Fix golangci linting errors

Signed-off-by: Alistair Hey <alistair@heyal.co.uk>

ecdsa.go

@@ -13,7 +13,7 @@ var (
 	ErrECDSAVerification = errors.New("crypto/ecdsa: verification error")
 )
 
-// Implements the ECDSA family of signing methods signing methods
+// SigningMethodECDSA Implements the ECDSA family of signing methods signing methods
 // Expects *ecdsa.PrivateKey for signing and *ecdsa.PublicKey for verification
 type SigningMethodECDSA struct {
 	Name      string
@@ -53,7 +53,7 @@ func (m *SigningMethodECDSA) Alg() string {
 	return m.Name
 }
 
-// Implements the Verify method from SigningMethod
+// Verify Implements the Verify method from SigningMethod
 // For this verify method, key must be an ecdsa.PublicKey struct
 func (m *SigningMethodECDSA) Verify(signingString, signature string, key interface{}) error {
 	var err error
@@ -85,7 +85,9 @@ func (m *SigningMethodECDSA) Verify(signingString, signature string, key interfa
 		return ErrHashUnavailable
 	}
 	hasher := m.Hash.New()
-	hasher.Write([]byte(signingString))
+	if _, err = hasher.Write([]byte(signingString)); err != nil {
+		return err
+	}
 
 	// Verify the signature
 	if verifystatus := ecdsa.Verify(ecdsaKey, hasher.Sum(nil), r, s); verifystatus {
@@ -95,7 +97,7 @@ func (m *SigningMethodECDSA) Verify(signingString, signature string, key interfa
 	return ErrECDSAVerification
 }
 
-// Implements the Sign method from SigningMethod
+// Sign Implements the Sign method from SigningMethod
 // For this signing method, key must be an ecdsa.PrivateKey struct
 func (m *SigningMethodECDSA) Sign(signingString string, key interface{}) (string, error) {
 	// Get the key
@@ -113,7 +115,9 @@ func (m *SigningMethodECDSA) Sign(signingString string, key interface{}) (string
 	}
 
 	hasher := m.Hash.New()
-	hasher.Write([]byte(signingString))
+	if _, err := hasher.Write([]byte(signingString)); err != nil {
+		return "", err
+	}
 
 	// Sign the string and return r, s
 	if r, s, err := ecdsa.Sign(rand.Reader, ecdsaKey, hasher.Sum(nil)); err == nil {

hmac.go

@@ -68,7 +68,9 @@ func (m *SigningMethodHMAC) Verify(signingString, signature string, key interfac
 	// by reproducing the signature from the signing string and key, then
 	// comparing that against the provided signature.
 	hasher := hmac.New(m.Hash.New, keyBytes)
-	hasher.Write([]byte(signingString))
+	if _, err = hasher.Write([]byte(signingString)); err != nil {
+		return err
+	}
 	if !hmac.Equal(sig, hasher.Sum(nil)) {
 		return ErrSignatureInvalid
 	}
@@ -77,7 +79,7 @@ func (m *SigningMethodHMAC) Verify(signingString, signature string, key interfac
 	return nil
 }
 
-// Implements the Sign method from SigningMethod for this signing method.
+// Sign Implements the Sign method from SigningMethod for this signing method.
 // Key must be []byte
 func (m *SigningMethodHMAC) Sign(signingString string, key interface{}) (string, error) {
 	if keyBytes, ok := key.([]byte); ok {
@@ -86,7 +88,9 @@ func (m *SigningMethodHMAC) Sign(signingString string, key interface{}) (string,
 		}
 
 		hasher := hmac.New(m.Hash.New, keyBytes)
-		hasher.Write([]byte(signingString))
+		if _, err := hasher.Write([]byte(signingString)); err != nil {
+			return "", err
+		}
 
 		return EncodeSegment(hasher.Sum(nil)), nil
 	}

http_example_test.go

@@ -32,9 +32,9 @@ var (
 	serverPort int
 	// storing sample username/password pairs
 	// don't do this on a real server
-	users = map[string]string{
-		"test": "known",
-	}
+	//users = map[string]string{
+	//	"test": "known",
+	//}
 )
 
 // read the key files before starting http handlers
@@ -65,7 +65,7 @@ func init() {
 	}()
 }
 
-var start func()
+//var start func()
 
 func fatal(err error) {
 	if err != nil {
@@ -101,8 +101,12 @@ func Example_getTokenViaHTTP() {
 
 	// Read the token out of the response body
 	buf := new(bytes.Buffer)
-	io.Copy(buf, res.Body)
-	res.Body.Close()
+	if _, err = io.Copy(buf, res.Body); err != nil {
+		fatal(err)
+	}
+	if err = res.Body.Close(); err != nil {
+		fatal(err)
+	}
 	tokenString := strings.TrimSpace(buf.String())
 
 	// Parse the token
@@ -136,8 +140,12 @@ func Example_useTokenViaHTTP() {
 
 	// Read the response body
 	buf := new(bytes.Buffer)
-	io.Copy(buf, res.Body)
-	res.Body.Close()
+	if _, err = io.Copy(buf, res.Body); err != nil {
+		panic(err)
+	}
+	if err = res.Body.Close(); err != nil {
+		panic(err)
+	}
 	fmt.Println(buf.String())
 
 	// Output: Welcome, foo
@@ -214,5 +222,4 @@ func restrictedHandler(w http.ResponseWriter, r *http.Request) {
 
