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-rw-r--r--srp/_ctsrp.py585
1 files changed, 585 insertions, 0 deletions
diff --git a/srp/_ctsrp.py b/srp/_ctsrp.py
new file mode 100644
index 0000000..6754e83
--- /dev/null
+++ b/srp/_ctsrp.py
@@ -0,0 +1,585 @@
+ # N A large safe prime (N = 2q+1, where q is prime)
+ # All arithmetic is done modulo N.
+ # g A generator modulo N
+ # k Multiplier parameter (k = H(N, g) in SRP-6a, k = 3 for legacy SRP-6)
+ # s User's salt
+ # I Username
+ # p Cleartext Password
+ # H() One-way hash function
+ # ^ (Modular) Exponentiation
+ # u Random scrambling parameter
+ # a,b Secret ephemeral values
+ # A,B Public ephemeral values
+ # x Private key (derived from p and s)
+ # v Password verifier
+
+import os
+import sys
+import hashlib
+import random
+import ctypes
+import time
+
+
+
+SHA1 = 0
+SHA224 = 1
+SHA256 = 2
+SHA384 = 3
+SHA512 = 4
+
+NG_1024 = 0
+NG_2048 = 1
+NG_4096 = 2
+NG_8192 = 3
+NG_CUSTOM = 4
+
+_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"),
+# 8192
+('''\
+FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08\
+8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B\
+302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9\
+A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE6\
+49286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8\
+FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D\
+670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C\
+180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718\
+3995497CEA956AE515D2261898FA051015728E5A8AAAC42DAD33170D\
+04507A33A85521ABDF1CBA64ECFB850458DBEF0A8AEA71575D060C7D\
+B3970F85A6E1E4C7ABF5AE8CDB0933D71E8C94E04A25619DCEE3D226\
+1AD2EE6BF12FFA06D98A0864D87602733EC86A64521F2B18177B200C\
+BBE117577A615D6C770988C0BAD946E208E24FA074E5AB3143DB5BFC\
+E0FD108E4B82D120A92108011A723C12A787E6D788719A10BDBA5B26\
+99C327186AF4E23C1A946834B6150BDA2583E9CA2AD44CE8DBBBC2DB\
+04DE8EF92E8EFC141FBECAA6287C59474E6BC05D99B2964FA090C3A2\
+233BA186515BE7ED1F612970CEE2D7AFB81BDD762170481CD0069127\
+D5B05AA993B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934028492\
+36C3FAB4D27C7026C1D4DCB2602646DEC9751E763DBA37BDF8FF9406\
+AD9E530EE5DB382F413001AEB06A53ED9027D831179727B0865A8918\
+DA3EDBEBCF9B14ED44CE6CBACED4BB1BDB7F1447E6CC254B33205151\
+2BD7AF426FB8F401378CD2BF5983CA01C64B92ECF032EA15D1721D03\
+F482D7CE6E74FEF6D55E702F46980C82B5A84031900B1C9E59E7C97F\
+BEC7E8F323A97A7E36CC88BE0F1D45B7FF585AC54BD407B22B4154AA\
+CC8F6D7EBF48E1D814CC5ED20F8037E0A79715EEF29BE32806A1D58B\
+B7C5DA76F550AA3D8A1FBFF0EB19CCB1A313D55CDA56C9EC2EF29632\
+387FE8D76E3C0468043E8F663F4860EE12BF2D5B0B7474D6E694F91E\
+6DBE115974A3926F12FEE5E438777CB6A932DF8CD8BEC4D073B931BA\
+3BC832B68D9DD300741FA7BF8AFC47ED2576F6936BA424663AAB639C\
+5AE4F5683423B4742BF1C978238F16CBE39D652DE3FDB8BEFC848AD9\
+22222E04A4037C0713EB57A81A23F0C73473FC646CEA306B4BCBC886\
+2F8385DDFA9D4B7FA2C087E879683303ED5BDD3A062B3CF5B3A278A6\
+6D2A13F83F44F82DDF310EE074AB6A364597E899A0255DC164F31CC5\
+0846851DF9AB48195DED7EA1B1D510BD7EE74D73FAF36BC31ECFA268\
+359046F4EB879F924009438B481C6CD7889A002ED5EE382BC9190DA6\
+FC026E479558E4475677E9AA9E3050E2765694DFC81F56E880B96E71\
+60C980DD98EDD3DFFFFFFFFFFFFFFFFF''',
+'13')
+)
+
+
+
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
+#G_HEX = "2"
+#HNxorg = None
+
+dlls = list()
+
+if 'win' in sys.platform:
+ for d in ('libeay32.dll', 'libssl32.dll', 'ssleay32.dll'):
+ try:
+ dlls.append( ctypes.cdll.LoadLibrary(d) )
+ except:
+ pass
+else:
+ dlls.append( ctypes.cdll.LoadLibrary('libssl.so') )
+
+
+class BIGNUM_Struct (ctypes.Structure):
+ _fields_ = [ ("d", ctypes.c_void_p),
+ ("top", ctypes.c_int),
+ ("dmax", ctypes.c_int),
+ ("neg", ctypes.c_int),
+ ("flags", ctypes.c_int) ]
+
+
