smallstep-certificates/api/api.go
2024-02-08 14:10:48 +01:00

593 lines
18 KiB
Go

package api
import (
"bytes"
"context"
"crypto"
"crypto/dsa" //nolint:staticcheck // support legacy algorithms
"crypto/ecdsa"
"crypto/ed25519"
"crypto/rsa"
"crypto/x509"
"encoding/asn1"
"encoding/base64"
"encoding/json"
"encoding/pem"
"fmt"
"net/http"
"strconv"
"strings"
"time"
"github.com/go-chi/chi/v5"
"github.com/pkg/errors"
"go.step.sm/crypto/sshutil"
"golang.org/x/crypto/ssh"
"github.com/smallstep/certificates/api/log"
"github.com/smallstep/certificates/api/models"
"github.com/smallstep/certificates/api/render"
"github.com/smallstep/certificates/authority"
"github.com/smallstep/certificates/authority/config"
"github.com/smallstep/certificates/authority/provisioner"
"github.com/smallstep/certificates/errs"
"github.com/smallstep/certificates/logging"
)
// Authority is the interface implemented by a CA authority.
type Authority interface {
SSHAuthority
// context specifies the Authorize[Sign|Revoke|etc.] method.
Authorize(ctx context.Context, ott string) ([]provisioner.SignOption, error)
AuthorizeRenewToken(ctx context.Context, ott string) (*x509.Certificate, error)
GetTLSOptions() *config.TLSOptions
Root(shasum string) (*x509.Certificate, error)
Sign(cr *x509.CertificateRequest, opts provisioner.SignOptions, signOpts ...provisioner.SignOption) ([]*x509.Certificate, error)
Renew(peer *x509.Certificate) ([]*x509.Certificate, error)
RenewContext(ctx context.Context, peer *x509.Certificate, pk crypto.PublicKey) ([]*x509.Certificate, error)
Rekey(peer *x509.Certificate, pk crypto.PublicKey) ([]*x509.Certificate, error)
LoadProvisionerByCertificate(*x509.Certificate) (provisioner.Interface, error)
LoadProvisionerByName(string) (provisioner.Interface, error)
GetProvisioners(cursor string, limit int) (provisioner.List, string, error)
Revoke(context.Context, *authority.RevokeOptions) error
GetEncryptedKey(kid string) (string, error)
GetRoots() ([]*x509.Certificate, error)
GetFederation() ([]*x509.Certificate, error)
Version() authority.Version
GetCertificateRevocationList() (*authority.CertificateRevocationListInfo, error)
}
// mustAuthority will be replaced on unit tests.
var mustAuthority = func(ctx context.Context) Authority {
return authority.MustFromContext(ctx)
}
// TimeDuration is an alias of provisioner.TimeDuration
type TimeDuration = provisioner.TimeDuration
// NewTimeDuration returns a TimeDuration with the defined time.
func NewTimeDuration(t time.Time) TimeDuration {
return provisioner.NewTimeDuration(t)
}
// ParseTimeDuration returns a new TimeDuration parsing the RFC 3339 time or
// time.Duration string.
func ParseTimeDuration(s string) (TimeDuration, error) {
return provisioner.ParseTimeDuration(s)
}
// Certificate wraps a *x509.Certificate and adds the json.Marshaler interface.
type Certificate struct {
*x509.Certificate
}
// NewCertificate is a helper method that returns a Certificate from a
// *x509.Certificate.
func NewCertificate(cr *x509.Certificate) Certificate {
return Certificate{
Certificate: cr,
}
}
// reset sets the inner x509.CertificateRequest to nil
func (c *Certificate) reset() {
if c != nil {
c.Certificate = nil
}
}
// MarshalJSON implements the json.Marshaler interface. The certificate is
// quoted string using the PEM encoding.
