Files

63 lines
1.4 KiB
Go

package pki
import (
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/x509"
"encoding/pem"
"errors"
"fmt"
"os"
)
// NewKey generates a secure ecdsa private key,
// or panics if it can't.
func NewKey() *ecdsa.PrivateKey {
key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
if err != nil {
panic(fmt.Errorf("Generating key: %w", err))
}
return key
}
// MarshalKeyToPEM returns the bytes of a single encoded PEM block containing
// the given private key. Panics if it can't encode the key.
func MarshalKeyToPEM(key *ecdsa.PrivateKey) []byte {
der, err := x509.MarshalPKCS8PrivateKey(key)
if err != nil {
panic(fmt.Errorf("Encoding key: %w", err))
}
return pem.EncodeToMemory(&pem.Block{
Type: PEMTypePrivateKey,
Bytes: der,
})
}
// ParseKeyFromFile retrieves a private key stored in PEM format from a file.
func ParseKeyFromFile(fn string) (*ecdsa.PrivateKey, error) {
pemBytes, err := os.ReadFile(fn)
if err != nil {
return nil, err
}
keyBlock, _ := pem.Decode(pemBytes)
if keyBlock == nil || keyBlock.Type != PEMTypePrivateKey {
return nil, fmt.Errorf("file was not PEM or first block wasn't %s", PEMTypePrivateKey)
}
rawKey, err := x509.ParsePKCS8PrivateKey(keyBlock.Bytes)
if err != nil {
return nil, err
}
var key *ecdsa.PrivateKey
var ok bool
key, ok = rawKey.(*ecdsa.PrivateKey)
if !ok {
return nil, errors.New("key was not ecdsa")
}
return key, nil
}