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/*
* Copyright (C) 2000-8 Brendan Cully <brendan@kublai.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/* common SASL helper routines */
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include "mutt.h"
#include "account.h"
#include "mutt_sasl.h"
#include "mutt_socket.h"
#include <errno.h>
#include <netdb.h>
#include <sasl/sasl.h>
#include <sys/socket.h>
#include <netinet/in.h>
static int getnameinfo_err(int ret)
{
int err;
dprint (1, (debugfile, "getnameinfo: "));
switch(ret)
{
case EAI_AGAIN:
dprint (1, (debugfile, "The name could not be resolved at this time. Future attempts may succeed.\n"));
err=SASL_TRYAGAIN;
break;
case EAI_BADFLAGS:
dprint (1, (debugfile, "The flags had an invalid value.\n"));
err=SASL_BADPARAM;
break;
case EAI_FAIL:
dprint (1, (debugfile, "A non-recoverable error occurred.\n"));
err=SASL_FAIL;
break;
case EAI_FAMILY:
dprint (1, (debugfile, "The address family was not recognized or the address length was invalid for the specified family.\n"));
err=SASL_BADPROT;
break;
case EAI_MEMORY:
dprint (1, (debugfile, "There was a memory allocation failure.\n"));
err=SASL_NOMEM;
break;
case EAI_NONAME:
dprint (1, (debugfile, "The name does not resolve for the supplied parameters. NI_NAMEREQD is set and the host's name cannot be located, or both nodename and servname were null.\n"));
err=SASL_FAIL; /* no real equivalent */
break;
case EAI_SYSTEM:
dprint (1, (debugfile, "A system error occurred. The error code can be found in errno(%d,%s)).\n",errno,strerror(errno)));
err=SASL_FAIL; /* no real equivalent */
break;
default:
dprint (1, (debugfile, "Unknown error %d\n",ret));
err=SASL_FAIL; /* no real equivalent */
break;
}
return err;
}
/* arbitrary. SASL will probably use a smaller buffer anyway. OTOH it's
* been a while since I've had access to an SASL server which negotiated
* a protection buffer. */
#define M_SASL_MAXBUF 65536
#define IP_PORT_BUFLEN 1024
static sasl_callback_t mutt_sasl_callbacks[5];
static int mutt_sasl_start (void);
/* callbacks */
static int mutt_sasl_cb_log (void* context, int priority, const char* message);
static int mutt_sasl_cb_authname (void* context, int id, const char** result,
unsigned int* len);
static int mutt_sasl_cb_pass (sasl_conn_t* conn, void* context, int id,
sasl_secret_t** psecret);
/* socket wrappers for a SASL security layer */
static int mutt_sasl_conn_open (CONNECTION* conn);
static int mutt_sasl_conn_close (CONNECTION* conn);
static int mutt_sasl_conn_read (CONNECTION* conn, char* buf, size_t len);
static int mutt_sasl_conn_write (CONNECTION* conn, const char* buf,
size_t count);
static int mutt_sasl_conn_poll (CONNECTION* conn);
/* utility function, stolen from sasl2 sample code */
static int iptostring(const struct sockaddr *addr, socklen_t addrlen,
char *out, unsigned outlen) {
char hbuf[NI_MAXHOST], pbuf[NI_MAXSERV];
int ret;
if(!addr || !out) return SASL_BADPARAM;
ret=getnameinfo(addr, addrlen, hbuf, sizeof(hbuf), pbuf, sizeof(pbuf),
NI_NUMERICHOST |
#ifdef NI_WITHSCOPEID
NI_WITHSCOPEID |
#endif
NI_NUMERICSERV);
if(ret)
return getnameinfo_err(ret);
if(outlen < strlen(hbuf) + strlen(pbuf) + 2)
return SASL_BUFOVER;
snprintf(out, outlen, "%s;%s", hbuf, pbuf);
return SASL_OK;
}
/* mutt_sasl_start: called before doing a SASL exchange - initialises library
* (if necessary). */
int mutt_sasl_start (void)
{
static unsigned char sasl_init = 0;
static sasl_callback_t callbacks[2];
int rc;
if (sasl_init)
return SASL_OK;
/* set up default logging callback */
callbacks[0].id = SASL_CB_LOG;
callbacks[0].proc = mutt_sasl_cb_log;
callbacks[0].context = NULL;
callbacks[1].id = SASL_CB_LIST_END;
callbacks[1].proc = NULL;
callbacks[1].context = NULL;
rc = sasl_client_init (callbacks);
if (rc != SASL_OK)
{
dprint (1, (debugfile, "mutt_sasl_start: libsasl initialisation failed.\n"));
return SASL_FAIL;
}
sasl_init = 1;
return SASL_OK;
}
/* mutt_sasl_client_new: wrapper for sasl_client_new which also sets various
