func makeSigningKeyWithChain(rootKey libtrust.PrivateKey, depth int) (libtrust.PrivateKey, error) {
if depth == 0 {
// Don't need to build a chain.
return rootKey, nil
}
var (
x5c = make([]string, depth)
parentKey = rootKey
key libtrust.PrivateKey
cert *x509.Certificate
err error
)
for depth > 0 {
if key, err = libtrust.GenerateECP256PrivateKey(); err != nil {
return nil, err
}
if cert, err = libtrust.GenerateCACert(parentKey, key); err != nil {
return nil, err
}
depth--
x5c[depth] = base64.StdEncoding.EncodeToString(cert.Raw)
parentKey = key
}
key.AddExtendedField("x5c", x5c)
return key, nil
}
