--- gvpe/src/hkdf.C	2013/07/17 04:36:03	1.2
+++ gvpe/src/hkdf.C	2013/09/20 11:57:03	1.3
@@ -33,12 +33,20 @@
 
 #include <cstring>
 
+#include <openssl/opensslv.h>
 #include <openssl/rand.h>
 #include <openssl/hmac.h>
 
 #include "util.h"
 #include "hkdf.h"
 
+// openssl 0.9.8 compatibility
+#if OPENSSL_VERSION_NUMBER < 0x10100000
+  #define require101(exp) exp
+#else
+  #define require101(exp) equire (exp)
+#endif
+
 hkdf::hkdf (const void *salt, int len, const EVP_MD *xtr_hash)
 {
   HMAC_CTX_init (&ctx);
@@ -50,7 +58,7 @@
       len  = EVP_MD_size (xtr_hash);
     }
 
-  require (HMAC_Init_ex (&ctx, salt, len, xtr_hash, 0));
+  require101 (HMAC_Init_ex (&ctx, salt, len, xtr_hash, 0));
 }
 
 hkdf::~hkdf ()
@@ -61,14 +69,14 @@
 void
 hkdf::extract (const void *ikm, int len)
 {
-  require (HMAC_Update (&ctx, (u8 *)ikm, len));
+  require101 (HMAC_Update (&ctx, (u8 *)ikm, len));
 }
 
 void
 hkdf::extract_done (const EVP_MD *prf_hash)
 {
-  require (HMAC_Final (&ctx, prk, 0));
-  require (HMAC_Init_ex (&ctx, 0, 0, prf_hash, 0));
+  require101 (HMAC_Final (&ctx, prk, 0));
+  require101 (HMAC_Init_ex (&ctx, 0, 0, prf_hash, 0));
 }
 
 void
@@ -80,20 +88,19 @@
 
   while (len)
     {
-      require (HMAC_Init_ex (&ctx, prk, md_size, 0, 0));
+      require101 (HMAC_Init_ex (&ctx, prk, md_size, 0, 0));
 
       if (iter)
-        require (HMAC_Update (&ctx, tn, md_size));
-
-      require (HMAC_Update (&ctx, (u8 *)info, infolen));
+        require101 (HMAC_Update (&ctx, tn, md_size));
 
+      require101 (HMAC_Update (&ctx, (u8 *)info, infolen));
 
       ++iter;
       require (iter);
 
-      require (HMAC_Update (&ctx, &iter, 1));
+      require101 (HMAC_Update (&ctx, &iter, 1));
 
-      require (HMAC_Final (&ctx, tn, 0));
+      require101 (HMAC_Final (&ctx, tn, 0));
 
       int ol = len > md_size ? md_size : len;