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Converting RSA signature to String

I'm creating my RSA Signature like this.
transactionStr = json.dumps(GenesisTransaction())
signature = rsa.sign(transactionStr.encode(), client.privateKey, 'SHA-1')
But I'm unable to get it to a string so I can save it.
I have tried decoding it using utf8
signature.decode("utf8")
but I get the error "'utf-8' codec can't decode byte 0xe3 in position 2"
any way I can do this?
A RSA signature looks like this
b'aL\xe3\xf4\xbeEM\xc4\x9e\n\x9e\xf4M`\xba\x85*\x13\xd52x\xd9\\\xe8F\x1c\x07\x90[/\x9dy\xce\xa9IV\x89\xe0\xcd9\\_3\x1e\xaa\x80\xdea\xd1\xbem/\x8e\x91\xbd\x13\x12o\x8c\xed\xf6\x89\xb5\x0b'

.decode('utf8') is used to decode text encoded in UTF8, not arbitrary bytes. Convert the byte string to a hexadecimal string instead:
>>> sig = b'aL\xe3\xf4\xbeEM\xc4\x9e\n\x9e\xf4M`\xba\x85*\x13\xd52x\xd9\\\xe8F\x1c\x07\x90[/\x9dy\xce\xa9IV\x89\xe0\xcd9\\_3\x1e\xaa\x80\xdea\xd1\xbem/\x8e\x91\xbd\x13\x12o\x8c\xed\xf6\x89\xb5\x0b'
>>> s = sig.hex()
>>> s
'614ce3f4be454dc49e0a9ef44d60ba852a13d53278d95ce8461c07905b2f9d79cea9495689e0cd395c5f331eaa80de61d1be6d2f8e91bd13126f8cedf689b50b'
To convert back, if needed:
>>> b = bytes.fromhex(s)
>>> b
b'aL\xe3\xf4\xbeEM\xc4\x9e\n\x9e\xf4M`\xba\x85*\x13\xd52x\xd9\\\xe8F\x1c\x07\x90[/\x9dy\xce\xa9IV\x89\xe0\xcd9\\_3\x1e\xaa\x80\xdea\xd1\xbem/\x8e\x91\xbd\x13\x12o\x8c\xed\xf6\x89\xb5\x0b'
>>> b==sig
True

Python adds extra to crypt result

I'm trying to create an API with token to communicate between an Raspberry Pi and a Webserver. Right now i'm tring to generate an Token with Python.
from Crypto.Cipher import AES
import base64
import os
import time
import datetime
import requests
BLOCK_SIZE = 32
BLOCK_SZ = 14
#!/usr/bin/python
salt = "123456789123" # Zorg dat de salt altijd even lang is! (12 Chars)
iv = "1234567891234567" # Zorg dat de salt altijd even lang is! (16 Chars)
currentDate = time.strftime("%d%m%Y")
currentTime = time.strftime("%H%M")
PADDING = '{'
pad = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * PADDING
EncodeAES = lambda c, s: base64.b64encode(c.encrypt(pad(s)))
DecodeAES = lambda c, e: c.decrypt(base64.b64decode(e)).rstrip(PADDING)
secret = salt + currentTime
cipher=AES.new(key=secret,mode=AES.MODE_CBC,IV=iv)
encode = currentDate
encoded = EncodeAES(cipher, encode)
print (encoded)
The problem is that the output of the script an exta b' adds to every encoded string.. And on every end a '
C:\Python36-32>python.exe encrypt.py
b'Qge6lbC+SulFgTk/7TZ0TKHUP0SFS8G+nd5un4iv9iI='
C:\Python36-32>python.exe encrypt.py
b'DTcotcaU98QkRxCzRR01hh4yqqyC92u4oAuf0bSrQZQ='
Hopefully someone can explain what went wrong.
FIXED!
I was able to fix it to decode it to utf-8 format.
sendtoken = encoded.decode('utf-8')

You are running Python 3.6, which uses Unicode (UTF-8) for string literals. I expect that the EncodeAES() function returns an ASCII string, which Python is indicating is a bytestring rather than a Unicode string by prepending the b to the string literal it prints.
You could strip the b out of the output post-Python, or you could print(str(encoded)), which should give you the same characters, since ASCII is valid UTF-8.
EDIT:
What you need to do is decode the bytestring into UTF-8, as mentioned in the answer and in a comment above. I was wrong about str() doing the conversion for you, you need to call decode('UTF-8') on the bytestring you wish to print. That converts the string into the internal UTF-8 representation, which then prints correctly.

