-
/*
* smtp.c -- nmh SMTP interface
*
* $Id$
+ *
+ * This code is Copyright (c) 2002, by the authors of nmh. See the
+ * COPYRIGHT file in the root directory of the nmh distribution for
+ * complete copyright information.
*/
#include <h/mh.h>
#include "smtp.h"
-#include <zotnet/mts/mts.h>
+#include <h/mts.h>
#include <signal.h>
#include <h/signals.h>
#ifdef MPOP
#include <errno.h>
#endif
+#ifdef CYRUS_SASL
+#include <sasl/sasl.h>
+#include <sasl/saslutil.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <errno.h>
+#endif /* CYRUS_SASL */
+
/*
* This module implements an interface to SendMail very similar
* to the MMDF mm_(3) routines. The sm_() routines herein talk
/*
* these codes must all be different!
*/
-#define SM_OPEN 90 /* Changed from 30 in case of nameserver flakiness */
+#define SM_OPEN 300 /* Changed to 5 minutes to comply with a SHOULD in RFC 1123 */
#define SM_HELO 20
#define SM_RSET 15
-#define SM_MAIL 40
-#define SM_RCPT 120
-#define SM_DATA 20
-#define SM_TEXT 150
-#define SM_DOT 180
+#define SM_MAIL 301 /* changed to 5 minutes and a second (for uniqueness), see above */
+#define SM_RCPT 302 /* see above */
+#define SM_DATA 120 /* see above */
+#define SM_TEXT 180 /* see above */
+#define SM_DOT 600 /* see above */
#define SM_QUIT 30
#define SM_CLOS 10
+#define SM_AUTH 45
static int sm_addrs = 0;
static int sm_alarmed = 0;
static char sm_tmpfil[BUFSIZ];
#endif /* MPOP */
+#ifdef CYRUS_SASL
+/*
+ * Some globals needed by SASL
+ */
+
+static sasl_conn_t *conn = NULL; /* SASL connection state */
+static int sasl_complete = 0; /* Has authentication succeded? */
+static sasl_ssf_t sasl_ssf; /* Our security strength factor */
+static char *sasl_pw_context[2]; /* Context to pass into sm_get_pass */
+static int maxoutbuf; /* Maximum crypto output buffer */
+static int sm_get_user(void *, int, const char **, unsigned *);
+static int sm_get_pass(sasl_conn_t *, void *, int, sasl_secret_t **);
+
+static sasl_callback_t callbacks[] = {
+ { SASL_CB_USER, sm_get_user, NULL },
+#define SM_SASL_N_CB_USER 0
+ { SASL_CB_PASS, sm_get_pass, NULL },
+#define SM_SASL_N_CB_PASS 1
+ { SASL_CB_AUTHNAME, sm_get_user, NULL },
+#define SM_SASL_N_CB_AUTHNAME 2
+ { SASL_CB_LIST_END, NULL, NULL },
+};
+#endif /* CYRUS_SASL */
+
static char *sm_noreply = "No reply text given";
static char *sm_moreply = "; ";
/*
* static prototypes
*/
-static int smtp_init (char *, char *, int, int, int, int, int);
+static int smtp_init (char *, char *, int, int, int, int, int, int,
+ char *, char *);
static int sendmail_init (char *, char *, int, int, int, int, int);
static int rclient (char *, char *, char *);
static char *EHLOset (char *);
#ifdef MPOP
+static int sm_perror (char *fmt, ...);
/*
* smtp.c's own static copy of several nmh library subroutines
*/
char **smail_copyip (char **, char **, int);
#endif
-/* from zotnet/mts/client.c */
+#ifdef CYRUS_SASL
+/*
+ * Function prototypes needed for SASL
+ */
+
+static int sm_auth_sasl(char *, char *, char *);
+#endif /* CYRUS_SASL */
+
+/* from mts/generic/client.c */
int client (char *, char *, char *, int, char *, int);
int
sm_init (char *client, char *server, int watch, int verbose,
- int debug, int onex, int queued)
+ int debug, int onex, int queued, int sasl, char *saslmech,
+ char *user)
{
if (sm_mts == MTS_SMTP)
return smtp_init (client, server, watch, verbose,
- debug, onex, queued);
+ debug, onex, queued, sasl, saslmech, user);
else
return sendmail_init (client, server, watch, verbose,
debug, onex, queued);
static int
smtp_init (char *client, char *server, int watch, int verbose,
- int debug, int onex, int queued)
+ int debug, int onex, int queued, int sasl, char *saslmech,
+ char *user)
{
+#ifdef CYRUS_SASL
+ char *server_mechs;
+#endif /* CYRUS_SASL */
int result, sd1, sd2;
if (watch)
}
}
+#ifdef CYRUS_SASL
+ /*
+ * If the user asked for SASL, then check to see if the SMTP server
