我正在尝试使用 SHA256 作为哈希在经典 ASP 中编写 HMAC 函数。我认为我做对了，但结果与 Wikipedia page 上列出的示例不同。 。我见过几个人们通过包含 WSC 在经典 ASP 中使用 HMAC SHA256 的示例。这不是我想做的。
这是函数:
Public Function HMAC_SHA256(prmKey, prmData)
Dim theKey : theKey = prmKey
Dim Block_Size, O_Pad, I_Pad
Block_Size = 64
O_Pad = 92 'HEX: 5c'
I_Pad = 54 'HEX: 36'
Dim iter, iter2
If Len(theKey) < Block_Size Then
For iter = 1 to Block_Size - Len(theKey)
theKey = theKey & chr(0)
Next
ElseIf Len(theKey) > Block_Size Then
theKey = SHA256(theKey)
End If
Dim o_key_pad : o_key_pad = ""
Dim i_key_pad : i_key_pad = ""
For iter = 1 to Block_Size
o_key_pad = o_key_pad & Chr(Asc(Mid(theKey,iter,1)) xor O_Pad)
i_key_pad = i_key_pad & Chr(Asc(Mid(theKey,iter,1)) xor I_Pad)
Next
HMAC_SHA256 = SHA256(o_key_pad & SHA256(i_key_pad & prmData))
End Function
这是来自 Wikipedia 的 HMAC 的伪代码:
function hmac (key, message)
if (length(key) > blocksize) then
key = hash(key) // keys longer than blocksize are shortened
end if
if (length(key) < blocksize) then
key = key ∥ [0x00 * (blocksize - length(key))] // keys shorter than blocksize are zero-padded (where ∥ is concatenation)
end if
o_key_pad = [0x5c * blocksize] ⊕ key // Where blocksize is that of the underlying hash function
i_key_pad = [0x36 * blocksize] ⊕ key // Where ⊕ is exclusive or (XOR)
return hash(o_key_pad ∥ hash(i_key_pad ∥ message)) // Where ∥ is concatenation
end function
我一生都无法确定这里出了什么问题。我想有人会告诉我这在 ASP 中是不可能的，这就是为什么有这么多建议使用 WSC。如果是这样，有人可以解释为什么这是不可能的吗？我没有看到任何事情会使这成为不可能。
谢谢!
编辑:我已经确保我使用的 SHA256 函数给出了正确的哈希值，因此与此无关。我还尝试过对 SHA256 函数的结果进行 UCase 处理，但没有结果。
EDIT2:从 wiki 页面添加示例。
最佳答案
嗯，我曾经在经典 ASP 中实现了 TEA(微型加密算法)并遇到了类似的问题。就我而言，根本原因是 ASP 将您连接的字符串 (& char) 再次保存为 UTF-16，因此偏移量并不总是与我期望的位置匹配。
我不知道这是否适用于您的用例，因为我必须使用 UTF-8 特殊字符。
我的解决方案是使用一组长整型数组，我可以使用我的二进制函数正确定位它。以下是使用该数组的函数，希望对您有所帮助。
'*******************************************************************************
' getArrayFromInputString (FUNCTION)
'
' PARAMETERS:
' (In) - s_source - Source string (format is defined by n_options)
' (In) - n_blocksize - Blocksize, which is corrected by padding
' (In) - n_options - Options using follobing bits:
' 1: string is in HEX format (e.g. DFD14DAFD9C555C07FEB8F3DA90DEA27)
' RETURN VALUE:
' long array
'
' DESCRIPTION:
' allows to import strings in various formats for all input functions
'*******************************************************************************
private function getArrayFromInputString(s_source, n_blocksize, n_options)
' n_options:
dim a_out, s_padded_string
if (n_options AND 1) = 1 then
s_padded_string = padString(s_source, n_blocksize * 2, "0")
a_out = convertHexStringToArray(s_padded_string)
else
if b_unicode_ then
s_padded_string = padString(s_source, int(n_blocksize / 2), " ")
a_out = convertStringToArray_Unicode(s_padded_string)
else
s_padded_string = padString(s_source, n_blocksize, " ")
a_out = convertStringToArray(s_padded_string)
end if
end if
getArrayFromInputString = a_out
end function
'*******************************************************************************
' convertStringToArray (FUNCTION)
'
' PARAMETERS:
' (In) - s_source - Source string to build the array from
' length MUST be in multiples of 4!
