Thread: MD5-based passwords

MD5-based passwords

From
Jeremy Wohl
Date:
Hey folks,

I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
working on this?

I'll take a stab, if not.

thanks,
-jeremy
_____________________________________________________________________
jeremy wohl ..: http://igmus.org

Re: MD5-based passwords

From
Bruce Momjian
Date:
> Hey folks,
>
> I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
> working on this?
>
> I'll take a stab, if not.

There is no one working on it.  ODBC needs it too.  It wasn't on the
TODO list but I just added it.

I can assist with any questions.  See libpq for a sample implementation.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Re: MD5-based passwords

From
Bruce Momjian
Date:
> On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
> > > Hey folks,
> > >
> > > I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
> > > working on this?
> > >
> > > I'll take a stab, if not.
> >
> > There is no one working on it.  ODBC needs it too.  It wasn't on the
> > TODO list but I just added it.
> >
> > I can assist with any questions.  See libpq for a sample implementation.
>
> Where are the MD5 passwords used by the driver? Sorry for my ignorance.
> Java has MD5 support in java.security.MessageDigest so it shouldn't
> be too hard...

See libpq/fe-auth.c for the libpq version of the MD5 communication with
the backend.  md5.c has the actual md5 computations.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Re: MD5-based passwords

From
"Thomas O'Dowd"
Date:
On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
> > Hey folks,
> >
> > I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
> > working on this?
> >
> > I'll take a stab, if not.
>
> There is no one working on it.  ODBC needs it too.  It wasn't on the
> TODO list but I just added it.
>
> I can assist with any questions.  See libpq for a sample implementation.

Where are the MD5 passwords used by the driver? Sorry for my ignorance.
Java has MD5 support in java.security.MessageDigest so it shouldn't
be too hard...

Tom.
--
Thomas O'Dowd. - Nooping - http://nooper.com
tom@nooper.com - Testing - http://nooper.co.jp/labs

Re: MD5-based passwords

From
Jeremy Wohl
Date:
On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
> > Hey folks,
> >
> > I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
> > working on this?
> >
> > I'll take a stab, if not.
>
> There is no one working on it.  ODBC needs it too.  It wasn't on the
> TODO list but I just added it.
>
> I can assist with any questions.  See libpq for a sample implementation.

OK, how about this?  Someone will have to help me with appropriate exception
behavior and where the bytesToHex util is placed.

I'm not clear on the SendInteger(5 + .. code, seen elsewhere.  Why isn't
this (4 + ...?

Index: Connection.java
===================================================================
RCS file: /projects/cvsroot/pgsql/src/interfaces/jdbc/org/postgresql/Connection.java,v
retrieving revision 1.34
diff -r1.34 Connection.java
6a7
> import java.security.*;
65a67
>         private static final int AUTH_REQ_MD5 = 5;
183c185
<                     // Get the password salt if there is one
---
>                     // Get the crypt password salt if there is one
190c192,204
<                         DriverManager.println("Salt=" + salt);
---
>                         DriverManager.println("Crypt salt=" + salt);
>                     }
>
>                     // Or get the md5 password salt if there is one
>                     if (areq == AUTH_REQ_MD5)
>                     {
>                         byte[] rst = new byte[4];
>                         rst[0] = (byte)pg_stream.ReceiveChar();
>                         rst[1] = (byte)pg_stream.ReceiveChar();
>                         rst[2] = (byte)pg_stream.ReceiveChar();
>                         rst[3] = (byte)pg_stream.ReceiveChar();
>                         salt = new String(rst, 0, 4);
>                         DriverManager.println("MD5 salt=" + salt);
197,198c211,212
<                         break;
<
---
>                         break;
>
223a238,266
>                     case AUTH_REQ_MD5:
>                             try {
>                             MessageDigest md = MessageDigest.getInstance("MD5");
>                             byte[] temp_digest, pass_digest;
>                             byte[] hex_digest = new byte[35];
>
>                             DriverManager.println("postgresql: MD5");
>
>                             md.update(PG_PASSWORD.getBytes());
>                             md.update(PG_USER.getBytes());
>                             temp_digest = md.digest();
>
>                             bytesToHex(temp_digest, hex_digest, 0);
>                             md.update(hex_digest, 0, 32);
>                             md.update(salt.getBytes());
>                             pass_digest = md.digest();
>
>                             bytesToHex(pass_digest, hex_digest, 3);
>                             hex_digest[0] = 'm'; hex_digest[1] = 'd'; hex_digest[2] = '5';
>
>                             pg_stream.SendInteger(5 + hex_digest.length, 4);
>                             pg_stream.Send(hex_digest);
>                             pg_stream.SendInteger(0, 1);
>                             pg_stream.flush();
>                         } catch (Exception e) {
>                             ; // "MessageDigest failure; " + e
>                         }
>                         break;
>
310a354,368
>
>         private static void bytesToHex(byte[] bytes, byte[] hex, int offset)
>         {
>             final char lookup[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
>                     'a', 'b', 'c', 'd', 'e', 'f' };
>
>         int i, c, j, pos = offset;
>
>         for (i = 0; i < 16; i++) {
>             c = bytes[i] & 0xFF; j = c >> 4;
>             hex[pos++] = (byte) lookup[j];
>             j = (c & 0xF);
>             hex[pos++] = (byte) lookup[j];
>         }
>         }

-jeremy
_____________________________________________________________________
jeremy wohl ..: http://igmus.org

Attachment

Re: MD5-based passwords

From
Bruce Momjian
Date:
Looks good.  Can I ask for a context diff, "diff -c"?

---------------------------------------------------------------------------

> On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
> > > Hey folks,
> > >
> > > I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
> > > working on this?
> > >
> > > I'll take a stab, if not.
> >
> > There is no one working on it.  ODBC needs it too.  It wasn't on the
> > TODO list but I just added it.
> >
> > I can assist with any questions.  See libpq for a sample implementation.
>
> OK, how about this?  Someone will have to help me with appropriate exception
> behavior and where the bytesToHex util is placed.
>
> I'm not clear on the SendInteger(5 + .. code, seen elsewhere.  Why isn't
> this (4 + ...?
>
> Index: Connection.java
> ===================================================================
> RCS file: /projects/cvsroot/pgsql/src/interfaces/jdbc/org/postgresql/Connection.java,v
> retrieving revision 1.34
> diff -r1.34 Connection.java
> 6a7
> > import java.security.*;
> 65a67
> >         private static final int AUTH_REQ_MD5 = 5;
> 183c185
> <                     // Get the password salt if there is one
> ---
> >                     // Get the crypt password salt if there is one
> 190c192,204
> <                         DriverManager.println("Salt=" + salt);
> ---
> >                         DriverManager.println("Crypt salt=" + salt);
> >                     }
> >
> >                     // Or get the md5 password salt if there is one
> >                     if (areq == AUTH_REQ_MD5)
> >                     {
> >                         byte[] rst = new byte[4];
> >                         rst[0] = (byte)pg_stream.ReceiveChar();
> >                         rst[1] = (byte)pg_stream.ReceiveChar();
> >                         rst[2] = (byte)pg_stream.ReceiveChar();
> >                         rst[3] = (byte)pg_stream.ReceiveChar();
> >                         salt = new String(rst, 0, 4);
> >                         DriverManager.println("MD5 salt=" + salt);
> 197,198c211,212
> <                         break;
> <
> ---
> >                         break;
> >
> 223a238,266
> >                     case AUTH_REQ_MD5:
> >                             try {
> >                             MessageDigest md = MessageDigest.getInstance("MD5");
> >                             byte[] temp_digest, pass_digest;
> >                             byte[] hex_digest = new byte[35];
> >
> >                             DriverManager.println("postgresql: MD5");
> >
> >                             md.update(PG_PASSWORD.getBytes());
> >                             md.update(PG_USER.getBytes());
> >                             temp_digest = md.digest();
> >
> >                             bytesToHex(temp_digest, hex_digest, 0);
> >                             md.update(hex_digest, 0, 32);
> >                             md.update(salt.getBytes());
> >                             pass_digest = md.digest();
> >
> >                             bytesToHex(pass_digest, hex_digest, 3);
> >                             hex_digest[0] = 'm'; hex_digest[1] = 'd'; hex_digest[2] = '5';
> >
> >                             pg_stream.SendInteger(5 + hex_digest.length, 4);
> >                             pg_stream.Send(hex_digest);
> >                             pg_stream.SendInteger(0, 1);
> >                             pg_stream.flush();
> >                         } catch (Exception e) {
> >                             ; // "MessageDigest failure; " + e
> >                         }
> >                         break;
> >
> 310a354,368
> >
> >         private static void bytesToHex(byte[] bytes, byte[] hex, int offset)
> >         {
> >             final char lookup[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
> >                     'a', 'b', 'c', 'd', 'e', 'f' };
> >
> >         int i, c, j, pos = offset;
> >
> >         for (i = 0; i < 16; i++) {
> >             c = bytes[i] & 0xFF; j = c >> 4;
> >             hex[pos++] = (byte) lookup[j];
> >             j = (c & 0xF);
> >             hex[pos++] = (byte) lookup[j];
> >         }
> >         }
>
> -jeremy
> _____________________________________________________________________
> jeremy wohl ..: http://igmus.org

[ Attachment, skipping... ]

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--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Re: MD5-based passwords

From
Bruce Momjian
Date:
> On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
> > > Hey folks,
> > >
> > > I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
> > > working on this?
> > >
> > > I'll take a stab, if not.
> >
> > There is no one working on it.  ODBC needs it too.  It wasn't on the
> > TODO list but I just added it.
> >
> > I can assist with any questions.  See libpq for a sample implementation.
>
> OK, how about this?  Someone will have to help me with appropriate exception
> behavior and where the bytesToHex util is placed.
>
> I'm not clear on the SendInteger(5 + .. code, seen elsewhere.  Why isn't
> this (4 + ...?

I think the 5+ is correct.  Looking at fe-auth.c, I see:

    ret = pqPacketSend(conn, crypt_pwd, strlen(crypt_pwd) + 1);

and pqPacketSend() has:

    if (pqPutInt(4 + len, 4, conn))

so I think it is the +1 and the +4 added together to make 5.  If you
want to put 4+1+, that would be fine too and perhaps be clearer.

One more question.  Have you tested this against a 7.2 backend to see if
it actually does MD5 encryption correctly?

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Re: MD5-based passwords

From
Jeremy Wohl
Date:
On Wed, Nov 07, 2001 at 02:23:28PM -0500, Bruce Momjian wrote:
> > On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
> > I'm not clear on the SendInteger(5 + .. code, seen elsewhere.  Why isn't
> > this (4 + ...?
>
> I think the 5+ is correct.  Looking at fe-auth.c, I see:
>
>     ret = pqPacketSend(conn, crypt_pwd, strlen(crypt_pwd) + 1);
>
> and pqPacketSend() has:
>
>     if (pqPutInt(4 + len, 4, conn))
>
> so I think it is the +1 and the +4 added together to make 5.  If you
> want to put 4+1+, that would be fine too and perhaps be clearer.

Right.  I read it right the first time, and proceeded to convince myself
the wrong way..

> One more question.  Have you tested this against a 7.2 backend to see if
> it actually does MD5 encryption correctly?

Yes, that's what I'm using.  Tested that the unpatched code fails, that the
patched code succeeds and md5-allows removed from pg_hba.conf still works with
crypt-based passwords.

A context diff is attached.  My indenting is probably off.

p.s. Your mailer doesn't seem to put "Jeremy wrote" tags anywhere.  Useful
     for following the conversation.
p.p.s. You don't need to Cc me.  I'm on the list. :)

-jeremy
_____________________________________________________________________
jeremy wohl ..: http://igmus.org

Attachment

Re: MD5-based passwords

From
Bruce Momjian
Date:
> On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
> > > Hey folks,
> > >
> > > I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
> > > working on this?
> > >
> > > I'll take a stab, if not.
> >
> > There is no one working on it.  ODBC needs it too.  It wasn't on the
> > TODO list but I just added it.
> >
> > I can assist with any questions.  See libpq for a sample implementation.
>
> OK, how about this?  Someone will have to help me with appropriate exception
> behavior and where the bytesToHex util is placed.
>
> I'm not clear on the SendInteger(5 + .. code, seen elsewhere.  Why isn't
> this (4 + ...?

