Commit 4e430a8a authored by Steve Holme's avatar Steve Holme
Browse files

pop3: Enhanced the extended authentication mechanism detection 

Enhanced the authentication type / mechanism detection in preparation
for the introduction of APOP support.
parent 6478e1d7

lib/pop3.c

+29 −6
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
 * RFC1939 POP3 protocol

 * RFC2195 CRAM-MD5 authentication

 * RFC2384 POP URL Scheme

 * RFC2449 POP3 Extension Mechanism

 * RFC2595 Using TLS with IMAP, POP3 and ACAP

 * RFC2831 DIGEST-MD5 authentication

 * RFC4616 PLAIN authentication
@@ -212,8 +213,8 @@ static const struct Curl_handler Curl_handler_pop3s_proxy = { 
#endif



/* Function that checks for an ending pop3 status code at the start of the

   given string, but also detects the allowed authentication mechanisms

   according to the CAPA response. */

   given string, but also detects the supported authentication types as well

   as the allowed SASL authentication mechanisms within the CAPA response. */

static int pop3_endofresp(struct pingpong *pp, int *resp)

{

  char *line = pp->linestart_resp;
@@ -239,11 +240,24 @@ static int pop3_endofresp(struct pingpong *pp, int *resp) 
      return TRUE;

    }



    /* We are only interested in the SASL line */

    if(len < 4 || memcmp(line, "SASL", 4)) {

    /* Does the server support clear text? */

    if(len >= 4 && !memcmp(line, "USER", 4)) {

      pop3c->authtypes |= POP3_TYPE_CLEARTEXT;

      return FALSE;

    }



    /* Does the server support APOP? */

    if(len >= 4 && !memcmp(line, "APOP", 4)) {

      pop3c->authtypes |= POP3_TYPE_APOP;

      return FALSE;

    }



    /* Does the server support SASL? */

    if(len < 4 || memcmp(line, "SASL", 4))

      return FALSE;



    pop3c->authtypes |= POP3_TYPE_SASL;



    /* Advance past the SASL keyword */

    line += 4;

    len -= 4;
@@ -524,8 +538,17 @@ static CURLcode pop3_state_capa_resp(struct connectdata *conn, 


  if(pop3code != '+')

    result = pop3_state_user(conn);

  else

  else {

    /* Check supported authentication types by decreasing order of security */

    if(conn->proto.pop3c.authtypes & POP3_TYPE_SASL)

      result = pop3_authenticate(conn);

    else if(conn->proto.pop3c.authtypes & POP3_TYPE_CLEARTEXT)

      result = pop3_state_user(conn);

    else {

      infof(conn->data, "No known authentication types supported!\n");

      result = CURLE_LOGIN_DENIED; /* Other types not supported */

    }

  }



  return result;

}

lib/pop3.h

+7 −1
Original line number Diff line number Diff line
@@ -57,14 +57,20 @@ struct pop3_conn { 
                             have been received so far */

  size_t strip;           /* Number of bytes from the start to ignore as

                             non-body */

  unsigned int authtypes; /* Supported authentication types */

  unsigned int authmechs; /* Accepted SASL authentication mechanisms */

  unsigned int authused;  /* Authentication method used for the connection */

  unsigned int authused;  /* SASL auth mechanism used for the connection */

  pop3state state;        /* Always use pop3.c:state() to change state! */

};



extern const struct Curl_handler Curl_handler_pop3;

extern const struct Curl_handler Curl_handler_pop3s;



/* Authentication type flags */

#define POP3_TYPE_CLEARTEXT 0x0001

#define POP3_TYPE_APOP      0x0002

#define POP3_TYPE_SASL      0x0004



/* This is the 5-bytes End-Of-Body marker for POP3 */

#define POP3_EOB "\x0d\x0a\x2e\x0d\x0a"

#define POP3_EOB_LEN 5