minio/bucket-handlers.go
Harshavardhana 88714e7c8e bucketpolicy: Improve bucket policy validation, avoid nested rules.
Bucket policy validation is more stricter now, to avoid nested
rules. The reason to do this is keep the rules simpler and more
meaningful avoiding conflicts.

This patch implements stricter checks.

Example policy to be generally avoided.
```
{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Action": [
				"s3:GetObject",
				"s3:DeleteObject"
			],
			"Effect": "Allow",
			"Principal": {
				"AWS": [
					"*"
				]
			},
			"Resource": [
				"arn:aws:s3:::jarjarbing/*"
			]
		},
		{
			"Action": [
				"s3:GetObject",
				"s3:DeleteObject"
			],
			"Effect": "Deny",
			"Principal": {
				"AWS": [
					"*"
				]
			},
			"Resource": [
				"arn:aws:s3:::jarjarbing/restic/key/*"
			]
		}
	]
}
```
2016-03-15 17:50:23 -07:00

662 lines
21 KiB
Go

/*
* Minio Cloud Storage, (C) 2015, 2016 Minio, Inc.
*
* 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 main
import (
"bytes"
"crypto/md5"
"encoding/base64"
"encoding/hex"
"encoding/xml"
"io"
"io/ioutil"
"mime/multipart"
"net/http"
"net/url"
"strings"
mux "github.com/gorilla/mux"
"github.com/minio/minio/pkg/crypto/sha256"
"github.com/minio/minio/pkg/fs"
"github.com/minio/minio/pkg/probe"
"github.com/minio/minio/pkg/s3/signature4"
)
// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
func enforceBucketPolicy(action string, bucket string, reqURL *url.URL) (s3Error APIErrorCode) {
// Read saved bucket policy.
policy, err := readBucketPolicy(bucket)
if err != nil {
errorIf(err.Trace(bucket), "GetBucketPolicy failed.", nil)
switch err.ToGoError().(type) {
case fs.BucketNotFound:
return ErrNoSuchBucket
case fs.BucketNameInvalid:
return ErrInvalidBucketName
default:
// For any other error just return AccessDenied.
return ErrAccessDenied
}
}
// Parse the saved policy.
bucketPolicy, e := parseBucketPolicy(policy)
if e != nil {
errorIf(probe.NewError(e), "Parse policy failed.", nil)
return ErrAccessDenied
}
// Construct resource in 'arn:aws:s3:::examplebucket' format.
resource := AWSResourcePrefix + strings.TrimPrefix(reqURL.Path, "/")
// Get conditions for policy verification.
conditions := make(map[string]string)
for queryParam := range reqURL.Query() {
conditions[queryParam] = reqURL.Query().Get("queryParam")
}
// Validate action, resource and conditions with current policy statements.
if !bucketPolicyEvalStatements(action, resource, conditions, bucketPolicy.Statements) {
return ErrAccessDenied
}
return ErrNone
}
// GetBucketLocationHandler - GET Bucket location.
// -------------------------
// This operation returns bucket location.
func (api storageAPI) GetBucketLocationHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
bucket := vars["bucket"]
switch getRequestAuthType(r) {
default:
// For all unknown auth types return error.
writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
return
case authTypeAnonymous:
// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
if s3Error := enforceBucketPolicy("s3:GetBucketLocation", bucket, r.URL); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
case authTypeSigned, authTypePresigned:
if s3Error := isReqAuthenticated(api.Signature, r); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
}
_, err := api.Filesystem.GetBucketInfo(bucket)
if err != nil {
errorIf(err.Trace(), "GetBucketInfo failed.", nil)
switch err.ToGoError().(type) {
case fs.BucketNotFound:
writeErrorResponse(w, r, ErrNoSuchBucket, r.URL.Path)
case fs.BucketNameInvalid:
writeErrorResponse(w, r, ErrInvalidBucketName, r.URL.Path)
default:
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
}
return
}
// Generate response.
encodedSuccessResponse := encodeResponse(LocationResponse{})
if api.Region != "us-east-1" {
encodedSuccessResponse = encodeResponse(LocationResponse{
Location: api.Region,
})
}
setCommonHeaders(w) // write headers.
writeSuccessResponse(w, encodedSuccessResponse)
}
// ListMultipartUploadsHandler - GET Bucket (List Multipart uploads)
// -------------------------
// This operation lists in-progress multipart uploads. An in-progress
// multipart upload is a multipart upload that has been initiated,
// using the Initiate Multipart Upload request, but has not yet been
// completed or aborted. This operation returns at most 1,000 multipart
// uploads in the response.