* security properties. If this turns out to be fine for POP too we can
* probably stop exporting mutt_sasl_get_callbacks(). */
int mutt_sasl_client_new (CONNECTION* conn, sasl_conn_t** saslconn)
{
sasl_security_properties_t secprops;
struct sockaddr_storage local, remote;
socklen_t size;
char iplocalport[IP_PORT_BUFLEN], ipremoteport[IP_PORT_BUFLEN];
char* plp = NULL;
char* prp = NULL;
const char* service;
int rc;
if (mutt_sasl_start () != SASL_OK)
return -1;
switch (conn->account.type)
{
case M_ACCT_TYPE_IMAP:
service = "imap";
break;
case M_ACCT_TYPE_POP:
service = "pop";
break;
case M_ACCT_TYPE_SMTP:
service = "smtp";
break;
default:
mutt_error (_("Unknown SASL profile"));
return -1;
}
size = sizeof (local);
if (!getsockname (conn->fd, (struct sockaddr *)&local, &size)) {
if (!iptostring((struct sockaddr *)&local, size, iplocalport,
IP_PORT_BUFLEN) != SASL_OK)
plp = iplocalport;
else
dprint (2, (debugfile, "SASL failed to parse local IP address\n"));
}
else
dprint (2, (debugfile, "SASL failed to get local IP address\n"));
size = sizeof (remote);
if (!getpeername (conn->fd, (struct sockaddr *)&remote, &size)){
if (!iptostring((struct sockaddr *)&remote, size, ipremoteport,
IP_PORT_BUFLEN) != SASL_OK)
prp = ipremoteport;
else
dprint (2, (debugfile, "SASL failed to parse remote IP address\n"));
}
else
dprint (2, (debugfile, "SASL failed to get remote IP address\n"));
dprint (2, (debugfile, "SASL local ip: %s, remote ip:%s\n", NONULL(plp),
NONULL(prp)));
rc = sasl_client_new (service, conn->account.host, plp, prp,
mutt_sasl_get_callbacks (&conn->account), 0, saslconn);
if (rc != SASL_OK)
{
mutt_error (_("Error allocating SASL connection"));
mutt_sleep (2);
return -1;
}
memset (&secprops, 0, sizeof (secprops));
/* Work around a casting bug in the SASL krb4 module */
secprops.max_ssf = 0x7fff;
secprops.maxbufsize = M_SASL_MAXBUF;
if (sasl_setprop (*saslconn, SASL_SEC_PROPS, &secprops) != SASL_OK)
{
mutt_error (_("Error setting SASL security properties"));
return -1;
}
if (conn->ssf)
{
/* I'm not sure this actually has an effect, at least with SASLv2 */
dprint (2, (debugfile, "External SSF: %d\n", conn->ssf));
if (sasl_setprop (*saslconn, SASL_SSF_EXTERNAL, &(conn->ssf)) != SASL_OK)
{
mutt_error (_("Error setting SASL external security strength"));
return -1;
}
}
if (conn->account.user[0])
{
dprint (2, (debugfile, "External authentication name: %s\n", conn->account.user));
if (sasl_setprop (*saslconn, SASL_AUTH_EXTERNAL, conn->account.user) != SASL_OK)
{
mutt_error (_("Error setting SASL external user name"));
return -1;
}
}
return 0;
}
sasl_callback_t* mutt_sasl_get_callbacks (ACCOUNT* account)
{
sasl_callback_t* callback;
callback = mutt_sasl_callbacks;
callback->id = SASL_CB_USER;
callback->proc = mutt_sasl_cb_authname;
callback->context = account;
callback++;
callback->id = SASL_CB_AUTHNAME;
callback->proc = mutt_sasl_cb_authname;
callback->context = account;
callback++;
callback->id = SASL_CB_PASS;
callback->proc = mutt_sasl_cb_pass;
callback->context = account;
callback++;
callback->id = SASL_CB_GETREALM;
callback->proc = NULL;
callback->context = NULL;
callback++;
callback->id = SASL_CB_LIST_END;
callback->proc = NULL;
callback->context = NULL;
return mutt_sasl_callbacks;
}
int mutt_sasl_interact (sasl_interact_t* interaction)
{
char prompt[SHORT_STRING];
char resp[SHORT_STRING];
while (interaction->id != SASL_CB_LIST_END)
{
dprint (2, (debugfile, "mutt_sasl_interact: filling in SASL interaction %ld.\n", interaction->id));
snprintf (prompt, sizeof (prompt), "%s: ", interaction->prompt);
resp[0] = '\0';
if (option (OPTNOCURSES) || mutt_get_field (prompt, resp, sizeof (resp), 0))
return SASL_FAIL;
interaction->len = mutt_strlen (resp)+1;
interaction->result = safe_malloc (interaction->len);
memcpy ((char *)interaction->result, resp, interaction->len);
interaction++;
}
return SASL_OK;
}
/* SASL can stack a protection layer on top of an existing connection.
