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)

diff --git a/doc/man3/EVP_KDF.pod b/doc/man3/EVP_KDF.pod
index 3c8914bd263a05ba77ba38816cbeb636c5344c1d..374318cbcfddad7dd733735b25b1bb8bd46a76f1 100644 (file)
--- 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.
@@ -229,7 +229,10 @@ sets the key.
 
 =item "info" (B<OSSL_KDF_PARAM_INFO>) <octet string>
 
-This parameter sets the info, fixed info, other info or shared info value.
+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.