T-SQL implementation of SKIPJACK

This source code is an T-SQL implementation of the crypt algorith SKIPJACK as a user function for MS-SQL 2000.

Requirements

1. MS SQL 2000
2. Script is case insensitive

Files

Run_Me_First.sql Init script
SkipJack_Crypt.sql Crypt functions
SkipJack_Dec.sql Decrypt functions
samples.sql Samples
Support_functions.sql Utility functions
customer.csv CSV file for import and crypt data

Installation

1. Run SQL Query Analyzer
   
2. Logon as Administrator or sa
   
3. Use master database (recomanded)
   
4. Open Run_Me_First.sql and run it (press F5)
   
5. Open support_functions.sql and run it
   
6. Open SkipJack_Crypt.sql and run it
   
7. Open SkipJack_Dec.sql and run it

Support functions

Name	Parameters	Return	Example
Exponential	Root (integer), Exponent(integer)	Big Integer	Exponential(2,3)=2^3=8
SHL *	Number1 (integer), Number2 - (integer)	Big Integer	SHL(5,10)=5*2^10=5120
SHR *	Number1 (integer), Number2 - (integer)	Big Integer	SHR(17,2)=17\2^2=4
StrToNum	String (char[2])	Integer	StrToNum(‘AB’)=16706
NumToStr	Number (integer)	String (char[2])	NumToStr(16706)=’AB’

* SHL = bitwise shift left, SHR = bitwise shift right

Examples

Print dbo.Exponential(2,3)
Print dbo.SHL(5,10)
Print dbo.SHR(17,2)
Print dbo.StrToNum('AB')
Print dbo.NumToStr(16706)

Crypt

Name	Parameters	Return
CryptText	Plain Text (nvarchar[4000]), crypt key (nvarchar[10])	Crypt text nvarchar(4000)

Sample

Print dbo.CryptText('Hello World!','Some key')

Decrypt

Name	Parameters	Return
DeCryptText	Crypt Text (nvarchar[4000]), crypt key (nvarchar[10])	Decrypt text nvarchar(4000)

Sample

Declare @C nvarchar(4000)
Set @C=dbo.CryptText('Hello World!','Some key')
Print dbo.DeCryptText(@C,'Some key')

For more examples, see sample.sql

Note

Computing size of a crypt text:

Length (Crypt text) = Length (Plain Text) + (Length (Plain text) MOD 8)