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workspaceapps.go
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workspaceapps.go
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package coderd
import (
"bytes"
"context"
"crypto/sha256"
"crypto/subtle"
"database/sql"
"encoding/base64"
"encoding/json"
"fmt"
"net/http"
"net/http/httputil"
"net/url"
"strconv"
"strings"
"time"
"github.com/go-chi/chi/v5"
"go.opentelemetry.io/otel/trace"
"golang.org/x/xerrors"
jose "gopkg.in/square/go-jose.v2"
"cdr.dev/slog"
"github.com/coder/coder/coderd/database"
"github.com/coder/coder/coderd/database/dbauthz"
"github.com/coder/coder/coderd/httpapi"
"github.com/coder/coder/coderd/httpmw"
"github.com/coder/coder/coderd/rbac"
"github.com/coder/coder/coderd/tracing"
"github.com/coder/coder/coderd/workspaceapps"
"github.com/coder/coder/codersdk"
"github.com/coder/coder/site"
)
const (
// This needs to be a super unique query parameter because we don't want to
// conflict with query parameters that users may use.
//nolint:gosec
subdomainProxyAPIKeyParam = "coder_application_connect_api_key_35e783"
// appLogoutHostname is the hostname to use for the logout redirect. When
// the dashboard logs out, it will redirect to this subdomain of the app
// hostname, and the server will remove the cookie and redirect to the main
// login page.
// It is important that this URL can never match a valid app hostname.
appLogoutHostname = "coder-logout"
)
// nonCanonicalHeaders is a map from "canonical" headers to the actual header we
// should send to the app in the workspace. Some headers (such as the websocket
// upgrade headers from RFC 6455) are not canonical according to the HTTP/1
// spec. Golang has said that they will not add custom cases for these headers,
// so we need to do it ourselves.
//
// Some apps our customers use are sensitive to the case of these headers.
//
// https://github.com/golang/go/issues/18495
var nonCanonicalHeaders = map[string]string{
"Sec-Websocket-Accept": "Sec-WebSocket-Accept",
"Sec-Websocket-Extensions": "Sec-WebSocket-Extensions",
"Sec-Websocket-Key": "Sec-WebSocket-Key",
"Sec-Websocket-Protocol": "Sec-WebSocket-Protocol",
"Sec-Websocket-Version": "Sec-WebSocket-Version",
}
// @Summary Get applications host
// @ID get-applications-host
// @Security CoderSessionToken
// @Produce json
// @Tags Applications
// @Success 200 {object} codersdk.AppHostResponse
// @Router /applications/host [get]
func (api *API) appHost(rw http.ResponseWriter, r *http.Request) {
host := api.AppHostname
if host != "" && api.AccessURL.Port() != "" {
host += fmt.Sprintf(":%s", api.AccessURL.Port())
}
httpapi.Write(r.Context(), rw, http.StatusOK, codersdk.AppHostResponse{
Host: host,
})
}
// workspaceAppsProxyPath proxies requests to a workspace application
// through a relative URL path.
func (api *API) workspaceAppsProxyPath(rw http.ResponseWriter, r *http.Request) {
if api.DeploymentValues.DisablePathApps.Value() {
site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
Status: http.StatusUnauthorized,
Title: "Unauthorized",
Description: "Path-based applications are disabled on this Coder deployment by the administrator.",
RetryEnabled: false,
DashboardURL: api.AccessURL.String(),
})
return
}
// If the username in the request is @me, then redirect to the current
// username. The resolveWorkspaceApp function does not accept @me for
// security purposes.
if chi.URLParam(r, "user") == codersdk.Me {
_, roles, ok := httpmw.ExtractAPIKey(rw, r, httpmw.ExtractAPIKeyConfig{
DB: api.Database,
OAuth2Configs: &httpmw.OAuth2Configs{
Github: api.GithubOAuth2Config,
OIDC: api.OIDCConfig,
},
RedirectToLogin: true,
DisableSessionExpiryRefresh: api.DeploymentValues.DisableSessionExpiryRefresh.Value(),
})
if !ok {
return
}
http.Redirect(rw, r, strings.Replace(r.URL.Path, "@me", "@"+roles.Username, 1), http.StatusTemporaryRedirect)
return
}
// Determine the real path that was hit. The * URL parameter in Chi will not
// include the leading slash if it was present, so we need to add it back.
