feat(quick-261009-dkv): Oeffentliche Links nach den Regeln der Nextcloud, Uebersichten und Annehmen, Schnittstelle

- Links anlegen und aendern: Passwort, Ablaufdatum und Bezeichnung nur im JSON-Koerper,
  Vorpruefung aus den frisch gelesenen Faehigkeiten (Passwort/Ablauf verlangt, Hochladen,
  mehrere Links), echte Datumspruefung, nur geaenderte Felder beim Aendern
- Routen shares/mine, shares/received (angenommen plus offen, 404/405 bei offen = leer)
  und POST shares/:id/accept am Ende der Klasse
- Fehlerzweige fuer Passwort und Ablauf mit Tests; nie Passwort in Antwort oder Fehler
- Live-Test e2e-shares.sh: Abschnitte links (Pflicht-Passwort und Pflicht-Ablauf per occ)
  und received (eingehend, offen, annehmen, verlassen)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.planning/quick/261009-dkv-modul-dateien-etappe-2a-teilen-von-datei/e2e/e2e-shares.sh

@@ -1,8 +1,9 @@
 #!/usr/bin/env bash
 # quick-261009-dkv: Teilen-Schnittstelle gegen die Test-Nextcloud (tessera-nc-test).
 #   Aufruf: e2e-shares.sh [people|links|received|version|all]   (Vorgabe: all)
-#   Aufgabe 1 liefert Aufbau, Aufraeumen und den Abschnitt "people"; links und received
-#   folgen in Aufgabe 2, version in Aufgabe 3.
+#   Aufgabe 1 liefert Aufbau, Aufraeumen und den Abschnitt "people"; Aufgabe 2 die Abschnitte
+#   "links" (Passwort- und Ablaufregeln der Nextcloud per occ umgeschaltet) und "received"
+#   (eingehende und offene Freigaben); version folgt in Aufgabe 3.
 # Setzt einen laufenden Stack (api neu gebaut: docker compose up -d --build api) und
 # nc-test-setup.sh voraus. Nur Testwerte; liest keine .env-Dateien.
 #
@@ -25,13 +26,20 @@ ANNA="anna:User1-Pass-12345"
 BEN="ben:User3-Pass-12345"
 EPOCH=$(date +%s)
 FIX="Tessera-Teilen-$EPOCH"
+BENFIX="Ben-Ordner-$EPOCH"
+BENBOX="Ben-Briefkasten-$EPOCH"
 START_ISO=$(date -u +%Y-%m-%dT%H:%M:%SZ)
+REPO="$(cd "$HERE/../../../.." && pwd)"
 
 # --- Aufraeumen: alles zuruecksetzen, was das Skript angefasst hat ----------------------------
 cleanup() {
   local rc=$?
   set +e
   curl -s -o /dev/null -u "$ANNA" -X DELETE "$NC_DAV/files/anna/$FIX" 2>/dev/null
+  curl -s -o /dev/null -u "$BEN" -X DELETE "$NC_DAV/files/ben/$BENFIX" 2>/dev/null
+  curl -s -o /dev/null -u "$BEN" -X DELETE "$NC_DAV/files/ben/$BENBOX" 2>/dev/null
+  # Papierkorb leeren, damit abgelehnte oder verlassene Ordner nicht liegen bleiben
+  NC_OCC trashbin:cleanup ben >/dev/null 2>&1
   NC_OCC config:system:delete ratelimit.protection.enabled >/dev/null 2>&1
   for key in shareapi_enforce_links_password shareapi_default_expire_date \
     shareapi_enforce_expire_date shareapi_expire_after_n_days; do
@@ -96,6 +104,50 @@ d=json.load(open(sys.argv[1]))["ocs"]["data"]
 print([s["permissions"] for s in d if s.get("file_target","").lstrip("/")==sys.argv[2]][0])' "$E2E_TMP/ben.out" "$1"
 }
 
+# policy_wait <python-ausdruck> <beschreibung> — wartet bis zu 30 s, bis die Richtlinie den Ausdruck
+# erfuellt. Die Nextcloud haelt ihre Faehigkeiten nach einer occ-Aenderung kurz noch in einem
+# Zwischenspeicher (gemessen: Sekunden), Tessera selbst speichert nichts.
+policy_wait() {
+  local i code ok=0
+  for i in $(seq 1 40); do
+    code=$(call GET shares/policy)
+    if [ "$code" = "200" ] && [ "$(jq_py "$1")" = "True" ]; then
+      ok=$((ok + 1))
+      # dreimal hintereinander, falls mehrere Nextcloud-Prozesse verschieden schnell nachziehen
+      [ "$ok" -ge 3 ] && return 0
+    else
+      ok=0
+      sleep 1
+    fi
+  done
+  e2e_expect True "$(jq_py "$1")" "$2"
+}
+
+# Direkt bei der Nextcloud: Anzahl der Link-Freigaben (Art 3) eines Pfads in annas Konto
+anna_link_count() {
+  curl -s -u "$ANNA" -H 'OCS-APIRequest: true' -H 'Accept: application/json' -G \
+    --data-urlencode "path=$1" "$NC_OCS/shares" -o "$E2E_TMP/anna.out"
+  python3 -I -c 'import json,sys
+d=json.load(open(sys.argv[1]))["ocs"]["data"]
+print(len([s for s in d if s.get("share_type")==3]))' "$E2E_TMP/anna.out"
+}
+
+# nc_put <id> <schluessel> <wert> — dieselbe Aenderung DIREKT bei der Nextcloud (nur zum Messen des
+# Status, den Tessera sonst hinter einem eigenen Fehlercode verbirgt); gibt den Status aus.
+nc_put() {
+  curl -s -o "$E2E_TMP/nc-put.out" -w '%{http_code}' -u "$ANNA" -X PUT \
+    -H 'OCS-APIRequest: true' -H 'Accept: application/json' \
+    --data-urlencode "$2=$3" "$NC_OCS/shares/$1"
+}
+
+# Direkt bei der Nextcloud: ben teilt einen Ordner mit anna (nur Ansehen); gibt den Status aus.
+ben_share_with_anna() {
+  curl -s -o /dev/null -w '%{http_code}' -u "$BEN" -X MKCOL "$NC_DAV/files/ben/$1" >/dev/null
+  curl -s -o "$E2E_TMP/ben-share.out" -w '%{http_code}' -u "$BEN" -X POST \
+    -H 'OCS-APIRequest: true' -H 'Accept: application/json' \
+    --data-urlencode "path=/$1" -d shareType=0 -d shareWith=anna -d permissions=1 "$NC_OCS/shares"
+}
+
 # --- Aufbau --------------------------------------------------------------------------------------
 e2e_wait_health
 e2e_login "$ADMIN"
@@ -209,8 +261,194 @@ section_people() {
   echo "e2e shares people ok"
 }
 
