add set  algo interface for custom verification callback
diff --git a/include/picotls/openssl.h b/include/picotls/openssl.h
index 8e26cf8..d8746e3 100644
--- a/include/picotls/openssl.h
+++ b/include/picotls/openssl.h
@@ -117,6 +117,8 @@
     X509_STORE *cert_store;
 } ptls_openssl_verify_certificate_t;
 
+void ptls_openssl_set_default_algos(ptls_verify_certificate_t *self);
+
 int ptls_openssl_init_verify_certificate(ptls_openssl_verify_certificate_t *self, X509_STORE *store);
 void ptls_openssl_dispose_verify_certificate(ptls_openssl_verify_certificate_t *self);
 X509_STORE *ptls_openssl_create_default_certificate_store(void);
diff --git a/lib/openssl.c b/lib/openssl.c
index 80613bb..0150ca2 100644
--- a/lib/openssl.c
+++ b/lib/openssl.c
@@ -1335,6 +1335,11 @@
     return ret;
 }
 
+void ptls_openssl_set_default_algos(ptls_verify_certificate_t *self)
+{
+    self->algos = default_signature_schemes;
+}
+
 int ptls_openssl_init_verify_certificate(ptls_openssl_verify_certificate_t *self, X509_STORE *store)
 {
     *self = (ptls_openssl_verify_certificate_t){{verify_cert, default_signature_schemes}};