>Does anyone know of a good Encryption Library for FoxPro and Visual FoxPro.


We have been using cipher in FPW 2.x with quite a bit of success. We are planning to use cipher50 in the VFP 5.0 rewrite. Follows is a cut from the readme file.

// CIPHER50.FLL
//
// Character encryption routine for VFP 5.0
//
// Usage: ENCRYPT(plaintext,password)
//
// Plaintext can be a character string or a memo field (memo fields
// must be passed by reference -- encrypt(@memo,password) ).
// If a memo field is passed to this function, it will not
// be modified, even though it is nominally passed by reference.
// A character string passed by reference will be modified. A
// variable (other than a character string or memo field) that
// is passed by reference will be unchanged (and the function return
// value will be the same value as the variable).
//
// Also, password must be at least 3 characters in length or the
// function will return the character string unchanged.
//
// To decrypt a string, just run it through this function again.
// Thus: ENCRYPT(ENCRYPT(plaintext,password),password) = plaintext
//
// Returns: Encrypted string of same length as plaintext
//
//
// History: Produced as CIPHER50.FLL for VFP 5.0 API by Guy Pardoe, 1/6/97
// Produced as CIPHER30.FLL for VFP 3.0 API by Roy Gerber, 8/95
// Modified by Walt Kennamer for FoxPro 2.0 API, 8/19/91
// Encryption logic originally written by Tom Rettig and Leonard Zerman,
// and placed in the public domain by Tom Rettig Associates, 10/22/1990
//
// CIPHER50.FLL is public domain software.
//
// Produced with MS VC++ 4.2. CIPHER50 has been successfully tested on plaintext strings (memo fields) in excess of 150,000 characters with snappy performance.
//
//
// Contact Guy Pardoe 73552,2477 if you have questions.
//
//
// DISCLAIMER: Not responsible for direct, indirect, incidental, or
// consequential damages resulting from any defect, error, or
// failure to perform. No other warranty expressed or implied.
//
// All Trademarks Recognized.
//
//
//
// Tech Note: On some Windows 95 PCs when you issue the command:
//
// SET LIBRARY TO cipher50.fll
//
// you may experience an error similar to:
//
// Error 1691 - Library file Cipher50.FLL is invalid.
//
// The error is a result of the Windows PC not having MSVCRT.DLL installed
// in its SYSTEM directory. The problem does not occur with Windows NT.
// Microsoft states that MSVCRT.DLL is required with multithreaded .DLLs
// [or .FLLs] by design. However, it is not shipped with all O/S products.
//
// Microsoft ships this .DLL with Windows NT 4.0, OEM Service Release 2 of
// Windows 95 (OSR 2), and MS VC++ 4.2 and higher. It does NOT ship with
// the original version of Windows 95, the Windows 95 Upgrade, the Win95
// Service Pack 1, or VFP 5.0.
//
// MSVCRT.DLL [version 5.0.7022] is now included with CIPHER50.ZIP. If you
// distribute CIPHER50 enabled applications with the VFP 5.0 Setup Wizard,
// remember to direct MSVCRT.DLL to WinSysDir in step 6 of the Setup Wizard.
//
// Occassionally, there may be difficulty installing a .DLL in the SYSTEM
// directory due to the .DLL being in use at the time of a new install.
// However, installing this particular .DLL should be fairly painless since
// it is not one of the active .DLLs that is always [or often] running. The
// fact that it is not part of the original version of Windows testifies to
// this.
//
// As another work around for a Windows 95 PC that does not have MSVCRT.DLL,
// copying MSVCRT40.DLL to MSVCRT.DLL in the SYSTEM directory has been known
// to work.
//
// Refer to the MS Knowledge Base Article Q157317 for additional information
// regarding .FLLs and MSVCRT.DLL.


End of Readme