-section_links() { echo "e2e shares links: folgt in Aufgabe 2"; }
-section_received() { echo "e2e shares received: folgt in Aufgabe 2"; }
+section_links() {
+  local code id1 id2 id3 id4 before pw plus3 plus30 measured ids urls=""
+
+  # Ausgangslage: keine Pflicht, kein Ablauf (Zustand des Skripts, nicht der Vorlauf)
+  NC_OCC config:app:delete core shareapi_enforce_links_password >/dev/null 2>&1 || true
+  policy_wait 'd["links"]["enabled"] is True and d["links"]["passwordRequired"] is False and d["links"]["expiryEnforced"] is False and d["links"]["expiryDefaultDays"] is None' "Ausgangslage: Links an, keine Pflicht"
+
+  # Link ohne Passwort und ohne Ablauf (freiwillig)
+  code=$(call POST shares "{\"path\":\"/$FIX\",\"kind\":\"link\",\"access\":\"view\",\"expireDate\":\"\"}")
+  e2e_expect 201 "$code" "Link anlegen"
+  e2e_expect True "$(jq_py 'd["kind"]=="link" and d["hasPassword"] is False and d["expiration"] is None and d["access"]=="view" and d["permissions"] & 15 == 1')" "Link: Ansehen, ohne Passwort, ohne Ablauf"
+  e2e_expect True "$(jq_py 'd["url"].startswith("'"$NC_BASE"'/")')" "Link-Adresse beginnt mit der Nextcloud-Adresse"
+  id1=$(jq_py 'd["id"]')
+  urls="$urls $(jq_py 'd["url"]')"
+
+  # Nur hochladen bei einem Ordner
+  code=$(call POST shares "{\"path\":\"/$FIX/Briefkasten\",\"kind\":\"link\",\"access\":\"upload\",\"expireDate\":\"\"}")
+  e2e_expect 201 "$code" "Briefkasten-Link anlegen"
+  e2e_expect True "$(jq_py 'd["permissions"] & 15 == 4 and d["access"]=="upload"')" "Briefkasten-Link: Berechtigung 4 (die Nextcloud setzt bei Links das Teilen-Bit dazu)"
+  id2=$(jq_py 'd["id"]')
+  urls="$urls $(jq_py 'd["url"]')"
+
+  # Nur hochladen bei einer Datei: abgelehnt, nichts bei der Nextcloud
+  before=$(anna_link_count "/$FIX/Bericht.txt")
+  code=$(call POST shares "{\"path\":\"/$FIX/Bericht.txt\",\"kind\":\"link\",\"access\":\"upload\",\"expireDate\":\"\"}")
+  e2e_expect 400 "$code" "Nur hochladen bei einer Datei"
+  e2e_contains "$E2E_TMP/body.out" '"code":"shareAccessInvalid"' "Datei-Upload: shareAccessInvalid"
+  e2e_expect "$before" "$(anna_link_count "/$FIX/Bericht.txt")" "Nextcloud hat keinen neuen Link fuer die Datei"
+
+  # --- Passwort wird von der Nextcloud verlangt ---
+  NC_OCC config:app:set core shareapi_enforce_links_password --value=true --type=boolean >/dev/null
+  policy_wait 'd["links"]["passwordRequired"] is True' "Richtlinie: Passwort verlangt"
+
+  before=$(anna_link_count "/$FIX")
+  code=$(call POST shares "{\"path\":\"/$FIX\",\"kind\":\"link\",\"access\":\"view\",\"expireDate\":\"\"}")
+  e2e_expect 400 "$code" "Link ohne Passwort bei Pflicht"
+  e2e_contains "$E2E_TMP/body.out" '"code":"sharePasswordRequired"' "ohne Passwort: sharePasswordRequired"
+  e2e_expect "$before" "$(anna_link_count "/$FIX")" "Nextcloud hat keinen neuen Link (Passwort fehlte)"
+
+  pw="Tessera-E2E-$(python3 -I -c 'import secrets,string;print("".join(secrets.choice(string.ascii_letters+string.digits) for _ in range(16)))')"
+  code=$(call POST shares "{\"path\":\"/$FIX\",\"kind\":\"link\",\"access\":\"view\",\"password\":\"$pw\",\"expireDate\":\"\",\"label\":\"Kunde\"}")
+  e2e_expect 201 "$code" "Link mit starkem Passwort"
+  e2e_expect True "$(jq_py 'd["hasPassword"] is True and d["label"]=="Kunde"')" "Link: hasPassword, Bezeichnung"
+  if grep -qF -- "$pw" "$E2E_TMP/body.out"; then e2e_fail "das Passwort steht in der Antwort"; fi
+  id3=$(jq_py 'd["id"]')
+  urls="$urls $(jq_py 'd["url"]')"
+
+  code=$(call PUT "shares/$id3" '{"password":"abc"}')
+  e2e_expect 400 "$code" "schwaches Passwort beim Aendern"
+  e2e_contains "$E2E_TMP/body.out" '"code":"sharePasswordRejected"' "schwach: sharePasswordRejected"
+  e2e_expect True "$(jq_py 'bool(d.get("ncMessage"))')" "schwach: Meldung der Nextcloud vorhanden"
+  measured=$(nc_put "$id3" password abc)
+  echo "gemessen: Nextcloud antwortet auf PUT mit schwachem Passwort mit Status $measured"
+
+  code=$(call PUT "shares/$id3" '{"password":""}')
+  e2e_expect 400 "$code" "Passwort entfernen bei Pflicht"
+  e2e_contains "$E2E_TMP/body.out" '"code":"sharePasswordRequired"' "entfernen: sharePasswordRequired"
+
+  NC_OCC config:app:delete core shareapi_enforce_links_password >/dev/null
+  policy_wait 'd["links"]["passwordRequired"] is False' "Richtlinie: Passwort wieder freiwillig"
+
+  # --- Ablaufdatum wird von der Nextcloud verlangt (7 Tage) ---
+  NC_OCC config:app:set core shareapi_default_expire_date --value=true --type=boolean >/dev/null
+  NC_OCC config:app:set core shareapi_enforce_expire_date --value=true --type=boolean >/dev/null
+  NC_OCC config:app:set core shareapi_expire_after_n_days --value=7 >/dev/null
+  policy_wait 'd["links"]["expiryDefaultDays"]==7 and d["links"]["expiryEnforced"] is True' "Richtlinie: Ablauf 7 Tage verlangt"
+
+  before=$(anna_link_count "/$FIX")
+  code=$(call POST shares "{\"path\":\"/$FIX\",\"kind\":\"link\",\"access\":\"view\",\"expireDate\":\"\"}")
+  e2e_expect 400 "$code" "Link ohne Ablauf bei Pflicht"
+  e2e_contains "$E2E_TMP/body.out" '"code":"shareExpiryRequired"' "ohne Ablauf: shareExpiryRequired"
+  e2e_expect "$before" "$(anna_link_count "/$FIX")" "Nextcloud hat keinen neuen Link (Ablauf fehlte)"
+
+  plus3=$(date -u -d '+3 days' +%F)
+  plus30=$(date -u -d '+30 days' +%F)
+  code=$(call POST shares "{\"path\":\"/$FIX\",\"kind\":\"link\",\"access\":\"view\",\"expireDate\":\"$plus3\"}")
+  e2e_expect 201 "$code" "Link mit Ablauf in 3 Tagen"
+  e2e_expect "$plus3" "$(jq_py 'd["expiration"]')" "Link: Ablauf wie gesendet"
+  id4=$(jq_py 'd["id"]')
+  urls="$urls $(jq_py 'd["url"]')"
+
+  code=$(call POST shares "{\"path\":\"/$FIX\",\"kind\":\"link\",\"access\":\"view\",\"expireDate\":\"$plus30\"}")
+  echo "gemessen: Tessera antwortet auf ein neues Datum jenseits des Hoechstwerts mit Status $code"
+  e2e_expect 400 "$code" "Link mit Ablauf jenseits des Hoechstwerts"
+  e2e_contains "$E2E_TMP/body.out" '"code":"shareExpiryInvalid"' "zu spaet: shareExpiryInvalid"
+
+  code=$(call PUT "shares/$id4" "{\"expireDate\":\"$plus30\"}")
+  e2e_expect 400 "$code" "Ablauf jenseits des Hoechstwerts beim Aendern"
+  e2e_contains "$E2E_TMP/body.out" '"code":"shareExpiryInvalid"' "Aendern, zu spaet: shareExpiryInvalid"
+  measured=$(nc_put "$id4" expireDate "$plus30")
+  echo "gemessen: Nextcloud antwortet auf PUT mit Ablauf jenseits des Hoechstwerts mit Status $measured"
+
+  code=$(call PUT "shares/$id4" '{"expireDate":""}')
+  e2e_expect 400 "$code" "Ablauf entfernen bei Pflicht"
+  e2e_contains "$E2E_TMP/body.out" '"code":"shareExpiryRequired"' "Ablauf entfernen: shareExpiryRequired"
+
+  before=$(anna_link_count "/$FIX")
+  code=$(call POST shares "{\"path\":\"/$FIX\",\"kind\":\"link\",\"access\":\"view\",\"expireDate\":\"31.12.2026x\"}")
+  e2e_expect 400 "$code" "Datum in falschem Format"
+  e2e_expect "$before" "$(anna_link_count "/$FIX")" "Nextcloud hat keinen neuen Link (Datum ungueltig)"
+
+  for key in shareapi_default_expire_date shareapi_enforce_expire_date shareapi_expire_after_n_days; do
+    NC_OCC config:app:delete core "$key" >/dev/null
+  done
+  policy_wait 'd["links"]["expiryDefaultDays"] is None and d["links"]["expiryEnforced"] is False' "Richtlinie: Ablauf wieder frei"
+
+  # Uebersicht und Aufraeumen
+  code=$(call GET shares/mine)
+  e2e_expect 200 "$code" "Eigene Freigaben"
+  ids="$id1 $id2 $id3 $id4"
+  for id in $ids; do
+    e2e_expect True "$(jq_py 'any(s["id"]=="'"$id"'" and s["kind"]=="link" for s in d["shares"])')" "mine enthaelt Link $id"
+  done
+  for id in $ids; do
+    code=$(call DELETE "shares/$id")
+    e2e_expect 200 "$code" "Link $id loeschen"
+  done
+  e2e_expect 0 "$(anna_link_count "/$FIX")" "alle Links der Fixture sind weg"
+
+  # Weder Passwort noch Link-Adresse im Protokoll der API
+  local log
+  log=$(cd "$REPO" && docker compose logs api --since "$START_ISO" 2>&1 || true)
+  case "$log" in *"$pw"*) e2e_fail "das Passwort steht im Protokoll der API" ;; esac
+  for u in $urls; do
+    case "$log" in *"$u"*) e2e_fail "eine Link-Adresse steht im Protokoll der API" ;; esac
+  done
+
+  echo "e2e shares links ok"
+}
+
+section_received() {
+  local code id sfx_letters pid
+
+  # Eingehend und angenommen (Vorgabe der Nextcloud: sofort angenommen)
+  NC_OCC user:setting --delete anna files_sharing default_accept >/dev/null 2>&1 || true
+  code=$(ben_share_with_anna "$BENFIX")
+  e2e_expect 200 "$code" "ben teilt einen Ordner mit anna"
+
+  code=$(call GET shares/received)
+  e2e_expect 200 "$code" "Mit mir geteilt"
+  e2e_expect True "$(jq_py 'any(s["target"]=="/'"$BENFIX"'" and s["ownerName"]=="Ben Beispiel" and s["canEdit"] is False and s["kind"]=="user" for s in d["shares"])')" "received: Ordner von Ben Beispiel, nicht aenderbar"
+  id=$(jq_py '[s["id"] for s in d["shares"] if s["target"]=="/'"$BENFIX"'"][0]')
+
+  code=$(qget files path /)
+  e2e_expect 200 "$code" "Wurzel auflisten"
+  sfx_letters=$(jq_py '[e["permissions"] for e in d["entries"] if e["name"]=="'"$BENFIX"'"][0]')
+  echo "gemessen: Berechtigungsbuchstaben des eingehenden Ordners: $sfx_letters"
+  case "$sfx_letters" in *S*) ;; *) e2e_fail "eingehender Eintrag ohne Buchstaben S ($sfx_letters): Kennzeichen auf nc:mount-type umstellen" ;; esac
+
+  code=$(call GET shares/mine)
+  e2e_expect 200 "$code" "Eigene Freigaben"
+  e2e_expect True "$(jq_py 'not any(s["target"]=="/'"$BENFIX"'" or s["path"]=="/'"$BENFIX"'" for s in d["shares"])')" "mine enthaelt die eingehende Freigabe nicht"
+
+  # Verlassen (DELETE durch die Empfaengerin)
+  code=$(call DELETE "shares/$id")
+  e2e_expect 200 "$code" "Freigabe verlassen"
+  code=$(call GET shares/received)
+  e2e_expect True "$(jq_py 'not any(s["target"]=="/'"$BENFIX"'" for s in d["shares"]+d["pending"])')" "received: die verlassene Freigabe ist weg"
+  curl -s -u "$BEN" -H 'OCS-APIRequest: true' -H 'Accept: application/json' -G \
+    --data-urlencode "path=/$BENFIX" "$NC_OCS/shares" -o "$E2E_TMP/ben-after.out"
+  echo "gemessen: bens eigene Liste nach dem Verlassen: $(python3 -I -c 'import json,sys
+d=json.load(open(sys.argv[1]))["ocs"]["data"]
+print(len(d), "Freigaben", [(s.get("share_type"), s.get("share_with"), s.get("permissions")) for s in d])' "$E2E_TMP/ben-after.out")"
+
+  # Offene Freigabe: annas Vorgabe auf "nicht automatisch annehmen"
+  NC_OCC user:setting anna files_sharing default_accept no >/dev/null
+  code=$(ben_share_with_anna "$BENBOX")
+  e2e_expect 200 "$code" "ben teilt den Briefkasten mit anna"
+  code=$(call GET shares/received)
+  e2e_expect 200 "$code" "Mit mir geteilt (offen)"
+  e2e_expect True "$(jq_py 'any(s["name"].startswith("'"$BENBOX"'") and s.get("pending") is True for s in d["pending"]) and not any(s["name"].startswith("'"$BENBOX"'") for s in d["shares"])')" "received: offene Freigabe nur unter pending"
+  pid=$(jq_py '[s["id"] for s in d["pending"] if s["name"].startswith("'"$BENBOX"'")][0]')
+
+  code=$(call POST "shares/$pid/accept")
+  e2e_expect 200 "$code" "offene Freigabe annehmen"
+  e2e_expect True "$(jq_py 'd["accepted"] is True')" "accept: accepted"
+  code=$(call GET shares/received)
+  e2e_expect True "$(jq_py 'any(s["name"].startswith("'"$BENBOX"'") for s in d["shares"]) and not d["pending"]')" "received: angenommen, nichts mehr offen"
+
+  code=$(call DELETE "shares/$pid")
+  e2e_expect 200 "$code" "angenommene Freigabe verlassen"
+  code=$(call POST "shares/abc/accept")
+  e2e_expect 404 "$code" "annehmen mit ungueltiger Kennung"
+  e2e_contains "$E2E_TMP/body.out" '"code":"shareNotFound"' "accept abc: shareNotFound"
+  NC_OCC user:setting --delete anna files_sharing default_accept >/dev/null 2>&1 || true
+
+  echo "e2e shares received ok"
+}
 section_version() { echo "e2e shares version: folgt in Aufgabe 3"; }
 