//
func (api storageAPI) ListMultipartUploadsHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
bucket := vars["bucket"]
switch getRequestAuthType(r) {
default:
// For all unknown auth types return error.
writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
return
case authTypeAnonymous:
// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
if s3Error := enforceBucketPolicy("s3:ListBucketMultipartUploads", bucket, r.URL); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
case authTypePresigned, authTypeSigned:
if s3Error := isReqAuthenticated(api.Signature, r); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
}
resources := getBucketMultipartResources(r.URL.Query())
if resources.MaxUploads < 0 {
writeErrorResponse(w, r, ErrInvalidMaxUploads, r.URL.Path)
return
}
if resources.MaxUploads == 0 {
resources.MaxUploads = maxObjectList
}
resources, err := api.Filesystem.ListMultipartUploads(bucket, resources)
if err != nil {
errorIf(err.Trace(), "ListMultipartUploads failed.", nil)
switch err.ToGoError().(type) {
case fs.BucketNotFound:
writeErrorResponse(w, r, ErrNoSuchBucket, r.URL.Path)
default:
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
}
return
}
// generate response
response := generateListMultipartUploadsResponse(bucket, resources)
encodedSuccessResponse := encodeResponse(response)
// write headers.
setCommonHeaders(w)
// write success response.
writeSuccessResponse(w, encodedSuccessResponse)
}
// ListObjectsHandler - GET Bucket (List Objects)
// -- -----------------------
// This implementation of the GET operation returns some or all (up to 1000)
// of the objects in a bucket. You can use the request parameters as selection
// criteria to return a subset of the objects in a bucket.
//
func (api storageAPI) ListObjectsHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
bucket := vars["bucket"]
switch getRequestAuthType(r) {
default:
// For all unknown auth types return error.
writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
return
case authTypeAnonymous:
// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
if s3Error := enforceBucketPolicy("s3:ListBucket", bucket, r.URL); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
case authTypeSigned, authTypePresigned:
if s3Error := isReqAuthenticated(api.Signature, r); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
}
// TODO handle encoding type.
prefix, marker, delimiter, maxkeys, _ := getBucketResources(r.URL.Query())
if maxkeys < 0 {
writeErrorResponse(w, r, ErrInvalidMaxKeys, r.URL.Path)
return
}
if maxkeys == 0 {
maxkeys = maxObjectList
}
listResp, err := api.Filesystem.ListObjects(bucket, prefix, marker, delimiter, maxkeys)
if err == nil {
// generate response
response := generateListObjectsResponse(bucket, prefix, marker, delimiter, maxkeys, listResp)
encodedSuccessResponse := encodeResponse(response)
// Write headers
setCommonHeaders(w)
// Write success response.
writeSuccessResponse(w, encodedSuccessResponse)
return
}
switch err.ToGoError().(type) {
case fs.BucketNameInvalid:
writeErrorResponse(w, r, ErrInvalidBucketName, r.URL.Path)
case fs.BucketNotFound:
writeErrorResponse(w, r, ErrNoSuchBucket, r.URL.Path)
case fs.ObjectNotFound:
writeErrorResponse(w, r, ErrNoSuchKey, r.URL.Path)
case fs.ObjectNameInvalid:
writeErrorResponse(w, r, ErrNoSuchKey, r.URL.Path)
default:
errorIf(err.Trace(), "ListObjects failed.", nil)
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
}
}
// ListBucketsHandler - GET Service
// -----------
// This implementation of the GET operation returns a list of all buckets
// owned by the authenticated sender of the request.
func (api storageAPI) ListBucketsHandler(w http.ResponseWriter, r *http.Request) {
// List buckets does not support bucket policies.
switch getRequestAuthType(r) {
default:
// For all unknown auth types return error.
writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
return
case authTypeSigned, authTypePresigned:
if s3Error := isReqAuthenticated(api.Signature, r); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
}
buckets, err := api.Filesystem.ListBuckets()
if err == nil {
// generate response
response := generateListBucketsResponse(buckets)
encodedSuccessResponse := encodeResponse(response)
// write headers
setCommonHeaders(w)
// write response
writeSuccessResponse(w, encodedSuccessResponse)
return
}
errorIf(err.Trace(), "ListBuckets failed.", nil)
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
}
// DeleteMultipleObjectsHandler - deletes multiple objects.
