使用 PHP 从 Microsoft Teams 自定义机器人验证 HMAC

我正在尝试使用 PHP 验证 Microsoft Teams 自定义机器人，遵循 Microsoft指示 https://learn.microsoft.com/en-us/microsoftteams/platform/concepts/custom-bot并阅读 C# 示例代码。

微软说明步骤：
1. 根据消息的请求正文生成 hmac。大多数平台上都有标准库。 Microsoft Teams 使用标准 SHA256 HMAC 加密。您需要将正文转换为字节 UTF8 格式的数组。
2. 要计算哈希值，请提供共享密钥的字节数组。
3. 使用 UTF8 编码将哈希值转换为字符串。
4. 将生成的哈希的字符串值与 HTTP 请求中提供的值进行比较。

我写了一个小的 php 脚本来在本地测试这个：

        <?php
        //Function to generate C# byte[] equivalent
        function unpak_str($val){
            $b = unpack('C*', $val);
            foreach ($b as $key => $value)
                $byte_a .= $value;

           return $byte_a;
          }

        //multi test outputs
        function hasher($values=[], &$output){
            //my secret share
            $secret="ejWiKHgsKY1ZfpJwJ+wIiN4+bgsFad/lkpu9/MWNXgM=";
            //diferent test
            $secret_64=base64_decode($secret);
            $secret_b=unpak_str($secret);
            $secret_b_64=unpak_str(base64_decode($secret));

            foreach($values as $msg){
                $hs = hash_hmac("sha256",$msg,$secret, true);
                $hs_64 = hash_hmac("sha256",$msg,$secret_64, true);
                $hs_b = hash_hmac("sha256",$msg,$secret_b, true);
                $hs_b_64 = hash_hmac("sha256",$msg,$secret_b_64, true);

                $output.=base64_encode($hs)." <BR>";
                $output.=base64_encode($hs_64)." <BR>";
                $output.=base64_encode($hs_b)." <BR>";
                $output.=base64_encode($hs_b_64)." <BR>";
             }
          }

    //Get data
    $data=file_get_contents('php://input');

    //real data request content for test
    $data ='{type":"message","id":"1512376018086","timestamp":"2017-12-04T08:26:58.237Z","localTimestamp":"2017-12-04T09:26:58.237+01:00","serviceUrl":"https://smba.trafficmanager.net/emea-client-ss.msg/","channelId":"msteams","from":{"id":"29:1aq6GCrC6lM9dv3YkAYi1gxTPiLnojGFgVr0_Th-2x6DhqmHAOhFwQHFzSyDy5RruXY4_FZjJebKHU7bpxfHpXA","name":"ROBERTO ALONSO FERNANDEZ","aadObjectId":"1e0dc7a0-9d5e-488b-bcf2-7e39c84076b8"},"conversation":{"isGroup":true,"id":"19:[email protected] /cdn-cgi/l/email-protection;messageid=1512376018086","name":null},"recipient":null,"textFormat":"plain","attachmentLayout":null,"membersAdded":[],"membersRemoved":[],"topicName":null,"historyDisclosed":null,"locale":null,"text":"<at>PandoBot</at> fff","speak":null,"inputHint":null,"summary":null,"suggestedActions":null,"attachments":[{"contentType":"text/html","contentUrl":null,"content":"<div><span itemscope=\"\" itemtype=\"http://schema.skype.com/Mention\" itemid=\"0\">PandoBot</span> fff</div>","name":null,"thumbnailUrl":null}],"entities":[{"type":"clientInfo","locale":"es-ES","country":"ES","platform":"iOS"}],"channelData":{"teamsChannelId":"19:[email protected] /cdn-cgi/l/email-protection","teamsTeamId":"19:[email protected] /cdn-cgi/l/email-protection","channel":{"id":"19:[email protected] /cdn-cgi/l/email-protection"},"team":{"id":"19:[email protected] /cdn-cgi/l/email-protection"},"tenant":{"id":"9744600e-3e04-492e-baa1-25ec245c6f10"}},"action":null,"replyToId":null,"value":null,"name":null,"relatesTo":null,"code":null}';


