SHA1 JavaScript實現了大串

Question

我有一樣的問題：Can SHA-1 algorithm be computed on a stream? With low memory footprint?

我正在尋找一個JavaScript實現其由一個非常大的字符串的塊計算塊。這個想法是將字符串分成512位塊並逐塊執行。

任何提示？

[更新] 感謝sunetos的幫助下，我寫了一個豆蔻HTML5 Java腳本程序：Generate SHA1 File Checksum Using HTML5 File API in Javascript

Answer 1

我相信我在http://pajhome.org.uk/crypt/md5/contrib/sha1_stream.js跨越一個來到保羅·約翰斯頓。它列在頁面http://pajhome.org.uk/crypt/md5/scripts.html上。我自己沒有測試過它，但我已經使用了他爲其修改的非流式版本。

更新：這裏是一些示例代碼（我對它進行了驗證，以證明它是正確的單獨的SHA1）。確保在流式sha1_stream.js之前包含原始sha1.js（在http://pajhome.org.uk/crypt/md5/sha1.js處找到）。

<script src="sha1.js" type="text/javascript" charset="utf-8"></script> 
<script src="sha1_stream.js" type="text/javascript" charset="utf-8"></script> 

<script type="text/javascript" charset="utf-8"> 

    var input = 'abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz'; 

    var blocksize = 512; 
    var h = naked_sha1_head(); 
    for (var i = 0; i < input.length; i += blocksize) { 
     var len = Math.min(blocksize, input.length - i); 
     var block = input.substr(i, len); 
     naked_sha1(str2binb(block), len*chrsz, h); 
    } 
    var result = binb2hex(naked_sha1_tail(h)); 

</script>