Si j’ai bien compris, tu veux générer des mots de passe alphanumériques à partir des nom/prénoms? C’est pas une méthode que je recommande: si quelqu’un tombe sur le fichier servant à générer les mots de passe, ou bien découvre l’algo par rétro-ingénierie, c’est pas cool niveau sécurité
En l’état actuel des choses, la solution la moins pire (enfin, celle que je te propose) consisterait à créer un password sur la base d’un hash, constitué par Nom+Prénom+Salt, puis une petite retouche (optionnelle) pour réduire un peu la taille du password.
Pour le hash, je propose d’implémenter une fonction VBA qui calcule un SHA-1 sur ta chaine de caractères. Pour faire tout ça, il “suffit” de créer un module dans le projet VBA, et d’y ajouter le code suivant:
Option Explicit
Private Type FourBytes
A As Byte
B As Byte
C As Byte
D As Byte
End Type
Private Type OneLong
L As Long
End Type
Function HexDefaultSHA1(Message() As Byte) As String
Dim H1 As Long, H2 As Long, H3 As Long, H4 As Long, H5 As Long
DefaultSHA1 Message, H1, H2, H3, H4, H5
HexDefaultSHA1 = DecToHex5(H1, H2, H3, H4, H5)
End Function
Function HexSHA1(Message() As Byte, ByVal Key1 As Long, ByVal Key2 As Long, ByVal Key3 As Long, ByVal Key4 As Long) As String
Dim H1 As Long, H2 As Long, H3 As Long, H4 As Long, H5 As Long
xSHA1 Message, Key1, Key2, Key3, Key4, H1, H2, H3, H4, H5
HexSHA1 = DecToHex5(H1, H2, H3, H4, H5)
End Function
Sub DefaultSHA1(Message() As Byte, H1 As Long, H2 As Long, H3 As Long, H4 As Long, H5 As Long)
xSHA1 Message, &H5A827999, &H6ED9EBA1, &H8F1BBCDC, &HCA62C1D6, H1, H2, H3, H4, H5
End Sub
Sub xSHA1(Message() As Byte, ByVal Key1 As Long, ByVal Key2 As Long, ByVal Key3 As Long, ByVal Key4 As Long, H1 As Long, H2 As Long, H3 As Long, H4 As Long, H5 As Long)
Dim U As Long, P As Long
Dim FB As FourBytes, OL As OneLong
Dim i As Integer
Dim W(80) As Long
Dim A As Long, B As Long, C As Long, D As Long, E As Long
Dim T As Long
H1 = &H67452301: H2 = &HEFCDAB89: H3 = &H98BADCFE: H4 = &H10325476: H5 = &HC3D2E1F0
U = UBound(Message) + 1: OL.L = U32ShiftLeft3(U): A = U \ &H20000000: LSet FB = OL 'U32ShiftRight29(U)
ReDim Preserve Message(0 To (U + 8 And -64) + 63)
Message(U) = 128
U = UBound(Message)
Message(U - 4) = A
Message(U - 3) = FB.D
Message(U - 2) = FB.C
Message(U - 1) = FB.B
Message(U) = FB.A
While P < U
For i = 0 To 15
FB.D = Message(P)
FB.C = Message(P + 1)
FB.B = Message(P + 2)
FB.A = Message(P + 3)
LSet OL = FB
W(i) = OL.L
P = P + 4
Next i
For i = 16 To 79
W(i) = U32RotateLeft1(W(i - 3) Xor W(i - 8) Xor W(i - 14) Xor W(i - 16))
Next i
A = H1: B = H2: C = H3: D = H4: E = H5
For i = 0 To 19
T = U32Add(U32Add(U32Add(U32Add(U32RotateLeft5(A), E), W(i)), Key1), ((B And C) Or ((Not B) And D)))
E = D: D = C: C = U32RotateLeft30(B): B = A: A = T
Next i
For i = 20 To 39
T = U32Add(U32Add(U32Add(U32Add(U32RotateLeft5(A), E), W(i)), Key2), (B Xor C Xor D))
E = D: D = C: C = U32RotateLeft30(B): B = A: A = T
Next i
For i = 40 To 59
T = U32Add(U32Add(U32Add(U32Add(U32RotateLeft5(A), E), W(i)), Key3), ((B And C) Or (B And D) Or (C And D)))
E = D: D = C: C = U32RotateLeft30(B): B = A: A = T
Next i
For i = 60 To 79
T = U32Add(U32Add(U32Add(U32Add(U32RotateLeft5(A), E), W(i)), Key4), (B Xor C Xor D))
E = D: D = C: C = U32RotateLeft30(B): B = A: A = T
