certificates/api/api.go
max furman c74fcd57a7 ca-component -> certificates
* fix redundant error check
* add README
2018-10-31 21:36:01 -07:00

333 lines
9.5 KiB
Go

package api
import (
"crypto/tls"
"crypto/x509"
"encoding/json"
"encoding/pem"
"net/http"
"strconv"
"strings"
"time"
"github.com/go-chi/chi"
"github.com/pkg/errors"
"github.com/smallstep/certificates/authority"
"github.com/smallstep/cli/crypto/tlsutil"
)
// Authority is the interface implemented by a CA authority.
type Authority interface {
Authorize(ott string) ([]interface{}, error)
GetTLSOptions() *tlsutil.TLSOptions
Root(shasum string) (*x509.Certificate, error)
Sign(cr *x509.CertificateRequest, signOpts authority.SignOptions, extraOpts ...interface{}) (*x509.Certificate, *x509.Certificate, error)
Renew(cert *x509.Certificate) (*x509.Certificate, *x509.Certificate, error)
GetProvisioners(cursor string, limit int) ([]*authority.Provisioner, string, error)
GetEncryptedKey(kid string) (string, error)
}
// 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,
}
}
// 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")
}
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,
}
}
// 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")
}
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)
}
// 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"`
}
// SignRequest is the request body for a certificate signature request.
type SignRequest struct {
CsrPEM CertificateRequest `json:"csr"`
OTT string `json:"ott"`
NotAfter time.Time `json:"notAfter"`
NotBefore time.Time `json:"notBefore"`
}
// ProvisionersResponse is the response object that returns the list of
// provisioners.
type ProvisionersResponse struct {
Provisioners []*authority.Provisioner `json:"provisioners"`
NextCursor string `json:"nextCursor"`
}
// ProvisionerKeyResponse is the response object that returns the encryptoed key
// of a provisioner.
type ProvisionerKeyResponse struct {
Key string `json:"key"`
}
// Validate checks the fields of the SignRequest and returns nil if they are ok
// or an error if something is wrong.
func (s *SignRequest) Validate() error {
if s.CsrPEM.CertificateRequest == nil {
return BadRequest(errors.New("missing csr"))
}
if err := s.CsrPEM.CertificateRequest.CheckSignature(); err != nil {
return BadRequest(errors.Wrap(err, "invalid csr"))
}
if s.OTT == "" {
return BadRequest(errors.New("missing ott"))
}
return nil
}
// SignResponse is the response object of the certificate signature request.
type SignResponse struct {
ServerPEM Certificate `json:"crt"`
CaPEM Certificate `json:"ca"`
TLSOptions *tlsutil.TLSOptions `json:"tlsOptions,omitempty"`
TLS *tls.ConnectionState `json:"-"`
}
// caHandler is the type used to implement the different CA HTTP endpoints.
type caHandler struct {
Authority Authority
}
// New creates a new RouterHandler with the CA endpoints.
func New(authority Authority) RouterHandler {
return &caHandler{
Authority: authority,
}
}
func (h *caHandler) Route(r Router) {
r.MethodFunc("GET", "/health", h.Health)
r.MethodFunc("GET", "/root/{sha}", h.Root)
r.MethodFunc("POST", "/sign", h.Sign)
r.MethodFunc("POST", "/renew", h.Renew)
r.MethodFunc("GET", "/provisioners", h.Provisioners)
r.MethodFunc("GET", "/provisioners/{kid}/encrypted-key", h.ProvisionerKey)
// For compatibility with old code:
r.MethodFunc("POST", "/re-sign", h.Renew)
}
// Health is an HTTP handler that returns the status of the server.
func (h *caHandler) Health(w http.ResponseWriter, r *http.Request) {
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 (h *caHandler) Root(w http.ResponseWriter, r *http.Request) {
sha := chi.URLParam(r, "sha")
sum := strings.ToLower(strings.Replace(sha, "-", "", -1))
// Load root certificate with the
cert, err := h.Authority.Root(sum)
if err != nil {
WriteError(w, NotFound(errors.Wrapf(err, "%s was not found", r.RequestURI)))
return
}
JSON(w, &RootResponse{RootPEM: Certificate{cert}})
}
// Sign is an HTTP handler that reads a certificate request and an
// one-time-token (ott) from the body and creates a new certificate with the
// information in the certificate request.
func (h *caHandler) Sign(w http.ResponseWriter, r *http.Request) {
var body SignRequest
if err := ReadJSON(r.Body, &body); err != nil {
WriteError(w, BadRequest(errors.Wrap(err, "error reading request body")))
return
}
if err := body.Validate(); err != nil {
WriteError(w, err)
return
}
signOpts := authority.SignOptions{
NotBefore: body.NotBefore,
NotAfter: body.NotAfter,
}
extraOpts, err := h.Authority.Authorize(body.OTT)
if err != nil {
WriteError(w, Unauthorized(err))
return
}
cert, root, err := h.Authority.Sign(body.CsrPEM.CertificateRequest, signOpts, extraOpts...)
if err != nil {
WriteError(w, Forbidden(err))
return
}
w.WriteHeader(http.StatusCreated)
JSON(w, &SignResponse{
ServerPEM: Certificate{cert},
CaPEM: Certificate{root},
TLSOptions: h.Authority.GetTLSOptions(),
})
}
// Renew uses the information of certificate in the TLS connection to create a
// new one.
func (h *caHandler) Renew(w http.ResponseWriter, r *http.Request) {
if r.TLS == nil || len(r.TLS.PeerCertificates) == 0 {
WriteError(w, BadRequest(errors.New("missing peer certificate")))
return
}
cert, root, err := h.Authority.Renew(r.TLS.PeerCertificates[0])
if err != nil {
WriteError(w, Forbidden(err))
return
}
w.WriteHeader(http.StatusCreated)
JSON(w, &SignResponse{
ServerPEM: Certificate{cert},
CaPEM: Certificate{root},
TLSOptions: h.Authority.GetTLSOptions(),
})
}
// Provisioners returns the list of provisioners configured in the authority.
func (h *caHandler) Provisioners(w http.ResponseWriter, r *http.Request) {
cursor, limit, err := parseCursor(r)
if err != nil {
WriteError(w, BadRequest(err))
return
}
p, next, err := h.Authority.GetProvisioners(cursor, limit)
if err != nil {
WriteError(w, InternalServerError(err))
return
}
JSON(w, &ProvisionersResponse{
Provisioners: p,
NextCursor: next,
})
}
// ProvisionerKey returns the encrypted key of a provisioner by it's key id.
func (h *caHandler) ProvisionerKey(w http.ResponseWriter, r *http.Request) {
kid := chi.URLParam(r, "kid")
key, err := h.Authority.GetEncryptedKey(kid)
if err != nil {
WriteError(w, NotFound(err))
return
}
JSON(w, &ProvisionerKeyResponse{key})
}
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, errors.Wrapf(err, "error converting %s to integer", v)
}
}
return
}