$NetBSD: patch-aa,v 1.4 2010/09/10 23:33:42 gdt Exp $

This patch has hunks for three separate reasons:

1) Ancient fix to avoid going beyond s2.

2) Added CVE-2010-1132 patch from:

  https://bugzilla.redhat.com/attachment.cgi?id=401011

3) (Most of, some in .h) patch to add option to not scan mail from
authenticated users, from:

  http://lists.freebsd.org/pipermail/freebsd-ports-bugs/2006-November/106024.html

--- spamass-milter.cpp.orig	2010-09-10 15:50:58.000000000 +0000
+++ spamass-milter.cpp
@@ -170,10 +170,7 @@ char *spambucket;
 bool flag_full_email = false;		/* pass full email address to spamc */
 bool flag_expand = false;	/* alias/virtusertable expansion */
 bool warnedmacro = false;	/* have we logged that we couldn't fetch a macro? */
-
-#if defined(__FreeBSD__) /* popen bug - see PR bin/50770 */
-static pthread_mutex_t popen_mutex = PTHREAD_MUTEX_INITIALIZER;
-#endif
+bool auth = false;		/* don't scan authenticated users */
 
 // {{{ main()
 
@@ -181,7 +178,7 @@ int
 main(int argc, char* argv[])
 {
    int c, err = 0;
-   const char *args = "fd:mMp:P:r:u:D:i:b:B:e:x";
+   const char *args = "fd:mMp:P:r:u:D:i:b:B:e:xa";
    char *sock = NULL;
    bool dofork = false;
    char *pidfilename = NULL;
@@ -196,6 +193,9 @@ main(int argc, char* argv[])
 	/* Process command line options */
 	while ((c = getopt(argc, argv, args)) != -1) {
 		switch (c) {
+			case 'a':
+				auth = true;
+				break;
 			case 'f':
 				dofork = true;
 				break;
@@ -281,7 +281,7 @@ main(int argc, char* argv[])
       cout << "SpamAssassin Sendmail Milter Plugin" << endl;
       cout << "Usage: spamass-milter -p socket [-b|-B bucket] [-d xx[,yy...]] [-D host]" << endl;
       cout << "                      [-e defaultdomain] [-f] [-i networks] [-m] [-M]" << endl;
-      cout << "                      [-P pidfile] [-r nn] [-u defaultuser] [-x]" << endl;
+      cout << "                      [-P pidfile] [-r nn] [-u defaultuser] [-x] [-a]" << endl;
       cout << "                      [-- spamc args ]" << endl;
       cout << "   -p socket: path to create socket" << endl;
       cout << "   -b bucket: redirect spam to this mail address.  The orignal" << endl;
@@ -302,6 +302,7 @@ main(int argc, char* argv[])
       cout << "   -u defaultuser: pass the recipient's username to spamc.\n"
               "          Uses 'defaultuser' if there are multiple recipients." << endl;
       cout << "   -x: pass email address through alias and virtusertable expansion." << endl;
+      cout << "   -a: don't scan messages over an authenticated connection." << endl;
       cout << "   -- spamc args: pass the remaining flags to spamc." << endl;
               
       exit(EX_USAGE);
@@ -461,59 +462,24 @@ assassinate(SMFICTX* ctx, SpamAssassin* 
 			   send another copy.  The milter API will not let you send the
 			   message AND return a failure code to the sender, so this is
 			   the only way to do it. */
-#if defined(__FreeBSD__)
-			int rv;
-#endif
-			
-#if defined(HAVE_ASPRINTF)
-			char *buf;
-#else
-			char buf[1024];
-#endif
-			char *fmt="%s \"%s\"";
+			char *popen_argv[3];
 			FILE *p;
 
-#if defined(HAVE_ASPRINTF)
-			asprintf(&buf, fmt, SENDMAIL, spambucket);
-#else
-#if defined(HAVE_SNPRINTF)
-			snprintf(buf, sizeof(buf)-1, fmt, SENDMAIL, spambucket);
-#else
-			/* XXX possible buffer overflow here */
-			sprintf(buf, fmt, SENDMAIL, spambucket);
-#endif
-#endif
-
-			debug(D_COPY, "calling %s", buf);
-#if defined(__FreeBSD__) /* popen bug - see PR bin/50770 */
-			rv = pthread_mutex_lock(&popen_mutex);
-			if (rv)
-			{
-				debug(D_ALWAYS, "Could not lock popen mutex: %s", strerror(rv));
-				abort();
-			}		
-#endif
-			p = popen(buf, "w");
+			popen_argv[0] = SENDMAIL;
+			popen_argv[1] = spambucket;
+			popen_argv[2] = NULL;
+			
+			debug(D_COPY, "calling %s %s", SENDMAIL, spambucket);
+			p = popenv(popen_argv, "w");
 			if (!p)
 			{
-				debug(D_COPY, "popen failed(%s).  Will not send a copy to spambucket", strerror(errno));
+				debug(D_COPY, "popenv failed(%s).  Will not send a copy to spambucket", strerror(errno));
 			} else
 			{
 				// Send message provided by SpamAssassin
 				fwrite(assassin->d().c_str(), assassin->d().size(), 1, p);
-				pclose(p); p = NULL;
+				fclose(p); p = NULL;
 			}
-#if defined(__FreeBSD__)
-			rv = pthread_mutex_unlock(&popen_mutex);
-			if (rv)
-			{
-				debug(D_ALWAYS, "Could not unlock popen mutex: %s", strerror(rv));
-				abort();
-			}		
-#endif
-#if defined(HAVE_ASPRINTF)
-			free(buf);
-#endif 
 		}
 		return SMFIS_REJECT;
 	}
@@ -783,6 +749,15 @@ mlfi_envfrom(SMFICTX* ctx, char** envfro
   }
   /* debug(D_ALWAYS, "ZZZ got private context %p", sctx); */
 
