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Algorithm for generating md5 encrypted password not found in documentation
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* Algorithm for generating md5 encrypted password not found in documentation
@ 2011-10-19 19:04 Fred Cox <sailorfred@yahoo.com>
  2011-10-20 13:56 ` Re: Algorithm for generating md5 encrypted password not found in documentation Derrick Rice <derrick.rice@gmail.com>
  0 siblings, 1 reply; 4+ messages in thread

From: Fred Cox @ 2011-10-19 19:04 UTC (permalink / raw)
  To: pgsql-docs

On http://www.postgresql.org/docs/9.1/interactive/sql-createrole.html there is mention of a possibility of setting a password for a new role by supplying it in md5 format.  This format doesn't seem to be documented.

"If the presented password string is already in MD5-encrypted format, then it is stored encrypted as-is"

Looking at pg_dumpall let me know that the string needs to start with "md5" but a naive running if my password through the command line md5 utility and prefixing "md5" was not correct.

If the algorithm is documented elsewhere, can it be linked from this page?

Thanks,

Fred

^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: Algorithm for generating md5 encrypted password not found in documentation
  2011-10-19 19:04 Algorithm for generating md5 encrypted password not found in documentation Fred Cox <sailorfred@yahoo.com>
@ 2011-10-20 13:56 ` Derrick Rice <derrick.rice@gmail.com>
  2011-10-20 13:57   ` Re: Algorithm for generating md5 encrypted password not found in documentation Derrick Rice <derrick.rice@gmail.com>
  0 siblings, 1 reply; 4+ messages in thread

From: Derrick Rice @ 2011-10-20 13:56 UTC (permalink / raw)
  To: Fred Cox <sailorfred@yahoo.com>; +Cc: pgsql-docs

On Wed, Oct 19, 2011 at 3:04 PM, Fred Cox <sailorfred@yahoo.com> wrote:
>
> On http://www.postgresql.org/docs/9.1/interactive/sql-createrole.html there is mention of a possibility of setting a password for a new role by supplying it in md5 format.  This format doesn't seem to be documented.
> "If the presented password string is already in MD5-encrypted format, then it is stored encrypted as-is"
> Looking at pg_dumpall let me know that the string needs to start with "md5" but a naive running if my password through the command line md5 utility and prefixing "md5" was not correct.

If I recall correctly, it's the username and the password concatenated
and md5'd, then "md5" prepended.

USER=...
PASS=...
MD5=`echo $USER$PASS | md5sum | cut -d' ' -f1`
echo "md5$MD5"

> If the algorithm is documented elsewhere, can it be linked from this page?

 I don't remember where I figured that out, and I cannot find a
reference in the documentation either.  +1 this suggestion.

Derrick



^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: Algorithm for generating md5 encrypted password not found in documentation
  2011-10-19 19:04 Algorithm for generating md5 encrypted password not found in documentation Fred Cox <sailorfred@yahoo.com>
  2011-10-20 13:56 ` Re: Algorithm for generating md5 encrypted password not found in documentation Derrick Rice <derrick.rice@gmail.com>
@ 2011-10-20 13:57   ` Derrick Rice <derrick.rice@gmail.com>
  2011-10-27 20:54     ` Re: Algorithm for generating md5 encrypted password not found in documentation Bruce Momjian <bruce@momjian.us>
  0 siblings, 1 reply; 4+ messages in thread

From: Derrick Rice @ 2011-10-20 13:57 UTC (permalink / raw)
  To: Fred Cox <sailorfred@yahoo.com>; +Cc: pgsql-docs

On Thu, Oct 20, 2011 at 9:56 AM, Derrick Rice <derrick.rice@gmail.com> wrote:
> If I recall correctly, it's the username and the password concatenated
> and md5'd, then "md5" prepended.
>
> USER=...
> PASS=...
> MD5=`echo $USER$PASS | md5sum | cut -d' ' -f1`
> echo "md5$MD5"

Figures I send the email then discover a small mistake.

It's password first.  So change $USER$PASS to $PASS$USER



^ permalink  raw  reply  [nested|flat] 4+ messages in thread

* Re: Algorithm for generating md5 encrypted password not found in documentation
  2011-10-19 19:04 Algorithm for generating md5 encrypted password not found in documentation Fred Cox <sailorfred@yahoo.com>
  2011-10-20 13:56 ` Re: Algorithm for generating md5 encrypted password not found in documentation Derrick Rice <derrick.rice@gmail.com>
  2011-10-20 13:57   ` Re: Algorithm for generating md5 encrypted password not found in documentation Derrick Rice <derrick.rice@gmail.com>
@ 2011-10-27 20:54     ` Bruce Momjian <bruce@momjian.us>
  0 siblings, 0 replies; 4+ messages in thread

From: Bruce Momjian @ 2011-10-27 20:54 UTC (permalink / raw)
  To: Derrick Rice <derrick.rice@gmail.com>; +Cc: Fred Cox <sailorfred@yahoo.com>; pgsql-docs

Derrick Rice wrote:
> On Thu, Oct 20, 2011 at 9:56 AM, Derrick Rice <derrick.rice@gmail.com> wrote:
> > If I recall correctly, it's the username and the password concatenated
> > and md5'd, then "md5" prepended.
> >
> > USER=...
> > PASS=...
> > MD5=`echo $USER$PASS | md5sum | cut -d' ' -f1`
> > echo "md5$MD5"
> 
> Figures I send the email then discover a small mistake.
> 
> It's password first.  So change $USER$PASS to $PASS$USER

We did document this for 9.2:

	http://developer.postgresql.org/pgdocs/postgres/protocol-flow.html#AEN92524

	AuthenticationMD5Password
	
	    The frontend must now send a PasswordMessage containing the password
	(with username) encrypted via MD5, then encrypted again using the 4-byte
	random salt specified in the AuthenticationMD5Password message. If this
	is the correct password, the server responds with an AuthenticationOk,
	otherwise it responds with an ErrorResponse. The actual PasswordMessage
	can be computed in SQL as concat('md5', md5(concat(md5(concat(password,
	username)), random-salt))). (Keep in mind the md5() function returns its
	result as a hex string.) 

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +



^ permalink  raw  reply  [nested|flat] 4+ messages in thread


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Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2011-10-19 19:04 Algorithm for generating md5 encrypted password not found in documentation Fred Cox <sailorfred@yahoo.com>
2011-10-20 13:56 ` Derrick Rice <derrick.rice@gmail.com>
2011-10-20 13:57   ` Derrick Rice <derrick.rice@gmail.com>
2011-10-27 20:54     ` Bruce Momjian <bruce@momjian.us>

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