Python: Convert utf-8 string to byte string [duplicate]

This question already has answers here:
Best way to convert string to bytes in Python 3?
(5 answers)
Closed 11 days ago.
I have the following function to parse a utf-8 string from a sequence of bytes
Note -- 'length_size' is the number of bytes it take to represent the length of the utf-8 string
def parse_utf8(self, bytes, length_size):
length = bytes2int(bytes[0:length_size])
value = ''.join(['%c' % b for b in bytes[length_size:length_size+length]])
return value
def bytes2int(raw_bytes, signed=False):
"""
Convert a string of bytes to an integer (assumes little-endian byte order)
"""
if len(raw_bytes) == 0:
return None
fmt = {1:'B', 2:'H', 4:'I', 8:'Q'}[len(raw_bytes)]
if signed:
fmt = fmt.lower()
return struct.unpack('<'+fmt, raw_bytes)[0]
I'd like to write the function in reverse -- i.e. a function that will take a utf-8 encoded string and return it's representation as a byte string.
So far, I have the following:
def create_utf8(self, utf8_string):
return utf8_string.encode('utf-8')
I run into the following error when attempting to test it:
File "writer.py", line 229, in create_utf8
return utf8_string.encode('utf-8')
UnicodeDecodeError: 'ascii' codec can't decode byte 0x98 in position 0: ordinal not in range(128)
If possible, I'd like to adopt a structure for the code similar to the parse_utf8 example. What am I doing wrong?
Thank you for your help!
UPDATE: test driver, now correct
def random_utf8_seq(self, length):
# from http://www.w3.org/2001/06/utf-8-test/postscript-utf-8.html
test_charset = u" !\"#$%&'()*+,-./0123456789:;<=>?#ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ ¡¢£¤¥¦§¨©ª«¬­ ®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿĂ㥹ĆćČčĎďĐđĘęĚěĹ弾ŁłŃńŇňŐőŒœŔŕŘřŚśŞşŠšŢţŤťŮůŰűŸŹźŻżŽžƒˆˇ˘˙˛˜˝–—‘’‚“”„†‡•…‰‹›€™"
utf8_seq = u""
for i in range(length):
utf8_seq += random.choice(test_charset)
return utf8_seq
I get the following error:
input_str = self.random_utf8_seq(200)
File "writer.py", line 226, in random_utf8_seq
print unicode(utf8_seq, "utf-8")
UnicodeDecodeError: 'utf8' codec can't decode byte 0xbb in position 0: invalid start byte

If utf-8 => bytestring conversion is what do you want then you may use str.encode, but first you need to properly mark the type of source string in your example - prefix with u for unicode:
# coding: utf-8
import random
def random_utf8_seq(length):
# from http://www.w3.org/2001/06/utf-8-test/postscript-utf-8.html
test_charset = u" !\"#$%&'()*+,-./0123456789:;<=>?#ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ ¡¢£¤¥¦§¨©ª«¬­ ®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿĂ㥹ĆćČčĎďĐđĘęĚěĹ弾ŁłŃńŇňŐőŒœŔŕŘřŚśŞşŠšŢţŤťŮůŰűŸŹźŻżŽžƒˆˇ˘˙˛˜˝–—‘’‚“”„†‡•…‰‹›€™"
utf8_seq = u''
for i in range(length):
utf8_seq += random.choice(test_charset)
print utf8_seq.encode('utf-8')
return utf8_seq.encode('utf-8')
print( type(random_utf8_seq(200)) )
-- output --
­
õ3×sÔP{Ć.s(Ë°˙ě÷xÓ#bűV—û´ő¢uZÓČn˜0|_"Ðyø`êš·ÏÝhunÍÅ=ä?
óP{tlÇűpb¸7s´ňƒG—čøň\zčłŢXÂYqLĆúěă(ÿî ¥PyÐÔŇnל¦Ì˝+•ì›
ŻÛ°Ñ^ÝC÷ŢŐIñJĹţÒył­"MťÆ‹ČČ4þ!»šåŮ#Öhň-
ÈLGĄ¢ß˛Đ¯.ªÆź˘Ř^ĽÛŹËaĂŕ¹#¢éüÜńlÊqš=VřU…‚–MŽÎÉèoÙŹŠ¨Ð
<type 'str'>

