Update description and references for X.509 files
diff --git a/library/x509_crl.c b/library/x509_crl.c
index 7f8600d..7dd53c2 100644
--- a/library/x509_crl.c
+++ b/library/x509_crl.c
@@ -1,5 +1,5 @@
/*
- * X.509 certificate and private key decoding
+ * X.509 Certidicate Revocation List (CRL) parsing
*
* Copyright (C) 2006-2014, Brainspark B.V.
*
@@ -25,10 +25,9 @@
/*
* The ITU-T X.509 standard defines a certificate format for PKI.
*
- * http://www.ietf.org/rfc/rfc3279.txt
- * http://www.ietf.org/rfc/rfc3280.txt
- *
- * ftp://ftp.rsasecurity.com/pub/pkcs/ascii/pkcs-1v2.asc
+ * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
+ * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
+ * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
*
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf