diff --git a/auth.go b/auth.go
index ccd9981c..8cfc6f6d 100644
--- a/auth.go
+++ b/auth.go
@@ -64,19 +64,15 @@ func (as *AuthServer) GenerateHeader() HeaderValue {
 		switch m {
 		case Basic:
 			ret = append(ret, (&HeaderAuth{
-				Prefix: "Basic",
-				Values: map[string]string{
-					"realm": as.realm,
-				},
+				Method: Basic,
+				Realm:  &as.realm,
 			}).Write()...)
 
 		case Digest:
 			ret = append(ret, (&HeaderAuth{
-				Prefix: "Digest",
-				Values: map[string]string{
-					"realm": as.realm,
-					"nonce": as.nonce,
-				},
+				Method: Digest,
+				Realm:  &as.realm,
+				Nonce:  &as.nonce,
 			}).Write()...)
 		}
 	}
@@ -110,46 +106,41 @@ func (as *AuthServer) ValidateHeader(v HeaderValue, method Method, ur *url.URL)
 			return err
 		}
 
-		inRealm, ok := auth.Values["realm"]
-		if !ok {
+		if auth.Realm == nil {
 			return fmt.Errorf("realm not provided")
 		}
 
-		inNonce, ok := auth.Values["nonce"]
-		if !ok {
+		if auth.Nonce == nil {
 			return fmt.Errorf("nonce not provided")
 		}
 
-		inUsername, ok := auth.Values["username"]
-		if !ok {
+		if auth.Username == nil {
 			return fmt.Errorf("username not provided")
 		}
 
-		inUri, ok := auth.Values["uri"]
-		if !ok {
+		if auth.URI == nil {
 			return fmt.Errorf("uri not provided")
 		}
 
-		inResponse, ok := auth.Values["response"]
-		if !ok {
+		if auth.Response == nil {
 			return fmt.Errorf("response not provided")
 		}
 
-		if inNonce != as.nonce {
+		if *auth.Nonce != as.nonce {
 			return fmt.Errorf("wrong nonce")
 		}
 
-		if inRealm != as.realm {
+		if *auth.Realm != as.realm {
 			return fmt.Errorf("wrong realm")
 		}
 
-		if inUsername != as.user {
+		if *auth.Username != as.user {
 			return fmt.Errorf("wrong username")
 		}
 
 		uri := ur.String()
 
-		if inUri != uri {
+		if *auth.URI != uri {
 			// VLC strips the subpath
 			newUrl := *ur
 			newUrl.Path = func() string {
@@ -163,7 +154,7 @@ func (as *AuthServer) ValidateHeader(v HeaderValue, method Method, ur *url.URL)
 			}()
 			uri = newUrl.String()
 
-			if inUri != uri {
+			if *auth.URI != uri {
 				return fmt.Errorf("wrong url")
 			}
 		}
@@ -171,7 +162,7 @@ func (as *AuthServer) ValidateHeader(v HeaderValue, method Method, ur *url.URL)
 		response := md5Hex(md5Hex(as.user+":"+as.realm+":"+as.pass) +
 			":" + as.nonce + ":" + md5Hex(string(method)+":"+uri))
 
-		if inResponse != response {
+		if *auth.Response != response {
 			return fmt.Errorf("wrong response")
 		}
 
@@ -209,13 +200,11 @@ func newAuthClient(v HeaderValue, user string, pass string) (*authClient, error)
 			return nil, err
 		}
 
-		realm, ok := auth.Values["realm"]
-		if !ok {
+		if auth.Realm == nil {
 			return nil, fmt.Errorf("realm not provided")
 		}
 
-		nonce, ok := auth.Values["nonce"]
-		if !ok {
+		if auth.Nonce == nil {
 			return nil, fmt.Errorf("nonce not provided")
 		}
 
@@ -223,8 +212,8 @@ func newAuthClient(v HeaderValue, user string, pass string) (*authClient, error)
 			user:   user,
 			pass:   pass,
 			method: Digest,
-			realm:  realm,
-			nonce:  nonce,
+			realm:  *auth.Realm,
+			nonce:  *auth.Nonce,
 		}, nil
 	}
 
@@ -241,8 +230,7 @@ func newAuthClient(v HeaderValue, user string, pass string) (*authClient, error)
 			return nil, err
 		}
 
