Commit 566a3638 authored by Steve Holme's avatar Steve Holme
Browse files

smtp: Added support for the STARTTLS capability (Part Two) 

Added honoring of the tls_supported flag when starting a TLS upgrade
rather than unconditionally attempting it. If the use_ssl flag is set
to CURLUSESSL_TRY and the server doesn't support TLS upgrades then the
connection will continue to authenticate. If this flag is set to
CURLUSESSL_ALL then the connection will complete with a failure as it
did previously.
parent e0f4af40

lib/smtp.c

+13 −3
Original line number Diff line number Diff line
@@ -334,6 +334,7 @@ static CURLcode smtp_state_ehlo(struct connectdata *conn) 
  smtpc->authmechs = 0;         /* No known authentication mechanisms yet */

  smtpc->authused = 0;          /* Clear the authentication mechanism used

                                   for esmtp connections */

  smtpc->tls_supported = FALSE; /* Clear the TLS capability */



  /* Send the EHLO command */

  result = Curl_pp_sendf(&smtpc->pp, "EHLO %s", smtpc->domain);
@@ -553,6 +554,7 @@ static CURLcode smtp_state_ehlo_resp(struct connectdata *conn, int smtpcode, 
{

  CURLcode result = CURLE_OK;

  struct SessionHandle *data = conn->data;

  struct smtp_conn *smtpc = &conn->proto.smtpc;



  (void)instate; /* no use for this yet */
@@ -566,9 +568,17 @@ static CURLcode smtp_state_ehlo_resp(struct connectdata *conn, int smtpcode, 
    }

  }

  else if(data->set.use_ssl && !conn->ssl[FIRSTSOCKET].use) {

    /* We don't have a SSL/TLS connection yet, but SSL is requested. Switch

       to TLS connection now */

    /* We don't have a SSL/TLS connection yet, but SSL is requested */

    if(smtpc->tls_supported)

      /* Switch to TLS connection now */

      result = smtp_state_starttls(conn);

    else if(data->set.use_ssl == CURLUSESSL_TRY)

      /* Fallback and carry on with authentication */

      result = smtp_authenticate(conn);

    else {

      failf(data, "STARTTLS not supported.");

      result = CURLE_USE_SSL_FAILED;

    }

  }

  else

    result = smtp_authenticate(conn);