From c91535f35c1f54bb30e5611791c93e78f2efd5d0 Mon Sep 17 00:00:00 2001
From: Philip Hazel <ph10@hermes.cam.ac.uk>
Date: Tue, 14 Feb 2006 14:12:06 +0000
Subject: [PATCH] Fix GnuTLS privatekey forced fail bug; in both TLS's treat an
 empty privatekey as unset.

---
 doc/doc-txt/ChangeLog |  6 +++++-
 doc/doc-txt/NewStuff  |  5 ++++-
 src/src/tls-gnu.c     | 11 +++++++++--
 src/src/tls-openssl.c | 12 ++++++++----
 4 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 522adcb0c..7c3a03f51 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.296 2006/02/14 10:26:26 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.297 2006/02/14 14:12:06 ph10 Exp $
 
 Change log file for Exim from version 4.21
 -------------------------------------------
@@ -154,6 +154,10 @@ PH/28 An enabling patch from MH: add new function child_open_exim2() which
       submitting a message from within Exim. Since child_open_exim() is
       documented for local_scan(), the new function should be too.
 
+PH/29 In GnuTLS, a forced expansion failure for tls_privatekey was not being
+      ignored. In both GnuTLS and OpenSSL, an expansion of tls_privatekey that
+      results in an empty string is now treated as unset.
+
 
 Exim version 4.60
 -----------------
diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index 0cc752e52..d4c307cff 100644
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.83 2006/02/13 12:02:59 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.84 2006/02/14 14:12:06 ph10 Exp $
 
 New Features in Exim
 --------------------
@@ -46,6 +46,9 @@ PH/05 The "control=freeze" ACL modifier can now be followed by /no_tell. If
       "control=freeze" modifiers that are obeyed in the current message have
       the /no_tell option.
 
+PH/06 In both GnuTLS and OpenSSL, an expansion of tls_privatekey that results
+      in an empty string is now treated as unset.
+
 
 Version 4.60
 ------------
diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c
index fa3073642..31f226b4e 100644
--- a/src/src/tls-gnu.c
+++ b/src/src/tls-gnu.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/tls-gnu.c,v 1.11 2006/02/07 11:19:00 ph10 Exp $ */
+/* $Cambridge: exim/src/src/tls-gnu.c,v 1.12 2006/02/14 14:12:07 ph10 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -455,12 +455,19 @@ may be required for different sessions. */
 if (!expand_check(certificate, US"tls_certificate", &cert_expanded))
   return DEFER;
 
+key_expanded = NULL;
 if (privatekey != NULL)
   {
   if (!expand_check(privatekey, US"tls_privatekey", &key_expanded))
     return DEFER;
   }
-else key_expanded = cert_expanded;
+
+/* If expansion was forced to fail, key_expanded will be NULL. If the result of
+the expansion is an empty string, ignore it also, and assume that the private
+key is in the same file as the certificate. */
+
+if (key_expanded == NULL || *key_expanded == 0)
+  key_expanded = cert_expanded;
 
 /* Set the certificate and private keys */
 
diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c
index f20c6f4f0..146cb6293 100644
--- a/src/src/tls-openssl.c
+++ b/src/src/tls-openssl.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/tls-openssl.c,v 1.6 2006/02/07 11:19:00 ph10 Exp $ */
+/* $Cambridge: exim/src/src/tls-openssl.c,v 1.7 2006/02/14 14:12:07 ph10 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -290,8 +290,8 @@ Returns:          OK/DEFER/FAIL
 */
 
 static int
-tls_init(host_item *host, uschar *dhparam, uschar *certificate, uschar *privatekey,
-  address_item *addr)
+tls_init(host_item *host, uschar *dhparam, uschar *certificate,
+  uschar *privatekey, address_item *addr)
 {
 SSL_load_error_strings();          /* basic set up */
 OpenSSL_add_ssl_algorithms();
@@ -386,7 +386,11 @@ if (certificate != NULL)
       !expand_check(privatekey, US"tls_privatekey", &expanded))
     return DEFER;
 
-  if (expanded != NULL)
+  /* If expansion was forced to fail, key_expanded will be NULL. If the result
+  of the expansion is an empty string, ignore it also, and assume the private
+  key is in the same file as the certificate. */
+
+  if (expanded != NULL && *expanded != 0)
     {
     DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded);
     if (!SSL_CTX_use_PrivateKey_file(ctx, CS expanded, SSL_FILETYPE_PEM))
-- 
2.25.1