68 lines
1.7 KiB
Python
68 lines
1.7 KiB
Python
import entry
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class FileFormatError(Exception): pass
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class VersionMismatch(Exception): pass
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def check_header(f):
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"""check_header(file(rb))
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Throw an error if the header isn't good"""
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# Magic is b'WOT'
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magic = f.read(3)
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if magic != b'WOT':
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raise FileFormatError('Invalid magic')
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# Version 0 is the current one
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version = f.read(1)
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if version == b'':
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raise FileFormatError('Unexpected end of file')
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if version != b'\0':
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raise VersionMismatch('Version %i not supported' % version[0])
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def read_entry(f):
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"""read_entry(file(rb)) → Entry / None
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Returns None if the end of file has been reached"""
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# u8[32]: salt
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salt = f.read(32)
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if len(salt) == 0:
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# End of file has been reached, return None to mark that
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return None
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elif len(salt) != 32:
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raise FileFormatError('Unexpected end of file')
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# u8[32]: hashed_host
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hashed_host = f.read(32)
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if len(hashed_host) != 32:
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raise FileFormatError('Unexpected end of file')
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# u8[32]: fingerprint
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fingerprint = f.read(32)
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if len(fingerprint) != 32:
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raise FileFormatError('Unexpected end of file')
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# u16le: comment_length
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length_bytes = f.read(2)
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if len(length_bytes) != 2:
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raise FileFormatError('Unexpected end of file')
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comment_length = length_bytes[0] | length_bytes[1] << 8
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# u8[comment_length]: comment
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comment = f.read(comment_length)
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if len(comment) != comment_length:
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raise FileFormatError('Unexpected end of file')
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return entry.Entry(salt, hashed_host, fingerprint, comment)
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def read(f):
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"""read_file(file(rb)) → [Entry]"""
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check_header(f)
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entries = []
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while True:
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# Read until we reach the end of file
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entry = read_entry(f)
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if entry is None: break
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entries.append(entry)
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return entries
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