| 0,0 → 1,43 |
|---|
| """ crypto.keyedHash.pbkdf2 |
| |
| |
| Password Based Key Derivation Function 2 |
| References: RFC2898, B. Kaliski, September 2000, PKCS #5 |
| |
| This function is used for IEEE 802.11/WPA passphrase to key hashing |
| |
| Copyright © (c) 2002 by Paul A. Lambert |
| Read LICENSE.txt for license information. |
| """ |
| from crypto.keyedHash.hmacHash import HMAC_SHA1 |
| from crypto.common import xor |
| from math import ceil |
| from struct import pack |
| |
| def pbkdf2(password, salt, iterations, keySize, PRF=HMAC_SHA1): |
| """ Create key of size keySize from password and salt """ |
| if len(password)>63: |
| raise 'Password too long for pbkdf2' |
| #if len(password)<8 : raise 'Password too short for pbkdf2' |
| if (keySize > 10000): # spec says >4294967295L*digestSize |
| raise 'keySize too long for PBKDF2' |
| |
| prf = PRF(key=password) # HMAC_SHA1 |
| numBlocks = ceil(1.*keySize/prf.digest_size) # ceiling function |
| key = '' |
| for block in range(1,numBlocks+1): |
| # Calculate F(P, salt, iterations, i) |
| F = prf(salt+pack('>i',block)) # i is packed into 4 big-endian bytes |
| U = prf(salt+pack('>i',block)) # i is packed into 4 big-endian bytes |
| for count in range(2,iterations+1): |
| U = prf(U) |
| F = xor(F,U) |
| key = key + F |
| return key[:keySize] |
| |
| def dot11PassPhraseToPSK(passPhrase,ssid): |
| """ The 802.11 TGi recommended pass-phrase-to-preshared-key mapping. |
| This function simply uses pbkdf2 with interations=4096 and keySize=32 |
| """ |
| assert( 7<len(passPhrase)<64 ), 'Passphrase must be greater than 7 or less than 64 characters' |
| return pbkdf2(passPhrase, ssid, iterations=4096, keySize=32) |