ms access - Cálculo de MD5 de cadena desde Microsoft Access

sha256 excel

Question

¿Cómo puedo calcular un MD5 de un lado del cliente de cadena en Microsoft Access?

Answer 1

En cuanto a mi conocimiento, no hay una función integrada en Access para calcular hash MD5. Necesita una API externa (como lo menciona casperOne) o puede usar una implementación propia de MD5 en VBA.

Buscando en Google, creé este módulo , que podrías agregar a tu proyecto, pero no puedo garantizar nada.

Answer 2

Parece que DW Fenton hizo lo mismo hace unos años en bytes.com

Aquí es donde encontró la solución

Aquí está el código relevante del ejemplo de ASP allí enumerado, esto debería ser bastante cercano al VBA:

'' Derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm,
'' as set out in the memo RFC1321.
''
'' See the VB6 project that accompanies this sample for full code comments on how
'' it works.
''
'' ASP VBScript code for generating an MD5 ''digest'' or ''signature'' of a string. The
'' MD5 algorithm is one of the industry standard methods for generating digital
'' signatures. It is generically known as a digest, digital signature, one-way
'' encryption, hash or checksum algorithm. A common use for MD5 is for password
'' encryption as it is one-way in nature, that does not mean that your passwords
'' are not free from a dictionary attack.
''
'' This is ''free'' software with the following restrictions:
''
'' You may not redistribute this code as a ''sample'' or ''demo''. However, you are free
'' to use the source code in your own code, but you may not claim that you created
'' the sample code. It is expressly forbidden to sell or profit from this source code
'' other than by the knowledge gained or the enhanced value added by your own code.
''
'' Use of this software is also done so at your own risk. The code is supplied as
'' is without warranty or guarantee of any kind.
''
'' Should you wish to commission some derivative work based on this code provided
'' here, or any consultancy work, please do not hesitate to contact us.
''
'' Web Site:  http://www.frez.co.uk
'' E-mail:    [email protected]

Private Const BITS_TO_A_BYTE = 8
Private Const BYTES_TO_A_WORD = 4
Private Const BITS_TO_A_WORD = 32

Private m_lOnBits(30)
Private m_l2Power(30)

    m_lOnBits(0) = CLng(1)
    m_lOnBits(1) = CLng(3)
    m_lOnBits(2) = CLng(7)
    m_lOnBits(3) = CLng(15)
    m_lOnBits(4) = CLng(31)
    m_lOnBits(5) = CLng(63)
    m_lOnBits(6) = CLng(127)
    m_lOnBits(7) = CLng(255)
    m_lOnBits(8) = CLng(511)
    m_lOnBits(9) = CLng(1023)
    m_lOnBits(10) = CLng(2047)
    m_lOnBits(11) = CLng(4095)
    m_lOnBits(12) = CLng(8191)
    m_lOnBits(13) = CLng(16383)
    m_lOnBits(14) = CLng(32767)
    m_lOnBits(15) = CLng(65535)
    m_lOnBits(16) = CLng(131071)
    m_lOnBits(17) = CLng(262143)
    m_lOnBits(18) = CLng(524287)
    m_lOnBits(19) = CLng(1048575)
    m_lOnBits(20) = CLng(2097151)
    m_lOnBits(21) = CLng(4194303)
    m_lOnBits(22) = CLng(8388607)
    m_lOnBits(23) = CLng(16777215)
    m_lOnBits(24) = CLng(33554431)
    m_lOnBits(25) = CLng(67108863)
    m_lOnBits(26) = CLng(134217727)
    m_lOnBits(27) = CLng(268435455)
    m_lOnBits(28) = CLng(536870911)
    m_lOnBits(29) = CLng(1073741823)
    m_lOnBits(30) = CLng(2147483647)

    m_l2Power(0) = CLng(1)
    m_l2Power(1) = CLng(2)
    m_l2Power(2) = CLng(4)
    m_l2Power(3) = CLng(8)
    m_l2Power(4) = CLng(16)
    m_l2Power(5) = CLng(32)
    m_l2Power(6) = CLng(64)
    m_l2Power(7) = CLng(128)
    m_l2Power(8) = CLng(256)
    m_l2Power(9) = CLng(512)
    m_l2Power(10) = CLng(1024)
    m_l2Power(11) = CLng(2048)
    m_l2Power(12) = CLng(4096)
    m_l2Power(13) = CLng(8192)
    m_l2Power(14) = CLng(16384)
    m_l2Power(15) = CLng(32768)
    m_l2Power(16) = CLng(65536)
    m_l2Power(17) = CLng(131072)
    m_l2Power(18) = CLng(262144)
    m_l2Power(19) = CLng(524288)
    m_l2Power(20) = CLng(1048576)
    m_l2Power(21) = CLng(2097152)
    m_l2Power(22) = CLng(4194304)
    m_l2Power(23) = CLng(8388608)
    m_l2Power(24) = CLng(16777216)
    m_l2Power(25) = CLng(33554432)
    m_l2Power(26) = CLng(67108864)
    m_l2Power(27) = CLng(134217728)
    m_l2Power(28) = CLng(268435456)
    m_l2Power(29) = CLng(536870912)
    m_l2Power(30) = CLng(1073741824)

