1 /* SASL server API implementation
4 * $Id: checkpw.c,v 1.49 2002/03/07 19:14:04 ken3 Exp $
6 /* Copyright (c) The Exim Maintainers 2021 - 2022 */
8 * Copyright (c) 2001 Carnegie Mellon University. All rights reserved.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in
19 * the documentation and/or other materials provided with the
22 * 3. The name "Carnegie Mellon University" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For permission or any other legal
25 * details, please contact
26 * Office of Technology Transfer
27 * Carnegie Mellon University
29 * Pittsburgh, PA 15213-3890
30 * (412) 268-4387, fax: (412) 268-7395
31 * tech-transfer@andrew.cmu.edu
33 * 4. Redistributions of any form whatsoever must retain the following
35 * "This product includes software developed by Computing Services
36 * at Carnegie Mellon University (http://www.cmu.edu/computing/)."
38 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
39 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
40 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
41 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
42 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
43 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
44 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
48 * Taken from Cyrus-SASL library and adapted by Alexander S. Sabourenkov
49 * Oct 2001 - Apr 2002: Slightly modified by Philip Hazel.
50 * Aug 2003: new code for saslauthd from Alexander S. Sabourenkov incorporated
51 * by Philip Hazel (minor mods to avoid compiler warnings)
52 * Oct 2006: (PH) removed redundant tests on "reply" being NULL - some were
53 * missing, and confused someone who was using this code for some
54 * other purpose. Here in Exim, "reply" is never NULL.
56 * screwdriver@lxnt.info
60 /* Originally this module supported only the pwcheck daemon, which is where its
61 name comes from. Nowadays it supports saslauthd as well; pwcheck is in fact
62 deprecated. The definitions of CYRUS_PWCHECK_SOCKET and CYRUS_SASLAUTHD_SOCKET
63 determine whether the facilities are actually supported or not. */
70 #if defined(CYRUS_PWCHECK_SOCKET) || defined(CYRUS_SASLAUTHD_SOCKET)
74 static int retry_read(int, void *, unsigned );
75 static int retry_writev(int, struct iovec *, int );
76 static int read_string(int, uschar **);
77 static int write_string(int, const uschar *, int);
82 /* A dummy function that always fails if pwcheck support is not
85 #ifndef CYRUS_PWCHECK_SOCKET
86 int pwcheck_verify_password(const char *userid,
90 *reply = "pwcheck support is not included in this Exim binary";
95 /* This is the real function */
99 /* taken from cyrus-sasl file checkpw.c */
100 /* pwcheck daemon-authenticated login */
101 int pwcheck_verify_password(const char *userid,
106 struct sockaddr_un srvaddr;
108 static char response[1024];
112 s = socket(AF_UNIX, SOCK_STREAM, 0);
113 if (s == -1) { return PWCHECK_FAIL; }
115 memset(CS &srvaddr, 0, sizeof(srvaddr));
116 srvaddr.sun_family = AF_UNIX;
117 strncpy(srvaddr.sun_path, CYRUS_PWCHECK_SOCKET, sizeof(srvaddr.sun_path));
118 r = connect(s, (struct sockaddr *)&srvaddr, sizeof(srvaddr));
121 debug_printf("Cannot connect to pwcheck daemon (at '%s')\n",CYRUS_PWCHECK_SOCKET);
122 *reply = "cannot connect to pwcheck daemon";
126 iov[0].iov_base = CS userid;
127 iov[0].iov_len = strlen(userid)+1;
128 iov[1].iov_base = CS passwd;
129 iov[1].iov_len = strlen(passwd)+1;
131 retry_writev(s, iov, 2);
134 while (start < sizeof(response) - 1) {
135 n = read(s, response+start, sizeof(response) - 1 - start);
142 if (start > 1 && !strncmp(response, "OK", 2)) {
146 response[start] = '\0';
155 /* A dummy function that always fails if saslauthd support is not
158 #ifndef CYRUS_SASLAUTHD_SOCKET
159 int saslauthd_verify_password(const uschar *userid,
160 const uschar *passwd,
161 const uschar *service,
163 const uschar **reply)
165 *reply = US"saslauthd support is not included in this Exim binary";
170 /* This is the real function */
173 /* written from scratch */
174 /* saslauthd daemon-authenticated login */
176 int saslauthd_verify_password(const uschar *userid,
177 const uschar *password,
178 const uschar *service,
180 const uschar **reply)
