Don't use getenv for critical functions when run as setuid/setgid

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5856)

CHANGES

@@ -9,6 +9,10 @@
 
  Changes between 1.1.0h and 1.1.1 [xx XXX xxxx]
 
+  *) Don't use OPENSSL_ENGINES and OPENSSL_CONF environment values
+     in libcrypto when run as setuid/setgid.
+     [Bernd Edlinger]
+
   *) Added new public header file <openssl/rand_drbg.h> and documentation
      for the RAND_DRBG API. See manual page RAND_DRBG(7) for an overview.
      [Matthias St. Pierre]

crypto/conf/conf_mod.c

@@ -480,9 +480,11 @@ char *CONF_get1_default_config_file(void)
     char *file, *sep = "";
     int len;
 
-    file = getenv("OPENSSL_CONF");
-    if (file)
-        return OPENSSL_strdup(file);
+    if (!OPENSSL_issetugid()) {
+        file = getenv("OPENSSL_CONF");
+        if (file)
+            return OPENSSL_strdup(file);
+    }
 
     len = strlen(X509_get_default_cert_area());
 #ifndef OPENSSL_SYS_VMS

crypto/engine/eng_list.c

@@ -317,7 +317,8 @@ ENGINE *ENGINE_by_id(const char *id)
      * Prevent infinite recursion if we're looking for the dynamic engine.
      */
     if (strcmp(id, "dynamic")) {
-        if ((load_dir = getenv("OPENSSL_ENGINES")) == NULL)
+        if (OPENSSL_issetugid()
+                || (load_dir = getenv("OPENSSL_ENGINES")) == NULL)
             load_dir = ENGINESDIR;
         iterator = ENGINE_by_id("dynamic");
         if (!iterator || !ENGINE_ctrl_cmd_string(iterator, "ID", id, 0) ||

doc/man3/ENGINE_add.pod

@@ -568,6 +568,7 @@ extension).
 =item B<OPENSSL_ENGINES>
 
 The path to the engines directory.
+Ignored in set-user-ID and set-group-ID programs.
 
 =back
 

doc/man3/OPENSSL_config.pod

@@ -48,6 +48,17 @@ application calls OPENSSL_config() it doesn't need to know or care about
 ENGINE control operations because they can be performed by editing a
 configuration file.
 
+=head1 ENVIRONMENT
+
+=over 4
+
+=item B<OPENSSL_CONF>
+
+The path to the config file.
+Ignored in set-user-ID and set-group-ID programs.
+
+=back
+
 =head1 RETURN VALUES
 
 Neither OPENSSL_config() nor OPENSSL_no_config() return a value.

doc/man5/config.pod

@@ -384,6 +384,22 @@ will output:
 
 showing that the OID "newoid1" has been added as "1.2.3.4.1".
 
+=head1 ENVIRONMENT
+
+=over 4
+
+=item B<OPENSSL_CONF>
+
+The path to the config file.
+Ignored in set-user-ID and set-group-ID programs.
+
+=item B<OPENSSL_ENGINES>
+
+The path to the engines directory.
+Ignored in set-user-ID and set-group-ID programs.
+
+=back
+
 =head1 BUGS
 
 Currently there is no way to include characters using the octal B<\nnn>