func (c Certificate) MarshalJSON() ([]byte, error) {
if c.Certificate == nil {
return []byte("null"), nil
}
block := pem.EncodeToMemory(&pem.Block{
Type: "CERTIFICATE",
Bytes: c.Raw,
})
return json.Marshal(string(block))
}
// UnmarshalJSON implements the json.Unmarshaler interface. The certificate is
// expected to be a quoted string using the PEM encoding.
func (c *Certificate) UnmarshalJSON(data []byte) error {
var s string
if err := json.Unmarshal(data, &s); err != nil {
return errors.Wrap(err, "error decoding certificate")
}
// Make sure the inner x509.Certificate is nil
if s == "null" || s == "" {
c.reset()
return nil
}
block, _ := pem.Decode([]byte(s))
if block == nil {
return errors.New("error decoding certificate")
}
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
return errors.Wrap(err, "error decoding certificate")
}
c.Certificate = cert
return nil
}
// CertificateRequest wraps a *x509.CertificateRequest and adds the
// json.Unmarshaler interface.
type CertificateRequest struct {
*x509.CertificateRequest
}
// NewCertificateRequest is a helper method that returns a CertificateRequest
// from a *x509.CertificateRequest.
func NewCertificateRequest(cr *x509.CertificateRequest) CertificateRequest {
return CertificateRequest{
CertificateRequest: cr,
}
}
// reset sets the inner x509.CertificateRequest to nil
func (c *CertificateRequest) reset() {
if c != nil {
c.CertificateRequest = nil
}
}
// MarshalJSON implements the json.Marshaler interface. The certificate request
// is a quoted string using the PEM encoding.
func (c CertificateRequest) MarshalJSON() ([]byte, error) {
if c.CertificateRequest == nil {
return []byte("null"), nil
}
block := pem.EncodeToMemory(&pem.Block{
Type: "CERTIFICATE REQUEST",
Bytes: c.Raw,
})
return json.Marshal(string(block))
}
// UnmarshalJSON implements the json.Unmarshaler interface. The certificate
// request is expected to be a quoted string using the PEM encoding.
func (c *CertificateRequest) UnmarshalJSON(data []byte) error {
var s string
if err := json.Unmarshal(data, &s); err != nil {
return errors.Wrap(err, "error decoding csr")
}
// Make sure the inner x509.CertificateRequest is nil
if s == "null" || s == "" {
c.reset()
return nil
}
block, _ := pem.Decode([]byte(s))
if block == nil {
return errors.New("error decoding csr")
}
cr, err := x509.ParseCertificateRequest(block.Bytes)
if err != nil {
return errors.Wrap(err, "error decoding csr")
}
c.CertificateRequest = cr
return nil
}
// Router defines a common router interface.
type Router interface {
// MethodFunc adds routes for `pattern` that matches
// the `method` HTTP method.
MethodFunc(method, pattern string, h http.HandlerFunc)
}
// RouterHandler is the interface that a HTTP handler that manages multiple
// endpoints will implement.
type RouterHandler interface {
Route(r Router)
}
// VersionResponse is the response object that returns the version of the
// server.
type VersionResponse struct {
Version string `json:"version"`
RequireClientAuthentication bool `json:"requireClientAuthentication,omitempty"`
}
// HealthResponse is the response object that returns the health of the server.
type HealthResponse struct {
Status string `json:"status"`
}
// RootResponse is the response object that returns the PEM of a root certificate.
type RootResponse struct {
RootPEM Certificate `json:"ca"`
}
// ProvisionersResponse is the response object that returns the list of
// provisioners.
type ProvisionersResponse struct {
Provisioners provisioner.List
NextCursor string
}
const redacted = "*** REDACTED ***"
func scepFromProvisioner(p *provisioner.SCEP) *models.SCEP {
return &models.SCEP{
ID: p.ID,
Type: p.Type,
Name: p.Name,
ForceCN: p.ForceCN,
ChallengePassword: redacted,
Capabilities: p.Capabilities,
IncludeRoot: p.IncludeRoot,
ExcludeIntermediate: p.ExcludeIntermediate,
MinimumPublicKeyLength: p.MinimumPublicKeyLength,
DecrypterCertificate: []byte(redacted),
DecrypterKeyPEM: []byte(redacted),
DecrypterKeyURI: redacted,
DecrypterKeyPassword: redacted,
EncryptionAlgorithmIdentifier: p.EncryptionAlgorithmIdentifier,
Options: p.Options,
Claims: p.Claims,
}
}
// MarshalJSON implements json.Marshaler. It marshals the ProvisionersResponse
// into a byte slice.
