/
utils_file.go
225 lines (182 loc) · 4.74 KB
/
utils_file.go
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package cmd
import (
"crypto"
"crypto/ecdsa"
"crypto/ed25519"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"fmt"
"io"
"io/ioutil"
"os"
"github.com/pkg/errors"
)
var (
errUnableToReadPEM = errors.New("can't read PEM data")
errKeyEncrypted = errors.New("key file is encrypted but no passphrase provided")
errPrivateKeyUnparsable = errors.New("unable to parse private key")
)
func keyToPEMFile(filename string, key crypto.PrivateKey, passphrase []byte, encryptionAlgorithm x509.PEMCipher) error {
file, err := os.Create(filename)
if err != nil {
return err
}
defer file.Close()
asn1, err := x509.MarshalPKCS8PrivateKey(key)
if err != nil {
return err
}
block := &pem.Block{Type: "PRIVATE KEY", Bytes: asn1}
if len(passphrase) > 0 {
block, err = x509.EncryptPEMBlock(rand.Reader, "ENCRYPTED PRIVATE KEY", asn1, passphrase, encryptionAlgorithm)
if err != nil {
return err
}
}
if err := pem.Encode(file, block); err != nil {
return err
}
return nil
}
func keyToDERFile(filename string, key crypto.PrivateKey) error {
file, err := os.Create(filename)
if err != nil {
return err
}
defer file.Close()
asn1, err := x509.MarshalPKCS8PrivateKey(key)
if err != nil {
return err
}
_, err = file.Write(asn1)
if err != nil {
return err
}
return nil
}
func certToFile(filename string, derBytes []byte) error {
certOut, err := os.Create(filename)
if err != nil {
return errors.Errorf("failed to open cert.pem for writing: %s", err)
}
if err := pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes}); err != nil {
return errors.Errorf("failed to write data to cert.pem: %s", err)
}
if err := certOut.Close(); err != nil {
return errors.Errorf("error closing cert.pem: %s", err)
}
return nil
}
// pemFileToASN1 opens a file and reads it contents and attempts to decode it as PEM.
// If we are unable to decode the file as PEM, the contents are returned with a error.
// If we are able to decode it, the first decoded PEM block is returned as ANSI bytes with no error.
func pemFileToASN1(filename string) ([]byte, error) {
file, err := os.Open(filename)
if err != nil {
return nil, err
}
defer file.Close()
bytes, err := ioutil.ReadAll(file)
if err != io.EOF && err != nil {
return nil, err
}
block, _ := pem.Decode(bytes)
if block == nil {
return bytes, errUnableToReadPEM
}
return block.Bytes, nil
}
func fileToCert(filename string) (*x509.Certificate, error) {
ans1Bytes, err := pemFileToASN1(filename)
if err != nil && err != errUnableToReadPEM {
return nil, err
}
cert, err := x509.ParseCertificate(ans1Bytes)
if err != nil {
return nil, err
}
return cert, nil
}
func fileToPrivateKey(filename string, passphrase []byte) (crypto.Signer, error) {
file, err := os.Open(filename)
if err != nil {
return nil, err
}
defer func() {
if err := file.Close(); err != nil {
panic(err)
}
}()
bytes, err := ioutil.ReadAll(file)
if err != io.EOF && err != nil {
return nil, err
}
ans1Bytes := bytes
block, _ := pem.Decode(bytes)
if block != nil {
ans1Bytes = block.Bytes
if x509.IsEncryptedPEMBlock(block) {
if len(passphrase) == 0 {
return nil, errKeyEncrypted
}
ans1Bytes, err = x509.DecryptPEMBlock(block, passphrase)
if err != nil {
return nil, err
}
}
}
if key, err := x509.ParsePKCS1PrivateKey(ans1Bytes); err == nil {
return key, nil
}
if key, err := x509.ParseECPrivateKey(ans1Bytes); err == nil {
return key, nil
}
if key, err := x509.ParsePKCS8PrivateKey(ans1Bytes); err == nil {
switch pkey := key.(type) {
case *rsa.PrivateKey:
return pkey, nil
case *ecdsa.PrivateKey:
return pkey, nil
case *ed25519.PrivateKey:
return pkey, nil
}
return nil, fmt.Errorf("Unsupported private key type '%T'", key)
}
return nil, errPrivateKeyUnparsable
}
func generateECPrivateKey(keysize int) (*ecdsa.PrivateKey, error) {
var ecCurve elliptic.Curve
switch keysize {
case 224:
ecCurve = elliptic.P224()
case 256:
ecCurve = elliptic.P256()
case 384:
ecCurve = elliptic.P384()
case 521:
ecCurve = elliptic.P521()
default:
return nil, errors.Errorf("%d is not a valid key size, Allowed values: 224, 256, 384 and 521\n", keysize)
}
return ecdsa.GenerateKey(ecCurve, rand.Reader)
}
func generateRSAPriveKey(keysize int) (*rsa.PrivateKey, error) {
allowed := false
for _, allowedBits := range []int{1024, 2048, 4096, 8192} {
if keysize == allowedBits {
allowed = true
break
}
}
if !allowed {
return nil, errors.Errorf("%d is not a valid key size Allowed values: 1024, 2048, 4096, 8192\n", keysize)
}
return rsa.GenerateKey(rand.Reader, keysize)
}
func generateEDPrivateKey() (ed25519.PrivateKey, error) {
_, key, err := ed25519.GenerateKey(rand.Reader)
return key, err
}