acl: add MaxTokenTTL field to auth methods (#7779)

When set to a non zero value it will limit the ExpirationTime of all
tokens created via the auth method.

agent/consul/acl_endpoint.go

@@ -2111,6 +2111,16 @@ func (a *ACL) AuthMethodSet(args *structs.ACLAuthMethodSetRequest, reply *struct
 		return fmt.Errorf("Invalid Auth Method: Type should be one of: %v", authmethod.Types())
 	}
 
+	if method.MaxTokenTTL != 0 {
+		if method.MaxTokenTTL > a.srv.config.ACLTokenMaxExpirationTTL {
+			return fmt.Errorf("MaxTokenTTL %s cannot be more than %s",
+				method.MaxTokenTTL, a.srv.config.ACLTokenMaxExpirationTTL)
+		} else if method.MaxTokenTTL < a.srv.config.ACLTokenMinExpirationTTL {
+			return fmt.Errorf("MaxTokenTTL %s cannot be less than %s",
+				method.MaxTokenTTL, a.srv.config.ACLTokenMinExpirationTTL)
+		}
+	}
+
 	// Instantiate a validator but do not cache it yet. This will validate the
 	// configuration.
 	if _, err := authmethod.NewValidator(a.srv.logger, method); err != nil {
@@ -2323,6 +2333,7 @@ func (a *ACL) Login(args *structs.ACLLoginRequest, reply *structs.ACLToken) erro
 			AuthMethod:        auth.AuthMethod,
 			ServiceIdentities: serviceIdentities,
 			Roles:             roleLinks,
+			ExpirationTTL:     method.MaxTokenTTL,
 			EnterpriseMeta:    *targetMeta,
 		},
 		WriteRequest: args.WriteRequest,

agent/consul/acl_endpoint_test.go

@@ -3468,6 +3468,89 @@ func TestACLEndpoint_AuthMethodSet(t *testing.T) {
 			}
 		})
 	}
+
+	t.Run("Create with MaxTokenTTL", func(t *testing.T) {
+		reqMethod := newAuthMethod("test")
+		reqMethod.MaxTokenTTL = 5 * time.Minute
+
+		req := structs.ACLAuthMethodSetRequest{
+			Datacenter:   "dc1",
+			AuthMethod:   reqMethod,
+			WriteRequest: structs.WriteRequest{Token: "root"},
+		}
+		resp := structs.ACLAuthMethod{}
+
+		err := acl.AuthMethodSet(&req, &resp)
+		require.NoError(t, err)
+
+		// Get the method directly to validate that it exists
+		methodResp, err := retrieveTestAuthMethod(codec, "root", "dc1", resp.Name)
+		require.NoError(t, err)
+		method := methodResp.AuthMethod
+
+		require.Equal(t, method.Name, "test")
+		require.Equal(t, method.Description, "test")
+		require.Equal(t, method.Type, "testing")
+		require.Equal(t, method.MaxTokenTTL, 5*time.Minute)
+	})
+
+	t.Run("Update - change MaxTokenTTL", func(t *testing.T) {
+		reqMethod := newAuthMethod("test")
+		reqMethod.DisplayName = "updated display name 2"
+		reqMethod.Description = "test modified 2"
+		reqMethod.MaxTokenTTL = 8 * time.Minute
+
+		req := structs.ACLAuthMethodSetRequest{
+			Datacenter:   "dc1",
+			AuthMethod:   reqMethod,
+			WriteRequest: structs.WriteRequest{Token: "root"},
+		}
+		resp := structs.ACLAuthMethod{}
+
+		err := acl.AuthMethodSet(&req, &resp)
+		require.NoError(t, err)
+
+		// Get the method directly to validate that it exists
+		methodResp, err := retrieveTestAuthMethod(codec, "root", "dc1", resp.Name)
+		require.NoError(t, err)
+		method := methodResp.AuthMethod
+
+		require.Equal(t, method.Name, "test")
+		require.Equal(t, method.DisplayName, "updated display name 2")
+		require.Equal(t, method.Description, "test modified 2")
+		require.Equal(t, method.Type, "testing")
+		require.Equal(t, method.MaxTokenTTL, 8*time.Minute)
+	})
+
+	t.Run("Create with MaxTokenTTL too small", func(t *testing.T) {
+		reqMethod := newAuthMethod("test")
+		reqMethod.MaxTokenTTL = 1 * time.Millisecond
+
+		req := structs.ACLAuthMethodSetRequest{
+			Datacenter:   "dc1",
+			AuthMethod:   reqMethod,
+			WriteRequest: structs.WriteRequest{Token: "root"},
+		}
+		resp := structs.ACLAuthMethod{}
+
+		err := acl.AuthMethodSet(&req, &resp)
+		testutil.RequireErrorContains(t, err, "MaxTokenTTL 1ms cannot be less than")
+	})
+
+	t.Run("Create with MaxTokenTTL too big", func(t *testing.T) {
+		reqMethod := newAuthMethod("test")
+		reqMethod.MaxTokenTTL = 25 * time.Hour
+
+		req := structs.ACLAuthMethodSetRequest{
+			Datacenter:   "dc1",
+			AuthMethod:   reqMethod,
+			WriteRequest: structs.WriteRequest{Token: "root"},
+		}
+		resp := structs.ACLAuthMethod{}
+
+		err := acl.AuthMethodSet(&req, &resp)
+		testutil.RequireErrorContains(t, err, "MaxTokenTTL 25h0m0s cannot be more than")
+	})
 }
 
