Using MD5 to encrypt registration information under ASP

Encryption

It may be necessary to use the MD5 to encrypt the user password when making the login behavior, which is a little more troublesome than other languages, but it is also feasible.

Core code:

<%
Privateconstbits_to_a_byte=8
Privateconstbytes_to_a_word=4
Privateconstbits_to_a_word=32

Privatem_lonbits (30)
Privatem_l2power (30)

Privatefunctionlshift (Lvalue,ishiftbits)
Ifishiftbits=0then
Lshift=lvalue
Exitfunction
Elseifishiftbits=31then
Iflvalueand1then
lshift=&h80000000
Else
Lshift=0
EndIf
Exitfunction
Elseifishiftbits<0orishiftbits>31then
Err.raise6
EndIf

If (Lvalueandm_l2power (31-ishiftbits)) Then
Lshift= ((Lvalueandm_lonbits (31-(ishiftbits+1)) *m_l2power (ishiftbits)) or&h80000000
Else
Lshift= ((Lvalueandm_lonbits (31-ishiftbits)) *m_l2power (ishiftbits))
EndIf
Endfunction

Privatefunctionrshift (Lvalue,ishiftbits)
Ifishiftbits=0then
Rshift=lvalue
Exitfunction
Elseifishiftbits=31then
Iflvalueand&h80000000then
Rshift=1
Else
Rshift=0
EndIf
Exitfunction
Elseifishiftbits<0orishiftbits>31then
Err.raise6
EndIf

rshift= (Lvalueand&h7ffffffe) m_l2power (ishiftbits)

If (lvalueand&h80000000) Then
Rshift= (Rshiftor (&h40000000 m_l2power (iShiftBits-1))
EndIf
Endfunction

Privatefunctionrotateleft (Lvalue,ishiftbits)
Rotateleft=lshift (lvalue,ishiftbits) Orrshift (LValue, (32-ishiftbits))
Endfunction

Privatefunctionaddunsigned (lx,ly)
DimlX4
DimlY4
DimlX8
DimlY8
Dimlresult

lx8=lxand&h80000000
ly8=lyand&h80000000
lx4=lxand&h40000000
ly4=lyand&h40000000

lresult= (LXAND&H3FFFFFFF) + (LYAND&H3FFFFFFF)

Iflx4andly4then
Lresult=lresultxor&h80000000xorlx8xorly8
Elseiflx4orly4then
Iflresultand&h40000000then
Lresult=lresultxor&hc0000000xorlx8xorly8
Else
Lresult=lresultxor&h40000000xorlx8xorly8
EndIf
Else
Lresult=lresultxorlx8xorly8
EndIf

Addunsigned=lresult
Endfunction

Privatefunctionmd5_f (X,y,z)
md5_f= (Xandy) Or (notx) Andz)
Endfunction

Privatefunctionmd5_g (X,y,z)
Md5_g= (Xandz) Or (Yand (Notz))
Endfunction

Privatefunctionmd5_h (X,y,z)
Md5_h= (Xxoryxorz)
Endfunction

Privatefunctionmd5_i (X,y,z)
Md5_i= (XOr yxor (Notz))
Endfunction

PRIVATESUBMD5_FF (A,B,C,D,X,S,AC)
A=addunsigned (a,addunsigned (addunsigned (Md5_f (b,c,d), x), AC)
A=rotateleft (A,s)
A=addunsigned (A,B)
Endsub

Privatesubmd5_gg (A,B,C,D,X,S,AC)
A=addunsigned (a,addunsigned (addunsigned (Md5_g (b,c,d), x), AC)
A=rotateleft (A,s)
A=addunsigned (A,B)
Endsub

PRIVATESUBMD5_HH (A,B,C,D,X,S,AC)
A=addunsigned (a,addunsigned (addunsigned (Md5_h (b,c,d), x), AC)
A=rotateleft (A,s)
A=addunsigned (A,B)
Endsub

Privatesubmd5_ii (A,B,C,D,X,S,AC)
A=addunsigned (a,addunsigned (addunsigned (Md5_i (b,c,d), x), AC)
A=rotateleft (A,s)
A=addunsigned (A,B)
Endsub

Privatefunctionconverttowordarray (smessage)
 dimlmessagelength
 dimlnumberofwords
  Dimlwordarray ()
 dimlbyteposition
 dimlbytecount
 dimlwordcount
 
  constmodulus_bits=512
 constcongruent_bits=448
 
 lmessagelength=len (sMessage)
&NBSP
 lnumberofwords= ((lmessagelength+ ((modulus_bits-congruent_bits)  bits_to_a_byte))   ( Modulus_bits bits_to_a_byte)) (+1) * (Modulus_bits bits_to_a_word)
 redimlwordarray ( lNumberOfWords-1)
 
 lbyteposition=0
 lbytecount=0
 dountillbytecount>= Lmessagelength
   lwordcount=lbytecount bytes_to_a_word
    lbyteposition= (Lbytecountmodbytes_to_a_word) *bits_to_a_byte
   lwordarray (lWordCount) = Lwordarray (Lwordcount) orlshift (ASC (Mid smessage,lbytecount+1,1), lbyteposition)
    Lbytecount=lbytecount+1
 loop

Lwordcount=lbytecount Bytes_to_a_word
lbyteposition= (Lbytecountmodbytes_to_a_word) *bits_to_a_byte

Lwordarray (Lwordcount) =lwordarray (lwordcount) orlshift (&h80,lbyteposition)

Lwordarray (lNumberOfWords-2) =lshift (lmessagelength,3)
Lwordarray (lNumberOfWords-1) =rshift (lmessagelength,29)