476 lines
14 KiB
Go
476 lines
14 KiB
Go
package upload
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import (
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"bytes"
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"crypto"
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"crypto/hmac"
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"crypto/md5"
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"crypto/rsa"
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"crypto/sha1"
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"crypto/x509"
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"encoding/base64"
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"encoding/json"
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"encoding/pem"
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"errors"
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"fmt"
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"hash"
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"io"
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"io/ioutil"
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"net/http"
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"strconv"
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"time"
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)
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type Oss struct {
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AccessKeyId string
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AccessKeySecret string
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Host string
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CallbackUrl string
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ExpireTime int64
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MaxByte int64
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}
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const (
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base64Table = "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_"
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)
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var coder = base64.NewEncoding(base64Table)
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func base64Encode(src []byte) []byte {
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return []byte(coder.EncodeToString(src))
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}
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func get_gmt_iso8601(expire_end int64) string {
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var tokenExpire = time.Unix(expire_end, 0).UTC().Format("2006-01-02T15:04:05Z")
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return tokenExpire
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}
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type ConfigStruct struct {
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Expiration string `json:"expiration"`
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Conditions [][]interface{} `json:"conditions"`
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}
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type PolicyToken struct {
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AccessKeyId string `json:"accessid"`
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Host string `json:"host"`
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Expire int64 `json:"expire"`
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Signature string `json:"signature"`
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Policy string `json:"policy"`
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Directory string `json:"dir"`
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Callback string `json:"callback"`
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}
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type CallbackParam struct {
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CallbackUrl string `json:"callbackUrl"`
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CallbackBody string `json:"callbackBody"`
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CallbackBodyType string `json:"callbackBodyType"`
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}
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type CallbackBaseForm struct {
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Bucket string `json:"bucket" form:"bucket"`
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Etag string `json:"etag" form:"etag"`
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Filename string `json:"filename" form:"filename"`
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Size string `json:"size" form:"size"`
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MimeType string `json:"mime_type" form:"mime_type"`
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Height string `json:"height" form:"height"`
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Width string `json:"width" form:"width"`
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Format string `json:"format" form:"format"`
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OriginFilename string `json:"origin_filename" form:"origin_filename"`
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}
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func (oc *Oss) GetPolicyToken(uploadDir string) string {
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now := time.Now().Unix()
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expire_end := now + oc.ExpireTime
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var tokenExpire = get_gmt_iso8601(expire_end)
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//create post policy json
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var config ConfigStruct
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config.Expiration = tokenExpire
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var condition = []interface{}{"starts-with", "$key", uploadDir}
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var condition_limit = []interface{}{"content-length-range", 0, oc.MaxByte}
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config.Conditions = append(config.Conditions, condition, condition_limit)
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//calucate signature
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result, err := json.Marshal(config)
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debyte := base64.StdEncoding.EncodeToString(result)
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h := hmac.New(func() hash.Hash {
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return sha1.New()
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}, []byte(oc.AccessKeySecret))
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io.WriteString(h, debyte)
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signedStr := base64.StdEncoding.EncodeToString(h.Sum(nil))
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var callbackParam CallbackParam
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callbackParam.CallbackUrl = oc.CallbackUrl
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callbackParam.CallbackBody =
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"bucket=${bucket}&" +
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"etag=${etag}&" +
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"filename=${object}&" +
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"size=${size}&" +
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"mime_type=${mimeType}&" +
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"height=${imageInfo.height}&" +
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"width=${imageInfo.width}&" +
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"format=${imageInfo.format}&" +
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"origin_filename=${x:origin_filename}"
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callbackParam.CallbackBodyType = "application/x-www-form-urlencoded"
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callback_str, err := json.Marshal(callbackParam)
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if err != nil {
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fmt.Println("callback json err:", err)
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}
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callbackBase64 := base64.StdEncoding.EncodeToString(callback_str)
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var policyToken PolicyToken
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policyToken.AccessKeyId = oc.AccessKeyId
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policyToken.Host = oc.Host
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policyToken.Expire = expire_end
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policyToken.Signature = string(signedStr)
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policyToken.Directory = uploadDir
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policyToken.Policy = string(debyte)
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policyToken.Callback = string(callbackBase64)
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response, err := json.Marshal(policyToken)
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if err != nil {
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fmt.Println("json err:", err)
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}
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return string(response)
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}
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func (oc *Oss) Verify(r *http.Request) bool {
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// Get PublicKey bytes
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bytePublicKey, err := getPublicKey(r)
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if err != nil {
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return false
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}
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// Get Authorization bytes : decode from Base64String
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byteAuthorization, err := getAuthorization(r)
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if err != nil {
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return false
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}
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// Get MD5 bytes from Newly Constructed Authrization String.
