DEA64encrypt (String function): Difference between revisions

From m204wiki
Jump to navigation Jump to search
m (this page content to become content for a "group" page for two method synonyms)
 
Line 1: Line 1:
{{Template:String:DEA64encrypt subtitle}}
#REDIRECT [[DEA64decrypt and DEA64encrypt (String functions)]]
This page is [[under construction]].
 
<var>RC4encrypt</var> and <var>RC4decrypt</var> are synonyms for the [[String class]] function that applies the DEA (Data Encryption Algorithm) using a 64-bit symmetric key to encrypt or decrypt each 64-bit block of input text. For more details about how the algorithm works, see [https://en.wikipedia.org/wiki/Data_Encryption_Standard Data Encryption Standard].
 
The length of the returned string is the same as that of the object string.
 
DEA is a two-way cipher, so encrypting a string with a key and then decrypting the result of that encryption with the same key produces the original string. That is, the following assertion should <b><i>always</i></b> hold:
<p class="code">[[Assert statement|assert]] %string:dea64encrypt(%key):dea64decrypt(%key) eq %string
</p>
You can use <var>RC4decrypt</var> to "document" that you are decrypting, and
use <var>RC4encrypt</var> to "document" that you are enrypting. You can use <var>RC4decrypt</var> and <var>RC4encrypt</var> interchangeably on the rest of this page.
 
==Syntax==
{{Template:String:DEA64encrypt syntax}}
{{Template:String:DEA64decrypt syntax}}
 
===Syntax terms===
<table>
<tr><th>%outString</th>
<td>A string variable to receive the encrypted or decrypted method object <var class="term">string</var>. Its length is the same as <var class="term">string</var>.</td></tr>
 
<tr><th>string</th>
<td>The string to which the method is applied. <var class="term">string</var> must be a multiple of eight bytes in length; its  maximum is 32768 bytes. It may be null.</td></tr>
 
<tr><th>key</th>
<td>An 8-byte (only) string variable whose value is used to encrypt or decrypt the method object, <var class="term">string</var>.</td></tr>
</table>
 
==Usage notes==
<ul>
<li>The <var>DEA64encrypt</var> and <var>DEA64decrypt</var> functions are available as of <var class="product">Model&nbsp;204</var> 7.6. </li>
</ul>
 
==Examples==
In the following example, the output string from the <var>DEA64encrypt</var> method is converted to hex using the <var>[[StringToHex (String function)|StringToHex]]</var> function to reveal its non-displayable characters, then decrypted to return the original input string:
 
<p class="code">b                   
%ls is longstring   
%string is longstring
%key is longstring
%string = 'onetwothreefour0onetwothreefour0'
%key = '12345678'
 
%ls = %string:dea64encrypt(%key)
[[PrintText statement|printText]] {~} is {%ls:stringTohex}
printText {~} is: {%ls:rc4decrypt(%key)}
end
</p>
The result is:
<p class="output">%ls:stringTohex is: A54138C10468C061567574F88567E221A54138C10468C061567574F88567E221
%ls:dea64decrypt(%key) is: onetwothreefour0onetwothreefour0
</p>
 
==See also==
<ul>
<li><var>[[DEA128encrypt (String function)|DEA128encrypt]]</var> </li>
 
<li><var>[[DEA256encrypt (String function)|DEA256encrypt]]</var> </li>
</ul>
 
{{Template:String:DEA64encrypt footer}}

Latest revision as of 21:01, 9 March 2016