OK, now that we have this, what do people want to do with it, 7.2 or
7.3?  It is a feature addition to JDBC to allow MD5 encryption.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Re: [HACKERS] MD5-based passwords

From
Ned Wolpert
Date:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

I'd vote to pop it into 7.2 if we can.

On 08-Nov-2001 Bruce Momjian wrote:
> OK, now that we have this, what do people want to do with it, 7.2 or
> 7.3?  It is a feature addition to JDBC to allow MD5 encryption.


Virtually,
Ned Wolpert <ned.wolpert@knowledgenet.com>

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Version: GnuPG v1.0.6 (GNU/Linux)
Comment: For info see http://www.gnupg.org

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=Y32n
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Re: MD5-based passwords

From
Jeremy Wohl
Date:
On Wed, Nov 07, 2001 at 08:26:49PM -0800, Barry Lind wrote:
> I think I would recommend moving most of this logic into a new class
> under org.postgresql.util, called MD5.java?? (that is where the
> UnixCrypt class is located).
>
> [...]

OK.  Attached is an abstracted version, with your cast fix.

Appropriate exception handling is still open.  As is indenting.

> PS.  When sending diffs please use context diff format (i.e.-c).  It
> makes it much easier to review.

How about unified? :)

-jeremy
_____________________________________________________________________
jeremy wohl ..: http://igmus.org

Attachment

Re: MD5-based passwords

From
"Dave Cramer"
Date:
We have quite a few code changes which I am unsure about at this point.
There are quite a few contributions which are coming in right now. I am
unclear as to how to handle the 7.2/7.3 thing

I don't want to lose momentum, but I also don't want to put out buggy
code?

A number of the contributions are implementations of the driver which
didn't exist before. Since none of the core code is being modified, I am
tending towards adding them as they com in?

The contributions that I am aware of include

MD5 passwords
Exported/Imported keys
Fixes to getTables

Suggestions?



Dave

-----Original Message-----
From: pgsql-jdbc-owner@postgresql.org
[mailto:pgsql-jdbc-owner@postgresql.org] On Behalf Of Bruce Momjian
Sent: November 8, 2001 12:38 PM
To: Jeremy Wohl
Cc: pgsql-jdbc@postgresql.org; PostgreSQL-development
Subject: Re: [JDBC] MD5-based passwords


> On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
> > > Hey folks,
> > >
> > > I don't see MD5-based password code in the JDBC CVS tree.  Is
anyone
> > > working on this?
> > >
> > > I'll take a stab, if not.
> >
> > There is no one working on it.  ODBC needs it too.  It wasn't on the
> > TODO list but I just added it.
> >
> > I can assist with any questions.  See libpq for a sample
implementation.
>
> OK, how about this?  Someone will have to help me with appropriate
exception
> behavior and where the bytesToHex util is placed.
>
> I'm not clear on the SendInteger(5 + .. code, seen elsewhere.  Why
isn't
> this (4 + ...?

OK, now that we have this, what do people want to do with it, 7.2 or
7.3?  It is a feature addition to JDBC to allow MD5 encryption.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania
19026

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Re: MD5-based passwords

From
Bruce Momjian
Date:
> We have quite a few code changes which I am unsure about at this point.
> There are quite a few contributions which are coming in right now. I am
> unclear as to how to handle the 7.2/7.3 thing

It is always a tough decision.

> I don't want to lose momentum, but I also don't want to put out buggy
> code?

Yep, that is the tradeoff.  At this point we usually only add bug fixes
or features that many people really need.

>
> A number of the contributions are implementations of the driver which
> didn't exist before. Since none of the core code is being modified, I am
> tending towards adding them as they com in?
>
> The contributions that I am aware of include
>
> MD5 passwords
> Exported/Imported keys
> Fixes to getTables

The decision is up to you guys now.  :-)

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Re: MD5-based passwords

From
Ned Wolpert
Date:
Well, if we're talking about 7.2 versus 7.3, I'd rather see them in the
7.2 release. If, however, we're talking about 7.2 version 7.2.x, then
we may want to wait until 7.2.x.

(For things like the Pooling and jdbc2 compliance stuff I'm working on, I
see that as 7.3 either way.  But these things are more basic.)

--- Dave Cramer <Dave@micro-automation.net> wrote:
> We have quite a few code changes which I am unsure about at this point.
> There are quite a few contributions which are coming in right now. I am
> unclear as to how to handle the 7.2/7.3 thing
>
> I don't want to lose momentum, but I also don't want to put out buggy
> code?
>
> A number of the contributions are implementations of the driver which
> didn't exist before. Since none of the core code is being modified, I am
> tending towards adding them as they com in?
>
> The contributions that I am aware of include
>
> MD5 passwords
> Exported/Imported keys
> Fixes to getTables
>
> Suggestions?


=====
Virtually,        |                   "Must you shout too?"
Ned Wolpert       |                                  -Dante
wolpert@yahoo.com |
_________________/              "Who watches the watchmen?"
4e75                                       -Juvenal, 120 AD

-- Place your commercial here --                      fnord

__________________________________________________
Do You Yahoo!?
Find a job, post your resume.
http://careers.yahoo.com

Re: MD5-based passwords

From
Ned Wolpert
Date:
Well, if we're talking about 7.2 versus 7.3, I'd rather see them in the
7.2 release. If, however, we're talking about 7.2 version 7.2.x, then
we may want to wait until 7.2.x.

(For things like the Pooling and jdbc2 compliance stuff I'm working on, I
see that as 7.3 either way.  But these things are more basic.)

--- Dave Cramer <Dave@micro-automation.net> wrote:
> We have quite a few code changes which I am unsure about at this point.
> There are quite a few contributions which are coming in right now. I am
> unclear as to how to handle the 7.2/7.3 thing
>
> I don't want to lose momentum, but I also don't want to put out buggy
> code?
>
> A number of the contributions are implementations of the driver which
> didn't exist before. Since none of the core code is being modified, I am
> tending towards adding them as they com in?
>
> The contributions that I am aware of include
>
> MD5 passwords
> Exported/Imported keys
> Fixes to getTables
>
> Suggestions?

=====
Virtually,        |                   "Must you shout too?"
Ned Wolpert       |                                  -Dante
wolpert@yahoo.com |
_________________/              "Who watches the watchmen?"
4e75                                       -Juvenal, 120 AD

-- Place your commercial here --                      fnord

__________________________________________________
Do You Yahoo!?
Find a job, post your resume.
http://careers.yahoo.com

Re: MD5-based passwords

From
Tom Lane
Date:
Ned Wolpert <wolpert@yahoo.com> writes:
> Well, if we're talking about 7.2 versus 7.3, I'd rather see them in the
> 7.2 release. If, however, we're talking about 7.2 version 7.2.x, then
> we may want to wait until 7.2.x.

Standard procedure for the Postgres project has always been that
dot-releases contain no new features, only bug-fixes (and, usually,
only fairly critical ones).

I think that it's okay to add the jdbc MD5 password code now; we can
call it a bug fix on either of two grounds:

    (a) if you stand back far enough that jdbc is indistinguishable
        from the rest of the system, then this is arguably
        completion of an existing feature, not adding a new one.

    (b) in any case, JDBC users will certainly see it as a bug
        if everyone but them can use MD5 passwords.

Also, if the code proves to have bugs, what's the downside?  Only that
JDBC users will be unable to use MD5 passwords; but that will certainly
be true if we don't try.  So I think I'd go for it.

On the other hand, some of the other stuff Dave mentioned sounded like
whole new features, and since we are in beta now I think the "no new
features during beta" rule ought to apply.

Just my $0.02 ...

            regards, tom lane

Re: MD5-based passwords

From
Justin Clift
Date:

Tom Lane wrote:
>
> Ned Wolpert <wolpert@yahoo.com> writes:
> > Well, if we're talking about 7.2 versus 7.3, I'd rather see them in the
> > 7.2 release. If, however, we're talking about 7.2 version 7.2.x, then
> > we may want to wait until 7.2.x.
>
> Standard procedure for the Postgres project has always been that
> dot-releases contain no new features, only bug-fixes (and, usually,
> only fairly critical ones).
>
> I think that it's okay to add the jdbc MD5 password code now; we can
> call it a bug fix on either of two grounds:
>
>         (a) if you stand back far enough that jdbc is indistinguishable
>             from the rest of the system, then this is arguably
>             completion of an existing feature, not adding a new one.
>
>         (b) in any case, JDBC users will certainly see it as a bug
>             if everyone but them can use MD5 passwords.
>
> Also, if the code proves to have bugs, what's the downside?  Only that
> JDBC users will be unable to use MD5 passwords; but that will certainly
> be true if we don't try.  So I think I'd go for it.
>
> On the other hand, some of the other stuff Dave mentioned sounded like
> whole new features, and since we are in beta now I think the "no new
> features during beta" rule ought to apply.

I believe we should include the new stuff, as it would assist in the 7.2
release having more of an "Enterprise" functionality level than
without.  Might as well have MD5 all round.

If bugs are found during our beta testing process, then it might delay
the release for a week or two, which is probably worth it.

+ Justin

>
> Just my $0.02 ...
>
>                         regards, tom lane
>
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"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
   - Indira Gandhi

Re: MD5-based passwords

From
Bruce Momjian
Date:
> Ned Wolpert <wolpert@yahoo.com> writes:
> > Well, if we're talking about 7.2 versus 7.3, I'd rather see them in the
> > 7.2 release. If, however, we're talking about 7.2 version 7.2.x, then
> > we may want to wait until 7.2.x.
>
> Standard procedure for the Postgres project has always been that
> dot-releases contain no new features, only bug-fixes (and, usually,
> only fairly critical ones).

Agreed.  I would get it into 7.2.0 or wait for 7.3.

> I think that it's okay to add the jdbc MD5 password code now; we can
> call it a bug fix on either of two grounds:
>
>     (a) if you stand back far enough that jdbc is indistinguishable
>         from the rest of the system, then this is arguably
>         completion of an existing feature, not adding a new one.

Yes, I thought of that too.  I like the "stand back far enough" comment.
When I implemented MD5 for 7.2, I couldn't do jdbc and didn't try ODBC,
until today.  It is a shame not to have all interfaces covered.

>     (b) in any case, JDBC users will certainly see it as a bug
>         if everyone but them can use MD5 passwords.

True.

> Also, if the code proves to have bugs, what's the downside?  Only that
> JDBC users will be unable to use MD5 passwords; but that will certainly
> be true if we don't try.  So I think I'd go for it.

Yes, just make sure that the feature can't adversely affect other parts
of the system, i.e. it doesn't compile on some jdbc implementations or
something like that.

> On the other hand, some of the other stuff Dave mentioned sounded like
> whole new features, and since we are in beta now I think the "no new
> features during beta" rule ought to apply.

Also agree.  I didn't comment on this earlier because I have a vested
interest in this.  I just did MD5 for ODBC and if someone tests it and
it works, I may ask to add that into 7.2 also.  :-)

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Re: MD5-based passwords

From
Tom Lane
Date:
Bruce Momjian <pgman@candle.pha.pa.us> writes:
>> I believe we should include the new stuff, as it would assist in the 7.2
>> release having more of an "Enterprise" functionality level than
>> without.  Might as well have MD5 all round.
>>
>> If bugs are found during our beta testing process, then it might delay
>> the release for a week or two, which is probably worth it.

> I can say pretty reliably that we are long past time in 7.2 where we can
> add code that will push back a final release date.  It is fine to slip
> stuff in and take the responsibility for it, but we are in beta now and
> anything that pushes back final is bad, because it pushes back _all_ 7.2
> features from the general user community.

