Initial QSfera import

Server/vendor/github.com/libregraph/oidc-go/http.go

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2019 Kopano
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package oidc
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/pquerna/cachecontrol"
+)
+
+// Basic HTTP related global settings.
+var (
+	DefaultHTTPClient       *http.Client
+	DefaultHTTPHeader       http.Header
+	DefaultMaxJSONFetchSize int64 = 5 * 1024 * 1024 // 5 MiB
+	DefaultJSONFetchExpiry        = time.Minute * 1
+	DefaultJSONFetchRetry         = time.Second * 3
+)
+
+func fetchJSON(ctx context.Context, u *url.URL, dst interface{}, client *http.Client, header http.Header) (time.Duration, error) {
+	if client == nil {
+		client = DefaultHTTPClient
+		if client == nil {
+			client = http.DefaultClient
+		}
+	}
+
+	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
+	if err != nil {
+		return DefaultJSONFetchRetry, fmt.Errorf("failed create fetch JSON request: %v", err)
+	}
+	if header == nil {
+		header = DefaultHTTPHeader
+	}
+	if header != nil {
+		for h, values := range header {
+			for _, v := range values {
+				req.Header.Add(h, v)
+			}
+		}
+	}
+
+	res, err := client.Do(req.WithContext(ctx))
+	if err != nil {
+		return DefaultJSONFetchRetry, fmt.Errorf("failed to fetch JSON: %v", err)
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusOK {
+		return DefaultJSONFetchRetry, fmt.Errorf("failed to fetch JSON (status: %d)", res.StatusCode)
+	}
+
+	_, expires, _ := cachecontrol.CachableResponse(req, res, cachecontrol.Options{})
+	err = json.NewDecoder(io.LimitReader(res.Body, DefaultMaxJSONFetchSize)).Decode(dst)
+	if err != nil {
+		return DefaultJSONFetchRetry, fmt.Errorf("failed to fetch JSON: %v", err)
+	}
+
+	expirationDuration := expires.Sub(time.Now())
+	if expirationDuration < DefaultJSONFetchRetry {
+		if err == nil {
+			expirationDuration = DefaultJSONFetchExpiry
+		} else {
+			expirationDuration = DefaultJSONFetchRetry
+		}
+	}
+
+	return expirationDuration, err
+}