>>ITEM: N00105
>>DATE: 08/26/96
>>TYPE: Information
>>TITLE: Encrypted file becomes decrypted after PACK or REINDEX
>>PRODUCT(S):
Netlib 6.5x for Clipper
NetLib 2.0x for FoxPro DOS
NetLib 2.0x for FoxPro Windows
>>PLATFORMS(S):
All
>>SUMMARY:
An encrypted DBF may "mysteriously" become decrypted after a PACK
operation, or an encrypted index file may become decrypted after
a PACK or REINDEX operation.
>>MORE INFORMATION:
FoxPro and Clipper PACK with the following internal procedure:
- COPY TO "temp.dbf" FOR .NOT. DELETED()
- DELETE "original.dbf"
- RENAME "temp.dbf" TO "original.dbf"
NetLib does not normally encrypt newly created files. Therefore,
in the above operation, temp.dbf is created as an unencrypted
file, even if original.dbf was encrypted.
>>RESOLUTION/FIX:
Use N_ENCODENEW(.T.) whenever performing file operations that may
use intermediate temporary work files. This includes (but may
not be limited to) PACK, INDEX ON and REINDEX. N_ENCODENEW(.T.)
instructs NetLib to automatically encrypted newly created files.
IMPORTANT:
Only specify N_ENCODENEW(.T.) when needed.
Immediately turn it off with N_ENCODENEW(.F.) when no longer
needed. In addition, make sure that you have specified the
appropriate encryption key with N_SETKEY before the operation.
ALTERNATIVE:
PACK or REINDEX without N_ENCODENEW(.T.). After the
operation use N_CODELVL to determine if the file has become
unencrypted and reencrypt if necessary using N_ENCODE.
>>EXAMPLE(S):
The following examples will PACK a my.dbf encrypted with the key "%$#@!"
=N_SETKEY("%$#@!")
USE "my.dbf"
=N_ENCODENEW(.T.)
PACK
=N_ENCODENEW(.F.)
ALTERNATIVE:
=N_SETKEY("%$#@!")
USE "my.dbf"
PACK
USE
IF N_CODELVL("my.dbf") == 1
* not encrypted anymore
=N_ENCODE("my.dbf" , "temp.dbf")
ERASE "my.dbf"
RENAME "temp.dbf" TO "my.dbf"
ENDIF
>>SEE ALSO:
>>COPYRIGHT 1997 Communication Horizons
All rights reserved worldwide.
No distribution without specific consent of publisher.
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