From c144c3562cd786f24b8d25444a823eb8ca09995a Mon Sep 17 00:00:00 2001
From: Thomas Geymayer <tomgey@gmail.com>
Date: Wed, 18 Jun 2014 18:07:42 +0200
Subject: [PATCH] Keep md5 inside simgear and use single encodeHex
 implementation.

---
 simgear/misc/strutils.cxx      | 45 +++++++++++++++++++++++++---------
 simgear/misc/strutils.hxx      |  7 ++++++
 simgear/package/CMakeLists.txt |  3 +--
 simgear/package/Install.cxx    | 16 +++++-------
 4 files changed, 47 insertions(+), 24 deletions(-)

diff --git a/simgear/misc/strutils.cxx b/simgear/misc/strutils.cxx
index bc56100a..c72d0058 100644
--- a/simgear/misc/strutils.cxx
+++ b/simgear/misc/strutils.cxx
@@ -27,6 +27,7 @@
 #include "strutils.hxx"
 
 #include <simgear/debug/logstream.hxx>
+#include <simgear/package/md5.h>
 
 using std::string;
 using std::vector;
@@ -401,8 +402,32 @@ std::string convertWindowsLocal8BitToUtf8(const std::string& a)
 #endif
 }
 
+//------------------------------------------------------------------------------
+std::string md5(const unsigned char* data, size_t num)
+{
+  SG_MD5_CTX md5_ctx;
+  SG_MD5Init(&md5_ctx);
+  SG_MD5Update(&md5_ctx, data, num);
 
+  unsigned char digest[MD5_DIGEST_LENGTH];
+  SG_MD5Final(digest, &md5_ctx);
 
+  return encodeHex(digest, MD5_DIGEST_LENGTH);
+}
+
+//------------------------------------------------------------------------------
+std::string md5(const char* data, size_t num)
+{
+  return md5(reinterpret_cast<const unsigned char*>(data), num);
+}
+
+//------------------------------------------------------------------------------
+std::string md5(const std::string& str)
+{
+  return md5(reinterpret_cast<const unsigned char*>(str.c_str()), str.size());
+}
+
+//------------------------------------------------------------------------------
 static const std::string base64_chars =
 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 "abcdefghijklmnopqrstuvwxyz"
@@ -482,28 +507,24 @@ void decodeBase64(const std::string& encoded_string, std::vector<unsigned char>&
   }
 }  
 
+//------------------------------------------------------------------------------
 const char hexChar[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
 
 std::string encodeHex(const std::string& bytes)
 {
-  std::string hex;
-  size_t count = bytes.size();
-  for (unsigned int i=0; i<count;++i) {
-      unsigned char c = bytes[i];
-      hex.push_back(hexChar[c >> 4]);
-      hex.push_back(hexChar[c & 0x0f]);
-  }
-  
-  return hex;
+  return encodeHex(
+    reinterpret_cast<const unsigned char*>(bytes.c_str()),
+    bytes.size()
+  );
 }
 
 std::string encodeHex(const unsigned char* rawBytes, unsigned int length)
 {
-  std::string hex;
+  std::string hex(length * 2, '\0');
   for (unsigned int i=0; i<length;++i) {
       unsigned char c = *rawBytes++;
-      hex.push_back(hexChar[c >> 4]);
-      hex.push_back(hexChar[c & 0x0f]);
+      hex[i * 2] = hexChar[c >> 4];
+      hex[i * 2 + 1] = hexChar[c & 0x0f];
   }
   
   return hex;
diff --git a/simgear/misc/strutils.hxx b/simgear/misc/strutils.hxx
index 9070b246..2b02909e 100644
--- a/simgear/misc/strutils.hxx
+++ b/simgear/misc/strutils.hxx
@@ -176,6 +176,13 @@ namespace simgear {
     WCharVec convertUtf8ToWString(const std::string& a);
 #endif
 
+    /**
+     * Get md5 hash of raw data.
+     */
+    std::string md5(const unsigned char* data, size_t num);
+    std::string md5(const char* data, size_t num);
+    std::string md5(const std::string& str);
+
     /**
      * convert base-64 encoded data to raw bytes (possibly with embedded
      * NULs). Throws an exception if input data is not base64, or is
diff --git a/simgear/package/CMakeLists.txt b/simgear/package/CMakeLists.txt
index cc660385..33672680 100644
--- a/simgear/package/CMakeLists.txt
+++ b/simgear/package/CMakeLists.txt
@@ -7,7 +7,6 @@ set(HEADERS
     Install.hxx
     Root.hxx
     Delegate.hxx
-    md5.h # TODO expose somehow more elegant (eg. a function accepting a string)
     )
 
 set(SOURCES 
@@ -16,7 +15,7 @@ set(SOURCES
     Install.cxx
     Root.cxx
 # internal helpers
-    md5.c
+    md5.h md5.c
     ioapi.c ioapi_mem.c ioapi.h
     unzip.h unzip.c
     )
diff --git a/simgear/package/Install.cxx b/simgear/package/Install.cxx
index 7d7b2fa9..b5c9487d 100644
--- a/simgear/package/Install.cxx
+++ b/simgear/package/Install.cxx
@@ -30,6 +30,7 @@
 #include <simgear/io/HTTPRequest.hxx>
 #include <simgear/io/HTTPClient.hxx>
 #include <simgear/misc/sg_dir.hxx>
+#include <simgear/misc/strutils.hxx>
 
 extern "C" {
     void fill_memory_filefunc (zlib_filefunc_def*);
@@ -91,17 +92,12 @@ protected:
 
         unsigned char digest[MD5_DIGEST_LENGTH];
         SG_MD5Final(digest, &m_md5);
-    // convert final sum to hex
-        const char hexChar[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
-        std::stringstream hexMd5;
-        for (int i=0; i<MD5_DIGEST_LENGTH;++i) {
-            hexMd5 << hexChar[digest[i] >> 4];
-            hexMd5 << hexChar[digest[i] & 0x0f];
-        }
-        
-        if (hexMd5.str() != m_owner->package()->md5()) {
+        std::string const hex_md5 =
+          strutils::encodeHex(digest, MD5_DIGEST_LENGTH);
+
+        if (hex_md5 != m_owner->package()->md5()) {
             SG_LOG(SG_GENERAL, SG_ALERT, "md5 verification failed:\n"
-                << "\t" << hexMd5.str() << "\n\t"
+                << "\t" << hex_md5 << "\n\t"
                 << m_owner->package()->md5() << "\n\t"
                 << "downloading from:" << url());
             doFailure(Delegate::FAIL_CHECKSUM);
-- 
2.39.5