+class BN_CTX_Struct (ctypes.Structure):
+ _fields_ = [ ("_", ctypes.c_byte) ]
+
+
+BIGNUM = ctypes.POINTER( BIGNUM_Struct )
+BN_CTX = ctypes.POINTER( BN_CTX_Struct )
+
+
+def load_func( name, args, returns = ctypes.c_int):
+ d = sys.modules[ __name__ ].__dict__
+ f = None
+
+ for dll in dlls:
+ try:
+ f = getattr(dll, name)
+ f.argtypes = args
+ f.restype = returns
+ d[ name ] = f
+ return
+ except:
+ pass
+ raise ImportError('Unable to load required functions from SSL dlls')
+
+
+load_func( 'BN_new', [], BIGNUM )
+load_func( 'BN_free', [ BIGNUM ], None )
+load_func( 'BN_init', [ BIGNUM ], None )
+load_func( 'BN_clear', [ BIGNUM ], None )
+
+load_func( 'BN_CTX_new', [] , BN_CTX )
+load_func( 'BN_CTX_init', [ BN_CTX ], None )
+load_func( 'BN_CTX_free', [ BN_CTX ], None )
+
+load_func( 'BN_cmp', [ BIGNUM, BIGNUM ], ctypes.c_int )
+
+load_func( 'BN_num_bits', [ BIGNUM ], ctypes.c_int )
+
+load_func( 'BN_add', [ BIGNUM, BIGNUM, BIGNUM ] )
+load_func( 'BN_sub', [ BIGNUM, BIGNUM, BIGNUM ] )
+load_func( 'BN_mul', [ BIGNUM, BIGNUM, BIGNUM, BN_CTX ] )
+load_func( 'BN_div', [ BIGNUM, BIGNUM, BIGNUM, BIGNUM, BN_CTX ] )
+load_func( 'BN_mod_exp', [ BIGNUM, BIGNUM, BIGNUM, BIGNUM, BN_CTX ] )
+
+load_func( 'BN_rand', [ BIGNUM, ctypes.c_int, ctypes.c_int, ctypes.c_int ] )
+
+load_func( 'BN_bn2bin', [ BIGNUM, ctypes.c_char_p ] )
+load_func( 'BN_bin2bn', [ ctypes.c_char_p, ctypes.c_int, BIGNUM ], BIGNUM )
+
+load_func( 'BN_hex2bn', [ ctypes.POINTER(BIGNUM), ctypes.c_char_p ] )
+load_func( 'BN_bn2hex', [ BIGNUM ], ctypes.c_char_p )
+
+load_func( 'CRYPTO_free', [ ctypes.c_char_p ] )
+
+load_func( 'RAND_seed', [ ctypes.c_char_p, ctypes.c_int ] )
+
+
+def BN_num_bytes(a):
+ return ((BN_num_bits(a)+7)/8)
+
+
+def BN_mod(rem,m,d,ctx):
+ return BN_div(None, rem, m, d, ctx)
+
+
+def BN_is_zero( n ):
+ return n[0].top == 0
+
+
+def bn_to_bytes( n ):
+ b = ctypes.create_string_buffer( BN_num_bytes(n) )
+ BN_bn2bin(n, b)
+ return b.raw
+
+
+def bytes_to_bn( dest_bn, bytes ):
+ BN_bin2bn(bytes, len(bytes), dest_bn)
+
+
+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( hash_class, dest, n ):
+ bin = ctypes.create_string_buffer( BN_num_bytes(n) )
+ BN_bn2bin(n, bin)
+ d = hash_class( bin.raw ).digest()
+ BN_bin2bn(d, len(d), dest)
+
+
+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)
+ BN_bn2bin(n2, bin2)
+ h.update( bin1.raw )
+ h.update( bin2.raw )
+ d = h.digest()
+ BN_bin2bn(d, len(d), dest)
+
+
+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 )
+ h.update( s )
+ d = h.digest()
+ BN_bin2bn(d, len(d), dest)
+
+
+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 ):
+ buff = ctypes.create_string_buffer( BN_num_bytes(n) )
+ BN_bn2bin(n, buff)
+ ctx.update( buff.raw )
+
+
+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 )
+ h.update( K )
+ return h.digest()
+
+
+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 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 = hash_class( bN.raw ).digest()
+ hg = hash_class( bg.raw ).digest()
+
+ 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 create_salted_verification_key( username, password, hash_alg=SHA1, ng_type=NG_2048, n_hex=None, g_hex=None ):
+ if ng_type == NG_CUSTOM and (n_hex is None or g_hex is None):
+ raise ValueError("Both n_hex and g_hex are required when ng_type = NG_CUSTOM")
+ 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( hash_class, x, s, username, password )
+
+ BN_mod_exp(v, g, x, N, ctx)
+
+ salt = bn_to_bytes( s )
+ verifier = bn_to_bytes( v )
+
+ 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
+
+
+
+class Verifier (object):
+ def __init__(self, username, bytes_s, bytes_v, bytes_A, hash_alg=SHA1, ng_type=NG_2048, n_hex=None, g_hex=None):
+ if ng_type == NG_CUSTOM and (n_hex is None or g_hex is None):
