SECURITY: DKIM DNS buffer overflow protection

[users/jgh/exim.git] / src / src / dkim.c

diff --git a/src/src/dkim.c b/src/src/dkim.c
index e25ff8c85e9095d4d950030de3d42e4102ecdd11..05b5fec56e62073f4f5d1d1640ee42d7ca782bad 100644 (file)
--- a/src/src/dkim.c
+++ b/src/src/dkim.c
@@ -1,5 +1,3 @@
-/* $Cambridge: exim/src/src/dkim.c,v 1.15 2010/06/12 13:54:38 jetmore Exp $ */
-
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
@@ -44,6 +42,9 @@ int dkim_exim_query_dns_txt(char *name, char *answer) {
                "%.*s", (int)len, (char *)((rr->data)+rr_offset));
       rr_offset+=len;
       answer_offset+=len;
+      if (answer_offset >= PDKIM_DNS_TXT_MAX_RECLEN) {
+        return PDKIM_FAIL;
+      }
     }
   }
   else return PDKIM_FAIL;
@@ -108,7 +109,7 @@ void dkim_exim_verify_finish(void) {
     /* Log a line for each signature */
     uschar *logmsg = string_append(NULL, &size, &ptr, 5,
 
-      string_sprintf( "DKIM: d=%s s=%s c=%s/%s a=%s ",
+      string_sprintf( "d=%s s=%s c=%s/%s a=%s ",
                       sig->domain,
                       sig->selector,
                       (sig->canon_headers == PDKIM_CANON_SIMPLE)?"simple":"relaxed",
@@ -176,7 +177,7 @@ void dkim_exim_verify_finish(void) {
     }
 
     logmsg[ptr] = '\0';
-    log_write(0, LOG_MAIN, (char *)logmsg);
+    log_write(0, LOG_MAIN, "DKIM: %s", logmsg);
 
     /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */
     dkim_signers = string_append(dkim_signers,