TLS: Introduced flag GWEN_SYNCIO_TLS_FLAGS_IGN_PREMATURE_CLOSE

If this flag is set the gnutls error GNUTLS_E_PREMATURE_TERMINATION is ignored upon gnutls_recv() and just reported as EOF. This might be necessary with some faulty servers which do not properly terminate an SSL connection.
cstim · Jul 13, 2016 · 160f436 · 160f436
1 parent 5f8c338
commit 160f436
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Showing 2 changed files with 24 additions and 13 deletions.
diff --git a/src/sio/syncio_tls.c b/src/sio/syncio_tls.c
@@ -1,6 +1,6 @@
 /***************************************************************************
  begin       : Wed Apr 28 2010
- copyright   : (C) 2010 by Martin Preuss
+ copyright   : (C) 2010, 2016 by Martin Preuss
  email       : martin@libchipcard.de
 
  ***************************************************************************
@@ -1327,7 +1327,14 @@ int GWENHYWFAR_CB GWEN_SyncIo_Tls_Read(GWEN_SYNCIO *sio,
     GWEN_SyncIo_Disconnect(baseIo);
 #ifdef GNUTLS_E_PREMATURE_TERMINATION
     if (rv==GNUTLS_E_PREMATURE_TERMINATION) {
-      return GWEN_ERROR_SSL_PREMATURE_CLOSE;
+      if (GWEN_SyncIo_GetFlags(sio) & GWEN_SYNCIO_TLS_FLAGS_IGN_PREMATURE_CLOSE) {
+	DBG_ERROR(GWEN_LOGDOMAIN, "Detected premature disconnect by server (violates specs!), ignoring.");
+	return 0; /* report EOF */
+      }
+      else {
+	DBG_ERROR(GWEN_LOGDOMAIN, "Detected premature disconnect by server (violates specs!)");
+	return GWEN_ERROR_SSL_PREMATURE_CLOSE;
+      }
     }
 #endif
     return GWEN_ERROR_SSL;

diff --git a/src/sio/syncio_tls.h b/src/sio/syncio_tls.h
@@ -1,6 +1,6 @@
 /***************************************************************************
  begin       : Wed Apr 28 2010
- copyright   : (C) 2010 by Martin Preuss
+ copyright   : (C) 2010, 2016 by Martin Preuss
  email       : martin@libchipcard.de
 
  ***************************************************************************
@@ -33,22 +33,26 @@
 #define GWEN_SYNCIO_TLS_TYPE "tls"
 
 
-#define GWEN_SYNCIO_TLS_FLAGS_REQUEST_CERT         0x00000001
+#define GWEN_SYNCIO_TLS_FLAGS_REQUEST_CERT          0x00000001
 #ifndef NO_DEPRECATED_SYMBOLS
-#define GWEN_SYNCIO_TLS_FLAGS_FORCE_SSL_V3         0x00000002	/* deprecated, will be removed in a future release */
+# define GWEN_SYNCIO_TLS_FLAGS_FORCE_SSL_V3         0x00000002	/* deprecated, will be removed in a future release */
 #endif // ifndef NO_DEPRECATED_SYMBOLS
-#define GWEN_SYNCIO_TLS_FLAGS_ALLOW_V1_CA_CRT      0x00000004
-#define GWEN_SYNCIO_TLS_FLAGS_NEED_PEER_CERT       0x00000008
-#define GWEN_SYNCIO_TLS_FLAGS_ADD_TRUSTED_CAS      0x00000010
-#define GWEN_SYNCIO_TLS_FLAGS_SET_PASSV_HOST_NAME  0x00000020
-#define GWEN_SYNCIO_TLS_FLAGS_SET_PASSV_HOST_IP    0x00000020
+
+#define GWEN_SYNCIO_TLS_FLAGS_ALLOW_V1_CA_CRT       0x00000004
+#define GWEN_SYNCIO_TLS_FLAGS_NEED_PEER_CERT        0x00000008
+#define GWEN_SYNCIO_TLS_FLAGS_ADD_TRUSTED_CAS       0x00000010
+#define GWEN_SYNCIO_TLS_FLAGS_SET_PASSV_HOST_NAME   0x00000020
+#define GWEN_SYNCIO_TLS_FLAGS_SET_PASSV_HOST_IP     0x00000020
 
 #ifndef NO_DEPRECATED_SYMBOLS
-#define GWEN_SYNCIO_TLS_FLAGS_ONLY_SAFE_CIPHERS    0x00000080	/* deprecated, will be removed in a future release */
-#define GWEN_SYNCIO_TLS_FLAGS_FORCE_UNSAFE_CIPHERS 0x00000100	/* deprecated, will be removed in a future release */
+# define GWEN_SYNCIO_TLS_FLAGS_ONLY_SAFE_CIPHERS    0x00000080	/* deprecated, will be removed in a future release */
+# define GWEN_SYNCIO_TLS_FLAGS_FORCE_UNSAFE_CIPHERS 0x00000100	/* deprecated, will be removed in a future release */
 #endif // ifndef NO_DEPRECATED_SYMBOLS
 
-#define GWEN_SYNCIO_TLS_FLAGS_SECURE               0x00008000
+/** ignore error "GNUTLS_E_PREMATURE_TERMINATION" */
+#define GWEN_SYNCIO_TLS_FLAGS_IGN_PREMATURE_CLOSE   0x00000200
+
+#define GWEN_SYNCIO_TLS_FLAGS_SECURE                0x00008000