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author | Mike Funk <mfunk@xulonpress.com> | 2011-10-10 16:31:56 +0200 |
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committer | Mike Funk <mfunk@xulonpress.com> | 2011-10-10 16:31:56 +0200 |
commit | 8afb848fded8fbdfa24b72df7f067e960c83c0e8 (patch) | |
tree | bf3d8fa70610253cb13a87c1aa9d634dcee9f413 /user_guide_src/source/libraries/security.rst | |
parent | 25246b6b29d87ad7a4f304a7b5623c9f57953356 (diff) | |
parent | bdbe6d222c15e9d1b42a8ee3a3e7fe04b753c1ba (diff) |
Codeigniter develop latest.
Diffstat (limited to 'user_guide_src/source/libraries/security.rst')
-rw-r--r-- | user_guide_src/source/libraries/security.rst | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/user_guide_src/source/libraries/security.rst b/user_guide_src/source/libraries/security.rst new file mode 100644 index 000000000..8ee0c6e77 --- /dev/null +++ b/user_guide_src/source/libraries/security.rst @@ -0,0 +1,93 @@ +############## +Security Class +############## + +The Security Class contains methods that help you create a secure +application, processing input data for security. + +XSS Filtering +============= + +CodeIgniter comes with a Cross Site Scripting Hack prevention filter +which can either run automatically to filter all POST and COOKIE data +that is encountered, or you can run it on a per item basis. By default +it does **not** run globally since it requires a bit of processing +overhead, and since you may not need it in all cases. + +The XSS filter looks for commonly used techniques to trigger Javascript +or other types of code that attempt to hijack cookies or do other +malicious things. If anything disallowed is encountered it is rendered +safe by converting the data to character entities. + +Note: This function should only be used to deal with data upon +submission. It's not something that should be used for general runtime +processing since it requires a fair amount of processing overhead. + +To filter data through the XSS filter use this function: + +$this->security->xss_clean() +============================= + +Here is an usage example:: + + $data = $this->security->xss_clean($data); + +If you want the filter to run automatically every time it encounters +POST or COOKIE data you can enable it by opening your +application/config/config.php file and setting this:: + + $config['global_xss_filtering'] = TRUE; + +Note: If you use the form validation class, it gives you the option of +XSS filtering as well. + +An optional second parameter, is_image, allows this function to be used +to test images for potential XSS attacks, useful for file upload +security. When this second parameter is set to TRUE, instead of +returning an altered string, the function returns TRUE if the image is +safe, and FALSE if it contained potentially malicious information that a +browser may attempt to execute. + +:: + + if ($this->security->xss_clean($file, TRUE) === FALSE) + { + // file failed the XSS test + } + +$this->security->sanitize_filename() +===================================== + +When accepting filenames from user input, it is best to sanitize them to +prevent directory traversal and other security related issues. To do so, +use the sanitize_filename() method of the Security class. Here is an +example:: + + $filename = $this->security->sanitize_filename($this->input->post('filename')); + +If it is acceptable for the user input to include relative paths, e.g. +file/in/some/approved/folder.txt, you can set the second optional +parameter, $relative_path to TRUE. + +:: + + $filename = $this->security->sanitize_filename($this->input->post('filename'), TRUE); + +Cross-site request forgery (CSRF) +================================= + +You can enable csrf protection by opening your +application/config/config.php file and setting this:: + + $config['csrf_protection'] = TRUE; + +If you use the :doc:`form helper <../helpers/form_helper>` the +form_open() function will automatically insert a hidden csrf field in +your forms. + +Select URIs can be whitelisted from csrf protection (for example API +endpoints expecting externally POSTed content). You can add these URIs +by editing the 'csrf_exclude_uris' config parameter:: + + $config['csrf_exclude_uris'] = array('api/person/add'); + |