/*

* Minio Cloud Storage, (C) 2015, 2016, 2017 Minio, Inc.

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

package cmd

import (

"bytes"

"crypto"

"crypto/ecdsa"

"crypto/tls"

"crypto/x509"

"encoding/pem"

"io/ioutil"

"os"

"github.com/minio/minio/pkg/certs"

)

// TLSPrivateKeyPassword is the environment variable which contains the password used

// to decrypt the TLS private key. It must be set if the TLS private key is

// password protected.

const TLSPrivateKeyPassword = "MINIO_CERT_PASSWD"

func parsePublicCertFile(certFile string) (x509Certs []*x509.Certificate, err error) {

// Read certificate file.

var data []byte

if data, err = ioutil.ReadFile(certFile); err != nil {

return nil, err

}

// Trimming leading and tailing white spaces.

data = bytes.TrimSpace(data)

// Parse all certs in the chain.

current := data

for len(current) > 0 {

var pemBlock *pem.Block

if pemBlock, current = pem.Decode(current); pemBlock == nil {

return nil, uiErrSSLUnexpectedData(nil).Msg("Could not read PEM block from file %s", certFile)

}

var x509Cert *x509.Certificate

if x509Cert, err = x509.ParseCertificate(pemBlock.Bytes); err != nil {

return nil, uiErrSSLUnexpectedData(err)

}

x509Certs = append(x509Certs, x509Cert)

}

if len(x509Certs) == 0 {

return nil, uiErrSSLUnexpectedData(nil).Msg("Empty public certificate file %s", certFile)

}

return x509Certs, nil

}

func getRootCAs(certsCAsDir string) (*x509.CertPool, error) {

// Get all CA file names.

var caFiles []string

fis, err := readDir(certsCAsDir)

if err != nil {

return nil, err

}

for _, fi := range fis {

// Skip all directories.

if hasSuffix(fi, slashSeparator) {

continue

}

// We are only interested in regular files here.

caFiles = append(caFiles, pathJoin(certsCAsDir, fi))

}

if len(caFiles) == 0 {

return nil, nil

}

rootCAs, _ := x509.SystemCertPool()

if rootCAs == nil {

// In some systems (like Windows) system cert pool is

// not supported or no certificates are present on the

// system - so we create a new cert pool.

rootCAs = x509.NewCertPool()

}

// Load custom root CAs for client requests

for _, caFile := range caFiles {

caCert, err := ioutil.ReadFile(caFile)

if err != nil {

return nil, err

}

rootCAs.AppendCertsFromPEM(caCert)

}

return rootCAs, nil

}

// load an X509 key pair (private key , certificate) from the provided

// paths. The private key may be encrypted and is decrypted using the

// ENV_VAR: MINIO_CERT_PASSWD.

func loadX509KeyPair(certFile, keyFile string) (tls.Certificate, error) {

certPEMBlock, err := ioutil.ReadFile(certFile)

if err != nil {

return tls.Certificate{}, uiErrSSLUnexpectedError(err)

}

keyPEMBlock, err := ioutil.ReadFile(keyFile)

if err != nil {

return tls.Certificate{}, uiErrSSLUnexpectedError(err)

}

key, rest := pem.Decode(keyPEMBlock)

if len(rest) > 0 {

return tls.Certificate{}, uiErrSSLUnexpectedData(nil).Msg("The private key contains additional data")

}

if x509.IsEncryptedPEMBlock(key) {

password, ok := os.LookupEnv(TLSPrivateKeyPassword)

if !ok {

return tls.Certificate{}, uiErrSSLNoPassword(nil)

}

decryptedKey, decErr := x509.DecryptPEMBlock(key, []byte(password))

if decErr != nil {

return tls.Certificate{}, uiErrSSLWrongPassword(decErr)

}

keyPEMBlock = pem.EncodeToMemory(&pem.Block{Type: key.Type, Bytes: decryptedKey})

}

cert, err := tls.X509KeyPair(certPEMBlock, keyPEMBlock)

if err != nil {

return tls.Certificate{}, uiErrSSLUnexpectedData(nil).Msg(err.Error())

}

// Ensure that the private key is not a P-384 or P-521 EC key.

// The Go TLS stack does not provide constant-time implementations of P-384 and P-521.

if priv, ok := cert.PrivateKey.(crypto.Signer); ok {

if pub, ok := priv.Public().(*ecdsa.PublicKey); ok {

if name := pub.Params().Name; name == "P-384" || name == "P-521" { // unfortunately there is no cleaner way to check

return tls.Certificate{}, uiErrSSLUnexpectedData(nil).Msg("tls: the ECDSA curve '%s' is not supported", name)

}

}

}

return cert, nil

}

func getSSLConfig() (x509Certs []*x509.Certificate, rootCAs *x509.CertPool, c *certs.Certs, secureConn bool, err error) {

if !(isFile(getPublicCertFile()) && isFile(getPrivateKeyFile())) {

return nil, nil, nil, false, nil

}

if x509Certs, err = parsePublicCertFile(getPublicCertFile()); err != nil {

return nil, nil, nil, false, err

}

c, err = certs.New(getPublicCertFile(), getPrivateKeyFile(), loadX509KeyPair)

if err != nil {

return nil, nil, nil, false, err

}

if rootCAs, err = getRootCAs(getCADir()); err != nil {

return nil, nil, nil, false, err

}

secureConn = true

return x509Certs, rootCAs, c, secureConn, nil

}