From 76a5e0584de36f6b49a9776deb67d3ded6e61f44 Mon Sep 17 00:00:00 2001
From: JT Olds <jt@spacemonkey.com>
Date: Mon, 24 Mar 2014 17:26:38 -0600
Subject: [PATCH] space monkey internal commit export

[katamari commit: 05c97fb8e733433a63dcedaa7408c63beedd286f]
---
 engine.go | 39 +++++++++++++++++++++++++++++++++++++++
 sha1.go   | 20 +++++++++++++++-----
 2 files changed, 54 insertions(+), 5 deletions(-)
 create mode 100644 engine.go

diff --git a/engine.go b/engine.go
new file mode 100644
index 0000000..bd2029c
--- /dev/null
+++ b/engine.go
@@ -0,0 +1,39 @@
+// Copyright (C) 2014 Space Monkey, Inc.
+// +build cgo
+
+package openssl
+
+/*
+#include "openssl/engine.h"
+*/
+import "C"
+
+import (
+	"fmt"
+	"runtime"
+	"unsafe"
+)
+
+type Engine struct {
+	e *C.ENGINE
+}
+
+func EngineById(name string) (*Engine, error) {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	e := &Engine{
+		e: C.ENGINE_by_id(cname),
+	}
+	if e.e == nil {
+		return nil, fmt.Errorf("engine %s missing", name)
+	}
+	if C.ENGINE_init(e.e) == 0 {
+		C.ENGINE_free(e.e)
+		return nil, fmt.Errorf("engine %s not initialized", name)
+	}
+	runtime.SetFinalizer(e, func(e *Engine) {
+		C.ENGINE_finish(e.e)
+		C.ENGINE_free(e.e)
+	})
+	return e, nil
+}
diff --git a/sha1.go b/sha1.go
index d88ba4a..4274ca2 100644
--- a/sha1.go
+++ b/sha1.go
@@ -20,13 +20,16 @@ import (
 )
 
 type SHA1Hash struct {
-	ctx C.EVP_MD_CTX
+	ctx    C.EVP_MD_CTX
+	engine *Engine
 }
 
-func NewSHA1Hash() (*SHA1Hash, error) {
-	hash := new(SHA1Hash)
+func NewSHA1Hash() (*SHA1Hash, error) { return NewSHA1HashWithEngine(nil) }
+
+func NewSHA1HashWithEngine(e *Engine) (*SHA1Hash, error) {
+	hash := &SHA1Hash{engine: e}
 	C.EVP_MD_CTX_init(&hash.ctx)
-	runtime.SetFinalizer(hash, func(h *SHA1Hash) { h.Close() })
+	runtime.SetFinalizer(hash, func(hash *SHA1Hash) { hash.Close() })
 	if err := hash.Reset(); err != nil {
 		return nil, err
 	}
@@ -37,8 +40,15 @@ func (s *SHA1Hash) Close() {
 	C.EVP_MD_CTX_cleanup(&s.ctx)
 }
 
+func engineRef(e *Engine) *C.ENGINE {
+	if e == nil {
+		return nil
+	}
+	return e.e
+}
+
 func (s *SHA1Hash) Reset() error {
-	if 1 != C.EVP_DigestInit_ex(&s.ctx, C.EVP_sha1(), nil) {
+	if 1 != C.EVP_DigestInit_ex(&s.ctx, C.EVP_sha1(), engineRef(s.engine)) {
 		return errors.New("openssl: sha1: cannot init digest ctx")
 	}
 	return nil