//
// Special treatment is given to the SCEP provisioner, as it contains a
// challenge secret that MUST NOT be leaked in (public) HTTP responses. The
// challenge value is thus redacted in HTTP responses.
func (p ProvisionersResponse) MarshalJSON() ([]byte, error) {
var responseProvisioners provisioner.List
for _, item := range p.Provisioners {
scepProv, ok := item.(*provisioner.SCEP)
if !ok {
responseProvisioners = append(responseProvisioners, item)
continue
}
responseProvisioners = append(responseProvisioners, scepFromProvisioner(scepProv))
}
var list = struct {
Provisioners []provisioner.Interface `json:"provisioners"`
NextCursor string `json:"nextCursor"`
}{
Provisioners: []provisioner.Interface(responseProvisioners),
NextCursor: p.NextCursor,
}
return json.Marshal(list)
}
// ProvisionerKeyResponse is the response object that returns the encrypted key
// of a provisioner.
type ProvisionerKeyResponse struct {
Key string `json:"key"`
}
// RootsResponse is the response object of the roots request.
type RootsResponse struct {
Certificates []Certificate `json:"crts"`
}
// FederationResponse is the response object of the federation request.
type FederationResponse struct {
Certificates []Certificate `json:"crts"`
}
// caHandler is the type used to implement the different CA HTTP endpoints.
type caHandler struct {
Authority Authority
}
// Route configures the http request router.
func (h *caHandler) Route(r Router) {
Route(r)
}
// New creates a new RouterHandler with the CA endpoints.
//
// Deprecated: Use api.Route(r Router)
func New(Authority) RouterHandler {
return &caHandler{}
}
func Route(r Router) {
r.MethodFunc("GET", "/version", Version)
r.MethodFunc("GET", "/health", Health)
r.MethodFunc("GET", "/root/{sha}", Root)
r.MethodFunc("POST", "/sign", Sign)
r.MethodFunc("POST", "/renew", Renew)
r.MethodFunc("POST", "/rekey", Rekey)
r.MethodFunc("POST", "/revoke", Revoke)
r.MethodFunc("GET", "/crl", CRL)
r.MethodFunc("GET", "/provisioners", Provisioners)
r.MethodFunc("GET", "/provisioners/{kid}/encrypted-key", ProvisionerKey)
r.MethodFunc("GET", "/roots", Roots)
r.MethodFunc("GET", "/roots.pem", RootsPEM)
r.MethodFunc("GET", "/federation", Federation)
// SSH CA
r.MethodFunc("POST", "/ssh/sign", SSHSign)
r.MethodFunc("POST", "/ssh/renew", SSHRenew)
r.MethodFunc("POST", "/ssh/revoke", SSHRevoke)
r.MethodFunc("POST", "/ssh/rekey", SSHRekey)
r.MethodFunc("GET", "/ssh/roots", SSHRoots)
r.MethodFunc("GET", "/ssh/federation", SSHFederation)
r.MethodFunc("POST", "/ssh/config", SSHConfig)
r.MethodFunc("POST", "/ssh/config/{type}", SSHConfig)
r.MethodFunc("POST", "/ssh/check-host", SSHCheckHost)
r.MethodFunc("GET", "/ssh/hosts", SSHGetHosts)
r.MethodFunc("POST", "/ssh/bastion", SSHBastion)
// For compatibility with old code:
r.MethodFunc("POST", "/re-sign", Renew)
r.MethodFunc("POST", "/sign-ssh", SSHSign)
r.MethodFunc("GET", "/ssh/get-hosts", SSHGetHosts)
}
// Version is an HTTP handler that returns the version of the server.
