From 82c14e00cec0f35a071707d63dd9bf943e040a6a Mon Sep 17 00:00:00 2001 From: Asher Date: Tue, 17 Jun 2025 09:00:32 -0800 Subject: [PATCH] feat: add csp headers for embedded apps (#18374) I modified the proxy host cache we already had and were using for websocket csp headers to also include the wildcard app host, then used those for frame-src policies. I did not add frame-ancestors, since if I understand correctly, those would go on the app, and this middleware does not come into play there. Maybe we will want to add it on workspace apps like we do with cors, if we find apps are setting it to `none` or something. Closes https://github.com/coder/internal/issues/684 --- coderd/coderd.go | 27 +++++++--- coderd/httpmw/csp.go | 41 +++++++------- coderd/httpmw/csp_test.go | 47 ++++++++++++---- coderd/proxyhealth/proxyhealth.go | 8 +++ coderd/workspaceapps/appurl/appurl.go | 20 +++++++ coderd/workspaceapps/appurl/appurl_test.go | 56 ++++++++++++++++++++ enterprise/coderd/proxyhealth/proxyhealth.go | 34 ++++++------ enterprise/coderd/workspaceproxy.go | 4 -- 8 files changed, 180 insertions(+), 57 deletions(-) create mode 100644 coderd/proxyhealth/proxyhealth.go diff --git a/coderd/coderd.go b/coderd/coderd.go index 24b34ea4db..0dd96b29df 100644 --- a/coderd/coderd.go +++ b/coderd/coderd.go @@ -76,6 +76,7 @@ import ( "github.com/coder/coder/v2/coderd/portsharing" "github.com/coder/coder/v2/coderd/prometheusmetrics" "github.com/coder/coder/v2/coderd/provisionerdserver" + "github.com/coder/coder/v2/coderd/proxyhealth" "github.com/coder/coder/v2/coderd/rbac" "github.com/coder/coder/v2/coderd/rbac/policy" "github.com/coder/coder/v2/coderd/rbac/rolestore" @@ -85,6 +86,7 @@ import ( "github.com/coder/coder/v2/coderd/updatecheck" "github.com/coder/coder/v2/coderd/util/slice" "github.com/coder/coder/v2/coderd/workspaceapps" + "github.com/coder/coder/v2/coderd/workspaceapps/appurl" "github.com/coder/coder/v2/coderd/workspacestats" "github.com/coder/coder/v2/codersdk" "github.com/coder/coder/v2/codersdk/healthsdk" @@ -1534,16 +1536,27 @@ func New(options *Options) *API { // browsers, so these don't make sense on api routes. cspMW := httpmw.CSPHeaders( api.Experiments, - options.Telemetry.Enabled(), func() []string { + options.Telemetry.Enabled(), func() []*proxyhealth.ProxyHost { if api.DeploymentValues.Dangerous.AllowAllCors { - // In this mode, allow all external requests - return []string{"*"} + // In this mode, allow all external requests. + return []*proxyhealth.ProxyHost{ + { + Host: "*", + AppHost: "*", + }, + } + } + // Always add the primary, since the app host may be on a sub-domain. + proxies := []*proxyhealth.ProxyHost{ + { + Host: api.AccessURL.Host, + AppHost: appurl.ConvertAppHostForCSP(api.AccessURL.Host, api.AppHostname), + }, } if f := api.WorkspaceProxyHostsFn.Load(); f != nil { - return (*f)() + proxies = append(proxies, (*f)()...) } - // By default we do not add extra websocket connections to the CSP - return []string{} + return proxies }, additionalCSPHeaders) // Static file handler must be wrapped with HSTS handler if the @@ -1582,7 +1595,7 @@ type API struct { AppearanceFetcher atomic.Pointer[appearance.Fetcher] // WorkspaceProxyHostsFn returns the hosts of healthy workspace proxies // for header reasons. - WorkspaceProxyHostsFn atomic.Pointer[func() []string] + WorkspaceProxyHostsFn atomic.Pointer[func() []*proxyhealth.ProxyHost] // TemplateScheduleStore