certificates/authority/config/config.go
Mariano Cano 8200d19894
Improve CRL implementation
This commit adds some changes to PR #731, some of them are:
- Add distribution point to the CRL
- Properly stop the goroutine that generates the CRLs
- CRL config validation
- Remove expired certificates from the CRL
- Require enable set to true to generate a CRL

This last point is the principal change in behaviour from the previous
implementation. The CRL will not be generated if it's not enabled, and
if it is enabled it will always be regenerated at some point, not only
if there is a revocation.
2022-10-26 18:55:24 -07:00

400 lines
13 KiB
Go

package config
import (
"encoding/json"
"fmt"
"net"
"os"
"time"
"github.com/pkg/errors"
kms "go.step.sm/crypto/kms/apiv1"
"go.step.sm/linkedca"
"github.com/smallstep/certificates/authority/policy"
"github.com/smallstep/certificates/authority/provisioner"
cas "github.com/smallstep/certificates/cas/apiv1"
"github.com/smallstep/certificates/db"
"github.com/smallstep/certificates/templates"
)
const (
legacyAuthority = "step-certificate-authority"
)
var (
// DefaultBackdate length of time to backdate certificates to avoid
// clock skew validation issues.
DefaultBackdate = time.Minute
// DefaultDisableRenewal disables renewals per provisioner.
DefaultDisableRenewal = false
// DefaultAllowRenewalAfterExpiry allows renewals even if the certificate is
// expired.
DefaultAllowRenewalAfterExpiry = false
// DefaultEnableSSHCA enable SSH CA features per provisioner or globally
// for all provisioners.
DefaultEnableSSHCA = false
// DefaultCRLCacheDuration is the default cache duration for the CRL.
DefaultCRLCacheDuration = &provisioner.Duration{Duration: 24 * time.Hour}
// DefaultCRLExpiredDuration is the default duration in which expired
// certificates will remain in the CRL after expiration.
DefaultCRLExpiredDuration = time.Hour
// GlobalProvisionerClaims is the default duration that expired certificates
// remain in the CRL after expiration.
GlobalProvisionerClaims = provisioner.Claims{
MinTLSDur: &provisioner.Duration{Duration: 5 * time.Minute}, // TLS certs
MaxTLSDur: &provisioner.Duration{Duration: 24 * time.Hour},
DefaultTLSDur: &provisioner.Duration{Duration: 24 * time.Hour},
MinUserSSHDur: &provisioner.Duration{Duration: 5 * time.Minute}, // User SSH certs
MaxUserSSHDur: &provisioner.Duration{Duration: 24 * time.Hour},
DefaultUserSSHDur: &provisioner.Duration{Duration: 16 * time.Hour},
MinHostSSHDur: &provisioner.Duration{Duration: 5 * time.Minute}, // Host SSH certs
MaxHostSSHDur: &provisioner.Duration{Duration: 30 * 24 * time.Hour},
DefaultHostSSHDur: &provisioner.Duration{Duration: 30 * 24 * time.Hour},
EnableSSHCA: &DefaultEnableSSHCA,
DisableRenewal: &DefaultDisableRenewal,
AllowRenewalAfterExpiry: &DefaultAllowRenewalAfterExpiry,
}
)
// Config represents the CA configuration and it's mapped to a JSON object.
type Config struct {
Root multiString `json:"root"`
FederatedRoots []string `json:"federatedRoots"`
IntermediateCert string `json:"crt"`
IntermediateKey string `json:"key"`
Address string `json:"address"`
InsecureAddress string `json:"insecureAddress"`
DNSNames []string `json:"dnsNames"`
KMS *kms.Options `json:"kms,omitempty"`
SSH *SSHConfig `json:"ssh,omitempty"`
Logger json.RawMessage `json:"logger,omitempty"`
DB *db.Config `json:"db,omitempty"`
Monitoring json.RawMessage `json:"monitoring,omitempty"`
AuthorityConfig *AuthConfig `json:"authority,omitempty"`
TLS *TLSOptions `json:"tls,omitempty"`
Password string `json:"password,omitempty"`
Templates *templates.Templates `json:"templates,omitempty"`
CommonName string `json:"commonName,omitempty"`
CRL *CRLConfig `json:"crl,omitempty"`
SkipValidation bool `json:"-"`
}
// CRLConfig represents config options for CRL generation
type CRLConfig struct {
Enabled bool `json:"enabled"`
GenerateOnRevoke bool `json:"generateOnRevoke,omitempty"`
CacheDuration *provisioner.Duration `json:"cacheDuration,omitempty"`
RenewPeriod *provisioner.Duration `json:"renewPeriod,omitempty"`
}
// IsEnabled returns if the CRL is enabled.
func (c *CRLConfig) IsEnabled() bool {
return c != nil && c.Enabled
}
// Validate validates the CRL configuration.
