Admin at 13:19, 4 February 2014

2014-02-04T13:19:43Z

Admin: Created page with "= Action = This statement of function uses the Xmega AES encryption engine to encrypt a block of data. ..."

2013-02-06T22:39:26Z

Created page with "= Action = This statement of function uses the Xmega AES encryption engine to encrypt a block of data. ..."

New page

= Action =

This statement of function uses the Xmega AES encryption engine to encrypt a block of data.

 

 

= Syntax =

AESENCRYPT  key, var , size

targ = AESENCRYPT ( key, var , size)

 

 

= Remarks =
<div style="padding: 0px; margin: 0px 0px 0px 4px;">
{| width="604" cellspacing="0" cellpadding="1" border="1" style="border: 2px solid rgb(0, 0, 0); border-spacing: 0px; border-collapse: collapse;"
|- style="vertical-align: top;"
| valign="top" width="14%" style="width: 81px; border: 1px solid rgb(0, 0, 0);" |
key

| valign="top" width="100%" style="width: 514px; border: 1px solid rgb(0, 0, 0);" |
The name of a label that contains 16 bytes of key data. Or an array holding 16 bytes of key data.

|- style="vertical-align: top;"
| valign="top" width="14%" style="width: 81px; border: 1px solid rgb(0, 0, 0);" |
var

| valign="top" width="100%" style="width: 514px; border: 1px solid rgb(0, 0, 0);" |
A variable or array containing the data to be encrypted. When you use the statement, this variable will contains the encrypted data after the conversion.

|- style="vertical-align: top;"
| valign="top" width="14%" style="width: 81px; border: 1px solid rgb(0, 0, 0);" |
size

| valign="top" width="100%" style="width: 514px; border: 1px solid rgb(0, 0, 0);" |
The number of bytes to encrypt. Encryption is done with blocks of 16 bytes. So the size should be a multiple of 16. If you supply only 14 bytes this is ok too, but the result will still be 16 bytes. It is important that your array is big enough to hold the result.

Without the full 16 byte result, you can not decrypt the data.

|- style="vertical-align: top;"
| valign="top" width="14%" style="width: 81px; border: 1px solid rgb(0, 0, 0);" |
targ

| valign="top" width="100%" style="width: 514px; border: 1px solid rgb(0, 0, 0);" |
In case you use the function, this variable will hold the result.

|}
</div>
 

This function only works for Xmega chips that have an AES encryption unit.

128 bit encryption is used.

 

You can either use a label with a fixed key, or use a variable.

You should use the same key data for encryption and decryption.

 

 

 

= See also =

[[AESDECRYPT]]

 

 

= Example =

 <source lang="bascomavr">
'----------------------------------------------------------------
' (c) 1995-2010, MCS
' xm128-AES.bas
' This sample demonstrates the Xmega128A1 AES encryption/decryption
'-----------------------------------------------------------------

$regfile = "xm128a1def.dat"
$crystal = 32000000
$hwstack = 64
$swstack = 40
$framesize = 40

'include the following lib and code, the routines will be replaced since they are a workaround
$lib "xmega.lib"
$external _xmegafix_clear
$external _xmegafix_rol_r1014

'first enable the osc of your choice
Config Osc = Enabled , 32mhzosc = Enabled

'configure the systemclock
Config Sysclock = 32mhz , Prescalea = 1 , Prescalebc = 1_1

Config Com1 = 38400 , Mode = Asynchroneous , Parity = None , Stopbits = 1 , Databits = 8

'$external _aes_enc

Dim Key(16) As Byte ' room for key
Dim Ar(34) As Byte
Dim Arenc(34) As Byte
Dim J As Byte
Print "AES test"

Restore Keydata
For J = 1 To 16 ' load a key to memory
Read Key(j)
Next

'load some data
For J = 1 To 32 ' fill some data to encrypt
Ar(j) = J
Next

Aesencrypt Keydata , Ar(1) , 32
Print "Encrypted data"
For J = 1 To 32 ' fill some data to encrypt
Print Ar(j)
Next

Aesdecrypt Keydata , Ar(1) , 32
Print "Decrypted data"
For J = 1 To 32 ' fill some data to encrypt
Print Ar(j)
Next

Print "Encrypt function"
Arenc(1) = Aesencrypt(keydata , Ar(1) , 32)
For J = 1 To 32 ' fill some data to encrypt
Print Ar(j) ; "-" ; Arenc(j)
Next

Print "Decrypt function"
Ar(1) = Aesdecrypt(keydata , Arenc(1) , 32)

For J = 1 To 32
Print J ; ">" ; Ar(j) ; "-" ; Arenc(j)
Next

End

Keydata:
Data 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16
</source> {{Languages}}

[[Category:BASCOM_Language_Reference]]

@@ Line 92: / Line 92: @@
 $swstack = 40
 $framesize = 40
@@ Line 160: / Line 155: @@
 </source><br/>{{Languages}}
-[[Category:BASCOM_Language_Reference]]
+[[Category:BASCOM Language Reference]]

AESENCRYPT - Revision history

Admin at 13:19, 4 February 2014

Admin: Created page with "= Action = This statement of function uses the Xmega AES encryption engine to encrypt a block of data. ..."