Re: Update encryption options doc for SCRAM-SHA-256

[Shay Rojansky]

Thanks for your attention to this.

I'm definitely not a cryptography expert, but it seems to me that the
actual mechanisms (MD5, SHA-256) are more important than the protocols used
to negotiate them (SASL, SCRAM). When some security expert unfamiliar with
PostgreSQL goes over itss documentation to determine whether it's secure, I
think it's important to make sure that the word SHA-256 is actually there.

On Sat, Feb 3, 2018 at 8:30 AM, Peter Eisentraut <
peter.eisentr...@2ndquadrant.com> wrote:

> On 2/2/18 18:42, PG Doc comments form wrote:
> > The following documentation comment has been logged on the website:
> >
> > Page: https://www.postgresql.org/docs/10/static/encryption-options.html
> > Description:
> >
> > Section "18.8. Encryption Options" only mentions MD5 as the password
> storage
> > encryption mechanism, although PostgreSQL 10 introduced the superior
> SHA256
> > - somebody looking at the docs would get a bad idea of PostgreSQL's
> > capabilities...
>
> I propose the attached patch.  I have combined the password storage and
> password transmission items, because I don't want to go into the details
> of how SCRAM works on the wire.
>
> --
> Peter Eisentraut  http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
>

Re: Update encryption options doc for SCRAM-SHA-256

[Peter Eisentraut]

On 2/2/18 18:42, PG Doc comments form wrote:
> The following documentation comment has been logged on the website:
> 
> Page: https://www.postgresql.org/docs/10/static/encryption-options.html
> Description:
> 
> Section "18.8. Encryption Options" only mentions MD5 as the password storage
> encryption mechanism, although PostgreSQL 10 introduced the superior SHA256
> - somebody looking at the docs would get a bad idea of PostgreSQL's
> capabilities...

I propose the attached patch.  I have combined the password storage and
password transmission items, because I don't want to go into the details
of how SCRAM works on the wire.

-- 
Peter Eisentraut  http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From 34eff9bd65ca051c3ba173476e3f9360ee0d51b9 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut 
Date: Sat, 3 Feb 2018 11:29:23 -0500
Subject: [PATCH] doc: Update mentions of MD5 in the documentation

---
 doc/src/sgml/runtime.sgml | 34 +-
 1 file changed, 9 insertions(+), 25 deletions(-)

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index d162acb2e8..71f02300c2 100644
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -2023,16 +2023,18 @@ Encryption Options
   
 
   
-   Password Storage Encryption
+   Password Encryption

 
 
- By default, database user passwords are stored as MD5 hashes, so
- the administrator cannot determine the actual password assigned
- to the user. If MD5 encryption is used for client authentication,
- the unencrypted password is never even temporarily present on the
- server because the client MD5-encrypts it before being sent
- across the network.
+ Database user passwords are stored as hashes (determined by the setting
+ ), so the administrator cannot
+ determine the actual password assigned to the user. If SCRAM or MD5
+ encryption is used for client authentication, the unencrypted password is
+ never even temporarily present on the server because the client encrypts
+ it before being sent across the network. SCRAM is preferred, because it
+ is an Internet standard and is more secure than the PostgreSQL-specific
+ MD5 authentication protocol.
 

   
@@ -2086,24 +2088,6 @@ Encryption Options

   
 
-  
-   Encrypting Passwords Across A Network
-
-   
- 
-  The MD5 authentication method double-encrypts the
-  password on the client before sending it to the server. It first
-  MD5-encrypts it based on the user name, and then encrypts it
-  based on a random salt sent by the server when the database
-  connection was made. It is this double-encrypted value that is
-  sent over the network to the server. Double-encryption not only
-  prevents the password from being discovered, it also prevents
-  another connection from using the same encrypted password to
-  connect to the database server at a later time.
- 
-
-  
-
   
Encrypting Data Across A Network
 
-- 
2.16.1

Update encryption options doc for SCRAM-SHA-256

[PG Doc comments form]

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/10/static/encryption-options.html
Description:

Section "18.8. Encryption Options" only mentions MD5 as the password storage
encryption mechanism, although PostgreSQL 10 introduced the superior SHA256
- somebody looking at the docs would get a bad idea of PostgreSQL's
capabilities...