minio/cmd/auth-handler.go

681 lines
22 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cmd
import (
"bytes"
"context"
"crypto/subtle"
"encoding/base64"
"encoding/hex"
"errors"
"io"
"io/ioutil"
"net/http"
"strconv"
"strings"
"sync/atomic"
"time"
xhttp "github.com/minio/minio/cmd/http"
xjwt "github.com/minio/minio/cmd/jwt"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/auth"
objectlock "github.com/minio/minio/pkg/bucket/object/lock"
"github.com/minio/minio/pkg/bucket/policy"
"github.com/minio/minio/pkg/etag"
"github.com/minio/minio/pkg/hash"
iampolicy "github.com/minio/minio/pkg/iam/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
}
func validateAdminSignature(ctx context.Context, r *http.Request, region string) (auth.Credentials, map[string]interface{}, bool, APIErrorCode) {
var cred auth.Credentials
var owner bool
s3Err := ErrAccessDenied
if _, ok := r.Header[xhttp.AmzContentSha256]; ok &&
getRequestAuthType(r) == authTypeSigned && !skipContentSha256Cksum(r) {
// We only support admin credentials to access admin APIs.
cred, owner, s3Err = getReqAccessKeyV4(r, region, serviceS3)
if s3Err != ErrNone {
return cred, nil, owner, s3Err
}
// 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), logger.Application)
return cred, nil, owner, s3Err
}
claims, s3Err := checkClaimsFromToken(r, cred)
if s3Err != ErrNone {
return cred, nil, owner, s3Err
}
return cred, claims, owner, ErrNone
}
// checkAdminRequestAuth checks for authentication and authorization for the incoming
// request. It only accepts V2 and V4 requests. Presigned, JWT and anonymous requests
// are automatically rejected.
func checkAdminRequestAuth(ctx context.Context, r *http.Request, action iampolicy.AdminAction, region string) (auth.Credentials, APIErrorCode) {
cred, claims, owner, s3Err := validateAdminSignature(ctx, r, region)
if s3Err != ErrNone {
return cred, s3Err
}
if globalIAMSys.IsAllowed(iampolicy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: iampolicy.Action(action),
ConditionValues: getConditionValues(r, "", cred.AccessKey, claims),
IsOwner: owner,
Claims: claims,
}) {
// Request is allowed return the appropriate access key.
return cred, ErrNone
}
return cred, ErrAccessDenied
}
// 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(getSessionToken(r))
return claims
}
// Fetch claims in the security token returned by the client.
func getClaimsFromToken(token string) (map[string]interface{}, error) {
if token == "" {
claims := xjwt.NewMapClaims()
return claims.Map(), nil
}
// 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.
claims, err := auth.ExtractClaims(token, globalActiveCred.SecretKey)
if err != nil {
return nil, errAuthentication
}
if globalPolicyOPA == nil {
// If OPA is not set and if ldap claim key is set, allow the claim.
if _, ok := claims.MapClaims[ldapUser]; ok {
return claims.Map(), nil
}
// If OPA is not set, session token should
// have a policy and its mandatory, reject
// requests without policy claim.
_, pokOpenID := claims.MapClaims[iamPolicyClaimNameOpenID()]
_, pokSA := claims.MapClaims[iamPolicyClaimNameSA()]
if !pokOpenID && !pokSA {
return nil, errAuthentication
}
sp, spok := claims.Lookup(iampolicy.SessionPolicyName)
if !spok {
return claims.Map(), nil
}
// 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(sp)
if err != nil {
// Base64 decoding fails, we should log to indicate
// something is malforming the request sent by client.
logger.LogIf(GlobalContext, err, logger.Application)
return nil, errAuthentication
}
claims.MapClaims[iampolicy.SessionPolicyName] = string(spBytes)
}
return claims.Map(), 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 cred.IsServiceAccount() && token == "" {
token = cred.SessionToken
}
if subtle.ConstantTimeCompare([]byte(token), []byte(cred.SessionToken)) != 1 {
return nil, ErrInvalidToken
}
claims, err := getClaimsFromToken(token)
if err != nil {
return nil, toAPIErrorCode(r.Context(), 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) {
_, _, s3Err = checkRequestAuthTypeCredential(ctx, r, action, bucketName, objectName)
return s3Err
}
// 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.
