Your emails come through to the mailing list, you can verify this from https://dovecot.org/pipermail/dovecot

Try turning on rawlogs for the oauth2 requests and see what google is sending you?

You can also try log_debug=category=oauth2 (2.3.13) to get more debug logs from oauth2.

Aki

> On 22/01/2021 02:51 福田泰葵 <taiki.fukuda@justsystems.com> wrote:
>
>
> Dear Mr. Tuomi,
>
> This is just to remind you that I haven’t received your response to my e-mail I sent you. I’m afraid my e-mail may not have reached you.
> If you have any questions or concerns, please let me know.
>
> Best regards,
>
>
> 2021年1月19日(火) 18:52 福田泰葵 <taiki.fukuda@justsystems.com>:
> > Thank you for your reply.
> > But I need more help.
> > How do I set request parameter of https://www.googleapis.com/oauth2/v2/userinfo？
> > Logs：
> > dovecot[30307]: lmtp(30320): Connect from 10.243.148.174
> > dovecot[30307]: lmtp(30320): Disconnect from 10.243.148.174 (http://10.243.148.174): Remote closed connection (state=READY)
> > dovecot[30307]: auth: Debug: http-client: host www.googleapis.com (http://www.googleapis.com): Host created
> > dovecot[30307]: auth: Debug: http-client: host www.googleapis.com (http://www.googleapis.com): Host session created
> > dovecot[30307]: auth: Debug: http-client: host www.googleapis.com (http://www.googleapis.com): Need to perform DNS lookup
> > dovecot[30307]: auth: Debug: http-client: host www.googleapis.com (http://www.googleapis.com): Performing asynchronous DNS lookup
> > dovecot[30307]: auth: Debug: http-client[1]: request [Req1: GET https://www.googleapis.com/oauth2/v2/userinfo]: Submitted (requests left=1)
> > dovecot[30307]: auth: Debug: http-client: host www.googleapis.com (http://www.googleapis.com): DNS lookup successful; got 20 IPs
> > dovecot[30307]: auth: Debug: http-client: peer 172.217.31.170:443 (http://172.217.31.170:443) (shared): Peer created
> > dovecot[30307]: auth: Debug: http-client: peer 172.217.31.170:443 (http://172.217.31.170:443): Peer pool created
> > dovecot[30307]: auth: Debug: http-client[1]: peer 172.217.31.170:443 (http://172.217.31.170:443): Peer created
> > dovecot[30307]: auth: Debug: http-client[1]: queue https://www.googleapis.com:443: Setting up connection to 172.217.31.170:443 (http://172.217.31.170:443) (SSL=www.googleapis.com (http://www.googleapis.com)) (1 requests pending)
> > dovecot[30307]: auth: Debug: http-client[1]: peer 172.217.31.170:443 (http://172.217.31.170:443): Linked queue https://www.googleapis.com:443 (1 queues linked)
> > dovecot[30307]: auth: Debug: http-client[1]: queue https://www.googleapis.com:443: Started new connection to 172.217.31.170:443 (http://172.217.31.170:443) (SSL=www.googleapis.com (http://www.googleapis.com))
> > dovecot[30307]: auth: Debug: http-client[1]: peer 172.217.31.170:443 (http://172.217.31.170:443): Creating 1 new connections to handle requests (already 0 usable, connecting to 0, closing 0)
> > dovecot[30307]: auth: Debug: http-client[1]: peer 172.217.31.170:443 (http://172.217.31.170:443): Making new connection 1 of 1 (0 connections exist, 0 pending)
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Connecting
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Waiting for connect (fd=22) to finish for max 0 msecs
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: HTTPS connection created (1 parallel connections exist)
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Client connected (fd=22)
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Connected
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Starting SSL handshake
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x10, ret=1: before/connect initialization
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: before/connect initialization
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv2/v3 write client hello A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1002, ret=-1: SSLv2/v3 read server hello A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1002, ret=-1: SSLv2/v3 read server hello A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1002, ret=-1: SSLv2/v3 read server hello A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 read server hello A
> > dovecot[30307]: auth: Received valid SSL certificate: /OU=GlobalSign Root CA - R2/O=GlobalSign/CN=GlobalSign
> > dovecot[30307]: auth: Received valid SSL certificate: /C=US/O=Google Trust Services/CN=GTS CA 1O1
> > dovecot[30307]: auth: Received valid SSL certificate: /C=US/ST=California/L=Mountain View/O=Google LLC/CN=upload.video.google.com (http://upload.video.google.com)
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 read server certificate A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 read server key exchange A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 read server done A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 write client key exchange A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 write change cipher spec A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 write finished A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 flush data