 	// Token is valid
 	fmt.Fprintln(w, "Welcome,", token.Claims.(*CustomClaimsExample).Name)
-	return
 }

map_claims_test.go

@@ -49,13 +49,10 @@ func TestVerifyAud(t *testing.T) {
 		{Name: "[]interface{} Aud wit match but invalid types", MapClaims: MapClaims{"aud": []interface{}{"a", 5, "example.com"}}, Expected: false, Required: true, Comparison: "example.com"},
 		{Name: "[]interface{} Aud int wit match required", MapClaims: MapClaims{"aud": intListInterface}, Expected: false, Required: true, Comparison: "example.com"},
 
-
 		// interface{}
 		{Name: "Empty interface{} Aud without match not required", MapClaims: MapClaims{"aud": nilInterface}, Expected: true, Required: false, Comparison: "example.com"},
-
 	}
 
-
 	for _, test := range tests {
 		t.Run(test.Name, func(t *testing.T) {
 			got := test.MapClaims.VerifyAudience(test.Comparison, test.Required)

request/extractor.go

@@ -5,19 +5,19 @@ import (
 	"net/http"
 )
 
-// Errors
+// ErrNoTokenInRequest Errors
 var (
 	ErrNoTokenInRequest = errors.New("no token present in request")
 )
 
-// Interface for extracting a token from an HTTP request.
+// Extractor Interface for extracting a token from an HTTP request.
 // The ExtractToken method should return a token string or an error.
 // If no token is present, you must return ErrNoTokenInRequest.
 type Extractor interface {
 	ExtractToken(*http.Request) (string, error)
 }
 
-// Extractor for finding a token in a header.  Looks at each specified
+// HeaderExtractor for finding a token in a header.  Looks at each specified
 // header in order until there's a match
 type HeaderExtractor []string
 
@@ -31,14 +31,16 @@ func (e HeaderExtractor) ExtractToken(req *http.Request) (string, error) {
 	return "", ErrNoTokenInRequest
 }
 
-// Extract token from request arguments.  This includes a POSTed form or
+// ArgumentExtractor Extract token from request arguments.  This includes a POSTed form or
 // GET URL arguments.  Argument names are tried in order until there's a match.
 // This extractor calls `ParseMultipartForm` on the request
 type ArgumentExtractor []string
 
 func (e ArgumentExtractor) ExtractToken(req *http.Request) (string, error) {
 	// Make sure form is parsed
-	req.ParseMultipartForm(10e6)
+	if err := req.ParseMultipartForm(10e6); err != nil {
+		return "", err
+	}
 
 	// loop over arg names and return the first one that contains data
 	for _, arg := range e {
@@ -50,7 +52,7 @@ func (e ArgumentExtractor) ExtractToken(req *http.Request) (string, error) {
 	return "", ErrNoTokenInRequest
 }
 
-// Tries Extractors in order until one returns a token string or an error occurs
+// MultiExtractor Tries Extractors in order until one returns a token string or an error occurs
 type MultiExtractor []Extractor
 
 func (e MultiExtractor) ExtractToken(req *http.Request) (string, error) {

rsa.go

@@ -44,7 +44,7 @@ func (m *SigningMethodRSA) Alg() string {
 	return m.Name
 }
 
-// Implements the Verify method from SigningMethod
+// Verify Implements the Verify method from SigningMethod
 // For this signing method, must be an *rsa.PublicKey structure.
 func (m *SigningMethodRSA) Verify(signingString, signature string, key interface{}) error {
 	var err error
@@ -67,13 +67,15 @@ func (m *SigningMethodRSA) Verify(signingString, signature string, key interface
 		return ErrHashUnavailable
 	}
 	hasher := m.Hash.New()
-	hasher.Write([]byte(signingString))
+	if _, err = hasher.Write([]byte(signingString)); err != nil {
+		return err
+	}
 
 	// Verify the signature
 	return rsa.VerifyPKCS1v15(rsaKey, m.Hash, hasher.Sum(nil), sig)
 }
 
-// Implements the Sign method from SigningMethod
+// Sign Implements the Sign method from SigningMethod
 // For this signing method, must be an *rsa.PrivateKey structure.
 func (m *SigningMethodRSA) Sign(signingString string, key interface{}) (string, error) {
 	var rsaKey *rsa.PrivateKey
@@ -90,7 +92,9 @@ func (m *SigningMethodRSA) Sign(signingString string, key interface{}) (string,
 	}
 
 	hasher := m.Hash.New()
-	hasher.Write([]byte(signingString))
+	if _, err := hasher.Write([]byte(signingString)); err != nil {
+		return "", err
+	}
 
 	// Sign the string and return the encoded bytes
 	if sigBytes, err := rsa.SignPKCS1v15(rand.Reader, rsaKey, m.Hash, hasher.Sum(nil)); err == nil {

rsa_utils.go

@@ -13,7 +13,7 @@ var (
 	ErrNotRSAPublicKey     = errors.New("Key is not a valid RSA public key")
 )
 
-// Parse PEM encoded PKCS1 or PKCS8 private key
+// ParseRSAPrivateKeyFromPEM Parse PEM encoded PKCS1 or PKCS8 private key
 func ParseRSAPrivateKeyFromPEM(key []byte) (*rsa.PrivateKey, error) {
 	var err error
 
@@ -39,7 +39,7 @@ func ParseRSAPrivateKeyFromPEM(key []byte) (*rsa.PrivateKey, error) {
 	return pkey, nil
 }
 
-// Parse PEM encoded PKCS1 or PKCS8 private key protected with password
+// ParseRSAPrivateKeyFromPEMWithPassword Parse PEM encoded PKCS1 or PKCS8 private key protected with password
 func ParseRSAPrivateKeyFromPEMWithPassword(key []byte, password string) (*rsa.PrivateKey, error) {
 	var err error