 case "$SECTION" in

apps/api/src/module-registry/module-manage-handlers.spec.ts

@@ -168,8 +168,11 @@ describe('Umgestellte Handler (Verwalten)', () => {
     'listSharesForPath',
     'searchSharees',
     'createShare',
+    'listMyShares',
+    'listReceivedShares',
     'updateShare',
     'deleteShare',
+    'acceptShare',
   ])('NextcloudFilesController.%s bleibt auf Benutzen-Ebene', (name) => {
     const fn = handler(NextcloudFilesController, name);
     expect(Reflect.getMetadata(MODULE_MANAGE_KEY, fn)).toBeUndefined();

apps/api/src/nextcloud-files/dto/nextcloud-files-shares.dto.ts

@@ -1,4 +1,12 @@
-import { IsIn, IsNotEmpty, IsOptional, IsString, Matches, MaxLength } from 'class-validator';
+import {
+  IsIn,
+  IsNotEmpty,
+  IsOptional,
+  IsString,
+  Matches,
+  MaxLength,
+  ValidateIf,
+} from 'class-validator';
 
 /**
  * Eingaben der Freigaberouten (quick-261009-dkv, D-11). Der Browser schickt nur
@@ -12,8 +20,11 @@ import { IsIn, IsNotEmpty, IsOptional, IsString, Matches, MaxLength } from 'clas
 // biome-ignore lint/suspicious/noControlCharactersInRegex: Steuerzeichen sind hier gerade der Pruefstoff
 const NO_CONTROL = /^[^\u0000-\u001f\u007f]*$/;
 
-export const SHARE_KINDS_PEOPLE = ['user', 'group'] as const;
+export const SHARE_KINDS = ['user', 'group', 'link'] as const;
 export const SHARE_ACCESS = ['view', 'edit', 'upload'] as const;
+/** Ablaufdatum: leer (ohne Ablauf) oder `YYYY-MM-DD`; ob es ein echtes Datum ist, prueft der Dienst. */
+const EXPIRE_DATE = /^(\d{4}-\d{2}-\d{2})?$/;
+
 export const ITEM_TYPES = ['file', 'folder'] as const;
 
 export class ShareByPathQueryDto {
@@ -40,21 +51,58 @@ export class CreateShareDto {
   @MaxLength(4096)
   path!: string;
 
-  @IsIn(SHARE_KINDS_PEOPLE)
-  kind!: (typeof SHARE_KINDS_PEOPLE)[number];
+  @IsIn(SHARE_KINDS)
+  kind!: (typeof SHARE_KINDS)[number];
 
+  /** Nur bei Personen und Gruppen; bei Links ohne Bedeutung. */
+  @ValidateIf((o: CreateShareDto) => o.kind !== 'link')
   @IsString()
   @IsNotEmpty()
   @MaxLength(255)
   @Matches(NO_CONTROL)
-  shareWith!: string;
+  shareWith?: string;
 
   @IsIn(SHARE_ACCESS)
   access!: (typeof SHARE_ACCESS)[number];
+
+  /** Nur Links. Nie in einer Adresse, nie in einer Antwort oder einem Log. */
+  @IsOptional()
+  @IsString()
+  @MaxLength(256)
+  password?: string;
+
+  @IsOptional()
+  @IsString()
+  @Matches(EXPIRE_DATE)
+  expireDate?: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(255)
+  @Matches(NO_CONTROL)
+  label?: string;
 }
 
 export class UpdateShareDto {
   @IsOptional()
   @IsIn(SHARE_ACCESS)
   access?: (typeof SHARE_ACCESS)[number];
+
+  /** Leer = Passwort entfernen (der Dienst prueft, ob die Nextcloud ein Passwort verlangt). */
+  @IsOptional()
+  @IsString()
+  @MaxLength(256)
+  password?: string;
+
+  /** Leer = Ablaufdatum entfernen. */
+  @IsOptional()
+  @IsString()
+  @Matches(EXPIRE_DATE)
+  expireDate?: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(255)
+  @Matches(NO_CONTROL)
+  label?: string;
 }

