document return values of the control function in EVP_MD_meth_set_ctrl(3)

diff --git a/lib/libcrypto/man/EVP_MD_meth_new.3 b/lib/libcrypto/man/EVP_MD_meth_new.3
index d6720ef..0876312 100644 (file)
--- a/lib/libcrypto/man/EVP_MD_meth_new.3
+++ b/lib/libcrypto/man/EVP_MD_meth_new.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: EVP_MD_meth_new.3,v 1.2 2023/07/09 06:47:51 tb Exp $
+.\" $OpenBSD: EVP_MD_meth_new.3,v 1.3 2023/08/12 16:48:23 schwarze Exp $
 .\" selective merge up to:
 .\" OpenSSL man3/EVP_MD_meth_new 0388d212 Dec 14 12:47:07 2018 -0800
 .\"
@@ -49,7 +49,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 .\" OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: July 9 2023 $
+.Dd $Mdocdate: August 12 2023 $
 .Dt EVP_MD_METH_NEW 3
 .Os
 .Sh NAME
@@ -130,7 +130,7 @@
 .Ft int
 .Fo EVP_MD_meth_set_ctrl
 .Fa "EVP_MD *md"
-.Fa "int (*ctrl)(EVP_MD_CTX *ctx, int cmd, int p1, void *p2)"
+.Fa "int (*control)(EVP_MD_CTX *ctx, int command, int p1, void *p2)"
 .Fc
 .Sh DESCRIPTION
 The
@@ -267,11 +267,21 @@ and
 .Xr EVP_MD_CTX_free 3 .
 .Pp
 .Fn EVP_MD_meth_set_ctrl
-sets the control function for
+sets the
+.Fa control
+function for
 .Fa md .
+The
+.Fa control
+function supplied by the application program has to return 1 to indicate
+success, 0 to indicate failure, or \-1 if the
+.Fa command
+is not supported for this digest method.
 See
 .Xr EVP_MD_CTX_ctrl 3
-for the available controls.
+for the available
+.Fa command
+arguments.
 .Sh RETURN VALUES
 .Fn EVP_MD_meth_new
 and