RFC 6960, "X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP", June 2013

Note: This RFC has been updated by RFC 8954

Errata ID: 6165
Status: Reported
Type: Technical
Publication Format(s) : TEXT
Reported By: Yury Strozhevsky
Date Reported: 2020-05-11

Section 1 says:

---

It should say:

   o  Appendix B.1 provides correct KeyHash type processing description. Now SHA-1 hash must be calculated for responder's public key ASN.1 value without tag, length and unused bits.

Notes:

The RFC6960 changes OCSP protocol in part of KeyHash type calculation. In RFC2560 there is the description:
KeyHash ::= OCTET STRING -- SHA-1 hash of responder's public key
(excluding the tag and length fields)

But in Appendix B.1, which is the major OCSP descriptive module, stated:
KeyHash ::= OCTET STRING -- SHA-1 hash of responder's public key
-- (i.e., the SHA-1 hash of the value of the
-- BIT STRING subjectPublicKey [excluding
-- the tag, length, and number of unused
-- bits] in the responder's certificate)

The difference is in what would be under SHA-1 hash. In RFC2560 KeyHash would be calculated for entire BIT STRING value, with "unused bits" byte (first byte in BIT STRING value), but Appendix B.1 in RFC6960 states that SHA-1 hash must be calculated for BIT STRING value without "unused bits".

Report New Errata