func computeSum(in []byte) (sum Sum, err error) {
	var data []byte
	p, _ := pem.Decode(in)
	if p == nil {
		err = errors.NewBadRequestString("not a CSR or certificate")
		return
	}

	switch p.Type {
	case "CERTIFICATE REQUEST":
		var req *x509.CertificateRequest
		req, err = x509.ParseCertificateRequest(p.Bytes)
		if err != nil {
			return
		}
		data = req.Raw
	case "CERTIFICATE":
		var cert *x509.Certificate
		cert, err = x509.ParseCertificate(p.Bytes)
		if err != nil {
			return
		}
		data = cert.Raw
	default:
		err = errors.NewBadRequestString("not a CSR or certificate")
		return
	}

	md5Sum := md5.Sum(data)
	sha1Sum := sha1.Sum(data)
	sum.MD5 = fmt.Sprintf("%X", md5Sum[:])
	sum.SHA1 = fmt.Sprintf("%X", sha1Sum[:])
	return
}

// Handle responds to revocation requests. It attempts to revoke
// a certificate with a given serial number
func (h *Handler) Handle(w http.ResponseWriter, r *http.Request) error {
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		return err
	}
	r.Body.Close()

	// Default the status to good so it matches the cli
	var req jsonRevokeRequest
	err = json.Unmarshal(body, &req)
	if err != nil {
		return errors.NewBadRequestString("Unable to parse revocation request")
	}

	if len(req.Serial) == 0 {
		return errors.NewBadRequestString("serial number is required but not provided")
	}

	var reasonCode int
	reasonCode, err = ocsp.ReasonStringToCode(req.Reason)
	if err != nil {
		return errors.NewBadRequestString("Invalid reason code")
	}

	err = h.dbAccessor.RevokeCertificate(req.Serial, req.AKI, reasonCode)
	if err != nil {
		return err
	}

	result := map[string]string{}
	return api.SendResponse(w, result)
}

// Handle responds to requests for a ocsp signature. It creates and signs
// a ocsp response for the provided certificate and status. If the status
// is revoked then it also adds reason and revoked_at. The response is
// base64 encoded.
func (h *Handler) Handle(w http.ResponseWriter, r *http.Request) error {
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		return err
	}
	r.Body.Close()

	// Default the status to good so it matches the cli
	req := &jsonSignRequest{
		Status: "good",
	}
	err = json.Unmarshal(body, req)
	if err != nil {
		return errors.NewBadRequestString("Unable to parse sign request")
	}

	cert, err := helpers.ParseCertificatePEM([]byte(req.Certificate))
	if err != nil {
		log.Error("Error from ParseCertificatePEM", err)
		return errors.NewBadRequestString("Malformed certificate")
	}

	signReq := ocsp.SignRequest{
		Certificate: cert,
		Status:      req.Status,
	}
	// We need to convert the time from being a string to a time.Time
	if req.Status == "revoked" {
		signReq.Reason = req.Reason
		// "now" is accepted and the default on the cli so default that here
		if req.RevokedAt == "" || req.RevokedAt == "now" {
			signReq.RevokedAt = time.Now()
		} else {
			signReq.RevokedAt, err = time.Parse("2006-01-02", req.RevokedAt)
			if err != nil {
				return errors.NewBadRequestString("Malformed revocation time")
			}
		}
	}
	if req.IssuerHash != "" {
		issuerHash, ok := nameToHash[req.IssuerHash]
		if !ok {
			return errors.NewBadRequestString("Unsupported hash algorithm in request")
		}
		signReq.IssuerHash = issuerHash
	}

	resp, err := h.signer.Sign(signReq)
	if err != nil {
		return err
	}

	b64Resp := base64.StdEncoding.EncodeToString(resp)
	result := map[string]string{"ocspResponse": b64Resp}
	return api.SendResponse(w, result)
}

