Viewing file:  auth_gss.c (14.25 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* ========================================================================
* 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: GSSAPI 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: 12 January 1998
* Last Edited: 30 August 2006
*/
long auth_gssapi_valid (void);
long auth_gssapi_client (authchallenge_t challenger,authrespond_t responder,
char *service,NETMBX *mb,void *stream,
unsigned long *trial,char *user);
long auth_gssapi_client_work (authchallenge_t challenger,gss_buffer_desc chal,
authrespond_t responder,char *service,NETMBX *mb,
void *stream,char *user,kinit_t ki);
char *auth_gssapi_server (authresponse_t responder,int argc,char *argv[]);
AUTHENTICATOR auth_gss = {
AU_SECURE | AU_AUTHUSER, /* secure authenticator */
"GSSAPI", /* authenticator name */
auth_gssapi_valid, /* check if valid */
auth_gssapi_client, /* client method */
auth_gssapi_server, /* server method */
NIL /* next authenticator */
};
#define AUTH_GSSAPI_P_NONE 1
#define AUTH_GSSAPI_P_INTEGRITY 2
#define AUTH_GSSAPI_P_PRIVACY 4
#define AUTH_GSSAPI_C_MAXSIZE 8192
#define SERVER_LOG(x,y) syslog (LOG_ALERT,x,y)
/* Check if GSSAPI valid on this system
* Returns: T if valid, NIL otherwise
*/
long auth_gssapi_valid (void)
{
char tmp[MAILTMPLEN];
OM_uint32 smn;
gss_buffer_desc buf;
gss_name_t name;
/* make service name */
sprintf (tmp,"%s@%s",(char *) mail_parameters (NIL,GET_SERVICENAME,NIL),
mylocalhost ());
buf.length = strlen (buf.value = tmp);
/* see if can build a name */
if (gss_import_name (&smn,&buf,GSS_C_NT_HOSTBASED_SERVICE,&name) !=
GSS_S_COMPLETE) return NIL;
/* remove server method if no keytab */
if (!kerberos_server_valid ()) auth_gss.server = NIL;
gss_release_name (&smn,&name);/* finished with name */
return LONGT;
}
/* 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_gssapi_client (authchallenge_t challenger,authrespond_t responder,
char *service,NETMBX *mb,void *stream,
unsigned long *trial,char *user)
{
gss_buffer_desc chal;
kinit_t ki = (kinit_t) mail_parameters (NIL,GET_KINIT,NIL);
long ret = NIL;
*trial = 65535; /* never retry */
/* get initial (empty) challenge */
if (chal.value = (*challenger) (stream,(unsigned long *) &chal.length)) {
if (chal.length) { /* abort if challenge non-empty */
mm_log ("Server bug: non-empty initial GSSAPI challenge",WARN);
(*responder) (stream,NIL,0);
ret = LONGT; /* will get a BAD response back */
}
else if (mb->authuser[0] && strcmp (mb->authuser,myusername ())) {
mm_log ("Can't use Kerberos: invalid /authuser",WARN);
(*responder) (stream,NIL,0);
ret = LONGT; /* will get a BAD response back */
}
else ret = auth_gssapi_client_work (challenger,chal,responder,service,mb,
stream,user,ki);
}
return ret;
}
/* Client authenticator worker function
* Accepts: challenger function
* responder function
* SASL service name
* parsed network mailbox structure
* stream argument for functions
* returned user name
* kinit function pointer if should retry with kinit
* Returns: T if success, NIL otherwise
*/
long auth_gssapi_client_work (authchallenge_t challenger,gss_buffer_desc chal,
