feat: implement imprint/impressum support (#706)

* feat: implement imprint/impressum support

Closes #362

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(docs/anubis): enable an imprint

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: fix the end of the sentence, comment out a default impressum

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: link back to impressum page

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/challenge/challenge.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 
 	"github.com/TecharoHQ/anubis/lib/policy"
+	"github.com/TecharoHQ/anubis/lib/policy/config"
 	"github.com/a-h/templ"
 )
 
@@ -40,12 +41,19 @@ func Methods() []string {
 	return result
 }
 
+type IssueInput struct {
+	Impressum *config.Impressum
+	Rule      *policy.Bot
+	Challenge string
+	OGTags    map[string]string
+}
+
 type Impl interface {
 	// Setup registers any additional routes with the Impl for assets or API routes.
 	Setup(mux *http.ServeMux)
 
 	// Issue a new challenge to the user, called by the Anubis.
-	Issue(r *http.Request, lg *slog.Logger, rule *policy.Bot, challenge string, ogTags map[string]string) (templ.Component, error)
+	Issue(r *http.Request, lg *slog.Logger, in *IssueInput) (templ.Component, error)
 
 	// Validate a challenge, making sure that it passes muster.
 	Validate(r *http.Request, lg *slog.Logger, rule *policy.Bot, challenge string) error

lib/challenge/metarefresh/metarefresh.go

@@ -23,7 +23,7 @@ type Impl struct{}
 
 func (i *Impl) Setup(mux *http.ServeMux) {}
 
-func (i *Impl) Issue(r *http.Request, lg *slog.Logger, rule *policy.Bot, challenge string, ogTags map[string]string) (templ.Component, error) {
+func (i *Impl) Issue(r *http.Request, lg *slog.Logger, in *challenge.IssueInput) (templ.Component, error) {
 	u, err := r.URL.Parse(anubis.BasePrefix + "/.within.website/x/cmd/anubis/api/pass-challenge")
 	if err != nil {
 		return nil, fmt.Errorf("can't render page: %w", err)
@@ -31,10 +31,10 @@ func (i *Impl) Issue(r *http.Request, lg *slog.Logger, rule *policy.Bot, challen
 
 	q := u.Query()
 	q.Set("redir", r.URL.String())
-	q.Set("challenge", challenge)
+	q.Set("challenge", in.Challenge)
 	u.RawQuery = q.Encode()
 
-	component, err := web.BaseWithChallengeAndOGTags("Making sure you're not a bot!", page(challenge, u.String(), rule.Challenge.Difficulty), challenge, rule.Challenge, ogTags)
+	component, err := web.BaseWithChallengeAndOGTags("Making sure you're not a bot!", page(in.Challenge, u.String(), in.Rule.Challenge.Difficulty), in.Impressum, in.Challenge, in.Rule.Challenge, in.OGTags)
 	if err != nil {
 		return nil, fmt.Errorf("can't render page: %w", err)
 	}

lib/challenge/proofofwork/proofofwork.go

@@ -28,8 +28,8 @@ func (i *Impl) Setup(mux *http.ServeMux) {
 	/* no implementation required */
 }
 
-func (i *Impl) Issue(r *http.Request, lg *slog.Logger, rule *policy.Bot, challenge string, ogTags map[string]string) (templ.Component, error) {
-	component, err := web.BaseWithChallengeAndOGTags("Making sure you're not a bot!", web.Index(), challenge, rule.Challenge, ogTags)
+func (i *Impl) Issue(r *http.Request, lg *slog.Logger, in *chall.IssueInput) (templ.Component, error) {
+	component, err := web.BaseWithChallengeAndOGTags("Making sure you're not a bot!", web.Index(), in.Impressum, in.Challenge, in.Rule.Challenge, in.OGTags)
 	if err != nil {
 		return nil, fmt.Errorf("can't render page: %w", err)
 	}

lib/challenge/proofofwork/proofofwork_test.go

@@ -124,7 +124,12 @@ func TestBasic(t *testing.T) {
 		t.Run(cs.name, func(t *testing.T) {
 			lg := slog.With()
 
-			if _, err := i.Issue(cs.req, lg, bot, cs.challengeStr, nil); err != nil {
+			inp := &challenge.IssueInput{
+				Rule:      bot,
+				Challenge: cs.challengeStr,
+			}
+
+			if _, err := i.Issue(cs.req, lg, inp); err != nil {
 				t.Errorf("can't issue challenge: %v", err)
 			}
 

lib/config.go

@@ -24,6 +24,7 @@ import (
 	"github.com/TecharoHQ/anubis/lib/policy/config"
 	"github.com/TecharoHQ/anubis/web"
 	"github.com/TecharoHQ/anubis/xess"
+	"github.com/a-h/templ"
 )
 
 type Options struct {
@@ -149,6 +150,14 @@ func New(opts Options) (*Server, error) {
 		}), "GET")
 	}
 
