fix(xmpp): treat disco#info result without 'from' as from the server

RFC 6120 §8.1.2.1: a stanza received over a c2s stream without a 'from'
attribute must be treated as coming from the server itself. The
on-connect disco#info handler passed the absent attribute as NULL into
connection_features_received(), where g_str_hash() dereferenced the NULL
key and crashed (remotely triggerable DoS on connect).

Substitute connection_get_domain() at both disco#info handler
boundaries, and make connection_features_received() and
connection_get_features() NULL-safe as defense in depth. Add a stabber
regression test answering the on-connect disco#info with a from-less
result.

Fixes #168

.github/workflows/docker-publish.yml

@@ -0,0 +1,44 @@
+name: Publish Docker image
+
+on:
+  push:
+    branches: [master]
+  release:
+    types: [published]
+
+jobs:
+  push_to_registry:
+    name: Push Docker image to Docker Hub
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Check out the repo
+        uses: actions/checkout@v7
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@f4ef78c080cd8ba55a85445d5b36e214a81df20a
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@c299e40c65443455700f0fdfc63efafe5b349051
+        with:
+          images: cproofdev/cproof
+          tags: |
+            type=raw,value=dev,enable={{is_default_branch}}
+            type=sha,prefix=nightly-,enable={{is_default_branch}}
+            type=ref,event=tag
+            type=raw,value=latest,enable=${{ startsWith(github.ref, 'refs/tags/') }}
+
+      - name: Build and push Docker image
+        id: push
+        uses: docker/build-push-action@2bd26e71295ee32cbf6a73510d165bf7232460f3
+        with:
+          context: .
+          file: ./ci/Dockerfile
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

ci/Dockerfile

@@ -0,0 +1,106 @@
+# =============================================================================
+# Stage 1: Build
+# =============================================================================
+FROM ubuntu:26.04 AS builder
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    build-essential \
+    autoconf \
+    automake \
+    autoconf-archive \
+    ca-certificates \
+    libtool \
+    pkg-config \
+    git \
+    wget \
+    libglib2.0-dev \
+    libcurl4-openssl-dev \
+    libsqlite3-dev \
+    libncurses-dev \
+    libreadline-dev \
+    libnotify-dev \
+    python3-dev \
+    python3 \
+    libgpgme-dev \
+    libotr5-dev \
+    libgtk-3-dev \
+    libgdk-pixbuf-2.0-dev \
+    libsignal-protocol-c-dev \
+    libgcrypt20-dev \
+    libqrencode-dev \
+    libxss-dev \
+    libcmocka-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+# Build libstrophe from source (not available as Ubuntu package)
+RUN git clone --depth 1 https://git.jabber.space/devs/libstrophe-gh-mirror.git /tmp/libstrophe \
+    && cd /tmp/libstrophe \
+    && autoreconf -i \
+    && ./configure --prefix=/usr \
+    && make -j$(nproc) \
+    && make install \
+    && rm -rf /tmp/libstrophe
+
+WORKDIR /src
+
+COPY . .
+
+RUN ./bootstrap.sh \
+    && ./configure \
+        --enable-notifications \
+        --enable-icons-and-clipboard \
+        --enable-otr \
+        --enable-pgp \
+        --enable-omemo \
+        --enable-plugins \
+        --enable-c-plugins \
+        --enable-python-plugins \
+        --with-xscreensaver \
+        --enable-omemo-qrcode \
+        --enable-gdk-pixbuf \
+    && make -j$(nproc) \
+    && make install
+
+# =============================================================================
+# Stage 2: Runtime (minimal)
+# =============================================================================
+FROM ubuntu:26.04
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    libglib2.0-0t64 \
+    libcurl4t64 \
+    libsqlite3-0 \
+    libncursesw6 \
+    libreadline8t64 \
+    libnotify4 \
+    python3 \
+    libpython3.14 \
+    libgpgme45 \
+    libotr5t64 \
+    libgtk-3-0t64 \
+    libgdk-pixbuf-2.0-0 \
+    libsignal-protocol-c2.3.2 \
+    libgcrypt20 \
+    libqrencode4 \
+    libxss1 \
+    && rm -rf /var/lib/apt/lists/* \
+    && apt-get clean
+
+COPY --from=builder /usr/local/bin/profanity /usr/local/bin/profanity
+COPY --from=builder /usr/local/lib/libprofanity* /usr/local/lib/
+COPY --from=builder /usr/local/include/profapi.h /usr/local/include/
+COPY --from=builder /usr/local/share/profanity /usr/local/share/profanity
+COPY --from=builder /usr/lib/libstrophe.so* /usr/lib/
+
+RUN ldconfig
+
+RUN ldd /usr/local/bin/profanity | grep 'not found' && exit 1 || true
+
+RUN mkdir -p /root/.config/profanity
+
+ENTRYPOINT ["profanity"]

