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/* ========================================================================
* Copyright 1988-2006 University of Washington
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
*
* ========================================================================
*/
/*
* Program: Plain authenticator
*
* Author: Mark Crispin
* Networks and Distributed Computing
* Computing & Communications
* University of Washington
* Administration Building, AG-44
* Seattle, WA 98195
* Internet: MRC@CAC.Washington.EDU
*
* Date: 22 September 1998
* Last Edited: 30 August 2006
*/
long auth_plain_client (authchallenge_t challenger,authrespond_t responder,
char *service,NETMBX *mb,void *stream,
unsigned long *trial,char *user);
char *auth_plain_server (authresponse_t responder,int argc,char *argv[]);
AUTHENTICATOR auth_pla = {
AU_AUTHUSER | AU_HIDE, /* allow authuser, hidden */
"PLAIN", /* authenticator name */
NIL, /* always valid */
auth_plain_client, /* client method */
auth_plain_server, /* server method */
NIL /* next authenticator */
};
/* Client authenticator
* Accepts: challenger function
* responder function
* SASL service name
* parsed network mailbox structure
* stream argument for functions
* pointer to current trial count
* returned user name
* Returns: T if success, NIL otherwise, number of trials incremented if retry
*/
long auth_plain_client (authchallenge_t challenger,authrespond_t responder,
char *service,NETMBX *mb,void *stream,
unsigned long *trial,char *user)
{
char *u, *pwd = NIL;
void *challenge;
unsigned long clen;
long ret = NIL;
/* snarl if not SSL/TLS session */
if (!mb->sslflag && !mb->tlsflag)
mm_log ("SECURITY PROBLEM: insecure server advertised AUTH=PLAIN",WARN);
/* get initial (empty) challenge */
if ((challenge = (*challenger) (stream,&clen)) != NULL) {
fs_give ((void **) &challenge);
if (clen) { /* abort if challenge non-empty */
mm_log ("Server bug: non-empty initial PLAIN challenge",WARN);
(*responder) (stream,NIL,0);
ret = LONGT; /* will get a BAD response back */
}
mm_login (mb,user, &pwd,*trial);
if (!pwd) { /* empty challenge or user requested abort */
(*responder) (stream,NIL,0);
*trial = 0; /* cancel subsequent attempts */
ret = LONGT; /* will get a BAD response back */
}
else {
unsigned long rlen =
strlen (mb->authuser) + strlen (user) + strlen (pwd) + 2;
char *response = (char *) fs_get (rlen);
char *t = response; /* copy authorization id */
if (mb->authuser[0]) for (u = user; *u; *t++ = *u++);
*t++ = '\0'; /* delimiting NUL */
/* copy authentication id */
for (u = mb->authuser[0] ? mb->authuser : user; *u; *t++ = *u++);
*t++ = '\0'; /* delimiting NUL */
/* copy password */
for (u = pwd; *u; *t++ = *u++);
/* send credentials */
if ((*responder) (stream,response,rlen)) {
if ((challenge = (*challenger) (stream,&clen)) != NULL)
fs_give ((void **) &challenge);
else {
++*trial; /* can try again if necessary */
ret = LONGT; /* check the authentication */
}
}
memset (response,0,rlen); /* erase credentials */
fs_give ((void **) &response);
fs_give ((void **) &pwd);
}
}
if(pwd) fs_give ((void **) &pwd);
if (!ret) *trial = 65535; /* don't retry if bad protocol */
return ret;
}
/* Server authenticator
* Accepts: responder function
* argument count
* argument vector
* Returns: authenticated user name or NIL
*/
char *auth_plain_server (authresponse_t responder,int argc,char *argv[])
{
char *ret = NIL;
char *user,*aid,*pass;
unsigned long len;
/* get user name */
if ((aid = (*responder) ("",0,&len)) != NULL) {
/* note: responders null-terminate */
if ((((unsigned long) ((user = aid + strlen (aid) + 1) - aid)) < len) &&
(((unsigned long) ((pass = user + strlen (user) + 1) - aid)) < len) &&
(((unsigned long) ((pass + strlen (pass)) - aid)) == len) &&
(*aid ? server_login (aid,pass,user,argc,argv) :
server_login (user,pass,NIL,argc,argv))) ret = myusername ();
fs_give ((void **) &aid);
}
return ret;
}
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