+	if opts.Policy.Impressum != nil {
+		registerWithPrefix(anubis.APIPrefix+"imprint", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			templ.Handler(
+				web.Base(opts.Policy.Impressum.Page.Title, opts.Policy.Impressum.Page, opts.Policy.Impressum),
+			).ServeHTTP(w, r)
+		}), "GET")
+	}
+
 	registerWithPrefix(anubis.APIPrefix+"pass-challenge", http.HandlerFunc(result.PassChallenge), "GET")
 	registerWithPrefix(anubis.APIPrefix+"check", http.HandlerFunc(result.maybeReverseProxyHttpStatusOnly), "")
 	registerWithPrefix("/", http.HandlerFunc(result.maybeReverseProxyOrPage), "")

lib/http.go

@@ -102,7 +102,14 @@ func (s *Server) RenderIndex(w http.ResponseWriter, r *http.Request, rule *polic
 		return
 	}
 
-	component, err := impl.Issue(r, lg, rule, challengeStr, ogTags)
+	in := &challenge.IssueInput{
+		Impressum: s.policy.Impressum,
+		Rule:      rule,
+		Challenge: challengeStr,
+		OGTags:    ogTags,
+	}
+
+	component, err := impl.Issue(r, lg, in)
 	if err != nil {
 		lg.Error("[unexpected] render failed, please open an issue", "err", err) // This is likely a bug in the template. Should never be triggered as CI tests for this.
 		s.respondWithError(w, r, "Internal Server Error: please contact the administrator and ask them to look for the logs around \"RenderIndex\"")
@@ -118,7 +125,7 @@ func (s *Server) RenderIndex(w http.ResponseWriter, r *http.Request, rule *polic
 
 func (s *Server) RenderBench(w http.ResponseWriter, r *http.Request) {
 	templ.Handler(
-		web.Base("Benchmarking Anubis!", web.Bench()),
+		web.Base("Benchmarking Anubis!", web.Bench(), s.policy.Impressum),
 	).ServeHTTP(w, r)
 }
 
@@ -127,7 +134,7 @@ func (s *Server) respondWithError(w http.ResponseWriter, r *http.Request, messag
 }
 
 func (s *Server) respondWithStatus(w http.ResponseWriter, r *http.Request, msg string, status int) {
-	templ.Handler(web.Base("Oh noes!", web.ErrorPage(msg, s.opts.WebmasterEmail)), templ.WithStatus(status)).ServeHTTP(w, r)
+	templ.Handler(web.Base("Oh noes!", web.ErrorPage(msg, s.opts.WebmasterEmail), s.policy.Impressum), templ.WithStatus(status)).ServeHTTP(w, r)
 }
 
 func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -180,7 +187,7 @@ func (s *Server) ServeHTTPNext(w http.ResponseWriter, r *http.Request) {
 		}
 
 		templ.Handler(
-			web.Base("You are not a bot!", web.StaticHappy()),
+			web.Base("You are not a bot!", web.StaticHappy(), s.policy.Impressum),
 		).ServeHTTP(w, r)
 	} else {
 		requestsProxied.WithLabelValues(r.Host).Inc()

lib/policy/config/config.go

@@ -327,6 +327,7 @@ type fileConfig struct {
 	Bots        []BotOrImport       `json:"bots"`
 	DNSBL       bool                `json:"dnsbl"`
 	OpenGraph   openGraphFileConfig `json:"openGraph,omitempty"`
+	Impressum   *Impressum          `json:"impressum,omitempty"`
 	StatusCodes StatusCodes         `json:"status_codes"`
 	Thresholds  []Threshold         `json:"thresholds"`
 }
@@ -421,6 +422,14 @@ func Load(fin io.Reader, fname string) (*Config, error) {
 		}
 	}
 
+	if c.Impressum != nil {
+		if err := c.Impressum.Valid(); err != nil {
+			validationErrs = append(validationErrs, err)
+		}
+
+		result.Impressum = c.Impressum
+	}
+
 	if len(c.Thresholds) == 0 {
 		c.Thresholds = DefaultThresholds
 	}
@@ -445,6 +454,7 @@ type Config struct {
 	Bots        []BotConfig
 	Thresholds  []Threshold
 	DNSBL       bool
+	Impressum   *Impressum
 	OpenGraph   OpenGraph
 	StatusCodes StatusCodes
 }

