746b63f685
* wip ca/ident cmds * minor improvements and commenting * combine id and ca commands and add $CONFDIR * add `NewIdenity` test * refactor `NewCA` benchmarks * linter fixes
115 lines
2.8 KiB
Go
115 lines
2.8 KiB
Go
// Copyright (C) 2018 Storj Labs, Inc.
|
|
// See LICENSE for copying information.
|
|
|
|
package peertls
|
|
|
|
// Many cryptography standards use ASN.1 to define their data structures,
|
|
// and Distinguished Encoding Rules (DER) to serialize those structures.
|
|
// Because DER produces binary output, it can be challenging to transmit
|
|
// the resulting files through systems, like electronic mail, that only
|
|
// support ASCII. The PEM format solves this problem by encoding the
|
|
// binary data using base64.
|
|
// (see https://en.wikipedia.org/wiki/Privacy-enhanced_Electronic_Mail)
|
|
|
|
import (
|
|
"crypto"
|
|
"crypto/ecdsa"
|
|
"crypto/elliptic"
|
|
"crypto/rand"
|
|
"crypto/x509"
|
|
"encoding/asn1"
|
|
"math/big"
|
|
|
|
"github.com/zeebo/errs"
|
|
)
|
|
|
|
type ecdsaSignature struct {
|
|
R, S *big.Int
|
|
}
|
|
|
|
var authECCurve = elliptic.P256()
|
|
|
|
func parseCertificateChains(rawCerts [][]byte) ([]*x509.Certificate, error) {
|
|
parsedCerts, err := parseCerts(rawCerts)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return parsedCerts, nil
|
|
}
|
|
|
|
func parseCerts(rawCerts [][]byte) ([]*x509.Certificate, error) {
|
|
certs := make([]*x509.Certificate, len(rawCerts))
|
|
for i, c := range rawCerts {
|
|
var err error
|
|
certs[i], err = x509.ParseCertificate(c)
|
|
if err != nil {
|
|
return nil, ErrVerifyPeerCert.New("unable to parse certificate: %v", err)
|
|
}
|
|
}
|
|
return certs, nil
|
|
}
|
|
|
|
func verifyChainSignatures(certs []*x509.Certificate) error {
|
|
for i, cert := range certs {
|
|
j := len(certs)
|
|
if i+1 < j {
|
|
isValid, err := verifyCertSignature(certs[i+1], cert)
|
|
if err != nil {
|
|
return ErrVerifyPeerCert.Wrap(err)
|
|
}
|
|
|
|
if !isValid {
|
|
return ErrVerifyPeerCert.New("certificate chain signature verification failed")
|
|
}
|
|
|
|
continue
|
|
}
|
|
|
|
rootIsValid, err := verifyCertSignature(cert, cert)
|
|
if err != nil {
|
|
return ErrVerifyPeerCert.Wrap(err)
|
|
}
|
|
|
|
if !rootIsValid {
|
|
return ErrVerifyPeerCert.New("certificate chain signature verification failed")
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func verifyCertSignature(parentCert, childCert *x509.Certificate) (bool, error) {
|
|
pubKey, ok := parentCert.PublicKey.(*ecdsa.PublicKey)
|
|
if !ok {
|
|
return false, ErrUnsupportedKey.New("%T", parentCert.PublicKey)
|
|
}
|
|
|
|
signature := new(ecdsaSignature)
|
|
|
|
if _, err := asn1.Unmarshal(childCert.Signature, signature); err != nil {
|
|
return false, ErrVerifySignature.New("unable to unmarshal ecdsa signature: %v", err)
|
|
}
|
|
|
|
h := crypto.SHA256.New()
|
|
_, err := h.Write(childCert.RawTBSCertificate)
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
digest := h.Sum(nil)
|
|
|
|
isValid := ecdsa.Verify(pubKey, digest, signature.R, signature.S)
|
|
|
|
return isValid, nil
|
|
}
|
|
|
|
func newSerialNumber() (*big.Int, error) {
|
|
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
|
|
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
|
|
if err != nil {
|
|
return nil, errs.New("failed to generateServerTls serial number: %s", err.Error())
|
|
}
|
|
|
|
return serialNumber, nil
|
|
}
|