chiPath := chi.URLParam(r, "*")
basePath := strings.TrimSuffix(r.URL.Path, chiPath)
if strings.HasSuffix(basePath, "/") {
chiPath = "/" + chiPath
}
ticket, ok := api.WorkspaceAppsProvider.ResolveRequest(rw, r, workspaceapps.Request{
AccessMethod: workspaceapps.AccessMethodPath,
BasePath: basePath,
UsernameOrID: chi.URLParam(r, "user"),
WorkspaceAndAgent: chi.URLParam(r, "workspace_and_agent"),
// We don't support port proxying on paths. The ResolveRequest method
// won't allow port proxying on path-based apps if the app is a number.
AppSlugOrPort: chi.URLParam(r, "workspaceapp"),
})
if !ok {
return
}
api.proxyWorkspaceApplication(rw, r, *ticket, chiPath)
}
// handleSubdomainApplications handles subdomain-based application proxy
// requests (aka. DevURLs in Coder V1).
//
// There are a lot of paths here:
// 1. If api.AppHostname is not set then we pass on.
// 2. If we can't read the request hostname then we return a 400.
// 3. If the request hostname matches api.AccessURL then we pass on.
// 5. We split the subdomain into the subdomain and the "rest". If there are no
// periods in the hostname then we pass on.
// 5. We parse the subdomain into a httpapi.ApplicationURL struct. If we
// encounter an error:
// a. If the "rest" does not match api.AppHostname then we pass on;
// b. Otherwise, we return a 400.
// 6. Finally, we verify that the "rest" matches api.AppHostname, else we
// return a 404.
//
// Rationales for each of the above steps:
// 1. We pass on if api.AppHostname is not set to avoid returning any errors if
// `--app-hostname` is not configured.
// 2. Every request should have a valid Host header anyways.
// 3. We pass on if the request hostname matches api.AccessURL so we can
// support having the access URL be at the same level as the application
// base hostname.
// 4. We pass on if there are no periods in the hostname as application URLs
// must be a subdomain of a hostname, which implies there must be at least
// one period.
// 5. a. If the request subdomain is not a valid application URL, and the
// "rest" does not match api.AppHostname, then it is very unlikely that
// the request was intended for this handler. We pass on.
// b. If the request subdomain is not a valid application URL, but the
// "rest" matches api.AppHostname, then we return a 400 because the
// request is probably a typo or something.
// 6. We finally verify that the "rest" matches api.AppHostname for security
// purposes regarding re-authentication and application proxy session
// tokens.
func (api *API) handleSubdomainApplications(middlewares ...func(http.Handler) http.Handler) func(http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
ctx := r.Context()
// Step 1: Pass on if subdomain-based application proxying is not
// configured.
if api.AppHostname == "" || api.AppHostnameRegex == nil {
next.ServeHTTP(rw, r)
return
}
// Step 2: Get the request Host.
host := httpapi.RequestHost(r)
if host == "" {
if r.URL.Path == "/derp" {
// The /derp endpoint is used by wireguard clients to tunnel
// through coderd. For some reason these requests don't set
// a Host header properly sometimes in tests (no idea how),
// which causes this path to get hit.
next.ServeHTTP(rw, r)
return
}
httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
Message: "Could not determine request Host.",
})
return
}
// Steps 3-6: Parse application from subdomain.
app, ok := api.parseWorkspaceApplicationHostname(rw, r, next, host)
if !ok {
return
}
// If the request has the special query param then we need to set a
// cookie and strip that query parameter.
if encryptedAPIKey := r.URL.Query().Get(subdomainProxyAPIKeyParam); encryptedAPIKey != "" {
// Exchange the encoded API key for a real one.
