certificates/pki/pki.go
2020-01-28 13:28:16 -08:00

529 lines
15 KiB
Go

package pki
import (
"crypto"
"crypto/sha256"
"crypto/x509"
"encoding/hex"
"encoding/json"
"encoding/pem"
"fmt"
"html"
"net"
"os"
"path/filepath"
"strconv"
"strings"
"github.com/pkg/errors"
"github.com/smallstep/certificates/authority"
"github.com/smallstep/certificates/authority/provisioner"
"github.com/smallstep/certificates/ca"
"github.com/smallstep/certificates/db"
"github.com/smallstep/cli/config"
"github.com/smallstep/cli/crypto/keys"
"github.com/smallstep/cli/crypto/pemutil"
"github.com/smallstep/cli/crypto/tlsutil"
"github.com/smallstep/cli/crypto/x509util"
"github.com/smallstep/cli/errs"
"github.com/smallstep/cli/jose"
"github.com/smallstep/cli/ui"
"github.com/smallstep/cli/utils"
"golang.org/x/crypto/ssh"
)
const (
// ConfigPath is the directory name under the step path where the configuration
// files will be stored.
configPath = "config"
// PublicPath is the directory name under the step path where the public keys
// will be stored.
publicPath = "certs"
// PublicPath is the directory name under the step path where the private keys
// will be stored.
privatePath = "secrets"
// DBPath is the directory name under the step path where the private keys
// will be stored.
dbPath = "db"
// templatesPath is the directory to store templates
templatesPath = "templates"
)
// GetDBPath returns the path where the file-system persistence is stored
// based on the STEPPATH environment variable.
func GetDBPath() string {
return filepath.Join(config.StepPath(), dbPath)
}
// GetConfigPath returns the directory where the configuration files are stored
// based on the STEPPATH environment variable.
func GetConfigPath() string {
return filepath.Join(config.StepPath(), configPath)
}
// GetPublicPath returns the directory where the public keys are stored based on
// the STEPPATH environment variable.
func GetPublicPath() string {
return filepath.Join(config.StepPath(), publicPath)
}
// GetSecretsPath returns the directory where the private keys are stored based
// on the STEPPATH environment variable.
func GetSecretsPath() string {
return filepath.Join(config.StepPath(), privatePath)
}
// GetRootCAPath returns the path where the root CA is stored based on the
// STEPPATH environment variable.
func GetRootCAPath() string {
return filepath.Join(config.StepPath(), publicPath, "root_ca.crt")
}
// GetOTTKeyPath returns the path where the one-time token key is stored based
// on the STEPPATH environment variable.
func GetOTTKeyPath() string {
return filepath.Join(config.StepPath(), privatePath, "ott_key")
}
// GetTemplatesPath returns the path where the templates are stored.
func GetTemplatesPath() string {
return filepath.Join(config.StepPath(), templatesPath)
}
// GetProvisioners returns the map of provisioners on the given CA.
func GetProvisioners(caURL, rootFile string) (provisioner.List, error) {
if len(rootFile) == 0 {
rootFile = GetRootCAPath()
}
client, err := ca.NewClient(caURL, ca.WithRootFile(rootFile))
if err != nil {
return nil, err
}
cursor := ""
provisioners := provisioner.List{}
for {
resp, err := client.Provisioners(ca.WithProvisionerCursor(cursor), ca.WithProvisionerLimit(100))
if err != nil {
return nil, err
}
provisioners = append(provisioners, resp.Provisioners...)
if resp.NextCursor == "" {
return provisioners, nil
}
cursor = resp.NextCursor
}
}
// GetProvisionerKey returns the encrypted provisioner key with the for the
// given kid.
func GetProvisionerKey(caURL, rootFile, kid string) (string, error) {
if len(rootFile) == 0 {
rootFile = GetRootCAPath()
}
client, err := ca.NewClient(caURL, ca.WithRootFile(rootFile))
if err != nil {
return "", err
}
resp, err := client.ProvisionerKey(kid)
if err != nil {
return "", err
}
return resp.Key, nil
}
// PKI represents the Public Key Infrastructure used by a certificate authority.