Next i
H1 = U32Add(H1, A): H2 = U32Add(H2, B): H3 = U32Add(H3, C): H4 = U32Add(H4, D): H5 = U32Add(H5, E)
Wend
End Sub
Function U32Add(ByVal A As Long, ByVal B As Long) As Long
If (A Xor B) < 0 Then
U32Add = A + B
Else
U32Add = (A Xor &H80000000) + B Xor &H80000000
End If
End Function
Function U32ShiftLeft3(ByVal A As Long) As Long
U32ShiftLeft3 = (A And &HFFFFFFF) * 8
If A And &H10000000 Then U32ShiftLeft3 = U32ShiftLeft3 Or &H80000000
End Function
Function U32ShiftRight29(ByVal A As Long) As Long
U32ShiftRight29 = (A And &HE0000000) \ &H20000000 And 7
End Function
Function U32RotateLeft1(ByVal A As Long) As Long
U32RotateLeft1 = (A And &H3FFFFFFF) * 2
If A And &H40000000 Then U32RotateLeft1 = U32RotateLeft1 Or &H80000000
If A And &H80000000 Then U32RotateLeft1 = U32RotateLeft1 Or 1
End Function
Function U32RotateLeft5(ByVal A As Long) As Long
U32RotateLeft5 = (A And &H3FFFFFF) * 32 Or (A And &HF8000000) \ &H8000000 And 31
If A And &H4000000 Then U32RotateLeft5 = U32RotateLeft5 Or &H80000000
End Function
Function U32RotateLeft30(ByVal A As Long) As Long
U32RotateLeft30 = (A And 1) * &H40000000 Or (A And &HFFFC) \ 4 And &H3FFFFFFF
If A And 2 Then U32RotateLeft30 = U32RotateLeft30 Or &H80000000
End Function
Function DecToHex5(ByVal H1 As Long, ByVal H2 As Long, ByVal H3 As Long, ByVal H4 As Long, ByVal H5 As Long) As String
Dim H As String, L As Long
DecToHex5 = "00000000 00000000 00000000 00000000 00000000"
H = Hex(H1): L = Len(H): Mid(DecToHex5, 9 - L, L) = H
H = Hex(H2): L = Len(H): Mid(DecToHex5, 18 - L, L) = H
H = Hex(H3): L = Len(H): Mid(DecToHex5, 27 - L, L) = H
H = Hex(H4): L = Len(H): Mid(DecToHex5, 36 - L, L) = H
H = Hex(H5): L = Len(H): Mid(DecToHex5, 45 - L, L) = H
End Function
Public Function SHA1HASH(str) As String
Dim i As Integer
Dim arr() As Byte
ReDim arr(0 To Len(str) - 1) As Byte
For i = 0 To Len(str) - 1
arr(i) = Asc(Mid(str, i + 1, 1))
Next i
SHA1HASH = Replace(LCase(HexDefaultSHA1(arr)), " ", "")
End Function
Function Hex2Dec(Hexa As String) As Double
Dim i As Integer, Multi As Integer
Hex2Dec = 0
Hexa = UCase(Trim(Hexa))
If Not Hexa Like "*[G-Z]*" Then
For i = 1 To Len(Hexa)
Multi = CInt("&H" & (Mid(Hexa, Len(Hexa) - i + 1, 1)))
Hex2Dec = Hex2Dec + (Multi * 16 ^ (i - 1))
Next i
End If
End Function
Public Function MDP(hash) As String
Dim i As Integer, str As String, j As Integer
str = ""
For i = 1 To Len(hash) Step 2
j = Hex2Dec(Mid(hash, i, 2)) Mod 62 + 48
While (j >= 58 And j <= 64) Or (j >= 91 And j <= 96)
j = j Mod 62 + 48
Wend
str = str & Chr(j)
Next
MDP = str
End Function
Ce code permet de créer de nouvelles fonctions, dont une qui s’appelle SHA1HASH. Donc, par exemple, si en A1 tu as DELBOS, en B1 Vincent, en C1 tu tapes ceci:
=SHA1HASH(A1&"-"&B1&"-Salt")
(NB.: tu peux remplacer “-Salt” par ce que tu veux, un truc au pif)
Chez moi, ça donne le résultat suivant:
b4bee44b5f1d79f334cdae52c834969e92a19529
La suite est optionnelle: comme c’est de l’hexadécimal, on reconvertit ce qu’on peut dans un jeu de caractères [Aa-Zz][0-9], via la fonction MDP:
=MDP("b4bee44b5f1d79f334cdae52c834969e92a19529")
==> h4ZmQMkidCbD0dJRFUIY
Pour avoir directement ce résultat, la formule est donc:
=MDP(SHA1HASH(A1&"-"&B1&"-Salt"))
Voili voilou, bon courage