X-Git-Url: http://git.marmaro.de/?p=mmh;a=blobdiff_plain;f=mts%2Fsmtp%2Fsmtp.c;h=ca56781a637e73ff82df35ee7aec64181deb8f42;hp=c8fb5548d8965eb7a4a1a47aa70447ab4d93bf05;hb=6c42153ad9362cc676ea66563bf400d7511b3b68;hpb=df7b16cb148474b3b80dbf1e226e858cf1e47edb

diff --git a/mts/smtp/smtp.c b/mts/smtp/smtp.c
index c8fb554..ca56781 100644
--- a/mts/smtp/smtp.c
+++ b/mts/smtp/smtp.c
@@ -1,19 +1,31 @@
-
 /*
  * 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.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
@@ -57,6 +69,7 @@
 #define	SM_DOT	180
 #define	SM_QUIT	 30
 #define	SM_CLOS	 10
+#define	SM_AUTH  45
 
 static int sm_addrs = 0;
 static int sm_alarmed = 0;
@@ -73,6 +86,28 @@ static int sm_ispool = 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_LIST_END, NULL, NULL },
+};
+#endif /* CYRUS_SASL */
+
 static char *sm_noreply = "No reply text given";
 static char *sm_moreply = "; ";
 
@@ -86,7 +121,8 @@ char *EHLOkeys[MAXEHLO + 1];
 /*
  * 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 *);
@@ -110,16 +146,25 @@ static int smail_brkany (char, char *);
 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);
@@ -127,8 +172,12 @@ sm_init (char *client, char *server, int watch, int verbose,
 
 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)
@@ -227,6 +276,35 @@ all_done: ;
 	}
     }
 
+#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");
@@ -423,6 +501,14 @@ rclient (char *server, char *protocol, char *service)
     return NOTOK;
 }
 
+#ifdef CYRUS_SASL
+#include <sasl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <errno.h>
+#endif /* CYRUS_SASL */
 
 int
 sm_winit (int mode, char *from)
@@ -644,9 +730,13 @@ sm_end (int type)
 	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;
     }
@@ -1007,6 +1097,306 @@ no_dice:
 #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, outlen;
+    unsigned int buflen;
+    char *buf, outbuf[BUFSIZ];
+    const char *chosen_mech;
+    sasl_security_properties_t secprops;
+    sasl_external_properties_t extprops;
+    sasl_ssf_t *ssf;
+    int *outbufmax;
+
+    /*
+     * Initialize the callback contexts
+     */
+
+    if (user == NULL)
+	user = getusername();
+
+    callbacks[SM_SASL_N_CB_USER].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, SASL_SECURITY_LAYER, &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 */
+    memset(&extprops, 0, sizeof(extprops));
+
+    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;
+    }
+
+    result = sasl_setprop(conn, SASL_SSF_EXTERNAL, &extprops);
+
+    if (result != SASL_OK) {
+	sm_ierror("SASL external 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, NULL, &buf, &buflen,
+			       &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);
+	free(buf);
+	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, &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, &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);
+	free(buf);
+
+	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;
+
+    /*
+     * Depending on the mechanism, we need to do a FINAL call to
+     * sasl_client_step().  Do that now.
+     */
+
+    result = sasl_client_step(conn, NULL, 0, NULL, &buf, &buflen);
+
+    if (result != SASL_OK) {
+	sm_ierror("SASL final client negotiation failed: %s",
+		  sasl_errstring(result, NULL, NULL));
+	return NOTOK;
+    }
+
+    /*
+     * We _should_ have completed the authentication successfully.
+     * Get a few properties from the authentication exchange.
+     */
+
+    result = sasl_getprop(conn, SASL_MAXOUTBUF, (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, (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)
+	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((*psecret)->data, pass);
+/*    free(pass); */
+
+    return SASL_OK;
+}
+#endif /* CYRUS_SASL */
+
 static int
 sm_ierror (char *fmt, ...)
 {