Subject: [Cfrg] [Errata Verified] RFC8439 (5689)

From: RFC Errata System <[email-masked]>
Date: Mon, 15 Apr 2019 03:54:31 -0700 (PDT)

The following errata report has been verified for RFC8439,
"ChaCha20 and Poly1305 for IETF Protocols". 

--------------------------------------
You may review the report below and at:
http://www.rfc-editor.org/errata/eid5689

--------------------------------------
Status: Verified
Type: Technical

Reported by: Stefan Heiss <[email-masked]>
Date Reported: 2019-04-11
Verified by: Colin Perkins (IRSG)

Section: 2.5.1

Original Text
-------------
for i=1 upto ceil(msg length in bytes / 16)
   n = le_bytes_to_num(msg[((i-1)*16)..(i*16)] | [0x01])
   a += n
   a = (r * a) % p
   end

Corrected Text
--------------
for i=1 upto ceil(msg length in bytes / 16)
   j = min(i*16-1, msg length in bytes - 1)
   n = le_bytes_to_num(msg[((i-1)*16)..j] | [0x01])
   a += n
   a = (r * a) % p
   end

Notes
-----
Correction of Errata 5675

--------------------------------------
RFC8439 (draft-nir-cfrg-rfc7539bis-04)
--------------------------------------
Title               : ChaCha20 and Poly1305 for IETF Protocols
Publication Date    : June 2018
Author(s)           : Y. Nir, A. Langley
Category            : INFORMATIONAL
Source              : Crypto Forum Research Group
Area                : N/A
Stream              : IRTF
Verifying Party     : IRSG