Skip to content

Editing base64, Adding average file, Editing find_lcm #673

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
dynamitechetan merged 4 commits into from
Jan 19, 2019
Merged

Editing base64, Adding average file, Editing find_lcm #673

Changes from 1 commit
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
3677ae0
avrage.py
mikelfried Dec 27, 2018
ae933ba
Update base64_cipher.py
mikelfried Dec 29, 2018
1512fdd
Update and rename avrage.py to average.py
mikelfried Dec 29, 2018
9c39006
update find_lcm algorithm
mikelfried Jan 19, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
Update base64_cipher.py 
encoding and decoding base64 without any module.
  • Loading branch information
@mikelfried
mikelfried authored Dec 29, 2018
commit ae933ba2d38b1486bdde74e4fe3c280c6203ba27
65 changes: 59 additions & 6 deletions ciphers/base64_cipher.py
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,11 +1,64 @@
import base64
def encodeBase64(text):
base64chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

r = "" #the result
c = 3 - len(text) % 3 #the length of padding
p = "=" * c #the padding
s = text + "\0" * c #the text to encode

i = 0
while i < len(s):
if i > 0 and ((i / 3 * 4) % 76) == 0:
r = r + "\r\n"

n = (ord(s[i]) << 16) + (ord(s[i+1]) << 8 ) + ord(s[i+2])

n1 = (n >> 18) & 63
n2 = (n >> 12) & 63
n3 = (n >> 6) & 63
n4 = n & 63

r += base64chars[n1] + base64chars[n2] + base64chars[n3] + base64chars[n4]
i += 3

return r[0: len(r)-len(p)] + p

def decodeBase64(text):
base64chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
s = ""

for i in text:
if i in base64chars:
s += i
c = ""
else:
if i == '=':
c += '='

p = ""
if c == "=":
p = 'A'
else:
if c == "==":
p = "AA"

r = ""
s = s + p

i = 0
while i < len(s):
n = (base64chars.index(s[i]) << 18) + (base64chars.index(s[i+1]) << 12) + (base64chars.index(s[i+2]) << 6) +base64chars.index(s[i+3])

r += chr((n >> 16) & 255) + chr((n >> 8) & 255) + chr(n & 255)

i += 4

return r[0: len(r) - len(p)]

def main():
inp = input('->')
encoded = inp.encode('utf-8') #encoded the input (we need a bytes like object)
b64encoded = base64.b64encode(encoded) #b64encoded the encoded string
print(b64encoded)
print(base64.b64decode(b64encoded).decode('utf-8'))#decoded it
print(encodeBase64("WELCOME to base64 encoding"))
print(decodeBase64(encodeBase64("WELCOME to base64 encoding")))


if __name__ == '__main__':
main()