func Version(w http.ResponseWriter, r *http.Request) {
v := mustAuthority(r.Context()).Version()
render.JSON(w, VersionResponse{
Version: v.Version,
RequireClientAuthentication: v.RequireClientAuthentication,
})
}
// Health is an HTTP handler that returns the status of the server.
func Health(w http.ResponseWriter, _ *http.Request) {
render.JSON(w, HealthResponse{Status: "ok"})
}
// Root is an HTTP handler that using the SHA256 from the URL, returns the root
// certificate for the given SHA256.
func Root(w http.ResponseWriter, r *http.Request) {
sha := chi.URLParam(r, "sha")
sum := strings.ToLower(strings.ReplaceAll(sha, "-", ""))
// Load root certificate with the
cert, err := mustAuthority(r.Context()).Root(sum)
if err != nil {
render.Error(w, errs.Wrapf(http.StatusNotFound, err, "%s was not found", r.RequestURI))
return
}
render.JSON(w, &RootResponse{RootPEM: Certificate{cert}})
}
func certChainToPEM(certChain []*x509.Certificate) []Certificate {
certChainPEM := make([]Certificate, 0, len(certChain))
for _, c := range certChain {
certChainPEM = append(certChainPEM, Certificate{c})
}
return certChainPEM
}
// Provisioners returns the list of provisioners configured in the authority.
func Provisioners(w http.ResponseWriter, r *http.Request) {
cursor, limit, err := ParseCursor(r)
if err != nil {
render.Error(w, err)
return
}
p, next, err := mustAuthority(r.Context()).GetProvisioners(cursor, limit)
if err != nil {
render.Error(w, errs.InternalServerErr(err))
return
}
render.JSON(w, &ProvisionersResponse{
Provisioners: p,
NextCursor: next,
})
}
// ProvisionerKey returns the encrypted key of a provisioner by it's key id.
func ProvisionerKey(w http.ResponseWriter, r *http.Request) {
kid := chi.URLParam(r, "kid")
key, err := mustAuthority(r.Context()).GetEncryptedKey(kid)
if err != nil {
render.Error(w, errs.NotFoundErr(err))
return
}
render.JSON(w, &ProvisionerKeyResponse{key})
}
// Roots returns all the root certificates for the CA.
func Roots(w http.ResponseWriter, r *http.Request) {
roots, err := mustAuthority(r.Context()).GetRoots()
if err != nil {
render.Error(w, errs.ForbiddenErr(err, "error getting roots"))
return
}
certs := make([]Certificate, len(roots))
for i := range roots {
certs[i] = Certificate{roots[i]}
}
render.JSONStatus(w, &RootsResponse{
Certificates: certs,
}, http.StatusCreated)
}
// RootsPEM returns all the root certificates for the CA in PEM format.
func RootsPEM(w http.ResponseWriter, r *http.Request) {
roots, err := mustAuthority(r.Context()).GetRoots()
if err != nil {
render.Error(w, errs.InternalServerErr(err))
return
}
w.Header().Set("Content-Type", "application/x-pem-file")
for _, root := range roots {
block := pem.EncodeToMemory(&pem.Block{
Type: "CERTIFICATE",
Bytes: root.Raw,
})
if _, err := w.Write(block); err != nil {
log.Error(w, err)
return
}
}
}
// Federation returns all the public certificates in the federation.
func Federation(w http.ResponseWriter, r *http.Request) {
federated, err := mustAuthority(r.Context()).GetFederation()
if err != nil {
render.Error(w, errs.ForbiddenErr(err, "error getting federated roots"))
return
}
certs := make([]Certificate, len(federated))
for i := range federated {
certs[i] = Certificate{federated[i]}
}
render.JSONStatus(w, &FederationResponse{
Certificates: certs,
}, http.StatusCreated)
}
var oidStepProvisioner = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 37476, 9000, 64, 1}
type stepProvisioner struct {
Type int
Name []byte
CredentialID []byte
}
func logOtt(w http.ResponseWriter, token string) {
if rl, ok := w.(logging.ResponseLogger); ok {
rl.WithFields(map[string]interface{}{
"ott": token,
})
}
}
// LogCertificate adds certificate fields to the log message.