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byteMD5, err := getMD5FromNewAuthString(r)
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if err != nil {
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return false
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}
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// verifySignature and response to client
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if verifySignature(bytePublicKey, byteMD5, byteAuthorization) {
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// do something you want accoding to callback_body ...
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return true
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} else {
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return false
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}
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}
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// getPublicKey : Get PublicKey bytes from Request.URL
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func getPublicKey(r *http.Request) ([]byte, error) {
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var bytePublicKey []byte
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// get PublicKey URL
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publicKeyURLBase64 := r.Header.Get("x-oss-pub-key-url")
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if publicKeyURLBase64 == "" {
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fmt.Println("GetPublicKey from Request header failed : No x-oss-pub-key-url field. ")
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return bytePublicKey, errors.New("no x-oss-pub-key-url field in Request header ")
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}
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publicKeyURL, _ := base64.StdEncoding.DecodeString(publicKeyURLBase64)
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// fmt.Printf("publicKeyURL={%s}\n", publicKeyURL)
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// get PublicKey Content from URL
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responsePublicKeyURL, err := http.Get(string(publicKeyURL))
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if err != nil {
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fmt.Printf("Get PublicKey Content from URL failed : %s \n", err.Error())
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return bytePublicKey, err
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}
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bytePublicKey, err = ioutil.ReadAll(responsePublicKeyURL.Body)
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if err != nil {
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fmt.Printf("Read PublicKey Content from URL failed : %s \n", err.Error())
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return bytePublicKey, err
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}
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defer responsePublicKeyURL.Body.Close()
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// fmt.Printf("publicKey={%s}\n", bytePublicKey)
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return bytePublicKey, nil
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}
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// getAuthorization : decode from Base64String
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func getAuthorization(r *http.Request) ([]byte, error) {
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var byteAuthorization []byte
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// Get Authorization bytes : decode from Base64String
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strAuthorizationBase64 := r.Header.Get("authorization")
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if strAuthorizationBase64 == "" {
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fmt.Println("Failed to get authorization field from request header. ")
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return byteAuthorization, errors.New("no authorization field in Request header")
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}
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byteAuthorization, _ = base64.StdEncoding.DecodeString(strAuthorizationBase64)
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return byteAuthorization, nil
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}
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// getMD5FromNewAuthString : Get MD5 bytes from Newly Constructed Authrization String.
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func getMD5FromNewAuthString(r *http.Request) ([]byte, error) {
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var byteMD5 []byte
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// Construct the New Auth String from URI+Query+Body
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bodyContent, err := ioutil.ReadAll(r.Body)
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r.Body.Close()
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r.Body = ioutil.NopCloser(bytes.NewBuffer(bodyContent))
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if err != nil {
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fmt.Printf("Read Request Body failed : %s \n", err.Error())
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return byteMD5, err
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}
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strCallbackBody := string(bodyContent)
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// fmt.Printf("r.URL.RawPath={%s}, r.URL.Query()={%s}, strCallbackBody={%s}\n", r.URL.RawPath, r.URL.Query(), strCallbackBody)
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strURLPathDecode, errUnescape := unescapePath(r.URL.Path, encodePathSegment) //url.PathUnescape(r.URL.Path) for Golang v1.8.2+
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if errUnescape != nil {
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fmt.Printf("url.PathUnescape failed : URL.Path=%s, error=%s \n", r.URL.Path, err.Error())
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return byteMD5, errUnescape
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}
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// Generate New Auth String prepare for MD5
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strAuth := ""
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if r.URL.RawQuery == "" {
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strAuth = fmt.Sprintf("%s\n%s", strURLPathDecode, strCallbackBody)
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} else {
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strAuth = fmt.Sprintf("%s?%s\n%s", strURLPathDecode, r.URL.RawQuery, strCallbackBody)
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}
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// fmt.Printf("NewlyConstructedAuthString={%s}\n", strAuth)
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// Generate MD5 from the New Auth String
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md5Ctx := md5.New()
