Connect MCS with Minio insecure TLS/Custom CAs

This PR adds support to connect MCS to minio instances running TLS with
self-signed certificates or  certificates signed by custom
Certificate Authorities

```
export MCS_MINIO_SERVER_TLS_ROOT_CAS=file1,file2,file3
```

Note: TLS Skip Verification is not supported unless there's a clear need
for it

Author: Alevsk

README.md

@@ -68,6 +68,15 @@ export MCS_MINIO_SERVER=http://localhost:9000
 ./mcs server
 ```
 
+## Connect MCS to a Minio using TLS and a self-signed certificate
+
+```
+...
+export MCS_MINIO_SERVER_TLS_SKIP_VERIFICATION=on
+export MCS_MINIO_SERVER=https://localhost:9000
+./mcs server
+```
+
 You can verify that the apis work by doing the request on `localhost:9090/api/v1/...`
 
 # Contribute to mcs Project

go.sum

@@ -12,6 +12,7 @@ github.com/Azure/azure-storage-blob-go v0.8.0 h1:53qhf0Oxa0nOjgbDeeYPUeyiNmafAFE
 github.com/Azure/azure-storage-blob-go v0.8.0/go.mod h1:lPI3aLPpuLTeUwh1sViKXFxwl2B6teiRqI0deQUvsw0=
 github.com/Azure/go-autorest v11.7.1+incompatible h1:M2YZIajBBVekV86x0rr1443Lc1F/Ylxb9w+5EtSyX3Q=
 github.com/Azure/go-autorest v11.7.1+incompatible/go.mod h1:r+4oMnoxhatjLLJ6zxSWATqVooLgysK6ZNox3g/xq24=
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/DataDog/datadog-go v2.2.0+incompatible/go.mod h1:LButxg5PwREeZtORoXG3tL4fMGNddJ+vMq1mwgfaqoQ=
 github.com/PuerkitoBio/purell v1.1.0/go.mod h1:c11w/QuzBsJSee3cPx9rAFu61PvFxuPbtSwDGJws/X0=

restapi/client-admin.go

@@ -44,7 +44,9 @@ func NewAdminClient(url, accessKey, secretKey string) (*madmin.AdminClient, *pro
 		AppName:     appName,
 		AppVersion:  McsVersion,
 		AppComments: []string{appName, runtime.GOOS, runtime.GOARCH},
+		Insecure:    false,
 	})
+	s3Client.SetCustomTransport(STSClient.Transport)
 	if err != nil {
 		return nil, err.Trace(url)
 	}
@@ -240,13 +242,15 @@ func newMAdminClient(jwt string) (*madmin.AdminClient, error) {
 
 // newAdminFromClaims creates a minio admin from Decrypted claims using Assume role credentials
 func newAdminFromClaims(claims *auth.DecryptedClaims) (*madmin.AdminClient, error) {
+	tlsEnabled := getMinIOEndpointIsSecure()
 	adminClient, err := madmin.NewWithOptions(getMinIOEndpoint(), &madmin.Options{
 		Creds:  credentials.NewStaticV4(claims.AccessKeyID, claims.SecretAccessKey, claims.SessionToken),
-		Secure: getMinIOEndpointIsSecure(),
+		Secure: tlsEnabled,
 	})
 	if err != nil {
 		return nil, err
 	}
+	adminClient.SetCustomTransport(STSClient.Transport)
 	return adminClient, nil
 }
 

restapi/client.go

@@ -18,6 +18,7 @@ package restapi
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	mc "github.com/minio/mc/cmd"
@@ -133,13 +134,45 @@ func (c mcsCredentials) Expire() {
 	c.minioCredentials.Expire()
 }
 
+// mcsSTSAssumeRole it's a STSAssumeRole wrapper, in general
+// there's no need to use this struct anywhere else in the project, it's only required
+// for passing a custom *http.Client to *credentials.STSAssumeRole
+type mcsSTSAssumeRole struct {
+	stsAssumeRole *credentials.STSAssumeRole
+}
+
+func (s mcsSTSAssumeRole) Retrieve() (credentials.Value, error) {
+	return s.stsAssumeRole.Retrieve()
+}
+
+func (s mcsSTSAssumeRole) IsExpired() bool {
+	return s.stsAssumeRole.IsExpired()
+}
+
+// STSClient contains http.client configuration need it by STSAssumeRole
+var STSClient = PrepareSTSClient()
+
 func newMcsCredentials(accessKey, secretKey, location string) (*credentials.Credentials, error) {
-	return credentials.NewSTSAssumeRole(getMinIOServer(), credentials.STSAssumeRoleOptions{
