What characters are acceptable for use in the passphrase? What characters are disallowed from a passphrase key?

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According to the online User Guide, spaces and punctuation characters are permitted for passphrase type wireless encryption keys.  Defined in practical terms, if a character can be typed on a standard American keyboard, then it is considered valid input for the passphrase.  Special (non-punctuation) characters, such as @#$%^&*(){}[]|\:<>`~_-, are also permitted.  

If configuring the passphrase key in the webmanager interface, simply type the desired characters for the passphrase key in the passphrase field.

Entering the key through the CLI requires a little more care.  
It is recommended to enclose space, punctuation-type, and other printable extended ASCII characters in double quotes to keep the CLI from attempting to interpret them.  For example, ~!@#$%^ should be entered as:

"~!@#$%^"

If the special characters are embedded within a passphrase key, then enclose the entire passphrase key in double quotes.  For example, Tim#$%^&land  should be entered as:

"Tim#$%^&land"

To include a double quote (")symbol in a passphrase, flag it with a backslash (\).  
For example:

"\""

(backslash+double-quote enclosed in double quotes) sets the passphrase to:

"

(a single double-quote symbol).

The TAB character is the only character that is disallowed in passphrase key type in both webmanager and CLI interfaces.  If TAB is required, then the key has to be entered in hex mode, not passphrase.

At the time of this writing, WLAN Profile and Wireless Security Settings are discussed on page 41 of the online User Guide.  Passphrase type Key is detailed on page 46.
http://www.lantronix.com/pdf/MatchPort-bg-Pro_UG.pdf

Background:

There is no industry-wide official standard for configuring a passphrase. A passphrase implies that the entered string of supported characters (as defined above) is used as a hash input that generates a key for authentication/key exchange.

The most common input methods used to generate the WiFi authentication key are hex key and passphrase. Some WiFi access points also support a third and less commonly used type of input called ascii key. The ascii key input translates the ASCII characters directly into hexadecimal values of a hex key.

 

The following example shows the relationship between hex and ascii keys.

For instance, if the actual key (in hex) is: 41 42 43 44 45 46 47 48 49 4A

then

 

Hex Key:      4142434445464748494A

Ascii Key:     ABCDEFGHIJ

 

Passphrase input method works a little differently. A passphrase goes through a complex hash computation to derive the authentication key to be used. Consequently, they authentication key generated from a passphrase is not the same as a hex or ascii key. The passphrase input method allows the user to enter an easy to remember phrase that will be mapped into a hex key of specific length as needed by the underlying algorithms.

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[Originally Published On: 10/07/2010 03:00 PM]