javascript - Having problems uploading blob directly to s3 -

i have following code:

var fd = new formdata();          var key = "events/" + (new date).gettime() + '-';          fd.append('key', key);         fd.append('acl', acl);         fd.append('content-type', "image/jpeg");         fd.append('awsaccesskeyid', awsaccesskeyid);         fd.append('policy', policy);         fd.append('name', "policy13492345");         fd.append('success_action_status', "201");         fd.append('signature', signature);                   fd.append("file",  blob);         fd.append("filename", filename + ".jpg");         var xhr = new xmlhttprequest();            xhr.upload.addeventlistener("progress", uploadprogress, false);         xhr.addeventlistener("load", uploadcomplete, false);         xhr.addeventlistener("error", uploadfailed, false);         xhr.addeventlistener("abort", uploadcanceled, false);          xhr.open('post', 'https://s3.amazonaws.com/' + bucket + '/', true);           xhr.send(fd); 

when request goes through following error:

<code>accessdenied</code><message>invalid according policy: policy condition failed: ["starts-with", "$filename", ""]</message>

i have no idea doing wrong, generate blob so:

function datauritoblob(datauri) {                 var binary = atob(datauri.split(',')[1]);                 var array = [];                 (var = 0; < binary.length; i++) {                     array.push(binary.charcodeat(i));                 }                 var mimestring = datauri.split(',')[0].split(':')[1].split(';')[0]                 return new blob([new uint8array(array)], { type: mimestring });             } 

this request:

------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="key"  events/1367541109750- ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="acl"  private ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="content-type"  image/jpeg ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="awsaccesskeyid"  asdfasdffasdfsdfaadsfhhvdq ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="policy"  fsny29udfuz2unlcawlcaxmdawmdawmdbdlaogicagicasdfasdfagifsgj3n0yxj0cy13axrojywgjyrrzxknlcanjybdlaogicagicagifsgj3n0yxj0cy13axrojywgjyrdb250zw50lvr5cgunlcanasdfjybdlao ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="name"  policy134722343242345 ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="success_action_status"  201 ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="signature"  basdfasdftwa/9asdfasdfx3/zasdfadsft6g= ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="file"; filename="blob" content-type: image/jpeg   ------webkitformboundaryxh8thnhamdhzquxe content-disposition: form-data; name="filename"  c:\fakepath\495845894.jpg ------webkitformboundaryxh8thnhamdhzquxe-- 

figured out issue, ordering formdata important, must follow correct order in order data post correctly.