is a pointer to an atomic pointer because this is // passed to another struct, and we want them all to be the same reference. TemplateScheduleStore *atomic.Pointer[schedule.TemplateScheduleStore] diff --git a/coderd/httpmw/csp.go b/coderd/httpmw/csp.go index afc19ddaf0..06897a45af 100644 --- a/coderd/httpmw/csp.go +++ b/coderd/httpmw/csp.go @@ -5,6 +5,7 @@ import ( "net/http" "strings" + "github.com/coder/coder/v2/coderd/proxyhealth" "github.com/coder/coder/v2/codersdk" ) @@ -47,18 +48,18 @@ const ( // for coderd. // // Arguments: -// - websocketHosts: a function that returns a list of supported external websocket hosts. -// This is to support the terminal connecting to a workspace proxy. -// The origin of the terminal request does not match the url of the proxy, -// so the CSP list of allowed hosts must be dynamic and match the current -// available proxy urls. +// - proxyHosts: a function that returns a list of supported proxy hosts +// (including the primary). This is to support the terminal connecting to a +// workspace proxy and for embedding apps in an iframe. The origin of the +// requests do not match the url of the proxy, so the CSP list of allowed +// hosts must be dynamic and match the current available proxy urls. // - staticAdditions: a map of CSP directives to append to the default CSP headers. // Used to allow specific static additions to the CSP headers. Allows some niche // use cases, such as embedding Coder in an iframe. // Example: https://github.com/coder/coder/issues/15118 // //nolint:revive -func CSPHeaders(experiments codersdk.Experiments, telemetry bool, websocketHosts func() []string, staticAdditions map[CSPFetchDirective][]string) func(next http.Handler) http.Handler { +func CSPHeaders(experiments codersdk.Experiments, telemetry bool, proxyHosts func() []*proxyhealth.ProxyHost, staticAdditions map[CSPFetchDirective][]string) func(next http.Handler) http.Handler { return func(next http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { // Content-Security-Policy disables loading certain content types and can prevent XSS injections. @@ -97,15 +98,6 @@ func CSPHeaders(experiments codersdk.Experiments, telemetry bool, websocketHosts // "require-trusted-types-for" : []string{"'script'"}, } - if experiments.Enabled(codersdk.ExperimentAITasks) { - // AI tasks use iframe embeds of local apps. - // TODO: Handle region domains too, not just path based apps - cspSrcs.Append(CSPFrameAncestors, `'self'`) - cspSrcs.Append(CSPFrameSource, `'self'`) - } else { - cspSrcs.Append(CSPFrameAncestors, `'none'`) - } - if telemetry { // If telemetry is enabled, we report to coder.com. cspSrcs.Append(CSPDirectiveConnectSrc, "https://coder.com") @@ -126,19 +118,26 @@ func CSPHeaders(experiments codersdk.Experiments, telemetry bool, websocketHosts cspSrcs.Append(CSPDirectiveConnectSrc, fmt.Sprintf("wss://%[1]s ws://%[1]s", host)) } - // The terminal requires a websocket connection to the workspace proxy. - // Make sure we allow this connection to healthy proxies. - extraConnect := websocketHosts() + // The terminal and iframed apps can use workspace proxies (which includes + // the primary). Make sure we allow connections to healthy proxies. + extraConnect := proxyHosts() if len(extraConnect) > 0 { for _, extraHost := range extraConnect { - if extraHost == "*" { + // Allow embedding the app host. + if experiments.Enabled(codersdk.ExperimentAITasks) { + cspSrcs.Append(CSPDirectiveFrameSrc, extraHost.AppHost) + } + if extraHost.Host == "*" { // '*' means all cspSrcs.Append(CSPDirectiveConnectSrc, "*") continue } - cspSrcs.Append(CSPDirectiveConnectSrc, fmt.Sprintf("wss://%[1]s ws://%[1]s", extraHost)) + // Avoid double-adding r.Host. + if extraHost.Host != r.Host { + cspSrcs.Append(CSPDirectiveConnectSrc, fmt.Sprintf("wss://%[1]s ws://%[1]s", extraHost.Host)) + } // We also require this to make http/https requests to the workspace proxy for latency checking. - cspSrcs.Append(CSPDirectiveConnectSrc, fmt.Sprintf("https://%[1]s http://%[1]s", extraHost)) + cspSrcs.Append(CSPDirectiveConnectSrc, fmt.Sprintf("https://%[1]s http://%[1]s", extraHost.Host)) } } diff --git a/coderd/httpmw/csp_test.go b/coderd/httpmw/csp_test.go index bef6ab196e..5fd4b5bbd3 100644 --- a/coderd/httpmw/csp_test.go +++ b/coderd/httpmw/csp_test.go @@ -1,28 +1,59 @@ package httpmw_test import ( - "fmt" "net/http" "net/http/httptest" + "strings" "testing" "github.com/stretchr/testify/require" "github.com/coder/coder/v2/coderd/httpmw" + "github.com/coder/coder/v2/coderd/proxyhealth" "github.com/coder/coder/v2/codersdk" ) -func TestCSPConnect(t *testing.T) { +func TestCSP(t *testing.T) { t.Parallel() - expected := []string{"example.com", "coder.com"} + proxyHosts := []*proxyhealth.ProxyHost{ + { + Host: "test.com", + AppHost: "*.test.com", + }, + { + Host: "coder.com", + AppHost: "*.coder.com", + }, + { + // Host is not added because it duplicates the host header. + Host: "example.com", + AppHost: "*.coder2.com", + }, + } expectedMedia := []string{"media.com", "media2.com"} + expected := []string{ + "frame-src 'self' *.test.com *.coder.com *.coder2.com", + "media-src 'self' media.com media2.com", + strings.Join([]string{ + "connect-src", "'self'", + // Added from host header. + "wss://example.com", "ws://example.com", + // Added via proxy hosts. + "wss://test.com", "ws://test.com", "https://test.com", "http://test.com", + "wss://coder.com", "ws://coder.com", "https://coder.com", "http://coder.com", + }, " "), + } + + // When the host is empty, it uses example.com. r := httptest.NewRequest(http.MethodGet, "/", nil) rw := httptest.NewRecorder() - httpmw.CSPHeaders(codersdk.Experiments{}, false, func() []string { - return expected + httpmw.CSPHeaders(codersdk.Experiments{ + codersdk.ExperimentAITasks, + }, false, func() []*proxyhealth.ProxyHost { + return proxyHosts }, map[httpmw.CSPFetchDirective][]string{ httpmw.CSPDirectiveMediaSrc: expectedMedia, })(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) { @@ -31,10 +62,6 @@ func TestCSPConnect(t *testing.T) { require.NotEmpty(t, rw.Header().Get("Content-Security-Policy"), "Content-Security-Policy header should not be empty") for _, e := range expected { - require.Containsf(t, rw.Header().Get("Content-Security-Policy"), fmt.Sprintf("ws://%s", e), "Content-Security-Policy header should contain ws://%s", e) - require.Containsf(t, rw.Header().Get("Content-Security-Policy"), fmt.Sprintf("wss://%s", e), "Content-Security-Policy header should contain wss://%s", e) - } - for _, e := range expectedMedia { - require.Containsf(t, rw.Header().Get("Content-Security-Policy"), e, "Content-Security-Policy header should contain %s", e) + require.Contains(t, rw.Header().Get("Content-Security-Policy"), e) } } diff --git a/coderd/proxyhealth/proxyhealth.go b/coderd/proxyhealth/proxyhealth.go new file mode 100644 index 0000000000..ac6dd5de59 --- /dev/null +++ b/coderd/proxyhealth/proxyhealth.go @@ -0,0 +1,8 @@ +package proxyhealth + +type ProxyHost struct { + // Host is the root host of the proxy. + Host string + // AppHost is the wildcard host where apps are hosted. + AppHost string +} diff --git a/coderd/workspaceapps/appurl/appurl.go b/coderd/workspaceapps/appurl/appurl.go index 1b1be9197b..2676c07164 100644 --- a/coderd/workspaceapps/appurl/appurl.go +++ b/coderd/workspaceapps/appurl/appurl.go @@ -289,3 +289,23 @@ func ExecuteHostnamePattern(pattern *regexp.Regexp, hostname string) (string, bo return matches[1], true } + +// ConvertAppHostForCSP converts the wildcard host to a format accepted by CSP. +// For example *--apps.coder.com must become *.coder.com. If there is no +// wildcard host, or it cannot be converted, return the base host. +func ConvertAppHostForCSP(host, wildcard string) string { + if wildcard == "" { + return host + } + parts := strings.Split(wildcard, ".") + for i, part := range parts { + if strings.Contains(part, "*") { + // The wildcard can only be in the first section. + if i != 0 { + return host + } + parts[i] = "*" + } + } + return strings.Join(parts, ".") +} diff --git a/coderd/workspaceapps/appurl/appurl_test.go b/coderd/workspaceapps/appurl/appurl_test.go index 8353768de1..3924949cb3 100644 --- a/coderd/workspaceapps/appurl/appurl_test.go +++ b/coderd/workspaceapps/appurl/appurl_test.go @@ -410,3 +410,59 @@ func TestCompileHostnamePattern(t *testing.T) { }) } } + +func TestConvertAppURLForCSP(t *testing.T) { + t.Parallel() + + testCases := []struct { + name string + host string + wildcard string + expected string + }{ + { + name: "Empty", + host: "example.com", + wildcard: "", + expected: "example.com", + }, + { + name: "NoAsterisk", + host: "example.com", + wildcard: "coder.com", + expected: "coder.com", + }, + { + name: "Asterisk", + host: "example.com", + wildcard: "*.coder.com", + expected: "*.coder.com", + }, + { + name: "FirstPrefix", + host: "example.com", + wildcard: "*--apps.coder.com", + expected: "*.coder.com", + }, + { + name: "FirstSuffix", + host: "example.com", + wildcard: "apps--*.coder.com", + expected: "*.coder.com", + }, + { + name: "Middle", + host: "example.com", + wildcard: "apps.*.com", + expected: "example.com", + }, + } + + for _, c := range testCases { + c := c + t.Run(c.name, func(t *testing.T) { + t.Parallel() + require.Equal(t, c.expected, appurl.ConvertAppHostForCSP(c.host, c.wildcard)) + }) + } +} diff --git a/enterprise/coderd/proxyhealth/proxyhealth.go b/enterprise/coderd/proxyhealth/proxyhealth.go index 33a5da7d26..7faac6a9e8 100644 --- a/enterprise/coderd/proxyhealth/proxyhealth.go +++ b/enterprise/coderd/proxyhealth/proxyhealth.go @@ -21,6 +21,8 @@ import ( "github.com/coder/coder/v2/coderd/database" "github.com/coder/coder/v2/coderd/database/dbauthz" "github.com/coder/coder/v2/coderd/prometheusmetrics" + agplproxyhealth "github.com/coder/coder/v2/coderd/proxyhealth" + "github.com/coder/coder/v2/coderd/workspaceapps/appurl" "github.com/coder/coder/v2/codersdk" ) @@ -63,7 +65,7 @@ type ProxyHealth struct { // Cached values for quick access to the health of proxies. cache *atomic.Pointer[map[uuid.UUID]ProxyStatus] - proxyHosts *atomic.Pointer[[]string] + proxyHosts *atomic.Pointer[[]*agplproxyhealth.ProxyHost] // PromMetrics