apps/api/src/nextcloud-files/nextcloud-files-shares.service.spec.ts

@@ -518,3 +518,476 @@ describe('NextcloudFilesSharesService — remove, lesen, Richtlinie', () => {
     expect([401, 403]).not.toContain(statusOf(e));
   });
 });
+
+// --- Links (quick-261009-dkv, Aufgabe 2) -----------------------------------------------------------
+
+const PW = 'Geheim-Pass-2026!';
+
+function linkJson(over: Record<string, unknown> = {}) {
+  return shareJson({
+    id: '31',
+    share_type: 3,
+    share_with: null,
+    share_with_displayname: null,
+    permissions: 1,
+    token: 'AbC123',
+    url: 'https://cloud.example/nc/index.php/s/AbC123',
+    password: 'redacted',
+    label: 'Kunde',
+    ...over,
+  });
+}
+
+/** Faehigkeiten mit Link-Regeln: `public` wird mit den angegebenen Werten ueberlagert. */
+const LINK_CAPS = (pub: Record<string, unknown> = {}, over: Record<string, unknown> = {}) =>
+  CAPS({ public: { enabled: true, upload: true, ...pub }, ...over });
+
+const LINK_INPUT = {
+  path: '/Projekte',
+  kind: 'link',
+  access: 'view',
+  password: PW,
+  expireDate: '',
+  label: 'Kunde',
+} as const;
+
+function linkReplies(
+  over: { stat?: Reply; caps?: Reply; list?: Reply; post?: Reply } = {},
+  withList = false,
+): Reply[] {
+  const replies: Reply[] = [
+    over.stat ?? { status: 207, text: statXml('Projekte', true, 'RGDNVCK') },
+    over.caps ?? { status: 200, text: LINK_CAPS() },
+  ];
+  if (withList) replies.push(over.list ?? { status: 200, text: ocs([]) });
+  replies.push(over.post ?? { status: 200, text: ocs(linkJson()) });
+  return replies;
+}
+
+describe('NextcloudFilesSharesService — Link anlegen', () => {
+  it('sendet genau den erwarteten JSON-Koerper und gibt weder Passwort noch Kennung heraus', async () => {
+    const { service, calls } = setup(linkReplies());
+    const share = await service.create('t1', 'u1', LINK_INPUT);
+    expect(calls.map((c) => `${c.method} ${c.url}`)).toEqual([
+      `PROPFIND ${DAV}/Projekte`,
+      `GET ${CAPS_URL}`,
+      `POST ${SHARES}`,
+    ]);
+    expect(calls[2].body).toBe(
+      '{"path":"/Projekte","shareType":3,"permissions":1,"password":"Geheim-Pass-2026!","expireDate":"","label":"Kunde"}',
+    );
+    expect(share).toMatchObject({
+      id: '31',
+      kind: 'link',
+      hasPassword: true,
+      url: 'https://cloud.example/nc/index.php/s/AbC123',
+      label: 'Kunde',
+    });
+    const text = JSON.stringify(share);
+    expect(text).not.toContain(PW);
+    expect(text).not.toContain('redacted');
+    expect(text).not.toContain('"token"');
+  });
+
+  it('ohne Passwort, Ablauf und Bezeichnung werden diese Felder nicht gesendet', async () => {
+    const { service, calls } = setup(linkReplies());
+    await service.create('t1', 'u1', { path: '/Projekte', kind: 'link', access: 'view' });
+    expect(calls[2].body).toBe('{"path":"/Projekte","shareType":3,"permissions":1}');
+  });
+
+  it('Nur hochladen bei einem Ordner sendet 4; bei einer Datei und ohne erlaubtes Hochladen: shareAccessInvalid ohne POST', async () => {
+    const ok = setup(linkReplies());
+    await ok.service.create('t1', 'u1', { ...LINK_INPUT, access: 'upload' });
+    expect(ok.calls[2].body).toContain('"permissions":4');
+
+    const file = setup(
+      linkReplies({ stat: { status: 207, text: statXml('Bericht.txt', false, 'RGDNVW') } }),
+    );
+    const e1 = await failure(
+      file.service.create('t1', 'u1', { ...LINK_INPUT, path: '/Bericht.txt', access: 'upload' }),
+    );
+    expect(codeOf(e1)).toBe('shareAccessInvalid');
+    expect(statusOf(e1)).toBe(400);
+    expect(file.calls.some((c) => c.method === 'POST')).toBe(false);
+
+    for (const access of ['edit', 'upload'] as const) {
+      const off = setup(linkReplies({ caps: { status: 200, text: LINK_CAPS({ upload: false }) } }));
+      const e2 = await failure(off.service.create('t1', 'u1', { ...LINK_INPUT, access }));
+      expect(codeOf(e2)).toBe('shareAccessInvalid');
+      expect(off.calls.some((c) => c.method === 'POST')).toBe(false);
+    }
+  });
+
+  it('Ordner ohne Schreibrecht (RG): Nur hochladen und Bearbeiten sind shareAccessInvalid', async () => {
+    for (const access of ['edit', 'upload'] as const) {
+      const { service, calls } = setup(
+        linkReplies({ stat: { status: 207, text: statXml('Projekte', true, 'RG') } }),
+      );
+      const e = await failure(service.create('t1', 'u1', { ...LINK_INPUT, access }));
+      expect(codeOf(e)).toBe('shareAccessInvalid');
+      expect(calls.some((c) => c.method === 'POST')).toBe(false);
+    }
+  });
+
+  it('Links ausgeschaltet: 409 linkSharingDisabled', async () => {
+    const { service, calls } = setup(
+      linkReplies({ caps: { status: 200, text: CAPS({ public: { enabled: false } }) } }),
+    );
+    const e = await failure(service.create('t1', 'u1', LINK_INPUT));
+    expect(codeOf(e)).toBe('linkSharingDisabled');
+    expect(statusOf(e)).toBe(409);
+    expect(calls.some((c) => c.method === 'POST')).toBe(false);
+  });
+
+  it('nur ein Link erlaubt und schon einer da: 409 shareAlreadyExists; mehrere erlaubt: keine Listenabfrage', async () => {
+    const one = setup(
+      linkReplies(
+        {
+          caps: { status: 200, text: LINK_CAPS({ multiple_links: false }) },
+          list: { status: 200, text: ocs([linkJson()]) },
+        },
+        true,
+      ),
+    );
+    const e = await failure(one.service.create('t1', 'u1', LINK_INPUT));
+    expect(codeOf(e)).toBe('shareAlreadyExists');
+    expect(one.calls.some((c) => c.method === 'POST')).toBe(false);
+
+    const many = setup(linkReplies());
+    await many.service.create('t1', 'u1', LINK_INPUT);
+    expect(many.calls.some((c) => c.url === BY_PATH)).toBe(false);
+  });
+
+  it('Passwort verlangt und keins gesendet: 400 sharePasswordRequired nach nur zwei Aufrufen', async () => {
+    for (const password of [undefined, '']) {
+      const { service, calls } = setup(
+        linkReplies({
+          caps: { status: 200, text: LINK_CAPS({ password: { enforced: true } }) },
+        }),
+      );
+      const e = await failure(service.create('t1', 'u1', { ...LINK_INPUT, password }));
+      expect(codeOf(e)).toBe('sharePasswordRequired');
+      expect(statusOf(e)).toBe(400);
+      expect(calls.map((c) => c.method)).toEqual(['PROPFIND', 'GET']);
+    }
+  });
+
+  it('Ablauf verlangt und fehlend oder leer: 400 shareExpiryRequired ohne POST', async () => {
+    for (const expireDate of [undefined, '']) {
+      const { service, calls } = setup(
+        linkReplies({
+          caps: {
+            status: 200,
+            text: LINK_CAPS({ expire_date: { enabled: true, days: '7', enforced: true } }),
+          },
+        }),
+      );
+      const e = await failure(service.create('t1', 'u1', { ...LINK_INPUT, expireDate }));
+      expect(codeOf(e)).toBe('shareExpiryRequired');
+      expect(calls.some((c) => c.method === 'POST')).toBe(false);
+    }
+  });
+
+  it('Ablauf verlangt und ein Datum gesendet: das Datum steht im Koerper', async () => {
+    const { service, calls } = setup(
+      linkReplies({
+        caps: {
+          status: 200,
+          text: LINK_CAPS({ expire_date: { enabled: true, days: '7', enforced: true } }),
+        },
+        post: { status: 200, text: ocs(linkJson({ expiration: '2026-12-01 00:00:00' })) },
+      }),
+    );
+    const share = await service.create('t1', 'u1', { ...LINK_INPUT, expireDate: '2026-12-01' });
+    expect(calls[2].body).toContain('"expireDate":"2026-12-01"');
+    expect(share.expiration).toBe('2026-12-01');
+  });
+
+  it("kein echtes Datum ('2026-02-30'): 400 shareExpiryInvalid ohne POST", async () => {
+    const { service, calls } = setup(linkReplies());
+    const e = await failure(
+      service.create('t1', 'u1', { ...LINK_INPUT, expireDate: '2026-02-30' }),
+    );
+    expect(codeOf(e)).toBe('shareExpiryInvalid');
+    expect(statusOf(e)).toBe(400);
+    expect(calls.some((c) => c.method === 'POST')).toBe(false);
+  });
+
+  it('Passwort, Ablauf und Bezeichnung werden bei Personen und Gruppen nie weitergegeben', async () => {
+    const { service, calls } = setup(createReplies());
+    await service.create('t1', 'u1', {
+      ...INPUT,
+      password: PW,
+      expireDate: '2026-12-01',
+      label: 'x',
+    });
+    expect(calls[3].body).toBe(
+      '{"path":"/Projekte","shareType":0,"shareWith":"ben","permissions":15}',
+    );
+  });
+
+  it('Person oder Gruppe ohne Empfaenger: 422 shareRecipientInvalid ohne Aufruf', async () => {
+    const { service, calls } = setup([]);
+    const e = await failure(
+      service.create('t1', 'u1', { path: '/Projekte', kind: 'user', access: 'view' }),
+    );
+    expect(codeOf(e)).toBe('shareRecipientInvalid');
+    expect(calls).toHaveLength(0);
+  });
+
+  it.each([
+    [400, 'Password is too short', { password: PW, expireDate: '' }, 'sharePasswordRejected', 400],
+    [
+      404,
+      'Expiration date is in the past',
+      { password: PW, expireDate: '2026-12-01' },
+      'shareExpiryInvalid',
+      400,
+    ],
+    [
+      403,
+      'Passwords are enforced for link and mail shares',
+      { password: PW, expireDate: '' },
+      'shareRejected',
+      422,
+    ],
+    [404, 'Could not create share', { password: PW, expireDate: '' }, 'notFound', 404],
+  ] as const)('POST antwortet %i (%s) -> %s', async (nc, message, extra, code, http) => {
+    const { service } = setup(linkReplies({ post: { status: nc, text: ocs([], nc, message) } }));
