From: Dr. David von Oheimb <David.von.Oheimb@siemens.com>
Date: Sun, 16 Jul 2023 12:55:35 +0000 (+0200)
Subject: EVP_KDF.pod: extend text on 'salt' and 'info' parameters
X-Git-Tag: openssl-3.1.2~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4316c6418d068ecf3b032f973d8b6cd12d000edd;p=thirdparty%2Fopenssl.git

EVP_KDF.pod: extend text on 'salt' and 'info' parameters

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21469)

(cherry picked from commit 61c8146aa36b84afd9d83c87c9a01138979ffd60)
---

diff --git a/doc/man3/EVP_KDF.pod b/doc/man3/EVP_KDF.pod
index bbff6dd41a8..b291c203d82 100644
--- a/doc/man3/EVP_KDF.pod
+++ b/doc/man3/EVP_KDF.pod
@@ -191,7 +191,7 @@ For those KDF implementations that support it, this parameter sets the password.
 
 =item "salt" (B<OSSL_KDF_PARAM_SALT>) <octet string>
 
-Some KDF implementations can take a salt.
+Some KDF implementations can take a non-secret unique cryptographic salt.
 For those KDF implementations that support it, this parameter sets the salt.
 
 The default value, if any, is implementation dependent.
@@ -227,6 +227,15 @@ Some KDF implementations require a key.
 For those KDF implementations that support it, this octet string parameter
 sets the key.
 
+=item "info" (B<OSSL_KDF_PARAM_INFO>) <octet string>
+
+Some KDF implementations, such as L<EVP_KDF-HKDF(7)>, take an 'info' parameter
+for binding the derived key material
+to application- and context-specific information.
+This parameter sets the info, fixed info, other info or shared info argument.
+You can specify this parameter multiple times, and each instance will
+be concatenated to form the final value.
+
 =item "maclen" (B<OSSL_KDF_PARAM_MAC_SIZE>) <unsigned integer>
 
 Used by implementations that use a MAC with a variable output size (KMAC).