func (api storageAPI) DeleteMultipleObjectsHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
bucket := vars["bucket"]
// Content-Length is required and should be non-zero
// http://docs.aws.amazon.com/AmazonS3/latest/API/multiobjectdeleteapi.html
if r.ContentLength <= 0 {
writeErrorResponse(w, r, ErrMissingContentLength, r.URL.Path)
return
}
// Content-Md5 is requied should be set
// http://docs.aws.amazon.com/AmazonS3/latest/API/multiobjectdeleteapi.html
if _, ok := r.Header["Content-Md5"]; !ok {
writeErrorResponse(w, r, ErrMissingContentMD5, r.URL.Path)
return
}
// Set http request for signature.
auth := api.Signature.SetHTTPRequestToVerify(r)
// Allocate incoming content length bytes.
deleteXMLBytes := make([]byte, r.ContentLength)
// Read incoming body XML bytes.
_, e := io.ReadFull(r.Body, deleteXMLBytes)
if e != nil {
errorIf(probe.NewError(e), "DeleteMultipleObjects failed.", nil)
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
return
}
switch getRequestAuthType(r) {
default:
// For all unknown auth types return error.
writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
return
case authTypeAnonymous:
// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
if s3Error := enforceBucketPolicy("s3:DeleteObject", bucket, r.URL); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
case authTypePresigned:
// Check if request is presigned.
ok, err := auth.DoesPresignedSignatureMatch()
if err != nil {
errorIf(err.Trace(r.URL.String()), "Presigned signature verification failed.", nil)
writeErrorResponse(w, r, ErrSignatureDoesNotMatch, r.URL.Path)
return
}
if !ok {
writeErrorResponse(w, r, ErrSignatureDoesNotMatch, r.URL.Path)
return
}
case authTypeSigned:
// Check if request is signed.
sha := sha256.New()
mdSh := md5.New()
sha.Write(deleteXMLBytes)
mdSh.Write(deleteXMLBytes)
ok, err := auth.DoesSignatureMatch(hex.EncodeToString(sha.Sum(nil)))
if err != nil {
errorIf(err.Trace(), "DeleteMultipleObjects failed.", nil)
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
return
}
if !ok {
writeErrorResponse(w, r, ErrSignatureDoesNotMatch, r.URL.Path)
return
}
// Verify content md5.
if r.Header.Get("Content-Md5") != base64.StdEncoding.EncodeToString(mdSh.Sum(nil)) {
writeErrorResponse(w, r, ErrBadDigest, r.URL.Path)
return
}
}
// Unmarshal list of keys to be deleted.
deleteObjects := &DeleteObjectsRequest{}
if e := xml.Unmarshal(deleteXMLBytes, deleteObjects); e != nil {
writeErrorResponse(w, r, ErrMalformedXML, r.URL.Path)
return
}
var deleteErrors []DeleteError
var deletedObjects []ObjectIdentifier
// Loop through all the objects and delete them sequentially.
for _, object := range deleteObjects.Objects {
err := api.Filesystem.DeleteObject(bucket, object.ObjectName)
if err == nil {
deletedObjects = append(deletedObjects, ObjectIdentifier{
ObjectName: object.ObjectName,
})
} else {
errorIf(err.Trace(object.ObjectName), "DeleteObject failed.", nil)
switch err.ToGoError().(type) {
case fs.BucketNameInvalid:
deleteErrors = append(deleteErrors, DeleteError{
Code: errorCodeResponse[ErrInvalidBucketName].Code,
Message: errorCodeResponse[ErrInvalidBucketName].Description,
Key: object.ObjectName,
})
case fs.BucketNotFound:
deleteErrors = append(deleteErrors, DeleteError{
Code: errorCodeResponse[ErrNoSuchBucket].Code,
Message: errorCodeResponse[ErrNoSuchBucket].Description,
Key: object.ObjectName,
})
case fs.ObjectNotFound:
deleteErrors = append(deleteErrors, DeleteError{
Code: errorCodeResponse[ErrNoSuchKey].Code,
Message: errorCodeResponse[ErrNoSuchKey].Description,
Key: object.ObjectName,
})
case fs.ObjectNameInvalid:
deleteErrors = append(deleteErrors, DeleteError{
Code: errorCodeResponse[ErrNoSuchKey].Code,
Message: errorCodeResponse[ErrNoSuchKey].Description,
Key: object.ObjectName,
})
default:
deleteErrors = append(deleteErrors, DeleteError{
Code: errorCodeResponse[ErrInternalError].Code,
Message: errorCodeResponse[ErrInternalError].Description,
Key: object.ObjectName,
})
}
}
}
// Generate response
response := generateMultiDeleteResponse(deleteObjects.Quiet, deletedObjects, deleteErrors)
encodedSuccessResponse := encodeResponse(response)
// Write headers
setCommonHeaders(w)
// Write success response.
