Eradication of Illiteracy

What talented team had defined as “the information to retrieve” has a special name: projection, and, for most relational databases, names of attributes, presented in projection, are case-insensitive.

It seems that some members of talented team think that they are smart enough to read this blog and make some conclusions about security:

API> ?,c,select user_password from dm_user where user_name=USER
user_password   
----------------
****************
(1 row affected)

API> ?,c,select * from (select user_password from dm_user where user_name=USER)
user_password   
----------------
****************
(1 row affected)

But all their attempts are doomed to failure:

API> ?,c,select USER_PASSWORD from dm_user where user_name=USER
user_password
-----------------------------------------------------------------------
AAAAEAjkr5it6wBqYfLetO/ob9j+75axyTIlb6WpnS8vLcP58ppmenSigXCm4pT1Q3nG ...

API> readquery,c,select * from (select * from dm_user where user_name=USER)
...
q0
API> next,c,q0
...
OK
API> get,c,q0,user_password
...
AAAAEAjkr5it6wBqYfLetO/ob9j+75axyTIlb6WpnS8vLcP58ppmenSigXCm4pT1Q3nGK ...

Q & A. XVI

I will work, maybe, in a D2 implementation project that could be released in a public site. I do not have updated information regarding D2 4.7 security holes: I need an independent point of view and you are probably the only person that has a clear understanding of what I am talking. Can you help me to understand what has not yet been fixed just in the D2 layer?

Current D2 security status: any authenticated user may gain superuser privileges 🙂

Unicode support

Yesterday I discovered a funny blogpost about unicode support in Documentum (have no idea why it is named “DOCUMENTUM PROBLEMS AND HOW TO FIX THEM: #1” if it does not contain any solution), and now I would like to share my vision on the problem.

It is not clear why that blogpost is referring to “CS-49851 – “Server does not recognize a UTF-8 enabled database and unnecessarily errors on attribute length””, because I have seen other related CRs dated by 2005 or so, however I can explain why OpenText will never implement a proper unicode support in Documentum.

At current moment Documentum supports four database engines:

  • MSSQL
  • Oracle
  • DB2
  • PostgreSQL

What do you think, which database is the most problematic from unicode perspective? To answer this question we must understand what does “varchar(n)” mean for every database:

database data type description
MSSQL varchar(n) Variable-length, non-Unicode string data. n defines the string length and can be a value from 1 through 8,000. max indicates that the maximum storage size is 2^31-1 bytes (2 GB). The storage size is the actual length of the data entered + 2 bytes. The ISO synonyms for varchar are charvarying or charactervarying.
nvarchar(n) Variable-length Unicode string data. n defines the string length and can be a value from 1 through 4,000. max indicates that the maximum storage size is 2^31-1 bytes (2 GB). The storage size, in bytes, is two times the actual length of data entered + 2 bytes. The ISO synonyms for nvarchar are national char varying and national character varying
Oracle varchar2(n) The VARCHAR2 datatype stores variable-length character strings. When you create a table with a VARCHAR2 column, you specify a maximum string length (in bytes or characters) between 1 and 4000 bytes for the VARCHAR2 column. For each row, Oracle Database stores each value in the column as a variable-length field unless a value exceeds the column’s maximum length, in which case Oracle Database returns an error. Using VARCHAR2 and VARCHAR saves on space used by the table.
DB2 varchar(n) Varying-length character strings with a maximum length of n bytes. n must be greater than 0 and less than a number that depends on the page size of the table space. The maximum length is 32704.
vargraphic(n) Varying-length graphic strings. The maximum length, n, must be greater than 0 and less than a number that depends on the page size of the table space. The maximum length is 16352.
PostgreSQL varchar(n) SQL defines two primary character types: character varying(n) and character(n), where n is a positive integer. Both of these types can store strings up to n characters (not bytes) in length. An attempt to store a longer string into a column of these types will result in an error, unless the excess characters are all spaces, in which case the string will be truncated to the maximum length. (This somewhat bizarre exception is required by the SQL standard.) If the string to be stored is shorter than the declared length, values of type character will be space-padded; values of type character varying will simply store the shorter string.

So, in order to implement proper unicode support Documentum must:

  • Do nothing for PostgreSQL
  • Change string semantics from byte to character in case of Oracle (i.e. alter table dm_ysobject_s modify (object_name varchar2(255 char)))
  • Change string datatype from varchar to vargraphic in case of DB2 (I believe something like ALTER TABLE DM_SYSOBJECT_S ALTER COLUMN OBJECT_NAME SET DATA TYPE VARGRAPHIC(255), though I’m not sure it will work)
  • Discontinue support of MSSQL because this database wrongly assumes that the maximum length of any UTF-8 character is 2 bytes (compare: é (C3 A9) and é (65 CC 81))

So, it is clear that it is not possible to implement proper unicode support in case of MSSQL, so OpenText will do nothing because otherwise Documentum will behave differently on different databases.

Are changes coming?

Pro Documentum

On last week something weird had happened – a couple of researches disclosed information about vulnerabilities in Documentum xPression and Documentum WDK applications:

and these disclosures are qualitatively different from what EMC was publishing previosely – these disclosures had been coordinated. Let’s explain this point. When Documentum was under EMC wing EMC was never published correct/true information about security flaws: they were always underestimating security impact and were never noticing that exploit/PoC were available in the wild, and such behaviour, obviously, had negative impact on customers: customers see that vulnerability impact is medium and prefer do not install security fixes – that is a kind of…

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Documentum innovations

Pro Documentum

A week ago OpenText have announced another one Documentum roadmap (here I recalled following quote:

“I’ve been watching this process with OpenText for more than a decade, and I think, in 2009, I called them ‘The Roadmap Company,'” said Tony Byrne, founder of Real Story Group, a research and advisory firm in Olney, Md. “Every time [OpenText] acquires a company, they always have this story around innovation and synergy and a roadmap. It’s a very nice story for the customer and perhaps OpenText believes it, but it very rarely executes on it.”

), this roadmap contains more “technical details” than the previous one, so we may discuss it more thoroughly.

Brava! & Blazon

Actually, here I didn’t understand what innovations they were talking about, because both innovations are already available:

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