182 uschar *daemon_reply = NULL;
184 struct sockaddr_un srvaddr;
187 debug_printf("saslauthd userid='%s' servicename='%s'"
188 " realm='%s'\n", userid, service, realm );
192 s = socket(AF_UNIX, SOCK_STREAM, 0);
194 *reply = CUstrerror(errno);
198 memset(CS &srvaddr, 0, sizeof(srvaddr));
199 srvaddr.sun_family = AF_UNIX;
200 strncpy(srvaddr.sun_path, CYRUS_SASLAUTHD_SOCKET,
201 sizeof(srvaddr.sun_path));
202 r = connect(s, (struct sockaddr *)&srvaddr, sizeof(srvaddr));
205 debug_printf("Cannot connect to saslauthd daemon (at '%s'): %s\n",
206 CYRUS_SASLAUTHD_SOCKET, strerror(errno));
207 *reply = string_sprintf("cannot connect to saslauthd daemon at "
208 "%s: %s", CYRUS_SASLAUTHD_SOCKET,
213 if ( write_string(s, userid, Ustrlen(userid)) < 0) {
215 debug_printf("Failed to send userid to saslauthd daemon \n");
220 if ( write_string(s, password, Ustrlen(password)) < 0) {
222 debug_printf("Failed to send password to saslauthd daemon \n");
227 memset((void *)password, 0, Ustrlen(password));
229 if ( write_string(s, service, Ustrlen(service)) < 0) {
231 debug_printf("Failed to send service name to saslauthd daemon \n");
236 if ( write_string(s, realm, Ustrlen(realm)) < 0) {
238 debug_printf("Failed to send realm to saslauthd daemon \n");
243 if ( read_string(s, &daemon_reply ) < 2) {
245 debug_printf("Corrupted answer '%s' received. \n", daemon_reply);
253 debug_printf("Answer '%s' received. \n", daemon_reply);
255 *reply = daemon_reply;
257 if ( (daemon_reply[0] == 'O') && (daemon_reply[1] == 'K') )
260 if ( (daemon_reply[0] == 'N') && (daemon_reply[1] == 'O') )
269 /* helper functions */
270 #if defined(CYRUS_PWCHECK_SOCKET) || defined(CYRUS_SASLAUTHD_SOCKET)
272 #define MAX_REQ_LEN 1024
274 /* written from scratch */
276 /* FUNCTION: read_string */
279 * read a sasld-style counted string into
280 * store-allocated buffer, set pointer to the buffer,
281 * return number of bytes read or -1 on failure.
284 static int read_string(int fd, uschar **retval) {
285 unsigned short count;
288 rc = (retry_read(fd, &count, sizeof(count)) < (int) sizeof(count));
290 count = ntohs(count);
291 if (count > MAX_REQ_LEN) {
294 /* Assume the file is trusted, so no tainting */
295 *retval = store_get(count + 1, GET_UNTAINTED);
296 rc = (retry_read(fd, *retval, count) < (int) count);
297 (*retval)[count] = '\0';
305 /* FUNCTION: write_string */
308 * write a sasld-style counted string into given fd
309 * written bytes on success, -1 on failure.
312 static int write_string(int fd, const uschar *string, int len) {
313 unsigned short count;
319 iov[0].iov_base = (void *) &count;
320 iov[0].iov_len = sizeof(count);
321 iov[1].iov_base = (void *) string;
322 iov[1].iov_len = len;
324 rc = retry_writev(fd, iov, 2);
330 /* taken from cyrus-sasl file saslauthd/saslauthd-unix.c */
332 /* FUNCTION: retry_read */
335 * Keep calling the read() system call with 'fd', 'buf', and 'nbyte'
336 * until all the data is read in or an error occurs.
338 static int retry_read(int fd, void *inbuf, unsigned nbyte)
342 char *buf = CS inbuf;
344 if (nbyte == 0) return 0;
347 n = read(fd, buf, nbyte);
353 if (errno == EINTR) continue;
359 if (n >= (int) nbyte) return nread;
366 /* END FUNCTION: retry_read */
368 /* FUNCTION: retry_writev */
371 * Keep calling the writev() system call with 'fd', 'iov', and 'iovcnt'
372 * until all the data is written out or an error occurs.
375 static int /* R: bytes written, or -1 on error */
378 int fd, /* I: fd to write on */
379 struct iovec *iov, /* U: iovec array base
380 * modified as data written */
381 int iovcnt /* I: number of iovec entries */
386 int n; /* return value from writev() */
387 int i; /* loop counter */
388 int written; /* bytes written so far */
389 static int iov_max; /* max number of iovec entries */
398 # else /* ! IOV_MAX */
400 # endif /* ! IOV_MAX */
401 #endif /* ! MAXIOV */
406 while (iovcnt && iov[0].iov_len == 0) {
415 n = writev(fd, iov, iovcnt > iov_max ? iov_max : iovcnt);
417 if (errno == EINVAL && iov_max > 10) {
421 if (errno == EINTR) {
429 for (i = 0; i < iovcnt; i++) {
430 if (iov[i].iov_len > (unsigned) n) {
431 iov[i].iov_base = CS iov[i].iov_base + n;
446 /* END FUNCTION: retry_writev */
449 /* End of auths/pwcheck.c */