Yup, exactly.  "One more feature" is a siren song that you gotta resist,
else we'll never get out of beta.

It might be appropriate to point out that we've already missed the
original target date for 7.2 beta by two months, and that if we can't
produce a release candidate in another week or so we'll likely not have
7.2 final until January.  That's a long time to keep the world waiting
for concurrent VACUUM, survival of transaction ID wraparound, and
several other absolutely *critical* improvements in 7.2.  If it looks
to me like JDBC MD5 passwords (or any other thing that's not clearly a
bug fix) are going to slip the schedule another week, I'll vote to pass
it over until 7.3.

Once we go beta, we have to focus on wrapping up what we have
and getting it out the door, not on squeezing in stuff that is
"almost ready".  There'll always be another release.

            regards, tom lane

Re: MD5-based passwords

From
Bruce Momjian
Date:
> > Also, if the code proves to have bugs, what's the downside?  Only that
> > JDBC users will be unable to use MD5 passwords; but that will certainly
> > be true if we don't try.  So I think I'd go for it.
> >
> > On the other hand, some of the other stuff Dave mentioned sounded like
> > whole new features, and since we are in beta now I think the "no new
> > features during beta" rule ought to apply.
>
> I believe we should include the new stuff, as it would assist in the 7.2
> release having more of an "Enterprise" functionality level than
> without.  Might as well have MD5 all round.
>
> If bugs are found during our beta testing process, then it might delay
> the release for a week or two, which is probably worth it.

I can say pretty reliably that we are long past time in 7.2 where we can
add code that will push back a final release date.  It is fine to slip
stuff in and take the responsibility for it, but we are in beta now and
anything that pushes back final is bad, because it pushes back _all_ 7.2
features from the general user community.

Thinking of it another way, the value of any single feature can not
possibly be large compared to all the new features in 7.2 already.  If
we add code now, patch appliers have to be willing to take the heat if
the patch delays final release.

Now, of course I myself am applying stuff, but if it delays final, I
have failed and must take the responsibility for it.  This is probably
the biggest difference between patch application during development
cycle and final.  During development, patches are applied if they look
good and no one complains.  During beta, responsibility lies solely with
the patch applier.

Of course, you can patch things up during 7.2.X, and this often happens.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Re: MD5-based passwords

From
"Dave Cramer"
Date:
Ok,

Thanks for all the input, I think at this point I am going to add some
of the code that has been contributed
None of it changes the drivers core behaviour.

Specifically it is Jason Davies updates to the DatabaseMetaData
getImported/Exported keys

Dave

-----Original Message-----
From: pgsql-jdbc-owner@postgresql.org
[mailto:pgsql-jdbc-owner@postgresql.org] On Behalf Of Bruce Momjian
Sent: November 8, 2001 9:13 PM
To: Justin Clift
Cc: Tom Lane; Ned Wolpert; psql-jdbc
Subject: Re: [JDBC] MD5-based passwords


> > Also, if the code proves to have bugs, what's the downside?  Only
that
> > JDBC users will be unable to use MD5 passwords; but that will
certainly
> > be true if we don't try.  So I think I'd go for it.
> >
> > On the other hand, some of the other stuff Dave mentioned sounded
like
> > whole new features, and since we are in beta now I think the "no new
> > features during beta" rule ought to apply.
>
> I believe we should include the new stuff, as it would assist in the
7.2
> release having more of an "Enterprise" functionality level than
> without.  Might as well have MD5 all round.
>
> If bugs are found during our beta testing process, then it might delay
> the release for a week or two, which is probably worth it.

I can say pretty reliably that we are long past time in 7.2 where we can
add code that will push back a final release date.  It is fine to slip
stuff in and take the responsibility for it, but we are in beta now and
anything that pushes back final is bad, because it pushes back _all_ 7.2
features from the general user community.

Thinking of it another way, the value of any single feature can not
possibly be large compared to all the new features in 7.2 already.  If
we add code now, patch appliers have to be willing to take the heat if
the patch delays final release.

Now, of course I myself am applying stuff, but if it delays final, I
have failed and must take the responsibility for it.  This is probably
the biggest difference between patch application during development
cycle and final.  During development, patches are applied if they look
good and no one complains.  During beta, responsibility lies solely with
the patch applier.

Of course, you can patch things up during 7.2.X, and this often happens.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania
19026

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Re: MD5-based passwords

From
Barry Lind
Date:
Jeremy,

The revised patch looks fine to me.  I will apply it tomorrow (unless
someone comes along objecting to the inclusion of this patch).

thanks,
--Barry


Jeremy Wohl wrote:

> On Wed, Nov 07, 2001 at 08:26:49PM -0800, Barry Lind wrote:
>
>>I think I would recommend moving most of this logic into a new class
>>under org.postgresql.util, called MD5.java?? (that is where the
>>UnixCrypt class is located).
>>
>>[...]
>>
>
> OK.  Attached is an abstracted version, with your cast fix.
>
> Appropriate exception handling is still open.  As is indenting.
>
>
>>PS.  When sending diffs please use context diff format (i.e.-c).  It
>>makes it much easier to review.
>>
>
> How about unified? :)
>
> -jeremy
> _____________________________________________________________________
> jeremy wohl ..: http://igmus.org
>
>
> ------------------------------------------------------------------------
>
> --- Connection.java.old    Wed Nov  7 11:19:11 2001
> +++ Connection.java    Thu Nov  8 10:20:13 2001
> @@ -63,6 +63,7 @@
>      private static final int AUTH_REQ_KRB5 = 2;
>      private static final int AUTH_REQ_PASSWORD = 3;
>      private static final int AUTH_REQ_CRYPT = 4;
> +        private static final int AUTH_REQ_MD5 = 5;
>
>      // New for 6.3, salt value for crypt authorisation
>      private String salt;
> @@ -180,22 +181,34 @@
>                      // Get the type of request
>                      areq = pg_stream.ReceiveIntegerR(4);
>
> -                    // Get the password salt if there is one
> +                    // Get the crypt password salt if there is one
>                      if (areq == AUTH_REQ_CRYPT)
>                      {
>                          byte[] rst = new byte[2];
>                          rst[0] = (byte)pg_stream.ReceiveChar();
>                          rst[1] = (byte)pg_stream.ReceiveChar();
>                          salt = new String(rst, 0, 2);
> -                        DriverManager.println("Salt=" + salt);
> +                        DriverManager.println("Crypt salt=" + salt);
> +                    }
> +
> +                    // Or get the md5 password salt if there is one
> +                    if (areq == AUTH_REQ_MD5)
> +                    {
> +                        byte[] rst = new byte[4];
> +                        rst[0] = (byte)pg_stream.ReceiveChar();
> +                        rst[1] = (byte)pg_stream.ReceiveChar();
> +                        rst[2] = (byte)pg_stream.ReceiveChar();
> +                        rst[3] = (byte)pg_stream.ReceiveChar();
> +                        salt = new String(rst, 0, 4);
> +                        DriverManager.println("MD5 salt=" + salt);
>                      }
>
>                      // now send the auth packet
>                      switch (areq)
>                      {
>                      case AUTH_REQ_OK:
> -                        break;
> -
> +                        break;
> +
>                      case AUTH_REQ_KRB4:
>                          DriverManager.println("postgresql: KRB4");
>                          throw new PSQLException("postgresql.con.kerb4");
> @@ -217,6 +230,15 @@
>                          String crypted = UnixCrypt.crypt(salt, PG_PASSWORD);
>                          pg_stream.SendInteger(5 + crypted.length(), 4);
>                          pg_stream.Send(crypted.getBytes());
> +                        pg_stream.SendInteger(0, 1);
> +                        pg_stream.flush();
> +                        break;
> +
> +                    case AUTH_REQ_MD5:
> +                            DriverManager.println("postgresql: MD5");
> +                        byte[] digest = MD5Digest.encode(PG_USER, PG_PASSWORD, salt);
> +                        pg_stream.SendInteger(5 + digest.length, 4);
> +                        pg_stream.Send(digest);
>                          pg_stream.SendInteger(0, 1);
>                          pg_stream.flush();
>                          break;
>
>
> ------------------------------------------------------------------------
>
> package org.postgresql.util;
>
> /**
>  * MD5-based utility function to obfuscate passwords before network transmission
>  *
>  * @author Jeremy Wohl
>  *
>  */
>
> import java.security.*;
>
> public class MD5Digest
> {
>     private MD5Digest() {}
>
>
>     /**
>      * Encodes user/password/salt information in the following way:
>      *   MD5(MD5(password + user) + salt)
>      *
>      * @param user      The connecting user.
>      * @param password  The connecting user's password.
>      * @param salt      A four-character string sent by the server.
>      *
>      * @return  A 35-byte array, comprising the string "md5", followed by an MD5 digest.
>      */
>     public static byte[] encode(String user, String password, String salt)
>     {
>     MessageDigest  md;
>     byte[]         temp_digest, pass_digest;
>     byte[]         hex_digest = new byte[35];
>
>
>     try {
>         md = MessageDigest.getInstance("MD5");
>
>         md.update(password.getBytes());
>         md.update(user.getBytes());
>         temp_digest = md.digest();
>
>         bytesToHex(temp_digest, hex_digest, 0);
>         md.update(hex_digest, 0, 32);
>         md.update(salt.getBytes());
>         pass_digest = md.digest();
>
>         bytesToHex(pass_digest, hex_digest, 3);
>         hex_digest[0] = (byte) 'm'; hex_digest[1] = (byte) 'd'; hex_digest[2] = (byte) '5';
>     } catch (Exception e) {
>         ; // "MessageDigest failure; " + e
>     }
>
>     return hex_digest;
>     }
>
>
>     /**
>      * Turn 16-byte stream into a human-readable 32-byte hex string
>      */
>     private static void bytesToHex(byte[] bytes, byte[] hex, int offset)
>     {
>     final char lookup[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
>                 'a', 'b', 'c', 'd', 'e', 'f' };
>
>     int i, c, j, pos = offset;
>
>     for (i = 0; i < 16; i++) {
>         c = bytes[i] & 0xFF; j = c >> 4;
>         hex[pos++] = (byte) lookup[j];
>         j = (c & 0xF);
>         hex[pos++] = (byte) lookup[j];
>     }
>     }
> }
>
>
> ------------------------------------------------------------------------
>
>
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>     (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)
>



Re: MD5-based passwords

From
Barry Lind
Date:
Tom,

I agree with your comments.  Especially now that the revised patch moves
most of the logic out into a separate class, there is little risk that
anything other than MD5 authentication will be impacted.