authrespond_t responder,char *service,NETMBX *mb,
void *stream,char *user,kinit_t ki)
{
char tmp[MAILTMPLEN];
OM_uint32 smj,smn,dsmj,dsmn;
OM_uint32 mctx = 0;
gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
gss_buffer_desc resp,buf;
long i;
int conf;
gss_qop_t qop;
gss_name_t crname = NIL;
blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
void *data;
long ret = NIL;
sprintf (tmp,"%s@%s",service,mb->host);
buf.length = strlen (buf.value = tmp);
/* get service name */
if (gss_import_name (&smn,&buf,GSS_C_NT_HOSTBASED_SERVICE,&crname) !=
GSS_S_COMPLETE) {
mm_log ("Can't import Kerberos service name",WARN);
(*responder) (stream,NIL,0);
}
else {
data = (*bn) (BLOCK_SENSITIVE,NIL);
/* negotiate with KDC */
smj = gss_init_sec_context (&smn,GSS_C_NO_CREDENTIAL,&ctx,crname,NIL,
GSS_C_INTEG_FLAG | GSS_C_MUTUAL_FLAG |
GSS_C_REPLAY_FLAG,0,GSS_C_NO_CHANNEL_BINDINGS,
GSS_C_NO_BUFFER,NIL,&resp,NIL,NIL);
(*bn) (BLOCK_NONSENSITIVE,data);
/* while continuation needed */
while (smj == GSS_S_CONTINUE_NEEDED) {
if (chal.value) fs_give ((void **) &chal.value);
/* send response, get next challenge */
i = (*responder) (stream,resp.value,resp.length) &&
(chal.value = (*challenger) (stream,(unsigned long *) &chal.length));
gss_release_buffer (&smn,&resp);
if (i) { /* negotiate continuation with KDC */
data = (*bn) (BLOCK_SENSITIVE,NIL);
switch (smj = /* make sure continuation going OK */
gss_init_sec_context (&smn,GSS_C_NO_CREDENTIAL,&ctx,
crname,GSS_C_NO_OID,GSS_C_INTEG_FLAG |
GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG,0,
GSS_C_NO_CHANNEL_BINDINGS,&chal,NIL,
&resp,NIL,NIL)) {
case GSS_S_CONTINUE_NEEDED:
case GSS_S_COMPLETE:
break;
default: /* error, don't need context any more */
gss_delete_sec_context (&smn,&ctx,NIL);
}
(*bn) (BLOCK_NONSENSITIVE,data);
}
else { /* error in continuation */
mm_log ("Error in negotiating Kerberos continuation",WARN);
(*responder) (stream,NIL,0);
/* don't need context any more */
gss_delete_sec_context (&smn,&ctx,NIL);
break;
}
}
switch (smj) { /* done - deal with final condition */
case GSS_S_COMPLETE:
if (chal.value) fs_give ((void **) &chal.value);
/* get prot mechanisms and max size */
if ((*responder) (stream,resp.value ? resp.value : "",resp.length) &&
(chal.value = (*challenger) (stream,(unsigned long *)&chal.length))&&
(gss_unwrap (&smn,ctx,&chal,&resp,&conf,&qop) == GSS_S_COMPLETE) &&
(resp.length >= 4) && (*((char *) resp.value) & AUTH_GSSAPI_P_NONE)){
/* make copy of flags and length */
memcpy (tmp,resp.value,4);
gss_release_buffer (&smn,&resp);
/* no session protection */
tmp[0] = AUTH_GSSAPI_P_NONE;
/* install user name */
strcpy (tmp+4,strcpy (user,mb->user[0] ? mb->user : myusername ()));
buf.value = tmp; buf.length = strlen (user) + 4;
/* successful negotiation */
switch (smj = gss_wrap (&smn,ctx,NIL,qop,&buf,&conf,&resp)) {
case GSS_S_COMPLETE:
if ((*responder) (stream,resp.value,resp.length)) ret = T;
gss_release_buffer (&smn,&resp);
break;
default:
do switch (dsmj = gss_display_status (&dsmn,smj,GSS_C_GSS_CODE,
GSS_C_NO_OID,&mctx,&resp)) {
case GSS_S_COMPLETE:
mctx = 0;
case GSS_S_CONTINUE_NEEDED:
sprintf (tmp,"Unknown gss_wrap failure: %s",(char *) resp.value);