_, token, err := decryptAPIKey(r.Context(), api.Database, encryptedAPIKey)
if err != nil {
site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
Status: http.StatusBadRequest,
Title: "Bad Request",
Description: "Could not decrypt API key. Please remove the query parameter and try again.",
// Retry is disabled because the user needs to remove
// the query parameter before they try again.
RetryEnabled: false,
DashboardURL: api.AccessURL.String(),
})
return
}
api.setWorkspaceAppCookie(rw, r, token)
// Strip the query parameter.
path := r.URL.Path
if path == "" {
path = "/"
}
q := r.URL.Query()
q.Del(subdomainProxyAPIKeyParam)
rawQuery := q.Encode()
if rawQuery != "" {
path += "?" + q.Encode()
}
http.Redirect(rw, r, path, http.StatusTemporaryRedirect)
return
}
ticket, ok := api.WorkspaceAppsProvider.ResolveRequest(rw, r, workspaceapps.Request{
AccessMethod: workspaceapps.AccessMethodSubdomain,
BasePath: "/",
UsernameOrID: app.Username,
WorkspaceNameOrID: app.WorkspaceName,
AgentNameOrID: app.AgentName,
AppSlugOrPort: app.AppSlugOrPort,
})
if !ok {
return
}
// Use the passed in app middlewares before passing to the proxy
// app.
mws := chi.Middlewares(middlewares)
mws.Handler(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
api.proxyWorkspaceApplication(rw, r, *ticket, r.URL.Path)
})).ServeHTTP(rw, r.WithContext(ctx))
})
}
}
// workspaceApplicationAuth is an endpoint on the main router that handles
// redirects from the subdomain handler.
//
// This endpoint is under /api so we don't return the friendly error page here.
// Any errors on this endpoint should be errors that are unlikely to happen
// in production unless the user messes with the URL.
//
// @Summary Redirect to URI with encrypted API key
// @ID redirect-to-uri-with-encrypted-api-key
// @Security CoderSessionToken
// @Tags Applications
// @Param redirect_uri query string false "Redirect destination"
// @Success 307
// @Router /applications/auth-redirect [get]
func (api *API) workspaceApplicationAuth(rw http.ResponseWriter, r *http.Request) {
ctx := r.Context()
if api.AppHostname == "" {
httpapi.Write(ctx, rw, http.StatusNotFound, codersdk.Response{
Message: "The server does not accept subdomain-based application requests.",
})
return
}
apiKey := httpmw.APIKey(r)
if !api.Authorize(r, rbac.ActionCreate, apiKey) {
httpapi.ResourceNotFound(rw)
return
}
// Get the redirect URI from the query parameters and parse it.
redirectURI := r.URL.Query().Get(workspaceapps.RedirectURIQueryParam)
if redirectURI == "" {
httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
Message: "Missing redirect_uri query parameter.",
})
return
}
u, err := url.Parse(redirectURI)
if err != nil {
httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
Message: "Invalid redirect_uri query parameter.",
Detail: err.Error(),
})
return
}
// Force the redirect URI to use the same scheme as the access URL for
// security purposes.
u.Scheme = api.AccessURL.Scheme
// Ensure that the redirect URI is a subdomain of api.AppHostname and is a
// valid app subdomain.
subdomain, ok := httpapi.ExecuteHostnamePattern(api.AppHostnameRegex, u.Host)
if !ok {
httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
Message: "The redirect_uri query parameter must be a valid app subdomain.",
})
return
}
_, err = httpapi.ParseSubdomainAppURL(subdomain)
if err != nil {
httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
Message: "The redirect_uri query parameter must be a valid app subdomain.",
Detail: err.Error(),
})
return
}
// Create the application_connect-scoped API key with the same lifetime as
// the current session.
