public static string HashMD5(string Chaine) 
{ 
          return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(Chaine,"md5"); 
}

<?php
$chaine = 'Voici ma chaine !';
$chaineMD5 = md5($chaine);
// Pour sha :
$chaineSHA = sha1($chaine);
?>

    Public Shared Function HashMD5(ByVal Chaine As String) As String
        Return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(Chaine, "md5")
    End Function


 
 

from md5 import md5
def hashMd5(chaine):
    return md5(chaine).hexdigest()

'contexte RSA signature
Private Const PROV_RSA_FULL As Long = 1&
Private Const CALG_MD5 As Long = &H8003&
'initialise un contexte de cryptage
Private Declare Function CryptAcquireContext Lib "advapi32.dll" Alias "CryptAcquireContextA" (ByRef phProv As Long, ByVal pszContainer As Long, ByVal pszProvider As String, ByVal dwProvType As Long, ByVal dwFlags As Long) As Long
'crée un hash
Private Declare Function CryptCreateHash Lib "advapi32.dll" (ByVal hProv As Long, ByVal AlgID As Long, ByVal hKey As Long, ByVal dwFlags As Long, ByRef phHash As Long) As Long
'ajoute des données au hash
Private Declare Function CryptHashData Lib "advapi32.dll" (ByVal hHash As Long, ByVal pbData As Long, ByVal dwDataLen As Long, ByVal dwFlags As Long) As Long
'termine le hash
Private Const HP_HASHVAL As Long = &H2
Private Declare Function CryptGetHashParam Lib "advapi32.dll" (ByVal hHash As Long, ByVal dwParam As Long, ByVal pByte As Long, ByRef pdwDataLen As Long, ByVal dwFlags As Long) As Long
Private Declare Function CryptSignHash Lib "advapi32.dll" Alias "CryptSignHashA" (ByVal hHash As Long, ByVal dwKeySpec As Long, ByVal sDescription As Long, ByVal dwFlags As Long, ByVal pbSignature As Long, ByRef pdwSigLen As Long) As Long
'libère les ressources associées au hash
Private Declare Function CryptDestroyHash Lib "advapi32.dll" (ByVal hHash As Long) As Long
'libère le contexte de cryptage
Private Declare Function CryptReleaseContext Lib "advapi32.dll" (ByVal hProv As Long, ByVal dwFlags As Long) As Long
'calcule le hash (en hexa ascii) des données pointées par pbData
'===============================================================
'pbData : pointeur vers les données à hasher
'dwDataLen : taille des données à hasher
Private Function GetHashString(ByVal AlgID As Long, ByVal pbData As Long, ByVal dwDataLen As Long) As String
    'buffer pour les données du hash
    Dim buff() As Byte, dwSigLen As Long, i As Long
    
    'calcule le hash
    dwSigLen = GetHashBin(AlgID, pbData, dwDataLen, buff)
    
    'convertit le hash en représentation ASCII
    GetHashString = vbNullString
    For i = 0 To dwSigLen - 1
        GetHashString = GetHashString & Right("00" & Hex$(buff(i)), 2)
    Next
End Function
'calcule le hash (en hexa) des données pointées par pbData
'===============================================================
'AlgID : algorithme de hash à utiliser
'pbData : pointeur vers les données à hasher
'dwDataLen : taille des données à hasher
'OUT buff : contient le hash binaire au retour
Private Function GetHashBin(ByVal AlgID As Long, ByVal pbData As Long, ByVal dwDataLen As Long, outBuff() As Byte) As Long
    Dim hProv As Long, hHash As Long, dwSigLen As Long
    Dim i As Long
    
    'initialise le système de crypto
    Call CryptAcquireContext(hProv, 0&, vbNullString, PROV_RSA_FULL, 0&)
    If hProv = 0 Then
        Call CryptAcquireContext(hProv, 0&, vbNullString, PROV_RSA_FULL, 8&)
    End If
    
    'crée un hasheur
    Call CryptCreateHash(hProv, AlgID, 0&, 0&, hHash)
    
    'hash les données
    Call CryptHashData(hHash, pbData, dwDataLen, 0&)
    'récupère la valeur du hash dans un buffer
    Call CryptGetHashParam(hHash, HP_HASHVAL, ByVal 0&, dwSigLen, 0)
    If (dwSigLen) Then
        ReDim outBuff(dwSigLen - 1)
        Call CryptGetHashParam(hHash, HP_HASHVAL, ByVal VarPtr(outBuff(0)), dwSigLen, 0)
    End If
    
    'libère le hasheur
    Call CryptDestroyHash(hHash)
    'libère le système de crypto
    Call CryptReleaseContext(hProv, 0&)
    
    'renvoie la taille du hash
    GetHashBin = dwSigLen
End Function
Public Function MD5Bin(ByVal pbData As Long, ByVal dwDataLen As Long) As Byte()
    Call GetHashBin(CALG_MD5, pbData, dwDataLen, MD5Bin)
End Function
Public Function MD5String(ByVal pbData As Long, ByVal dwDataLen As Long) As String
    MD5String = GetHashString(CALG_MD5, pbData, dwDataLen)
End Function

# utilise Tcllib - http://www.tcl.tk/software/tcllib/
package require md5
proc hashMD5 s {return [md5::md5 -hex $s]}