// Handle responds to requests for the CA to sign the certificate request
// present in the "certificate_request" parameter for the host named
// in the "hostname" parameter. The certificate should be PEM-encoded. If
// provided, subject information from the "subject" parameter will be used
// in place of the subject information from the CSR.
func (h *SignHandler) Handle(w http.ResponseWriter, r *http.Request) error {
	log.Info("signature request received")

	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		return err
	}
	r.Body.Close()

	var req signer.SignRequest
	err = json.Unmarshal(body, &req)
	if err != nil {
		return err
	}

	if len(req.Hosts) == 0 {
		return errors.NewBadRequestString("missing paratmeter 'hosts'")
	}

	if req.Request == "" {
		return errors.NewBadRequestString("missing parameter 'certificate_request'")
	}

	var cert []byte
	var profile *config.SigningProfile

	policy := h.signer.Policy()
	if policy != nil && policy.Profiles != nil && req.Profile != "" {
		profile = policy.Profiles[req.Profile]
	}

	if profile == nil && policy != nil {
		profile = policy.Default
	}

	if profile.Provider != nil {
		log.Error("profile requires authentication")
		return errors.NewBadRequestString("authentication required")
	}

	cert, err = h.signer.Sign(req)
	if err != nil {
		log.Warningf("failed to sign request: %v", err)
		return err
	}

	result := map[string]string{"certificate": string(cert)}
	log.Info("wrote response")
	return api.SendResponse(w, result)
}

// Handle accepts client information requests, and uses the label to
// look up the signer whose public certificate should be retrieved. If
// the label is empty, the default label is used.
func (h *MultiHandler) Handle(w http.ResponseWriter, r *http.Request) error {
	req := new(info.Req)
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}
	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	log.Debug("checking label")
	if req.Label == "" {
		req.Label = h.defaultLabel
	}

	if _, ok := h.signers[req.Label]; !ok {
		log.Warningf("request for invalid endpoint")
		return errors.NewBadRequestString("bad label")
	}

	log.Debug("getting info")
	resp, err := h.signers[req.Label].Info(*req)
	if err != nil {
		log.Infof("error getting certificate: %v", err)
		return err
	}

	response := api.NewSuccessResponse(resp)
	w.Header().Set("Content-Type", "application/json")
	enc := json.NewEncoder(w)
	return enc.Encode(response)
}

// scanHandler is an HTTP handler that accepts GET parameters for host (required)
// family and scanner, and uses these to perform scans, returning a JSON blob result.
func scanHandler(w http.ResponseWriter, r *http.Request) error {
	if err := r.ParseForm(); err != nil {
		log.Warningf("failed to parse body: %v", err)
		return errors.NewBadRequest(err)
	}

	family := r.Form.Get("family")
	scanner := r.Form.Get("scanner")
	ip := r.Form.Get("ip")
	host := r.Form.Get("host")
	if host == "" {
		log.Warningf("no host given")
		return errors.NewBadRequestString("no host given")
	}

	results, err := scan.Default.RunScans(host, ip, family, scanner, 0)
	if err != nil {
		log.Warningf("%v", err)
		return errors.NewBadRequest(err)
	}

	response := api.NewSuccessResponse(results)
	enc := json.NewEncoder(w)
	return enc.Encode(response)
}

// scanHandler is an HTTP handler that accepts GET parameters for host (required)
// family and scanner, and uses these to perform scans, returning a JSON blob result.
func scanHandler(w http.ResponseWriter, r *http.Request) error {
	if err := r.ParseForm(); err != nil {
		log.Warningf("failed to parse body: %v", err)
		return errors.NewBadRequest(err)
	}

	if len(r.Form["host"]) == 0 {
		log.Warningf("no host given")
		return errors.NewBadRequestString("no host given")
	}
	host := r.Form["host"][0]

	var family, scanner string
	if len(r.Form["family"]) > 0 {
		family = r.Form["family"][0]
	}

	if len(r.Form["scanner"]) > 0 {
		scanner = r.Form["scanner"][0]
	}

	results, err := scan.Default.RunScans(host, family, scanner)
	if err != nil {
		log.Warningf("%v", err)
		return errors.NewBadRequest(err)
	}

	response := api.NewSuccessResponse(results)
	enc := json.NewEncoder(w)
	return enc.Encode(response)
}

func missingParamsError(missing []string) error {
	s := "Missing parameter"
	if len(missing) > 1 {
		s += "s"
	}
	s += " "
	s += strings.Join(missing, ", ")
	return errors.NewBadRequestString(s)
}