+    const e = await failure(service.create('t1', 'u1', { ...LINK_INPUT, ...extra }));
+    expect(codeOf(e)).toBe(code);
+    expect(statusOf(e)).toBe(http);
+    expect([401, 403]).not.toContain(statusOf(e));
+    if (code !== 'notFound') expect(bodyOf(e).ncMessage).toBe(message);
+    expect(JSON.stringify(bodyOf(e))).not.toContain(PW);
+  });
+});
+
+describe('NextcloudFilesSharesService — Link aendern', () => {
+  const PUT31 = `PUT ${SHARES}/31`;
+  const linkWith = (over: Record<string, unknown> = {}) => ({
+    status: 200,
+    text: ocs([linkJson(over)]),
+  });
+  const caps = (pub: Record<string, unknown> = {}): Reply => ({
+    status: 200,
+    text: LINK_CAPS(pub),
+  });
+
+  it('sendet nur die geaenderten Felder', async () => {
+    const cases: Array<[Record<string, unknown>, string]> = [
+      [{ password: 'Neu-Pass-2026!x' }, '{"password":"Neu-Pass-2026!x"}'],
+      [{ expireDate: '' }, '{"expireDate":""}'],
+      [{ access: 'upload' }, '{"permissions":4}'],
+      [{ label: 'Angebot' }, '{"label":"Angebot"}'],
+    ];
+    for (const [input, body] of cases) {
+      const { service, calls } = setup([
+        linkWith({ expiration: '2026-12-01 00:00:00' }),
+        caps(),
+        { status: 200, text: ocs(linkJson()) },
+      ]);
+      await service.update('t1', 'u1', '31', input);
+      expect(calls.map((c) => `${c.method} ${c.url}`)).toEqual([
+        `GET ${SHARES}/31`,
+        `GET ${CAPS_URL}`,
+        PUT31,
+      ]);
+      expect(calls[2].body).toBe(body);
+    }
+  });
+
+  it('unveraenderte Werte ergeben kein PUT', async () => {
+    const { service, calls } = setup([
+      linkWith({ expiration: '2026-12-01 00:00:00', label: 'Kunde', password: null }),
+      caps(),
+    ]);
+    await service.update('t1', 'u1', '31', {
+      access: 'view',
+      expireDate: '2026-12-01',
+      label: 'Kunde',
+      password: '',
+    });
+    expect(calls.some((c) => c.method === 'PUT')).toBe(false);
+  });
+
+  it("Passwort '' bei verlangtem Passwort: 400 sharePasswordRequired ohne PUT", async () => {
+    const { service, calls } = setup([linkWith(), caps({ password: { enforced: true } })]);
+    const e = await failure(service.update('t1', 'u1', '31', { password: '' }));
+    expect(codeOf(e)).toBe('sharePasswordRequired');
+    expect(calls.some((c) => c.method === 'PUT')).toBe(false);
+  });
+
+  it("Ablauf '' bei verlangtem Ablauf: 400 shareExpiryRequired ohne PUT", async () => {
+    const { service, calls } = setup([
+      linkWith({ expiration: '2026-12-01 00:00:00' }),
+      caps({ expire_date: { enabled: true, days: '7', enforced: true } }),
+    ]);
+    const e = await failure(service.update('t1', 'u1', '31', { expireDate: '' }));
+    expect(codeOf(e)).toBe('shareExpiryRequired');
+    expect(calls.some((c) => c.method === 'PUT')).toBe(false);
+  });
+
+  it("Passwort '' ohne Pflicht entfernt das Passwort (nur wenn eins gesetzt ist)", async () => {
+    const { service, calls } = setup([
+      linkWith(),
+      caps(),
+      { status: 200, text: ocs(linkJson({ password: null })) },
+    ]);
+    const share = await service.update('t1', 'u1', '31', { password: '' });
+    expect(calls[2].body).toBe('{"password":""}');
+    expect(share.hasPassword).toBe(false);
+  });
+
+  it('Links ausgeschaltet: 409 linkSharingDisabled', async () => {
+    const { service } = setup([
+      linkWith(),
+      { status: 200, text: CAPS({ public: { enabled: false } }) },
+    ]);
+    expect(codeOf(await failure(service.update('t1', 'u1', '31', { label: 'x' })))).toBe(
+      'linkSharingDisabled',
+    );
+  });
+
+  it('Bearbeiten oder Hochladen ohne erlaubtes Hochladen: shareAccessInvalid', async () => {
+    const { service } = setup([linkWith(), caps({ upload: false })]);
+    expect(codeOf(await failure(service.update('t1', 'u1', '31', { access: 'edit' })))).toBe(
+      'shareAccessInvalid',
+    );
+  });
+
+  it('kein echtes Datum: 400 shareExpiryInvalid ohne PUT', async () => {
+    const { service, calls } = setup([linkWith(), caps()]);
+    const e = await failure(service.update('t1', 'u1', '31', { expireDate: '2026-13-01' }));
+    expect(codeOf(e)).toBe('shareExpiryInvalid');
+    expect(calls.some((c) => c.method === 'PUT')).toBe(false);
+  });
+
+  it.each([
+    [400, { password: 'schwach' }, 'sharePasswordRejected', 400],
+    [400, { expireDate: '2027-01-01' }, 'shareExpiryInvalid', 400],
+    [404, { expireDate: '2027-01-01' }, 'shareExpiryInvalid', 400],
+    [404, { label: 'x' }, 'shareNotFound', 404],
+    [400, { label: 'x' }, 'shareRejected', 422],
+    [403, { label: 'x' }, 'shareRejected', 422],
+  ] as const)('PUT antwortet %i mit %j -> %s', async (nc, input, code, http) => {
+    const { service } = setup([
+      linkWith(),
+      caps(),
+      { status: nc, text: ocs([], nc, 'Failed to update share.') },
+    ]);
+    const e = await failure(service.update('t1', 'u1', '31', input));
+    expect(codeOf(e)).toBe(code);
+    expect(statusOf(e)).toBe(http);
+    if (code !== 'shareNotFound') expect(bodyOf(e).ncMessage).toBe('Failed to update share.');
+    expect(JSON.stringify(bodyOf(e))).not.toContain('schwach');
+  });
+
+  it('bei Personenfreigaben werden Link-Felder verworfen', async () => {
+    const { service, calls } = setup([{ status: 200, text: ocs([shareJson()]) }]);
+    await service.update('t1', 'u1', '17', { password: 'x', expireDate: '2026-12-01', label: 'y' });
+    expect(calls).toHaveLength(1);
+  });
+});
+
+describe('NextcloudFilesSharesService — Uebersichten und Annehmen', () => {
+  const received = (over: Record<string, unknown> = {}) =>
+    shareJson({
+      id: '40',
+      uid_owner: 'ben',
+      displayname_owner: 'Ben Beispiel',
+      share_with: 'anna',
+      path: '/Ben-Ordner',
+      file_target: '/Ben-Ordner',
+      permissions: 1,
+      can_edit: false,
+      ...over,
+    });
+
+  it('mine: GET auf die Freigaben ohne Abfrage, Arten 0/1/3, andere nur als Zahl', async () => {
+    const { service, calls } = setup([
+      {
+        status: 200,
+        text: ocs([shareJson(), linkJson(), { share_type: 4, id: '5' }]),
+      },
+    ]);
+    const out = await service.mine('t1', 'u1');
+    expect(calls).toHaveLength(1);
+    expect(`${calls[0].method} ${calls[0].url}`).toBe(`GET ${SHARES}`);
+    expect(out.shares.map((s) => s.kind)).toEqual(['user', 'link']);
+    expect(out.hidden).toBe(1);
+    expect(out.truncated).toBe(false);
+  });
+
+  it('received: angenommene plus offene Freigaben, nur Arten 0/1, offene mit pending', async () => {
+    const { service, calls } = setup([
+      {
+        status: 200,
+        text: ocs([
+          received(),
+          received({ id: '41', share_type: 1 }),
+          linkJson({ uid_owner: 'ben' }),
+        ]),
+      },
+      { status: 200, text: ocs([received({ id: '42', file_target: '/Ben-Briefkasten' })]) },
+    ]);
+    const out = await service.received('t1', 'u1');
+    expect(calls.map((c) => `${c.method} ${c.url}`)).toEqual([
+      `GET ${SHARES}?shared_with_me=true`,
+      `GET ${SHARES}/pending`,
+    ]);
+    expect(out.shares.map((s) => s.id)).toEqual(['40', '41']);
+    expect(out.pending.map((s) => [s.id, s.pending])).toEqual([['42', true]]);
+    expect(out.pending[0].name).toBe('Ben-Briefkasten');
+    expect(out.shares.every((s) => s.pending === undefined)).toBe(true);
+    expect(out.hidden).toBe(1);
+  });
+
+  it('received: eine offene Freigabe steht nicht doppelt bei den angenommenen', async () => {
+    const { service } = setup([
+      { status: 200, text: ocs([received()]) },
+      { status: 200, text: ocs([received()]) },
+    ]);
+    const out = await service.received('t1', 'u1');
+    expect(out.shares).toHaveLength(0);
+    expect(out.pending.map((s) => s.id)).toEqual(['40']);
+  });
+
+  it.each([
+    404, 405,
+  ])('received: die offene Liste antwortet %i -> leer, kein Fehler', async (nc) => {
+    const { service } = setup([
+      { status: 200, text: ocs([received()]) },
+      { status: nc, text: ocs([], nc, 'nope') },
+    ]);
+    const out = await service.received('t1', 'u1');
+    expect(out.pending).toEqual([]);
+    expect(out.shares).toHaveLength(1);
+  });
+
+  it('received: 500 bei der offenen Liste ist ein Fehler, 401 markiert die Verbindung', async () => {
+    const boom = setup([
+      { status: 200, text: ocs([]) },
+      { status: 500, text: ocs([], 500, 'x') },
+    ]);
+    expect(codeOf(await failure(boom.service.received('t1', 'u1')))).toBe('nextcloudError');
+    const dead = setup([{ status: 401 }]);
+    expect(codeOf(await failure(dead.service.received('t1', 'u1')))).toBe('connectionExpired');
+    expect(dead.account.markExpired).toHaveBeenCalledTimes(1);
+  });
+
+  it('accept: POST auf pending/<Kennung>', async () => {
+    const { service, calls } = setup([{ status: 200, text: ocs([]) }]);
+    await expect(service.accept('t1', 'u1', '17')).resolves.toEqual({ accepted: true });
+    expect(`${calls[0].method} ${calls[0].url}`).toBe(`POST ${SHARES}/pending/17`);
+    expect(calls[0].body).toBeNull();
+  });
+
+  it('accept: 404 -> shareNotFound, falsche Kennung ohne Aufruf', async () => {
+    const nf = setup([{ status: 404, text: ocs([], 404, 'Wrong share ID') }]);
+    expect(codeOf(await failure(nf.service.accept('t1', 'u1', '17')))).toBe('shareNotFound');
+    const bad = setup([]);
+    expect(codeOf(await failure(bad.service.accept('t1', 'u1', 'x')))).toBe('shareNotFound');
+    expect(bad.calls).toHaveLength(0);
+  });
+});

