v0.4.1 merge http and simple token into one file

token.go

@@ -2,6 +2,7 @@ package auth
 
 import (
 	"crypto/sha256"
+	"strings"
 	"sync"
 )
 
@@ -57,3 +58,35 @@ func (v *SimpleTokenValidator) RemoveToken(token string) {
 	defer v.mu.Unlock()
 	delete(v.tokens, h)
 }
+
+// ParseBearerToken parses an RFC 6750 Bearer authorization value. The scheme is
+// case-insensitive; tokens must use the b64token alphabet and contain no spaces.
+// Parsing does not validate the token's signature or grant authorization.
+func ParseBearerToken(header string) (string, error) {
+	// Bound before scanning, including an allowance for separator spaces.
+	if len(header) > MaxTokenLen+16 {
+		return "", ErrTokenTooLong
+	}
+	scheme, token, ok := strings.Cut(header, " ")
+	if !ok || !strings.EqualFold(scheme, "Bearer") {
+		return "", ErrAuthInvalidBearerFormat
+	}
+	token = strings.TrimLeft(token, " ")
+	if token == "" {
+		return "", ErrAuthEmptyBearerToken
+	}
+	if len(token) > MaxTokenLen {
+		return "", ErrTokenTooLong
+	}
+	padding := false
+	for i, ch := range []byte(token) {
+		if ch == '=' && i > 0 {
+			padding = true
+			continue
+		}
+		if padding || !(ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' || ch >= '0' && ch <= '9' || strings.ContainsRune("-._~+/", rune(ch))) {
+			return "", ErrAuthInvalidBearerFormat
+		}
+	}
+	return token, nil
+}