2 * Copyright notice from original mutt:
3 * Copyright (C) 2000-5 Brendan Cully <brendan@kublai.com>
5 * This file is part of mutt-ng, see http://www.muttng.org/.
6 * It's licensed under the GNU General Public License,
7 * please see the file GPL in the top level source directory.
10 /* common SASL helper routines */
12 #include <lib-lib/lib-lib.h>
17 #include <sasl/sasl.h>
18 #include <sys/socket.h>
19 #include <netinet/in.h>
21 #include <lib-ui/curses.h>
22 #include <lib-sys/mutt_socket.h>
26 #include "mutt_sasl.h"
28 /* arbitrary. SASL will probably use a smaller buffer anyway. OTOH it's
29 * been a while since I've had access to an SASL server which negotiated
30 * a protection buffer. */
31 #define M_SASL_MAXBUF 65536
33 #define IP_PORT_BUFLEN 1024
35 static sasl_callback_t mutt_sasl_callbacks[5];
38 static int mutt_sasl_cb_authname (void *context, int id, const char **result,
40 static int mutt_sasl_cb_pass (sasl_conn_t * conn, void *context, int id,
41 sasl_secret_t ** psecret);
43 /* socket wrappers for a SASL security layer */
44 static int mutt_sasl_conn_open (CONNECTION * conn);
45 static int mutt_sasl_conn_close (CONNECTION * conn);
46 static int mutt_sasl_conn_read (CONNECTION * conn, char *buf, ssize_t len);
47 static int mutt_sasl_conn_write (CONNECTION * conn, const char *buf,
51 iptostring(const struct sockaddr_storage *addr, char *out, unsigned outlen)
53 char hbuf[NI_MAXHOST], pbuf[NI_MAXSERV];
55 if (getnameinfo((struct sockaddr*)addr, sizeof(*addr),
56 hbuf, sizeof(hbuf), pbuf, sizeof(pbuf),
57 NI_NUMERICHOST | NI_NUMERICSERV))
60 snprintf(out, outlen, "%s;%s", hbuf, pbuf);
64 /* mutt_sasl_start: called before doing a SASL exchange - initialises library
66 static int mutt_sasl_start (void)
68 static int sasl_init = 0;
73 if (sasl_client_init(NULL) != SASL_OK)
81 static sasl_callback_t *mutt_sasl_get_callbacks (ACCOUNT * account)
83 sasl_callback_t *callback;
85 callback = mutt_sasl_callbacks;
87 callback->id = SASL_CB_USER;
88 callback->proc = mutt_sasl_cb_authname;
89 callback->context = account;
92 callback->id = SASL_CB_AUTHNAME;
93 callback->proc = mutt_sasl_cb_authname;
94 callback->context = account;
97 callback->id = SASL_CB_PASS;
98 callback->proc = mutt_sasl_cb_pass;
99 callback->context = account;
102 callback->id = SASL_CB_GETREALM;
103 callback->proc = NULL;
104 callback->context = NULL;
107 callback->id = SASL_CB_LIST_END;
108 callback->proc = NULL;
109 callback->context = NULL;
111 return mutt_sasl_callbacks;
114 int mutt_sasl_client_new (CONNECTION * conn, sasl_conn_t ** saslconn)
116 sasl_security_properties_t secprops;
118 struct sockaddr_storage local, remote;
120 char iplocalport[IP_PORT_BUFLEN], ipremoteport[IP_PORT_BUFLEN];
124 if (mutt_sasl_start() != SASL_OK)
127 switch (conn->account.type) {
128 case M_ACCT_TYPE_IMAP:
132 case M_ACCT_TYPE_POP:
140 size = sizeof(local);
141 if (getsockname(conn->fd, (struct sockaddr *) &local, &size)
142 || iptostring(&local, iplocalport, IP_PORT_BUFLEN) != SASL_OK)
147 size = sizeof(remote);
148 if (getpeername(conn->fd, (struct sockaddr *) &remote, &size)
149 || iptostring(&remote, ipremoteport, IP_PORT_BUFLEN) != SASL_OK)
154 rc = sasl_client_new(service, conn->account.host, iplocalport,
156 mutt_sasl_get_callbacks(&conn->account), 0, saslconn);
162 /* set security properties. We use NOPLAINTEXT globally, since we can
163 * just fall back to LOGIN in the IMAP case anyway. If that doesn't
164 * work for POP, we can make it a flag or move this code into
165 * imap/auth_sasl.c */
166 p_clear(&secprops, 1);
167 /* Work around a casting bug in the SASL krb4 module */
168 secprops.max_ssf = 0x7fff;
169 secprops.maxbufsize = M_SASL_MAXBUF;
170 secprops.security_flags |= SASL_SEC_NOPLAINTEXT;
171 if (sasl_setprop (*saslconn, SASL_SEC_PROPS, &secprops) != SASL_OK) {
176 if (sasl_setprop (*saslconn, SASL_SSF_EXTERNAL, &(conn->ssf)) != SASL_OK)
180 if (sasl_setprop (*saslconn, SASL_AUTH_EXTERNAL, conn->account.user) !=
189 int mutt_sasl_interact (sasl_interact_t * interaction)
194 while (interaction->id != SASL_CB_LIST_END) {
195 snprintf (prompt, sizeof (prompt), "%s: ", interaction->prompt);
197 if (mutt_get_field (prompt, resp, sizeof (resp), 0))
200 interaction->len = m_strlen(resp) + 1;
201 interaction->result = p_dupstr(resp, interaction->len - 1);
208 /* SASL can stack a protection layer on top of an existing connection.
209 * To handle this, we store a saslconn_t in conn->sockdata, and write
210 * wrappers which en/decode the read/write stream, then replace sockdata
211 * with an embedded copy of the old sockdata and call the underlying
212 * functions (which we've also preserved). I thought about trying to make
213 * a general stackable connection system, but it seemed like overkill -
214 * something is wrong if we have 15 filters on top of a socket. Anyway,
215 * anything else which wishes to stack can use the same method. The only
216 * disadvantage is we have to write wrappers for all the socket methods,
217 * even if we only stack over read and write. Thinking about it, the
218 * abstraction problem is that there is more in CONNECTION than there
219 * needs to be. Ideally it would have only (void*)data and methods. */
221 /* mutt_sasl_setup_conn: replace connection methods, sockdata with
222 * SASL wrappers, for protection layers. Also get ssf, as a fastpath
223 * for the read/write methods. */
224 void mutt_sasl_setup_conn (CONNECTION * conn, sasl_conn_t * saslconn)
226 SASL_DATA *sasldata = p_new(SASL_DATA, 1);
228 sasldata->saslconn = saslconn;
229 /* get ssf so we know whether we have to (en|de)code read/write */
230 sasl_getprop (saslconn, SASL_SSF, (const void **)(void *)&sasldata->ssf);
232 /* Add SASL SSF to transport SSF */
233 conn->ssf += *sasldata->ssf;
234 sasl_getprop (saslconn, SASL_MAXOUTBUF,
235 (const void **)(void *)&sasldata->pbufsize);
237 /* clear input buffer */
238 sasldata->buf = NULL;
242 /* preserve old functions */
243 sasldata->sockdata = conn->sockdata;
244 sasldata->msasl_open = conn->conn_open;
245 sasldata->msasl_close = conn->conn_close;
246 sasldata->msasl_read = conn->conn_read;
247 sasldata->msasl_write = conn->conn_write;
249 /* and set up new functions */
250 conn->sockdata = sasldata;
251 conn->conn_open = mutt_sasl_conn_open;
252 conn->conn_close = mutt_sasl_conn_close;
253 conn->conn_read = mutt_sasl_conn_read;
254 conn->conn_write = mutt_sasl_conn_write;
257 void mutt_sasl_done (void) {
261 /* mutt_sasl_cb_authname: callback to retrieve authname or user from ACCOUNT */
262 static int mutt_sasl_cb_authname (void *context, int id, const char **result,
265 ACCOUNT *account = (ACCOUNT *) context;
272 return SASL_BADPARAM;
274 if (id == SASL_CB_AUTHNAME) {
275 if (mutt_account_getlogin (account))
277 *result = account->login;
279 if (mutt_account_getuser (account))
281 *result = account->user;
285 *len = m_strlen(*result);