-		realm, ok := auth.Values["realm"]
-		if !ok {
+		if auth.Realm == nil {
 			return nil, fmt.Errorf("realm not provided")
 		}
 
@@ -250,7 +238,7 @@ func newAuthClient(v HeaderValue, user string, pass string) (*authClient, error)
 			user:   user,
 			pass:   pass,
 			method: Basic,
-			realm:  realm,
+			realm:  *auth.Realm,
 		}, nil
 	}
 
@@ -271,14 +259,15 @@ func (ac *authClient) GenerateHeader(method Method, ur *url.URL) HeaderValue {
 			ac.nonce + ":" + md5Hex(string(method)+":"+ur.String()))
 
 		return (&HeaderAuth{
-			Prefix: "Digest",
-			Values: map[string]string{
-				"username": ac.user,
-				"realm":    ac.realm,
-				"nonce":    ac.nonce,
-				"uri":      ur.String(),
-				"response": response,
-			},
+			Method:   Digest,
+			Username: &ac.user,
+			Realm:    &ac.realm,
+			Nonce:    &ac.nonce,
+			URI: func() *string {
+				v := ur.String()
+				return &v
+			}(),
+			Response: &response,
 		}).Write()
 	}
 
diff --git a/header-auth.go b/header-auth.go
index 05ee4dbb..4e9895e6 100644
--- a/header-auth.go
+++ b/header-auth.go
@@ -2,18 +2,68 @@ package gortsplib
 
 import (
 	"fmt"
-	"regexp"
-	"sort"
 	"strings"
 )
 
 // HeaderAuth is an Authenticate or a WWWW-Authenticate header.
 type HeaderAuth struct {
-	Prefix string
-	Values map[string]string
+	// authentication method
+	Method AuthMethod
+
+	// (optional) username
+	Username *string
+
+	// (optional) realm
+	Realm *string
+
+	// (optional) nonce
+	Nonce *string
+
+	// (optional) uri
+	URI *string
+
+	// (optional) response
+	Response *string
+
+	// (optional) opaque
+	Opaque *string
+
+	// (optional) stale
+	Stale *string
+
+	// (optional) algorithm
+	Algorithm *string
 }
 
-var regHeaderAuthKeyValue = regexp.MustCompile("^([a-z]+)=(\"(.*?)\"|([a-zA-Z0-9]+))(, *|$)")
+func findValue(v0 string) (string, string, error) {
+	if v0 == "" {
+		return "", "", nil
+	}
+
+	if v0[0] == '"' {
+		i := 1
+		for {
+			if i >= len(v0) {
+				return "", "", fmt.Errorf("apices not closed (%v)", v0)
+			}
+
+			if v0[i] == '"' {
+				return v0[1:i], v0[i+1:], nil
+			}
+
+			i++
+		}
+	}
+
+	i := 0
+	for {
+		if i >= len(v0) || v0[i] == ',' {
+			return v0[:i], v0[i:], nil
+		}
+
+		i++
+	}
+}
 
 // ReadHeaderAuth parses an Authenticate or a WWW-Authenticate header.
 func ReadHeaderAuth(v HeaderValue) (*HeaderAuth, error) {
@@ -25,28 +75,79 @@ func ReadHeaderAuth(v HeaderValue) (*HeaderAuth, error) {
 		return nil, fmt.Errorf("value provided multiple times (%v)", v)
 	}
 
-	ha := &HeaderAuth{
-		Values: make(map[string]string),
-	}
+	ha := &HeaderAuth{}
 
 	v0 := v[0]
 
-	i := strings.IndexByte(v[0], ' ')
+	i := strings.IndexByte(v0, ' ')
 	if i < 0 {
-		return nil, fmt.Errorf("unable to find prefix (%s)", v0)
+		return nil, fmt.Errorf("unable to find method (%s)", v0)
 	}
-	ha.Prefix, v0 = v0[:i], v0[i+1:]
+
+	switch v0[:i] {
+	case "Basic":
+		ha.Method = Basic
+
+	case "Digest":
+		ha.Method = Digest
+
+	default:
+		return nil, fmt.Errorf("invalid method (%s)", v0[:i])
+	}
+	v0 = v0[i+1:]
 
 	for len(v0) > 0 {
-		m := regHeaderAuthKeyValue.FindStringSubmatch(v0)
-		if m == nil {
-			return nil, fmt.Errorf("unable to parse key-value (%s)", v0)
+		i := strings.IndexByte(v0, '=')
+		if i < 0 {
+			return nil, fmt.Errorf("unable to find key (%s)", v0)
 		}
-		v0 = v0[len(m[0]):]
+		var key string
+		key, v0 = v0[:i], v0[i+1:]
 