apps/api/src/nextcloud-files/nextcloud-files-shares.service.ts

@@ -8,6 +8,7 @@ import { NextcloudLoginGuard } from './nextcloud-login-guard';
 import type { NcEntry } from './nextcloud-propfind';
 import {
   CAPABILITIES_SEGMENTS,
+  isRealDate,
   isShareId,
   type NcItemType,
   type NcShareKind,
@@ -42,16 +43,27 @@ import { mapNcFailure } from './nextcloud-upstream';
  * Nie loggen: Koerper, Passwoerter, Kennungen, Link-Adressen.
  */
 
-/** Eingabe fuer eine neue Freigabe an Person oder Gruppe (Links folgen in Aufgabe 2). */
+/**
+ * Eingabe fuer eine neue Freigabe. Bei Links gelten `password`, `expireDate` und `label`
+ * (`expireDate: ''` heisst "ohne Ablauf" und wird gesendet; fehlt das Feld, gilt die
+ * Voreinstellung der Nextcloud); bei Personen und Gruppen werden diese Felder verworfen.
+ */
 export interface CreateShareInput {
   path: string;
-  kind: 'user' | 'group';
-  shareWith: string;
+  kind: 'user' | 'group' | 'link';
+  shareWith?: string;
   access: 'view' | 'edit' | 'upload';
+  password?: string;
+  expireDate?: string;
+  label?: string;
 }
 
+/** Leere Zeichenkette heisst bei Passwort/Ablauf "entfernen", bei der Bezeichnung "leeren". */
 export interface UpdateShareInput {
   access?: 'view' | 'edit' | 'upload';
+  password?: string;
+  expireDate?: string;
+  label?: string;
 }
 
 /** Welche Felder gesendet wurden: bestimmt, wie ein Fehler gedeutet wird (D-15). */
@@ -273,9 +285,32 @@ export class NextcloudFilesSharesService {
     return /[WCK]/.test(entry.permissions);
   }
 
+  /** Passwort- und Ablaufregeln fuer einen Link; Fehler bevor irgendetwas an Nextcloud geht (D-16). */
+  private checkLinkRules(
+    policy: NcSharePolicy,
+    password: string | undefined,
+    expireDate: string | undefined,
+    mode: 'create' | 'update',
+  ): void {
+    // Beim Anlegen fehlt das Passwort, beim Aendern heisst '' "Passwort entfernen".
+    const passwordMissing = mode === 'create' ? !password : password === '';
+    if (policy.links.passwordRequired && passwordMissing) {
+      throw ncErrorDefault('sharePasswordRequired');
+    }
+    if (expireDate !== undefined && expireDate !== '' && !isRealDate(expireDate)) {
+      throw ncErrorDefault('shareExpiryInvalid');
+    }
+    const expiryMissing = mode === 'create' ? !expireDate : expireDate === '';
+    if (policy.links.expiryEnforced && expiryMissing) {
+      throw ncErrorDefault('shareExpiryRequired');
+    }
+  }
+
   async create(tenantId: string, userId: string, input: CreateShareInput): Promise<NcShareView> {
     const segments = parseUserPath(input.path);
     if (segments.length === 0) throw ncErrorDefault('invalidPath');
+    const isLink = input.kind === 'link';
+    if (!isLink && !input.shareWith) throw ncErrorDefault('shareRecipientInvalid');
     const session = await this.session(tenantId, userId);
 
     // Art und Schreibbarkeit kommen aus der eigenen Abfrage, nie aus dem Browser (T-dkv-01).
@@ -292,17 +327,45 @@ export class NextcloudFilesSharesService {
     if (input.kind === 'group' && !policy.groupsEnabled) {
       throw ncErrorDefault('sharingDisabled', { scope: 'groups' }, GROUPS_OFF);
     }
+    if (isLink && !policy.links.enabled) throw ncErrorDefault('linkSharingDisabled');
     if (!entry.permissions.includes('R')) throw ncErrorDefault('shareRejected');
-    if (input.access === 'upload' || (input.access === 'edit' && !this.entryWritable(entry))) {
+    if (
+      (input.access === 'upload' && !isLink) ||
+      (input.access !== 'view' && !this.entryWritable(entry)) ||
+      (isLink && input.access !== 'view' && !policy.links.uploadAllowed)
+    ) {
       throw ncErrorDefault('shareAccessInvalid');
     }
     const permissions = permissionsFor(input.access, entry.type);
     if (permissions === null) throw ncErrorDefault('shareAccessInvalid');
+    if (isLink) this.checkLinkRules(policy, input.password, input.expireDate, 'create');
 
     const path = pathOf(segments);
+    // Doppelte Freigaben wuerden bei Nextcloud die Benachrichtigung erneut ausloesen (T-dkv-09);
+    // bei Links nur noetig, wenn die Nextcloud nur einen Link je Eintrag erlaubt.
+    if (!isLink || !policy.links.multipleLinks) {
       const existing = await this.listByPath(tenantId, userId, session, path);
-    if (existing.shares.some((s) => s.kind === input.kind && s.shareWith === input.shareWith)) {
-      throw ncErrorDefault('shareAlreadyExists');
+      const duplicate = isLink
+        ? existing.shares.some((s) => s.kind === 'link')
+        : existing.shares.some((s) => s.kind === input.kind && s.shareWith === input.shareWith);
+      if (duplicate) throw ncErrorDefault('shareAlreadyExists');
+    }
+
+    const json: Record<string, unknown> = isLink
+      ? { path, shareType: 3, permissions }
+      : { path, shareType: input.kind === 'user' ? 0 : 1, shareWith: input.shareWith, permissions };
+    const sent: SentFields = { kind: input.kind };
+    if (isLink) {
+      if (input.password) {
+        json.password = input.password;
+        sent.passwordNonEmpty = true;
+      }
+      if (input.expireDate !== undefined) {
+        json.expireDate = input.expireDate;
+        sent.expireDateSent = true;
+        sent.expireDateNonEmpty = input.expireDate !== '';
+      }
+      if (input.label) json.label = input.label;
     }
 