type PKI struct {
root, rootKey, rootFingerprint string
intermediate, intermediateKey string
sshHostPubKey, sshHostKey string
sshUserPubKey, sshUserKey string
config, defaults string
ottPublicKey *jose.JSONWebKey
ottPrivateKey *jose.JSONWebEncryption
provisioner string
address string
dnsNames []string
caURL string
enableSSH bool
}
// New creates a new PKI configuration.
func New() (*PKI, error) {
public := GetPublicPath()
private := GetSecretsPath()
config := GetConfigPath()
// Create directories
dirs := []string{public, private, config, GetTemplatesPath()}
for _, name := range dirs {
if _, err := os.Stat(name); os.IsNotExist(err) {
if err = os.MkdirAll(name, 0700); err != nil {
return nil, errs.FileError(err, name)
}
}
}
// get absolute path for dir/name
getPath := func(dir string, name string) (string, error) {
s, err := filepath.Abs(filepath.Join(dir, name))
return s, errors.Wrapf(err, "error getting absolute path for %s", name)
}
var err error
p := &PKI{
provisioner: "step-cli",
address: "127.0.0.1:9000",
dnsNames: []string{"127.0.0.1"},
}
if p.root, err = getPath(public, "root_ca.crt"); err != nil {
return nil, err
}
if p.rootKey, err = getPath(private, "root_ca_key"); err != nil {
return nil, err
}
if p.intermediate, err = getPath(public, "intermediate_ca.crt"); err != nil {
return nil, err
}
if p.intermediateKey, err = getPath(private, "intermediate_ca_key"); err != nil {
return nil, err
}
if p.sshHostPubKey, err = getPath(public, "ssh_host_ca_key.pub"); err != nil {
return nil, err
}
if p.sshUserPubKey, err = getPath(public, "ssh_user_ca_key.pub"); err != nil {
return nil, err
}
if p.sshHostKey, err = getPath(private, "ssh_host_ca_key"); err != nil {
return nil, err
}
if p.sshUserKey, err = getPath(private, "ssh_user_ca_key"); err != nil {
return nil, err
}
if len(config) > 0 {
if p.config, err = getPath(config, "ca.json"); err != nil {
return nil, err
}
if p.defaults, err = getPath(config, "defaults.json"); err != nil {
return nil, err
}
}
return p, nil
}
// GetCAConfigPath returns the path of the CA configuration file.
func (p *PKI) GetCAConfigPath() string {
return p.config
}
// GetRootFingerprint returns the root fingerprint.
func (p *PKI) GetRootFingerprint() string {
return p.rootFingerprint
}
// SetProvisioner sets the provisioner name of the OTT keys.
func (p *PKI) SetProvisioner(s string) {
p.provisioner = s
}
// SetAddress sets the listening address of the CA.
func (p *PKI) SetAddress(s string) {
p.address = s
}
// SetDNSNames sets the dns names of the CA.
func (p *PKI) SetDNSNames(s []string) {
p.dnsNames = s
}
// SetCAURL sets the ca-url to use in the defaults.json.
func (p *PKI) SetCAURL(s string) {
p.caURL = s
}
// GenerateKeyPairs generates the key pairs used by the certificate authority.
func (p *PKI) GenerateKeyPairs(pass []byte) error {
var err error
// Create OTT key pair, the user doesn't need to know about this.
p.ottPublicKey, p.ottPrivateKey, err = jose.GenerateDefaultKeyPair(pass)
if err != nil {
return err
}
return nil
}
// GenerateRootCertificate generates a root certificate with the given name.
func (p *PKI) GenerateRootCertificate(name string, pass []byte) (*x509.Certificate, interface{}, error) {
rootProfile, err := x509util.NewRootProfile(name)
if err != nil {
return nil, nil, err
}
rootBytes, err := rootProfile.CreateWriteCertificate(p.root, p.rootKey, string(pass))
if err != nil {
return nil, nil, err
}
rootCrt, err := x509.ParseCertificate(rootBytes)
if err != nil {
return nil, nil, errors.Wrap(err, "error parsing root certificate")
}
sum := sha256.Sum256(rootCrt.Raw)
p.rootFingerprint = strings.ToLower(hex.EncodeToString(sum[:]))
return rootCrt, rootProfile.SubjectPrivateKey(), nil
}
// WriteRootCertificate writes to disk the given certificate and key.
