CHANGELOG.md

@@ -20,6 +20,7 @@ This document outlines major changes between releases.
 - Support string `Action` and `Resource` fields in `bucketPolicy.Statement` (TrueCloudLab#32)
 - Add new `kludge.use_default_xmlns_for_complete_multipart` config param (TrueCloudLab#40)
 - Support dump metrics descriptions (#80)
+- Support impersonate bearer token (#81)
 
 ### Changed
 - Update syncTree.sh due to recent renaming (#73)

api/layer/layer.go

@@ -329,7 +329,7 @@ func (n *layer) Owner(ctx context.Context) user.ID {
 
 func (n *layer) prepareAuthParameters(ctx context.Context, prm *PrmAuth, bktOwner user.ID) {
 	if bd, ok := ctx.Value(api.BoxData).(*accessbox.Box); ok && bd != nil && bd.Gate != nil && bd.Gate.BearerToken != nil {
-		if bktOwner.Equals(bearer.ResolveIssuer(*bd.Gate.BearerToken)) {
+		if bd.Gate.BearerToken.Impersonate() || bktOwner.Equals(bearer.ResolveIssuer(*bd.Gate.BearerToken)) {
 			prm.BearerToken = bd.Gate.BearerToken
 			return
 		}

authmate/authmate.go

@@ -99,6 +99,7 @@ type (
 		FrostFSKey            *keys.PrivateKey
 		GatesPublicKeys       []*keys.PublicKey
 		EACLRules             []byte
+		Impersonate           bool
 		SessionTokenRules     []byte
 		SkipSessionRules      bool
 		Lifetime              time.Duration
@@ -344,16 +345,21 @@ func restrictedRecords() (records []*eacl.Record) {
 	return
 }
 
-func buildBearerToken(key *keys.PrivateKey, table *eacl.Table, lifetime lifetimeOptions, gateKey *keys.PublicKey) (*bearer.Token, error) {
+func buildBearerToken(key *keys.PrivateKey, impersonate bool, table *eacl.Table, lifetime lifetimeOptions, gateKey *keys.PublicKey) (*bearer.Token, error) {
 	var ownerID user.ID
 	user.IDFromKey(&ownerID, (ecdsa.PublicKey)(*gateKey))
 
 	var bearerToken bearer.Token
-	bearerToken.SetEACLTable(*table)
+
+	if !impersonate {
+		bearerToken.SetEACLTable(*table)
+	}
+
 	bearerToken.ForUser(ownerID)
 	bearerToken.SetExp(lifetime.Exp)
 	bearerToken.SetIat(lifetime.Iat)
 	bearerToken.SetNbf(lifetime.Iat)
+	bearerToken.SetImpersonate(impersonate)
 
 	err := bearerToken.Sign(key.PrivateKey)
 	if err != nil {
@@ -363,10 +369,10 @@ func buildBearerToken(key *keys.PrivateKey, table *eacl.Table, lifetime lifetime
 	return &bearerToken, nil
 }
 
-func buildBearerTokens(key *keys.PrivateKey, table *eacl.Table, lifetime lifetimeOptions, gatesKeys []*keys.PublicKey) ([]*bearer.Token, error) {
+func buildBearerTokens(key *keys.PrivateKey, impersonate bool, table *eacl.Table, lifetime lifetimeOptions, gatesKeys []*keys.PublicKey) ([]*bearer.Token, error) {
 	bearerTokens := make([]*bearer.Token, 0, len(gatesKeys))
 	for _, gateKey := range gatesKeys {
-		tkn, err := buildBearerToken(key, table, lifetime, gateKey)
+		tkn, err := buildBearerToken(key, impersonate, table, lifetime, gateKey)
 		if err != nil {
 			return nil, fmt.Errorf("build bearer token: %w", err)
 		}
@@ -413,7 +419,8 @@ func createTokens(options *IssueSecretOptions, lifetime lifetimeOptions) ([]*acc
 	if err != nil {
 		return nil, fmt.Errorf("failed to build eacl table: %w", err)
 	}
-	bearerTokens, err := buildBearerTokens(options.FrostFSKey, table, lifetime, options.GatesPublicKeys)
+
+	bearerTokens, err := buildBearerTokens(options.FrostFSKey, options.Impersonate, table, lifetime, options.GatesPublicKeys)
 	if err != nil {
 		return nil, fmt.Errorf("failed to build bearer tokens: %w", err)
 	}