+ * supports it. Otherwise, error out (because the SMTP server
+ * might have been spoofed; we don't want to just silently not
+ * do authentication
+ */
+
+ if (sasl) {
+ if (! (server_mechs = EHLOset("AUTH"))) {
+ sm_end(NOTOK);
+ return sm_ierror("SMTP server does not support SASL");
+ }
+
+ if (saslmech && stringdex(saslmech, server_mechs) == -1) {
+ sm_end(NOTOK);
+ return sm_ierror("Requested SASL mech \"%s\" is not in the "
+ "list of supported mechanisms:\n%s",
+ saslmech, server_mechs);
+ }
+
+ if (sm_auth_sasl(user, saslmech ? saslmech : server_mechs,
+ server) != RP_OK) {
+ sm_end(NOTOK);
+ return NOTOK;
+ }
+ }
+#endif /* CYRUS_SASL */
+
send_options: ;
if (watch && EHLOset ("XVRB"))
smtalk (SM_HELO, "VERB on");
return NOTOK;
}
-
int
sm_winit (int mode, char *from)
{
#ifdef MPOP
if (sm_ispool && !sm_wfp) {
- strlen (strcpy (sm_reply.text, "unable to create new spool file"));
+ sm_reply.length = strlen (strcpy (sm_reply.text, "unable to create new spool file"));
sm_reply.code = NOTOK;
return RP_BHST;
}
case NOTOK:
sm_note.code = sm_reply.code;
- strncpy (sm_note.text, sm_reply.text, sm_note.length = sm_reply.length);/* fall */
+ sm_note.length = sm_reply.length;
+ memcpy (sm_note.text, sm_reply.text, sm_reply.length + 1);/* fall */
case DONE:
if (smtalk (SM_RSET, "RSET") == 250 && type == DONE)
return RP_OK;
}
if (type == NOTOK) {
sm_reply.code = sm_note.code;
- strncpy (sm_reply.text, sm_note.text, sm_reply.length = sm_note.length);
+ sm_reply.length = sm_note.length;
+ memcpy (sm_reply.text, sm_note.text, sm_note.length + 1);
}
break;
}
alarm (0);
}
- if (sm_mts == MTS_SMTP)
+ if (sm_mts == MTS_SMTP) {
status = 0;
- else {
+#ifdef CYRUS_SASL
+ if (conn)
+ sasl_dispose(&conn);
+#endif /* CYRUS_SASL */
+ } else {
status = pidwait (sm_child, OK);
sm_child = NOTOK;
}
gp = NULL;
k = strlen (file) - sizeof(".bulk");
if ((fp = fopen (file, "r")) == NULL) {
- int len;
-
- snprintf (sm_reply.text, sizeof(sm_reply.text),
- "unable to read %s: ", file);
- bp = sm_reply.text;
- len = strlen (bp);
- bp += len;
- if ((s = strerror (errno)))
- strncpy (bp, s, sizeof(sm_reply.text) - len);
- else
- snprintf (bp, sizeof(sm_reply.text) - len, "Error %d", errno);
- sm_reply.length = strlen (sm_reply.text);
- sm_reply.code = NOTOK;
- return RP_BHST;
+ return sm_perror("unable to read %s: ", file);
}
if (sm_debug) {
printf ("reading file %s\n", file);
if ((cc = write (fileno (sm_wfp), dp, i)) == NOTOK) {
int len;
losing3:
- strcpy (sm_reply.text, "error writing to server: ",
- sizeof(sm_reply.text));
- bp = sm_reply.text;
- len = strlen (bp);
- bp += len;
- if ((s = strerror (errno)))
- strncpy (bp, s, sizeof(sm_reply.text) - len);
- else
- snprintf (bp, sizeof(sm_reply.text) - len,
- "unknown error %d", errno);
- sm_reply.length = strlen (sm_reply.text);
+ sm_perror("error writing to server: ");
goto losing2;
}
else
free (cp);
{
-#ifdef HAVE_ST_BLKSIZE
+#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
struct stat st;
if (fstat (fileno (sm_wfp), &st) == NOTOK || (cc = st.st_blksize) < BUFSIZ)
for (dp = cp, i = cc; i > 0; dp += j, i -= j)
if ((j = fread (cp, sizeof(*cp), i, fp)) == OK) {
if (ferror (fp)) {
- int len;
-
- snprintf (sm_reply.text, sizeof(sm_reply.text),
- "error reading %s: ", file);
- bp = sm_reply.text;
- len = strlen (bp);
- bp += len;
- if ((s = strerror (errno)))
- strncpy (bp, s, sizeof(sm_reply.text) - len);
- else
- snprintf (bp, sizeof(sm_reply.text) - len,
- "unknown error %d", errno);
- sm_reply.length = strlen (sm_reply.text);
+ sm_perror("error reading %s: ", file);
goto losing2;
}
cc = dp - cp;
#endif /* MPOP */
+#ifdef CYRUS_SASL
+/*
+ * This function implements SASL authentication for SMTP. If this function
+ * completes successfully, then authentication is successful and we've
+ * (optionally) negotiated a security layer.
