X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/4398228719841b08524520b8c07faeb3bee89705..56ac062a3ff94fc4e1bbfc2293119c079a4e980b:/src/src/arc.c

diff --git a/src/src/arc.c b/src/src/arc.c
index c860aed36..6c4bcc641 100644
--- a/src/src/arc.c
+++ b/src/src/arc.c
@@ -93,6 +93,7 @@ static time_t now;
 static time_t expire;
 static hdr_rlist * headers_rlist;
 static arc_ctx arc_sign_ctx = { NULL };
+static arc_ctx arc_verify_ctx = { NULL };
 
 
 /******************************************************************************/
@@ -382,7 +383,7 @@ static uschar *
 arc_insert_hdr(arc_ctx * ctx, header_line * h, unsigned off, unsigned hoff,
   BOOL instance_only)
 {
-int i;
+unsigned i;
 arc_set * as;
 arc_line * al = store_get(sizeof(arc_line)), ** alp;
 uschar * e;
@@ -395,6 +396,7 @@ if ((e = arc_parse_line(al, h, off, instance_only)))
   return US"line parse";
   }
 if (!(i = arc_instance_from_hdr(al)))	return US"instance find";
+if (i > 50)				return US"overlarge instance number";
 if (!(as = arc_find_set(ctx, i)))	return US"set find";
 if (*(alp = (arc_line **)(US as + hoff))) return US"dup hdr";
 
@@ -767,24 +769,26 @@ arc_headers_check(arc_ctx * ctx)
 arc_set * as;
 int inst;
 BOOL ams_fail_found = FALSE;
-uschar * ret = NULL;
 
-if (!(as = ctx->arcset_chain))
+if (!(as = ctx->arcset_chain_last))
   return US"none";
 
-for(inst = 0; as; as = as->next)
+for(inst = as->instance; as; as = as->prev, inst--)
   {
-  if (  as->instance != ++inst
-     || !as->hdr_aar || !as->hdr_ams || !as->hdr_as
-     || arc_cv_match(as->hdr_as, US"fail")
-     )
-    {
-    arc_state_reason = string_sprintf("i=%d"
-      " (cv, sequence or missing header)", as->instance);
-    DEBUG(D_acl) debug_printf("ARC chain fail at %s\n", arc_state_reason);
-    return US"fail";
-    }
+  if (as->instance != inst)
+    arc_state_reason = string_sprintf("i=%d (sequence; expected %d)",
+      as->instance, inst);
+  else if (!as->hdr_aar || !as->hdr_ams || !as->hdr_as)
+    arc_state_reason = string_sprintf("i=%d (missing header)", as->instance);
+  else if (arc_cv_match(as->hdr_as, US"fail"))
+    arc_state_reason = string_sprintf("i=%d (cv)", as->instance);
+  else
+    goto good;
+
+  DEBUG(D_acl) debug_printf("ARC chain fail at %s\n", arc_state_reason);
+  return US"fail";
 
+  good:
   /* Evaluate the oldest-pass AMS validation while we're here.
   It does not affect the AS chain validation but is reported as
   auxilary info. */
@@ -796,23 +800,29 @@ for(inst = 0; as; as = as->next)
       arc_oldest_pass = inst;
   arc_state_reason = NULL;
   }
+if (inst != 0)
+  {
+  arc_state_reason = string_sprintf("(sequence; expected i=%d)", inst);
+  DEBUG(D_acl) debug_printf("ARC chain fail %s\n", arc_state_reason);
+  return US"fail";
+  }
 
 arc_received = ctx->arcset_chain_last;
-arc_received_instance = inst;
-if (ret)
-  return ret;
+arc_received_instance = arc_received->instance;
 
 /* We can skip the latest-AMS validation, if we already did it. */
 
 as = ctx->arcset_chain_last;
-if (as->ams_verify_done && !as->ams_verify_passed)
+if (!as->ams_verify_passed)
   {
-  arc_state_reason = as->ams_verify_done;
-  return US"fail";
+  if (as->ams_verify_done)
+    {
+    arc_state_reason = as->ams_verify_done;
+    return US"fail";
+    }
+  if (!!arc_ams_verify(ctx, as))
+    return US"fail";
   }
-if (!!arc_ams_verify(ctx, as))
-  return US"fail";
-
 return NULL;
 }
 
@@ -974,16 +984,13 @@ return NULL;
 static const uschar *
 arc_verify_seals(arc_ctx * ctx)
 {
-arc_set * as = ctx->arcset_chain;
+arc_set * as = ctx->arcset_chain_last;
 
 if (!as)
   return US"none";
 