Private Function LShift(lValue, iShiftBits)
    If iShiftBits = 0 Then
        LShift = lValue
        Exit Function
    ElseIf iShiftBits = 31 Then
        If lValue And 1 Then
            LShift = &H80000000
        Else
            LShift = 0
        End If
        Exit Function
    ElseIf iShiftBits < 0 Or iShiftBits > 31 Then
        Err.Raise 6
    End If

    If (lValue And m_l2Power(31 - iShiftBits)) Then
        LShift = ((lValue And m_lOnBits(31 - (iShiftBits + 1))) * m_l2Power(iShiftBits)) Or &H80000000
    Else
        LShift = ((lValue And m_lOnBits(31 - iShiftBits)) * m_l2Power(iShiftBits))
    End If
End Function

Private Function RShift(lValue, iShiftBits)
    If iShiftBits = 0 Then
        RShift = lValue
        Exit Function
    ElseIf iShiftBits = 31 Then
        If lValue And &H80000000 Then
            RShift = 1
        Else
            RShift = 0
        End If
        Exit Function
    ElseIf iShiftBits < 0 Or iShiftBits > 31 Then
        Err.Raise 6
    End If

    RShift = (lValue And &H7FFFFFFE) / m_l2Power(iShiftBits)

    If (lValue And &H80000000) Then
        RShift = (RShift Or (&H40000000 / m_l2Power(iShiftBits - 1)))
    End If
End Function

Private Function RotateLeft(lValue, iShiftBits)
    RotateLeft = LShift(lValue, iShiftBits) Or RShift(lValue, (32 - iShiftBits))
End Function

Private Function AddUnsigned(lX, lY)
    Dim lX4
    Dim lY4
    Dim lX8
    Dim lY8
    Dim lResult

    lX8 = lX And &H80000000
    lY8 = lY And &H80000000
    lX4 = lX And &H40000000
    lY4 = lY And &H40000000

    lResult = (lX And &H3FFFFFFF) + (lY And &H3FFFFFFF)

    If lX4 And lY4 Then
        lResult = lResult Xor &H80000000 Xor lX8 Xor lY8
    ElseIf lX4 Or lY4 Then
        If lResult And &H40000000 Then
            lResult = lResult Xor &HC0000000 Xor lX8 Xor lY8
        Else
            lResult = lResult Xor &H40000000 Xor lX8 Xor lY8
        End If
    Else
        lResult = lResult Xor lX8 Xor lY8
    End If

    AddUnsigned = lResult
End Function

Private Function F(x, y, z)
    F = (x And y) Or ((Not x) And z)
End Function

Private Function G(x, y, z)
    G = (x And z) Or (y And (Not z))
End Function

Private Function H(x, y, z)
    H = (x Xor y Xor z)
End Function

Private Function I(x, y, z)
    I = (y Xor (x Or (Not z)))
End Function

Private Sub FF(a, b, c, d, x, s, ac)
    a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac))
    a = RotateLeft(a, s)
    a = AddUnsigned(a, b)
End Sub

Private Sub GG(a, b, c, d, x, s, ac)
    a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac))
    a = RotateLeft(a, s)
    a = AddUnsigned(a, b)
End Sub

Private Sub HH(a, b, c, d, x, s, ac)
    a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac))
    a = RotateLeft(a, s)
    a = AddUnsigned(a, b)
End Sub

Private Sub II(a, b, c, d, x, s, ac)
    a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac))
    a = RotateLeft(a, s)
    a = AddUnsigned(a, b)
End Sub

Private Function ConvertToWordArray(sMessage)
    Dim lMessageLength
    Dim lNumberOfWords
    Dim lWordArray()
    Dim lBytePosition
    Dim lByteCount
    Dim lWordCount

