#!/usr/bin/python

import sys, struct, traceback
from Crypto.Util import number

def inflate_long(s, always_positive=0):
    "turns a normalized byte string into a long-int (adapted from Crypto.Util.number)"
    out = 0L
    negative = 0
    if not always_positive and (len(s) > 0) and (ord(s[0]) >= 0x80):
        negative = 1
    if len(s) % 4:
        filler = '\x00'
        if negative:
            filler = '\xff'
        s = filler * (4 - len(s) % 4) + s
    for i in range(0, len(s), 4):
        out = (out << 32) + struct.unpack('>I', s[i:i+4])[0]
    if negative:
        out -= (1L << (8 * len(s)))
    return out

def deflate_long(n, add_sign_padding=1):
    "turns a long-int into a normalized byte string (adapted from Crypto.Util.number)"
    # after much testing, this algorithm was deemed to be the fastest
    s = ''
    n = long(n)
    while (n != 0) and (n != -1):
        s = struct.pack('>I', n & 0xffffffffL) + s
        n = n >> 32
    # strip off leading zeros, FFs
    for i in enumerate(s):
        if (n == 0) and (i[1] != '\000'):
            break
        if (n == -1) and (i[1] != '\xff'):
            break
    else:
        # degenerate case, n was either 0 or -1
        i = (0,)
        if n == 0:
            s = '\000'
        else:
            s = '\xff'
    s = s[i[0]:]
    if add_sign_padding:
        if (n == 0) and (ord(s[0]) >= 0x80):
            s = '\x00' + s
        if (n == -1) and (ord(s[0]) < 0x80):
            s = '\xff' + s
    return s

def format_binary_weird(data):
    out = ''
    for i in enumerate(data):
        out += '%02X' % ord(i[1])
        if i[0] % 2:
            out += ' '
        if i[0] % 16 == 15:
            out += '\n'
    return out

def format_binary(data, prefix=''):
    x = 0
    out = []
    while len(data) > x + 16:
        out.append(format_binary_line(data[x:x+16]))
        x += 16
    if x < len(data):
        out.append(format_binary_line(data[x:]))
    return [prefix + x for x in out]

def format_binary_line(data):
    left = ' '.join(['%02X' % ord(c) for c in data])
    right = ''.join([('.%c..' % c)[(ord(c)+61)//94] for c in data])
    return '%-50s %s' % (left, right)

def hexify(s):
    "turn a string into a hex sequence"
    return ''.join(['%02X' % ord(c) for c in s])

def safe_string(s):
    out = ''
    for c in s:
        if (ord(c) >= 32) and (ord(c) <= 127):
            out += c
        else:
            out += '%%%02X' % ord(c)
    return out

# ''.join([['%%%02X' % ord(c), c][(ord(c) >= 32) and (ord(c) <= 127)] for c in s])

def bit_length(n):
    norm = deflate_long(n, 0)
    hbyte = ord(norm[0])
    bitlen = len(norm) * 8
    while not (hbyte & 0x80):
        hbyte <<= 1
        bitlen -= 1
    return bitlen

def generate_prime(bits, randpool):
    hbyte_mask = pow(2, bits % 8) - 1
    x = randpool.get_bytes((bits+7) // 8)
    if hbyte_mask > 0:
        x = chr(ord(x[0]) & hbyte_mask) + x[1:]
    n = inflate_long(x, 1)
    n |= 1
    n |= (1 << (bits - 1))
    while 1:
        # loop catches the case where we increment n into a higher bit-range
        while not number.isPrime(n):
            n += 2
        if bit_length(n) == bits:
            return n

def tb_strings():
    return ''.join(traceback.format_exception(*sys.exc_info())).split('\n')