def encrypt(N, e, message, L = ""):
lHash = SHA.new(L).digest()
hLen = len(lHash)
mLen = len(message)
k = numOctets(N)
if mLen > k - (2*hLen) - 2:
print "Message too long"
return -1
lPS = (k - mLen - 2*hLen - 2)
PS = '\x00' * lPS
DB = ''.join((lHash, PS, '\x01', message))
seed = I2OSP(utils.gen_random(hLen * 8), hLen)
dbMask = MGF(seed, k - hLen - 1)
maskedDB = stringXOR(DB, dbMask)
seedMask = MGF(maskedDB, hLen)
maskedSeed = stringXOR(seed, seedMask)
EM = ''.join(('\x00', maskedSeed, maskedDB))
m = OS2IP(EM)
c = RSAEP(N, e, m)
cipherText = I2OSP(c, k)
return cipherText
def encrypt(N, e, message, L=""):
lHash = SHA.new(L).digest()
hLen = len(lHash)
mLen = len(message)
k = numOctets(N)
if mLen > k - (2 * hLen) - 2:
print "Message too long"
return -1
lPS = (k - mLen - 2 * hLen - 2)
PS = '\x00' * lPS
DB = ''.join((lHash, PS, '\x01', message))
seed = I2OSP(utils.gen_random(hLen * 8), hLen)
dbMask = MGF(seed, k - hLen - 1)
maskedDB = stringXOR(DB, dbMask)
seedMask = MGF(maskedDB, hLen)
maskedSeed = stringXOR(seed, seedMask)
EM = ''.join(('\x00', maskedSeed, maskedDB))
m = OS2IP(EM)
c = RSAEP(N, e, m)
cipherText = I2OSP(c, k)
return cipherText
def generateKeys(security_level = 1):
prime_size, random_size = 0, 0
if security_level == 1: prime_size, random_size = 160, 864
elif security_level == 2: prime_size, random_size = 224, 1824
elif security_level == 3: prime_size, random_size = 256, 2816
else: return
q = number.getPrime(prime_size)
k = number.getRandomInteger(random_size)
p = k * q + 1
while utils.rm_primality(p) != True:
k = utils.gen_random(random_size)
p = k * q + 1
a = number.getRandomRange(0, p)
g = utils.mod_exp(a, (p - 1) / q, p)
while g == 1:
a = number.getRandomRange(0, p)
g = utils.mod_exp(a, (p - 1) / q, p)
x = number.getRandomRange(1, q - 2)
y = utils.mod_exp(g, x, p)
return p, q, g, x, y
def EMSAPSSENC(M, emBits, sLen = 16):
mHash = SHA.new(M).digest()
hLen = len(mHash)
emLen = utils.ceil(emBits, 8)
if emLen < hLen + sLen + 2:
print "Encoding error"
return
salt = I2OSP(utils.gen_random(sLen * 8), sLen)
m_prime = '\x00' * 8 + mHash + salt
H = SHA.new(m_prime).digest()
PS = '\x00' * (emLen - sLen - hLen - 2)
DB = PS + '\x01' + salt
dbMask = MGF(H, emLen - hLen - 1)
maskedDB = stringXOR(DB, dbMask)
octets, bits = (8 * emLen - emBits) / 8, (8 * emLen - emBits) % 8
maskedDB = ('\x00' * octets) + maskedDB[octets:]
newByte = chr(ord(maskedDB[octets]) & (255 >> bits))
maskedDB = maskedDB[:octets] + newByte + maskedDB[octets+1:]
EM = maskedDB + H + '\xbc'
return EM
def EMSAPSSENC(M, emBits, sLen=16):
mHash = SHA.new(M).digest()
hLen = len(mHash)
emLen = utils.ceil(emBits, 8)
if emLen < hLen + sLen + 2:
print "Encoding error"
return
salt = I2OSP(utils.gen_random(sLen * 8), sLen)
m_prime = '\x00' * 8 + mHash + salt
H = SHA.new(m_prime).digest()
PS = '\x00' * (emLen - sLen - hLen - 2)
DB = PS + '\x01' + salt
dbMask = MGF(H, emLen - hLen - 1)
maskedDB = stringXOR(DB, dbMask)
octets, bits = (8 * emLen - emBits) / 8, (8 * emLen - emBits) % 8
maskedDB = ('\x00' * octets) + maskedDB[octets:]
newByte = chr(ord(maskedDB[octets]) & (255 >> bits))
maskedDB = maskedDB[:octets] + newByte + maskedDB[octets + 1:]
EM = maskedDB + H + '\xbc'
return EM
# image caption
img_caption = ''
textfile = np.random.choice(text_list)
with open(args.pathText + textfile) as f:
text = f.read()
text_length = np.random.randint(
args.capLengthMin, args.capLengthMax)
text_starter = np.random.randint(
len(text) - text_length)
text = text[text_starter:(text_starter + text_length)]
section = img_caption
# img path
img_path = args.pathFig + np.random.choice(chart_list)
img_width_ratio = utils.gen_random(args.imgWidthMinRatio,
args.imgWidthMaxRatio)
img_width = int(img_width_ratio * column_width)
img = Image.open(img_path)
img_height = img_width * img.size[1] / img.size[0]
if img_height > args.imgHeightMaxRatio * column_width:
img_height = img_height * 0.5
img_width = img_width * 0.5
if img_height > args.pageHeight - offset_y - marginPt:
continue
# caption
if img_width_ratio > 0.8 or num_columns > 1:
caption_location = np.random.choice(['top', 'bottom'])
else:
caption_location = np.random.choice(