src/xmpp/connection.c

@@ -753,7 +753,11 @@ void
 connection_features_received(const char* const jid)
 {
     log_info("[CONNECTION] connection_features_received %s", jid);
-    if (g_hash_table_remove(conn.requested_features, jid) && g_hash_table_size(conn.requested_features) == 0) {
+    const char* key = jid ? jid : conn.domain; // g_str_hash crashes on NULL; NULL 'from' means the server (RFC 6120 §8.1.2.1)
+    if (!key) {
+        return;
+    }
+    if (g_hash_table_remove(conn.requested_features, key) && g_hash_table_size(conn.requested_features) == 0) {
         sv_ev_connection_features_received();
     }
 }
@@ -761,7 +765,11 @@ connection_features_received(const char* const jid)
 GHashTable*
 connection_get_features(const char* const jid)
 {
-    return g_hash_table_lookup(conn.features_by_jid, jid);
+    const char* key = jid ? jid : conn.domain;
+    if (!key || !conn.features_by_jid) {
+        return NULL;
+    }
+    return g_hash_table_lookup(conn.features_by_jid, key);
 }
 
 GList*

src/xmpp/iq.c

@@ -2314,6 +2314,7 @@ _disco_info_response_id_handler(xmpp_stanza_t* const stanza, void* const userdat
         log_debug("Received disco#info response from: %s", from);
     } else {
         log_debug("Received disco#info response");
+        from = connection_get_domain(); // RFC 6120 §8.1.2.1: no 'from' means the server itself
     }
 
     // handle error responses
@@ -2397,6 +2398,7 @@ _disco_info_response_id_handler_onconnect(xmpp_stanza_t* const stanza, void* con
         log_debug("Received disco#info response from: %s", from);
     } else {
         log_debug("Received disco#info response");
+        from = connection_get_domain(); // RFC 6120 §8.1.2.1: no 'from' means the server itself
     }
 
     // handle error responses

tests/functionaltests/functionaltests.c

@@ -173,6 +173,7 @@ main(int argc, char* argv[])
         PROF_FUNC_TEST(disco_info_without_name),
         PROF_FUNC_TEST(disco_items_without_name),
         PROF_FUNC_TEST(disco_info_service_unavailable),
+        PROF_FUNC_TEST(disco_info_result_no_from),
 
         /* Roster management - add/remove/rename contacts */
         PROF_FUNC_TEST(sends_new_item),

tests/functionaltests/test_disco.c

@@ -396,6 +396,35 @@ disco_items_without_name(void **state)
     prof_timeout_reset();
 }
 
+void
+disco_info_result_no_from(void **state)
+{
+    /*
+     * Test that a disco#info result without a 'from' attribute is treated as
+     * coming from the server itself (RFC 6120 §8.1.2.1). The on-connect
+     * disco#info handler used to crash on such responses (issue #168).
+     */
+    stbbr_for_query("http://jabber.org/protocol/disco#info",
+        "<iq to='stabber@localhost/profanity' type='result'>"
+            "<query xmlns='http://jabber.org/protocol/disco#info'>"
+                "<identity category='server' type='im' name='NoFromServer'/>"
+                "<feature var='urn:xmpp:ping'/>"
+            "</query>"
+        "</iq>"
+    );
+
+    /* the on-connect disco#info gets the same from-less response */
+    prof_connect();
+
+    prof_input("/disco info");
+
+    prof_timeout(10);
+    /* client survived and attributed the response to the server */
+    assert_true(prof_output_exact("Service discovery info for localhost"));
+    assert_true(prof_output_regex("NoFromServer.*im.*server"));
+    prof_timeout_reset();
+}
+
 void
 disco_info_service_unavailable(void **state)
 {

tests/functionaltests/test_disco.h

@@ -17,3 +17,4 @@ void disco_info_multiple_identities(void **state);
 void disco_info_without_name(void **state);
 void disco_items_without_name(void **state);
 void disco_info_service_unavailable(void **state);
+void disco_info_result_no_from(void **state);