    Const MODULUS_BITS = 512
    Const CONGRUENT_BITS = 448

    lMessageLength = Len(sMessage)

    lNumberOfWords = (((lMessageLength + ((MODULUS_BITS - CONGRUENT_BITS) / BITS_TO_A_BYTE)) / (MODULUS_BITS / BITS_TO_A_BYTE)) + 1) * (MODULUS_BITS / BITS_TO_A_WORD)
    ReDim lWordArray(lNumberOfWords - 1)

    lBytePosition = 0
    lByteCount = 0
    Do Until lByteCount >= lMessageLength
        lWordCount = lByteCount / BYTES_TO_A_WORD
        lBytePosition = (lByteCount Mod BYTES_TO_A_WORD) * BITS_TO_A_BYTE
        lWordArray(lWordCount) = lWordArray(lWordCount) Or LShift(Asc(Mid(sMessage, lByteCount + 1, 1)), lBytePosition)
        lByteCount = lByteCount + 1
    Loop

    lWordCount = lByteCount / BYTES_TO_A_WORD
    lBytePosition = (lByteCount Mod BYTES_TO_A_WORD) * BITS_TO_A_BYTE

    lWordArray(lWordCount) = lWordArray(lWordCount) Or LShift(&H80, lBytePosition)

    lWordArray(lNumberOfWords - 2) = LShift(lMessageLength, 3)
    lWordArray(lNumberOfWords - 1) = RShift(lMessageLength, 29)

    ConvertToWordArray = lWordArray
End Function

Private Function WordToHex(lValue)
    Dim lByte
    Dim lCount

    For lCount = 0 To 3
        lByte = RShift(lValue, lCount * BITS_TO_A_BYTE) And m_lOnBits(BITS_TO_A_BYTE - 1)
        WordToHex = WordToHex & Right("0" & Hex(lByte), 2)
    Next
End Function

Public Function MD5(sMessage)
    Dim x
    Dim k
    Dim AA
    Dim BB
    Dim CC
    Dim DD
    Dim a
    Dim b
    Dim c
    Dim d

    Const S11 = 7
    Const S12 = 12
    Const S13 = 17
    Const S14 = 22
    Const S21 = 5
    Const S22 = 9
    Const S23 = 14
    Const S24 = 20
    Const S31 = 4
    Const S32 = 11
    Const S33 = 16
    Const S34 = 23
    Const S41 = 6
    Const S42 = 10
    Const S43 = 15
    Const S44 = 21

    x = ConvertToWordArray(sMessage)

    a = &H67452301
    b = &HEFCDAB89
    c = &H98BADCFE
    d = &H10325476

    For k = 0 To UBound(x) Step 16
        AA = a
        BB = b
        CC = c
        DD = d

        FF a, b, c, d, x(k + 0), S11, &HD76AA478
        FF d, a, b, c, x(k + 1), S12, &HE8C7B756
        FF c, d, a, b, x(k + 2), S13, &H242070DB
        FF b, c, d, a, x(k + 3), S14, &HC1BDCEEE
        FF a, b, c, d, x(k + 4), S11, &HF57C0FAF
        FF d, a, b, c, x(k + 5), S12, &H4787C62A
        FF c, d, a, b, x(k + 6), S13, &HA8304613
        FF b, c, d, a, x(k + 7), S14, &HFD469501
        FF a, b, c, d, x(k + 8), S11, &H698098D8
        FF d, a, b, c, x(k + 9), S12, &H8B44F7AF
        FF c, d, a, b, x(k + 10), S13, &HFFFF5BB1
        FF b, c, d, a, x(k + 11), S14, &H895CD7BE
        FF a, b, c, d, x(k + 12), S11, &H6B901122
        FF d, a, b, c, x(k + 13), S12, &HFD987193
        FF c, d, a, b, x(k + 14), S13, &HA679438E
        FF b, c, d, a, x(k + 15), S14, &H49B40821

        GG a, b, c, d, x(k + 1), S21, &HF61E2562
        GG d, a, b, c, x(k + 6), S22, &HC040B340
        GG c, d, a, b, x(k + 11), S23, &H265E5A51
        GG b, c, d, a, x(k + 0), S24, &HE9B6C7AA
        GG a, b, c, d, x(k + 5), S21, &HD62F105D
        GG d, a, b, c, x(k + 10), S22, &H2441453
        GG c, d, a, b, x(k + 15), S23, &HD8A1E681
        GG b, c, d, a, x(k + 4), S24, &HE7D3FBC8
        GG a, b, c, d, x(k + 9), S21, &H21E1CDE6
        GG d, a, b, c, x(k + 14), S22, &HC33707D6
        GG c, d, a, b, x(k + 3), S23, &HF4D50D87
        GG b, c, d, a, x(k + 8), S24, &H455A14ED
        GG a, b, c, d, x(k + 13), S21, &HA9E3E905
        GG d, a, b, c, x(k + 2), S22, &HFCEFA3F8
        GG c, d, a, b, x(k + 7), S23, &H676F02D9
        GG b, c, d, a, x(k + 12), S24, &H8D2A4C8A

