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This utility can be used to encrypt and decrypt c-tree data files.
Operational Model:
Standalone Usage
ctcmpcif <data file name> <user> <pass> <server> <-sectors> <options>
Where:
ctcmpcif xx8.dat ADMIN ADMIN FAIRCOMSMS -256
<options> can be:
Client-Side Usage
# ctcmpcif DataFileName [-purge] [-updifil] [<UserId>]
[<UserPassword> [<ServerName>]]
Where:
UserID, UserPassword, and ServerName are only needed for client versions of this utility. FairCom recommends building this utility as a Single-user Standalone application.
ctcmpcif reads the IFIL structure from DataFileName and calls CompactIFileXtd() and RebuildIFileXtd() to compact and rebuild DataFileName and its associated indexes. If ctcmpcif cannot extract the IFIL from the target file, it will ask for the name of another copy of the file from which to extract the IFIL information.
Prior to FairCom DB V9.3, several option values were defined such as updateIFIL, purgeIFIL, and badpartIFIL, that can be specified. These values are specified by adding them together. For example: myifil.tfilno = updateIFIL + purgeIFIL. A new approach simplifies checking of these options. The following option values are now specified in ctport.h:
#define updateIFILoption 0x0002
#define purgeIFILoption 0x0004
#define badpartIFILoption 0x0008
#define redosrlIFILoption 0x0010
These values can now be OR-ed together and the negative of the result stored in the tfilno field of the IFIL structure passed to the compact or rebuild function. For example, to indicate that you want to assign new serial numbers, do the following:
myifil.tfilno = -redosrlIFILoption;
CMPIFIL(&myifil);
If you want to also use more than one option when compacting or rebuilding a file, OR them in to the value and negate the result. For example,
/* assign new serial numbers and update IFIL resource. */
myifil.tfilno = -(redosrlIFILoption | updateIFILoption);
CMPIFIL(&myifil);
ctcmpcif will attempt to open files of any page size definition. In addition, in standalone mode, it will create the new file based on the provided page size.
Note: This tool does not compact partitioned files. If you attempt to compact a partitioned file, the tool will return PCMP_ERR (954, compacting partitioned file not supported).
Changing Encryption Attributes
In V11 and later, the compact utility can optionally change the encryption attributes. To use this option, OR in the setencryptIFILoption bit into the tfilno field of the IFIL structure whose address you pass to the compact API function. When using this and other options, remember to negate the tfilno value after you OR in the options. For example:
myifil.tfilno = -(redosrlIFILoption | setencryptIFILoption);
CMPIFIL(&myifil);
Specifying the Encryption Cipher
In V11 and later, the ctcmpcif utility supports an option to specify the encryption cipher for the data and index files created by the compact operation. Usage:
-encrypt=cipher - Create the compacted file using the specified cipher:
Note: If an index file does not exist, the original data file's encryption attributes are used when creating that index file.
To change the encryption attributes of a file using this ctcmpcif compact utility or the compact API function from a client, you must add the option CHANGE_ENCRYPTION_ON_COMPACT YES to ctsrvr.cfg. Otherwise, the operation fails with error NSUP_ERR (454, not supported).
Environment Variable to Enable Advanced Encryption
In V11.5 and later, c-tree supports enabling advanced encryption at run time using an environment variable. Set the environment variable CTREE_ADVANCED_ENCRYPTION to YES to enable advanced encryption if it is supported. This environment variable can be used to allow c-tree utilities to enable advanced encryption even if they haven't been updated yet to automatically enable advanced encryption when needed. Examples include the rebuild and compact utilities, ctrbldif and ctcmpcif.
Note: If c-tree does not support advanced encryption and this environment variable is set, the c-tree initialization will fail.
Considerations
When an application calls the standalone version of the Xtd8 file compact or rebuild functions (for example, CMPIFILX8() or RBLIFILX8()), index files created by the compact or rebuild no longer have the 6-byte transaction number attribute enabled if the specified extended create block's x8mode field has the ctNO6BTRAN bit set.
See also
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In V10.3 and later, the ctrbldif utility assigns data file owner/group/permissions to index files and ctcmpcif assigns original data file owner/group/permissions to compacted data/index files.
The rebuild and compact utilities now read the permission mask, owner, and group settings from the original data file and after the rebuild or compact is completed, the utilities assign these same attributes to the new files.