func (p *PKI) WriteRootCertificate(rootCrt *x509.Certificate, rootKey interface{}, pass []byte) error {
if err := utils.WriteFile(p.root, pem.EncodeToMemory(&pem.Block{
Type: "CERTIFICATE",
Bytes: rootCrt.Raw,
}), 0600); err != nil {
return err
}
_, err := pemutil.Serialize(rootKey, pemutil.WithPassword([]byte(pass)), pemutil.ToFile(p.rootKey, 0600))
if err != nil {
return err
}
return nil
}
// GenerateIntermediateCertificate generates an intermediate certificate with
// the given name.
func (p *PKI) GenerateIntermediateCertificate(name string, rootCrt *x509.Certificate, rootKey interface{}, pass []byte) error {
interProfile, err := x509util.NewIntermediateProfile(name, rootCrt, rootKey)
if err != nil {
return err
}
_, err = interProfile.CreateWriteCertificate(p.intermediate, p.intermediateKey, string(pass))
return err
}
// GenerateSSHSigningKeys generates and encrypts a private key used for signing
// SSH user certificates and a private key used for signing host certificates.
func (p *PKI) GenerateSSHSigningKeys(password []byte) error {
var pubNames = []string{p.sshHostPubKey, p.sshUserPubKey}
var privNames = []string{p.sshHostKey, p.sshUserKey}
for i := 0; i < 2; i++ {
pub, priv, err := keys.GenerateDefaultKeyPair()
if err != nil {
return err
}
if _, ok := priv.(crypto.Signer); !ok {
return errors.Errorf("key of type %T is not a crypto.Signer", priv)
}
sshKey, err := ssh.NewPublicKey(pub)
if err != nil {
return errors.Wrapf(err, "error converting public key")
}
_, err = pemutil.Serialize(priv, pemutil.WithFilename(privNames[i]), pemutil.WithPassword(password))
if err != nil {
return err
}
if err = utils.WriteFile(pubNames[i], ssh.MarshalAuthorizedKey(sshKey), 0600); err != nil {
return err
}
}
p.enableSSH = true
return nil
}
func (p *PKI) askFeedback() {
ui.Println()
ui.Printf("\033[1mFEEDBACK\033[0m %s %s\n",
html.UnescapeString("&#"+strconv.Itoa(128525)+";"),
html.UnescapeString("&#"+strconv.Itoa(127867)+";"))
ui.Println(" The \033[1mstep\033[0m utility is not instrumented for usage statistics. It does not")
ui.Println(" phone home. But your feedback is extremely valuable. Any information you")
ui.Println(" can provide regarding how you’re using `step` helps. Please send us a")
ui.Println(" sentence or two, good or bad: \033[1mfeedback@smallstep.com\033[0m or join")
ui.Println(" \033[1mhttps://gitter.im/smallstep/community\033[0m.")
}
// TellPKI outputs the locations of public and private keys generated
// generated for a new PKI. Generally this will consist of a root certificate
// and key and an intermediate certificate and key.
func (p *PKI) TellPKI() {
p.tellPKI()
p.askFeedback()
}
func (p *PKI) tellPKI() {
ui.Println()
ui.PrintSelected("Root certificate", p.root)
ui.PrintSelected("Root private key", p.rootKey)
ui.PrintSelected("Root fingerprint", p.rootFingerprint)
ui.PrintSelected("Intermediate certificate", p.intermediate)
ui.PrintSelected("Intermediate private key", p.intermediateKey)
if p.enableSSH {
ui.PrintSelected("SSH user root certificate", p.sshUserPubKey)
ui.PrintSelected("SSH user root private key", p.sshUserKey)
ui.PrintSelected("SSH host root certificate", p.sshHostPubKey)
ui.PrintSelected("SSH host root private key", p.sshHostKey)
}
}
type caDefaults struct {
CAUrl string `json:"ca-url"`
CAConfig string `json:"ca-config"`
Fingerprint string `json:"fingerprint"`
Root string `json:"root"`
}
// Option is the type for modifiers over the auth config object.
