sha1 implementation



  • Dear pythonist,
    When do sha1 will be included in hashlib
    or
    anyone have a pure py implementation working on micropython ?
    Cheers



  • Found myself :

    #!/usr/bin/env python
    
    import struct
    
    def leftrotate(i, n):
        return ((i << n) & 0xffffffff) | (i >> (32 - n))
    
    class SHA1(object):
        def __init__(self, data=b""):
            self.h = [
                    0x67452301,
                    0xEFCDAB89,
                    0x98BADCFE,
                    0x10325476,
                    0xC3D2E1F0
                    ]
            self.remainder = data
            self.count = 0
    
        def _add_chunk(self, chunk):
            self.count += 1
            w = list( struct.unpack(">16I", chunk) + (None,) * (80-16) )
            for i in range(16, 80):
                n = w[i-3] ^ w[i-8] ^ w[i-14] ^ w[i-16]
                w[i] = leftrotate(n, 1)
            a,b,c,d,e = self.h
            for i in range(80):
                f = None
                k = None
                if i < 20:
                    f = (b & c) ^ (~b & d)
                    k = 0x5A827999
                elif i < 40:
                    f = b ^ c ^ d
                    k = 0x6ED9EBA1
                elif i < 60:
                    f = (b & c) ^ (b & d) ^ (c & d)
                    k = 0x8F1BBCDC
                else:
                    f = b ^ c ^ d
                    k = 0xCA62C1D6
    
                temp = (leftrotate(a,5) + f + e + k + w[i]) % 2**32
                e = d
                d = c
                c = leftrotate(b, 30)
                b = a
                a = temp
            self.h[0] = (self.h[0] + a) % 2**32
            self.h[1] = (self.h[1] + b) % 2**32
            self.h[2] = (self.h[2] + c) % 2**32
            self.h[3] = (self.h[3] + d) % 2**32
            self.h[4] = (self.h[4] + e) % 2**32
    
        def add(self, data):
            message = self.remainder + data
            r = len(message) % 64
            if r != 0:
                self.remainder = message[-r:]
            else:
                self.remainder = b""
            for chunk in range(0, len(message)-r, 64):
                self._add_chunk( message[chunk:chunk+64] )
            return self
    
        def finish(self):
            l = len(self.remainder) + 64 * self.count
            #ll = struct.pack(">Q", l * 8)
            #FIXED
            ll2 = struct.pack('>II', (l*8)>>32,l*8) 
            self.add( b"\x80" + b"\x00" * ((55 - l) % 64) + ll2 )
            h = tuple(x for x in self.h)
            self.__init__()
            return struct.pack(">5I", *h)
    
    def main():
        s=SHA1(b"test")
        print(s.finish())
    if __name__ == '__main__':
        main()
    

    So now have websocket working !!!
    Cheers


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