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asmcrypto - example - hash large file
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| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <meta charset="utf-8" /> | |
| <title>Hash large File Example</title> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/asmCrypto/0.22.0/asmcrypto.min.js"></script> | |
| <script type="text/javascript" language="javascript"> | |
| function on_hash_done(hash, time_elapsed_seconds) { | |
| document.getElementById('progress').innerText = ''; | |
| document.getElementById('result').innerText = 'sha256: ' + hash + ' took: ' + time_elapsed_seconds + 's'; | |
| document.getElementById('file_input').disabled = false; | |
| } | |
| function on_hash_progress(progress, time_elapsed_seconds) { | |
| document.getElementById('progress').innerText = Math.round(progress * 1000)/10 + '% ' + time_elapsed_seconds + 's'; | |
| } | |
| function on_hash_error(error) { | |
| document.getElementById('progress').innerText = ''; | |
| document.getElementById('error').innerText = error; | |
| document.getElementById('file_input').disabled = false; | |
| } | |
| function hash_file(file, on_hash_done, on_hash_progress, on_hash_error) { | |
| var file_size = file.size; | |
| var chunk_size = 1 * 1024 * 1024; | |
| var offset = 0; | |
| var time_started = Date.now(); | |
| var hasher = new asmCrypto.SHA256(); | |
| var file_reader = new FileReader(); | |
| file_reader.onload = function(e) { | |
| if (e.target.error === null) { | |
| offset += e.loaded; | |
| const uint8_data = new Uint8Array(e.target.result) | |
| hasher.process(uint8_data); | |
| } else { | |
| on_hash_error(e.target.error); | |
| return; | |
| } | |
| var time_elapsed_seconds = Math.floor((Date.now() - time_started) / 100) / 10; | |
| on_hash_progress(offset / file_size, time_elapsed_seconds); | |
| if (offset < file_size) { | |
| file_reader.readAsArrayBuffer(file.slice(offset, chunk_size + offset)); | |
| } else { | |
| hasher.finish(); | |
| on_hash_done(asmCrypto.bytes_to_hex(hasher.result), time_elapsed_seconds); | |
| return; | |
| } | |
| } | |
| file_reader.readAsArrayBuffer(file.slice(offset, chunk_size + offset)); | |
| } | |
| function on_file_select(e) { | |
| if (e.target.files.length == 1) { | |
| document.getElementById('file_input').disabled = true; | |
| document.getElementById('result').innerText = ''; | |
| hash_file(e.target.files[0], on_hash_done, on_hash_progress, on_hash_error); | |
| } | |
| } | |
| </script> | |
| </head> | |
| <body> | |
| <h1>SHA256 large file</h1> | |
| <input id="file_input" type="file" onchange="on_file_select(event)" /> | |
| <div id="progress"></div> | |
| <div id="result"></div> | |
| <div id="error"></div> | |
| </body> | |
| </html> |
Yes, that's right. I also found this at some point, but forgot to update the gist.
thx
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Thanks a lot for this example, it helped me a lot. I just noticed an strange behavior running this example and that was hash mismatch problem for files with identical contents, between C# using
SHA256ManagedClass and the hash returned from this example. So, after a lot of trial & errors, I noticed that we need to explicitly convertArrayBufferinstance toUint8Arrayin line 38, so it becomes:hasher.process(new Uint8Array(e.target.result));