X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/c4ceed07f17f67af7d96e7fd27c92eb374e62e19..f98442df114d9dda7efdc34a3ddfde088021299f:/src/src/tls.c

diff --git a/src/src/tls.c b/src/src/tls.c
index 92a36332d..55295108c 100644
--- a/src/src/tls.c
+++ b/src/src/tls.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* Copyright (c) University of Cambridge 1995 - 2016 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* This module provides TLS (aka SSL) support for Exim. The code for OpenSSL is
@@ -17,6 +17,7 @@ functions from the OpenSSL or GNU TLS libraries. */
 
 
 #include "exim.h"
+#include "transports/smtp.h"
 
 /* This module is compiled only when it is specifically requested in the
 build-time configuration. However, some compilers don't like compiling empty
@@ -30,15 +31,19 @@ static void dummy(int x) { dummy(x-1); }
 #else
 
 /* Static variables that are used for buffering data by both sets of
-functions and the common functions below. */
+functions and the common functions below.
 
+We're moving away from this; GnuTLS is already using a state, which
+can switch, so we can do TLS callouts during ACLs. */
 
-static uschar *ssl_xfer_buffer = NULL;
 static const int ssl_xfer_buffer_size = 4096;
+#ifndef USE_GNUTLS
+static uschar *ssl_xfer_buffer = NULL;
 static int ssl_xfer_buffer_lwm = 0;
 static int ssl_xfer_buffer_hwm = 0;
 static int ssl_xfer_eof = 0;
 static int ssl_xfer_error = 0;
+#endif
 
 uschar *tls_channelbinding_b64 = NULL;
 
@@ -75,14 +80,46 @@ return TRUE;
 }
 
 
+/*************************************************
+*        Timezone environment flipping           *
+*************************************************/
+
+static uschar *
+to_tz(uschar * tz)
+{
+uschar * old = US getenv("TZ");
+(void) setenv("TZ", CCS tz, 1);
+tzset();
+return old;
+}
+
+static void
+restore_tz(uschar * tz)
+{
+if (tz)
+  (void) setenv("TZ", CCS tz, 1);
+else
+  (void) os_unsetenv(US"TZ");
+tzset();
+}
+
 /*************************************************
 *        Many functions are package-specific     *
 *************************************************/
 
 #ifdef USE_GNUTLS
-#include "tls-gnu.c"
+# include "tls-gnu.c"
+# include "tlscert-gnu.c"
+
+# define ssl_xfer_buffer (state_server.xfer_buffer)
+# define ssl_xfer_buffer_lwm (state_server.xfer_buffer_lwm)
+# define ssl_xfer_buffer_hwm (state_server.xfer_buffer_hwm)
+# define ssl_xfer_eof (state_server.xfer_eof)
+# define ssl_xfer_error (state_server.xfer_error)
+
 #else
-#include "tls-openssl.c"
+# include "tls-openssl.c"
+# include "tlscert-openssl.c"
 #endif
 
 
@@ -93,6 +130,7 @@ return TRUE;
 
 /* Puts a character back in the input buffer. Only ever
 called once.
+Only used by the server-side TLS.
 
 Arguments:
   ch           the character
@@ -114,6 +152,7 @@ return ch;
 *************************************************/
 
 /* Tests for a previous EOF
+Only used by the server-side TLS.
 
 Arguments:     none
 Returns:       non-zero if the eof flag is set
@@ -133,6 +172,7 @@ return ssl_xfer_eof;
 
 /* Tests for a previous read error, and returns with errno
 restored to what it was when the error was detected.
+Only used by the server-side TLS.
 
 >>>>> Hmm. Errno not handled yet. Where do we get it from?  >>>>>
 
@@ -152,6 +192,7 @@ return ssl_xfer_error;
 *************************************************/
 
 /* Tests for unused chars in the TLS input buffer.
+Only used by the server-side TLS.
 
