chromium/third_party/libxslt/src/libxslt/security.c

/*
 * security.c: Implementation of the XSLT security framework
 *
 * See Copyright for the status of this software.
 *
 * [email protected]
 */

#define IN_LIBXSLT
#include "libxslt.h"

#include <string.h>

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif

#if defined(_WIN32)
#include <windows.h>
#ifndef INVALID_FILE_ATTRIBUTES
#define INVALID_FILE_ATTRIBUTES …
#endif
#endif

#ifndef HAVE_STAT
#  ifdef HAVE__STAT
     /* MS C library seems to define stat and _stat. The definition
      *         is identical. Still, mapping them to each other causes a warning. */
#    ifndef _MSC_VER
#define stat …
#    endif
#define HAVE_STAT
#  endif
#endif

#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include <libxml/uri.h>
#include "xslt.h"
#include "xsltInternals.h"
#include "xsltutils.h"
#include "extensions.h"
#include "security.h"


struct _xsltSecurityPrefs { … };

static xsltSecurityPrefsPtr xsltDefaultSecurityPrefs = …;

/************************************************************************
 *									*
 *			Module interfaces				*
 *									*
 ************************************************************************/

/**
 * xsltNewSecurityPrefs:
 *
 * Create a new security preference block
 *
 * Returns a pointer to the new block or NULL in case of error
 */
xsltSecurityPrefsPtr
xsltNewSecurityPrefs(void) { … }

/**
 * xsltFreeSecurityPrefs:
 * @sec:  the security block to free
 *
 * Free up a security preference block
 */
void
xsltFreeSecurityPrefs(xsltSecurityPrefsPtr sec) { … }

/**
 * xsltSetSecurityPrefs:
 * @sec:  the security block to update
 * @option:  the option to update
 * @func:  the user callback to use for this option
 *
 * Update the security option to use the new callback checking function
 *
 * Returns -1 in case of error, 0 otherwise
 */
int
xsltSetSecurityPrefs(xsltSecurityPrefsPtr sec, xsltSecurityOption option,
                     xsltSecurityCheck func) { … }

/**
 * xsltGetSecurityPrefs:
 * @sec:  the security block to update
 * @option:  the option to lookup
 *
 * Lookup the security option to get the callback checking function
 *
 * Returns NULL if not found, the function otherwise
 */
xsltSecurityCheck
xsltGetSecurityPrefs(xsltSecurityPrefsPtr sec, xsltSecurityOption option) { … }

/**
 * xsltSetDefaultSecurityPrefs:
 * @sec:  the security block to use
 *
 * Set the default security preference application-wide
 */
void
xsltSetDefaultSecurityPrefs(xsltSecurityPrefsPtr sec) { … }

/**
 * xsltGetDefaultSecurityPrefs:
 *
 * Get the default security preference application-wide
 *
 * Returns the current xsltSecurityPrefsPtr in use or NULL if none
 */
xsltSecurityPrefsPtr
xsltGetDefaultSecurityPrefs(void) { … }

/**
 * xsltSetCtxtSecurityPrefs:
 * @sec:  the security block to use
 * @ctxt:  an XSLT transformation context
 *
 * Set the security preference for a specific transformation
 *
 * Returns -1 in case of error, 0 otherwise
 */
int
xsltSetCtxtSecurityPrefs(xsltSecurityPrefsPtr sec,
	                 xsltTransformContextPtr ctxt) { … }


/**
 * xsltSecurityAllow:
 * @sec:  the security block to use
 * @ctxt:  an XSLT transformation context
 * @value:  unused
 *
 * Function used to always allow an operation
 *
 * Returns 1 always
 */
int
xsltSecurityAllow(xsltSecurityPrefsPtr sec ATTRIBUTE_UNUSED,
	          xsltTransformContextPtr ctxt ATTRIBUTE_UNUSED,
		  const char *value ATTRIBUTE_UNUSED) { … }

/**
 * xsltSecurityForbid:
 * @sec:  the security block to use
 * @ctxt:  an XSLT transformation context
 * @value:  unused
 *
 * Function used to always forbid an operation
 *
 * Returns 0 always
 */
int
xsltSecurityForbid(xsltSecurityPrefsPtr sec ATTRIBUTE_UNUSED,
	          xsltTransformContextPtr ctxt ATTRIBUTE_UNUSED,
		  const char *value ATTRIBUTE_UNUSED) { … }

/************************************************************************
 *									*
 *			Internal interfaces				*
 *									*
 ************************************************************************/

/**
 * xsltCheckFilename
 * @path:  the path to check
 *
 * function checks to see if @path is a valid source
 * (file, socket...) for XML.
 *
 * TODO: remove at some point !!!
 * Local copy of xmlCheckFilename to avoid a hard dependency on
 * a new version of libxml2
 *
 * if stat is not available on the target machine,
 * returns 1.  if stat fails, returns 0 (if calling
 * stat on the filename fails, it can't be right).
 * if stat succeeds and the file is a directory,
 * returns 2.  otherwise returns 1.
 */

static int
xsltCheckFilename (const char *path)
{ … }

static int
xsltCheckWritePath(xsltSecurityPrefsPtr sec,
		   xsltTransformContextPtr ctxt,
		   const char *path)
{ … }

/**
 * xsltCheckWrite:
 * @sec:  the security options
 * @ctxt:  an XSLT transformation context
 * @URL:  the resource to be written
 *
 * Check if the resource is allowed to be written, if necessary makes
 * some preliminary work like creating directories
 *
 * Return 1 if write is allowed, 0 if not and -1 in case or error.
 */
int
xsltCheckWrite(xsltSecurityPrefsPtr sec,
	       xsltTransformContextPtr ctxt, const xmlChar *URL) { … }


/**
 * xsltCheckRead:
 * @sec:  the security options
 * @ctxt: an XSLT transformation context
 * @URL:  the resource to be read
 *
 * Check if the resource is allowed to be read
 *
 * Return 1 if read is allowed, 0 if not and -1 in case or error.
 */
int
xsltCheckRead(xsltSecurityPrefsPtr sec,
	      xsltTransformContextPtr ctxt, const xmlChar *URL) { … }