I intend to apply this MD5 patch tomorrow, unless anyone objects.

thanks,
--Barry

Tom Lane wrote:

> Ned Wolpert <wolpert@yahoo.com> writes:
>
>>Well, if we're talking about 7.2 versus 7.3, I'd rather see them in the
>>7.2 release. If, however, we're talking about 7.2 version 7.2.x, then
>>we may want to wait until 7.2.x.
>>
>
> Standard procedure for the Postgres project has always been that
> dot-releases contain no new features, only bug-fixes (and, usually,
> only fairly critical ones).
>
> I think that it's okay to add the jdbc MD5 password code now; we can
> call it a bug fix on either of two grounds:
>
>     (a) if you stand back far enough that jdbc is indistinguishable
>         from the rest of the system, then this is arguably
>         completion of an existing feature, not adding a new one.
>
>     (b) in any case, JDBC users will certainly see it as a bug
>         if everyone but them can use MD5 passwords.
>
> Also, if the code proves to have bugs, what's the downside?  Only that
> JDBC users will be unable to use MD5 passwords; but that will certainly
> be true if we don't try.  So I think I'd go for it.
>
> On the other hand, some of the other stuff Dave mentioned sounded like
> whole new features, and since we are in beta now I think the "no new
> features during beta" rule ought to apply.
>
> Just my $0.02 ...
>
>             regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: you can get off all lists at once with the unregister command
>     (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)
>
>



Re: [HACKERS] MD5-based passwords

From
Barry Lind
Date:
I think we need to evaluate each patch on a case by case basis.  With
that said, there certainly are guidelines we probably should follow:
   1) new functionality = next release
   2) bugfix (simple or low risk fix) = this release
   3) bugfix (complex or high risk fix) = next release (unless it is
really important and gets a lot of testing and extensive code review
then possibly this release)

If we are going to start to see a lot of activity for jdbc (something I
am certainly hoping for), we might decide to have a jdbc only release
between 7.2 and 7.3 as the next release.  We could create a branch in
CVS for this work if necessary then release the result on the
jdbc.postgresql.org web site.  I don't think this work should go into
the 7.2.x branch.

thanks,
--Barry


Bruce Momjian wrote:

>>We have quite a few code changes which I am unsure about at this point.
>>There are quite a few contributions which are coming in right now. I am
>>unclear as to how to handle the 7.2/7.3 thing
>>
>
> It is always a tough decision.
>
>
>>I don't want to lose momentum, but I also don't want to put out buggy
>>code?
>>
>
> Yep, that is the tradeoff.  At this point we usually only add bug fixes
> or features that many people really need.
>
>
>>A number of the contributions are implementations of the driver which
>>didn't exist before. Since none of the core code is being modified, I am
>>tending towards adding them as they com in?
>>
>>The contributions that I am aware of include
>>
>>MD5 passwords
>>Exported/Imported keys
>>Fixes to getTables
>>
>
> The decision is up to you guys now.  :-)
>
>



Re: MD5-based passwords

From
Barry Lind
Date:
Dave,

I think it would make people feel better to say that you are going to
'apply some bug fixes that have been contributed' instead of saying 'I
am going to add some of the code that has been contributed'.  The latter
makes it sound like new functionality, when in reality this patch mostly
fixes bugs (with a little code refactoring thrown in for good measure).

I think you should go ahead and apply this.  This area of the code
didn't work at all in 7.1, partly works in 7.2beta2, and I think will
mostly work for 7.2.0 with this set of fixes.

thanks,
--Barry

Dave Cramer wrote:

> Ok,
>
> Thanks for all the input, I think at this point I am going to add some
> of the code that has been contributed
> None of it changes the drivers core behaviour.
>
> Specifically it is Jason Davies updates to the DatabaseMetaData
> getImported/Exported keys
>
> Dave
>
> -----Original Message-----
> From: pgsql-jdbc-owner@postgresql.org
> [mailto:pgsql-jdbc-owner@postgresql.org] On Behalf Of Bruce Momjian
> Sent: November 8, 2001 9:13 PM
> To: Justin Clift
> Cc: Tom Lane; Ned Wolpert; psql-jdbc
> Subject: Re: [JDBC] MD5-based passwords
>
>
>
>>>Also, if the code proves to have bugs, what's the downside?  Only
>>>
> that
>
>>>JDBC users will be unable to use MD5 passwords; but that will
>>>
> certainly
>
>>>be true if we don't try.  So I think I'd go for it.
>>>
>>>On the other hand, some of the other stuff Dave mentioned sounded
>>>
> like
>
>>>whole new features, and since we are in beta now I think the "no new
>>>features during beta" rule ought to apply.
>>>
>>I believe we should include the new stuff, as it would assist in the
>>
> 7.2
>
>>release having more of an "Enterprise" functionality level than
>>without.  Might as well have MD5 all round.
>>
>>If bugs are found during our beta testing process, then it might delay
>>the release for a week or two, which is probably worth it.
>>
>
> I can say pretty reliably that we are long past time in 7.2 where we can
> add code that will push back a final release date.  It is fine to slip
> stuff in and take the responsibility for it, but we are in beta now and
> anything that pushes back final is bad, because it pushes back _all_ 7.2
> features from the general user community.
>
> Thinking of it another way, the value of any single feature can not
> possibly be large compared to all the new features in 7.2 already.  If
> we add code now, patch appliers have to be willing to take the heat if
> the patch delays final release.
>
> Now, of course I myself am applying stuff, but if it delays final, I
> have failed and must take the responsibility for it.  This is probably
> the biggest difference between patch application during development
> cycle and final.  During development, patches are applied if they look
> good and no one complains.  During beta, responsibility lies solely with
> the patch applier.
>
> Of course, you can patch things up during 7.2.X, and this often happens.
>
>



Re: MD5-based passwords

From
Barry Lind
Date:
Jeremy,

I think I would recommend moving most of this logic into a new class
under org.postgresql.util, called MD5.java?? (that is where the
UnixCrypt class is located).

I couldn't get what you sent to compile for me, I needed to add some casts:

hex_digest[0] = 'm'; hex_digest[1] = 'd'; hex_digest[2] = '5';

became:

hex_digest[0] = (byte)'m'; hex_digest[1] = (byte)'d'; hex_digest[2] =
(byte)'5';

Otherwise with this above fix it compiled fine under both jdk1.1 and
jdk1.2.  I didn't do any testing of the result though.

thanks,
--Barry

PS.  When sending diffs please use context diff format (i.e.-c).  It
makes it much easier to review.




Jeremy Wohl wrote:

> On Wed, Nov 07, 2001 at 12:27:53AM -0500, Bruce Momjian wrote:
>
>>>Hey folks,
>>>
>>>I don't see MD5-based password code in the JDBC CVS tree.  Is anyone
>>>working on this?
>>>
>>>I'll take a stab, if not.
>>>
>>There is no one working on it.  ODBC needs it too.  It wasn't on the
>>TODO list but I just added it.
>>
>>I can assist with any questions.  See libpq for a sample implementation.
>>
>
> OK, how about this?  Someone will have to help me with appropriate exception
> behavior and where the bytesToHex util is placed.
>
> I'm not clear on the SendInteger(5 + .. code, seen elsewhere.  Why isn't
> this (4 + ...?
>
> Index: Connection.java
> ===================================================================
> RCS file: /projects/cvsroot/pgsql/src/interfaces/jdbc/org/postgresql/Connection.java,v
> retrieving revision 1.34
> diff -r1.34 Connection.java
> 6a7
>
>>import java.security.*;
>>
> 65a67
>
>>        private static final int AUTH_REQ_MD5 = 5;
>>
> 183c185
> <                     // Get the password salt if there is one
> ---
>
>>                    // Get the crypt password salt if there is one
>>
> 190c192,204
> <                         DriverManager.println("Salt=" + salt);
> ---
>
>>                        DriverManager.println("Crypt salt=" + salt);
>>                    }
>>
>>                    // Or get the md5 password salt if there is one
>>                    if (areq == AUTH_REQ_MD5)
>>                    {
>>                        byte[] rst = new byte[4];
>>                        rst[0] = (byte)pg_stream.ReceiveChar();
>>                        rst[1] = (byte)pg_stream.ReceiveChar();
>>                        rst[2] = (byte)pg_stream.ReceiveChar();
>>                        rst[3] = (byte)pg_stream.ReceiveChar();
>>                        salt = new String(rst, 0, 4);
>>                        DriverManager.println("MD5 salt=" + salt);
>>
> 197,198c211,212
> <                         break;
> <
> ---
>
>>                        break;
>>
>>
> 223a238,266
>
>>                    case AUTH_REQ_MD5:
>>                            try {
>>                            MessageDigest md = MessageDigest.getInstance("MD5");
>>                            byte[] temp_digest, pass_digest;
>>                            byte[] hex_digest = new byte[35];
>>
>>                            DriverManager.println("postgresql: MD5");
>>
>>                            md.update(PG_PASSWORD.getBytes());
>>                            md.update(PG_USER.getBytes());
>>                            temp_digest = md.digest();
>>
>>                            bytesToHex(temp_digest, hex_digest, 0);
>>                            md.update(hex_digest, 0, 32);
>>                            md.update(salt.getBytes());
>>                            pass_digest = md.digest();
>>
>>                            bytesToHex(pass_digest, hex_digest, 3);
>>                            hex_digest[0] = 'm'; hex_digest[1] = 'd'; hex_digest[2] = '5';
>>
>>                            pg_stream.SendInteger(5 + hex_digest.length, 4);
>>                            pg_stream.Send(hex_digest);
>>                            pg_stream.SendInteger(0, 1);
>>                            pg_stream.flush();
>>                        } catch (Exception e) {
>>                            ; // "MessageDigest failure; " + e
>>                        }
>>                        break;
>>
>>
> 310a354,368
>
>>        private static void bytesToHex(byte[] bytes, byte[] hex, int offset)
>>        {
>>            final char lookup[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
>>                    'a', 'b', 'c', 'd', 'e', 'f' };
>>
>>        int i, c, j, pos = offset;
>>
>>        for (i = 0; i < 16; i++) {
>>            c = bytes[i] & 0xFF; j = c >> 4;
>>            hex[pos++] = (byte) lookup[j];
>>            j = (c & 0xF);
>>            hex[pos++] = (byte) lookup[j];
>>        }
>>        }
>>
>
> -jeremy
> _____________________________________________________________________
> jeremy wohl ..: http://igmus.org
>
>
> ------------------------------------------------------------------------
>
> package org.postgresql;
>
> import java.io.*;
> import java.net.*;
> import java.sql.*;
> import java.util.*;
> import java.security.*;
> import org.postgresql.Field;
> import org.postgresql.fastpath.*;
> import org.postgresql.largeobject.*;
> import org.postgresql.util.*;
> import org.postgresql.core.*;
>
> /**
>  * $Id: Connection.java,v 1.34 2001/11/01 01:08:36 barry Exp $
>  *
>  * This abstract class is used by org.postgresql.Driver to open either the JDBC1 or
>  * JDBC2 versions of the Connection class.
>  *
>  */
> public abstract class Connection
> {
>     // This is the network stream associated with this connection
>     public PG_Stream pg_stream;
>
>     private String PG_HOST;
>     private int PG_PORT;
>     private String PG_USER;
>     private String PG_PASSWORD;
>     private String PG_DATABASE;
>     private boolean PG_STATUS;
>     private String compatible;
>
>     /**
>      *    The encoding to use for this connection.
>      */
>     private Encoding encoding = Encoding.defaultEncoding();
>
>     private String dbVersionNumber;
>
>     public boolean CONNECTION_OK = true;
>     public boolean CONNECTION_BAD = false;
>
>     public boolean autoCommit = true;
>     public boolean readOnly = false;
>
>     public Driver this_driver;
>     private String this_url;
>     private String cursor = null;    // The positioned update cursor name
>
>     // These are new for v6.3, they determine the current protocol versions
>     // supported by this version of the driver. They are defined in
>     // src/include/libpq/pqcomm.h
>     protected static final int PG_PROTOCOL_LATEST_MAJOR = 2;
>     protected static final int PG_PROTOCOL_LATEST_MINOR = 0;
>     private static final int SM_DATABASE    = 64;
>     private static final int SM_USER    = 32;
>     private static final int SM_OPTIONS = 64;
>     private static final int SM_UNUSED    = 64;
>     private static final int SM_TTY = 64;
>
>     private static final int AUTH_REQ_OK = 0;
>     private static final int AUTH_REQ_KRB4 = 1;
>     private static final int AUTH_REQ_KRB5 = 2;
>     private static final int AUTH_REQ_PASSWORD = 3;
>     private static final int AUTH_REQ_CRYPT = 4;
>         private static final int AUTH_REQ_MD5 = 5;
>
>     // New for 6.3, salt value for crypt authorisation
>     private String salt;
>
>     // These are used to cache oids, PGTypes and SQLTypes
>     private static Hashtable sqlTypeCache = new Hashtable();  // oid -> SQLType
>     private static Hashtable pgTypeCache = new Hashtable();  // oid -> PGType
>     private static Hashtable typeOidCache = new Hashtable();  //PGType -> oid
>
>     // Now handle notices as warnings, so things like "show" now work
>     public SQLWarning firstWarning = null;
>
>     /**
>      * Cache of the current isolation level
>      */
>     private int isolationLevel = java.sql.Connection.TRANSACTION_READ_COMMITTED;
>
>     // The PID an cancellation key we get from the backend process
>     public int pid;
>     public int ckey;
>
>     /**
>      * This is called by Class.forName() from within org.postgresql.Driver
>      */
>     public Connection()
>     {}
>
>     /**
>      * This method actually opens the connection. It is called by Driver.
>      *
>      * @param host the hostname of the database back end
>      * @param port the port number of the postmaster process
>      * @param info a Properties[] thing of the user and password
>      * @param database the database to connect to
>      * @param u the URL of the connection
>      * @param d the Driver instantation of the connection
>      * @return a valid connection profile
>      * @exception SQLException if a database access error occurs
>      */
>     protected void openConnection(String host, int port, Properties info, String database, String url, Driver d)
throwsSQLException 
>     {
>         // Throw an exception if the user or password properties are missing
>         // This occasionally occurs when the client uses the properties version
>         // of getConnection(), and is a common question on the email lists
>         if (info.getProperty("user") == null)
>             throw new PSQLException("postgresql.con.user");
>
>         this_driver = d;
>         this_url = url;
>         PG_DATABASE = database;
>         PG_USER = info.getProperty("user");
>                 PG_PASSWORD = info.getProperty("password","");
>         PG_PORT = port;
>         PG_HOST = host;
>         PG_STATUS = CONNECTION_BAD;
>         if (info.getProperty("compatible") == null)
>         {
>             compatible = d.getMajorVersion() + "." + d.getMinorVersion();
>         }
>         else
>         {
>             compatible = info.getProperty("compatible");
>         }
>
>         // Now make the initial connection
>         try
>         {
>             pg_stream = new PG_Stream(host, port);
>         }
>         catch (ConnectException cex)
>         {
>             // Added by Peter Mount <peter@retep.org.uk>
>             // ConnectException is thrown when the connection cannot be made.
>             // we trap this an return a more meaningful message for the end user
>             throw new PSQLException ("postgresql.con.refused");
>         }
>         catch (IOException e)
>         {
>             throw new PSQLException ("postgresql.con.failed", e);
>         }
>
>         // Now we need to construct and send a startup packet
>         try
>         {
>             // Ver 6.3 code
>             pg_stream.SendInteger(4 + 4 + SM_DATABASE + SM_USER + SM_OPTIONS + SM_UNUSED + SM_TTY, 4);
>             pg_stream.SendInteger(PG_PROTOCOL_LATEST_MAJOR, 2);
>             pg_stream.SendInteger(PG_PROTOCOL_LATEST_MINOR, 2);
>             pg_stream.Send(database.getBytes(), SM_DATABASE);
>
>             // This last send includes the unused fields
>             pg_stream.Send(PG_USER.getBytes(), SM_USER + SM_OPTIONS + SM_UNUSED + SM_TTY);
>
>             // now flush the startup packets to the backend
>             pg_stream.flush();
>
>             // Now get the response from the backend, either an error message
>             // or an authentication request
>             int areq = -1; // must have a value here
>             do
>             {
>                 int beresp = pg_stream.ReceiveChar();
>                 switch (beresp)
>                 {
>                 case 'E':
>                     // An error occured, so pass the error message to the
>                     // user.
>                     //
>                     // The most common one to be thrown here is:
>                     // "User authentication failed"
>                     //
>                     throw new SQLException(pg_stream.ReceiveString(encoding));
>
>                 case 'R':
>                     // Get the type of request
>                     areq = pg_stream.ReceiveIntegerR(4);
>
>                     // Get the crypt password salt if there is one
>                     if (areq == AUTH_REQ_CRYPT)
>                     {
>                         byte[] rst = new byte[2];
>                         rst[0] = (byte)pg_stream.ReceiveChar();
>                         rst[1] = (byte)pg_stream.ReceiveChar();
>                         salt = new String(rst, 0, 2);
>                         DriverManager.println("Crypt salt=" + salt);
>                     }
>
>                     // Or get the md5 password salt if there is one
>                     if (areq == AUTH_REQ_MD5)
>                     {
>                         byte[] rst = new byte[4];
>                         rst[0] = (byte)pg_stream.ReceiveChar();
>                         rst[1] = (byte)pg_stream.ReceiveChar();
>                         rst[2] = (byte)pg_stream.ReceiveChar();
>                         rst[3] = (byte)pg_stream.ReceiveChar();
>                         salt = new String(rst, 0, 4);
>                         DriverManager.println("MD5 salt=" + salt);
>                     }
>
>                     // now send the auth packet
>                     switch (areq)
>                     {
>                     case AUTH_REQ_OK:
>                         break;
>
>                     case AUTH_REQ_KRB4:
>                         DriverManager.println("postgresql: KRB4");
>                         throw new PSQLException("postgresql.con.kerb4");
>
>                     case AUTH_REQ_KRB5:
>                         DriverManager.println("postgresql: KRB5");
>                         throw new PSQLException("postgresql.con.kerb5");
>
>                     case AUTH_REQ_PASSWORD:
>                         DriverManager.println("postgresql: PASSWORD");
>                         pg_stream.SendInteger(5 + PG_PASSWORD.length(), 4);
>                         pg_stream.Send(PG_PASSWORD.getBytes());
>                         pg_stream.SendInteger(0, 1);
>                         pg_stream.flush();
>                         break;
>
>                     case AUTH_REQ_CRYPT:
>                         DriverManager.println("postgresql: CRYPT");
>                         String crypted = UnixCrypt.crypt(salt, PG_PASSWORD);
>                         pg_stream.SendInteger(5 + crypted.length(), 4);
>                         pg_stream.Send(crypted.getBytes());
>                         pg_stream.SendInteger(0, 1);
>                         pg_stream.flush();
>                         break;
>
>                     case AUTH_REQ_MD5:
>                             try {
>                             MessageDigest md = MessageDigest.getInstance("MD5");
>                             byte[] temp_digest, pass_digest;
>                             byte[] hex_digest = new byte[35];
>
>                             DriverManager.println("postgresql: MD5");
>
>                             md.update(PG_PASSWORD.getBytes());
>                             md.update(PG_USER.getBytes());
>                             temp_digest = md.digest();
>
>                             bytesToHex(temp_digest, hex_digest, 0);
>                             md.update(hex_digest, 0, 32);
>                             md.update(salt.getBytes());
>                             pass_digest = md.digest();
>
>                             bytesToHex(pass_digest, hex_digest, 3);
>                             hex_digest[0] = 'm'; hex_digest[1] = 'd'; hex_digest[2] = '5';
>
>                             pg_stream.SendInteger(5 + hex_digest.length, 4);
>                             pg_stream.Send(hex_digest);
>                             pg_stream.SendInteger(0, 1);
>                             pg_stream.flush();
>                         } catch (Exception e) {
>                             ; // "MessageDigest failure; " + e
>                         }
>                         break;
>
>                     default:
>                         throw new PSQLException("postgresql.con.auth", new Integer(areq));
>                     }
>                     break;
>
>                 default:
>                     throw new PSQLException("postgresql.con.authfail");
>                 }
>             }
>             while (areq != AUTH_REQ_OK);
>
>         }
>         catch (IOException e)
>         {
>             throw new PSQLException("postgresql.con.failed", e);
>         }
>
>
>         // As of protocol version 2.0, we should now receive the cancellation key and the pid
>         int beresp = pg_stream.ReceiveChar();
>         switch (beresp)
>         {
>         case 'K':
>             pid = pg_stream.ReceiveInteger(4);
>             ckey = pg_stream.ReceiveInteger(4);
>             break;
>         case 'E':
>         case 'N':
>             throw new SQLException(pg_stream.ReceiveString(encoding));
>         default:
>             throw new PSQLException("postgresql.con.setup");
>         }
>
>         // Expect ReadyForQuery packet
>         beresp = pg_stream.ReceiveChar();
>         switch (beresp)
>         {
>         case 'Z':
>             break;
>         case 'E':
>         case 'N':
>             throw new SQLException(pg_stream.ReceiveString(encoding));
>         default:
>             throw new PSQLException("postgresql.con.setup");
>         }
>
>         firstWarning = null;
>
>         // "pg_encoding_to_char(1)" will return 'EUC_JP' for a backend compiled with multibyte,
