From 6189439d951a0568d117de85f2422a1f5be1ecfe Mon Sep 17 00:00:00 2001 From: Tom Cocagne Date: Wed, 24 Nov 2010 16:23:48 -0500 Subject: started migration to optional hash/prime number specification --- _ctsrp.py | 210 ++++++++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 151 insertions(+), 59 deletions(-) (limited to '_ctsrp.py') diff --git a/_ctsrp.py b/_ctsrp.py index 4675591..93accf5 100644 --- a/_ctsrp.py +++ b/_ctsrp.py @@ -18,15 +18,75 @@ import sys import hashlib import random import ctypes -import atexit import time -SHA256_DIGEST_LENGTH = 32 -N_HEX = "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" -G_HEX = "2" -HNxorg = None +SHA1 = 0 +SHA224 = 1 +SHA256 = 3 +SHA384 = 4 +SHA512 = 5 + +NG_1024 = 0 +NG_2048 = 1 +NG_4096 = 2 +NG_CUSTOM = 3 + +_hash_map = { SHA1 : hashlib.sha1, + SHA224 : hashlib.sha224, + SHA256 : hashlib.sha256, + SHA384 : hashlib.sha384, + SHA512 : hashlib.sha512 } + + +_ng_const = ( +# 1024-bit +('''\ +EEAF0AB9ADB38DD69C33F80AFA8FC5E86072618775FF3C0B9EA2314C9C256576D674DF7496\ +EA81D3383B4813D692C6E0E0D5D8E250B98BE48E495C1D6089DAD15DC7D7B46154D6B6CE8E\ +F4AD69B15D4982559B297BCF1885C529F566660E57EC68EDBC3C05726CC02FD4CBF4976EAA\ +9AFD5138FE8376435B9FC61D2FC0EB06E3''', +"2"), +# 2048 +('''\ +AC6BDB41324A9A9BF166DE5E1389582FAF72B6651987EE07FC3192943DB56050A37329CBB4\ +A099ED8193E0757767A13DD52312AB4B03310DCD7F48A9DA04FD50E8083969EDB767B0CF60\ +95179A163AB3661A05FBD5FAAAE82918A9962F0B93B855F97993EC975EEAA80D740ADBF4FF\ +747359D041D5C33EA71D281E446B14773BCA97B43A23FB801676BD207A436C6481F1D2B907\ +8717461A5B9D32E688F87748544523B524B0D57D5EA77A2775D2ECFA032CFBDBF52FB37861\ +60279004E57AE6AF874E7303CE53299CCC041C7BC308D82A5698F3A8D0C38271AE35F8E9DB\ +FBB694B5C803D89F7AE435DE236D525F54759B65E372FCD68EF20FA7111F9E4AFF73''', +"2"), +# 4096 +('''\ +FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08\ +8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B\ +302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9\ +A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE6\ +49286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8\ +FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D\ +670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C\ +180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718\ +3995497CEA956AE515D2261898FA051015728E5A8AAAC42DAD33170D\ +04507A33A85521ABDF1CBA64ECFB850458DBEF0A8AEA71575D060C7D\ +B3970F85A6E1E4C7ABF5AE8CDB0933D71E8C94E04A25619DCEE3D226\ +1AD2EE6BF12FFA06D98A0864D87602733EC86A64521F2B18177B200C\ +BBE117577A615D6C770988C0BAD946E208E24FA074E5AB3143DB5BFC\ +E0FD108E4B82D120A92108011A723C12A787E6D788719A10BDBA5B26\ +99C327186AF4E23C1A946834B6150BDA2583E9CA2AD44CE8DBBBC2DB\ +04DE8EF92E8EFC141FBECAA6287C59474E6BC05D99B2964FA090C3A2\ +233BA186515BE7ED1F612970CEE2D7AFB81BDD762170481CD0069127\ +D5B05AA993B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934063199\ +FFFFFFFFFFFFFFFF''', +"5") +) + + + +#N_HEX = "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" +#G_HEX = "2" +#HNxorg = None dlls = list() @@ -126,21 +186,21 @@ def bytes_to_bn( dest_bn, bytes ): BN_bin2bn(bytes, len(bytes), dest_bn) -def H_str( dest_bn, s ): - d = hashlib.sha256(s).digest() +def H_str( hash_class, dest_bn, s ): + d = hash_class(s).digest() buff = ctypes.create_string_buffer( s ) BN_bin2bn(d, len(d), dest) -def H_bn( dest, n ): +def H_bn( hash_class, dest, n ): bin = ctypes.create_string_buffer( BN_num_bytes(n) ) BN_bn2bin(n, bin) - d = hashlib.sha256( bin.raw ).digest() + d = hash_class( bin.raw ).digest() BN_bin2bn(d, len(d), dest) -def