diff --git a/include/fc/crypto/dh.hpp b/include/fc/crypto/dh.hpp
index 5e6f89f..9bd4d7b 100644
--- a/include/fc/crypto/dh.hpp
+++ b/include/fc/crypto/dh.hpp
@@ -1,11 +1,12 @@
 #pragma once
+#include <fc/crypto/openssl.hpp>
 #include <vector>
 #include <stdint.h>
 
 namespace fc {
 
     struct diffie_hellman {
-        diffie_hellman():valid(0),g(5){}
+        diffie_hellman():valid(0),g(5){ fc::init_openssl(); }
         bool generate_params( int s, uint8_t g );
         bool generate_pub_key();
         bool compute_shared_key( const char* buf, uint32_t s );
diff --git a/include/fc/crypto/openssl.hpp b/include/fc/crypto/openssl.hpp
index 5811390..af883d6 100644
--- a/include/fc/crypto/openssl.hpp
+++ b/include/fc/crypto/openssl.hpp
@@ -22,11 +22,10 @@ namespace fc
     {
         ssl_wrapper(ssl_type* obj):obj(obj) {}
 
-        operator ssl_type*()
-        {
-            return obj;
-        }
+        operator ssl_type*() { return obj; }
+        operator const ssl_type*() const { return obj; }
         ssl_type* operator->() { return obj; }
+        const ssl_type* operator->() const { return obj; }
 
         ssl_type* obj;
     };
diff --git a/src/crypto/dh.cpp b/src/crypto/dh.cpp
index 7b49398..cbd7dcc 100644
--- a/src/crypto/dh.cpp
+++ b/src/crypto/dh.cpp
@@ -2,52 +2,45 @@
 #include <openssl/dh.h>
 
 namespace fc {
+    SSL_TYPE(ssl_dh, DH, DH_free)
+
+    static bool validate( const ssl_dh& dh, bool& valid ) {
+        int check;
+        DH_check(dh,&check);
+        return valid = !(check /*& DH_CHECK_P_NOT_SAFE_PRIME*/);
+    }
+
    bool diffie_hellman::generate_params( int s, uint8_t g )
    {
-        DH* dh = DH_generate_parameters( s, g, NULL, NULL );
+        ssl_dh dh = DH_generate_parameters( s, g, NULL, NULL );
         p.resize( BN_num_bytes( dh->p ) );
         if( p.size() )
             BN_bn2bin( dh->p, (unsigned char*)&p.front()  );
         this->g = g;
-
-        int check;
-        DH_check(dh,&check);
-        DH_free(dh);
-
-        if( check & DH_CHECK_P_NOT_SAFE_PRIME )
-            return valid = false;
-        return valid = true;
+        return fc::validate( dh, valid );
    }
+
    bool diffie_hellman::validate()
    {
         if( !p.size() ) 
             return valid = false;
-        DH* dh = DH_new(); 
+        ssl_dh dh = DH_new();
         dh->p = BN_bin2bn( (unsigned char*)&p.front(), p.size(), NULL );
         dh->g = BN_bin2bn( (unsigned char*)&g, 1, NULL );
-
-        int check;
-        DH_check(dh,&check);
-        DH_free(dh);
-        if( check & DH_CHECK_P_NOT_SAFE_PRIME )
-            return valid = false;
-        return valid = true;
+        return fc::validate( dh, valid );
    }
 
    bool diffie_hellman::generate_pub_key()
    {
         if( !p.size() ) 
             return valid = false;
-        DH* dh = DH_new(); 
+        ssl_dh dh = DH_new();
         dh->p = BN_bin2bn( (unsigned char*)&p.front(), p.size(), NULL );
         dh->g = BN_bin2bn( (unsigned char*)&g, 1, NULL );
 
-        int check;
-        DH_check(dh,&check);
-        if( check & DH_CHECK_P_NOT_SAFE_PRIME )
+        if( !fc::validate( dh, valid ) )
         {
-            DH_free(dh);
-            return valid = false;
+            return false;
         }
         DH_generate_key(dh);
 
@@ -58,11 +51,10 @@ namespace fc {
         if( priv_key.size() )
             BN_bn2bin( dh->priv_key, (unsigned char*)&priv_key.front()  );
 
-        DH_free(dh);
-        return valid = true;
+        return true;
    }
    bool diffie_hellman::compute_shared_key( const char* buf, uint32_t s ) {
-        DH* dh = DH_new(); 
+        ssl_dh dh = DH_new();
         dh->p = BN_bin2bn( (unsigned char*)&p.front(), p.size(), NULL );
         dh->pub_key = BN_bin2bn( (unsigned char*)&pub_key.front(), pub_key.size(), NULL );
         dh->priv_key = BN_bin2bn( (unsigned char*)&priv_key.front(), priv_key.size(), NULL );
@@ -70,22 +62,19 @@ namespace fc {
 
         int check;
         DH_check(dh,&check);
-        if( check & DH_CHECK_P_NOT_SAFE_PRIME )
+        if( !fc::validate( dh, valid ) )
         {
-            DH_free(dh);
-            return valid = false;
+            return false;
         }
 
-
-        BIGNUM* pk = BN_bin2bn( (unsigned char*)buf, s, NULL ); 
+        ssl_bignum pk;
+        BN_bin2bn( (unsigned char*)buf, s, pk );
         shared_key.resize( DH_size(dh) ); 
         DH_compute_key( (unsigned char*)&shared_key.front(), pk, dh );
-        BN_free(pk);
-        DH_free(dh);
-        return valid = true;
+
+        return true;
    }
    bool diffie_hellman::compute_shared_key( const std::vector<char>& pubk ) {
       return compute_shared_key( &pubk.front(), pubk.size() );
    }
-
 }