Added python-only fallback for SHA-256 and SHA-512

RNS/Cryptography/Hashes.py

@@ -1,4 +1,18 @@
-import hashlib
+import importlib
+if importlib.util.find_spec('hashlib') != None:
+    import hashlib
+else:
+    hashlib = None
+
+if hasattr(hashlib, "sha512"):
+    from hashlib import sha512 as ext_sha512
+else:
+    from .SHA512 import sha512 as ext_sha512
+
+if hasattr(hashlib, "sha256"):
+    from hashlib import sha256 as ext_sha256
+else:
+    from .SHA256 import sha256 as ext_sha256
 
 """
 The SHA primitives are abstracted here to allow platform-
@@ -8,13 +22,13 @@ calls in RNS end up here.
 """
 
 def sha256(data):
-    digest = hashlib.sha256()
+    digest = ext_sha256()
     digest.update(data)
 
     return digest.digest()
 
 def sha512(data):
-    digest = hashlib.sha512()
+    digest = ext_sha512()
     digest.update(data)
 
     return digest.digest()

RNS/Cryptography/SHA256.py

@@ -0,0 +1,111 @@
+#!/usr/bin/python
+__author__ = 'Thomas Dixon'
+__license__ = 'MIT'
+
+import copy
+import struct
+import sys
+
+
+def new(m=None):
+    return sha256(m)
+
+class sha256(object):
+    _k = (0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
+          0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+          0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+          0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+          0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
+          0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+          0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
+          0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+          0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+          0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+          0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
+          0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+          0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
+          0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+          0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+          0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2)
+    _h = (0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
+          0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19)
+    _output_size = 8
+    
+    blocksize = 1
+    block_size = 64
+    digest_size = 32
+    
+    def __init__(self, m=None):        
+        self._buffer = b""
+        self._counter = 0
+        
+        if m is not None:
+            if type(m) is not bytes:
+                raise TypeError('%s() argument 1 must be bytes, not %s' % (self.__class__.__name__, type(m).__name__))
+            self.update(m)
+        
+    def _rotr(self, x, y):
+        return ((x >> y) | (x << (32-y))) & 0xFFFFFFFF
+                    
+    def _sha256_process(self, c):
+        w = [0]*64
+        w[0:16] = struct.unpack('!16L', c)
+        
+        for i in range(16, 64):
+            s0 = self._rotr(w[i-15], 7) ^ self._rotr(w[i-15], 18) ^ (w[i-15] >> 3)
+            s1 = self._rotr(w[i-2], 17) ^ self._rotr(w[i-2], 19) ^ (w[i-2] >> 10)
+            w[i] = (w[i-16] + s0 + w[i-7] + s1) & 0xFFFFFFFF
+        
+        a,b,c,d,e,f,g,h = self._h
+        
+        for i in range(64):
+            s0 = self._rotr(a, 2) ^ self._rotr(a, 13) ^ self._rotr(a, 22)
+            maj = (a & b) ^ (a & c) ^ (b & c)
+            t2 = s0 + maj
+            s1 = self._rotr(e, 6) ^ self._rotr(e, 11) ^ self._rotr(e, 25)
+            ch = (e & f) ^ ((~e) & g)
+            t1 = h + s1 + ch + self._k[i] + w[i]
+            
+            h = g
+            g = f
+            f = e
+            e = (d + t1) & 0xFFFFFFFF
+            d = c
+            c = b
+            b = a
+            a = (t1 + t2) & 0xFFFFFFFF
+            
+        self._h = [(x+y) & 0xFFFFFFFF for x,y in zip(self._h, [a,b,c,d,e,f,g,h])]
+        
+    def update(self, m):
+        if not m:
+            return
+
+        if type(m) is not bytes:
+            raise TypeError('%s() argument 1 must be bytes, not %s' % (sys._getframe().f_code.co_name, type(m).__name__))
+        
+        self._buffer += m
+        self._counter += len(m)
+        
+        while len(self._buffer) >= 64:
+            self._sha256_process(self._buffer[:64])
+            self._buffer = self._buffer[64:]
+            
+    def digest(self):
+        mdi = self._counter & 0x3F
+        length = struct.pack('!Q', self._counter<<3)
+        
+        if mdi < 56:
+            padlen = 55-mdi
+        else:
+            padlen = 119-mdi
+        
+        r = self.copy()
+        r.update(b'\x80'+(b'\x00'*padlen)+length)
+        return b''.join([struct.pack('!L', i) for i in r._h[:self._output_size]])
+        
+    def hexdigest(self):
+        return self.digest().encode('hex')
+        
+    def copy(self):
+        return copy.deepcopy(self)

