minio/cmd/auth-handler.go
Harshavardhana c43f745449
Ensure that we use constants everywhere (#7845)
This allows for canonicalization of the strings
throughout our code and provides a common space
for all these constants to reside.

This list is rather non-exhaustive but captures
all the headers used in AWS S3 API operations
2019-07-02 22:34:32 -07:00

508 lines
16 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"
"crypto/subtle"
"encoding/base64"
"encoding/hex"
"errors"
"io"
"io/ioutil"
"net/http"
"strings"
jwtgo "github.com/dgrijalva/jwt-go"
xhttp "github.com/minio/minio/cmd/http"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/auth"
"github.com/minio/minio/pkg/hash"
iampolicy "github.com/minio/minio/pkg/iam/policy"
"github.com/minio/minio/pkg/policy"
)
// Verify if request has JWT.
func isRequestJWT(r *http.Request) bool {
return strings.HasPrefix(r.Header.Get(xhttp.Authorization), jwtAlgorithm)
}
// Verify if request has AWS Signature Version '4'.
func isRequestSignatureV4(r *http.Request) bool {
return strings.HasPrefix(r.Header.Get(xhttp.Authorization), signV4Algorithm)
}
// Verify if request has AWS Signature Version '2'.
func isRequestSignatureV2(r *http.Request) bool {
return (!strings.HasPrefix(r.Header.Get(xhttp.Authorization), signV4Algorithm) &&
strings.HasPrefix(r.Header.Get(xhttp.Authorization), signV2Algorithm))
}
// Verify if request has AWS PreSign Version '4'.
func isRequestPresignedSignatureV4(r *http.Request) bool {
_, ok := r.URL.Query()[xhttp.AmzCredential]
return ok
}
// Verify request has AWS PreSign Version '2'.
func isRequestPresignedSignatureV2(r *http.Request) bool {
_, ok := r.URL.Query()[xhttp.AmzAccessKeyID]
return ok
}
// Verify if request has AWS Post policy Signature Version '4'.
func isRequestPostPolicySignatureV4(r *http.Request) bool {
return strings.Contains(r.Header.Get(xhttp.ContentType), "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(xhttp.AmzContentSha256) == 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
authTypeSTS
)
// 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.URL.Query()[xhttp.Action]; ok {
return authTypeSTS
} else if _, ok := r.Header[xhttp.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(ctx context.Context, r *http.Request, region string) APIErrorCode {
s3Err := ErrAccessDenied
if _, ok := r.Header[xhttp.AmzContentSha256]; ok &&
getRequestAuthType(r) == authTypeSigned && !skipContentSha256Cksum(r) {
// We only support admin credentials to access admin APIs.
var owner bool
_, owner, s3Err = getReqAccessKeyV4(r, region, serviceS3)
if s3Err != ErrNone {
return s3Err
}
if !owner {
return ErrAccessDenied
}
// we only support V4 (no presign) with auth body
s3Err = isReqAuthenticated(ctx, r, region, serviceS3)
}
if s3Err != ErrNone {
reqInfo := (&logger.ReqInfo{}).AppendTags("requestHeaders", dumpRequest(r))
ctx := logger.SetReqInfo(ctx, reqInfo)
logger.LogIf(ctx, errors.New(getAPIError(s3Err).Description))
}
return s3Err
}
// Fetch the security token set by the client.
func getSessionToken(r *http.Request) (token string) {
token = r.Header.Get(xhttp.AmzSecurityToken)
if token != "" {
return token
}
return r.URL.Query().Get(xhttp.AmzSecurityToken)
}
// Fetch claims in the security token returned by the client, doesn't return
// errors - upon errors the returned claims map will be empty.
func mustGetClaimsFromToken(r *http.Request) map[string]interface{} {
claims, _ := getClaimsFromToken(r)
return claims
}
// Fetch claims in the security token returned by the client.
