def decrypt(key,msgfile): msg=read_data(msgfile) keys=read_keys() if msg[0] is '$': msg=list(msg[1:]) #print msg k1=len(msg) i=0 z=[] t=cal_inverse(key) while i<k1: y=list(msg[0:2]) y[0]=keys.index(y[0]) y[1]=keys.index(y[1]) z+=cal_mul(y,t) msg=msg[2:] i+=2 j=0 l=[] while j<len(z): l+=keys[int(z[j])] j+=1 l=''.join(l) fileoperation(msgfile,l,0) else: decrypt_error() return
def encrypt(key,readmsg):
y=[]
keys=read_keys()
msg=read_data(readmsg)
k=len(msg)
i=0
if msg[0] is '$':
encrypt_error()
return
if k%2 is not 0:
msg+=(' ')
while i<k:
x=list(msg[0:2])
#print x
x[0]=keys.index(x[0])
x[1]=keys.index(x[1])
#print x
y+=cal_mul(x,key)
if inverse_exists(key)==0:
unpossible()
return
msg=msg[2:]
i=i+2
#print y
j=0
l=[]
while j<len(y):
l+=keys[int(y[j])]
j+=1
#print l
data=''.join(l)
fileoperation(readmsg,data,1)
def decrypt(a,b,msgfile): s=read_data(msgfile) bit=s[0] if bit!='$': decrypt_error() return s=s[1:] k2=len(s) keys=read_keys() m=26 j=0 p=[] inv=compute_inverse(a,m) while j<k2: index=(inv*(keys.index(s[j])-b))%m p.append(keys[index]) j=j+1 data=''.join(p) fileoperation(msgfile,data,0)
def encrypt(a,b,msgfile):
s=read_data(msgfile)
keys=read_keys()
#print keys
m=26
j=0
e=[]
k2=len(s)
if s[0]=='$':
encrypt_error()
return
try:
while j<k2:
k=((a*keys.index(s[j]))+b)%m
e.append(keys[k])
j=j+1
data=''.join(e)
fileoperation(msgfile,data,1)
except IndexError:
print("error occured while performing operation")
def decrypt(key,msg):
message=list(read_data(msg))
keys=read_keys()
n=len(key)
if message[0]!='$':
decrypt_error()
return
m2=len(message)
i=1
d=[]
m=28
j=0
while i<m2:
d.append(keys[(keys.index(message[i])-int(key[j]))%m])
j=j+1
i=i+1
if j==n:
j=0
data=''.join(d)
fileoperation(msg,data,0)
def encrypt(key,msg): message=read_data(msg) message=list(message) keys=read_keys() n=len(key) if message[0]=='$': encrypt_error() return m2=len(message) i=0 e=[] m=28 j=0 while i<m2: e.append(keys[(keys.index(message[i])+int(key[j]))%m]) j=j+1 i=i+1 if j==n: j=0 data=''.join(e) fileoperation(msg,data,1)
