Print a more user-friendly error when tls-crypt-v2 client auth fails

While it might be clear to people being (too?) well versed in
typical crypto applications that an authentication failure probably
mean wrong decryption key, this is not really obvious for the typical
user/server admin.

Change-Id: If0f0e7d53f915d39ab69aaaac43dc73bb9c26ae9
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20230522091231.2837468-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg26718.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpn/tls_crypt.c b/src/openvpn/tls_crypt.c
index c97f9257afcbab8510170345916cc8cba0815af9..975d31fafb5192eed0a46872ad30e9d12c663784 100644 (file)
--- a/src/openvpn/tls_crypt.c
+++ b/src/openvpn/tls_crypt.c
@@ -522,6 +522,8 @@ tls_crypt_v2_unwrap_client_key(struct key2 *client_key, struct buffer *metadata,
         dmsg(D_CRYPTO_DEBUG, "tag_check: %s",
              format_hex(tag_check, sizeof(tag_check), 0, &gc));
         CRYPT_ERROR("client key authentication error");
+        msg(D_TLS_DEBUG_LOW, "This might be a client-key that was generated for "
+            "a different tls-crypt-v2 server key)");
     }
 
     if (buf_len(&plaintext) < sizeof(client_key->keys))