-		m[2] = strings.TrimPrefix(m[2], "\"")
-		m[2] = strings.TrimSuffix(m[2], "\"")
-		ha.Values[m[1]] = m[2]
+		var val string
+		var err error
+		val, v0, err = findValue(v0)
+		if err != nil {
+			return nil, err
+		}
+
+		switch key {
+		case "username":
+			ha.Username = &val
+
+		case "realm":
+			ha.Realm = &val
+
+		case "nonce":
+			ha.Nonce = &val
+
+		case "uri":
+			ha.URI = &val
+
+		case "response":
+			ha.Response = &val
+
+		case "opaque":
+			ha.Opaque = &val
+
+		case "stale":
+			ha.Stale = &val
+
+		case "algorithm":
+			ha.Algorithm = &val
+
+			// ignore non-standard keys
+		}
+
+		// skip comma
+		if len(v0) > 0 && v0[0] == ',' {
+			v0 = v0[1:]
+		}
+
+		// skip spaces
+		for len(v0) > 0 && v0[0] == ' ' {
+			v0 = v0[1:]
+		}
 	}
 
 	return ha, nil
@@ -54,48 +155,53 @@ func ReadHeaderAuth(v HeaderValue) (*HeaderAuth, error) {
 
 // Write encodes an Authenticate or a WWW-Authenticate header.
 func (ha *HeaderAuth) Write() HeaderValue {
-	ret := ha.Prefix + " "
+	ret := ""
 
-	// follow a specific order, otherwise some clients/servers do not work correctly
-	var sortedKeys []string
-	for key := range ha.Values {
-		sortedKeys = append(sortedKeys, key)
-	}
-	score := func(v string) int {
-		switch v {
-		case "username":
-			return 0
-		case "realm":
-			return 1
-		case "nonce":
-			return 2
-		case "uri":
-			return 3
-		case "response":
-			return 4
-		case "opaque":
-			return 5
-		case "stale":
-			return 6
-		case "algorithm":
-			return 7
-		}
-		return 8
-	}
-	sort.Slice(sortedKeys, func(a, b int) bool {
-		sa := score(sortedKeys[a])
-		sb := score(sortedKeys[b])
-		if sa != sb {
-			return sa < sb
-		}
-		return a < b
-	})
+	switch ha.Method {
+	case Basic:
+		ret += "Basic"
 
-	var tmp []string
-	for _, key := range sortedKeys {
-		tmp = append(tmp, key+"=\""+ha.Values[key]+"\"")
+	case Digest:
+		ret += "Digest"
 	}
-	ret += strings.Join(tmp, ", ")
+
+	ret += " "
+
+	var vals []string
+
+	if ha.Username != nil {
+		vals = append(vals, "username=\""+*ha.Username+"\"")
+	}
+
+	if ha.Realm != nil {
+		vals = append(vals, "realm=\""+*ha.Realm+"\"")
+	}
+
+	if ha.Nonce != nil {
+		vals = append(vals, "nonce=\""+*ha.Nonce+"\"")
+	}
+
+	if ha.URI != nil {
+		vals = append(vals, "uri=\""+*ha.URI+"\"")
+	}
+
+	if ha.Response != nil {
+		vals = append(vals, "response=\""+*ha.Response+"\"")
+	}
+
+	if ha.Opaque != nil {
+		vals = append(vals, "opaque=\""+*ha.Opaque+"\"")
+	}
+
+	if ha.Stale != nil {
+		vals = append(vals, "stale=\""+*ha.Stale+"\"")
+	}
+
+	if ha.Algorithm != nil {
+		vals = append(vals, "algorithm=\""+*ha.Algorithm+"\"")
+	}
+
+	ret += strings.Join(vals, ", ")
 