     // Erst nach jeder Vorpruefung zaehlen: abgelehnte Eingaben verbrauchen kein Kontingent.
@@ -311,18 +374,9 @@ export class NextcloudFilesSharesService {
       tenantId,
       userId,
       session,
-      {
-        method: 'POST',
-        segments: SHARES_BASE_SEGMENTS,
-        json: {
-          path,
-          shareType: input.kind === 'user' ? 0 : 1,
-          shareWith: input.shareWith,
-          permissions,
-        },
-      },
+      { method: 'POST', segments: SHARES_BASE_SEGMENTS, json },
       'create',
-      { kind: input.kind },
+      sent,
     );
     const created = parseShareList(data, session.ncUserId).shares[0];
     if (!created) throw ncErrorDefault('nextcloudError');
@@ -339,23 +393,60 @@ export class NextcloudFilesSharesService {
     const session = await this.session(tenantId, userId);
     const current = await this.loadShare(tenantId, userId, session, id);
     if (!current.canEdit) throw ncErrorDefault('shareRejected');
-    if (input.access === undefined) return current;
+    const isLink = current.kind === 'link';
+    // Passwort, Ablauf und Bezeichnung gibt es nur bei Links (bei anderen Arten verworfen).
+    const wantsLinkFields =
+      isLink &&
+      (input.password !== undefined || input.expireDate !== undefined || input.label !== undefined);
+    if (input.access === undefined && !wantsLinkFields) return current;
 
-    if (current.kind === 'link') throw ncErrorDefault('shareAccessInvalid');
-    if (input.access === 'upload' || (input.access === 'edit' && !current.itemWritable)) {
+    const policy = isLink ? await this.loadPolicy(tenantId, userId, session) : null;
+    if (policy !== null) {
+      if (!policy.enabled) throw ncErrorDefault('sharingDisabled');
+      if (!policy.links.enabled) throw ncErrorDefault('linkSharingDisabled');
+    }
+
+    const json: Record<string, unknown> = {};
+    const sent: SentFields = { kind: current.kind };
+
+    if (input.access !== undefined) {
+      if (
+        (input.access === 'upload' && !isLink) ||
+        (input.access !== 'view' && !current.itemWritable) ||
+        (policy !== null && input.access !== 'view' && !policy.links.uploadAllowed)
+      ) {
         throw ncErrorDefault('shareAccessInvalid');
       }
       const permissions = permissionsFor(input.access, current.itemType);
       if (permissions === null) throw ncErrorDefault('shareAccessInvalid');
-    if (current.access === input.access) return current;
+      if (current.access !== input.access) json.permissions = permissions;
+    }
 
+    if (policy !== null && wantsLinkFields) {
+      this.checkLinkRules(policy, input.password, input.expireDate, 'update');
+      // Das Passwort laesst sich nicht vergleichen: nicht leer wird gesendet, leer nur wenn eins gesetzt ist.
+      if (input.password) {
+        json.password = input.password;
+        sent.passwordNonEmpty = true;
+      } else if (input.password === '' && current.hasPassword) {
+        json.password = '';
+      }
+      if (input.expireDate !== undefined && input.expireDate !== (current.expiration ?? '')) {
+        json.expireDate = input.expireDate;
+        sent.expireDateSent = true;
+        sent.expireDateNonEmpty = input.expireDate !== '';
+      }
+      if (input.label !== undefined && input.label !== current.label) json.label = input.label;
+    }
+
+    if (Object.keys(json).length === 0) return current;
     const data = await this.run(
       tenantId,
       userId,
       session,
-      { method: 'PUT', segments: [...SHARES_BASE_SEGMENTS, id], json: { permissions } },
+      { method: 'PUT', segments: [...SHARES_BASE_SEGMENTS, id], json },
       'update',
-      { kind: current.kind },
+      sent,
     );
     const updated = parseShareList(data, session.ncUserId).shares[0];
     if (!updated) throw ncErrorDefault('nextcloudError');
@@ -374,4 +465,74 @@ export class NextcloudFilesSharesService {
     );
     return { deleted: true };
   }
+
+  // --- Uebersichten und Annehmen (D-17) --------------------------------------------------------
+
+  /** Alle eigenen Freigaben (Personen, Gruppen, Links); andere Arten nur als Zahl. */
+  async mine(tenantId: string, userId: string) {
+    const session = await this.session(tenantId, userId);
+    const data = await this.run(
+      tenantId,
+      userId,
+      session,
+      { method: 'GET', segments: SHARES_BASE_SEGMENTS },
+      'other',
+    );
+    return parseShareList(data, session.ncUserId);
+  }
+
+  /**
+   * Mit mir geteilt: angenommene (`shared_with_me`) und noch offene Freigaben (`pending`).
+   * Nur Personen- und Gruppenfreigaben; die offene Liste fehlt auf aelteren Servern (404/405
+   * -> leer, kein Fehler). Eine offene Freigabe steht nie zugleich bei den angenommenen.
+   */
+  async received(tenantId: string, userId: string) {
+    const session = await this.session(tenantId, userId);
+    const accepted = await this.run(
+      tenantId,
+      userId,
+      session,
+      { method: 'GET', segments: SHARES_BASE_SEGMENTS, query: { shared_with_me: 'true' } },
+      'other',
+    );
+    const pendingResult = await ocsShareRequest(this.transport, this.gate, session, {
+      method: 'GET',
+      segments: [...SHARES_BASE_SEGMENTS, 'pending'],
+    });
+    let pendingData: unknown = [];
+    if (!pendingResult.ok || pendingResult.status < 200 || pendingResult.status >= 300) {
+      const missing =
+        pendingResult.ok && (pendingResult.status === 404 || pendingResult.status === 405);
+      if (!missing) return this.mapShareFailure(tenantId, userId, 'other', pendingResult, {});
+    } else {
+      pendingData = pendingResult.data;
+    }
+
+    const a = parseShareList(accepted, session.ncUserId);
+    const p = parseShareList(pendingData, session.ncUserId);
+    const people = (shares: NcShareView[]) => shares.filter((s) => s.kind !== 'link');
+    const pending = people(p.shares).map((s) => ({ ...s, pending: true }));
+    const pendingIds = new Set(pending.map((s) => s.id));
+    const shares = people(a.shares).filter((s) => !pendingIds.has(s.id));
+    const links = a.shares.length - people(a.shares).length + (p.shares.length - pending.length);
+    return {
+      shares,
+      pending,
+      hidden: a.hidden + p.hidden + links,
+      truncated: a.truncated || p.truncated,
+    };
+  }
+
+  async accept(tenantId: string, userId: string, id: string): Promise<{ accepted: true }> {
+    if (!isShareId(id)) throw ncErrorDefault('shareNotFound');
+    const session = await this.session(tenantId, userId);
+    await this.run(
+      tenantId,
+      userId,
+      session,
+      { method: 'POST', segments: [...SHARES_BASE_SEGMENTS, 'pending', id] },
+      'accept',
+    );
+    return { accepted: true };
+  }
 }

apps/api/src/nextcloud-files/nextcloud-files.controller.spec.ts

@@ -22,8 +22,11 @@ const SHARE_HANDLERS = [
   'listSharesForPath',
   'searchSharees',
   'createShare',
+  'listMyShares',
+  'listReceivedShares',
   'updateShare',
   'deleteShare',
+  'acceptShare',
 ];
 const TRANSFER_HANDLERS = [...TRANSFER_STATIC, ...TRANSFER_PARAM];
 
