// 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/sha256"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"os"
	"runtime"
	"strings"
	"testing"
	"time"

	"github.com/minio/madmin-go"
	minio "github.com/minio/minio-go/v7"
	"github.com/minio/minio-go/v7/pkg/credentials"
	cr "github.com/minio/minio-go/v7/pkg/credentials"
	"github.com/minio/minio-go/v7/pkg/s3utils"
	"github.com/minio/minio-go/v7/pkg/set"
	"github.com/minio/minio-go/v7/pkg/signer"
	"github.com/minio/minio/internal/auth"
)

const (
	testDefaultTimeout = 30 * time.Second
)

// API suite container for IAM
type TestSuiteIAM struct {
	TestSuiteCommon

	ServerTypeDescription string

	// Flag to turn on tests for etcd backend IAM
	withEtcdBackend bool

	endpoint string
	adm      *madmin.AdminClient
	client   *minio.Client
}

func newTestSuiteIAM(c TestSuiteCommon, withEtcdBackend bool) *TestSuiteIAM {
	etcdStr := ""
	if withEtcdBackend {
		etcdStr = " (with etcd backend)"
	}
	return &TestSuiteIAM{
		TestSuiteCommon:       c,
		ServerTypeDescription: fmt.Sprintf("%s%s", c.serverType, etcdStr),
		withEtcdBackend:       withEtcdBackend,
	}
}

func (s *TestSuiteIAM) iamSetup(c *check) {
	var err error
	// strip url scheme from endpoint
	s.endpoint = strings.TrimPrefix(s.endPoint, "http://")
	if s.secure {
		s.endpoint = strings.TrimPrefix(s.endPoint, "https://")
	}

	s.adm, err = madmin.New(s.endpoint, s.accessKey, s.secretKey, s.secure)
	if err != nil {
		c.Fatalf("error creating admin client: %v", err)
	}
	// Set transport, so that TLS is handled correctly.
	s.adm.SetCustomTransport(s.TestSuiteCommon.client.Transport)

	s.client, err = minio.New(s.endpoint, &minio.Options{
		Creds:     credentials.NewStaticV4(s.accessKey, s.secretKey, ""),
		Secure:    s.secure,
		Transport: s.TestSuiteCommon.client.Transport,
	})
	if err != nil {
		c.Fatalf("error creating minio client: %v", err)
	}
}

// List of all IAM test suites (i.e. test server configuration combinations)
// common to tests.
var iamTestSuites = func() []*TestSuiteIAM {
	baseTestCases := []TestSuiteCommon{
		// Init and run test on ErasureSD backend with signature v4.
		{serverType: "ErasureSD", signer: signerV4},
		// Init and run test on ErasureSD backend, with tls enabled.
		{serverType: "ErasureSD", signer: signerV4, secure: true},
		// Init and run test on Erasure backend.
		{serverType: "Erasure", signer: signerV4},
		// Init and run test on ErasureSet backend.
		{serverType: "ErasureSet", signer: signerV4},
	}
	testCases := []*TestSuiteIAM{}
	for _, bt := range baseTestCases {
		testCases = append(testCases,
			newTestSuiteIAM(bt, false),
			newTestSuiteIAM(bt, true),
		)
	}
	return testCases
}()

const (
	EnvTestEtcdBackend = "ETCD_SERVER"
)

func (s *TestSuiteIAM) setUpEtcd(c *check, etcdServer string) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	configCmds := []string{
		"etcd",
		"endpoints=" + etcdServer,
		"path_prefix=" + mustGetUUID(),
	}
	_, err := s.adm.SetConfigKV(ctx, strings.Join(configCmds, " "))
	if err != nil {
		c.Fatalf("unable to setup Etcd for tests: %v", err)
	}

	s.RestartIAMSuite(c)
}

func (s *TestSuiteIAM) SetUpSuite(c *check) {
	// If etcd backend is specified and etcd server is not present, the test
	// is skipped.
	etcdServer := os.Getenv(EnvTestEtcdBackend)
	if s.withEtcdBackend && etcdServer == "" {
		c.Skip("Skipping etcd backend IAM test as no etcd server is configured.")
	}

	s.TestSuiteCommon.SetUpSuite(c)

	s.iamSetup(c)

	if s.withEtcdBackend {
		s.setUpEtcd(c, etcdServer)
	}
}

func (s *TestSuiteIAM) RestartIAMSuite(c *check) {
	s.TestSuiteCommon.RestartTestServer(c)

	s.iamSetup(c)
}

func (s *TestSuiteIAM) getAdminClient(c *check, accessKey, secretKey, sessionToken string) *madmin.AdminClient {
	madmClnt, err := madmin.NewWithOptions(s.endpoint, &madmin.Options{
		Creds:  credentials.NewStaticV4(accessKey, secretKey, sessionToken),
		Secure: s.secure,
	})
	if err != nil {
		c.Fatalf("error creating user admin client: %s", err)
	}
	madmClnt.SetCustomTransport(s.TestSuiteCommon.client.Transport)
	return madmClnt
}

func (s *TestSuiteIAM) getUserClient(c *check, accessKey, secretKey, sessionToken string) *minio.Client {
	client, err := minio.New(s.endpoint, &minio.Options{
		Creds:     credentials.NewStaticV4(accessKey, secretKey, sessionToken),
		Secure:    s.secure,
		Transport: s.TestSuiteCommon.client.Transport,
	})
	if err != nil {
		c.Fatalf("error creating user minio client: %s", err)
	}
	return client
}