+ raise ValueError("Both n_hex and g_hex are required when ng_type = NG_CUSTOM")
+ self.A = BN_new()
+ self.B = BN_new()
+ self.K = None
+ self.S = BN_new()
+ self.u = BN_new()
+ self.b = BN_new()
+ self.s = BN_new()
+ self.v = BN_new()
+ self.tmp1 = BN_new()
+ self.tmp2 = BN_new()
+ self.ctx = BN_CTX_new()
+ self.I = username
+ self.M = None
+ self.H_AMK = None
+ self._authenticated = False
+
+ 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 )
+
+ # SRP-6a safety check
+ BN_mod(self.tmp1, self.A, N, self.ctx)
+
+ if BN_is_zero(self.tmp1):
+ self.safety_failed = True
+ else:
+ BN_rand(self.b, 256, -1, 0)
+
+ # B = kv + g^b
+ BN_mul(self.tmp1, k, self.v, self.ctx)
+ BN_mod_exp(self.tmp2, g, self.b, N, self.ctx)
+ BN_add(self.B, self.tmp1, self.tmp2)
+
+ 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 = hash_class( bn_to_bytes(self.S) ).digest()
+
+ 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):
+ if not hasattr(self, 'A'):
+ return # __init__ threw exception. no clean up required
+ BN_free(self.A)
+ BN_free(self.B)
+ BN_free(self.S)
+ BN_free(self.u)
+ 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)
+
+
+ def authenticated(self):
+ return self._authenticated
+
+
+ def get_username(self):
+ return self.I
+
+
+ def get_session_key(self):
+ return self.K if self._authenticated else None
+
+
+ # returns (bytes_s, bytes_B) on success, (None,None) if SRP-6a safety check fails
+ def get_challenge(self):
+ if self.safety_failed:
+ return None, None
+ else:
+ return (bn_to_bytes(self.s), bn_to_bytes(self.B))
+
+
+ def verify_session(self, user_M):
+ if user_M == self.M:
+ self._authenticated = True
+ return self.H_AMK
+
+
+
+
+class User (object):
+ def __init__(self, username, password, hash_alg=SHA1, ng_type=NG_2048, n_hex=None, g_hex=None):
+ if ng_type == NG_CUSTOM and (n_hex is None or g_hex is None):
+ raise ValueError("Both n_hex and g_hex are required when ng_type = NG_CUSTOM")
+ self.username = username
+ self.password = password
+ self.a = BN_new()
+ self.A = BN_new()
+ self.B = BN_new()
+ self.s = BN_new()
+ self.S = BN_new()
+ self.u = BN_new()
+ self.x = BN_new()
+ self.v = BN_new()
+ self.tmp1 = BN_new()
+ self.tmp2 = BN_new()
+ self.tmp3 = BN_new()
+ self.ctx = BN_CTX_new()
+ self.M = None
+ self.K = None
+ 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)
+
+
+ def __del__(self):
+ if not hasattr(self, 'a'):
+ return # __init__ threw exception. no clean up required
+ BN_free(self.a)
+ BN_free(self.A)
+ BN_free(self.B)
+ BN_free(self.s)
+ BN_free(self.S)
+ 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)
+ BN_CTX_free(self.ctx)
+
+
+ def authenticated(self):
+ return self._authenticated
+
+
+ def get_username(self):
+ return self.username
+
+
+ def get_session_key(self):
+ return self.K if self._authenticated else None
+
+
+ def start_authentication(self):
+ return (self.username, bn_to_bytes(self.A))
+
+
+ # 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 )
+
+ # SRP-6a safety check
+ if BN_is_zero(self.B):
+ return None
+
+ 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( hash_class, self.x, self.s, self.username, self.password )
+
+ BN_mod_exp(self.v, g, self.x, N, self.ctx)
+
+ # S = (B - k*(g^x)) ^ (a + ux)
+
+ BN_mul(self.tmp1, self.u, self.x, self.ctx)
+ BN_add(self.tmp2, self.a, self.tmp1) # tmp2 = (a + ux)
+ BN_mod_exp(self.tmp1, g, self.x, N, self.ctx)
+ BN_mul(self.tmp3, k, self.tmp1, self.ctx) # tmp3 = k*(g^x)
+ 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 = 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
+
+
+ def verify_session(self, host_HAMK):
+ if self.H_AMK == host_HAMK:
+ self._authenticated = True
+
+
+
+#---------------------------------------------------------
+# Init
+#
+RAND_seed( os.urandom(32), 32 )
+