func LogCertificate(w http.ResponseWriter, cert *x509.Certificate) {
if rl, ok := w.(logging.ResponseLogger); ok {
m := map[string]interface{}{
"serial": cert.SerialNumber.String(),
"subject": cert.Subject.CommonName,
"issuer": cert.Issuer.CommonName,
"valid-from": cert.NotBefore.Format(time.RFC3339),
"valid-to": cert.NotAfter.Format(time.RFC3339),
"public-key": fmtPublicKey(cert),
"certificate": base64.StdEncoding.EncodeToString(cert.Raw),
}
for _, ext := range cert.Extensions {
if !ext.Id.Equal(oidStepProvisioner) {
continue
}
val := &stepProvisioner{}
rest, err := asn1.Unmarshal(ext.Value, val)
if err != nil || len(rest) > 0 {
break
}
if len(val.CredentialID) > 0 {
m["provisioner"] = fmt.Sprintf("%s (%s)", val.Name, val.CredentialID)
} else {
m["provisioner"] = string(val.Name)
}
break
}
rl.WithFields(m)
}
}
// LogSSHCertificate adds SSH certificate fields to the log message.
func LogSSHCertificate(w http.ResponseWriter, cert *ssh.Certificate) {
if rl, ok := w.(logging.ResponseLogger); ok {
mak := bytes.TrimSpace(ssh.MarshalAuthorizedKey(cert))
var certificate string
parts := strings.Split(string(mak), " ")
if len(parts) > 1 {
certificate = parts[1]
}
var userOrHost string
if cert.CertType == ssh.HostCert {
userOrHost = "host"
} else {
userOrHost = "user"
}
certificateType := fmt.Sprintf("%s %s certificate", parts[0], userOrHost) // e.g. ecdsa-sha2-nistp256-cert-v01@openssh.com user certificate
m := map[string]interface{}{
"serial": cert.Serial,
"principals": cert.ValidPrincipals,
"valid-from": time.Unix(int64(cert.ValidAfter), 0).Format(time.RFC3339),
"valid-to": time.Unix(int64(cert.ValidBefore), 0).Format(time.RFC3339),
"certificate": certificate,
"certificate-type": certificateType,
}
fingerprint, err := sshutil.FormatFingerprint(mak, sshutil.DefaultFingerprint)
if err == nil {
fpParts := strings.Split(fingerprint, " ")
if len(fpParts) > 3 {
m["public-key"] = fmt.Sprintf("%s %s", fpParts[1], fpParts[len(fpParts)-1])
}
}
rl.WithFields(m)
}
}
// ParseCursor parses the cursor and limit from the request query params.
func ParseCursor(r *http.Request) (cursor string, limit int, err error) {
q := r.URL.Query()
cursor = q.Get("cursor")
if v := q.Get("limit"); len(v) > 0 {
limit, err = strconv.Atoi(v)
if err != nil {
return "", 0, errs.BadRequestErr(err, "limit '%s' is not an integer", v)
}
}
return
}
func fmtPublicKey(cert *x509.Certificate) string {
var params string
switch pk := cert.PublicKey.(type) {
case *ecdsa.PublicKey:
params = pk.Curve.Params().Name
case *rsa.PublicKey:
params = strconv.Itoa(pk.Size() * 8)
case ed25519.PublicKey:
return cert.PublicKeyAlgorithm.String()
case *dsa.PublicKey:
params = strconv.Itoa(pk.Q.BitLen() * 8)
default:
params = "unknown"
}
return fmt.Sprintf("%s %s", cert.PublicKeyAlgorithm, params)
}