lib/policy/config/impressum.go

@@ -0,0 +1,71 @@
+package config
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+)
+
+var ErrMissingValue = errors.New("config: missing value")
+
+type Impressum struct {
+	Footer string        `json:"footer" yaml:"footer"`
+	Page   ImpressumPage `json:"page" yaml:"page"`
+}
+
+func (i Impressum) Render(_ context.Context, w io.Writer) error {
+	if _, err := fmt.Fprint(w, i.Footer); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (i Impressum) Valid() error {
+	var errs []error
+
+	if len(i.Footer) == 0 {
+		errs = append(errs, fmt.Errorf("%w: impressum footer must be defined", ErrMissingValue))
+	}
+
+	if err := i.Page.Valid(); err != nil {
+		errs = append(errs, err)
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(errs...)
+	}
+
+	return nil
+}
+
+type ImpressumPage struct {
+	Title string `json:"title" yaml:"title"`
+	Body  string `json:"body" yaml:"body"`
+}
+
+func (ip ImpressumPage) Render(_ context.Context, w io.Writer) error {
+	if _, err := fmt.Fprint(w, ip.Body); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (ip ImpressumPage) Valid() error {
+	var errs []error
+
+	if len(ip.Title) == 0 {
+		errs = append(errs, fmt.Errorf("%w: impressum page title must be defined", ErrMissingValue))
+	}
+
+	if len(ip.Body) == 0 {
+		errs = append(errs, fmt.Errorf("%w: impressum body title must be defined", ErrMissingValue))
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(errs...)
+	}
+
+	return nil
+}

lib/policy/config/impressum_test.go

@@ -0,0 +1,62 @@
+package config
+
+import (
+	"bytes"
+	"errors"
+	"testing"
+)
+
+func TestImpressumValid(t *testing.T) {
+	for _, cs := range []struct {
+		name string
+		inp  Impressum
+		err  error
+	}{
+		{
+			name: "basic happy path",
+			inp: Impressum{
+				Footer: "<p>Website hosted by Techaro.<p>",
+				Page: ImpressumPage{
+					Title: "Techaro Imprint",
+					Body:  "<p>This is an imprint page.</p>",
+				},
+			},
+			err: nil,
+		},
+		{
+			name: "no footer",
+			inp: Impressum{
+				Footer: "",
+				Page: ImpressumPage{
+					Title: "Techaro Imprint",
+					Body:  "<p>This is an imprint page.</p>",
+				},
+			},
+			err: ErrMissingValue,
+		},
+		{
+			name: "page not valid",
+			inp: Impressum{
+				Footer: "test page please ignore",
+			},
+			err: ErrMissingValue,
+		},
+	} {
+		t.Run(cs.name, func(t *testing.T) {
+			if err := cs.inp.Valid(); !errors.Is(err, cs.err) {
+				t.Logf("want: %v", cs.err)
+				t.Logf("got:  %v", err)
+				t.Error("validation failed")
+			}
+
+			var buf bytes.Buffer
+			if err := cs.inp.Render(t.Context(), &buf); err != nil {
+				t.Errorf("can't render footer: %v", err)
+			}
+
+			if err := cs.inp.Page.Render(t.Context(), &buf); err != nil {
+				t.Errorf("can't render page: %v", err)
+			}
+		})
+	}
+}

lib/policy/config/testdata/bad/impressum-no-footer.yaml

@@ -0,0 +1,11 @@
+bots:
+  - name: simple-weight-adjust
+    action: WEIGH
+    user_agent_regex: Mozilla
+    weight:
+      adjust: 5
+
+impressum:
+  page:
+    title: Test
+    body: <p>This is a test</p>

lib/policy/config/testdata/bad/impressum-no-page-contents.yaml

@@ -0,0 +1,10 @@
+bots:
+  - name: simple-weight-adjust
+    action: WEIGH
+    user_agent_regex: Mozilla
+    weight:
+      adjust: 5
+
+impressum:
+  footer: "Hi there these are WORDS on the INTERNET."
+  page: {}

lib/policy/config/testdata/good/impressum.yaml

@@ -0,0 +1,10 @@
+bots:
+  - name: simple
+    action: CHALLENGE
+    user_agent_regex: Mozilla
+
+impressum:
+  footer: "Hi these are WORDS on the INTERNET."
+  page:
+    title: Test
+    body: <p>This is a test</p>

lib/policy/policy.go

@@ -31,6 +31,7 @@ type ParsedConfig struct {
 	Bots              []Bot
 	Thresholds        []*Threshold
 	DNSBL             bool
+	Impressum         *config.Impressum
 	OpenGraph         config.OpenGraph
 	DefaultDifficulty int
 	StatusCodes       config.StatusCodes
@@ -150,6 +151,8 @@ func ParseConfig(ctx context.Context, fin io.Reader, fname string, defaultDiffic
 			parsedBot.Weight = b.Weight
 		}
 
+		result.Impressum = c.Impressum
+
 		parsedBot.Rules = cl
 
 		result.Bots = append(result.Bots, parsedBot)