SRS: fix encode operation for empty sender addresses.

6 files changed, 68 insertions, 50 deletions

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index e2111554c..7b92a2f21 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -42171,6 +42171,9 @@ There is no need to periodically change this key; a timestamp is also
 encoded.
 The second argument should be given as the envelope sender address before this
 encoding operation.
+.new
+If this value is empty the the expansion result will be empty.
+.wen
 The third argument should be the recipient domain of the message when
 it arrived at this system.
 .endlist
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index ff35328a1..72cd3c667 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -145,6 +145,9 @@ JH/32 Fix CHUNKING for a second message on a connection when the first was
       erroneously rejected the BDAT command.  Investigation help from
       Jesse Hathaway.
 
+JH/33 Fis ${srs_encode ...} to handle an empty sender address, now returning
+      an empty address.  Previously the expansion returned an error.
+
 
 Exim version 4.95
 -----------------
diff --git a/src/src/expand.c b/src/src/expand.c
index e59625858..06dc58cb1 100644
--- a/src/src/expand.c
+++ b/src/src/expand.c
@@ -6943,68 +6943,73 @@ while (*s)
         case 3: goto EXPAND_FAILED;
         }
 
-      g = string_catn(g, US"SRS0=", 5);
-
-      /* ${l_4:${hmac{md5}{SRS_SECRET}{${lc:$return_path}}}}= */
-      hmac_md5(sub[0], string_copylc(sub[1]), cksum, sizeof(cksum));
-      g = string_catn(g, cksum, sizeof(cksum));
-      g = string_catn(g, US"=", 1);
-
-      /* ${base32:${eval:$tod_epoch/86400&0x3ff}}= */
+      if (sub[1] && *(sub[1]))
 	{
-	struct timeval now;
-	unsigned long i;
-	gstring * h = NULL;
-
-	gettimeofday(&now, NULL);
-	for (unsigned long i = (now.tv_sec / 86400) & 0x3ff; i; i >>= 5)
-	  h = string_catn(h, &base32_chars[i & 0x1f], 1);
-	if (h) while (h->ptr > 0)
-	  g = string_catn(g, &h->s[--h->ptr], 1);
-	}
-      g = string_catn(g, US"=", 1);
+	g = string_catn(g, US"SRS0=", 5);
 
-      /* ${domain:$return_path}=${local_part:$return_path} */
-	{
-        int start, end, domain;
-        uschar * t = parse_extract_address(sub[1], &expand_string_message,
-					  &start, &end, &domain, FALSE);
-	uschar * s;
+	/* ${l_4:${hmac{md5}{SRS_SECRET}{${lc:$return_path}}}}= */
+	hmac_md5(sub[0], string_copylc(sub[1]), cksum, sizeof(cksum));
+	g = string_catn(g, cksum, sizeof(cksum));
+	g = string_catn(g, US"=", 1);
 
-        if (!t)
-	  goto EXPAND_FAILED;
+	/* ${base32:${eval:$tod_epoch/86400&0x3ff}}= */
+	  {
+	  struct timeval now;
+	  unsigned long i;
+	  gstring * h = NULL;
 
-	if (domain > 0) g = string_cat(g, t + domain);
+	  gettimeofday(&now, NULL);
+	  for (unsigned long i = (now.tv_sec / 86400) & 0x3ff; i; i >>= 5)
+	    h = string_catn(h, &base32_chars[i & 0x1f], 1);
+	  if (h) while (h->ptr > 0)
+	    g = string_catn(g, &h->s[--h->ptr], 1);
+	  }
 	g = string_catn(g, US"=", 1);
 
