I am trying to create an LM/NTLM response for which I require encrypting the challenge sent by server using DES algorithm
The following is what I did:
from M2Crypto.EVP import Cipher def encryptChallenge(magic, key): str_key = "" for iter1 in key: str_key = str_key + chr(iter1) encrypt = 1 cipher = Cipher(alg='des_ede_ecb', key=str_key, op=encrypt, iv='\0'*16) ciphertext = cipher.update(magic) ciphertext += cipher.final() return ciphertext However when I try encrypting "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" using DES, I get the following result:
Key used to encrypt: ['0xfe', '0x9b', '0xd5', '0x16', '0xcd', '0x15', '0xc8', '0x49']
Challenge after encryption:
Encrypted_server_challenge_using_key_1 : ['0x66', '0xf7', '0xa', '0xf8', '0xda', '0x4e', '0x7', '0xaa', '0x65', '0xc3', '0x8d', '0xaa', '0x48', '0xcc', '0x67', '0x57', '0xe2', '0xb0', '0x6e', '0x10', '0xb', '0x5e', '0xdd', '0xb4'] The above response was not accepted by the server
Tried using a tool called DEScalc.jar (http://www.unsw.adfa.edu.au/~lpb/src/DEScalc/index.html) and found that the encrypted result is:
setKey(fe9bd516cd15c849) encryptDES(0123456789abcdef) IP: L0=cc00ccff, R0=f0aaf0aa Rnd1 f(R0=f0aaf0aa, SK1=0b 2c 23 12 33 1c 2b 09 ) = 988995a0 Rnd2 f(R1=5489595f, SK2=21 15 0d 11 1c 1a 3b 38 ) = 63200664 Rnd3 f(R2=938af6ce, SK3=01 35 2f 05 3e 19 30 1f ) = c206c318 Rnd4 f(R3=968f9a47, SK4=06 37 07 01 03 37 1a 3e ) = bdf738ef Rnd5 f(R4=2e7dce21, SK5=06 14 17 29 0f 17 27 25 ) = 76c68d3d Rnd6 f(R5=e049177a, SK6=34 14 06 0d 28 2c 23 37 ) = c182a1c7 Rnd7 f(R6=efff6fe6, SK7=04 18 2e 05 31 3a 3e 17 ) = c3e45497 Rnd8 f(R7=23ad43ed, SK8=04 13 22 27 2f 30 1f 19 ) = 4977a92c Rnd9 f(R8=a688c6ca, SK9=12 0a 38 0c 3d 33 19 26 ) = 4975507e Rnd10 f(R9=6ad81393, SK10=10 0b 30 1e 1f 08 2f 2e ) = d52a9361 Rnd11 f(R10=73a255ab, SK11=19 0a 31 22 05 0f 33 1f ) = 38b2a619 Rnd12 f(R11=526ab58a, SK12=38 2e 30 22 1b 3b 13 31 ) = e9dec064 Rnd13 f(R12=9a7c95cf, SK13=3a 0a 1c 12 2a 3e 35 2b ) = d88ee399 Rnd14 f(R13=8ae45613, SK14=19 09 18 1b 0b 2d 3c 16 ) = 9de6ddb2 Rnd15 f(R14=079a487d, SK15=19 39 01 12 37 14 17 36 ) = 5fb60a90 Rnd16 f(R15=d5525c83, SK16=24 05 0d 39 31 1f 2d 34 ) = 6a40b6ea FP: L=c337cd5c, R=bd44fc97 returns c337cd5cbd44fc97 Noticed that the above result is accepted by the server
Is there a specific algorithm that is used by DEScalc.jar which I am missing, because of which I don't get the results obtained by DEScalc.jar
Hi Everyone, Thanks a lot for your help; The issue was with the way I represented the hexadecimal in python; I used the following function to convert "0123456789abcdef" to hex representation as Keith mentioned and it worked:
def HexToByte( hexStr ): """ Convert a string hex byte values into a byte string. The Hex Byte values may or may not be space separated. """ # The list comprehension implementation is fractionally slower in this case # # hexStr = ''.join( hexStr.split(" ") ) # return ''.join( ["%c" % chr( int ( hexStr[i:i+2],16 ) ) \ # for i in range(0, len( hexStr ), 2) ] ) bytes = [] hexStr = ''.join( hexStr.split(" ") ) for i in range(0, len(hexStr), 2): bytes.append( chr( int (hexStr[i:i+2], 16 ) ) ) return ''.join( bytes ) Thanks a lot