-while (as)
-  {
-  if (arc_seal_verify(ctx, as)) return US"fail";
-  as = as->next;
-  }
+for ( ; as; as = as->prev) if (arc_seal_verify(ctx, as)) return US"fail";
+
 DEBUG(D_acl) debug_printf("ARC: AS vfy overall pass\n");
 return NULL;
 }
@@ -998,9 +1005,10 @@ Return:  The ARC state, or NULL on error.
 const uschar *
 acl_verify_arc(void)
 {
-arc_ctx ctx = { NULL };
 const uschar * res;
 
+memset(&arc_verify_ctx, 0, sizeof(arc_verify_ctx));
+
 if (!dkim_verify_ctx)
   {
   DEBUG(D_acl) debug_printf("ARC: no DKIM verify context\n");
@@ -1014,7 +1022,7 @@ https://tools.ietf.org/html/draft-ietf-dmarc-arc-protocol-10#section-6
        none, the ARC state is "none" and the algorithm stops here.
 */
 
-if ((res = arc_vfy_collect_hdrs(&ctx)))
+if ((res = arc_vfy_collect_hdrs(&arc_verify_ctx)))
   goto out;
 
 /* 2.  If the form of any ARC set is invalid (e.g., does not contain
@@ -1032,7 +1040,7 @@ if ((res = arc_vfy_collect_hdrs(&ctx)))
        then the chain state is "fail" and the algorithm stops here.
 */
 
-if ((res = arc_headers_check(&ctx)))
+if ((res = arc_headers_check(&arc_verify_ctx)))
   goto out;
 
 /* 4.  For each ARC-Seal from the "N"th instance to the first, apply the
@@ -1074,7 +1082,7 @@ if ((res = arc_headers_check(&ctx)))
        the algorithm is complete.
 */
 
-if ((res = arc_verify_seals(&ctx)))
+if ((res = arc_verify_seals(&arc_verify_ctx)))
   goto out;
 
 res = US"pass";
@@ -1186,7 +1194,7 @@ arc_line * al = (arc_line *)(as+1);
 header_line * h = (header_line *)(al+1);
 
 g = string_catn(g, ARC_HDR_AAR, ARC_HDRLEN_AAR);
-g = string_cat(g, string_sprintf(" i=%d; %s;\r\n\t", instance, identity));
+g = string_fmt_append(g, " i=%d; %s;\r\n\t", instance, identity);
 g = string_catn(g, US ar->data, ar->len);
 
 h->slen = g->ptr - aar_off;
@@ -1247,6 +1255,9 @@ if (  (errstr = exim_dkim_signing_init(privkey, &sctx))
    || (errstr = exim_dkim_sign(&sctx, hm, &hhash, sig)))
   {
   log_write(0, LOG_MAIN, "ARC: %s signing: %s\n", why, errstr);
+  DEBUG(D_transport)
+    debug_printf("private key, or private-key file content, was: '%s'\n",
+      privkey);
   return FALSE;
   }
 return TRUE;
@@ -1296,20 +1307,14 @@ header_line * h = (header_line *)(al+1);
 /* Construct the to-be-signed AMS pseudo-header: everything but the sig. */
 
 ams_off = g->ptr;
-g = string_append(g, 7,
-      ARC_HDR_AMS,
-      US" i=", string_sprintf("%d", instance),
-      US"; a=rsa-sha256; c=relaxed; d=", identity,		/*XXX hardwired */
-      US"; s=", selector);
+g = string_fmt_append(g, "%s i=%d; a=rsa-sha256; c=relaxed; d=%s; s=%s",
+      ARC_HDR_AMS, instance, identity, selector);	/*XXX hardwired a= */
 if (options & ARC_SIGN_OPT_TSTAMP)
-  g = string_append(g, 2,
-      US"; t=", string_sprintf("%lu", (u_long)now));
+  g = string_fmt_append(g, "; t=%lu", (u_long)now);
 if (options & ARC_SIGN_OPT_EXPIRE)
-  g = string_append(g, 2,
-      US"; x=", string_sprintf("%lu", (u_long)expire));
-g = string_append(g, 3,
-      US";\r\n\tbh=", pdkim_encode_base64(bodyhash),
-      US";\r\n\th=");
+  g = string_fmt_append(g, "; x=%lu", (u_long)expire);
+g = string_fmt_append(g, ";\r\n\tbh=%s;\r\n\th=",
+      pdkim_encode_base64(bodyhash));
 
 for(col = 3; rheaders; rheaders = rheaders->prev)
   {
@@ -1569,7 +1574,7 @@ expire = now = 0;
 
