From 6b5cbf740022f7f57a425d212499f156b1641d49 Mon Sep 17 00:00:00 2001
From: Jeremy Harris <jgh146exb@wizmail.org>
Date: Mon, 14 Oct 2019 10:45:32 +0100
Subject: [PATCH] environment grooming

---
 src/src/environment.c |  3 +++
 src/src/functions.h   |  1 +
 src/src/tls.c         | 29 +++++++++++++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/src/src/environment.c b/src/src/environment.c
index c29cc6c8d..f3a90660e 100644
--- a/src/src/environment.c
+++ b/src/src/environment.c
@@ -59,6 +59,9 @@ else if (Ustrcmp(keep_environment, "*") != 0)
     }
   store_reset(reset_point);
   }
+#ifndef DISABLE_TLS
+tls_clean_env();
+#endif
 if (add_environment)
   {
   uschar * p;
diff --git a/src/src/functions.h b/src/src/functions.h
index 37f6b1b6f..35600ba2a 100644
--- a/src/src/functions.h
+++ b/src/src/functions.h
@@ -48,6 +48,7 @@ extern uschar * tls_cert_fprt_md5(void *);
 extern uschar * tls_cert_fprt_sha1(void *);
 extern uschar * tls_cert_fprt_sha256(void *);
 
+extern void    tls_clean_env(void);
 extern BOOL    tls_client_start(client_conn_ctx *, smtp_connect_args *,
 		  void *, tls_support *, uschar **);
 
diff --git a/src/src/tls.c b/src/src/tls.c
index 796bc6d61..63d98c806 100644
--- a/src/src/tls.c
+++ b/src/src/tls.c
@@ -369,6 +369,35 @@ else if ((subjdn = tls_cert_subject(cert, NULL)))
   }
 return FALSE;
 }
+
+
+/* Environment cleanup: The GnuTLS library spots SSLKEYLOGFILE in the envonment
+and writes a file by that name.  We might make the OpenSSL support do the same,
+in some future release.  Restrict that filename to be under the spool directory.
+
+If the path is absolute, require it starts with the spooldir; otherwise delete
+the env variable.  If relative, prefix the spooldir.
+*/
+void
+tls_clean_env(void)
+{
+uschar * path = US getenv("SSLKEYLOGFILE");
+if (path)
+  if (!*path)
+    unsetenv("SSLKEYLOGFILE");
+  else if (*path != '/')
+    {
+    DEBUG(D_tls)
+      debug_printf("prepending spooldir to  env SSLKEYLOGFILE\n");
+    setenv("SSLKEYLOGFILE", CCS string_sprintf("%s/%s", spool_directory, path), 1);
+    }
+  else if (Ustrncmp(path, spool_directory, Ustrlen(spool_directory)) != 0)
+    {
+    DEBUG(D_tls)
+      debug_printf("removing env SSLKEYLOGFILE: not under spooldir\n");
+    unsetenv("SSLKEYLOGFILE");
+    }
+}
 #endif	/*!DISABLE_TLS*/
 #endif	/*!MACRO_PREDEF*/
 
-- 
2.25.1