Files
fleet/ee/server/service/est/est.go
T

136 lines
4.0 KiB
Go

package est
import (
"context"
"encoding/base64"
"io"
"net/http"
"net/url"
"os"
"strings"
"time"
"github.com/fleetdm/fleet/v4/pkg/fleethttp"
"github.com/fleetdm/fleet/v4/server/contexts/ctxerr"
"github.com/fleetdm/fleet/v4/server/fleet"
kitlog "github.com/go-kit/log"
)
// defaultTimeout is the timeout for requests.
const defaultTimeout = 20 * time.Second
type Service struct {
logger kitlog.Logger
timeout time.Duration
client *http.Client
}
// Compile-time check for ESTService interface
var _ fleet.ESTService = (*Service)(nil)
func NewService(opts ...Opt) fleet.ESTService {
s := &Service{}
s.populateOpts(opts)
s.client = fleethttp.NewClient(fleethttp.WithTimeout(s.timeout))
return s
}
// Opt is the type for EST integration options.
type Opt func(*Service)
// WithTimeout sets the timeout to use for the HTTP client.
func WithTimeout(t time.Duration) Opt {
return func(s *Service) {
s.timeout = t
}
}
// WithLogger sets the logger to use for the service.
func WithLogger(logger kitlog.Logger) Opt {
return func(s *Service) {
s.logger = logger
}
}
func (s *Service) populateOpts(opts []Opt) {
for _, opt := range opts {
opt(s)
}
if s.timeout <= 0 {
s.timeout = defaultTimeout
}
if s.logger == nil {
s.logger = kitlog.NewLogfmtLogger(kitlog.NewSyncWriter(os.Stdout))
}
}
func (s *Service) ValidateESTURL(ctx context.Context, estCA fleet.ESTProxyCA) error {
reqURL := estCA.URL + "/cacerts"
req, err := http.NewRequestWithContext(ctx, "GET", reqURL, nil)
if err != nil {
return ctxerr.Wrap(ctx, err, "creating EST CA request")
}
resp, err := s.client.Do(req)
if err != nil {
return ctxerr.Wrap(ctx, err, "sending EST CA request")
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return ctxerr.Errorf(ctx, "unexpected EST CA status code: %d", resp.StatusCode)
}
contentType := resp.Header.Get("Content-Type")
if !strings.HasPrefix(contentType, "application/pkcs7-mime") {
return ctxerr.Errorf(ctx, "unexpected EST CA content type: %s", contentType)
}
// For now we are just verifying that there is a body of the reportedly correct format. We could
// possibly do more. A better implementation would be similar to Digicert's which validates the
// credentials in addition to the URL but I don't see a way to do that with Hydrant's API.
caCerts, err := io.ReadAll(resp.Body)
if err != nil {
return ctxerr.Wrap(ctx, err, "reading EST CA response body")
}
if len(caCerts) == 0 {
return ctxerr.Errorf(ctx, "no CA certificates found in EST CA /cacerts response. URL may be incorrect")
}
return nil
}
func (s *Service) GetCertificate(ctx context.Context, estCA fleet.ESTProxyCA, csr string) (*fleet.ESTCertificate, error) {
reqURL, err := url.Parse(estCA.URL + "/simpleenroll")
if err != nil {
return nil, ctxerr.Wrap(ctx, err, "parsing EST CA URL")
}
apiCredential := estCA.Username + ":" + estCA.Password
encodedCredential := base64.StdEncoding.EncodeToString([]byte(apiCredential))
estRequest, err := http.NewRequestWithContext(ctx, "POST", reqURL.String(), strings.NewReader(csr))
if err != nil {
return nil, ctxerr.Wrap(ctx, err, "creating EST CA request")
}
estRequest.Header.Set("Content-Type", "application/pkcs10")
estRequest.Header.Set("Accept", "application/pkcs7-mime")
estRequest.Header.Set("Authorization", "Basic "+encodedCredential)
resp, err := s.client.Do(estRequest)
if err != nil {
return nil, ctxerr.Wrap(ctx, err, "sending EST CA request")
}
defer resp.Body.Close()
bytes, err := io.ReadAll(resp.Body)
if err != nil {
return nil, ctxerr.Wrap(ctx, err, "reading EST CA response body")
}
if resp.StatusCode != http.StatusOK {
bytesToLog := bytes
// Limit logged data in case we get a huge response(a certificate perhaps?)
if len(bytes) > 1000 {
bytesToLog = bytes[:1000]
}
s.logger.Log("msg", "unexpected EST CA status code", "status_code", resp.StatusCode, "response_body", string(bytesToLog))
return nil, ctxerr.Errorf(ctx, "unexpected EST CA status code: %d", resp.StatusCode)
}
return &fleet.ESTCertificate{
Certificate: bytes,
}, nil
}