func getClaimsFromToken(r *http.Request) (map[string]interface{}, error) {
claims := make(map[string]interface{})
token := getSessionToken(r)
if token == "" {
return claims, nil
}
stsTokenCallback := func(jwtToken *jwtgo.Token) (interface{}, error) {
// JWT token for x-amz-security-token is signed with admin
// secret key, temporary credentials become invalid if
// server admin credentials change. This is done to ensure
// that clients cannot decode the token using the temp
// secret keys and generate an entirely new claim by essentially
// hijacking the policies. We need to make sure that this is
// based an admin credential such that token cannot be decoded
// on the client side and is treated like an opaque value.
return []byte(globalServerConfig.GetCredential().SecretKey), nil
}
p := &jwtgo.Parser{
ValidMethods: []string{
jwtgo.SigningMethodHS256.Alg(),
jwtgo.SigningMethodHS512.Alg(),
},
}
jtoken, err := p.ParseWithClaims(token, jwtgo.MapClaims(claims), stsTokenCallback)
if err != nil {
return nil, err
}
if !jtoken.Valid {
return nil, errAuthentication
}
v, ok := claims["accessKey"]
if !ok {
return nil, errInvalidAccessKeyID
}
if _, ok = v.(string); !ok {
return nil, errInvalidAccessKeyID
}
if globalPolicyOPA == nil {
// If OPA is not set, session token should
// have a policy and its mandatory, reject
// requests without policy claim.
p, pok := claims[iampolicy.PolicyName]
if !pok {
return nil, errAuthentication
}
if _, pok = p.(string); !pok {
return nil, errAuthentication
}
sp, spok := claims[iampolicy.SessionPolicyName]
// Sub policy is optional, if not set return success.
if !spok {
return claims, nil
}
// Sub policy is set but its not a string, reject such requests
spStr, spok := sp.(string)
if !spok {
return nil, errAuthentication
}
// Looks like subpolicy is set and is a string, if set then its
// base64 encoded, decode it. Decoding fails reject such requests.
spBytes, err := base64.StdEncoding.DecodeString(spStr)
if err != nil {
// Base64 decoding fails, we should log to indicate
// something is malforming the request sent by client.
logger.LogIf(context.Background(), err)
return nil, errAuthentication
}
claims[iampolicy.SessionPolicyName] = string(spBytes)
}
return claims, nil
}
// Fetch claims in the security token returned by the client and validate the token.
func checkClaimsFromToken(r *http.Request, cred auth.Credentials) (map[string]interface{}, APIErrorCode) {
token := getSessionToken(r)
if token != "" && cred.AccessKey == "" {
return nil, ErrNoAccessKey
}
if subtle.ConstantTimeCompare([]byte(token), []byte(cred.SessionToken)) != 1 {
return nil, ErrInvalidToken
}
claims, err := getClaimsFromToken(r)
if err != nil {
return nil, toAPIErrorCode(context.Background(), err)
}
return claims, ErrNone
}
// Check request auth type verifies the incoming http request
// - validates the request signature
// - validates the policy action if anonymous tests bucket policies if any,
// for authenticated requests validates IAM policies.
// returns APIErrorCode if any to be replied to the client.
func checkRequestAuthType(ctx context.Context, r *http.Request, action policy.Action, bucketName, objectName string) (s3Err APIErrorCode) {
var cred auth.Credentials
var owner bool
switch getRequestAuthType(r) {
case authTypeUnknown, authTypeStreamingSigned:
return ErrAccessDenied
case authTypePresignedV2, authTypeSignedV2:
if s3Err = isReqAuthenticatedV2(r); s3Err != ErrNone {
return s3Err
}
cred, owner, s3Err = getReqAccessKeyV2(r)
case authTypeSigned, authTypePresigned:
region := globalServerConfig.GetRegion()
switch action {
case policy.GetBucketLocationAction, policy.ListAllMyBucketsAction:
region = ""
}
if s3Err = isReqAuthenticated(ctx, r, region, serviceS3); s3Err != ErrNone {
return s3Err
}
cred, owner, s3Err = getReqAccessKeyV4(r, region, serviceS3)
}
if s3Err != ErrNone {
return s3Err
}
claims, s3Err := checkClaimsFromToken(r, cred)
if s3Err != ErrNone {
return s3Err
}
// 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 cred.AccessKey == "" {
if globalPolicySys.IsAllowed(policy.Args{
AccountName: cred.AccessKey,
Action: action,
BucketName: bucketName,
ConditionValues: getConditionValues(r, locationConstraint, ""),
IsOwner: false,
ObjectName: objectName,
}) {
return ErrNone
}
return ErrAccessDenied
}
if globalIAMSys.IsAllowed(iampolicy.Args{
AccountName: cred.AccessKey,
Action: iampolicy.Action(action),
BucketName: bucketName,
ConditionValues: getConditionValues(r, "", cred.AccessKey),
ObjectName: objectName,
IsOwner: owner,
Claims: claims,
}) {
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, stype serviceType) (s3Error APIErrorCode) {
sha256sum := getContentSha256Cksum(r, stype)
switch {
case isRequestSignatureV4(r):
return doesSignatureMatch(sha256sum, r, region, stype)
case isRequestPresignedSignatureV4(r):
return doesPresignedSignatureMatch(sha256sum, r, region, stype)
default:
return ErrAccessDenied
}
}
// Verify if request has valid AWS Signature Version '4'.
