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241 lines (212 loc) · 7 KB
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/*
* 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 cmd
import (
"bytes"
"io/ioutil"
"net/http"
"strings"
)
// Verify if the request http Header "x-amz-content-sha256" == "UNSIGNED-PAYLOAD"
func isRequestUnsignedPayload(r *http.Request) bool {
return r.Header.Get("x-amz-content-sha256") == unsignedPayload
}
// 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 == httpPOST
}
// 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 == httpPUT
}
// 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
}
func checkRequestAuthType(r *http.Request, bucket, policyAction, region string) APIErrorCode {
reqAuthType := getRequestAuthType(r)
switch reqAuthType {
case authTypePresignedV2, authTypeSignedV2:
// Signature V2 validation.
s3Error := isReqAuthenticatedV2(r)
if s3Error != ErrNone {
errorIf(errSignatureMismatch, "%s", dumpRequest(r))
}
return s3Error
case authTypeSigned, authTypePresigned:
s3Error := isReqAuthenticated(r, region)
if s3Error != ErrNone {
errorIf(errSignatureMismatch, "%s", dumpRequest(r))
}
return s3Error
}
if reqAuthType == authTypeAnonymous && policyAction != "" {
// http://docs.aws.amazon.com/AmazonS3/latest/dev/using-with-s3-actions.html
return enforceBucketPolicy(bucket, policyAction, r.URL.Path,
r.Referer(), r.URL.Query())
}
// By default return ErrAccessDenied
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 r == nil {
return ErrInternalError
}
if errCode := reqSignatureV4Verify(r, region); errCode != ErrNone {
return errCode
}
payload, err := ioutil.ReadAll(r.Body)
if err != nil {
errorIf(err, "Unable to read request body for signature verification")
return ErrInternalError
}
// Populate back the payload.
r.Body = ioutil.NopCloser(bytes.NewReader(payload))
// Verify Content-Md5, if payload is set.
if r.Header.Get("Content-Md5") != "" {
if r.Header.Get("Content-Md5") != getMD5HashBase64(payload) {
return ErrBadDigest
}
}
if skipContentSha256Cksum(r) {
return ErrNone
}
// Verify that X-Amz-Content-Sha256 Header == sha256(payload)
// If X-Amz-Content-Sha256 header is not sent then we don't calculate/verify sha256(payload)
sum := r.Header.Get("X-Amz-Con
62EE
tent-Sha256")
if isRequestPresignedSignatureV4(r) {
sum = r.URL.Query().Get("X-Amz-Content-Sha256")
}
if sum != "" && sum != getSHA256Hash(payload) {
return ErrContentSHA256Mismatch
}
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)
}