func TestIAMInternalIDPServerSuite(t *testing.T) {
	if runtime.GOOS == globalWindowsOSName {
		t.Skip("windows is clunky disable these tests")
	}
	for i, testCase := range iamTestSuites {
		t.Run(
			fmt.Sprintf("Test: %d, ServerType: %s", i+1, testCase.ServerTypeDescription),
			func(t *testing.T) {
				suite := testCase
				c := &check{t, testCase.serverType}

				suite.SetUpSuite(c)
				suite.TestUserCreate(c)
				suite.TestUserPolicyEscalationBug(c)
				suite.TestPolicyCreate(c)
				suite.TestCannedPolicies(c)
				suite.TestGroupAddRemove(c)
				suite.TestServiceAccountOpsByAdmin(c)
				suite.TestServiceAccountOpsByUser(c)
				suite.TestAddServiceAccountPerms(c)
				suite.TearDownSuite(c)
			},
		)
	}
}

func (s *TestSuiteIAM) TestUserCreate(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	// 1. Create a user.
	accessKey, secretKey := mustGenerateCredentials(c)
	err := s.adm.SetUser(ctx, accessKey, secretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to set user: %v", err)
	}

	// 2. Check new user appears in listing
	usersMap, err := s.adm.ListUsers(ctx)
	if err != nil {
		c.Fatalf("error listing: %v", err)
	}
	v, ok := usersMap[accessKey]
	if !ok {
		c.Fatalf("user not listed: %s", accessKey)
	}
	c.Assert(v.Status, madmin.AccountEnabled)

	// 3. Associate policy and check that user can access
	err = s.adm.SetPolicy(ctx, "readwrite", accessKey, false)
	if err != nil {
		c.Fatalf("unable to set policy: %v", err)
	}

	client := s.getUserClient(c, accessKey, secretKey, "")
	err = client.MakeBucket(ctx, getRandomBucketName(), minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("user could not create bucket: %v", err)
	}

	// 3.10. Check that user's password can be updated.
	_, newSecretKey := mustGenerateCredentials(c)
	err = s.adm.SetUser(ctx, accessKey, newSecretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to update user's secret key: %v", err)
	}
	// 3.10.1 Check that old password no longer works.
	err = client.MakeBucket(ctx, getRandomBucketName(), minio.MakeBucketOptions{})
	if err == nil {
		c.Fatalf("user was unexpectedly able to create bucket with bad password!")
	}
	// 3.10.2 Check that new password works.
	client = s.getUserClient(c, accessKey, newSecretKey, "")
	err = client.MakeBucket(ctx, getRandomBucketName(), minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("user could not create bucket: %v", err)
	}

	// 4. Check that user can be disabled and verify it.
	err = s.adm.SetUserStatus(ctx, accessKey, madmin.AccountDisabled)
	if err != nil {
		c.Fatalf("could not set user account to disabled")
	}
	usersMap, err = s.adm.ListUsers(ctx)
	if err != nil {
		c.Fatalf("error listing: %v", err)
	}
	v, ok = usersMap[accessKey]
	if !ok {
		c.Fatalf("user was not listed after disabling: %s", accessKey)
	}
	c.Assert(v.Status, madmin.AccountDisabled)
	err = client.MakeBucket(ctx, getRandomBucketName(), minio.MakeBucketOptions{})
	if err == nil {
		c.Fatalf("user account was not disabled!")
	}

	// 5. Check that user can be deleted and verify it.
	err = s.adm.RemoveUser(ctx, accessKey)
	if err != nil {
		c.Fatalf("user could not be deleted: %v", err)
	}
	usersMap, err = s.adm.ListUsers(ctx)
	if err != nil {
		c.Fatalf("error listing: %v", err)
	}
	_, ok = usersMap[accessKey]
	if ok {
		c.Fatalf("user not deleted: %s", accessKey)
	}
	err = client.MakeBucket(ctx, getRandomBucketName(), minio.MakeBucketOptions{})
	if err == nil {
		c.Fatalf("user account was not deleted!")
	}
}

func (s *TestSuiteIAM) TestUserPolicyEscalationBug(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	bucket := getRandomBucketName()
	err := s.client.MakeBucket(ctx, bucket, minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("bucket creat error: %v", err)
	}

	// 2. Create a user, associate policy and verify access
	accessKey, secretKey := mustGenerateCredentials(c)
	err = s.adm.SetUser(ctx, accessKey, secretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to set user: %v", err)
	}
	// 2.1 check that user does not have any access to the bucket
	uClient := s.getUserClient(c, accessKey, secretKey, "")
	c.mustNotListObjects(ctx, uClient, bucket)

	// 2.2 create and associate policy to user
	policy := "mypolicy-test-user-update"
	policyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject",
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))
	err = s.adm.AddCannedPolicy(ctx, policy, policyBytes)
	if err != nil {
		c.Fatalf("policy add error: %v", err)
	}
	err = s.adm.SetPolicy(ctx, policy, accessKey, false)
	if err != nil {
		c.Fatalf("Unable to set policy: %v", err)
	}
	// 2.3 check user has access to bucket
	c.mustListObjects(ctx, uClient, bucket)
	// 2.3 check that user cannot delete the bucket
	err = uClient.RemoveBucket(ctx, bucket)
	if err == nil || err.Error() != "Access Denied." {
		c.Fatalf("bucket was deleted unexpectedly or got unexpected err: %v", err)
	}

