Clarify the documentation on the use of ChaCha20

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8780)
This commit is contained in:
Matt Caswell 2019-04-18 10:54:58 +01:00
parent 6caf7f3aec
commit 6f3aae256d

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@ -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()