OpenSSL: log conns rejected for bad ALPN, with the offered value

[exim.git] / src / src / tls-openssl.c

diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c
index 4d0f99ea91b3132703c493fe2da833e18df78c82..513ba0d3a5c5b54f01c5fded80cc5b5bdbf2d12a 100644 (file)
--- a/src/src/tls-openssl.c
+++ b/src/src/tls-openssl.c
@@ -786,8 +786,9 @@ if (  (nid = OBJ_sn2nid       (CCS exp_curve)) == NID_undef
 #   endif
    )
   {
-  tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", exp_curve),
-    NULL, NULL, errstr);
+  uschar * s = string_sprintf("Unknown curve name tls_eccurve '%s'", exp_curve);
+  DEBUG(D_tls) debug_printf("TLS error '%s'\n", s);
+  if (errstr) *errstr = s;
   return FALSE;
   }
 
@@ -803,7 +804,7 @@ if (  (nid = OBJ_sn2nid       (CCS exp_curve)) == NID_undef
   /* The "tmp" in the name here refers to setting a temporary key
   not to the stability of the interface. */
 
-  if ((rc = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0))
+  if ((rc = SSL_CTX_set_tmp_ecdh(sctx, ecdh)) == 0)
     tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), NULL, NULL, errstr);
   else
     DEBUG(D_tls) debug_printf(" ECDH: enabled '%s' curve\n", exp_curve);
@@ -2323,6 +2324,8 @@ static int
 tls_server_alpn_cb(SSL *ssl, const uschar ** out, uschar * outlen,
   const uschar * in, unsigned int inlen, void * arg)
 {
+gstring * g = NULL;
+
 server_seen_alpn = TRUE;
 DEBUG(D_tls)
   {
@@ -2353,12 +2356,19 @@ if (  inlen > 1         /* at least one name */
       }
   }
 
-/* More than one name from clilent, or name did not match our list. */
+/* More than one name from client, or name did not match our list. */
 
 /* This will be fatal to the TLS conn; would be nice to kill TCP also.
 Maybe as an option in future; for now leave control to the config (must-tls). */
 
-DEBUG(D_tls) debug_printf("TLS ALPN rejected\n");
+for (int pos = 0, siz; pos < inlen; pos += siz+1)
+  {
+  siz = in[pos];
+  if (pos + 1 + siz > inlen) siz = inlen - pos - 1;
+  g = string_append_listele_n(g, ':', in + pos + 1, siz);
+  }
+log_write(0, LOG_MAIN, "TLS ALPN (%s) rejected", string_from_gstring(g));
+gstring_release_unused(g);
 return SSL_TLSEXT_ERR_ALERT_FATAL;
 }
 #endif /* EXIM_HAVE_ALPN */