	// 3. Craft a request to update the user's permissions
	ep := s.adm.GetEndpointURL()
	urlValue := url.Values{}
	urlValue.Add("accessKey", accessKey)
	u, err := url.Parse(fmt.Sprintf("%s://%s/minio/admin/v3/add-user?%s", ep.Scheme, ep.Host, s3utils.QueryEncode(urlValue)))
	if err != nil {
		c.Fatalf("unexpected url parse err: %v", err)
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodPut, u.String(), nil)
	if err != nil {
		c.Fatalf("unexpected new request err: %v", err)
	}
	reqBodyArg := madmin.UserInfo{
		SecretKey:  secretKey,
		PolicyName: "consoleAdmin",
		Status:     madmin.AccountEnabled,
	}
	buf, err := json.Marshal(reqBodyArg)
	if err != nil {
		c.Fatalf("unexpected json encode err: %v", err)
	}
	buf, err = madmin.EncryptData(secretKey, buf)
	if err != nil {
		c.Fatalf("unexpected encryption err: %v", err)
	}

	req.ContentLength = int64(len(buf))
	sum := sha256.Sum256(buf)
	req.Header.Set("X-Amz-Content-Sha256", hex.EncodeToString(sum[:]))
	req.Body = ioutil.NopCloser(bytes.NewReader(buf))
	req = signer.SignV4(*req, accessKey, secretKey, "", "")

	// 3.1 Execute the request.
	resp, err := s.TestSuiteCommon.client.Do(req)
	if err != nil {
		c.Fatalf("unexpected request err: %v", err)
	}
	if resp.StatusCode != 200 {
		c.Fatalf("got unexpected response: %#v\n", resp)
	}

	// 3.2 check that user cannot delete the bucket
	err = uClient.RemoveBucket(ctx, bucket)
	if err == nil || err.Error() != "Access Denied." {
		c.Fatalf("User was able to escalate privileges (Err=%v)!", err)
	}
}

func (s *TestSuiteIAM) TestAddServiceAccountPerms(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	// 1. Create a policy
	policy1 := "deny-svc"
	policy2 := "allow-svc"
	policyBytes := []byte(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Deny",
   "Action": [
    "admin:CreateServiceAccount"
   ]
  }
 ]
}`)

	newPolicyBytes := []byte(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::testbucket/*"
   ]
  }
 ]
}`)

	err := s.adm.AddCannedPolicy(ctx, policy1, policyBytes)
	if err != nil {
		c.Fatalf("policy add error: %v", err)
	}

	err = s.adm.AddCannedPolicy(ctx, policy2, newPolicyBytes)
	if err != nil {
		c.Fatalf("policy add error: %v", err)
	}

	// 2. Verify that policy json is validated by server
	invalidPolicyBytes := policyBytes[:len(policyBytes)-1]
	err = s.adm.AddCannedPolicy(ctx, policy1+"invalid", invalidPolicyBytes)
	if err == nil {
		c.Fatalf("invalid policy creation success")
	}

	// 3. Create a user, associate policy and verify access
	accessKey, secretKey := mustGenerateCredentials(c)
	err = s.adm.SetUser(ctx, accessKey, secretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to set user: %v", err)
	}
	// 3.1 check that user does not have any access to the bucket
	uClient := s.getUserClient(c, accessKey, secretKey, "")
	c.mustNotListObjects(ctx, uClient, "testbucket")

	// 3.2 associate policy to user
	err = s.adm.SetPolicy(ctx, policy1, accessKey, false)
	if err != nil {
		c.Fatalf("Unable to set policy: %v", err)
	}

	admClnt := s.getAdminClient(c, accessKey, secretKey, "")

	// 3.3 check user does not have explicit permissions to create service account.
	c.mustNotCreateSvcAccount(ctx, accessKey, admClnt)

	// 4. Verify the policy appears in listing
	ps, err := s.adm.ListCannedPolicies(ctx)
	if err != nil {
		c.Fatalf("policy list err: %v", err)
	}
	_, ok := ps[policy1]
	if !ok {
		c.Fatalf("policy was missing!")
	}

	// 3.2 associate policy to user
	err = s.adm.SetPolicy(ctx, policy2, accessKey, false)
	if err != nil {
		c.Fatalf("Unable to set policy: %v", err)
	}

	// 3.3 check user can create service account implicitly.
	c.mustCreateSvcAccount(ctx, accessKey, admClnt)

	_, ok = ps[policy2]
	if !ok {
		c.Fatalf("policy was missing!")
	}

	err = s.adm.RemoveUser(ctx, accessKey)
	if err != nil {
		c.Fatalf("user could not be deleted: %v", err)
	}

	err = s.adm.RemoveCannedPolicy(ctx, policy1)
	if err != nil {
		c.Fatalf("policy del err: %v", err)
	}

	err = s.adm.RemoveCannedPolicy(ctx, policy2)
	if err != nil {
		c.Fatalf("policy del err: %v", err)
	}
}

func (s *TestSuiteIAM) TestPolicyCreate(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	bucket := getRandomBucketName()
	err := s.client.MakeBucket(ctx, bucket, minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("bucket creat error: %v", err)
	}