+	stsEndpoint := getMinIOServer()
+	if stsEndpoint == "" {
+		return nil, errors.New("STS endpoint cannot be empty")
+	}
+	if accessKey == "" || secretKey == "" {
+		return nil, errors.New("AssumeRole credentials access/secretkey is mandatory")
+	}
+	opts := credentials.STSAssumeRoleOptions{
 		AccessKey:       accessKey,
 		SecretKey:       secretKey,
 		Location:        location,
 		DurationSeconds: xjwt.GetMcsSTSAndJWTDurationInSeconds(),
-	})
+	}
+	stsAssumeRole := &credentials.STSAssumeRole{
+		Client:      STSClient,
+		STSEndpoint: stsEndpoint,
+		Options:     opts,
+	}
+	mcsSTSWrapper := mcsSTSAssumeRole{stsAssumeRole: stsAssumeRole}
+	return credentials.New(mcsSTSWrapper), nil
 }
 
 // getMcsCredentialsFromJWT returns the *minioCredentials.Credentials associated to the
@@ -160,14 +193,15 @@ func newMinioClient(jwt string) (*minio.Client, error) {
 	if err != nil {
 		return nil, err
 	}
-	adminClient, err := minio.NewWithOptions(getMinIOEndpoint(), &minio.Options{
+	minioClient, err := minio.NewWithOptions(getMinIOEndpoint(), &minio.Options{
 		Creds:  creds,
 		Secure: getMinIOEndpointIsSecure(),
 	})
 	if err != nil {
 		return nil, err
 	}
-	return adminClient, nil
+	minioClient.SetCustomTransport(STSClient.Transport)
+	return minioClient, nil
 }
 
 // newS3BucketClient creates a new mc S3Client to talk to the server based on a bucket

restapi/config.go

@@ -48,7 +48,17 @@ func getSecretKey() string {
 }
 
 func getMinIOServer() string {
-	return env.Get(McsMinIOServer, "http://localhost:9000")
+	return strings.TrimSpace(env.Get(McsMinIOServer, "http://localhost:9000"))
+}
+
+// If MCS_MINIO_SERVER_TLS_ROOT_CAS is true mcs will load a list of certificates into the
+// http.client rootCAs store, this is useful for testing or when working with self-signed certificates
+func getMinioServerTLSRootCAs() []string {
+	caCertFileNames := strings.TrimSpace(env.Get(McsMinIOServerTLSRootCAs, ""))
+	if caCertFileNames == "" {
+		return []string{}
+	}
+	return strings.Split(caCertFileNames, ",")
 }
 
 func getMinIOEndpoint() string {
@@ -67,7 +77,7 @@ func getMinIOEndpointIsSecure() bool {
 	if strings.Contains(server, "://") {
 		parts := strings.Split(server, "://")
 		if len(parts) > 1 {
-			if parts[1] == "https" {
+			if parts[0] == "https" {
 				return true
 			}
 		}

restapi/consts.go

@@ -18,15 +18,16 @@ package restapi
 
 const (
 	// consts for common configuration
-	McsVersion        = `0.1.0`
-	McsAccessKey      = "MCS_ACCESS_KEY"
-	McsSecretKey      = "MCS_SECRET_KEY"
-	McsMinIOServer    = "MCS_MINIO_SERVER"
-	McsProductionMode = "MCS_PRODUCTION_MODE"
-	McsHostname       = "MCS_HOSTNAME"
-	McsPort           = "MCS_PORT"
-	McsTLSHostname    = "MCS_TLS_HOSTNAME"
-	McsTLSPort        = "MCS_TLS_PORT"
+	McsVersion               = `0.1.0`
+	McsAccessKey             = "MCS_ACCESS_KEY"
+	McsSecretKey             = "MCS_SECRET_KEY"
+	McsMinIOServer           = "MCS_MINIO_SERVER"
+	McsMinIOServerTLSRootCAs = "MCS_MINIO_SERVER_TLS_ROOT_CAS"
+	McsProductionMode        = "MCS_PRODUCTION_MODE"
+	McsHostname              = "MCS_HOSTNAME"
+	McsPort                  = "MCS_PORT"
+	McsTLSHostname           = "MCS_TLS_HOSTNAME"
+	McsTLSPort               = "MCS_TLS_PORT"
 
 	// consts for Secure middleware
 	McsSecureAllowedHosts                    = "MCS_SECURE_ALLOWED_HOSTS"

restapi/tls.go

@@ -0,0 +1,95 @@
+// This file is part of MinIO Orchestrator
+// Copyright (c) 2020 MinIO, Inc.
