[xmlsec] disable xslt read/write by default and allow user to overwrite it

[Aleksey Sanin <aleksey src gnome org>]

commit 35eaacde6093d6711339754fc2146341b8b9f5fa
Author: Aleksey Sanin <aleksey aleksey com>
Date:   Tue Mar 29 18:04:53 2011 -0700

    disable xslt read/write by default and allow user to overwrite it

 include/xmlsec/private/Makefile.am |    1 +
 include/xmlsec/private/xslt.h      |   34 +++++++++++++++++++++++
 include/xmlsec/transforms.h        |    3 ++
 src/transforms.c                   |   10 +++++++
 src/xslt.c                         |   53 ++++++++++++++++++++++++++++++++++++
 5 files changed, 101 insertions(+), 0 deletions(-)
---
diff --git a/include/xmlsec/private/Makefile.am b/include/xmlsec/private/Makefile.am
index aab78c8..74de46a 100644
--- a/include/xmlsec/private/Makefile.am
+++ b/include/xmlsec/private/Makefile.am
@@ -3,6 +3,7 @@ NULL =
 xmlsecprivateincdir = $(includedir)/xmlsec1/xmlsec/private
 
 xmlsecprivateinc_HEADERS = \
+xslt.h \
 xkms.h \
 $(NULL)
 
diff --git a/include/xmlsec/private/xslt.h b/include/xmlsec/private/xslt.h
new file mode 100644
index 0000000..e9ba697
--- /dev/null
+++ b/include/xmlsec/private/xslt.h
@@ -0,0 +1,34 @@
+/**
+ * XML Security Library (http://www.aleksey.com/xmlsec).
+ *
+ * XSLT helper functions
+ *
+ * This is free software; see Copyright file in the source
+ * distribution for preciese wording.
+ *
+ * Copyright (C) 2002-2003 Aleksey Sanin <aleksey aleksey com>
+ */
+#ifndef __XMLSEC_PRIVATE_XSLT_H__
+#define __XMLSEC_PRIVATE_XSLT_H__
+
+#ifndef XMLSEC_PRIVATE
+#error "xmlsec/private/xslt.h file contains private xmlsec definitions and should not be used outside xmlsec or xmlsec-<crypto> libraries"
+#endif /* XMLSEC_PRIVATE */
+
+#ifndef XMLSEC_NO_XSLT
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+void xmlSecTransformXsltInitialize                          (void);
+void xmlSecTransformXsltShutdown                            (void);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* XMLSEC_NO_XSLT */
+
+#endif /* __XMLSEC_PRIVATE_XSLT_H__ */
+
diff --git a/include/xmlsec/transforms.h b/include/xmlsec/transforms.h
index f0d3d08..f0c70c9 100644
--- a/include/xmlsec/transforms.h
+++ b/include/xmlsec/transforms.h
@@ -950,6 +950,8 @@ XMLSEC_EXPORT int               xmlSecTransformXPointerSetExpr          (xmlSecT
                                                                          xmlSecNodeSetType nodeSetType,
                                                                          xmlNodePtr hereNode);
 #ifndef XMLSEC_NO_XSLT
+#include <libxslt/security.h>
+
 /**
  * xmlSecTransformXsltId:
  *
@@ -958,6 +960,7 @@ XMLSEC_EXPORT int               xmlSecTransformXPointerSetExpr          (xmlSecT
 #define xmlSecTransformXsltId \
         xmlSecTransformXsltGetKlass()
 XMLSEC_EXPORT xmlSecTransformId xmlSecTransformXsltGetKlass             (void);
+XMLSEC_EXPORT void              xmlSecTransformXsltSetDefaultSecurityPrefs(xsltSecurityPrefsPtr sec);
 #endif /* XMLSEC_NO_XSLT */
 
 /**
diff --git a/src/transforms.c b/src/transforms.c
index 8ef38b5..8a2ded2 100644
--- a/src/transforms.c
+++ b/src/transforms.c
@@ -61,6 +61,8 @@
 #include <xmlsec/parser.h>
 #include <xmlsec/errors.h>
 
+#include <xmlsec/private/xslt.h>
+
 /**************************************************************************
  *
  * Global xmlSecTransformIds list functions
@@ -113,6 +115,10 @@ xmlSecTransformIdsInit(void) {
         return(-1);
     }
 
+#ifndef XMLSEC_NO_XSLT
+    xmlSecTransformXsltInitialize();
+#endif /* XMLSEC_NO_XSLT */
+
     return(0);
 }
 
