Files
probo/pkg/crypto/pem/pem.go
Sacha Al Himdani 8c02c53315 Update copyright headers across all Go files
Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>
2026-03-25 17:38:32 +01:00

109 lines
2.9 KiB
Go

// Copyright (c) 2025-2026 Probo Inc <hello@getprobo.com>.
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
package pem
import (
"crypto"
"crypto/ecdsa"
"crypto/ed25519"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"fmt"
)
const (
BlockTypeCertificate = "CERTIFICATE"
BlockTypeECPrivateKey = "EC PRIVATE KEY"
BlockTypeRSAPrivateKey = "RSA PRIVATE KEY"
BlockTypePKCS8PrivateKey = "PRIVATE KEY"
)
func EncodeCertificate(der []byte) []byte {
block := &pem.Block{
Type: BlockTypeCertificate,
Bytes: der,
}
return pem.EncodeToMemory(block)
}
func EncodeCertificateChain(derCerts [][]byte) []byte {
var chain []byte
for _, der := range derCerts {
chain = append(chain, EncodeCertificate(der)...)
}
return chain
}
func EncodePrivateKey(key crypto.Signer) ([]byte, error) {
var keyDER []byte
var keyType string
switch k := key.(type) {
case *ecdsa.PrivateKey:
der, err := x509.MarshalECPrivateKey(k)
if err != nil {
return nil, fmt.Errorf("cannot marshal EC private key: %w", err)
}
keyDER = der
keyType = BlockTypeECPrivateKey
case *rsa.PrivateKey:
keyDER = x509.MarshalPKCS1PrivateKey(k)
keyType = BlockTypeRSAPrivateKey
case ed25519.PrivateKey:
der, err := x509.MarshalPKCS8PrivateKey(k)
if err != nil {
return nil, fmt.Errorf("cannot marshal ED25519 private key: %w", err)
}
keyDER = der
keyType = BlockTypePKCS8PrivateKey
default:
return nil, fmt.Errorf("unsupported key type: %T", key)
}
block := &pem.Block{
Type: keyType,
Bytes: keyDER,
}
return pem.EncodeToMemory(block), nil
}
func DecodePrivateKey(pemData []byte) (crypto.Signer, error) {
block, _ := pem.Decode(pemData)
if block == nil {
return nil, fmt.Errorf("cannot to decode PEM block")
}
switch block.Type {
case BlockTypeECPrivateKey:
return x509.ParseECPrivateKey(block.Bytes)
case BlockTypeRSAPrivateKey:
return x509.ParsePKCS1PrivateKey(block.Bytes)
case BlockTypePKCS8PrivateKey:
key, err := x509.ParsePKCS8PrivateKey(block.Bytes)
if err != nil {
return nil, fmt.Errorf("cannot parse PKCS8 private key: %w", err)
}
signer, ok := key.(crypto.Signer)
if !ok {
return nil, fmt.Errorf("key is not a crypto.Signer")
}
return signer, nil
default:
return nil, fmt.Errorf("unsupported PEM block type: %s", block.Type)
}
}