How to print out 0xfb in python

I'm falling the unicode hell.
My environment in on unix, python 2.7.3
LC_CTYPE=zh_TW.UTF-8
LANG=en_US.UTF-8
I'm trying to dump hex encoded data in human readable format, here is simplified code
#! /usr/bin/env python
# encoding:utf-8
import sys
s=u"readable\n" # previous result keep in unicode string
s2="fb is not \xfb" # data read from binary file
s += s2
print s # method 1
print s.encode('utf-8') # method 2
print s.encode('utf-8','ignore') # method 3
print s.decode('iso8859-1') # method 4
# method 1-4 display following error message
#UnicodeDecodeError: 'ascii' codec can't decode byte 0xfb
# in position 0: ordinal not in range(128)
f = open('out.txt','wb')
f.write(s)
I just want to print out the 0xfb.
I should describe more here. The key is 's += s2'.
Where s will keep my previous decoded string.
And the s2 is next string which should append into s.
If I modified as following, it occurs on write file.
s=u"readable\n"
s2="fb is not \xfb"
s += s2.decode('cp437')
print s
f=open('out.txt','wb')
f.write(s)
# UnicodeEncodeError: 'ascii' codec can't encode character
# u'\u221a' in position 1: ordinal not in range(128)
I wish the result of out.txt is
readable
fb is not \xfb
or
readable
fb is not 0xfb
[Solution]
#! /usr/bin/env python
# encoding:utf-8
import sys
import binascii
def fmtstr(s):
r = ''
for c in s:
if ord(c) > 128:
r = ''.join([r, "\\x"+binascii.hexlify(c)])
else:
r = ''.join([r, c])
return r
s=u"readable"
s2="fb is not \xfb"
s += fmtstr(s2)
print s
f=open('out.txt','wb')
f.write(s)

I strongly suspect that your code is actually erroring out on the previous line: the s += s2 one. s2 is just a series of bytes, which can't be arbitrarily tacked on to a unicode object (which is instead a series of code points).
If you had intended the '\xfb' to represent U+FB, LATIN SMALL LETTER U WITH CIRCUMFLEX, it would have been better to assign it like this instead:
s2 = u"\u00fb"
But you said that you just want to print out \xHH codes for control characters. If you just want it to be something humans can understand which still makes it apparent that special characters are in a string, then repr may be enough. First, don't have s be a unicode object, because you're treating your strings here as a series of bytes, not a series of code points.
s = s.encode('utf-8')
s += s2
print repr(s)
Finally, if you don't want the extra quotes on the outside that repr adds, for nice pretty printing or whatever, there's not a simple builtin way to do that in Python (that I know of). I've used something like this before:
import re
controlchars_re = re.compile(r'[\x00-\x31\x7f-\xff]')
def _show_control_chars(match):
txt = repr(match.group(0))
return txt[1:-1]
def escape_special_characters(s):
return controlchars_re.sub(_show_control_chars, s.replace('\\', '\\\\'))
You can pretty easily tweak the controlchars_re regex to define which characters you care about escaping.

KOI8-R: Having trouble translating a string

This Python script gets translit for Russian letters:
s = u'Код Обмена Информацией, 8 бит'.encode('koi8-r')
print ''.join([chr(ord(c) & 0x7F) for c in s]) # kOD oBMENA iNFORMACIEJ, 8 BIT
That works. But I want to modify it so as to get user input. Now I'm stuck at this:
s = raw_input("Enter a string you want to translit: ")
s = unicode(s)
s = s.encode('koi8-r')
print ''.join([chr(ord(c) & 0x7F) for c in s])
Ending up with this:
UnicodeDecodeError: 'ascii' codec can't decode byte 0xef in position 0: ordinal not in range(128)
What's wrong?

s = unicode(s) expects ascii encoding by default. You need to supply it an encoding your input is in, e.g. s = unicode(s, 'utf-8').

try unicode(s, encoding) where encoding is whatever your terminal is in.

Looking at the error messages that you are seeing, it seems to me that your terminal encoding is probably set to KOI8-R, in which case you don't need to perform any decoding on the input data. If this is the case then all you need is:
>>> s = raw_input("Enter a string you want to translit: ")
>>> print ''.join([chr(ord(c) & 0x7F) for c in s])
kOD oBMENA iNFORMACIEJ, 8 BIT
You can double check this by s.decode('koi8-r') which should succeed and return the equivalent unicode string.