+//
+// 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 restapi
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"time"
+)
+
+var (
+	certDontExists = "File certificate doesn't exists: %s"
+)
+
+func prepareSTSClientTransport() *http.Transport {
+	// This takes github.com/minio/minio/pkg/madmin/transport.go as an example
+	//
+	// DefaultTransport - this default transport is similar to
+	// http.DefaultTransport but with additional param  DisableCompression
+	// is set to true to avoid decompressing content with 'gzip' encoding.
+	DefaultTransport := &http.Transport{
+		Proxy: http.ProxyFromEnvironment,
+		DialContext: (&net.Dialer{
+			Timeout:   5 * time.Second,
+			KeepAlive: 15 * time.Second,
+		}).DialContext,
+		MaxIdleConns:          1024,
+		MaxIdleConnsPerHost:   1024,
+		ResponseHeaderTimeout: 60 * time.Second,
+		IdleConnTimeout:       60 * time.Second,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+		DisableCompression:    true,
+	}
+	// If Minio instance is running with TLS enabled and it's using a self-signed certificate
+	// or a certificate issued by a custom certificate authority we prepare a new custom *http.Transport
+	if getMinIOEndpointIsSecure() {
+		caCertFileNames := getMinioServerTLSRootCAs()
+		tlsConfig := &tls.Config{
+			// Can't use SSLv3 because of POODLE and BEAST
+			// Can't use TLSv1.0 because of POODLE and BEAST using CBC cipher
+			// Can't use TLSv1.1 because of RC4 cipher usage
+			MinVersion: tls.VersionTLS12,
+		}
+		// If root CAs are configured we save them to the http.Client RootCAs store
+		if len(caCertFileNames) > 0 {
+			certs := x509.NewCertPool()
+			for _, caCert := range caCertFileNames {
+				// Validate certificate exists
+				if FileExists(caCert) {
+					pemData, err := ioutil.ReadFile(caCert)
+					if err != nil {
+						// if there was an error reading pem file stop mcs
+						panic(err)
+					}
+					certs.AppendCertsFromPEM(pemData)
+				} else {
+					// if provided cert filename doesn't exists stop mcs
+					panic(fmt.Sprintf(certDontExists, caCert))
+				}
+			}
+			tlsConfig.RootCAs = certs
+		}
+		DefaultTransport.TLSClientConfig = tlsConfig
+	}
+	return DefaultTransport
+}
+
+// PrepareSTSClient returns an http.Client with custom configurations need it by *credentials.STSAssumeRole
+// custom configurations include skipVerification flag, and root CA certificates
+func PrepareSTSClient() *http.Client {
+	transport := prepareSTSClientTransport()
+	// Return http client with default configuration
+	return &http.Client{
+		Transport: transport,
+	}
+}

restapi/user_login.go

@@ -32,7 +32,8 @@ import (
 )
 
 var (
-	errorGeneric = errors.New("an error occurred, please try again")
+	errorGeneric          = errors.New("an error occurred, please try again")
+	errInvalidCredentials = errors.New("invalid Credentials")
 )
 
 func registerLoginHandlers(api *operations.McsAPI) {
@@ -61,35 +62,35 @@ func registerLoginHandlers(api *operations.McsAPI) {
 	})
 }
 
-var errInvalidCredentials = errors.New("invalid minioCredentials")
-
 // login performs a check of minioCredentials against MinIO
 func login(credentials MCSCredentials) (*string, error) {
 	// try to obtain minioCredentials,
 	tokens, err := credentials.Get()
 	if err != nil {
+		log.Println("error authenticating user", err)
 		return nil, errInvalidCredentials
 	}
 	// if we made it here, the minioCredentials work, generate a jwt with claims
 	jwt, err := auth.NewJWTWithClaimsForClient(&tokens, getMinIOServer())
 	if err != nil {
+		log.Println("error authenticating user", err)