// Handle responds to requests for the CA to sign the certificate request
// present in the "certificate_request" parameter for the host named
// in the "hostname" parameter. The certificate should be PEM-encoded. If
// provided, subject information from the "subject" parameter will be used
// in place of the subject information from the CSR.
func (h *Handler) Handle(w http.ResponseWriter, r *http.Request) error {
	log.Info("signature request received")

	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		return err
	}
	r.Body.Close()

	var req jsonSignRequest

	err = json.Unmarshal(body, &req)
	if err != nil {
		return errors.NewBadRequestString("Unable to parse sign request")
	}

	signReq := jsonReqToTrue(req)

	if req.Request == "" {
		return errors.NewBadRequestString("missing parameter 'certificate_request'")
	}

	var cert []byte
	profile, err := signer.Profile(h.signer, req.Profile)
	if err != nil {
		return err
	}

	if profile.Provider != nil {
		log.Error("profile requires authentication")
		return errors.NewBadRequestString("authentication required")
	}

	cert, err = h.signer.Sign(signReq)
	if err != nil {
		log.Warningf("failed to sign request: %v", err)
		return err
	}

	result := map[string]string{"certificate": string(cert)}
	log.Info("wrote response")
	return api.SendResponse(w, result)
}

// ProcessRequestOneOf reads a JSON blob for the request and makes
// sure it contains one of a set of keywords. For example, a request
// might have the ('foo' && 'bar') keys, OR it might have the 'baz'
// key.  In either case, we want to accept the request; however, if
// none of these sets shows up, the request is a bad request, and it
// should be returned.
func ProcessRequestOneOf(r *http.Request, keywordSets [][]string) (map[string]string, []string, error) {
	blob, err := readRequestBlob(r)
	if err != nil {
		return nil, nil, err
	}

	var matched []string
	for _, set := range keywordSets {
		if matchKeywords(blob, set) {
			if matched != nil {
				return nil, nil, errors.NewBadRequestString("mismatched parameters")
			}
			matched = set
		}
	}
	if matched == nil {
		return nil, nil, errors.NewBadRequestString("no valid parameter sets found")
	}
	return blob, matched, nil
}

// ProcessRequestFirstMatchOf reads a JSON blob for the request and returns
// the first match of a set of keywords. For example, a request
// might have one of the following combinations: (foo=1, bar=2), (foo=1), and (bar=2)
// By giving a specific ordering of those combinations, we could decide how to accept
// the request.
func ProcessRequestFirstMatchOf(r *http.Request, keywordSets [][]string) (map[string]string, []string, error) {
	blob, err := readRequestBlob(r)
	if err != nil {
		return nil, nil, err
	}

	for _, set := range keywordSets {
		if matchKeywords(blob, set) {
			return blob, set, nil
		}
	}
	return nil, nil, errors.NewBadRequestString("no valid parameter sets found")
}