    //generate HMAC hash with diferent $data formats
    $test = [$data, unpak_str($data), base64_encode($data), unpak_str(base64_encode($data))];
    hasher($test, $output);


    //microsoft provided HMAC
    $output.="<HR>EW2993goL1q7nGhytIb3jKmV6luXLz15Bq2aYwuCeiE="; 


    echo $output;
    /*
    Calculates: 
    0HsKoHza/QBvdz+nZw9tOti/eSWjyMMt/U77bfDqiE8=
    3jSq3I0HNQkjB9QfnnsxC1c3pF5PjqweHlSVcicrShY=
    bTQcGVTHX8/Gh4xovnN0WiJUiNaOQwvUZnwyFfiCaJE=
    qHBT2Y2ITyoxz2gmBbG8P1CrClvETus6dTffET3bAR8=
    8BcrXEQDDi77qgxCZLYyb/6ez8p9Qg2ZhTyZPWkdn/g=
    +8RSU5SSJKxqRLKkI+NkTE01xwu6PwPkKKMuvyyUvlo=
    PdL5ZpEwcN6Fe5kfX7zeAZLJvt0uLNTzu7lhuoOcr2o=
    s6M5pYruEgWeNMEOFfQRjVKQqtPBVaW3TJb2MzObF2c=
    xOTLhddbAwczQVneuTDQhPzmoIXGQljpf27c+hlhQII=
    aUMm5b2sKfmwGZOglfiu228fWqoLlwjc7z1QRdIbakE=
    5a7bAj9tzqhP9l85OvfVasURW0GSV5rykRutFFPO2fk=
    kwg6P2LoDL9rc3SSwJxQeoYJzZYlh+FHFefe38UokBM=
    eHeAzI7TV6vYDzxTxwyKWxMeVKFiFlIffWRiIMAk6fk=
    ZCyj2UppacQOTXogLPMFLDeMArQg03rhhlIwhynDvng=
    uQYK+7u9fppb62zXqtVYfkNK9wVawB3g+BlTyu4dc74=
    vjOFA3fqpwUx/VO9dQv3XviNhpjTNQsUwaJIwH4JjdY=
    ------------ MS PROVIDED HMAC ---------------
    EW2993goL1q7nGhytIb3jKmV6luXLz15Bq2aYwuCeiE=
     */

我的哈希匹配为零...

最后，经过多次尝试，这让我发疯，并决定启动一个具有新秘密的新机器人。现在工作正常。我是人类，而 MS Teams 不...我想这是我复制/粘贴的错，但这是一件非常奇怪的事情，另一方面旧机器人失败了很多次，没有响应，最新的没有

适用于 Microsoft Teams 自定义机器人的 PHP 中的完整示例验证 HMAC：

        <?php

        //The secret share with Microsoft Teams
        $secret="jond3021g9imMkrt8txF5AVPIwPFouNV/I72cQFii18=";

        //get headers
        $a = getallheaders();
        $provided_hmac=substr($a['Authorization'],5);

        //Get data from request
        $data=file_get_contents('php://input');

        //json decode into array
        $json=json_decode($data, true);

        //hashing
        $hash = hash_hmac("sha256",$data,base64_decode($secret), true);
        $calculated_hmac = base64_encode($hash);

        //start log var
        $log = "\n========".date("Y-m-d H:i:s")."========\n".$provided_hmac."\n".$calculated_hmac."\n";

        try{
            //compare hashs
            if(!hash_equals($provided_hmac,$calculated_hmac))
                throw new Exception("No hash matching");
            //response text
            $txt="Hi {$json["from"]["name"]} welcome to your custom bot";
            echo '{
                "type": "message",
                "text": "'.$txt.'"
                 }';
            $log .= "Sended: {$txt}";
        }catch (Exception $e){
            $log .= $e->getMessage();
        }
        //write log
        $fp = fopen("log.txt","a");
        fwrite($fp, $log . PHP_EOL);
        fclose($fp);