writeSuccessResponse(w, encodedSuccessResponse)
}
// PutBucketHandler - PUT Bucket
// ----------
// This implementation of the PUT operation creates a new bucket for authenticated request
func (api storageAPI) PutBucketHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
bucket := vars["bucket"]
// Set http request for signature.
auth := api.Signature.SetHTTPRequestToVerify(r)
switch getRequestAuthType(r) {
default:
// For all unknown auth types return error.
writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
return
case authTypePresigned:
ok, err := auth.DoesPresignedSignatureMatch()
if err != nil {
errorIf(err.Trace(r.URL.String()), "Presigned signature verification failed.", nil)
writeErrorResponse(w, r, ErrSignatureDoesNotMatch, r.URL.Path)
return
}
if !ok {
writeErrorResponse(w, r, ErrSignatureDoesNotMatch, r.URL.Path)
return
}
case authTypeSigned:
// Verify signature for the incoming body if any.
locationBytes, e := ioutil.ReadAll(r.Body)
if e != nil {
errorIf(probe.NewError(e), "MakeBucket failed.", nil)
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
return
}
sh := sha256.New()
sh.Write(locationBytes)
ok, err := auth.DoesSignatureMatch(hex.EncodeToString(sh.Sum(nil)))
if err != nil {
errorIf(err.Trace(), "MakeBucket failed.", nil)
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
return
}
if !ok {
writeErrorResponse(w, r, ErrSignatureDoesNotMatch, r.URL.Path)
return
}
}
// Make bucket.
err := api.Filesystem.MakeBucket(bucket)
if err != nil {
errorIf(err.Trace(), "MakeBucket failed.", nil)
switch err.ToGoError().(type) {
case fs.BucketNameInvalid:
writeErrorResponse(w, r, ErrInvalidBucketName, r.URL.Path)
case fs.BucketExists:
writeErrorResponse(w, r, ErrBucketAlreadyExists, r.URL.Path)
default:
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
}
return
}
// Make sure to add Location information here only for bucket
w.Header().Set("Location", getLocation(r))
writeSuccessResponse(w, nil)
}
func extractHTTPFormValues(reader *multipart.Reader) (io.Reader, map[string]string, *probe.Error) {
/// HTML Form values
formValues := make(map[string]string)
filePart := new(bytes.Buffer)
var e error
for e == nil {
var part *multipart.Part
part, e = reader.NextPart()
if part != nil {
if part.FileName() == "" {
buffer, e := ioutil.ReadAll(part)
if e != nil {
return nil, nil, probe.NewError(e)
}
formValues[http.CanonicalHeaderKey(part.FormName())] = string(buffer)
} else {
if _, e := io.Copy(filePart, part); e != nil {
return nil, nil, probe.NewError(e)
}
}
}
}
return filePart, formValues, nil
}
// PostPolicyBucketHandler - POST policy
// ----------
// This implementation of the POST operation handles object creation with a specified
// signature policy in multipart/form-data
func (api storageAPI) PostPolicyBucketHandler(w http.ResponseWriter, r *http.Request) {
// Here the parameter is the size of the form data that should
// be loaded in memory, the remaining being put in temporary
// files
reader, e := r.MultipartReader()
if e != nil {
errorIf(probe.NewError(e), "Unable to initialize multipart reader.", nil)
writeErrorResponse(w, r, ErrMalformedPOSTRequest, r.URL.Path)
return
}
fileBody, formValues, err := extractHTTPFormValues(reader)
if err != nil {
errorIf(err.Trace(), "Unable to parse form values.", nil)
writeErrorResponse(w, r, ErrMalformedPOSTRequest, r.URL.Path)
return
}
bucket := mux.Vars(r)["bucket"]
formValues["Bucket"] = bucket
object := formValues["Key"]
var ok bool
// Set http request for signature.
