Prepare to provide EVP_PKEY_check()

This allows checking the validity of an EVP_PKEY. Only RSA and EC keys
are supported. If a check function is set the EVP_PKEY_METHOD, it will
be used, otherwise the check function on the EVP_PKEY_ASN1_METHOD is
used.  The default ASN.1 methods wrap RSA_check_key() and
EC_KEY_check_key(), respectively.

The corresponding setters are EVP_PKEY_{asn1,meth}_set_check().

It is unclear why the PKEY method has no const while the ASN.1 method
has const.

Requested by tobhe and used by PHP 8.1.
Based on OpenSSL commit 2aee35d3

ok inoguchi jsing

1 files changed, 8 insertions, 1 deletions

diff --git a/src/lib/libcrypto/asn1/ameth_lib.c b/src/lib/libcrypto/asn1/ameth_lib.c
index ed7f5bd3e4..96669bbd2f 100644
--- a/src/lib/libcrypto/asn1/ameth_lib.c
+++ b/src/lib/libcrypto/asn1/ameth_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ameth_lib.c,v 1.23 2021/12/12 21:30:13 tb Exp $ */
+/* $OpenBSD: ameth_lib.c,v 1.24 2022/01/10 11:52:43 tb Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2006.
  */
@@ -429,3 +429,10 @@ EVP_PKEY_asn1_set_ctrl(EVP_PKEY_ASN1_METHOD *ameth,
 {
         ameth->pkey_ctrl = pkey_ctrl;
 }
+
+void
+EVP_PKEY_asn1_set_check(EVP_PKEY_ASN1_METHOD *ameth,
+    int (*pkey_check)(const EVP_PKEY *pk))
+{
+        ameth->pkey_check = pkey_check;
+}