k8s.io/client-go@v0.31.1/util/cert/pem.go (about)

     1  /*
     2  Copyright 2014 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package cert
    18  
    19  import (
    20  	"bytes"
    21  	"crypto/x509"
    22  	"encoding/pem"
    23  	"errors"
    24  )
    25  
    26  const (
    27  	// CertificateBlockType is a possible value for pem.Block.Type.
    28  	CertificateBlockType = "CERTIFICATE"
    29  	// CertificateRequestBlockType is a possible value for pem.Block.Type.
    30  	CertificateRequestBlockType = "CERTIFICATE REQUEST"
    31  )
    32  
    33  // ParseCertsPEM returns the x509.Certificates contained in the given PEM-encoded byte array
    34  // Returns an error if a certificate could not be parsed, or if the data does not contain any certificates
    35  func ParseCertsPEM(pemCerts []byte) ([]*x509.Certificate, error) {
    36  	ok := false
    37  	certs := []*x509.Certificate{}
    38  	for len(pemCerts) > 0 {
    39  		var block *pem.Block
    40  		block, pemCerts = pem.Decode(pemCerts)
    41  		if block == nil {
    42  			break
    43  		}
    44  		// Only use PEM "CERTIFICATE" blocks without extra headers
    45  		if block.Type != CertificateBlockType || len(block.Headers) != 0 {
    46  			continue
    47  		}
    48  
    49  		cert, err := x509.ParseCertificate(block.Bytes)
    50  		if err != nil {
    51  			return certs, err
    52  		}
    53  
    54  		certs = append(certs, cert)
    55  		ok = true
    56  	}
    57  
    58  	if !ok {
    59  		return certs, errors.New("data does not contain any valid RSA or ECDSA certificates")
    60  	}
    61  	return certs, nil
    62  }
    63  
    64  // EncodeCertificates returns the PEM-encoded byte array that represents by the specified certs.
    65  func EncodeCertificates(certs ...*x509.Certificate) ([]byte, error) {
    66  	b := bytes.Buffer{}
    67  	for _, cert := range certs {
    68  		if err := pem.Encode(&b, &pem.Block{Type: CertificateBlockType, Bytes: cert.Raw}); err != nil {
    69  			return []byte{}, err
    70  		}
    71  	}
    72  	return b.Bytes(), nil
    73  }