auth := api.Signature.SetHTTPRequestToVerify(r)
// Verify policy signature.
ok, err = auth.DoesPolicySignatureMatch(formValues)
if err != nil {
errorIf(err.Trace(), "Unable to verify signature.", nil)
writeErrorResponse(w, r, ErrSignatureDoesNotMatch, r.URL.Path)
return
}
if !ok {
writeErrorResponse(w, r, ErrSignatureDoesNotMatch, r.URL.Path)
return
}
if err = signature4.ApplyPolicyCond(formValues); err != nil {
errorIf(err.Trace(), "Invalid request, policy doesn't match with the endpoint.", nil)
writeErrorResponse(w, r, ErrMalformedPOSTRequest, r.URL.Path)
return
}
objectInfo, err := api.Filesystem.CreateObject(bucket, object, "", -1, fileBody, nil)
if err != nil {
errorIf(err.Trace(), "CreateObject failed.", nil)
switch err.ToGoError().(type) {
case fs.RootPathFull:
writeErrorResponse(w, r, ErrRootPathFull, r.URL.Path)
case fs.BucketNotFound:
writeErrorResponse(w, r, ErrNoSuchBucket, r.URL.Path)
case fs.BucketNameInvalid:
writeErrorResponse(w, r, ErrInvalidBucketName, r.URL.Path)
case fs.BadDigest:
writeErrorResponse(w, r, ErrBadDigest, r.URL.Path)
case fs.IncompleteBody:
writeErrorResponse(w, r, ErrIncompleteBody, r.URL.Path)
case fs.InvalidDigest:
writeErrorResponse(w, r, ErrInvalidDigest, r.URL.Path)
default:
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
}
return
}
if objectInfo.MD5Sum != "" {
w.Header().Set("ETag", "\""+objectInfo.MD5Sum+"\"")
}
writeSuccessResponse(w, nil)
}
// HeadBucketHandler - HEAD Bucket
// ----------
// This operation is useful to determine if a bucket exists.
// The operation returns a 200 OK if the bucket exists and you
// have permission to access it. Otherwise, the operation might
// return responses such as 404 Not Found and 403 Forbidden.
func (api storageAPI) HeadBucketHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
bucket := vars["bucket"]
switch getRequestAuthType(r) {
default:
// For all unknown auth types return error.
writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
return
case authTypePresigned, authTypeSigned:
if s3Error := isReqAuthenticated(api.Signature, r); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
}
_, err := api.Filesystem.GetBucketInfo(bucket)
if err != nil {
errorIf(err.Trace(), "GetBucketInfo failed.", nil)
switch err.ToGoError().(type) {
case fs.BucketNotFound:
writeErrorResponse(w, r, ErrNoSuchBucket, r.URL.Path)
case fs.BucketNameInvalid:
writeErrorResponse(w, r, ErrInvalidBucketName, r.URL.Path)
default:
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
}
return
}
writeSuccessResponse(w, nil)
}
// DeleteBucketHandler - Delete bucket
func (api storageAPI) DeleteBucketHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
bucket := vars["bucket"]
switch getRequestAuthType(r) {
default:
// For all unknown auth types return error.
writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
return
case authTypePresigned, authTypeSigned:
if s3Error := isReqAuthenticated(api.Signature, r); s3Error != ErrNone {
writeErrorResponse(w, r, s3Error, r.URL.Path)
return
}
}
err := api.Filesystem.DeleteBucket(bucket)
if err != nil {
errorIf(err.Trace(), "DeleteBucket failed.", nil)
switch err.ToGoError().(type) {
case fs.BucketNotFound:
writeErrorResponse(w, r, ErrNoSuchBucket, r.URL.Path)
case fs.BucketNotEmpty:
writeErrorResponse(w, r, ErrBucketNotEmpty, r.URL.Path)
default:
writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
}
return
}
// Delete bucket access policy, if present - ignore any errors.
removeBucketPolicy(bucket)
// Write success response.
writeSuccessNoContent(w)
}