Minor lint fixes

- Remove redundant nil check in NewHMACSHA256Signer
- Remove unused keyID field in TestNewRSASigner1
- Replace interface{} with any for modern Go idiom
- Add lint ignore directive for intentional reEncodeQPs naming
- Add error handling in test
- Add explanatory comments for intentional lowercase header keys

Author: yaronf

crypto.go

@@ -34,7 +34,7 @@ type Signer struct {
 // NewHMACSHA256Signer returns a new Signer structure. Key must be at least 64 bytes long.
 // Config may be nil for a default configuration.
 func NewHMACSHA256Signer(key []byte, config *SignConfig, fields Fields) (*Signer, error) {
-	if key == nil || len(key) < 64 {
+	if len(key) < 64 {
 		return nil, fmt.Errorf("key must be at least 64 bytes long")
 	}
 	if config == nil {

crypto_test.go

@@ -71,7 +71,7 @@ func TestNewHMACSHA256Signer(t *testing.T) {
 
 func TestSigner_sign(t *testing.T) {
 	type fields struct {
-		key interface{}
+		key any
 		alg string
 	}
 	type args struct {
@@ -210,7 +210,6 @@ func makeRSAPrivateKey() *rsa.PrivateKey {
 }
 func TestNewRSASigner1(t *testing.T) {
 	type args struct {
-		keyID  string
 		key    *rsa.PrivateKey
 		config *SignConfig
 		fields Fields
@@ -256,7 +255,7 @@ func TestNewRSASigner1(t *testing.T) {
 func TestNewJWSVerifier(t *testing.T) {
 	type args struct {
 		alg    jwa.SignatureAlgorithm
-		key    interface{}
+		key    any
 		keyID  string
 		config *VerifyConfig
 		fields Fields
@@ -418,7 +417,7 @@ func TestMessageForeignSignerV3(t *testing.T) {
 func TestNewJWSVerifierV3(t *testing.T) {
 	type args struct {
 		alg    jwav3.SignatureAlgorithm
-		key    interface{}
+		key    any
 		config *VerifyConfig
 		fields Fields
 	}

httpparse.go

@@ -41,6 +41,7 @@ func parseRequest(req *http.Request, withTrailers bool) (*parsedMessage, error)
 	return parseMessage(msg, withTrailers)
 }
 
+//lint:ignore ST1003 QPs is intentional abbreviation for Query Parameters
 func reEncodeQPs(values url.Values) url.Values {
 	escaped := url.Values{}
 	for key, v := range values { // Re-escape query parameters, both names and values

signatures.go

@@ -464,15 +464,17 @@ func ResponseSignatureNames(res *http.Response, withTrailers bool) ([]string, er
 }
 
 func messageSignatureNames(parsedMessage *parsedMessage, withTrailers bool) ([]string, error) {
-	//lint:ignore SA1008 the Header type expects canonicalized names, tough
+	// Note: parsedMessage.headers intentionally uses lowercase keys (see httpparse.go)
+	// Linter warning about non-canonical key is expected and can be ignored
 	signatureField := parsedMessage.headers["signature"]
 	dict, err := httpsfv.UnmarshalDictionary(signatureField)
 	if err != nil {
 		return nil, fmt.Errorf("cannot parse signature field: %w", err)
 	}
 	names := dict.Names()
 	if withTrailers {
-		//lint:ignore SA1008 the Header type expects canonicalized names, tough
+		// Note: parsedMessage.trailers intentionally uses lowercase keys (see httpparse.go)
+		// Linter warning about non-canonical key is expected and can be ignored
 		signatureField := parsedMessage.trailers["signature"]
 		dict, err := httpsfv.UnmarshalDictionary(signatureField)
 		if err != nil {

signatures_test.go

@@ -3062,6 +3062,7 @@ func TestMessageRequestBindingSignedResponse17(t *testing.T) {
 
 	res := readResponse(httpres10)
 	msg, err := NewMessage(NewMessageConfig().WithResponse(res, req))
+	assert.NoError(t, err, "cannot create message")
 	pubKey2, err := parseECPublicKeyFromPemStr(p256PubKey2)
 	assert.NoError(t, err, "read pub key")
 	fields2 := *NewFields().AddHeaders("@status", "content-digest", "content-type").