+  if (auth) {
+    const char *auth_type = smfi_getsymval(ctx, "{auth_type}");
+
+    if (auth_type) {
+      debug(D_MISC, "auth_type=%s", auth_type);
+      return SMFIS_ACCEPT;
+    }
+  }
+
   debug(D_FUNC, "mlfi_envfrom: enter");
   try {
     // launch new SpamAssassin
@@ -842,30 +817,19 @@ mlfi_envrcpt(SMFICTX* ctx, char** envrcp
 		/* open a pipe to sendmail so we can do address expansion */
 
 		char buf[1024];
-		char *fmt="%s -bv \"%s\" 2>&1";
-
-#if defined(HAVE_SNPRINTF)
-		snprintf(buf, sizeof(buf)-1, fmt, SENDMAIL, envrcpt[0]);
-#else
-		/* XXX possible buffer overflow here */
-		sprintf(buf, fmt, SENDMAIL, envrcpt[0]);
-#endif
-
-		debug(D_RCPT, "calling %s", buf);
+		char *popen_argv[4];
+		
+		popen_argv[0] = SENDMAIL;
+		popen_argv[1] = "-bv";
+		popen_argv[2] = envrcpt[0];
+		popen_argv[3] = NULL;
 
-#if defined(__FreeBSD__) /* popen bug - see PR bin/50770 */
-		rv = pthread_mutex_lock(&popen_mutex);
-		if (rv)
-		{
-			debug(D_ALWAYS, "Could not lock popen mutex: %s", strerror(rv));
-			abort();
-		}		
-#endif
+		debug(D_RCPT, "calling %s -bv %s", SENDMAIL, envrcpt[0]);
 
-		p = popen(buf, "r");
+		p = popenv(popen_argv, "r");
 		if (!p)
 		{
-			debug(D_RCPT, "popen failed(%s).  Will not expand aliases", strerror(errno));
+			debug(D_RCPT, "popenv failed(%s).  Will not expand aliases", strerror(errno));
 			assassin->expandedrcpt.push_back(envrcpt[0]);
 		} else
 		{
@@ -890,16 +854,8 @@ mlfi_envrcpt(SMFICTX* ctx, char** envrcp
 					assassin->expandedrcpt.push_back(p+7);
 				}
 			}
-			pclose(p); p = NULL;
+			fclose(p); p = NULL;
 		}
-#if defined(__FreeBSD__)
-		rv = pthread_mutex_unlock(&popen_mutex);
-		if (rv)
-		{
-			debug(D_ALWAYS, "Could not unlock popen mutex: %s", strerror(rv));
-			abort();
-		}		
-#endif
 	} else
 	{
 		assassin->expandedrcpt.push_back(envrcpt[0]);
@@ -2033,7 +1989,7 @@ cmp_nocase_partial(const string& s, cons
   string::const_iterator p=s.begin();
   string::const_iterator p2=s2.begin();
 
-  while ( p != s.end() && p2 <= s2.end() ) {
+  while ( p != s.end() ) {
     if (toupper(*p) != toupper(*p2))
     {
       debug(D_STR, "c_nc_p: <%s><%s> : miss", s.c_str(), s2.c_str());
@@ -2157,5 +2113,71 @@ void warnmacro(char *macro, char *scope)
 	warnedmacro = true;
 }
 
+/*
+   untrusted-argument-safe popen function - only supports "r" and "w" modes
+   for simplicity, and always reads stdout and stderr in "r" mode.  Call
+   fclose to close the FILE.
+*/
+FILE *popenv(char *const argv[], const char *type)
+{
+	FILE *iop;
+	int pdes[2];
+	int save_errno;
+	if ((*type != 'r' && *type != 'w') || type[1])
+	{
+		errno = EINVAL;
+		return (NULL);
+	}
+	if (pipe(pdes) < 0)
+		return (NULL);
+	switch (fork()) {
+	
+	case -1:			/* Error. */
+		save_errno = errno;
+		(void)close(pdes[0]);
+		(void)close(pdes[1]);
+		errno = save_errno;
+		return (NULL);
+		/* NOTREACHED */
+	case 0:				/* Child. */
+		if (*type == 'r') {
+			/*
+			 * The dup2() to STDIN_FILENO is repeated to avoid
+			 * writing to pdes[1], which might corrupt the
+			 * parent's copy.  This isn't good enough in
+			 * general, since the exit() is no return, so
+			 * the compiler is free to corrupt all the local
+			 * variables.
+			 */
+			(void)close(pdes[0]);
+			(void)dup2(pdes[1], STDOUT_FILENO);
+			(void)dup2(pdes[1], STDERR_FILENO);
+			if (pdes[1] != STDOUT_FILENO && pdes[1] != STDERR_FILENO) {
+				(void)close(pdes[1]);
+			} 
+		} else {
+			if (pdes[0] != STDIN_FILENO) {
+				(void)dup2(pdes[0], STDIN_FILENO);
+				(void)close(pdes[0]);
+			}
+			(void)close(pdes[1]);
+		}
+		execv(argv[0], argv);
+		exit(127);
+		/* NOTREACHED */
+	}
+
+	/* Parent; assume fdopen can't fail. */
+	if (*type == 'r') {
+		iop = fdopen(pdes[0], type);
+		(void)close(pdes[1]);
+	} else {
+		iop = fdopen(pdes[1], type);
+		(void)close(pdes[0]);
+	}
+
+	return (iop);
+}
+
 // }}}
 // vim6:ai:noexpandtab