	// 1. Create a policy
	policy := "mypolicy"
	policyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject",
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))
	err = s.adm.AddCannedPolicy(ctx, policy, policyBytes)
	if err != nil {
		c.Fatalf("policy add error: %v", err)
	}

	// 2. Verify that policy json is validated by server
	invalidPolicyBytes := policyBytes[:len(policyBytes)-1]
	err = s.adm.AddCannedPolicy(ctx, policy+"invalid", invalidPolicyBytes)
	if err == nil {
		c.Fatalf("invalid policy creation success")
	}

	// 3. Create a user, associate policy and verify access
	accessKey, secretKey := mustGenerateCredentials(c)
	err = s.adm.SetUser(ctx, accessKey, secretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to set user: %v", err)
	}
	// 3.1 check that user does not have any access to the bucket
	uClient := s.getUserClient(c, accessKey, secretKey, "")
	c.mustNotListObjects(ctx, uClient, bucket)

	// 3.2 associate policy to user
	err = s.adm.SetPolicy(ctx, policy, accessKey, false)
	if err != nil {
		c.Fatalf("Unable to set policy: %v", err)
	}
	// 3.3 check user has access to bucket
	c.mustListObjects(ctx, uClient, bucket)
	// 3.4 Check that user cannot exceed their permissions
	err = uClient.RemoveBucket(ctx, bucket)
	if err == nil {
		c.Fatalf("bucket was deleted!")
	}

	// 4. Verify the policy appears in listing
	ps, err := s.adm.ListCannedPolicies(ctx)
	if err != nil {
		c.Fatalf("policy list err: %v", err)
	}
	_, ok := ps[policy]
	if !ok {
		c.Fatalf("policy was missing!")
	}

	// 5. Check that policy cannot be deleted when attached to a user.
	err = s.adm.RemoveCannedPolicy(ctx, policy)
	if err == nil {
		c.Fatalf("policy could be unexpectedly deleted!")
	}

	// 6. Delete the user and then delete the policy.
	err = s.adm.RemoveUser(ctx, accessKey)
	if err != nil {
		c.Fatalf("user could not be deleted: %v", err)
	}
	err = s.adm.RemoveCannedPolicy(ctx, policy)
	if err != nil {
		c.Fatalf("policy del err: %v", err)
	}
}

func (s *TestSuiteIAM) TestCannedPolicies(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	policies, err := s.adm.ListCannedPolicies(ctx)
	if err != nil {
		c.Fatalf("unable to list policies: %v", err)
	}

	defaultPolicies := []string{
		"readwrite",
		"readonly",
		"writeonly",
		"diagnostics",
		"consoleAdmin",
	}

	for _, v := range defaultPolicies {
		if _, ok := policies[v]; !ok {
			c.Fatalf("Failed to find %s in policies list", v)
		}
	}

	bucket := getRandomBucketName()
	err = s.client.MakeBucket(ctx, bucket, minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("bucket creat error: %v", err)
	}

	policyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject",
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))

	// Check that default policies can be overwritten.
	err = s.adm.AddCannedPolicy(ctx, "readwrite", policyBytes)
	if err != nil {
		c.Fatalf("policy add error: %v", err)
	}

	info, err := s.adm.InfoCannedPolicy(ctx, "readwrite")
	if err != nil {
		c.Fatalf("policy info err: %v", err)
	}

	infoStr := string(info)
	if !strings.Contains(infoStr, `"s3:PutObject"`) || !strings.Contains(infoStr, ":"+bucket+"/") {
		c.Fatalf("policy contains unexpected content!")
	}
}

func (s *TestSuiteIAM) TestGroupAddRemove(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	bucket := getRandomBucketName()
	err := s.client.MakeBucket(ctx, bucket, minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("bucket creat error: %v", err)
	}

	policy := "mypolicy"
	policyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject",
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))
	err = s.adm.AddCannedPolicy(ctx, policy, policyBytes)
	if err != nil {
		c.Fatalf("policy add error: %v", err)
	}

	accessKey, secretKey := mustGenerateCredentials(c)
	err = s.adm.SetUser(ctx, accessKey, secretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to set user: %v", err)
	}

	// 1. Add user to a new group
	group := "mygroup"
	err = s.adm.UpdateGroupMembers(ctx, madmin.GroupAddRemove{
		Group:   group,
		Members: []string{accessKey},
	})
	if err != nil {
		c.Fatalf("Unable to add user to group: %v", err)
	}

	// 2. Check that user has no access
	uClient := s.getUserClient(c, accessKey, secretKey, "")
	c.mustNotListObjects(ctx, uClient, bucket)

	// 3. Associate policy to group and check user got access.
	err = s.adm.SetPolicy(ctx, policy, group, true)
	if err != nil {
		c.Fatalf("Unable to set policy: %v", err)
	}
	// 3.1 check user has access to bucket
	c.mustListObjects(ctx, uClient, bucket)
	// 3.2 Check that user cannot exceed their permissions
	err = uClient.RemoveBucket(ctx, bucket)
	if err == nil {
		c.Fatalf("bucket was deleted!")
	}