H_bn_bn( dest, n1, n2 ): - h = hashlib.sha256() +def H_bn_bn( hash_class, dest, n1, n2 ): + h = hash_class() bin1 = ctypes.create_string_buffer( BN_num_bytes(n1) ) bin2 = ctypes.create_string_buffer( BN_num_bytes(n2) ) BN_bn2bin(n1, bin1) @@ -151,8 +211,8 @@ def H_bn_bn( dest, n1, n2 ): BN_bin2bn(d, len(d), dest) -def H_bn_str( dest, n, s ): - h = hashlib.sha256() +def H_bn_str( hash_class, dest, n, s ): + h = hash_class() bin = ctypes.create_string_buffer( BN_num_bytes(n) ) BN_bn2bin(n, bin) h.update( bin.raw ) @@ -161,9 +221,9 @@ def H_bn_str( dest, n, s ): BN_bin2bn(d, len(d), dest) -def calculate_x( dest, salt, username, password ): - up = hashlib.sha256('%s:%s' % (username, password )).digest() - H_bn_str( dest, salt, up ) +def calculate_x( hash_class, dest, salt, username, password ): + up = hash_class('%s:%s' % (username, password )).digest() + H_bn_str( hash_class, dest, salt, up ) def update_hash( ctx, n ): @@ -172,10 +232,10 @@ def update_hash( ctx, n ): ctx.update( buff.raw ) -def calculate_M( I, s, A, B, K ): - h = hashlib.sha256() - h.update( HNxorg ) - h.update( hashlib.sha256(I).digest() ) +def calculate_M( hash_class, N, g, I, s, A, B, K ): + h = hash_class() + h.update( HNxorg( hash_class, N, g ) ) + h.update( hash_class(I).digest() ) update_hash( h, s ) update_hash( h, A ) update_hash( h, B ) @@ -183,38 +243,55 @@ def calculate_M( I, s, A, B, K ): return h.digest() -def calculate_H_AMK( A, M, K ): - h = hashlib.sha256() +def calculate_H_AMK( hash_class, A, M, K ): + h = hash_class() update_hash( h, A ) h.update( M ) h.update( K ) return h.digest() -def calculate_HN_xor_Hg(): - global HNxorg - +def HNxorg( hash_class, N, g ): bN = ctypes.create_string_buffer( BN_num_bytes(N) ) bg = ctypes.create_string_buffer( BN_num_bytes(g) ) BN_bn2bin(N, bN) BN_bn2bin(g, bg) - hN = hashlib.sha256( bN.raw ).digest() - hg = hashlib.sha256( bg.raw ).digest() + hN = hash_class( bN.raw ).digest() + hg = hash_class( bg.raw ).digest() - HNxorg = ''.join( chr( ord(hN[i]) ^ ord(hg[i]) ) for i in range(0,len(hN)) ) + return ''.join( chr( ord(hN[i]) ^ ord(hg[i]) ) for i in range(0,len(hN)) ) + + + +def get_ngk( hash_class, ng_type, n_hex, g_hex ): + if ng_type < NG_CUSTOM: + n_hex, g_hex = _ng_const[ ng_type ] + N = BN_new() + g = BN_new() + k = BN_new() + + BN_hex2bn( N, n_hex ) + BN_hex2bn( g, g_hex ) + H_bn_bn(hash_class, k, N, g) + + return N, g, k + -def gen_sv( username, password ): +def gen_sv( username, password, hash_alg=SHA1, ng_type=NG_1024, n_hex=None, g_hex=None ): s = BN_new() v = BN_new() x = BN_new() ctx = BN_CTX_new() + + hash_class = _hash_map[ hash_alg ] + N,g,k = get_ngk( hash_class, ng_type, n_hex, g_hex ) BN_rand(s, 32, -1, 0); - calculate_x(x, s, username, password ) + calculate_x( hash_class, x, s, username, password ) BN_mod_exp(v, g, x, N, ctx) @@ -224,6 +301,9 @@ def gen_sv( username, password ): BN_free(s) BN_free(v) BN_free(x) + BN_free(N) + BN_free(g) + BN_free(k) BN_CTX_free(ctx) return salt, verifier @@ -231,7 +311,7 @@ def gen_sv( username, password ): class Verifier (object): - def __init__(self, username, bytes_s, bytes_v, bytes_A): + def __init__(self, username, bytes_s, bytes_v, bytes_A, hash_alg=SHA1, ng_type=NG_1024, n_hex=None, g_hex=None): self.A = BN_new() self.B = BN_new() self.K = None @@ -250,6 +330,14 @@ class Verifier (object): self.safety_failed = False + hash_class = _hash_map[ hash_alg ] + N,g,k = get_ngk( hash_class, ng_type, n_hex, g_hex ) + + self.hash_class = hash_class + self.N = N + self.g = g + self.k = k + bytes_to_bn( self.s, bytes_s ) bytes_to_bn( self.v, bytes_v ) bytes_to_bn( self.A, bytes_A ) @@ -267,17 +355,17 @@ class Verifier (object): BN_mod_exp(self.tmp2, g, self.b, N, self.ctx) BN_add(self.B, self.tmp1, self.tmp2) - H_bn_bn(self.u, self.A, self.B) + H_bn_bn(hash_class, self.u, self.A, self.B) # S = (A *(v^u)) ^ b BN_mod_exp(self.tmp1, self.v, self.u, N, self.ctx) BN_mul(self.tmp2, self.A, self.tmp1, self.ctx) BN_mod_exp(self.S, self.tmp2, self.b, N, self.ctx) - self.K = hashlib.sha256( bn_to_bytes(self.S) ).digest() + self.K = hash_class( bn_to_bytes(self.S) ).digest() - self.M = calculate_M( self.I, self.s, self.A, self.B, self.K ) - self.H_AMK = calculate_H_AMK( self.A, self.M, self.K ) + self.M = calculate_M( hash_class, N, g, self.I, self.s, self.A, self.B, self.K ) + self.H_AMK = calculate_H_AMK( hash_class, self.A, self.M, self.K ) def __del__(self): @@ -288,6 +376,9 @@ class Verifier (object): BN_free(self.b) BN_free(self.s) BN_free(self.v) + BN_free(self.N) + BN_free(self.g) + BN_free(self.k) BN_free(self.tmp1) BN_free(self.tmp2) BN_CTX_free(self.ctx) @@ -322,7 +413,7 @@ class Verifier (object): class User (object): - def __init__(self, username, password): + def __init__(self, username, password, hash_alg=SHA1, ng_type=NG_1024, n_hex=None, g_hex=None): self.username = username self.password = password self.a = BN_new() @@ -342,6 +433,14 @@ class User (object): self.H_AMK = None self._authenticated = False + hash_class = _hash_map[ hash_alg ] + N,g,k = get_ngk( hash_class, ng_type, n_hex, g_hex ) + + self.hash_class = hash_class + self.N = N + self.g = g + self.k = k + BN_rand(self.a, 256, -1, 0) BN_mod_exp(self.A, g, self.a, N, self.ctx) @@ -356,6 +455,9 @@ class User (object): BN_free(self.u) BN_free(self.x) BN_free(self.v) + BN_free(self.N) + BN_free(self.g) + BN_free(self.k) BN_free(self.tmp1) BN_free(self.tmp2) BN_free(self.tmp3) @@ -380,6 +482,11 @@ class User (object): # Returns M or None if SRP-6a safety check is violated def process_challenge(self, bytes_s, bytes_B): + + hash_class = self.hash_class + N = self.N + g = self.g + k = self.k bytes_to_bn( self.s, bytes_s ) bytes_to_bn( self.B, bytes_B ) @@ -388,13 +495,13 @@ class User (object): if BN_is_zero(self.B): return None - H_bn_bn(self.u, self.A, self.B) + H_bn_bn(hash_class, self.u, self.A, self.B) # SRP-6a safety check if BN_is_zero(self.u): return None - calculate_x( self.x, self.s, self.username, self.password ) + calculate_x( hash_class, self.x, self.s, self.username, self.password ) BN_mod_exp(self.v, g, self.x, N, self.ctx) @@ -407,9 +514,9 @@ class User (object): BN_sub(self.tmp1, self.B, self.tmp3) # tmp1 = (B - K*(g^x)) BN_mod_exp(self.S, self.tmp1, self.tmp2, N, self.ctx) - self.K = hashlib.sha256( bn_to_bytes(self.S) ).digest() - self.M = calculate_M( self.username, self.s, self.A, self.B, self.K ) - self.H_AMK = calculate_H_AMK( self.A, self.M, self.K ) + self.K = hash_class( bn_to_bytes(self.S) ).digest() + self.M = calculate_M( hash_class, N, g, self.username, self.s, self.A, self.B, self.K ) + self.H_AMK = calculate_H_AMK( hash_class, self.A, self.M, self.K ) return self.M @@ -417,26 +524,11 @@ class User (object): def verify_session(self, host_HAMK): if self.H_AMK == host_HAMK: self._authenticated = True - + + + #--------------------------------------------------------- # Init # -N = BN_new() -g = BN_new() -k = BN_new() -HNxorg = None - -BN_hex2bn( N, N_HEX ) -BN_hex2bn( g, G_HEX ) -H_bn_bn(k, N, g) - -calculate_HN_xor_Hg() - RAND_seed( os.urandom(32), 32 ) -def cleanup(): - BN_free( N ) - BN_free( g ) - BN_free( k ) - -atexit.register( cleanup ) -- cgit v1.2.3