Commit 7ba07c80 authored by Steve Holme's avatar Steve Holme
Browse files

smtp: Fixed non-escaping of dot character at beginning of line 

A dot character at the beginning of a line would not be escaped to a
double dot as required by RFC-2821, instead it would be deleted by the
mail server. Please see section 4.5.2 of the RFC for more information.

Note: This fix also simplifies the detection of repeated CRLF.CRLF
combinations, such as CRLF.CRLF.CRLF, a little rather than having to
advance the eob counter to 2.
parent fec096f1

lib/smtp.c

+12 −16
Original line number Diff line number Diff line
@@ -1929,9 +1929,11 @@ static CURLcode smtp_setup_connection(struct connectdata *conn) 


CURLcode Curl_smtp_escape_eob(struct connectdata *conn, ssize_t nread)

{

  /* When sending SMTP payload, we must detect CRLF.CRLF sequences in

   * the data and make sure it is sent as CRLF..CRLF instead, as

   * otherwise it will wrongly be detected as end of data by the server.

  /* When sending a SMTP payload we must detect CRLF. sequences making sure

     they are sent as CRLF.. instead, as a . on the beginning of a line will

     be deleted by the server when not part of an EOB terminator and a

     genuine CRLF.CRLF which isn't escaped will wrongly be detected as end of

     data by the server.

  */

  ssize_t i;

  ssize_t si;
@@ -1965,18 +1967,12 @@ CURLcode Curl_smtp_escape_eob(struct connectdata *conn, ssize_t nread) 
        smtpc->eob = 0;

    }



    if(SMTP_EOB_LEN == smtpc->eob) {

      /* It matched, copy the replacement data to the target buffer

         instead. Note that the replacement does not contain the

         trailing CRLF but we instead continue to match on that one

         to deal with repeated sequences. Like CRLF.CRLF.CRLF etc

      */

      memcpy(&data->state.scratch[si], SMTP_EOB_REPL,

             SMTP_EOB_REPL_LEN);

    /* Do we have a match for CRLF. as per RFC-2821, sect. 4.5.2 */

    if(SMTP_EOB_FIND_LEN == smtpc->eob) {

      /* Copy the replacement data to the target buffer */

      memcpy(&data->state.scratch[si], SMTP_EOB_REPL, SMTP_EOB_REPL_LEN);

      si += SMTP_EOB_REPL_LEN;



      /* Start over at two bytes */

      smtpc->eob = 2;

      smtpc->eob = 0;

    }

    else if(!smtpc->eob)

      data->state.scratch[si++] = data->req.upload_fromhere[i];

lib/smtp.h

+1 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ extern const struct Curl_handler Curl_handler_smtps; 
/* this is the 5-bytes End-Of-Body marker for SMTP */

#define SMTP_EOB "\x0d\x0a\x2e\x0d\x0a"

#define SMTP_EOB_LEN 5

#define SMTP_EOB_FIND_LEN 3



/* if found in data, replace it with this string instead */

#define SMTP_EOB_REPL "\x0d\x0a\x2e\x2e"