func isReqAuthenticated(ctx context.Context, r *http.Request, region string, stype serviceType) (s3Error APIErrorCode) {
if errCode := reqSignatureV4Verify(r, region, stype); errCode != ErrNone {
return errCode
}
var (
err error
contentMD5, contentSHA256 []byte
)
// Extract 'Content-Md5' if present.
if _, ok := r.Header[xhttp.ContentMD5]; ok {
contentMD5, err = base64.StdEncoding.Strict().DecodeString(r.Header.Get(xhttp.ContentMD5))
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()[xhttp.AmzContentSha256]; ok && len(sha256Sum) > 0 {
contentSHA256, err = hex.DecodeString(sha256Sum[0])
if err != nil {
return ErrContentSHA256Mismatch
}
}
} else if _, ok := r.Header[xhttp.AmzContentSha256]; !skipSHA256 && ok {
contentSHA256, err = hex.DecodeString(r.Header.Get(xhttp.AmzContentSha256))
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), -1, globalCLIContext.StrictS3Compat)
if err != nil {
return toAPIErrorCode(ctx, 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 _, _, authErr := webRequestAuthenticate(r); authErr != nil {
w.WriteHeader(http.StatusUnauthorized)
return
}
a.handler.ServeHTTP(w, r)
return
} else if aType == authTypeSTS {
a.handler.ServeHTTP(w, r)
return
}
writeErrorResponse(context.Background(), w, errorCodes.ToAPIErr(ErrSignatureVersionNotSupported), r.URL, guessIsBrowserReq(r))
}
// isPutAllowed - check if PUT operation is allowed on the resource, this
// call verifies bucket policies and IAM policies, supports multi user
// checks etc.
func isPutAllowed(atype authType, bucketName, objectName string, r *http.Request) (s3Err APIErrorCode) {
var cred auth.Credentials
var owner bool
switch atype {
case authTypeUnknown:
return ErrAccessDenied
case authTypeSignedV2, authTypePresignedV2:
cred, owner, s3Err = getReqAccessKeyV2(r)
case authTypeStreamingSigned, authTypePresigned, authTypeSigned:
region := globalServerConfig.GetRegion()
cred, owner, s3Err = getReqAccessKeyV4(r, region, serviceS3)
}
if s3Err != ErrNone {
return s3Err
}
claims, s3Err := checkClaimsFromToken(r, cred)
if s3Err != ErrNone {
return s3Err
}
if cred.AccessKey == "" {
if globalPolicySys.IsAllowed(policy.Args{
AccountName: cred.AccessKey,
Action: policy.PutObjectAction,
BucketName: bucketName,
ConditionValues: getConditionValues(r, "", ""),
IsOwner: false,
ObjectName: objectName,
}) {
return ErrNone
}
return ErrAccessDenied
}
if globalIAMSys.IsAllowed(iampolicy.Args{
AccountName: cred.AccessKey,
Action: policy.PutObjectAction,
BucketName: bucketName,
ConditionValues: getConditionValues(r, "", cred.AccessKey),
ObjectName: objectName,
IsOwner: owner,
Claims: claims,
}) {
return ErrNone
}
return ErrAccessDenied
}