func (c *CRLConfig) Validate() error {
if c == nil {
return nil
}
if c.CacheDuration != nil && c.CacheDuration.Duration < 0 {
return errors.New("crl.cacheDuration must be greater than or equal to 0")
}
if c.RenewPeriod != nil && c.RenewPeriod.Duration < 0 {
return errors.New("crl.renewPeriod must be greater than or equal to 0")
}
if c.RenewPeriod != nil && c.CacheDuration != nil &&
c.RenewPeriod.Duration > c.CacheDuration.Duration {
return errors.New("crl.cacheDuration must be greater than or equal to crl.renewPeriod")
}
return nil
}
// TickerDuration the renewal ticker duration. This is set by renewPeriod, of it
// is not set is ~2/3 of cacheDuration.
func (c *CRLConfig) TickerDuration() time.Duration {
if !c.IsEnabled() {
return 0
}
if c.RenewPeriod != nil && c.RenewPeriod.Duration > 0 {
return c.RenewPeriod.Duration
}
return (c.CacheDuration.Duration / 3) * 2
}
// ASN1DN contains ASN1.DN attributes that are used in Subject and Issuer
// x509 Certificate blocks.
type ASN1DN struct {
Country string `json:"country,omitempty"`
Organization string `json:"organization,omitempty"`
OrganizationalUnit string `json:"organizationalUnit,omitempty"`
Locality string `json:"locality,omitempty"`
Province string `json:"province,omitempty"`
StreetAddress string `json:"streetAddress,omitempty"`
SerialNumber string `json:"serialNumber,omitempty"`
CommonName string `json:"commonName,omitempty"`
}
// AuthConfig represents the configuration options for the authority. An
// underlaying registration authority can also be configured using the
// cas.Options.
type AuthConfig struct {
*cas.Options
AuthorityID string `json:"authorityId,omitempty"`
DeploymentType string `json:"deploymentType,omitempty"`
Provisioners provisioner.List `json:"provisioners,omitempty"`
Admins []*linkedca.Admin `json:"-"`
Template *ASN1DN `json:"template,omitempty"`
Claims *provisioner.Claims `json:"claims,omitempty"`
Policy *policy.Options `json:"policy,omitempty"`
DisableIssuedAtCheck bool `json:"disableIssuedAtCheck,omitempty"`
Backdate *provisioner.Duration `json:"backdate,omitempty"`
EnableAdmin bool `json:"enableAdmin,omitempty"`
DisableGetSSHHosts bool `json:"disableGetSSHHosts,omitempty"`
}
// init initializes the required fields in the AuthConfig if they are not
// provided.
func (c *AuthConfig) init() {
if c.Provisioners == nil {
c.Provisioners = provisioner.List{}
}
if c.Template == nil {
c.Template = &ASN1DN{}
}
if c.Backdate == nil {
c.Backdate = &provisioner.Duration{
Duration: DefaultBackdate,
}
}
}
// Validate validates the authority configuration.
func (c *AuthConfig) Validate(audiences provisioner.Audiences) error {
if c == nil {
return errors.New("authority cannot be undefined")
}
// Initialize required fields.
c.init()
// Check that only one K8sSA is enabled
var k8sCount int
for _, p := range c.Provisioners {
if p.GetType() == provisioner.TypeK8sSA {
k8sCount++
}
}
if k8sCount > 1 {
return errors.New("cannot have more than one kubernetes service account provisioner")
}
if c.Backdate.Duration < 0 {
return errors.New("authority.backdate cannot be less than 0")
}
return nil
}
// LoadConfiguration parses the given filename in JSON format and returns the
// configuration struct.
func LoadConfiguration(filename string) (*Config, error) {
f, err := os.Open(filename)
if err != nil {
return nil, errors.Wrapf(err, "error opening %s", filename)
}
defer f.Close()
var c Config
if err := json.NewDecoder(f).Decode(&c); err != nil {
return nil, errors.Wrapf(err, "error parsing %s", filename)
}
c.Init()
return &c, nil
}
// Init initializes the minimal configuration required to create an authority. This
// is mainly used on embedded authorities.
func (c *Config) Init() {
if c.DNSNames == nil {
c.DNSNames = []string{"localhost", "127.0.0.1", "::1"}
}
if c.TLS == nil {
c.TLS = &DefaultTLSOptions
}
if c.AuthorityConfig == nil {
c.AuthorityConfig = &AuthConfig{}
}
if c.CommonName == "" {
c.CommonName = "Step Online CA"
}
if c.CRL != nil && c.CRL.Enabled && c.CRL.CacheDuration == nil {
c.CRL.CacheDuration = DefaultCRLCacheDuration
}
c.AuthorityConfig.init()
}
// Save saves the configuration to the given filename.
func (c *Config) Save(filename string) error {
f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
return errors.Wrapf(err, "error opening %s", filename)
}
defer f.Close()
enc := json.NewEncoder(f)
enc.SetIndent("", "\t")
return errors.Wrapf(enc.Encode(c), "error writing %s", filename)
}
// Validate validates the configuration.