// Additionally returns the accessKey used in the request, and if this request is by an admin.
func checkRequestAuthTypeCredential(ctx context.Context, r *http.Request, action policy.Action, bucketName, objectName string) (cred auth.Credentials, owner bool, s3Err APIErrorCode) {
switch getRequestAuthType(r) {
case authTypeUnknown, authTypeStreamingSigned:
return cred, owner, ErrSignatureVersionNotSupported
case authTypePresignedV2, authTypeSignedV2:
if s3Err = isReqAuthenticatedV2(r); s3Err != ErrNone {
return cred, owner, s3Err
}
cred, owner, s3Err = getReqAccessKeyV2(r)
case authTypeSigned, authTypePresigned:
region := globalServerRegion
switch action {
case policy.GetBucketLocationAction, policy.ListAllMyBucketsAction:
region = ""
}
if s3Err = isReqAuthenticated(ctx, r, region, serviceS3); s3Err != ErrNone {
return cred, owner, s3Err
}
cred, owner, s3Err = getReqAccessKeyV4(r, region, serviceS3)
}
if s3Err != ErrNone {
return cred, owner, s3Err
}
var claims map[string]interface{}
claims, s3Err = checkClaimsFromToken(r, cred)
if s3Err != ErrNone {
return cred, owner, 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, logger.Application)
return cred, owner, 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 cred, owner, s3Error
}
// Populate payload again to handle it in HTTP handler.
r.Body = ioutil.NopCloser(bytes.NewReader(payload))
}
if cred.AccessKey != "" {
logger.GetReqInfo(ctx).AccessKey = cred.AccessKey
}
if action != policy.ListAllMyBucketsAction && cred.AccessKey == "" {
// Anonymous checks are not meant for ListBuckets action
if globalPolicySys.IsAllowed(policy.Args{
AccountName: cred.AccessKey,
Action: action,
BucketName: bucketName,
ConditionValues: getConditionValues(r, locationConstraint, "", nil),
IsOwner: false,
ObjectName: objectName,
}) {
// Request is allowed return the appropriate access key.
return cred, owner, ErrNone
}
if action == policy.ListBucketVersionsAction {
// In AWS S3 s3:ListBucket permission is same as s3:ListBucketVersions permission
// verify as a fallback.
if globalPolicySys.IsAllowed(policy.Args{
AccountName: cred.AccessKey,
Action: policy.ListBucketAction,
BucketName: bucketName,
ConditionValues: getConditionValues(r, locationConstraint, "", nil),
IsOwner: false,
ObjectName: objectName,
}) {
// Request is allowed return the appropriate access key.
return cred, owner, ErrNone
}
}
return cred, owner, ErrAccessDenied
}
if globalIAMSys.IsAllowed(iampolicy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: iampolicy.Action(action),
BucketName: bucketName,
ConditionValues: getConditionValues(r, "", cred.AccessKey, claims),
ObjectName: objectName,
IsOwner: owner,
Claims: claims,
}) {
// Request is allowed return the appropriate access key.
return cred, owner, ErrNone
}
if action == policy.ListBucketVersionsAction {
// In AWS S3 s3:ListBucket permission is same as s3:ListBucketVersions permission
// verify as a fallback.
if globalIAMSys.IsAllowed(iampolicy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: iampolicy.ListBucketAction,
BucketName: bucketName,
ConditionValues: getConditionValues(r, "", cred.AccessKey, claims),
ObjectName: objectName,
IsOwner: owner,
Claims: claims,
}) {
// Request is allowed return the appropriate access key.
return cred, owner, ErrNone
}
}
return cred, owner, 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
}
clientETag, err := etag.FromContentMD5(r.Header)
if err != nil {
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.
var contentSHA256 []byte
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, clientETag.String(), hex.EncodeToString(contentSHA256), -1)
if err != nil {
return toAPIErrorCode(ctx, err)
}
r.Body = reader
return ErrNone
}
// 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
}
// setAuthHandler to validate authorization header for the incoming request.
func setAuthHandler(h http.Handler) http.Handler {
// handler for validating incoming authorization headers.
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
aType := getRequestAuthType(r)
if isSupportedS3AuthType(aType) {
// Let top level caller validate for anonymous and known signed requests.
