--- a/common/certhelp.c	Mon Sep 29 13:02:41 2014 +0200
+++ b/common/certhelp.c	Mon Sep 29 13:12:58 2014 +0200
@@ -50,3 +50,42 @@
     }
   return str;
 }
+
+#ifdef WIN32
+PCCERT_CONTEXT
+b64_to_cert_context(char *b64_data, size_t b64_size)
+{
+  size_t buf_size = 0;
+  char *buf = NULL;
+  PCCERT_CONTEXT pCert = NULL;
+  int ret = -1;
+
+  ret = str_base64_decode (&buf, &buf_size, b64_data, b64_size);
+
+  if (ret != 0)
+    {
+      ERRORPRINTF ("decoding certificate failed\n");
+      return NULL;
+    }
+
+  pCert = CertCreateContext (CERT_STORE_CERTIFICATE_CONTEXT,
+                             X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
+                             (const PBYTE) buf,
+                             (DWORD) buf_size,
+                             0,
+                             NULL);
+  free (buf); /* Windows has a copy */
+
+  if (pCert == NULL)
+    {
+      char *error = getLastErrorMsg();
+      if (error)
+        {
+          ERRORPRINTF ("Failed to create cert context: %s \n", error);
+          free (error);
+        }
+      return NULL;
+    }
+  return pCert;
+}
+#endif