Subject: auth-digest: Handle missing nonce
From: Patrick Griffis <[email-masked]>
Date: Thu, 26 Dec 2024 18:18:35 -0600

(cherry picked from commit 405a8a34597a44bd58c4759e7d5e23f02c3b556a)

Upstream-Status: Backport [import from debian https://salsa.debian.org/gnome-team/libsoup/-/blob/debian/bullseye/debian/patches/CVE-2025-32910-2.patch?ref_type=heads
Upstream commit https://gitlab.gnome.org/GNOME/libsoup/-/commit/405a8a34597a44bd58c4759e7d5e23f02c3b556a]
CVE: CVE-2025-32910
Signed-off-by: Vijay Anusuri <[email-masked]>
---
 libsoup/soup-auth-digest.c | 45 +++++++++++++++++++++++++++++++++++----------
 tests/auth-test.c          | 19 +++++++++++--------
 2 files changed, 46 insertions(+), 18 deletions(-)

diff --git a/libsoup/soup-auth-digest.c b/libsoup/soup-auth-digest.c
index 263a15a..393adb6 100644
--- a/libsoup/soup-auth-digest.c
+++ b/libsoup/soup-auth-digest.c
@@ -132,6 +132,19 @@ soup_auth_digest_get_qop (SoupAuthDigestQop qop)
 	return g_string_free (out, FALSE);
 }
 
+static gboolean
+validate_params (SoupAuthDigest *auth_digest)
+{
+        SoupAuthDigestPrivate *priv = soup_auth_digest_get_instance_private (auth_digest);
+
+        if (priv->qop || priv->algorithm == SOUP_AUTH_DIGEST_ALGORITHM_MD5_SESS) {
+                if (!priv->nonce)
+                        return FALSE;
+        }
+
+        return TRUE;
+}
+
 static gboolean
 soup_auth_digest_update (SoupAuth *auth, SoupMessage *msg,
 			 GHashTable *auth_params)
@@ -169,16 +182,21 @@ soup_auth_digest_update (SoupAuth *auth, SoupMessage *msg,
 	if (priv->algorithm == -1)
 		ok = FALSE;
 
-	stale = g_hash_table_lookup (auth_params, "stale");
-	if (stale && !g_ascii_strcasecmp (stale, "TRUE") && *priv->hex_urp)
-		recompute_hex_a1 (priv);
-	else {
-		g_free (priv->user);
-		priv->user = NULL;
-		g_free (priv->cnonce);
-		priv->cnonce = NULL;
-		memset (priv->hex_urp, 0, sizeof (priv->hex_urp));
-		memset (priv->hex_a1, 0, sizeof (priv->hex_a1));
+        if (!validate_params (auth_digest))
+                ok = FALSE;
+
+        if (ok) {
+                stale = g_hash_table_lookup (auth_params, "stale");
+                if (stale && !g_ascii_strcasecmp (stale, "TRUE") && *priv->hex_urp)
+                        recompute_hex_a1 (priv);
+                else {
+                        g_free (priv->user);
+                        priv->user = NULL;
+                        g_free (priv->cnonce);
+                        priv->cnonce = NULL;
+                        memset (priv->hex_urp, 0, sizeof (priv->hex_urp));
+                        memset (priv->hex_a1, 0, sizeof (priv->hex_a1));
+                }
         }
 
 	return ok;
@@ -269,6 +287,8 @@ soup_auth_digest_compute_hex_a1 (const char              *hex_urp,
 
 		/* In MD5-sess, A1 is hex_urp:nonce:cnonce */
 
+                g_assert (nonce && cnonce);
+
 		checksum = g_checksum_new (G_CHECKSUM_MD5);
 		g_checksum_update (checksum, (guchar *)hex_urp, strlen (hex_urp));
 		g_checksum_update (checksum, (guchar *)":", 1);
@@ -359,6 +379,8 @@ soup_auth_digest_compute_response (const char        *method,
 	if (qop) {
 		char tmp[9];
 
+                g_assert (cnonce);
+
 		g_snprintf (tmp, 9, "%.8x", nc);
 		g_checksum_update (checksum, (guchar *)tmp, strlen (tmp));
 		g_checksum_update (checksum, (guchar *)":", 1);
@@ -422,6 +444,9 @@ soup_auth_digest_get_authorization (SoupAuth *auth, SoupMessage *msg)
 	g_return_val_if_fail (uri != NULL, NULL);
 	url = soup_uri_to_string (uri, TRUE);
 
+        g_assert (priv->nonce);
+        g_assert (!priv->qop || priv->cnonce);
+
 	soup_auth_digest_compute_response (msg->method, url, priv->hex_a1,
 					   priv->qop, priv->nonce,
 					   priv->cnonce, priv->nc,
diff --git a/tests/auth-test.c b/tests/auth-test.c
index dfc6b09..6fb1e4a 100644
--- a/tests/auth-test.c
+++ b/tests/auth-test.c
@@ -1550,16 +1550,17 @@ do_cancel_after_retry_test (void)
 }
 
 static void
-on_request_read_for_missing_realm (SoupServer        *server,
-                                   SoupServerMessage *msg,
-                                   gpointer           user_data)
+on_request_read_for_missing_params (SoupServer        *server,
+                                      SoupServerMessage *msg,
+                                      gpointer           user_data)
 {
+        const char *auth_header = user_data;
         SoupMessageHeaders *response_headers = soup_server_message_get_response_headers (msg);
-        soup_message_headers_replace (response_headers, "WWW-Authenticate", "Digest qop=\"auth\"");
+        soup_message_headers_replace (response_headers, "WWW-Authenticate", auth_header);
 }
 
 static void
-do_missing_realm_test (void)
+do_missing_params_test (gconstpointer auth_header)
 {
         SoupSession *session;
         SoupMessage *msg;
@@ -1582,8 +1583,8 @@ do_missing_realm_test (void)
         g_object_unref (digest_auth_domain);
 
         g_signal_connect (server, "request-read",
-                          G_CALLBACK (on_request_read_for_missing_realm),
-                          NULL);
+                          G_CALLBACK (on_request_read_for_missing_params),
+                          (gpointer)auth_header);
 
         session = soup_test_session_new (NULL);
         msg = soup_message_new_from_uri ("GET", uri);
@@ -1625,7 +1626,9 @@ main (int argc, char **argv)
 	g_test_add_func ("/auth/async-message-do-not-use-auth-cache", do_async_message_do_not_use_auth_cache_test);
 	g_test_add_func ("/auth/authorization-header-request", do_message_has_authorization_header_test);
 	g_test_add_func ("/auth/cancel-after-retry", do_cancel_after_retry_test);
-        g_test_add_func ("/auth/missing-realm", do_missing_realm_test);
+        g_test_add_data_func ("/auth/missing-params/realm", "Digest qop=\"auth\"", do_missing_params_test);
+        g_test_add_data_func ("/auth/missing-params/nonce", "Digest realm=\"auth-test\", qop=\"auth,auth-int\", opaque=\"5ccc069c403ebaf9f0171e9517f40e41\"", do_missing_params_test);
+        g_test_add_data_func ("/auth/missing-params/nonce-md5-sess", "Digest realm=\"auth-test\", qop=\"auth,auth-int\", opaque=\"5ccc069c403ebaf9f0171e9517f40e41\" algorithm=\"MD5-sess\"", do_missing_params_test);
 
 	ret = g_test_run ();