pki_helpers.go

Documentation: k8s.io/kubernetes/test/utils

     1  /*
     2  Copyright 2019 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 utils
    18  
    19  import (
    20  	"crypto"
    21  	cryptorand "crypto/rand"
    22  	"crypto/rsa"
    23  	"crypto/x509"
    24  	"crypto/x509/pkix"
    25  	"encoding/pem"
    26  	"fmt"
    27  	"math"
    28  	"math/big"
    29  	"time"
    30  
    31  	certutil "k8s.io/client-go/util/cert"
    32  )
    33  
    34  const (
    35  	certificateBlockType = "CERTIFICATE"
    36  	rsaKeySize           = 2048
    37  	duration365d         = time.Hour * 24 * 365
    38  )
    39  
    40  // NewPrivateKey creates an RSA private key
    41  func NewPrivateKey() (*rsa.PrivateKey, error) {
    42  	return rsa.GenerateKey(cryptorand.Reader, rsaKeySize)
    43  }
    44  
    45  // EncodeCertPEM returns PEM-endcoded certificate data
    46  func EncodeCertPEM(cert *x509.Certificate) []byte {
    47  	block := pem.Block{
    48  		Type:  certificateBlockType,
    49  		Bytes: cert.Raw,
    50  	}
    51  	return pem.EncodeToMemory(&block)
    52  }
    53  
    54  // NewSignedCert creates a signed certificate using the given CA certificate and key
    55  func NewSignedCert(cfg *certutil.Config, key crypto.Signer, caCert *x509.Certificate, caKey crypto.Signer) (*x509.Certificate, error) {
    56  	// returns a uniform random value in [0, max-1), then add 1 to serial to make it a uniform random value in [1, max).
    57  	serial, err := cryptorand.Int(cryptorand.Reader, new(big.Int).SetInt64(math.MaxInt64-1))
    58  	if err != nil {
    59  		return nil, err
    60  	}
    61  	serial = new(big.Int).Add(serial, big.NewInt(1))
    62  	if len(cfg.CommonName) == 0 {
    63  		return nil, fmt.Errorf("must specify a CommonName")
    64  	}
    65  	if len(cfg.Usages) == 0 {
    66  		return nil, fmt.Errorf("must specify at least one ExtKeyUsage")
    67  	}
    68  
    69  	certTmpl := x509.Certificate{
    70  		Subject: pkix.Name{
    71  			CommonName:   cfg.CommonName,
    72  			Organization: cfg.Organization,
    73  		},
    74  		DNSNames:     cfg.AltNames.DNSNames,
    75  		IPAddresses:  cfg.AltNames.IPs,
    76  		SerialNumber: serial,
    77  		NotBefore:    caCert.NotBefore,
    78  		NotAfter:     time.Now().Add(duration365d).UTC(),
    79  		KeyUsage:     x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
    80  		ExtKeyUsage:  cfg.Usages,
    81  	}
    82  	certDERBytes, err := x509.CreateCertificate(cryptorand.Reader, &certTmpl, caCert, key.Public(), caKey)
    83  	if err != nil {
    84  		return nil, err
    85  	}
    86  	return x509.ParseCertificate(certDERBytes)
    87  }
    88
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