// scanHandler is an HTTP handler that accepts GET parameters for host (required)
// family and scanner, and uses these to perform scans, returning a JSON blob result.
func scanHandler(w http.ResponseWriter, r *http.Request) error {
	if err := r.ParseForm(); err != nil {
		log.Warningf("failed to parse body: %v", err)
		return errors.NewBadRequest(err)
	}

	family := r.Form.Get("family")
	scanner := r.Form.Get("scanner")
	ip := r.Form.Get("ip")
	timeoutStr := r.Form.Get("timeout")
	var timeout time.Duration
	var err error
	if timeoutStr != "" {
		if timeout, err = time.ParseDuration(timeoutStr); err != nil {
			return errors.NewBadRequest(err)
		}
		if timeout < time.Second || timeout > 5*time.Minute {
			return errors.NewBadRequestString("invalid timeout given")
		}
	} else {
		timeout = time.Minute
	}

	host := r.Form.Get("host")
	if host == "" {
		log.Warningf("no host given")
		return errors.NewBadRequestString("no host given")
	}

	results, err := scan.Default.RunScans(host, ip, family, scanner, timeout)
	if err != nil {
		return errors.NewBadRequest(err)
	}

	return json.NewEncoder(w).Encode(api.NewSuccessResponse(results))
}

// Handle responds to requests for the CA to generate a new private
// key and certificate request on behalf of the client. The format for
// these requests is documented in the API documentation.
func (g *Handler) Handle(w http.ResponseWriter, r *http.Request) error {
	log.Info("request for CSR")
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}
	r.Body.Close()

	req := new(csr.CertificateRequest)
	req.KeyRequest = csr.NewBasicKeyRequest()
	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	if req.CA != nil {
		log.Warningf("request received with CA section")
		return errors.NewBadRequestString("ca section only permitted in initca")
	}

	csr, key, err := g.generator.ProcessRequest(req)
	if err != nil {
		log.Warningf("failed to process CSR: %v", err)
		// The validator returns a *cfssl/errors.HttpError
		return err
	}

	sum, err := computeSum(csr)
	if err != nil {
		return errors.NewBadRequest(err)
	}

	// Both key and csr are returned PEM-encoded.
	response := api.NewSuccessResponse(&CertRequest{
		Key:  string(key),
		CSR:  string(csr),
		Sums: map[string]Sum{"certificate_request": sum},
	})
	w.Header().Set("Content-Type", "application/json")
	enc := json.NewEncoder(w)
	err = enc.Encode(response)
	return err
}

// Handle responds to requests for the CA to generate a new private
// key and certificate on behalf of the client. The format for these
// requests is documented in the API documentation.
func (cg *CertGeneratorHandler) Handle(w http.ResponseWriter, r *http.Request) error {
	log.Info("request for CSR")

	req := new(genSignRequest)
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}

	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	if req.Request == nil {
		log.Warning("empty request received")
		return errors.NewBadRequestString("missing request section")
	}

	if req.Request.CA != nil {
		log.Warningf("request received with CA section")
		return errors.NewBadRequestString("ca section only permitted in initca")
	}

	csr, key, err := cg.generator.ProcessRequest(req.Request)
	if err != nil {
		log.Warningf("failed to process CSR: %v", err)
		// The validator returns a *cfssl/errors.HttpError
		return err
	}

	signReq := signer.SignRequest{
		Request: string(csr),
		Profile: req.Profile,
		Label:   req.Label,
	}

	certBytes, err := cg.signer.Sign(signReq)
	if err != nil {
		log.Warningf("failed to sign request: %v", err)
		return err
	}

	reqSum, err := computeSum(csr)
	if err != nil {
		return errors.NewBadRequest(err)
	}

	certSum, err := computeSum(certBytes)
	if err != nil {
		return errors.NewBadRequest(err)
	}

	result := map[string]interface{}{
		"private_key":         string(key),
		"certificate_request": string(csr),
		"certificate":         string(certBytes),
		"sums": map[string]Sum{
			"certificate_request": reqSum,
			"certificate":         certSum,
		},
	}
	return api.SendResponse(w, result)
}

// Handle responds to requests for crl generation. It creates this crl
// based off of the given certificate, serial numbers, and private key
func crlHandler(w http.ResponseWriter, r *http.Request) error {

	var revokedCerts []pkix.RevokedCertificate
	var oneWeek = time.Duration(604800) * time.Second
	var newExpiryTime = time.Now()