 	return HeaderValue{ret}
 }
diff --git a/header-auth_test.go b/header-auth_test.go
index bf91d969..c3e26b3c 100644
--- a/header-auth_test.go
+++ b/header-auth_test.go
@@ -17,10 +17,11 @@ var casesHeaderAuth = []struct {
 		HeaderValue{`Basic realm="4419b63f5e51"`},
 		HeaderValue{`Basic realm="4419b63f5e51"`},
 		&HeaderAuth{
-			Prefix: "Basic",
-			Values: map[string]string{
-				"realm": "4419b63f5e51",
-			},
+			Method: Basic,
+			Realm: func() *string {
+				v := "4419b63f5e51"
+				return &v
+			}(),
 		},
 	},
 	{
@@ -28,12 +29,19 @@ var casesHeaderAuth = []struct {
 		HeaderValue{`Digest realm="4419b63f5e51", nonce="8b84a3b789283a8bea8da7fa7d41f08b", stale="FALSE"`},
 		HeaderValue{`Digest realm="4419b63f5e51", nonce="8b84a3b789283a8bea8da7fa7d41f08b", stale="FALSE"`},
 		&HeaderAuth{
-			Prefix: "Digest",
-			Values: map[string]string{
-				"realm": "4419b63f5e51",
-				"nonce": "8b84a3b789283a8bea8da7fa7d41f08b",
-				"stale": "FALSE",
-			},
+			Method: Digest,
+			Realm: func() *string {
+				v := "4419b63f5e51"
+				return &v
+			}(),
+			Nonce: func() *string {
+				v := "8b84a3b789283a8bea8da7fa7d41f08b"
+				return &v
+			}(),
+			Stale: func() *string {
+				v := "FALSE"
+				return &v
+			}(),
 		},
 	},
 	{
@@ -41,12 +49,19 @@ var casesHeaderAuth = []struct {
 		HeaderValue{`Digest realm="4419b63f5e51", nonce="8b84a3b789283a8bea8da7fa7d41f08b", stale=FALSE`},
 		HeaderValue{`Digest realm="4419b63f5e51", nonce="8b84a3b789283a8bea8da7fa7d41f08b", stale="FALSE"`},
 		&HeaderAuth{
-			Prefix: "Digest",
-			Values: map[string]string{
-				"realm": "4419b63f5e51",
-				"nonce": "8b84a3b789283a8bea8da7fa7d41f08b",
-				"stale": "FALSE",
-			},
+			Method: Digest,
+			Realm: func() *string {
+				v := "4419b63f5e51"
+				return &v
+			}(),
+			Nonce: func() *string {
+				v := "8b84a3b789283a8bea8da7fa7d41f08b"
+				return &v
+			}(),
+			Stale: func() *string {
+				v := "FALSE"
+				return &v
+			}(),
 		},
 	},
 	{
@@ -54,12 +69,19 @@ var casesHeaderAuth = []struct {
 		HeaderValue{`Digest realm="4419b63f5e51",nonce="133767111917411116111311118211673010032",  stale="FALSE"`},
 		HeaderValue{`Digest realm="4419b63f5e51", nonce="133767111917411116111311118211673010032", stale="FALSE"`},
 		&HeaderAuth{
-			Prefix: "Digest",
-			Values: map[string]string{
-				"realm": "4419b63f5e51",
-				"nonce": "133767111917411116111311118211673010032",
-				"stale": "FALSE",
-			},
+			Method: Digest,
+			Realm: func() *string {
+				v := "4419b63f5e51"
+				return &v
+			}(),
+			Nonce: func() *string {
+				v := "133767111917411116111311118211673010032"
+				return &v
+			}(),
+			Stale: func() *string {
+				v := "FALSE"
+				return &v
+			}(),
 		},
 	},
 	{
@@ -67,14 +89,27 @@ var casesHeaderAuth = []struct {
 		HeaderValue{`Digest username="aa", realm="bb", nonce="cc", uri="dd", response="ee"`},
 		HeaderValue{`Digest username="aa", realm="bb", nonce="cc", uri="dd", response="ee"`},
 		&HeaderAuth{
-			Prefix: "Digest",
-			Values: map[string]string{
-				"username": "aa",
-				"realm":    "bb",
-				"nonce":    "cc",
-				"uri":      "dd",
-				"response": "ee",
-			},
+			Method: Digest,
+			Username: func() *string {
+				v := "aa"
+				return &v
+			}(),
