Beispiel #1
0
// ProblemDetailsForError turns an error into a ProblemDetails with the special
// case of returning the same error back if its already a ProblemDetails. If the
// error is of an type unknown to ProblemDetailsForError, it will return a
// ServerInternal ProblemDetails.
func ProblemDetailsForError(err error, msg string) *probs.ProblemDetails {
	switch e := err.(type) {
	case *probs.ProblemDetails:
		return e
	case MalformedRequestError:
		return probs.Malformed(fmt.Sprintf("%s :: %s", msg, err))
	case NotSupportedError:
		return &probs.ProblemDetails{
			Type:       probs.ServerInternalProblem,
			Detail:     fmt.Sprintf("%s :: %s", msg, err),
			HTTPStatus: http.StatusNotImplemented,
		}
	case UnauthorizedError:
		return probs.Unauthorized(fmt.Sprintf("%s :: %s", msg, err))
	case NotFoundError:
		return probs.NotFound(fmt.Sprintf("%s :: %s", msg, err))
	case LengthRequiredError:
		prob := probs.Malformed("missing Content-Length header")
		prob.HTTPStatus = http.StatusLengthRequired
		return prob
	case SignatureValidationError:
		return probs.Malformed(fmt.Sprintf("%s :: %s", msg, err))
	case RateLimitedError:
		return probs.RateLimited(fmt.Sprintf("%s :: %s", msg, err))
	case BadNonceError:
		return probs.BadNonce(fmt.Sprintf("%s :: %s", msg, err))
	default:
		// Internal server error messages may include sensitive data, so we do
		// not include it.
		return probs.ServerInternal(msg)
	}
}
Beispiel #2
0
// verifyPOST reads and parses the request body, looks up the Registration
// corresponding to its JWK, verifies the JWS signature, checks that the
// resource field is present and correct in the JWS protected header, and
// returns the JWS payload bytes, the key used to verify, and the corresponding
// Registration (or error).  If regCheck is false, verifyPOST will still try to
// look up a registration object, and will return it if found. However, if no
// registration object is found, verifyPOST will attempt to verify the JWS using
// the key in the JWS headers, and return the key plus a dummy registration if
// successful. If a caller passes regCheck = false, it should plan on validating
// the key itself.  verifyPOST also appends its errors to requestEvent.Errors so
// code calling it does not need to if they immediately return a response to the
// user.
func (wfe *WebFrontEndImpl) verifyPOST(logEvent *requestEvent, request *http.Request, regCheck bool, resource core.AcmeResource) ([]byte, *jose.JsonWebKey, core.Registration, *probs.ProblemDetails) {
	// TODO: We should return a pointer to a registration, which can be nil,
	// rather the a registration value with a sentinel value.
	// https://github.com/letsencrypt/boulder/issues/877
	reg := core.Registration{ID: 0}

	if _, ok := request.Header["Content-Length"]; !ok {
		wfe.stats.Inc("WFE.HTTP.ClientErrors.LengthRequiredError", 1, 1.0)
		logEvent.AddError("missing Content-Length header on POST")
		return nil, nil, reg, probs.ContentLengthRequired()
	}

	// Read body
	if request.Body == nil {
		wfe.stats.Inc("WFE.Errors.NoPOSTBody", 1, 1.0)
		logEvent.AddError("no body on POST")
		return nil, nil, reg, probs.Malformed("No body on POST")
	}

	bodyBytes, err := ioutil.ReadAll(request.Body)
	if err != nil {
		wfe.stats.Inc("WFE.Errors.UnableToReadRequestBody", 1, 1.0)
		logEvent.AddError("unable to read request body")
		return nil, nil, reg, probs.ServerInternal("unable to read request body")
	}

	body := string(bodyBytes)
	// Parse as JWS
	parsedJws, err := jose.ParseSigned(body)
	if err != nil {
		wfe.stats.Inc("WFE.Errors.UnableToParseJWS", 1, 1.0)
		logEvent.AddError("could not JSON parse body into JWS: %s", err)
		return nil, nil, reg, probs.Malformed("Parse error reading JWS")
	}