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1002, ret=-1: SSLv3 read finished A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1002, ret=-1: SSLv3 read finished A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1002, ret=-1: SSLv3 read finished A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1002, ret=-1: SSLv3 read finished A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1001, ret=1: SSLv3 read finished A
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x20, ret=1: SSL negotiation finished successfully
> > dovecot[30307]: auth: Debug: www.googleapis.com (http://www.googleapis.com): SSL: where=0x1002, ret=1: SSL negotiation finished successfully
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: SSL handshake successful
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Ready for requests
> > dovecot[30307]: auth: Debug: http-client[1]: peer 172.217.31.170:443 (http://172.217.31.170:443): Successfully connected (1 connections exist, 0 pending)
> > dovecot[30307]: auth: Debug: http-client: peer 172.217.31.170:443 (http://172.217.31.170:443): Successfully connected (1 connections exist, 0 pending)
> > dovecot[30307]: auth: Debug: http-client[1]: peer 172.217.31.170:443 (http://172.217.31.170:443): Using 1 idle connections to handle 1 requests (1 total connections ready)
> > dovecot[30307]: auth: Debug: http-client[1]: queue https://www.googleapis.com:443: Connection to peer 172.217.31.170:443 (http://172.217.31.170:443) claimed request [Req1: GET https://www.googleapis.com/oauth2/v2/userinfo]
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Claimed request [Req1: GET https://www.googleapis.com/oauth2/v2/userinfo]
> > dovecot[30307]: auth: Debug: http-client[1]: request [Req1: GET https://www.googleapis.com/oauth2/v2/userinfo]: Sent header
> > dovecot[30307]: auth: Debug: http-client[1]: peer 172.217.31.170:443 (http://172.217.31.170:443): No more requests to service for this peer (1 connections exist, 0 pending)
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Got 401 response for request [Req1: GET https://www.googleapis.com/oauth2/v2/userinfo]: Unauthorized (took 46 ms + 59 ms in queue)
> > dovecot[30307]: auth: Error: oauth2(fukudata,118.103.29.199,<mgm9vz25BTZ2Zx3H>): oauth2 failed: No username returned
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: Response payload stream destroyed (0 ms after initial response)
> > dovecot[30307]: auth: Debug: http-client[1]: request [Req1: GET https://www.googleapis.com/oauth2/v2/userinfo]: Finished
> > dovecot[30307]: auth: Debug: http-client[1]: queue https://www.googleapis.com:443: Dropping request [Req1: GET https://www.googleapis.com/oauth2/v2/userinfo]
> > dovecot[30307]: auth: Debug: http-client: host www.googleapis.com (http://www.googleapis.com): Host is idle (timeout = 1799906 msecs)
> > dovecot[30307]: auth: Debug: http-client[1]: request [Req1: GET https://www.googleapis.com/oauth2/v2/userinfo]: Free (requests left=1)
> > dovecot[30307]: auth: Debug: http-client[1]: peer 172.217.31.170:443 (http://172.217.31.170:443): No requests to service for this peer (1 connections exist, 0 pending)
> > dovecot[30307]: auth: Debug: http-client: conn 172.217.31.170:443 (http://172.217.31.170:443) [1]: No more requests queued; going idle (timeout = 60000 msecs)
> > dovecot[30307]: lmtp(30309): Connect from 10.243.148.174
> > dovecot[30307]: lmtp(30309): Disconnect from 10.243.148.174 (http://10.243.148.174): Remote closed connection (state=READY)
> > dovecot[30307]: lmtp(30320): Connect from 10.243.148.174
> > dovecot[30307]: lmtp(30320): Disconnect from 10.243.148.174 (http://10.243.148.174): Remote closed connection (state=READY)
> > dovecot[30307]: lmtp(30320): Connect from 10.243.148.174
> > dovecot[30307]: lmtp(30320): Disconnect from 10.243.148.174 (http://10.243.148.174): Remote closed connection (state=READY)
> > dovecot[30307]: lmtp(30309): Connect from 10.243.148.174
> > dovecot[30307]: lmtp(30309): Disconnect from 10.243.148.174 (http://10.243.148.174): Remote closed connection (state=READY)
> > dovecot[30307]: lmtp(30309): Connect from 10.243.148.110
> > dovecot[30307]: lmtp(30309): Disconnect from 10.243.148.110 (http://10.243.148.110): Remote closed connection (state=READY)
> > dovecot[30307]: lmtp(30309): Connect from 10.243.148.110
> > dovecot[30307]: lmtp(30309): Disconnect from 10.243.148.110 (http://10.243.148.110): Remote closed connection (state=READY)
> > dovecot[30307]: lmtp(30309): Connect from 10.243.148.110
> > dovecot[30307]: lmtp(30309): Disconnect from 10.243.148.110 (http://10.243.148.110): Remote closed connection (state=READY)
> > sshd[30475]: Connection closed by 10.243.150.20 port 48174 [preauth]
> > dovecot[30307]: imap-login: Disconnected (auth service reported temporary failure): user=<fukudata>, method=PLAIN, rip=118.103.29.199, lip=10.243.150.190, session=<mgm9vz25BTZ2Zx3H>
> > dovecot[30307]: lmtp(30317): Connect from 10.243.148.174
> > dovecot[30307]: lmtp(30317): Disconnect from 10.243.148.174 (http://10.243.148.174): Remote closed connection (state=READY)
> >
> > I would appreciate your reply.