	// 4. List groups and members and verify
	groups, err := s.adm.ListGroups(ctx)
	if err != nil {
		c.Fatalf("group list err: %v", err)
	}
	if !set.CreateStringSet(groups...).Contains(group) {
		c.Fatalf("created group not present!")
	}
	groupInfo, err := s.adm.GetGroupDescription(ctx, group)
	if err != nil {
		c.Fatalf("group desc err: %v", err)
	}
	c.Assert(groupInfo.Name, group)
	c.Assert(set.CreateStringSet(groupInfo.Members...), set.CreateStringSet(accessKey))
	c.Assert(groupInfo.Policy, policy)
	c.Assert(groupInfo.Status, string(madmin.GroupEnabled))

	// 5. Disable/enable the group and verify that user access is revoked/restored.
	err = s.adm.SetGroupStatus(ctx, group, madmin.GroupDisabled)
	if err != nil {
		c.Fatalf("group set status err: %v", err)
	}
	groupInfo, err = s.adm.GetGroupDescription(ctx, group)
	if err != nil {
		c.Fatalf("group desc err: %v", err)
	}
	c.Assert(groupInfo.Status, string(madmin.GroupDisabled))
	c.mustNotListObjects(ctx, uClient, bucket)

	err = s.adm.SetGroupStatus(ctx, group, madmin.GroupEnabled)
	if err != nil {
		c.Fatalf("group set status err: %v", err)
	}
	groupInfo, err = s.adm.GetGroupDescription(ctx, group)
	if err != nil {
		c.Fatalf("group desc err: %v", err)
	}
	c.Assert(groupInfo.Status, string(madmin.GroupEnabled))
	c.mustListObjects(ctx, uClient, bucket)

	// 6. Verify that group cannot be deleted with users.
	err = s.adm.UpdateGroupMembers(ctx, madmin.GroupAddRemove{
		Group:    group,
		IsRemove: true,
	})
	if err == nil {
		c.Fatalf("group was removed!")
	}
	groupInfo, err = s.adm.GetGroupDescription(ctx, group)
	if err != nil {
		c.Fatalf("group desc err: %v", err)
	}
	c.Assert(groupInfo.Name, group)

	// 7. Remove user from group and verify access is revoked.
	err = s.adm.UpdateGroupMembers(ctx, madmin.GroupAddRemove{
		Group:    group,
		Members:  []string{accessKey},
		IsRemove: true,
	})
	if err != nil {
		c.Fatalf("group update err: %v", err)
	}
	c.mustNotListObjects(ctx, uClient, bucket)

	// 7.1 verify group still exists
	groupInfo, err = s.adm.GetGroupDescription(ctx, group)
	if err != nil {
		c.Fatalf("group desc err: %v", err)
	}
	c.Assert(groupInfo.Name, group)
	c.Assert(len(groupInfo.Members), 0)

	// 8. Delete group and verify
	err = s.adm.UpdateGroupMembers(ctx, madmin.GroupAddRemove{
		Group:    group,
		IsRemove: true,
	})
	if err != nil {
		c.Fatalf("group update err: %v", err)
	}
	groups, err = s.adm.ListGroups(ctx)
	if err != nil {
		c.Fatalf("group list err: %v", err)
	}
	if set.CreateStringSet(groups...).Contains(group) {
		c.Fatalf("created group still present!")
	}
	groupInfo, err = s.adm.GetGroupDescription(ctx, group)
	if err == nil {
		c.Fatalf("group appears to exist")
	}
}

func (s *TestSuiteIAM) TestServiceAccountOpsByUser(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	bucket := getRandomBucketName()
	err := s.client.MakeBucket(ctx, bucket, minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("bucket creat error: %v", err)
	}

	// Create policy, user and associate policy
	policy := "mypolicy"
	policyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject",
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))
	err = s.adm.AddCannedPolicy(ctx, policy, policyBytes)
	if err != nil {
		c.Fatalf("policy add error: %v", err)
	}

	accessKey, secretKey := mustGenerateCredentials(c)
	err = s.adm.SetUser(ctx, accessKey, secretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to set user: %v", err)
	}

	err = s.adm.SetPolicy(ctx, policy, accessKey, false)
	if err != nil {
		c.Fatalf("Unable to set policy: %v", err)
	}

	// Create an madmin client with user creds
	userAdmClient, err := madmin.NewWithOptions(s.endpoint, &madmin.Options{
		Creds:  cr.NewStaticV4(accessKey, secretKey, ""),
		Secure: s.secure,
	})
	if err != nil {
		c.Fatalf("Err creating user admin client: %v", err)
	}
	userAdmClient.SetCustomTransport(s.TestSuiteCommon.client.Transport)

	// Create svc acc
	cr := c.mustCreateSvcAccount(ctx, accessKey, userAdmClient)

	// 1. Check that svc account appears in listing
	c.assertSvcAccAppearsInListing(ctx, userAdmClient, accessKey, cr.AccessKey)

	// 2. Check that svc account info can be queried
	c.assertSvcAccInfoQueryable(ctx, userAdmClient, accessKey, cr.AccessKey, false)

	// 3. Check S3 access
	c.assertSvcAccS3Access(ctx, s, cr, bucket)

	// 4. Check that svc account can restrict the policy, and that the
	// session policy can be updated.
	c.assertSvcAccSessionPolicyUpdate(ctx, s, userAdmClient, accessKey, bucket)

	// 4. Check that service account's secret key and account status can be
	// updated.
	c.assertSvcAccSecretKeyAndStatusUpdate(ctx, s, userAdmClient, accessKey, bucket)

	// 5. Check that service account can be deleted.
	c.assertSvcAccDeletion(ctx, s, userAdmClient, accessKey, bucket)