        HH a, b, c, d, x(k + 5), S31, &HFFFA3942
        HH d, a, b, c, x(k + 8), S32, &H8771F681
        HH c, d, a, b, x(k + 11), S33, &H6D9D6122
        HH b, c, d, a, x(k + 14), S34, &HFDE5380C
        HH a, b, c, d, x(k + 1), S31, &HA4BEEA44
        HH d, a, b, c, x(k + 4), S32, &H4BDECFA9
        HH c, d, a, b, x(k + 7), S33, &HF6BB4B60
        HH b, c, d, a, x(k + 10), S34, &HBEBFBC70
        HH a, b, c, d, x(k + 13), S31, &H289B7EC6
        HH d, a, b, c, x(k + 0), S32, &HEAA127FA
        HH c, d, a, b, x(k + 3), S33, &HD4EF3085
        HH b, c, d, a, x(k + 6), S34, &H4881D05
        HH a, b, c, d, x(k + 9), S31, &HD9D4D039
        HH d, a, b, c, x(k + 12), S32, &HE6DB99E5
        HH c, d, a, b, x(k + 15), S33, &H1FA27CF8
        HH b, c, d, a, x(k + 2), S34, &HC4AC5665

        II a, b, c, d, x(k + 0), S41, &HF4292244
        II d, a, b, c, x(k + 7), S42, &H432AFF97
        II c, d, a, b, x(k + 14), S43, &HAB9423A7
        II b, c, d, a, x(k + 5), S44, &HFC93A039
        II a, b, c, d, x(k + 12), S41, &H655B59C3
        II d, a, b, c, x(k + 3), S42, &H8F0CCC92
        II c, d, a, b, x(k + 10), S43, &HFFEFF47D
        II b, c, d, a, x(k + 1), S44, &H85845DD1
        II a, b, c, d, x(k + 8), S41, &H6FA87E4F
        II d, a, b, c, x(k + 15), S42, &HFE2CE6E0
        II c, d, a, b, x(k + 6), S43, &HA3014314
        II b, c, d, a, x(k + 13), S44, &H4E0811A1
        II a, b, c, d, x(k + 4), S41, &HF7537E82
        II d, a, b, c, x(k + 11), S42, &HBD3AF235
        II c, d, a, b, x(k + 2), S43, &H2AD7D2BB
        II b, c, d, a, x(k + 9), S44, &HEB86D391

        a = AddUnsigned(a, AA)
        b = AddUnsigned(b, BB)
        c = AddUnsigned(c, CC)
        d = AddUnsigned(d, DD)
    Next

    MD5 = LCase(WordToHex(a) & WordToHex(b) & WordToHex(c) & WordToHex(d))
End Function

Answer 3

Puede instalar un componente COM freeware como este y luego usarlo desde VBA

Answer 4

Puede usar la API de criptografía: próxima generación, cuya referencia se encuentra aquí:

http://msdn.microsoft.com/en-us/library/aa376210(VS.85).aspx

Puede ser un poco difícil usar esto a través de instrucciones DECLARE en VBA (que deberá usar), de modo que siempre puede usar interoperabilidad COM para llamar a métodos en .NET que acceden a la clase MD5 en el espacio de nombres System.Security.Cryptography.

Answer 5

Si está implementando MD5 a través de un módulo VBA, hay varias opciones.

No he intentado esto, pero una búsqueda rápida de "md5 vba" devolvió este archivo basMD5.bas . Sin embargo, no es una de las licencias de código abierto más comunes.

Desde la " Página principal de MD5 (no oficial) " en la sección de Visual Basic:

• Francisco Carlos Piragibe de Almeida ha creado una DLL con un módulo contenedor BAS para su uso en proyectos VB (descarga de 19K) y un contenedor de proceso en proceso de ActiveX alrededor de la DLL original (incluye la DLL) (descarga 1394K). (parece estar roto - 2005-11-14)
• MD5 para VB . Referencia de benjamin pritchard.
• MD5 para VB y VBScript . Referencia de Dominik Deobald.