github.com/mendersoftware/go-lib-micro@v0.0.0-20240304135804-e8e39c59b148/keys/key.go (about)

     1  // Copyright 2023 Northern.tech AS
     2  //
     3  //	Licensed under the Apache License, Version 2.0 (the "License");
     4  //	you may not use this file except in compliance with the License.
     5  //	You may obtain a copy of the License at
     6  //
     7  //	    http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  //	Unless required by applicable law or agreed to in writing, software
    10  //	distributed under the License is distributed on an "AS IS" BASIS,
    11  //	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  //	See the License for the specific language governing permissions and
    13  //	limitations under the License.
    14  package keys
    15  
    16  import (
    17  	"crypto/rsa"
    18  	"crypto/x509"
    19  	"encoding/pem"
    20  	"io/ioutil"
    21  
    22  	"github.com/pkg/errors"
    23  )
    24  
    25  const (
    26  	ErrMsgPrivKeyReadFailed    = "failed to read server private key file"
    27  	ErrMsgPrivKeyNotPEMEncoded = "server private key not PEM-encoded"
    28  )
    29  
    30  func LoadRSAPrivate(privKeyPath string) (*rsa.PrivateKey, error) {
    31  	// read key from file
    32  	pemData, err := ioutil.ReadFile(privKeyPath)
    33  	if err != nil {
    34  		return nil, errors.Wrap(err, ErrMsgPrivKeyReadFailed)
    35  	}
    36  	// decode pem key
    37  	block, _ := pem.Decode(pemData)
    38  	if block == nil {
    39  		return nil, errors.New(ErrMsgPrivKeyNotPEMEncoded)
    40  	}
    41  	// check if it is a RSA PRIVATE KEY
    42  	if got, want := block.Type, "RSA PRIVATE KEY"; got != want {
    43  		return nil, errors.Errorf(
    44  			"unknown server private key type; got: %s, want: %s", got, want)
    45  	}
    46  	// return parsed key
    47  	return x509.ParsePKCS1PrivateKey(block.Bytes)
    48  }