Prepare to provide DH_security_bits()

ok beck jsing

1 files changed, 14 insertions, 1 deletions

diff --git a/src/lib/libcrypto/dh/dh_lib.c b/src/lib/libcrypto/dh/dh_lib.c
index d4d0c9dda3..35a22d1ec8 100644
--- a/src/lib/libcrypto/dh/dh_lib.c
+++ b/src/lib/libcrypto/dh/dh_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh_lib.c,v 1.36 2022/01/07 09:27:13 tb Exp $ */
+/* $OpenBSD: dh_lib.c,v 1.37 2022/06/27 12:31:38 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -245,6 +245,19 @@ DH_bits(const DH *dh)
         return BN_num_bits(dh->p);
 }
 
+int
+DH_security_bits(const DH *dh)
+{
+        int N = -1;
+
+        if (dh->q != NULL)
+                N = BN_num_bits(dh->q);
+        else if (dh->length > 0)
+                N = dh->length;
+
+        return BN_security_bits(BN_num_bits(dh->p), N);
+}
+
 ENGINE *
 DH_get0_engine(DH *dh)
 {