'
' RETURN VALUE:
' Array of type Long - Length is 4 times smaller than the string length
'
' DESCRIPTION:
' Blocks of four characters are calculated into one Long entry of the result array
'*******************************************************************************
private function convertStringToArray(s_source) ' returns long array
dim a_out, n_index, n_length, n_temp
dim n_array_index, n_nibble
n_length = len(s_source)
redim a_out(int(n_length / 4))
for n_index=0 to n_length - 1
n_temp = asc(mid(s_source, n_index + 1, 1))
n_array_index = int(n_index / 4)
n_nibble = n_index MOD 4
a_out(n_array_index) = AddUnsigned(a_out(n_array_index), LShift(n_temp, (3 - n_nibble) * 8))
next
convertStringToArray = a_out
end function
'*******************************************************************************
' convertHexStringToArray (unicode version)
private function convertStringToArray_Unicode(s_source) ' returns long array
dim a_out, n_index, n_length, n_temp
dim n_array_index, n_nibble
n_length = len(s_source)
redim a_out(int(n_length / 2))
for n_index=0 to n_length - 1
n_temp = ascw(mid(s_source, n_index + 1, 1))
n_array_index = int(n_index / 2)
n_nibble = (n_index MOD 2)
a_out(n_array_index) = AddUnsigned(a_out(n_array_index), LShift(n_temp, (1 - n_nibble) * 16))
next
convertStringToArray_Unicode = a_out
end function
'*******************************************************************************
' convertHexStringToArray (FUNCTION)
'
' PARAMETERS:
' (In) - s_source - Source string in hex format, e.g. "EFCE016503CDDB53"
' length MUST be in multiples of 8!
'
' RETURN VALUE:
' Array of type Long - Length is 8 times smaller than the string length
'
' DESCRIPTION:
' Blocks of eight characters are calculated into one Long entry of the result array
'*******************************************************************************
private function convertHexStringToArray(s_source) ' returns long array
dim a_out, n_index, n_length, n_temp
dim n_array_index, n_nibble
n_length = len(s_source)
redim a_out(int(n_length / 8))
for n_index=0 to n_length - 1 step 2
n_temp = CInt("&H" & mid(s_source, n_index + 1, 2))
n_array_index = int(n_index / 8)
n_nibble = int((n_index MOD 8) / 2)
a_out(n_array_index) = AddUnsigned(a_out(n_array_index), LShift(n_temp, (3 - n_nibble) * 8))
next
convertHexStringToArray = a_out
end function
'*******************************************************************************
' padString (FUNCTION)
'
' PARAMETERS:
' (In) - s_source
' (In) - n_blocksize
' (In) - s_padding_char
'
' RETURN VALUE:
' String - padded source string
'
' DESCRIPTION:
' ensure, that the plaintext is multiples of n_blocksize bytes long, the needed amount of s_padding_char is applied
'*******************************************************************************
private function padString(s_source, n_blocksize, s_padding_char)
dim s_out, n_length, n_padding, n_index
s_out = s_source
n_length = len(s_source)
if n_length MOD n_blocksize>0 then
n_padding = n_blocksize - n_length MOD n_blocksize
for n_index=1 to n_padding
s_out = s_out & left(s_padding_char, 1)
next
end if
padString = s_out
end function
'*******************************************************************************
' printArray (FUNCTION)
'
' PARAMETERS:
' (In) - s_prefix - just a string to be written in front for distinction of multiple arrays
' (In) - a_data - long array to print out
'
' RETURN VALUE:
' none
'
' DESCRIPTION:
' debug output function
'*******************************************************************************
private function printArray(s_prefix, a_data)
dim n_index
for n_index=0 to UBound(a_data) - 1
Response.Write "<p>" & s_prefix & a_data(n_index) & " - " & getHex(a_data(n_index)) & "</p>" & vbNewline
next
end function
'*******************************************************************************
' Some more little helper functions
'*******************************************************************************
private function getHex(n_value)
getHex = Right("00000000" & Hex(n_value), 8)
end function
private function getStringFromLong(n_value)
getStringFromLong = _
Chr(RShift(n_value, 24) AND &HFF) & _
Chr(RShift(n_value, 16) AND &HFF) & _
Chr(RShift(n_value, 8) AND &HFF) & _
Chr(n_value AND &HFF)
end function
private function getStringFromLong_Unicode(n_value)
dim s_temp
s_temp = getHex(n_value)
getStringFromLong_Unicode = _
ChrW(int("&H" & mid(s_temp, 1, 4))) & _
ChrW(int("&H" & mid(s_temp, 5, 4)))
end function
关于asp-classic - 经典 ASP VBScript 中的 HMAC 算法 (SHA256)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32029595/