RT3462: Document actions when data==NULL

[openssl.git] / doc / crypto / EVP_BytesToKey.pod

diff --git a/doc/crypto/EVP_BytesToKey.pod b/doc/crypto/EVP_BytesToKey.pod
index d07ae6c7b514a92f9d2c85aa0500cc742c3f7efb..cd3aa027ee929e59a4a25b9107e41d0cb9c7ea9e 100644 (file)
--- a/doc/crypto/EVP_BytesToKey.pod
+++ b/doc/crypto/EVP_BytesToKey.pod
@@ -55,7 +55,10 @@ the IV.
 
 =head1 RETURN VALUES
 
-EVP_BytesToKey() returns the size of the derived key in bytes, or 0 on error.
+If B<data> is NULL, then EVP_BytesToKey() returns the number of bytes
+needed to store the derived key.
+Otherwise, EVP_BytesToKey() returns the size of the derived key in bytes,
+or 0 on error.
 
 =head1 SEE ALSO