 func TestACLEndpoint_AuthMethodDelete(t *testing.T) {
@@ -4942,6 +5025,81 @@ func TestACLEndpoint_Login(t *testing.T) {
 	})
 }
 
+func TestACLEndpoint_Login_with_MaxTokenTTL(t *testing.T) {
+	t.Parallel()
+
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLsEnabled = true
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	codec := rpcClient(t, s1)
+	defer codec.Close()
+
+	testrpc.WaitForLeader(t, s1.RPC, "dc1")
+
+	acl := ACL{srv: s1}
+
+	testSessionID := testauth.StartSession()
+	defer testauth.ResetSession(testSessionID)
+
+	testauth.InstallSessionToken(
+		testSessionID,
+		"fake-web", // no rules
+		"default", "web", "abc123",
+	)
+
+	method, err := upsertTestCustomizedAuthMethod(codec, "root", "dc1", func(method *structs.ACLAuthMethod) {
+		method.MaxTokenTTL = 5 * time.Minute
+		method.Config = map[string]interface{}{
+			"SessionID": testSessionID,
+		}
+	})
+	require.NoError(t, err)
+
+	_, err = upsertTestBindingRule(
+		codec, "root", "dc1", method.Name,
+		"",
+		structs.BindingRuleBindTypeService,
+		"web",
+	)
+	require.NoError(t, err)
+
+	// Create a token.
+	req := structs.ACLLoginRequest{
+		Auth: &structs.ACLLoginParams{
+			AuthMethod:  method.Name,
+			BearerToken: "fake-web",
+			Meta:        map[string]string{"pod": "pod1"},
+		},
+		Datacenter: "dc1",
+	}
+
+	resp := structs.ACLToken{}
+	require.NoError(t, acl.Login(&req, &resp))
+
+	got := &resp
+	got.CreateIndex = 0
+	got.ModifyIndex = 0
+	got.AccessorID = ""
+	got.SecretID = ""
+	got.Hash = nil
+
+	expect := &structs.ACLToken{
+		AuthMethod:     method.Name,
+		Description:    `token created via login: {"pod":"pod1"}`,
+		Local:          true,
+		CreateTime:     got.CreateTime,
+		ExpirationTime: timePointer(got.CreateTime.Add(method.MaxTokenTTL)),
+		ServiceIdentities: []*structs.ACLServiceIdentity{
+			{ServiceName: "web"},
+		},
+	}
+	require.Equal(t, got, expect)
+}
+
 func TestACLEndpoint_Login_k8s(t *testing.T) {
 	t.Parallel()
 

agent/structs/acl.go

@@ -2,6 +2,7 @@ package structs
 
 import (
 	"encoding/binary"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"hash"
@@ -1048,6 +1049,9 @@ type ACLAuthMethod struct {
 	// Description is just an optional bunch of explanatory text.
 	Description string `json:",omitempty"`
 