	// Verify JWS
	// NOTE: It might seem insecure for the WFE to be trusted to verify
	// client requests, i.e., that the verification should be done at the
	// RA.  However the WFE is the RA's only view of the outside world
	// *anyway*, so it could always lie about what key was used by faking
	// the signature itself.
	if len(parsedJws.Signatures) > 1 {
		wfe.stats.Inc("WFE.Errors.TooManyJWSSignaturesInPOST", 1, 1.0)
		logEvent.AddError("too many signatures in POST body: %d", len(parsedJws.Signatures))
		return nil, nil, reg, probs.Malformed("Too many signatures in POST body")
	}
	if len(parsedJws.Signatures) == 0 {
		wfe.stats.Inc("WFE.Errors.JWSNotSignedInPOST", 1, 1.0)
		logEvent.AddError("no signatures in POST body")
		return nil, nil, reg, probs.Malformed("POST JWS not signed")
	}

	submittedKey := parsedJws.Signatures[0].Header.JsonWebKey
	if submittedKey == nil {
		wfe.stats.Inc("WFE.Errors.NoJWKInJWSSignatureHeader", 1, 1.0)
		logEvent.AddError("no JWK in JWS signature header in POST body")
		return nil, nil, reg, probs.Malformed("No JWK in JWS header")
	}

	var key *jose.JsonWebKey
	reg, err = wfe.SA.GetRegistrationByKey(*submittedKey)
	// Special case: If no registration was found, but regCheck is false, use an
	// empty registration and the submitted key. The caller is expected to do some
	// validation on the returned key.
	if _, ok := err.(core.NoSuchRegistrationError); ok && !regCheck {
		// When looking up keys from the registrations DB, we can be confident they
		// are "good". But when we are verifying against any submitted key, we want
		// to check its quality before doing the verify.
		if err = wfe.keyPolicy.GoodKey(submittedKey.Key); err != nil {
			wfe.stats.Inc("WFE.Errors.JWKRejectedByGoodKey", 1, 1.0)
			logEvent.AddError("JWK in request was rejected by GoodKey: %s", err)
			return nil, nil, reg, probs.Malformed(err.Error())
		}
		key = submittedKey
	} else if err != nil {
		// For all other errors, or if regCheck is true, return error immediately.
		wfe.stats.Inc("WFE.Errors.UnableToGetRegistrationByKey", 1, 1.0)
		logEvent.AddError("unable to fetch registration by the given JWK: %s", err)
		if _, ok := err.(core.NoSuchRegistrationError); ok {
			return nil, nil, reg, probs.Unauthorized(unknownKey)
		}

		return nil, nil, reg, core.ProblemDetailsForError(err, "")
	} else {
		// If the lookup was successful, use that key.
		key = &reg.Key
		logEvent.Requester = reg.ID
		logEvent.Contacts = reg.Contact
	}

	if statName, err := checkAlgorithm(key, parsedJws); err != nil {
		wfe.stats.Inc(statName, 1, 1.0)
		return nil, nil, reg, probs.Malformed(err.Error())
	}

	payload, err := parsedJws.Verify(key)
	if err != nil {
		wfe.stats.Inc("WFE.Errors.JWSVerificationFailed", 1, 1.0)
		n := len(body)
		if n > 100 {
			n = 100
		}
		logEvent.AddError("verification of JWS with the JWK failed: %v; body: %s", err, body[:n])
		return nil, nil, reg, probs.Malformed("JWS verification error")
	}

	// Check that the request has a known anti-replay nonce
	nonce := parsedJws.Signatures[0].Header.Nonce
	logEvent.RequestNonce = nonce
	if len(nonce) == 0 {
		wfe.stats.Inc("WFE.Errors.JWSMissingNonce", 1, 1.0)
		logEvent.AddError("JWS is missing an anti-replay nonce")
		return nil, nil, reg, probs.BadNonce("JWS has no anti-replay nonce")
	} else if !wfe.nonceService.Valid(nonce) {
		wfe.stats.Inc("WFE.Errors.JWSInvalidNonce", 1, 1.0)
		logEvent.AddError("JWS has an invalid anti-replay nonce: %s", nonce)
		return nil, nil, reg, probs.BadNonce(fmt.Sprintf("JWS has invalid anti-replay nonce %v", nonce))
	}

	// Check that the "resource" field is present and has the correct value
	var parsedRequest struct {
		Resource string `json:"resource"`
	}
	err = json.Unmarshal([]byte(payload), &parsedRequest)
	if err != nil {
		wfe.stats.Inc("WFE.Errors.UnparsableJWSPayload", 1, 1.0)
		logEvent.AddError("unable to JSON parse resource from JWS payload: %s", err)
		return nil, nil, reg, probs.Malformed("Request payload did not parse as JSON")
	}
	if parsedRequest.Resource == "" {
		wfe.stats.Inc("WFE.Errors.NoResourceInJWSPayload", 1, 1.0)
		logEvent.AddError("JWS request payload does not specify a resource")
		return nil, nil, reg, probs.Malformed("Request payload does not specify a resource")
	} else if resource != core.AcmeResource(parsedRequest.Resource) {
		wfe.stats.Inc("WFE.Errors.MismatchedResourceInJWSPayload", 1, 1.0)
		logEvent.AddError("JWS request payload does not match resource")
		return nil, nil, reg, probs.Malformed("JWS resource payload does not match the HTTP resource: %s != %s", parsedRequest.Resource, resource)
	}

	return []byte(payload), key, reg, nil
}