/
pem.go
123 lines (104 loc) · 3.07 KB
/
pem.go
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package rsa
import (
"bytes"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
)
import (
"github.com/pkg/errors"
)
const (
publicBlockType = "PUBLIC KEY"
rsaPrivateBlockType = "RSA PRIVATE KEY"
rsaPublicBlockType = "RSA PUBLIC KEY"
)
func FromPrivateKeyToPEMBytes(key *rsa.PrivateKey) ([]byte, error) {
block := pem.Block{
Type: rsaPrivateBlockType,
Bytes: x509.MarshalPKCS1PrivateKey(key),
}
var keyBuf bytes.Buffer
if err := pem.Encode(&keyBuf, &block); err != nil {
return nil, err
}
return keyBuf.Bytes(), nil
}
func FromPrivateKeyToPublicKeyPEMBytes(key *rsa.PrivateKey) ([]byte, error) {
block := pem.Block{
Type: rsaPublicBlockType,
Bytes: x509.MarshalPKCS1PublicKey(&key.PublicKey),
}
var keyBuf bytes.Buffer
if err := pem.Encode(&keyBuf, &block); err != nil {
return nil, err
}
return keyBuf.Bytes(), nil
}
func FromPrivateKeyPEMBytesToPublicKeyPEMBytes(b []byte) ([]byte, error) {
privateKey, err := FromPEMBytesToPrivateKey(b)
if err != nil {
return nil, err
}
return FromPrivateKeyToPublicKeyPEMBytes(privateKey)
}
func FromPEMBytesToPrivateKey(b []byte) (*rsa.PrivateKey, error) {
block, _ := pem.Decode(b)
if block.Type != rsaPrivateBlockType {
return nil, errors.Errorf("invalid key encoding %q", block.Type)
}
return x509.ParsePKCS1PrivateKey(block.Bytes)
}
func FromPEMBytesToPublicKey(b []byte) (*rsa.PublicKey, error) {
block, _ := pem.Decode(b)
switch block.Type {
case rsaPublicBlockType:
return x509.ParsePKCS1PublicKey(block.Bytes)
case publicBlockType:
return rsaKeyFromPKIX(block.Bytes)
default:
return nil, errors.Errorf("invalid key encoding %q", block.Type)
}
}
func IsPrivateKeyPEMBytes(b []byte) bool {
block, _ := pem.Decode(b)
return block != nil && block.Type == rsaPrivateBlockType
}
func IsPublicKeyPEMBytes(b []byte) bool {
block, _ := pem.Decode(b)
if block != nil && block.Type == rsaPublicBlockType {
return true
}
if block != nil && block.Type == publicBlockType {
_, err := rsaKeyFromPKIX(block.Bytes)
return err == nil
}
return false
}
func rsaKeyFromPKIX(bytes []byte) (*rsa.PublicKey, error) {
key, err := x509.ParsePKIXPublicKey(bytes)
if err != nil {
return nil, err
}
rsaKey, ok := key.(*rsa.PublicKey)
if !ok {
return nil, errors.Errorf("encoded key is not a RSA key")
}
return rsaKey, nil
}