@@ -124,6 +130,10 @@ xmlSecTransformIdsInit(void) {
  */
 void
 xmlSecTransformIdsShutdown(void) {
+#ifndef XMLSEC_NO_XSLT
+    xmlSecTransformXsltShutdown();
+#endif /* XMLSEC_NO_XSLT */
+
     xmlSecPtrListFinalize(xmlSecTransformIdsGet());
 }
 
diff --git a/src/xslt.c b/src/xslt.c
index 21b502d..b752c35 100644
--- a/src/xslt.c
+++ b/src/xslt.c
@@ -28,6 +28,7 @@
 #include <xmlsec/keys.h>
 #include <xmlsec/parser.h>
 #include <xmlsec/errors.h>
+#include <xmlsec/private/xslt.h>
 
 /**************************************************************************
  *
@@ -95,6 +96,51 @@ static xmlSecTransformKlass xmlSecXsltKlass = {
     NULL,                                       /* void* reserved1; */
 };
 
+
+#define XMLSEC_XSLT_COPY_SEC_PREF(src, dst, pref) \
+    xsltSetSecurityPrefs((dst), (pref),  xsltGetSecurityPrefs((src), (pref)))
+
+static xsltSecurityPrefsPtr g_xslt_default_security_prefs = NULL;
+
+void xmlSecTransformXsltInitialize(void) {
+    xmlSecAssert(g_xslt_default_security_prefs == NULL);
+
+    g_xslt_default_security_prefs = xsltNewSecurityPrefs();
+    xmlSecAssert(g_xslt_default_security_prefs != NULL);
+    xsltSetSecurityPrefs(g_xslt_default_security_prefs,  XSLT_SECPREF_READ_FILE,        xsltSecurityForbid);
+    xsltSetSecurityPrefs(g_xslt_default_security_prefs,  XSLT_SECPREF_WRITE_FILE,       xsltSecurityForbid);
+    xsltSetSecurityPrefs(g_xslt_default_security_prefs,  XSLT_SECPREF_CREATE_DIRECTORY, xsltSecurityForbid);
+    xsltSetSecurityPrefs(g_xslt_default_security_prefs,  XSLT_SECPREF_READ_NETWORK,     xsltSecurityForbid);
+    xsltSetSecurityPrefs(g_xslt_default_security_prefs,  XSLT_SECPREF_WRITE_NETWORK,    xsltSecurityForbid);
+}
+
+void xmlSecTransformXsltShutdown(void) {
+    if(g_xslt_default_security_prefs != NULL) {
+        xsltFreeSecurityPrefs(g_xslt_default_security_prefs);
+        g_xslt_default_security_prefs = NULL;
+    }
+}
+
+/**
+ * xmlSecTransformXsltSetDefaultSecurityPrefs:
+ * @sec: the new security preferences
+ *
+ * Sets the new default security preferences. The xmlsec default security policy is 
+ * to disable everything.
+ */
+XMLSEC_EXPORT void
+xmlSecTransformXsltSetDefaultSecurityPrefs(xsltSecurityPrefsPtr sec) {
+    xmlSecAssert(sec != NULL);
+    xmlSecAssert(g_xslt_default_security_prefs != NULL);
+    
+    /* copy prefs */
+    XMLSEC_XSLT_COPY_SEC_PREF(sec, g_xslt_default_security_prefs, XSLT_SECPREF_READ_FILE);
+    XMLSEC_XSLT_COPY_SEC_PREF(sec, g_xslt_default_security_prefs, XSLT_SECPREF_WRITE_FILE);
+    XMLSEC_XSLT_COPY_SEC_PREF(sec, g_xslt_default_security_prefs, XSLT_SECPREF_CREATE_DIRECTORY);
+    XMLSEC_XSLT_COPY_SEC_PREF(sec, g_xslt_default_security_prefs, XSLT_SECPREF_READ_NETWORK);
+    XMLSEC_XSLT_COPY_SEC_PREF(sec, g_xslt_default_security_prefs, XSLT_SECPREF_WRITE_NETWORK);
+}
+
 /**
  * xmlSecTransformXsltGetKlass:
  *
@@ -135,6 +181,7 @@ xmlSecTransformXsltGetKlass(void) {
 static int
 xmlSecXsltInitialize(xmlSecTransformPtr transform) {
     xmlSecXsltCtxPtr ctx;
+    int ret;
 
     xmlSecAssert2(xmlSecTransformCheckId(transform, xmlSecTransformXsltId), -1);
     xmlSecAssert2(xmlSecTransformCheckSize(transform, xmlSecXsltSize), -1);
@@ -144,6 +191,12 @@ xmlSecXsltInitialize(xmlSecTransformPtr transform) {
 
     /* initialize context */
     memset(ctx, 0, sizeof(xmlSecXsltCtx));
+    
+    /* set security prefs  */
+    ret = xsltSetCtxtSecurityPrefs(g_xslt_default_security_prefs, ctx);
+    xmlSecAssert2(ret == 0, -1);
+
+    /* done */
     return(0);
 }