BACKPORT: Merge system certificate pool with custom certificates

Upstream reference: moby#27918
Upstream reference: moby#12756

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

registry/registry.go

@@ -3,7 +3,6 @@ package registry
 
 import (
 	"crypto/tls"
-	"crypto/x509"
 	"errors"
 	"fmt"
 	"io/ioutil"
@@ -64,8 +63,11 @@ func ReadCertsDirectory(tlsConfig *tls.Config, directory string) error {
 	for _, f := range fs {
 		if strings.HasSuffix(f.Name(), ".crt") {
 			if tlsConfig.RootCAs == nil {
-				// TODO(dmcgowan): Copy system pool
-				tlsConfig.RootCAs = x509.NewCertPool()
+				systemPool, err := tlsconfig.SystemCertPool()
+				if err != nil {
+					return fmt.Errorf("unable to get system cert pool: %v", err)
+				}
+				tlsConfig.RootCAs = systemPool
 			}
 			logrus.Debugf("crt: %s", filepath.Join(directory, f.Name()))
 			data, err := ioutil.ReadFile(filepath.Join(directory, f.Name()))

vendor/src/github.com/docker/go-connections/tlsconfig/certpool_go17.go

@@ -0,0 +1,21 @@
+// +build go1.7
+
+package tlsconfig
+
+import (
+	"crypto/x509"
+	"runtime"
+
+	"github.com/Sirupsen/logrus"
+)
+
+// SystemCertPool returns a copy of the system cert pool,
+// returns an error if failed to load or empty pool on windows.
+func SystemCertPool() (*x509.CertPool, error) {
+	certpool, err := x509.SystemCertPool()
+	if err != nil && runtime.GOOS == "windows" {
+		logrus.Warnf("Unable to use system certificate pool: %v", err)
+		return x509.NewCertPool(), nil
+	}
+	return certpool, err
+}

vendor/src/github.com/docker/go-connections/tlsconfig/certpool_other.go

@@ -0,0 +1,16 @@
+// +build !go1.7
+
+package tlsconfig
+
+import (
+	"crypto/x509"
+
+	"github.com/Sirupsen/logrus"
+)
+
+// SystemCertPool returns an new empty cert pool,
+// accessing system cert pool is supported in go 1.7
+func SystemCertPool() (*x509.CertPool, error) {
+	logrus.Warn("Unable to use system certificate pool: requires building with go 1.7 or later")
+	return x509.NewCertPool(), nil
+}

vendor/src/github.com/docker/go-connections/tlsconfig/config.go

@@ -65,9 +65,13 @@ var ClientDefault = tls.Config{
 func certPool(caFile string) (*x509.CertPool, error) {
 	// If we should verify the server, we need to load a trusted ca
 	certPool := x509.NewCertPool()
+	certPool, err := SystemCertPool()
+	if err != nil {
+		return nil, fmt.Errorf("failed to read system certificates: %v", err)
+	}
 	pem, err := ioutil.ReadFile(caFile)
 	if err != nil {
-		return nil, fmt.Errorf("Could not read CA certificate %q: %v", caFile, err)
+		return nil, fmt.Errorf("could not read CA certificate %q: %v", caFile, err)
 	}
 	if !certPool.AppendCertsFromPEM(pem) {
 		return nil, fmt.Errorf("failed to append certificates from PEM file: %q", caFile)

vendor/src/github.com/docker/libnetwork/config/config.go

@@ -6,7 +6,7 @@ import (
 	"github.com/BurntSushi/toml"
 	log "github.com/Sirupsen/logrus"
 	"github.com/docker/docker/pkg/discovery"
-	"github.com/docker/docker/pkg/tlsconfig"
+	"github.com/docker/go-connections/tlsconfig"
 	"github.com/docker/libkv/store"
 	"github.com/docker/libnetwork/cluster"
 	"github.com/docker/libnetwork/datastore"