+			Realm: func() *string {
+				v := "bb"
+				return &v
+			}(),
+			Nonce: func() *string {
+				v := "cc"
+				return &v
+			}(),
+			URI: func() *string {
+				v := "dd"
+				return &v
+			}(),
+			Response: func() *string {
+				v := "ee"
+				return &v
+			}(),
 		},
 	},
 	{
@@ -82,14 +117,27 @@ var casesHeaderAuth = []struct {
 		HeaderValue{`Digest username="", realm="IPCAM", nonce="5d17cd12b9fa8a85ac5ceef0926ea5a6", uri="rtsp://localhost:8554/mystream", response="c072ae90eb4a27f4cdcb90d62266b2a1"`},
 		HeaderValue{`Digest username="", realm="IPCAM", nonce="5d17cd12b9fa8a85ac5ceef0926ea5a6", uri="rtsp://localhost:8554/mystream", response="c072ae90eb4a27f4cdcb90d62266b2a1"`},
 		&HeaderAuth{
-			Prefix: "Digest",
-			Values: map[string]string{
-				"username": "",
-				"realm":    "IPCAM",
-				"nonce":    "5d17cd12b9fa8a85ac5ceef0926ea5a6",
-				"uri":      "rtsp://localhost:8554/mystream",
-				"response": "c072ae90eb4a27f4cdcb90d62266b2a1",
-			},
+			Method: Digest,
+			Username: func() *string {
+				v := ""
+				return &v
+			}(),
+			Realm: func() *string {
+				v := "IPCAM"
+				return &v
+			}(),
+			Nonce: func() *string {
+				v := "5d17cd12b9fa8a85ac5ceef0926ea5a6"
+				return &v
+			}(),
+			URI: func() *string {
+				v := "rtsp://localhost:8554/mystream"
+				return &v
+			}(),
+			Response: func() *string {
+				v := "c072ae90eb4a27f4cdcb90d62266b2a1"
+				return &v
+			}(),
 		},
 	},
 	{
@@ -97,14 +145,27 @@ var casesHeaderAuth = []struct {
 		HeaderValue{`Digest realm="Please log in with a valid username",nonce="752a62306daf32b401a41004555c7663",opaque="",stale=FALSE,algorithm=MD5`},
 		HeaderValue{`Digest realm="Please log in with a valid username", nonce="752a62306daf32b401a41004555c7663", opaque="", stale="FALSE", algorithm="MD5"`},
 		&HeaderAuth{
-			Prefix: "Digest",
-			Values: map[string]string{
-				"realm":     "Please log in with a valid username",
-				"nonce":     "752a62306daf32b401a41004555c7663",
-				"opaque":    "",
-				"stale":     "FALSE",
-				"algorithm": "MD5",
-			},
+			Method: Digest,
+			Realm: func() *string {
+				v := "Please log in with a valid username"
+				return &v
+			}(),
+			Nonce: func() *string {
+				v := "752a62306daf32b401a41004555c7663"
+				return &v
+			}(),
+			Opaque: func() *string {
+				v := ""
+				return &v
+			}(),
+			Stale: func() *string {
+				v := "FALSE"
+				return &v
+			}(),
+			Algorithm: func() *string {
+				v := "MD5"
+				return &v
+			}(),
 		},
 	},
 }
diff --git a/header-transport.go b/header-transport.go
index 2eb7fa64..b885b9d2 100644
--- a/header-transport.go
+++ b/header-transport.go
@@ -75,15 +75,14 @@ func ReadHeaderTransport(v HeaderValue) (*HeaderTransport, error) {
 	switch parts[0] {
 	case "RTP/AVP", "RTP/AVP/UDP":
 		ht.Protocol = StreamProtocolUDP
-		parts = parts[1:]
 
 	case "RTP/AVP/TCP":
 		ht.Protocol = StreamProtocolTCP
-		parts = parts[1:]
 
 	default:
 		return nil, fmt.Errorf("invalid protocol (%v)", v)
 	}
+	parts = parts[1:]
 
 	switch parts[0] {
 	case "unicast":
@@ -144,6 +143,8 @@ func ReadHeaderTransport(v HeaderValue) (*HeaderTransport, error) {
 			v = strings.TrimSuffix(v, "\"")
 			ht.Mode = &v
 		}
+
+		// ignore non-standard keys
 	}
 
 	return ht, nil