certificates/authority/options.go
2022-09-20 18:52:47 -07:00

354 lines
10 KiB
Go

package authority
import (
"context"
"crypto"
"crypto/x509"
"encoding/pem"
"github.com/pkg/errors"
"golang.org/x/crypto/ssh"
"go.step.sm/crypto/kms"
"github.com/smallstep/certificates/authority/admin"
"github.com/smallstep/certificates/authority/config"
"github.com/smallstep/certificates/authority/provisioner"
"github.com/smallstep/certificates/cas"
casapi "github.com/smallstep/certificates/cas/apiv1"
"github.com/smallstep/certificates/db"
)
// Option sets options to the Authority.
type Option func(*Authority) error
// WithConfig replaces the current config with the given one. No validation is
// performed in the given value.
func WithConfig(cfg *config.Config) Option {
return func(a *Authority) error {
a.config = cfg
return nil
}
}
// WithConfigFile reads the given filename as a configuration file and replaces
// the current one. No validation is performed in the given configuration.
func WithConfigFile(filename string) Option {
return func(a *Authority) (err error) {
a.config, err = config.LoadConfiguration(filename)
return
}
}
// WithPassword set the password to decrypt the intermediate key as well as the
// ssh host and user keys if they are not overridden by other options.
func WithPassword(password []byte) Option {
return func(a *Authority) (err error) {
a.password = password
return
}
}
// WithSSHHostPassword set the password to decrypt the key used to sign SSH host
// certificates.
func WithSSHHostPassword(password []byte) Option {
return func(a *Authority) (err error) {
a.sshHostPassword = password
return
}
}
// WithSSHUserPassword set the password to decrypt the key used to sign SSH user
// certificates.
func WithSSHUserPassword(password []byte) Option {
return func(a *Authority) (err error) {
a.sshUserPassword = password
return
}
}
// WithIssuerPassword set the password to decrypt the certificate issuer private
// key used in RA mode.
func WithIssuerPassword(password []byte) Option {
return func(a *Authority) (err error) {
a.issuerPassword = password
return
}
}
// WithDatabase sets an already initialized authority database to a new
// authority. This option is intended to be use on graceful reloads.
func WithDatabase(d db.AuthDB) Option {
return func(a *Authority) error {
a.db = d
return nil
}
}
// WithGetIdentityFunc sets a custom function to retrieve the identity from
// an external resource.
func WithGetIdentityFunc(fn func(ctx context.Context, p provisioner.Interface, email string) (*provisioner.Identity, error)) Option {
return func(a *Authority) error {
a.getIdentityFunc = fn
return nil
}
}
// WithAuthorizeRenewFunc sets a custom function that authorizes the renewal of
// an X.509 certificate.
func WithAuthorizeRenewFunc(fn func(ctx context.Context, p *provisioner.Controller, cert *x509.Certificate) error) Option {
return func(a *Authority) error {
a.authorizeRenewFunc = fn
return nil
}
}
// WithAuthorizeSSHRenewFunc sets a custom function that authorizes the renewal
// of a SSH certificate.
func WithAuthorizeSSHRenewFunc(fn func(ctx context.Context, p *provisioner.Controller, cert *ssh.Certificate) error) Option {
return func(a *Authority) error {
a.authorizeSSHRenewFunc = fn
return nil
}
}
// WithSSHBastionFunc sets a custom function to get the bastion for a
// given user-host pair.
func WithSSHBastionFunc(fn func(ctx context.Context, user, host string) (*config.Bastion, error)) Option {
return func(a *Authority) error {
a.sshBastionFunc = fn
return nil
}
}
// WithSSHGetHosts sets a custom function to return a list of step ssh enabled
// hosts.
func WithSSHGetHosts(fn func(ctx context.Context, cert *x509.Certificate) ([]config.Host, error)) Option {
return func(a *Authority) error {
a.sshGetHostsFunc = fn
return nil
}
}
// WithSSHCheckHost sets a custom function to check whether a given host is
// step ssh enabled. The token is used to validate the request, while the roots
// are used to validate the token.
func WithSSHCheckHost(fn func(ctx context.Context, principal string, tok string, roots []*x509.Certificate) (bool, error)) Option {
return func(a *Authority) error {
a.sshCheckHostFunc = fn
return nil
}
}
// WithKeyManager defines the key manager used to get and create keys, and sign
// certificates.
func WithKeyManager(k kms.KeyManager) Option {
return func(a *Authority) error {
a.keyManager = k
return nil
}
}
// WithX509Signer defines the signer used to sign X509 certificates.
func WithX509Signer(crt *x509.Certificate, s crypto.Signer) Option {
return WithX509SignerChain([]*x509.Certificate{crt}, s)
}
// WithX509SignerChain defines the signer used to sign X509 certificates. This
// option is similar to WithX509Signer but it supports a chain of intermediates.
func WithX509SignerChain(issuerChain []*x509.Certificate, s crypto.Signer) Option {
return func(a *Authority) error {
srv, err := cas.New(context.Background(), casapi.Options{
Type: casapi.SoftCAS,
Signer: s,
CertificateChain: issuerChain,
})
if err != nil {
return err
}
a.x509CAService = srv
a.intermediateX509Certs = append(a.intermediateX509Certs, issuerChain...)