RNS/Cryptography/SHA512.py

@@ -0,0 +1,111 @@
+#!/usr/bin/python
+__author__ = 'Thomas Dixon'
+__license__ = 'MIT'
+
+import copy, struct, sys
+
+def new(m=None):
+    return sha512(m)
+
+class sha512(object):
+    _k = (0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
+          0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118,
+          0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
+          0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
+          0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
+          0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
+          0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
+          0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
+          0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
+          0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
+          0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30,
+          0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
+          0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
+          0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3,
+          0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
+          0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
+          0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
+          0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
+          0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
+          0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817)
+    _h = (0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
+          0x510e527fade682d1, 0x9b05688c2b3e6c1f, 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179)
+    _output_size = 8
+
+    blocksize = 1
+    block_size = 128
+    digest_size = 64
+
+    def __init__(self, m=None):
+        self._buffer = b''
+        self._counter = 0
+
+        if m is not None:
+            if type(m) is not bytes:
+                raise TypeError('%s() argument 1 must be bytes, not %s' % (self.__class__.__name__, type(m).__name__))
+            self.update(m)
+
+    def _rotr(self, x, y):
+        return ((x >> y) | (x << (64-y))) & 0xFFFFFFFFFFFFFFFF
+
+    def _sha512_process(self, chunk):
+        w = [0]*80
+        w[0:16] = struct.unpack('!16Q', chunk)
+
+        for i in range(16, 80):
+            s0 = self._rotr(w[i-15], 1) ^ self._rotr(w[i-15], 8) ^ (w[i-15] >> 7)
+            s1 = self._rotr(w[i-2], 19) ^ self._rotr(w[i-2], 61) ^ (w[i-2] >> 6)
+            w[i] = (w[i-16] + s0 + w[i-7] + s1) & 0xFFFFFFFFFFFFFFFF
+
+        a,b,c,d,e,f,g,h = self._h
+
+        for i in range(80):
+            s0 = self._rotr(a, 28) ^ self._rotr(a, 34) ^ self._rotr(a, 39)
+            maj = (a & b) ^ (a & c) ^ (b & c)
+            t2 = s0 + maj
+            s1 = self._rotr(e, 14) ^ self._rotr(e, 18) ^ self._rotr(e, 41)
+            ch = (e & f) ^ ((~e) & g)
+            t1 = h + s1 + ch + self._k[i] + w[i]
+
+            h = g
+            g = f
+            f = e
+            e = (d + t1) & 0xFFFFFFFFFFFFFFFF
+            d = c
+            c = b
+            b = a
+            a = (t1 + t2) & 0xFFFFFFFFFFFFFFFF
+
+        self._h = [(x+y) & 0xFFFFFFFFFFFFFFFF for x,y in zip(self._h, [a,b,c,d,e,f,g,h])]
+
+    def update(self, m):
+        if not m:
+            return
+        if type(m) is not bytes:
+            raise TypeError('%s() argument 1 must be bytes, not %s' % (sys._getframe().f_code.co_name, type(m).__name__))
+
+        self._buffer += m
+        self._counter += len(m)
+
+        while len(self._buffer) >= 128:
+            self._sha512_process(self._buffer[:128])
+            self._buffer = self._buffer[128:]
+
+    def digest(self):
+        mdi = self._counter & 0x7F
+        length = struct.pack('!Q', self._counter<<3)
+
+        if mdi < 112:
+            padlen = 111-mdi
+        else:
+            padlen = 239-mdi
+
+        r = self.copy()
+        r.update(b'\x80'+(b'\x00'*(padlen+8))+length)
+        return b''.join([struct.pack('!Q', i) for i in r._h[:self._output_size]])
+
+    def hexdigest(self):
+        return self.digest().encode('hex')
+
+    def copy(self):
+        return copy.deepcopy(self)

RNS/Cryptography/__init__.py

@@ -2,6 +2,7 @@ import os
 import glob
 
 from .Hashes import sha256
+from .Hashes import sha512
 from .HKDF import hkdf
 from .PKCS7 import PKCS7
 from .Fernet import Fernet