exp := apiKey.ExpiresAt
lifetimeSeconds := apiKey.LifetimeSeconds
if exp.IsZero() || time.Until(exp) > api.DeploymentValues.SessionDuration.Value() {
exp = database.Now().Add(api.DeploymentValues.SessionDuration.Value())
lifetimeSeconds = int64(api.DeploymentValues.SessionDuration.Value().Seconds())
}
cookie, _, err := api.createAPIKey(ctx, createAPIKeyParams{
UserID: apiKey.UserID,
LoginType: database.LoginTypePassword,
ExpiresAt: exp,
LifetimeSeconds: lifetimeSeconds,
Scope: database.APIKeyScopeApplicationConnect,
})
if err != nil {
httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
Message: "Failed to create API key.",
Detail: err.Error(),
})
return
}
// Encrypt the API key.
encryptedAPIKey, err := encryptAPIKey(encryptedAPIKeyPayload{
APIKey: cookie.Value,
})
if err != nil {
httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
Message: "Failed to encrypt API key.",
Detail: err.Error(),
})
return
}
// Redirect to the redirect URI with the encrypted API key in the query
// parameters.
q := u.Query()
q.Set(subdomainProxyAPIKeyParam, encryptedAPIKey)
u.RawQuery = q.Encode()
http.Redirect(rw, r, u.String(), http.StatusTemporaryRedirect)
}
func (api *API) parseWorkspaceApplicationHostname(rw http.ResponseWriter, r *http.Request, next http.Handler, host string) (httpapi.ApplicationURL, bool) {
// Check if the hostname matches the access URL. If it does, the user was
// definitely trying to connect to the dashboard/API.
if httpapi.HostnamesMatch(api.AccessURL.Hostname(), host) {
next.ServeHTTP(rw, r)
return httpapi.ApplicationURL{}, false
}
// If there are no periods in the hostname, then it can't be a valid
// application URL.
if !strings.Contains(host, ".") {
next.ServeHTTP(rw, r)
return httpapi.ApplicationURL{}, false
}
// Split the subdomain so we can parse the application details and verify it
// matches the configured app hostname later.
subdomain, ok := httpapi.ExecuteHostnamePattern(api.AppHostnameRegex, host)
if !ok {
// Doesn't match the regex, so it's not a valid application URL.
next.ServeHTTP(rw, r)
return httpapi.ApplicationURL{}, false
}
// Check if the request is part of a logout flow.
if subdomain == appLogoutHostname {
api.handleWorkspaceSubdomainAppLogout(rw, r)
return httpapi.ApplicationURL{}, false
}
// Parse the application URL from the subdomain.
app, err := httpapi.ParseSubdomainAppURL(subdomain)
if err != nil {
site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
Status: http.StatusBadRequest,
Title: "Invalid application URL",
Description: fmt.Sprintf("Could not parse subdomain application URL %q: %s", subdomain, err.Error()),
RetryEnabled: false,
DashboardURL: api.AccessURL.String(),
})
return httpapi.ApplicationURL{}, false
}
return app, true
}
func (api *API) handleWorkspaceSubdomainAppLogout(rw http.ResponseWriter, r *http.Request) {
ctx := r.Context()
// Delete the API key and cookie first before attempting to parse/validate
// the redirect URI.
cookie, err := r.Cookie(codersdk.DevURLSessionTokenCookie)
if err == nil && cookie.Value != "" {
id, secret, err := httpmw.SplitAPIToken(cookie.Value)
// If it's not a valid token then we don't need to delete it from the
// database, but we'll still delete the cookie.
if err == nil {
// To avoid a situation where someone overloads the API with
// different auth formats, and tricks this endpoint into deleting an
// unchecked API key, we validate that the secret matches the secret
// we store in the database.