 Arguments:     none
 Returns:       TRUE/FALSE
@@ -166,4 +207,154 @@ return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm;
 
 #endif  /* SUPPORT_TLS */
 
+void
+tls_modify_variables(tls_support * dest_tsp)
+{
+modify_variable(US"tls_bits",                 &dest_tsp->bits);
+modify_variable(US"tls_certificate_verified", &dest_tsp->certificate_verified);
+modify_variable(US"tls_cipher",               &dest_tsp->cipher);
+modify_variable(US"tls_peerdn",               &dest_tsp->peerdn);
+#if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
+modify_variable(US"tls_sni",                  &dest_tsp->sni);
+#endif
+}
+
+
+#ifdef SUPPORT_TLS
+/************************************************
+*	TLS certificate name operations         *
+************************************************/
+
+/* Convert an rfc4514 DN to an exim comma-sep list.
+Backslashed commas need to be replaced by doublecomma
+for Exim's list quoting.  We modify the given string
+inplace.
+*/
+
+static void
+dn_to_list(uschar * dn)
+{
+uschar * cp;
+for (cp = dn; *cp; cp++)
+  if (cp[0] == '\\' && cp[1] == ',')
+    *cp++ = ',';
+}
+
+
+/* Extract fields of a given type from an RFC4514-
+format Distinguished Name.  Return an Exim list.
+NOTE: We modify the supplied dn string during operation.
+
+Arguments:
+	dn	Distinguished Name string
+	mod	list containing optional output list-sep and
+		field selector match, comma-separated
+Return:
+	allocated string with list of matching fields,
+	field type stripped
+*/
+
+uschar *
+tls_field_from_dn(uschar * dn, const uschar * mod)
+{
+int insep = ',';
+uschar outsep = '\n';
+uschar * ele;
+uschar * match = NULL;
+int len;
+uschar * list = NULL;
+
+while ((ele = string_nextinlist(&mod, &insep, NULL, 0)))
+  if (ele[0] != '>')
+    match = ele;	/* field tag to match */
+  else if (ele[1])
+    outsep = ele[1];	/* nondefault output separator */
+
+dn_to_list(dn);
+insep = ',';
+len = match ? Ustrlen(match) : -1;
+while ((ele = string_nextinlist(CUSS &dn, &insep, NULL, 0)))
+  if (  !match
+     || Ustrncmp(ele, match, len) == 0 && ele[len] == '='
+     )
+    list = string_append_listele(list, outsep, ele+len+1);
+return list;
+}
+
+
+/* Compare a domain name with a possibly-wildcarded name. Wildcards
+are restricted to a single one, as the first element of patterns
+having at least three dot-separated elements.  Case-independent.
+Return TRUE for a match
+*/
+static BOOL
+is_name_match(const uschar * name, const uschar * pat)
+{
+uschar * cp;
+return *pat == '*'		/* possible wildcard match */
+  ?    *++pat == '.'		/* starts star, dot              */
+    && !Ustrchr(++pat, '*')	/* has no more stars             */
+    && Ustrchr(pat, '.')	/* and has another dot.          */
+    && (cp = Ustrchr(name, '.'))/* The name has at least one dot */
+    && strcmpic(++cp, pat) == 0 /* and we only compare after it. */
+  :    !Ustrchr(pat+1, '*')
+    && strcmpic(name, pat) == 0;
+}
+
+/* Compare a list of names with the dnsname elements
+of the Subject Alternate Name, if any, and the
+Subject otherwise.
+
+Arguments:
+	namelist names to compare
+	cert	 certificate
+
+Returns:
+	TRUE/FALSE
+*/
+
+BOOL
+tls_is_name_for_cert(const uschar * namelist, void * cert)
+{
+uschar * altnames = tls_cert_subject_altname(cert, US"dns");
+uschar * subjdn;
+uschar * certname;
+int cmp_sep = 0;
+uschar * cmpname;
+
+if ((altnames = tls_cert_subject_altname(cert, US"dns")))
+  {
+  int alt_sep = '\n';
+  while ((cmpname = string_nextinlist(&namelist, &cmp_sep, NULL, 0)))
+    {
+    const uschar * an = altnames;
+    while ((certname = string_nextinlist(&an, &alt_sep, NULL, 0)))
+      if (is_name_match(cmpname, certname))
+	return TRUE;
+    }
+  }
+
+else if ((subjdn = tls_cert_subject(cert, NULL)))
+  {
+  int sn_sep = ',';
+
+  dn_to_list(subjdn);
+  while ((cmpname = string_nextinlist(&namelist, &cmp_sep, NULL, 0)))
+    {
+    const uschar * sn = subjdn;
+    while ((certname = string_nextinlist(&sn, &sn_sep, NULL, 0)))
+      if (  *certname++ == 'C'
+	 && *certname++ == 'N'
+	 && *certname++ == '='
+	 && is_name_match(cmpname, certname)
+	 )
+	return TRUE;
+    }
+  }
+return FALSE;
+}
+#endif	/*SUPPORT_TLS*/
+
+/* vi: aw ai sw=2
+*/
 /* End of tls.c */