>         // otherwise it's hardcoded to 'SQL_ASCII'.
>         // If the backend doesn't know about multibyte we can't assume anything about the encoding
>         // used, so we denote this with 'UNKNOWN'.
>         //Note: begining with 7.2 we should be using pg_client_encoding() which
>         //is new in 7.2.  However it isn't easy to conditionally call this new
>         //function, since we don't yet have the information as to what server
>         //version we are talking to.  Thus we will continue to call
>         //getdatabaseencoding() until we drop support for 7.1 and older versions
>         //or until someone comes up with a conditional way to run one or
>         //the other function depending on server version that doesn't require
>         //two round trips to the server per connection
>
>         final String encodingQuery =
>             "case when pg_encoding_to_char(1) = 'SQL_ASCII' then 'UNKNOWN' else getdatabaseencoding() end";
>
>         // Set datestyle and fetch db encoding in a single call, to avoid making
>         // more than one round trip to the backend during connection startup.
>
>         java.sql.ResultSet resultSet =
>             ExecSQL("set datestyle to 'ISO'; select version(), " + encodingQuery + ";");
>
>         if (! resultSet.next())
>         {
>             throw new PSQLException("postgresql.con.failed", "failed getting backend encoding");
>         }
>         String version = resultSet.getString(1);
>         dbVersionNumber = extractVersionNumber(version);
>
>         String dbEncoding = resultSet.getString(2);
>         encoding = Encoding.getEncoding(dbEncoding, info.getProperty("charSet"));
>
>         // Initialise object handling
>         initObjectTypes();
>
>         // Mark the connection as ok, and cleanup
>         firstWarning = null;
>         PG_STATUS = CONNECTION_OK;
>     }
>
>         private static void bytesToHex(byte[] bytes, byte[] hex, int offset)
>         {
>             final char lookup[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
>                     'a', 'b', 'c', 'd', 'e', 'f' };
>
>         int i, c, j, pos = offset;
>
>         for (i = 0; i < 16; i++) {
>             c = bytes[i] & 0xFF; j = c >> 4;
>             hex[pos++] = (byte) lookup[j];
>             j = (c & 0xF);
>             hex[pos++] = (byte) lookup[j];
>         }
>         }
>
>     // These methods used to be in the main Connection implementation. As they
>     // are common to all implementations (JDBC1 or 2), they are placed here.
>     // This should make it easy to maintain the two specifications.
>
>     /**
>      * This adds a warning to the warning chain.
>      * @param msg message to add
>      */
>     public void addWarning(String msg)
>     {
>         DriverManager.println(msg);
>
>         // Add the warning to the chain
>         if (firstWarning != null)
>             firstWarning.setNextWarning(new SQLWarning(msg));
>         else
>             firstWarning = new SQLWarning(msg);
>
>         // Now check for some specific messages
>
>         // This is obsolete in 6.5, but I've left it in here so if we need to use this
>         // technique again, we'll know where to place it.
>         //
>         // This is generated by the SQL "show datestyle"
>         //if(msg.startsWith("NOTICE:") && msg.indexOf("DateStyle")>0) {
>         //// 13 is the length off "DateStyle is "
>         //msg = msg.substring(msg.indexOf("DateStyle is ")+13);
>         //
>         //for(int i=0;i<dateStyles.length;i+=2)
>         //if(msg.startsWith(dateStyles[i]))
>         //currentDateStyle=i+1; // this is the index of the format
>         //}
>     }
>
>     /**
>      * Send a query to the backend.  Returns one of the ResultSet
>      * objects.
>      *
>      * <B>Note:</B> there does not seem to be any method currently
>      * in existance to return the update count.
>      *
>      * @param sql the SQL statement to be executed
>      * @return a ResultSet holding the results
>      * @exception SQLException if a database error occurs
>      */
>     public java.sql.ResultSet ExecSQL(String sql) throws SQLException
>     {
>         return ExecSQL(sql, null);
>     }
>
>     /**
>      * Send a query to the backend.  Returns one of the ResultSet
>      * objects.
>      *
>      * <B>Note:</B> there does not seem to be any method currently
>      * in existance to return the update count.
>      *
>      * @param sql the SQL statement to be executed
>      * @param stat The Statement associated with this query (may be null)
>      * @return a ResultSet holding the results
>      * @exception SQLException if a database error occurs
>      */
>     public java.sql.ResultSet ExecSQL(String sql, java.sql.Statement stat) throws SQLException
>     {
>         return new QueryExecutor(sql, stat, pg_stream, this).execute();
>     }
>
>     /**
>      * In SQL, a result table can be retrieved through a cursor that
>      * is named.  The current row of a result can be updated or deleted
>      * using a positioned update/delete statement that references the
>      * cursor name.
>      *
>      * We support one cursor per connection.
>      *
>      * setCursorName sets the cursor name.
>      *
>      * @param cursor the cursor name
>      * @exception SQLException if a database access error occurs
>      */
>     public void setCursorName(String cursor) throws SQLException
>     {
>         this.cursor = cursor;
>     }
>
>     /**
>      * getCursorName gets the cursor name.
>      *
>      * @return the current cursor name
>      * @exception SQLException if a database access error occurs
>      */
>     public String getCursorName() throws SQLException
>     {
>         return cursor;
>     }
>
>     /**
>      * We are required to bring back certain information by
>      * the DatabaseMetaData class.    These functions do that.
>      *
>      * Method getURL() brings back the URL (good job we saved it)
>      *
>      * @return the url
>      * @exception SQLException just in case...
>      */
>     public String getURL() throws SQLException
>     {
>         return this_url;
>     }
>
>     /**
>      * Method getUserName() brings back the User Name (again, we
>      * saved it)
>      *
>      * @return the user name
>      * @exception SQLException just in case...
>      */
>     public String getUserName() throws SQLException
>     {
>         return PG_USER;
>     }
>
>     /**
>      * Get the character encoding to use for this connection.
>      */
>     public Encoding getEncoding() throws SQLException
>     {
>         return encoding;
>     }
>
>     /**
>      * This returns the Fastpath API for the current connection.
>      *
>      * <p><b>NOTE:</b> This is not part of JDBC, but allows access to
>      * functions on the org.postgresql backend itself.
>      *
>      * <p>It is primarily used by the LargeObject API
>      *
>      * <p>The best way to use this is as follows:
>      *
>      * <p><pre>
>      * import org.postgresql.fastpath.*;
>      * ...
>      * Fastpath fp = ((org.postgresql.Connection)myconn).getFastpathAPI();
>      * </pre>
>      *
>      * <p>where myconn is an open Connection to org.postgresql.
>      *
>      * @return Fastpath object allowing access to functions on the org.postgresql
>      * backend.
>      * @exception SQLException by Fastpath when initialising for first time
>      */
>     public Fastpath getFastpathAPI() throws SQLException
>     {
>         if (fastpath == null)
>             fastpath = new Fastpath(this, pg_stream);
>         return fastpath;
>     }
>
>     // This holds a reference to the Fastpath API if already open
>     private Fastpath fastpath = null;
>
>     /**
>      * This returns the LargeObject API for the current connection.
>      *
>      * <p><b>NOTE:</b> This is not part of JDBC, but allows access to
>      * functions on the org.postgresql backend itself.
>      *
>      * <p>The best way to use this is as follows:
>      *
>      * <p><pre>
>      * import org.postgresql.largeobject.*;
>      * ...
>      * LargeObjectManager lo = ((org.postgresql.Connection)myconn).getLargeObjectAPI();
>      * </pre>
>      *
>      * <p>where myconn is an open Connection to org.postgresql.
>      *
>      * @return LargeObject object that implements the API
>      * @exception SQLException by LargeObject when initialising for first time
>      */
>     public LargeObjectManager getLargeObjectAPI() throws SQLException
>     {
>         if (largeobject == null)
>             largeobject = new LargeObjectManager(this);
>         return largeobject;
>     }
>
>     // This holds a reference to the LargeObject API if already open
>     private LargeObjectManager largeobject = null;
>
>     /**
>      * This method is used internally to return an object based around
>      * org.postgresql's more unique data types.
>      *
>      * <p>It uses an internal Hashtable to get the handling class. If the
>      * type is not supported, then an instance of org.postgresql.util.PGobject
>      * is returned.
>      *
>      * You can use the getValue() or setValue() methods to handle the returned
>      * object. Custom objects can have their own methods.
>      *
>      * In 6.4, this is extended to use the org.postgresql.util.Serialize class to
>      * allow the Serialization of Java Objects into the database without using
>      * Blobs. Refer to that class for details on how this new feature works.
>      *
>      * @return PGobject for this type, and set to value
>      * @exception SQLException if value is not correct for this type
>      * @see org.postgresql.util.Serialize
>      */
>     public Object getObject(String type, String value) throws SQLException
>     {
>         try
>         {
>             Object o = objectTypes.get(type);
>
>             // If o is null, then the type is unknown, so check to see if type
>             // is an actual table name. If it does, see if a Class is known that
>             // can handle it
>             if (o == null)
>             {
>                 Serialize ser = new Serialize(this, type);
>                 objectTypes.put(type, ser);
>                 return ser.fetch(Integer.parseInt(value));
>             }
>
>             // If o is not null, and it is a String, then its a class name that
>             // extends PGobject.
>             //
>             // This is used to implement the org.postgresql unique types (like lseg,
>             // point, etc).
>             if (o instanceof String)
>             {
>                 // 6.3 style extending PG_Object
>                 PGobject obj = null;
>                 obj = (PGobject)(Class.forName((String)o).newInstance());
>                 obj.setType(type);
>                 obj.setValue(value);
>                 return (Object)obj;
>             }
>             else
>             {
>                 // If it's an object, it should be an instance of our Serialize class
>                 // If so, then call it's fetch method.
>                 if (o instanceof Serialize)
>                     return ((Serialize)o).fetch(Integer.parseInt(value));
>             }
>         }
>         catch (SQLException sx)
>         {
>             // rethrow the exception. Done because we capture any others next
>             sx.fillInStackTrace();
>             throw sx;
>         }
>         catch (Exception ex)
>         {
>             throw new PSQLException("postgresql.con.creobj", type, ex);
>         }
>
>         // should never be reached
>         return null;
>     }
>
>     /**
>      * This stores an object into the database.
>      * @param o Object to store
>      * @return OID of the new rectord
>      * @exception SQLException if value is not correct for this type
>      * @see org.postgresql.util.Serialize
>      */
>     public int putObject(Object o) throws SQLException
>     {
>         try
>         {
>             String type = o.getClass().getName();
>             Object x = objectTypes.get(type);
>
>             // If x is null, then the type is unknown, so check to see if type
>             // is an actual table name. If it does, see if a Class is known that
>             // can handle it
>             if (x == null)
>             {
>                 Serialize ser = new Serialize(this, type);
>                 objectTypes.put(type, ser);
>                 return ser.store(o);
>             }
>
>             // If it's an object, it should be an instance of our Serialize class
>             // If so, then call it's fetch method.
>             if (x instanceof Serialize)
>                 return ((Serialize)x).store(o);
>
>             // Thow an exception because the type is unknown
>             throw new PSQLException("postgresql.con.strobj");
>
>         }
>         catch (SQLException sx)
>         {
>             // rethrow the exception. Done because we capture any others next
>             sx.fillInStackTrace();
>             throw sx;
>         }
>         catch (Exception ex)
>         {
>             throw new PSQLException("postgresql.con.strobjex", ex);
>         }
>     }
>
>     /**
>      * This allows client code to add a handler for one of org.postgresql's
>      * more unique data types.
>      *
>      * <p><b>NOTE:</b> This is not part of JDBC, but an extension.
>      *
>      * <p>The best way to use this is as follows:
>      *
>      * <p><pre>
>      * ...
>      * ((org.postgresql.Connection)myconn).addDataType("mytype","my.class.name");
>      * ...
>      * </pre>
>      *
>      * <p>where myconn is an open Connection to org.postgresql.
>      *
>      * <p>The handling class must extend org.postgresql.util.PGobject
>      *
>      * @see org.postgresql.util.PGobject
>      */
>     public void addDataType(String type, String name)
>     {
>         objectTypes.put(type, name);
>     }
>
>     // This holds the available types
>     private Hashtable objectTypes = new Hashtable();
>
>     // This array contains the types that are supported as standard.
>     //
>     // The first entry is the types name on the database, the second
>     // the full class name of the handling class.
>     //
>     private static final String defaultObjectTypes[][] = {
>                 {"box", "org.postgresql.geometric.PGbox"},
>                 {"circle", "org.postgresql.geometric.PGcircle"},
>                 {"line", "org.postgresql.geometric.PGline"},
>                 {"lseg", "org.postgresql.geometric.PGlseg"},
>                 {"path", "org.postgresql.geometric.PGpath"},
>                 {"point", "org.postgresql.geometric.PGpoint"},
>                 {"polygon", "org.postgresql.geometric.PGpolygon"},
>                 {"money", "org.postgresql.util.PGmoney"}
>             };
>
>     // This initialises the objectTypes hashtable
>     private void initObjectTypes()
>     {
>         for (int i = 0;i < defaultObjectTypes.length;i++)
>             objectTypes.put(defaultObjectTypes[i][0], defaultObjectTypes[i][1]);
>     }
>
>     // These are required by other common classes
>     public abstract java.sql.Statement createStatement() throws SQLException;
>
>     /**
>      * This returns a resultset. It must be overridden, so that the correct
>      * version (from jdbc1 or jdbc2) are returned.
>      */
>     public abstract java.sql.ResultSet getResultSet(org.postgresql.Connection conn, java.sql.Statement stat, Field[]
fields,Vector tuples, String status, int updateCount, int insertOID, boolean binaryCursor) throws SQLException; 
>
>     /**
>      * In some cases, it is desirable to immediately release a Connection's
>      * database and JDBC resources instead of waiting for them to be
>      * automatically released (cant think why off the top of my head)
>      *
>      * <B>Note:</B> A Connection is automatically closed when it is
>      * garbage collected.  Certain fatal errors also result in a closed
>      * connection.
>      *
>      * @exception SQLException if a database access error occurs
>      */
>     public void close() throws SQLException
>     {
>         if (pg_stream != null)
>         {
>             try
>             {
>                 pg_stream.SendChar('X');
>                 pg_stream.flush();
>                 pg_stream.close();
>             }
>             catch (IOException e)
>             {}
>             pg_stream = null;