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md5Ctx.Write([]byte(strAuth))
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byteMD5 = md5Ctx.Sum(nil)
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return byteMD5, nil
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}
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/* VerifySignature
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* VerifySignature需要三个重要的数据信息来进行签名验证： 1>获取公钥PublicKey; 2>生成新的MD5鉴权串; 3>解码Request携带的鉴权串;
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* 1>获取公钥PublicKey : 从RequestHeader的"x-oss-pub-key-url"字段中获取 URL, 读取URL链接的包含的公钥内容， 进行解码解析， 将其作为rsa.VerifyPKCS1v15的入参。
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* 2>生成新的MD5鉴权串 : 把Request中的url中的path部分进行urldecode， 加上url的query部分， 再加上body， 组合之后进行MD5编码， 得到MD5鉴权字节串。
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* 3>解码Request携带的鉴权串 ： 获取RequestHeader的"authorization"字段， 对其进行Base64解码，作为签名验证的鉴权对比串。
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* rsa.VerifyPKCS1v15进行签名验证，返回验证结果。
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* */
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func verifySignature(bytePublicKey []byte, byteMd5 []byte, authorization []byte) bool {
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pubBlock, _ := pem.Decode(bytePublicKey)
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if pubBlock == nil {
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fmt.Printf("Failed to parse PEM block containing the public key")
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return false
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}
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pubInterface, err := x509.ParsePKIXPublicKey(pubBlock.Bytes)
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if (pubInterface == nil) || (err != nil) {
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fmt.Printf("x509.ParsePKIXPublicKey(publicKey) failed : %s \n", err.Error())
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return false
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}
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pub := pubInterface.(*rsa.PublicKey)
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errorVerifyPKCS1v15 := rsa.VerifyPKCS1v15(pub, crypto.MD5, byteMd5, authorization)
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if errorVerifyPKCS1v15 != nil {
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fmt.Printf("\nSignature Verification is Failed : %s \n", errorVerifyPKCS1v15.Error())
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//printByteArray(byteMd5, "AuthMd5(fromNewAuthString)")
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//printByteArray(bytePublicKey, "PublicKeyBase64")
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//printByteArray(authorization, "AuthorizationFromRequest")
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return false
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}
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fmt.Printf("\nSignature Verification is Successful. \n")
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return true
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}
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func printByteArray(byteArrary []byte, arrName string) {
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fmt.Printf("++++++++ printByteArray : ArrayName=%s, ArrayLength=%d \n", arrName, len(byteArrary))
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for i := 0; i < len(byteArrary); i++ {
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fmt.Printf("%02x", byteArrary[i])
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}
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fmt.Printf("\n-------- printByteArray : End . \n")
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}
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type EscapeError string
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func (e EscapeError) Error() string {
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return "invalid URL escape " + strconv.Quote(string(e))
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}
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type InvalidHostError string
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func (e InvalidHostError) Error() string {
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return "invalid character " + strconv.Quote(string(e)) + " in host name"
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}
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type encoding int
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const (
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encodePath encoding = 1 + iota
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encodePathSegment
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encodeHost
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encodeZone
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encodeUserPassword
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encodeQueryComponent
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encodeFragment
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)
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// unescapePath : unescapes a string; the mode specifies, which section of the URL string is being unescaped.
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func unescapePath(s string, mode encoding) (string, error) {
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// Count %, check that they're well-formed.
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mode = encodePathSegment
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n := 0
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hasPlus := false
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for i := 0; i < len(s); {
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switch s[i] {
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case '%':
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n++
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if i+2 >= len(s) || !ishex(s[i+1]) || !ishex(s[i+2]) {
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s = s[i:]
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if len(s) > 3 {
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s = s[:3]
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}
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return "", EscapeError(s)
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}
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// Per https://tools.ietf.org/html/rfc3986#page-21
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// in the host component %-encoding can only be used
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// for non-ASCII bytes.
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// But https://tools.ietf.org/html/rfc6874#section-2
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// introduces %25 being allowed to escape a percent sign
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// in IPv6 scoped-address literals. Yay.