* To handle this, we store a saslconn_t in conn->sockdata, and write
* wrappers which en/decode the read/write stream, then replace sockdata
* with an embedded copy of the old sockdata and call the underlying
* functions (which we've also preserved). I thought about trying to make
* a general stackable connection system, but it seemed like overkill -
* something is wrong if we have 15 filters on top of a socket. Anyway,
* anything else which wishes to stack can use the same method. The only
* disadvantage is we have to write wrappers for all the socket methods,
* even if we only stack over read and write. Thinking about it, the
* abstraction problem is that there is more in CONNECTION than there
* needs to be. Ideally it would have only (void*)data and methods. */
/* mutt_sasl_setup_conn: replace connection methods, sockdata with
* SASL wrappers, for protection layers. Also get ssf, as a fastpath
* for the read/write methods. */
void mutt_sasl_setup_conn (CONNECTION* conn, sasl_conn_t* saslconn)
{
SASL_DATA* sasldata = (SASL_DATA*) safe_malloc (sizeof (SASL_DATA));
/* work around sasl_getprop aliasing issues */
const void* tmp;
sasldata->saslconn = saslconn;
/* get ssf so we know whether we have to (en|de)code read/write */
sasl_getprop (saslconn, SASL_SSF, &tmp);
sasldata->ssf = tmp;
dprint (3, (debugfile, "SASL protection strength: %u\n", *sasldata->ssf));
/* Add SASL SSF to transport SSF */
conn->ssf += *sasldata->ssf;
sasl_getprop (saslconn, SASL_MAXOUTBUF, &tmp);
sasldata->pbufsize = tmp;
dprint (3, (debugfile, "SASL protection buffer size: %u\n", *sasldata->pbufsize));
/* clear input buffer */
sasldata->buf = NULL;
sasldata->bpos = 0;
sasldata->blen = 0;
/* preserve old functions */
sasldata->sockdata = conn->sockdata;
sasldata->msasl_open = conn->conn_open;
sasldata->msasl_close = conn->conn_close;
sasldata->msasl_read = conn->conn_read;
sasldata->msasl_write = conn->conn_write;
sasldata->msasl_poll = conn->conn_poll;
/* and set up new functions */
conn->sockdata = sasldata;
conn->conn_open = mutt_sasl_conn_open;
conn->conn_close = mutt_sasl_conn_close;
conn->conn_read = mutt_sasl_conn_read;
conn->conn_write = mutt_sasl_conn_write;
conn->conn_poll = mutt_sasl_conn_poll;
}
/* mutt_sasl_cb_log: callback to log SASL messages */
static int mutt_sasl_cb_log (void* context, int priority, const char* message)
{
dprint (priority, (debugfile, "SASL: %s\n", message));
return SASL_OK;
}
void mutt_sasl_done (void)
{
sasl_done ();
}
/* mutt_sasl_cb_authname: callback to retrieve authname or user from ACCOUNT */
static int mutt_sasl_cb_authname (void* context, int id, const char** result,
unsigned* len)
{
ACCOUNT* account = (ACCOUNT*) context;
if (!result)
return SASL_FAIL;
*result = NULL;
if (len)
*len = 0;
if (!account)
return SASL_BADPARAM;
dprint (2, (debugfile, "mutt_sasl_cb_authname: getting %s for %s:%u\n",
id == SASL_CB_AUTHNAME ? "authname" : "user",
account->host, account->port));
if (id == SASL_CB_AUTHNAME)
{
if (mutt_account_getlogin (account))
return SASL_FAIL;
*result = account->login;
}
else
{
if (mutt_account_getuser (account))
return SASL_FAIL;
*result = account->user;
}
if (len)
*len = strlen (*result);
return SASL_OK;
}
static int mutt_sasl_cb_pass (sasl_conn_t* conn, void* context, int id,
sasl_secret_t** psecret)
{
ACCOUNT* account = (ACCOUNT*) context;
int len;
if (!account || !psecret)
return SASL_BADPARAM;
dprint (2, (debugfile,
"mutt_sasl_cb_pass: getting password for %s@%s:%u\n", account->login,
account->host, account->port));
if (mutt_account_getpass (account))
return SASL_FAIL;
len = strlen (account->pass);
*psecret = (sasl_secret_t*) safe_malloc (sizeof (sasl_secret_t) + len);