mm_log (tmp,WARN);
gss_release_buffer (&dsmn,&resp);
}
while (dsmj == GSS_S_CONTINUE_NEEDED);
do switch (dsmj = gss_display_status (&dsmn,smn,GSS_C_MECH_CODE,
GSS_C_NO_OID,&mctx,&resp)) {
case GSS_S_COMPLETE:
case GSS_S_CONTINUE_NEEDED:
sprintf (tmp,"GSSAPI mechanism status: %s",(char *) resp.value);
mm_log (tmp,WARN);
gss_release_buffer (&dsmn,&resp);
}
while (dsmj == GSS_S_CONTINUE_NEEDED);
(*responder) (stream,NIL,0);
}
}
/* flush final challenge */
if (chal.value) fs_give ((void **) &chal.value);
/* don't need context any more */
gss_delete_sec_context (&smn,&ctx,NIL);
break;
case GSS_S_CREDENTIALS_EXPIRED:
if (chal.value) fs_give ((void **) &chal.value);
/* retry if application kinits */
if (ki && (*ki) (mb->host,"Kerberos credentials expired"))
ret = auth_gssapi_client_work (challenger,chal,responder,service,mb,
stream,user,NIL);
else { /* application can't kinit */
sprintf (tmp,"Kerberos credentials expired (try running kinit) for %s",
mb->host);
mm_log (tmp,WARN);
(*responder) (stream,NIL,0);
}
break;
case GSS_S_FAILURE:
if (chal.value) fs_give ((void **) &chal.value);
do switch (dsmj = gss_display_status (&dsmn,smn,GSS_C_MECH_CODE,
GSS_C_NO_OID,&mctx,&resp)) {
case GSS_S_COMPLETE: /* end of message, can kinit? */
if (ki && kerberos_try_kinit (smn) &&
(*ki) (mb->host,(char *) resp.value)) {
gss_release_buffer (&dsmn,&resp);
ret = auth_gssapi_client_work (challenger,chal,responder,service,mb,
stream,user,NIL);
break; /* done */
}
else (*responder) (stream,NIL,0);
case GSS_S_CONTINUE_NEEDED:
sprintf (tmp,kerberos_try_kinit (smn) ?
"Kerberos error: %.80s (try running kinit) for %.80s" :
"GSSAPI failure: %s for %.80s",(char *) resp.value,mb->host);
mm_log (tmp,WARN);
gss_release_buffer (&dsmn,&resp);
} while (dsmj == GSS_S_CONTINUE_NEEDED);
break;
default: /* miscellaneous errors */
if (chal.value) fs_give ((void **) &chal.value);
do switch (dsmj = gss_display_status (&dsmn,smj,GSS_C_GSS_CODE,
GSS_C_NO_OID,&mctx,&resp)) {
case GSS_S_COMPLETE:
mctx = 0;
case GSS_S_CONTINUE_NEEDED:
sprintf (tmp,"Unknown GSSAPI failure: %s",(char *) resp.value);
mm_log (tmp,WARN);
gss_release_buffer (&dsmn,&resp);
}
while (dsmj == GSS_S_CONTINUE_NEEDED);
do switch (dsmj = gss_display_status (&dsmn,smn,GSS_C_MECH_CODE,
GSS_C_NO_OID,&mctx,&resp)) {
case GSS_S_COMPLETE:
case GSS_S_CONTINUE_NEEDED:
sprintf (tmp,"GSSAPI mechanism status: %s",(char *) resp.value);
mm_log (tmp,WARN);
gss_release_buffer (&dsmn,&resp);
}
while (dsmj == GSS_S_CONTINUE_NEEDED);
(*responder) (stream,NIL,0);
break;
}
/* finished with credentials name */
if (crname) gss_release_name (&smn,&crname);
}
return ret; /* return status */
}
/* Server authenticator
* Accepts: responder function
* argument count
* argument vector
* Returns: authenticated user name or NIL
*/
char *auth_gssapi_server (authresponse_t responder,int argc,char *argv[])
{
char *ret = NIL;
char tmp[MAILTMPLEN];
unsigned long maxsize = htonl (AUTH_GSSAPI_C_MAXSIZE);
int conf;
OM_uint32 smj,smn,dsmj,dsmn,flags;
OM_uint32 mctx = 0;
gss_name_t crname,name;
gss_OID mech;
gss_buffer_desc chal,resp,buf;
gss_cred_id_t crd;
gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