//nolint:gocritic // needed for workspace app logout
apiKey, err := api.Database.GetAPIKeyByID(dbauthz.AsSystemRestricted(ctx), id)
if err != nil && !xerrors.Is(err, sql.ErrNoRows) {
httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
Message: "Failed to lookup API key.",
Detail: err.Error(),
})
return
}
// This is wrapped in `err == nil` because if the API key doesn't
// exist, we still want to delete the cookie.
if err == nil {
hashedSecret := sha256.Sum256([]byte(secret))
if subtle.ConstantTimeCompare(apiKey.HashedSecret, hashedSecret[:]) != 1 {
httpapi.Write(ctx, rw, http.StatusUnauthorized, codersdk.Response{
Message: httpmw.SignedOutErrorMessage,
Detail: "API key secret is invalid.",
})
return
}
//nolint:gocritic // needed for workspace app logout
err = api.Database.DeleteAPIKeyByID(dbauthz.AsSystemRestricted(ctx), id)
if err != nil {
httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
Message: "Failed to delete API key.",
Detail: err.Error(),
})
return
}
}
}
}
if !api.setWorkspaceAppCookie(rw, r, "") {
return
}
// Read the redirect URI from the query string.
redirectURI := r.URL.Query().Get(workspaceapps.RedirectURIQueryParam)
if redirectURI == "" {
redirectURI = api.AccessURL.String()
} else {
// Validate that the redirect URI is a valid URL and exists on the same
// host as the access URL or an app URL.
parsedRedirectURI, err := url.Parse(redirectURI)
if err != nil {
site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
Status: http.StatusBadRequest,
Title: "Invalid redirect URI",
Description: fmt.Sprintf("Could not parse redirect URI %q: %s", redirectURI, err.Error()),
RetryEnabled: false,
DashboardURL: api.AccessURL.String(),
})
return
}
// Check if the redirect URI is on the same host as the access URL or an
// app URL.
ok := httpapi.HostnamesMatch(api.AccessURL.Hostname(), parsedRedirectURI.Hostname())
if !ok && api.AppHostnameRegex != nil {
// We could also check that it's a valid application URL for
// completeness, but this check should be good enough.
_, ok = httpapi.ExecuteHostnamePattern(api.AppHostnameRegex, parsedRedirectURI.Hostname())
}
if !ok {
// The redirect URI they provided is not allowed, but we don't want
// to return an error page because it'll interrupt the logout flow,
// so we just use the default access URL.
parsedRedirectURI = api.AccessURL
}
redirectURI = parsedRedirectURI.String()
}
http.Redirect(rw, r, redirectURI, http.StatusTemporaryRedirect)
}
// setWorkspaceAppCookie sets a cookie on the workspace app domain. If the app
// hostname cannot be parsed properly, a static error page is rendered and false
// is returned.
//
// If an empty token is supplied, it will clear the cookie.
func (api *API) setWorkspaceAppCookie(rw http.ResponseWriter, r *http.Request, token string) bool {
hostSplit := strings.SplitN(api.AppHostname, ".", 2)
if len(hostSplit) != 2 {
// This should be impossible as we verify the app hostname on
// startup, but we'll check anyways.
api.Logger.Error(r.Context(), "could not split invalid app hostname", slog.F("hostname", api.AppHostname))
site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
Status: http.StatusInternalServerError,
Title: "Internal Server Error",
Description: "The app is configured with an invalid app wildcard hostname. Please contact an administrator.",
RetryEnabled: false,
DashboardURL: api.AccessURL.String(),
})
return false
}
// Set the app cookie for all subdomains of api.AppHostname. This cookie is
// handled properly by the ExtractAPIKey middleware.
//
// We don't set an expiration because the key in the database already has an
// expiration.
maxAge := 0
if token == "" {
maxAge = -1
}
cookieHost := "." + hostSplit[1]
http.SetCookie(rw, &http.Cookie{
Name: codersdk.DevURLSessionTokenCookie,
Value: token,
Domain: cookieHost,
Path: "/",
MaxAge: maxAge,
HttpOnly: true,
SameSite: http.SameSiteLaxMode,
Secure: api.SecureAuthCookie,
})
return true
}
func (api *API) proxyWorkspaceApplication(rw http.ResponseWriter, r *http.Request, ticket workspaceapps.Ticket, path string) {
ctx := r.Context()
// Filter IP headers from untrusted origins.
httpmw.FilterUntrustedOriginHeaders(api.RealIPConfig, r)
// Ensure proper IP headers get sent to the forwarded application.
