Initial

internal/client/fetch_status.go

@@ -0,0 +1,102 @@
+package client
+
+import (
+	"bytes"
+	"compress/gzip"
+	"context"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"netisjwt/internal/jws"
+)
+
+// PridobiInPreveriStatus poklice GET endpoint, preveri JWS in vrne status.
+func PridobiInPreveriStatus(ctx context.Context, targetURL string) (bool, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, targetURL, nil)
+	if err != nil {
+		return false, err
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return false, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
+	}
+
+	rawToken, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return false, err
+	}
+	token := strings.TrimSpace(string(rawToken))
+
+	claims, err := jws.PreveriZeton(token)
+	if err != nil {
+		return false, err
+	}
+	if err := jws.PreveriTrditve(claims, izdajateljIzURL(targetURL), time.Now()); err != nil {
+		return false, err
+	}
+
+	values, err := dekodirajKodiranSeznam(claims.Status.EncodedList)
+	if err != nil {
+		return false, err
+	}
+	return preberiBit(values, claims.Status.Index)
+}
+
+// izdajateljIzURL vrne url brez zadnjega segmenta index.
+func izdajateljIzURL(url string) string {
+	parts := strings.Split(url, "/")
+	if len(parts) < 5 {
+		return ""
+	}
+	return strings.Join(parts[:len(parts)-1], "/")
+}
+
+// dekodirajKodiranSeznam pretvori base64+gzip seznam v surove bajte.
+func dekodirajKodiranSeznam(encoded string) ([]byte, error) {
+	compressed, err := base64.StdEncoding.DecodeString(encoded)
+	if err != nil {
+		return nil, err
+	}
+
+	reader, err := newGzipBralnik(compressed)
+	if err != nil {
+		return nil, err
+	}
+	defer reader.Close()
+
+	return io.ReadAll(reader)
+}
+
+// preberiBit prebere en bit iz podanega bajtnega zaporedja.
+func preberiBit(data []byte, index int) (bool, error) {
+	if index < 0 {
+		return false, errors.New("index must be >= 0")
+	}
+	byteIdx := index / 8
+	if byteIdx >= len(data) {
+		return false, errors.New("index is out of encoded list range")
+	}
+	mask := byte(1 << (index % 8))
+	return data[byteIdx]&mask != 0, nil
+}
+
+type gzipReader interface {
+	io.Reader
+	Close() error
+}
+
+// newGzipBralnik ustvari gzip reader iz podanih bajtov.
+func newGzipBralnik(input []byte) (gzipReader, error) {
+	return gzip.NewReader(bytes.NewReader(input))
+}

internal/client/fetch_status_test.go

@@ -0,0 +1,48 @@
+package client
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	appcrypto "netisjwt/internal/crypto"
+	"netisjwt/internal/jws"
+	"netisjwt/internal/statuslist"
+)
+
+func TestFetchAndVerifyStatus(t *testing.T) {
+	privatePEM, err := appcrypto.UstvariZasebniKljucECDSAP256PEM()
+	if err != nil {
+		t.Fatalf("key gen: %v", err)
+	}
+
+	list := statuslist.New()
+	list.Dodaj(false)
+	list.Dodaj(true)
+
+	tokenPath := "/api/status/demo/1"
+	var baseURL string
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		claims, err := jws.SestaviTrditve(baseURL+"/api/status/demo", list, 1, time.Now())
+		if err != nil {
+			t.Fatalf("build claims: %v", err)
+		}
+		token, err := jws.UstvariZetonIzPEM(privatePEM, claims)
+		if err != nil {
+			t.Fatalf("create token: %v", err)
+		}
+		_, _ = w.Write([]byte(token))
+	}))
+	defer server.Close()
+	baseURL = server.URL
+
+	value, err := PridobiInPreveriStatus(context.Background(), server.URL+tokenPath)
+	if err != nil {
+		t.Fatalf("fetch and verify: %v", err)
+	}
+	if !value {
+		t.Fatalf("expected true")
+	}
+}