gss_qop_t qop = GSS_C_QOP_DEFAULT;
/* make service name */
sprintf (tmp,"%s@%s",(char *) mail_parameters (NIL,GET_SERVICENAME,NIL),
tcp_serverhost ());
buf.length = strlen (buf.value = tmp);
/* acquire credentials */
if ((gss_import_name (&smn,&buf,GSS_C_NT_HOSTBASED_SERVICE,&crname)) ==
GSS_S_COMPLETE) {
if ((smj = gss_acquire_cred (&smn,crname,0,NIL,GSS_C_ACCEPT,&crd,NIL,NIL))
== GSS_S_COMPLETE) {
if (resp.value = (*responder) ("",0,(unsigned long *) &resp.length)) {
do { /* negotiate authentication */
smj = gss_accept_sec_context (&smn,&ctx,crd,&resp,
GSS_C_NO_CHANNEL_BINDINGS,&name,&mech,
&chal,&flags,NIL,NIL);
/* don't need response any more */
fs_give ((void **) &resp.value);
switch (smj) { /* how did it go? */
case GSS_S_COMPLETE: /* successful */
case GSS_S_CONTINUE_NEEDED:
if (chal.value) { /* send challenge, get next response */
resp.value = (*responder) (chal.value,chal.length,
(unsigned long *) &resp.length);
gss_release_buffer (&smn,&chal);
}
break;
}
}
while (resp.value && resp.length && (smj == GSS_S_CONTINUE_NEEDED));
/* successful exchange? */
if ((smj == GSS_S_COMPLETE) &&
(gss_display_name (&smn,name,&buf,&mech) == GSS_S_COMPLETE)) {
/* send security and size */
memcpy (resp.value = tmp,(void *) &maxsize,resp.length = 4);
tmp[0] = AUTH_GSSAPI_P_NONE;
if (gss_wrap (&smn,ctx,NIL,qop,&resp,&conf,&chal) == GSS_S_COMPLETE){
resp.value = (*responder) (chal.value,chal.length,
(unsigned long *) &resp.length);
gss_release_buffer (&smn,&chal);
if (gss_unwrap (&smn,ctx,&resp,&chal,&conf,&qop)==GSS_S_COMPLETE) {
/* client request valid */
if (chal.value && (chal.length > 4) &&
(chal.length < (MAILTMPLEN - 1)) &&
memcpy (tmp,chal.value,chal.length) &&
(tmp[0] & AUTH_GSSAPI_P_NONE)) {
/* tie off authorization ID */
tmp[chal.length] = '\0';
ret = kerberos_login (tmp+4,buf.value,argc,argv);
}
/* done with user name */
gss_release_buffer (&smn,&chal);
}
/* finished with response */
fs_give ((void **) &resp.value);
}
/* don't need name buffer any more */
gss_release_buffer (&smn,&buf);
}
/* don't need client name any more */
gss_release_name (&smn,&name);
/* don't need context any more */
if (ctx != GSS_C_NO_CONTEXT) gss_delete_sec_context (&smn,&ctx,NIL);
}
/* finished with credentials */
gss_release_cred (&smn,&crd);
}
else { /* can't acquire credentials! */
if (gss_display_name (&dsmn,crname,&buf,&mech) == GSS_S_COMPLETE)
SERVER_LOG ("Failed to acquire credentials for %s",buf.value);
if (smj != GSS_S_FAILURE) do
switch (dsmj = gss_display_status (&dsmn,smj,GSS_C_GSS_CODE,
GSS_C_NO_OID,&mctx,&resp)) {
case GSS_S_COMPLETE:
mctx = 0;
case GSS_S_CONTINUE_NEEDED:
SERVER_LOG ("Unknown GSSAPI failure: %s",resp.value);
gss_release_buffer (&dsmn,&resp);
}
while (dsmj == GSS_S_CONTINUE_NEEDED);
do switch (dsmj = gss_display_status (&dsmn,smn,GSS_C_MECH_CODE,
GSS_C_NO_OID,&mctx,&resp)) {
case GSS_S_COMPLETE:
case GSS_S_CONTINUE_NEEDED:
SERVER_LOG ("GSSAPI mechanism status: %s",resp.value);
gss_release_buffer (&dsmn,&resp);
}
while (dsmj == GSS_S_CONTINUE_NEEDED);
}
/* finished with credentials name */
gss_release_name (&smn,&crname);
}
return ret; /* return status */
}
|