Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

pkg/filemanager/driver/oss/callback.go

@@ -0,0 +1,122 @@
+package oss
+
+import (
+	"bytes"
+	"crypto"
+	"crypto/md5"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"github.com/cloudreve/Cloudreve/v4/pkg/cache"
+	"github.com/cloudreve/Cloudreve/v4/pkg/request"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+const (
+	pubKeyHeader      = "x-oss-pub-key-url"
+	pubKeyPrefix      = "http://gosspublic.alicdn.com/"
+	pubKeyPrefixHttps = "https://gosspublic.alicdn.com/"
+	pubKeyCacheKey    = "oss_public_key"
+)
+
+// GetPublicKey 从回调请求或缓存中获取OSS的回调签名公钥
+func GetPublicKey(r *http.Request, kv cache.Driver, client request.Client) ([]byte, error) {
+	var pubKey []byte
+
+	// 尝试从缓存中获取
+	pub, exist := kv.Get(pubKeyCacheKey)
+	if exist {
+		return pub.([]byte), nil
+	}
+
+	// 从请求中获取
+	pubURL, err := base64.StdEncoding.DecodeString(r.Header.Get(pubKeyHeader))
+	if err != nil {
+		return pubKey, err
+	}
+
+	// 确保这个 public key 是由 OSS 颁发的
+	if !strings.HasPrefix(string(pubURL), pubKeyPrefix) &&
+		!strings.HasPrefix(string(pubURL), pubKeyPrefixHttps) {
+		return pubKey, errors.New("public key url invalid")
+	}
+
+	// 获取公钥
+	body, err := client.Request("GET", string(pubURL), nil).
+		CheckHTTPResponse(200).
+		GetResponse()
+	if err != nil {
+		return pubKey, err
+	}
+
+	// 写入缓存
+	_ = kv.Set(pubKeyCacheKey, []byte(body), 86400*7)
+
+	return []byte(body), nil
+}
+
+func getRequestMD5(r *http.Request) ([]byte, error) {
+	var byteMD5 []byte
+
+	// 获取请求正文
+	body, err := io.ReadAll(r.Body)
+	r.Body.Close()
+	if err != nil {
+		return byteMD5, err
+	}
+	r.Body = io.NopCloser(bytes.NewReader(body))
+
+	strURLPathDecode, err := url.PathUnescape(r.URL.Path)
+	if err != nil {
+		return byteMD5, err
+	}
+
+	strAuth := fmt.Sprintf("%s\n%s", strURLPathDecode, string(body))
+	md5Ctx := md5.New()
+	md5Ctx.Write([]byte(strAuth))
+	byteMD5 = md5Ctx.Sum(nil)
+
+	return byteMD5, nil
+}
+
+// VerifyCallbackSignature 验证OSS回调请求
+func VerifyCallbackSignature(r *http.Request, kv cache.Driver, client request.Client) error {
+	bytePublicKey, err := GetPublicKey(r, kv, client)
+	if err != nil {
+		return err
+	}
+
+	byteMD5, err := getRequestMD5(r)
+	if err != nil {
+		return err
+	}
+
+	strAuthorizationBase64 := r.Header.Get("authorization")
+	if strAuthorizationBase64 == "" {
+		return errors.New("no authorization field in Request header")
+	}
+	authorization, _ := base64.StdEncoding.DecodeString(strAuthorizationBase64)
+
+	pubBlock, _ := pem.Decode(bytePublicKey)
+	if pubBlock == nil {
+		return errors.New("pubBlock not exist")
+	}
+	pubInterface, err := x509.ParsePKIXPublicKey(pubBlock.Bytes)
+	if (pubInterface == nil) || (err != nil) {
+		return err
+	}
+	pub := pubInterface.(*rsa.PublicKey)
+
+	errorVerifyPKCS1v15 := rsa.VerifyPKCS1v15(pub, crypto.MD5, byteMD5, authorization)
+	if errorVerifyPKCS1v15 != nil {
+		return errorVerifyPKCS1v15
+	}
+
+	return nil
+}