Scott Baker | e7144bc | 2019-10-01 14:16:47 -0700 | [diff] [blame^] | 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 | "crypto" |
| 21 | "crypto/ecdsa" |
| 22 | "crypto/rsa" |
| 23 | "crypto/x509" |
| 24 | "encoding/pem" |
| 25 | "fmt" |
| 26 | "io/ioutil" |
| 27 | "os" |
| 28 | "path/filepath" |
| 29 | ) |
| 30 | |
| 31 | // CanReadCertAndKey returns true if the certificate and key files already exists, |
| 32 | // otherwise returns false. If lost one of cert and key, returns error. |
| 33 | func CanReadCertAndKey(certPath, keyPath string) (bool, error) { |
| 34 | certReadable := canReadFile(certPath) |
| 35 | keyReadable := canReadFile(keyPath) |
| 36 | |
| 37 | if certReadable == false && keyReadable == false { |
| 38 | return false, nil |
| 39 | } |
| 40 | |
| 41 | if certReadable == false { |
| 42 | return false, fmt.Errorf("error reading %s, certificate and key must be supplied as a pair", certPath) |
| 43 | } |
| 44 | |
| 45 | if keyReadable == false { |
| 46 | return false, fmt.Errorf("error reading %s, certificate and key must be supplied as a pair", keyPath) |
| 47 | } |
| 48 | |
| 49 | return true, nil |
| 50 | } |
| 51 | |
| 52 | // If the file represented by path exists and |
| 53 | // readable, returns true otherwise returns false. |
| 54 | func canReadFile(path string) bool { |
| 55 | f, err := os.Open(path) |
| 56 | if err != nil { |
| 57 | return false |
| 58 | } |
| 59 | |
| 60 | defer f.Close() |
| 61 | |
| 62 | return true |
| 63 | } |
| 64 | |
| 65 | // WriteCert writes the pem-encoded certificate data to certPath. |
| 66 | // The certificate file will be created with file mode 0644. |
| 67 | // If the certificate file already exists, it will be overwritten. |
| 68 | // The parent directory of the certPath will be created as needed with file mode 0755. |
| 69 | func WriteCert(certPath string, data []byte) error { |
| 70 | if err := os.MkdirAll(filepath.Dir(certPath), os.FileMode(0755)); err != nil { |
| 71 | return err |
| 72 | } |
| 73 | return ioutil.WriteFile(certPath, data, os.FileMode(0644)) |
| 74 | } |
| 75 | |
| 76 | // WriteKey writes the pem-encoded key data to keyPath. |
| 77 | // The key file will be created with file mode 0600. |
| 78 | // If the key file already exists, it will be overwritten. |
| 79 | // The parent directory of the keyPath will be created as needed with file mode 0755. |
| 80 | func WriteKey(keyPath string, data []byte) error { |
| 81 | if err := os.MkdirAll(filepath.Dir(keyPath), os.FileMode(0755)); err != nil { |
| 82 | return err |
| 83 | } |
| 84 | return ioutil.WriteFile(keyPath, data, os.FileMode(0600)) |
| 85 | } |
| 86 | |
| 87 | // LoadOrGenerateKeyFile looks for a key in the file at the given path. If it |
| 88 | // can't find one, it will generate a new key and store it there. |
| 89 | func LoadOrGenerateKeyFile(keyPath string) (data []byte, wasGenerated bool, err error) { |
| 90 | loadedData, err := ioutil.ReadFile(keyPath) |
| 91 | // Call verifyKeyData to ensure the file wasn't empty/corrupt. |
| 92 | if err == nil && verifyKeyData(loadedData) { |
| 93 | return loadedData, false, err |
| 94 | } |
| 95 | if !os.IsNotExist(err) { |
| 96 | return nil, false, fmt.Errorf("error loading key from %s: %v", keyPath, err) |
| 97 | } |
| 98 | |
| 99 | generatedData, err := MakeEllipticPrivateKeyPEM() |
| 100 | if err != nil { |
| 101 | return nil, false, fmt.Errorf("error generating key: %v", err) |
| 102 | } |
| 103 | if err := WriteKey(keyPath, generatedData); err != nil { |
| 104 | return nil, false, fmt.Errorf("error writing key to %s: %v", keyPath, err) |
