Building an Encrypted Virtual Filesystem in the Browser

Transcript

1. BUILDING AN ENCRYPTED VIRTUAL FILESYSTEM IN THE BROWSER
2. @campedersen Minneapolis •
5. WHY? window.requestFileSystem is young Only supported in WebKit File APIs are local to the machine Want to store the files remotely
6. VIRTUAL FILE SYSTEMS user applications operating system hardware
7. VIRTUAL FILE SYSTEMS user applications operating system hardware
8. kernel space API inode/dentry caches drivers specific filesystems page/buffer caches VFS
9. VIRTUAL FILESYSTEMS ALLOW ABSTRACTION FROM HARDWARE AND DATA STRUCTURE DETAILS open() read() write() close() unlink() etc.
10. VFS DATA STRUCTURES superblock inodes dentries files
11. VFS DATA STRUCTURES superblock inodes dentries files metadata index nodes directory entries points to data
12. –Atwood’s Law “Any application that can be written in JavaScript, will eventually be written in JavaScript”
13. DIFFERENCES Everything has to live in user space Async is hard Data structures are different
14. CRATE ARCHITECTURE Superblock() coordination Inode() Dentry() File() just data Crate() API driver backend glue
15. ENTER ENCRYPTION Just use Crypton Everything is a container Eventually we can share files easily
16. CONTAINER KEYS inodes dentries files just data _crate_inode_123 _crate_file_321
17. CONTAINER KEYS inodes dentries files just data f8c30f7cd2a0acf2f69313 1867d3f4ff36e6a8ffb6b1 a4ea27ede8fc099e8738 01fb7afcd76a62b1bd722e 813cbecf560991241cf557 e5400c9f1026b965b684
18. CONTAINER DATA inodes dentries files just data {“id":2, “dentries":[{"id":1,"name":".."}], “links":1, “atime":0, “mtime":1386954461254, “ctime":1386954455150, “size":71498, “isDirectory":false, “fileId":3, "custom":{"type":"image/png"}} {“value":"data:image/png;base64, iVBORw0KGgoAAAANSUhEUgAAB7sAAAUn CAYAAAAsNwN2AAAABHNCS…="}
19. CONTAINER DATA inodes dentries files just data {“iv":"6dBwnCXN8dV8B4iruDH4lw","v":1, “iter":1000,"ks":128,"ts":64, “mode":"gcm","adata":"","cipher":"aes", “ct”:”fsUndHDCsROgLHglmzPN48oPF1+s…"} {“iv”:"GRcbuBDEIuCVJno/4xIrnA","v":1, “iter":1000,"ks":128,"ts":64,"mode":"gcm", “adata":"","cipher":"aes", “ct”:”a0b9/ggRWslifA..."}
20. crate in userspace var fs = new Crate({ driver: 'localStorage', }, function (err) { fs.open(‘/foo’, function (err, file) { file.write(‘bar’, function (err) { console.log(‘i made a file in js!’); }); }); }); !
21. crate with encryption var fs = new Crate({ driver: ‘crypton', options: { session: cryptonSession } }, function (err) { fs.open(‘/foo’, function (err, file) { file.write(‘bar’, function (err) { console.log(‘i encrypted a file!’); }); }); }); !
22. opening files fs.open(path, function (err, file) { file.read(function (err, data) { var blob = dataURItoBlob(data); var url = URL.createObjectURL(blob); var name = file.name; var reference = window.open(url, name, null); URL.revokeObjectURL(url); }); });
23. saving files fs.open(path, function (err, file) { file.read(function (err, data) { var link = document.createElement('a'); link.href = data; link.download = file.name; document.body.appendChild(link); link.click(); document.body.removeChild(link); }); });
24. PROBLEMS Inconsistent APIs No Web Workers in Crypton Took a lot of shortcuts
25. IT’S NOT DONE YET Tests Symlinks General features More drivers/backends
26. @campedersen ! cam@spideroak.com ! github.com/ecto/crate IF IT SOUNDS INTERESTING, COME HACK WITH ME