don't panic 🤓

fixes #93

crypto/cert_compression.go

@@ -6,6 +6,7 @@ import (
 	"compress/zlib"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"hash/fnv"
 
 	"github.com/lucas-clemente/quic-go/utils"
@@ -63,7 +64,7 @@ func compressChain(chain [][]byte, pCommonSetHashes, pCachedHashes []byte) ([]by
 	if totalUncompressedLen > 0 {
 		gz, err := zlib.NewWriterLevelDict(res, flate.BestCompression, buildZlibDictForEntries(entries, chain))
 		if err != nil {
-			panic(err)
+			return nil, fmt.Errorf("cert compression failed: %s", err.Error())
 		}
 
 		utils.WriteUint32(res, uint32(totalUncompressedLen))

crypto/curve_25519.go

@@ -17,17 +17,17 @@ type curve25519KEX struct {
 var _ KeyExchange = &curve25519KEX{}
 
 // NewCurve25519KEX creates a new KeyExchange using Curve25519, see https://cr.yp.to/ecdh.html
-func NewCurve25519KEX() KeyExchange {
+func NewCurve25519KEX() (KeyExchange, error) {
 	c := &curve25519KEX{}
 	if _, err := io.ReadFull(rand.Reader, c.secret[:]); err != nil {
-		panic("Curve25519: could not create private key")
+		return nil, errors.New("Curve25519: could not create private key")
 	}
 	// See https://cr.yp.to/ecdh.html
 	c.secret[0] &= 248
 	c.secret[31] &= 127
 	c.secret[31] |= 64
 	curve25519.ScalarBaseMult(&c.public, &c.secret)
-	return c
+	return c, nil
 }
 
 func (c *curve25519KEX) PublicKey() []byte {

crypto/curve_25519_test.go

@@ -7,8 +7,10 @@ import (
 
 var _ = Describe("ProofRsa", func() {
 	It("works", func() {
-		a := NewCurve25519KEX()
-		b := NewCurve25519KEX()
+		a, err := NewCurve25519KEX()
+		Expect(err).ToNot(HaveOccurred())
+		b, err := NewCurve25519KEX()
+		Expect(err).ToNot(HaveOccurred())
 		sA, err := a.CalculateSharedKey(b.PublicKey())
 		Expect(err).ToNot(HaveOccurred())
 		sB, err := b.CalculateSharedKey(a.PublicKey())