err := httpmw.EnsureXForwardedForHeader(r)
if err != nil {
httpapi.InternalServerError(rw, err)
return
}
appURL, err := url.Parse(ticket.AppURL)
if err != nil {
site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
Status: http.StatusBadRequest,
Title: "Bad Request",
Description: fmt.Sprintf("Application has an invalid URL %q: %s", ticket.AppURL, err.Error()),
RetryEnabled: true,
DashboardURL: api.AccessURL.String(),
})
return
}
// Verify that the port is allowed. See the docs above
// `codersdk.MinimumListeningPort` for more details.
port := appURL.Port()
if port != "" {
portInt, err := strconv.Atoi(port)
if err != nil {
httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
Message: fmt.Sprintf("App URL %q has an invalid port %q.", ticket.AppURL, port),
Detail: err.Error(),
})
return
}
if portInt < codersdk.WorkspaceAgentMinimumListeningPort {
httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
Message: fmt.Sprintf("Application port %d is not permitted. Coder reserves ports less than %d for internal use.", portInt, codersdk.WorkspaceAgentMinimumListeningPort),
})
return
}
}
// Ensure path and query parameter correctness.
if path == "" {
// Web applications typically request paths relative to the
// root URL. This allows for routing behind a proxy or subpath.
// See https://github.com/coder/code-server/issues/241 for examples.
http.Redirect(rw, r, r.URL.Path+"/", http.StatusTemporaryRedirect)
return
}
if path == "/" && r.URL.RawQuery == "" && appURL.RawQuery != "" {
// If the application defines a default set of query parameters,
// we should always respect them. The reverse proxy will merge
// query parameters for server-side requests, but sometimes
// client-side applications require the query parameters to render
// properly. With code-server, this is the "folder" param.
r.URL.RawQuery = appURL.RawQuery
http.Redirect(rw, r, r.URL.String(), http.StatusTemporaryRedirect)
return
}
r.URL.Path = path
appURL.RawQuery = ""
proxy := httputil.NewSingleHostReverseProxy(appURL)
proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
Status: http.StatusBadGateway,
Title: "Bad Gateway",
Description: "Failed to proxy request to application: " + err.Error(),
RetryEnabled: true,
DashboardURL: api.AccessURL.String(),
})
}
conn, release, err := api.workspaceAgentCache.Acquire(r, ticket.AgentID)
if err != nil {
site.RenderStaticErrorPage(rw, r, site.ErrorPageData{
Status: http.StatusBadGateway,
Title: "Bad Gateway",
Description: "Could not connect to workspace agent: " + err.Error(),
RetryEnabled: true,
DashboardURL: api.AccessURL.String(),
})
return
}
defer release()
proxy.Transport = conn.HTTPTransport()
// This strips the session token from a workspace app request.
cookieHeaders := r.Header.Values("Cookie")[:]
r.Header.Del("Cookie")
for _, cookieHeader := range cookieHeaders {
r.Header.Add("Cookie", httpapi.StripCoderCookies(cookieHeader))
}
// Convert canonicalized headers to their non-canonicalized counterparts.
// See the comment on `nonCanonicalHeaders` for more information on why this
// is necessary.
for k, v := range r.Header {
if n, ok := nonCanonicalHeaders[k]; ok {
r.Header.Del(k)
r.Header[n] = v
}
}
// end span so we don't get long lived trace data
tracing.EndHTTPSpan(r, http.StatusOK, trace.SpanFromContext(ctx))
proxy.ServeHTTP(rw, r)
}
type encryptedAPIKeyPayload struct {
APIKey string `json:"api_key"`
ExpiresAt time.Time `json:"expires_at"`
}
// encryptAPIKey encrypts an API key with it's own hashed secret. This is used
// for smuggling (application_connect scoped) API keys securely to app
// hostnames.
