certificates/authority/authorize.go
2019-03-06 18:32:56 -08:00

128 lines
3.8 KiB
Go

package authority
import (
"crypto/x509"
"net/http"
"net/url"
"time"
"github.com/pkg/errors"
"github.com/smallstep/certificates/authority/provisioner"
"github.com/smallstep/cli/jose"
)
type idUsed struct {
UsedAt int64 `json:"ua,omitempty"`
Subject string `json:"sub,omitempty"`
}
// Claims extends jose.Claims with step attributes.
type Claims struct {
jose.Claims
SANs []string `json:"sans,omitempty"`
Email string `json:"email,omitempty"`
Nonce string `json:"nonce,omitempty"`
}
// matchesAudience returns true if A and B share at least one element.
func matchesAudience(as, bs []string) bool {
if len(bs) == 0 || len(as) == 0 {
return false
}
for _, b := range bs {
for _, a := range as {
if b == a || stripPort(a) == stripPort(b) {
return true
}
}
}
return false
}
// stripPort attempts to strip the port from the given url. If parsing the url
// produces errors it will just return the passed argument.
func stripPort(rawurl string) string {
u, err := url.Parse(rawurl)
if err != nil {
return rawurl
}
u.Host = u.Hostname()
return u.String()
}
// Authorize authorizes a signature request by validating and authenticating
// a OTT that must be sent w/ the request.
// TODO(mariano): protection against reuse for oidc
func (a *Authority) Authorize(ott string) ([]provisioner.SignOption, error) {
var errContext = map[string]interface{}{"ott": ott}
// Validate payload
token, err := jose.ParseSigned(ott)
if err != nil {
return nil, &apiError{errors.Wrapf(err, "authorize: error parsing token"),
http.StatusUnauthorized, errContext}
}
// Get claims w/out verification. We need to look up the provisioner
// key in order to verify the claims and we need the issuer from the claims
// before we can look up the provisioner.
var claims Claims
if err = token.UnsafeClaimsWithoutVerification(&claims); err != nil {
return nil, &apiError{err, http.StatusUnauthorized, errContext}
}
// Do not accept tokens issued before the start of the ca.
// This check is meant as a stopgap solution to the current lack of a persistence layer.
if a.config.AuthorityConfig != nil && !a.config.AuthorityConfig.DisableIssuedAtCheck {
if claims.IssuedAt > 0 && claims.IssuedAt.Time().Before(a.startTime) {
return nil, &apiError{errors.New("token issued before the bootstrap of certificate authority"),
http.StatusUnauthorized, errContext}
}
}
// This method will also validate the audiences for JWK provisioners.
p, ok := a.provisioners.LoadByToken(token, &claims.Claims)
if !ok {
return nil, &apiError{errors.New("authorize: provisioner not found or invalid audience"),
http.StatusUnauthorized, errContext}
}
// Store the token to protect against reuse.
if p.GetType() == provisioner.TypeJWK && claims.ID != "" {
if _, ok := a.ottMap.LoadOrStore(claims.ID, &idUsed{
UsedAt: time.Now().Unix(),
Subject: claims.Subject,
}); ok {
return nil, &apiError{errors.Errorf("token already used"), http.StatusUnauthorized,
errContext}
}
}
return p.Authorize(ott)
}
// authorizeRenewal tries to locate the step provisioner extension, and checks
// if for the configured provisioner, the renewal is enabled or not. If the
// extra extension cannot be found, authorize the renewal by default.
//
// TODO(mariano): should we authorize by default?
func (a *Authority) authorizeRenewal(crt *x509.Certificate) error {
errContext := map[string]interface{}{"serialNumber": crt.SerialNumber.String()}
p, ok := a.provisioners.LoadByCertificate(crt)
if !ok {
return &apiError{
err: errors.New("provisioner not found"),
code: http.StatusUnauthorized,
context: errContext,
}
}
if err := p.AuthorizeRenewal(crt); err != nil {
return &apiError{
err: err,
code: http.StatusUnauthorized,
context: errContext,
}
}
return nil
}