From: Tomas Mraz <tomas@openssl.org>
Date: Fri, 15 Oct 2021 12:50:17 +0000 (+0200)
Subject: doc: EVP_PKEY_get_utf8/octet_string_param() clarify NULL buffer behavior
X-Git-Tag: openssl-3.2.0-alpha1~3444
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cde5a12d5e83ba0d7c5b2dd7bafa4d2abe2d45bf;p=thirdparty%2Fopenssl.git

doc: EVP_PKEY_get_utf8/octet_string_param() clarify NULL buffer behavior

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/16843)
---

diff --git a/doc/man3/EVP_PKEY_gettable_params.pod b/doc/man3/EVP_PKEY_gettable_params.pod
index b28ed699399..23ac4bd8b06 100644
--- a/doc/man3/EVP_PKEY_gettable_params.pod
+++ b/doc/man3/EVP_PKEY_gettable_params.pod
@@ -52,11 +52,15 @@ buffer I<str> of maximum size I<max_buf_sz> associated with a name of
 I<key_name>.  The maximum size must be large enough to accomodate the string
 value including a terminating NUL byte, or this function will fail.
 If I<out_len> is not NULL, I<*out_len> is set to the length of the string
-not including the terminating NUL byte.
+not including the terminating NUL byte. The required buffer size not including
+the terminating NUL byte can be obtained from I<*out_len> by calling the
+function with I<str> set to NULL.
 
 EVP_PKEY_get_octet_string_param() get a key I<pkey>'s octet string value into a
 buffer I<buf> of maximum size I<max_buf_sz> associated with a name of I<key_name>.
 If I<out_len> is not NULL, I<*out_len> is set to the length of the contents.
+The required buffer size can be obtained from I<*out_len> by calling the
+function with I<buf> set to NULL.
 
 =head1 NOTES