 		return nil, errInvalidCredentials
 	}
 	return &jwt, nil
 }
 
-func getConfiguredRegion(client MinioAdmin) string {
+func getConfiguredRegionForLogin(client MinioAdmin) (string, error) {
 	location := ""
 	configuration, err := getConfig(client, "region")
 	if err != nil {
 		log.Println("error obtaining MinIO region:", err)
-		return location
+		return location, errorGeneric
 	}
 	// region is an array of 1 element
 	if len(configuration) > 0 {
 		location = configuration[0].Value
 	}
-	return location
+	return location, nil
 }
 
 // getLoginResponse performs login() and serializes it to the handler's output
@@ -102,16 +103,18 @@ func getLoginResponse(lr *models.LoginRequest) (*models.LoginResponse, error) {
 	adminClient := adminClient{client: mAdmin}
 	// obtain the configured MinIO region
 	// need it for user authentication
-	location := getConfiguredRegion(adminClient)
+	location, err := getConfiguredRegionForLogin(adminClient)
+	if err != nil {
+		return nil, err
+	}
 	creds, err := newMcsCredentials(*lr.AccessKey, *lr.SecretKey, location)
 	if err != nil {
 		log.Println("error login:", err)
-		return nil, err
+		return nil, errInvalidCredentials
 	}
 	credentials := mcsCredentials{minioCredentials: creds}
 	sessionID, err := login(credentials)
 	if err != nil {
-		log.Println("error login:", err)
 		return nil, err
 	}
 	// serialize output
@@ -131,7 +134,8 @@ func getLoginDetailsResponse() (*models.LoginDetails, error) {
 		// initialize new oauth2 client
 		oauth2Client, err := oauth2.NewOauth2ProviderClient(ctx, nil)
 		if err != nil {
-			return nil, err
+			log.Println("error getting new oauth2 provider client", err)
+			return nil, errorGeneric
 		}
 		// Validate user against IDP
 		identityProvider := &auth.IdentityProvider{Client: oauth2Client}
@@ -147,7 +151,8 @@ func getLoginDetailsResponse() (*models.LoginDetails, error) {
 func loginOauth2Auth(ctx context.Context, provider *auth.IdentityProvider, code, state string) (*oauth2.User, error) {
 	userIdentity, err := provider.VerifyIdentity(ctx, code, state)
 	if err != nil {
-		return nil, err
+		log.Println("error validating user identity against idp:", err)
+		return nil, errorGeneric
 	}
 	return userIdentity, nil
 }
@@ -166,8 +171,7 @@ func getLoginOauth2AuthResponse(lr *models.LoginOauth2AuthRequest) (*models.Logi
 		// Validate user against IDP
 		identity, err := loginOauth2Auth(ctx, identityProvider, *lr.Code, *lr.State)
 		if err != nil {
-			log.Println("error validating user identity against idp:", err)
-			return nil, errorGeneric
+			return nil, err
 		}
 		mAdmin, err := newSuperMAdminClient()
 		if err != nil {
@@ -179,7 +183,10 @@ func getLoginOauth2AuthResponse(lr *models.LoginOauth2AuthRequest) (*models.Logi
 		secretKey := utils.RandomCharString(32)
 		// obtain the configured MinIO region
 		// need it for user authentication
-		location := getConfiguredRegion(adminClient)
+		location, err := getConfiguredRegionForLogin(adminClient)
+		if err != nil {
+			return nil, err
+		}
 		// create user in MinIO
 		if _, err := addUser(ctx, adminClient, &accessKey, &secretKey, []string{}); err != nil {
 			log.Println("error adding user:", err)
@@ -207,8 +214,7 @@ func getLoginOauth2AuthResponse(lr *models.LoginOauth2AuthRequest) (*models.Logi
 		credentials := mcsCredentials{minioCredentials: creds}
 		jwt, err := login(credentials)
 		if err != nil {
-			log.Println("error login:", err)
-			return nil, errorGeneric
+			return nil, err
 		}
 		// serialize output
 		loginResponse := &models.LoginResponse{