	// 6. Check that service account cannot be created for some other user.
	c.mustNotCreateSvcAccount(ctx, globalActiveCred.AccessKey, userAdmClient)
}

func (s *TestSuiteIAM) TestServiceAccountOpsByAdmin(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	bucket := getRandomBucketName()
	err := s.client.MakeBucket(ctx, bucket, minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("bucket creat error: %v", err)
	}

	// Create policy, user and associate policy
	policy := "mypolicy"
	policyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject",
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))
	err = s.adm.AddCannedPolicy(ctx, policy, policyBytes)
	if err != nil {
		c.Fatalf("policy add error: %v", err)
	}

	accessKey, secretKey := mustGenerateCredentials(c)
	err = s.adm.SetUser(ctx, accessKey, secretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to set user: %v", err)
	}

	err = s.adm.SetPolicy(ctx, policy, accessKey, false)
	if err != nil {
		c.Fatalf("Unable to set policy: %v", err)
	}

	// 1. Create a service account for the user
	cr := c.mustCreateSvcAccount(ctx, accessKey, s.adm)

	// 1.2 Check that svc account appears in listing
	c.assertSvcAccAppearsInListing(ctx, s.adm, accessKey, cr.AccessKey)

	// 1.3 Check that svc account info can be queried
	c.assertSvcAccInfoQueryable(ctx, s.adm, accessKey, cr.AccessKey, false)

	// 2. Check that svc account can access the bucket
	c.assertSvcAccS3Access(ctx, s, cr, bucket)

	// 3. Check that svc account can restrict the policy, and that the
	// session policy can be updated.
	c.assertSvcAccSessionPolicyUpdate(ctx, s, s.adm, accessKey, bucket)

	// 4. Check that service account's secret key and account status can be
	// updated.
	c.assertSvcAccSecretKeyAndStatusUpdate(ctx, s, s.adm, accessKey, bucket)

	// 5. Check that service account can be deleted.
	c.assertSvcAccDeletion(ctx, s, s.adm, accessKey, bucket)
}

func (s *TestSuiteIAM) SetUpAccMgmtPlugin(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	pluginEndpoint := os.Getenv("POLICY_PLUGIN_ENDPOINT")
	if pluginEndpoint == "" {
		c.Skip("POLICY_PLUGIN_ENDPOINT not given - skipping.")
	}

	configCmds := []string{
		"policy_plugin",
		"url=" + pluginEndpoint,
	}

	_, err := s.adm.SetConfigKV(ctx, strings.Join(configCmds, " "))
	if err != nil {
		c.Fatalf("unable to setup access management plugin for tests: %v", err)
	}

	s.RestartIAMSuite(c)
}

// TestIAM_AMPInternalIDPServerSuite - tests for access management plugin
func TestIAM_AMPInternalIDPServerSuite(t *testing.T) {
	for i, testCase := range iamTestSuites {
		t.Run(
			fmt.Sprintf("Test: %d, ServerType: %s", i+1, testCase.ServerTypeDescription),
			func(t *testing.T) {
				suite := testCase
				c := &check{t, testCase.serverType}

				suite.SetUpSuite(c)
				defer suite.TearDownSuite(c)

				suite.SetUpAccMgmtPlugin(c)

				suite.TestAccMgmtPlugin(c)
			},
		)
	}
}

// TestAccMgmtPlugin - this test assumes that the access-management-plugin is
// the same as the example in `docs/iam/access-manager-plugin.go` -
// specifically, it denies only `s3:Put*` operations on non-root accounts.
func (s *TestSuiteIAM) TestAccMgmtPlugin(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	// 0. Check that owner is able to make-bucket.
	bucket := getRandomBucketName()
	err := s.client.MakeBucket(ctx, bucket, minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("bucket creat error: %v", err)
	}

	// 1. Create a user.
	accessKey, secretKey := mustGenerateCredentials(c)
	err = s.adm.SetUser(ctx, accessKey, secretKey, madmin.AccountEnabled)
	if err != nil {
		c.Fatalf("Unable to set user: %v", err)
	}

	// 2. Check new user appears in listing
	usersMap, err := s.adm.ListUsers(ctx)
	if err != nil {
		c.Fatalf("error listing: %v", err)
	}
	v, ok := usersMap[accessKey]
	if !ok {
		c.Fatalf("user not listed: %s", accessKey)
	}
	c.Assert(v.Status, madmin.AccountEnabled)

	// 3. Check that user is able to make a bucket.
	client := s.getUserClient(c, accessKey, secretKey, "")
	err = client.MakeBucket(ctx, getRandomBucketName(), minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("user not create bucket: %v", err)
	}

	// 3.1 check user has access to bucket
	c.mustListObjects(ctx, client, bucket)

	// 3.2 check that user cannot upload an object.
	_, err = client.PutObject(ctx, bucket, "objectName", bytes.NewBuffer([]byte("some content")), 12, minio.PutObjectOptions{})
	if err == nil {
		c.Fatalf("user was able to upload unexpectedly")
	}

	// Create an madmin client with user creds
	userAdmClient, err := madmin.NewWithOptions(s.endpoint, &madmin.Options{
		Creds:  cr.NewStaticV4(accessKey, secretKey, ""),
		Secure: s.secure,
	})
	if err != nil {
		c.Fatalf("Err creating user admin client: %v", err)
	}
	userAdmClient.SetCustomTransport(s.TestSuiteCommon.client.Transport)