(*psecret)->len = len;
strcpy ((char*)(*psecret)->data, account->pass); /* __STRCPY_CHECKED__ */
return SASL_OK;
}
/* mutt_sasl_conn_open: empty wrapper for underlying open function. We
* don't know in advance that a connection will use SASL, so we
* replace conn's methods with sasl methods when authentication
* is successful, using mutt_sasl_setup_conn */
static int mutt_sasl_conn_open (CONNECTION* conn)
{
SASL_DATA* sasldata;
int rc;
sasldata = (SASL_DATA*) conn->sockdata;
conn->sockdata = sasldata->sockdata;
rc = (sasldata->msasl_open) (conn);
conn->sockdata = sasldata;
return rc;
}
/* mutt_sasl_conn_close: calls underlying close function and disposes of
* the sasl_conn_t object, then restores connection to pre-sasl state */
static int mutt_sasl_conn_close (CONNECTION* conn)
{
SASL_DATA* sasldata;
int rc;
sasldata = (SASL_DATA*) conn->sockdata;
/* restore connection's underlying methods */
conn->sockdata = sasldata->sockdata;
conn->conn_open = sasldata->msasl_open;
conn->conn_close = sasldata->msasl_close;
conn->conn_read = sasldata->msasl_read;
conn->conn_write = sasldata->msasl_write;
conn->conn_poll = sasldata->msasl_poll;
/* release sasl resources */
sasl_dispose (&sasldata->saslconn);
FREE (&sasldata);
/* call underlying close */
rc = (conn->conn_close) (conn);
return rc;
}
static int mutt_sasl_conn_read (CONNECTION* conn, char* buf, size_t len)
{
SASL_DATA* sasldata;
int rc;
unsigned int olen;
sasldata = (SASL_DATA*) conn->sockdata;
/* if we still have data in our read buffer, copy it into buf */
if (sasldata->blen > sasldata->bpos)
{
olen = (sasldata->blen - sasldata->bpos > len) ? len :
sasldata->blen - sasldata->bpos;
memcpy (buf, sasldata->buf+sasldata->bpos, olen);
sasldata->bpos += olen;
return olen;
}
conn->sockdata = sasldata->sockdata;
sasldata->bpos = 0;
sasldata->blen = 0;
/* and decode the result, if necessary */
if (*sasldata->ssf)
{
do
{
/* call the underlying read function to fill the buffer */
rc = (sasldata->msasl_read) (conn, buf, len);
if (rc <= 0)
goto out;
rc = sasl_decode (sasldata->saslconn, buf, rc, &sasldata->buf,
&sasldata->blen);
if (rc != SASL_OK)
{
dprint (1, (debugfile, "SASL decode failed: %s\n",
sasl_errstring (rc, NULL, NULL)));
goto out;
}
}
while (!sasldata->blen);
olen = (sasldata->blen - sasldata->bpos > len) ? len :
sasldata->blen - sasldata->bpos;
memcpy (buf, sasldata->buf, olen);
sasldata->bpos += olen;
rc = olen;
}
else
rc = (sasldata->msasl_read) (conn, buf, len);
out:
conn->sockdata = sasldata;
return rc;
}
static int mutt_sasl_conn_write (CONNECTION* conn, const char* buf,
size_t len)
{
SASL_DATA* sasldata;
int rc;
const char *pbuf;
unsigned int olen, plen;
sasldata = (SASL_DATA*) conn->sockdata;
conn->sockdata = sasldata->sockdata;
/* encode data, if necessary */
if (*sasldata->ssf)
{
/* handle data larger than MAXOUTBUF */
do
{
olen = (len > *sasldata->pbufsize) ? *sasldata->pbufsize : len;
rc = sasl_encode (sasldata->saslconn, buf, olen, &pbuf, &plen);
if (rc != SASL_OK)
{
dprint (1, (debugfile, "SASL encoding failed: %s\n",
sasl_errstring (rc, NULL, NULL)));
goto fail;
}
rc = (sasldata->msasl_write) (conn, pbuf, plen);
if (rc != plen)
goto fail;
len -= olen;
buf += olen;
}
while (len > *sasldata->pbufsize);
}
else
/* just write using the underlying socket function */
rc = (sasldata->msasl_write) (conn, buf, len);
conn->sockdata = sasldata;
return rc;
fail:
conn->sockdata = sasldata;
return -1;
}
static int mutt_sasl_conn_poll (CONNECTION* conn)
{
SASL_DATA* sasldata = conn->sockdata;
int rc;
conn->sockdata = sasldata->sockdata;
rc = sasldata->msasl_poll (conn);
conn->sockdata = sasldata;
return rc;
}