+ *
+ * Right now we don't support session encryption.
+ */
+static int
+sm_auth_sasl(char *user, char *mechlist, char *host)
+{
+ int result, status;
+ unsigned int buflen, outlen;
+ char *buf, outbuf[BUFSIZ];
+ const char *chosen_mech;
+ sasl_security_properties_t secprops;
+ sasl_ssf_t *ssf;
+ int *outbufmax;
+
+ /*
+ * Initialize the callback contexts
+ */
+
+ if (user == NULL)
+ user = getusername();
+
+ callbacks[SM_SASL_N_CB_USER].context = user;
+ callbacks[SM_SASL_N_CB_AUTHNAME].context = user;
+
+ /*
+ * This is a _bit_ of a hack ... but if the hostname wasn't supplied
+ * to us on the command line, then call getpeername and do a
+ * reverse-address lookup on the IP address to get the name.
+ */
+
+ if (!host) {
+ struct sockaddr_in sin;
+ int len = sizeof(sin);
+ struct hostent *hp;
+
+ if (getpeername(fileno(sm_wfp), (struct sockaddr *) &sin, &len) < 0) {
+ sm_ierror("getpeername on SMTP socket failed: %s",
+ strerror(errno));
+ return NOTOK;
+ }
+
+ if ((hp = gethostbyaddr((void *) &sin.sin_addr, sizeof(sin.sin_addr),
+ sin.sin_family)) == NULL) {
+ sm_ierror("DNS lookup on IP address %s failed",
+ inet_ntoa(sin.sin_addr));
+ return NOTOK;
+ }
+
+ host = strdup(hp->h_name);
+ }
+
+ sasl_pw_context[0] = host;
+ sasl_pw_context[1] = user;
+
+ callbacks[SM_SASL_N_CB_PASS].context = sasl_pw_context;
+
+ result = sasl_client_init(callbacks);
+
+ if (result != SASL_OK) {
+ sm_ierror("SASL library initialization failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ result = sasl_client_new("smtp", host, NULL, NULL, NULL, 0, &conn);
+
+ if (result != SASL_OK) {
+ sm_ierror("SASL client initialization failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ /*
+ * Initialize the security properties
+ */
+
+ memset(&secprops, 0, sizeof(secprops));
+ secprops.maxbufsize = BUFSIZ;
+ secprops.max_ssf = 0; /* XXX change this when we do encryption */
+
+ result = sasl_setprop(conn, SASL_SEC_PROPS, &secprops);
+
+ if (result != SASL_OK) {
+ sm_ierror("SASL security property initialization failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ /*
+ * Start the actual protocol. Feed the mech list into the library
+ * and get out a possible initial challenge
+ */
+
+ result = sasl_client_start(conn, mechlist, NULL, (const char **) &buf,
+ &buflen, (const char **) &chosen_mech);
+
+ if (result != SASL_OK && result != SASL_CONTINUE) {
+ sm_ierror("SASL client start failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ /*
+ * If we got an initial challenge, send it as part of the AUTH
+ * command; otherwise, just send a plain AUTH command.
