F_MD4
A = ROTL_MD4((A + F_MD4(B, C, D) + W[idx] + C1_MD4[12]), C1_MD4[8]);
D = ROTL_MD4((D + F_MD4(A, B, C) + W[idx] + C1_MD4[12]), C1_MD4[9]);
C = ROTL_MD4((C + F_MD4(D, A, B) + W[idx] + C1_MD4[12]), C1_MD4[10]);
B = ROTL_MD4((B + F_MD4(C, D, A) + W[idx] + C1_MD4[12]), C1_MD4[11]);