Cutlery/calibre
1
0
Fork 0
mirror of https://github.com/kovidgoyal/calibre.git synced 2025-07-09 03:04:10 -04:00
Code Issues Packages Projects Releases Wiki Activity

Some niceties for the AES implementation

Browse Source
This commit is contained in:
Kovid Goyal 2016-03-21 22:09:56 +05:30
parent 19c1d25c24
commit 9e18735d07
1 changed files with 18 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
src/pyj/aes.pyj
View File

@ -15,6 +15,9 @@ def string_to_bytes_slow(string):
) )
return ua return ua
def as_hex(bytes):
return [str.format('{:02x}', x) for x in bytes].join(' ')
def bytes_to_string_decoder(bytes, offset): def bytes_to_string_decoder(bytes, offset):
offset = offset or 0 offset = offset or 0
if offset: if offset:
@ -79,9 +82,8 @@ def convert_to_int32(bytes, output, offset, length):
class AES: class AES:
def __init__(self, key): def __init__(self, key):
self.key = key
self.working_mem = [Uint32Array(4), Uint32Array(4)] self.working_mem = [Uint32Array(4), Uint32Array(4)]
rounds = number_of_rounds[self.key.length] rounds = number_of_rounds[key.length]
if not rounds: if not rounds:
raise ValueError('invalid key size (must be length 16, 24 or 32)') raise ValueError('invalid key size (must be length 16, 24 or 32)')
@ -96,11 +98,11 @@ class AES:
self._Kd.push(Uint32Array(4)) self._Kd.push(Uint32Array(4))
round_key_count = (rounds + 1) * 4 round_key_count = (rounds + 1) * 4
KC = self.key.length / 4 KC = key.length / 4
# convert the key into ints # convert the key into ints
tk = Uint32Array(self.key.length / 4) tk = Uint32Array(KC)
convert_to_int32(self.key, tk) convert_to_int32(key, tk)
# copy values into round key arrays # copy values into round key arrays
index = 0 index = 0
@ -222,13 +224,18 @@ def generate_key(sz):
raise ValueError('Invalid key size, must be: 16, 24 or 32') raise ValueError('Invalid key size, must be: 16, 24 or 32')
return random_bytes(sz) return random_bytes(sz)
def as_hex(bytes): def generate_tag(sz):
return [str.format('{:02x}', x) for x in bytes].join(' ') return String.fromCharCode.apply(None, random_bytes(sz or 16))
class CBC: class CBC:
def __init__(self, key): def __init__(self, key):
self.aes = AES(key or generate_key(32)) self.key = key or generate_key(32)
self.aes = AES(self.key)
@property
def key_as_js(self):
return '(new Uint8Array(' + JSON.stringify(Array.prototype.slice.call(self.key)) + '))'
def encrypt_bytes(self, bytes, tag_bytes): def encrypt_bytes(self, bytes, tag_bytes):
iv = first_iv = random_bytes(16) iv = first_iv = random_bytes(16)
@ -286,6 +293,7 @@ if __name__ == '__main__':
crypted = cbc.encrypt(text) crypted = cbc.encrypt(text)
decrypted = cbc.decrypt(crypted) decrypted = cbc.decrypt(crypted)
print('Roundtrip:', 'OK' if text is decrypted else 'FAILED') print('Roundtrip:', 'OK' if text is decrypted else 'FAILED')
crypted = cbc.encrypt(text, 'secret-tag') secret_tag = generate_tag()
decrypted = cbc.decrypt(crypted, 'secret-tag') crypted = cbc.encrypt(text, secret_tag)
decrypted = cbc.decrypt(crypted, secret_tag)
print('Roundtrip with tag:', 'OK' if text is decrypted else 'FAILED') print('Roundtrip with tag:', 'OK' if text is decrypted else 'FAILED')