	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		return err
	}
	r.Body.Close()

	req := &jsonCRLRequest{}

	err = json.Unmarshal(body, req)
	if err != nil {
		log.Error(err)
	}

	if req.ExpiryTime != "" {
		expiryTime := strings.TrimSpace(req.ExpiryTime)
		expiryInt, err := strconv.ParseInt(expiryTime, 0, 32)
		if err != nil {
			return err
		}

		newExpiryTime = time.Now().Add((time.Duration(expiryInt) * time.Second))
	}

	if req.ExpiryTime == "" {
		newExpiryTime = time.Now().Add(oneWeek)
	}

	if err != nil {
		return err
	}

	cert, err := helpers.ParseCertificatePEM([]byte(req.Certificate))
	if err != nil {
		log.Error("Error from ParseCertificatePEM", err)
		return errors.NewBadRequestString("Malformed certificate")
	}

	for _, value := range req.SerialNumber {
		tempBigInt := new(big.Int)
		tempBigInt.SetString(value, 10)
		tempCert := pkix.RevokedCertificate{
			SerialNumber:   tempBigInt,
			RevocationTime: time.Now(),
		}
		revokedCerts = append(revokedCerts, tempCert)
	}

	key, err := helpers.ParsePrivateKeyPEM([]byte(req.PrivateKey))
	if err != nil {
		log.Debug("Malformed private key %v", err)
		return errors.NewBadRequestString("Malformed Private Key")
	}

	result, err := cert.CreateCRL(rand.Reader, key, revokedCerts, time.Now(), newExpiryTime)

	return api.SendResponse(w, result)
}

// Handle responds to requests for the CA to generate a new private
// key and certificate on behalf of the client. The format for these
// requests is documented in the API documentation.
func (cg *CertGeneratorHandler) Handle(w http.ResponseWriter, r *http.Request) error {
	log.Info("request for CSR")

	req := new(genSignRequest)
	req.Request = csr.New()

	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		log.Warningf("failed to read request body: %v", err)
		return errors.NewBadRequest(err)
	}

	err = json.Unmarshal(body, req)
	if err != nil {
		log.Warningf("failed to unmarshal request: %v", err)
		return errors.NewBadRequest(err)
	}

	if req.Request == nil {
		log.Warning("empty request received")
		return errors.NewBadRequestString("missing request section")
	}

	if req.Request.CA != nil {
		log.Warningf("request received with CA section")
		return errors.NewBadRequestString("ca section only permitted in initca")
	}

	csr, key, err := cg.generator.ProcessRequest(req.Request)
	if err != nil {
		log.Warningf("failed to process CSR: %v", err)
		// The validator returns a *cfssl/errors.HttpError
		return err
	}

	signReq := signer.SignRequest{
		Request: string(csr),
		Profile: req.Profile,
		Label:   req.Label,
	}

	certBytes, err := cg.signer.Sign(signReq)
	if err != nil {
		log.Warningf("failed to sign request: %v", err)
		return err
	}

	reqSum, err := computeSum(csr)
	if err != nil {
		return errors.NewBadRequest(err)
	}

	certSum, err := computeSum(certBytes)
	if err != nil {
		return errors.NewBadRequest(err)
	}

	var file string
	if req.Format.Type == "pkcs12" {
		var password []byte
		if req.Format.Password != "" {
			password = []byte(req.Format.Password)
		}
		file = pkcs12.ParseAndEncode(key, certBytes, password)
	}

	result := map[string]interface{}{
		"private_key":         string(key),
		"certificate_request": string(csr),
		"certificate":         string(certBytes),
		"format":              file,
		"sums": map[string]Sum{
			"certificate_request": reqSum,
			"certificate":         certSum,
		},
	}

	if len(req.Request.Hosts) == 0 {
		return api.SendResponseWithMessage(w, result, CSRNoHostMessage,
			errors.New(errors.PolicyError, errors.InvalidRequest).ErrorCode)
	}

	return api.SendResponse(w, result)
}