 identity = string_nextinlist(&signspec, &sep, NULL, 0);
 selector = string_nextinlist(&signspec, &sep, NULL, 0);
-if (  !*identity | !*selector
+if (  !*identity || !*selector
    || !(privkey = string_nextinlist(&signspec, &sep, NULL, 0)) || !*privkey)
   {
   log_write(0, LOG_MAIN, "ARC: bad signing-specification (%s)",
@@ -1594,13 +1599,13 @@ if ((opts = string_nextinlist(&signspec, &sep, NULL, 0)))
       if (*(s += 6) == '=')
 	if (*++s == '+')
 	  {
-	  if (!(expire = (time_t)atoi(++s)))
+	  if (!(expire = (time_t)atoi(CS ++s)))
 	    expire = ARC_SIGN_DEFAULT_EXPIRE_DELTA;
 	  if (!now) now = time(NULL);
 	  expire += now;
 	  }
 	else
-	  expire = (time_t)atol(s);
+	  expire = (time_t)atol(CS s);
       else
 	{
 	if (!now) now = time(NULL);
@@ -1618,18 +1623,17 @@ string_from_gstring(sigheaders);
 if ((rheaders = arc_sign_scan_headers(&arc_sign_ctx, sigheaders)))
   {
   hdr_rlist ** rp;
-  for (rp = &rheaders; *rp; ) rp = &(*rp)->prev;
-  *rp = headers_rlist;
-  headers_rlist = rheaders;
+  for (rp = &headers_rlist; *rp; ) rp = &(*rp)->prev;
+  *rp = rheaders;
   }
-else
-  rheaders = headers_rlist;
 
 /* Finally, build a normal-order headers list */
 /*XXX only needed for hunt-the-AR? */
+/*XXX also, we really should be accepting any number of ADMD-matching ARs */
   {
   header_line * hnext = NULL;
-  for (; rheaders; hnext = rheaders->h, rheaders = rheaders->prev)
+  for (rheaders = headers_rlist; rheaders;
+       hnext = rheaders->h, rheaders = rheaders->prev)
     rheaders->h->next = hnext;
   headers = hnext;
   }
@@ -1686,12 +1690,13 @@ g = arc_sign_append_ams(g, &arc_sign_ctx, instance, identity, selector,
         including self (but with an empty b= in self)
 */
 
-g = arc_sign_prepend_as(g, &arc_sign_ctx, instance, identity, selector, &ar,
+if (g)
+  g = arc_sign_prepend_as(g, &arc_sign_ctx, instance, identity, selector, &ar,
       privkey, options);
 
 /* Finally, append the dkim headers and return the lot. */
 
-g = string_catn(g, sigheaders->s, sigheaders->ptr);
+if (sigheaders) g = string_catn(g, sigheaders->s, sigheaders->ptr);
 (void) string_from_gstring(g);
 gstring_reset_unused(g);
 return g;
@@ -1773,7 +1778,37 @@ return is_vfy ? arc_header_vfy_feed(g) : arc_header_sign_feed(g);
 
 /******************************************************************************/
 
-/* Construct an Authenticate-Results header portion, for the ARC module */
+/* Construct the list of domains from the ARC chain after validation */
+
+uschar *
+fn_arc_domains(void)
+{
+arc_set * as;
+unsigned inst;
+gstring * g = NULL;
+
+for (as = arc_verify_ctx.arcset_chain, inst = 1; as; as = as->next, inst++)
+  {
+  arc_line * hdr_as = as->hdr_as;
+  if (hdr_as)
+    {
+    blob * d = &hdr_as->d;
+
+    for (; inst < as->instance; inst++)
+      g = string_catn(g, US":", 1);
+
+    g = d->data && d->len
+      ? string_append_listele_n(g, ':', d->data, d->len)
+      : string_catn(g, US":", 1);
+    }
+  else
+    g = string_catn(g, US":", 1);
+  }
+return g ? g->s : US"";
+}
+
+
+/* Construct an Authentication-Results header portion, for the ARC module */
 
 gstring *
 authres_arc(gstring * g)
@@ -1787,19 +1822,17 @@ if (arc_state)
   g = string_append(g, 2, US";\n\tarc=", arc_state);
   if (arc_received_instance > 0)
     {
-    g = string_append(g, 3, US" (i=",
-      string_sprintf("%d", arc_received_instance), US")");
+    g = string_fmt_append(g, " (i=%d)", arc_received_instance);
     if (arc_state_reason)
       g = string_append(g, 3, US"(", arc_state_reason, US")");
     g = string_catn(g, US" header.s=", 10);
     highest_ams = arc_received->hdr_ams;
     g = string_catn(g, highest_ams->s.data, highest_ams->s.len);
 
-    g = string_append(g, 2,
-      US" arc.oldest-pass=", string_sprintf("%d", arc_oldest_pass));
+    g = string_fmt_append(g, " arc.oldest-pass=%d", arc_oldest_pass);
 
     if (sender_host_address)
-      g = string_append(g, 2, US" smtp.client-ip=", sender_host_address);
+      g = string_append(g, 2, US" smtp.remote-ip=", sender_host_address);
     }
   else if (arc_state_reason)
     g = string_append(g, 3, US" (", arc_state_reason, US")");