php sha1 does not match .Net sha1Managed

我在匹配PHP和c# . net中的SHA1算法时遇到了问题。我需要修改PHP代码以匹配。net值。

DateTime dtNow = DateTime.parse("4/29/2013 11:50:18 PM");
//Create the site token header
var siteTokenMessageHeader = new SiteTokenMessageHeader
{
    MessageId = "0289ED53-D69B-451C-BCBB-C7412D07AFFE",
    //Unquie Id per message, use for auditing
    TimeStamp = dtNow,
    //Current Time
    SiteId = _siteId,
};
//Construct Token 
var token = string.Format(
    "{0}:'"MessageId'":'"{1}'"'"SiteId'":'"{2}'"'"TimeStamp'":'"{3}'"",
    _siteKey,
    siteTokenMessageHeader.MessageId,
    siteTokenMessageHeader.SiteId,
    siteTokenMessageHeader.TimeStamp.ToString(new CultureInfo("en-US"))); //1/1/2000 12:00:00 AM
//Construct signature from token
var shaProvider = new SHA1Managed();
var rawKey = Encoding.Unicode.GetBytes(token);
var rawHash = shaProvider.ComputeHash(rawKey);
var signature = BitConverter.ToString(rawHash).Replace("-", "").ToLower();
siteTokenMessageHeader.SiteSignature = signature;

签名变量值:8cf9000e9b1a6da0e898bada5bf6dd8f6d17d72a

$str = $SiteKey.':"MessageId":"0289ED53-D69B-451C-BCBB-C7412D07AFFE""SiteId":"'.$SiteId.'""TimeStamp":"4/29/2013 11:50:18 AM"';
$hash = sha1($str);

$hash变量值:1d2fb85fd63a14de0b5e0a95be253eac1a625128

同样的话题已经回答了很多次，但在这种情况下没有一个是有用的。任何人的帮助都是值得感激的。