@@ -125,6 +128,13 @@ describe('NextcloudFilesController — Metadaten', () => {
     expect(route('createShare')).toEqual([1, 'shares']);
     expect(route('updateShare')).toEqual([2, 'shares/:id']);
     expect(route('deleteShare')).toEqual([3, 'shares/:id']);
+    expect(route('listMyShares')).toEqual([0, 'shares/mine']);
+    expect(route('listReceivedShares')).toEqual([0, 'shares/received']);
+    expect(route('acceptShare')).toEqual([1, 'shares/:id/accept']);
+  });
+
+  it('acceptShare antwortet mit 200 statt 201', () => {
+    expect(Reflect.getMetadata('__httpCode__', proto.acceptShare)).toBe(200);
   });
 
   it('die Teilen-Handler tragen weder Verwalten noch einen Rollen-Decorator', () => {
@@ -136,7 +146,14 @@ describe('NextcloudFilesController — Metadaten', () => {
 
   it('die beiden :id-Handler des Teilens stehen nach allen statischen Handlern', () => {
     const names = routeHandlers();
-    for (const name of ['getSharePolicy', 'listSharesForPath', 'searchSharees', 'createShare']) {
+    for (const name of [
+      'getSharePolicy',
+      'listSharesForPath',
+      'searchSharees',
+      'createShare',
+      'listMyShares',
+      'listReceivedShares',
+    ]) {
       expect(names.indexOf(name), name).toBeLessThan(names.indexOf('pollFlow'));
     }
     const staticLast = Math.max(
@@ -146,6 +163,7 @@ describe('NextcloudFilesController — Metadaten', () => {
     );
     expect(names.indexOf('updateShare')).toBeGreaterThan(staticLast);
     expect(names.indexOf('deleteShare')).toBeGreaterThan(staticLast);
+    expect(names.indexOf('acceptShare')).toBeGreaterThan(staticLast);
   });
 
   it('keiner der Anmelde-Handler traegt Verwalten oder einen Rollen-Decorator', () => {
@@ -291,6 +309,9 @@ describe('NextcloudFilesController — Delegation', () => {
       create: vi.fn(async (..._a: unknown[]) => ({ id: '1' })),
       update: vi.fn(async (..._a: unknown[]) => ({ id: '1' })),
       remove: vi.fn(async (..._a: unknown[]) => ({ deleted: true })),
+      mine: vi.fn(async (..._a: unknown[]) => ({ shares: [] })),
+      received: vi.fn(async (..._a: unknown[]) => ({ shares: [], pending: [] })),
+      accept: vi.fn(async (..._a: unknown[]) => ({ accepted: true })),
     };
   }
 
@@ -447,12 +468,18 @@ describe('NextcloudFilesController — Delegation', () => {
     await controller.createShare(r, dto);
     await controller.updateShare(r, '17', { access: 'view' } as any);
     await controller.deleteShare(r, '17');
+    await controller.listMyShares(r);
+    await controller.listReceivedShares(r);
+    await controller.acceptShare(r, '18');
     expect(shares.policy).toHaveBeenCalledWith('t1', 'u1');
     expect(shares.sharesForPath).toHaveBeenCalledWith('t1', 'u1', '/Projekte');
     expect(shares.sharees).toHaveBeenCalledWith('t1', 'u1', 'ben', 'folder');
     expect(shares.create).toHaveBeenCalledWith('t1', 'u1', dto);
     expect(shares.update).toHaveBeenCalledWith('t1', 'u1', '17', { access: 'view' });
     expect(shares.remove).toHaveBeenCalledWith('t1', 'u1', '17');
+    expect(shares.mine).toHaveBeenCalledWith('t1', 'u1');
+    expect(shares.received).toHaveBeenCalledWith('t1', 'u1');
+    expect(shares.accept).toHaveBeenCalledWith('t1', 'u1', '18');
   });
 
   it('Teilen-Handler ohne Benutzer im Token: ForbiddenException, kein Dienstaufruf', async () => {
@@ -469,6 +496,8 @@ describe('NextcloudFilesController — Delegation', () => {
     await expect(controller.getSharePolicy(r)).rejects.toBeInstanceOf(ForbiddenException);
     await expect(controller.createShare(r, {} as any)).rejects.toBeInstanceOf(ForbiddenException);
     await expect(controller.deleteShare(r, '1')).rejects.toBeInstanceOf(ForbiddenException);
+    await expect(controller.listMyShares(r)).rejects.toBeInstanceOf(ForbiddenException);
+    await expect(controller.acceptShare(r, '1')).rejects.toBeInstanceOf(ForbiddenException);
     const noTenant = userReq(undefined, 'u1');
     await expect(controller.getSharePolicy(noTenant)).rejects.toBeInstanceOf(ForbiddenException);
     for (const fn of Object.values(shares)) expect(fn).not.toHaveBeenCalled();

apps/api/src/nextcloud-files/nextcloud-files.controller.ts

@@ -72,11 +72,12 @@ import { NextcloudServerInfoService } from './nextcloud-server-info';
  *             DELETE connect, GET files, DELETE files, POST folders, POST move,
  *             GET preview, GET download, POST download/zip, POST uploads, PUT
  *             uploads/file, GET shares/policy, GET shares/by-path, GET sharees,
- *             POST shares (quick-261009-dkv: Teilen); danach die Parameterrouten am
- *             ENDE: GET/DELETE connect/flow/:flowId, PUT uploads/:uploadId/chunks/:n,
- *             POST uploads/:uploadId/complete, GET uploads/:uploadId/state, DELETE
- *             uploads/:uploadId, PUT/DELETE shares/:id. Jeder Benutzer arbeitet nur
- *             im eigenen Konto.
+ *             GET shares/mine, GET shares/received, POST shares (quick-261009-dkv:
+ *             Teilen); danach die Parameterrouten am ENDE: GET/DELETE
+ *             connect/flow/:flowId, PUT uploads/:uploadId/chunks/:n, POST
+ *             uploads/:uploadId/complete, GET uploads/:uploadId/state, DELETE
+ *             uploads/:uploadId, PUT/DELETE shares/:id, POST shares/:id/accept.
+ *             Jeder Benutzer arbeitet nur im eigenen Konto.
  * Auf Verwalten-Handlern steht NIE ein Rollen-Decorator — der globale
  * RolesGuard wuerde Verwalter sonst aussperren. Der reine Administrator-Handler
  * traegt dafuer kein `@ModuleManage` (Muster wie `TendersController.getSourceConfig`).
@@ -328,6 +329,18 @@ export class NextcloudFilesController {
     );
   }
 
+  /** Eigene Freigaben (Personen, Gruppen, Links). */
+  @Get('shares/mine')
+  async listMyShares(@Req() req: AuthenticatedRequest) {
+    return this.shares.mine(this.requireTenantId(req), this.requireUserId(req));
+  }
+
+  /** Mit mir geteilt, auch die noch nicht angenommenen. */
+  @Get('shares/received')
+  async listReceivedShares(@Req() req: AuthenticatedRequest) {
+    return this.shares.received(this.requireTenantId(req), this.requireUserId(req));
+  }
+
   @Post('shares')
   async createShare(@Req() req: AuthenticatedRequest, @Body() dto: CreateShareDto) {
     return this.shares.create(this.requireTenantId(req), this.requireUserId(req), dto);
@@ -407,8 +420,15 @@ export class NextcloudFilesController {
     return this.shares.update(this.requireTenantId(req), this.requireUserId(req), id, dto);
   }
 
+  /** Loeschen, Ablehnen und Verlassen sind fuer Nextcloud dasselbe (DELETE durch den Empfaenger). */
   @Delete('shares/:id')
   async deleteShare(@Req() req: AuthenticatedRequest, @Param('id') id: string) {
     return this.shares.remove(this.requireTenantId(req), this.requireUserId(req), id);
   }
+
+  @Post('shares/:id/accept')
+  @HttpCode(200)
+  async acceptShare(@Req() req: AuthenticatedRequest, @Param('id') id: string) {
+    return this.shares.accept(this.requireTenantId(req), this.requireUserId(req), id);
+  }
 }

apps/api/src/nextcloud-files/nextcloud-shares.spec.ts

@@ -5,6 +5,7 @@ import type { NcSession } from './nextcloud-files.types';
 import type { NcTransportRequest, NextcloudTransport } from './nextcloud-http';
 import {
   accessOf,
+  isRealDate,
   OCS_OK_MAX_BYTES,
   ocsShareRequest,
   parseShare,
@@ -595,3 +596,21 @@ describe('parseSharePolicy', () => {
     expect(policy.passwordMinLength).toBeNull();
   });
 });
+
+describe('isRealDate', () => {
+  it('nimmt nur echte Kalendertage im Format JJJJ-MM-TT an', () => {
+    expect(isRealDate('2026-10-09')).toBe(true);
+    expect(isRealDate('2028-02-29')).toBe(true);
+    for (const bad of [
+      '2026-02-30',
+      '2027-02-29',
+      '2026-13-01',
+      '31.12.2026',
+      '2026-1-1',
+      '2026-12-31x',
+      '',
+    ]) {
+      expect(isRealDate(bad), bad).toBe(false);
+    }
+  });
+});

apps/api/src/nextcloud-files/nextcloud-shares.ts

@@ -254,7 +254,7 @@ function lastSegment(path: string): string {
   return parts.length > 0 ? parts[parts.length - 1] : '';
 }
 
-function isRealDate(value: string): boolean {
+export function isRealDate(value: string): boolean {
   if (!DATE_RE.test(value)) return false;
   const d = new Date(`${value}T00:00:00Z`);
   return !Number.isNaN(d.getTime()) && d.toISOString().slice(0, 10) === value;