A command-line option has been added to the utilities to restore the previous security attribute behavior. Use the -oldsec option to cause the rebuild and compact utilities to set the security attributes as they did before this revision. For example:
ctrbldif mark.dat -oldsec ADMIN ADMIN FAIRCOMS
The -oldsec option can be used if rebuild and compact are failing with error 455 (user does not belong to group) if you delete an index then run the rebuild or compact utility on the data file using a user account that does not belong to the group that is assigned to the data file.
Note: These changes only apply to the client and server versions of these utilities. Setting the security attributes is not supported in standalone mode, so the standalone rebuild and compact utilities behave as follows:
1) When the standalone mode rebuild utility creates new index files instead of reusing the new index files (for example if the original index files have been deleted before running the rebuild utility), the new index files are assigned a permission mask of zero (no restrictions on permissions), and the owner and group are unassigned (empty).
2) The standalone mode compact utility always preserves the security attributes of the data file. If the index files do not exist, the newly-created index files are assigned the same values as the standalone rebuild does when it creates new index files.
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In most cases, compact and/or rebuild operations perform as expected: scanning your data file for potential invalid record headers, fixing those it finds invalid, and finally writing out a new compressed file and rebuilding indexes. Recently, a case was investigated where our default behavior should not be used due to potential data file corruption.
In a few rare and select cases, FairCom identified situations where compacting a variable-length and (typically) non-transaction enabled (non-TRNLOG) file, using the ctcmpcif compact utility or any of the CompactIFile functions, can fail, potentially, and unexpectedly, also altering your original file being compacted such that further attempts result in data loss.
Typically, it is only expected to see this situation occur with non-TRNLOG enabled files. However, in case #2 discussed below, a valid TRNLOG enabled file data file was found to exhibit this very unusual behavior. This raises an important point – if you encounter situations where you believe you must rebuild TRNLOG enabled files, please contact FairCom, as this is a highly unexpected event and we want to fully understand the context and nature of your data integrity situation. The recoverable nature of TRNLOG files should always maintain full data integrity through nearly any circumstance.
We have modified prior behavior to take a much more conservative approach protecting your original data state. Compact and rebuild (which can produce similar results) facilities listed below have been altered such that, when any data file integrity issue is detected, default behavior is now to stop further operations. In addition, no changes are made to existing original data records.
Note: This is a compatibility Change.
Full List of Functions Changed
The following utilities and function calls now default to stopping if an error is encountered:
ctcmpcif – Compact utility
ctrbldif – Rebuild utility
GUI tool - Dr. ctree has compact and rebuild functionality
Long function name |
Short function name |
|---|---|
CompactIFile() |
CMPIFIL() |
CompactIFileXtd() |
CMPIFILX() |
CompactIFileXtd8() |
CMPIFILX8() |
RebuildIFil() |
RBLIFIL() |
RebuildIFileXtd() |
RBLIFILX() |
RebuildIFileXtd8() |
RBLIFILX8() |
Default Behavior Changes the Original File
Prior to FairCom DB V11.5, the default behavior for compact and rebuild operations over variable-length record data files was to scan for invalid record headers before compacting a file. If the logic found invalid headers, it attempted to fix the headers in the original file. If the operation failed at this point, the original file could become corrupted. Two significant classes of situations are known to arise:
To ensure the second case does not cause data loss, observe our recommendations below and always back up all concerned data files before compacting or rebuilding.
Compact and Rebuild Best Practice
To avoid potential data loss, FairCom strongly recommends only using our latest FairCom DB V11.5 compact and rebuild logic that default to stopping if a corrupt data record header is encountered, and returns error DCPT_ERR (1107) rather than attempting to repair the data link in the record header. This allows an administrator to know with greater certainty that serious damage has occurred and they may prefer to recover the file from a backup.
If an administrator prefers allowing FairCom DB to attempt to recover a file, as done prior to V11.5, the following options are available to revert to prior behavior:
For example:
myIFIL.tfilno = setIFILoptions(repairCorruptIFILoption | updateIFILoption);
Best Practices:
1.) It is always important to back up concerned data files before you attempt to compact or rebuild them.
2.) Ensure sufficient disk space is available before starting a compact or rebuild. You will need up to at least 3X the size of the data file plus index files (original files + new files + copy) for a successful compact or rebuild.
3.) Consider keeping a copy of the data file for sufficient time and ensure all expected data is available before removing the backup.