cmd/s3-authmate/main.go

@@ -56,6 +56,7 @@ var (
 	accountAddressFlag       string
 	peerAddressFlag          string
 	eaclRulesFlag            string
+	disableImpersonateFlag   bool
 	gateWalletPathFlag       string
 	gateAccountAddressFlag   string
 	accessKeyIDFlag          string
@@ -207,10 +208,16 @@ func issueSecret() *cli.Command {
 			},
 			&cli.StringFlag{
 				Name:        "bearer-rules",
-				Usage:       "rules for bearer token (filepath or a plain json string are allowed)",
+				Usage:       "rules for bearer token (filepath or a plain json string are allowed, can be used only with --disable-impersonate)",
 				Required:    false,
 				Destination: &eaclRulesFlag,
 			},
+			&cli.BoolFlag{
+				Name:        "disable-impersonate",
+				Usage:       "mark token as not impersonate to don't consider token signer as request owner (must be provided to use --bearer-rules flag)",
+				Required:    false,
+				Destination: &disableImpersonateFlag,
+			},
 			&cli.StringSliceFlag{
 				Name:        "gate-public-key",
 				Usage:       "public 256r1 key of a gate (use flags repeatedly for multiple gates)",
@@ -345,6 +352,10 @@ It will be ceil rounded to the nearest amount of epoch.`,
 				return cli.Exit(fmt.Sprintf("couldn't parse container policy: %s", err.Error()), 6)
 			}
 
+			if !disableImpersonateFlag && eaclRulesFlag != "" {
+				return cli.Exit("--bearer-rules flag can be used only with --disable-impersonate", 6)
+			}
+
 			bearerRules, err := getJSONRules(eaclRulesFlag)
 			if err != nil {
 				return cli.Exit(fmt.Sprintf("couldn't parse 'bearer-rules' flag: %s", err.Error()), 7)
@@ -364,6 +375,7 @@ It will be ceil rounded to the nearest amount of epoch.`,
 				FrostFSKey:            key,
 				GatesPublicKeys:       gatesPublicKeys,
 				EACLRules:             bearerRules,
+				Impersonate:           !disableImpersonateFlag,
 				SessionTokenRules:     sessionRules,
 				SkipSessionRules:      skipSessionRules,
 				ContainerPolicies:     policies,

docs/authmate.md

@@ -139,12 +139,19 @@ the secret. Format of `access_key_id`: `%cid0%oid`, where 0(zero) is a delimiter
 
 Creation of bearer tokens is mandatory.
 
-Rules for a bearer token can be set via parameter `--bearer-rules` (json-string and file path allowed):
+By default, bearer token will be created with `impersonate` flag and won't have eACL table. It means that gate which will use such token
+to interact with node can have access to your private containers or to containers in which eACL grants access to you 
+by public key.
+
+Rules for a bearer token can be set via parameter `--bearer-rules` (json-string and file path allowed). 
+But you must provide `--disable-impersonate` flag:
+
 ```shell
 $ frostfs-s3-authmate issue-secret --wallet wallet.json \
 --peer 192.168.130.71:8080 \
 --gate-public-key 0313b1ac3a8076e155a7e797b24f0b650cccad5941ea59d7cfd51a024a8b2a06bf \
---bearer-rules bearer-rules.json  
+--bearer-rules bearer-rules.json \
+--disable-impersonate
 ```
 where content of `bearer-rules.json`:
 ```json

internal/frostfs/services/tree_client_grpc.go

@@ -8,12 +8,13 @@ import (
 	"strings"
 	"sync/atomic"
 
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
+
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
 	grpcService "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/services/tree"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/pkg/service/tree"
-	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"go.uber.org/zap"
 	"google.golang.org/grpc"
@@ -385,7 +386,7 @@ func metaToKV(meta map[string]string) []*grpcService.KeyValue {
 func getBearer(ctx context.Context, bktInfo *data.BucketInfo) []byte {
 	if bd, ok := ctx.Value(api.BoxData).(*accessbox.Box); ok && bd != nil && bd.Gate != nil {
 		if bd.Gate.BearerToken != nil {
-			if bktInfo.Owner.Equals(bearer.ResolveIssuer(*bd.Gate.BearerToken)) {
+			if bd.Gate.BearerToken.Impersonate() || bktInfo.Owner.Equals(bearer.ResolveIssuer(*bd.Gate.BearerToken)) {
 				return bd.Gate.BearerToken.Marshal()
 			}
 		}