+ */
+
+ if (buflen) {
+ status = sasl_encode64(buf, buflen, outbuf, sizeof(outbuf), NULL);
+ if (status != SASL_OK) {
+ sm_ierror("SASL base64 encode failed: %s",
+ sasl_errstring(status, NULL, NULL));
+ return NOTOK;
+ }
+
+ status = smtalk(SM_AUTH, "AUTH %s %s", chosen_mech, outbuf);
+ } else
+ status = smtalk(SM_AUTH, "AUTH %s", chosen_mech);
+
+ /*
+ * Now we loop until we either fail, get a SASL_OK, or a 235
+ * response code. Receive the challenges and process them until
+ * we're all done.
+ */
+
+ while (result == SASL_CONTINUE) {
+
+ /*
+ * If we get a 235 response, that means authentication has
+ * succeeded and we need to break out of the loop (yes, even if
+ * we still get SASL_CONTINUE from sasl_client_step()).
+ *
+ * Otherwise, if we get a message that doesn't seem to be a
+ * valid response, then abort
+ */
+
+ if (status == 235)
+ break;
+ else if (status < 300 || status > 399)
+ return RP_BHST;
+
+ /*
+ * Special case; a zero-length response from the SMTP server
+ * is returned as a single =. If we get that, then set buflen
+ * to be zero. Otherwise, just decode the response.
+ */
+
+ if (strcmp("=", sm_reply.text) == 0) {
+ outlen = 0;
+ } else {
+ result = sasl_decode64(sm_reply.text, sm_reply.length,
+ outbuf, sizeof(outbuf), &outlen);
+
+ if (result != SASL_OK) {
+ smtalk(SM_AUTH, "*");
+ sm_ierror("SASL base64 decode failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+ }
+
+ result = sasl_client_step(conn, outbuf, outlen, NULL,
+ (const char **) &buf, &buflen);
+
+ if (result != SASL_OK && result != SASL_CONTINUE) {
+ smtalk(SM_AUTH, "*");
+ sm_ierror("SASL client negotiation failed: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ status = sasl_encode64(buf, buflen, outbuf, sizeof(outbuf), NULL);
+
+ if (status != SASL_OK) {
+ smtalk(SM_AUTH, "*");
+ sm_ierror("SASL base64 encode failed: %s",
+ sasl_errstring(status, NULL, NULL));
+ return NOTOK;
+ }
+
+ status = smtalk(SM_AUTH, outbuf);
+ }
+
+ /*
+ * Make sure that we got the correct response
+ */
+
+ if (status < 200 || status > 299)
+ return RP_BHST;
+
+ /*
+ * We _should_ have completed the authentication successfully.
+ * Get a few properties from the authentication exchange.
+ */
+
+ result = sasl_getprop(conn, SASL_MAXOUTBUF, (const void **) &outbufmax);
+
+ if (result != SASL_OK) {
+ sm_ierror("Cannot retrieve SASL negotiated output buffer size: %s",
+ sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ maxoutbuf = *outbufmax;
+
+ result = sasl_getprop(conn, SASL_SSF, (const void **) &ssf);
+
+ sasl_ssf = *ssf;
+
+ if (result != SASL_OK) {
+ sm_ierror("Cannot retrieve SASL negotiated security strength "
+ "factor: %s", sasl_errstring(result, NULL, NULL));
+ return NOTOK;
+ }
+
+ if (maxoutbuf == 0 || maxoutbuf > BUFSIZ)
+ maxoutbuf = BUFSIZ;
+
+ sasl_complete = 1;
+
+ return RP_OK;
+}
+
+/*
+ * Our callback functions to feed data to the SASL library
+ */
+
+static int
+sm_get_user(void *context, int id, const char **result, unsigned *len)
+{
+ char *user = (char *) context;
+
+ if (! result || ((id != SASL_CB_USER) && (id != SASL_CB_AUTHNAME)))
+ return SASL_BADPARAM;
+
+ *result = user;
+ if (len)
+ *len = strlen(user);
+
+ return SASL_OK;
+}
+
+static int
+sm_get_pass(sasl_conn_t *conn, void *context, int id,
+ sasl_secret_t **psecret)
+{
+ char **pw_context = (char **) context;
+ char *pass = NULL;
+ int len;
+
+ if (! psecret || id != SASL_CB_PASS)
+ return SASL_BADPARAM;
+
+ ruserpass(pw_context[0], &(pw_context[1]), &pass);
+
+ len = strlen(pass);
+
+ *psecret = (sasl_secret_t *) malloc(sizeof(sasl_secret_t) + len);
+
+ if (! *psecret) {
+ free(pass);
+ return SASL_NOMEM;
+ }
+
+ (*psecret)->len = len;
+ strcpy((char *) (*psecret)->data, pass);
+/* free(pass); */
+
+ return SASL_OK;
+}
+#endif /* CYRUS_SASL */
+
static int
sm_ierror (char *fmt, ...)