+	// MaxTokenTTL this is the maximum life of a token created by this method.
+	MaxTokenTTL time.Duration `json:",omitempty"`
+
 	// Configuration is arbitrary configuration for the auth method. This
 	// should only contain primitive values and containers (such as lists and
 	// maps).
@@ -1060,6 +1064,47 @@ type ACLAuthMethod struct {
 	RaftIndex `hash:"ignore"`
 }
 
+func (m *ACLAuthMethod) MarshalJSON() ([]byte, error) {
+	type Alias ACLAuthMethod
+	exported := &struct {
+		MaxTokenTTL string `json:",omitempty"`
+		*Alias
+	}{
+		MaxTokenTTL: m.MaxTokenTTL.String(),
+		Alias:       (*Alias)(m),
+	}
+	if m.MaxTokenTTL == 0 {
+		exported.MaxTokenTTL = ""
+	}
+
+	return json.Marshal(exported)
+}
+
+func (m *ACLAuthMethod) UnmarshalJSON(data []byte) (err error) {
+	type Alias ACLAuthMethod
+	aux := &struct {
+		MaxTokenTTL interface{}
+		*Alias
+	}{
+		Alias: (*Alias)(m),
+	}
+	if err = lib.UnmarshalJSON(data, &aux); err != nil {
+		return err
+	}
+	if aux.MaxTokenTTL != nil {
+		switch v := aux.MaxTokenTTL.(type) {
+		case string:
+			if m.MaxTokenTTL, err = time.ParseDuration(v); err != nil {
+				return err
+			}
+		case float64:
+			m.MaxTokenTTL = time.Duration(v)
+		}
+	}
+
+	return nil
+}
+
 type ACLReplicationType string
 
 const (

api/acl.go

@@ -1,6 +1,7 @@
 package api
 
 import (
+	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -184,6 +185,7 @@ type ACLAuthMethod struct {
 	Type        string
 	DisplayName string        `json:",omitempty"`
 	Description string        `json:",omitempty"`
+	MaxTokenTTL time.Duration `json:",omitempty"`
 
 	// Configuration is arbitrary configuration for the auth method. This
 	// should only contain primitive values and containers (such as lists and
@@ -198,6 +200,43 @@ type ACLAuthMethod struct {
 	Namespace string `json:",omitempty"`
 }
 
+func (m *ACLAuthMethod) MarshalJSON() ([]byte, error) {
+	type Alias ACLAuthMethod
+	exported := &struct {
+		MaxTokenTTL string `json:",omitempty"`
+		*Alias
+	}{
+		MaxTokenTTL: m.MaxTokenTTL.String(),
+		Alias:       (*Alias)(m),
+	}
+	if m.MaxTokenTTL == 0 {
+		exported.MaxTokenTTL = ""
+	}
+
+	return json.Marshal(exported)
+}
+
+func (m *ACLAuthMethod) UnmarshalJSON(data []byte) error {
+	type Alias ACLAuthMethod
+	aux := &struct {
+		MaxTokenTTL string
+		*Alias
+	}{
+		Alias: (*Alias)(m),
+	}
+	if err := json.Unmarshal(data, &aux); err != nil {
+		return err
+	}
+	var err error
+	if aux.MaxTokenTTL != "" {
+		if m.MaxTokenTTL, err = time.ParseDuration(aux.MaxTokenTTL); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 type ACLAuthMethodListEntry struct {
 	Name        string
 	Type        string

command/acl/authmethod/create/authmethod_create.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"strings"
+	"time"
 
