1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
# Utilities for printing ASN.1 values
def bits_to_hex(bit_array, delimiter=":"):
"""Convert a bit array to a prettily formated hex string. If the array
length is not a multiple of 8, it is padded with 0-bits from the left.
For example, [1,0,0,1,1,0,1,0,0,1,0] becomes 04:d2.
Args:
bit_array: the bit array to convert
Returns:
the formatted hex string."""
# Pad the first partial byte.
partial_bits = len(bit_array) % 8
pad_length = 8 - partial_bits if partial_bits else 0
bitstring = "0"*pad_length + "".join(map(str, bit_array))
byte_array = [int(bitstring[i:i+8], 2) for i in range(0, len(bitstring), 8)]
return delimiter.join(map(lambda x: "%02x" % x, byte_array))
return bytes_to_hex(byte_array, delimiter=delimiter)
def bytes_to_hex(byte_string, delimiter=":"):
"""Convert a bytestring to a prettily formated hex string: for example,
'\x04\xd2' becomes 04:d2.
Args:
byte_string: the bytes to convert.
Returns:
the formatted hex string."""
return delimiter.join([("%02x" % ord(b)) for b in byte_string])
def int_to_hex(int_value, delimiter=":"):
"""Convert an integer to a prettily formated hex string: for example,
1234 (0x4d2) becomes 04:d2 and -1234 becomes ' -:04:d2'
Args:
int_value: the value to convert.
Returns:
the formatted hex string."""
hex_string = "%x" % int_value
ret = ""
pos = 0
# Accommodate for negative integers.
if hex_string[0] == '-':
ret += ' -' + delimiter
hex_string = hex_string[1:]
# If the first digit is a half-byte, pad with a 0.
remaining_len = len(hex_string) - pos
hex_string = hex_string.zfill(remaining_len + remaining_len % 2)
byte_values = [hex_string[i:i+2] for i in range(pos, len(hex_string), 2)]
return ret + delimiter.join(byte_values)
def wrap_lines(long_string, wrap):
"""Split the long string into line chunks according to the wrap limit and
existing newlines.
Args:
long_string: a long, possibly multiline string
wrap: maximum number of characters per line. 0 or negative
wrap means no limit.
Returns:
a list of lines of at most |wrap| characters each."""
if not long_string:
return []
long_lines = long_string.split('\n')
if wrap <= 0:
return long_lines
ret = []
for line in long_lines:
if not line:
# Empty line
ret += [line]
else:
ret += [line[i:i+wrap] for i in range(0, len(line), wrap)]
return ret
def append_lines(lines, wrap, buf):
"""Append lines to the buffer. If the first line can be appended to the last
line of the buf without exceeding wrap characters, the two lines are merged.
Args:
lines: an iterable of lines to append
wrap: maximum number of characters per line. 0 or negative wrap means
no limit.
buf: an iterable of lines to append to"""
if not lines:
return
if not buf or wrap > 0 and len(buf[-1]) + len(lines[0]) > wrap:
buf += lines
else:
buf[-1] += lines[0]
buf += lines[1:]
|
