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Projects/Reporting-friendly KDB dump format

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This is an early stage project for MIT Kerberos. It is being fleshed out by its proponents. Feel free to help flesh out the details of this project. After the project is ready, it will be presented for review and approval.


This project is targeted at release 1.14.


This is split from Projects/KDB reporting and bulk operations.

Contents

Background

Operators often want to perform reporting operations on KDB data, but the dump format is optimized for loading by kdb5_util, not human reading or reporting using simple scripts. For example, the number of columns on each principal dump line depends on the number of keydata entries associated with that principal. Also, some useful metadata such as modification date are only present in a human-unfriendly hexadecimal format, as an artifact of being stored in the tl_data of the principal.

Format choice

Tab-separated value formats are probably acceptable to the largest variety of tools. These tools range from simple awk scripts to SQL databases. Comma-separated values are easy to add. Various quoting and escaping options exist in various dialects of CSV format. Opinions vary on whether tab-separated formats can use quoting, but in any case, most of the fields will not require quoting if tab-separated.

There are several conceptual database tables, each of which will have a different set of columns. To allow a single combined dump format, each dump line will have a first column that indicates the conceptual table to which it belongs. Another option is to provide command line options to select an individual conceptual table to dump, in which case the table name prefix would be omitted from each line. Headers should be optional, because some tools work better without them.

Examples

These are some examples of how commonly available tools could be used to manipulate output from one of these dumps.

$ cat keyinfo.txt
name	keyindex	kvno	enctype	salttype	salt
foo@EXAMPLE.COM	0	1	aes128-cts-hmac-sha1-96	normal	-1
bar@EXAMPLE.COM	0	1	aes128-cts-hmac-sha1-96	normal	-1
bar@EXAMPLE.COM	1	1	des-cbc-crc	normal	-1
$ sqlite3
sqlite> .mode tabs
sqlite> .import keyinfo.txt keyinfo
sqlite> select * from keyinfo where enctype like 'des-cbc-%';
bar@EXAMPLE.COM	1	1	des-cbc-crc	normal	-1
sqlite> .quit
$ awk -F'\t' '$4 ~ /des-cbc-/ { print }' keyinfo.txt
bar@EXAMPLE.COM	1	1	des-cbc-crc	normal	-1

Formatting options

Symbolic names

Some values such as enctypes and salttypes can be printed numerically or using symbolic names. The default will be for symbolic names.

Date/time

Time stamps print as ISO 8601 UTC date and time. Numeric output is decimal POSIX time_t values.

Durations can print as decimal seconds. Later options could include ISO 8601 durations (although technically ISO 8601 duration representations are only supposed to designate intervals by context, and not pure durations).

Conceptual tables

This is an attempt to split KDB data fields into a somewhat more normalized schema that is somewhat easier to manipulate for reporting purposes. The rectype is the string used to request a specific conceptual table. Initially, only one table can print at a time. Eventually, there will be a combined output format where each line is prefixed with the rectype. Additional possibilities include outputting a directory with one file per table.

Principal metadata

rectype
princ_meta
name
Principal name (krb5_kdb_entry)
modby
Last modified by (principal name) (KRB5_TL_MOD_PRINC)
modtime
Last modification date (KRB5_TL_MOD_PRINC)
lastpwd
Last password change (KRB5_TL_LAST_PWD_CHANGE)
policy
Policy object name (osa_princ_ent_rec)
mkvno
Master key version used for this principal's key data (KRB5_TL_MKVNO)
hist_kvno
kadmin history principal kvno for this principal's key history (osa_princ_ent_rec)

Principal keys

There will generally be multiple dump key data dump lines per principal. The order is significant (though typically it's only important within the active kvno), so there will need to be a key index number in case the user imports the dump into a data store that doesn't preserve the ordering of input lines (such as most relational databases).

rectype
keyinfo (or keydata)
name
Principal name (krb5_kdb_entry)
keyindex
Key index
kvno
Key version number
enctype
Enctype
key
hex string (only for keydata rectype)
salttype
Salt type
salt
Salt data as hex string (might be "-1" to denote no salt or normal/default salt)

A sample implementation of a "keyinfo" dump format is at https://github.com/tlyu/krb5/tree/keyinfo

Per-principal policy data

rectype
princ_tktpolicy
name
Principal name
expiration
Principal expiration date
pw_expiration
Password expiration date
max_life
Max ticket lifetime
max_renew_life
Max renewable ticket lifetime

Per-principal lockout data

These are the per-KDC (non-replicated) data that track failed logins due to incorrect passwords.

rectype
princ_lockout
name
Principal name
last_success
Last success
last_failed
Last failure
fail_count
Count of failed attempts

Principal boolean attributes

rectype
princ_flags
name
Principal name
flag
Attribute name (string form, or hexadecimal if numeric is requested)
value
Boolean value (1 or 0)

Feedback from operators indicates that having a row for each attribute, regardless of whether or not it's set, can be useful to satisfy auditors.

Unknown attributes print as hexadecimal numbers, if set. If the user requests numeric output, output all flag settings, including unset flags, as hexadecimal.

Principal string attributes

rectype
princ_stringattrs
name
Principal name
key
Attribute name
value
Attribute value

Principal key history

This is very similar to the keyinfo/keydata table. There is some weird ring buffer stuff that we may or may not want to reflect in the dump.

  • Principal name
  • Key index
  • Key version number (kvno)
  • Enctype
  • Salt type
  • Salt data as hex string (might be "-1" to denote no salt or normal/default salt)

Password policy

  • Policy name
  • Min password life
  • Max password life
  • Min password length
  • Min password character classes
  • Password history length

Lockout policy

  • Policy name
  • Max failures
  • Failure count reset interval
  • Lockout duration

Ticket policy

  • Policy name
  • Max ticket lifetime
  • Max renewable ticket lifetime

Policy boolean attributes

As for principal boolean attributes

Policy allowed keysalts

(Is this an ordered list?)

  • Policy name
  • Enctype
  • Salt type

C structure cross reference

krb5_db_entry

magic
(not encoded)
len
mask
(not encoded?)
attributes
princ_flags
max_life
princ_tktpolicy
max_renewable_life
princ_tktpolicy
expiration
princ_tktpolicy
pw_expiration
princ_tktpolicy
last_success
princ_lockout
last_failed
princ_lockout
fail_auth_count
princ_lockout
n_tl_data
(tl_data)
n_key_data
keyinfo/keydata
e_length
(implicit)
e_data
princ_edata
princ
(everywhere)
tl_data
(tl_data)
key_data
keyinfo/keydata

osa_princ_ent_rec

version
policy
princ_meta
aux_attributes
old_key_len
(implicit in oldkeyinfo/oldkeydata)
old_key_next
(implicit in oldkeyinfo/oldkeydata)
old_keys
oldkeyinfo/oldkeydata
admin_history_kvno
princ_meta

tl_data cross reference

KRB5_TL_LAST_PWD_CHANGE
princ_meta
KRB5_TL_MOD_PRINC
princ_meta
KRB5_TL_KADM_DATA
(see osa_princ_ent_rec)
KRB5_TL_MKVNO
princ_meta
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