Thread: [GENERAL] pgAdmin4 needs information of v10 SCRAM authentication

On Fri, Apr 21, 2017 at 3:27 PM, Akshay Joshi
<akshay.joshi@enterprisedb.com> wrote:
> from passlib.hash import scram
> hash = scram.encrypt(data['newPassword']) -- This function provide password for all the supported digest like [md5,
sha-1,sha-256, sha-512]. Didn't work I have tried with all the passwords. 
> test = scram.extract_digest_info(hash, "sha-256") -- This function extract info for specified digest "sha-256". I
haveretrieve the password which was in hexadecimal. Didn't work as well. 
>
> Now I am stuck here and no clue how to encrypt/decrypt the password for SCRAM authentication. Can someone guide me
outhere. 

Here you go:
https://www.postgresql.org/message-id/76ac7e67-4e3a-f4df-e087-fbac90151907@iki.fi
--
Michael

On Fri, Apr 21, 2017 at 3:43 PM, Akshay Joshi
<akshay.joshi@enterprisedb.com> wrote:
>    Thanks Michael, will check this.

One thing I forgot to mention... Both StoredKey and ServerKey are now
encoded in hex, but there is still an open item related to the
handling of psql's \password on which I have written a patch to switch
their encoding to base64 for simplicity. Not sure what is Heikki's
take on the matter, but I would recommend to be careful about that. My
last set of patches is here:
https://www.postgresql.org/message-id/CAB7nPqSbsCBCxy8-DtwzRxYgTnbGUtY4uFEkLQhG=R=uo=g8Fw@mail.gmail.com
--
Michael

On Mon, Apr 24, 2017 at 3:04 PM, Akshay Joshi
<akshay.joshi@enterprisedb.com> wrote:
>    I have gone through this, but still facing issue to encrypt/change the database server password. In pgAdmin4 we
have"Change Password" feature where user will enter the old and new password for the database server, now we will have
toencrypt it (in Python) as per SCRAM standards and set it to the database. 

By using SET password_encryption = 'scram-sha-256' and sending the raw
password you would be able to hash the password correctly. Or you
could just mimic scram_build_password() (routine in Postgres code to
generate that correctly).

>   The example you have given in https://www.postgresql.org/message-id/76ac7e67-4e3a-f4df-e087-fbac90151907@iki.fi I
havebelow questions: 
> To encode the password you already have entry from pg_authid table which won't be possible for non superuser to
accessthat table. How we can get that value from pg_authid table or do we have any other solution to this. 

I don't understand this question, any user can update this field using
CREATE/ALTER ROLE, and the client has no need to know this value for
the exchange.

> For constructing  the whole client-final-message, we need to calculate  ClientSignature and ClientProof, which depend
onthe nonces, and is  therefore different on every authentication exchange. How to calculate ClientSignature and
ClientProof?
>   Can you please guide me here, how can we achieve that in python.

You will need a C equivalent of what is proposed in fe-auth-scram.c in
the Postgres code to build the messages that are exchanged from the
server, see particularly calculate_client_proof() which describes step
by step the calculation of the client proof when building the last
message for the client. I didn't check in details, but the routines
are the same as in the message above. The format of the hashed
password has changed a bit since commit 68e61ee though.
--
Michael