protocol_dump: tls-crypt support

Add support for tls-crypt packets in protocol_dump(). Currently, protocol_dump() will print garbage for tls-crypt packets. This patch makes protocol_dump print the clear text parts of the packet such as the auth tag and replay packet id. It does not try to print the wKc for HARD_RESET_CLIENT_V3 or CONTROL_WKC_V1 packets. It also intentionally does not print ENCRYPTED placeholders for ack list and DATA, to cut down on the noise. Signed-off-by: Reynir Björnsson <[email protected]> Acked-by: Arne Schwabe <[email protected]> Message-Id: <[email protected]> URL: https://www.mail-archive.com/[email protected]/msg27310.html Signed-off-by: Gert Doering <[email protected]>
OpenVPN · Nov 20, 2023 · 227799b · 227799b
1 parent b5faf1b
commit 227799b
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Showing 3 changed files with 29 additions and 1 deletion.
diff --git a/src/openvpn/openvpn.h b/src/openvpn/openvpn.h
@@ -541,7 +541,8 @@ struct context
 #define PROTO_DUMP(buf, gc) protocol_dump((buf), \
                                           PROTO_DUMP_FLAGS   \
                                           |(c->c2.tls_multi ? PD_TLS : 0)   \
-                                          |(c->options.tls_auth_file ? md_kt_size(c->c1.ks.key_type.digest) : 0), \
+                                          |(c->options.tls_auth_file ? md_kt_size(c->c1.ks.key_type.digest) : 0) \
+                                          |(c->options.tls_crypt_file || c->options.tls_crypt_v2_file ? PD_TLS_CRYPT : 0), \
                                           gc)
 
 /* this represents "disabled peer-id" */

diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c
@@ -4272,6 +4272,32 @@ protocol_dump(struct buffer *buffer, unsigned int flags, struct gc_arena *gc)
         }
         buf_printf(&out, " pid=%s", packet_id_net_print(&pin, (flags & PD_VERBOSE), gc));
     }
+    /*
+     * packet_id + tls-crypt hmac
+     */
+    if (flags & PD_TLS_CRYPT)
+    {
+        struct packet_id_net pin;
+        uint8_t tls_crypt_hmac[TLS_CRYPT_TAG_SIZE];
+
+        if (!packet_id_read(&pin, &buf, true))
+        {
+            goto done;
+        }
+        buf_printf(&out, " pid=%s", packet_id_net_print(&pin, (flags & PD_VERBOSE), gc));
+        if (!buf_read(&buf, tls_crypt_hmac, TLS_CRYPT_TAG_SIZE))
+        {
+            goto done;
+        }
+        if (flags & PD_VERBOSE)
+        {
+            buf_printf(&out, " tls_crypt_hmac=%s", format_hex(tls_crypt_hmac, TLS_CRYPT_TAG_SIZE, 0, gc));
+        }
+        /*
+         * Remainder is encrypted and optional wKc
+         */
+        goto done;
+    }
 
     /*
      * ACK list

diff --git a/src/openvpn/ssl.h b/src/openvpn/ssl.h
@@ -525,6 +525,7 @@ tls_set_single_session(struct tls_multi *multi)
 #define PD_SHOW_DATA               (1<<8)
 #define PD_TLS                     (1<<9)
 #define PD_VERBOSE                 (1<<10)
+#define PD_TLS_CRYPT               (1<<11)
 
 const char *protocol_dump(struct buffer *buffer,
                           unsigned int flags,