add all the plugins

plugins/registry/kubernetes/client/utils.go

@@ -0,0 +1,74 @@
+package client
+
+import (
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io/ioutil"
+)
+
+// COPIED FROM
+// https://github.com/kubernetes/kubernetes/blob/7a725418af4661067b56506faabc2d44c6d7703a/pkg/util/crypto/crypto.go
+
+// CertPoolFromFile returns an x509.CertPool containing the certificates in the given PEM-encoded file.
+// Returns an error if the file could not be read, a certificate could not be parsed, or if the file does not contain any certificates
+func CertPoolFromFile(filename string) (*x509.CertPool, error) {
+	certs, err := certificatesFromFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	pool := x509.NewCertPool()
+	for _, cert := range certs {
+		pool.AddCert(cert)
+	}
+	return pool, nil
+}
+
+// certificatesFromFile returns the x509.Certificates contained in the given PEM-encoded file.
+// Returns an error if the file could not be read, a certificate could not be parsed, or if the file does not contain any certificates
+func certificatesFromFile(file string) ([]*x509.Certificate, error) {
+	if len(file) == 0 {
+		return nil, errors.New("error reading certificates from an empty filename")
+	}
+	pemBlock, err := ioutil.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+	certs, err := CertsFromPEM(pemBlock)
+	if err != nil {
+		return nil, fmt.Errorf("error reading %s: %s", file, err)
+	}
+	return certs, nil
+}
+
+// CertsFromPEM returns the x509.Certificates contained in the given PEM-encoded byte array
+// Returns an error if a certificate could not be parsed, or if the data does not contain any certificates
+func CertsFromPEM(pemCerts []byte) ([]*x509.Certificate, error) {
+	ok := false
+	certs := []*x509.Certificate{}
+	for len(pemCerts) > 0 {
+		var block *pem.Block
+		block, pemCerts = pem.Decode(pemCerts)
+		if block == nil {
+			break
+		}
+		// Only use PEM "CERTIFICATE" blocks without extra headers
+		if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
+			continue
+		}
+
+		cert, err := x509.ParseCertificate(block.Bytes)
+		if err != nil {
+			return certs, err
+		}
+
+		certs = append(certs, cert)
+		ok = true
+	}
+
+	if !ok {
+		return certs, errors.New("could not read any certificates")
+	}
+	return certs, nil
+}