290 static int mutt_sasl_cb_pass(sasl_conn_t *conn __attribute__ ((unused)),
291 void *context, int id __attribute__ ((unused)),
292 sasl_secret_t **psecret)
294 ACCOUNT *account = (ACCOUNT *) context;
297 if (!account || !psecret)
298 return SASL_BADPARAM;
300 if (mutt_account_getpass (account))
303 len = m_strlen(account->pass);
305 *psecret = xmalloc(sizeof(sasl_secret_t) + len);
306 (*psecret)->len = len;
307 memcpy((char*)(*psecret)->data, account->pass, len);
312 /* mutt_sasl_conn_open: empty wrapper for underlying open function. We
313 * don't know in advance that a connection will use SASL, so we
314 * replace conn's methods with sasl methods when authentication
315 * is successful, using mutt_sasl_setup_conn */
316 static int mutt_sasl_conn_open (CONNECTION * conn)
321 sasldata = (SASL_DATA *) conn->sockdata;
322 conn->sockdata = sasldata->sockdata;
323 rc = (sasldata->msasl_open) (conn);
324 conn->sockdata = sasldata;
329 /* mutt_sasl_conn_close: calls underlying close function and disposes of
330 * the sasl_conn_t object, then restores connection to pre-sasl state */
331 static int mutt_sasl_conn_close(CONNECTION * conn)
336 sasldata = (SASL_DATA *) conn->sockdata;
338 /* restore connection's underlying methods */
339 conn->sockdata = sasldata->sockdata;
340 conn->conn_open = sasldata->msasl_open;
341 conn->conn_close = sasldata->msasl_close;
342 conn->conn_read = sasldata->msasl_read;
343 conn->conn_write = sasldata->msasl_write;
345 /* release sasl resources */
346 sasl_dispose (&sasldata->saslconn);
347 p_delete(&sasldata->buf);
350 /* call underlying close */
351 rc = (conn->conn_close) (conn);
356 static int mutt_sasl_conn_read (CONNECTION * conn, char *buf, ssize_t len)
363 sasldata = (SASL_DATA *) conn->sockdata;
365 /* if we still have data in our read buffer, copy it into buf */
366 if (sasldata->blen > sasldata->bpos) {
367 olen = (sasldata->blen - sasldata->bpos > len) ? len :
368 sasldata->blen - sasldata->bpos;
370 memcpy (buf, sasldata->buf + sasldata->bpos, olen);
371 sasldata->bpos += olen;
376 conn->sockdata = sasldata->sockdata;
378 p_delete(&sasldata->buf);
382 /* and decode the result, if necessary */
383 if (*sasldata->ssf) {
385 /* call the underlying read function to fill the buffer */
386 rc = (sasldata->msasl_read) (conn, buf, len);
390 rc = sasl_decode(sasldata->saslconn, buf, rc,
391 (const char **)&sasldata->buf, &sasldata->blen);
396 while (!sasldata->blen);
398 olen = (sasldata->blen - sasldata->bpos > len) ? len :
399 sasldata->blen - sasldata->bpos;
401 memcpy (buf, sasldata->buf, olen);
402 sasldata->bpos += olen;
407 rc = (sasldata->msasl_read) (conn, buf, len);
410 conn->sockdata = sasldata;
416 mutt_sasl_conn_write(CONNECTION * conn, const char *buf, ssize_t len)
422 unsigned int olen, plen;
424 sasldata = (SASL_DATA *) conn->sockdata;
425 conn->sockdata = sasldata->sockdata;
427 /* encode data, if necessary */
428 if (*sasldata->ssf) {
429 /* handle data larger than MAXOUTBUF */
431 olen = (len > *sasldata->pbufsize) ? *sasldata->pbufsize : len;
433 rc = sasl_encode(sasldata->saslconn, buf, olen,
434 (const char **)&pbuf, &plen);
439 plen -= (sasldata->msasl_write)(conn, pbuf, plen);
446 } while (len > *sasldata->pbufsize);
448 /* just write using the underlying socket function */
449 rc = (sasldata->msasl_write) (conn, buf, len);
452 conn->sockdata = sasldata;
457 conn->sockdata = sasldata;
461 #endif /* USE_SASL */