> > Yours faithfully,
> > 2021年1月19日(火) 15:34 Aki Tuomi <aki.tuomi@open-xchange.com>:
> >
> > >
> > >  > On 19/01/2021 07:17 福田泰葵 <taiki.fukuda@justsystems.com> wrote:
> > >  >
> > >  >
> > >  > Dear Sir or Madam
> > >  > Unable to build OAuth2.0 authentication to Gmail using dovecot as proxy.
> > >  > I have a question about how to use dovecot as a proxy to perform OAuth 2.0 authentication to Gmail using a mail client.
> > > 
> > >  Mail client is required, in this case, to provide valid oauth2 bearer token. I don't think google supports other ways.
> > > 
> > >  > 1. Is the following all I need to do to authenticate to Gmail using dovecot as a proxy?
> > >  > * passdb
> > >  > passdb {
> > >  > driver = oauth2
> > >  > mechanisms = oauthbearer xoauth2
> > >  > args = /etc/dovecot/dovecot-oauth2.token.conf.ext
> > >  > }
> > >  > passdb {
> > >  > driver = oauth2
> > >  > mechanisms = plain login
> > >  > args = /etc/dovecot/dovecot-oauth2.plain.conf.ext
> > >  > }
> > >  >
> > > 
> > >  The plain config is a way to do 'password grant' authentication. This is when username and password is used to acquire a bearer token.
> > > 
> > >  > * create dovecot-oauth2.token.conf.ext and dovecot-oauth2.plain.conf.ext
> > >  > * create gmail service account api
> > >  > 2. grant_url in dovecot-oauth2.token.conf.ext and dovecot-oauth2.plain.conf.ext is URL for obtaining a Google access token for a web server that I have built myself?
> > >  > 3. I use a Gmail service account, so I don’t need a client ID and secret ID, right?
> > >  > 4. Do I set introspection_url to the URL of my own web server with the access token used for authentication to Google as the response?
> > > 
> > >  No. The introspection URL needs to point to a location where dovecot can figure out more information about the user with token. If I recall correctly, the token endpoint
> > > 
> > >  For gmail, you need to use https://www.googleapis.com/oauth2/v2/userinfo
> > > 
> > >  > 5. The documentation says “pass_attrs = host=127.0.0.1”, but if you are authenticating to Gmail, I should use
> > >  > “pass_attrs = proxy=y host=%{if;%s;eq;imap;imap.gmail.com (http://imap.gmail.com) (http://imap.gmail.com);%{if;%s;eq;pop3;smtp .gmail.com (http://gmail.com) (http://gmail.com);pop.gmail.com (http://pop.gmail.com) (http://pop.gmail.com)}} port=%{if;%s;eq;imap;993;%{if;%s;eq;pop3;587;465}} proxy_mech=xoauth2 pass=%{oauth2:access_token} user=%{oauth2:email oauth2:email}”?
> > > 
> > >  I would use something more readable, like passwd-file driver with username_format=%s
> > > 
> > >  The access token is also imported as %{token} in passdb.
> > > 
> > >  > 6. What is the difference between dovecot-oauth2.token.conf.ext and dovecot-oauth2.plain.conf.ext ? Do I need to configure both?
> > >  > I used https://doc.dovecot.org/configuration_manual/authentication/oauth2/#proxy as a reference.
> > >  > I would appreciate your reply.
> > >  > Yours faithfully,
> > >  > ------------------------------
> > >  > e-mail: taiki.fukuda@justsystems.com
> > >  > TEL: 03-5324-7900
> > >  > mobile: 080-6198-7328
> > >  > ------------------------------
> > > 
> > >  So this might work
> > > 
> > >  /etc/dovecot/oauth2-token.conf.ext
> > > 
> > >  introspection_url = https://www.googleapis.com/oauth2/v2/userinfo
> > >  introspection_mode = auth
> > >  username_attribute = email
> > >  pass_attrs = proxy=y proxy_mech=xoauth2
> > > 
> > >  /etc/dovecot/dovecot.conf
> > > 
> > >  auth_mechanisms = xoauth2 oauthbearer
> > > 
> > >  passdb {
> > >  driver = oauth2
> > >  args = /etc/dovecot/oauth2-token.conf.ext
> > >  result_success = continue-ok
> > >  }
> > > 
> > >  passdb {
> > >  driver = passwd-file
> > >  args = username_format=%s /etc/dovecot/endpoints
> > >  skip = unauthenticated
> > >  }
> > > 
> > >  /etc/dovecot/endpoints
> > > 
> > >  imap::::::: host=imap.gmail.com (http://imap.gmail.com)
> > >  pop3::::::: host=pop3.gmail.com (http://pop3.gmail.com)
> > >  submission::::::: host=smtp.gmail.com (http://smtp.gmail.com)
> > > 
> > >  Aki
> > >