>         }
>     }
>
>     /**
>      * A driver may convert the JDBC sql grammar into its system's
>      * native SQL grammar prior to sending it; nativeSQL returns the
>      * native form of the statement that the driver would have sent.
>      *
>      * @param sql a SQL statement that may contain one or more '?'
>      *    parameter placeholders
>      * @return the native form of this statement
>      * @exception SQLException if a database access error occurs
>      */
>     public String nativeSQL(String sql) throws SQLException
>     {
>         return sql;
>     }
>
>     /**
>      * The first warning reported by calls on this Connection is
>      * returned.
>      *
>      * <B>Note:</B> Sebsequent warnings will be changed to this
>      * SQLWarning
>      *
>      * @return the first SQLWarning or null
>      * @exception SQLException if a database access error occurs
>      */
>     public SQLWarning getWarnings() throws SQLException
>     {
>         return firstWarning;
>     }
>
>     /**
>      * After this call, getWarnings returns null until a new warning
>      * is reported for this connection.
>      *
>      * @exception SQLException if a database access error occurs
>      */
>     public void clearWarnings() throws SQLException
>     {
>         firstWarning = null;
>     }
>
>
>     /**
>      * You can put a connection in read-only mode as a hunt to enable
>      * database optimizations
>      *
>      * <B>Note:</B> setReadOnly cannot be called while in the middle
>      * of a transaction
>      *
>      * @param readOnly - true enables read-only mode; false disables it
>      * @exception SQLException if a database access error occurs
>      */
>     public void setReadOnly(boolean readOnly) throws SQLException
>     {
>         this.readOnly = readOnly;
>     }
>
>     /**
>      * Tests to see if the connection is in Read Only Mode.  Note that
>      * we cannot really put the database in read only mode, but we pretend
>      * we can by returning the value of the readOnly flag
>      *
>      * @return true if the connection is read only
>      * @exception SQLException if a database access error occurs
>      */
>     public boolean isReadOnly() throws SQLException
>     {
>         return readOnly;
>     }
>
>     /**
>      * If a connection is in auto-commit mode, than all its SQL
>      * statements will be executed and committed as individual
>      * transactions.  Otherwise, its SQL statements are grouped
>      * into transactions that are terminated by either commit()
>      * or rollback().  By default, new connections are in auto-
>      * commit mode.  The commit occurs when the statement completes
>      * or the next execute occurs, whichever comes first.  In the
>      * case of statements returning a ResultSet, the statement
>      * completes when the last row of the ResultSet has been retrieved
>      * or the ResultSet has been closed.  In advanced cases, a single
>      * statement may return multiple results as well as output parameter
>      * values.    Here the commit occurs when all results and output param
>      * values have been retrieved.
>      *
>      * @param autoCommit - true enables auto-commit; false disables it
>      * @exception SQLException if a database access error occurs
>      */
>     public void setAutoCommit(boolean autoCommit) throws SQLException
>     {
>         if (this.autoCommit == autoCommit)
>             return ;
>         if (autoCommit)
>             ExecSQL("end");
>         else
>         {
>             if (haveMinimumServerVersion("7.1"))
>             {
>                 ExecSQL("begin;" + getIsolationLevelSQL());
>             }
>             else
>             {
>                 ExecSQL("begin");
>                 ExecSQL(getIsolationLevelSQL());
>             }
>         }
>         this.autoCommit = autoCommit;
>     }
>
>     /**
>      * gets the current auto-commit state
>      *
>      * @return Current state of the auto-commit mode
>      * @exception SQLException (why?)
>      * @see setAutoCommit
>      */
>     public boolean getAutoCommit() throws SQLException
>     {
>         return this.autoCommit;
>     }
>
>     /**
>      * The method commit() makes all changes made since the previous
>      * commit/rollback permanent and releases any database locks currently
>      * held by the Connection.    This method should only be used when
>      * auto-commit has been disabled.  (If autoCommit == true, then we
>      * just return anyhow)
>      *
>      * @exception SQLException if a database access error occurs
>      * @see setAutoCommit
>      */
>     public void commit() throws SQLException
>     {
>         if (autoCommit)
>             return ;
>         if (haveMinimumServerVersion("7.1"))
>         {
>             ExecSQL("commit;begin;" + getIsolationLevelSQL());
>         }
>         else
>         {
>             ExecSQL("commit");
>             ExecSQL("begin");
>             ExecSQL(getIsolationLevelSQL());
>         }
>     }
>
>     /**
>      * The method rollback() drops all changes made since the previous
>      * commit/rollback and releases any database locks currently held by
>      * the Connection.
>      *
>      * @exception SQLException if a database access error occurs
>      * @see commit
>      */
>     public void rollback() throws SQLException
>     {
>         if (autoCommit)
>             return ;
>         if (haveMinimumServerVersion("7.1"))
>         {
>             ExecSQL("rollback; begin;" + getIsolationLevelSQL());
>         }
>         else
>         {
>             ExecSQL("rollback");
>             ExecSQL("begin");
>             ExecSQL(getIsolationLevelSQL());
>         }
>     }
>
>     /**
>      * Get this Connection's current transaction isolation mode.
>      *
>      * @return the current TRANSACTION_* mode value
>      * @exception SQLException if a database access error occurs
>      */
>     public int getTransactionIsolation() throws SQLException
>     {
>         clearWarnings();
>         ExecSQL("show xactisolevel");
>
>         SQLWarning warning = getWarnings();
>         if (warning != null)
>         {
>             String message = warning.getMessage();
>             clearWarnings();
>             if (message.indexOf("READ COMMITTED") != -1)
>                 return java.sql.Connection.TRANSACTION_READ_COMMITTED;
>             else if (message.indexOf("READ UNCOMMITTED") != -1)
>                 return java.sql.Connection.TRANSACTION_READ_UNCOMMITTED;
>             else if (message.indexOf("REPEATABLE READ") != -1)
>                 return java.sql.Connection.TRANSACTION_REPEATABLE_READ;
>             else if (message.indexOf("SERIALIZABLE") != -1)
>                 return java.sql.Connection.TRANSACTION_SERIALIZABLE;
>         }
>         return java.sql.Connection.TRANSACTION_READ_COMMITTED;
>     }
>
>     /**
>      * You can call this method to try to change the transaction
>      * isolation level using one of the TRANSACTION_* values.
>      *
>      * <B>Note:</B> setTransactionIsolation cannot be called while
>      * in the middle of a transaction
>      *
>      * @param level one of the TRANSACTION_* isolation values with
>      *    the exception of TRANSACTION_NONE; some databases may
>      *    not support other values
>      * @exception SQLException if a database access error occurs
>      * @see java.sql.DatabaseMetaData#supportsTransactionIsolationLevel
>      */
>     public void setTransactionIsolation(int level) throws SQLException
>     {
>         //In 7.1 and later versions of the server it is possible using
>         //the "set session" command to set this once for all future txns
>         //however in 7.0 and prior versions it is necessary to set it in
>         //each transaction, thus adding complexity below.
>         //When we decide to drop support for servers older than 7.1
>         //this can be simplified
>         isolationLevel = level;
>         String isolationLevelSQL;
>
>         if (!haveMinimumServerVersion("7.1"))
>         {
>             isolationLevelSQL = getIsolationLevelSQL();
>         }
>         else
>         {
>             isolationLevelSQL = "SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL ";
>             switch (isolationLevel)
>             {
>             case java.sql.Connection.TRANSACTION_READ_COMMITTED:
>                 isolationLevelSQL += "READ COMMITTED";
>                 break;
>             case java.sql.Connection.TRANSACTION_SERIALIZABLE:
>                 isolationLevelSQL += "SERIALIZABLE";
>                 break;
>             default:
>                 throw new PSQLException("postgresql.con.isolevel",
>                                         new Integer(isolationLevel));
>             }
>         }
>         ExecSQL(isolationLevelSQL);
>     }
>
>     /**
>      * Helper method used by setTransactionIsolation(), commit(), rollback()
>      * and setAutoCommit(). This returns the SQL string needed to
>      * set the isolation level for a transaction.  In 7.1 and later it
>      * is possible to set a default isolation level that applies to all
>      * future transactions, this method is only necesary for 7.0 and older
>      * servers, and should be removed when support for these older
>      * servers are dropped
>      */
>     protected String getIsolationLevelSQL() throws SQLException
>     {
>         //7.1 and higher servers have a default specified so
>         //no additional SQL is required to set the isolation level
>         if (haveMinimumServerVersion("7.1"))
>         {
>             return "";
>         }
>         StringBuffer sb = new StringBuffer("SET TRANSACTION ISOLATION LEVEL");
>
>         switch (isolationLevel)
>         {
>         case java.sql.Connection.TRANSACTION_READ_COMMITTED:
>             sb.append(" READ COMMITTED");
>             break;
>
>         case java.sql.Connection.TRANSACTION_SERIALIZABLE:
>             sb.append(" SERIALIZABLE");
>             break;
>
>         default:
>             throw new PSQLException("postgresql.con.isolevel", new Integer(isolationLevel));
>         }
>         return sb.toString();
>     }
>
>     /**
>      * A sub-space of this Connection's database may be selected by
>      * setting a catalog name.    If the driver does not support catalogs,
>      * it will silently ignore this request
>      *
>      * @exception SQLException if a database access error occurs
>      */
>     public void setCatalog(String catalog) throws SQLException
>     {
>         //no-op
>     }
>
>     /**
>      * Return the connections current catalog name, or null if no
>      * catalog name is set, or we dont support catalogs.
>      *
>      * @return the current catalog name or null
>      * @exception SQLException if a database access error occurs
>      */
>     public String getCatalog() throws SQLException
>     {
>         return PG_DATABASE;
>     }
>
>     /**
>      * Overides finalize(). If called, it closes the connection.
>      *
>      * This was done at the request of Rachel Greenham
>      * <rachel@enlarion.demon.co.uk> who hit a problem where multiple
>      * clients didn't close the connection, and once a fortnight enough
>      * clients were open to kill the org.postgres server.
>      */
>     public void finalize() throws Throwable
>     {
>         close();
>     }
>
>     private static String extractVersionNumber(String fullVersionString)
>     {
>         StringTokenizer versionParts = new StringTokenizer(fullVersionString);
>         versionParts.nextToken(); /* "PostgreSQL" */
>         return versionParts.nextToken(); /* "X.Y.Z" */
>     }
>
>     /**
>      * Get server version number
>      */
>     public String getDBVersionNumber()
>     {
>         return dbVersionNumber;
>     }
>
>     public boolean haveMinimumServerVersion(String ver) throws SQLException
>     {
>         return (getDBVersionNumber().compareTo(ver) >= 0);
>     }
>
>     /**
>      * This method returns true if the compatible level set in the connection
>      * (which can be passed into the connection or specified in the URL)
>      * is at least the value passed to this method.  This is used to toggle
>      * between different functionality as it changes across different releases
>      * of the jdbc driver code.  The values here are versions of the jdbc client
>      * and not server versions.  For example in 7.1 get/setBytes worked on
>      * LargeObject values, in 7.2 these methods were changed to work on bytea
>      * values.    This change in functionality could be disabled by setting the
>      * "compatible" level to be 7.1, in which case the driver will revert to
>      * the 7.1 functionality.
>      */
>     public boolean haveMinimumCompatibleVersion(String ver) throws SQLException
>     {
>         return (compatible.compareTo(ver) >= 0);
>     }
>
>
>     /**
>      * This returns the java.sql.Types type for a PG type oid
>      *
>      * @param oid PostgreSQL type oid
>      * @return the java.sql.Types type
>      * @exception SQLException if a database access error occurs
>      */
>     public int getSQLType(int oid) throws SQLException
>     {
>         Integer sqlType = (Integer)typeOidCache.get(new Integer(oid));
>
>         // it's not in the cache, so perform a query, and add the result to the cache
>         if (sqlType == null)
>         {
>             ResultSet result = (org.postgresql.ResultSet)ExecSQL("select typname from pg_type where oid = " + oid);
>             if (result.getColumnCount() != 1 || result.getTupleCount() != 1)
>                 throw new PSQLException("postgresql.unexpected");
>             result.next();
>             String pgType = result.getString(1);
>             Integer iOid = new Integer(oid);
>             sqlType = new Integer(getSQLType(result.getString(1)));
>             sqlTypeCache.put(iOid, sqlType);
>             pgTypeCache.put(iOid, pgType);
>             result.close();
>         }
>
>         return sqlType.intValue();
>     }
>
>     /**
>      * This returns the java.sql.Types type for a PG type
>      *
>      * @param pgTypeName PostgreSQL type name
>      * @return the java.sql.Types type
>      */
>     public abstract int getSQLType(String pgTypeName);
>
>     /**
>      * This returns the oid for a given PG data type
>      * @param typeName PostgreSQL type name
>      * @return PostgreSQL oid value for a field of this type
>      */
>     public int getOID(String typeName) throws SQLException
>     {
>         int oid = -1;
>         if (typeName != null)
>         {
>             Integer oidValue = (Integer) typeOidCache.get(typeName);
>             if (oidValue != null)
>             {
>                 oid = oidValue.intValue();
>             }
>             else
>             {
>                 // it's not in the cache, so perform a query, and add the result to the cache
>                 ResultSet result = (org.postgresql.ResultSet)ExecSQL("select oid from pg_type where typname='"
>                                    + typeName + "'");
>                 if (result.getColumnCount() != 1 || result.getTupleCount() != 1)
>                     throw new PSQLException("postgresql.unexpected");
>                 result.next();
>                 oid = Integer.parseInt(result.getString(1));
>                 typeOidCache.put(typeName, new Integer(oid));
>                 result.close();
>             }
>         }
>         return oid;
>     }
>
>     /**
>      * We also need to get the PG type name as returned by the back end.
>      *
>      * @return the String representation of the type of this field
>      * @exception SQLException if a database access error occurs
>      */
>     public String getPGType(int oid) throws SQLException
>     {
>         String pgType = (String) pgTypeCache.get(new Integer(oid));
>         if (pgType == null)
>         {
>             getSQLType(oid);
>             pgType = (String) pgTypeCache.get(new Integer(oid));
>         }
>         return pgType;
>     }
>
> }
>
>
>
> ------------------------------------------------------------------------
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 3: if posting/reading through Usenet, please send an appropriate
> subscribe-nomail command to majordomo@postgresql.org so that your
> message can get through to the mailing list cleanly
>