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if mode == encodeHost && unhex(s[i+1]) < 8 && s[i:i+3] != "%25" {
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return "", EscapeError(s[i : i+3])
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}
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if mode == encodeZone {
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// RFC 6874 says basically "anything goes" for zone identifiers
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// and that even non-ASCII can be redundantly escaped,
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// but it seems prudent to restrict %-escaped bytes here to those
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// that are valid host name bytes in their unescaped form.
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// That is, you can use escaping in the zone identifier but not
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// to introduce bytes you couldn't just write directly.
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// But Windows puts spaces here! Yay.
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v := unhex(s[i+1])<<4 | unhex(s[i+2])
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if s[i:i+3] != "%25" && v != ' ' && shouldEscape(v, encodeHost) {
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return "", EscapeError(s[i : i+3])
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}
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}
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i += 3
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case '+':
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hasPlus = mode == encodeQueryComponent
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i++
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default:
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if (mode == encodeHost || mode == encodeZone) && s[i] < 0x80 && shouldEscape(s[i], mode) {
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return "", InvalidHostError(s[i : i+1])
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}
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i++
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}
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}
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if n == 0 && !hasPlus {
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return s, nil
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}
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t := make([]byte, len(s)-2*n)
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j := 0
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for i := 0; i < len(s); {
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switch s[i] {
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case '%':
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t[j] = unhex(s[i+1])<<4 | unhex(s[i+2])
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j++
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i += 3
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case '+':
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if mode == encodeQueryComponent {
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t[j] = ' '
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} else {
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t[j] = '+'
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}
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j++
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i++
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default:
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t[j] = s[i]
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j++
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i++
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}
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}
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return string(t), nil
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}
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// Please be informed that for now shouldEscape does not check all
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// reserved characters correctly. See golang.org/issue/5684.
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func shouldEscape(c byte, mode encoding) bool {
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// §2.3 Unreserved characters (alphanum)
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if 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' {
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return false
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}
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if mode == encodeHost || mode == encodeZone {
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// §3.2.2 Host allows
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// sub-delims = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "="
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// as part of reg-name.
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// We add : because we include :port as part of host.
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// We add [ ] because we include [ipv6]:port as part of host.
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// We add < > because they're the only characters left that
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// we could possibly allow, and Parse will reject them if we
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// escape them (because hosts can't use %-encoding for
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// ASCII bytes).
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switch c {
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case '!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '=', ':', '[', ']', '<', '>', '"':
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return false
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}
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}
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switch c {
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case '-', '_', '.', '~': // §2.3 Unreserved characters (mark)
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return false
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case '$', '&', '+', ',', '/', ':', ';', '=', '?', '@': // §2.2 Reserved characters (reserved)
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// Different sections of the URL allow a few of
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// the reserved characters to appear unescaped.
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switch mode {
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case encodePath: // §3.3
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// The RFC allows : @ & = + $ but saves / ; , for assigning
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// meaning to individual path segments. This package
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// only manipulates the path as a whole, so we allow those
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// last three as well. That leaves only ? to escape.
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return c == '?'
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case encodePathSegment: // §3.3
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// The RFC allows : @ & = + $ but saves / ; , for assigning
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// meaning to individual path segments.
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return c == '/' || c == ';' || c == ',' || c == '?'
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case encodeUserPassword: // §3.2.1
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// The RFC allows ';', ':', '&', '=', '+', '$', and ',' in
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// userinfo, so we must escape only '@', '/', and '?'.
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// The parsing of userinfo treats ':' as special so we must escape
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// that too.
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return c == '@' || c == '/' || c == '?' || c == ':'
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case encodeQueryComponent: // §3.4
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// The RFC reserves (so we must escape) everything.
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return true
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case encodeFragment: // §4.1
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// The RFC text is silent but the grammar allows
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// everything, so escape nothing.
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return false
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}
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}
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// Everything else must be escaped.
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return true
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}
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func ishex(c byte) bool {
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switch {
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case '0' <= c && c <= '9':
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return true
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case 'a' <= c && c <= 'f':
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return true
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case 'A' <= c && c <= 'F':
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return true
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}
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return false
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}
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func unhex(c byte) byte {
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switch {
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case '0' <= c && c <= '9':
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return c - '0'
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case 'a' <= c && c <= 'f':
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return c - 'a' + 10
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case 'A' <= c && c <= 'F':
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return c - 'A' + 10
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}
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return 0
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}
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