return nil
}
}
// WithX509SignerFunc defines the function used to get the chain of certificates
// and signer used when we sign X.509 certificates.
func WithX509SignerFunc(fn func() ([]*x509.Certificate, crypto.Signer, error)) Option {
return func(a *Authority) error {
srv, err := cas.New(context.Background(), casapi.Options{
Type: casapi.SoftCAS,
CertificateSigner: fn,
})
if err != nil {
return err
}
a.x509CAService = srv
return nil
}
}
// WithSSHUserSigner defines the signer used to sign SSH user certificates.
func WithSSHUserSigner(s crypto.Signer) Option {
return func(a *Authority) error {
signer, err := ssh.NewSignerFromSigner(s)
if err != nil {
return errors.Wrap(err, "error creating ssh user signer")
}
a.sshCAUserCertSignKey = signer
// Append public key to list of user certs
pub := signer.PublicKey()
a.sshCAUserCerts = append(a.sshCAUserCerts, pub)
a.sshCAUserFederatedCerts = append(a.sshCAUserFederatedCerts, pub)
return nil
}
}
// WithSSHHostSigner defines the signer used to sign SSH host certificates.
func WithSSHHostSigner(s crypto.Signer) Option {
return func(a *Authority) error {
signer, err := ssh.NewSignerFromSigner(s)
if err != nil {
return errors.Wrap(err, "error creating ssh host signer")
}
a.sshCAHostCertSignKey = signer
// Append public key to list of host certs
pub := signer.PublicKey()
a.sshCAHostCerts = append(a.sshCAHostCerts, pub)
a.sshCAHostFederatedCerts = append(a.sshCAHostFederatedCerts, pub)
return nil
}
}
// WithX509RootCerts is an option that allows to define the list of root
// certificates to use. This option will replace any root certificate defined
// before.
func WithX509RootCerts(rootCerts ...*x509.Certificate) Option {
return func(a *Authority) error {
a.rootX509Certs = rootCerts
return nil
}
}
// WithX509FederatedCerts is an option that allows to define the list of
// federated certificates. This option will replace any federated certificate
// defined before.
func WithX509FederatedCerts(certs ...*x509.Certificate) Option {
return func(a *Authority) error {
a.federatedX509Certs = certs
return nil
}
}
// WithX509RootCerts is an option that allows to define the list of intermediate
// certificates that the CA will be using. This option will replace any
// intermediate certificate defined before.
//
// Note that these certificates will not be bundled with the certificates signed
// by the CA, the CAS service will take care of that, although they should
// match, this is not guaranteed. These certificates will be mainly used for
// constraint purposes.
//
// This option should only used on specific configurations, for example when
// WithX509SignerFunc is used, as we don't know the list of intermediates on
// advance.
func WithX509IntermediateCerts(intermediateCerts ...*x509.Certificate) Option {
return func(a *Authority) error {
a.intermediateX509Certs = intermediateCerts
return nil
}
}
// WithX509RootBundle is an option that allows to define the list of root
// certificates. This option will replace any root certificate defined before.
func WithX509RootBundle(pemCerts []byte) Option {
return func(a *Authority) error {
certs, err := readCertificateBundle(pemCerts)
if err != nil {
return err
}
a.rootX509Certs = certs
return nil
}
}
// WithX509FederatedBundle is an option that allows to define the list of
// federated certificates. This option will replace any federated certificate
// defined before.
func WithX509FederatedBundle(pemCerts []byte) Option {
return func(a *Authority) error {
certs, err := readCertificateBundle(pemCerts)
if err != nil {
return err
}
a.federatedX509Certs = certs
return nil
}
}
// WithAdminDB is an option to set the database backing the admin APIs.
func WithAdminDB(d admin.DB) Option {
return func(a *Authority) error {
a.adminDB = d
return nil
}
}
// WithProvisioners is an option to set the provisioner collection.
//
// Deprecated: provisioner collections will likely change
func WithProvisioners(ps *provisioner.Collection) Option {
return func(a *Authority) error {
a.provisioners = ps
return nil
}
}
// WithLinkedCAToken is an option to set the authentication token used to enable
// linked ca.
func WithLinkedCAToken(token string) Option {
return func(a *Authority) error {
a.linkedCAToken = token
return nil
}
}
// WithX509Enforcers is an option that allows to define custom certificate
// modifiers that will be processed just before the signing of the certificate.
func WithX509Enforcers(ces ...provisioner.CertificateEnforcer) Option {
return func(a *Authority) error {
a.x509Enforcers = ces
return nil
}
}
// WithSkipInit is an option that allows the constructor to skip initializtion
// of the authority.
func WithSkipInit() Option {
return func(a *Authority) error {
a.skipInit = true
return nil
}
}
func readCertificateBundle(pemCerts []byte) ([]*x509.Certificate, error) {
var block *pem.Block
var certs []*x509.Certificate
for len(pemCerts) > 0 {
block, pemCerts = pem.Decode(pemCerts)
if block == nil {
break
}
if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
continue
}
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
return nil, err
}
certs = append(certs, cert)
}
return certs, nil
}