{
return RP_BHST;
}
+#ifdef MPOP
+static int
+sm_perror (char *fmt, ...)
+{
+ /* Fill in sm_reply with a suitable error string based on errno.
+ * This isn't particularly MPOP specific, it just happens that that's
+ * the only code that uses it currently.
+ */
+ char *bp, *s;
+ int len, eno = errno;
+
+ va_list ap;
+ va_start(ap,fmt);
+ vsnprintf (sm_reply.text, sizeof(sm_reply.text), fmt, ap);
+ va_end(ap);
+
+ bp = sm_reply.text;
+ len = strlen(bp);
+ bp += len;
+ if ((s = strerror(eno)))
+ snprintf(bp, sizeof(sm_reply.text) - len, "%s", s);
+ else
+ snprintf(bp, sizeof(sm_reply.text) - len, "unknown error %d", eno);
+
+ sm_reply.length = strlen (sm_reply.text);
+ sm_reply.code = NOTOK;
+
+ return RP_BHST;
+}
+#endif
static int
smtalk (int time, char *fmt, ...)
snprintf (file, sizeof(file), "%s%c.bulk", sm_tmpfil,
(char) (sm_ispool + 'a' - 1));
if (rename (sm_tmpfil, file) == NOTOK) {
- int len;
- char *bp;
-
- snprintf (sm_reply.text, sizeof(sm_reply.text),
- "error renaming %s to %s: ", sm_tmpfil, file);
- bp = sm_reply.text;
- len = strlen (bp);
- bp += len;
- if ((s = strerror (errno)))
- strncpy (bp, s, sizeof(sm_reply.text) - len);
- else
- snprintf (bp, sizeof(sm_reply.text) - len,
- "unknown error %d", errno);
- sm_reply.length = strlen (sm_reply.text);
- sm_reply.code = NOTOK;
- return RP_BHST;
+ return sm_perror("error renaming %s to %s: ", sm_tmpfil, file);
}
fclose (sm_wfp);
if (sm_wfp = fopen (sm_tmpfil, "w"))
smhear (void)
{
int i, code, cont, bc, rc, more;
- char *bp, *rp;
+ unsigned char *bp;
+ char *rp;
char **ehlo, buffer[BUFSIZ];
if (doingEHLO) {
sm_reply.code = code;
more = cont;
if (bc <= 0) {
+ /* can never fail to 0-terminate because of size of buffer vs fixed string */
strncpy (buffer, sm_noreply, sizeof(buffer));
bp = buffer;
bc = strlen (sm_noreply);
}
if ((i = min (bc, rc)) > 0) {
- strncpy (rp, bp, i);
+ memcpy (rp, bp, i);
rp += i;
rc -= i;
- if (more && rc > strlen (sm_moreply) + 1) {
- strncpy (sm_reply.text + rc, sm_moreply, sizeof(sm_reply.text) - rc);
- rc += strlen (sm_moreply);
+ i = strlen(sm_moreply);
+ if (more && rc > i + 1) {
+ memcpy (rp, sm_moreply, i); /* safe because of check in if() */
+ rp += i;
+ rc -= i;
}
}
if (more)
}
sm_reply.length = rp - sm_reply.text;
+ sm_reply.text[sm_reply.length] = 0;
return sm_reply.code;
}
return NOTOK;
fgets (buffer, BUFSIZ, sm_rfp);
*len = strlen (buffer);
- if (ferror (sm_rfp) || feof (sm_rfp))
+ /* *len should be >0 except on EOF, but check for safety's sake */
+ if (ferror (sm_rfp) || feof (sm_rfp) || (*len == 0))
return sm_rerror ();
if (buffer[*len - 1] != '\n')
while (getc (sm_rfp) != '\n' && !ferror (sm_rfp) && !feof (sm_rfp))
continue;
else
- if (buffer[*len - 2] == '\r')
+ if ((*len > 1) && (buffer[*len - 2] == '\r'))
*len -= 1;
- buffer[*len - 1] = 0;
+ *len -= 1;
+ buffer[*len] = 0;
return OK;
}