type Option func(c *authority.Config) error
// WithDefaultDB is a configuration modifier that adds a default DB stanza to
// the authority config.
func WithDefaultDB() Option {
return func(c *authority.Config) error {
c.DB = &db.Config{
Type: "badger",
DataSource: GetDBPath(),
}
return nil
}
}
// WithoutDB is a configuration modifier that adds a default DB stanza to
// the authority config.
func WithoutDB() Option {
return func(c *authority.Config) error {
c.DB = nil
return nil
}
}
// GenerateConfig returns the step certificates configuration.
func (p *PKI) GenerateConfig(opt ...Option) (*authority.Config, error) {
key, err := p.ottPrivateKey.CompactSerialize()
if err != nil {
return nil, errors.Wrap(err, "error serializing private key")
}
prov := &provisioner.JWK{
Name: p.provisioner,
Type: "JWK",
Key: p.ottPublicKey,
EncryptedKey: key,
}
config := &authority.Config{
Root: []string{p.root},
FederatedRoots: []string{},
IntermediateCert: p.intermediate,
IntermediateKey: p.intermediateKey,
Address: p.address,
DNSNames: p.dnsNames,
Logger: []byte(`{"format": "text"}`),
DB: &db.Config{
Type: "badger",
DataSource: GetDBPath(),
},
AuthorityConfig: &authority.AuthConfig{
DisableIssuedAtCheck: false,
Provisioners: provisioner.List{prov},
},
TLS: &tlsutil.TLSOptions{
MinVersion: x509util.DefaultTLSMinVersion,
MaxVersion: x509util.DefaultTLSMaxVersion,
Renegotiation: x509util.DefaultTLSRenegotiation,
CipherSuites: x509util.DefaultTLSCipherSuites,
},
Templates: p.getTemplates(),
}
if p.enableSSH {
enableSSHCA := true
config.SSH = &authority.SSHConfig{
HostKey: p.sshHostKey,
UserKey: p.sshUserKey,
}
prov.Claims = &provisioner.Claims{
EnableSSHCA: &enableSSHCA,
}
}
// Apply configuration modifiers
for _, o := range opt {
if err = o(config); err != nil {
return nil, err
}
}
return config, nil
}
// Save stores the pki on a json file that will be used as the certificate
// authority configuration.
func (p *PKI) Save(opt ...Option) error {
p.tellPKI()
// Generate and write ca.json
config, err := p.GenerateConfig(opt...)
if err != nil {
return err
}
b, err := json.MarshalIndent(config, "", " ")
if err != nil {
return errors.Wrapf(err, "error marshaling %s", p.config)
}
if err = utils.WriteFile(p.config, b, 0644); err != nil {
return errs.FileError(err, p.config)
}
// Generate the CA URL.
if p.caURL == "" {
p.caURL = p.dnsNames[0]
var port string
_, port, err = net.SplitHostPort(p.address)
if err != nil {
return errors.Wrapf(err, "error parsing %s", p.address)
}
if port == "443" {
p.caURL = fmt.Sprintf("https://%s", p.caURL)
} else {
p.caURL = fmt.Sprintf("https://%s:%s", p.caURL, port)
}
}
// Generate and write defaults.json
defaults := &caDefaults{
Root: p.root,
CAConfig: p.config,
CAUrl: p.caURL,
Fingerprint: p.rootFingerprint,
}
b, err = json.MarshalIndent(defaults, "", " ")
if err != nil {
return errors.Wrapf(err, "error marshaling %s", p.defaults)
}
if err = utils.WriteFile(p.defaults, b, 0644); err != nil {
return errs.FileError(err, p.defaults)
}
// Generate and write templates
if err := generateTemplates(config.Templates); err != nil {
return err
}
if config.DB != nil {
ui.PrintSelected("Database folder", config.DB.DataSource)
}
if config.Templates != nil {
ui.PrintSelected("Templates folder", GetTemplatesPath())
}
ui.PrintSelected("Default configuration", p.defaults)
ui.PrintSelected("Certificate Authority configuration", p.config)
ui.Println()
ui.Println("Your PKI is ready to go. To generate certificates for individual services see 'step help ca'.")
p.askFeedback()
return nil
}