diff options
Diffstat (limited to 'user_guide/libraries')
| -rw-r--r-- | user_guide/libraries/encryption.html | 44 |
1 files changed, 39 insertions, 5 deletions
diff --git a/user_guide/libraries/encryption.html b/user_guide/libraries/encryption.html index dac1db911..fbffd63c6 100644 --- a/user_guide/libraries/encryption.html +++ b/user_guide/libraries/encryption.html @@ -58,12 +58,11 @@ Encryption Class <h1>Encryption Class</h1> -<p>The Encryption Class provides two-way data encryption. It uses a scheme that pre-compiles -the message using a randomly hashed bitwise XOR encoding scheme, which is then encrypted using +<p>The Encryption Class provides two-way data encryption. It uses a scheme that either compiles +the message using a randomly hashed bitwise XOR encoding scheme, or is encrypted using the Mcrypt library. If Mcrypt is not available on your server the encoded message will still provide a reasonable degree of security for encrypted sessions or other such "light" purposes. -If Mcrypt is available, you'll effectively end up with a double-encrypted message string, which should -provide a very high degree of security.</p> +If Mcrypt is available, you'll be provided with a high degree of security appropriate for storage.</p> <h2>Setting your Key</h2> @@ -153,7 +152,7 @@ $encrypted_string = $this->encrypt->decode($msg, $key);</code> <h2>$this->encrypt->set_mode();</h2> -<p>Permits you to set an Mcrypt mode. By default it uses <samp>MCRYPT_MODE_ECB</samp>. Example:</p> +<p>Permits you to set an Mcrypt mode. By default it uses <samp>MCRYPT_MODE_CBC</samp>. Example:</p> <code>$this->encrypt->set_mode(MCRYPT_MODE_CFB);</code> <p>Please visit php.net for a list of <a href="http://php.net/mcrypt">available modes</a>.</p> @@ -169,7 +168,42 @@ function:</p> <p>If your server does not support SHA1 you can use the provided function.</p> +<h2 id="legacy">$this->encrypt->encode_from_legacy(<kbd>$orig_data</kbd>, <kbd>$legacy_mode</kbd> = MCRYPT_MODE_ECB, <kbd>$key</kbd> = '');</h2> +<p>Enables you to re-encode data that was originally encrypted with CodeIgniter 1.x to be compatible with the Encryption library in CodeIgniter 2.x. It is only + necessary to use this method if you have encrypted data stored permanently such as in a file or database and are on a server that supports Mcrypt. "Light" use encryption + such as encrypted session data or transitory encrypted flashdata require no intervention on your part. However, existing encrypted Sessions will be + destroyed since data encrypted prior to 2.x will not be decoded.</p> +<p class="important"><strong>Why only a method to re-encode the data instead of maintaining legacy methods for both encoding and decoding?</strong> The algorithms in + the Encryption library have improved in CodeIgniter 2.x both for performance and security, and we do not wish to encourage continued use of the older methods. + You can of course extend the Encryption library if you wish and replace the new methods with the old and retain seamless compatibility with CodeIgniter 1.x + encrypted data, but this a decision that a developer should make cautiously and deliberately, if at all.</p> + +<code>$new_data = $this->encrypt->encode_from_legacy(<kbd>$old_encrypted_string</kbd>);</code> + +<table cellpadding="0" cellspacing="1" border="0" style="width:100%" class="tableborder"> +<tr> + <th>Parameter</th> + <th>Default</th> + <th>Description</th> +</tr> +<tr> + <td class="td"><strong>$orig_data</strong></td> + <td class="td">n/a</td> + <td class="td">The original encrypted data from CodeIgniter 1.x's Encryption library</td> +</tr> +<tr> + <td class="td"><strong>$legacy_mode</strong></td> + <td class="td">MCRYPT_MODE_ECB</td> + <td class="td">The Mcrypt mode that was used to generate the original encrypted data. CodeIgniter 1.x's default was MCRYPT_MODE_ECB, and it will + assume that to be the case unless overridden by this parameter.</td> +</tr> +<tr> + <td class="td"><strong>$key</strong></td> + <td class="td">n/a</td> + <td class="td">The encryption key. This it typically specified in your config file as outlined above.</td> +</tr> +</table> </div> <!-- END CONTENT --> |