// Verify verifies all the signatures and returns the list of
// public keys used to sign. Any x509 chains are not checked.
func (js *JSONSignature) Verify() ([]libtrust.PublicKey, error) {
keys := make([]libtrust.PublicKey, len(js.signatures))
for i, signature := range js.signatures {
signBytes, err := js.signBytes(signature.Protected)
if err != nil {
return nil, err
}
var publicKey libtrust.PublicKey
if len(signature.Header.Chain) > 0 {
certBytes, err := base64.StdEncoding.DecodeString(signature.Header.Chain[0])
if err != nil {
return nil, err
}
cert, err := x509.ParseCertificate(certBytes)
if err != nil {
return nil, err
}
publicKey, err = FromCryptoPublicKey(cert.PublicKey)
if err != nil {
return nil, err
}
} else if signature.Header.JWK != nil {
publicKey = signature.Header.JWK
} else {
return nil, errors.New("missing public key")
}
sigBytes, err := joseBase64UrlDecode(signature.Signature)
if err != nil {
return nil, err
}
err = publicKey.Verify(bytes.NewReader(signBytes), signature.Header.Algorithm, sigBytes)
if err != nil {
return nil, err
}
keys[i] = publicKey
}
return keys, nil
}
// VerifyChains verifies all the signatures and the chains associated
// with each signature and returns the list of verified chains.
// Signatures without an x509 chain are not checked.
func (js *JSONSignature) VerifyChains(ca *x509.CertPool) ([][]*x509.Certificate, error) {
chains := make([][]*x509.Certificate, 0, len(js.signatures))
for _, signature := range js.signatures {
signBytes, err := js.signBytes(signature.Protected)
if err != nil {
return nil, err
}
var publicKey libtrust.PublicKey
if len(signature.Header.Chain) > 0 {
certBytes, err := base64.StdEncoding.DecodeString(signature.Header.Chain[0])
if err != nil {
return nil, err
}
cert, err := x509.ParseCertificate(certBytes)
if err != nil {
return nil, err
}
publicKey, err = FromCryptoPublicKey(cert.PublicKey)
if err != nil {
return nil, err
}
intermediates := x509.NewCertPool()
if len(signature.Header.Chain) > 1 {
intermediateChain := signature.Header.Chain[1:]
for i := range intermediateChain {
certBytes, err := base64.StdEncoding.DecodeString(intermediateChain[i])
if err != nil {
return nil, err
}
intermediate, err := x509.ParseCertificate(certBytes)
if err != nil {
return nil, err
}
intermediates.AddCert(intermediate)
}
}
verifyOptions := x509.VerifyOptions{
Intermediates: intermediates,
Roots: ca,
}
verifiedChains, err := cert.Verify(verifyOptions)
if err != nil {
return nil, err
}
chains = append(chains, verifiedChains...)
sigBytes, err := joseBase64UrlDecode(signature.Signature)
if err != nil {
return nil, err
}
err = publicKey.Verify(bytes.NewReader(signBytes), signature.Header.Algorithm, sigBytes)
if err != nil {
return nil, err
}
}
}
return chains, nil
}
