SHA1 JavaScript实现了大串

Question

我有一样的问题：Can SHA-1 algorithm be computed on a stream? With low memory footprint?

我正在寻找一个JavaScript实现其由一个非常大的字符串的块计算块。这个想法是将字符串分成512位块并逐块执行。

任何提示？

[更新] 感谢sunetos的帮助下，我写了一个豆蔻HTML5 Java脚本程序：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跨越一个来到保罗·约翰斯顿。它列在页面http://pajhome.org.uk/crypt/md5/scripts.html上。我自己没有测试过它，但我已经使用了他为其修改的非流式版本。

更新：这里是一些示例代码（我对它进行了验证，以证明它是正确的单独的SHA1）。确保在流式sha1_stream.js之前包含原始sha1.js（在http://pajhome.org.uk/crypt/md5/sha1.js处找到）。

<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>