PYTHON3 SHA256

python3 实现的SHA256 算法

算法原型参考：

https://en.wikipedia.org/wiki/SHA-2
https://web.archive.org/web/20140102193727/http://csrc.nist.gov/groups/STM/cavp/documents/shs/sha256-384-512.pdf

import struct
def out_hex(list1): 
        for i in list1: 
                print ("%08x" % i) 
        print ("\n") 

def rotate_left(a, k): 
        k = k % 32 
        return ((a << k) & 0xFFFFFFFF) | ((a & 0xFFFFFFFF) >> (32 - k)) 
def rotate_right(a, k): 
        k = k % 32 
        return (((a >> k) & 0xFFFFFFFF) | ((a & 0xFFFFFFFF) << (32 - k))) & 0xFFFFFFFF

def rotate_shift(a,k):
    k = k%32
    return ((a >> k) & 0xFFFFFFFF);  

def P_0(X): 
        return (rotate_right(X, 7)) ^ (rotate_right(X, 18)) ^ (rotate_shift(X,3))

def P_1(X): 
        return (rotate_right(X, 17)) ^ (rotate_right(X, 19)) ^ (rotate_shift(X,10)) 

IV="0x6A09E667 0xBB67AE85 0x3C6EF372 0xA54FF53A 0x510E527F 0x9B05688C 0x1F83D9AB 0x5BE0CD19" 

IV=IV.replace("0x","")
IV=int(IV.replace(" ",""),16)

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 """

K=K.replace("\n","")
K=K.replace(", ","")
K=K.replace(" ","")
K=K.replace("0x","")
K=int(K,16)

a = [] 
for i in range(0, 8): 
        a.append(0) 
        a[i] = (IV >> ((7 - i) * 32)) & 0xFFFFFFFF 
IV = a

k = []
for i in range(0,64):
    k.append(0)
    k[i]= (K >> ((63-i)*32)) & 0xFFFFFFFF
K = k

def CF(V_i, B_i): 
        W = [] 
        for j in range(0, 16): 
                W.append(0) 
                unpack_list = struct.unpack(">I", B_i[j*4:(j+1)*4]) 
                W[j] = unpack_list[0] 
        for j in range(16, 64): 
                W.append(0) 
                s0 = P_0(W[j-15])
                s1 = P_1(W[j-2])
                W[j] = (W[j-16] + s0 + W[j-7] + s1) & 0xFFFFFFFF
                str1 = "%08x" % W[j] 
        W_1 = [] 


        A, B, C, D, E, F, G, H = V_i 
        """ 
        print "00", 
        out_hex([A, B, C, D, E, F, G, H]) 
        """ 
        """
        S1 := (e rightrotate 6) xor (e rightrotate 11) xor (e rightrotate 25)
        ch := (e and f) xor ((not e) and g)
        temp1 := h + S1 + ch + k[i] + w[i]
        S0 := (a rightrotate 2) xor (a rightrotate 13) xor (a rightrotate 22)
        maj := (a and b) xor (a and c) xor (b and c)
        temp2 := S0 + maj

        h := g
        g := f
        f := e
        e := d + temp1
        d := c
        c := b
        b := a
        a := temp1 + temp2
        T1 = H + LSigma_1(E) + Conditional(E, F, G) + K[i] + W[i];  
        T2 = LSigma_0(A) + Majority(A, B, C); 
        """
        for j in range(0, 64): 
                SS1 = rotate_right(E,6) ^ rotate_right(E,11) ^ rotate_right(E,25) 
                SS0 = rotate_right(A,2) ^ rotate_right(A,13) ^ rotate_right(A,22)
                ch  = (E & F) ^ ((~E) & G)
                temp1 = (H + SS1 + ch + K[j] + W[j]) & 0xFFFFFFFF
                maj = (A & B) ^ (A & C) ^ ( B & C)
                temp2 = (SS0 + maj) & 0xFFFFFFFF

                H = G 
                G = F
                F = E
                E = (D + temp1) 
                D = C 
                C = B 
                B = A 
                A = (temp1 + temp2) 


                A = A & 0xFFFFFFFF 
                B = B & 0xFFFFFFFF 
                C = C & 0xFFFFFFFF 
                D = D & 0xFFFFFFFF 
                E = E & 0xFFFFFFFF 
                F = F & 0xFFFFFFFF 
                G = G & 0xFFFFFFFF 
                H = H & 0xFFFFFFFF 
                """ 
                str1 = "%02d" % j 
                if str1[0] == "0": 
                        str1 = ' ' + str1[1:] 
                print str1, 
                out_hex([A, B, C, D, E, F, G, H]) 
                """ 

        V_i_1 = [] 
        V_i_1.append((A + V_i[0]) & 0xFFFFFFFF)
        V_i_1.append((B + V_i[1]) & 0xFFFFFFFF)
        V_i_1.append((C + V_i[2]) & 0xFFFFFFFF)
        V_i_1.append((D + V_i[3]) & 0xFFFFFFFF)
        V_i_1.append((E + V_i[4]) & 0xFFFFFFFF)
        V_i_1.append((F + V_i[5]) & 0xFFFFFFFF)
        V_i_1.append((G + V_i[6]) & 0xFFFFFFFF)
        V_i_1.append((H + V_i[7]) & 0xFFFFFFFF)

        return V_i_1 

def hash_msg(msg): 
        len1 = len(msg) 
        reserve1 = len1 % 64 
        msg1 = msg.encode() + struct.pack("B",128)
        reserve1 = reserve1 + 1 
        for i in range(reserve1, 56): 
                msg1 = msg1 + struct.pack("B",0) 

        bit_length = (len1) * 8 
        bit_length_string = struct.pack(">Q", bit_length) 
        msg1 = msg1 + bit_length_string 

        print (len(msg1) )
        group_count = int(len(msg1) / 64 )
        print(group_count)

        m_1 = B = [] 
        for i in range(0, group_count): 
                B.append(0) 
                B[i] = msg1[i*64:(i+1)*64] 

        V = [] 
        V.append(0) 
        V[0] = IV 
        for i in range(0, group_count): 
                V.append(0) 
                V[i+1] = CF(V[i], B[i]) 

        return V[i+1] 

print ("abc") 
y = hash_msg("abc") 
print ("result: ")
out_hex(y) 

import hashlib

sh = hashlib.sha256()
msg1 = "abc"
hashlib.sha256(msg1.encode()).hexdigest()