certificates/authority/authority.go
Mariano Cano 4e544344f9 Initialize the required config fields on embedded authorities.
This change is to make easier the use of embedded authorities. It
can be difficult for third parties to know what fields are required.
The new init methods will define the minimum usable configuration.
2020-05-06 13:00:42 -07:00

331 lines
9.3 KiB
Go

package authority
import (
"context"
"crypto"
"crypto/sha256"
"crypto/x509"
"encoding/hex"
"sync"
"time"
"github.com/pkg/errors"
"github.com/smallstep/certificates/authority/provisioner"
"github.com/smallstep/certificates/db"
"github.com/smallstep/certificates/kms"
kmsapi "github.com/smallstep/certificates/kms/apiv1"
"github.com/smallstep/certificates/sshutil"
"github.com/smallstep/certificates/templates"
"github.com/smallstep/cli/crypto/pemutil"
"golang.org/x/crypto/ssh"
)
const (
legacyAuthority = "step-certificate-authority"
)
// Authority implements the Certificate Authority internal interface.
type Authority struct {
config *Config
keyManager kms.KeyManager
provisioners *provisioner.Collection
db db.AuthDB
// X509 CA
rootX509Certs []*x509.Certificate
federatedX509Certs []*x509.Certificate
x509Signer crypto.Signer
x509Issuer *x509.Certificate
certificates *sync.Map
// SSH CA
sshCAUserCertSignKey ssh.Signer
sshCAHostCertSignKey ssh.Signer
sshCAUserCerts []ssh.PublicKey
sshCAHostCerts []ssh.PublicKey
sshCAUserFederatedCerts []ssh.PublicKey
sshCAHostFederatedCerts []ssh.PublicKey
// Do not re-initialize
initOnce bool
startTime time.Time
// Custom functions
sshBastionFunc func(ctx context.Context, user, hostname string) (*Bastion, error)
sshCheckHostFunc func(ctx context.Context, principal string, tok string, roots []*x509.Certificate) (bool, error)
sshGetHostsFunc func(ctx context.Context, cert *x509.Certificate) ([]sshutil.Host, error)
getIdentityFunc provisioner.GetIdentityFunc
}
// New creates and initiates a new Authority type.
func New(config *Config, opts ...Option) (*Authority, error) {
err := config.Validate()
if err != nil {
return nil, err
}
var a = &Authority{
config: config,
certificates: new(sync.Map),
}
// Apply options.
for _, fn := range opts {
if err := fn(a); err != nil {
return nil, err
}
}
// Initialize authority from options or configuration.
if err := a.init(); err != nil {
return nil, err
}
return a, nil
}
// NewEmbedded initializes an authority that can be embedded in a different
// project without the limitations of the config.
func NewEmbedded(opts ...Option) (*Authority, error) {
a := &Authority{
config: &Config{},
certificates: new(sync.Map),
}
// Apply options.
for _, fn := range opts {
if err := fn(a); err != nil {
return nil, err
}
}
// Validate required options
switch {
case a.config == nil:
return nil, errors.New("cannot create an authority without a configuration")
case len(a.rootX509Certs) == 0 && a.config.Root.HasEmpties():
return nil, errors.New("cannot create an authority without a root certificate")
case a.x509Issuer == nil && a.config.IntermediateCert == "":
return nil, errors.New("cannot create an authority without an issuer certificate")
case a.x509Signer == nil && a.config.IntermediateKey == "":
return nil, errors.New("cannot create an authority without an issuer signer")
}
// Initialize config required fields.
a.config.init()
// Initialize authority from options or configuration.
if err := a.init(); err != nil {
return nil, err
}
return a, nil
}
// init performs validation and initializes the fields of an Authority struct.
func (a *Authority) init() error {
// Check if handler has already been validated/initialized.
if a.initOnce {
return nil
}
var err error
// Initialize key manager if it has not been set in the options.
if a.keyManager == nil {
var options kmsapi.Options
if a.config.KMS != nil {
options = *a.config.KMS
}
a.keyManager, err = kms.New(context.Background(), options)
if err != nil {
return err
}
}
// Initialize step-ca Database if it's not already initialized with WithDB.
// If a.config.DB is nil then a simple, barebones in memory DB will be used.
if a.db == nil {
if a.db, err = db.New(a.config.DB); err != nil {
return err
}
}
// Read root certificates and store them in the certificates map.
if len(a.rootX509Certs) == 0 {
a.rootX509Certs = make([]*x509.Certificate, len(a.config.Root))
for i, path := range a.config.Root {
crt, err := pemutil.ReadCertificate(path)
if err != nil {
return err
}
a.rootX509Certs[i] = crt
}
}
for _, crt := range a.rootX509Certs {
sum := sha256.Sum256(crt.Raw)
a.certificates.Store(hex.EncodeToString(sum[:]), crt)
}
// Read federated certificates and store them in the certificates map.
if len(a.federatedX509Certs) == 0 {
a.federatedX509Certs = make([]*x509.Certificate, len(a.config.FederatedRoots))
for i, path := range a.config.FederatedRoots {
crt, err := pemutil.ReadCertificate(path)
if err != nil {
return err
}
a.federatedX509Certs[i] = crt
}
}
for _, crt := range a.federatedX509Certs {
sum := sha256.Sum256(crt.Raw)
a.certificates.Store(hex.EncodeToString(sum[:]), crt)
}
// Read intermediate and create X509 signer.
if a.x509Signer == nil {
crt, err := pemutil.ReadCertificate(a.config.IntermediateCert)
if err != nil {
return err
}
signer, err := a.keyManager.CreateSigner(&kmsapi.CreateSignerRequest{
SigningKey: a.config.IntermediateKey,
Password: []byte(a.config.Password),
})
if err != nil {
return err
}
a.x509Signer = signer
a.x509Issuer = crt
}
// Decrypt and load SSH keys
if a.config.SSH != nil {
if a.config.SSH.HostKey != "" {
signer, err := a.keyManager.CreateSigner(&kmsapi.CreateSignerRequest{
SigningKey: a.config.SSH.HostKey,
Password: []byte(a.config.Password),
})
if err != nil {
return err
}
a.sshCAHostCertSignKey, err = ssh.NewSignerFromSigner(signer)
if err != nil {
return errors.Wrap(err, "error creating ssh signer")
}
// Append public key to list of host certs
a.sshCAHostCerts = append(a.sshCAHostCerts, a.sshCAHostCertSignKey.PublicKey())
a.sshCAHostFederatedCerts = append(a.sshCAHostFederatedCerts, a.sshCAHostCertSignKey.PublicKey())
}
if a.config.SSH.UserKey != "" {
signer, err := a.keyManager.CreateSigner(&kmsapi.CreateSignerRequest{
SigningKey: a.config.SSH.UserKey,
Password: []byte(a.config.Password),
})
if err != nil {
return err
}
a.sshCAUserCertSignKey, err = ssh.NewSignerFromSigner(signer)
if err != nil {
return errors.Wrap(err, "error creating ssh signer")
}
// Append public key to list of user certs
a.sshCAUserCerts = append(a.sshCAUserCerts, a.sshCAUserCertSignKey.PublicKey())
a.sshCAUserFederatedCerts = append(a.sshCAUserFederatedCerts, a.sshCAUserCertSignKey.PublicKey())
}
// Append other public keys
for _, key := range a.config.SSH.Keys {
switch key.Type {
case provisioner.SSHHostCert:
if key.Federated {
a.sshCAHostFederatedCerts = append(a.sshCAHostFederatedCerts, key.PublicKey())
} else {
a.sshCAHostCerts = append(a.sshCAHostCerts, key.PublicKey())
}
case provisioner.SSHUserCert:
if key.Federated {
a.sshCAUserFederatedCerts = append(a.sshCAUserFederatedCerts, key.PublicKey())
} else {
a.sshCAUserCerts = append(a.sshCAUserCerts, key.PublicKey())
}
default:
return errors.Errorf("unsupported type %s", key.Type)
}
}
}
// Merge global and configuration claims
claimer, err := provisioner.NewClaimer(a.config.AuthorityConfig.Claims, globalProvisionerClaims)
if err != nil {
return err
}
// TODO: should we also be combining the ssh federated roots here?
// If we rotate ssh roots keys, sshpop provisioner will lose ability to
// validate old SSH certificates, unless they are added as federated certs.
sshKeys, err := a.GetSSHRoots(context.Background())
if err != nil {
return err
}
// Initialize provisioners
audiences := a.config.getAudiences()
a.provisioners = provisioner.NewCollection(audiences)
config := provisioner.Config{
Claims: claimer.Claims(),
Audiences: audiences,
DB: a.db,
SSHKeys: &provisioner.SSHKeys{
UserKeys: sshKeys.UserKeys,
HostKeys: sshKeys.HostKeys,
},
GetIdentityFunc: a.getIdentityFunc,
}
// Store all the provisioners
for _, p := range a.config.AuthorityConfig.Provisioners {
if err := p.Init(config); err != nil {
return err
}
if err := a.provisioners.Store(p); err != nil {
return err
}
}
// Configure protected template variables:
if t := a.config.Templates; t != nil {
if t.Data == nil {
t.Data = make(map[string]interface{})
}
var vars templates.Step
if a.config.SSH != nil {
if a.sshCAHostCertSignKey != nil {
vars.SSH.HostKey = a.sshCAHostCertSignKey.PublicKey()
vars.SSH.HostFederatedKeys = append(vars.SSH.HostFederatedKeys, a.sshCAHostFederatedCerts[1:]...)
}
if a.sshCAUserCertSignKey != nil {
vars.SSH.UserKey = a.sshCAUserCertSignKey.PublicKey()
vars.SSH.UserFederatedKeys = append(vars.SSH.UserFederatedKeys, a.sshCAUserFederatedCerts[1:]...)
}
}
t.Data["Step"] = vars
}
// JWT numeric dates are seconds.
a.startTime = time.Now().Truncate(time.Second)
// Set flag indicating that initialization has been completed, and should
// not be repeated.
a.initOnce = true
return nil
}
// GetDatabase returns the authority database. If the configuration does not
// define a database, GetDatabase will return a db.SimpleDB instance.
func (a *Authority) GetDatabase() db.AuthDB {
return a.db
}
// Shutdown safely shuts down any clients, databases, etc. held by the Authority.
func (a *Authority) Shutdown() error {
return a.db.Shutdown()
}