func (c *Config) Validate() error {
switch {
case c.SkipValidation:
return nil
case c.Address == "":
return errors.New("address cannot be empty")
case len(c.DNSNames) == 0:
return errors.New("dnsNames cannot be empty")
case c.AuthorityConfig == nil:
return errors.New("authority cannot be nil")
}
// Options holds the RA/CAS configuration.
ra := c.AuthorityConfig.Options
// The default RA/CAS requires root, crt and key.
if ra.Is(cas.SoftCAS) {
switch {
case c.Root.HasEmpties():
return errors.New("root cannot be empty")
case c.IntermediateCert == "":
return errors.New("crt cannot be empty")
case c.IntermediateKey == "":
return errors.New("key cannot be empty")
}
}
// Validate address (a port is required)
if _, _, err := net.SplitHostPort(c.Address); err != nil {
return errors.Errorf("invalid address %s", c.Address)
}
if c.TLS == nil {
c.TLS = &DefaultTLSOptions
} else {
if len(c.TLS.CipherSuites) == 0 {
c.TLS.CipherSuites = DefaultTLSOptions.CipherSuites
}
if c.TLS.MaxVersion == 0 {
c.TLS.MaxVersion = DefaultTLSOptions.MaxVersion
}
if c.TLS.MinVersion == 0 {
c.TLS.MinVersion = DefaultTLSOptions.MinVersion
}
if c.TLS.MinVersion > c.TLS.MaxVersion {
return errors.New("tls minVersion cannot exceed tls maxVersion")
}
c.TLS.Renegotiation = c.TLS.Renegotiation || DefaultTLSOptions.Renegotiation
}
// Validate KMS options, nil is ok.
if err := c.KMS.Validate(); err != nil {
return err
}
// Validate RA/CAS options, nil is ok.
if err := ra.Validate(); err != nil {
return err
}
// Validate ssh: nil is ok
if err := c.SSH.Validate(); err != nil {
return err
}
// Validate templates: nil is ok
if err := c.Templates.Validate(); err != nil {
return err
}
// Validate crl config: nil is ok
if err := c.CRL.Validate(); err != nil {
return err
}
return c.AuthorityConfig.Validate(c.GetAudiences())
}
// GetAudiences returns the legacy and possible urls without the ports that will
// be used as the default provisioner audiences. The CA might have proxies in
// front so we cannot rely on the port.
func (c *Config) GetAudiences() provisioner.Audiences {
audiences := provisioner.Audiences{
Sign: []string{legacyAuthority},
Revoke: []string{legacyAuthority},
SSHSign: []string{},
SSHRevoke: []string{},
SSHRenew: []string{},
}
for _, name := range c.DNSNames {
hostname := toHostname(name)
audiences.Sign = append(audiences.Sign,
fmt.Sprintf("https://%s/1.0/sign", hostname),
fmt.Sprintf("https://%s/sign", hostname),
fmt.Sprintf("https://%s/1.0/ssh/sign", hostname),
fmt.Sprintf("https://%s/ssh/sign", hostname))
audiences.Renew = append(audiences.Renew,
fmt.Sprintf("https://%s/1.0/renew", hostname),
fmt.Sprintf("https://%s/renew", hostname))
audiences.Revoke = append(audiences.Revoke,
fmt.Sprintf("https://%s/1.0/revoke", hostname),
fmt.Sprintf("https://%s/revoke", hostname))
audiences.SSHSign = append(audiences.SSHSign,
fmt.Sprintf("https://%s/1.0/ssh/sign", hostname),
fmt.Sprintf("https://%s/ssh/sign", hostname),
fmt.Sprintf("https://%s/1.0/sign", hostname),
fmt.Sprintf("https://%s/sign", hostname))
audiences.SSHRevoke = append(audiences.SSHRevoke,
fmt.Sprintf("https://%s/1.0/ssh/revoke", hostname),
fmt.Sprintf("https://%s/ssh/revoke", hostname))
audiences.SSHRenew = append(audiences.SSHRenew,
fmt.Sprintf("https://%s/1.0/ssh/renew", hostname),
fmt.Sprintf("https://%s/ssh/renew", hostname))
audiences.SSHRekey = append(audiences.SSHRekey,
fmt.Sprintf("https://%s/1.0/ssh/rekey", hostname),
fmt.Sprintf("https://%s/ssh/rekey", hostname))
}
return audiences
}
// Audience returns the list of audiences for a given path.
func (c *Config) Audience(path string) []string {
audiences := make([]string, len(c.DNSNames)+1)
for i, name := range c.DNSNames {
hostname := toHostname(name)
audiences[i] = "https://" + hostname + path
}
// For backward compatibility
audiences[len(c.DNSNames)] = path
return audiences
}
func toHostname(name string) string {
// ensure an IPv6 address is represented with square brackets when used as hostname
if ip := net.ParseIP(name); ip != nil && ip.To4() == nil {
name = "[" + name + "]"
}
return name
}