| 105 | } |
| 106 | return generatedData, true, nil |
| 107 | } |
| 108 | |
| 109 | // MarshalPrivateKeyToPEM converts a known private key type of RSA or ECDSA to |
| 110 | // a PEM encoded block or returns an error. |
| 111 | func MarshalPrivateKeyToPEM(privateKey crypto.PrivateKey) ([]byte, error) { |
| 112 | switch t := privateKey.(type) { |
| 113 | case *ecdsa.PrivateKey: |
| 114 | derBytes, err := x509.MarshalECPrivateKey(t) |
| 115 | if err != nil { |
| 116 | return nil, err |
| 117 | } |
| 118 | privateKeyPemBlock := &pem.Block{ |
| 119 | Type: ECPrivateKeyBlockType, |
| 120 | Bytes: derBytes, |
| 121 | } |
| 122 | return pem.EncodeToMemory(privateKeyPemBlock), nil |
| 123 | case *rsa.PrivateKey: |
| 124 | return EncodePrivateKeyPEM(t), nil |
| 125 | default: |
| 126 | return nil, fmt.Errorf("private key is not a recognized type: %T", privateKey) |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | // NewPool returns an x509.CertPool containing the certificates in the given PEM-encoded file. |
| 131 | // 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 |
| 132 | func NewPool(filename string) (*x509.CertPool, error) { |
| 133 | certs, err := CertsFromFile(filename) |
| 134 | if err != nil { |
| 135 | return nil, err |
| 136 | } |
| 137 | pool := x509.NewCertPool() |
| 138 | for _, cert := range certs { |
| 139 | pool.AddCert(cert) |
| 140 | } |
| 141 | return pool, nil |
| 142 | } |
| 143 | |
| 144 | // CertsFromFile returns the x509.Certificates contained in the given PEM-encoded file. |
| 145 | // 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 |
| 146 | func CertsFromFile(file string) ([]*x509.Certificate, error) { |
| 147 | pemBlock, err := ioutil.ReadFile(file) |
| 148 | if err != nil { |
| 149 | return nil, err |
| 150 | } |
| 151 | certs, err := ParseCertsPEM(pemBlock) |
| 152 | if err != nil { |
| 153 | return nil, fmt.Errorf("error reading %s: %s", file, err) |
| 154 | } |
| 155 | return certs, nil |
| 156 | } |
| 157 | |
| 158 | // PrivateKeyFromFile returns the private key in rsa.PrivateKey or ecdsa.PrivateKey format from a given PEM-encoded file. |
| 159 | // Returns an error if the file could not be read or if the private key could not be parsed. |
| 160 | func PrivateKeyFromFile(file string) (interface{}, error) { |
| 161 | data, err := ioutil.ReadFile(file) |
| 162 | if err != nil { |
| 163 | return nil, err |
| 164 | } |
| 165 | key, err := ParsePrivateKeyPEM(data) |
| 166 | if err != nil { |
| 167 | return nil, fmt.Errorf("error reading private key file %s: %v", file, err) |
| 168 | } |
| 169 | return key, nil |
| 170 | } |
| 171 | |
| 172 | // PublicKeysFromFile returns the public keys in rsa.PublicKey or ecdsa.PublicKey format from a given PEM-encoded file. |
| 173 | // Reads public keys from both public and private key files. |
| 174 | func PublicKeysFromFile(file string) ([]interface{}, error) { |
| 175 | data, err := ioutil.ReadFile(file) |
| 176 | if err != nil { |
| 177 | return nil, err |
| 178 | } |
| 179 | keys, err := ParsePublicKeysPEM(data) |
| 180 | if err != nil { |
| 181 | return nil, fmt.Errorf("error reading public key file %s: %v", file, err) |
| 182 | } |
| 183 | return keys, nil |
| 184 | } |
| 185 | |
| 186 | // verifyKeyData returns true if the provided data appears to be a valid private key. |
| 187 | func verifyKeyData(data []byte) bool { |
| 188 | if len(data) == 0 { |
| 189 | return false |
| 190 | } |
| 191 | _, err := ParsePrivateKeyPEM(data) |
| 192 | return err == nil |
| 193 | } |