From: Matt Caswell <matt@openssl.org>
Date: Thu, 18 Apr 2019 09:54:58 +0000 (+0100)
Subject: Clarify the documentation on the use of ChaCha20
X-Git-Tag: OpenSSL_1_1_1c~40
X-Git-Url: https://git.librecmc.org/?p=oweals%2Fopenssl.git;a=commitdiff_plain;h=d0a2b73b9c823d155ac3880bf193a2fb08a4b4bb

Clarify the documentation on the use of ChaCha20

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8780)

(cherry picked from commit 6f3aae256d62cfcc48c07cc0ead5080b070f371b)
---

diff --git a/doc/man3/EVP_chacha20.pod b/doc/man3/EVP_chacha20.pod
index 96da825cde..4636a1e9cc 100644
--- a/doc/man3/EVP_chacha20.pod
+++ b/doc/man3/EVP_chacha20.pod
@@ -21,7 +21,15 @@ The ChaCha20 stream cipher for EVP.
 
 =item EVP_chacha20()
 
-The ChaCha20 stream cipher. The key length is 256 bits, the IV is 96 bits long.
+The ChaCha20 stream cipher. The key length is 256 bits, the IV is 128 bits long.
+The first 32 bits consists of a counter in little-endian order followed by a 96
+bit nonce. For example a nonce of:
+
+000000000000000000000002
+
+With an initial counter of 42 (2a in hex) would be expressed as:
+
+2a000000000000000000000000000002
 
 =item EVP_chacha20_poly1305()