//
// We encrypt API keys when smuggling them in query parameters to avoid them
// getting accidentally logged in access logs or stored in browser history.
func encryptAPIKey(data encryptedAPIKeyPayload) (string, error) {
if data.APIKey == "" {
return "", xerrors.New("API key is empty")
}
if data.ExpiresAt.IsZero() {
// Very short expiry as these keys are only used once as part of an
// automatic redirection flow.
data.ExpiresAt = database.Now().Add(time.Minute)
}
payload, err := json.Marshal(data)
if err != nil {
return "", xerrors.Errorf("marshal payload: %w", err)
}
// We use the hashed key secret as the encryption key. The hashed secret is
// stored in the API keys table. The HashedSecret is NEVER returned from the
// API.
//
// We chose to use the key secret as the private key for encryption instead
// of a shared key for a few reasons:
// 1. A single private key used to encrypt every API key would also be
// stored in the database, which means that the risk factor is similar.
// 2. The secret essentially rotates for each key (for free!), since each
// key has a different secret. This means that if someone acquires an
// old database dump they can't decrypt new API keys.
// 3. These tokens are scoped only for application_connect access.
keyID, keySecret, err := httpmw.SplitAPIToken(data.APIKey)
if err != nil {
return "", xerrors.Errorf("split API key: %w", err)
}
// SHA256 the key secret so it matches the hashed secret in the database.
// The key length doesn't matter to the jose.Encrypter.
privateKey := sha256.Sum256([]byte(keySecret))
// JWEs seem to apply a nonce themselves.
encrypter, err := jose.NewEncrypter(
jose.A256GCM,
jose.Recipient{
Algorithm: jose.A256GCMKW,
KeyID: keyID,
Key: privateKey[:],
},
&jose.EncrypterOptions{
Compression: jose.DEFLATE,
},
)
if err != nil {
return "", xerrors.Errorf("initializer jose encrypter: %w", err)
}
encryptedObject, err := encrypter.Encrypt(payload)
if err != nil {
return "", xerrors.Errorf("encrypt jwe: %w", err)
}
encrypted := encryptedObject.FullSerialize()
return base64.RawURLEncoding.EncodeToString([]byte(encrypted)), nil
}
// decryptAPIKey undoes encryptAPIKey and is used in the subdomain app handler.
func decryptAPIKey(ctx context.Context, db database.Store, encryptedAPIKey string) (database.APIKey, string, error) {
encrypted, err := base64.RawURLEncoding.DecodeString(encryptedAPIKey)
if err != nil {
return database.APIKey{}, "", xerrors.Errorf("base64 decode encrypted API key: %w", err)
}
object, err := jose.ParseEncrypted(string(encrypted))
if err != nil {
return database.APIKey{}, "", xerrors.Errorf("parse encrypted API key: %w", err)
}
// Lookup the API key so we can decrypt it.
keyID := object.Header.KeyID
//nolint:gocritic // needed to check API key
key, err := db.GetAPIKeyByID(dbauthz.AsSystemRestricted(ctx), keyID)
if err != nil {
return database.APIKey{}, "", xerrors.Errorf("get API key by key ID: %w", err)
}
// Decrypt using the hashed secret.
decrypted, err := object.Decrypt(key.HashedSecret)
if err != nil {
return database.APIKey{}, "", xerrors.Errorf("decrypt API key: %w", err)
}
// Unmarshal the payload.
var payload encryptedAPIKeyPayload
if err := json.Unmarshal(decrypted, &payload); err != nil {
return database.APIKey{}, "", xerrors.Errorf("unmarshal decrypted payload: %w", err)
}
// Validate expiry.
if payload.ExpiresAt.Before(database.Now()) {
return database.APIKey{}, "", xerrors.New("encrypted API key expired")
}
// Validate that the key matches the one we got from the DB.
gotKeyID, gotKeySecret, err := httpmw.SplitAPIToken(payload.APIKey)
if err != nil {
return database.APIKey{}, "", xerrors.Errorf("split API key: %w", err)
}
gotHashedSecret := sha256.Sum256([]byte(gotKeySecret))
if gotKeyID != key.ID || !bytes.Equal(key.HashedSecret, gotHashedSecret[:]) {
return database.APIKey{}, "", xerrors.New("encrypted API key does not match key in database")
}
return key, payload.APIKey, nil
}