	// Create svc acc
	cr := c.mustCreateSvcAccount(ctx, accessKey, userAdmClient)

	// 1. Check that svc account appears in listing
	c.assertSvcAccAppearsInListing(ctx, userAdmClient, accessKey, cr.AccessKey)

	// 2. Check that svc account info can be queried
	c.assertSvcAccInfoQueryable(ctx, userAdmClient, accessKey, cr.AccessKey, false)

	// 3. Check S3 access
	c.assertSvcAccS3Access(ctx, s, cr, bucket)

	// Check that session policies do not apply - as policy enforcement is
	// delegated to plugin.
	{
		svcAK, svcSK := mustGenerateCredentials(c)

		// This policy does not allow listing objects.
		policyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))
		cr, err := userAdmClient.AddServiceAccount(ctx, madmin.AddServiceAccountReq{
			Policy:     policyBytes,
			TargetUser: accessKey,
			AccessKey:  svcAK,
			SecretKey:  svcSK,
		})
		if err != nil {
			c.Fatalf("Unable to create svc acc: %v", err)
		}
		svcClient := s.getUserClient(c, cr.AccessKey, cr.SecretKey, "")
		// Though the attached policy does not allow listing, it will be
		// ignored because the plugin allows it.
		c.mustListObjects(ctx, svcClient, bucket)
	}

	// 4. Check that service account's secret key and account status can be
	// updated.
	c.assertSvcAccSecretKeyAndStatusUpdate(ctx, s, userAdmClient, accessKey, bucket)

	// 5. Check that service account can be deleted.
	c.assertSvcAccDeletion(ctx, s, userAdmClient, accessKey, bucket)

	// 6. Check that service account **can** be created for some other user.
	// This is possible because of the policy enforced in the plugin.
	c.mustCreateSvcAccount(ctx, globalActiveCred.AccessKey, userAdmClient)
}

func (c *check) mustCreateIAMUser(ctx context.Context, admClnt *madmin.AdminClient) madmin.Credentials {
	randUser := mustGetUUID()
	randPass := mustGetUUID()
	err := admClnt.AddUser(ctx, randUser, randPass)
	if err != nil {
		c.Fatalf("should be able to create a user: %v", err)
	}
	return madmin.Credentials{
		AccessKey: randUser,
		SecretKey: randPass,
	}
}

func (c *check) mustGetIAMUserInfo(ctx context.Context, admClnt *madmin.AdminClient, accessKey string) madmin.UserInfo {
	ui, err := admClnt.GetUserInfo(ctx, accessKey)
	if err != nil {
		c.Fatalf("should be able to get user info: %v", err)
	}
	return ui
}

func (c *check) mustNotCreateIAMUser(ctx context.Context, admClnt *madmin.AdminClient) {
	randUser := mustGetUUID()
	randPass := mustGetUUID()
	err := admClnt.AddUser(ctx, randUser, randPass)
	if err == nil {
		c.Fatalf("should not be able to create a user")
	}
}

func (c *check) mustCreateSvcAccount(ctx context.Context, tgtUser string, admClnt *madmin.AdminClient) madmin.Credentials {
	cr, err := admClnt.AddServiceAccount(ctx, madmin.AddServiceAccountReq{
		TargetUser: tgtUser,
	})
	if err != nil {
		c.Fatalf("user should be able to create service accounts %s", err)
	}
	return cr
}

func (c *check) mustNotCreateSvcAccount(ctx context.Context, tgtUser string, admClnt *madmin.AdminClient) {
	_, err := admClnt.AddServiceAccount(ctx, madmin.AddServiceAccountReq{
		TargetUser: tgtUser,
	})
	if err == nil {
		c.Fatalf("user was able to add service accounts unexpectedly!")
	}
}

func (c *check) mustNotListObjects(ctx context.Context, client *minio.Client, bucket string) {
	res := client.ListObjects(ctx, bucket, minio.ListObjectsOptions{})
	v, ok := <-res
	if !ok || v.Err == nil {
		c.Fatalf("user was able to list unexpectedly! on %s", bucket)
	}
}

func (c *check) mustListObjects(ctx context.Context, client *minio.Client, bucket string) {
	res := client.ListObjects(ctx, bucket, minio.ListObjectsOptions{})
	v, ok := <-res
	if ok && v.Err != nil {
		c.Fatalf("user was unable to list: %v", v.Err)
	}
}

func (c *check) mustNotUpload(ctx context.Context, client *minio.Client, bucket string) {
	_, err := client.PutObject(ctx, bucket, "some-object", bytes.NewBuffer([]byte("stuff")), 5, minio.PutObjectOptions{})
	if e, ok := err.(minio.ErrorResponse); ok {
		if e.Code == "AccessDenied" {
			return
		}
	}
	c.Fatalf("upload did not get an AccessDenied error - got %#v instead", err)
}

func (c *check) assertSvcAccS3Access(ctx context.Context, s *TestSuiteIAM, cr madmin.Credentials, bucket string) {
	svcClient := s.getUserClient(c, cr.AccessKey, cr.SecretKey, "")
	c.mustListObjects(ctx, svcClient, bucket)
}