Re: MD5-based passwords

From
"Dave Cramer"
Date:
Barry,

Yes, you are probably correct, poor choice of words.

I did commit it earlier this evening; mainly because there is another
related patch which has been stalled due to this section of the code
changing so quickly.

Dave

-----Original Message-----
From: Barry Lind [mailto:barry@xythos.com]
Sent: November 8, 2001 10:47 PM
To: Dave@micro-automation.net
Cc: 'Bruce Momjian'; 'psql-jdbc'
Subject: Re: MD5-based passwords


Dave,

I think it would make people feel better to say that you are going to
'apply some bug fixes that have been contributed' instead of saying 'I
am going to add some of the code that has been contributed'.  The latter

makes it sound like new functionality, when in reality this patch mostly

fixes bugs (with a little code refactoring thrown in for good measure).

I think you should go ahead and apply this.  This area of the code
didn't work at all in 7.1, partly works in 7.2beta2, and I think will
mostly work for 7.2.0 with this set of fixes.

thanks,
--Barry

Dave Cramer wrote:

> Ok,
>
> Thanks for all the input, I think at this point I am going to add some
> of the code that has been contributed
> None of it changes the drivers core behaviour.
>
> Specifically it is Jason Davies updates to the DatabaseMetaData
> getImported/Exported keys
>
> Dave
>
> -----Original Message-----
> From: pgsql-jdbc-owner@postgresql.org
> [mailto:pgsql-jdbc-owner@postgresql.org] On Behalf Of Bruce Momjian
> Sent: November 8, 2001 9:13 PM
> To: Justin Clift
> Cc: Tom Lane; Ned Wolpert; psql-jdbc
> Subject: Re: [JDBC] MD5-based passwords
>
>
>
>>>Also, if the code proves to have bugs, what's the downside?  Only
>>>
> that
>
>>>JDBC users will be unable to use MD5 passwords; but that will
>>>
> certainly
>
>>>be true if we don't try.  So I think I'd go for it.
>>>
>>>On the other hand, some of the other stuff Dave mentioned sounded
>>>
> like
>
>>>whole new features, and since we are in beta now I think the "no new
>>>features during beta" rule ought to apply.
>>>
>>I believe we should include the new stuff, as it would assist in the
>>
> 7.2
>
>>release having more of an "Enterprise" functionality level than
>>without.  Might as well have MD5 all round.
>>
>>If bugs are found during our beta testing process, then it might delay
>>the release for a week or two, which is probably worth it.
>>
>
> I can say pretty reliably that we are long past time in 7.2 where we
can
> add code that will push back a final release date.  It is fine to slip
> stuff in and take the responsibility for it, but we are in beta now
and
> anything that pushes back final is bad, because it pushes back _all_
7.2
> features from the general user community.
>
> Thinking of it another way, the value of any single feature can not
> possibly be large compared to all the new features in 7.2 already.  If
> we add code now, patch appliers have to be willing to take the heat if
> the patch delays final release.
>
> Now, of course I myself am applying stuff, but if it delays final, I
> have failed and must take the responsibility for it.  This is probably
> the biggest difference between patch application during development
> cycle and final.  During development, patches are applied if they look
> good and no one complains.  During beta, responsibility lies solely
with
> the patch applier.
>
> Of course, you can patch things up during 7.2.X, and this often
happens.
>
>




Re: MD5-based passwords

From
Peter Eisentraut
Date:
Dave Cramer writes:

> A number of the contributions are implementations of the driver which
> didn't exist before. Since none of the core code is being modified, I am
> tending towards adding them as they com in?

Once you add them they become core code and you're liable for them.

--
Peter Eisentraut   peter_e@gmx.net


Re: MD5-based passwords

From
Justin Clift
Date:
Tom Lane wrote:
>
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
<snip>
> > I can say pretty reliably that we are long past time in 7.2 where we can
> > add code that will push back a final release date.  It is fine to slip
> > stuff in and take the responsibility for it, but we are in beta now and
> > anything that pushes back final is bad, because it pushes back _all_ 7.2
> > features from the general user community.
>
> Yup, exactly.  "One more feature" is a siren song that you gotta resist,
> else we'll never get out of beta.
>
> It might be appropriate to point out that we've already missed the
> original target date for 7.2 beta by two months, and that if we can't
> produce a release candidate in another week or so we'll likely not have
> 7.2 final until January.  That's a long time to keep the world waiting
> for concurrent VACUUM, survival of transaction ID wraparound, and
> several other absolutely *critical* improvements in 7.2.  If it looks
> to me like JDBC MD5 passwords (or any other thing that's not clearly a
> bug fix) are going to slip the schedule another week, I'll vote to pass
> it over until 7.3.
>
> Once we go beta, we have to focus on wrapping up what we have
> and getting it out the door, not on squeezing in stuff that is
> "almost ready".  There'll always be another release.
>
>                         regards, tom lane

Thanks guys.  Consider me "better educated" now about our release
priorities.

:)

Regards and best wishes,

Justin Clift


--
"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
   - Indira Gandhi

Re: MD5-based passwords

From
Barry Lind
Date:
Patch applied.

thanks,
--Barry


Jeremy Wohl wrote:

> On Wed, Nov 07, 2001 at 08:26:49PM -0800, Barry Lind wrote:
>
>>I think I would recommend moving most of this logic into a new class
>>under org.postgresql.util, called MD5.java?? (that is where the
>>UnixCrypt class is located).
>>
>>[...]
>>
>
> OK.  Attached is an abstracted version, with your cast fix.
>
> Appropriate exception handling is still open.  As is indenting.
>
>
>>PS.  When sending diffs please use context diff format (i.e.-c).  It
>>makes it much easier to review.
>>
>
> How about unified? :)
>
> -jeremy
> _____________________________________________________________________
> jeremy wohl ..: http://igmus.org
>
>
> ------------------------------------------------------------------------
>
> --- Connection.java.old    Wed Nov  7 11:19:11 2001
> +++ Connection.java    Thu Nov  8 10:20:13 2001
> @@ -63,6 +63,7 @@
>      private static final int AUTH_REQ_KRB5 = 2;
>      private static final int AUTH_REQ_PASSWORD = 3;
>      private static final int AUTH_REQ_CRYPT = 4;
> +        private static final int AUTH_REQ_MD5 = 5;
>
>      // New for 6.3, salt value for crypt authorisation
>      private String salt;
> @@ -180,22 +181,34 @@
>                      // Get the type of request
>                      areq = pg_stream.ReceiveIntegerR(4);
>
> -                    // Get the password salt if there is one
> +                    // Get the crypt password salt if there is one
>                      if (areq == AUTH_REQ_CRYPT)
>                      {
>                          byte[] rst = new byte[2];
>                          rst[0] = (byte)pg_stream.ReceiveChar();
>                          rst[1] = (byte)pg_stream.ReceiveChar();
>                          salt = new String(rst, 0, 2);
> -                        DriverManager.println("Salt=" + salt);
> +                        DriverManager.println("Crypt salt=" + salt);
> +                    }
> +
> +                    // Or get the md5 password salt if there is one
> +                    if (areq == AUTH_REQ_MD5)
> +                    {
> +                        byte[] rst = new byte[4];
> +                        rst[0] = (byte)pg_stream.ReceiveChar();
> +                        rst[1] = (byte)pg_stream.ReceiveChar();
> +                        rst[2] = (byte)pg_stream.ReceiveChar();
> +                        rst[3] = (byte)pg_stream.ReceiveChar();
> +                        salt = new String(rst, 0, 4);
> +                        DriverManager.println("MD5 salt=" + salt);
>                      }
>
>                      // now send the auth packet
>                      switch (areq)
>                      {
>                      case AUTH_REQ_OK:
> -                        break;
> -
> +                        break;
> +
>                      case AUTH_REQ_KRB4:
>                          DriverManager.println("postgresql: KRB4");
>                          throw new PSQLException("postgresql.con.kerb4");
> @@ -217,6 +230,15 @@
>                          String crypted = UnixCrypt.crypt(salt, PG_PASSWORD);
>                          pg_stream.SendInteger(5 + crypted.length(), 4);
>                          pg_stream.Send(crypted.getBytes());
> +                        pg_stream.SendInteger(0, 1);
> +                        pg_stream.flush();
> +                        break;
> +
> +                    case AUTH_REQ_MD5:
> +                            DriverManager.println("postgresql: MD5");
> +                        byte[] digest = MD5Digest.encode(PG_USER, PG_PASSWORD, salt);
> +                        pg_stream.SendInteger(5 + digest.length, 4);
> +                        pg_stream.Send(digest);
>                          pg_stream.SendInteger(0, 1);
>                          pg_stream.flush();
>                          break;
>
>
> ------------------------------------------------------------------------
>
> package org.postgresql.util;
>
> /**
>  * MD5-based utility function to obfuscate passwords before network transmission
>  *
>  * @author Jeremy Wohl
>  *
>  */
>
> import java.security.*;
>
> public class MD5Digest
> {
>     private MD5Digest() {}
>
>
>     /**
>      * Encodes user/password/salt information in the following way:
>      *   MD5(MD5(password + user) + salt)
>      *
>      * @param user      The connecting user.
>      * @param password  The connecting user's password.
>      * @param salt      A four-character string sent by the server.
>      *
>      * @return  A 35-byte array, comprising the string "md5", followed by an MD5 digest.
>      */
>     public static byte[] encode(String user, String password, String salt)
>     {
>     MessageDigest  md;
>     byte[]         temp_digest, pass_digest;
>     byte[]         hex_digest = new byte[35];
>
>
>     try {
>         md = MessageDigest.getInstance("MD5");
>
>         md.update(password.getBytes());
>         md.update(user.getBytes());
>         temp_digest = md.digest();
>
>         bytesToHex(temp_digest, hex_digest, 0);
>         md.update(hex_digest, 0, 32);
>         md.update(salt.getBytes());
>         pass_digest = md.digest();
>
>         bytesToHex(pass_digest, hex_digest, 3);
>         hex_digest[0] = (byte) 'm'; hex_digest[1] = (byte) 'd'; hex_digest[2] = (byte) '5';
>     } catch (Exception e) {
>         ; // "MessageDigest failure; " + e
>     }
>
>     return hex_digest;
>     }
>
>
>     /**
>      * Turn 16-byte stream into a human-readable 32-byte hex string
>      */
>     private static void bytesToHex(byte[] bytes, byte[] hex, int offset)
>     {
>     final char lookup[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
>                 'a', 'b', 'c', 'd', 'e', 'f' };
>
>     int i, c, j, pos = offset;
>
>     for (i = 0; i < 16; i++) {
>         c = bytes[i] & 0xFF; j = c >> 4;
>         hex[pos++] = (byte) lookup[j];
>         j = (c & 0xF);
>         hex[pos++] = (byte) lookup[j];
>     }
>     }
> }
>
>
> ------------------------------------------------------------------------
>
>
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