+/*
+ * This module uses several "new" interfaces, among which is
+ * CertGetCertificateContextProperty. CERT_KEY_PROV_INFO_PROP_ID is
+ * one of possible values you can pass to function in question. By
+ * checking if it's defined we can see if wincrypt.h and accompanying
+ * crypt32.lib are in shape. The native MingW32 headers up to and
+ * including __W32API_VERSION 3.14 lack of struct DSSPUBKEY and the
+ * defines CERT_STORE_PROV_SYSTEM_A and CERT_STORE_READONLY_FLAG,
+ * so we check for these too and avoid compiling.
+ * Yes, it's rather "weak" test and if compilation fails,
+ * then re-configure with -DOPENSSL_NO_CAPIENG.
+ */
+#if defined(CERT_KEY_PROV_INFO_PROP_ID) && \
+ defined(CERT_STORE_PROV_SYSTEM_A) && \
+ defined(CERT_STORE_READONLY_FLAG)
+# define __COMPILE_CAPIENG
+#endif /* CERT_KEY_PROV_INFO_PROP_ID */
+#endif /* OPENSSL_NO_CAPIENG */
+#endif /* OPENSSL_SYS_WIN32 */
+
+#ifdef __COMPILE_CAPIENG
+
+#undef X509_EXTENSIONS
+#undef X509_CERT_PAIR
+
+/* Definitions which may be missing from earlier version of headers */
+#ifndef CERT_STORE_OPEN_EXISTING_FLAG
+#define CERT_STORE_OPEN_EXISTING_FLAG 0x00004000
+#endif
+
+#ifndef CERT_STORE_CREATE_NEW_FLAG
+#define CERT_STORE_CREATE_NEW_FLAG 0x00002000
+#endif
+
+#ifndef CERT_SYSTEM_STORE_CURRENT_USER
+#define CERT_SYSTEM_STORE_CURRENT_USER 0x00010000
+#endif
+
+#include <openssl/engine.h>
+#include <openssl/pem.h>
+#include <openssl/x509v3.h>