha)
+	pwd, err := crypto.GetRandomString(lenPwd, tty.RunesAlpha)
 	if err != nil {
 		panic(err)
 	}