 	"github.com/hashicorp/consul/api"
 	"github.com/hashicorp/consul/command/acl/authmethod"
@@ -30,11 +31,12 @@ type cmd struct {
 	name           string
 	displayName    string
 	description    string
+	maxTokenTTL    time.Duration
+	config         string
 
 	k8sHost              string
 	k8sCACert            string
 	k8sServiceAccountJWT string
-	config               string
 
 	showMeta bool
 	format   string
@@ -77,6 +79,12 @@ func (c *cmd) init() {
 		"",
 		"A description of the auth method.",
 	)
+	c.flags.DurationVar(
+		&c.maxTokenTTL,
+		"max-token-ttl",
+		0,
+		"Duration of time all tokens created by this auth method should be valid for",
+	)
 
 	c.flags.StringVar(
 		&c.k8sHost,
@@ -150,6 +158,9 @@ func (c *cmd) Run(args []string) int {
 		DisplayName: c.displayName,
 		Description: c.description,
 	}
+	if c.maxTokenTTL > 0 {
+		newAuthMethod.MaxTokenTTL = c.maxTokenTTL
+	}
 
 	if c.config != "" {
 		if c.k8sHost != "" || c.k8sCACert != "" || c.k8sServiceAccountJWT != "" {

command/acl/authmethod/create/authmethod_create_test.go

@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/hashicorp/consul/agent"
 	"github.com/hashicorp/consul/agent/connect"
@@ -121,6 +122,35 @@ func TestAuthMethodCreateCommand(t *testing.T) {
 		}
 		require.Equal(t, expect, got)
 	})
+
+	t.Run("create testing with max token ttl", func(t *testing.T) {
+		args := []string{
+			"-http-addr=" + a.HTTPAddr(),
+			"-token=root",
+			"-type=testing",
+			"-name=test",
+			"-description=desc",
+			"-display-name=display",
+			"-max-token-ttl=5m",
+		}
+
+		ui := cli.NewMockUi()
+		cmd := New(ui)
+
+		code := cmd.Run(args)
+		require.Equal(t, code, 0, "err: "+ui.ErrorWriter.String())
+		require.Empty(t, ui.ErrorWriter.String())
+
+		got := getTestMethod(t, client, "test")
+		expect := &api.ACLAuthMethod{
+			Name:        "test",
+			Type:        "testing",
+			DisplayName: "display",
+			Description: "desc",
+			MaxTokenTTL: 5 * time.Minute,
+		}
+		require.Equal(t, expect, got)
+	})
 }
 
 func TestAuthMethodCreateCommand_JSON(t *testing.T) {
@@ -190,6 +220,53 @@ func TestAuthMethodCreateCommand_JSON(t *testing.T) {
 		}
 		require.Equal(t, expect, got)
 	})
+
+	t.Run("create testing with max token ttl", func(t *testing.T) {
+		args := []string{
+			"-http-addr=" + a.HTTPAddr(),
+			"-token=root",
+			"-type=testing",
+			"-name=test",
+			"-description=desc",
+			"-display-name=display",
+			"-max-token-ttl=5m",
+			"-format=json",
+		}
+
+		ui := cli.NewMockUi()
+		cmd := New(ui)
+
+		code := cmd.Run(args)
+		out := ui.OutputWriter.String()
+
+		require.Equal(t, code, 0)
+		require.Empty(t, ui.ErrorWriter.String())
+		require.Contains(t, out, "test")
+
+		got := getTestMethod(t, client, "test")
+		expect := &api.ACLAuthMethod{
+			Name:        "test",
+			Type:        "testing",
+			DisplayName: "display",
+			Description: "desc",
+			MaxTokenTTL: 5 * time.Minute,
+		}
+		require.Equal(t, expect, got)
+
+		var raw map[string]interface{}
+		require.NoError(t, json.Unmarshal([]byte(out), &raw))
+		delete(raw, "CreateIndex")
+		delete(raw, "ModifyIndex")
+
+		require.Equal(t, map[string]interface{}{
+			"Name":        "test",
+			"Type":        "testing",
+			"DisplayName": "display",
+			"Description": "desc",
+			"MaxTokenTTL": "5m0s",
+			"Config":      nil,
+		}, raw)
+	})
 }
 
 func TestAuthMethodCreateCommand_k8s(t *testing.T) {

command/acl/authmethod/update/authmethod_update.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"strings"
+	"time"
 