-	s = domain > 0 ? string_copyn(t, domain - 1) : t;
-	if ((quoted = Ustrchr(s, '"') != NULL))
+	/* ${domain:$return_path}=${local_part:$return_path} */
 	  {
-	  gstring * h = NULL;
-	  DEBUG(D_expand) debug_printf_indent("auto-quoting local part\n");
-	  while (*s)		/* de-quote */
+	  int start, end, domain;
+	  uschar * t = parse_extract_address(sub[1], &expand_string_message,
+					    &start, &end, &domain, FALSE);
+	  uschar * s;
+
+	  if (!t)
+	    goto EXPAND_FAILED;
+
+	  if (domain > 0) g = string_cat(g, t + domain);
+	  g = string_catn(g, US"=", 1);
+
+	  s = domain > 0 ? string_copyn(t, domain - 1) : t;
+	  if ((quoted = Ustrchr(s, '"') != NULL))
 	    {
-	    while (*s && *s != '"') h = string_catn(h, s++, 1);
-	    if (*s) s++;
-	    while (*s && *s != '"') h = string_catn(h, s++, 1);
-	    if (*s) s++;
+	    gstring * h = NULL;
+	    DEBUG(D_expand) debug_printf_indent("auto-quoting local part\n");
+	    while (*s)		/* de-quote */
+	      {
+	      while (*s && *s != '"') h = string_catn(h, s++, 1);
+	      if (*s) s++;
+	      while (*s && *s != '"') h = string_catn(h, s++, 1);
+	      if (*s) s++;
+	      }
+	    gstring_release_unused(h);
+	    s = string_from_gstring(h);
 	    }
-	  gstring_release_unused(h);
-	  s = string_from_gstring(h);
+	  g = string_cat(g, s);
 	  }
-	g = string_cat(g, s);
-        }
 
-      /* Assume that if the original local_part had quotes
-      it was for good reason */
+	/* Assume that if the original local_part had quotes
+	it was for good reason */
 
-      if (quoted) yield = string_catn(yield, US"\"", 1);
-      yield = string_catn(yield, g->s, g->ptr);
-      if (quoted) yield = string_catn(yield, US"\"", 1);
+	if (quoted) yield = string_catn(yield, US"\"", 1);
+	yield = string_catn(yield, g->s, g->ptr);
+	if (quoted) yield = string_catn(yield, US"\"", 1);
 
-      /* @$original_domain */
-      yield = string_catn(yield, US"@", 1);
-      yield = string_cat(yield, sub[2]);
+	/* @$original_domain */
+	yield = string_catn(yield, US"@", 1);
+	yield = string_cat(yield, sub[2]);
+	}
+      else
+	DEBUG(D_expand) debug_printf_indent("null return_path for srs-encode\n");
 
       if (skipping) continue;
       break;
diff --git a/src/src/parse.c b/src/src/parse.c
index f156865c8..bdba3ecd0 100644
--- a/src/src/parse.c
+++ b/src/src/parse.c
@@ -658,7 +658,7 @@ followed by a route-addr (more words must follow). */
 
 if (*s != '@' && *s != '<')
   {
-  if (*s == 0 || *s == ';')
+  if (!*s || *s == ';')
     {
     if (!*t) FAILED(US"empty address");
     endptr = last_comment_position;
diff --git a/test/scripts/4620-SRS/4620 b/test/scripts/4620-SRS/4620
index f180142a6..8119c295f 100644
--- a/test/scripts/4620-SRS/4620
+++ b/test/scripts/4620-SRS/4620
@@ -40,4 +40,9 @@ exim -DCONTROL=remote -q
 exim -q
 ****
 #
+# Sender which is empty (already a bounce)
+exim -be
+>${srs_encode {mysecret} {} {test.ex}}<
+****
+#
 killdaemon
diff --git a/test/stdout/4620 b/test/stdout/4620
index 7883638a6..c1fcaf1d1 100644
--- a/test/stdout/4620
+++ b/test/stdout/4620
@@ -1,3 +1,5 @@
 > SRS0=ZZZZ=YY=the.local.host.name=CALLER@test.ex
 > "SRS0=ZZZZ=YY=the.local.host.name=CALLER"@test.ex
 > 
+> ><
+>