add support for multi-target docker image(oci) proxy

proxy/authparse.go

@@ -0,0 +1,62 @@
+package proxy
+
+import (
+	"fmt"
+	"strings"
+)
+
+// BearerAuthParams 用于存放解析出的 Bearer 认证参数
+type BearerAuthParams struct {
+	Realm   string
+	Service string
+	Scope   string
+}
+
+// parseBearerWWWAuthenticateHeader 解析 Bearer 方案的 Www-Authenticate Header。
+// 它期望格式为 'Bearer key1="value1",key2="value2",...'
+// 并尝试将已知参数解析到 BearerAuthParams struct 中。
+func parseBearerWWWAuthenticateHeader(headerValue string) (*BearerAuthParams, error) {
+	if headerValue == "" {
+		return nil, fmt.Errorf("header value is empty")
+	}
+
+	// 检查 Scheme 是否是 "Bearer"
+	parts := strings.SplitN(headerValue, " ", 2)
+	if len(parts) != 2 || strings.ToLower(parts[0]) != "bearer" {
+		return nil, fmt.Errorf("invalid or non-bearer header format: got '%s'", headerValue)
+	}
+	paramsStr := parts[1]
+
+	paramPairs := strings.Split(paramsStr, ",")
+	tempMap := make(map[string]string)
+
+	for _, pair := range paramPairs {
+		trimmedPair := strings.TrimSpace(pair)
+		keyValue := strings.SplitN(trimmedPair, "=", 2)
+		if len(keyValue) != 2 {
+			logWarning("Skipping malformed parameter '%s' in Www-Authenticate header: %s", pair, headerValue)
+			continue
+		}
+		key := strings.TrimSpace(keyValue[0])
+		value := strings.TrimSpace(keyValue[1])
+		if strings.HasPrefix(value, "\"") && strings.HasSuffix(value, "\"") {
+			value = value[1 : len(value)-1]
+		}
+		tempMap[key] = value
+	}
+
+	//从 map 中提取值并填充到 struct
+	authParams := &BearerAuthParams{}
+
+	if realm, ok := tempMap["realm"]; ok {
+		authParams.Realm = realm
+	}
+	if service, ok := tempMap["service"]; ok {
+		authParams.Service = service
+	}
+	if scope, ok := tempMap["scope"]; ok {
+		authParams.Scope = scope
+	}
+
+	return authParams, nil
+}