 	"github.com/hashicorp/consul/api"
 	"github.com/hashicorp/consul/command/acl/authmethod"
@@ -30,7 +31,9 @@ type cmd struct {
 
 	displayName string
 	description string
+	maxTokenTTL time.Duration
 	config      string
+
 	k8sHost              string
 	k8sCACert            string
 	k8sServiceAccountJWT string
@@ -74,6 +77,13 @@ func (c *cmd) init() {
 		"A description of the auth method.",
 	)
 
+	c.flags.DurationVar(
+		&c.maxTokenTTL,
+		"max-token-ttl",
+		0,
+		"Duration of time all tokens created by this auth method should be valid for",
+	)
+
 	c.flags.StringVar(
 		&c.config,
 		"config",
@@ -169,6 +179,10 @@ func (c *cmd) Run(args []string) int {
 			DisplayName: c.displayName,
 			Description: c.description,
 		}
+		if c.maxTokenTTL > 0 {
+			method.MaxTokenTTL = c.maxTokenTTL
+		}
+
 		if c.config != "" {
 			if c.k8sHost != "" || c.k8sCACert != "" || c.k8sServiceAccountJWT != "" {
 				c.UI.Error(fmt.Sprintf("Cannot use command line arguments with '-config' flag"))
@@ -184,6 +198,7 @@ func (c *cmd) Run(args []string) int {
 				return 1
 			}
 		}
+
 		if currentAuthMethod.Type == "kubernetes" {
 			if c.k8sHost == "" {
 				c.UI.Error(fmt.Sprintf("Missing required '-kubernetes-host' flag"))
@@ -211,6 +226,9 @@ func (c *cmd) Run(args []string) int {
 		if c.displayName != "" {
 			method.DisplayName = c.displayName
 		}
+		if c.maxTokenTTL > 0 {
+			method.MaxTokenTTL = c.maxTokenTTL
+		}
 		if c.config != "" {
 			if c.k8sHost != "" || c.k8sCACert != "" || c.k8sServiceAccountJWT != "" {
 				c.UI.Error(fmt.Sprintf("Cannot use command line arguments with '-config' flag"))

website/pages/api-docs/acl/auth-methods.mdx

@@ -51,6 +51,14 @@ The table below shows this endpoint's support for
 - `DisplayName` `(string: "")` - An optional name to use instead of the `Name`
   field when displaying information about this auth method. Added in Consul 1.8.0.
 
+- `MaxTokenTTL` `(duration: 0s)` - This specifies the maximum life of any token
+  created by this auth method. When set it will initialize the
+  [`ExpirationTime`](/api/acl/tokens.html#expirationtime) field on all tokens
+  to a value of `Token.CreateTime + AuthMethod.MaxTokenTTL`.  This field is not
+  persisted beyond its initial use. Can be specified in the form of `"60s"` or
+  `"5m"` (i.e., 60 seconds or 5 minutes, respectively). This value must be no
+  smaller than 1 minute and no longer than 24 hours. Added in Consul 1.8.0.
+
 - `Config` `(map[string]string: <required>)` - The raw configuration to use for
   the chosen auth method. Contents will vary depending upon the type chosen.
   For more information on configuring specific auth method types, see the [auth
@@ -191,6 +199,14 @@ The table below shows this endpoint's support for
 - `DisplayName` `(string: "")` - An optional name to use instead of the `Name`
   field when displaying information about this auth method. Added in Consul 1.8.0.
 
+- `MaxTokenTTL` `(duration: 0s)` - This specifies the maximum life of any token
+  created by this auth method. When set it will initialize the
+  [`ExpirationTime`](/api/acl/tokens.html#expirationtime) field on all tokens
+  to a value of `Token.CreateTime + AuthMethod.MaxTokenTTL`.  This field is not
+  persisted beyond its initial use. Can be specified in the form of `"60s"` or
+  `"5m"` (i.e., 60 seconds or 5 minutes, respectively). This value must be no
+  smaller than 1 minute and no longer than 24 hours. Added in Consul 1.8.0.
+
 - `Config` `(map[string]string: <required>)` - The raw configuration to use for
   the chosen auth method. Contents will vary depending upon the type chosen.
   For more information on configuring specific auth method types, see the [auth