diff --git a/vendor/resty/hmac.lua b/vendor/resty/hmac.lua
index efb3b3b..1c4fa83 100644
--- a/vendor/resty/hmac.lua
+++ b/vendor/resty/hmac.lua
@@ -1,15 +1,17 @@
 
 local str_util = require "resty.string"
+local to_hex = str_util.to_hex
 local ffi = require "ffi"
 local ffi_new = ffi.new
 local ffi_str = ffi.string
 local ffi_gc = ffi.gc
+local ffi_typeof = ffi.typeof
 local C = ffi.C
 local setmetatable = setmetatable
 local error = error
 
 
-local _M = { _VERSION = '0.01' }
+local _M = { _VERSION = '0.02' }
 
 local mt = { __index = _M }
 
@@ -60,10 +62,15 @@ typedef struct hmac_ctx_st
     unsigned char key[128];
     } HMAC_CTX;
 
+//OpenSSL 1.0
 void HMAC_CTX_init(HMAC_CTX *ctx);
 void HMAC_CTX_cleanup(HMAC_CTX *ctx);
 
-int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,const EVP_MD *md, ENGINE *impl);
+//OpenSSL 1.1
+HMAC_CTX *HMAC_CTX_new(void);
+void HMAC_CTX_free(HMAC_CTX *ctx);
+
+int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md, ENGINE *impl);
 int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len);
 int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len);
 
@@ -75,7 +82,7 @@ const EVP_MD *EVP_sha512(void);
 
 local buf = ffi_new("unsigned char[64]")
 local res_len = ffi_new("unsigned int[1]")
-local ctx_ptr_type = ffi.typeof("HMAC_CTX[1]")
+local ctx_ptr_type = ffi_typeof("HMAC_CTX[1]")
 local hashes = {
     MD5 = C.EVP_md5(),
     SHA1 = C.EVP_sha1(),
@@ -83,14 +90,35 @@ local hashes = {
     SHA512 = C.EVP_sha512()
 }
 
+local ctx_new, ctx_free
+local openssl11, e = pcall(function ()
+    local ctx = C.HMAC_CTX_new()
+    C.HMAC_CTX_free(ctx)
+end)
+if openssl11 then
+    ctx_new = function ()
+        return C.HMAC_CTX_new()
+    end
+    ctx_free = function (ctx)
+        C.HMAC_CTX_free(ctx)
+    end
+else
+    ctx_new = function ()
+        local ctx = ffi_new(ctx_ptr_type)
+        C.HMAC_CTX_init(ctx)
+        return ctx
+    end
+    ctx_free = function (ctx) 
+        C.HMAC_CTX_cleanup(ctx)
+    end
+end
+
 
 _M.ALGOS = hashes
 
 
 function _M.new(self, key, hash_algo)
-    local ctx = ffi_new(ctx_ptr_type)
-
-    C.HMAC_CTX_init(ctx)
+    local ctx = ctx_new()
 
     local _hash_algo = hash_algo or hashes.md5
 
@@ -98,7 +126,7 @@ function _M.new(self, key, hash_algo)
         return nil
     end
 
-    ffi_gc(ctx, C.HMAC_CTX_cleanup)
+    ffi_gc(ctx, ctx_free)
 
     return setmetatable({ _ctx = ctx }, mt)
 end
@@ -119,7 +147,7 @@ function _M.final(self, s, hex_output)
 
     if C.HMAC_Final(self._ctx, buf, res_len) == 1 then
         if hex_output == true then
-            return str_util.to_hex(ffi_str(buf, res_len[0]))
+            return to_hex(ffi_str(buf, res_len[0]))
         end
         return ffi_str(buf, res_len[0])
     end