minio/cmd/auth-handler.go
Andreas Auernhammer 9fb94e6aa8 ensure authenticated request bodies for Admin-API (#5984)
This commit adds a check to the server's admin-API such that it only
accepts Admin-API requests with authenticated bodies. Further this
commit updates the `madmin` package to always add the
`X-Amz-Content-Sha256` header.

This change improves the Admin-API security since the server does not
accept unauthenticated request bodies anymore.

After this commit `mc` must be updated to the new `madmin` api because
requests over TLS connections will fail.
2018-05-30 14:49:03 -07:00

299 lines
9 KiB
Go

/*
* Minio Cloud Storage, (C) 2015-2018 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 cmd
import (
"bytes"
"context"
"encoding/base64"
"encoding/hex"
"errors"
"io"
"io/ioutil"
"net/http"
"strings"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/hash"
"github.com/minio/minio/pkg/policy"
)
// Verify if request has JWT.
func isRequestJWT(r *http.Request) bool {
return strings.HasPrefix(r.Header.Get("Authorization"), jwtAlgorithm)
}
// Verify if request has AWS Signature Version '4'.
func isRequestSignatureV4(r *http.Request) bool {
return strings.HasPrefix(r.Header.Get("Authorization"), signV4Algorithm)
}
// Verify if request has AWS Signature Version '2'.
func isRequestSignatureV2(r *http.Request) bool {
return (!strings.HasPrefix(r.Header.Get("Authorization"), signV4Algorithm) &&
strings.HasPrefix(r.Header.Get("Authorization"), signV2Algorithm))
}
// Verify if request has AWS PreSign Version '4'.
func isRequestPresignedSignatureV4(r *http.Request) bool {
_, ok := r.URL.Query()["X-Amz-Credential"]
return ok
}
// Verify request has AWS PreSign Version '2'.
func isRequestPresignedSignatureV2(r *http.Request) bool {
_, ok := r.URL.Query()["AWSAccessKeyId"]
return ok
}
// Verify if request has AWS Post policy Signature Version '4'.
func isRequestPostPolicySignatureV4(r *http.Request) bool {
return strings.Contains(r.Header.Get("Content-Type"), "multipart/form-data") &&
r.Method == http.MethodPost
}
// Verify if the request has AWS Streaming Signature Version '4'. This is only valid for 'PUT' operation.
func isRequestSignStreamingV4(r *http.Request) bool {
return r.Header.Get("x-amz-content-sha256") == streamingContentSHA256 &&
r.Method == http.MethodPut
}
// Authorization type.
type authType int
// List of all supported auth types.
const (
authTypeUnknown authType = iota
authTypeAnonymous
authTypePresigned
authTypePresignedV2
authTypePostPolicy
authTypeStreamingSigned
authTypeSigned
authTypeSignedV2
authTypeJWT
)
// Get request authentication type.
func getRequestAuthType(r *http.Request) authType {
if isRequestSignatureV2(r) {
return authTypeSignedV2
} else if isRequestPresignedSignatureV2(r) {
return authTypePresignedV2
} else if isRequestSignStreamingV4(r) {
return authTypeStreamingSigned
} else if isRequestSignatureV4(r) {
return authTypeSigned
} else if isRequestPresignedSignatureV4(r) {
return authTypePresigned
} else if isRequestJWT(r) {
return authTypeJWT
} else if isRequestPostPolicySignatureV4(r) {
return authTypePostPolicy
} else if _, ok := r.Header["Authorization"]; !ok {
return authTypeAnonymous
}
return authTypeUnknown
}
// checkAdminRequestAuthType checks whether the request is a valid signature V2 or V4 request.
// It does not accept presigned or JWT or anonymous requests.
func checkAdminRequestAuthType(r *http.Request, region string) APIErrorCode {
s3Err := ErrAccessDenied
if _, ok := r.Header["X-Amz-Content-Sha256"]; ok && getRequestAuthType(r) == authTypeSigned && !skipContentSha256Cksum(r) { // we only support V4 (no presign) with auth. body
s3Err = isReqAuthenticated(r, region)
}
if s3Err != ErrNone {
reqInfo := (&logger.ReqInfo{}).AppendTags("requestHeaders", dumpRequest(r))
ctx := logger.SetReqInfo(context.Background(), reqInfo)
logger.LogIf(ctx, errors.New(getAPIError(s3Err).Description))
}
return s3Err
}
func checkRequestAuthType(ctx context.Context, r *http.Request, action policy.Action, bucketName, objectName string) APIErrorCode {
isOwner := true
accountName := globalServerConfig.GetCredential().AccessKey
switch getRequestAuthType(r) {
case authTypeUnknown:
return ErrAccessDenied
case authTypePresignedV2, authTypeSignedV2:
if errorCode := isReqAuthenticatedV2(r); errorCode != ErrNone {
return errorCode
}
case authTypeSigned, authTypePresigned:
region := globalServerConfig.GetRegion()
switch action {
case policy.GetBucketLocationAction, policy.ListAllMyBucketsAction:
region = ""
}
if errorCode := isReqAuthenticated(r, region); errorCode != ErrNone {
return errorCode
}
default:
isOwner = false
accountName = ""
}
// LocationConstraint is valid only for CreateBucketAction.
var locationConstraint string
if action == policy.CreateBucketAction {
// To extract region from XML in request body, get copy of request body.
payload, err := ioutil.ReadAll(io.LimitReader(r.Body, maxLocationConstraintSize))
if err != nil {
logger.LogIf(ctx, err)
return ErrMalformedXML
}
// Populate payload to extract location constraint.
r.Body = ioutil.NopCloser(bytes.NewReader(payload))
var s3Error APIErrorCode
locationConstraint, s3Error = parseLocationConstraint(r)
if s3Error != ErrNone {
return s3Error
}
// Populate payload again to handle it in HTTP handler.
r.Body = ioutil.NopCloser(bytes.NewReader(payload))
}
if globalPolicySys.IsAllowed(policy.Args{
AccountName: accountName,
Action: action,
BucketName: bucketName,
ConditionValues: getConditionValues(r, locationConstraint),
IsOwner: isOwner,
ObjectName: objectName,
}) {
return ErrNone
}
return ErrAccessDenied
}
// Verify if request has valid AWS Signature Version '2'.
func isReqAuthenticatedV2(r *http.Request) (s3Error APIErrorCode) {
if isRequestSignatureV2(r) {
return doesSignV2Match(r)
}
return doesPresignV2SignatureMatch(r)
}
func reqSignatureV4Verify(r *http.Request, region string) (s3Error APIErrorCode) {
sha256sum := getContentSha256Cksum(r)
switch {
case isRequestSignatureV4(r):
return doesSignatureMatch(sha256sum, r, region)
case isRequestPresignedSignatureV4(r):
return doesPresignedSignatureMatch(sha256sum, r, region)
default:
return ErrAccessDenied
}
}
// Verify if request has valid AWS Signature Version '4'.
func isReqAuthenticated(r *http.Request, region string) (s3Error APIErrorCode) {
if errCode := reqSignatureV4Verify(r, region); errCode != ErrNone {
return errCode
}
var (
err error
contentMD5, contentSHA256 []byte
)
// Extract 'Content-Md5' if present.
if _, ok := r.Header["Content-Md5"]; ok {
contentMD5, err = base64.StdEncoding.Strict().DecodeString(r.Header.Get("Content-Md5"))
if err != nil || len(contentMD5) == 0 {
return ErrInvalidDigest
}
}
// Extract either 'X-Amz-Content-Sha256' header or 'X-Amz-Content-Sha256' query parameter (if V4 presigned)
// Do not verify 'X-Amz-Content-Sha256' if skipSHA256.
if skipSHA256 := skipContentSha256Cksum(r); !skipSHA256 && isRequestPresignedSignatureV4(r) {
if sha256Sum, ok := r.URL.Query()["X-Amz-Content-Sha256"]; ok && len(sha256Sum) > 0 {
contentSHA256, err = hex.DecodeString(sha256Sum[0])
if err != nil {
return ErrContentSHA256Mismatch
}
}
} else if _, ok := r.Header["X-Amz-Content-Sha256"]; !skipSHA256 && ok {
contentSHA256, err = hex.DecodeString(r.Header.Get("X-Amz-Content-Sha256"))
if err != nil || len(contentSHA256) == 0 {
return ErrContentSHA256Mismatch
}
}
// Verify 'Content-Md5' and/or 'X-Amz-Content-Sha256' if present.
// The verification happens implicit during reading.
reader, err := hash.NewReader(r.Body, -1, hex.EncodeToString(contentMD5), hex.EncodeToString(contentSHA256))
if err != nil {
return toAPIErrorCode(err)
}
r.Body = ioutil.NopCloser(reader)
return ErrNone
}
// authHandler - handles all the incoming authorization headers and validates them if possible.
type authHandler struct {
handler http.Handler
}
// setAuthHandler to validate authorization header for the incoming request.
func setAuthHandler(h http.Handler) http.Handler {
return authHandler{h}
}
// List of all support S3 auth types.
var supportedS3AuthTypes = map[authType]struct{}{
authTypeAnonymous: {},
authTypePresigned: {},
authTypePresignedV2: {},
authTypeSigned: {},
authTypeSignedV2: {},
authTypePostPolicy: {},
authTypeStreamingSigned: {},
}
// Validate if the authType is valid and supported.
func isSupportedS3AuthType(aType authType) bool {
_, ok := supportedS3AuthTypes[aType]
return ok
}
// handler for validating incoming authorization headers.
func (a authHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
aType := getRequestAuthType(r)
if isSupportedS3AuthType(aType) {
// Let top level caller validate for anonymous and known signed requests.
a.handler.ServeHTTP(w, r)
return
} else if aType == authTypeJWT {
// Validate Authorization header if its valid for JWT request.
if !isHTTPRequestValid(r) {
w.WriteHeader(http.StatusUnauthorized)
return
}
a.handler.ServeHTTP(w, r)
return
}
writeErrorResponse(w, ErrSignatureVersionNotSupported, r.URL)
}