h.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)
w.Write([]byte(authErr.Error()))
return
}
h.ServeHTTP(w, r)
return
} else if aType == authTypeSTS {
h.ServeHTTP(w, r)
return
}
writeErrorResponse(r.Context(), w, errorCodes.ToAPIErr(ErrSignatureVersionNotSupported), r.URL, guessIsBrowserReq(r))
atomic.AddUint64(&globalHTTPStats.rejectedRequestsAuth, 1)
})
}
func validateSignature(atype authType, r *http.Request) (auth.Credentials, bool, map[string]interface{}, APIErrorCode) {
var cred auth.Credentials
var owner bool
var s3Err APIErrorCode
switch atype {
case authTypeUnknown, authTypeStreamingSigned:
return cred, owner, nil, ErrSignatureVersionNotSupported
case authTypeSignedV2, authTypePresignedV2:
if s3Err = isReqAuthenticatedV2(r); s3Err != ErrNone {
return cred, owner, nil, s3Err
}
cred, owner, s3Err = getReqAccessKeyV2(r)
case authTypePresigned, authTypeSigned:
region := globalServerRegion
if s3Err = isReqAuthenticated(GlobalContext, r, region, serviceS3); s3Err != ErrNone {
return cred, owner, nil, s3Err
}
cred, owner, s3Err = getReqAccessKeyV4(r, region, serviceS3)
}
if s3Err != ErrNone {
return cred, owner, nil, s3Err
}
claims, s3Err := checkClaimsFromToken(r, cred)
if s3Err != ErrNone {
return cred, owner, nil, s3Err
}
return cred, owner, claims, ErrNone
}
func isPutRetentionAllowed(bucketName, objectName string, retDays int, retDate time.Time, retMode objectlock.RetMode, byPassSet bool, r *http.Request, cred auth.Credentials, owner bool, claims map[string]interface{}) (s3Err APIErrorCode) {
var retSet bool
if cred.AccessKey == "" {
conditions := getConditionValues(r, "", "", nil)
conditions["object-lock-mode"] = []string{string(retMode)}
conditions["object-lock-retain-until-date"] = []string{retDate.Format(time.RFC3339)}
if retDays > 0 {
conditions["object-lock-remaining-retention-days"] = []string{strconv.Itoa(retDays)}
}
if retMode == objectlock.RetGovernance && byPassSet {
byPassSet = globalPolicySys.IsAllowed(policy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: policy.BypassGovernanceRetentionAction,
BucketName: bucketName,
ConditionValues: conditions,
IsOwner: false,
ObjectName: objectName,
})
}
if globalPolicySys.IsAllowed(policy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: policy.PutObjectRetentionAction,
BucketName: bucketName,
ConditionValues: conditions,
IsOwner: false,
ObjectName: objectName,
}) {
retSet = true
}
if byPassSet || retSet {
return ErrNone
}
return ErrAccessDenied
}
conditions := getConditionValues(r, "", cred.AccessKey, claims)
conditions["object-lock-mode"] = []string{string(retMode)}
conditions["object-lock-retain-until-date"] = []string{retDate.Format(time.RFC3339)}
if retDays > 0 {
conditions["object-lock-remaining-retention-days"] = []string{strconv.Itoa(retDays)}
}
if retMode == objectlock.RetGovernance && byPassSet {
byPassSet = globalIAMSys.IsAllowed(iampolicy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: iampolicy.BypassGovernanceRetentionAction,
BucketName: bucketName,
ObjectName: objectName,
ConditionValues: conditions,
IsOwner: owner,
Claims: claims,
})
}
if globalIAMSys.IsAllowed(iampolicy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: iampolicy.PutObjectRetentionAction,
BucketName: bucketName,
ConditionValues: conditions,
ObjectName: objectName,
IsOwner: owner,
Claims: claims,
}) {
retSet = true
}
if byPassSet || retSet {
return ErrNone
}
return ErrAccessDenied
}
// isPutActionAllowed - check if PUT operation is allowed on the resource, this
// call verifies bucket policies and IAM policies, supports multi user
// checks etc.
func isPutActionAllowed(ctx context.Context, atype authType, bucketName, objectName string, r *http.Request, action iampolicy.Action) (s3Err APIErrorCode) {
var cred auth.Credentials
var owner bool
switch atype {
case authTypeUnknown:
return ErrSignatureVersionNotSupported
case authTypeSignedV2, authTypePresignedV2:
cred, owner, s3Err = getReqAccessKeyV2(r)
case authTypeStreamingSigned, authTypePresigned, authTypeSigned:
region := globalServerRegion
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 != "" {
logger.GetReqInfo(ctx).AccessKey = cred.AccessKey
}
// Do not check for PutObjectRetentionAction permission,
// if mode and retain until date are not set.
// Can happen when bucket has default lock config set
if action == iampolicy.PutObjectRetentionAction &&
r.Header.Get(xhttp.AmzObjectLockMode) == "" &&
r.Header.Get(xhttp.AmzObjectLockRetainUntilDate) == "" {
return ErrNone
}
if cred.AccessKey == "" {
if globalPolicySys.IsAllowed(policy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: policy.Action(action),
BucketName: bucketName,
ConditionValues: getConditionValues(r, "", "", nil),
IsOwner: false,
ObjectName: objectName,
}) {
return ErrNone
}
return ErrAccessDenied
}
if globalIAMSys.IsAllowed(iampolicy.Args{
AccountName: cred.AccessKey,
Groups: cred.Groups,
Action: action,
BucketName: bucketName,
ConditionValues: getConditionValues(r, "", cred.AccessKey, claims),
ObjectName: objectName,
IsOwner: owner,
Claims: claims,
}) {
return ErrNone
}
return ErrAccessDenied
}