func (c *check) assertSvcAccAppearsInListing(ctx context.Context, madmClient *madmin.AdminClient, parentAK, svcAK string) {
	listResp, err := madmClient.ListServiceAccounts(ctx, parentAK)
	if err != nil {
		c.Fatalf("unable to list svc accounts: %v", err)
	}
	if !set.CreateStringSet(listResp.Accounts...).Contains(svcAK) {
		c.Fatalf("service account did not appear in listing!")
	}
}

func (c *check) assertSvcAccInfoQueryable(ctx context.Context, madmClient *madmin.AdminClient, parentAK, svcAK string, skipParentUserCheck bool) {
	infoResp, err := madmClient.InfoServiceAccount(ctx, svcAK)
	if err != nil {
		c.Fatalf("unable to get svc acc info: %v", err)
	}
	if !skipParentUserCheck {
		c.Assert(infoResp.ParentUser, parentAK)
	}
	c.Assert(infoResp.AccountStatus, "on")
	c.Assert(infoResp.ImpliedPolicy, true)
}

// This test assumes that the policy for `accessKey` allows listing on the given
// bucket. It creates a session policy that restricts listing on the bucket and
// then enables it again in a session policy update call.
func (c *check) assertSvcAccSessionPolicyUpdate(ctx context.Context, s *TestSuiteIAM, madmClient *madmin.AdminClient, accessKey, bucket string) {
	svcAK, svcSK := mustGenerateCredentials(c)

	// This policy does not allow listing objects.
	policyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:PutObject",
    "s3:GetObject"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))
	cr, err := madmClient.AddServiceAccount(ctx, madmin.AddServiceAccountReq{
		Policy:     policyBytes,
		TargetUser: accessKey,
		AccessKey:  svcAK,
		SecretKey:  svcSK,
	})
	if err != nil {
		c.Fatalf("Unable to create svc acc: %v", err)
	}
	svcClient := s.getUserClient(c, cr.AccessKey, cr.SecretKey, "")
	c.mustNotListObjects(ctx, svcClient, bucket)

	// This policy allows listing objects.
	newPolicyBytes := []byte(fmt.Sprintf(`{
 "Version": "2012-10-17",
 "Statement": [
  {
   "Effect": "Allow",
   "Action": [
    "s3:ListBucket"
   ],
   "Resource": [
    "arn:aws:s3:::%s/*"
   ]
  }
 ]
}`, bucket))
	err = madmClient.UpdateServiceAccount(ctx, svcAK, madmin.UpdateServiceAccountReq{
		NewPolicy: newPolicyBytes,
	})
	if err != nil {
		c.Fatalf("unable to update session policy for svc acc: %v", err)
	}
	c.mustListObjects(ctx, svcClient, bucket)
}

func (c *check) assertSvcAccSecretKeyAndStatusUpdate(ctx context.Context, s *TestSuiteIAM, madmClient *madmin.AdminClient, accessKey, bucket string) {
	svcAK, svcSK := mustGenerateCredentials(c)
	cr, err := madmClient.AddServiceAccount(ctx, madmin.AddServiceAccountReq{
		TargetUser: accessKey,
		AccessKey:  svcAK,
		SecretKey:  svcSK,
	})
	if err != nil {
		c.Fatalf("Unable to create svc acc: %v", err)
	}
	svcClient := s.getUserClient(c, cr.AccessKey, cr.SecretKey, "")
	c.mustListObjects(ctx, svcClient, bucket)

	_, svcSK2 := mustGenerateCredentials(c)
	err = madmClient.UpdateServiceAccount(ctx, svcAK, madmin.UpdateServiceAccountReq{
		NewSecretKey: svcSK2,
	})
	if err != nil {
		c.Fatalf("unable to update secret key for svc acc: %v", err)
	}
	// old creds should not work:
	c.mustNotListObjects(ctx, svcClient, bucket)
	// new creds work:
	svcClient2 := s.getUserClient(c, cr.AccessKey, svcSK2, "")
	c.mustListObjects(ctx, svcClient2, bucket)

	// update status to disabled
	err = madmClient.UpdateServiceAccount(ctx, svcAK, madmin.UpdateServiceAccountReq{
		NewStatus: "off",
	})
	if err != nil {
		c.Fatalf("unable to update secret key for svc acc: %v", err)
	}
	c.mustNotListObjects(ctx, svcClient2, bucket)
}

func (c *check) assertSvcAccDeletion(ctx context.Context, s *TestSuiteIAM, madmClient *madmin.AdminClient, accessKey, bucket string) {
	svcAK, svcSK := mustGenerateCredentials(c)
	cr, err := madmClient.AddServiceAccount(ctx, madmin.AddServiceAccountReq{
		TargetUser: accessKey,
		AccessKey:  svcAK,
		SecretKey:  svcSK,
	})
	if err != nil {
		c.Fatalf("Unable to create svc acc: %v", err)
	}
	svcClient := s.getUserClient(c, cr.AccessKey, cr.SecretKey, "")
	c.mustListObjects(ctx, svcClient, bucket)

	err = madmClient.DeleteServiceAccount(ctx, svcAK)
	if err != nil {
		c.Fatalf("unable to delete svc acc: %v", err)
	}
	c.mustNotListObjects(ctx, svcClient, bucket)
}

func mustGenerateCredentials(c *check) (string, string) {
	ak, sk, err := auth.GenerateCredentials()
	if err != nil {
		c.Fatalf("unable to generate credentials: %v", err)
	}
	return ak, sk
}