healthCheckDuration prometheus.Histogram @@ -116,7 +118,7 @@ func New(opts *Options) (*ProxyHealth, error) { logger: opts.Logger, client: client, cache: &atomic.Pointer[map[uuid.UUID]ProxyStatus]{}, - proxyHosts: &atomic.Pointer[[]string]{}, + proxyHosts: &atomic.Pointer[[]*agplproxyhealth.ProxyHost]{}, healthCheckDuration: healthCheckDuration, healthCheckResults: healthCheckResults, }, nil @@ -144,9 +146,9 @@ func (p *ProxyHealth) Run(ctx context.Context) { } func (p *ProxyHealth) storeProxyHealth(statuses map[uuid.UUID]ProxyStatus) { - var proxyHosts []string + var proxyHosts []*agplproxyhealth.ProxyHost for _, s := range statuses { - if s.ProxyHost != "" { + if s.ProxyHost != nil { proxyHosts = append(proxyHosts, s.ProxyHost) } } @@ -190,23 +192,22 @@ type ProxyStatus struct { // then the proxy in hand. AKA if the proxy was updated, and the status was for // an older proxy. Proxy database.WorkspaceProxy - // ProxyHost is the host:port of the proxy url. This is included in the status - // to make sure the proxy url is a valid URL. It also makes it easier to - // escalate errors if the url.Parse errors (should never happen). - ProxyHost string + // ProxyHost is the base host:port and app host of the proxy. This is included + // in the status to make sure the proxy url is a valid URL. It also makes it + // easier to escalate errors if the url.Parse errors (should never happen). + ProxyHost *agplproxyhealth.ProxyHost Status Status Report codersdk.ProxyHealthReport CheckedAt time.Time } -// ProxyHosts returns the host:port of all healthy proxies. -// This can be computed from HealthStatus, but is cached to avoid the -// caller needing to loop over all proxies to compute this on all -// static web requests. -func (p *ProxyHealth) ProxyHosts() []string { +// ProxyHosts returns the host:port and wildcard host of all healthy proxies. +// This can be computed from HealthStatus, but is cached to avoid the caller +// needing to loop over all proxies to compute this on all static web requests. +func (p *ProxyHealth) ProxyHosts() []*agplproxyhealth.ProxyHost { ptr := p.proxyHosts.Load() if ptr == nil { - return []string{} + return []*agplproxyhealth.ProxyHost{} } return *ptr } @@ -350,7 +351,10 @@ func (p *ProxyHealth) runOnce(ctx context.Context, now time.Time) (map[uuid.UUID status.Report.Errors = append(status.Report.Errors, fmt.Sprintf("failed to parse proxy url: %s", err.Error())) status.Status = Unhealthy } - status.ProxyHost = u.Host + status.ProxyHost = &agplproxyhealth.ProxyHost{ + Host: u.Host, + AppHost: appurl.ConvertAppHostForCSP(u.Host, proxy.WildcardHostname), + } // Set the prometheus metric correctly. switch status.Status { diff --git a/enterprise/coderd/workspaceproxy.go b/enterprise/coderd/workspaceproxy.go index f495f1091a..16fe079d20 100644 --- a/enterprise/coderd/workspaceproxy.go +++ b/enterprise/coderd/workspaceproxy.go @@ -965,12 +965,8 @@ func convertRegion(proxy database.WorkspaceProxy, status proxyhealth.ProxyStatus func convertProxy(p database.WorkspaceProxy, status proxyhealth.ProxyStatus) codersdk.WorkspaceProxy { now := dbtime.Now() if p.IsPrimary() { - // Primary is always healthy since the primary serves the api that this - // is returned from. - u, _ := url.Parse(p.Url) status = proxyhealth.ProxyStatus{ Proxy: p, - ProxyHost: u.Host, Status: proxyhealth.Healthy, Report: codersdk.ProxyHealthReport{}, CheckedAt: now,