// 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)
}
}
// 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 = ®.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
}